Cam shaft phase setter comprising an annular reflux valve

Abstract

A phase setter for adjusting the rotational angular position of a cam shaft relative to a crankshaft of an internal combustion engine. The phase setter includes a stator; a rotor which together with the stator forms a first and second pressure chambers; a control valve featuring a pressure port, and first and second working ports; a feed for the inflow of pressure fluid to the pressure port, a first connecting channel connecting the first pressure chamber to the first working port, and a second connecting channel connecting the second pressure chamber to the second working port; and a reflux valve device acts in the feed and includes a valve structure extending annularly around the rotational axis and has one or more spring tongues or can be axially moved to restrict backflow of pressure fluid through the feed more significantly than the inflow of pressure fluid to the pressure port.

Claims

1. A phase setter for adjusting a rotational angular position of a cam shaft relative to a crankshaft of an internal combustion engine, the phase setter comprising: (a) a stator for rotary-driving the phase setter using the crankshaft; (b) a rotor configured to rotate relative to the stator about a rotational axis and coupled to the cam shaft so as to drive the cam shaft, and which together with the stator forms a first pressure chamber and a second pressure chamber configured to be charged with a pressure fluid so as to adjust the rotor relative to the stator about the rotational axis; (c) a control valve featuring a pressure port, a first working port and a second working port for the pressure fluid; (d) a feed for an inflow of the pressure fluid to the pressure port, a first connecting channel for connecting the first pressure chamber to the first working port, and a second connecting channel for connecting the second pressure chamber to the second working port; (e) and a reflux valve device which acts in the feed and comprises a valve structure which extends annularly around the rotational axis and the reflux valve device is a constituent of a rotor unit comprising the rotor, and the valve structure comprises one or more axially movable spring tongues or the valve structure is configured to be axially moved so as to restrict a backflow of the pressure fluid through the feed more than the inflow of pressure fluid to the pressure port, (f1) wherein the valve structure is positioned in a space between a cylinder defined by the pressure port and a cylinder defined by the second working port, when the pressure fluid is not flowing through the valve structure.

2. The phase setter according to claim 1, wherein the feed passes the second connecting channel at an offset in a circumferential direction.

3. The phase setter according to claim 1, wherein the first connecting channel and the second connecting channel are axially spaced from each other, and the valve structure is positioned in a space between a cylinder defined by the first connecting channel and a cylinder defined by the second connecting channel, when the pressure fluid is not flowing through the valve structure.

4. The phase setter according to claim 1, wherein the feed is deflected towards the rotational axis by the valve structure such that the pressure fluid flows off from the valve structure towards the rotational axis.

5. The phase setter according to claim 1, further comprising a holding device which extends around the rotational axis and holds the valve structure on an inner end-facing support surface of the rotor unit and which is a constituent of the rotor unit.

6. The phase setter according to claim 5, wherein the valve structure comprises one or more spring tongues, and the rotor unit further comprises a respective assigned contact surface for each spring tongue, axially opposite each spring tongue, wherein each spring tongue protrudes in a circumferential direction and is elongated in the circumferential direction.

7. The phase setter according to claim 6, wherein the feed comprises an upstream feed portion which the respective contact surface axially faces across the valve structure, and the pressure fluid flowing through the reflux valve device is deflected towards the rotational axis at the one or more spring tongues and/or the respective assigned contact surface for each spring tongue.

8. The phase setter according to claim 6, wherein the respective contact surface is inclined in relation to the rotational axis, such that an axial distance between a cross-sectional plane, in which the valve structure extends, and the respective contact surface changes in a circumferential direction.

9. The phase setter according to claim 5, wherein the valve structure as a whole is axially moved back and forth between a minimum flow position, which is a blocking position for preventing backflow, and a maximum flow position, and the reflux valve device comprises one or more springs configured to generate a spring force which moves the valve structure towards the minimum flow position.

10. The phase setter according to claim 9, wherein each spring is supported on the holding device.

11. The phase setter according to claim 1, wherein the rotor unit comprises an insert which is arranged in an accommodating space of the rotor, which extends around the rotational axis, and delineates the feed and delineates at least one of the first and second connecting channels and separates said at least one of the first and second connecting channels from the feed, wherein the insert is a holding device.

12. The phase setter according to claim 11, wherein the feed and the at least one of the first and second connecting channels emerge in the accommodating space, and the insert separates the feed in the accommodating space from the at least one of the first and second connecting channels.

13. The phase setter according to claim 11, wherein the feed comprises an upstream feed portion, which extends through the insert, and/or downstream feed portion which extends from an inner circumference of the insert radially outwards through the insert.

14. The phase setter according to claim 11, wherein: the rotor comprises a rotor hub, featuring an inner circumference which extends around the rotational axis and an outer circumference which extends around the inner circumference, and one or more rotor vanes, and each rotor vane protrudes radially outwards from the outer circumference of the rotor hub; the rotor hub comprises the accommodating space which extends radially around the rotational axis between the inner circumference and the outer circumference; a linear bore traverses the rotor hub, from the outer circumference towards the inner circumference, in a region of the accommodating space; the linear bore comprises an outer bore portion, which extends from the outer circumference up to the accommodating space, and an inner bore portion which extends from the inner circumference up to the accommodating space and forms a feed portion of the feed; and the insert seals the outer bore portion and thus separates the outer bore portion from the feed portion of the feed.

15. The phase setter according to claim 11, wherein: the rotor comprises a rotor hub, featuring a central axial passage and an outer circumference which extends around the central axial passage, and one or more rotor vanes, and each rotor vane protrudes radially outwards from the outer circumference of the rotor hub; the central axial passage comprises a narrow axial portion and a wide axial portion and widens in steps from the narrow axial portion into the wide axial portion, such that an inner end-facing surface of the rotor is obtained in the central axial passage; and the wide axial portion forms the accommodating space in which the insert is arranged, wherein the insert forms an inner circumference of the rotor unit.

16. The phase setter according to claim 1, further comprising a dirt filter which is arranged in the feed and extends around the rotational axis, wherein the feed extends through the dirt filter from a radially outer side towards the rotational axis.

17. The phase setter according to claim 1, comprising: a pressure storage comprising a storage space, which extends in the stator and around the rotational axis, and a piston configured to be moved within the storage space; and a storage feed channel which connects a pressure volume of the storage space to the feed, wherein the storage feed channel extends through or along the rotor unit.

18. The phase setter according to claim 17, wherein the storage feed channel diverts from the feed in the rotor unit.

19. The phase setter according to claim 1, wherein the pressure port, the first working port and the second working port are arranged, axially offset with respect to each other, on a circumference of the control valve, wherein the pressure port is arranged axially between the first working port and the second working port.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Aspects of the invention will be described below on the basis of example embodiments. Features disclosed by the example embodiments, each individually and in any combination of features, advantageously develop the subject-matter of the claims, the subject-matter of the aspects and also the embodiments described at the beginning. Features disclosed only by the respective example embodiment can also be implemented in the other example embodiments, providing there is no obvious contradiction. There is shown:

(2) FIG. 1 a phase setter of a first example embodiment, fitted on a cam shaft, in a longitudinal section;

(3) FIG. 2 components of a rotor unit of the phase setter of the first example embodiment, which are non-rotationally connected to the cam shaft, in the longitudinal section in FIG. 1;

(4) FIG. 3 the cross-section A-A in FIG. 1;

(5) FIG. 4 the longitudinal section B-B in FIG. 3;

(6) FIG. 5 components of the rotor unit of the first example embodiment, in an isometric representation;

(7) FIG. 6 a rotor and a holding device of the first example embodiment, in an isometric representation;

(8) FIG. 7 a phase setter of a second example embodiment, fitted on a cam shaft, in a longitudinal section;

(9) FIG. 8 components of a rotor unit of the phase setter of the second example embodiment, which are non-rotationally connected to the cam shaft, in the longitudinal section in FIG. 7;

(10) FIG. 9 the cross-section A-A in FIG. 7;

(11) FIG. 10 the longitudinal section B-B in FIG. 9;

(12) FIG. 11 components of the rotor unit of the second example embodiment, in an isometric representation;

(13) FIG. 12 a rotor and a holding device of the second example embodiment, in an isometric representation;

(14) FIG. 13 a phase setter of a third example embodiment, in a longitudinal section;

(15) FIG. 14 the cross-section A-A in FIG. 13;

(16) FIG. 15 a phase setter of a fourth example embodiment, in a longitudinal section;

(17) FIG. 16 the cross-section A-A in FIG. 15;

(18) FIG. 17 the rotor unit of the first example embodiment, as in FIG. 2; and

(19) FIG. 18 the rotor unit of the second example embodiment, as in FIG. 8.

