Shift device and axle assembly

Abstract

The invention relates to a shift device (1) for a powertrain of a motor vehicle, comprising a housing (2) in which a first drive shaft (3) and a second drive shaft (4) are mounted in a rotatable manner, the first drive shaft (3) and the second drive shaft (4) being arranged coaxially relative to one another such that they have a common axis of rotation (5), and a shiftable clutch device (6) which is arranged between the first drive shaft (3) and the second drive shaft (4), the clutch device (6) being able to be shifted into an open shift position in which it is disengaged, in which the first drive shaft (3) is able to rotate freely relative to the second drive shaft (4), and into a shift position in which it is engaged, in which the first drive shaft (3) is connected to the second drive shaft (4) via the clutch device (6) for joint rotation. According to the invention, the control element (7) is formed by a sliding sleeve, wherein an annular space (30) is formed between each of the clutch elements (12, 13), the corresponding drive shaft (3, 4) and the control element (7), which is arranged displaceable relative to the clutch elements (12, 13) on a defined axial movement path x, such that the volume of the annular space (30) can be varied.

Description

TECHNICAL FIELD

[0001] The invention relates to a shift device for a powertrain of a motor vehicle, comprising a housing, in which a first drive shaft and a second drive shaft are mounted in a rotatable manner, wherein the first drive shaft and the second drive shaft are arranged coaxially to one another such that they have a common axis of rotation. Furthermore, a shiftable clutch device is provided, which is arranged between the first drive shaft and the second drive shaft, wherein a first clutch element is connected to the first drive shaft for joint rotation and a second clutch element is connected to the second drive shaft in an axially displaceable manner for joint rotation. The clutch device can be shifted into an open shift position in which the first drive shaft can rotate freely relative to the second drive shaft and into a shift position in which the first drive shaft is connected to the second drive shaft in a rotationally fixed manner via the clutch device, wherein a control element is provided, which can be displaced in the direction of the axis of rotation of the drive shafts and which switches the clutch device into the open shift position or into the shift position depending on the displacement position of the control element. BACKGROUND

[0002] Such shift devices are already known from the prior art.

[0003] From DE 10 2014 217 066 A1 a clutch for a shiftable all-wheel drive is known, in which two aligned drive shafts are connected to one another by a clutch part, which enables a rigid connection between the two drive shafts. The clutch has a shift element in the form of a shift fork, by means of which the axially displaceable clutch part is displaced such that a rigid connection between the two drive shafts is established.

[0004] From WO 2011 / 098 595 A1 a coupling assembly for a powertrain of a motor vehicle is known, which comprises at least one clutch arranged on a rotary shaft to selectively couple the rotary shaft to a drive element of the powertrain. The coupling assembly further comprises at least one actuating device for actuating the clutch. The actuating device is designed to selectively engage an engagement section with a thread section rotating with the shaft in order to cause a relative movement of the engagement section and the thread section in the axial direction of the rotary shaft and thereby actuate the clutch in the axial direction. SUMMARY

[0005] The invention is based on the object of providing a shift device for coupling and decoupling two drive shafts or two drivable shaft sections, which shift device is improved in terms of noise generation. Advantageously, the shift device should also have improved wear characteristics or less wear. Furthermore, it is an object of the invention to provide an axle arrangement having a shift device designed according to the invention, which axle arrangement precisely has these characteristics.

[0006] The shift device according to the invention comprises a housing, in which a first drive shaft and a second drive shaft are mounted in a rotatable manner, wherein the first drive shaft and the second drive shaft are arranged coaxially to one another such that they have a common rotational axis. Furthermore, a shiftable clutch device is provided, which is arranged between the first drive shaft and the second drive shaft, wherein a first clutch element is connected to the first drive shaft for joint rotation and a second clutch element is connected to the second drive shaft for joint rotation in an axially displaceable manner. The clutch device can be shifted into an open shift position in which the first drive shaft can rotate freely relative to the second drive shaft and into a shift position in which the first drive shaft is connected to the second drive shaft in a rotationally fixed manner via the clutch device, wherein a control element is provided, which can be displaced in the direction of the rotational axis of the drive shafts and which switches the clutch device into the open shift position or into the shift position depending on the displacement position of the control element. According to the invention, the control element is formed by a sliding sleeve, which surrounds at least one of the two drive shafts in an axial partial region and also surrounds one of the two clutch elements in a partial region, such that an annular space is formed between the respective clutch element of the respective drive shaft and the control element. The control element is arranged such that it can be displaced relative to the clutch element on a limited axial displacement path, such that the volume of the annular space can be changed and the volume of a damping medium present in the annular space, such as an air volume enclosed in the annular space, can be compressed, such that axial vibrations of the clutch elements forming the annular space can be damped. In this way, the impacts that usually occur during unwanted shift operations and lead to excessive force and noise emissions can be significantly reduced. Furthermore, the sliding sleeve can be implemented as a particularly simple and cost-effective control element, which, due to its stability, enables a particularly advantageous positioning accuracy.

