Creep-resistant bearing

Abstract

The objective is to provide a creep-resistant bearing that can suppress the occurrence of creep while ensuring sufficient rigidity in the fixed wheel. [Solution] The creep-resistant bearing (bearing 100) according to the present invention comprises an outer ring 110, an inner ring 120, and rolling elements (balls 130) that roll between the outer ring and the inner ring. When one of the outer ring or inner ring is a stationary ring and the other is a rotating ring, an annular groove 140 is formed on the outer circumferential surface of the stationary outer ring or on the inner circumferential surface of the stationary inner ring at a position corresponding to the load area when the stationary ring is subjected to a load. The annular groove 140 has deep groove portions 142 with greater groove depth at both ends, and shallow raised portions 144 are formed between the deep groove portions 142.

Description

Technical Field

[0001] The present invention relates to a creep-resistant bearing.

Background Art

[0002] In the case of a bearing having a structure in which the bearing is fitted into a housing and a shaft is inserted into the inner ring of the bearing and the inner ring rotates together with the shaft, outer ring creep may occur. As an example, when a load is applied to the bearing, the outer ring raceway portion is distorted by the rolling element load within the load zone. This distortion also affects the outer diameter of the outer ring, and the distortion of the outer diameter surface of the outer ring propagates in the moving direction of the rolling elements together with the revolution motion of the rolling elements. Such distortion propagation causes the outer ring to move relative to the housing, which is called so-called outer ring distortion creep.

[0003] For example, Patent Document 1 discloses "a rolling bearing including an inner ring, an outer ring, a plurality of rolling elements interposed between the inner ring and the outer ring, and a cage for holding the plurality of rolling elements, wherein one of the inner ring and the outer ring is a rotating ring and the other is a fixed ring".

[0004] The rolling bearing of Patent Document 1 is described as follows: "An annular groove for creep suppression is formed on the fitting surface with the mating member to which the fixed ring is attached. The annular groove has a groove bottom portion and a pair of tapered surface portions extending from both axial sides of the groove bottom portion and widening the groove width as they extend toward the fitting surface side. The cross-sectional shape of the tapered surface portion in a cross-section including the bearing center line is a linear shape inclined with respect to the fitting surface." According to Patent Document 1, "it is possible to relieve the local increase in the contact surface pressure caused by the contact between the fixed ring and the mating member, and even if creep occurs in the fixed ring, wear is less likely to progress."

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] In a configuration where an annular groove is provided on the outer ring (or inner ring) as in Patent Document 1, if the groove is made deeper to suppress creep, the rigidity of the outer ring (or inner ring) decreases, which in turn leads to a reduction in bearing life due to raceway deformation. On the other hand, if the annular groove is made shallower to ensure rigidity, the creep suppression effect is reduced.

[0007] In view of these problems, the present invention aims to provide a creep-resistant bearing that can suppress the occurrence of creep while ensuring sufficient rigidity in the fixed wheel. [Means for solving the problem]

[0008] To solve the above problems, a typical configuration of the creep-resistant bearing according to the present invention comprises an outer ring, an inner ring, and rolling elements that roll between the outer ring and the inner ring, wherein when one of the outer ring or inner ring is a stationary ring and the other is a rotating ring, an annular groove is formed on the outer circumferential surface of the stationary outer ring or on the inner circumferential surface of the stationary inner ring at a position corresponding to the load area when the stationary ring is subjected to a load, and the annular groove has deep groove sections with greater groove depth at both ends, and shallower raised sections formed between the deep groove sections.

[0009] The raised portion described above should preferably have a rectangular cross-section.

[0010] The above-mentioned raised portion should preferably have an arch-shaped cross-section.

[0011] The raised portion described above should preferably have a trapezoidal cross-section. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a creep-resistant bearing that can ensure sufficient rigidity in the fixed wheel while suppressing the occurrence of creep. [Brief explanation of the drawing]

[0013] [Figure 1] This is a diagram illustrating a creep-resistant bearing according to the first embodiment. [Figure 2] This figure illustrates a creep-resistant bearing according to a second embodiment. [Figure 3] This is a diagram illustrating a creep-resistant bearing according to a third embodiment. [Figure 4] This figure illustrates a creep-resistant bearing according to the fourth embodiment. [Modes for carrying out the invention]

[0014] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings. The dimensions, materials, and other specific numerical values ​​shown in these embodiments are merely examples to facilitate understanding of the invention and do not limit the present invention unless otherwise specified. In this specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals to avoid redundant explanations, and elements not directly related to the present invention are omitted from the illustrations.

[0015] (First Embodiment) Figure 1 is a diagram illustrating a creep-resistant bearing (hereinafter referred to as bearing 100) according to the first embodiment. As shown in Figure 1, the bearing 100 of this embodiment comprises an outer ring 110, an inner ring 120, and balls 130 which are rolling elements that roll between them.

[0016] Bearings are often used with one ring fixed and the other rotating, and creep occurs in the fixed ring. There are several modes of creep, but this discussion will focus on strain creep. In the following explanation, we will assume that the outer ring is a fixed ring fixed to the housing (mating member). The case where the inner ring is a fixed ring will be discussed later using Figure 4.

[0017] As a feature of the first embodiment, an annular groove 140 is formed in an outer circumferential surface 112 of an outer ring 110 which is a fixed ring. Specifically, the annular groove 140 is formed at a position corresponding to a load zone L when the fixed ring receives a load, in the outer circumferential surface 112 of the outer ring 110 which is a fixed ring, and a width W1 of the annular groove 140 is set wider than a width W2 of the load zone L.

