Creep-resistant bearing

Abstract

The objective is to provide a creep-resistant bearing that can reduce fretting wear while suppressing the occurrence of creep. [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 110 and the inner ring 120, and is characterized in that when one of the outer ring 110 or the inner ring 120 is a stationary ring and the other is a rotating ring, a plurality of recesses 140 are arranged periodically in the circumferential direction on the mating surface of the mating member to which the stationary ring is attached.

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 it is fitted into a housing and a shaft is inserted into the inner ring of the bearing so that 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 rolling element load within the load zone causes distortion in the outer ring raceway portion. 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 along with the revolution motion of the rolling elements. Such distortion propagation causes the outer ring to move relative to the housing, which is what is 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 alleviate the local increase in the contact surface pressure due to 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 the configuration described in Patent Document 1, the surface pressure at the edge of the annular groove increases, leading to increased fretting wear. Furthermore, in a configuration where an annular groove is provided on the outer ring (or inner ring) as in Patent Document 1, the rigidity of the outer ring (or inner ring) decreases, resulting in a reduction in bearing life due to raceway deformation.

[0007] In view of these problems, the present invention aims to provide a creep-resistant bearing that can reduce fretting wear while suppressing the occurrence of creep. [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, and is characterized in that, when one of the outer ring or inner ring is a stationary ring and the other is a rotating ring, a plurality of recesses are arranged periodically in the circumferential direction on the mating surface of the mating member to which the stationary ring is attached.

[0009] The aforementioned multiple recesses should preferably be arranged such that they include a position on the mating surface of the fixed wheel that corresponds to the center of the raceway surface of the fixed wheel.

[0010] The aforementioned multiple recesses are preferably arranged alternately in the axial direction, including a position on the mating surface of the fixed wheel that corresponds to the center of the raceway surface of the fixed wheel.

[0011] The shape of the recess described above may be a rectangle, an ellipse, or a rhombus. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a creep-resistant bearing that can reduce fretting wear while suppressing the occurrence of creep. [Brief explanation of the drawing]

[0013] [Figure 1] This is a perspective view illustrating the creep-resistant bearing according to this embodiment. [Figure 2] This is a diagram illustrating a bearing. [Figure 3] This is a diagram illustrating another example of an outer ring. [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] Figure 1 is a perspective view illustrating a creep-resistant bearing (hereinafter referred to as bearing 100) according to this 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 primarily occurs in the fixed ring. In the following explanation, the outer ring is a fixed ring fixed to the housing (matting member), and the mating surface is described as the outer circumferential surface of the outer ring. When the inner ring is a fixed ring, the inner circumferential surface of the inner ring becomes the mating surface.

[0017] Figure 2 is a diagram illustrating the bearing 100. Figure 2(a) is a cross-sectional view of the bearing 100, and Figure 2(b) is a partial cross-sectional view of the outer ring 110. A feature of the bearing 100 in this embodiment is that a plurality of recesses 140 are arranged periodically in the circumferential direction on the outer circumferential surface 112 of the outer ring 110. In other words, a plurality of recesses 140 are arranged intermittently (discontinuously) at predetermined intervals on the outer circumferential surface 112 of the outer ring 110.

[0018] According to such a configuration, even if the outer ring 110 is distorted by the load applied from the ball 130 during the rotation of the bearing 100, the distortion can be released into the recess 140. Thereby, it is possible to prevent the distortion of the outer peripheral surface 112 of the outer ring 110 from being transmitted to a housing (counterpart member) not shown. Therefore, it is possible to suppress the occurrence of creep caused by the propagation of distortion.

[0019] Also, if the portion between the recesses 140 is referred to as a lattice portion 141, the lattice portion 141 is a part of the outer peripheral surface 112 and abuts on the housing. For this reason, compared with the case where an annular groove is provided in the outer ring as in the prior art, the area of the non-contact portion becomes intermittent (discontinuous), so the area of each recess 140 becomes smaller, and the stress concentration generated at the edge portion can be suppressed. Therefore, it is possible to suitably suppress the occurrence of fretting wear caused by an increase in surface pressure at the edge portion.

[0020] Furthermore, according to the configuration of the bearing 100 of the present embodiment, higher rigidity can be ensured in the outer ring 110 compared with the configuration in which an annular groove is provided in the outer ring 110 as in the prior art, and thus it is possible to achieve a longer life of the bearing 100. Also, by giving periodicity to the arrangement of the plurality of recesses 140, anti-creep properties can be obtained regardless of the direction of the load.