DETAILED DESCRIPTION OF THE INVENTION

(20) FIG. 1 shows a cam shaft phase setter of a first example embodiment, in a longitudinal section. The phase setter is fitted on an axial end of a cam shaft N of an internal combustion engine, for example a drive motor of a motor vehicle. The phase setter comprises a stator 1 which can be coupled to a crankshaft of the internal combustion engine for rotary-driving the phase setter about a central rotational axis R. The phase setter also comprises a rotor 10 which can be rotated about the rotational axis R and which is non-rotationally connected to the cam shaft N. A bearing body LK of the internal combustion engine, which mounts the cam shaft N such that it can rotate about the rotational axis R, is indicated in FIG. 1. The rotor 10 can be rotationally adjusted back and forth relative to the stator 1 by a particular rotational angle about the rotational axis R, in order to be able to adjust the phase position of the cam shaft N relative to the crankshaft, i.e. the rotational angular position of the cam shaft N relative to the crankshaft.

(21) The stator 1 comprises a stator ring 2, a drive gear tooth system 3, a cover 5 on a side facing the cam shaft N, and a cover 6 on a side facing away from the cam shaft N. The stator ring 2 and the drive gear tooth system 3 are formed together in one piece in an original-moulding method. The covers 5 and 6 are non-rotationally joined to the stator ring 2. The stator ring 2 and its drive gear tooth system 3 together form a drive wheel for rotary-driving the phase setter and the cam shaft N which is driven via the phase setter. The drive gear tooth system 3 encircles the outer circumference of the stator ring 2. It can in particular be a drive gear tooth system for a belt drive.

(22) The stator 1 and the rotor 10 form multiple first pressure chambers K.sub.1 and multiple second pressure chambers K.sub.2 in a distribution around the rotational axis R, wherein the pressure chambers are shown in the cross-section in FIG. 3. The drive gear tooth system 3 overlaps axially with the pressure chambers K.sub.1 and K.sub.2. In modifications, the drive gear tooth system can be formed axially next to the pressure chambers K.sub.1 and K.sub.2. The overall length of the phase setter can be shortened by means of the axial overlap.

(23) The phase setter comprises a control valve 20 for hydraulically controlling or regulating the phase position of the rotor 10 relative to the stator 1 and therefore that of the cam shaft N relative to the crankshaft. The control valve 20 comprises a valve housing 21 featuring a housing hollow space 25, a valve piston 30 which can be axially moved back and forth in the housing hollow space 25, and a valve spring 31 which is arranged in the housing hollow space 25. The valve spring 31 charges the valve piston 30 with a spring force in an axial direction in which it can be moved. The valve piston 30 is embodied as a hollow piston. The valve spring 31 protrudes axially into a hollow space 32 of the valve piston 30. One end of the valve spring 31 is supported on the valve piston 30, and the other end of the valve spring 31 is supported on the valve housing 21. The valve spring 31 is embodied as a helical pressure spring.

(24) The phase position of the rotor 10 is hydraulically adjusted relative to the stator 1 by means of the control valve 20 within the context of controlling or regulating. The control valve 20 forms a setting member of a superordinate controller, for example an engine controller of a motor vehicle.

(25) The phase setter is supplied with pressure fluid via supply channels V which extend through the cam shaft N into a hollow end portion of the cam shaft. The pressure fluid can, as for instance in the example embodiment, be guided to the supply channels V via the bearing body LK. If the phase setter is connected via the supply channels V to a lubricating oil system for lubricating the internal combustion engine, then the pressure fluid is lubricating oil which is diverted from the lubricating oil system, for the phase setter. The supply channels V emerge in the hollow end portion of the cam shaft N into an annular supplying portion 24 which is delineated on the radially outer side by the cam shaft N and on the inner side by the valve housing 21. The control valve 20 controls the inflow and outflow of the pressure fluid, supplied via the supplying portion 24, to and from the pressure chambers K.sub.1 and K.sub.2.

(26) The control state or switched state of the control valve 20 is controlled or regulated by means of an electromagnetic device 9. The electromagnetic device 9 is connected to the superordinate controller or regulator, for example an engine controller of a motor vehicle, when the phase setter is fitted, and controls or regulates the control states and/or switched states of the control valve 20 in accordance with control signals of the controller or regulator. The control signals can in particular be current signals. The electromagnetic device 9 comprises an electric coil 9a and an anchor which can be axially moved back and forth and which comprises a plunger 9b which acts on the valve piston 30. The plunger 9b mounts a spherical body 9c which is in an axial abutting contact with the valve piston 30. The valve spring 31 presses the valve piston 30 axially into the abutting contact with the spherical body 9c of the plunger 9b. The electromagnetic device 9 acts counter to the valve spring 31.

(27) The electromagnetic device 9 can be arranged stationarily. The rear side of the stator cover 6 which faces away from the cam shaft N and towards the electromagnetic device 9 comprises an annular appendage 7 which is surrounded by an annular appendage 9d on a housing of the electromagnetic device 9. A gasket 8 is arranged in an annular gap remaining between the annular appendages 7 and 9d, in order to seal off the space which exists between the electromagnetic device 9 and the rotating part of the phase setter.

(28) The control valve 20 serves a second function of non-rotationally connecting the rotor 10 to the cam shaft N. Together with other components which will be described further below, the rotor 10 is a constituent of a rotor unit 100 which can be fitted on the cam shaft N by means of the control valve 20. In order to fit it, the valve housing 21 protrudes axially through the rotor 10, and a shaft portion of the valve housing 21 protrudes axially beyond the rotor 10 and into the hollow end portion of the cam shaft N. Within the hollow end portion of the cam shaft N, the valve housing 21 is joined to the cam shaft N in a joining portion 22, wherein the supplying portion 24 remains free. The joining portion 22 can in particular be a screwing portion. The valve housing 21 likewise protrudes axially beyond the rotor 10 in the other axial direction and comprises, in that end region, a radial widening in the form of a collar 23. The valve housing 21 serves as a central joining element, for example a screwing element. When joined and/or fitted, the rotor 10 is axially clamped between the cam shaft N and the collar by to the cam shaft N and thus non-rotationally connected to the cam shaft N. Control valves like the control valve 20 are also referred to as central valves because they are arranged centrally in the phase setter.

(29) FIG. 2 shows only the control valve 20, and the rotor unit 100 which is non-rotationally connected by the control valve 20 to the cam shaft N, of the phase setter of the first example embodiment. For simplicity, the stator 1 and the electromagnetic device 9 and the bearing body LK are not shown.

(30) The phase setter is connected to the external pressure fluid supply system via the cam shaft N and the annular supplying portion 24 which remains between the cam shaft N and the valve housing 21. An outer circumference of the control valve 20 comprises a pressure port P in axial overlap with the rotor 10, a first working port A axially next to the pressure port P on one side, and a second working port B axially next to the pressure port P on the other side. The ports P, A and B are each embodied as a circumferential connecting groove on the outer circumference of the valve housing 21. They are connected to the central housing hollow space 25 via valve channels which extend radially in the valve housing 21.

(31) The outer circumference of the valve piston 30 comprises a control groove 33 which advantageously encircles the entire circumference. The pressure port P is connected to the control groove 33 in every axial position of the valve piston 30. The control groove 33 is axially delineated on both sides by control edges 34 and 35. Each of the control edges 34 and 35 is axially adjoined by a piston stay. The valve piston 30 is guided in the housing hollow space 25 such that it can slide within the axial region of these two piston stays, wherein the piston stays seal off the control groove 33 on both sides. Arranging the pressure port P axially between the working ports A and B favours the use of the valve piston 30 which, with only one control groove 33, is comparatively simple and axially short.

(32) In a co-operation between the electromagnetic device 9 (FIG. 1) and the valve spring 31, the valve piston 30 can be axially moved back and forth between a first piston position and a second piston position. In the first piston position, which the valve piston 30 has assumed in FIG. 2, the control groove 33 overlaps with the valve channels for the working port A, while one piston stay separates the valve channels of the working port B from the control groove 33, such that the pressure port P is connected to the working port A via the control groove 33 and is separated from the working port B. If the valve piston 30 is moved into the second piston position by means of the electromagnetic device 9, counter to the spring force of the valve spring 31, the control groove 33 passes out of the axial overlap with the working port A and its assigned valve channels and into an overlap with the working port B and its valve channels. In the second piston position, the pressure port P is thus connected to the working port B via the control groove 33 and is separated from the working port A.

(33) If the valve piston 30 assumes the first piston position, as shown in FIGS. 1, 2 and 4, the working port B is short-circuited with the housing hollow space 25, thus bypassing the valve piston 30, such that pressure fluid can flow from the second pressure chambers K.sub.2 via the working port B into the housing hollow space 25, whence it can flow off through an adjoining axial outflow portion 26 of the valve housing 21 towards a pressure fluid reservoir of the supply system, and the pressure chambers K.sub.2 are relieved of pressure. If the valve piston 30 assumes the second piston position, the working port A is connected to the outflow portion 26 via the valve piston 30. For draining fluid from the working port A, the valve piston 30 comprises an aperture 36 which connects the housing hollow space 25 to the piston hollow space 32. The pressure fluid can thus flow off from the working port A into the housing hollow space 25, then through the aperture 36 into the piston hollow space 32 and from there through the outflow portion 26. The two groups of pressure chambers K.sub.1 and K.sub.2 are thus respectively relieved of pressure via the central housing hollow space 25 and the outflow portion 26, wherein the pressure chambers K.sub.2 are relieved directly and the pressure chambers K.sub.1 are relieved via the piston hollow space 32.