[0018] The annular groove 140 is configured to include a pair of deep groove portions 142 and a raised portion 144. The pair of deep groove portions 142 are arranged at both ends in the annular groove 140, and are portions where the depth of the groove is deep. The raised portion 144 is arranged between the pair of deep groove portions 142, that is, at a position corresponding to the load zone L, and is a portion where the depth of the groove is shallow. The name "raised portion" means that it is raised toward the outer circumferential surface 112 with reference to the bottom of the deep groove portion 142. If observed in the depth direction of the groove with reference to the outer circumferential surface 112, it may be read as a "shallow groove portion". In other words, the raised portion 144 is a portion where the wall thickness of the outer ring 110 which is a fixed ring is thick in the annular groove 140.

[0019] In the bearing 100 of the first embodiment, the raised portion 144 has a rectangular cross section. The height of the raised portion 144 is set such that the raised portion 144 does not contact the housing (counter member) even when the maximum load of the allowable load is applied to the bearing 100.

[0020] According to the above configuration, by forming the annular groove 140 in the outer ring 110 which is a fixed ring, even when distortion occurs in the outer circumferential surface 112 of the outer ring 110 during rotation of the bearing 100, the distorted portion does not contact the housing. That is, the distortion can be absorbed in the annular groove 140. Therefore, it is possible to suppress the occurrence of creep due to the distortion of the outer ring 110.

[0021] And, by arranging a raised portion 144 with a shallow depth at the center of the annular groove 140, there is less distortion compared to the case where the entire annular groove 140 has the depth of the deep groove portion 142. Therefore, it is possible to sufficiently secure the rigidity of the outer ring 110 which is a fixed ring while ensuring the function (creep prevention) of the annular groove 140.

[0022] (Second Embodiment) FIG. 2 is a diagram for explaining a creep-resistant bearing (hereinafter referred to as bearing 100a) according to the second embodiment. In the embodiments described below, for the components common to the bearing of the previously described embodiment, the description will be omitted by assigning the same reference numerals.

[0023] The bearing 100a of the second embodiment shown in FIG. 2 includes an annular groove 140a instead of the annular groove 140 of the bearing 100 of the first embodiment. The annular groove 140a is composed of a pair of deep groove portions 142 and a raised portion 144a. As a feature of the bearing 100a of the second embodiment, the raised portion 144a has an arch-shaped cross section. Since the load distribution applied to the load zone L is highest at the center in the width direction of the outer ring 110, the load can be efficiently received by adopting an arch-shaped cross section. Even in such a configuration, the same effects as those of the bearing 100 of the first embodiment can be obtained.

[0024] (Third Embodiment) FIG. 3 is a diagram for explaining a creep-resistant bearing (hereinafter referred to as bearing 100b) according to the third embodiment. The bearing 100b of the third embodiment shown in FIG. 3 includes an annular groove 140b instead of the annular groove 140 of the bearing 100 of the first embodiment. As a feature of the bearing 100b of the third embodiment, the raised portion 144b has a trapezoidal cross section. Even in such a configuration, the same effects as those of the bearing 100 of the first embodiment can be obtained.

[0025] (Fourth Embodiment) FIG. 4 is a diagram for explaining a creep-resistant bearing (hereinafter referred to as bearing 100c) according to the fourth embodiment. While the outer ring 110 of the bearing 100 of the first embodiment is a fixed ring, the inner ring 120 of the bearing 100c of the fourth embodiment is a fixed ring. For this reason, an annular groove 140 is formed on the inner peripheral surface 122 of the inner ring 120 which is the fixed ring.

[0026] With the above configuration, even if distortion occurs on the inner circumferential surface 122 of the inner ring 120 when the bearing 100 rotates, the distortion can be absorbed in the annular groove 140. Therefore, it is possible to suppress the occurrence of creep caused by distortion of the inner ring 120. Furthermore, even in the configuration of the bearing 100c of the fourth embodiment, it is possible to ensure sufficient rigidity of the inner ring 120, which is a fixed ring.

[0027] Preferred embodiments of the present invention have been described above with reference to the attached drawings, but it goes without saying that the present invention is not limited to these examples. It will be obvious to those skilled in the art that various modifications or alterations can be conceived within the scope of the claims, and these will naturally also fall within the technical scope of the present invention. [Industrial applicability]

[0028] This invention can be used as a creep-resistant bearing. [Explanation of Symbols]

[0029] 100...Bearing, 100a...Bearing, 100b...Bearing, 100c...Bearing, 110...Outer ring, 112...Outer surface, 120...Inner ring, 122...Inner surface, 130...Ball, 140...Annular groove, 140a...Annular groove, 140b...Annular groove, 142...Deep groove, 144...Raised section, 144a...Raised section, 144b...Raised section, L...Load area

Claims

1. Outer ring and, Insider, A rolling element that rolls between the outer ring and the inner ring, Equipped with, When one of the outer ring or inner ring is a stationary ring and the other is a rotating ring, an annular groove is formed on the outer circumferential surface of the stationary outer ring or on the inner circumferential surface of the stationary inner ring at a position corresponding to the load area when the stationary ring is subjected to a load. The aforementioned annular groove is characterized in that deep groove sections with greater groove depth are formed at both ends, and shallower raised sections are formed between the deep groove sections.

2. The creep-resistant bearing according to claim 1, characterized in that the raised portion has a rectangular cross-section.

3. The creep-resistant bearing according to claim 1, characterized in that the raised portion has an arched cross-section.

4. The creep-resistant bearing according to claim 1, characterized in that the raised portion has a trapezoidal cross-section.

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