Positively locking clutch, parking lock unit, transmission decoupling unit and motor vehicle

Abstract

The invention relates to a positively locking clutch (1), to a parking lock unit, and to a transmission decoupling unit, which each have the positively locking clutch (1). The invention additionally relates to a motor vehicle which has the parking lock unit and / or the transmission decoupling unit. The positively locking clutch (1) comprises two clutch bodies (2, 3) which lie opposite one another along an adjustment direction (4) of the positively locking clutch (1) and on each of which a positively locking structure (5, 6) is arranged so as not to rotate, wherein the positively locking structures (5, 6) each have first positively locking elements (7) and second positively locking elements (8), and the first positively locking elements (7) each extend further to the opposite clutch body (2, 3) than the second positively locking elements (8), and wherein the first positively locking elements (7) and the second positively locking elements (8) are arranged alternately on the respective clutch body (2, 3).

Description

[0001] 24-1006

[0002] 1

[0003] Positive locking coupling, parking lock unit, transmission decoupling unit and motor vehicle

[0004] The present invention relates to a positive-lock coupling by means of which a rotationally fixed, torque-transmitting connection between two transmission elements, such as shafts, gears, etc., of a transmission device can be selectively engaged and disengaged. The invention further relates to a parking lock unit and a transmission decoupling unit—each for a motor vehicle—each comprising the positive-lock coupling. The invention also relates to a motor vehicle comprising the parking lock unit and / or the transmission decoupling unit.

[0005] To prevent a motor vehicle from rolling away unintentionally when not in use, parking lock systems are employed today. Conventional parking lock units are known, for example, from DE 102007 062 349 A1, DE 10029 628 A1, or WO 2020 119 853 A2. Such parking lock systems function via positive-lock couplings and are characterized by symmetrical coupling structure geometries (e.g., tooth geometries). It is necessary to design the coupling structure geometries with a specific operating clearance to allow coupling even when the coupling structures involved in creating a rotationally fixed connection are rotated relative to each other. The greater the differential rotational speed between the two coupling structures, the greater this operating clearance must be to prevent unwanted rejection of the coupling structures.There is of course a need to avoid such an undesirable rejection of the coupling structures and to produce the corresponding torque-transmitting connection as reliably as possible- 24-1006.

[0006] 2 len. This need also exists for gearbox decoupling systems, which also function via such positive locking couplings.

[0007] The object of the present invention is to avoid an undesirable rejection of two coupling structures of a positive locking coupling when they are moved into a coupling position.

[0008] This problem is solved by the subject matter of the independent claims. Further possible embodiments of the invention are disclosed in the dependent claims, the description, and the figures. Features, advantages, and possible embodiments set forth in the description for one of the subject matter of the independent claims are to be regarded, at least analogously, across categories and embodiments as features, advantages, and possible embodiments of the respective subject matter of the other independent claims, as well as of any possible combination of the subject matter of the independent claims, optionally in conjunction with one or more of the dependent claims.

[0009] According to the invention, a positive-lock coupling is proposed, comprising two coupling bodies that are positioned opposite each other along an adjustment direction of the positive-lock coupling and on which a positive-locking structure is arranged in a rotationally fixed manner. The positive-lock coupling can be adjusted by moving the coupling bodies along an adjustment direction between a engaged position, in which the positive-locking structures engage and thereby connect the coupling bodies to each other in a positive-locking and rotationally fixed manner, and a disengagement position, in which the coupling bodies can be rotated relative to each other about the adjustment direction. Thus, a torque-transmitting connection between the coupling bodies can be selectively engaged and disengaged by means of the positive-lock coupling.

