JP7017960B2 - Ball bearing holding structure - Google Patents

Description

The present invention relates to a holding structure of a ball bearing in a cylindrical rotating member of a drive system.

FIG. 13 is a vertical sectional view showing a driven side pulley device of a conventional general continuously variable transmission (CVT). The pulley device 10 has a fixed sheave 3 and a movable sheave 4, a fixed sheave boss 5 and a movable sheave boss 6, a cam mechanism 7, a spring 8, and a centrifugal clutch 9. The fixed sheave boss 5 is formed in a cylindrical shape, and an output shaft (not shown) that transmits torque to the rear wheel side is provided through the inside thereof. A needle bearing 18 and a ball bearing 14 are provided between the inner peripheral surface of the boss 5 and the output shaft.

By the way, the ball bearing 14 is prevented from coming off from the boss 5 by the snap ring 16. The snap ring 16 is grooved on the inner peripheral surface of the boss 5 and set in the groove.

JP-A-2015-64014

However, the holding structure of the ball bearing 14 using the snap ring 16 as described above has the following problems.
(1) It is difficult to evaluate the quality of the groove processing applied to the inner part of the boss 5 because the required accuracy is high.
(2) It is difficult to set the snap ring 16 in the groove machined in the inner part of the boss 5.
(3) It is difficult to confirm whether or not the snap ring 16 is set correctly.

An object of the present invention is to provide a holding structure for a ball bearing, which can solve the above-mentioned problems.

In the present invention, in the holding structure of the ball bearing in the cylindrical rotating member of the drive system, the rotating member has an engaging projection protruding radially inward on the inner peripheral surface, and the engaging projection is provided. However, the ball bearing is formed so as to elastically deform radially outward when it receives pressure from the inside in the radial direction, and the ball bearing overcomes the engaging protrusion from the front in the axial direction to the rear in the axial direction. It is characterized in that it is locked to an engaging protrusion.

According to the present invention, since the holding structure of the ball bearing can be realized without using the snap ring, all the above-mentioned problems when the snap ring is used can be solved.

It is a vertical sectional view which shows the holding structure of the ball bearing by one Embodiment of this invention. It is a vertical sectional view which shows the boss before the ball bearing is attached. FIG. 2 is a cross-sectional view taken along the line III-III in FIG. It is a partially enlarged sectional view of a boss. It is a vertical sectional view which shows the state of inserting a ball bearing into a boss. It is a vertical cross-sectional view which shows how the ball bearing gets over the engaging protrusion. It is an enlarged vertical sectional view which shows the state of elastic deformation of an engagement protrusion. It is a vertical cross-sectional view which shows the 1st deformation form in which a groove is formed only in the front in the axial direction. It is a vertical cross-sectional view which shows the 2nd deformation form in which a groove is formed only in the rear in the axial direction. It is a vertical cross-sectional enlarged partial view which shows the 3rd deformation form in which the guide surface of an engagement protrusion is a curved surface. It is a figure corresponding to FIG. 3 which shows the 4th deformation form in which the engaging protrusion was formed intermittently in the circumferential direction on the inner peripheral surface of a boss. It is a vertical cross-sectional enlarged partial view which shows the 5th deformation form in which a groove is formed on the outer peripheral surface of a boss. It is a vertical sectional view which shows the driven side pulley device of a continuously variable transmission including a cylindrical rotating member of a drive system.

FIG. 1 is a vertical sectional view showing a holding structure of a ball bearing according to an embodiment of the present invention, and shows a part of a cylindrical rotating member of a drive system. In the present embodiment, the drive system is the driven side pulley device 10 of the CVT shown in FIG. 13, and the cylindrical rotating member is the fixed sheave boss 5.

