JPH01101232A - Motive power distributor to front and rear wheels - Google Patents

Abstract

PURPOSE:To arrange so as to be economically advantageous by assembling rotatably pinion gears against a pinion gear shaft through an eccentric ring and limiting the change of a prior constituting member to a minimum. CONSTITUTION:A plurality of long holes 31b extending in the axial direction ot side gears 34, 35 are formed at the main body 3la of a differential case 31 at a center differential 30, and respective shaft portions 33a of a pinion gear shaft 33 are assembled movably along the axial direction of side gears 34, 35 to respective long holes 31b. Also, respective pinion gears 32 are assembled to respective shaft portions 33a of the pinion gear shaft 33 through an eccentric ring 37.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a power distribution device for front and rear wheels in a four-wheel drive vehicle.

(Prior art) As a type of power distribution device between the front and rear wheels, there is a differential case that rotates with the output of the transmission, and a pinion gear that is rotatably assembled on the pinion gear shaft that is attached to the case. A plurality of pinion gears are housed therein, and a pair of side gears are rotatably assembled in the case, mesh with each of the pinion gears, and are connected to front wheels and rear wheels so as to transmit torque, respectively. Currently, this is called a center differential.

Incidentally, it is preferable that the distribution of power to the front and rear wheels of a four-wheel drive vehicle is controlled to an appropriate value depending on the driving condition of the vehicle and the coefficient of friction of the road surface. However, at present, the center differential does not have a mechanism for making the distribution of power variable, and the distribution of power is generally constant. This is only recognized in the power transmission device disclosed in Japanese Patent Application Laid-Open No. 62-12421.

In the center differential of such a power transmission device, the teeth of each side gear that mesh with each pinion gear are formed in an arcuate concave shape, and the teeth of each pinion gear are formed in an arcuate shape corresponding to the teeth. The pinion gear is formed in a convex shape, and each pinion gear is assembled between both side gears so as to mesh with the same side gear and rotate in an arc shape along the teeth of the side gear. As a result, each pinion gear is appropriately rotated by external operation, the distance from the axis of each side gear to the meshing portion of each pinion gear changes, and the power distribution to the front and rear wheels changes.

(Problems to be Solved by the Invention) By the way, in such a center differential, each pinion gear and each side gear have a unique shape that is significantly different from the conventional one, and the assembly structure of each pinion gear is also different from the conventional one. It is a different and unique construction. Therefore, when adopting such a center differential, it is necessary to change all or many of the components of the conventional center differential, and the method of assembling each component must also be changed, making it economical. This will be extremely disadvantageous.

Accordingly, an object of the present invention is to provide a center differential of the type described above with a variable power distribution function while minimizing changes to conventional components, thereby making it extremely economically advantageous.

(Means for Solving the Problems) The present invention includes a differential case that rotates with the output of a transmission, and a differential case that is rotatably assembled on a binion gear shaft that is assembled to the case. Front and rear wheels comprising a plurality of housed pinion gears, and a pair of side gears that are rotatably assembled in the case, mesh with each of the pinion gears, and are connected to the front wheel side and the rear wheel side so as to be able to transmit torque, respectively. The power distribution device is a power distribution device in which the pinion gear shaft is assembled to the case so as to be movable by a predetermined amount in the axial direction of the side gear by external operation, and the pinion gear is assembled to the case so that it can move by a predetermined amount in the axial direction of the side gear. It is characterized in that it is rotatably assembled via an eccentric ring.

(Operations and Effects of the Invention) In the power distribution device configured as described above, the power from the transmission is distributed to the front wheels and the rear wheels through the side gear shafts by the operation of the differential case, each pinion gear, the pinion gear shaft, and each side gear. distributed to each. When an attempt is made to move the pinion gear shaft in the axial direction of the side gear by external operation, the differential case, pinion gear shaft and eccentric ring, and the pinion gear and side gear rotate relative to each other about the same axis of the side gear. As a result, the pinion gear shaft also moves in the axial direction of the side gear, and the distance between the axial center of the pinion gear shaft and each of the meshing parts of the pinion gear and each side gear changes, and accordingly, the pinion gear shaft moves toward the front and rear wheels. The power distribution will also change.

