JP2011094727A - Creep prevention device for rolling bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a creep prevention device for a rolling bearing capable of positively preventing the creeping of an outer ring with respect to an aluminum alloy housing. <P>SOLUTION: The creep prevention device for a rolling bearing includes the outer ring having an outer ring track on an inner peripheral surface, an inner ring having an inner ring track on an outer peripheral surface, a plurality of rolling elements provided so as to freely roll between the outer ring track and the inner ring track, an eccentric circumferential groove formed on an outer peripheral surface of the outer ring in a recessed state from the outer peripheral surface and in an eccentric state of a center axis of a groove bottom face with respect to a center axis of the outer ring, a segmental snap ring having elasticity, and the housing having a cylindrical inner peripheral surface. The device is comprised by internally fitting and fixing the snap ring to the inner peripheral surface of the housing in a state of fitting the snap ring to an inner side of the eccentric circumferential groove. The snap ring is formed of polyamide 9T, and does not include glass fiber. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a creep preventing device for a rolling bearing. More specifically, for example, a rolling bearing outer ring incorporated in a rotation support part of various auxiliary equipments for automobiles such as an alternator and a car air conditioner compressor is used to prevent the so-called creep from rotating inside the housing. The present invention relates to a bearing creep prevention device.

In general, various auxiliary machines for automobiles often incorporate a rolling bearing for supporting a rotating shaft inside a housing. In the assembled state, the outer ring constituting the rolling bearing is fitted and fixed inside the housing by an interference fit.
By the way, the thermal expansion coefficient of the aluminum alloy widely used as the material of the housing is larger than the thermal expansion coefficient of the bearing steel constituting the outer ring of the rolling bearing. For this reason, when the rolling bearing is fixed to the inner ring housing in the aluminum alloy housing, when the temperature rises, the allowance of the outer ring relative to the housing is reduced or lost, and so-called creep occurs in which the outer ring rotates inside the housing. In addition, rattling may occur in the rotation support portion due to the rolling bearing. In addition, when creep occurs, the inner peripheral surface of the housing wears with the rotation of the outer ring, and the rattling tends to gradually increase.

  As a bearing provided with a device for preventing such creep, for example, a bearing as shown in FIGS. 5 to 7 is known (see, for example, Patent Document 1). An eccentric circumferential groove 2 is formed on the outer diameter surface 1A of the outer ring 1 of the bearing over the entire circumference. In the eccentric circumferential groove 2, the center O1 of the groove bottom surface 4 having the radius R1 is eccentric with respect to the center O of the outer circumferential circle having the radius R of the outer ring 1 (see FIGS. 5A and 5B). The depth of the shallowest portion of the eccentric circumferential groove 2 is Δd1, and the depth of the deepest portion is Δd2. The eccentric circumferential groove 2 is fitted with a metal retaining ring 6 having a predetermined thickness and having an annular shape with a radius R2 and a small curved portion 5 with a radius R3 projecting to the center. The wall thickness t of the retaining ring 6 is larger than the depth Δd1 of the shallowest portion of the eccentric circumferential groove 2. At the time of mounting, the small curved portion 5 of the retaining ring 6 is located at the deepest portion of the eccentric circumferential groove 2 and protrudes from the outer diameter surface 1A of the outer ring 1 by Δl1, but other portions do not protrude from the eccentric circumferential groove 2. (See FIGS. 7A and 7B).

  When the bearing is fitted to the housing inner diameter surface 7 (the inner diameter is substantially equal to the outer diameter D of the retaining ring 6) in this state, the protruding portion of the small curved portion 5 of the retaining ring 6 is elastically pressed against the wall surface of the housing inner diameter surface 7. The Therefore, both end portions 6 </ b> A of the retaining ring 6 extend toward the shallow side of the eccentric circumferential groove 2 and bite as wedges between the groove bottom surface 4 and the inner wall surface 7 of the housing. Therefore, even when a clearance is generated in the fitting surface between the outer diameter surface 1A of the bearing and the wall surface of the housing inner diameter surface 7, the outer ring 1 of the bearing does not rotate relative to the housing in the direction opposite to the rotation direction of the rotational load. Does not occur. As such a metal retaining ring 6, for example, a heat treated spring steel such as SWH72A is used.

