JPH0610208Y2 - Inner ring fixing device for rolling bearings - Google Patents

Description

Detailed Description of the Invention a. The purpose of the invention (industrial application field) The inner ring fixing device for a rolling bearing according to the present invention is applied to a case where a shaft and various members are freely rotatable relative to each other to increase the rotational torque of the rolling bearing. At the same time, it is intended to improve the performance and durability of the bearing.

(Prior Art) Rolling bearings are widely used when a shaft and various members are freely combined for relative rotation.

The shaft is rotatably inserted through the bearing housing through the bearing,
The structure of such a rolling bearing will be described with reference to FIG. 2 showing a structure in which a gear is fixed to one end of this shaft.

In FIG. 2, reference numeral 1 denotes a bearing housing, which is an outer ring 4 of the bearing.
A circular hole 3 for internally fitting is formed. In the circular hole 3, a plurality of rolling elements 7, 7 are provided in an annular gap 6 between the inner peripheral surface of the outer ring 4 and the outer peripheral surface of the inner ring 5 that is concentrically inserted inside the outer ring 4. The shaft 2 is rotatably supported via a rolling bearing 18 provided with.

That is, a small diameter portion 8 is formed at the end of the shaft 2 so that the inner ring 5 can be fitted onto the shaft 2 without rattling.
The end portion of the inner ring 5 is abutted against the center end of the
Are formed. A screw hole 10 is formed in the center of the end surface of the shaft 2, and a bolt 11 screwed into the screw hole 10 is formed.
Thereby presses the gear 12 which is fitted onto the outer peripheral surface of the end portion of the shaft 2 in a non-rotatable manner toward the other end surface of the inner ring 5, so that the inner ring 5 is connected to the step portion 9 and the inner peripheral portion of the gear 12. The inner ring 5 is fixed to the outer peripheral surface of the shaft 2 by being strongly sandwiched between them.

The inner peripheral surface of the outer ring 4 and the outer peripheral surface of the inner ring 5 each have a radius of curvature R (R> R) that is slightly larger than the radius r of the rolling elements 7, 7.
forming tracks 13 and 14 having r).

By mounting the rolling bearing 18 as described above, the shaft 2 can be rotatably supported inside the circular hole 3 formed in the bearing housing 1, and the shaft 2 can be supported in the thrust direction (left and right direction in FIG. 2). ) Will not move.

(Problems to be Solved by the Invention) However, in the rolling bearing constructed and used as described above, the following disadvantages have conventionally occurred.

That is, the step portion 9 and the gear 12 formed on the outer peripheral surface of the end portion of the shaft 2
The inner ring 5, which is strongly sandwiched by a member that is pressed by the tightening of the bolt 11, etc., is made of a highly rigid material such as bearing steel (see JIS G 4805). It is inevitable that the pressing force causes a slight elastic deformation.

In order to assemble the rolling bearing 18 in the state shown in FIG. 2, when compressive stress is applied to the inner ring 5 in the axial direction,
As exaggeratedly shown in the figure, the inner ring 5 having the shape shown by the chain line in the figure before applying the stress is changed to the shape shown by the solid line in the figure by applying the stress, and the track 14 , 14 has a radius of curvature from R to R '(R>R') and a pitch of P to P '.
(P> P '), respectively.

For example, according to an experiment conducted by the present inventor, when the tightening torque of the bolt 11 is gradually increased, the radii of curvature R of the tracks 14, 14 formed on the outer peripheral surface of the inner ring 5 are almost as shown in FIG. It turned out to be linearly smaller.

Further, when a plurality of raceways 14, 14 are formed on the outer peripheral surface of the inner ring 5, the pitch P between adjacent raceways 14, 14 is P.
Also, as shown in FIG. 5, as the tightening torque increases, it decreases almost linearly, and as a result, the riding limit misalignment (in the range where the rolling element 7 does not contact the shoulder portion of the raceway 14, It has been found that the maximum angle at which the inner ring 5 can be inclined with respect to the outer ring 4) decreases linearly as shown in FIG.

Further, the size of the axial clearance existing between the rolling elements 7 and 7 and the inner and outer wheels 5 and 4 may decrease substantially linearly as shown in FIG. 6 as the tightening torque increases. I understand.

In this way, when the dimensions of the raceways 14, 14 on the outer peripheral surface of the inner ring 5 constituting the bearing 18 are changed due to the tightening of the bolt 11, for example, when the radius of curvature R of the raceway 14 is reduced, the bearing portion is allowed. The thrust load is reduced and the rolling element 7,
7 easily rides on the shoulder portion of the track 14, and the durability of the bearing portion deteriorates.