[0007] According to an advantageous embodiment of the application, it can be provided that at least one bearing element designed as a rolling bearing is arranged between the control element and the clutch element to be moved, which at least one bearing element in particular enables a displacement movement of the control element in the direction of the rotational axis of the drive shaft. The bearing element can ensure that the control element can reliably switch the clutch device into both the open shift position, in which the clutch device is disengaged, and the engaged shift position. Depending on the configuration, it can be reliably prevented that the control element rotates together with the rotational movement of the drive shaft. Preferably, a plurality of bearing elements, for example exactly two bearing elements, are provided, which are arranged in such a way that the two bearing elements support the control element at opposite points.

[0008] According to a further development of the application which is particularly preferred, it can also be provided that a circular ring-shaped sealing element is arranged between the bearing element and the annular space. The sealing element is advantageously designed as an annular disk. The advantageous effect of this configuration is based on the fact that an effective damping mechanism is produced by a structurally simple means without requiring additional installation space.

[0009] According to a further particularly preferred embodiment of the application, it can be provided that the control element designed as a sliding sleeve is designed in such a way that a radial play is formed between the control element and the drive shaft in order to achieve a predetermined damping characteristic. Alternatively or additionally, one or more axial ventilation channels can be formed between the sliding sleeve and the drive shaft, so that a predetermined damping characteristic of the control element can be set. Thus, a desired damping characteristic can be set by a structurally simple means.

[0010] Furthermore, the application can also be further developed in such a way that the control element designed as a sliding sleeve has one or more throttle openings in its peripheral sleeve wall, due to which the adjustment options for the damping characteristic can be further improved.

[0011] In an equally preferred embodiment variant of the application, it can also be provided that the control element has an annular recess on its inner side surface, which annular recess has an axial width which limits the adjustment path and which annular recess is dimensioned in such a way that the control element can be moved relative to the clutch element on the adjustment path. Furthermore, the annular recess can form a receiving space for arranging a spring element / rolling bearing between the sliding sleeve and the clutch element, due to which the formation of the receiving space can find a further installation space-saving design.

[0012] The spring element advantageously interacts with the annular space volume having a damping effect, such that the combination of the compressible annular space volume and the spring element results in a type of damper. The spring element is designed and arranged, for example, such that a first clutch element arranged on the side facing away from the control element is pressurized in the direction of the control element by the spring force, and / or such that a second clutch element directly coupled to the control element is subjected to the spring force in the direction of the first clutch element.

[0013] The spring element in the first embodiment can be formed, for example, by a compression spring which exerts a spring force on the first clutch element in the direction of the second clutch element or the control element against the first drive shaft, in which case the first clutch element must then also be arranged in a displaceable manner on the first drive shaft. According to the second embodiment described, the spring element can be arranged within the annular space, the spring force acting in the direction of the first clutch element against the compression direction, in particular bearing on the second drive shaft, on the second clutch element. A further improved damping of vibrations can thus be achieved in a minimum of space.

[0014] It can also be advantageous to further develop the application such that a gear element is provided on the outer circumference of the sliding sleeve, wherein the gear element is preferably formed by an external toothing or an external thread. An easily accessible gear element can be achieved by the external toothing. The external toothing is preferably configured to engage with a pinion shaft. The external toothing is preferably designed in the manner of a rack similar to the external toothing. A rotation of the pinion shaft then causes the external toothing to advance such that the control element is also moved in the direction of the axis of rotation.

[0015] It is further proposed that the clutch device is formed by a dog clutch, wherein each drive shaft is connected to the dog clutch for joint rotation. By switching at least one of the dog clutch elements in the direction of the axis of rotation, the dog clutch makes it possible to establish a connection for joint rotation via a form fit.

