JPH0667950U - Ring gear fastening structure in differential gear - Google Patents

Abstract

(57) [Summary] [Purpose] The purpose is to improve the fastening strength of the ring gear to the differential case, and even in such a case, the differential case does not become heavy and the mechanical loss when the differential case rotates. So that it does not grow. [Structure] In a diff device 1 in which a ring gear 9 is fastened to a diff case 3, a recess 19 is formed in a fastening surface 18 of the diff case 3 corresponding to the ring gear 9.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a structure for fastening a differential case and a ring gear in a differential (differential) device.

[0002]

[Prior art]

 Conventionally, there is a differential device disclosed in Japanese Utility Model Laid-Open No. 61-99753.

According to this, the ring gear is fastened to the differential case, and the driving force is input to the ring gear, so that the differential case rotates together with the ring gear around its axis.

[0004]

[Problems to be solved by the device]

 By the way, when trying to improve the strength of fastening the ring gear to the differential case, it is conceivable to increase the thickness of the fastening surface of the differential case corresponding to the ring gear at the fastening portion.

However, in this case, there is a problem that the differential case becomes heavy, and there is a limit in increasing the wall thickness.

On the other hand, in the above-mentioned conventional example, ribs are provided on the outer surface of the differential case, so that it is considered that the fastening strength can be improved without increasing the wall thickness as described above. However, in this case, since the differential case is normally bathed in an oil bath, the rib rotating with the differential case stirs the oil, and the stirring resistance causes mechanical loss when the differential case rotates. There is a problem of getting bigger.

[0007]

[The purpose of the device]

 The present invention was made in view of the above circumstances and aims to improve the fastening strength of the ring gear with respect to the differential case, and even in such a case, the differential case does not become heavy. The purpose is to prevent the mechanical loss from increasing when the differential case rotates.

[0008]

[Means for Solving the Problems]

 A feature of the present invention for achieving the above object is that in a diff device in which a ring gear is fastened to a diff case, a recess is formed on a fastening surface of the diff case corresponding to the ring gear.

[0009]

[Work]

 The operation of the above configuration is as follows.

In the diff device 1 in which the ring gear 9 is fastened to the differential case 3, a recess 19 is formed in the fastening surface 18 of the differential case 3 corresponding to the ring gear 9.

Therefore, even if the fastening strength of the ring gear 9 to the differential case 3 is improved by increasing the wall thickness of the differential case 3 corresponding to the ring gear 9 on the fastening surface 18 side, the recess 19 is formed in the differential case 3. This prevents the differential case 3 from becoming heavier.

Further, since the recess 19 is formed on the fastening surface 18 of the differential case 3 corresponding to the ring gear 9, the recess 19 is not exposed to the outside, so that the outer surface of the differential case 3 is kept smooth.

Therefore, the stirring resistance of the oil when the differential case 3 is rotated can be suppressed to be small.

[0014]

【Example】

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

Reference numeral 1 in FIG. 1 denotes a diff device provided in an automobile. The diff device 1 is composed of a diff carrier 2 supported on a vehicle body side and a diff case 3 housed in the diff carrier 2. The differential case 3 is oil bathed in the differential carrier 2. The differential case 3 is rotatably supported on the differential carrier 2 about its axis 5 by a pair of left and right bearings (hereinafter referred to as a direction toward FIG. 1, the same applies hereinafter).

The differential case 3 is composed of a case body 7 and an outwardly facing flange 8 that integrally projects from left and right midway portions of the case body 7. A spur gear type ring gear 9 is provided on the shaft center 5. The outward flange 8 and the ring gear 9 are detachably fastened by six bolts 10. Then, when the driving force on the engine side is input to the ring gear 9 via the intermediate gear 11 or the like, the differential case 3 rotates around the axis 5 accordingly.

A pinion shaft 13 having an axis perpendicular to the axis 5 is attached to the case body 7, and a pair of pinion gears 14, 14 are rotatably supported on the pinion shaft 13.

Inside the case body 7, a pair of left and right differential side gears 15, 15 that mesh with both pinion gears 14, 14 and are located on the axis 5 are provided. Each of the differential side gears 15 is rotatably supported on the case body 7 about the axis 5. One end of an axle 16 is connected to each of the differential side gears 15, and a wheel is connected to the other end of each of the axles 16.

When a driving force is input from the engine to the differential case 3 via the ring gear 9, the pinion gears 14, 14 rotate together with the differential case 3 around the axis 5 and mesh with the pinion gears 14, 14. The respective diff side gears 15, 15 are rotated about the same axis 5 as above. As a result, the torque is substantially evenly distributed to the left and right wheels via the axle 16.

In FIGS. 1 and 2, six recesses 19 are formed in the fastening surface 18 of the differential case 3 corresponding to the ring gear 9. The opening of each of the recesses 19 is hermetically closed by the fastening surface 20 of the ring gear 9 corresponding to the differential case 3. These recesses 19 are arranged at equal intervals around the axis 5, have the same shape and size, and have an arc shape with the axis 5 as the center. Further, the above-mentioned bolt 10 is located in the middle of the adjacent recesses 19, 19.

In the above case, the wall thickness of the outward flange 8 is increased, and the fastening strength of the ring gear 9 with respect to the differential case 3 is improved.

At this time, since the concave portion 19 is formed in the outward flange 8, the thickness of the outward flange 8 is large, but the differential case 3 may be heavy due to the formation of the concave portion 19. To be prevented.

Further, in the above case, since the concave portion 19 is formed on the fastening surface 18 of the differential case 3 corresponding to the ring gear 9, the concave portion 19 is not exposed to the outside, so the outer surface of the differential case 3 is kept smooth. Is dripping

In this way, the stirring resistance of the oil in the differential carrier 2 when the differential case 3 is rotated is suppressed to be small, and the mechanical loss when the differential case 3 is rotated is prevented from increasing. ing.

[0025]

[Effect of device]

 According to this invention, in the diff device in which the ring gear is fastened to the differential case, the recess is formed on the fastening surface of the differential case corresponding to the ring gear.

Therefore, even if the fastening strength of the ring gear with respect to the differential case is improved by increasing the thickness of the fastening surface side of the differential case corresponding to the ring gear, the recessed portion is formed in the differential case. The differential case is prevented from becoming heavy.

Further, since the recess is formed on the fastening surface of the differential case corresponding to the ring gear, the recess is not exposed to the outside, so that the outer surface of the differential case is kept smooth.

Therefore, the agitation resistance of the oil when the differential case is rotated is suppressed to be small, and the mechanical loss when the differential case is rotated is prevented from increasing.

[Brief description of drawings]

FIG. 1 is a sectional view of a differential device.

FIG. 2 is a view taken along the line 2-2 of FIG.

[Explanation of reference numerals] 1 diff device 3 diff case 5 shaft center 7 case body 8 outward flange 9 ring gear 18 fastening surface 19 recess

Claims (1)

[Scope of utility model registration request] 1. A structure of a ring gear fastening portion in a diff device, wherein a ring gear is fastened to a diff case, and a recess is formed in a fastening surface of the diff case corresponding to the ring gear.