Differential and transmission device
By using bearings to support the planetary gear shaft in the differential and combining this with the clutch switching state design, the wear problem between the engagement sleeve and the differential housing is solved, achieving high reliability and transmission accuracy of the differential, simplifying the structure and improving NVH performance.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- SCHAEFFLER TECHNOLOGIES AG & CO KG
- Filing Date
- 2024-11-26
- Publication Date
- 2026-06-04
AI Technical Summary
In the disengaged state, existing differentials suffer from wear between the engagement sleeve and the differential housing, leading to deterioration of transmission accuracy and damage to parts, thus reducing the reliability of the differential.
The bearing design supporting the planetary gear shaft allows the housing and planetary gear shaft to rotate relative to each other without causing wear. The clutch switches between different states to avoid relative rotation or integral rotation between parts. Combined with the spline and return spring-free design, the reliability of the differential is improved.
It effectively avoids the deterioration of transmission accuracy and damage to parts, improves the reliability of the differential, simplifies the structure, and enhances the NVH performance and compactness of the transmission device.
Smart Images
Figure CN2024134397_04062026_PF_FP_ABST
Abstract
Description
Differential and transmission Technical Field
[0001] This disclosure relates to the field of transmission devices, and particularly to a differential and a transmission device. Background Technology
[0002] Chinese invention patent application CN115962268A discloses a speed reducer and its control method, and an electric off-road vehicle equipped with the speed reducer. When the differential is in the disengaged state, the internal spline of the connecting gear and the external spline of the engaging gear sleeve are not engaged. However, in this state, the vehicle's half-shaft drives the engaging gear sleeve to rotate, while the differential housing does not rotate, resulting in wear between the engaging gear sleeve and the differential housing. With the use of the differential, wear between parts can cause deterioration of transmission accuracy or even damage to parts. This makes the reliability of the differential relatively low. Summary of the Invention
[0003] This disclosure is made in view of the state of the prior art described above. The object of this disclosure is to provide a differential and transmission device that overcomes at least one of the disadvantages described in the background art.
[0004] To achieve the above objectives, the present disclosure adopts the following technical solution.
[0005] This disclosure provides a differential comprising: a housing; a planetary gear shaft supported on the housing by bearings to allow the housing and the planetary gear shaft to rotate relative to each other about an input axis of the differential; and a clutch connected between the housing and the planetary gear shaft and configured to switch between a first state and a second state, wherein when the clutch is in the first state, the housing and the planetary gear shaft are capable of rotating integrally about the input axis, and when the clutch is in the second state, the housing and the planetary gear shaft are capable of rotating relative to each other about the input axis.
[0006] In one alternative embodiment, the differential includes a radial bearing and a thrust bearing as the bearing.
[0007] In another alternative, the race of the radial bearing is fixedly connected to the race of the thrust bearing.
[0008] In another alternative embodiment, the housing includes a first half-shell and a second half-shell fixed to each other, the first half-shell and the second half-shell being arranged opposite each other along the input axis, the planetary gear shaft being disposed between the first half-shell and the second half-shell, and the differential including a first bearing and a second bearing as the bearing, the first half-shell being connected to the planetary gear shaft via the first bearing, and the second half-shell being connected to the planetary gear shaft via the second bearing.
[0009] In another alternative embodiment, the clutch includes a first engagement element and a second engagement element, the first engagement element being torsionally connected to the housing and the second engagement element being torsionally connected to the planetary gear shaft. When the clutch is in the first state, the first engagement element and the second engagement element are engaged with each other, such that torque can be transmitted from the housing to the planetary gear shaft via the first engagement element and the second engagement element. When the clutch is in the second state, the first engagement element and the second engagement element are disengaged from each other.
[0010] In another alternative embodiment, when the clutch is in the first state, the first engagement element and the second engagement element engage with each other via dog teeth or splines.
[0011] In another alternative embodiment, the first engaging element is splined to the housing, and the housing guides the first engaging element toward and away from the second engaging element via the spline.
[0012] In another alternative embodiment, the clutch further includes an actuator configured to cause the first engagement element to move closer to and further away from the second engagement element.
[0013] In another alternative embodiment, the actuator includes a fork and an actuation ring. The fork includes a pawl that holds the actuation ring, which is connected to the first engagement element. The fork is movable along the input axis to drive the first engagement element toward and away from the second engagement element.
[0014] This disclosure also provides a transmission device comprising: a differential as described in any of the above technical solutions; and a reducer, wherein at least a portion of the output end of the reducer is integrally formed with at least a portion of the housing.
