JP2895390B2 - Differential device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a differential gear, and more particularly, to a differential gear comprising a planetary gear device constituted by a helical gear and a friction clutch pressed by a thrust force generated in a sun gear of the planetary gear device. And a differential device having a mechanism.

[0002]

2. Description of the Related Art A helical gear constitutes a planetary gear device,
2. Description of the Related Art There is known a differential device in which a multi-plate clutch is pressed by utilizing a thrust force generated at a meshing portion of a helical gear during torque transmission to exert a differential limiting force (Japanese Patent Laid-Open No. 4-95641). Gazette etc.).

In order to obtain a stable differential limiting force with the differential device having the above-described structure, it is important that the sun gear be sufficiently free to move in the axial direction. The thrust force applied to the clutch becomes unstable, and particularly a transient differential limiting force cannot be obtained, which may adversely affect the vehicle's maneuverability.

On the other hand, in the differential device having the above-described structure, if the clutch plates are excessively worn, they come into metallic contact with each other to generate abnormal noise or seizure. By defining the movable amount of the member in the pressing direction, such inconvenience is prevented (see Japanese Utility Model Laid-Open No. 1-166158).

The axial movement of the differential case to the outside is restricted by the set ring, and the axial movement of the differential case to the inside projects between a part of the axle and the end of the axle support of the differential case. Is regulated by
It is common that the inward axial movement of the differential case is substantially not allowed.

[0006]

In such a conventional structure, as the wear of the clutch plate progresses, the required movement amount of the sun gear for applying a pressing force to the clutch pressing member increases. In some cases, the sun gear may move over the set ring mounted on the axle. In such a state, the clutch pressing force is lost due to the force of the sun gear trying to ride on the set ring, so that sufficient pressing force is not applied to the multi-plate clutch, and the differential limiting force becomes insufficient. In addition, the connection between the sun gear and the axle may be incomplete.

[0007] The present invention has been devised to solve such disadvantages of the prior art, and its main objects are as follows.
An improved differential device that can exhibit a stable differential limiting force with high responsiveness and that does not cause abnormalities in the connection between the sun gear and the axle even when the friction clutch is worn. To provide.

[0008]

SUMMARY OF THE INVENTION According to the present invention, there is provided an internal gear composed of a helical gear integrated with a driven gear and a differential case, wherein the internal gear is coaxial with the differential case. A sun gear composed of a helical gear rotatably provided, a first planetary gear composed of a helical gear meshing with the internal gear, a second planetary gear composed of the first planetary gear and a helical gear meshing with the sun gear, A carrier rotatably supported on the first and second planetary gears and rotatably provided relative to the differential case, and a differential caused by a thrust force generated in the sun gear by the action of the helical gear during torque transmission. Having a friction clutch provided between the carrier and the differential case to exert a limiting force,
A differential device comprising one driven shaft member connected to the sun gear by spline fitting, and the other driven shaft member connected to the carrier by spline fitting. The one driven shaft member is supported by a differential case so as to be able to follow a predetermined range with respect to the movement of the sun gear at times, and the clutch pressing direction movement amount of the carrier is taken into consideration in consideration of the wear allowance of the friction clutch. A differential device characterized by providing a stopper means for defining the above, and setting a margin for moving the one driven shaft member inwardly larger than a margin for moving the carrier in the clutch pressing direction. Achieved.

[0009]

According to such a configuration, the thrust force generated in the sun gear at the time of the differential limitation is not affected by the sliding resistance of the spline fitting portion with the inner end of one of the driven shaft members, and the frictional force is not affected. It is transmitted to the clutch. Therefore, a differential limiting force is generated with high responsiveness. In addition to this, the wear limit of the friction clutch is defined by defining the movement limit of the carrier in the clutch pressing direction, and the movement allowance of the sun gear is secured even when the wear limit is reached, The differential limiting force can be reliably generated until the wear limit is reached.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction of the present invention will be described below in detail with reference to specific embodiments shown in the accompanying drawings.

FIG. 1 shows a differential device constructed according to the present invention. In the differential gear 1, a driven gear 3 meshed with a final drive gear 2 provided on an output shaft of a transmission is formed on an outer periphery, and an internal gear 4 formed of a helical gear concentric with the driven gear 3 has an internal gear. A pair of left and right differential cases 6a and 6b bolted with a ring gear 5 formed around the periphery therebetween, and both differential cases 6a
A pair of left and right axles 9a and 9b (driven shafts) rotatably inserted into central holes 8a and 8b of shaft bosses 7a and 7b protruding outwardly concentrically with the internal gear 4 on the side surface of the central portion of 6b. ), A sun gear 10 composed of a helical gear spline-fitted to the inner end of the left axle 9a, a first planetary gear 11 composed of a helical gear meshing with the internal gear 4 to rotate and revolve, and a first planetary gear A second planetary gear 12 consisting of a helical gear that meshes with the gear 11 and the sun gear 10 and rotates and revolves at the same time; and rotatably supports the first and second planetary gears 11 and 12, respectively, and a right axle 9b. And a carrier 13 fitted with a spline at the shaft end thereof, and a roller bearing 15 fitted respectively to the shaft bosses 7a and 7b of both differential cases.
And is rotatably supported by the transmission housing 16 via the.

