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EP-4741683-A1 - VEHICLE DIFFERENTIAL DEVICE AND VEHICLE

EP4741683A1EP 4741683 A1EP4741683 A1EP 4741683A1EP-4741683-A1

Abstract

A vehicle differential device capable of adjusting a differential limiting force with a simple configuration is provided. It includes: a differential case 40 rotated by receiving driving force of a rear drive motor 21; a pair of side gears 60 coaxial with a rotation axis O of the differential case; a pinion gear 52 meshing with both of the pair of side gears; and a differential limiting mechanism 70 that generates differential limiting force F for limiting differential motion of rear wheels 3 of a vehicle 1. The differential limiting mechanism has a plurality of friction plates 80 pressed by each side gear in an axial direction X.

Inventors

  • OKA, NOBUYUKI
  • OHKAWA, YUZO

Assignees

  • MAZDA MOTOR CORPORATION

Dates

Publication Date
20260513
Application Date
20251107

Claims (13)

  1. A vehicle differential device to be mounted on a vehicle (1), the vehicle differential device comprising: a differential case (40) that is rotated by receiving a driving force of a drive source (21); a pair of side gears (60) that are disposed in the differential case (40) and coaxial with a rotation axis (O)of the differential case (40); a pinion gear (52) that is disposed in the differential case (40) and meshes with both of the pair of side gears (60); and a differential limiting mechanism (70) that generates a differential limiting force (F) for limiting differential motion of wheels (2,3) of the vehicle (1), wherein the differential limiting mechanism (70) has a plurality of friction plates (80) that are pressed by each of the side gears (60) in an axial direction (X) in which the rotation axis (O) extends, some of the plurality of friction plates (80) are a plurality of case-side friction plates (81) provided in the differential case (40), others of the plurality of friction plates (80) are a plurality of gear-side friction plates (82) provided in the side gear (60), the case-side friction plates (81) and the gear-side friction plates (82) are arranged side by side in the axial direction (X) and slide relative to each other to generate the differential limiting force (F), characterized in that in the differential limiting mechanism (70), a friction-plates-adjacent portion (90) is formed in which among at least either type of the case-side friction plates (81) and the gear-side friction plates (82), two or more of the friction plates of the same type are adjacent to each other.
  2. The vehicle differential device according to claim 1, wherein the friction-plates-adjacent portion (90) includes a case-side friction-plates-adjacent portion (91) in which two or more of the case-side friction plates (81) are adjacent to each other.
  3. The vehicle differential device according to claim 1 or 2, wherein the friction-plates-adjacent portion (90) includes a gear-side friction-plates-adjacent portion (92) in which two or more of the gear-side friction plates (82) are adjacent to each other.
  4. The vehicle differential device according to any one of claims 1 to 3, wherein except for the friction-plates-adjacent portion (90), the case-side friction plates (81) and the gear-side friction plates are alternately arranged in the axial direction (X).
  5. The vehicle differential device according to any one of claims 1 to 4, wherein the differential limiting mechanism (70) includes a first differential limiting mechanism (71) provided on one side of the pinion gear (52) in the axial direction (X), and a second differential limiting mechanism (72) provided on another side of the pinion gear (52) in the axial direction (X), and the friction-plates-adjacent portion(90) is formed in both of the first differential limiting mechanism (71) and the second differential limiting mechanism (72).
  6. The vehicle differential device according to any one of claims 1 to 5, wherein the differential limiting mechanism (70) includes a first differential limiting mechanism (71) provided on one side of the pinion gear (52) in the axial direction(X), and a second differential limiting mechanism (72) provided on another side of the pinion gear (52) in the axial direction (X), and the number of sliding surfaces (83) between the case-side friction plates (81) and the gear-side friction plates (82) in the first differential limiting mechanism (71) and the number of sliding surfaces (83) between the case-side friction plates (81) and the gear-side friction plates (82) in the second differential limiting mechanism (72) are different from each other.
  7. The vehicle differential device according to any one of claims 1 to 6, wherein each of the side gears (60) has a gear main body (61) that meshes with the pinion gear (52), and a pressing body (62) that holds, together with the gear main body (61), the plurality of friction plates (80) therebetween, the gear main body (61) and the pressing body (62) are engaged with each other, and the gear-side friction plates (82) are mounted to the pressing body (62).
  8. The vehicle differential device according to claim 7, wherein among the plurality of friction plates (80) one specific friction plate has a greater thickness than the other friction plates (80) and is in contact with the gear main body (61) and with a disc spring (62e).
  9. The vehicle differential device according to claim 8, wherein the disc spring (62e) is disposed between the pressing body (62) and the gear main body (61) of the side gear (60) and presses the friction plates (80) in the axial direction (X).
  10. A vehicle comprising the vehicle differential device according to any one claims 1 to 9.
  11. The vehicle of claim 10, the vehicle comprising: a front drive unit (10) that rotates front wheels (2); and a rear drive unit (20) that rotates rear wheels (3) independently of the front drive unit (10), and has the vehicle differential device.
  12. The vehicle (1) according to claim 10, wherein the vehicle (1) is of a rear-wheel drive type or an all-wheel drive type, and the vehicle differential device is used for differential control of rear wheels (3) of the vehicle (1).
  13. The vehicle (1) according to any one of claims 10 to 12, wherein the vehicle (1) is an electric vehicle.

