ROTARY TRANSMISSION APPARATUS FOR THE TRANSMISSION OF CONTROL AND/OR WORKING PRESSURES TO A FLUID DUCT IN THE INTERIOR OF A SHAFT

Abstract

The invention relates to a rotary transmission apparatus (1) for the transmission of control and/or working pressures to a fluid duct (51) which is received or configured at least in regions in the interior of a shaft (50), in particular a drive shaft. The rotary transmission apparatus (1) has a stator assembly (2) which is arranged in a stationary manner with respect to a rotational movement of the shaft (50) and has at least one fluid feed/discharge line (3) and a control element (4) which can be displaced in the shaft longitudinal direction (L) relative to the shaft (50) between a first position and a second position. A flow connection between the at least one fluid feed/discharge line (3) and the fluid duct (51) is interrupted in the first position of the control element (4), and a flow connection between the at least one fluid feed/discharge line (3) and the fluid duct (51) is established in the second position of the control element (4).

Claims

1. A rotary transmission apparatus (1) for the transmission of control and/or working pressures to a fluid duct (51) which is received or configured at least in regions in the interior of a shaft (50), the rotary transmission apparatus (1) comprising: a stator assembly (2) which is arranged in a stationary manner with respect to a rotational movement of the shaft (50) and has at least one fluid feed/discharge line (3) and a control element (4) which can be displaced in a shaft longitudinal direction (L) relative to the shaft (50) between a first position and a second position, a flow connection between the at least one fluid feed/discharge line (3) and the fluid duct (51) being interrupted in the first position of the control element (4), and a flow connection between the at least one fluid feed/discharge line (3) and the fluid duct (51) established in the second position of the control element (4).

2. The rotary transmission apparatus (I) according to claim 1, the stator assembly (2) further comprising a seal arrangement which is assigned to the control element (4) and has at least one seal (7, 8), in particular in the form of a sealing lip, the at least one seal (7, 8) and/or a topology of a circumferential face of the shaft (50) in the region of the stator assembly (2) being configured in such a way that, in relation to the shaft (50), the at least one seal (7, 8) is at least substantially contact-free in the first position of the control element (4) and is in contact and at least substantially has a sealing action in the second position of the control element (4).

3. A rotary transmission apparatus (1) for the transmission of control and/or working pressures to a fluid duct (SI) which is received or configured at least in regions in the interior of a shaft (50), the rotary transmission apparatus (1) comprising: a stator assembly (2) which is arranged in a stationary manner with respect to a rotational movement of the shaft (50) and has at least one fluid feed/discharge line (3) and a control element (4) which can be displaced in the shaft longitudinal direction (L) relative to the shaft (50) between a first position and a second position, a fluid space (5) which is configured as an annular space between the control element (4) and a circumferential face of the shaft (50), the stator assembly (2) having a seal arrangement which is assigned to the control element (4) and has at least one seal (7, 8), in the form of a sealing lip, the at least one seal (7, 8) and/or a topology of the circumferential face of the shaft (50) in the region of the stator assembly (2) being configured in such a way that, in relation to the shaft (50), the at least one seal (7, 8) is at least substantially contact-free in the first position of the control element (4) and is in contact and at least substantially has a sealing action in the second position of the control element (4).

4. The rotary transmission apparatus (1) according to claim 1 further comprising a fluid space (5), in the form of an annular space, between the control element (4) and a circumferential face of the shaft (50), and a fluid duct (6) being configured in the control element (4), which fluid duct (6), at least in the second position of the control element (4), connects the at least one fluid feed/discharge line (3) in flow terms to the fluid space (5) which is configured as an annular space.

5. The rotary transmission apparatus (1) according to claim 3 further comprising at least one branch duct (55) being configured in the shaft (50), which branch duct (55) connects the fluid duct (51) which is received or configured in the interior of the shaft (50) in flow terms to the fluid space (5) which is configured, in particular, as an annular space.

6. The rotary transmission apparatus (1) according to claim 1 wherein the control element (4) is configured as a control ring which is configured coaxially with respect to the shall longitudinal axis, and includes a guide face which interacts with a guide face of a housing (12) of the stator assembly (2), and is mounted such that it can be displaced between the first and second position relative to the housing (12) of the stator assembly (2) and in the longitudinal direction (L) of the shaft longitudinal axis relative to the shaft (50).

7. The rotary transmission apparatus (1) according to claim 3 wherein the circumferential face of the shaft (50) having, in the region of the fluid space (5), at least one region (56, 57) which tapers conically in relation to the shaft longitudinal axis (L), the at least one seal (7, 8) also being displaced in the feed direction of the conically tapering region (56, 57) in the case of the displacement of the control element (4) in the direction of its first position.

