Creep-resistant bearings

Abstract

An object of the present invention is to provide a creep-resistant bearing that can suppress the occurrence of creep while reducing fretting wear. [Solution] The creep-resistant bearing (bearing 100) of 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 fixed ring and the other is a rotating ring, a plurality of recesses 140 are arranged periodically in the circumferential direction on the mating surface with the mating member to which the fixed ring is attached.

Description

[Technical field]

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

[0002] In bearings that are fitted into a housing and have a shaft inserted into the bearing inner ring so that the inner ring rotates with the shaft, outer ring creep can occur. For example, when a load is applied to the bearing, the load of the rolling elements within the load zone causes distortion in the outer ring raceway. This distortion also spreads to the outer diameter of the outer ring, and distortion on the outer diameter surface of the outer ring propagates in the direction of movement of the rolling elements along with the orbital motion of the rolling elements. This type of distortion propagation causes the outer ring to move relative to the housing, which is known as outer ring distortion creep.

[0003] For example, Patent Document 1 discloses "a rolling bearing comprising an inner ring, an outer ring, a plurality of rolling elements interposed between the inner ring and the outer ring, and a cage that holds the plurality of rolling elements, one of the inner ring and the outer ring being a rotating ring and the other being a fixed ring."

[0004] The rolling bearing of Patent Document 1 states that "an annular groove for suppressing creep is formed on the mating surface of the fixed ring with the mating member, the annular groove having a groove bottom and a pair of tapered surface portions extending from both axial sides of the groove bottom and widening the groove width toward the mating surface, the cross-sectional shape of the tapered surface portions in a cross section including the bearing centerline is a straight line shape inclined with respect to the mating surface." Patent Document 1 also states that "it is possible to mitigate localized increases in contact surface pressure caused by contact between the fixed ring and the mating member, and wear is less likely to progress even if creep occurs in the fixed ring." [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2020-125850 A Summary of the Invention [Problem to be solved by the invention]

[0006] In the configuration of Patent Document 1, the surface pressure at the edge of the annular groove increases, which increases fretting wear. In addition, in the configuration in which an annular groove is provided in the outer ring (or inner ring) as in Patent Document 1, the rigidity of the outer ring (or inner ring) decreases, which in turn shortens the life of the bearing due to raceway deformation.

[0007] In view of the above problems, an object of the present invention is to provide a creep-resistant bearing that can suppress the occurrence of creep while reducing fretting wear. [Means for solving the problem]

[0008] In order to solve the above problems, a typical configuration of a creep-resistant bearing according to the present invention comprises an outer ring, an inner ring, and rolling elements which roll between the outer ring and the inner ring, and when one of the outer ring or the inner ring is a fixed ring and the other is a rotating ring, is characterized in that a plurality of recesses are arranged periodically in the circumferential direction on the mating surface with a mating member to which the fixed ring is attached.

[0009] The plurality of recesses may be arranged on the fitting surface of the fixed ring so as to include a position corresponding to the center of the raceway surface of the fixed ring.

[0010] The plurality of recesses may be arranged alternately shifted in the axial direction so as to include a position on the fitting surface of the fixed ring that corresponds to the center of the raceway surface of the fixed ring.

[0011] The shape of the recess may be rectangular, elliptical or diamond. Effect of the Invention

[0012] According to the present invention, it is possible to provide a creep-resistant bearing that is capable of suppressing the occurrence of creep while reducing fretting wear. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a perspective view illustrating a creep-resistant bearing according to an embodiment of the present invention. [Diagram 2] FIG. [Diagram 3] FIG. 11 is a diagram illustrating another example of the outer ring. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. The dimensions, materials, and other specific values ​​shown in the embodiment are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In this specification and drawings, elements having substantially the same functions and configurations are given the same reference numerals to avoid repeated explanations, and elements not directly related to the present invention are not shown.

[0015] Fig. 1 is a perspective view illustrating a creep-resistant bearing according to this embodiment (hereinafter referred to as bearing 100). As shown in Fig. 1, the bearing 100 of this embodiment includes an outer ring 110, an inner ring 120, and balls 130 that are rolling elements that roll between the outer ring 110 and inner ring 120.

[0016] In many cases, bearings are used with one side as a fixed ring and the other as a rotating ring, and creep mainly occurs in the fixed ring. In the following explanation, the outer ring is the fixed ring fixed to the housing (mating member), and the mating surface is the outer peripheral surface of the outer ring. When the inner ring is the fixed ring, the inner peripheral surface of the inner ring becomes the mating surface.