As shown in FIG. 1, the ball bearing 14 is arranged in the inner part of the boss 5 and is locked to the engaging protrusion 1 in a state of being in contact with the step portion 51 of the boss 5. , The boss 5 is prevented from coming off. FIG. 2 is a vertical sectional view showing a boss 5 before the ball bearing 14 is attached. FIG. 3 is a cross-sectional view taken along the line III-III of FIG. As shown in FIG. 2, in the inner part of the boss 5, an engaging protrusion 1 protruding inward in the radial direction is formed on the inner peripheral surface 52, and further, a shaft with respect to the engaging protrusion 1. Grooves 21 and 22 are formed adjacent to each other in the direction and on both sides of the engaging protrusion 1 in the axial direction. The engaging protrusion 1 and the grooves 21 and 22 are continuously formed on the entire circumference in the circumferential direction. The ball bearing 14 has a conventional general structure, that is, a structure in which a large number of balls 141 are held between the outer race 142 and the inner race 143 by the retainer 144.

FIG. 4 is a partially enlarged cross-sectional view of the boss 5. The engaging projection 1 has a guide surface 11 on a portion on the front side in the axial direction. The guide surface 11 is an inclined surface that is inclined so that the protrusion height T gradually increases from the front in the axial direction to the rear in the axial direction. The portion 12 on the rear side in the axial direction of the engaging protrusion 1 has an edge shape.

The protruding height T of the engaging protrusion 1 from the inner peripheral surface 52 is preferably 0.3 mm to 0.7 mm, and particularly preferably 0.5 mm. The axial width W1 of the engaging protrusion 1 is preferably 1.5 mm to 2.5 mm, and particularly preferably 2.0 mm. The inclination angle α of the inclined surface 11 is preferably 20 degrees to 40 degrees, and particularly preferably 30 degrees. The depth D of the groove 21 is preferably 0.4 mm to 0.6 mm, and particularly preferably 0.5 mm. The axial width W2 of the groove 21 is preferably 0.8 mm to 1.2 mm, and particularly preferably 1.0 mm. The groove 22 preferably has the same depth and width as the groove 21 within the range of the depth D and the width W2 of the groove 21, but may be different.

As shown in FIG. 5, the ball bearing 14 is inserted inside the boss 5 from the front in the axial direction to the rear in the axial direction. By the way, since the grooves 21 and 22 exist on both sides of the engaging protrusion 1 in the axial direction, the wall portion 50 of the boss 5 having the engaging protrusion 1 is outside the radial direction when pressure is received from the inside in the radial direction. It can be elastically deformed in the direction. Therefore, as shown in FIG. 6, the inserted ball bearing 14 overcomes the engaging protrusion 1 from the front in the axial direction to the rear in the axial direction while elastically deforming the engaging protrusion 1 in the outward direction in the radial direction. .. FIG. 7 is an enlarged vertical sectional view showing a state of elastic deformation of the engaging protrusion 1. In FIG. 7, the wall portion 50 including the engaging projection 1 is elastically deformed outward in the radial direction. At this time, since the ball bearing 14 is guided by the guide surface 11, the engaging projection 1 can be easily overcome. Then, the ball bearing 14 is locked to the engaging protrusion 1 recovered from the elastic deformation as shown in FIG. 1 in a state of getting over the engaging protrusion 1. Since the portion 12 on the rear side in the axial direction of the engaging protrusion 1 has an edge shape, the ball bearing 14 is firmly locked.

As described above, the holding structure of the ball bearing of the present invention is realized by providing the elastically deformable engaging projection 1.

As described above, the ball bearing holding structure according to the present embodiment can be realized without using a snap ring, so that the following effects can be exhibited.
(1) The cost required for the snap ring can be reduced.
(2) Quality evaluation of grooving with high required accuracy can be eliminated, and therefore quality evaluation work can be simplified.
(3) Since the setting work of the snap ring can be eliminated and the ball bearing can be attached by simply press-fitting it into the boss 5 at once, the workability of manufacturing can be improved.
(4) Since it is possible to eliminate the work of confirming whether or not the snap ring is set correctly, the workability of manufacturing can be improved.