[0010] Furthermore, according to the invention, a parking lock unit and a transmission decoupling unit are proposed, each designed for a motor vehicle. The parking lock unit and the transmission decoupling unit each feature the positive-locking coupling according to the invention, meaning that the positive-locking coupling forms a component of the parking lock unit and the transmission decoupling unit, respectively. 24-1006

[0011] 3

[0012] The parking lock unit or the transmission decoupling unit, in its intended installation position, forms a component of the motor vehicle that constitutes a further object of the present invention. The motor vehicle is, in particular, designed as a purely electric or hybrid-electric vehicle and accordingly has an electric traction motor on board. It is specifically provided that a parking lock wheel of the parking lock unit is directly and rotationally fixed to a rotor shaft of the electric traction motor, with the parking lock wheel forming one of the clutch bodies.

[0013] The positive locking structures of the positive locking coupling each feature first and second positive locking elements, with the first positive locking elements extending further towards the opposite coupling body than the second positive locking elements. Furthermore, the first and second positive locking elements are arranged alternately on each coupling body. It can be seen that the first positive locking elements are longer in the direction towards the opposite coupling body than the second positive locking elements. Thus, along a circumferential and / or rotational direction of the coupling body, a first, longer positive locking element and a second, shorter positive locking element are always arranged alternately.

[0014] Due to this design and arrangement of the first and second positive-locking elements, successful adjustment of the positive-locking coupling from its disengaged position to its engaged position is possible, even if the two coupling bodies are rotated relative to each other at a differential speed. This is because successful adjustment—that is, a successful switching operation—is defined, for a given coupling geometry, by the differential speed (i.e., the relative circumferential speed between the coupling bodies) in combination with the axial switching speed. The axial switching speed is the speed at which the coupling bodies are moved axially, i.e., along the adjustment direction of the positive-locking coupling, to establish / close the torque-transmitting connection. In the engaged state, the interlocking positive-locking structures enable...-elements, thanks to their geometry, exhibit extremely low circumferential / torsional play, thus largely preventing impacts from load changes and the associated loss of comfort. 24-1006.

[0015] 4

[0016] According to a possible further development, the positive locking elements along a common rotational or circumferential direction of the coupling bodies have a common arc width. In other words, the first positive locking elements and the second positive locking elements along a predetermined path of the coupling bodies are the same width. This allows the positive locking elements to interlock without gaps, resulting in particularly unobtrusive and therefore advantageous acoustic behavior of the positive locking coupling. This is because, in the coupled position, there is no gap between the flanks of the positive locking elements through which the flanks could strike each other.

[0017] In another possible embodiment, the first positive locking element and the adjacent second positive locking element along the direction of rotation are spaced apart by a positive locking element gap equal to the arc width. In other words, along the direction of rotation or circumferentially, a first and a second positive locking element of the respective coupling body are always spaced apart by a positive locking element width. This allows one of the positive locking elements of the opposite coupling body to engage between a first and a second positive locking element of the corresponding coupling body when the positive locking coupling is adjusted into its coupled position. The circumferential or rotational clearance is specifically designed to be the sum of a positive locking element width and a positive locking element gap width – i.e., twice the arc width.This enables reliable adjustment of the positive locking coupling even at particularly high differential speeds.

[0018] According to another possible embodiment of the positive-locking coupling, the coupling bodies are each designed as a claw coupling body, so that the positive-locking coupling is configured as a claw coupling. The positive-locking elements are therefore designed as claw elements and arranged on an end face of the respective claw coupling body. Accordingly, the respective positive-locking structure is designed as a claw structure. A longitudinal center axis of the positive-locking or claw elements and the adjustment direction of the claw coupling intersect perpendicularly. The claw coupling bodies are, in particular, designed to be mirror-symmetrical.