(34) Starting from the housing hollow space 25, the outflow portion 26 extends through the shaft portion of the valve housing 21 which protrudes into the cam shaft N. The outflow portion 26 extends coaxially with the supplying portion 24, wherein the supplying portion 24 surrounds the outflow portion 26.

(35) The pressure port P is connected to the supplying portion 24 via a feed which leads through the rotor 10. The feed is composed of multiple feed portions 14, 44 and 15 which are consecutive in a flow direction, wherein the downstream end of the annular supplying portion 24 emerges into the upstream feed portion 14 which is formed in the rotor 10 and adjoined in an inflow direction by the feed portion 44. In the feed portion 44, the pressure fluid flowing to the pressure port P is deflected inwards, towards the rotational axis R. Due to this function, the feed portion 44 is referred to hereinafter as the deflecting portion 44. The deflecting portion 44 is adjoined by the downstream feed portion 15 which emerges into the pressure port P.

(36) The working port A is connected to the pressure chambers K.sub.1 via first connecting channels 16 which extend from the inner circumference 11a (FIGS. 5 and 6) to the outer circumference 11c of the rotor hub 11. The working port B is connected to the pressure chambers K.sub.2 via second connecting channels 17 which likewise extend from the inner circumference 11a to the outer circumference 11c of the rotor hub 11. One of the connecting channels 16, which connects the working port A to one of the pressure chambers K.sub.1, is shown in FIG. 2. One of the connecting channels 17, which connects the working port B to one of the assigned pressure chambers K.sub.2, is shown in the longitudinal section in FIG. 4.

(37) In order to separate it from the connecting channels 17 (FIG. 4) which extend in axial overlap with it, the feed portion 14 (FIG. 2) which extends in the rotor 10 is sub-divided into multiple feed channels which are spaced from each other in a circumferential direction around the rotational axis R and which extend in a circumferential direction between respectively adjacent connecting channels 17.

(38) The annular supplying portion 24 extends in an axially straight line from the supply channels V towards the rotor 10 up to a connecting region and extends at an inclination radial outwards in the connecting region up to the feed portion 14. The supplying portion 24 thus widens radially in the connecting region in an axial direction towards the feed portion 14. The feed channels of the feed portion 14 each comprise an upstream channel portion 14a, which is immediately adjoined by the connecting region of the supplying portion 24, and a downstream channel portion 14b which overlaps on the radially outer side with the upstream channel portion 14a. The feed portion 14 therefore has a stepped profile as viewed in a longitudinal section. In the example embodiment, each of the assembled feed channels 14a, 14b extends outwards in steps from the supplying portion 24 into the deflecting portion 44.

(39) A reflux valve device 50, which is arranged in the region where the feed portion 14 transitions into the deflecting portion 44, allows an inflow to the pressure port P with little resistance but prevents or at least significantly restricts a backflow. The reflux valve device 50 is shaped as an annular disc and extends axially around the rotational axis R between a cross-sectional plane which intersects the pressure port P and a cross-sectional plane which intersects the working port B. It axially exhibits a distance from the connecting channels 17 (FIG. 4) adjoining the working port B and, when fluid is not flowing through it, also from the downstream feed portion 15. Thus, when fluid is not flowing through it, it axially overlaps with neither the feed portion 15 nor the connecting channels 17. Since the feed portion 14 extends outwards in steps, but then extends in the axial direction in its downstream axial portion 14b up to the reflux valve device 50, the pressure fluid in the feed portion 14 is initially guided radially outwards but then guided at least substantially in an axial direction against the reflux valve device 50.

(40) The reflux valve device 50 is held clamped in position by means of a holding device 40. The holding device 40 is arranged in an annular accommodating space 13 of the rotor 10. It extends annularly around the rotational axis R and presses the reflux valve device 50 against an inner end-facing surface 18 of the rotor 10 in a seal circumferentially around the rotational axis R, uniformly throughout.

(41) The accommodating space 13 is open on an end-facing side of the rotor 10, such that the reflux valve device 50 and the holding device 40 can be axially inserted into the open accommodating space 13. In the example embodiment, the rotor 10 is open on its rear side which faces away from the cam shaft N. In modifications, however, the accommodating space 13 can instead also be closed on its rear side and open on the front side of the rotor 10 which faces the cam shaft N. An accommodating space 13 which is open towards the rear side does however make it easier to embody the rotor 10 such that the rotor 10 is directly pressed against the end-facing side of the cam shaft N by means of the valve housing 21.

(42) A closure cover 39 seals the accommodating space 13 on the end-facing side which is open towards the rear. When fitted, the collar 23 of the valve housing 21 presses the closure cover 39 axially against the rear side of the rotor 10 and also against the rear side of the holding device 40, such that the holding device 40 is pressed against the reflux valve device 50 and the reflux valve spring presses against the inner end-facing surface 18 of the rotor 10. The closure cover 39 can for example be a sheet-metal cover.

(43) In modifications, the holding device 40 can seal the accommodating space 13 on the rear side, such that the closure cover 39 can be omitted. In such embodiments, the collar 23 of the valve housing 21 would however be directly in contact with the holding device 40. If, as is preferred, the valve housing 21 serves as a fastening screw, there would be a danger in such embodiments of whittling on the rear side of the holding device 40 when screwing-in the valve housing 21.

(44) The connecting channels 16 are each composed of multiple portions which are consecutive in a radial direction, as shown in particular in FIG. 2 by the example of one of the connecting channels 16 and in the isometric representation in FIG. 5. The connecting channels 16 each comprise an inner connecting portion 16.1 which extends outwards from the working port A into the accommodating space 13. An outer connecting portion 16.2 extends from the accommodating space 13 up to the outer circumference 11c of the rotor hub 11 and into the respectively assigned pressure chamber K.sub.1. Since the holding device 40 is annular and extends in the accommodating space 13 up to and against the closure cover 39 due to being pressed onto it, the holding device 40 comprises multiple connecting portions 46, each in the form of a passage, in a distribution in a circumferential direction, in order to enable the inflow and outflow of pressure fluid to and from the pressure chambers K.sub.1 through the accommodating space 13. The connecting portions 46 can, as in the example embodiment, overlap axially and in a circumferential direction with the connecting portions 16.1 and 16.2, in order to connect the working port A to the pressure chambers K.sub.1 via a short route.

(45) The connecting portions 46 of the holding device 40 on the one hand allow the flow of pressure fluid between the working port A and the pressure chambers K.sub.1, but conversely separate the connecting channels 16 from the pressure fluid feed 14, 15, 44 by providing a seal between the connecting channels 16 and the feed 14, 15, 44 in the accommodating space 13. The holding device 40 thus not only performs the function of holding the reflux valve device 50 but also delineates a part of the respective connecting channel 16 and thus separates the connecting channels 16 from the feed 14, 15, 44.

(46) The holding device 40 delineates the deflecting portion 44. It particularly advantageously serves to deflect the inflowing pressure fluid, i.e. the holding device 40 performs a function of deflecting the pressure fluid which flows to the pressure port P, by deflecting the pressure fluid which is inflowing in the feed portion 14 radially inwards from its inflow direction towards the rotational axis R. As it flows through the deflecting region 44, the pressure fluid flows along the holding device 40, wherein it is deflected. The holding device 40 delineates the deflecting portion 44 in an axial direction and on the radially outer side. The deflecting portion 44 which is delineated by the holding device 40 and the rotor 10 comprises: an inflow region 44a which, when fluid is not flowing through it, adjoins the feed portion 14 across the reflux valve device 50; and an outflow region 44b which extends around the rotational axis R in an inflow direction downstream of the inflow region 44a and is delineated on the radially outer side by an inner circumference 41a of the holding device 40. The outflow region 44b directly adjoins the inflow region 44a.

(47) The holding device 40 also serves to hold a dirt filter 55. The dirt filter 55 extends around the rotational axis R. The inner circumference 41a of the holding device 40 surrounds the dirt filter 55 at a radial distance, thus providing a collecting space for dirt particles around the dirt filter 55 in the outflow region 44b.

(48) FIG. 3 shows the cross-section A-A in FIG. 1. As marked in FIG. 1, the section A-A extends in an upper sectional plane and a lower sectional plane which each extend as far as the rotational axis R and which are axially offset with respect to each other along the rotational axis R.

(49) The phase setter is embodied to have a vane-cell design. Multiple stator vanes 4 protrude inwards from the stator ring 2 towards the rotational axis R in a distribution over the circumference. The rotor 10 comprises a rotor hub 11 and multiple rotor vanes 12 which protrude radially outwards in a distribution over the circumference of the rotor hub 11. Each of the rotor vanes 12 protrudes outwards between two stator vanes 4 which are adjacent in a circumferential direction. The rotor vanes 12 divide each of the spaces delineated radially by the stator ring 2 and rotor hub 11 and in a circumferential direction by adjacent stator vanes 4 into one of the first pressure chambers K.sub.1 and one of the second pressure chamber K.sub.2. By charging the first pressure chambers K.sub.1 with pressure, while simultaneously relieving the second pressure chamber K.sub.2 of pressure, it is possible to adjust the cam shaft N to lead (or trail) relative to the crankshaft via the rotor 10 and, by reversing the pressure conditions, to adjust the cam shaft N to trail (or lead) relative to the crankshaft via the rotor 10.