8. The rotary transmission apparatus (1) according to claim 1 wherein the control element (4) includes a front end region (as viewed in the shaft longitudinal direction (L)) and an opposite rear end region, the front end region being assigned a first seal (7), in particular in the form of a sealing lip, and the rear end region being assigned a second seal (8), in particular in the form of a sealing lip, the first and second seal (7, 8) being connected to the control element (4) in such a way that they are also moved in the case of a longitudinal displacement of the control element (4) relative to the shaft (50), and, in the second position of the control element (4), the seals (7, 8) sealing the fluid space (5) with respect to the circumferential face of the shaft (50), which fluid space (5) is configured, in particular, as an annular space, whereas, in the first position of the control element (4), the seals (7, 8) are contact-free or at least substantially contact-free in relation to the circumferential face of the shaft (50).

9. The rotary transmission apparatus (1) according to claim 8, the circumferential face of the shaft (50) having, in the region of the fluid space (5), a first region (56) which tapers conically in relation to the shaft longitudinal axis (L) and is assigned to the first seal (7), and a second region (57) which tapers conically in relation to the shaft longitudinal axis (L) and is assigned to the second seal (8), the feed direction of the first and second conically tapering region (56, 57) corresponding in each case with the direction in which the control element (4) moves when it is displaced in the direction of its first position.

10. The rotary transmission apparatus (1) according to claim 1, the circumferential face of the shaft (50) having, in the region of the stator assembly (2), at least one region which projects radially in relation to the shaft longitudinal axis (L) and at least one region which is recessed radially in relation to the shaft longitudinal axis (L), the at least one seal (7, 8) and/or the at least one radially projecting region of the shaft circumferential face being configured in such a way that, in the second position of the control element (4), the at least one seal (7, 8) is in contact with the at least one radially projecting region, and the at least one seal (7, 8) and/or the at least one radially recessed region being configured in such a way that, in the first position of the control element (4), the at least one seal (7, 8) is present in the radially recessed region.

11. The rotary transmission apparatus (I) according to claim 8, the circumferential face of the shaft (50) having, in the region of the or a fluid space (5) which is configured between the control element (4) and the circumferential face of the shaft (50), a first section which is assigned to the first seal (7) and a second section which is assigned to the second seal (8), the first and second section in each case having a region which projects radially in relation to the shaft longitudinal axis (L) and a region which is recessed radially in relation to the shaft longitudinal axis (L), the first and second seal (7, 8) being arranged in the radially recessed region of the respective circumferential face section of the shaft (50) in the first position of the control element (4) and in the radially projecting region of the respective circumferential face section of the shaft (50) in the second position of the control element (4).

12. The rotary transmission apparatus (1) according to claim 1, the at least one fluid feed/discharge line (3) being connected in flow terms to a control space (9) which is delimited at least in regions by the control element (4) and is configured in such a way that, in the case of pressure loading of the control space (9), the control element (4) can be moved into its second position, a control line (11) which is connected in flow terms to a further control space (10) optionally and/or preferably being provided, the further control space (10) being delimited at least in regions by the control element (4) and being configured in such a way that, in the case of pressure loading of the further control space (10), the control element (4) can be moved into its first position.

13. The rotary transmission apparatus (1) according to claim 12, the control space (9) which is connected in flow terms to the at least one fluid feed/discharge line (3) being connected in flow terms via a fluid duct (6) which is configured in the control element (4) to the or to a fluid space (5) which is configured between the control element (4) and the circumferential face of the shaft (50).

14. A system having a rotary transmission apparatus (1) according to claim 1 and a shaft (50), on which the rotary transmission apparatus (1) is mounted, the shall (50) being configured as a drive shaft of a vehicle.

15. A tire pressure adjusting system for at least one wheel, driven rotationally relative to a vehicle body, of a pneumatically wheeled vehicle having at least one drive shaft (50) for driving the wheel, a fluid duct (51) being received or configured in the interior of the drive shaft, and at least one rotary transmission apparatus (1) according to claim 1 being provided for feeding and/or discharging a pressurized fluid to/from the fluid duct (51) as required.

Description

[0031] An exemplary embodiment of a system with an exemplary embodiment of the rotary transmission apparatus according to the invention will be described in greater detail below with reference to the attached drawings.

