JP3197362B2 - 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 device used for a vehicle.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication No. 59-97346 discloses a differential device 201 as shown in FIG.
A pair of side gears 205 and 207 are housed in a differential case 203 of the differential device 201.
Side gear 205 is a pinion gear (not shown)
And the side gear 207 is connected to the pinion gear 20.
9 is engaged. These pinion gears are housed in housing holes 211 of the differential case 203 and mesh with each other. The driving force of the engine input from the differential case 203 is distributed from the respective pinion gears to the side gears 205 and 207 and transmitted to the respective wheels. When a difference in driving resistance occurs between the wheels, the driving force differs between the respective wheels due to the rotation of the respective pinion gears. Dynamic distribution. On the other hand, a differential limiting force is obtained by the frictional resistance between the outer periphery of each pinion gear and the housing hole 211 and the frictional resistance of each gear meshing portion.

[0003]

However, the above-mentioned differential limiting force is proportional to the magnitude of the transmission torque, and a sufficient differential limiting force cannot be obtained in a range where the transmission torque is small. To obtain such a differential limiting force, for example, a differential limiting means such as a friction clutch having a friction plate and a spring for applying initial torque to the friction plate is required, and the structure becomes complicated.

Accordingly, an object of the present invention is to provide a differential device capable of obtaining an appropriate differential limiting force irrespective of a transmission torque without using dedicated differential limiting means.

[0005]

SUMMARY OF THE INVENTION A differential device according to the present invention comprises a differential case rotatably driven by the driving force of an engine, and one and the other pinion gears rotatably housed in housing holes of the differential case and meshing with each other. A plurality of pinion gear sets, a pair of side gears meshing with one and the other pinion gears, and a gear portion meshing with a side gear and a gear portion meshing with another pinion gear in the pinion gears of some pinion gear sets; Are connected with a phase difference via a flexible connecting portion, and the connecting portion is assembled in a state where the connecting portion is twisted by the phase difference.

[0006]

The driving force of the engine is distributed to each side gear from the differential case via a pinion gear set. At this time, the frictional resistance between the outer periphery of the pinion gear and the housing hole of the differential case and the meshing portion of each gear generates a differential limiting force having a strength corresponding to the transmission torque. In the pinion gears of some pinion gear sets, a phase difference is given to each meshing portion between the side gear and the other pinion gears. Is twisted at the connecting portion of the. The torque due to this torsion is applied to the meshing portions of the gears to generate frictional resistance, and a constant differential limiting force is obtained irrespective of the transmission torque.

In this way, in addition to the differential limiting force proportional to the transmission torque, a differential limiting force independent of the transmission torque can be obtained, and the exclusive differential limiting means having the initial torque is not used. Small, inexpensive.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment will be described with reference to FIGS. FIG. 1 shows this embodiment, and FIG. 4 shows a power system of a vehicle using this embodiment. Hereinafter, the left and right directions are the left and right directions in this vehicle and FIG. 1, and members without reference numerals are not shown.

As shown in FIG. 4, the power system includes an engine 1, a transmission 3, a propeller shaft 5, a rear differential 7 (differential device of FIG. 1 disposed on the rear wheel side), rear axles 9, 11, right and left rears. The wheels 13 and 15 and the left and right front wheels 17 and 19 are provided. In the rear differential 7, the differential case 21 is rotatably disposed in a differential carrier 23, and a ring gear 25 fixed to the differential case 21 meshes with a drive pinion gear 27. The drive pinion gear 27 is formed integrally with a drive pinion shaft 29 connected to the propeller shaft 5 side. Thus, the driving force of the engine 1 is transmitted to the rear differential 7 via the transmission 3 and the propeller shaft 5 to drive the differential case 21 to rotate.

[0010] As shown in FIG.
And a cover 35 fixed to the main body 31 with bolts 33, and left and right side gears 37 and 39 are disposed inside. Each of the side gears 37 and 39 includes a cover 35 and a shaft support 4 of the main body 31, respectively.
5, 47 are rotatably supported, and each free end is supported by a shaft support 49 formed therebetween. A washer 51 is arranged between the right side gear 39 and the main body 31. The left rear axle 9 is spline-connected to the left side gear 37, and the right rear axle 11 is spline-connected to the right side gear 39, and left and right positioning is performed by retaining rings 53, 53, respectively.

The main body 31 has side gears 37 and 3 respectively.
9, a long storage hole 55 is provided at regular intervals in the circumferential direction.
A plurality of short storage holes are provided adjacent to each storage hole 55 in the circumferential direction. A pinion gear 57 and a pinion gear 59 are alternately slidably and rotatably stored in the long storage hole 55, and a pinion gear 61 is slidably and rotatably stored in the short storage hole. In this way, two pinion gear sets 63 each including the pinion gears 57 and 61 as one set.
, And two pinion gear sets 65 including the pinion gears 59 and 61 as one set.

As shown in FIG. 1, in the pinion gear set 63, the pinion gear 57 is composed of left and right gear portions 67 and 69 and a small-diameter shaft portion 71 (connecting portion) connecting these gear portions. By doing so, interference with the left side gear 37 is avoided and appropriate flexibility is given. The gear portion 67 meshes with the left end side of the pinion gear 61, and the gear portion 69 meshes with the right side gear 39.
The right end of the pinion gear 61 meshes with the left side gear 37. A phase difference is provided between the gear portions 67 and 69.