Further, in the case of a so-called multi-row bearing having a plurality of raceways 14, when the pitch of the raceways 14 and 14 is reduced and the allowable misalignment is reduced, the rolling elements 7 and 7 are also driven by the raceway 14.
It becomes easier to ride on the shoulder part of the and the durability of the bearing part deteriorates.

Further, when the axial clearance becomes small, the torque required for the rotation of the rolling bearing increases, and at the same time, the wear of each component becomes significant and the durability of the bearing portion deteriorates.

The inner ring fixing device for a rolling bearing according to the present invention eliminates any of the above inconveniences by preventing elastic deformation of the inner ring 5 caused by tightening the bolt 11.

b. Configuration of the Invention (Means for Solving the Problem) An inner ring fixing device for a rolling bearing according to the present invention is provided between an outer peripheral surface of a shaft and an inner peripheral surface of a circular hole formed in a member rotatable relative to the shaft. The inner ring that makes up the rolling bearing
It is fixed to the outer peripheral surface of the shaft. This rolling bearing is configured by interposing a plurality of rolling elements between a raceway formed on the outer peripheral surface of the inner ring and a raceway formed on the inner peripheral surface of the outer ring.

Furthermore, in the rolling bearing inner ring fixing device of the present invention,
A convex portion is formed on the inner circumference of the inner ring, and the convex portion is formed between a step portion formed on the outer peripheral surface of the end portion of the shaft and a member fixed to the shaft at a portion near the end surface of the shaft. It is sandwiched.

(Operation) The bearing operation itself of the rolling bearing fixed to the outer peripheral surface of the shaft by the inner ring fixing device of the rolling bearing of the present invention configured as described above is the same as that of the conventional rolling bearing described above. The shaft and the member are rotatably supported by the relative rotation of the inner and outer wheels associated with the rolling of the moving body.

However, in the rolling bearing inner ring fixing device of the present invention,
Since the inner ring of the rolling bearing is fixed to the outer peripheral surface of the shaft, it is done by sandwiching the convex part formed on the inner periphery of the inner ring.
During the fixing work, no compressive stress is applied to a portion other than the convex portion of the inner ring, and the curvature or pitch of the track formed on the outer peripheral surface of the inner ring does not change.

(Embodiment) Next, the present invention will be described in more detail with reference to the illustrated embodiment.

FIG. 1 shows an embodiment in which the present invention is applied to a multi-row bearing.

A circular hole 3 for inserting the shaft 2 is formed in the bearing housing 1, and between the inner peripheral surface of the outer ring 4 and the outer peripheral surface of the inner ring 5 concentrically inserted inside the outer ring 4. Annular gap 6
Rolling bearing 18 having a plurality of rolling elements 7, 7 provided therein
Are mounted between the outer peripheral surface of the shaft 2 and the inner peripheral surface of the circular hole 3.

A small-diameter portion 8 is formed at the end of the shaft 2 so that the inner ring 5 can be fitted without rattling, and a screw hole 10 is formed at the center of the end surface of the shaft 2. A portion of the small-diameter portion 8 near the shaft end is a gear mounting portion 16 having a smaller diameter.
A step portion 17 is formed between 16.

An inward flange-shaped convex portion 15 is formed on the inner peripheral edge of the end portion (right end portion in FIG. 1) of the inner ring 5 that constitutes the rolling bearing 18, and the side surface of the convex portion 15 near the shaft center ( Step portion 17 formed on the outer peripheral surface of the end portion of the shaft 2 on the left side of FIG.
Abutting against.

The gear 12 is externally fitted to the small-diameter gear mounting portion 16 formed closer to the shaft end than the small-diameter portion 8 to which the inner ring 5 is externally fitted. The inner peripheral portion of the gear 12 is pressed against the end surface of the inner ring 5 by tightening a bolt 11 screwed into a screw hole 10 formed in the end surface of the second gear 2.

By the pressing of the gear 12 accompanying the tightening of the bolt 11, the convex portion 15 formed on the inner peripheral edge of the end portion of the inner ring 5 is strongly sandwiched between the step portion 17 and the inner peripheral portion of the gear 12, and rolling. The inner ring 5 that constitutes the bearing 18 is fixed to the outer peripheral surface of the shaft 2. In this state, the end face of the inner ring 5 closer to the center of the shaft 2 does not collide with the step 9 at the end of the small diameter portion 8 but the step 9
There is a minute gap 19 between the inner ring 5 and the end surface of the inner ring 5. An outer ring 4 mounted on the outer side of the inner ring 5 via a plurality of rolling elements 7, 7 is fitted in a circular hole 3 formed in the bearing housing 1 without rattling.

The inner peripheral surface of the outer ring 4 and the outer peripheral surface of the inner ring 5 have a radius of curvature R (R> r) slightly larger than the radius r of the rolling elements 7 and 7, respectively, as in the case of the conventional rolling bearing described above. Are formed so that the rolling elements 7 and 7 do not move in the width direction of the inner and outer wheels 5 and 4 (left and right direction in FIG. 1).