[0016] Furthermore, the object on which the application is based is achieved by a vehicle axle arrangement having a differential gear for a motor vehicle, wherein a shift device is arranged between the differential gear and the vehicle wheel, and the vehicle wheel can be switched between a driving operating state and a non-driving operating state by means of the shift device. BRIEF DESCRIPTION OF DRAWINGS

[0017] The present invention and the technical field will be explained in more detail below with reference to the drawings. It should be noted that the present invention is not intended to be limited by the illustrated exemplary embodiments. In particular, parts of the essential subject matter outlined in the drawings can also be extracted and combined with other parts and knowledge from the present specification and / or the drawings, unless explicitly stated otherwise. In particular, it should be noted that the drawings and in particular the scales shown are merely schematic. Identical reference signs indicate identical objects, so that explanations from other drawings can also be used.

[0018] In the drawings:

[0019] Figure 1 A schematic view of an axial section of a shift device in a possible embodiment of the invention is shown, and

[0020] Figure 2 A perspective view of a shift device according to Figure 1 is shown. DETAILED DESCRIPTION

[0021] Figure 1 A shift device 1 with a first drive shaft 3 and a second drive shaft 4 is shown, which can be connected to one another for joint rotation via a clutch device 6. The second drive shaft 4, which protrudes from the housing on the right-hand side, comprises two subshafts, which can be inserted into one another in some regions and which are connected to one another for joint rotation via a toothing 9. The second drive shaft 4 is mounted in a retainer 25 of the first drive shaft 3 at one axial end via a radial needle bearing at a section with a reduced diameter. The second drive shaft 4 is mounted at its other axial end relative to the housing 2 via a ball bearing 23. The first drive shaft 3 is supported within the housing 2 by a ball bearing 24 and by an extension of the second drive shaft 4, which protrudes into the retainer 25 of the first drive shaft 3. The first drive shaft 3 and the second drive shaft 4 are coaxially aligned with one another and thus rotate about a common axis of rotation 5.

[0022] One end of each of the first drive shaft 3 and the second drive shaft 4 protrudes from the housing 2. In the assembled state, the first drive shaft 3 can be connected to a differential gear for joint rotation, for example, and the second drive shaft 4 can be connected to a drive wheel, for example, or vice versa.

[0023] At the ends of the first drive shaft 3 and the second drive shaft 4 opposite to each other, a clutch device 6 is provided, which comprises a first (dog) clutch element 12 assigned to the first drive shaft 3 and a second (dog) clutch element 13 assigned to the second drive shaft 4. The clutch device 6 can be switched into an open shift position of disengaged opening, in which the first drive shaft 3 and the second drive shaft 4 are not connected to each other for joint rotation. Furthermore, the clutch device 6 can be switched into a shift position of engagement, in which the first drive shaft 3 is connected to the second drive shaft 4 for joint rotation. The clutch device 6 is controlled by means of a control element 7, which is mounted in an axially displaceable manner, i.e. in the direction of the rotational axis 5, on the second drive shaft 4. In this embodiment, the control element 7 is designed as a sliding sleeve, wherein the sleeve shape extends from a transfer element 8 having a section of enlarged diameter to the point at which the control force is introduced into the clutch device 6.

[0024] The gear element 8 has a toothing in the form of a rack, so that the gear element 8 can be displaced together with the control element 7 in the direction of the rotational axis 5. The transfer element 8 can be driven, for example, via a pinion shaft not shown in Figure 1 , so that the feed of the control element 7 along the rotational axis 5 results from the rotational movement of the pinion shaft.

[0025] The movement of the control element 7 is transferred to the second dog clutch element 13 via a rolling bearing 28. The rolling bearing 28 ensures that at most a minimum torque is transferred to the control element 7 due to any rotational movement of the second dog clutch element 13. The clutch device 6 can thus be switched into the shift position of engagement or the open shift position of disengaged by means of the control device 7. By moving the control element 7 in the direction of the rotational axis 5 towards the first dog clutch element 12, the second dog clutch element 13 can be connected in a form-fit manner with the first dog clutch element 12 in the shift position of engagement. By moving the control element 7 in the opposite direction, the clutch device 6 can be switched into the open shift position of disengaged, in which the dog clutch elements 12 and 13 are not engaged with each other. The control element 7 also has an extension 26, which extends outwards in the radial direction and which comes into contact with the housing 2 in the open shift position of disengaged, so that the end position of the control element 7 is fixed.

