JPH06101742A - Differential gear device - Google Patents

Abstract

PURPOSE:To obtain a constant differential restricting force independently of the transmission torque by connecting a gear part meshed with a side gear in a part of a pinion gear and a gear part meshed with an another pinion gear through a flexible connection part, keeping a phase difference, and assembling the connection part in a distorted state. CONSTITUTION:As for an assembly of pinion gears 63, a pinion gear 57 consists of gear parts 67 and 69 and a shaft part 71 as connection part, and the proper flexibility is applied by reducing the diameter of the shaft part 71, and a phase difference is generated between the gear parts 67 and 69. When each gear is assembled on a differential gear case 21 and meshed, the shaft 71 is distorted by receiving a resistance from a pinion gear assembly 65, and the shaft part 77 of the pinion gear 59 of the pinion gear assembly 65 is applied with a torsion, and each torsion angle of the shaft ports 71 and 77 is made uniform. Each torsional torque of the gear trains 85 and 87 is offset because of the application in the opposite direction. In such a balance state, the gears are pushed each other in each meshing-out part by the torsional torque, and a frictional resistance is generated, and a differential restricting force is obtained, and kept constant independently of the transmission torque.

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 in 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 the differential case 203 of the differential device 201,
The side gear 205 is a pinion gear (not shown)
And the side gear 207 is engaged with the pinion gear 20.
It is in mesh with 9. These pinion gears are housed in the housing hole 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 each pinion gear to the side gears 205 and 207 and transmitted to each wheel, and when a driving resistance difference occurs between the wheels, the driving force varies between the wheels due to the rotation of each pinion gear. Be dynamically distributed. On the other hand, the differential limiting force can be obtained by the frictional resistance between the outer periphery of each pinion gear and the housing hole 211, the frictional resistance of each gear meshing portion, and the like.

[0003]

However, all of the differential limiting forces described above are proportional to the magnitude of the transmission torque, and a sufficient differential limiting force cannot be obtained in the range where the transmission torque is small. In order to obtain such a differential limiting force, for example, a differential limiting means such as a friction clutch provided with a friction plate and a spring that gives an initial torque to the friction plate is required, which complicates the structure.

Therefore, an object of the present invention is to provide a differential device which can obtain an appropriate differential limiting force irrespective of transmission torque without using a dedicated differential limiting means.

[0005]

A differential device of the present invention comprises a differential case which is rotationally driven by a driving force of an engine, and one and the other pinion gears which are rotatably accommodated in an accommodation hole of the differential case and meshed with each other. A plurality of pinion gear sets and a pair of side gears that mesh with one of the other pinion gears and the other side gears, respectively. Are coupled with a phase difference via a flexible coupling part, and the coupling part is assembled in a state of being twisted by this phase difference.

[0006]

The driving force of the engine is distributed from the differential case to each side gear through the pinion gear set. At this time, due to the frictional resistance between the outer periphery of the pinion gear and the storage hole of the differential case and the meshing portion of each gear, a differential limiting force having a strength corresponding to the transmission torque is generated. In the pinion gears of some pinion gear groups, by giving a phase difference to each meshing part of the side gear and other pinion gears, the pinion gears receive the resistance to torsion of other pinion gear groups in the assembled state and Twist occurs at the connection part of. Torque due to this twist is applied to the meshing portion of each gear to generate frictional resistance, and a constant differential limiting force is obtained regardless of the transmitted torque.

Thus, in addition to the differential limiting force proportional to the transmission torque, a differential limiting force unrelated to the transmission torque can be obtained, and a dedicated differential limiting means having an initial torque is not used, so the structure is simpler. It is small and 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 and the like without reference numerals are not shown.

As shown in FIG. 4, this power system includes an engine 1, a transmission 3, a propeller shaft 5, a rear differential 7 (a differential device of FIG. 1 arranged on the rear wheel side), rear axles 9, 11 and left and right rear wheels. It is composed of wheels 13 and 15, left and right front wheels 17 and 19, and the like. In the rear differential 7, the differential case 21 is rotatably arranged in the differential carrier 23, and the ring gear 25 fixed to the differential case 21 meshes with the 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. In this way, the driving force of the engine 1 is transmitted to the rear differential 7 via the transmission 3 and the propeller shaft 5 to rotationally drive the differential case 21.

