JP2002195390A - Differential device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely make lubricating oil flow in/out between a pinion gear and a storage hole of the pinion gear. SOLUTION: In this differential device 7, at least one pinion gear 125 of a pair of pinion gears disposed within a differential case 83 has left and right gear parts 129 and 131 and a shaft part 133 of a small diameter for connecting the gear parts 129 and 131, and the shaft part 133 is provided with an opening 139 for making lubricating oil flow in/out between space 221 between the shaft part 133 and the storage hole 127 for storing the pinion gear 125 and the outside of the differential case 83 on a peripheral wall of the facing differential case 83.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art A differential apparatus 201 as shown in FIG. 6 is described in EP0130806A2.
This is a differential case 203 driven by the engine.
And pinion gears 211 and 213 slidably and rotatably housed in housing holes 207 and 209 formed through the differential case 203 and the cam gear 205, a side gear 215 connected to one wheel side, and a pinion gear 211 and 213 connected to the other wheel side. The pinion gears 211 and 213 mesh with each other on a radially outer side of the cam gear 205 and mesh with the side gears.

[0003]

However, since the prior art does not include a means for allowing lubricating oil to flow in and out of the differential device 201, if the high-load differential operation state continues for a long time, the differential device 201 may be stored. Lubrication failure may occur between the holes 207, 209 and the pinion gears 211, 213.

Accordingly, an object of the present invention is to provide a differential device capable of reliably flowing lubricating oil between a pinion gear and a housing hole of the pinion gear.

[0005]

SUMMARY OF THE INVENTION A differential device according to the present invention includes a differential case which is rotated by a driving force of an engine, a pair of helical side gears respectively connected to left and right axles, and a sliding hole provided in the differential case. A pair of helical pinion gears that are rotatably housed and connect the side gears so that the side gears can rotate relative to each other; at least one of the pair of pinion gears has left and right gear portions and a small diameter that connects these left and right gear portions An opening through which lubricating oil flows in and out of a space between the shaft and the housing hole and the outside of the differential case is provided on a peripheral wall of the differential case where the small-diameter shaft is opposed. It is characterized by the following.

[0006]

According to the differential device of the present invention, the opening is provided on the peripheral wall of the differential case so as to face the small-diameter shaft portion of the pinion gear. The lubricating oil flows between the inside of the differential case and the outside of the differential case through the space between the pinion gear and the frictional torque between the pinion gears and other sliding parts such as storage holes and gears. The part can be lubricated.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment will be described with reference to FIGS. 1 to 3 and FIG. FIG. 1 shows a differential device of this embodiment, and FIG. 5 shows a power system of a vehicle using the differential device. The left and right directions are the left and right directions in this vehicle and FIG.

As shown in FIG. 5, this power system includes an engine 1, a transmission 3, a propeller shaft 5, a rear differential 7 (differential device of FIG. 1 arranged 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.

The differential case 21 of the rear differential 7 is rotatably supported in a differential carrier 23.
, A ring gear 25 is fixed. Ring gear 25
Meshes with the drive pinion gear 27, and the drive pinion gear 27 is formed integrally with the drive pinion shaft 29 on the propeller shaft 5 side. Thus, the driving force of the engine 1 rotationally drives the differential case 21 via the transmission 3 and the propeller shaft 5.

As shown in FIG. 1, right and left helical side gears 31, 33 are coaxially arranged inside a differential case 21. These side gears 31 and 33 are supported on the differential case 21 by shaft support portions 39 and 41 formed between the boss portions 35 and 37 on the outside in the axial direction and the differential case 21, respectively. The supporting ends are supported by each other, and the free ends are centered.
The side gears 31, 33 are connected to left and right rear axles 9, 11 by splines 45, 47, respectively. Between the side gears 31, 33 and the right side gear 33 and the differential case 2
Washers 49 and 51 are arranged between the first and second washers.

A cam gear 53 having a shape as shown in FIG. 2 is disposed on the outer periphery of the left boss portion 35.
1 is centered.

