Pump unit with integrated piston pump and electric motor

Abstract

An automotive hydraulic actuating system for actuating a movable vehicle part, like a roof part or a wheel suspension. The actuating system comprises a pump unit. The pump unit comprises a piston pump which has a pump rotor and an electric motor which has a motor rotor. The pump rotor and motor rotor are incorporated into a single common rotor. The rotor is a one piece item. The rotor is positioned inside a pump chamber around a pump stator of the piston pump. The pump stator provides a full support to the common rotor. Advantageously, without a separate motor stator, the pump unit has a more compact configuration. Additionally, the pump unit has an improved dynamic performance which contributes to a silent and reliable operation at a high rotational speed.

Claims

1. A pump unit for pressurising a hydraulic actuating system, wherein the pump unit comprises a pump housing including a pump chamber for housing a piston pump, and wherein the pump unit further comprises an electric motor for driving the piston pump, wherein the electric motor comprises: a motor rotor, wherein the motor rotor comprises a longitudinal motor rotor body including several magnets at an outer surface, wherein the motor rotor body defines an axial axis; a field coil which is positioned opposite the magnets of the motor rotor body for rotationally driving the motor rotor body; wherein the piston pump comprises: a pump stator which is stationary inside the pump chamber, which pump stator has a longitudinal stator body which includes at least two channels serving respectively as an inlet or outlet channel; a pump rotor positioned around the pump stator body, which pump rotor has a pump rotor body which is driveable in a rotational direction about the axial axis, wherein the pump rotor body includes several cylinder holes for each receiving a piston which is slidable with respect to the pump rotor body in a radial direction; a ring positioned around the pump rotor body, wherein the ring is eccentrically positioned at an eccentricity with respect to the pump rotor body to provide a pump capacity; wherein the motor rotor and the pump rotor are incorporated into a common rotor such that the motor rotor body and the pump rotor body are formed as a one piece item with the motor rotor and the pump rotor located on opposite axial ends and wherein the pump stator is fixed to the pump housing adjacent to the pump rotor as a cantilever which extends axially through the pump rotor body to a position beyond the cylinder holes such that the common rotor is fully supported by the cantilevered pump stator.

2. The pump unit according to claim 1, wherein the pump stator extends through the common rotor over at least half a length of the common rotor.

3. The pump unit according to claim 1, wherein the common rotor is manufactured from a solid part.

4. The pump unit according to claim 1, wherein the magnets of the motor rotor are positioned at an outer circumferential motor rotor surface.

5. The pump unit according to claim 1, wherein the common rotor has a motor rotor recess which is open at a motor rotor end face, wherein the motor rotor recess has an inner circumferential surface and an inner bottom surface, wherein the magnets are positioned at the inner circumferential surface or at the inner bottom surface.

6. The pump unit according to claim 1, wherein the magnets of the motor rotor are positioned at a motor rotor end face of the common rotor.

7. The pump unit according to claim 1, wherein the field coil is positioned outside the pump chamber of the pump housing.

8. The pump unit according to claim 1, wherein the pump unit further comprises a control unit for controlling the pump capacity, wherein the control unit is connectable to a closure of the pump housing for closing a pump chamber, wherein the control unit and the closure form a subassembly which is mountable as a module to the pump housing.

9. The pump unit according to claim 8, wherein the module of the control unit and closure further comprises at least one field coil of the electric motor.

10. The pump unit according to claim 1, wherein a reservoir is formed by the pump chamber in the pump housing.

11. The pump unit according to claim 1, wherein the pump stator extends into the motor rotor body to an axial position of the magnets.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be explained in more detail with reference to the appended drawings. The drawings show a practical embodiment according to the invention, which may not be interpreted as limiting the scope of the invention. Specific features may also be considered apart from the shown embodiment and may be taken into account in a broader context as a delimiting feature, not only for the shown embodiment but as a common feature for all embodiments falling within the scope of the appended claims, in which:

(2) FIG. 1 shows a schematic side view of a vehicle provided with a convertible roof system;

(3) FIG. 2 shows a schematic view of the convertible roof system of a FIG. 1 comprising a hydraulic actuating system which includes a pump unit for pressurising several cylinders;

(4) FIG. 3 shows a first embodiment of a pump unit in a schematic sectional view about an axial axis, wherein the pump unit comprises an electric motor and a piston pump which are both received in a pump chamber of a pump housing and wherein the electric motor includes radially arranged magnets and field coils, wherein the field coils are outwardly positioned with respect to magnets;

(5) FIG. 4 shows a second embodiment of a pump unit as in FIG. 3, wherein the field coils are inwardly positioned with respect to the magnets;

(6) FIG. 5 shows a third embodiment of a pump unit as in FIG. 3, wherein the field coils of the electric motor are axially arranged with respect to the magnets.

(7) In the figures, the same reference numbers are used to indicate identical or similar components.

DETAILED DESCRIPTION

(8) FIG. 1 discloses in a schematic view of a vehicle 1. The vehicle 1 comprises an automotive actuating system for hydraulically actuating movable vehicle parts, like a sunroof, hood lid, boot lid, spoiler, convertible roof or a wheel suspension. As illustrated here, the vehicle 1 is provided with a convertible roof system 2 for selectively opening or covering a passenger space. The convertible roof system 2 has a well known mechanical structure.

(9) Here, the convertible roof system 2 has a convertible roof 20 which includes a front roof part 200. The roof part 200 is pivotally connected about a pivot axis to a remaining roof part 201 of the convertible roof 20. Here, the front roof part 200 is shown in released from a front window frame 11. In a closed configuration of the convertible roof, the front roof part 200 is connected to the front window frame 11 and locked by a locking member 12.

(10) FIG. 2 shows an embodiment of the convertible roof system 2 in further detail. The general mechanical structure of such a convertible roof system is well known in the art. FIG. 2 further shows a hydraulic actuating system 21. The hydraulic actuating system 21 is arranged to actuate the convertible roof 20, locking member 12 and additionally a cover plate 202. The cover plate 202 is provided to cover a compartment of the vehicle 1 which compartment is configured to receive the convertible roof 20 when transformed into an open configuration.

(11) The hydraulic actuating system 21 comprises two pairs of hydraulic cylinders 23, 23; 24, 24 for moving the roof parts 200, 201 of the convertible roof 2. A hydraulic cylinder 25 is provided to move the cover plate 202 and a hydraulic cylinder 22 is provided to actuate the locking member 12. The cylinders 22; 23, 23; 24, 24; 25 are hydraulically connected by hydraulic conduits to a hydraulic pump unit 26.

(12) The pump unit 26 has a pump housing 261. The pump housing 261 is block shaped. A control unit 29 is provided to control the pump unit 26. The control unit 29 is electrically connected to an electric motor 3 for driving and internally positioned piston pump 4. The electric motor 3 is connected to a front side of the pump housing 261. The piston pump 4 is internally arranged inside the pump housing in a pump chamber 264. The pump chamber 264 is an inner space which is configured for housing the piston pump 4. The arrangement of the piston pump 4 in the pump chamber 264 is further illustrated by FIGS. 3-5 which show a sectional view of the pump unit 26 about a longitudinal axis.

(13) As shown in FIG. 2, the pump unit 26 comprises a valve unit 28. The valve unit is mounted to a mounting face which is here positioned at a top side of the pump housing. Further, the pump unit 26 comprises a reservoir 263 for accumulating hydraulic liquid. The reservoir 263 is here positioned at a backside of the pump housing 261.

(14) According to an aspect of the present invention, an improvement is provided by incorporating the electric motor 3 with the piston pump 4. Particularly, by incorporating a motor rotor 31 of the electric motor 3 with a pump rotor 46 of the piston pump 4 into a common rotor 6 as shown in FIG. 3-5. The common rotor 6 is a one piece item. The common rotor 6 is a separately mountable component of an assembled pump unit 26. The common rotor 6 is mountable as a whole to remaining parts of the pump unit 26.