[0019] In an alternative embodiment of the positive-locking coupling, the coupling bodies are each designed as a toothed coupling body, so that the positive-locking coupling is designed as a toothed coupling. The positive-locking elements are therefore toothed elements. 24-1006

[0020] The coupling body is designed with five elements, meaning that in this case, the respective positive locking structure is a tooth or wedge structure. The tooth elements or the tooth / wedge structures are arranged on a circumferential surface of the respective tooth coupling body. In one of the coupling bodies, the positive locking or tooth elements are arranged on an inner circumferential surface of the coupling body, whereas in the other coupling body, the positive locking or tooth elements are arranged on an outer circumferential surface of the coupling body. The respective longitudinal center axis of the coupling bodies of the tooth coupling and the adjustment direction are arranged parallel to each other. Due to the possibility of designing the positive locking coupling as a tooth or as a jaw coupling, the positive locking coupling can be used particularly flexibly and in a wide variety of applications.

[0021] It may be optionally provided that the positive-locking coupling, the parking lock unit, and / or the gearbox decoupling unit have / have an actuator by means of which the coupling bodies can be moved axially towards each other, i.e., along the adjustment direction. For example, the actuator may have a ball ramp mechanism. Furthermore, the actuator may have a locking device, such as a ball detent mechanism, to secure the coupling bodies bistablely in the respective position of the positive-locking coupling.

[0022] Further features of the invention may become apparent from the claims, the figures, and the description of the figures. The features and combinations of features mentioned above in the description, as well as the features and combinations of features shown below in the description of the figures and / or in the figures themselves, can be used not only in the combinations specified, but also in other combinations or on their own, without departing from the scope of the invention.

[0023] The drawing shows in

[0024] Fig. 1 shows a schematic view of a positive locking coupling designed as a claw coupling in its disconnected position,

[0025] Fig. 2 a schematic view of the jaw coupling after adjustment to its coupling position at a small differential speed between the coupling bodies of the positive locking coupling, 24-1006

[0026] 6

[0027] Fig. 3 shows a schematic view of the claw coupling after adjustment to its coupling position at a high differential speed between the coupling bodies.

[0028] Fig. 4 shows a schematic view of the positive locking coupling designed as a tooth coupling in its disconnected position,

[0029] Fig. 5 shows a schematic view of the gear coupling after adjustment to its coupling position at a small differential speed between the coupling bodies and in

[0030] Fig. 6 shows a schematic view of the gear coupling after adjustment to its coupling position at a high differential speed between the coupling bodies.

[0031] The following section describes a positive-locking coupling 1, a parking lock unit, and a transmission decoupling unit, each comprising the positive-locking coupling 1, as well as a motor vehicle comprising the parking lock unit and / or the transmission decoupling unit. In the figures, identical and functionally equivalent elements are designated with the same reference numeral. The parking lock unit, transmission decoupling unit, and motor vehicle are not shown in the figures.

[0032] In this example, the vehicle is designed as a purely electric or hybrid-electric vehicle and features either the parking lock unit or the transmission decoupling unit, or both. The parking lock unit and the transmission decoupling unit each have the positive-locking coupling 1, which is shown schematically in Fig. 1 and Fig. 4.

[0033] The positive-lock coupling 1 has two coupling bodies 2, 3 which are opposite each other along an adjustment direction 4 of the positive-lock coupling 1. A positive-locking structure 5, 6 is arranged on each of the coupling bodies 2, 3 in a rotationally fixed manner. In the present example, the respective coupling body 2, 3 is materially bonded to the corresponding positive-locking structure 5, 6; in particular, the respective coupling body 2, 3 and the corresponding positive-locking structure 5, 6 are formed integrally. By means of the positive-lock coupling 1, a torque-transmitting connection between the coupling bodies 2, 3 is selectively engaged and disengaged.

[0034] 7 separable by adjusting the coupling bodies 2, 3 along the adjustment direction 4 between a separation position (see Fig. 1 and Fig. 4), in which the positive locking structures 5, 6 or coupling bodies 2, 3 are rotatable relative to each other about the adjustment direction 4, and a coupling position (see Fig. 2, Fig. 3, Fig. 5, Fig. 6), in which the positive locking structures 5, 6 engage with each other and thereby positively connect the coupling bodies 2, 3 to each other in a rotationally fixed manner. For this purpose, the positive locking coupling 1 or the device into which it is installed or integrated, i.e., the parking lock unit or the transmission decoupling unit, has an actuator (not shown).To hold the positive-locking coupling in its current position, a locking device (not shown) is provided according to the present example, by means of which the coupling bodies 2, 3 are bistable in the respective position of the positive-locking coupling 1. The locking device has, for example, a ball detent mechanism.