As shown in FIG. 1, the differential case 21 has a main body 31.
And a cover 35 fixed to the body 31 with bolts 33, and left and right side gears 37 and 39 are arranged inside. The side gears 37, 39 have bosses 41, 43 respectively for the cover 35 and the shaft support 4 of the body 31.
5, 47 are rotatably supported, and their free ends are supported by shaft supporting portions 49 formed between them. A washer 51 is arranged between the right side gear 39 and the main body 31. The left rear gear 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 also includes side gears 37, 3
On the radially outer side of 9, long storage holes 55 are provided at equal intervals in the circumferential direction.
Each of the storage holes 55 is provided with four short storage holes adjacent to each other in the circumferential direction. A pinion gear 57 and a pinion gear 59 are alternately slidably stored in the long storage hole 55, and a pinion gear 61 is slidably stored in the short storage hole. In this way, two sets of pinion gears 63 including the pinion gears 57 and 61 as one set are formed.
And two sets of pinion gears 65 including one set of the pinion gears 59 and 61.

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

Further, as shown in FIG. 2, a pinion gear set 65 is provided.
In the pinion gear 59, the left and right gear parts 73, 75
And a shaft portion 77 connecting them, and 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.

Oil is sealed in the differential carrier 23, and the oil is contained in the openings 79, 81 of the differential case 21,
It flows in and out through 83 and lubricates each shaft support portion, the meshing portion of each gear, and the like.

The rear differential 7 is thus constructed.

The driving force of the engine 1 for rotating the differential case 21 is from the pinion gear sets 63, 65 to the side gears 3.
7 and 39, and is transmitted to the left and right rear wheels 13 and 15 via the rear axles 9 and 11. When a driving resistance difference occurs between the rear wheels, the engine 1 is rotated by the rotation of the pinion gear sets 63 and 65.
Drive force 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 pinion gear 57, 59, 61 and each housing hole, the frictional resistance of each gear meshing portion due to torque transmission, and the meshing thrust force of the helical gear. Due to the frictional resistance due to this, a differential limiting force that changes in proportion to the transmitted torque is obtained.

Since the pinion gear 57 of the pinion gear set 63 has a phase difference between the gear parts 67 and 69 as described above, when the gears are assembled to the differential case 21 and meshed with each other, the resistance from the pinion gear set 65 is increased. As a result, the shaft portion 71 of the pinion gear 57 is twisted. The twisting torque imparts a twist to the shaft portion 77 of the pinion gear 59 of the pinion gear set 65, and the twist angles of the shaft portions 71 and 77 become uniform.

Thus, the gear train 85 formed by the pinion gear set 63 and the side gears 37, 39, and the gear train 8 formed by the pinion gear set 65 and the side gears 37, 39
Since the twisting torque of 7 is opposite in direction, the gear part 69 tries to rotate the side gear 39 in the direction of arrow 89 and the gear part 75 rotates the side gear 39 in the direction of arrow 91 as shown in FIG. The twisting torque to be caused is canceled between the gear trains 85 and 87. In such a balanced state, the twisting torque causes the gears to be pressed against each other at each meshing portion to generate frictional resistance, and a differential limiting force is obtained. This differential limiting force is constant regardless of the transmitted torque.

In this way, the rear differential 7 can obtain the differential limiting force that changes in proportion to the transmission torque and the constant differential limiting force irrelevant to the transmission torque. Moreover, unlike the conventional example, since a friction clutch having an initial torque is not used,
Its structure is simple, compact and inexpensive.

The rear wheels 1 while the vehicle of 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, due to the differential limiting force due to the torsion torque, the posture stability and the running performance of the vehicle are good in the low output region of the engine such as during low-speed traveling.

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 the assembled state. Therefore, for example, when the tooth pitch is narrow, a pinion gear that does not have a phase difference by itself may be assembled by twisting one tooth width. Further, each gear may be a spur gear.

[0022]

According to the differential device of the present invention, in the pinion gear rotatably housed in the housing hole of the differential case, a phase difference is given between the gear parts, and twisting occurs in the connecting parts of the gear parts when assembled. Because it was configured like
A constant differential limiting force can be obtained by the frictional resistance of each gear meshing portion caused by this twisting torque. Further, since a dedicated friction clutch or the like for obtaining such a differential limiting force is unnecessary, the structure is simple, the size is small, and the cost is low.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment.

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

FIG. 3 is a cross-sectional view of a gear that constitutes this embodiment.

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

FIG. 5 is a cross-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 (connecting part)

Claims (1)

[Claims] 1. A differential case which is rotationally driven by a driving force of an engine, a plurality of pinion gear sets which are rotatably accommodated in an accommodation hole of the differential case and which are engaged with each other, and a pair of pinion gears, and one of these and the other. It has a pinion gear and a pair of side gears that mesh with each other.In some pinion gear pairs, the gear part that meshes with the side gear and the gear part that meshes with other pinion gears have a phase difference via a flexible connecting part. The differential device is characterized in that the connection part is assembled in a state in which the connection part is twisted by the phase difference.