JPH0728443Y2 - Idle gear support device for transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a transmission mainly provided in a power transmission system of an automobile, and more particularly to a device for supporting an idle gear thereof.

[Conventional technology]

As a conventional idle gear support device for a transmission, there is one as shown in FIG. 2 (longitudinal sectional view), which includes a shaft 1 attached to a transmission casing C and a pair of inclined roller type bearings 2 on the shaft 1.
And an idle gear 3 which is rotatably supported via. Further, it is provided with a flange 1a formed at the inner end of the shaft 1 and engaging with the side surface of the bearing 2 so as to tighten the bearing 2 with the transmission casing C, and the transmission casing C is provided at one end of the shaft 1 on the flange side. Is provided with a female screw hole to be screwed into the male screw portion, and the other end is provided with a jig receiving hole.

With such a configuration, when assembling, the shaft 1 is tightened by using a jig so that the flange 1a provided on the shaft 1 tightens the bearing 2 between the bearing 2 and the transmission casing C, whereby a predetermined preload is applied to the bearing 2. Can be given.

[Problems to be solved by the device]

However, since the conventional idle gear support device for a transmission has a structure in which the male screw portion is provided at the end portion of the shaft 1 that receives a radial load, the male screw portion of the shaft 1 and the female screw portion of the transmission casing C are screwed together. Since the length of the part that is engaged is short, the screw part cannot be tightened with a large tightening torque, and since the diameter of the shaft 1 must be increased, elasticity against the tightening torque is increased. Since the amount of deformation is small, the shaft axial force of the shaft 1 as a whole is weak, the bearing 2 is worn over a long period of time using the device, and the pair of bearings 2 are arranged at a predetermined interval. The problem that the preload given to the bearing 2 is easy to be lost when the space between the inner races is narrowed. There is. Hereinafter, this problem is also referred to as "preload loss".

Further, when tightening the shaft 1, it is necessary to adjust the tightening torque of the shaft 1 while measuring the rotating torque of the idle gear 3, and there is a problem that the efficiency of assembly is greatly impaired.

SUMMARY OF THE INVENTION The present invention is intended to solve the above problems, and an object thereof is to provide an idle gear support device for a transmission, in which preload loss of the bearing is prevented and assembly efficiency is improved.

[Means for Solving the Problems]

In order to achieve the above object, an idle gear support device for a transmission according to the present invention is an inclined roller that is attached to the inner periphery of an idle gear in a transmission and that includes a pair of roller rows, a pair of inner races, and a common outer race. Type bearing, both ends of which are supported by the casing of the transmission, and a flange which engages with the side surface of the bearing is formed on one of the both ends and extends along the central axis. And a shaft having a bolt hole penetrating therethrough, and both side surfaces of the bearing are respectively inserted between the flange and the casing so as to be sandwiched between the flange and the casing. Tightening bolt protruding and screwed into the female screw hole formed in the casing It is characterized by having a.

[Action]

In the above-described idle gear support device for a transmission of the present invention, when the tightening bolts inserted in the bolt holes along the central axis of the shaft are tightened, the flange formed at one end of the shaft and the other end of the shaft are supported. The both sides of the bearing are tightened with the wall surface of the transmission casing, and the tightening force compresses the pair of inner races of the bearing to give a predetermined preload. At this time, the tension also acts on the tightening bolts and causes elastic deformation, so the tightening bolts function as tension bolts, and even if the distance between the pair of inner races is narrowed, the tension of the tightening bolts keeps the bearing tightened. To act.

〔Example〕

An idle gear support device for a transmission as one embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 is a vertical sectional view thereof. As shown in FIG. 1, a tilted roller type cartridge bearing mounted on the inner periphery of the idle gear 3 and comprising a pair of roller rows Ra and Rb, a pair of inner races 2a and 2b, and a common outer race 2c. The shaft 1 through which the shaft 2 is inserted is supported at both ends by the casing C of the transmission, and the inner race 2a of the bearing 2 is provided at one of the ends.
Is formed with a flange 1a that engages with the side surface of the. Then, the tightening bolt 4 is inserted from one end side of the bolt hole along the central axis of the shaft 1 on the side where the flange 1a is formed, and protrudes from the other end side of the bolt hole to form a female screw hole of the casing C. It is screwed to. Bending washers 5a and 5b are interposed between the shaft 1 and the tightening bolt 4 and between the inner race Rb and the casing C, respectively.

Since the idle gear support device for a transmission as one embodiment of the present invention is configured as described above, when the tightening bolt 4 is tightened to the specified torque, the flange 1a and the casing C of the transmission are fitted to the bearing 2 of the bearing 2. The inner races Ra and Rb are tightened and compressed, and the bearing 2 is given a predetermined preload.

In this embodiment, since the radial load acting on the idle gear 3 is supported only by the shaft 1, the tightening bolt 4 only needs to support the thrust load, and it is possible to use a long bolt having a small diameter and the casing C. It is possible to increase the screwing length of.

Therefore, the tightening bolt 4 can be tightened with a tightening torque larger than the conventional tightening torque of the shaft 1. As a result, the amount by which the tightening bolt 4 is elastically deformed by the tightening torque is increased, and the tightening bolt is effectively used as a tension bolt. Even if the bearing 2 is worn and the distance between the inner races 2a and 2b is narrowed, a sufficient preload can be given and the preload is lost and preload loss can be prevented. .

[Effect of device]

As described in detail above, according to the idle gear supporting device for a transmission of the present invention, the following effects and advantages are obtained.

(1) Since the radial load input from the idle gear is supported by the shaft whose both ends are supported by the transmission casing, the tightening bolt only needs to support the thrust load, and the tightening bolt has a small diameter and a long length. In addition, the length of the threaded portion between the tightening bolt and the transmission casing can be increased. Therefore, it is possible to tighten with a large tightening torque to increase the amount of elastic deformation generated in the tightening bolt, and to give a large preload to the tightening bearing to prevent preload loss.

(2) In order to set the preload applied to the bearing to a predetermined value, it is only necessary to tighten the tightening bolt with a specified torque, which improves the efficiency of assembly.

(3) Since the tightening torque of the tightening bolt is increased, the clamping force of the bearing is increased, and the rigidity of the bearing as the bearing is improved.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an idle gear supporting device for a transmission as one embodiment of the present invention, and FIG. 2 is a vertical sectional view showing a conventional idle gear supporting device for a transmission. 1 ... Shaft, 1a ... Flange, 2 ... Bearing,
2a, 2b …… Inner race, 2c …… Outer race, 3 ……
Idle gear, 4 ... Tightening bolts, 5a, 5b ... Bending washer, C ... Transmission casing, Ra, Rb
…… Roller row.

Claims (1)

[Scope of utility model registration request] 1. In a transmission, an inclined roller type bearing attached to the inner periphery of an idle gear and comprising a pair of roller rows, a pair of inner races and a common outer race, and both end portions inserted into the bearings. A shaft that is supported by the casing of the transmission, has a flange that engages a side surface of the bearing formed at one of the both ends, and has a bolt hole formed through the center axis. Both side surface portions of the bolt hole are inserted from the end portion on the flange side of the bolt hole so as to be sandwiched between the flange and the casing, and protruded from the other end side and screwed into the female screw hole formed in the casing. Idling gear support device for a transmission, characterized in that .