[0032] In the drawings:

[0033] FIG. 1 shows a schematic top view of an exemplary embodiment of a (whole) drive shaft of a wheel drive for a steered and driven vehicle wheel;

[0034] FIG. 2a shows a schematic sectional view along the line A-A in FIG. 1 of the exemplary embodiment of the drive shaft, with a rotary transmission apparatus assigned to the drive shaft in its first operating state in which no pressurized medium is being transmitted to the drive shaft;

[0035] FIG. 2b shows a schematic sectional view along the line B-B in FIG. 2a;

[0036] FIG. 3 shows a schematic detail view from FIG. 2b;

[0037] FIG. 4a shows a schematic sectional view through an exemplary embodiment of a drive shaft with a rotary transmission apparatus in its first operating state in which no pressurized medium is being transmitted to the drive shaft;

[0038] FIG. 4b shows a schematic detail view of a region of the rotary transmission apparatus according to FIG. 4a;

[0039] FIG. 4c shows a schematic detail view from FIG. 4b;

[0040] FIG. 5a shows a schematic sectional view of the drive shaft according to FIG. 4a with the rotary transmission apparatus in a second operating state in which a pressurized medium can be transmitted to the drive shaft;

[0041] FIG. 5b shows a schematic detail view of the rotary transmission apparatus according to FIG. 5a; and

[0042] FIG. 5c shows a schematic detail view of FIG. 5b.

[0043] In the following, with reference to the depictions in FIGS. 1 and 2a & b, an exemplary embodiment of a drive shaft 50 will first be described, which is provided with an embodiment of the rotary transmission apparatus 1 according to the invention. In this case, FIG. 2a and FIG. 2b each show the rotary transmission apparatus 1 in its first operating state in which no pressurized medium is being transmitted via the rotary transmission apparatus 1 to a fluid duct 51 that is received or configured in the drive shaft 50. Then the second operating state of the rotary transmission apparatus 1, in which pressurized medium can be transmitted via the rotary transmission apparatus 1 to the fluid duct 51 that is received or configured in the interior of the drive shaft 50, will be described with reference to the depictions in FIGS. 5a, 5b, and 5c.

[0044] As shown in FIG. 1 and FIG. 2a and FIG. 2b, the drive shaft 50 is for example the drive shaft 50 of a wheel drive for a steered and driven vehicle wheel 54. The drive shaft 50 has a first shaft 53 oriented toward the wheel, a universal joint 52, and a second shaft oriented toward the axle. Since the steering axle of the wheel must be located as close to the wheel plane as possible in such a drive shaft 50 so that the scrub radius is as small as possible, a certain space problem exists with regard to the rotary transmission apparatus 1. Particularly in such drive shafts for a steered and driven vehicle wheel 54, there is thus a need to provide a particularly compactly designed rotary transmission apparatus 1, which in particular, is configured in a way that is as wear-free as possible.

[0045] The rotary transmission apparatus 1, which is shown together with the drive shaft 50 in FIG. 2a and FIG. 2b, can in particular be part of a tire pressure control system of a motor vehicle.

[0046] The rotary transmission apparatus 1 schematically depicted in FIG. 2a and FIG. 2b is mounted on the drive shaft 50 and in particular, is connected to the latter in a torque-engaged way. Although this is not shown, the drive shaft 50 can be enclosed by an axle housing at the end oriented toward the vehicle. In at least some regions, the axle housing can constitute the housing 12 of a stator assembly 2 of the rotary transmission apparatus 1.

[0047] The free segment of the drive shaft 50, i.e. end region of the drive shaft 50 oriented toward the wheel, is connected to the wheel unit 54 via the above-mentioned universal joint 52 and in the figurative sense, is used to fasten one or more wheels to the drive shaft 50 so that they can be driven by the drive shaft 50.

[0048] The design and function of the rotary transmission apparatus 1 will be described in greater detail below with reference to the depictions in FIG. 4a to FIG. 4c and FIG. 5a to FIG. 5c.

[0049] In detail, FIG. 4a and FIG. 4b show the exemplary embodiment of the rotary transmission apparatus 1 according to the invention in its first operating state in which no pressurized medium and no control- and/or working pressures are being transmitted via the rotary transmission apparatus 1 to a fluid duct 51 received or configured in the drive shaft 50. By contrast, particularly in FIG. 5a and FIG. 5b, the exemplary embodiment of the rotary transmission apparatus 1 according to the invention is shown in its second operating state in which a transmission of control- and/or working pressures or a transmission of a pressurized medium via the rotary transmission apparatus 1 to the fluid duct 51 received or configured in the interior of the drive shaft 50 are possible.

