JPH07190169A - Differential gear - Google Patents

Abstract

PURPOSE:To facilitate the machining of the storage holes of helical pinion gears and make the end faces of both helical side gears equal to the contact area of a differential case. CONSTITUTION:A differential gear 7 is provided with a differential case 21 formed of plural case members 31, 33; helical pinion gears 55, 57 having gear parts 59, 61 enclosed in the storage holes 51, 53 of the case member 33 and meshed on one axial side, and gear parts 63, 65 connected to the gear parts 59, 61 through small diameter shaft parts 67, 69; helical side gears 37, 39 individually meshed with the gear parts 63, 65; and a collar part 73 formed at the case member 31 and opposed to the end face of a side gear 37.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle differential device.

[0002]

2. Description of the Related Art US Pat. No. 3,706,239 discloses a differential device 201 as shown in FIG. 8, and Japanese Unexamined Patent Publication No. 5-280596 discloses a differential device 203 as shown in FIG.

The former is a storage hole 207 of the differential case 205,
Helical pinion gears 211 and 21 housed in 209
3 and helical side gears 215 and 217 connected via these gears 211 and 213.
In the latter case, the helical pinion gear 223 housed in the housing hole 221 of the differential case 219, another helical pinion gear housed in another housing hole, and the helical side gear 22 connected via these helical pinion gears.
5, 227.

In any case, the rotation of the engine input from the differential case 205, 219 is transmitted through the helical pinion gear to the helical side gears 215, 217, 225, 227.
And the differential distribution by the rotation of the helical pinion gear. This differential rotation is limited by the frictional resistance between each helical pinion gear and the housing hole as well as the frictional resistance generated at each end face by the meshing thrust force of the helical side gears 215, 217, 225, 227.

[0005]

However, each of the differential cases 205 and 219 has two case members 229 and 23.
1, 233, and 235 have a divided structure, and each storage hole is formed so as to extend over these. Therefore, it is necessary to reduce the dimensional tolerance of each housing hole by the dimensional tolerance between the case members, which is difficult to process and the yield is poor.

Further, FIG. 10 is a side gear 225 shown in FIG.
227 and the case members 233 and 235 are in contact with each other, and solid lines show the outer diameters of the end faces of the side gears 225 and 227. The case member 233 has a recess 237 formed by a storage hole as shown by a broken line,
Since 5 does not have such a recess, the contact area of the end face of the side gear 225 is smaller than the contact area of the side gear 227 by the shaded portion. This difference makes the differential limiting forces uneven when the wheels on the side gear 225 side idle and when the wheels on the side gear 227 side idle.

Therefore, an object of the present invention is to provide a differential device in which the accommodation hole of the helical pinion gear can be easily machined and the contact surfaces of the end faces of both the helical side gears and the differential case are equal.

[0008]

SUMMARY OF THE INVENTION A differential device of the present invention comprises a differential case which is composed of a plurality of case members and is rotationally driven by a driving force of an engine, and a storage hole formed in one case member so as to be slidably rotatable. A long and short helical pinion gear that is housed and that has a first gear portion that meshes with each other on one side in the axial direction and a second gear portion that is connected to the first gear portion via a small diameter shaft portion; A pair of helical side gears, each of which is connected to the wheel side and meshes with the second gear portion separately, and a flange portion formed on another case member and facing the end surface of the helical side gear on the side of the first gear portion. It is characterized by having.

[0009]

In the differential case, the case is divided into a plurality of case members. The helical pinion gear is slidably rotated, and the accommodating hole for receiving the meshing reaction force is formed in one of the case members. Unlike the conventional example in which the storage hole extends over two members, there is no need to make the dimensional accuracy of the storage hole excessively strict, and the yield and cost are greatly improved.

Further, a flange portion is formed on the other case member, and the flange portion is arranged between the first gear portion of the helical pinion gear and the helical side gear adjacent to the first gear portion, and the side gears and the differential case are brought into contact with each other. The area was made uniform. Therefore,
Even if any wheel spins, a uniform differential limiting force can be obtained,
The maneuverability of the vehicle is improved.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment will be described with reference to FIGS. 1 to 3 and 7. FIG. 1 shows this embodiment, and FIG. 7 shows a power system of a vehicle using this embodiment. The left and right directions are the left and right directions in this vehicle and FIG.

As shown in FIG. 7, this power system includes an engine 1, a transmission 3, a propeller shaft 5, a rear differential 7 (a differential device of the embodiment arranged on the rear wheel side), rear axles 9 and 11, left and right rear. It is composed of wheels 13 and 15, left and right front wheels 17 and 19, and the like.

