transmission

Abstract

A transmission (1) comprising a shift fork (2) is provided. The transmission (1) has a first gear state and a second gear state which can be selected by means of the shift fork (2). The shift fork (2) is displaceable along an axial direction (3) between a first predetermined position (4) and a second predetermined position (5). The first gear state is provided when the shift fork (2) is placed in the first predetermined position (4), and the second gear state is provided when the shift fork (2) is placed in the second predetermined position (5). The first predetermined position (4) and the second predetermined position (5) are arranged successively, and there are no further predetermined positions between the first predetermined position (4) and the second predetermined position (5) which can provide further selectable gear states. The first gear state can provide a first gear of the transmission (1), and the second gear state can provide a second gear or a park lock state of the transmission (1).

Description

TECHNICAL FIELD

[0001] The invention relates to a transmission comprising a shift fork, wherein the transmission has a first gear state and a second gear state which can be selected by means of the shift fork, and the shift fork can be displaced along an axial direction between a first predetermined position and a second predetermined position, wherein the first gear state is provided when the shift fork is placed in the first predetermined position and the second gear state is provided when the shift fork is placed in the second predetermined position. BACKGROUND

[0002] Today transmissions for vehicles with electric motors do not require some of the elements used in manual transmissions and other elements have to be improved to fit these new technologies. One important issue is the space limitation and how to reduce the size of the actuators of the transmission. One actuator system is usually used to switch two different elements in an attempt to reduce the size and complexity of the actuator system. This switching is performed from a neutral position where the sleeve is centrally arranged with respect to the hub. By movement of the sleeve to the left from the central neutral position, one dog clutch is engaged and by movement of the sleeve to the right from the central neutral position, the other dog clutch is engaged. In this way, different gear states of the transmission can be achieved. SUMMARY

[0003] It is an object of the invention to provide a transmission which can be achieved with a reduced size and complexity.

[0004] This object is achieved by a transmission comprising a shift fork, wherein the transmission has a first gear state and a second gear state which can be selected by means of the shift fork, the shift fork can be displaced along an axial direction between a first predetermined position and a second predetermined position, and the first gear state is provided when the shift fork is placed in the first predetermined position and the second gear state is provided when the shift fork is placed in the second predetermined position, wherein the first predetermined position and the second predetermined position are arranged successively and there is no further predetermined position between the first predetermined position and the second predetermined position which can provide a further selectable gear state, and wherein the first gear state can provide a first gear of the transmission and the second gear state can provide a second gear or a park lock state of the transmission.

[0005] The present invention is based on the insight that with such a transmission, a switching of two different elements (e.g. the engagement of two dog clutches) can be performed by a movement of the shift fork in only one direction. This allows for a more compact design and also reduces the switching time. Unlike with conventional solutions, where a sleeve has to be moved from a central neutral position to the left in order to engage one element, then back to the central neutral position and further to the right in order to engage the other element, it is possible to realize a transmission with a non-central neutral position or without a neutral position.

[0006] The first predetermined position and the second predetermined position are arranged successively, without any gear state in between that can be selected by means of the shift fork. However, this does not exclude that any intermediate "gear state" can temporarily occur (i.e. temporarily present) during the transition between the first predetermined position and the second predetermined position, although such "gear state" is not selectable (gear) and has no substantial effect on the torque provided by the transmission.

[0007] The "first gear" and the "second gear" have different gear ratios that can provide different gears for the transmission. The expression "parking lock state" refers to a shaft of the transmission being locked against rotation, so that no torque can be transmitted by the transmission.

[0008] The transmission can comprise a first shaft; a rotating member arranged on the first shaft, the rotating member being rotatably journaled with respect to the first shaft; a bushing arranged on the first shaft, the bushing being rotatably locked to the first shaft (i.e. the former is locked to the latter so that the former cannot rotate relative to the latter); and a sleeve that is movable in axial direction by means of the shift fork, wherein the sleeve and the bushing are engageable and, when engaged, rotatably locked to each other, and the sleeve and the rotating member are engageable and, when engaged, rotatably locked to each other, and preferably, in the first predetermined position of the shift fork, the sleeve and the rotating member are engaged and the sleeve and the bushing are engaged. Thereby, the first gear state can be realized in an efficient way. The rotating member can be a gearwheel, for example.

