JP2891395B2 - 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 drive system of a vehicle.

[0002]

2. Description of the Related Art As a conventional differential device,
For example, there is one shown in FIG. 5 described in JP-A-3-37455.

[0003] This is a case 101 for receiving a rotation input,
A pair of side gears 103 and 105 arranged coaxially in the case 101 coaxially with the rotation axis of the case 101 and a pair of mutually intersecting cylindrical openings 107 and 109 formed in the case 101 are provided. And pinion gears 111 and 113 rotatably fitted in the circle. Each pair of pinions 111 and 113 mesh with each other, and one pinion gear 111 of each pair is connected to one side gear 103.
The other pinion gear 113 of each pair meshes with the other side gear 105, and connects the one side gear 103 to one drive shaft and connects the other side gear 105 to the other drive shaft.

[0004]

However, in such a conventional device, a pair of pinion gears 11 are provided.
One of the openings 107 is formed from one side of the case 101 to a substantially central portion, and the other is formed from the other side of the case 101 to a substantially central portion. In this central part, both openings 107, 109
Cross each other, and at this portion, the pinion gears 111, 1
Since the gears 13 are engaged with each other, there is a problem that the size of the apparatus is increased and processing and assemblability are deteriorated.

Accordingly, an object of the present invention is to provide a differential device which can be reduced in size and weight and can be improved in processing and assembling properties.

[0006]

In order to solve the above-mentioned problems, the invention according to claim 1 comprises a case for receiving a rotation input, and a pair of rotatably disposed in the case coaxially with the rotation axis of the case. A side gear; and a pinion gear rotatably fitted in a pair of intersecting receiving holes formed in the case in parallel with a rotation axis of the case in a tooth circle. Along with
In a differential device in which one pinion gear meshes with one side gear and the other pinion gear meshes with the other side gear, the one side gear is connected to one drive shaft, and the other side gear is connected to the other drive shaft. A case main body having one end opened to the case, and a case cover covering an open portion of the case main body, wherein positioning of one end of each of the pair of pinion gears is performed by positioning a concave end wall of a housing hole formed in the case cover. And the mutual meshing position of each pair of pinion gears is arranged on one end side of the case.

[0007]

Since the positioning of one end of each pair of pinion gears is performed by the concave end wall of the accommodation hole formed in the case cover, the surface accuracy of the wall can be improved by easy processing, and the pinion gear set can be improved. Mounting is also easy, and positioning accuracy can be improved.

Further, since the mutual meshing position of each pair of pinion gears is arranged at one end of the case, the device can be reduced in size and weight.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view taken along line AA of FIG. 2 of a differential device according to one embodiment of the present invention, and FIG. 2 is a side view and a view seen from the inside of a case cover. 3 is a sectional view taken along line AA of FIG. The left and right directions are the left and right directions in FIG.
Members and the like without reference numerals are not shown.

The differential device 1 of this embodiment is
For example, the present invention is applied to a final reduction gear of a vehicle. In a differential case (case) 3, left and right boss portions 5, 7 are rotatably supported by a differential carrier via bearings. A ring gear is fixed to the flange 9 of the differential case 3 by bolts or the like. This ring gear meshes with a drive pinion of a propeller shaft, and the differential case 3 is driven to rotate by the driving force of the engine via the transmission and the propeller shaft.

The differential case 3 has a cylindrical case body 11.
And a case cover 13 fastened to the left end thereof by bolts or the like.

Inside the differential case 3, left and right side gears 15 and 17 are arranged coaxially with the rotation axis of the differential case 3.

The left side gear 15 is rotatably supported via a guide boss 23 in a support hole 21 formed in a boss 19 of the case cover 13, and has teeth in side gear receiving holes 25 formed in the case body 11. It is fitted rotatably in the addendum circle. The right side gear 17 is rotatably supported by a support hole 27 formed in the case main body 11 through a guide boss 29, and has a tooth portion formed in the side gear housing hole 2.
5 is rotatably fitted in the addendum circle. Further, the left and right side gears 15 and 17 are provided at substantially the center of the differential case 3 with guide bosses 31 formed on the left side gear 15 and support holes 33 formed on the right side gear 17.
And are rotatably engaged with each other.