Four pairs of a long helical pinion gear 55 and a short helical pinion gear 56 are arranged radially outside the side gears 31, 33, and these are formed through the differential case 21 and the cam gear 53 as shown in FIGS. Are accommodated slidably and rotatably in the long and short storage holes 57, 59, respectively. The long pinion gear 55 is composed of left and right gear portions 61 and 63 and a small-diameter shaft portion 65 connecting them, the left gear portion 61 meshes with the left end of the short pinion gear 56, and the right gear portion 63 is the right side gear. 33 is engaged. The right end of the short pinion gear 56 meshes with the left side gear 31.

The driving force of the engine 1 for rotating the differential case 21 is distributed from each pinion gear to the right and left rear wheels 13 and 15 via side gears 31 and 33. When a difference in driving resistance occurs between the rear wheels, the rotation of the pinion gear causes the left and right wheels to rotate. Differential distribution to each side.

During transmission of the torque, the pinion gears are pressed against the wall surfaces of the housing holes 57, 59 by a reaction force of the engagement with the side gears 31, 33 to generate frictional torque, and the side gears 31, 3 by the engagement thrust force of the helical gear.
3 and between the side gears 31, 33 and the differential case 21. These friction torques provide a differential limiting force.

As shown in FIG. 1, the left side wall 6 of the differential case 21
An opening 69 is provided in 7.

The long storage hole 57 penetrates the differential case 21 on the right side wall 71 to form an opening 73 as shown in FIG. Oil is sealed in the differential carrier 23, and the oil is splashed on the differential case 21 by the rotation of the ring gear, flows out and in through the openings 69 and 73, and lubricates meshing portions and sliding portions of the gears.

As shown in FIG. 3, the cam gear 53 has
Concave portions 75 and 77 forming a part of the components 7 and 59 are provided, and are non-rotatably fixed to the differential case 21 with the remaining cylindrical surface 79. As described above, the outer circumference is fixed, and the entire inner circumference is centered on the differential case 21 via the boss 35 as described above. Therefore, unlike the conventional example of FIG. No hit occurs, and the differential limiting force is stabilized.

Next, a second embodiment will be described with reference to FIG. This embodiment is similar to the rear differential 7 of the first embodiment in FIG.
As a rear differential 81 of the vehicle. Hereinafter, the left and right directions are the left and right directions in this vehicle and FIG.

The differential case 83 of the rear differential 81 includes a main body 85
And a cover 89 fixed to the main body 85 with bolts 87. The ring gear 25 is fixed to the main body 85.

As shown in FIG. 4, right and left helical side gears 91 and 93 are coaxially arranged inside a differential case 83. These side gears 91 and 93 are supported by the differential case 83 by axial support portions 103 and 105 formed between the axially outer bosses 95 and 97 and the side walls 99 and 101 of the differential case 83, and between the side gears 91 and 93. The free ends of each other are supported by the formed shaft support portion 107 to perform centering. Each boss 95, 97 has an oil groove 109, 1
11 are provided.

Each of the side gears 91 and 93 has a spline 11
3, 115 are connected to the left and right rear axles 9, 11, respectively. A washer 117 is disposed between the side gears 91 and 93, and a thrust block 121 for transmitting and receiving a mutual thrust force is disposed between the axles 9 and 11.

A cam gear 1 is provided on the outer periphery of each boss 95, 97.
23 and 123 are arranged, and the entire inner peripheral surface thereof is
97 is centered with respect to the differential case 83 by sliding contact with the outer periphery.

The helical pinion gear 125 and four other helical pinion gears are arranged radially outside the side gears 91 and 93. The differential case 83 and each of the cam gears 123 are provided with storage holes 127 for storing these pinion gears so as to be slidable and rotatable. The pinion gear 125 includes left and right gear portions 129 and 131 and a small-diameter shaft portion 133 for connecting these, and the other pinion gears also include left and right gear portions and a small-diameter shaft portion for connecting these.

The left end of the gear 129 of the pinion gear 125 meshes with the left gear of the other pinion gear, and the right end meshes with the left side gear 91. The right gear portion of the other pinion gear meshes with the right side gear 93 at the left end, and meshes with the gear portion 131 of the pinion gear 125 at the right end.