[0009] According to one embodiment, the shift fork can be placed in a further predetermined position that can provide a further gear state that is a neutral for the transmission, wherein the shift fork can be displaced from the further predetermined position to the first predetermined position and further in the same direction from the first predetermined position to the second predetermined position. Thereby, a non-central neutral position can be realized in addition to the first gear state and the second gear state.

[0010] In order to realize such a non-centered neutral position, optionally, the rotating member, such as a gear in a non-centered neutral position, can be idling, and further, in a further predetermined position of the shift fork, the sleeve and the rotating member are engaged, and the sleeve and the bushing are disengaged.

[0011] For the engagement of the sleeve and the rotating member, the sleeve can have splines arranged on an outer surface of the sleeve for engagement with splines of the rotating member arranged on an inner surface of the rotating member. Furthermore, for the engagement of the sleeve and the bushing, the sleeve can have splines arranged on an inner surface of the sleeve for engagement with splines of the bushing arranged on an outer surface of the bushing. Optionally, this design can even consume less space by an undercut for receiving the rotating member of the sleeve.

[0012] According to a further embodiment, the transmission comprises a further component, which is actuated by the shift fork in the second predetermined position of the shift fork. Thereby, the second gear state can be realized in a reasonable manner, wherein the further component can be arranged on the first shaft of the transmission or on the second shaft of the transmission.

[0013] For example, the further component can be a park lock mechanism, which locks a shaft of the transmission against rotation when it is actuated by the shift fork, or the further component can be a further rotating member, such as a gear, arranged on a shaft, wherein the further rotating member is rotatably connected with respect to the shaft by a journal and is rotatably lockable to the shaft when actuated by the shift fork. The shaft to be locked by the park lock mechanism or the shaft on which the further rotating member is arranged can be the first shaft of the transmission or the second shaft of the transmission.

[0014] According to a further embodiment, the first predetermined position of the shift fork is a first end position, in which the shift fork cannot be moved further away from the second predetermined position, and the second predetermined position of the shift fork is a second end position, in which the shift fork cannot be moved further away from the first predetermined position. Thereby, a compact transmission with a first gear state and a second gear state can be realized.

[0015] According to a further embodiment, the further predetermined position of the shift fork is a first end position, in which the shift fork cannot be moved further away from the second predetermined position, and the second predetermined position of the shift fork is a second end position, in which the shift fork cannot be moved further away from the further predetermined position. Thereby, a compact transmission with a first gear state, a second gear state and a non-centered neutral position can be realized.

[0016] Further advantages and advantageous features of the present application are disclosed in the following description and in the dependent claims. BRIEF DESCRIPTION OF DRAWINGS

[0017] With reference to the appended drawings, below follows a more detailed description of embodiments of the application cited as examples.

[0018] In the drawings:

[0019] Figure 1A is a view of the vehicle transmission in the first gear state providing the first gear, wherein the shift fork is located in a first predetermined position,

[0020] Figure 1B is a view of the vehicle transmission in the second gear state providing the second gear or the parking lock, wherein the shift fork is located in a second predetermined position, Figure 1A

[0021] Figure 2A is a view of a variant of the vehicle transmission in a further gear state being a non-centralized neutral, wherein the shift fork is located in a further predetermined position,

[0022] Figure 2B is a view of the vehicle transmission in the first gear state providing the first gear, wherein the shift fork is located in a first predetermined position, Figure 2A

[0023] is a view of the vehicle transmission in the second gear state providing the second gear or the parking lock, wherein the shift fork is located in a second predetermined position, Figure 2C Figure 2A

[0024] Figure 3A is a view of a further variant of the vehicle transmission in a further gear state being a non-centralized neutral, wherein the shift fork is located in a further predetermined position,