[0015] By adopting the above technical solution and setting bearings to support the planetary gear shaft, the housing and planetary gear shaft will not cause wear problems when rotating relative to each other, thereby avoiding the deterioration of transmission accuracy and damage to parts, and making the differential highly reliable. Attached Figure Description
[0016] Figure 1 is a schematic diagram of a transmission device according to an embodiment of the present disclosure.
[0017] Figure 2 is a cross-sectional view of the transmission device in Figure 1, in which the planetary gears of the reducer are omitted.
[0018] Figure 3 is an exploded view of the transmission device in Figure 1.
[0019] Figure 4 is an exploded view of part of the differential structure of the transmission device in Figure 3.
[0020] Figures 5 and 6 are schematic diagrams of the actuator of the transmission device in Figure 1.
[0021] Figures 7 and 8 are schematic diagrams of the first half-shell of the transmission device in Figure 1.
[0022] Figure 9 is a schematic diagram of the transmission elements of the transmission device in Figure 1.
[0023] Figures 10 and 11 are schematic diagrams of the first engaging element of the transmission device in Figure 1.
[0024] Figures 12 and 13 are schematic diagrams of the second engagement element of the transmission device in Figure 1. Detailed Implementation
[0025] As shown in Figure 1, this embodiment of the present disclosure provides a differential 30.
[0026] As shown in Figures 1 to 4, the differential 30 includes a housing 32, a planetary gear shaft 34, and a clutch 36. The planetary gear shaft 34 is supported on the housing 32 by bearings to allow the housing 32 and the planetary gear shaft 34 to rotate relative to each other about the input axis A of the differential 30. The clutch 36 is connected between the housing 32 and the planetary gear shaft 34 and is configured to switch between a first state and a second state. When the clutch 36 is in the first state, the housing 32 and the planetary gear shaft 34 can rotate together about the input axis A. When the clutch 36 is in the second state, the housing 32 and the planetary gear shaft 34 can rotate relative to each other about the input axis A.
[0027] The technical solution provided in this disclosure, by setting a bearing to support the planetary gear shaft 34, will not cause wear problems when the housing 32 and the planetary gear shaft 34 rotate relative to each other, thereby avoiding the deterioration of transmission accuracy and damage to parts, and making the differential 30 have high reliability.
[0028] In some examples, as shown in Figure 2, the housing 32 is arranged coaxially with the input axis A.
[0029] In some examples, as shown in Figure 2, the central axis of the planetary gear shaft 34 intersects and is orthogonal to the input axis A.
[0030] In some examples, as shown in Figure 4, multiple planetary gear shafts 34 are integrally formed.
[0031] In some examples, the bearing is a needle roller bearing.
[0032] In some examples, as shown in Figures 2 and 4, the differential 30 also includes a planetary gear 80. The planetary gear 80 is rotatably supported on the planetary gear shaft 34.
[0033] In some examples, as shown in Figures 2 and 4, planetary gear 80 is a bevel gear.
[0034] In some examples, as shown in Figures 2 and 4, the planetary gear 80 is coaxially fitted onto the planetary gear shaft 34.
[0035] In some examples, as shown in Figures 2 to 4, the differential 30 includes a radial bearing 38 and a thrust bearing 40, which function as the aforementioned bearings. This allows the bearings to simultaneously bear axial and radial loads, enabling the differential 30 to achieve good transmission accuracy.
[0036] In some examples, as shown in Figure 2, the race of the radial bearing 38 is fixedly connected to the race of the thrust bearing 40.
[0037] In some examples, as shown in Figure 2, the outer ring of the radial bearing 38 is integrally formed with a seat ring of the thrust bearing 40.
[0038] In some examples, as shown in Figures 1 to 3, 7, and 8, the housing 32 includes a first half-shell 42 and a second half-shell 44 fixed to each other. The first half-shell 42 and the second half-shell 44 are arranged opposite each other along the input axis A (i.e., axially opposite each other), and the planetary gear shaft 34 is disposed between the first half-shell 42 and the second half-shell 44. The differential 30 includes a first bearing 46 and a second bearing 48, which are the aforementioned bearings. The first half-shell 42 is connected to the planetary gear shaft 34 via the first bearing 46, and the second half-shell 44 is connected to the planetary gear shaft 34 via the second bearing 48. Here, the first half-shell 42 and the second half-shell 44 may have different shapes, volumes, or dimensions, etc.