(50) In FIG. 3, the upper sectional half shows the connection between the working port A and the pressure chambers K.sub.1, and the lower sectional half shows the pressure port P and feed channels of the downstream feed portion 15 which adjoin the deflecting portion 44 (FIG. 2) at their upstream ends and emerge downstream into the pressure port P. In the state shown, the pressure chambers K.sub.1 are charged with the pressure fluid via the respectively assigned connecting channel 16, while the pressure chambers K.sub.2 are connected to a pressure fluid reservoir and are correspondingly relieved of pressure.

(51) Bore portions 15b which are shown in FIG. 3 emerge into the pressure chambers K.sub.2, but are sealed by the holding device 40, as also shown in FIG. 2, and merely represent a certain dead volume. The disadvantage of a dead volume is more than made up for by a reduction in the production effort for producing the feed portion 15. When manufacturing the rotor 10, the feed channels of the feed portion 15 can be produced in a very simple way as transit bores in the rotor hub 11 and sealed by the holding device 40. Multiple simple bores, preferably radial bores, thus extend from the outer circumference 11c to the inner circumference 11a of the rotor hub 11. The portions of these transit bores which extend from the accommodating space 13 up to the outer circumference 11c of the rotor hub 11 are sealed off by means of the holding device 40 on an inner circumference 11b (FIG. 5) of the rotor hub 11 which surrounds the accommodating space 13. This creates, on the radially inner side, the feed channels which extend from the inner circumference 11a of the rotor hub 11 up to and into the accommodating space 13 and form the feed portion 15, each in the form of an inner bore portion, and on the radially outer side, the blind bore portions 15b which are sealed by the holding device 40.

(52) FIG. 4 shows the phase setter of the first example embodiment, in the longitudinal section B-B in FIG. 3. The section B-B extends, from the radially outer side, initially through the stator 1 and then through one of the rotor vanes 12 (and, in the process, through a locking pin 28 which is accommodated in the relevant rotor vane 12 such that it can axially shift), from the locking pin 28 a short distance in a circumferential direction up to the level of one of the connecting channels 16, then through the relevant connecting channel 16 and further radially inwards towards the rotational axis R and from there, axially level with the pressure port P, through the feed portion 15 outwards in a straight line.

(53) In an accommodating space of the stator ring 2 which is open on its end-facing side, the locking pin 28 is arranged such that it can axially shift and is tensed axially towards the stator cover 6 by a locking spring 29. The stator cover 6 comprises a local recess which the locking pin 28 can enter when the rotor 10 assumes a particular rotational angular position relative to the stator 1. A lock is particularly desirable when there is still air in the pressure chambers, such as for instance when an engine is started, or when particularly low pressures prevail, again such as when the engine is started. The recess in the stator cover 6 is charged with the pressure fluid, such that when a particular minimum pressure is reached, the locking pin 28 is pressed out of the recess, against the force of the locking spring 29, and the lock is thus released. A relief channel 29a serves to drain leakage fluid from the region of the accommodating space in which the locking spring 29 is arranged.

(54) The section in FIG. 4 also in particular shows one of the connecting channels 17, via which the working port B is connected to one of the second pressure chambers K.sub.2. The connecting channels 17 can be linear bores, which is favourable in terms of production, which extend through the rotor hub 11 from the outer circumference 11c to the inner circumference 11a of the rotor hub 11. The connecting channels 17 are preferably radial bores.

(55) The isometric representation in FIG. 5 shows the rotor 10, the reflux valve device 50, the dirt filter 55, the holding device 40, the closure cover 39 and also the locking pin 28 and the locking spring 29, lined up axially in a view into the accommodating space 13 of the rotor 10 which is open towards the rear. The rotor 10, the reflux valve device 50, the dirt filter 55, the holding device 40 and the closure cover 39 form the rotor unit 100 when assembled, wherein the reflux valve device 50, the filter 55 and the holding device 40 are accommodated in the accommodating space 13 of the rotor 10.

(56) The accommodating space 13 sub-divides the rotor hub 11 axially into a front axial portion, which faces the cam shaft N, and a rear axial portion which extends axially as far as the inner end-facing surface 18 of the rotor. The end-facing surface 18 of the rotor is a bottom surface of the accommodating space 13. The accommodating space 13 sub-divides the rear axial portion into an inner ring, which comprises the inner circumference 11a, and an outer ring which surrounds the inner ring and forms the outer circumference 11c of the rotor hub 11. The inner connecting portions 16.1 of the connecting channels 16 (FIG. 2) extend through the inner ring as passages which are open on their rear side, and the outer connecting portions 16.2 of the connecting channel 16 extend through the outer ring into the respective first pressure chamber K.sub.1 (FIGS. 2 and 3). The bore portions of the feed portion 15 traverse the inner ring of the rotor hub. The bore portions 15b traverse the outer ring of the rotor hub 11.

(57) Each of the connecting channels 17 extends in the front axial portion of the rotor hub 11 from the inner circumference 11a up to the outer circumference 11c of the rotor hub 11 and emerges on the outer side into the second pressure chamber K.sub.2 (FIGS. 3 and 4) assigned to the respective connecting channel 17. The connecting channels 17 thus lead from the respective pressure chamber K.sub.2 to the working port B via the shortest route in a straight line. Two of the channel portions 14b of the feed portion 14 which is upstream in the rotor unit 100, which emerge into the accommodating space 13, are also shown. The feed channels 14a, 14b of the feed portion 14, which are respectively composed of the channel portions 14a (FIG. 2) and 14b, are offset at an angle to the connecting channels 17. Each of the assembled feed channels 14a, 14b respectively extends between two connecting channels 17 which are adjacent in a circumferential direction.

(58) The reflux valve device 50 is an axially thin valve structure 51 which is shaped as an annular disc and extends around the rotational axis R when fitted, as shown in FIGS. 1 to 4. The valve structure 51 is circumferentially closed on the radially inner side, which is advantageous with regard to fitting it, but is not essential in order for it to perform its function. Multiple spring-elastic valve tongues, hereinafter spring tongues 52, extend around the inner ring 52a formed in this way, successively in a circumferential direction, and can be elastically bent in an axial direction. The spring tongues 52, which can be bent and thus axially moved, are isolated from the inner ring 52a of the valve structure 51 by radially narrow clearances 53 which are elongated in a circumferential direction. Starting from a root region of the respective spring tongue 52 which adjoins the ring 52a, the clearances 53 extend in a circumferential direction and then taper radially outwards. The reflux valve device 50 and/or valve structure 51 as a whole exhibits the shape of an annular disc which is sub-divided by the narrow clearances 53 into the ring 52a and the spring tongues 52 which project radially from it in the respective root region and then extend in a circumferential direction. The spring tongues 52 form the outer circumference of the valve structure 51. The spring tongues 52 can be correspondingly dimensioned so as to have a large area.

(59) In order to position the reflux valve device 50 relative to the holding device 40 and, via the latter, relative to the channel segments of the feed portion 14 in a circumferential direction, the valve structure 51 is provided with engaging structures 54 which co-operate with valve engaging structures 49 (FIG. 6) of the holding device 40. Advantageously, the reflux valve device 50 is not only positioned but also held on the holding device 40 by means of the engaging structures 54, which can make fitting it easier.

(60) The channel portions 14b of the feed portion 14 are elongated in a circumferential direction, i.e. the flow cross-section of the respective channel portion is wider in a circumferential direction than in a radial direction. On the one hand, this provides an advantageously large flow cross-section for pressure fluid flowing to the pressure port P. On the other hand, the elongated cross-sectional shape of the channel portions 14b is adapted to the spring tongues 52 of the reflux valve device 50 which are likewise elongated in a circumferential direction. Due to the elongated cross-section of the channel portions 14b of the feed portion 14, fluid flows onto a large area of the spring tongues 52.

(61) A Reed valve is respectively formed by means of the spring tongues 52 in the region where one of the channel portions 14b of the feed portion 14 transitions into the adjoining deflecting portion 44.

(62) The holding device 40 is sleeve-shaped. It comprises a front axial portion 41, which axially faces the reflux valve device 50, and a rear axial portion 42 which protrudes from the front axial portion 41. The axial portion 41 is adapted to the shape and dimensions of the accommodating space 13, such that when fitted, the holding device 40 separates the feed 14, 15, 44 from the connecting channels 16 in the region of the axial portion 41 and seals the radially outer bore portions 15b (FIG. 2). The comparatively narrower axial portion 42 axially adjoins the axial portion 41 directly. The connecting portions 46 traverse the axial portion 42. When fitted, they overlap axially and in a circumferential direction with the inner connecting portions 16.1 and the outer connecting portions 16.2 of the rotor 10. Like the inner connecting portions 16.1, they are open on the rearward end-facing side of the holding device 40, i.e. the connecting portions 46 terminate in an opening on the rearward end-facing side of the holding device 40.

