JPH0447468Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to a differential device, and particularly to an improvement in the anti-rotation structure of a pinion washer thereof.

[Prior Art] In this type of differential device, which includes a pinion gear and a side gear that are rotatably housed in a case and mesh with each other, there is a gap between the pinion gear and the case in order to receive the thrust force acting on the pinion gear. A pinion washer is provided.

By the way, in such a differential device, when the differential gear is operated, rotational force is transmitted from the pinion gear to the pinion washer, and this rotational force causes slippage between the case and the pinion washer, causing the case to wear out. It is necessary to aim for this.

Therefore, a non-circular hole is drilled in the pinion washer, and the non-circular part of the pinion shaft is fitted into the hole to prevent rotation, or a protrusion is provided in the pinion washer, and the protrusion is engaged with a recess on the case side. A rotation-preventing structure was adopted.
(Refer to Publication No. 152239).

[Problems to be solved by the invention] However, in the case of the above-mentioned former anti-rotation structure, stress concentration may occur at the corner portion of the non-circular hole drilled in the pinion washer, and cracks may occur in this portion. In addition, in the case of the latter anti-rotation structure, since there is no anti-rotation between the pinion washer and the pinion shaft during assembly, the protrusion of the pinion washer cannot be positioned, which impedes assembly workability. There was a problem that it was bad.

This idea was made in view of the above problems,
The objective is to provide a differential device that can simultaneously improve the durability of a pinion washer and improve the ease of assembly.

[Means for Solving the Problems] In order to achieve the above object, this invention includes a pinion shaft supported within a differential case, a pinion gear rotatably supported by the pinion shaft,
In a differential device comprising a pair of side gears meshing with these pinion gears, and a pinion washer interposed between the differential case and the pinion gear, a flat portion is formed on the outer surface of an end of the pinion shaft and formed on the differential case. 1. A differential gear that fits into a support groove, and the pinion washer has a non-circular hole that fits into a flat part of a pinion shaft, and a protrusion that fits into the support groove.

[Function] Since the inside of the non-circular hole formed in the pinion washer is fitted into the flat part of the pinion shaft, the pinion washer is prevented from rotating relative to the pinion shaft, and the pinion washer does not rotate during assembly, and the protrusion of the pinion washer positioning, improving assembly workability. Furthermore, while the differential device is in operation, the pinion washer is prevented from rotating by fitting a protrusion provided thereon into a support groove formed on the inner periphery of the case, and fitting a non-circular hole into a flat portion of the pinion shaft. Since this is done by the pinion washer, cracks due to stress concentration do not occur at the corners of the non-circular holes formed in the pinion washer, and the durability of the pinion washer itself is improved.

[Embodiment] An embodiment of this invention will be described below based on the accompanying drawings.

FIG. 1 is a longitudinal sectional view of a differential device having a rotation prevention structure according to an embodiment of the invention, and FIG. 2 is an exploded perspective view showing the same rotation prevention structure. In Fig. 1, 1 is a differential case,
Inside this, a viscous cut spring device 3, a pair of side gears 5, 7, and these side gears 5,
A plurality of (four in this embodiment) pinion gears 9 meshing with the pinion gears 7 are housed. In the viscous coupling device 3, a sealed chamber 3a is filled with viscous fluid such as silicone oil, a plurality of resistance plates are engaged with one member 3b, and these resistance plates are arranged adjacent to the other member 3c alternately. A plurality of resistance plates are engaged to limit the differential motion between the members 3b and 3c. As shown in FIG.
... are formed in the axial direction (horizontal direction in FIG. 1), and a flat portion 13a on the outer surface of the end of the pinion shaft 13 that rotatably supports the pinion gear 9 is fitted and held in each support groove 11. ing. and,
A pinion washer 15 is interposed between the differential case 1 and each pinion gear 9 to receive thrust force acting on the pinion gear 9.

One of the left and right output shafts is connected to the axial center of one member 3b of the viscous coupling device 3, and the other is connected to the axial center of the other member 3c and the axial center of the side gear 7. be. When a differential occurs between both shafts, the differential is absorbed by the rotation of the pinion gear 9, and the members 3b,
The viscous coupling device 3 works with the differential between 3c and limits the differential.