[0039] In some examples, as shown in Figure 2, the first bearing 46 and the second bearing 48 are combined bearings including a radial bearing 38 and a thrust bearing 40.
[0040] In some examples, as shown in Figures 2 and 4, the differential 30 further includes a first output gear 84 and a second output gear 86. The first output gear 84 and the second output gear 86 mesh with the planetary gear 80 and are arranged opposite to each other along the input axis A. The first output gear 84 is rotatably supported on the first half-shell 42, and the second output gear 86 is rotatably supported on the second half-shell 44.
[0041] In some examples, as shown in Figure 2, the first output gear 84 and the second output gear 86 are arranged coaxially with the input axis A.
[0042] In some examples, as shown in Figures 2 and 4, the first output gear 84 and the second output gear 86 are bevel gears.
[0043] In some examples, as shown in Figures 2 to 4 and Figures 10 to 13, the clutch 30 includes a first engagement element 50 and a second engagement element 52. The first engagement element 50 is torsionally connected to the housing 32 (i.e., they cannot rotate relative to each other), and the second engagement element 52 is torsionally connected to the planetary gear shaft 34 (i.e., they cannot rotate relative to each other). In a first state, the clutch 30 is engaged with the first engagement element 50 and the second engagement element 52, allowing torque to be transmitted from the housing 32 to the planetary gear shaft 34 via the first engagement element 50 and the second engagement element 52. In a second state, the clutch 30 is disengaged from the first engagement element 50 and the second engagement element 52.
[0044] In some examples, as shown in Figure 2 and Figures 10 to 13, the first engagement element 50 and the second engagement element 52 are annular and arranged coaxially with the input axis A.
[0045] In some examples, as shown in Figure 2, the first half-shell 42 is coaxially fitted onto the first coupling element 50 and the second coupling element 52.
[0046] In some examples, as shown in Figure 2, a first bearing 46 is disposed on one axial side of a second coupling element 52, and a second bearing 48 is disposed on the other axial side of the second coupling element 52. A planetary gear shaft 34 is disposed radially inside the second coupling element 52 and is connected to the first bearing 46 and the second bearing 48 via the second coupling element 52.
[0047] In some examples, as shown in Figure 2, the first bearing 46 and the second bearing 48 are fitted onto the second engagement element 52.
[0048] In some examples, as shown in Figures 2, 12 and 13, the inner periphery of the second engaging element 52 is provided with a mounting groove 74, which receives the end of the planetary gear shaft 34.
[0049] In some examples, as shown in Figures 12 and 13, the mounting groove 74 extends through the second engagement element 52 along its axial direction.
[0050] In some examples, as shown in Figures 2 and 4, the differential 30 further includes a first retaining ring 76 and a second retaining ring 78. The first retaining ring 76 and the second retaining ring 78 are arranged coaxially with the second engaging element 52 and are respectively disposed on opposite axial sides of the second engaging element 52. The first retaining ring 76 is disposed between the first bearing 46 and the second engaging element 52 and covers at least a portion of the axial opening of the mounting groove 74. The second retaining ring 78 is disposed between the second bearing 48 and the second engaging element 52 and covers at least a portion of the axial opening of the mounting groove 74 on the other side.
[0051] In some examples, as shown in Figures 2 and 4, the differential 30 also includes a washer 82. The washer 82 separates the second engagement element 52 and the planetary gear 80.
[0052] In some examples, as shown in Figures 11 and 12, when the clutch 30 is in the first state, the first engagement element 50 and the second engagement element 52 engage with each other via dog teeth 54, 56 or splines. Here, the first engagement element 50 is provided with dog teeth 54, and the second engagement element 52 is provided with dog teeth 56.
[0053] In some examples, as shown in Figures 8, 10, and 11, the first engaging element 50 is splinedly connected to the housing 32, and the housing 32 guides the first engaging element 50 toward and away from the second engaging element 52 via splines 58 and 60. Here, the first engaging element 50 is provided with spline 58, and the housing 32 is provided with spline 60. Thus, compared to the prior art method of guiding the connecting teeth through slots, guiding the first engaging element 50 via splines 58 and 60 is less likely to damage parts, thereby further improving the reliability of the differential 30.
[0054] In some examples, as shown in Figures 8, 10 and 11, spline 58 is an external spline and spline 60 is an internal spline.