On the inner surface of the peripheral wall of the right half 6b of the differential case,
An internal spline 17 is formed, and an external spline 18 is formed on an outer peripheral surface of a fitting portion of the carrier 13 facing the right axle 9b. These internal splines 17
And a plurality of friction plates 1 on the external tooth spline 18.
9a and 19b are mounted alternately on top of each other. These friction plates 19a and 19b are sandwiched between the right side surface of the planetary gear support of the carrier 13 and the stopper plate 20 interposed on the inner surface of the side wall of the right half 6b of the differential case. A multiple disc clutch C is configured.

The spline fitting portion between the sun gear 10 and the left axle 9a is prevented from falling out of the left axle 9a by a set ring 21 attached to the shaft end. The inward movement of the left axle 9a is restricted by the shaft end abutting on the inward flange 22 formed at the end. This allows the sun gear 10 to move axially with the left axle 9a.

Between the inner surface of the side wall of the left half 6a of the differential case and the sun gear 10, between the sun gear 10 and the carrier 13,
Thrust needle bearings 24a to 24c are interposed between the carrier 13 and the inner peripheral flange 23 of the stopper plate 20 provided on the right half 6b of the differential case, respectively. When the carrier 13 is fully pressed in the clutch pressing direction in the initial state where the plurality of friction plates 19a and 19b of the wet multi-plate clutch C are not worn,
A predetermined axial gap G1 is set between the right thrust needle bearing 24c and the inner peripheral flange 23 of the stopper plate 20.

The left axle 9a has a left half 6a of a differential case.
The enlarged diameter step 25 facing the end face of the shaft boss 7a is formed, and a dimension G2 between the enlarged diameter step 25 and the end face of the axis boss 7a is set to be larger than the axial gap G1.

Between the left side plate 13a of the carrier and the inner surface of the side wall of the left half 6a of the differential case, a pair of friction plates 19c and 19d similar to the friction plates 19a and 19b of the wet multi-plate clutch C is provided with a disc spring 26. A predetermined connection preload is applied between the differential case 6 and the carrier 13.

Inside the shaft boss 7b of the right half 6b of the differential case supporting the right axle 9b, there is provided an oil passage 28a communicating with a lubricating oil supply passage 27 provided in the transmission housing 16. The sun gear 10 and the carrier 13 are also provided with oil passages 28b and 28c penetrating in the axial direction. The lubricating oil supplied from an oil pump (not shown) is supplied to the oil passage 2 of the shaft boss 7b.
8a and the two axles 9a via the oil passage 28b of the carrier 13.
9b flows between the opposed end faces, and is diverted to the oil passage 28c side and the carrier oil plate 29 side integrally connected to the carrier 13 by the oil plate 33 fitted to the inner peripheral portion of the sun gear 10, One flows into the thrust needle bearing 24a on the left side, and the other from the notch 30 provided in the carrier oil plate 29 through the mounting portion of the intermediate thrust needle bearing 24b to the meshing portion between the sun gear 10 and the planetary gears 11 and 12. Inflow. In this way,
The flow of the lubricating oil is prevented from being blocked by the thrust needle bearings or the like, and the lubricating oil can sufficiently flow into the end faces of both the thrust needle bearings 24a and 24b and the planetary gears 11 and 12.

In such a planetary gear type differential, the power input to the driven gear 3 is distributed to both axles 9a and 9b via the sun gear 10 and the carrier 13. Here, when there is no rotational speed difference between the right and left wheels, that is, when both axles 9a and 9b are rotating at a constant speed, the rotational speeds of the ring gear 5, the sun gear 10, and the carrier 13 are equal to each other, and each planetary gear 11・ 12 does not rotate.
When a rotational speed difference occurs between the two wheels, each planetary gear 11
12 rotates and revolves to allow a difference in rotational speed between the two wheels. However, in this differential device, since each gear is formed by a helical gear, when a driving force is input, the differential gear is driven through the carrier 13. A force for pressing the friction plates 19a and 19b is generated in the sun gear 10. As a result, a differential limiting force is generated between the carrier 13 and the right half 6b of the differential case by the wet multi-plate clutch C, and the speed difference between the two axles 9a and 9b is limited.

