JP2003239991A - Rolling bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly reliable rolling bearing which prevents a device from being damaged even if defect such as seizure of the bearing occurs. <P>SOLUTION: In this roller bearing in which a rolling element 13 and a cage 14 retaining the rolling element 13 are arranged between a first bearing ring 11 and a second bearing ring 12 rotating relatively, a support projection 11a provided in the first bearing ring 11 and extended in the radial direction toward a second bearing ring 12 side is provided, and a tip of the support projection 11a opposes to the second bearing ring 12 or a member fixed to the second bearing ring 12 with a minute clearance S. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling bearing used for industrial machines, and more particularly to a rolling bearing applicable to a radial ball bearing used for an electric motor or the like.

[0002]

2. Description of the Related Art Conventional bearings have a problem in that when a malfunction such as seizure occurs, the rotating shaft locks and stops, or abnormal noises or abnormal vibrations occur to confirm abnormalities. I was invited to stop. After the device is stopped, the defective bearing is replaced with a normal product and the operation of the device is restored. Even if the bearing becomes hot during seizure, if the cage is made of old metal, it will not be damaged enough to shift the center (axial center) of the inner and outer rings. It was difficult to cause damage due to contact between the rotor and stator, damage to the gears of the reduction gear, etc.).

[0003]

However, in recent years, this situation has changed with the use of so-called self-lubricating resin cages for bearings (particularly ball bearings) in many cases. In other words, if the bearing gets hot and seizes,
The heat causes softening and melting of the resin cage, which makes it impossible to maintain equal distribution of the rolling elements by the cage (holding the rolling elements at predetermined intervals in the circumferential direction in the bearing space). As a result of rolling elements rolling in the circumferential direction, or rolling elements (balls) deformed by seizure due to deformation of the resin cage due to softening and melting fall out of the bearings, the inner and outer rings approach and Will move. Then, for example, in the case of an electric motor, a trouble that affects the entire device, such as damage due to contact between a rotor and a stator, which is expensive, and in the case of a reduction gear, damage of gears, occurs.

Further, in the ceramic ball bearings that have been widely used these days, even if seizure occurs, the balls do not melt and the bearings do not easily lock, so that the shaft rotation continues at an abnormally high temperature. The above problems are more likely to occur. In order to prevent this, the cage should be made of metal with less deformation, but the effect of preventing deterioration of grease lubricity due to metal abrasion powder, which is a merit of resin cage, is lost,
The problem of reduced seizure life due to grease deterioration occurs.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a highly reliable rolling bearing which does not damage the device even if a defect such as seizure of the bearing occurs. is there.

[0006]

The object of the present invention is achieved by the following constitution. (1) In a rolling bearing in which a rolling element and a retainer for holding the rolling element are arranged between a relatively rotating first race and a second race, the rolling bearing is provided on the first race. And a supporting protrusion extending in a radial direction toward the second bearing ring side, and a tip of the supporting protrusion is provided with a minute gap with respect to the second bearing ring or a member fixed to the second bearing ring. A rolling bearing characterized by being opposed to each other. (2) The rolling bearing according to (1), wherein the cage is made of resin.

According to the rolling bearing having the above structure, even if a problem such as seizure of the bearing occurs and a part of the cage is melted and deformed, the support projection provided on the first bearing ring is By abutting on the two bearing rings, it is possible to prevent the radial relative positions of the first bearing ring and the second bearing ring from being significantly displaced. Therefore, it is possible to prevent harmful movement of the shaft center (for example, movement of more than the gap between the stator and the rotor in the case of an electric motor) due to clogging or falling of the rolling elements. In particular, when the cage is completely made of resin, the effect of the present invention is remarkable, but even when the cage is made of resin and metal, the effect of the present invention can be obtained.