[0055] In some examples, as shown in Figures 1 to 3, 5, and 6, the clutch 30 also includes an actuator 62. The actuator 62 is configured to cause the first engagement element 50 to move closer to and further away from the second engagement element 52. This eliminates the need for a return spring in the prior art, simplifying the differential 30's structure. Furthermore, in the prior art, there is a wear problem between the return spring and the connecting teeth and engagement sleeves. By eliminating the return spring, the differential 30 avoids this wear problem. Therefore, the reliability of the differential 30 is further improved.
[0056] In some examples, as shown in FIG2, actuator 62 is configured to cause first engagement element 50 to move along input axis A to cause first engagement element 50 to move closer to and away from second engagement element 52.
[0057] In some examples, as shown in Figures 1, 5, and 6, actuator 62 includes a fork 64 and an actuation ring 66. The fork 64 includes a pawl 68 that grips the actuation ring 66. The actuation ring 66 is connected to a first engagement element 50. The fork 64 is movable along the input axis A to drive the first engagement element 50 toward and away from a second engagement element 52.
[0058] In some examples, as shown in Figure 2, the actuation ring 62 is arranged coaxially with the input axis A.
[0059] In some examples, as shown in Figure 2, the actuation ring 62 is disposed on the outside of the housing 32, for example, the actuation ring 62 may be sleeved on the first half-shell 42.
[0060] In some examples, as shown in Figures 2, 3, and 9, the differential 30 also includes a transmission element 88. The transmission element 88 extends through the housing 32, and the actuating ring 66 is connected to the first engagement element 50 via the transmission element 88.
[0061] In some examples, as shown in Figure 2, the transmission element 88 is fixedly connected to the first engagement element 50.
[0062] In some examples, as shown in Figures 2 and 7 through 9, the transmission element 88 includes a base 90 and an arm 92. The base 90 is annular, and the arm 92 extends from the base 90 toward one axial side of the base 90 (the side opposite to the first engaging element 50). The first half-shell 42 is provided with a window 94. The base 90 is located inside the first half-shell 42, and the arm 92 extends through the window 94 to the outside of the first half-shell 42.
[0063] In some examples, as shown in Figure 2, the base 90 is arranged coaxially with the input axis A.
[0064] In some examples, as shown in Figures 2 and 7 to 9, multiple arms 92 are arranged circumferentially along the base 90, and each arm 92 corresponds to a window 94. In other words, the first half-shell 42 is provided with multiple windows 94, which are arranged circumferentially along the first half-shell 42.
[0065] In some examples, as shown in Figure 2, the actuating ring 66 is fitted and engaged with the arm portion 92, and the first engaging element 50 is engaged with the end face of the base portion 90. In some examples, the arm portion 92 is provided with a engaging groove 102 for engaging the actuating ring 66.
[0066] As shown in Figure 1, this embodiment of the present disclosure also provides a transmission device 70.
[0067] As shown in Figures 2 and 3, the transmission 70 includes the aforementioned differential 30 and reducer 72. At least a portion of the output end of the reducer 72 is integrally formed with at least a portion of the housing 32. This eliminates the need for an input gear in the differential 30, allowing for a more compact arrangement of the differential 30 and reducer 72, thus contributing to the miniaturization of the transmission 70. Furthermore, by eliminating the input gear, the differential 30 and reducer 72 are rigidly connected instead of geared transmission, resulting in better rigidity of the transmission 70 and consequently, better NVH performance.
[0068] In some examples, as shown in Figures 1 to 3, the reducer 72 is a planetary reducer. The reducer 72 includes a planet carrier 96 as the output end, which is integrally formed with the second half-shell 44.
[0069] In some examples, as shown in Figures 1 and 3, the reducer 72 also includes a planetary gear 98. The planetary gear 98 is rotatably supported on the planet carrier 96.
[0070] In some examples, as shown in Figures 1 to 3, the reducer 72 also includes a ring gear 100. The ring gear 100 is coaxially mounted on the planet carrier 96 and meshes with the planet gear 98.
[0071] The terminology used in the embodiments of this disclosure is for illustrative purposes only and is not intended to limit the disclosure. Unless otherwise defined, the technical or scientific terms used in the embodiments of this disclosure should be understood in their ordinary sense by one of ordinary skill in the art to which this disclosure pertains. The terms "first," "second," and similar words used in this specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, "a" or "one," and similar words do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms "comprising," "including," and similar words mean that the elements or objects preceding "comprising" or "including" encompass the elements or objects listed following "comprising" or "including" and their equivalents, but do not exclude other elements or objects. "Upper," "lower," "left," "right," etc., are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly. "A plurality" refers to two or more, unless otherwise expressly defined.