At the time of deceleration such as engine braking, the sun gear 10 moves in the direction to release the wet-type multi-plate clutch C, and releases the pressing force from the left half 6a of the differential case.

In such a differential device that amplifies the differential limiting force mainly only during acceleration, the ability of the sun gear 10 to freely move in the axial direction can provide a stable differential limiting force in response. This is an essential condition for good occurrence. In the present invention, the sun gear 10 is provided with an axial positioning structure at the inner end of the left axle 9a so that the sun gear 10 can move together with the left axle 9a, thereby enabling the sun gear 10 to move in the axial direction. I try to increase the degree of freedom.

On the other hand, as the wear of the plurality of friction plates 19a and 19b of the wet multi-plate clutch C progresses, the amount of movement of the carrier 13 in the clutch pressing direction increases, and the right thrust needle bearing 24c at the time of exerting the operation limiting force. The gap G1 in the axial direction between the shaft and the inner peripheral flange 23 of the stopper plate decreases. Here, the gap G1 becomes zero when the operation limiting force is exerted when the wear limit of the friction plates 19a and 19b is reached. The initial size of the gap G1 is set such that At the same time, the dimension G2 between the enlarged diameter step 25 of the left axle 9a and the end face of the shaft boss 7a is set so that G2> G1 in the initial state. Therefore, even if the gap G1 becomes 0, there is still room for the axial movement allowance of the sun gear 10 and the left axle 9a, and the sun gear 10 and the left axle 9a are caused by wear of the friction plates 19a and 19b. The occurrence of an abnormality in the connecting portion of the first embodiment is prevented.

[0022]

As described above, according to the structure of the present invention, the degree of freedom of the axial movement of the sun gear is increased, so that the thrust force generated in the sun gear at the time of the differential limitation is reduced by one of the driven shaft members ( Without being affected by the sliding resistance of the spline fitting portion with the inner end of the left axle), it is efficiently transmitted to the multi-plate clutch with high responsiveness. In addition to this, the wear limit of the friction plate is defined by defining the movement limit of the carrier in the clutch pressing direction, and when the wear limit is reached, the movement allowance of one driven shaft member is secured. Therefore, the differential limiting force can be reliably generated until the friction plate reaches the wear limit. Therefore, by applying the present invention, a great effect can be obtained in that a differential limiting force having a high transient response is stably generated over a long period of time.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a differential device with a differential limiting mechanism according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 differential gear 2 final drive gear 3 driven gear 4 internal gear 5 ring gear 6 differential case 7 shaft boss 8 center hole 9 axle (driven shaft member) 10 sun gear 11/12 planetary gear 13 carrier 14 planetary gear device 15 roller Bearing 16 Transmission housing 17 Internal spline 18 External spline 19 Friction plate 20 Stopper plate 21 Set ring 22/23 Inward flange 24 Thrust needle bearing 25 Large diameter step 26 Disc spring 27 Lubricating oil supply passage 28 Oil passage 29 Carrier Oil plate 30 Notch 33 Oil plate

Continuation of the front page (72) Inventor Hiroshi Wakui 1-4-1 Chuo, Wako-shi, Saitama Prefecture Honda Technical Research Institute Co., Ltd. (56) References JP-A-61-153041 (JP, A) JP-A-2-1-14021 (JP, A) JP-A 1-166158 (JP, U) JP-A 63-188322 (JP, U) JP 5-18522 (JP, Y2) (58) Fields surveyed (Int. Cl. ⁶⁾ , DB name) F16H 48/20

Claims (1)

(57) [Claims] An internal gear formed of a helical gear integrated with a driven gear and a differential case; a sun gear formed of a helical gear rotatably provided coaxially with the internal gear with respect to the differential case; A first planetary gear comprising a helical gear meshing with the first planetary gear and a second planetary gear comprising a helical gear meshing with the sun gear;
, A carrier rotatably supporting the first and second planetary gears and rotatably provided with respect to the differential case, and a thrust generated in the sun gear by the action of the helical gear during torque transmission. A friction clutch provided between the carrier and the differential case to exert a differential limiting force by force, and one driven shaft member is connected to the sun gear by spline fitting, and the sun gear is connected to the carrier. A differential device in which the other driven shaft member is connected by spline fitting, wherein the one driven shaft member can follow a predetermined range of movement of the sun gear when exerting a differential limiting force. A stopper means is provided for supporting the drive shaft member in the differential case, and for defining a margin of movement of the carrier in the clutch pressing direction in consideration of a wear margin of the friction clutch. And a margin for moving the one driven shaft member inward is set to be larger than a margin for moving the carrier in the clutch pressing direction.