(Another embodiment)
The present invention may adopt the following modified configurations.

(A) As shown in FIG. 8, only the groove 21 in the front in the axial direction is formed. That is, the groove is formed only on one side in the axial direction of the engaging protrusion. Even with this, since the wall portion 50 can be elastically deformed, the same effect as that of the above embodiment can be exhibited.

(B) As shown in FIG. 9, only the groove 22 rearward in the axial direction is formed. That is, the groove is formed only on one side in the axial direction of the engaging protrusion. Even with this, since the wall portion 50 can be elastically deformed, the same effect as that of the above embodiment can be exhibited.

(C) As shown in FIG. 10, the guide surface 11 of the engaging projection 1 is a curved surface. Even with this, since the ball bearing 14 is guided by the guide surface 11, the engaging projection 1 can be easily overcome.

(D) FIG. 11 is a diagram corresponding to FIG. As shown in FIG. 11, the engaging protrusion 1 is formed intermittently in the circumferential direction on the inner peripheral surface 52 of the boss 5. Here, the engaging protrusions 1 are formed at three points in the circumferential direction at equal intervals, and are continuous at each place by an equal distance L. Even with this, since the wall portion 50 can be elastically deformed, the same effect as that of the above embodiment can be exhibited.

(E) As shown in FIG. 12, the grooves 21 and 22 are formed on the outer peripheral surface 53 of the boss 5 instead of the inner peripheral surface 52. Even with this, since the wall portion 50 can be elastically deformed, the same effect as that of the above embodiment can be exhibited. The grooves 21 and 22 formed on the outer peripheral surface 53 are in a front-to-back relationship with the grooves 21 and 22 formed on the inner peripheral surface 52.

(F) The holding structure of the ball bearing of the present invention can be applied to the cylindrical rotating member of the drive system. Examples of the cylindrical rotating member include a pulley or a boss of another rotating body.

The holding structure of the ball bearing of the present invention can eliminate all the conventional problems when the snap ring is used, and therefore has great industrial utility value.

1 Engagement protrusion 5 Boss for fixed sheave 11 Guide surface 14 Ball bearings 21, 22 Grooves

Claims (9)

In the holding structure of the ball bearing in the cylindrical rotating member of the drive system,
The rotating member has an engaging protrusion that protrudes inward in the radial direction on the inner peripheral surface.
The engaging projection is formed so as to elastically deform radially outward when pressure is applied from the inside in the radial direction.
The ball bearing is locked to the engaging protrusion in a state where the ball bearing gets over the engaging protrusion from the front in the axial direction to the rear in the axial direction .
A holding structure for a ball bearing , wherein the engaging protrusion is elastically deformable by a groove formed on the inner peripheral surface adjacent to the axial direction . The grooves are formed on both sides of the engaging protrusion in the axial direction.
The ball bearing holding structure according to claim 1 . The groove is formed only on one side in the axial direction of the engaging protrusion.
The ball bearing holding structure according to claim 1 . The engaging projection has an inclined or curved guide surface in a portion on the front side in the axial direction.
The ball bearing holding structure according to any one of claims 1 to 3 . The engaging protrusions are continuously formed on the inner peripheral surface over the entire circumference in the circumferential direction.
The ball bearing holding structure according to any one of claims 1 to 4 . The engaging protrusions are formed intermittently in the circumferential direction on the inner peripheral surface.
The ball bearing holding structure according to any one of claims 1 to 4 . The depth of the groove is 0.4 mm to 0.6 mm, and the groove depth is 0.4 mm to 0.6 mm.
The axial width of the groove is 0.8 mm to 1.2 mm.
The ball bearing holding structure according to any one of claims 1 to 6 . The rotating member is the boss of the pulley.
The ball bearing holding structure according to any one of claims 1 to 7 . The pulley is a driven side pulley of the CVT, and the boss is a fixed sheave boss.
The ball bearing holding structure according to claim 8 .

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