[0072] The above description is merely an optional embodiment of this disclosure and is not intended to limit this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the principles of this disclosure should be included within the protection scope of this disclosure.
[0073] List of reference numerals
[0074] 30 Differential
[0075] 32. Shell
[0076] 34 Planetary Gear Shaft
[0077] 36. Clutch
[0078] 38 radial bearing
[0079] 40 Thrust Bearing
[0080] 42 First Half Shell
[0081] 44 Second half shell
[0082] 46 First Bearing
[0083] 48 Second Bearing
[0084] 50 First Connecting Element
[0085] 52 Second coupling element
[0086] 54 Canines
[0087] 56 canines
[0088] 58 splines
[0089] 60 splines
[0090] 62 Actuators
[0091] 64. Shift fork
[0092] 66 Actuating Ring
[0093] 68 claws
[0094] 70 Transmission device
[0095] 72 Reducer
[0096] 74 mounting slots
[0097] 76 First gear
[0098] 78 Second lap
[0099] 80 Planetary Gears
[0100] 82 Washer
[0101] 84 First output gear
[0102] 86 Second Output Gear
[0103] 88 Transmission Components
[0104] 90 base
[0105] 92 Arm
[0106] 94 windows
[0107] 96 Planetary Carrier
[0108] 98 Planetary Gears
[0109] 100 gear ring
[0110] 102 Card slot
[0111] A input axis
Claims
1. A differential, characterized in that, include: Shell (32); Planetary gear shaft (34), which is supported on the housing (32) by bearings to allow the housing (32) and the planetary gear shaft (34) to rotate relative to each other about the input axis (A) of the differential; as well as A clutch (36) is connected between the housing (32) and the planetary gear shaft (34) and is configured to switch between a first state and a second state, wherein When the clutch (36) is in the first state, the housing (32) and the planetary gear shaft (34) can rotate as a whole around the input axis (A). When the clutch (36) is in the second state, the housing (32) and the planetary gear shaft (34) are able to rotate relative to each other about the input axis (A).
2. The differential according to claim 1, characterized in that, The differential includes a radial bearing (38) and a thrust bearing (40) that serve as the bearings.
3. The differential according to claim 2, characterized in that, The race of the radial bearing (38) is fixedly connected to the race of the thrust bearing (40).
4. The differential according to any one of claims 1 to 3, characterized in that, The housing (32) includes a first half-shell (42) and a second half-shell (44) fixed to each other, the first half-shell (42) and the second half-shell (44) being arranged opposite to each other along the input axis (A), and the planetary gear shaft (34) being disposed between the first half-shell (42) and the second half-shell (44). The differential includes a first bearing (46) and a second bearing (48) as the bearings, the first half-shell (42) being connected to the planetary gear shaft (34) via the first bearing (46), and the second half-shell (44) being connected to the planetary gear shaft (34) via the second bearing (48).
5. The differential according to any one of claims 1 to 3, characterized in that, The clutch (36) includes a first engagement element (50) and a second engagement element (52), the first engagement element (50) being torsionally connected to the housing (32) and the second engagement element (52) being torsionally connected to the planetary gear shaft (34). When the clutch (36) is in the first state, the first engagement element (50) and the second engagement element (52) engage with each other, such that torque can be transmitted from the housing (32) to the planetary gear shaft (34) via the first engagement element (50) and the second engagement element (52). When the clutch (36) is in the second state, the first engagement element (50) and the second engagement element (52) are separated from each other.
6. The differential according to claim 5, characterized in that, When the clutch (36) is in the first state, the first engagement element (50) and the second engagement element (52) engage with each other by canine teeth (54, 56) or splines.
7. The differential according to claim 5, characterized in that, The first engaging element (50) is splinedly connected to the housing (32), and the housing (32) guides the first engaging element (50) toward and away from the second engaging element (52) via splines (58, 60).
8. The differential according to claim 5, characterized in that, The clutch (36) also includes an actuator (62) configured to cause the first engagement element (50) to move closer to and further away from the second engagement element (52).
9. The differential according to claim 8, characterized in that, The actuator (62) includes a fork (64) and an actuation ring (66). The fork (64) includes a claw (68) that holds the actuation ring (66). The actuation ring (66) is connected to the first engagement element (50). The fork (64) is movable along the input axis (A) to drive the first engagement element (50) closer to and further away from the second engagement element (52).
10. A transmission device, characterized in that, include: The differential as described in any one of claims 1 to 9; as well as A speed reducer (72), at least a portion of the output end of the speed reducer (72) is integrally formed with at least a portion of the housing (32).