The pinion washer 15 has a substantially disk shape as shown in FIG. 2, and its lower surface is formed in a concave shape along the convex surface of the pinion gear 9. Further, a non-circular hole 15a having a substantially rectangular shape to be inserted into the flat portion 13a of the pinion shaft 13 is bored in the center of the pinion washer 15, and support holes for the differential case 1 are formed on both sides of the non-circular hole 15a. Groove 1
1, protrusions 15b, 15b, which are to be fitted into each other, are integrally provided in a protruding manner.

When assembling the pinion washer 15, the pinion washer 15 has the flat portion 13a of the pinion shaft 13 inserted into the non-circular hole 15a.
By fitting the protrusion 1 into the pinion shaft 13, the rotation can be prevented.
5b is now positioned, and the ease of assembly when fitting it into the support groove 11 is significantly improved. Furthermore, after the pinion washer 15 is assembled, the protrusions 15b, 15b protruding from the pinion washer 15 are fitted into the support grooves 11 formed in the case 1, so that the pinion washer 15 cannot be prevented from rotating relative to the case 1. exclusively protrusion 15
b, 15b are fitted into the support groove 11. Furthermore, the prevention of rotation of the pinion washer 15 is also assisted by the fitting of the non-circular hole 15a into the flat portion 13a of the pinion shaft 13. Therefore, when the pinion washer 15 tries to rotate as the pinion gear 9 rotates, the force for stopping this is shared between the protrusion 15b and the non-circular hole 15a, and stress concentration occurs around the periphery of the non-circular hole 15a of the pinion washer 15. There is no pinion washer 1.
5 will not be damaged by cracks, and its durability can be improved.

As a result of the above, the problems of reduced durability and poor assembly workability of conventional pinion washers can be solved at the same time.

FIGS. 3 and 4 relate to another embodiment of this invention, which will be explained by assigning the same reference numerals to the same components as in the above embodiment. A pair of ribs 17 are provided on both sides of a non-circular hole 15a, These ribs 17 are configured to fit into support grooves 11 of the differential case 1. Therefore, the rotational input is transmitted from the differential case 1 to the rib 17 of the pinion washer 15, and from this pinion washer 15 to the pinion shaft 13 and pinion gear 9 in turn. Therefore, even if the area of the flat portion 13a of the pinion shaft 13 is small, it contacts the support groove 11 over a wide area via the rib 17, and the surface pressure against the support groove 11 can be further reduced. Then, the flat part 13a of the pinion shaft 13 is lengthened and the support groove 1 is
It is extremely advantageous in terms of space since there is no need to increase the depth of 1 to secure the area. Further, the presence of the rib 17 ensures the strength of the pinion washer 15 itself. It goes without saying that other effects similar to those of the above embodiment can be achieved.

[Effect of the invention] As is clear from the above explanation, according to this invention,
Since the non-circular hole formed in the pinion washer is structured to fit into the flat part of the outer surface of the end of the pinion shaft, the pinion washer does not rotate during assembly, and the assembly workability is improved. In addition, during the operation of the differential device, the pinion washer is mainly prevented from rotating by fitting a projection provided on the pinion into a support groove formed on the inner periphery of the differential case. Stress is not concentrated on the periphery of the non-circular hole, etc., and its durability is improved.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a differential device according to an embodiment of the invention, FIG. 2 is an exploded perspective view showing the same anti-rotation structure, and FIG. 3 is a sectional view of main parts according to another embodiment. FIG. 4 is a sectional view taken along the line shown in FIG. 3. 1... Differential case, 5, 7... Side gear, 9
... Pinion gear, 11 ... Support groove, 13 ... Pinion shaft, 13a ... Flat part, 15 ... Pinion washer, 15a ... Non-circular hole, 15b ...
…protrusion.

Claims (1)

[Scope of utility model registration request] A differential Allen comprising a pinion shaft supported within a differential case, a pinion gear rotatably supported by the pinion shaft, a pair of side gears meshing with these pinion gears, and a pinion washer interposed between the differential case and the pinion gear. In the shear device, a flat part is formed on the outer surface of an end of the pinion shaft to fit into a support groove formed in the differential case, and the pinion washer has a non-circular hole that fits into the flat part of the pinion shaft and a flat part in the support groove. A differential device characterized in that a protrusion is formed to fit into the differential gear.