  A bearing provided with a device that prevents creep using a synthetic resin retaining ring 8 as shown in FIG. 8 is also known (see, for example, Patent Document 2). Such an anti-creep device for a rolling bearing is formed with an eccentric circumferential groove on the outer peripheral surface of the outer ring, with the central axis of the groove bottom surface of the eccentric peripheral groove being eccentric with respect to the central axis of the outer ring. Then, a retaining ring, which is formed entirely of an annular shape with an elastic synthetic resin and in which the central axis of the inner peripheral surface and the central axis of the outer peripheral surface are eccentric from each other, is fitted inside the eccentric peripheral groove. is doing. When the rolling bearing is fitted and fixed inside the housing, the retaining ring is fitted into the inner peripheral surface of the housing.

  The thermal expansion coefficient of the synthetic resin constituting the retaining ring is larger than the thermal expansion coefficient of the aluminum alloy constituting the housing. For this reason, even if the outer ring tightening allowance with respect to the housing tends to decrease as the temperature rises, the decrease in the tightening allowance is compensated for by increasing the thickness dimension over the diameter direction of the retaining ring. Moreover, since the groove bottom surface of the eccentric circumferential groove and the inner peripheral surface of the retaining ring are eccentric with respect to the outer peripheral surface of the outer ring and retaining ring, the retaining ring does not rotate with respect to the outer ring. As a result, even when the temperature rises, the bearing steel outer ring does not rotate inside the aluminum alloy housing. As such a synthetic resin retaining ring, for example, polyamide 11, polyamide 46, polyamide 66, polybutylene terephthalate (PBT), modified polyphenylene oxide (polyamide sulfide resin (PPS) containing 10 to 40% by volume of glass fiber) A synthetic resin retaining ring reinforced with 10 to 40% by volume of glass fiber is used for PPO) and the like.

JP 2007-162870 A Japanese Patent Laid-Open No. 10-082428

  However, in these prior arts, since the prevention of creep is performed by the wedge action of the limited portion called the tip of the metal retaining ring, the tip of the metal retaining ring, such as when shaken by vibration, is applied. In some cases, the aluminum alloy housing is damaged or deformed at the edges, and a sufficient creep prevention effect cannot be obtained. Further, in the case of a synthetic resin retaining ring containing glass fibers, the housing made of aluminum alloy is similarly damaged or deformed by the glass fibers, so that a sufficient creep preventing effect may not be obtained.

  An object of the present invention is to provide an anti-creep device that does not cause damage or deformation of an aluminum alloy housing, maintains performance at high temperatures, and can perform anti-creep measures at low cost. is there.

  In order to solve the above problems, the present invention provides an outer ring having an outer ring raceway on an inner peripheral surface, an inner ring having an inner ring raceway on an outer peripheral surface, and a plurality of rolls provided between the outer ring raceway and the inner ring raceway. And an eccentric circumferential groove formed in a state where the outer peripheral surface of the outer ring is recessed from the outer peripheral surface and the central axis of the groove bottom surface is eccentric with respect to the central axis of the outer ring, and elasticity. And a housing having a cylindrical inner peripheral surface, and the retaining ring is fitted to the inner peripheral surface of the housing in a state where the retaining ring is fitted inside the eccentric peripheral groove. In the creep preventing device for a rolling bearing formed by internal fitting, the retaining ring is made of polyamide 9T and does not contain glass fiber.

  According to the present invention, there is no fear that the aluminum alloy housing is damaged or deformed by using a resin retaining ring made of polyamide 9T having high heat resistance and not containing glass fiber, and at a high temperature. It is possible to maintain the performance at the same time and to perform the anti-creep measures at a low cost.

Sectional drawing which shows one example of embodiment of this invention. The figure which looked at the retaining ring used for one example of embodiment of this invention from the side of FIG. The figure similar to FIG. 2 which shows the other example of a retaining ring. (A) is a figure which shows an example with two circular arc-shaped contact parts, (b) is a figure which shows an example with three circular arc-shaped contact parts. The fragmentary sectional view which shows four examples of the formation position of an eccentric circumferential groove. (A) is a figure explaining the eccentric circumferential groove formed in the bearing outer ring, (b) is a longitudinal sectional view of the bearing. It is a top view of a metal retaining ring. (A) is the top view which fitted the metal retaining ring to the eccentric circumferential groove, (b) is the longitudinal cross-sectional view of (a). FIG. 8 is a plan view of a synthetic resin retaining ring.