[0050] As shown in the drawings, in the exemplary embodiment of the rotary transmission apparatus 1, it has a stator assembly 2 which is arranged in a stationary manner with respect to a rotational movement of the shaft 50. The stator assembly 2 has a housing 12 (cage structure), which can, for example, be connected to an axle housing (not shown in the drawings).

[0051] The stator assembly 2, which is arranged in a stationary manner with respect to a rotational movement of the shaft 50, has a connection (fluid feed/discharge line 3) via which a pressurized medium can be fed to the stator assembly 2 as required. In this connection, it is naturally possible to provide a plurality of different fluid feed/discharge lines and corresponding connections for them, particularly in the housing 12 of the stator assembly 2. It is also possible for there to be other embodiments for feeding control and/or working pressures or pressurized mediums into the housing 12 of the stator assembly 2.

[0052] As can particularly be seen in the detail views according to FIG. 4b and FIG. 5b, in addition to the fluid feed/discharge line 3, a connection for a control line 11 to the stator assembly 2 is also provided.

[0053] The stator assembly 2 has a control element 4, which in the exemplary embodiment of the rotary transmission apparatus 1 according to the invention shown in the drawings, is configured as a control ring that is configured coaxially with respect to the shaft longitudinal axis L. This control element 4 (control ring) is in particular received so that it is supported in at least some regions in the housing 12 of the stator assembly 2 so that it is able to move in the shaft longitudinal direction L. In detail, the control element 4 is supported so that it is able to move between a first position shown in FIG. 4b and a second position shown in FIG. 5b relative to the drive shaft 50 (and likewise relative to the housing 12 of the stator assembly 2).

[0054] Although it is not provided in the embodiment shown in the drawings, the control element 4 can be configured in such a way that a flow connection between the fluid feed/discharge line 3 and the fluid duct 51 received or configured in the interior of the drive shaft 50 is interrupted in the first position of the control element (see FIG. 4b) whereas a flow connection between the at least one fluid feed/discharge line 3 and the fluid duct 51 received or configured in the interior of the drive shaft 50 is established in the second position of the control element (see FIG. 5b).

[0055] As can be seen in the depictions in FIGS. 4b and 5b and in the corresponding detail views according to FIGS. 4c and 5c, the stator assembly 2 also has a seal arrangement which is assigned to the control element 4 and has at least one seal 7, 8, in particular in the form of a sealing lip, the at least one seal 7,8 and/or a topology of the circumferential face of the drive shaft 50 in the region of the stator assembly 2 being configured in such a way that, in relation to the drive shaft 50, the at least one seal 7, 8 is at least substantially contact-free relative to the circumferential face of the drive shaft 50 in the first position of the control element (see FIG. 4b and FIG. 4c) and the at least one seal 7, 8 is in contact and at least substantially has a sealing action relative to the circumferential face of the drive shaft 50 in the second position of the control element (see FIG. 5b and FIG. 5c).

[0056] In detail, in the rotary transmission apparatus 1 shown in the drawings, the control element 4 has front end region as viewed in the shaft longitudinal direction L and an opposite rear end region, the front end region being assigned a first seal 7, in particular in the form of a sealing lip, and the rear end region being assigned a second seal 8, in particular in the form of a sealing lip. In this case, the first and second seal 7, 8 are connected to the control element 4 in such a way that they are also moved in the case of a longitudinal displacement of the control element 4 relative to the drive shaft 50. In the second position of the control element (see FIG. 5b and FIG. 5c), the seals 7, 8 seal a fluid space 5 with respect to the circumferential face of the drive shaft 50, which fluid space 5 is configured, in particular, as an annular space, whereas in the first position of the control element (see FIGS. 4b and 4c), the seals 7, 8 are contact-free or at least substantially contact-free in relation to the circumferential face of the drive shaft 50.

[0057] As can also be seen in the detail views in FIG. 4b and in FIG. 5b, the control element 4, which is particularly configured as a control ring which is configured coaxially with respect to the shaft longitudinal axis L, has a guide face which interacts with a guide face of a housing of the stator assembly 2 and is mounted such that it can be displaced between the first and second position relative to the housing 12 of the stator assembly 2 and can be displaced relative to the drive shaft 50 in the longitudinal direction of the shaft longitudinal axis L.

[0058] As can also be seen in the detail views in FIG. 4b and FIG. 5b, between the control element 4 and the circumference face of the drive shaft 50, an in particular annular fluid space 5 is formed, at least one fluid duct 6 being configured in the control element 4, which fluid duct 6, at least in the second position of the control element 4 (see FIG. 5b), connects the at least one fluid feed/discharge line 3 in flow terms to the fluid space 5, which is configured, in particular, as an annular space.