(15) The common rotor 6 is positioned inside the pump chamber 264. The common rotor 6 defines an axial axis A. The axial axis A is an axis of rotation of the common rotor 6. The common rotor 6 includes a motor rotor portion 61 which serves as a motor rotor 31 and a pump rotor portion 62 which serves as a pump rotor 46.

(16) The electric motor 3 is a brushless DC motor. The DC motor is advantageous, because of its relatively long lifetime without intervening servicing. The electric motor 3 has a motor rotor 31 which forms the motor portion 61 of the common rotor 6. The motor rotor 31 has a motor rotor body 610. The motor rotor body 610 is cylindrically shaped and elongated. The motor rotor body 610 has an outer circumferential surface 611 and a motor rotor end face 612.

(17) Further, the electric motor 3 comprises several field coils 32. The field coils 32 are DC field coils which in operation generate a magnetic field. The field coils 32 are positioned opposite the magnets 33 at the motor rotor body 610. Several embodiments including a rotor with magnets and opposite positioned field coils are possible and further illustrated in FIGS. 3-5.

(18) According to an aspect of the invention, the motor rotor 31 and the pump rotor 46 are both supported by the pump stator 42. In contrast to conventional motors, the electric motor 3 according to the invention has no separate component serving as motor stator. The electric motor 3 has a motor rotor 31 which is supported by the pump stator 42 which makes a motor stator redundant.

(19) The piston pump 4 is a rotary piston pump. Such a type of a piston pump is well known in the art. Such a rotary piston pump 40 includes pistons 41 which in operation rotate together with a pump rotor.

(20) Such a rotary piston pump 40 has a pump rotor 46 and a pump stator 42. The pump stator 42 has an elongated stator body 420 which extends in an axial direction. The pump stator body 420 is beam shaped. The pump stator body 420 is stationarily fixed to the pump housing 261. The pump stator body 420 is fixed as a cantilever. The pump stator body 420 has a proximal stator end 421 which is fixed to the bottom surface 2641 of the pump chamber 264. The pump stator body 420 extends along the axial axis of the pump unit 26. The pump stator body 420 has a free distal stator end 422 which is positioned in the inner space provided by the pump chamber 264. The pump stator body 420 includes at least two channels forming at least one inlet channel 43 and at least one outlet channel 44 for transferring hydraulic liquid.

(21) The pump rotor 46 has a pump rotor body 460 which is rotationally connected to the pump stator body 420 of the pump stator 42. The pump rotor body 460 is co-axially positioned with respect to the pump stator 42. The pump stator 42 supports the pump rotor 46. The pump rotor 46 is supported from one side. The pump stator 42 provides a single sided support to the pump rotor 46 as the pump stator 42 is only fixed at the proximal stator end 421 to the pump housing.

(22) The pump rotor body 460 comprises several cylinder holes for each receiving a piston 41. The piston 41 has a longitudinal piston body 410. The piston body 410 has a proximal piston end which is directed to stator body 420 and a distal piston end which is directed radially outwards to a ring-shaped element which surrounds the rotor body 460. The ring-shaped element is a so-called eccentric ring 48. The rotor body 460 is positioned inside the eccentric ring 48.

(23) To reduce wear, the eccentric ring 48 is formed as a bearing. The bearing may be a plain bearing. Here, the eccentric ring 48 is formed by a ball bearing having an inner ring and an outer ring, wherein the inner ring is beared by ball bearings with respect to the outer ring. The outer ring is stationarily positioned and fixed to the pump housing 261 and the inner ring is rotatably positioned. The inner ring of the eccentric ring 48 is movable in rotation together with the inside positioned pump rotor 46.