[0021] Particularly, as shown in FIG. 2(b), in the bearing 100 of the present embodiment, the plurality of recesses 140 are arranged so as to include a position corresponding to the center C of the raceway surface 114 of the outer ring 110 in the outer peripheral surface 112 of the outer ring 110. In the drawing, it coincides with the axial center of the outer ring 110, but the important thing is to include the center C of the raceway surface 114.

[0022] In the outer ring 110 of a deep groove ball bearing (radial bearing), in the case of a pure radial load, the load is most applied to the center C of the raceway surface 114, so the center C of the raceway surface 114 becomes the location where distortion is most likely to occur. For this reason, as shown in Fig. 2(b), by arranging a plurality of recesses 140 at a position corresponding to the center C of the raceway surface 114 of the outer ring 110, that is, at the location where distortion is most likely to occur when receiving a load, the distortion can be released most efficiently. Therefore, it becomes possible to enhance the above-described effects.

[0023] Fig. 3 is a diagram for explaining another example of the outer ring. In the example shown in Fig. 3, elements common to the outer ring 110 shown in Figs. 1 and 2 are denoted by the same reference numerals and the description thereof is omitted.

[0024] On the outer peripheral surface 112 of the outer ring 110a illustrated in Fig. 3(a), a plurality of recesses 140 are arranged to be alternately shifted in the axial direction. The plurality of recesses 140 are arranged to be shifted within a range including the position corresponding to the center C of the raceway surface 114 of the outer ring 110a. Even with such a configuration, the same effects as those of the outer ring 110 shown in Figs. 1 and 2 can be obtained. Further, since the plurality of recesses 140 are alternately shifted by the same amount in the axial direction, the balance of the rigidity of the outer ring 110a in the axial direction can be suitably maintained.

[0025] The recesses 140 in Figs. 2(b) and 3(a) were rectangular. In contrast, on the outer peripheral surface 112 of the outer ring 110b illustrated in Fig. 3(b), elliptical recesses 142 are arranged. Also, on the outer peripheral surface 112 of the outer ring 110c illustrated in Fig. 3(c), diamond-shaped recesses 144 are arranged. Even with such elliptical recesses 142 or diamond-shaped recesses 144, the same effects as those when rectangular recesses 144 are formed can be obtained.

[0026] Note that the elliptical recess 142 in Figure 3(b) and the rhombus-shaped recess 144 in Figure 3(c) are arranged without axial displacement at a position corresponding to the center C of the outer ring raceway surface 114, but are not limited to this arrangement. The elliptical recess 142 in Figure 3(b) and the rhombus-shaped recess 144 in Figure 3(c) may also be arranged with alternating axial displacements, as shown in Figure 3(a), so as to include a position corresponding to the center C of the outer ring raceway surface 114.

[0027] Furthermore, while rectangular, elliptical, and rhombus shapes have been given as examples for the shape of the recesses in this embodiment, the design is not limited to these. The multiple recesses may have shapes other than those exemplified, such as parallelograms, V-shapes (boomerang shapes), grid patterns, or tread patterns. Even if the multiple recesses have other shapes, the above-described effects can be obtained as long as they are arranged periodically in the circumferential direction on the outer peripheral surface 112 of the outer ring.

[0028] 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]

[0029] This invention can be used as a creep-resistant bearing. [Explanation of Symbols]

[0030] 100...Bearing, 110...Outer ring, 110a...Outer ring, 110b...Outer ring, 110c...Outer ring, 112...Outer circumference, 114...Raceway surface, 120...Inner ring, 130...Ball, 140, 142, 144...Recess, 141...Grid section, C...Center

Claims

1. Outer ring and, Insider, A rolling element that rolls between the outer ring and the inner ring, Equipped with, A creep-resistant bearing characterized in that, when one of the outer ring or inner ring is a fixed ring and the other is a rotating ring, a plurality of recesses are arranged periodically in the circumferential direction on the mating surface with the mating member to which the fixed ring is attached.

2. The creep-resistant bearing according to claim 1, characterized in that the plurality of recesses are arranged such that they include a position on the fitting surface of the fixed ring that corresponds to the center of the raceway surface of the fixed ring.

3. The creep-resistant bearing according to claim 1, characterized in that the plurality of recesses are arranged alternately in the axial direction, including a position on the fitting surface of the fixed ring that corresponds to the center of the raceway surface of the fixed ring.

4. The creep-resistant bearing according to claim 1, characterized in that the shape of the recess is either rectangular, elliptical, or rhombic.

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