[0035] The positive locking structures 5, 6 of the positive locking coupling 1 each have first positive locking elements 6 and second positive locking elements 8, wherein the first positive locking elements 7 extend further towards the opposite coupling body 2, 3 than the second positive locking elements 8. It can be seen that the first positive locking elements 7 are longer in the direction towards the opposite coupling body 2, 3 than the second positive locking elements 8. Furthermore, the first positive locking elements 7 and the second positive locking elements 8 are arranged alternately on the respective coupling body 2, 3 along a circumferential and / or rotational direction 9 of the coupling body 2, 3. In Fig. 1 and Fig. 4, it can also be seen that the positive locking elements 7, 8 have a common arc width 10 along the common circumferential / rotational direction 9 of the coupling body 2, 3.This means that the positive locking elements 7, 8 are of equal width along a predetermined path of the coupling bodies 2, 3. Furthermore, in the example described here, the respective first positive locking element 7 and the respective second positive locking element 8 adjacent to it along the circumferential / rotational direction 9 are spaced apart by a positive locking element spacing 11, which has an arc width 10. In other words: Along the circumferential / rotational direction 9, a first positive locking element 7 and a second positive locking element 8 of the respective coupling body 2, 3 are always spaced apart by a positive locking element width 10. In this case, the circumferential or rotational clearance of the positive locking coupling 1 is also designed such that it is the sum of a positive locking element width and a positive locking element spacing width – i.e., twice the arc width 10. 24-1006.

[0036] 8

[0037] Figures 1 to 3 show a first embodiment of the positive-lock coupling 1, in which it is designed as a jaw coupling 12. For this purpose, Figure 1 shows a highly schematic perspective view of the positive-lock coupling 1, designed as a jaw coupling 12, in area A. Outside area A, the coupling bodies 2, 3 are shown as if unfolded – the viewer of Figure 1 thus always follows a radius of the coupling bodies 2, 3, with the radius always intersecting the plane of the drawing sheet or image plane perpendicularly. Particular attention should be paid to the arrow labeled 9, which visualizes the circumferential / rotational direction of the positive-lock coupling 1, both in relation to the perspective view in area A and in the unfolded or unrolled representation.

[0038] The coupling bodies 2, 3 are each designed as a claw coupling body 13, 14, which have a disc-shaped form. Furthermore, the claw coupling bodies 13,

[0039] 14 mirror-symmetrical designs and arrangements. On each end face

[0040] The positive locking structures 5, 6 are arranged on the disc-shaped claw coupling bodies 13, 14. Consequently, the positive locking elements 7, 8, which are each designed as claw elements in the claw coupling 12, are arranged on the end face 15 and project axially from it, i.e., along the adjustment direction 4. A respective longitudinal center axis of the positive locking or claw elements 7, 8 and the adjustment direction 4 of the claw coupling 12 intersect each other perpendicularly. The longitudinal center axes of the positive locking or claw elements 7, 8 and the radius of the coupling bodies 2, 3 are parallel, i.e., both always intersect the plane of the drawing or image plane of Fig. 1 perpendicularly.

[0041] Fig. 2 shows, in the same manner as Fig. 1, the positive-locking coupling 1, designed as the jaw coupling 12, after it has been moved from the disengaged position (Fig. 1) to the engaged position about a longitudinal center axis 16 of the positive-locking coupling 1 at a small differential rotational speed of the coupling body 3 or the jaw coupling body 14 relative to the opposing coupling body 2 or jaw coupling body 13. At a given axial switching speed of the positive-locking coupling 1, in particular its actuator, the coupling body 3 or jaw coupling body 14 (i.e., its positive-locking / jaw elements 7, 8) was moved along a first adjustment vector 17 (see Fig. 1).