[0025] Figure 3B is a view of the vehicle transmission in the first gear state providing the first gear, wherein the shift fork is located in a first predetermined position, Figure 3A

[0026] is a view of the vehicle transmission in the second gear state providing the second gear, wherein the shift fork is located in a second predetermined position, Figure 3C Figure 3A is a view of a further variant of the vehicle transmission in the first gear state providing the first gear, wherein the shift fork is located in a first predetermined position, and

[0027] Figure 4A is a view of the vehicle transmission in the second gear state providing the second gear, wherein the shift fork is located in a second predetermined position,

[0028] Figure 4B Figure 4A ​​​​​a view into the vehicle transmission showing a second gear state providing a park lock state, wherein the shift fork is located in a second predetermined position. DETAILED DESCRIPTION

[0029] Figure 1A and 1B is an overview schematic view of a vehicle transmission 1. The transmission 1 comprises a shift fork 2. The transmission has a first gear state and a second gear state which can be provided by means of the shift fork 2. The shift fork 2 is displaceable along an axial direction 3 between a first predetermined position 4 (shown in Figure 1A ) which can provide the first gear state and a second predetermined position 5 (shown in Figure 1B ) which can provide the second gear state.

[0030] In other words, the first gear state is provided when the shift fork 2 is placed in the first predetermined position 4 and the second gear state is provided when the shift fork 2 is placed in the second predetermined position 5. Furthermore, the first predetermined position 4 and the second predetermined position 5 are arranged in succession, without other predetermined positions being arranged between the first predetermined position and the second predetermined position which can provide other selectable gear states. The first gear state provides a first gear of the transmission and the second gear state provides a second gear or a park lock state of the transmission, i.e. neither the first gear state nor the second gear state is a neutral position of the transmission.

[0031] The transmission 1 comprises a first shaft 6, a rotational member 7 arranged on the first shaft 6, wherein the rotational member 7 is rotatably connected to the first shaft 6 by means of a journal. Suitably, the rotational member 7 is a gear wheel. The gear wheel 7 is a so-called idler gear wheel (idler) which is connected to the first shaft 6 by means of a journal, but can be rotatably locked to the first shaft 6 (i.e. locked to the first shaft 6 without being able to rotate relative thereto) by further components for transmitting torque between the gear wheel 7 and the first shaft 6.

[0032] In Figure 1A and 1BIn the exemplary embodiment shown, the transmission 1 further comprises a sleeve 9 and a bushing 8 arranged on the first shaft 6, wherein the bushing 8 is rotatably locked to the first shaft 6 and the sleeve 9 is movable by means of the shift fork 2. The sleeve 9 and the bushing 8 are engageable with each other and, when engaged, are rotatably locked to each other. The sleeve 9 and the rotating member 7 are engageable with each other and, when engaged, are rotatably locked to each other. The sleeve 9 can have splines 10 arranged on an outer surface of the sleeve for engagement with splines 11 of the rotating member 7 arranged on an inner surface of the rotating member. Furthermore, the sleeve 9 can have splines 12 arranged on an inner surface of the sleeve for engagement with splines 13 of the bushing 8 arranged on an outer surface of the bushing. In other words, the sleeve 9 is movable by means of the shift fork 2 along the axial direction 3 for engagement and disengagement with respect to the rotating member 7 and the bushing 8.

[0033] Alternatively, the sleeve can have splines arranged on an inner surface for engagement with splines arranged on an outer surface of the rotating member, such as a claw ring of a gear wheel. See Figure 4A and 4B the embodiment shown.

[0034] In the first predetermined position 4 of the shift fork 2, the sleeve 9 and the rotating member 7 are engaged and the sleeve 9 and the bushing 8 are engaged and the gear wheel 7 is thereby rotatably locked to the first shaft 6. For example, the gear wheel 7 can mesh with another gear wheel of another shaft for transmitting torque between the two shafts (not shown).