Description

[Technical Field] The present disclosure relates to a vehicle differential device and a vehicle. [Background Art] Vehicle differential devices having differential limiting mechanisms are known. For example, a vehicle differential device disclosed in Patent Literature 1 includes: a differential case that is driven to rotate by a driving force of an engine; a differential gear mechanism that distributes the rotation of the differential case to wheel sides through a pair of side gears; a cone clutch that is formed between the differential case and a clutch member, is fastened by receiving a meshing reaction force of the side gear, and limits differential motion of the differential gear mechanism; and a cam mechanism that is provided between the clutch member and the side gear and presses the cone clutch by receiving the driving force. [Citation List] [Patent Literature] [Patent Literature 1] Japanese Unexamined Patent Publication No. H09-49560 [Summary of Invention] [Problems to be Solved by the Invention] When a differential limiting force of the differential limiting mechanism is large, the stability of a vehicle while traveling in a straight line is improved, but it is difficult for the vehicle to turn. When the differential limiting force of the differential limiting mechanism is small, it is easy for the vehicle to turn, but the stability of the vehicle while traveling in a straight line lowers. In order to balance the stability of the vehicle while traveling in a straight line and the ease of turning the vehicle, it is desired to adjust the differential limiting force of the differential limiting mechanism in the vehicle differential device. The object of the present disclosure is to provide a vehicle differential device capable of adjusting the differential limiting force with a simple configuration. [Means for Solving the Problems] A vehicle differential device according to the present embodiment is to be mounted on a vehicle, and includes: a differential case that is rotated by receiving a driving force of a drive source; a pair of side gears that are disposed in the differential case and coaxial with a rotation axis of the differential case; a pinion gear that is disposed in the differential case and meshes with both of the pair of side gears; and a differential limiting mechanism that generates a differential limiting force for limiting differential motion of wheels of the vehicle, wherein the differential limiting mechanism has a plurality of friction plates that are pressed by each of the side gears in an axial direction in which the rotation axis extends, some of the plurality of friction plates are a plurality of case-side friction plates provided in the differential case, others of the plurality of friction plates are a plurality of gear-side friction plates provided in the side gear, the case-side friction plates and the gear-side friction plates are arranged side by side in the axial direction and slide relative to each other to generate the differential limiting force, and in the differential limiting mechanism, a friction-plates-adjacent portion is formed in which among at least either type of the case-side friction plates and the gear-side friction plates, two or more of the friction plates of same type are adjacent to each other. When the friction-plates-adjacent portion is increased in number or when the number of the friction plates of same type that constitute the friction-plates-adjacent portion is increased, the number of sliding surfaces between the case-side friction plates and the gear-side friction plates is decreased, and consequently the differential limiting force becomes smaller. When the friction-plates-adjacent portion is decreased in number or when the number of the friction plates of same type that constitute the friction-plates-adjacent portion is decreased, the number of sliding surfaces between the case-side friction plates and the gear-side friction plates is increased, and consequently the differential limiting force becomes larger. Thus, by adjusting the number of friction-plates-adjacent portions or the number of the friction plates of same type that constitute the friction-plates-adjacent portion, the differential limiting force for limiting the differential motion of the wheels of the vehicle can be adjusted. As described above, it is possible to provide a vehicle differential device capable of adjusting the differential limiting force with a simple configuration. In one embodiment, the friction-plates-adjacent portion includes a case-side friction-plates-adjacent portion in which two or more of the case-side friction plates are adjacent to each other. The case-side friction-plates-adjacent portion as the friction-plates-adjacent portion can be easily formed by arranging a plurality of case-side friction plates adjacent to each other. In one embodiment, the friction-plates-adjacent portion includes a gear-side friction-plates-adjacent portion in which two or more