(24) The eccentric ring 48 comprises an inner bearing surface which serves as a running surface 481 for the distal ends of the pistons 41. The running surface 481 is positioned opposite an outer circumferential rotor surface 621 of the pump rotor body 460. The eccentric ring 48 is eccentrically positioned with respect to the pump rotor body 460. A ring-shaped intermediate space in between the outer circumferential rotor surface 461 and the inner running surface 481 is provided to allow in operation the pistons 41 held by the pump rotor body 460 to move in a radial direction. Due to a present eccentricity , a height of the intermediate space in between the outer circumferential rotor surface 621 and the running surface 481 is varying which will cause the pistons 41 to move in the radial direction when rotationally driving the pump rotor body 460. Radially inward moving pistons 41 will provide a pressure to the hydraulic liquid and will push hydraulic liquid through the outlet channel 44 and radially outward moving pistons 41 will provide an underpressure to the hydraulic liquid which will suck hydraulic liquid through the inlet channel 43. Herewith, the radially moving pistons 41 generate a pumping force working to power the hydraulic circuit.

(25) FIG. 3-5 show schematic sectional views about a longitudinal axis of several embodiments of a pump unit in which several aspects of the invention are shown.

(26) According to an aspect of the invention, the reservoir 263 is formed by the pump chamber 264. An inlet channel 43 of the pump stator 42 is in fluid communication with the pump chamber, such that hydraulic liquid can be transferred from the pump chamber 264 as a reservoir 263.

(27) FIG. 3-5 schematically show three alternative embodiments of such improved pump units 26 including a common rotor 6 supported by only one individual stator. The shown embodiments include the same or similar components, but these components are spatially differently positioned.

(28) The pump unit 26 comprises a pump housing 261 including a pump chamber 264 for housing the electric motor 3 and the piston pump 4 and a closure 265 to close the pump chamber 264. In FIGS. 3 and 4, the electric motor 3 and piston pump for are fully received in the pump chamber 264. In FIG. 5, a part of the electric motor 3 is positioned outside the pump chamber 264.

(29) The pump housing 261 has a compact configuration. Here, the pump housing 261 is cylindrically shaped. The pump housing 261 has at least one external mounting face at an outer surface for mounting e.g. a valve unit 28, a control unit 29, an electrical supply and/or a reservoir 263.

(30) The pump chamber 264 inside the pump housing 261 defines the axial axis A which extends from a front side F to a backside B of the pump housing. The pump chamber 264 is open at the front side F of the pump housing 261. The pump chamber 264 is formed by an inner space which is cylindrically shaped. The pump chamber 264 has a bottom surface 2641 and an inner circumferential surface 2642. The pump chamber 264 is adapted for at least partially receiving both the electric motor 3 and the piston pump 4.

(31) The closure 265 is provided for closing the pump chamber 264 in an assembled configuration of the pump unit 26. The closure 265 is plate shaped. Here, the closure 265 is a lid which fits to the pump chamber opening. The closure 265 is sealably connectable to the pump housing 261 for hydraulically sealing the pump chamber 264.

(32) Further, the pump unit 26 comprises a control unit 29. The control unit 29 has a compact configuration. The control unit 29 includes a printed circuit board PCB which is designed for controlling the pump unit 26. A functional scheme of controllable movements of a particular hydraulic actuating system 21, which is in particular a convertible roof system 2, is embedded in the design of the printed circuit board of the control unit 29. The control unit 29 is plate shaped and connectable to an external surface of the closure 265. The control unit 29 is adapted to the closure 265 from a module of the pump unit 26. The control unit 29 is sized in correspondence with the diameter of the closure 265. According to an aspect of the invention, the control unit 29 and the closure 265 form a subassembly. The subassembly of the control unit 29 and the closure 265 form the separate mountable module of the pump unit 26.

(33) As shown in FIG. 3, the motor rotor body 610 comprises several magnets 33 which are positioned at the outer circumferential rotor surface 621. Field coils 32 are positioned opposite the magnets 33. The field coils 32 are radially positioned with respect to the magnets 33. The field coils 32 are positioned around the motor rotor 31. The field coils 32 are radially outwardly spaced from the magnets 33 which are supported by the motor rotor body 610. The field coils 32 are positioned inside the pump chamber 264 at the inner circumferential surface 2642.