(63) A front facing end of the holding device 40 which faces the closure cover 39 comprises an equalising structure 47 which serves to compensate for production tolerances and fitting tolerances and optionally also to compensate for different thermal expansions of the rotor 10 and the holding device 40. The equalising structure 47 is formed by a radially narrow projection on the rear end-facing surface of the axial portion 42. The equalising structure 47 is annular. It extends around the rotational axis R and is interrupted only by the connecting portions 46 which are open at the rear facing end. In modifications, the equalising structure 47 can be formed by means of a circumferential furrow-shaped recess or by multiple axially protruding studs which are arranged in a distribution over the circumference. When fitted, the closure cover 39 presses against the equalising structure 47, which is correspondingly deformed when being fitted but which advantageously still exhibits, once fitted, an elasticity which is sufficient to compensate for differences in thermal expansion.

(64) The dirt filter 55 is likewise sleeve-shaped. It comprises a sleeve-shaped filter screen 56 and a supporting structure 57 comprising supporting rings between which the filter screen 56 extends around the rotational axis R (FIG. 2). The supporting structure 57 also comprises radially protruding engaging structures 58 for establishing a positive-fit and optionally also frictional-fit holding engagement with filter engaging structures 48 (FIG. 6) of the holding device 40.

(65) The closure cover 39 is a thin annular disc comprising a circumferential recess near the outer circumference, wherein the recess is produced by reshaping and provides a lip on the outer circumference of the closure cover 39 and rigidifies the closure cover 39. When assembled, the closure cover 39 is placed in the axially rearward end of the accommodating space 13, and its lip which is circumferential on the outer side presses against an inner circumference 11b of the rotor hub 11. This seals off the accommodating space 13 on the outer circumference of the closure cover 39, as shown for instance in FIG. 2.

(66) The rotor 10 and the holding device 40 are lined up along the rotational axis R in the isometric representation in FIG. 6. The other components of the rotor unit 100, for example the reflux valve device 50, are not shown for reasons of simplicity. FIG. 6 is a view onto the inflow and/or feed side of the rotor 10 and holding device 40.

(67) The upstream channel portion 14a of each of the feed channels 14a, 14b of the feed portion 14 of the rotor 10 is shown, wherein the upstream channel portion 14a emerges on a front outer end-facing surface of the rotor 10. When fitted, said end-facing surface of the rotor 10 is pressed axially against an end-facing surface of the cam shaft N by means of the valve housing 21, as shown in FIG. 2. The upstream channel portions 14a of the feed channels 14a, 14b of the feed portion 14 are narrower in a circumferential direction than the downstream channel portions 14b.

(68) The end-facing side 41s of the holding device 40, which axially faces the inner end-facing surface 18 (FIGS. 2, 4 and 5) of the rotor 10 when assembled, comprises multiple axial recesses 43 in a distribution over the circumference, wherein said recesses 43 together form the inflow region 44a of the deflecting portion 44. When assembled, the recesses 43 overlap in a circumferential direction with the channel segments 14b of the feed portion 14. They are each delineated on the radially outer side by a circumferential wall of the holding device 40. The recesses 43 are open, radially inwards, on the inner circumference 41a. The recesses 43 are delineated in an axial direction by end-facing bases, i.e. segmental end-facing surfaces, of the holding device 40. The bases form contact surfaces 45 for the spring tongues 52 of the reflux valve device 50 (FIG. 5). The recesses 43 are thus also yielding spaces into which the spring tongues 52 can yield until the respective spring tongue 52 comes to rest against the axially facing contact surface 45. In this respect, the spring tongues 52 and the corresponding contact surfaces 45 can be embodied as is known from other applications of Reed valves.

(69) The contact surfaces 45 each extend at an axial inclination in a circumferential direction, such that the axial depth of the respective recess 43 increases in a circumferential direction from a flat region up to a deep region. As is preferred, the depth respectively increases continuously in a circumferential direction, starting from the front end-facing surface 41s of the holding device 40. The contact surfaces 45 are correspondingly inclined continuously in an axial direction. The angle of inclination of the contact surfaces 45 can in particular be constant, such that the contact surfaces 45 are oblique surfaces. In modifications, the angle of inclination can however also vary, for example progressively increase in a circumferential direction starting from the respective flat region, such that a contact surface 45 shaped in this way is convexly bulged in an axial direction in relation to the opposing spring tongue 52. The contact surfaces 45 axially slope continuously from the end-facing surface 41s into the respective recess 43. In such embodiments, the spring tongues 52 are placed onto the assigned contact surface 45 over their whole area. When they yield, the respective spring tongue 52 rolls off on the assigned contact surface 45.

(70) As it flows through the inflow region 44a, the pressure fluid experiences a deflection in a circumferential direction because the depth of the recesses 43 increases in a circumferential direction, i.e. a tangential directional component (a rotational impulse) relative to the rotor unit 100 is imposed on the pressure fluid in the inflow region 44a. As it flows through the deflecting portion 44, the pressure fluid therefore exhibits a tangential directional component in the outflow region 44b, in particular in the annular gap between the dirt filter 55 and the inner circumference 41a of the holding device 40. In the annular gap around the dirt filter 55, therefore, not only the centrifugal forces caused by the rotational movement of the rotor unit 100 but also tangential forces which relieve the dirt filter 55 act on the dirt particles contained in the pressure fluid.

(71) As already mentioned, the recesses 43 are open radially inwards towards the inner circumference 41a, such that the pressure fluid in the inflow region 44a of the deflecting portion 44 is deflected, at the spring tongues 52 which are bent into the recesses 43, from an at least substantially axial inflow direction, radially inwards towards the rotational axis R.

(72) The rotor unit 100 comprising the rotor 10, the holding device 40, the reflux valve device 50 and the dirt filter 55 forms a fitted unit. In order to be able to handle them as a unit, i.e. a fitted unit, the components mentioned are advantageously held on each other in a releasable holding engagement. It is advantageous if the reflux valve device 50 and the dirt filter 55 are held on the holding device 40 in a holding engagement with the holding device 40 even before the rotor unit 100 is assembled, and for the holding device 40, reflux valve device 50 and dirt filter 55 to comprise mutually adapted engaging structures for establishing the respective holding engagement. The rotor unit 100 is completed by the closure cover 39 which is expediently pressed into the accommodating space 13 of the rotor 10 in order to ensure that the components of the rotor unit 100 are firmly held together in a pressing fit.

(73) FIG. 6 shows the filter engaging structures 48 for the dirt filter 55 which are formed on the front end-facing side 41s of the holding device 40. The filter engaging structures 48 are formed on the front end-facing surface 41s as recesses into which the engaging structures 58 of the dirt filter 55 can be inserted. When the structures 48 and 58 are in engagement, the dirt filter 55 is advantageously held on the holding device 40 in a positive fit and/or frictional fit. The valve engaging structures 49, which protrude in the shape of pins or studs on the front end-facing side 41s of the holding device 40 in a distribution in a circumferential direction, are also shown. The valve engaging structures 49 serve to position and hold the reflux valve device 50, by engaging with the engaging structures 54 (FIG. 5) of the reflux valve device 50. In the example embodiment, they protrude through the engaging structures 54 of the reflux valve device 50, such that they also serve an additional function of positioning the holding device 40 relative to the rotor 10, i.e. in order to position the recesses 43 in relation to the circumferential direction relative to the channel segments 14b of the feed portion 14 of the rotor 10. This positioning engagement is also preferably a holding engagement in which the holding device 40 together with the reflux valve device 50 and the dirt filter 55 is held on the rotor 10, in order to make it easier to assemble the phase setter.

(74) As already mentioned, arranging the holding device 40 in the accommodating space 13 of the rotor 10 makes it easier to produce the feed channels and connecting channels which cross the rotor unit 100, and in particular easier to produce the downstream feed portion 15 and the connecting channels 16. The rotor hub 11 with its projecting rotor vanes 12 can then be formed as a cast part in a casting method or advantageously as a sintered part by pressing and sintering. The rotor 10 can be a plastic part or, as is preferred, a metal part or a plastic part comprising one or more embedded metal structures. The cast or sintered part can already comprise the accommodating space 13. Alternatively, the accommodating space 13 can be produced by machine-cutting the cast or sintered part. The connecting portions 16.1 and 16.2 of the connecting channels 16 and/or the connecting channels 17 and/or the feed channels of the feed portion 15 which emerges at the inner circumference 11a of the rotor hub 11 can each be produced as linear, radial or at least substantially radial bores which traverse the rotor hub 11 from the radially outer side to the radially inner side. If, as is preferred, the rotor 10 is a sintered part, the connecting channels 16 and/or the connecting channels 17 and/or the feed channels of the feed portion 15 can be produced particularly cheaply by drilling the compact, i.e. the powder compact which has been pressed into shape. The outer bore portions 15b are sealed in the accommodating space 13 by the holding device 40. The connecting portions 16.1 and 16.2 of the connecting channels 16 are separated from the feed 14, 15, 44 in the accommodating space 13 by means of the holding device 40.