Further, as shown in FIG.
, The pinion gear 59 includes left and right gear portions 73 and 75.
And a shaft portion 77 for connecting these components. The shaft portion 77 has a small diameter so as not to interfere with the left side gear 37. The gear portion 73 meshes with the left end side of the pinion gear 61, and the gear portion 75 meshes with the right side gear 39. The right end of the pinion gear 61 meshes with the left side gear 37. As shown in FIG. 2, each gear is a helical gear.

An oil is sealed in the differential carrier 23, and the oil is supplied to the openings 79, 81,
The lubricating oil flows into and out of the lubricating member 83, and lubricates each shaft supporting portion and a meshing portion of each gear.

Thus, the rear differential 7 is formed.

The driving force of the engine 1 for rotating the differential case 21 is transmitted from the pinion gear sets 63 and 65 to the side gears 3.
7 and 39 and transmitted to the right and left rear wheels 13 and 15 via the rear axles 9 and 11. When a driving resistance difference occurs between the rear wheels, the rotation of the pinion gear sets 63 and 65 causes the engine 1 to rotate.
Is differentially distributed to the left and right sides. At this time, each gear is pressed against the differential case 21 by the sliding resistance between the outer periphery of each of the pinion gears 57, 59, 61 and each of the storage holes, the frictional resistance of each gear meshing portion due to torque transmission, and the meshing thrust force of the helical gear. As a result, a differential limiting force that changes in proportion to the transmission torque is obtained.

Since the pinion gear 57 of the pinion gear set 63 is provided with a phase difference between the gear portions 67 and 69 as described above, when the gears are assembled and engaged with the differential case 21, the resistance from the pinion gear set 65 is reduced. Accordingly, the shaft portion 71 of the pinion gear 57 is twisted. The torsion is applied to the shaft portion 77 of the pinion gear 59 of the pinion gear set 65 by this torsion torque, and the torsion angles of the shaft portions 71 and 77 become uniform.

As described above, the gear train 85 composed of the pinion gear set 63 and the side gears 37 and 39, and the gear train 8 composed of the pinion gear set 65 and the side gears 37 and 39.
7, the torsion torque causes the gear 69 to rotate the side gear 39 in the direction of arrow 89 and the gear 75 rotates the side gear 39 in the direction of arrow 91, as shown in FIG. The torsional torque to be made is canceled between the gear trains 85 and 87. In such a balanced state, the gears are pressed against each other by the torsional torque at the respective meshing portions to generate frictional resistance, and a differential limiting force is obtained. This differential limiting force is constant regardless of the transmission torque.

Thus, the rear differential 7 can obtain a differential limiting force that changes in proportion to the transmission torque and a constant differential limiting force that is independent of the transmission torque. Also, unlike the conventional example, since a friction clutch with initial torque is not used,
It is simple, small, and inexpensive.

When the vehicle shown in FIG.
When one of the wheels 3 and 15 idles, the driving force is sent to the other wheel by the differential limiting force of the rear differential 7, and the running performance is kept high. In particular, the vehicle has good posture stability and running performance in the low output range of the engine, such as during low-speed running, due to the differential limiting force due to the torsional torque.

In the present invention, the phase difference of the pinion gear includes not only the phase difference before assembling but also the phase difference in an assembled state. Therefore, for example, when the pitch of the teeth is narrow, a pinion gear having no phase difference by itself may be assembled by applying a twist of one tooth width. Further, each gear may be constituted by a spur gear.

[0022]

According to the differential device of the present invention, a phase difference is given between the respective gear portions in the pinion gear rotatably housed in the housing hole of the differential case, and a twist is generated at the connecting portion of the respective gear portions in an assembled state. Because it was configured as
A constant differential limiting force is obtained by the frictional resistance of each gear meshing portion caused by the torsional torque. Further, since a dedicated friction clutch or the like for obtaining such a differential limiting force is not required, the structure is simple, small, and inexpensive.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of one embodiment.

FIG. 2 is a perspective view showing a gear train of the embodiment.

FIG. 3 is a cross-sectional view of a gear constituting the embodiment.

FIG. 4 is a skeleton mechanism diagram showing a power system of a vehicle using the embodiment of FIG. 1;

FIG. 5 is a sectional view of a conventional example.

[Explanation of symbols]

 7 Rear differential (differential device) 21 Differential case 37, 39 Side gear 55 Storage hole 57, 59, 61 Pinion gear 63, 65 Pinion gear set 67, 69 Gear part 71 Shaft part (connection part)

Claims (1)

(57) [Claims] 1. A differential case rotatably driven by the driving force of an engine, a plurality of pinion gear sets each including one and the other pinion gears rotatably housed in a housing hole of the differential case and meshing with each other; A pinion gear and a pair of side gears meshing with each other are provided. In a pinion gear of a part of the pinion gear set, a gear portion meshing with the side gear and a gear portion meshing with another pinion gear have a phase difference through a flexible connecting portion. The differential device is connected in a state where the connecting portion is twisted by the phase difference.