(34) FIG. 3 shows the pump stator 42 which extends through the rotor 6. Here, the pump stator 42 extends substantially until the motor rotor end face 612 of the rotor 6.

(35) FIG. 4 shows a different spatial arrangement of the field coils 32 and the magnets 33. The field coils 32 are radially positioned with respect to the magnets 33. The motor rotor 31 comprises a rotor recess 613. The rotor recess 613 is open at the motor rotor end face 612 of the motor rotor portion 61. The rotor recess 613 is configured for receiving the field coils 32. The field coils 32 for generating a magnetic field are positioned opposite the magnets 33.

(36) The magnets 33 are positioned at an inner surface, in particular an inner bottom or circumferential surface, of the rotor recess 613. Here, the magnets 33 are positioned at the inner circumferential surface of the rotor recess 613.

(37) The field coils 32 are positioned inside the rotor recess 613. The field coils 32 are radially inwardly positioned with respect to the magnets 33 which are here positioned at the inner circumferential surface of the rotor recess 613. The field coils 32 are positioned inside the pump chamber 264. The field coils 32 are connected to the closure 265. The field coils 32 are centrally positioned and connected to an inner surface of the closure 265.

(38) FIG. 4 shows the pump stator 42 which extends through the rotor 6. Here, the pump stator 42 extends substantially until the bottom surface of the rotor recess 613. The pump stator 42 extends about at least half a length of the common rotor 6.

(39) FIG. 5 shows a further different spatial arrangement of the field coils 32 and the magnets 33. The magnets 33 are positioned at the motor rotor end face 612 of the rotor 6. Field coils 32 are positioned opposite the magnets 33. The field coils 32 are located outside the pump chamber 264. The field coils 32 are connected to be closure 265 which covers the pump chamber 264. The closure 265 is positioned in between the field coils 32 and the magnets 33 on the rotor 6. The control unit 29 is connected via the field coils to the closure 265. Advantageously, in comparison with the radially arranged field coils and magnets as shown in FIGS. 3 and 4, the rotor 6 of the pump unit 26 in FIG. 5 including the axial arranged field coils and magnets has a very compact configuration.

(40) FIG. 5 shows the pump stator 42 which extends through the rotor 6. Here the pump stator 42 extends until the motor rotor end face 612 of the rotor 6.

(41) Besides the illustrated embodiments of the pump unit according to the invention, several variants are possible without departing from the scope.

(42) Thus, the invention provides several aspects which allow a compact configuration of a pump unit. Such a compact pump unit is especially advantageous to be installed in a hydraulic actuating system for an automotive appliance, like a convertible roof system, in which the pump unit has to be build-in into narrow chassis compartments.

(43) The above-mentioned aspects of the invention are to be considered independent from each other. In particular, the aspect regarding the arrangement of the field coils and magnets is considered to be technically independent from the aspect of the one piece common rotor supported by the pump stator only and from the aspect of the pump chamber which houses the piston pump and electric motor and which pump chamber serves as a reservoir of the pump unit.