The first bearing ring provided with the support protrusion may be an outer ring or an inner ring. A housing directly provided with the outer ring raceway, a shaft directly provided with the inner ring raceway, or the like may function as the first bearing ring. The second bearing ring also
Not limited to the outer ring and the inner ring, it may be a housing or a shaft.
The support protrusion may be formed separately and attached to the first bearing ring later, but in this case there is an advantage that the material can be changed freely with the bearing ring, but in terms of workability, it is integrated with the first bearing ring. It is preferable to mold. Usually, as the material of the bearing ring,
Since a hard and strong material exceeding HRC (Rockwell hardness) 58 is used, it is preferable to form the support protrusion with such a hard and strong material and to integrally provide it to the first bearing ring. The support protrusion may extend in a direction slightly inclined with respect to the radial direction.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a rolling bearing 10 according to the first embodiment of the present invention. In the rolling bearing 10, a plurality of balls (rolling elements) 13 are interposed between an outer ring (race ring) 11 which is a first race ring and an inner ring (race ring) 12 which is a second race ring. The plurality of balls 13 are rollably held by a cage 14 at equal intervals in the circumferential direction. A rolling bearing (here, an angular contact ball bearing of an outer ring counterbore) 10 is preferably used to support a rotating shaft (not shown) that rotates at high speed. The cage (here, a cage type cage) 14 is molded from a resin material such as glass fiber reinforced polyamide.

A support protrusion 11a is integrally provided on the counter ring side of the outer ring 11 (on the left side in the figure).
The support protrusion 11a projects inward in the radial direction from the inner diameter surface of the outer race 11, and its tip (inner end) faces the outer diameter surface of the inner race 12 with a minute gap S therebetween. The small gap S is
For example, it can be set to about 0.1 mm to 1 mm. Outer ring 11
The inner ring 12 is formed of a hard material such as SUJ2 that exceeds HRC58.

In the present embodiment, the support protrusion 11a is formed in an annular shape and also functions as a seal structure on the counter counterbore side. The side surface of the support protrusion 11a is flush with the side surface of the inner ring 12 and the side surface of the outer ring 11 on the counter counterbore side. Although not shown, a recess (seal groove or the like) may be formed at the axial end of the outer diameter surface of the inner ring 12, and the tip of the support protrusion 11a may be inserted into the recess.

According to the rolling bearing 10 having the above-described structure, a problem such as seizure occurs during rotation,
Even if the cage 14 is partially melted and deformed by the heat,
The tip of the support protrusion 11a provided on the outer ring 11 is the inner ring 12
By contacting the outer diameter surface of the outer ring 11, the radial relative positions of the outer ring 11 and the inner ring 12 can be prevented from being significantly displaced. That is, the relative movement of the outer ring 11 and the inner ring 12 can be suppressed within the range of the minute gap S. Therefore, it is possible to prevent the harmful movement of the shaft center due to the balls 13 getting clogged or falling off (for example, in the case of an electric motor, movement beyond the gap between the stator and the rotor). In addition, since there is no change in the basic dimensions of the bearing (bearing outer diameter, bearing inner diameter, width, etc.), this rolling bearing 10
There is no need to perform special processing or change the design of the housing that is fitted onto the housing or the shaft that is fitted inside.

FIG. 2 shows a rolling bearing 20 according to the second embodiment of the present invention. In the embodiment described below,
The members having the same configurations and operations as those already described are given the same or corresponding reference numerals in the drawings to simplify or omit the description.

In this embodiment, the outer ring 2 which is the first bearing ring.
1 axial end (counterbore side; left end in the figure)
Is extended from the end of the inner ring 12 which is the second bearing ring, and the support protrusion 21a is extended from the inner diameter surface of the extended portion.
Project inward in the radial direction. The tip (inner end) of the support protrusion 21a faces the outer peripheral surface of the shaft 28 fitted in the inner ring 12 with a minute gap S therebetween. In the present embodiment, the tip end of the support protrusion 21a comes into contact with the outer peripheral surface of the shaft 28 at the time of abnormality such as seizure.

According to the rolling bearing 20 as described above, the bearing space can be widened, and the size (width size) of the cage (penetration type resin cage) 24 is increased to improve the strength of the cage 24. In addition, a sufficient amount of lubricant (grease or the like) can be enclosed in the bearing space to maintain a good lubrication state for a long period of time. Further, a high sealing function can be obtained by the support protrusion 21a. Further, by incorporating the rolling bearing 20 in a housing (not shown) and abutting a corner portion 21b of the outer ring 21 on which the support protrusion 21a is provided, with a step in the housing, the support protrusion 21a prevents axial misalignment. The effect can be enhanced.