  1 and 2 show an example of an embodiment of the present invention. In the rolling bearing creep prevention device of the present invention, the outer ring 21 of the rolling bearing 20 fitted and fixed inside the housing 3 made of aluminum alloy and having a cylindrical inner peripheral surface rotates (creep) with respect to the housing 3. It is to prevent that.

  The rolling bearing 20 is provided between the outer ring 21 having the outer ring raceway 26 on the inner peripheral surface, the inner ring 23 having the inner ring raceway 27 on the outer peripheral surface, and the outer ring raceway 26 and the inner ring raceway 27 so as to be able to roll. A plurality of rolling elements 25 and 25 are provided. An eccentric circumferential groove 22 is formed in the outer peripheral surface of the outer ring 21 so as to be recessed from the outer peripheral surface. The central axis of the groove bottom surface 24 of the eccentric circumferential groove 22 is eccentric with respect to the central axis of the outer ring 21.

  On the other hand, the retaining ring 9a fitted in the eccentric circumferential groove 22 is softer than the aluminum alloy housing 3, has a toughness that does not require handling, and absorbs water. Considering the fact that there is no significant dimensional change, polyamide 9T made of no glass fiber is optimal.

  As shown in FIG. 2, the retaining ring 9 a is formed in a partially annular shape as a whole. Further, the central axis of the inner peripheral surface 10a and the central axis of the outer peripheral surface 11a are eccentric from each other. The direction in which the central axes of these peripheral surfaces are eccentric is the direction in which the central axis of the inner peripheral surface 10a is biased toward the discontinuous portion (end portion) 12a side of the retaining ring 9a with respect to the central axis of the outer peripheral surface 11a. Yes. Therefore, the thickness dimension of the retaining ring 9a in the diameter direction is the largest at the central portion, and gradually decreases toward the both end portions.

  Further, an elastic deformation portion 13a protruding outward in the diameter direction of the retaining ring 9a is provided on a part of the retaining ring 9a. An arcuate contact portion 14a is provided in the middle portion of the elastic deformation portion 13a. An outer peripheral surface 15a of the arcuate contact portion 14a is concentric with the outer peripheral surface 11a of the retaining ring 9a and is long in the circumferential direction. The elastic deformation portion 13a has such an arcuate contact portion 14a and a main body portion of the retaining ring 9a via bent portions 16a and 16a provided at both circumferential ends of the arcuate contact portion 14a. Consecutively. Accordingly, the outer peripheral surface 15a of the arc-shaped contact portion 14a is in contact with the inner peripheral surface of the housing 3 almost uniformly over the entire length in a state where the retaining ring 9a is fitted in the housing 3.

  In order to assemble the creep prevention device for a rolling bearing according to the present invention having the rolling bearing 20 and the retaining ring 9a as described above, first, the inner side of the eccentric circumferential groove 22 on the outer circumferential surface of the outer ring 21 constituting the rolling bearing 20 is described. The above retaining ring 9a is fitted. At this time, the eccentric direction of the eccentric circumferential groove 22 and the eccentric direction of the retaining ring 9a are made to coincide with each other, and the outer peripheral surface 11a of the retaining ring 9a is separated from the portion excluding the elastic deformation portion 13a and the outer peripheral surface of the outer ring 21. The positional relationship in the diameter direction is made substantially uniform over the entire circumference. When the retaining ring 9 a is thus fitted inside the eccentric circumferential groove 22, the retaining ring 9 a is fitted into the inner peripheral surface of the housing 3 together with the outer ring 21.

  In the case of the anti-creep device for a rolling bearing according to the present invention in which the constituent members are assembled as described above, the elastically deforming portion 13a formed on the retaining ring 9a is attached to the housing 3 in the housing 3 state. It is crushed elastically between the circumferential surface and the groove bottom surface 24 of the eccentric circumferential groove 22.

  As a result, the outer peripheral surface 15a of the arc-shaped contact portion 14a constituting the intermediate portion of the elastic deformation portion 13a elastically contacts the inner peripheral surface of the housing 3. Therefore, even if there is a slight error between the diameter of the inner peripheral surface of the housing 3 and the diameter of the groove bottom surface 24 of the eccentric peripheral groove 22, the retaining ring 9a with respect to the inner peripheral surface of the housing 3 is used. Can prevent slipping.