By the way, in this power distribution device, in order to assemble the pinion gear shaft into the differential case so as to be movable in the axial direction, the case is provided with a long hole in the axial direction through which the shaft passes, and the pinion gear is attached to the differential case with an eccentric ring. The only difference is that a hole, etc., into which the eccentric ring rotatably fits is provided in the same gear so that it can be assembled through the gear, and a new eccentric ring is used. Therefore, the conventional pinion gear shaft,
The side gears can be used as they are, and the differential case and pinion gear can be used with slight hole machining, and the power distribution device has minimal changes to each conventional component and uses a new eccentric ring. This is extremely advantageous economically.

(Embodiment) The present invention will be described below based on the drawings. FIG. 1 shows a power distribution device according to a first embodiment of the present invention.

As shown in FIG. 2, the power distribution device is used as a center differential of a power transmission device for a four-wheel drive vehicle.

The power transmission device includes a transmission 20 housed in a case 11, a center differential 30, a front differential 40, and a direction changer [50. The transmission 20 is assembled to one side of the engine via a clutch mechanism 12. The transmission 20 includes an input shaft 21, an output shaft 22, and each speed change gear unit, and an output gear 23 on the output shaft 22.
It is equipped with

The center differential 30 includes a differential case 31, a plurality of pinion gears 32, a pinion gear shaft 33, a pair of side gears 34 and 35, and a ring gear 36 on the outward flange of the differential case 31. The ring gear 36 meshes with the output gear 23 of the transmission 20 and transmits the power output from the transmission 20 to the differential case 31.

Front differential 40 and direction changing mechanism 5
0 is disposed coaxially with respect to the center differential 30, and the front differential 40 is housed in a mount case 51 constituting a direction changing mechanism 50.

The front differential 40 includes a differential case 41, a plurality of pinion gears 42, and a pair of side gears 43.4.
4, and the differential case 41 is connected to the left side gear 34 of the center differential 30 via a hollow shaft 45 so as to be able to transmit torque. In such a front differential 40, the side gear shaft 13a, which rotatably passes through the hollow shaft 45 and the left end of the case 11, connects to the left side gear 43 and the differential case 4.
A side gear shaft 13b rotatably passes through the right ends of the case 1 and the case 11 and is connected to the right side gear 44 so as to be able to transmit torque.

The direction changing mechanism 50 includes a ring gear 52 assembled to the outward flange portion of the mount case 51, and also includes a ring gear 52 assembled to the outward flange portion of the mount case 51, and the case 51 and the front differential 40.
A sleeve 53 is provided to disconnect the connection with the differential case 41. The mount case 51 is connected to the hollow shaft portion of the right side gear 35 of the center differential 30 so as to be able to transmit torque, and the ring gear 52 meshes with the binion shaft 54. The pinion shaft 54 is connected to the rear wheel propeller shaft.

In a power transmission device having such a configuration, power from the engine is transmitted to the output gear 2 of the transmission 20.
3 and ring gear 36 to the differential case 31 of the center differential 30, and is distributed from the pinion gear 32 to each side gear 34, 35. The power distributed to the left side gear 34 is transmitted to the front differential 40 and output to the front wheels, and the power distributed to the right side gear 35 is transmitted to the direction changer W.
It is transmitted to the i50 and output to the rear wheels.

As shown in FIG. 1, in the center differential 30, a plurality of elongated holes 31b are formed in the main body 31a of the differential case 31 and extend in the axial direction of the side gears 34.35. As shown in the same figure and FIG. 3, each shaft portion 33a is attached to the side gear 34, 35 so as to be movable along the axial direction. In addition, each pinion gear 32 is connected to a pinion gear shaft 33 as shown in FIGS. 1 and 4.
It is assembled to each shaft portion 33a of , with an eccentric ring 37 interposed therebetween. Each pinion gear 32 has each eccentric ring 37
It is rotatably attached to the pinion gear 3
The distance between the meshing parts for each side gear 34 and 35 of 2 is L, the distance between the axis of the pinion gear shaft 33 and the meshing part of the left side gear 34 is Lf, and the distance from the meshing part of the right side gear 35 is Lr. In this case, the axial center of the pinion gear shaft 33 is offset from the meshing portion of each side gear 34, 35 as shown in the first row and FIG. 4. The pinion gear shaft 33 is a sleeve 3 attached to the outer periphery of the main body 31a of the differential case 31 so as to be slidable in the axial direction.
8a, and is movable along the elongated hole 31b by external operation (for example, by means of hydraulic pressure, vacuum, etc.) via a sleeve yoke 38b that engages with the sleeve 38a.