[0059] As can be seen in the detail views in in FIG. 4c and FIG. 5c, in the region of the fluid space 5, the circumferential face of the drive shaft 50 has at least one region 56, 57 which tapers conically in relation to the shaft longitudinal axis L, where in the case of the displacement of the control element 4 in the direction of its first position, the at least one seal 7, 8 is also displaced in the feed direction of the conically tapering region 56, 57.

[0060] In detail, the views according to FIG. 4b and FIG. 5b particularly show that in the region of the fluid space 5, the circumferential face of the drive shaft 50 has a first region 56, which tapers conically in relation to the shaft longitudinal axis L and is assigned to the first seal 7, and a second region 57, which tapers conically in relation to the shaft longitudinal axis L and is assigned to the second seal 8. In this case, the feed direction of the first and second conically tapering region 56, 57 corresponds in each case with the direction in which the control element 4 moves when it is displaced in the direction of its first position.

[0061] However, the invention is not limited to embodiments in which the topology of the circumference face of the drive shaft 50 has corresponding conically tapering regions 56, 57 as shown by way of example in the drawings. Instead, it is basically conceivable that in the region of the fluid space 5, the circumference face of the drive shaft 50 has a first section which is assigned to the first seal 7 and a second section which is assigned to the second seal 8, the first and second section in each case having a region which projects radially in relation to the shaft longitudinal axis L and a region which is recessed radially in relation to the shaft longitudinal axis L, the first and second seal 7, 8 being arranged in the radially recessed region of the respective circumferential face section of the drive shaft 50 in the first position of the control element 4 and in the radially projecting region of the respective circumferential face section of the drive shaft 50 in the second position of the control element 4.

[0062] As indicated above, the fluid feed/discharge line 3 of the stator assembly 2 is connected in flow terms to a control space 9 which is delimited at least in regions by the control element 4 and is configured in such a way that, in the case of pressure loading of the control space 9, the control element 4 can be moved into its second position.

[0063] Also in the exemplary embodiment of the rotary transmission apparatus 1 according to the invention shown by way of example in the drawings, another control line 11 is used, which is connected in flow terms to another (second) control space 10, this other (second) control space 10 being delimited at least in regions by the control element 4 and configured in such a way that, in the case of pressure loading of the other (second) control space 10, the control element 4 can be moved into its first position.

[0064] In the exemplary embodiment shown in the drawings, the control space 9 which is connected in flow terms to the fluid feed/discharge line 3 (first control space) is connected in flow terms to the fluid space 5 configured between the control element 4 and the circumference face of the drive shaft 50 via a fluid duct 51 configured in the control element 4.

[0065] Summarized briefly, the exemplary embodiment of the rotary transmission apparatus 1 according to the invention shown in the drawings can be characterized as follows:

[0066] In order, during operation of the rotary transmission apparatus 1, to reduce the wear and friction losses to a minimum, the rotary transmission apparatus 1 is configured in such a way that only for the time period of a transmission of the pressurized medium to the fluid duct 51 configured in the drive shaft 50 do the corresponding sealing elements 7, 8 (sealing lips) of the sealing arrangement assigned to the control element 4 engage or come into contact with the drive shaft 50, which is rotating relative to the stator assembly 2.

[0067] The drive shaft 50, which is configured, for example, as a hollow shaft or partially hollow shaft, can have an arbitrary number of ducts. Each duct of the drive shaft 50 extending parallel to the rotation axis of the drive shaft 50 has an arbitrary number of branch ducts to the drive shaft surface and all of the branch ducts that are located in the region of the stator assembly 2 “see” the same control pressure. The outer contour (topology) of the drive shaft 50 is configured so that in the region of the transmission, the drive shaft 50 has sealing sections in relation to the rotation axis. A sealing section is a section of the longitudinal axis of the drive shaft 50 that is delimited by two seals 7, 8, in particular sealing lips, or by rotationally symmetrical accumulations of material.

[0068] The above-described exemplary embodiment relates to a two-duct rotary feed-through comprising a working duct and a control duct. It can likewise be embodied with a single duct or also with more than two ducts.

[0069] The description of the invention makes it clear that the rotary transmission apparatus 1 according to the invention is also primarily suitable for retrofitting.

[0070] The invention is not limited to the embodiment shown in the drawings, but instead ensues from a consideration of all of the features disclosed herein.