(44) Particular embodiments according to the invention are defined in the following clauses: 1. Pump unit (26) for pressurising a hydraulic actuating system (21), in particular for pressurising an automotive actuating system, like a convertible roof system (2), boot lid, hood cover system or wheel suspension of a vehicle (1), wherein the pump unit comprises a pump housing (261) including a pump chamber (264) for housing a piston pump (4) and wherein the pump unit (26) further comprises an electric motor (3) for driving the piston pump wherein the electric motor (3) comprises: a motor rotor (31), wherein the motor rotor comprises a longitudinal motor rotor body (610) including several magnets (33) at an outer surface, wherein the motor rotor body (610) defines an axial axis; a field coil (32) which is positioned opposite the magnets of the motor rotor body (610) for rotationally driving the motor rotor body (610); wherein the piston pump (4) comprises: a pump stator (42) which is stationarily positioned inside the pump chamber (264), which pump stator has a longitudinal stator body (420), in which the pump stator body (420) includes at least two channels serving respectively as an inlet or outlet channel (43, 44); a pump rotor (46) positioned around the pump stator body (420), which pump rotor has a pump rotor body (620) which is driveable in a rotational direction about the axial axis, wherein the pump rotor body (620) includes several cylinder holes for each receiving a piston (41) which is slidable with respect to the pump rotor body (620) in a radial direction; an eccentric ring (48) positioned around the pump rotor body (620), in which the eccentric ring (48) is eccentrically positioned at an eccentricity E with respect to the pump rotor body (620) to provide a pump capacity; wherein the motor rotor (31) and the pump rotor (46) are incorporated into a common rotor (6) which is a one piece item including a motor and a pump rotor portion (61,62) and wherein the common rotor (6) is only supported by the pump stator (42). 2. Pump unit (26) for pressurising a hydraulic actuating system (21), in particular for pressurising an automotive actuating system, like a convertible roof system (2), boot lid, hood cover system or wheel suspension of a vehicle (1), wherein the pump unit comprises a pump housing (261) including a pump chamber (264) for housing a piston pump (4) and wherein the pump unit (26) further comprises an electric motor (3) for driving the piston pump wherein the electric motor (3) comprises: a motor rotor (31), wherein the motor rotor comprises a longitudinal motor rotor body (610) including several magnets (33) at an outer surface, wherein the motor rotor body (610) defines an axial axis; a field coil (32) which is positioned opposite the magnets of the motor rotor body (610) for rotationally driving the motor rotor body (610); wherein the piston pump (4) comprises: a pump stator (42) which is stationarily positioned inside the pump chamber (264), which pump stator has a longitudinal stator body (420), in which the pump stator body (420) includes at least two channels serving respectively as an inlet or outlet channel (43, 44); a pump rotor (46) positioned around the pump stator body (420), which pump rotor has a pump rotor body (620) which is driveable in a rotational direction about the axial axis, wherein the pump rotor body (620) includes several cylinder holes for each receiving a piston (41) which is slidable with respect to the pump rotor body (620) in a radial direction; an eccentric ring (48) positioned around the pump rotor body (620), in which the eccentric ring (48) is eccentrically positioned at an eccentricity E with respect to the pump rotor body (620) to provide a pump capacity; wherein the motor rotor (31) and the pump rotor (46) are incorporated into a common rotor (6) which is a one piece item including a motor and a pump rotor portion (61,62) and, wherein the magnets (33) of the motor rotor (31) are positioned at an outer circumferential motor rotor surface (611). 3. Pump unit (26) for pressurising a hydraulic actuating system (21), in particular for pressurising an automotive actuating system, like a convertible roof system (2), boot lid, hood cover system or wheel suspension of a vehicle (1), wherein the pump unit comprises a pump housing (261) including a pump chamber (264) for housing a piston pump (4) and wherein the pump unit (26) further comprises an electric motor (3) for driving the piston pump wherein the electric motor (3) comprises: a motor rotor (31), wherein the motor rotor comprises a longitudinal motor rotor body (610) including several magnets (33) at an outer surface, wherein the motor rotor body (610) defines an axial axis; a field coil (32) which is positioned opposite the magnets of the motor rotor body (610) for rotationally driving the motor rotor body (610); wherein the piston pump (4) comprises: a pump stator (42) which is stationarily positioned inside the pump chamber (264), which pump stator has a longitudinal stator body (420), in which the pump stator body (420) includes at least two channels serving respectively as an inlet or outlet channel (43, 44); a pump rotor (46) positioned around the pump stator body (420), which pump rotor has a pump rotor body (620) which is driveable in a rotational direction about the axial axis, wherein the pump rotor body (620) includes several cylinder holes for each receiving a piston (41) which is slidable with respect to the pump rotor body (620) in a radial direction; an eccentric ring (48) positioned around the pump rotor body (620), in which the eccentric ring (48) is eccentrically positioned at an eccentricity E with respect to the pump rotor body (620) to provide a pump capacity; wherein the motor rotor (31) and the pump rotor (46) are incorporated into a common rotor (6) which is a one piece item including a motor and a pump rotor portion (61, 62) and wherein the common rotor (6) has a motor rotor recess (613) which is open at a motor rotor end face (612), wherein the motor rotor recess (613) has an inner circumferential surface (614) and an inner bottom surface (615), wherein the magnets are positioned at the inner circumferential or bottom surface. 