JPH0673436U - Double-row needle roller bearings for idler gears - Google Patents

Abstract

(57) [Abstract] [Purpose] To reduce the width of the idler gear by reducing the width of the double-row needle roller bearing without lowering the surface pressure, thereby making the idler gear compact and lightweight. Is. [Structure] In a double-row needle roller bearing for an idler gear, in which left and right two rows of rollers 3, 3'are loaded differently for each row, the surface pressure of each row of rollers 3, 3'is substantially the same. The lengths of the rollers 3 and 3'for each row are different.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a double-row needle roller bearing used when supporting an idler gear for a transmission such as a transmission and a transaxle.

[0002]

[Prior art]

 The idler gear is used to obtain the required gear ratio in a multi-speed transmission, and when a large load is applied, needle roller bearings are arranged in two rows. Fig. 2 shows an example of such arrangement. Needle roller bearings 3 and 3 with cages are arranged in two rows between a pair of thrust washers 2 and 2 fitted around a shaft 1, and an idler gear 4 is arranged around them. It is fitted. The rollers 5 of each of the needle roller bearings 3 have the same length on the left and right sides.

[0003]

[Problems to be solved by the device]

 Since the idler gear 4 has a helix angle, a thrust force is generated thereby, and a moment load is applied to the bearing. Further, in many gears, the meshing point of the gears is not located in the center of the width of the bearing, so the bearing is used as an unbalanced load.

Under such conditions, as described above, when the double-row needle roller bearing 3 having the rollers 5 having the same length on the left and right sides is used, a difference occurs in the load applied to the left and right rollers 5. In this case, conventionally, the length has been set with reference to the roller 5 to which a large load is applied, and the left and right rollers 5 are set to the same length. Therefore, the left and right needle roller bearings 3 have the same width, and the width W of the idler gear 4 is determined according to this width, and the width of the idler gear 4 cannot be made smaller than that.

In view of this, the present invention reduces the width of the bearing by setting the length of the left and right rollers in accordance with the eccentric load acting on the bearing while keeping the surface pressure at the contact surface of the roller constant. The challenge is to make the width of the idler gear smaller according to the width.

[0006]

[Means for Solving the Problems]

 In order to solve the above problems, the present invention is directed to a double-row needle roller bearing for an idler gear, which has two rows of right and left rollers, so that the surface pressure of the rollers in each row is substantially the same. It has a different length.

[0007]

[Action]

 Determine the length of one of the left and right rollers according to the larger load, and determine the other roller with the smaller load as the roller bearing with the larger load and the surface pressure on the raceway surface is substantially the same. If the length is set to, the roller with the smaller load will be shorter than the roller with the larger load. Since the width of the bearing also decreases according to the length of the roller, the width of the idler gear can be reduced according to the width of the bearing.

[0008]

【Example】

 FIG. 1 shows a structure for supporting the idler gear 4, which is basically the same structure as the conventional example shown in FIG. 2, and the same parts are designated by the same reference numerals. In this case, the left side roller 5 and the needle roller bearing 3 are the same as the conventional ones, but the right side roller 5'is shorter than the conventional one, and thus the width of the needle roller bearing 3'is smaller. There is. Therefore, the width W'of the idler gear 4 becomes smaller than the conventional width W.

A thrust force Fa and a radial force Fr act on the idler gear 4, and the needle roller bearings 3 and 3 ′ have a radial load due to a moment force generated from the thrust force Fr and a radial force Fr. Two loads, a radial load due to

In the figure, the load applied to the roller 3 on the left side is larger than the load applied to the roller 3 ′ on the right side, and the radial load due to the moment force generated from the thrust force Fa is the same on the left and right, and the direction is The opposite (left is inward, right is outward). Therefore, since the left roller 5 receives a larger load, the length is determined with the left roller 5 as a reference. Then, the contact surface pressure between the roller 5 and the raceway surface of the shaft 1 is obtained, and the length of the right roller 5'is determined so that the surface pressure is the same as the contact surface pressure. In this way, the length of the right roller 5'is always shorter than that of the left roller 5, and therefore the width of the needle roller bearing 3'is also smaller. Therefore, the width W'of the idler gear 4 is also reduced.

Each of the needle roller bearings 3 and 3 ′ described above is of a one-piece type in which rollers 5 and 5 ′ having different lengths are incorporated in one cage, and rollers of different lengths are separately provided in left and right cages. There are separate types that incorporate 5, 5 '. Further, in any case, each needle roller bearing 3, 3'may be formed in a half arc shape.

[0012]

[Effect of device]

 As described above, the present invention reduces the width of the double-row needle roller bearing by changing the length of each row of rollers so that the surface pressures of the rows of rollers are substantially the same. The width of the idler gear can also be reduced accordingly. Therefore, the idler gear can be made compact and lightweight.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment.

FIG. 2 is a sectional view of a conventional example.

[Explanation of symbols]

 1 axis 2 thrust washer 3, 3'needle roller bearing 4 idler gear 5, 5'roller

Claims (1)

[Scope of utility model registration request] 1. In a double-row needle roller bearing for an idler gear having two rows of right and left rollers, the length of each row of rollers is made different so that the surface pressure of the rollers of each row is substantially the same. Double row needle roller bearings for idler gears.