[0026] Figure 1It is also shown that the control element 7 is formed by a sliding sleeve which circumferentially surrounds at least one of the two drive shafts 3, 4 in an axial partial region and also circumferentially surrounds one of the two clutch elements 12, 13 in a partial region, such that an annular space 30 is formed between the respective clutch element 12, 13, the respective drive shaft 3, 4 and the control element 7, wherein the control element 7 is arranged such that it can be displaced relative to the clutch elements 12, 13 on a limited axial displacement path x, such that the annular space 30 can vary in its volume and the volume of the damping medium present in the annular space 30 can be compressed. In this way, for example, the volume of air enclosed in the annular space can be compressed and any vibrations of the second clutch element 13, which also forms the annular space 30, can be damped. The spring element 35 or the spring element 36 interacts with the annular space volume having a damping effect, such that the combination of the compressible annular space volume and the spring element 35, 36 results in a type of damper. The spring element 36 in the illustrated embodiment is formed by a compression spring which exerts a spring force on the first clutch element 12 in the direction of the second clutch element 13 or the control element 7, against the first drive shaft 3. For this purpose, the first clutch element 12 is then also arranged in a slidable manner on the first drive shaft 3. Furthermore, in the illustrated embodiment, the other spring element 35 is formed by a compression spring which bears against the second clutch element 13 on a radially widened protrusion of the second rotor shaft 4 in the direction of the first clutch element 12.

[0027] From Figure 1 It can also be seen that at least one bearing element 28 designed as a rolling bearing is provided between the control element 7 and the clutch elements 12, 13 to be moved. A circular ring-shaped sealing element 31 designed as a ring disk to seal the annular space is arranged between the bearing element 10 and the annular space 30.

[0028] The control element 7 designed as a sliding sleeve is designed such that a predetermined radial play 32 is present between the control element 7 and the drive shafts 3, 4 or such that one or more axial ventilation channels are formed between the sliding sleeve and the drive shaft 4, such that a predetermined damping characteristic of the control element 7 can be set.

[0029] Figure 1 It is also shown that the control element 7 designed as a sliding sleeve has one or more throttle openings 33 in the sleeve wall of its peripheral edge, which are also provided to be able to set a predetermined damping characteristic of the control element 7. The control element 7 has an annular recess 34 on its inner side surface, which limits the axial width b of the adjustment path x. The recess 34 is dimensioned such that the control element 7 can be displaced relative to the clutch elements 12, 13 on the adjustment path x.

[0030] Figure 1 It is also shown that a gear element 8 is provided on the outer circumference of the sliding sleeve, wherein the gear element 8 can be formed by an external toothing.

[0031] Figure 2 A representation of a shift device 1 according to Figure 1 is shown in perspective view, wherein the segmentation of the housing 2 can be seen. The housing 2 has a mounting flange 20 with fastening means 21 via which the shift device 1 can be fastened to a transmission housing. Preferably, a plurality of fastening means 21 is provided so that a stable and reliable connection to the transmission housing is possible. The fastening means 21 are preferably formed by holes in the mounting flange 20 so that a simple fastening, for example using bolts or screws, is possible.

[0032] The housing 2 is segmented into a first housing part 17 and a second housing part 19. The first housing part 17 has a cylindrical outer contour so that it can be inserted into and stored in a likewise cylindrical holder of the transmission housing. In the installed state, the first housing part 17 protrudes into the transmission housing so that the mounting flange 20 rests on the transmission housing. The second housing part 19 then comprises the part of the housing 2 with the mounting flange 20 protruding from the transmission housing.

[0033] The invention is not limited to the embodiments shown in the drawings. The above description should therefore not be regarded as limiting but as illustrative. The following claims are to be understood as the named features being present in at least one embodiment of the invention. This does not exclude the presence of further features. If the patent claims and the above description name "first" and "second" features, the names are used to distinguish between two features of the same type and do not define a priority order.