[0017] Fig. 2 is a diagram illustrating the bearing 100. Fig. 2(a) is a cross-sectional view of the bearing 100, and Fig. 2(b) is a partial cross-sectional view of the outer ring 110. A feature of the bearing 100 of this embodiment is that a plurality of recesses 140 are arranged periodically in the circumferential direction on the outer peripheral 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 peripheral surface 112 of the outer ring 110.

[0018] With this configuration, even if the load applied from the balls 130 during rotation of the bearing 100 causes distortion in the outer ring 110, the distortion can be released into the recesses 140. This makes it possible to prevent distortion in the outer peripheral surface 112 of the outer ring 110 from propagating to a housing (not shown) (a mating member). This makes it possible to suppress the occurrence of creep caused by the propagation of distortion.

[0019] Furthermore, if the area between the recesses 140 is referred to as lattice portion 141, then lattice portion 141 is part of outer peripheral surface 112 and abuts against the housing. Therefore, compared to the case where an annular groove is provided in the outer ring as in the prior art, the area of ​​the non-contacting portions becomes intermittent (discontinuous), so the area of ​​each recess 140 becomes smaller and stress concentration occurring in the edge portions can be suppressed. Therefore, the occurrence of fretting wear caused by an increase in surface pressure in the edge portions can be effectively suppressed.

[0020] Furthermore, according to the configuration of the bearing 100 of this embodiment, compared to the conventional configuration in which an annular groove is provided in the outer ring 110, it is possible to ensure high rigidity in the outer ring 110, thereby enabling the life of the bearing 100 to be extended. Also, by providing a periodic arrangement of the multiple recesses 140, creep resistance can be obtained regardless of the load direction.

[0021] 2(b), in the bearing 100 of this embodiment, the multiple recesses 140 are arranged in the outer peripheral surface 112 of the outer ring 110 so as to include a position that corresponds to the center C of the raceway surface 114 of the outer ring 110. In the figure, it coincides with the axial center of the outer ring 110, but what is important is that it includes the center C of the raceway surface 114.

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

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

[0024] In the outer peripheral surface 112 of the outer ring 110a illustrated in Fig. 3(a), a plurality of recesses 140 are arranged with an alternating offset in the axial direction. The plurality of recesses 140 are arranged with an offset within a range including a position corresponding to the center C of the raceway surface 114 of the outer ring 110a. With such a configuration, it is possible to obtain the same effect as the outer ring 110 shown in Figs. 1 and 2. Furthermore, by arranging the plurality of recesses 140 alternately with the same offset in the axial direction, it is possible to preferably maintain a balance in the rigidity of the outer ring 110a in the axial direction.

[0025] The recesses 140 in Fig. 2(b) and Fig. 3(a) are rectangular. In contrast, elliptical recesses 142 are arranged on the outer peripheral surface 112 of the outer ring 110b shown in Fig. 3(b). Diamond-shaped recesses 144 are arranged on the outer peripheral surface 112 of the outer ring 110c shown in Fig. 3(c). Even with the elliptical recesses 142 and diamond-shaped recesses 144, it is possible to obtain the same effect as when rectangular recesses 144 are formed.

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

[0027] In this embodiment, the recesses are exemplified as having a rectangular, elliptical, or diamond shape, but are not limited thereto. The recesses may have a shape other than those exemplified, such as a parallelogram, a V-shape (boomerang shape), a lattice shape, or a tread pattern. Even if the recesses have a different shape, the above-mentioned 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] Although the preferred embodiment of the present invention has been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such an example. It is clear that a person skilled in the art can think of various modified or altered examples within the scope of the claims, and it is understood that such examples also naturally belong to the technical scope of the present invention. [Industrial Applicability]

[0029] The present 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 peripheral surface, 114...raceway surface, 120...inner ring, 130...ball, 140, 142, 144...recess, 141...lattice portion, C...center

Claims

1. The outer ring and With the inner circle, A rolling element that rolls between the outer ring and the inner ring; Equipped with When one of the outer ring and the inner ring is a fixed ring and the other is a rotating ring, a plurality of recesses are periodically arranged in the circumferential direction on a fitting surface of the fixed ring with a mating member, A creep-resistant bearing characterized in that the multiple recesses are arranged alternately in the axial direction so as to include a position on the fitting surface of the fixed ring that corresponds to the center of the raceway surface of the fixed ring.

2. 2. The creep resistant bearing according to claim 1, wherein the shape of the recess is any one of a rectangle, an ellipse, and a diamond.

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