4. Pump unit (26) for pressurising a hydraulic actuating system (21), in particular for pressurising an automotive actuating system, like a convertible roof system (2), boot lid, hood cover system or wheel suspension of a vehicle (1), wherein the pump unit comprises a pump housing (261) including a pump chamber (264) for housing a piston pump (4) and wherein the pump unit (26) further comprises an electric motor (3) for driving the piston pump wherein the electric motor (3) comprises: a motor rotor (31), wherein the motor rotor comprises a longitudinal motor rotor body (610) including several magnets (33) at an outer surface, wherein the motor rotor body (610) defines an axial axis; a field coil (32) which is positioned opposite the magnets of the motor rotor body (610) for rotationally driving the motor rotor body (610); wherein the piston pump (4) comprises: a pump stator (42) which is stationarily positioned inside the pump chamber (264), which pump stator has a longitudinal stator body (420), in which the pump stator body (420) includes at least two channels serving respectively as an inlet or outlet channel (43, 44); a pump rotor (46) positioned around the pump stator body (420), which pump rotor has a pump rotor body (620) which is driveable in a rotational direction about the axial axis, wherein the pump rotor body (620) includes several cylinder holes for each receiving a piston (41) which is slidable with respect to the pump rotor body (620) in a radial direction; an eccentric ring (48) positioned around the pump rotor body (620), in which the eccentric ring (48) is eccentrically positioned at an eccentricity E with respect to the pump rotor body (620) to provide a pump capacity; wherein the motor rotor (31) and the pump rotor (46) are incorporated into a common rotor (6) which is a one piece item including a motor and a pump rotor portion (61,62) and wherein the magnets (33) of the motor rotor (31) are positioned at the motor rotor end face (612) of the common rotor (6). 5. Pump unit (26) for pressurising a hydraulic actuating system (21), in particular for pressurising an automotive actuating system, like a convertible roof system (2), boot lid, hood cover system or wheel suspension of a vehicle (1), wherein the pump unit comprises a pump housing (261) including a pump chamber (264) for housing a piston pump (4) and wherein the pump unit (26) further comprises an electric motor (3) for driving the piston pump wherein the electric motor (3) comprises: a motor rotor (31), wherein the motor rotor comprises a longitudinal motor rotor body (610) including several magnets (33) at an outer surface, wherein the motor rotor body (610) defines an axial axis; a field coil (32) which is positioned opposite the magnets of the motor rotor body (610) for rotationally driving the motor rotor body (610); wherein the piston pump (4) comprises: a pump stator (42) which is stationarily positioned inside the pump chamber (264), which pump stator has a longitudinal stator body (420), in which the pump stator body (420) includes at least two channels serving respectively as an inlet or outlet channel (43, 44); a pump rotor (46) positioned around the pump stator body (420), which pump rotor has a pump rotor body (620) which is driveable in a rotational direction about the axial axis, wherein the pump rotor body (620) includes several cylinder holes for each receiving a piston (41) which is slidable with respect to the pump rotor body (620) in a radial direction; an eccentric ring (48) positioned around the pump rotor body (620), in which the eccentric ring (48) is eccentrically positioned at an eccentricity E with respect to the pump rotor body (620) to provide a pump capacity; wherein the motor rotor (31) and the pump rotor (46) are incorporated into a common rotor (6) which is a one piece item including a motor and a pump rotor portion (61,62) and wherein the pump unit (26) further comprises a control unit (29) for controlling the pump capacity, wherein the control unit (29) is connectable to a closure (265) of the pump housing (261) for closing a pump chamber (264), wherein the control unit (29) and the closure (265) form a subassembly which is mountable as a module to the pump housing. 6. Pump unit (26) for pressurising a hydraulic actuating system (21), in particular for pressurising an automotive actuating system, like a convertible roof system (2), boot lid, hood cover system or wheel suspension of a vehicle (1), wherein the pump unit comprises a pump housing (261) including a pump chamber (264) for housing a piston pump (4) and wherein the pump unit (26) further comprises an electric motor (3) for driving the piston pump wherein the electric motor (3) comprises: a motor rotor (31), wherein the motor rotor comprises a longitudinal motor rotor body (610) including several magnets (33) at an outer surface, wherein the motor rotor body (610) defines an axial axis; a field coil (32) which is positioned opposite the magnets of the motor rotor body (610) for rotationally driving the motor rotor body (610); wherein the piston pump (4) comprises: a pump stator (42) which is stationarily positioned inside the pump chamber (264), which pump stator has a longitudinal stator body (420), in which the pump stator body (420) includes at least two channels serving respectively as an inlet or outlet channel (43, 44); a pump rotor (46) positioned around the pump stator body (420), which pump rotor has a pump rotor body (620) which is driveable in a rotational direction about the axial axis, wherein the pump rotor body (620) includes several cylinder holes for each receiving a piston (41) which is slidable with respect to the pump rotor body (620) in a radial direction; an eccentric ring (48) positioned around the pump rotor body (620), in which the eccentric ring (48) is eccentrically positioned at an eccentricity E with respect to the pump rotor body (620) to provide a pump capacity; wherein the motor rotor (31) and the pump rotor (46) are incorporated into a common rotor (6) which is a one piece item including a motor and a pump rotor portion (61,62) and wherein the reservoir (263) is formed by the pump chamber in the pump housing.