[0035] Suitably, the transmission 1 comprises a further component 14. The further component 14 is schematically shown in Figure 1A and 1B by a square box. In Figure 1B , a vehicle transmission in Figure 1A is shown in a second gear state, wherein the shift fork 2 is in the second predetermined position 5.

[0036] Although in the example shown, the further component 14 is actuated by the shift fork 2 in the second shift fork position 5, as schematically shown by the arm 15 of the shift fork 2 acting against the further component 14, in another embodiment, the further component 14 can be actuated by the sleeve 9, if the further component 14 is arranged on the first shaft 6. The further component 14 can be arranged on the first shaft 6 of the transmission 1 or on a second shaft of the transmission.

[0037] Optionally, the further component 14 can be actuated directly by the shift fork 2 or via a sleeve 9 or similar component arranged on the first shaft 6 or on another shaft. For example, the further component 14 can be a parking lock mechanism which, when actuated by the shift fork 2, locks a shaft of the transmission to prevent rotation. The shaft can be the first shaft 6 of the transmission 1 or another shaft of the transmission. In another embodiment, the further component can be a further rotary member, such as a gear, arranged on a shaft, wherein the further rotary member is rotatably connected to the shaft via a journal and is rotatably locked to the shaft, for example via a sleeve, when actuated by the shift fork. The shaft can be the first shaft 6 of the transmission 1 or another shaft of the transmission.

[0038] In Figure 1B The second predetermined position 5 is shown in which the sleeve 9 has just been disengaged from the gearwheel 7 and the sleeve 9 and the gearwheel 7 are disengaged. Without immediate actuation of the further component 14, the shift fork 2 can have to be moved further away from the gearwheel 7 along the axial direction 3 to reach the second predetermined position 5. Depending on the design of the transmission, the sleeve 9 and the shaft sleeve 8 can optionally be engaged or disengaged in the second predetermined position 5, while the sleeve 9 and the gearwheel 7 are always disengaged in this position.

[0039] For example, if a second sleeve is to be brought into engagement with the further component for the implementation of a second gear state, the second sleeve can have to be displaced by a certain distance while being in engagement with the further component before reaching the second predetermined position, and in this case the sleeve has to be disengaged from the gearwheel immediately before the second sleeve begins to engage with the further component and remains disengaged during the further movement of the shift fork towards the second predetermined position.

[0040] Furthermore, the first predetermined position 4 of the shift fork 2 is suitably a first end position in which the shift fork 2 cannot be moved further away from the second predetermined position 5, and the second predetermined position 5 of the shift fork 2 is suitably a second end position in which the shift fork 2 cannot be moved further away from the first predetermined position 4.

[0041] Figure 2A , 2B Figures 2A and 2C show a variant of the vehicle transmission 1’. With reference to these figures, the main features of the transmission 1’ with respect to the transmission 1 in Figure 1A and 1B will be described. For features not explicitly described, reference is made to the description of the transmission 1 in Figure 1A and 1B .

[0042] In Figure 2A , a transmission 1’ is shown having a shift fork 2 located at a further predetermined position 16.

[0043] In the further predetermined position 16, the sleeve 8 and the sleeve 9 are disengaged and the sleeve 9 and the rotating member 7 are engaged. As mentioned above, the further predetermined position 16 can constitute a neutral gear of the transmission 1'. Figure 2A is a view of the vehicle transmission 1' showing a further gear state as a non-centralized neutral gear, wherein the shift fork 2 is located in the further predetermined position 16, i.e. on the right side in Figure 2A . In the further gear state, the axle-journal-connected gear wheel 7 is idling, i.e. the gear wheel 7 is locked non-rotatably to the first shaft 6. The shift fork 2 is displaceable from the further predetermined position 16 to the first predetermined position 4' and further in the same direction from the first predetermined position 4' to the second predetermined position 5'.

[0044] Figure 2B is a view of the vehicle transmission 1' in Figure 2A showing a first gear state enabling the first gear, wherein the shift fork 2 is located in the first predetermined position 4'. This position of the shift fork 2 corresponds to the position shown for the transmission in Figure 1A .