  Moreover, in the case of the elastic deformation portion 13a provided on the retaining ring 9a constituting the creep preventing device for the rolling bearing according to the present invention, an arcuate contact portion 14a exists in the middle portion, and the outer periphery of the arcuate contact portion 14a. The surface 15a abuts almost uniformly on the inner peripheral surface of the housing 3 over its entire length. For this reason, the contact area between the outer peripheral surface 15a of the arcuate contact portion 14a constituting the elastic deformation portion 13a and the inner peripheral surface of the housing 3 can be sufficiently widened. Therefore, even when conditions are severe, such as when a dimensional error becomes large, it is possible to sufficiently ensure the effect of preventing the retaining ring 9a from slipping with respect to the housing 3. As a result, the outer ring 21 can be more reliably prevented from rotating inside the housing 3. Further, a plurality of arcuate contact portions 14a may be provided as in the retaining ring shown in FIGS. Moreover, there may not be an arc-shaped contact part like the retaining ring shown in FIG. In the case of the rolling bearing creep prevention device of the present invention, an effect can be obtained regardless of the shape of the retaining ring. Therefore, the rolling bearing creep prevention device using various known retaining rings is effective.

  Furthermore, the position and width dimension of the eccentric circumferential groove formed on the outer peripheral surface of the outer ring can be appropriately changed according to the necessary creep prevention performance and the structure of the rolling bearing. In the case of the example of the embodiment described above, as shown in FIG. 4A, one narrow circumferential groove 22 is provided so as to be biased to one side of the outer peripheral surface of the outer ring 21. On the other hand, as shown in FIG. 4B, two narrow circumferential grooves 32, 32 are provided on both sides of the outer peripheral surface of the outer ring 31, or the outer ring 41 as shown in FIG. 4C. Creep prevention performance can be improved by providing one wide eccentric circumferential groove 42 at the center of the outer peripheral surface. Furthermore, when the rolling bearing 50 is a double row ball bearing as shown in FIG. 4D, two narrow circumferential grooves 52, 52 are provided on both sides of the outer peripheral surface of the outer ring 51. Ensure anti-creep performance.

  The rolling bearing creep prevention device of the present invention is configured and operates as described above, and thus reliably prevents creep of the outer ring with respect to the housing, and improves the reliability and durability of the rotation support portion incorporating the rolling bearing. Can be planned.

  The rolling bearing creep prevention device of the present invention generates so-called creep when the outer ring of a rolling bearing incorporated in a rotation support portion of various auxiliary equipment for automobiles such as an alternator and a compressor for a car air conditioner rotates inside the housing. It can be suitably used for a part that is easy to do.

1,21,31,41,51 Bearing outer ring
1A Outer diameter surface of bearing outer ring
2,22,32,42,52 Eccentric circumferential groove
3 Housing
4,24,34,44,54 Eccentric groove bottom
5 Small bend
6,8,9a, 9b, 9c, 9d, 9e, 9f retaining ring
End of 6A retaining ring
7 Housing inner surface
10a, 10b, 10c Retaining ring inner peripheral surface
11a, 11b, 11c Retaining ring outer peripheral surface
12a, 12b, 12c Discontinuity
13a, 13b, 13c Elastic deformation part
14a, 14b, 14c Arc contact
15a, 15b, 15c Outer peripheral surface of arcuate contact
16a, 16b, 16c Bent part
20,30,40,50 Rolling bearing
23,33,43.53 Bearing outer ring
25,35,45,55 Rolling elements
26,36,46,56 Outer ring raceway
27,37,47,57 Inner ring raceway

Claims (1)

An outer ring having an outer ring raceway on the inner peripheral surface;
An inner ring having an inner ring raceway on the outer peripheral surface;
A plurality of rolling elements provided to freely roll between the outer ring raceway and the inner ring raceway;
An eccentric circumferential groove formed in a state of being recessed from the outer circumferential surface of the outer ring and the center axis of the groove bottom surface being decentered with respect to the central axis of the outer ring;
A non-circular retaining ring having elasticity;
A housing having a cylindrical inner peripheral surface,
In a creep prevention device for a rolling bearing, in which the retaining ring is fitted inside the inner peripheral surface of the housing with the retaining ring fitted inside the eccentric circumferential groove,
An anti-creep device for a rolling bearing, wherein the retaining ring is made of polyamide 9T and does not contain glass fiber.

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