[0042] In contrast, Fig. 3 shows the jaw coupling 12 in the same representation as Fig. 1, after it has rotated about the coupling longitudinal center axis 24-1006 at a high differential speed of the jaw coupling body 14 in relation to the opposite jaw coupling body 13.

[0043] 9

[0044] 16 has been moved from the disengaging position (Fig. 1) to the engaging position. At a given axial switching speed, the jaw coupling body 14, or rather its positive-locking / jaw elements 7, 8, was moved along a second adjustment vector 18 (see Fig. 1). It can be seen from the imaginary collision point 19 shown in Fig. 1 that the second adjustment vector 18 would not be possible if the positive-locking / jaw elements 7, 8 were of the same length – this would result in an unintended repulsion of the jaw elements 7, 8, which would make establishing the torque-transmitting connection between the coupling bodies 2, 3 unreliable. The design and arrangement of the positive-locking structures 5, 6 of the jaw coupling 12 described here ensures that the torque-transmitting connection is reliably established even at higher differential speeds.

[0045] Figures 4 to 6 show a second embodiment of the positive-lock coupling 1, in which it is designed as a gear coupling 20. Figure 4 shows a highly schematic perspective view of the positive-lock coupling 1, configured as the gear coupling 20, in area B. Outside area B, the coupling bodies 2, 3 are shown as if unfolded – the viewer of Figure 1 thus always follows a radius of the coupling bodies 2, 3, with the radius always intersecting the plane of the drawing or image perpendicularly. Particular attention should be paid to the arrow labeled 9, which visualizes the circumferential / rotational direction of the positive-lock coupling 1, both in relation to the perspective view in area B and in the unfolded or unrolled representation.

[0046] The coupling bodies 2, 3 are each configured as a toothed coupling body 21, 22, wherein coupling body 2 or toothed coupling body 21 has a hollow shaft shape and coupling body 3 or toothed coupling body 22 has a solid shaft shape. A positive-locking structure 5, configured here as an internal keyway or internal tooth structure, is arranged on an inner circumferential surface 23 of the hollow shaft-shaped coupling body 2 or toothed coupling body 21. A positive-locking structure 6, configured here as an external keyway or external tooth structure, is arranged on an outer circumferential surface 24 of the solid shaft-shaped coupling body 3 or toothed coupling body 22. Therefore, the positive locking elements 7, 8, which in the case of the tooth coupling 20 are designed as tooth or wedge elements respectively, are arranged on the corresponding circumferential surface 23 or 24 and protrude radially from it, i.e. transversely to the adjustment direction 4.The longitudinal center axis of the positive locking or tooth elements 7, 8 and the adjustment direction 4 of the jaw coupling 12 run parallel to each other.

[0047] Fig. 5 shows, in the same manner as Fig. 4, the positive-locking coupling 1, designed as the toothed coupling 20, after it has been moved from the disengaged position (Fig. 4) to the engaged position about the longitudinal center axis 16 of the positive-locking coupling 1 at a small differential rotational speed of the coupling body 3 or the toothed coupling body 22 relative to the opposing coupling body 2 or toothed coupling body 22. At the given axial switching speed of the positive-locking coupling 1, in particular its actuator, the coupling body 3 or toothed coupling body 22 (i.e., its positive-locking / tooth elements 7, 8) was moved along a first adjustment vector 25 (see Fig. 4).