The embodiment of the inner ring fixing device for a rolling bearing of the present invention is constructed as described above. The bearing action itself of the rolling bearing fixed to the outer peripheral surface of the shaft 2 by this inner ring fixing device is the same as the conventional rolling device described above. Similar to bearings.

That is, the inner and outer wheels 5, which accompany the rolling of the plurality of rolling elements 7,
Due to the relative rotation of 4, the shaft 2 is rotatably supported in the circular hole 3 of the bearing housing 1.

However, in the rolling bearing inner ring fixing device of the present invention,
The inner ring 5 that constitutes the rolling bearing 18 is fixed to the outer peripheral surface of the end portion of the shaft 2 by clamping the inward flange-shaped convex portion 15 formed on the inner peripheral edge of the end portion of the inner ring 5, so that the bolt is used. During the work of fixing the inner ring 5 accompanying the tightening of 11, the compressive stress is not applied to the part other than the convex portion 15 of the inner ring 5. That is, when fixing the inner ring 5,
Since only 5 receives the compressive stress and the portion of the inner race 5 where the raceways 14, 14 are formed on the outer peripheral surface does not receive the compressive stress, the curvature R and the pitch P of the raceways 14, 14 change. There is nothing to do.

Since the inner ring 5 is fixed to the outer peripheral surface of the shaft 2, the convex portion 15 formed on the inner peripheral surface of the inner ring 5 may be formed over the entire inner peripheral surface of the inner ring 5 or may be discontinuous. You may form. Further, the position where the convex portion 15 is formed is not limited to the end portion of the inner ring 5, and can be provided at an arbitrary position in relation to the mating member that holds the convex portion 15.

c. Effect of the Invention Since the inner ring fixing device for a rolling bearing of the present invention is configured and operates as described above, it is possible to prevent elastic deformation of the inner ring due to the work of fixing the rolling bearing, and to prevent elastic deformation of the inner ring. It is possible to improve the performance and durability of the rolling bearing that is fixedly used on the outer peripheral surface of the shaft by preventing the accompanying malfunction of the rolling bearing and deterioration of the durability.

[Brief description of drawings]

FIG. 1 is a partial sectional view showing an embodiment of an inner ring fixing device for a rolling bearing of the present invention, and FIG. 2 is a sectional view similar to FIG. 1 showing a rolling bearing fixed to an outer peripheral surface of a shaft by a conventional structure, Fig. 3 is a diagram comparing the shapes of the inner ring before and after applying stress, Fig. 4 is a diagram showing the change in the radius of curvature of the track with the magnitude of stress, and Fig. 5 is the magnitude of stress. Fig. 6 is a diagram showing the change in the pitch of the orbit due to the stress, Fig. 6 is a diagram showing the change in the axial clearance with the magnitude of stress, and Fig. 7 is the riding limit with the magnitude of stress. It is a diagram which shows the change of misalignment. 1: bearing housing, 2: shaft, 3: circular hole, 4: outer ring,
5: inner ring, 6: clearance, 7: rolling element, 8: small diameter part, 9: stepped part, 10: screw hole, 11: bolt, 12: gear, 13,
14: raceway, 15: convex portion, 16: gear mounting portion, 17: step portion, 18: rolling bearing, 19: gap.

Claims (5)

[Scope of utility model registration request] 1. An inner ring of a rolling bearing in which a plurality of rolling elements are interposed between a raceway formed on an outer peripheral surface of an inner ring and a raceway formed on an inner peripheral surface of an outer ring, is fixed to an outer peripheral surface of an end portion of a shaft. In an inner ring fixing device for a rolling bearing, a convex portion formed on the inner periphery of the inner ring has a step portion formed on the outer peripheral surface of the end portion of the shaft, and the shaft portion is closer to the end surface of the shaft than the step portion. An inner ring fixing device for a rolling bearing, characterized in that it is sandwiched between a member fixed to the inner ring. 2. The inner ring fixing device for a rolling bearing according to claim 1, wherein the convex portion is formed over the entire inner circumference of the inner ring. 3. The inner ring fixing device for a rolling bearing according to claim 1, wherein the convex portion is formed on a part of the inner circumference of the inner ring. 4. The inner ring of a rolling bearing according to claim 1, 2 or 3, wherein the member is a head of a bolt screwed into a screw hole formed in the end surface of the shaft. Fixing device. 5. The utility model registration claim 1 or claim 1, wherein the member is a component fixed to the outer peripheral surface of the end portion of the shaft by a bolt screwed into a screw hole formed in the end surface of the shaft. An inner ring fixing device for a rolling bearing according to item 2 or item 3.