The driving force of the engine 1 for rotating the differential case 83 is distributed from each pinion gear to the left and right rear wheels 13 and 15 via side gears 91 and 93, and when a driving resistance difference occurs between the rear wheels, the pinion gear rotates by itself. It is differentially distributed to each side.

During transmission of the torque, each pinion gear is pressed against the wall surface of the housing hole 127 by the reaction force of the engagement with the side gears 91 and 93 to generate friction torque, and at the same time, between the side gears 91 and 93 by the engagement thrust force of the helical gear. Friction torque is generated between the side gears 91 and 93 and the cam gear 123. These friction torques provide a differential limiting force.

In the differential case 83, in addition to an opening 135 formed through the right side wall 101, a storage hole 127, an opening 137 formed in a cover 89, and a pinion gear 125 are formed.
An opening 139 through which oil flows in and out between a space 138 between the shaft portion 133 and the storage hole 127 and the outside of the differential case is provided on a peripheral wall of the differential case 83 opposed to the small diameter shaft portion 133. The applied oil flows in and out of these openings 135, 137, and 139, and lubricates each sliding portion and gear meshing portion.

The left cam gear 123 is non-rotatably fixed to the differential case 83 by an outer cylindrical portion 143 excluding a concave portion 141 forming a part of the storage hole 127. On the other hand, the right cam gear 123 is centered on the differential case 83 by a centering portion 142 on the outer periphery of the cam gear 123, and is press-fitted and fixed to the differential case 83 so as not to rotate. As described above, since the outer periphery is fixed and the entire inner periphery is centered on the differential case 83 via the bosses 95 and 97 as described above, the centering is different from the conventional example of FIG. It is reliable and does not cause a partial contact with the pinion gear, and the differential limiting force is stabilized.

The side gears 91 and 93 and the washer 11
7, the side gears 91 and 93 and the cam gear 1
By changing the friction coefficient between the two, the differential limiting force due to the cam thrust force can be changed between when the vehicle is moving forward and when the vehicle is moving backward.

[0030]

According to the differential device of the present invention, the opening is provided on the peripheral wall of the differential case so as to face the small-diameter shaft portion of the pinion gear. By ensuring that lubricating oil flows between the inside of the differential case and the outside of the differential case through the space between the storage holes, the sliding parts such as storage holes and gears that generate friction torque with the pinion gears The engagement portion can be lubricated.

[Brief description of the drawings]

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

FIG. 2 is a perspective view of a cam gear used in the embodiment of FIG.

FIG. 3 is a sectional view taken along line AA of FIG. 1;

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

FIG. 5 is a skeleton mechanism diagram showing a power system of a vehicle using each embodiment.

FIG. 6 is a sectional view of a conventional example.

[Explanation of symbols]

 7, 81 Rear differential (differential device) 21, 83 Differential case 31, 33, 91, 93 Side gear 35, 37, 95, 97 Boss 53, 123 Cam gear 55, 56, 125 Pinion gear 57, 59, 127 Storage hole 138 Space

Continued on front page F-term (reference) 3D042 AA00 AB01 CA09 CC03 CC04 3J027 FA25 FB02 HA01 HB01 HC07 HC10 HC13 HC29 HE01 HF06 HG02 HH13 3J063 AA01 AB12 AC11 BA11 CA05 CB04 CD41 XD03 XD17 XD33 XD47 XD62 XD72

Claims (1)

[Claims] 1. A differential case which is rotated by a driving force of an engine, a pair of helical side gears respectively connected to left and right axles, and the side gears are slidably and rotatably stored in storage holes provided in the differential case. A pair of helical pinion gears rotatably connected to each other, wherein at least one of the pair of pinion gears has left and right gear portions and a small-diameter shaft portion connecting the left and right gear portions; A differential device, wherein an opening through which lubricating oil flows in and out of a space between the shaft portion and the housing hole and the outside of the differential case is provided on a peripheral wall of the differential case whose portion faces each other.