[0045] Figure 2C is a view of the vehicle transmission 1' in Figure 2A showing a second gear state or a parking lock state enabling the second gear, wherein the shift fork 2 is located in the second predetermined position 5'. This position of the shift fork 2 corresponds to the position shown for the transmission in Figure 1B .

[0046] Further, the further predetermined position 16 of the shift fork 2 is a first end position in which the shift fork 2 cannot be moved further away from the second predetermined position 5' and the second predetermined position 5' of the shift fork 2 is a second end position in which the shift fork 2 cannot be moved further away from the further predetermined position 16.

[0047] In Figure 3A , 3B and 3C a further variant of the transmission is shown. A further component is a further gear wheel 14' arranged on the first shaft 6.

[0048] in the same way as described for Figure 2A , Figure 3A is a view of the vehicle transmission 1" showing a further gear state as a non-centralized neutral gear, wherein the shift fork 2 is located in the further predetermined position 16', i.e. on the right side in Figure 3A . In the further gear state, the axle-journal-connected gear wheel 7 is idling, i.e. the gear wheel 7 is locked non-rotatably to the first shaft 6. The sleeve 9 and the gear wheel 7 are engaged, while the sleeve 9 and the sleeve 8 are disengaged.

[0049] Figure 3B isFigure 3A A view of the vehicle's transmission 1, showing a first gear position capable of providing the first gear, with the shift fork 2 in a first predetermined position 4. Figure 3B The predetermined first position 4” is shown. The bushing 8 and sleeve 9 engage, and the sleeve 9 engages with the gear 7, such that the gear 7 can be rotatably locked onto the first shaft 6 to provide a first gear position. For example, the gear 7 can mesh with another gear on another shaft to transmit torque between two shafts (not shown).

[0050] Figure 3C yes Figure 3A A view of the vehicle's transmission 1, showing a second gear position capable of providing the second gear, with the shift fork 2 in the second predetermined position 5. Figure 3C The second predetermined position 5” shown disengages the sleeve 9 and gear 7, engages the sleeve 9 with another gear 14', and engages the sleeve 9 with the bushing 8, allowing the other gear 14' to be rotatably locked onto the first shaft 6 to provide a second gear position. For example, gear 14' can mesh with another gear on another shaft to transmit torque between two shafts (not shown).

[0051] Figure 4A This is a view of another variant of the vehicle transmission 100, showing a first gear position capable of providing a first gear, wherein the shift fork 20 is located in a first predetermined position 40. A sleeve 90 engages with the claw gear ring 70b of the gear 70, and the sleeve 90 also engages with a bushing 80. The sleeve 90 has splines arranged on its inner surface for engagement with splines arranged on the outer surface of the bushing 80, and for engagement with splines arranged on the outer surface of the claw gear ring 70b.

[0052] Another component is a parking lock mechanism 140 arranged on the second shaft 17 to lock the second shaft 17 to prevent rotation. The parking lock mechanism 140 has a wheel 18 and a pawl 19, which can engage to lock the second shaft 17. In the first predetermined position 40 of the shift fork 20, the parking lock state is not activated, that is, the wheel 18 and the pawl 19 are disengaged from each other.

[0053] Figure 4B yes Figure 4A A view of the vehicle's transmission, showing a second gear position capable of providing a parking lock, with the shift fork 20 in a second predetermined position 50. Figure 4A In comparison, Figure 4BIn the middle, the sleeve 90 has been displaced along the axial direction 30 by means of the shift fork 20, which has moved from the first predetermined position 40 to the second predetermined position 50. The sleeve 90 is disengaged from the dog ring 70b of the gear wheel 70. Conversely, the arm 150 of the shift fork 20 has actuated the parking lock mechanism 140, so that the wheel 18 and the pawl 19 engage, thereby locking the second shaft 17.