[0034] List of reference signs

[0035] 1 shift device

[0036] 2 housing

[0037] 3 drive shaft

[0038] 4 drive shaft

[0039] 5 axis of rotation

[0040] 6 clutch device

[0041] 7 control element

[0042] 8 gear element

[0043] 9 toothing (drive shaft)

[0044] 12 first clutch element

[0045] 13 second clutch element

[0046] 17 first housing part

[0047] 19 second housing part

[0048] 20 mounting flange

[0049] 21 fastening means

[0050] 23 ball bearing

[0051] 24 ball bearing

[0052] 25 retainer (drive shaft)

[0053] 26 radial extension (control element)

[0054] 28 bearing element

[0055] 30 annular space

[0056] 31 sealing element

[0057] 32 play

[0058] 33 throttle opening

[0059] 34 recess

[0060] 35 spring element

[0061] 36 spring element (annular space)

[0062] x adjustment path

[0063] b width (recess)

Claims

1. A shift device (1) for a powertrain of a motor vehicle, comprising - a housing (2) in which a first drive shaft (3) and a second drive shaft (4) are mounted in a rotatable manner, wherein the first drive shaft (3) and the second drive shaft (4) are arranged coaxially relative to one another such that they have a common axis of rotation (5), and - a shiftable clutch device (6) arranged between the first drive shaft (3) and the second drive shaft (4), wherein a first clutch element (12) is connected to the first drive shaft (3) for joint rotation and a second clutch element (13) is connected to the second drive shaft (4) for joint rotation in an axially displaceable manner, and - the clutch device (6) is switchable into an open shift position of disengaged opening in which the first drive shaft (3) is freely rotatable relative to the second drive shaft (4), and - the clutch device (6) is switchable into a shift position of engagement in which the first drive shaft (3) is connected to the second drive shaft (4) for joint rotation via the clutch device (6), wherein - a control element (7) is provided which is displaceable in the direction of the axis of rotation (5) of the drive shafts (3, 4) and which switches the clutch device (6) into the open shift position of disengaged opening or into the shift position of engagement depending on the displacement position of the control element, characterized in that - the control element (7) is formed by a sliding sleeve which, on the one hand, circumferentially surrounds at least one of the two drive shafts (3, 4) in an axial partial region and, on the other hand, circumferentially surrounds a clutch element (12, 13) which is jointed in rotation with the at least one of the two drive shafts in a partial region, such that an annular space (30) is formed between the clutch element (12, 13), the drive shafts (3, 4) and the control element (7), wherein the control element (7) is arranged such that it is displaceable relative to the clutch element (12, 13) on a limited axial adjustment path x, such that the annular space (30) can be varied in its volume and the volume of a damping medium present in the annular space (30) can be compressed, such that axial vibrations of the clutch element (12, 13) forming the annular space (30) can be damped.

2. The shift device (1) according to claim 1, characterized in that - at least one bearing element (28) designed as a rolling bearing is provided between the control element (7) and the clutch element (12, 13) to be moved.

3. The shift device (1) according to claim 2, characterized in that - an annular sealing element (31) is arranged between the bearing element (28) and the annular space (30). ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 4. Shift device (1) according to claim 3, characterized in that the sealing element (31) is designed as an annular disk.

5. Shift device (1) according to claim 1, characterized in that the control element (7) designed as a sliding sleeve is designed in such a way that a radial play (32) between the control element (7) and the drive shaft (3, 4) exists or is designed with one or more axial ventilation channels, so that a predetermined damping behavior of the control element (7) can be set.

6. Shift device (1) according to claim 1, characterized in that the control element (7) designed as a sliding sleeve has one or more throttle openings (33) in the peripheral sleeve wall of the control element, so that a predetermined damping behavior of the control element (7) can be set.

7. Shift device (1) according to any one of claims 1 to 6, characterized in that the control element (7) has an annular recess (34) on the inner side surface of the control element, which annular recess limits the axial width b of the adjustment path x and which annular recess is dimensioned in such a way that the control element (7) can be displaced relative to the clutch element (12, 13) on the adjustment path x.

8. Shift device according to claim 7, characterized in that a spring element (35) is provided which acts on the second clutch element (13) in the direction of the first clutch element (12) with a spring force and / or a spring element (36) is provided which acts on the first clutch element (12) in the direction of the second clutch element (13) with a spring force.

9. Shift device (1) according to claim 1, characterized in that a gear element (8) is provided on the outer circumference of the sliding sleeve, wherein the gear element (8) is formed by an external toothing or an external thread.

10. Shift device (1) according to claim 1, characterized in that the clutch device (6) is formed by a dog clutch, wherein the first clutch element (12) and the second clutch element (13) are designed in the form of dog clutch elements.

11. Axle arrangement with a differential gear for a motor vehicle, wherein a shift device (1) according to any one of the preceding claims is arranged between the differential gear and a wheel, which wheel can be switched between a driving operating state and a non-driving operating state by means of the shift device.

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