In the center differential 3o having such a configuration, power from the engine is transmitted to each side gear 34.35 via the differential case 31, pinion gear shaft 33, eccentric ring 37, and pinion gear 32; in this case, each side gear 34.35 ( The power distribution ratios to the front wheels and rear wheels are L f i L and L r /L. Therefore, when an attempt is made to move the pinion gear shaft 33 in the axial direction of the side gear 34.35 by external operation, the differential case 31, the pinion gear shaft 33, the eccentric ring 37, the pinion gear 32, and the side gear 34.35
The gears 34 and 35 rotate relative to each other around the axes of the gears 34 and 35. As a result, the pinion gear shaft 33 is connected to the side gear 3.
4. Also moves in the axial direction of 35, pinion gear shaft 3
Distance L between the axis of 3 and the meshing part of each side gear 34.35
f and Lr change. Therefore, the power distribution ratio Lf/L to the front wheels and the rear wheels.

Lr/L changes according to the movement of the pinion gear shaft 33 in the axial direction, and if the amount of movement is appropriately controlled according to the vehicle running condition and the friction coefficient of the road surface, the power distribution between the front and rear wheels can be appropriately controlled. The value can be controlled.

By the way, in the center differential 30, each conventional component is used to provide a long hole 31b in the differential case 31 and a hole into which the eccentric ring 37 fits in the pinion gear 32, and also newly adopts the eccentric ring 37. Therefore, it is extremely advantageous economically since it does not require any major changes to the conventional center differential 30.

FIG. 5 shows a center differential 30A which is a power distribution device according to a second embodiment of the present invention. The center differential 30A has an eccentric ring 37
It is greatly different from the center differential 30 of the first embodiment in that a ring whose outer periphery forms part of a spherical surface (hereinafter referred to as spherical shape) is adopted as A, and along with the adoption of such an eccentric ring 37A. The outer side of the inner hole in each pinion gear 32A is formed into a spherical shape corresponding to the ring 37A, and the ring 3'? The difference is that A is elastically supported at a stepped portion of a cylindrical portion 33t) of a pinion gear shaft 33A via a compression spring 38c.

Therefore, in the center differential 3°A that is bent, the side gear 34 of the pinion gear shaft 33A
+ When the pinion gear shaft 33A and each eccentric ring 37A rotate relative to each pinion gear 32A around the axial center when moving in the axial direction of 35, each eccentric ring 37A is freely rotatable with respect to each pinion gear 32A. Therefore, the inclinations of the axes of the ring 37A and the pinion gear shaft 33A always match, and the restriction on the movement of the pinion gear shaft 33A in the axial direction caused by the rotation restriction of each eccentric ring 37A by each pinion gear 32A is eliminated. .

4. Brief explanation of Fi1 side Figure 1 is a sectional view of a center differential which is the first embodiment of the power distribution device according to the present invention, and Figure 2 is a schematic diagram of a power transmission device employing the same differential. Configuration diagram, Figure 3 is a sectional view along the arrow ■-■ line in Figure 1, Figure 4 is a cross-sectional view along the arrow ■-■ line in Figure 1.
FIG. 5 is a cross-sectional view of a center differential which is a second embodiment of the power distribution device according to the present invention.

Explanation of symbols 20...Transmission, 3o, 30A.1. Center differential, 31... Differential case, 32
．． 32A... Pinion gear, 33.33 A... Pinion gear shaft, 34.35... Side gear, 3
6... Ring gear, 37.37 A... Eccentric ring, 38 a... Sleeve, 38 c... Compression spring, 4o... Front differential, 5o...
...Direction change mechanism.

Applicant: Toyota Motor Corporation.

Agent: Patent attorney Teru Hase (1 other person)

Claims (1)

[Claims] a differential case that rotates with the output of the transmission; a plurality of pinion gears that are rotatably assembled on a pinion gear shaft that is assembled to the case and housed within the case;
A pair of side gears are rotatably assembled in the case, mesh with each of the pinion gears, and are connected to the front wheel side and the rear wheel side respectively so as to be able to transmit torque, and the pinion gear shaft is externally connected to the case. Power to the front and rear wheels, characterized in that the side gear is assembled to be movable by a predetermined amount in the axial direction of the side gear by operation, and the pinion gear is rotatably assembled to the pinion gear shaft via an eccentric ring. distribution device.