(75) FIGS. 7 to 12 show a phase setter of a second example embodiment. The same sections and isometric representations have been chosen as in the first example embodiment. The phase setter, which is shown completely in FIG. 7, corresponds to the first example embodiment in relation to its stator 1, control valve 20 and electromagnetic device 9. The pressure fluid supply via the cam shaft N and the annular supplying portion 24 corresponds to the pressure fluid supply of the first example embodiment. In relation to the identically designed components and the pressure fluid supply, reference is therefore made to the statements made regarding the first example embodiment. Differences do however exist with regard to the rotor unit, which comprises: a rotor 10 which has been modified in the region of the rotor hub 11; a modified holding device 60; a modified reflux valve device 70; and a modified dirt filter 80.

(76) FIG. 8 shows the rotor unit 101 of the second example embodiment, when fitted on a cam shaft N. The stator 1 and the electromagnetic device 9 and also the bearing body LK (FIG. 7) are not shown.

(77) The rotor 10 comprises a central axial passage through which the valve housing 21 protrudes. The passage narrows in steps from a front axial portion, which adjoins the cam shaft N, to a rear axial portion 42, wherein it forms an end-facing surface 19 which faces the cam shaft N. The wide front axial portion of the passage forms an accommodating space 19 (FIG. 12) for the holding device 60. Unlike the accommodating space 13 of the first example embodiment, the accommodating space 19 is therefore not formed within the rotor 10 but rather radially between the rotor 10 and the valve housing 21. Correspondingly, the holding device 60 forms an inner circumference 60a of the rotor unit 101, which immediately surrounds the outer circumference of the valve housing 21 in the region of the pressure port P and working port B and thus establishes the pressure fluid connection between the rotor unit 101 and the control valve 20.

(78) The rotor 10 comprises first connecting channels 16 which extend through the rotor hub 11 and connect the working port A to one of the first pressure chambers K.sub.1, respectively. Unlike the first example embodiment, the connecting channels 16 extend over their entire length from the inner circumference 11a to the outer circumference 11c (FIG. 11) of the rotor hub 11.

(79) In the second example embodiment, the feed which connects the supplying portion 24 to the pressure port P extends in sections through the holding device 60. For instance, an upstream feed portion 64 which extends from the supplying portion 24 as far as the reflux valve device 70 extends through the holding device 60. As in the first example embodiment, the upstream feed portion 64 comprises an upstream channel portion 64a, which immediately adjoins the supplying portion 24, and a downstream channel portion 64b which adjoins the upstream channel portion 64a further on the radially outer side within the holding device 60 and extends as far as the reflux valve device 70.

(80) In the inflow direction to the pressure port P, the feed portion 64 is adjoined in the central passage of the rotor 10 by a deflecting portion 65 in which the pressure fluid which is axially inflowing through the feed portion 64 is deflected towards the rotational axis R and the pressure port P. The reflux valve device 70 acts in the region where the feed portion 64 transitions into the deflecting portion 65. The deflecting portion 65 is an annular space which extends around the rotational axis R and which is delineated on the radially outer side by an inner circumference 11b of the rotor 10 and on the radially inner side by the holding device 60. The end-facing surface 19 of the rotor 10 delineates the deflecting portion 65 on one end-facing side. When fluid is not flowing through it, the reflux valve device 70 delineates the deflecting portion 65 on the other end-facing side.

(81) The deflecting portion 65 is adjoined on the radially inner side across the dirt filter 80 by the downstream feed portion 66 which extends through the holding device 60 up to the pressure port P.

(82) In the second example embodiment, the rotor 10 can be configured very simply with regard to the feed 64, 65, 66 due to the holding device 60. The inner circumference 11b and end-facing surface 19 of the rotor hub 11 merely delineate the deflecting portion 65.

(83) In the cross-section in FIG. 9, the lower sectional half shows the connection between the working port B and the pressure chambers K.sub.2. In the state shown, the pressure chambers K.sub.1 are charged with the pressure fluid via the connecting channels 16 (FIG. 2), while the pressure chambers K.sub.2 are connected to the pressure fluid reservoir via the respectively assigned connecting channel 17 and are correspondingly relieved of pressure. The connecting channels 17 are each composed of an inner channel portion 67 which extends through the holding device 60, an outer channel portion 17 which extends through the rotor hub 11, and an annular gap 11d of the rotor hub 11. The annular gap 11d extends around the rotational axis R on the inner circumference 11b of the rotor hub 11. The channel portions 17 of the holding device 60 emerge from the radially inner side, and the channel portions 67 emerge from the radially outer side, into the annular gap 11d. The lower sectional plane in FIG. 9 respectively shows a channel segment 64b of the feed portion 64, which is elongated in a circumferential direction, between connecting channels 17 which are adjacent in a circumferential direction. In the second example embodiment, the channel segments 64a, 64b (FIG. 2) of the feed portion 64 cross the radially inner channel portions 17 of the connecting channels 17 in the holding device 60, each at a distance as measured in a circumferential direction. The feed portion 64 is thus separated from the connecting channels 17 within the holding device 60.

(84) FIG. 10 shows the phase setter of the second example embodiment, without the electromagnetic device 9 (FIG. 1), in the section B-B in FIG. 9. The section extends in the upper sectional half, above the rotational axis R, through the pressure port P and extends in the lower sectional half through the working port B and the connecting channels 17, such that the aligned arrangement of the channel portions 67 and 17 is shown, as in the cross-section in FIG. 9.

(85) The components of the rotor unit 101 of the second example embodiment are lined up axially, in the viewing direction onto the rear side of the rotor 10 which faces away from the cam shaft N, in the isometric representation in FIG. 11. The connecting channels 16 traverse the rotor hub 11 from the outer circumference 11c to the inner circumference 11a. The connecting channels 16 are transit bores which emerge on the outer circumference 11c at a slight axial distance from the facing end of the rotor hub 11 and, directly adjoining the inner circumference 11a, are axially elongated such that they open at the facing end of the rotor hub 11. When fitted, they are sealed at the facing end by means of the collar 23 of the valve housing 21 (FIG. 2).

(86) The holding device 60 comprises a radially wide front axial portion 61 and a rear axial portion 62 which is radially narrower by comparison and axially protrudes from the front axial portion 61. In the front axial portion 61, which faces the cam shaft N when assembled, the channel portions 67 traverse the holding device 60 from the radially outer side to the radially inner side. The channel portions 64a (FIG. 8) and 64b of the feed portion 64 each extend in an axial direction in the axial portion 61 and emerge on a rearward end-facing surface 63 of the axial portion 61. The feed channels of the feed portion 66 extend through the rear axial portion 62 from the radially outer side to the radially inner side.

(87) The reflux valve device 70 comprises a valve structure 71, which is shaped as an annular disc, and a spring/guiding device comprising multiple reflux valve springs 73 and multiple pin-shaped or bolt-shaped guiding elements 74. The guiding elements 74 are fastened to the holding device 60 by means of holding elements 76. The holding elements 76 can be inserted into recesses 69 which are formed on the end-facing surface 63 of the holding device 60. They serve to hold the guiding elements 74 on the holding device 60. The guiding elements 74 can for example be screwed to the holding elements 76. The ends of the guiding elements 74 which face away from the end-facing surface 63 comprise radial widenings which form a counter bearing 75 for each one of the reflux valve springs 73. When assembled, the guiding elements 74 on the end-facing surface 63 axially protrude from the holding device 60 freely, wherein they protrude through the valve structure 71 which comprises, for this purpose, a complementary guiding element 72 in the form of for example an axial passage for each of the guiding elements 74. The reflux valve springs 73 are each axially supported at one end on the valve structure 71 and axially supported at the other end on the counter bearing 75 of the respective guiding element 74. The spring forces are thus absorbed by the holding device 60.

(88) When fitted, the valve structure 71 is charged with a spring force towards the end-facing surface 63 of the holding device 60. In accordance with the pressure conditions prevailing in the feed 64, 65, 66, the valve structure 71 is either pressed against the end-facing surface 63 and seals the channel portions 64b of the feed portion 64 against a backflow or is lifted off the end-facing surface 63, against the force of the reflux valve spring 73, such that pressure fluid can flow to the pressure port P. When the valve structure 71 and the guiding elements 74 are in guiding engagement, the valve structure 71 is axially guided on the guiding elements 74. In order to rigidify the valve structure 71 which can be axially moved back and forth as a whole, it is circumferentially provided with an outer rigidifying periphery 77 which is obtained by reshaping.