(45) Thus, an automotive hydraulic actuating system is provided for actuating a movable vehicle part, like a roof part or a wheel suspension. The actuating system comprises a pump unit. The pump unit comprises a piston pump which has a pump rotor and an electric motor which has a motor rotor. The pump rotor and motor rotor are incorporated into a single common rotor. The rotor is a one piece item. The rotor is positioned inside a pump chamber around a pump stator of the piston pump. The pump stator provides a full support to the common rotor. Advantageously, without a separate motor stator, the pump unit has a more compact configuration. Additionally, the pump unit has an improved dynamic performance which contributes to a silent and reliable operation at a high rotational speed.

LEGEND TO THE FIGURES

(46) 1 vehicle 11 front window frame 12 locking member 2 convertible roof system 20 convertible roof 200 roof part 201 remaining roof part 202 cover plate 21 hydraulic actuating system 23, 23 hydraulic cylinder 24, 24 hydraulic cylinder 25 hydraulic cylinder 22 hydraulic cylinder 26 pump unit 261 pump housing 263 reservoir 264 pump chamber 2641 bottom surface 2642 circumferential surface 265 closure 28 valve unit 29 control unit 3 electric motor 31 motor rotor 32 field coil 33 magnet 4 piston pump 40 rotary piston pump 41 piston 410 piston body 42 pump stator 420 pump stator body 421 pump stator proximal end 422 pump stator distal end 43 inlet channel 44 outlet channel 46 pump rotor 48 eccentric ring 481 running surface 482 outer circumferential ring surface 484 motor end face 49 link E eccentricity 5 ring actuator 53 lever 6 common rotor 61 motor rotor portion 610 motor rotor body 611 motor rotor outer circumferential surface 612 motor rotor end face 613 motor rotor recess 614 motor rotor inner circumferential surface 615 motor rotor inner bottom surface 62 pump rotor portion 620 pump rotor body 621 outer circumferential rotor surface 622 pump rotor end face