[0054] It will be appreciated that the present application is not limited to the embodiments described above and exemplified in the drawings; rather, the skilled person will recognize that many changes and modifications can be made within the scope of the appended claims.

Claims

1. A gearbox (1) comprising a shift fork (2), the gearbox (1) having a first gear state and a second gear state selectable by means of the shift fork (2), the shift fork (2) being displaceable along an axial direction (3) between a first predetermined position (4) and a second predetermined position (5), the first gear state being provided when the shift fork (2) is placed in the first predetermined position (4) and the second gear state being provided when the shift fork (2) is placed in the second predetermined position (5), the first predetermined position (4) and the second predetermined position (5) being arranged successively and without any further predetermined position between the first predetermined position and the second predetermined position which can provide a further selectable gear state, wherein, The first gear state provides a first gear of the transmission (1) and the second gear state provides a second gear or a park lock state of the transmission (1), characterized in that the shift fork (2) can be placed in a further predetermined position (16) which provides a further gear state as a neutral gear of the transmission (1'), the shift fork (2) can be displaced from the further predetermined position (16) to the first predetermined position (4') and further in the same direction from the first predetermined position (4') to the second predetermined position (5').

2. The transmission of claim 1, wherein, The transmission comprises a first shaft (6), a rotary member (7) arranged on the first shaft, which is rotatably journaled relative to the first shaft (6), a sleeve (8) arranged on the first shaft (6), which is rotatably locked to the first shaft (6), and a sleeve (9) which can be moved in the axial direction (3) by means of the shift fork (2), which sleeve (9) and the sleeve (8) can be engaged and, when engaged, rotatably locked to one another, and which sleeve (9) and the rotary member (7) can be engaged and, when engaged, rotatably locked to one another.

3. The transmission of claim 2, wherein, The rotary member is a gear wheel (7).

4. The transmission of claim 2, wherein, In the first predetermined position (4) of the shift fork (2), the sleeve (9) and the rotary member (7) are engaged, and the sleeve (9) and the sleeve (8) are engaged.

5. The transmission of claim 2, wherein, In the further predetermined position (16) of the shift fork (2), the sleeve (9) and the rotary member (7) are engaged, and the sleeve (9) and the sleeve (8) are disengaged.

6. The transmission of any of the preceding claims, The transmission (1) comprises a further component (14) which is actuated by the shift fork (2) in the second predetermined position (5) of the shift fork (2).

7. The transmission of claim 6, wherein, The further component is a further rotary member (14') arranged on a shaft (6), which is rotatably journaled relative to the shaft (6), and which, when actuated by the shift fork (2), can be rotatably locked to the shaft (6).

8. The transmission of claim 7, wherein, The further rotary member is a gear wheel (14').

9. The transmission of claim 6, wherein, The further component is a park lock mechanism (140) which, when actuated by the shift fork (2), locks a shaft (17) of the transmission (1) against rotation.

10. The transmission of claim 6, wherein, The further component is arranged on a first shaft (6) of the transmission (1).

11. The transmission of claim 6, wherein, The further component is arranged on a second shaft (17) of the transmission (1).

12. The transmission of any of claims 2-4, characterized by The sleeve (9) has splines (10) arranged on its outer surface for engagement with splines (11) of the rotary member (7) arranged on its inner surface, and the sleeve (9) has splines (12) arranged on its inner surface for engagement with splines (13) of the bushing (8) arranged on its outer surface.

13. The transmission of claim 1, wherein, The first predetermined position (4) of the shift fork (2) is a first end position in which the shift fork cannot be moved further away from the second predetermined position (5), and the second predetermined position (5) of the shift fork (2) is a second end position in which the shift fork cannot be moved further away from the first predetermined position (4).

14. The transmission of claim 1, wherein, The further predetermined position (16) of the shift fork (2) is a first end position in which the shift fork cannot be moved further away from the second predetermined position (5), and the second predetermined position (5) of the shift fork (2) is a second end position in which the shift fork cannot be moved further away from the further predetermined position (16).

Images