(89) As in the first example embodiment, the dirt filter 80 comprises a sleeve-shaped filter screen 81, which extends around the rotational axis R, and a supporting structure 82 which frames the filter screen 81 on the left and right. When fitted, the filter screen 81 surrounds the holding device 60 in the region of the feed portion 66, wherein the supporting structure 82 is in a releasable and for example frictional-fit holding engagement with a filter engaging structure 68 of the holding device 60. The filter engaging structure 68 extends in the shape of a furrow around the rotational axis R on the end-facing surface 63. In the holding engagement, the supporting structure 82 of the dirt filter 80 protrudes axially into the filter engaging structure 68. The feed channels of the feed portion 66 emerge on an outer circumference of the holding device 60 which is radially set back, such that the filter screen 81 surrounds where the feed channels of the feed portion 66 emerge, at a certain radial distance, and the dirt filter 80 is radially supported in the region of the supporting structure 82 to the left and right of the feed portion 66. When fitted, the dirt filter 80when it is in engagement with the filter engaging structure 68is axially supported on the holding device 60 and axially supported on the other side on the end-facing surface 19 (FIG. 2) of the rotor 10 and thus axially secured. When fitted, the counter bearings 75 of the guiding elements 74 come to rest in radial recesses 83 of the dirt filter 80, such that there is no contact between the dirt filter 80 and the reflux valve springs 73.

(90) In the axial portion 61 on the outer circumference axially next to the connecting channels 67, the holding device 60 circumferentially comprises a furrow 61a for accommodating a gasket ring 61b. The gasket ring 61b ensures that the joining gap which extends around the rotational axis R between the rotor 10 and the holding device 60, and the annular gap 11d which is circumferential in the region of the joining gap and connects the channel portions 17 and 67 (FIG. 10), are sealed within the rotor unit 101.

(91) FIG. 12 shows just the rotor 10 and holding device 60 of the rotor unit 101 of the second example embodiment, axially lined up and in a view in an inflow direction of the pressure fluid and thus a view into the accommodating space 19 of the rotor 10.

(92) Arranging the holding device 60 in the accommodating space 19 of the rotor 10 makes it easier to produce the feed channels and connecting channels which cross the rotor unit 101, and in particular easier to produce the deflecting portion 65 (FIG. 8). The feed portions 64 and 66 are directly provided in their entirety in the holding device 60. The rotor hub 11 with its projecting rotor vanes 12 can then be formed as a cast part in a casting method or advantageously as a sintered part by pressing and sintering. In the second example embodiment, the rotor 10 can again be a plastic part or, as is preferred, a metal part or a plastic part comprising one or more embedded metal structures. The cast or sintered part can already comprise the accommodating space 19. Alternatively, the accommodating space 19 can be produced by machine-cutting the cast or sintered part. The connecting channels 16 and/or the channel portions 17 can each be produced as linear, radial or at least substantially radial bores which traverse the rotor hub 11 from the radially outer side to the radially inner side.

(93) The respective holding device 40 and/or 60 can be manufactured in one piece in an original-moulding method, preferably injection moulding. In preferred embodiments, the holding device 40 is a plastic injection-moulded part. In equally preferred alternative embodiments, the holding device 40 and/or the holding device 60 can be formed from a metal material, preferably a light metal. It also holds for the metallic holding device 40 and/or 60 that it is preferably formed in one piece in an original-moulding method, expediently by casting. In embodiments in which it is made of metal, the holding device 40 and/or the holding device 60 can in particular be an aluminium or zinc die-cast part.

(94) FIGS. 13 and 14 show a phase setter of a third example embodiment, fitted on the cam shaft N. The phase setter is derived from the phase setter of the first example embodiment. For reasons of simplicity, the only parts of the phase setter shown are the stator 1 and the rotor unit which is non-rotationally connected to the cam shaft N. The phase setter of the third example embodiment differs from the phase setter of the first example embodiment only in relation to an integrated pressure storage 90. In order to obtain the pressure storage 90, the stator 1 and rotor 10 are modified, while the other components of the phase setter correspond to the functionally identical components of the first example embodiment, such that reference is made to the statements made in this respect regarding the first example embodiment. Because they are otherwise identical, the rotor unit is denoted by the reference sign 100, as in the first example embodiment.

(95) The pressure storage 90 comprises a storage space which extends around the rotational axis R and in which a pressure storage piston 93 can be moved back and forth in an axial direction. The piston 93 axially sub-divides the storage space into a pressure volume 91 and a relief volume 92. The pressure volume 91 is connected to the pressure fluid supply, such that the pressure storage piston 93 can be charged with the pressurised pressure fluid on a side of the piston in the pressure volume 91. In the relief volume 92, a pressure storage spring 94 is accommodated which charges the pressure storage piston 93 with a restoring spring force counter to the pressure exerted by the pressure fluid.

(96) The storage space 91, 92 is an annular gap which extends around the rotational axis R completely circumferentially in the stator ring 2 and is sealed at its open end-facing side by means of the stator cover 6. Instead of an annular gap which is completely circumferential around the rotational axis R, the storage space 91, 92 could also be formed as an annular gap segment which extends only partially around the rotational axis R or could be formed by multiple annular gap segments which each extend around the rotational axis R and which are arranged successively in a circumferential direction. Forming it as a completely circumferential annular gap does however simplify the pressure storage 90 in several respects. One annular piston which is completely circumferential around the rotational axis R is then sufficient as the pressure storage piston 93, and the pressure storage spring 94 can be provided in the form of a simple helical pressure spring. Just one storage feed channel 95 can ensure that the pressure volume 91 is supplied with pressure fluid. One storage relief channel 99 is sufficient for relieving the relief volume 92 of pressure. In principle, it would however also be possible, in the chosen embodiment, to provide two or more storage feed channels, comparable to the storage feed channel 95 of the example embodiment, and/or two or more storage relief channels, comparable to the storage relief channel 99 of the example embodiment, in a distribution over the circumference of the storage space 91, 92.

(97) The pressure volume 91 is connected to the pressure fluid supply within the rotor unit 100. The storage feed channel 95 diverts from the feed 14, 15, 44 (FIG. 8). In the example embodiment, the storage feed channel 95 diverts from the upstream feed portion 14.

(98) The storage feed channel 95 is composed of multiple channel portions 96, 97 and 98. The upstream channel portion 96 diverts from the feed portion 14in the example embodiment, from one of the downstream channel segments 14b of the feed portion 14immediately upstream of the reflux valve device 50. Starting from where it diverts, the channel portion 96 extends radially or at least substantially radially through the rotor hub 11 and through one of the rotor vanes 12 up to an outer circumference 12a of the relevant rotor vane which, in order to distinguish it, is denoted by 12. The outer circumference 12a of this rotor vane 12 comprises a recess which forms a pocket-shaped channel portion 97 which is elongated in the shape of a strip in a circumferential direction. The channel portion 96 emerges into the pocket-shaped channel portion 97 at the outer circumference 12a of the rotor vane 12. The upstream channel portion 98 extends from the inner circumference 2a of the stator ring 2 into the pressure volume 91 and emerges from the radially outer side into the pocket-shaped channel portion 97. The inner circumference 2a lies directly opposite the outer circumference 12a of the rotor vane 12, radially facing it. The rotor vane 12 is in a sliding contact with the stator ring 2 in the region of the inner circumference 2a. When the rotor vane 12 and stator ring 2 are in sliding contact, the channel portion 97 is circumferentially sealed off, aside from unavoidable leakage losses, along its outer periphery.

(99) The pocket-shaped channel portion 97 extends over at least the majority of the width of the rotor vane 12 as measured in a circumferential direction. The channel portion 97 is long enough in a circumferential direction that the channel portion 98 which extends in the stator ring 2 is connected to the channel portion 97 in every rotational angular position which the rotor 10 can assume relative to the stator 1, and the pressure fluid supply of the pressure storage 90 is ensured in every relative rotational angular position between the stator 1 and the rotor 10.

(100) Where pressure fluid passes out of the pressure volume 91 across the pressure storage piston 93 into the relief volume 92 due to unavoidable leakage losses, such leakage fluid is drained via the storage relief channel 99. The storage relief channel 99 is likewise composed of multiple channel portions 99a, 99b and 99c. Starting from the relief volume 92, a channel portion 99a which is upstream in an outflow direction extends through the stator ring 2 up to and into a channel portion 99b which is likewise pocket-shaped and situated axially next to the channel portion 97 on the outer circumference 12a of said rotor vane 12 and which, like the channel portion 97, is long enough in a circumferential direction to maintain the connection to the relief volume 92 in every relative rotational angular position between the rotor 10 and the stator 1. A downstream channel portion 99c leads from the pocket-shaped channel portion 99b through the rotor vane 12. In this downstream channel portion, the leakage fluid can flow off radially inwards and ultimately towards the pressure fluid reservoir.

(101) The pocket-shaped channel portions 97 and 99b each extend in the shape of a strip, axially next to each other at a distance, on the outer circumference 12a of the same rotor vane 12. The rotor vane 12 widens in a circumferential direction in its radially outer region, such that its outer circumference 12a, which is in sliding contact with the stator ring 2, is longer in a circumferential direction than the outer circumference of the other rotor vanes 12. The widening is favourable for sealing off the elongated pocket-shaped channel portions 97 and 99b, since this leaves more area for the seal at the ends of the channel portions 97 and 99b on the outer circumference 12a. In the example embodiment, the rotor vane 12 is mushroom-shaped in cross-section, with a bulge on both sides. The base regions of the adjacent stator vanes 4 respectively comprise an indentation on the side facing the rotor vane 12, which one of the bulges of the rotor vane 12 can enter when pivoted.