The drive shaft of the left wheel is spline-connected to the left side gear 15, and the drive shaft of the right wheel is spline-connected to the right side gear 17.

Inside the differential case 3, four pairs of first pinion gears 35 and second pinion gears 37 meshing with each other between the side gears 15 and 17 are arranged at 90 ° intervals. Since these four pairs of first and second pinion gears 35 and 37 are arranged in the differential case 3 with the same configuration, the arrangement of the pair of first and second pinion gears 35 and 37 will be described, and the other parts will be omitted.

The first pinion gear 35 has a first gear portion 39 and a second gear portion 41. The first pinion gear 35 has a cylindrical pinion gear receiving hole 43 formed along the side gear receiving hole 25 of the differential case 3 at its tip circle. It is fitted rotatably. Further, the second pinion gear 37 has a gear portion as a whole, and is rotatably fitted in a cylindrical pinion gear receiving hole 45 formed adjacent to the pinion gear receiving hole 43 at a tip circle thereof. Left and right side gears 15, 1
7 and the case body 11, the case cover 13, and between the left and right side gears 15 and 17, washers 51, 53,
55 are arranged.

The axes of the pinion gear receiving holes 43 and 45 are parallel to the rotation axes of the side gears 15 and 17.

The pinion gear receiving hole 43 is
The housing cover 43 includes a housing hole 43a formed on one side and opening on the left side, and a housing hole 43b formed on the case cover 13 side coaxially communicating with the housing hole 43a.
It has a length from the concave end wall 43c on the side to the wall 43d at the right end of the tooth portion of the right side gear 17 on the case body 11 side. The pinion gear housing hole 45 includes a housing hole 45a formed in the case main body and opening on the left side, and a housing hole 45b formed on the case cover 13 side coaxially communicating with the housing hole 45a. 13 to the left side gear 1 of the case body 11 from the concave end wall 45c on the 13th side.
5 has a length up to the wall 45d at the right end of the tooth portion.

In the first pinion gear 35, the first gear portion 39 is fitted into the housing hole 43a on the case body 11 side, and the second gear portion 41 is fitted into the housing hole 43b on the case cover 13 side. The left end is positioned by the concave end wall 43c on the case cover 13 side, and the right end is positioned by the wall 43d on the case body 11 side. The second pinion gear 37 is fitted in the housing hole 45, the left end is positioned by the concave end wall 45c on the case cover 13 side, and the right end is positioned by the wall 45d on the case body 11 side.

Case body 11 of pinion gear housing hole 43
The side receiving hole 43a intersects the side gear receiving hole 25 in the axial direction, and the first gear portion 39 of the first pinion gear 35 meshes with the right side gear 17 in this area. Also,
The accommodation hole 4 on the case body 11 side of the pinion gear accommodation hole 45
5a crosses the side gear housing hole 25 in the axial direction,
In this area, the second pinion 37 meshes with the left side gear 15. Furthermore, the pinion gear receiving hole 43 and the pinion gear receiving hole 45
The second hole 41b of the first pinion gear 35 and the second pinion gear 37 mesh with each other in this area.

The left and right side gears 15 and 17, the first gear portion 39 and the second gear portion 41 of the first pinion gear 35,
Each of the pinion gears 37 is formed of a helical gear, and factors such as a module, a pressure angle, and a twist angle are equal to each other.

The degree of fitting of the pinion gear receiving holes 43, 45 in the addendum circles of the first and second pinion gears 35, 37 is set densely for the purpose of generating friction torque. As the material of the fitting portion, a material having high wear resistance,
For example, a surface-hardened steel material or the like is preferably used.

The first and second pinion gears 35, 37
The friction torque can also be increased by increasing the surface roughness of the outer peripheral surface of the tooth tip and the inner peripheral surfaces of the pinion gear housing holes 43 and 45.

The case cover 13 has a receiving hole 43b.
Hole 4 as an oil hole for communicating the oil hole with the housing hole 45b.
7 are formed.

Next, the operation of the above embodiment will be described.

The rotational force input from the engine to the differential case 3 is transmitted from the differential case 3 to the first and second pinion gears 3.
The power is transmitted to the left and right side gears 15 and 17 via the gears 5 and 37, and is transmitted from the side gears 15 and 17 to the left and right drive shafts.