[0048] In contrast, Fig. 6 shows the gear coupling 20 in the same manner as Fig. 4, after it has been moved from the disengaged position (Fig. 4) to the engaged position around the coupling's longitudinal center axis 16 at a high differential rotational speed of the gear coupling body 22 relative to the opposing gear coupling body 21. At a given axial switching speed, the gear coupling body 22, or rather its positive-locking or tooth elements 7, 8, was moved along a second adjustment vector 26 (see Fig. 4). It can be seen from the imaginary collision point 27 shown in Fig. 4 that the second adjustment vector 26 would not be possible if the positive-locking or tooth elements 7, 8 were of the same length – this would lead to an unintended repulsion of the tooth elements 7, 8, which would make establishing the torque-transmitting connection between the coupling bodies 2, 3 unreliable.The design and arrangement of the positive locking structures 5, 6 of the gear coupling 20 described here ensures that the torque-transmitting connection is reliably established even at higher differential speeds.

[0049] The positive-lock coupling 1, the parking lock unit, the transmission decoupling unit, and the motor vehicle each demonstrate a way in which the problem explained at the beginning—namely, preventing an undesired rejection of two coupling structures of a positive-lock coupling when it is moved into a coupling position—can be solved. 11

[0050] Reference symbol list

[0051] 1 Positive locking coupling

[0052] 2 coupling bodies

[0053] 3 coupling bodies

[0054] 4. Adjustment direction

[0055] 5 Positive locking structure

[0056] 6 Positive locking structure

[0057] 7 first positive locking element

[0058] 8 second positive locking element

[0059] 9 Circumferential / Direction of Rotation

[0060] 10 arc width

[0061] 11 Form-locking element spacing

[0062] 12 claw coupling

[0063] 13 claw coupling bodies

[0064] 14 claw coupling bodies

[0065] 15 Front surface

[0066] 16 Coupling longitudinal center axis

[0067] 17 first adjustment vector

[0068] 18 second adjustment vector

[0069] 19 Collision point

[0070] 20-tooth clutch

[0071] 21 gear coupling bodies

[0072] 22 gear coupling bodies

[0073] 23 Inner perimeter area

[0074] 24 external perimeter area

[0075] 25 first adjustment vector

[0076] 26 second adjustment vector

[0077] 27 Collision point

[0078] Area

[0079] Area B

Claims

24-1006 12 Patent claims 1. Positive locking coupling (1) with two coupling bodies (2, 3) which are opposite each other along an adjustment direction (4) of the positive locking coupling (1) and on which a positive locking structure (5, 6) is arranged in a rotational manner, wherein the positive locking structures (5, 6) each have first positive locking elements (7) and second positive locking elements (8), and the first positive locking elements (7) extend further to the opposite coupling body (2, 3) than the second positive locking elements (8), and wherein the first positive locking elements (7) and the second positive locking elements (8) are arranged alternately on the respective coupling body (2, 3).

2. Positive locking coupling (1) according to claim 1 , characterized in that the positive locking elements (7, 8) have a common arc width (10) along a common direction of rotation (9) of the coupling bodies (2, 3).

3. Positive locking coupling (1) according to claim 2, characterized in that the respective first positive locking element (7) and the respective second positive locking element (8) adjacent along the direction of rotation (9) are spaced apart from each other by a positive locking element spacing (11) which has the arc width (10).

4. Positive locking coupling (1) according to one of the preceding claims, characterized in that the coupling bodies (2, 3) are each designed as a claw coupling body (13, 14), wherein the positive locking elements (7, 8) are arranged on an end face (15) of the respective claw coupling body (13, 14). 24-1006 13 5. Positive locking coupling (1) according to one of claims 1 to 3, characterized in that the coupling bodies (2, 3) are each designed as a toothed coupling body (21 , 22), wherein the positive locking elements (7, 8) are arranged on a circumferential surface (23, 24) of the respective toothed coupling body (21 , 22).

6. Parking lock unit for a motor vehicle, wherein the parking lock unit comprises a positive locking coupling (1) designed according to any one of the preceding claims.

7. Transmission decoupling unit for a motor vehicle, wherein the transmission decoupling unit comprises a positive locking coupling (1) designed according to any one of claims 1 to 5.

8. Motor vehicle with a parking lock unit designed according to claim 6 and / or with a transmission decoupling unit designed according to claim 7.

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