FIG. 3 shows a rolling bearing 30 according to the third embodiment of the present invention. The rolling bearing (deep groove ball bearing) 30 includes a crown-shaped cage 34 made of resin. In this embodiment,
One end portion in the axial direction of the inner ring 32 that is the first bearing ring (the cage 34
Pocket opening side (left end in the figure) is extended from the end of the outer ring 31 which is the second bearing ring, and the support projection 32a projects radially outward from the outer diameter surface of the extended portion. ing. The tip (outer end) of the support protrusion 32a faces the inner peripheral surface of the housing 36 with a minute gap S therebetween. In the present embodiment, the tip end of the support protrusion 32a comes into contact with the inner peripheral surface of the housing 36 at the time of abnormality such as seizure.
Here, the corner portion 32b of the inner ring 32 on the side where the support protrusion 32a is provided is abutted against the step portion of the shaft 38 formed in a stepped columnar shape to enhance the effect of preventing the axial misalignment by the support protrusion 32a. There is. Further, the rolling bearing 30 is fixed in the housing 36 by pushing the outer ring 31 toward the support protrusion 32a side by the fixing member 37 provided in the housing 36.

FIG. 4 shows a rolling bearing 40 according to a fourth embodiment of the present invention. The present embodiment is an angular contact ball bearing for an outer ring counterbore that is substantially similar to the first embodiment, but unlike the first embodiment, the support protrusion 41a is formed separately from the outer ring 41 and is retrofitted to the outer ring 41. Has been done. According to this embodiment, the supporting protrusion can be easily attached to the conventional outer ring only by processing the fitting surface. The fit may be a tight fit or may be glued. Although not shown, a support protrusion formed separately may be attached to a conventional inner ring afterwards.

The present invention is not limited to the above-described embodiment, but can be appropriately modified and improved. For example, the present invention can be applied to rolling bearings having rolling elements (rollers, tapered rollers, etc.) other than balls. Further, the present invention can be applied to a double row rolling bearing. For example, a plurality of support protrusions may be provided on the first bearing ring at intervals in the circumferential direction.

When a plurality of rolling bearings are used in combination, each rolling bearing may be provided with a supporting protrusion, but as shown in FIG. 5, one rolling bearing 50 may be provided with a supporting protrusion 51a. . Further, as shown in FIG. 6, a pair of bearings 5a, 5b incorporated in the case 4 of the motor.
A rolling bearing provided with the above-described support protrusion may be used for both or one of them. The motor includes a rotor shaft 2 on which the rotor 1 is mounted, and a stator core 3 arranged on the outer periphery of the rotor shaft 2, and these are housed in a case 4. Both ends of the rotor shaft 2 are supported by a pair of bearings 5 a and 5 b incorporated in the case 4. A wave washer is inserted into the side surface of the bearing 5b, and a preload is axially applied to the bearings 5a and 5b.

[0020]

As described above, according to the present invention,
It is possible to provide a highly reliable rolling bearing that does not damage the device even if a problem such as seizure of the bearing occurs.

[Brief description of drawings]

FIG. 1 is a sectional view of a first embodiment.

FIG. 2 is a sectional view of a second embodiment.

FIG. 3 is a sectional view of a third embodiment.

FIG. 4 is a sectional view of a fourth embodiment.

FIG. 5 is a diagram showing another embodiment of the present invention.

FIG. 6 is a diagram showing another embodiment of the present invention.

[Explanation of symbols]

10, 20, 30, 40 Rolling bearing 11,21,31,41 outer ring 11a, 21a, 32a, 41a Support protrusion 12,32 inner ring 13 balls (rolling elements) 14, 24, 34 cage

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 3J016 AA02 BB12 CA00                 3J101 AA02 AA32 AA52 AA62 BA50                       BA54 EA36 FA33 GA24

Claims (2)

[Claims] 1. A rolling bearing in which a rolling element and a retainer for holding the rolling element are arranged between a first bearing ring and a second bearing ring which rotate relatively to each other. A support protrusion provided in the radial direction toward the second race is provided, and a tip of the support protrusion forms a minute gap with respect to the second race or a member fixed to the second race. A rolling bearing characterized by being open and facing each other. 2. The rolling bearing according to claim 1, wherein the cage is made of resin.