In the torque transmission performed in this manner, when the left and right drive shafts rotate at a high speed differential rotation, for example, when the left side gear 15 tries to rotate faster than the differential case 3,
First pinion gear 35 meshing with side gear 15
And the second pinion gear 37 meshing with the first pinion gear 35 tends to move in the same direction. But,
Since the movement of the pinion receiving holes 43, 45 of the differential case 3 in the same direction is lower than the speed at which the first and second pinions 35, 37 move, the first pinion gear 35 is in friction with the inner peripheral surface of the pinion receiving hole 43. While rotating while the second
The pinion gear 37 also rotates while rubbing against the inner peripheral surface of the pinion housing hole 45, and the pinion gears 35 and 37 mesh with each other while pressing the tooth surfaces. The rotation of the left side gear 15 is limited by these actions, and the right side gear 17 rotates as a reaction force.

In the differential device 1 acting as described above, in this embodiment, the meshing portion of the pair of first and second pinion gears 35 and 37 is arranged on one end side of the differential case 3, so that the differential device 1 is compact. , Can be reduced in weight.

The first and second pinion gears 35, 37
Receiving hole 43 of case cover 13 for positioning one end of
Processing for increasing the surface accuracy of the concave end walls 43c, 45c of the b, 45b is facilitated, whereby the positioning accuracy of the first and second pinion gears 35, 37 can be improved.

FIG. 4 schematically shows an assembling procedure.

First, the case cover 13 is fixed on the assembly table 49, and the guide boss 23 of the left side gear 15 is
1, the side gear is assembled to the case cover 13, and the support hole 33 of the right side gear 17 is fitted to the guide boss 31 of the left side gear 15 to engage the right side gear 17 with the left side gear 15. .

Subsequently, the second gear portion 41 of the first pinion gear 35 is fitted into the pinion receiving hole 43b of the case cover 13, and its end is positioned by the concave end wall 43c, and the second pinion gear 37 is connected to the pinion receiving hole. 45b, and its end is positioned by the concave end wall 45c.

Next, the first gear portion 39 of the first pinion gear 35 is fitted into the pinion receiving hole 43a of the case body 11, and the second pinion gear 37 is fitted into the pinion receiving hole 45a. Walls 43d, 45d
By fitting the guide boss 29 of the right side gear 17 into the support hole 27 of the case main body 11, the receiving holes 43a and 45a are closed and assembled by the concave end walls 43c and 45c.

As described above, since all the components can be assembled from one side, the assemblability can be improved.

[0036]

As is apparent from the above description, according to the present invention, it is possible to obtain a differential device which can be reduced in size and weight and can be improved in workability and assemblability.

[Brief description of the drawings]

FIG. 1 is a sectional view similar to the section taken along line AA in FIG. 2 of one embodiment of the present invention.

FIG. 2 is a side view of the case cover according to the embodiment of the present invention as viewed from the inside.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a schematic view showing an assembling procedure according to one embodiment of the present invention.

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Differential device 3 Differential case (case) 11 Case main body 13 Case cover 15 Side gear 17 Side gear 35 1st pinion gear (pinion gear) 37 2nd pinion gear (pinion gear) 39 1st gear part 41 2nd gear part 43 Pinion accommodation hole (accommodation hole) 43c Recessed end wall 45 Pinion accommodation hole (accommodation hole) 45c Recessed end wall

Claims (1)

(57) [Claims] 1. A case for receiving a rotation input, a pair of side gears disposed in the case so as to be rotatable coaxially with a rotation axis of the case, and a pair of side gears formed in the case in parallel with the rotation axis of the case. Pinion gears rotatably fitted in a plurality of pairs of intersecting receiving holes in a tip circle; each pair of pinion gears mesh with each other; one pinion gear meshes with one side gear; and the other pinion gear engages with the other. And a case body having one end open to the case, the case body having one end opened, the one side gear being connected to one drive shaft, and the other side gear being connected to the other drive shaft. And a case cover for covering the opening of the pair of pinion gears. A differential device characterized by a concave end wall of a hole, wherein the mutual meshing position of each pair of pinion gears is arranged at one end side of a case.