The differential case 21 of the rear differential 7 is arranged in the differential carrier 23, and the ring gear 25 is fixed to the differential case 21. The ring gear 25 meshes with the drive pinion gear 27, and the drive pinion gear 27
Is integrally formed with a drive pinion shaft 29 connected to the propeller shaft 5 side. In this way, the driving force of the engine 1 rotationally drives the differential case 21 from the transmission 3 via the propeller shaft 5. The differential carrier 23 is filled with oil to form an oil reservoir.

As shown in FIG. 1, the differential case 21 has a main body 31.
(One case member) and cover 33 (another case member) are divided into two parts, and are integrated by bolts 35.

Inside the differential case 21, hollow helical side gears 37, 39 are arranged on the left and right. The side gears 37 and 39 are rotatably supported by shaft supporting portions 41 and 43 formed between the cover 33 and the main body 31, respectively, and the free ends thereof are supported by the shaft supporting portions 45 formed between each other. They fit together and are centered on each other.
The left and right side gears 37, 39 are spline-coupled to the left and right rear axles 9, 11 respectively so as to be axially movable. A washer 47 is disposed between the side gears 37 and 39, and a thrust block 49 that abuts the rear axles 9 and 11 is disposed on each inner circumference.

The body 31 of the differential case 21 is shown in FIGS.
As described above, four sets of storage holes 51, 53 are formed alternately in the circumferential direction, and long and short helical pinion gears 55, 57 are slidably and rotatably housed therein. Each of the pinion gears 55, 57 comprises a first gear portion 59, 61 and a second gear portion 63, 65, and a small diameter shaft portion 67, 69 connecting them. First gear part 59, 6
1 is meshed with the left side gear 37 (one side in the axial direction), the second gear portion 65 is meshed with the left side gear 37, and the second gear portion 63 is meshed with the right side gear 39. Further, as shown in FIGS. 1 and 3, the cover 33 is provided with a concave portion 71 for avoiding interference with the first gear portions 59 and 61.

The cover 33 of the differential case 21 is provided with a collar portion 73 disposed between the first gear portions 59 and 61 and the left side gear 37, and the contact area between the side gear 37 and the collar portion 73 and the side gear portion. The contact area between 39 and the main body 31 is made equal. The pinion gears 55 and 57 are assembled to the differential case 21 by first covering the cover 3 as shown in FIG.
The first gear portions 59 and 61 are attached to the outer peripheral portion 3 from the outside in the radial direction, and the cover 33 is assembled to the main body 31 from the left in this state.

In this way, the rear differential 7 is constructed,
The driving force of the engine 1 that rotates the differential case 21 is distributed from the pinion gears 55 and 57 to the left and right rear wheels 13 and 15 via the side gears 37 and 39. When a driving resistance difference occurs between the rear wheels, the driving force of the pinion gears 55 and 57 is increased. Due to the rotation, the driving force of the engine 1 is differentially distributed to the left and right sides.

While transmitting the torque in this way, the tooth tips of the pinion gears 55 and 57 are pressed against the outer wall surfaces of the storage holes 51 and 53 by the reaction force of meshing with the side gears 37 and 39, so that frictional resistance is generated. . This meshing reaction force does not act on the concave portion 71 of the cover 33 because it is directed radially outward.
Further, the side gears 37, 39 receive an inward or outward thrust force by meshing with the pinion gears 55, 57, and frictional resistance is generated through the washer 47 or with the differential case 21. Due to these friction resistance, the rear differential 7
The differential of is limited.

When an inward thrust force is generated in the side gears 37, 39, in addition to the differential limiting force due to the sum of the thrust forces of the side gears 37, 39, the side gears of the rear wheel on the grip side and the side gears of the rear wheel on the slip side are also added. The difference in thrust force is input to the side gear on the idling side to obtain the differential limiting force.
In the rear differential 7, since the side gears 37, 39 and the differential case 21 have the same contact area by providing the collar 73 as described above, even if either of the side gears 37, 39 is on the idling side, the differential Limited power is obtained.
Further, even when the outward thrust force is generated, the contact areas are equal to each other, so that the differential limiting force is equal regardless of which of the rear wheels 13 and 15 idles.

While the vehicle of FIG. 7 is traveling on a bad road, the rear wheels 1
Even if one of the wheels 3 and 15 runs idly, a large driving force is sent to the rear wheel of the other side by the uniform differential limiting force generated in the rear differential 7, and the running performance on rough roads and the steering stability are kept high. Further, while traveling on a good road, smooth and stable traveling performance and turning performance can be obtained by the differential limiting force of the rear differential 7 which is uniform on the left and right sides.