(102) In the example embodiment, the storage feed channel 95 and the storage relief channel 99 extend through the same rotor vane 12. In modifications, the storage channel 95 can extend through a first rotor vane 12, and the relief channel 99 can extend through another, second rotor vane 12.

(103) For connecting the pressure volume 91 to the pressure fluid supply, it is advantageous for the feed portion 14 to comprise channel segments 14b which are elongated in a circumferential direction (FIG. 14). The large width of the channel segments 14b as measured in a circumferential direction makes it easier to provide the channel portion 96 as a simple linear radial bore, as shown for instance in FIG. 14. Reference may be made, merely peripherally, to the fact that the locking pin 28 is arranged in the rotor vane 12, next to the channel portions 96 and 99c in a circumferential direction. If greater demands are made for a minimum leakage of oil in the transition between the channel portion 97 and the channel portion 98 and/or channel portions 99a and 99b, respectively, the region of the outer circumference 12a can be sealed off on the left and right in a circumferential direction, and optionally around the pocket-shaped channel portion 97, by means of one or more sealing elements.

(104) FIGS. 15 and 16 show a phase setter of a fourth example embodiment. The phase setter is derived from the phase setter of the first example embodiment and differs from the first example embodiment by the integrated pressure storage 90 which corresponds to the pressure storage 90 of the third example embodiment with regard to the storage space 91, 92, the pressure storage piston 93, pressure storage spring 94 and the relief channel 99.

(105) The phase setter of the fourth example embodiment differs from the phase setter of the third example embodiment only in that the pressure fluid for the pressure volume 91 in the rotor unit 100 is diverted from the feed 14, 15, 44 downstream of the reflux valve device 50. The storage feed channel is therefore denoted by 85.

(106) The storage feed channel 85 comprises an upstream channel portion 86 which extends through the rotor hub 11 and, in a radial elongation, through one of the rotor vanes 12 and diverts from the feed 14, 15, 44 in the deflecting portion 44 and extends, from the location where it diverts, up to the outer circumference 12a of one of the rotor vanes 12. The relevant rotor vane is denoted in FIG. 16 by 12. The channel portion 86 emerges at the outer circumference 12a of the rotor vane 12 into a pocket-shaped channel portion 87 which is elongated in a circumferential direction and comparable to the channel portion 97 of the third example embodiment. The connection between the pressure volume 91 and the channel portion 97 is created by a channel portion 88 which extends in the stator ring 2 and which is comparable to the channel portion 98 of the third example embodiment. Aside from the diversion being formed differently, the descriptions regarding the third example embodiment are incorporated by reference.

(107) The channel portion 86 diverts in the inflow region 44a of the deflecting portion 44. The channel portion 86 thus also comprises a sub-portion which extends through a circumferential wall of the holding device 40 and into one of the recesses 43 (FIG. 6) which together form the inflow region 44a.

(108) Diverting downstream of the reflux valve device 50 means that the pressure volume 91 is secured by the reflux valve device 50 if a drop in pressure occurs upstream of the reflux valve device 50. Drops in pressure can occur in the pressure fluid system for example when connecting up additional pressure fluid consumers. By diverting downstream of the reflux valve device 50, momentary pressure fluctuations of this type can be bridged.

(109) FIG. 17 shows the rotor unit 100 of the first example embodiment, fitted on the cam shaft N. It is the same longitudinal section as in FIG. 2. Cross-sectional planes Q.sub.P, Q.sub.A and Q.sub.B which are respectively orthogonal to the rotational axis R are marked. The cross-sectional plane Q.sub.P extends through the pressure port P. The cross-sectional plane Q.sub.A extends through the working port A, and the cross-sectional plane Q.sub.B extends through the working port B. The planar valve structure 51 extends axially between the cross-sectional planes Q.sub.P and Q.sub.B and exhibits a distance of more than zero from each of the cross-sectional planes Q.sub.P and Q.sub.B, at least when fluid is not flowing through it, as shown. The rotor unit 100 of the third example embodiment (FIGS. 13 and 14) and the rotor unit 100 of the fourth example embodiment (FIGS. 15 and 16) correspond in this respect to the first example embodiment.

(110) FIG. 18 shows the proportions in the longitudinal section for the second example embodiment, corresponding to FIG. 8. The valve structure 71 of the second example embodiment is also planar. As in the first example embodiment, the valve structure 71 extends axially between a cross-sectional plane Q.sub.P, which intersects the pressure port P, and a cross-sectional plane Q.sub.B which intersects the working port B, each at an axial distance of more than zero.

(111) In all the example embodiments, the pressure port P and the working ports A and B are arranged axially next to each other on an outer circumference of the control valve 20, and the pressure port P is arranged between the working ports A and B. It therefore necessarily follows that the valve structures 51 and 71 also extend axially between the respective cross-sectional planes Q.sub.P and Q.sub.B.

(112) The cross-sectional planes Q.sub.P, Q.sub.A and Q.sub.B are each axially offset with respect to the axially central cross-sectional plane of the respective port P, A and B, in order to show that the characteristic of extending between the cross-sectional planes is also deemed to be fulfilled when the cross-sectional plane Q.sub.P intersects the pressure port P near its periphery, and the cross-sectional plane Q.sub.B intersects the working port B near its periphery. In the example embodiments, it advantageously holds that the respective valve structure 51 and 71 extends between two immediately adjacent cross-sectional planes Q.sub.P and Q.sub.B, at least when fluid is not flowing through it. The valve structures 51 and 71 are axially offset, with no overlap, with respect to the respective pressure port P and the respective working port B, when fluid is not flowing through them.

(113) In the first example embodiment, the feed portion 14 (FIG. 2) passes the connecting channels 16 on its way to the valve structure 51 within the rotor unit 100. In the second example embodiment, the feed portion 64 (FIG. 8) passes the connecting channels 16 on its way to the valve structure 71 within the rotor unit 101, wherein the feed channels 14a, 14b in the first example embodiment and the feed channels 64a, 64b in the second example embodiment pass the respective connecting channels 16 at an offset in a circumferential direction.

REFERENCE SIGNS

(114) 1 stator 2 stator ring 2a inner circumference 3 drive gear tooth system 4 stator vane 5 stator cover 6 stator cover 7 appendage 8 gasket 9 electromagnetic device 9a coil 9b plunger 9c spherical body 9d appendage 10 rotor 11 rotor hub 11a inner circumference 11b inner circumference 11c outer circumference 12 rotor vane 12 rotor vane 12 rotor vane 12a outer circumference 13 accommodating space 14 feed portion 14a feed channel, channel portion 14b feed channel, channel portion 15 feed portion 15b bore portion 16 connecting channel 16.1 connecting portion 16.2 connecting portion 17 connecting channel 18 inner end-facing surface of the rotor 19 accommodating space 19 inner end-facing surface of the rotor 20 control valve 21 valve housing 22 joining portion 23 collar 24 supplying portion 25 housing hollow space 26 outflow portion 27 - 28 locking pin 29 locking spring 29a relief channel 30 valve piston 31 valve spring 32 piston hollow space 33 control groove 34 control edge 35 control edge 36 aperture 37 - 38 - 39 cover 40 holding device 41 axial portion 41a inner circumference 41s end-facing surface, end-facing side 42 axial portion 43 recess, yielding space 44 deflecting portion 44a inflow region 44b outflow region 45 contact surface 46 connecting portion 47 equalising structure 48 filter engaging structure 49 valve engaging structure 50 reflux valve device 51 valve structure 52 spring tongue 52a ring 53 clearance 54 engaging structure 55 dirt filter 56 filter screen 57 supporting structure 58 engaging structure 59 - 60 holding device 60a inner circumference 60s end-facing surface 61 axial portion 61a equalising structure 62 axial portion 63 contact surface 64 feed portion 64a feed channel, channel portion 64b feed channel, channel portion 65 deflecting portion 66 feed portion 67 connecting portion 68 filter engaging structure 69 valve mount 70 reflux valve device 71 valve structure 72 complementary guiding element 73 reflux valve spring 74 guiding element 75 counter bearing 76 holding element 77 rigidifying periphery 78 - 79 - 80 dirt filter 81 filter screen 82 supporting structure 83 recess 84 - 85 storage feed channel 86 channel portion 87 channel portion 88 channel portion 89 - 90 pressure storage 91 storage space, pressure volume 92 storage space, relief volume 93 pressure storage piston 94 pressure storage spring 95 storage feed channel 96 channel portion 97 channel portion 98 channel portion 99 storage relief channel 100 rotor unit 101 rotor unit A working port B working port K.sub.1 pressure chamber K.sub.2 pressure chamber LK bearing body N cam shaft P pressure port Q.sub.A cross-sectional plane Q.sub.B cross-sectional plane Q.sub.P cross-sectional plane R rotational axis V supply channel