Since the rear differential 7 has the storage holes 51, 53 formed in the main body 31 of the differential case 21, unlike the conventional example in which the storage holes extend over two members, the dimensional tolerances of the storage holes 51, 53 are appropriately reduced. No need. In addition, the concave portion 71 of the cover 33
Since the meshing reaction force of the pinion gears 55 and 57 is not applied, the dimensional tolerance can be relaxed to some extent. Therefore, the processing yield is improved and the cost is reduced. Further, the collar portion 73 is provided as described above to improve the steerability of the vehicle.

Next, referring to FIG. 4 to FIG. 6 and FIG.
An example will be described. The differential device of this embodiment is used as the rear differential 75 of the vehicle shown in FIG.
4 to 6 and the following description, members having the same functions as those of the first embodiment are designated by the same reference numerals. The left and right directions are the left and right directions in the vehicle of FIG. 7 and FIG. The differences from the first embodiment will be described below.

The cover 33 is provided with a large-diameter collar portion 77 arranged between the first gear portions 59 and 61 of the pinion gears 55 and 57 and the side gear 37. As shown in FIGS. 4 and 5, a recess 79 is formed in the flange 77 to avoid interference with the shafts 67, 69 of the pinion gears 55, 57, and the cover 33 is provided on the left side of the flange 77. As shown in FIGS. 4 and 6, a recess 81 is formed to avoid interference with the first gear parts 59 and 61. Further, the collar portion 77 and the gear portion 5
Pinion gears 55, 5 with their end faces in contact with each other
Gaps 83 and 85 are formed between the right end portion of 7 and the main body 31 of the differential case 21. As shown in FIG. 5, since the large-diameter flange portion 77 is in contact with about half of the end faces of the gear portions 59, 61 on the shaft portions 67, 69 side, the right-hand meshing thrust force of the pinion gears 55, 57 is sufficient. Can receive. Therefore, the pinion gear 5 that forms the gaps 83 and 85
It is not necessary to finish the right end surfaces of 5, 57 and the wall surface of the main body 31, and the cost is reduced accordingly.

Similar to the first embodiment, since the housing holes 51 and 53 are formed in the main body 31, it is easy to process and the cover 33 is formed.
Since the meshing reaction force of the pinion gears 55 and 57 is not applied to the recesses 79 and 81 on the side, the dimensional tolerance can be loosened accordingly. Therefore, the processing yield is improved and the cost is reduced. Further, the flanges 77 make the contact areas of the side gears 37, 39 and the differential case 21 equal to each other, so that the rear wheels 13, 15
Even if any of these slips, the differential limiting force of the rear differential 75 becomes uniform, and the maneuverability of the vehicle is improved.

[0026]

According to the differential device of the present invention, the housing hole for receiving the meshing reaction force of the helical pinion gear is formed in one case member of the differential case, and the flange portion is formed in the other case member to form the side gears and the differential case. The contact areas of Therefore, the processing of the accommodation hole is facilitated, the cost is reduced, and even if any of the side gear wheels idles, a uniform differential limiting force can be obtained.

[Brief description of drawings]

FIG. 1 is a sectional view of a first embodiment.

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

FIG. 3 is a first BB sectional view.

FIG. 4 is a sectional view of a second embodiment.

5 is a cross-sectional view taken along line CC of FIG.

6 is a cross-sectional view taken along line DD of FIG.

FIG. 7 is a skeleton mechanism diagram showing a power system of a vehicle using each embodiment.

FIG. 8 is a sectional view of a conventional example.

FIG. 9 is a cross-sectional view of another conventional example.

10 is a schematic diagram comparing the contact state between the end surface of each side gear and the differential case in FIG. 9. FIG.

[Explanation of symbols]

 7,75 Rear differential (differential device) 21 Differential case 31 Main body (one case member) 33 Cover (other case member) 37,39 Helical side gear 51,53 Storage hole 55,57 Helical pinion gear 59,61 First gear part 63 , 65 Second gear part 67, 69 Shaft part 73, 77 Collar part

Claims (1)

[Claims] 1. A differential case made up of a plurality of case members, which is rotationally driven by a driving force of an engine, and a slidably rotatably housed in a housing hole formed in one case member, and mutually axially on one side. A long and short helical pinion gear having a meshed first gear portion and a second gear portion coupled to the first gear portion via a shaft portion having a small diameter; A differential device comprising: a pair of helical side gears respectively meshing with the gear part of the above, and a flange portion formed on another case member and facing the end surface of the helical side gear on the side of the first gear portion.