bearings

Abstract

The object is to provide a bearing that can sufficiently ensure creep resistance and NV characteristics. [Solution] The bearing configuration of the present invention is a bearing 100 comprising a steel outer ring 110, a steel inner ring 120, and rolling elements (balls 130) that roll between them, and is characterized by having a resin or rubber coating 150 that covers the outer surface 112 of the outer ring 110, and where the total thickness of the outer ring 110 and coating 150 is H and the thickness of coating 150 is x, satisfying the following formula: 0.05≦x / H≦0.3.

Description

[Technical Field]

[0001] The present invention relates to a bearing having a steel outer ring, a steel inner ring, and rolling elements that roll between them. [Background technology]

[0002] Bearings that support shafts are used in vehicles such as electric cars (EVs) and hybrid cars (HVs). For example, Patent Document 1 discloses "a rolling bearing comprising an outer ring having an outer ring raceway surface on its inner peripheral surface, an inner ring having an inner ring raceway surface on its outer peripheral surface, and a plurality of rolling elements arranged to roll freely between the outer ring raceway surface and the inner ring raceway surface."

[0003] The rolling bearing of Patent Document 1 "has at least one annular groove formed around the entire circumference of the outer ring, and an annular elastic body for preventing creep is fitted in the annular groove." The rolling bearing of Patent Document 1 is also described as "designed to satisfy the following relationships: 0.29·(P / Cr)+0.26≦h1 / Da≦0.8 and 0.29·(P / Cr)+0.26≦h2 / Da≦0.8, where h1 is the minimum radial thickness of the outer ring, h2 is the minimum thickness between the annular groove and the outer ring raceway surface, Da is the diameter of the rolling elements, P is the bearing load, and Cr is the basic dynamic load rating." Patent Document 1 also states that "creep on the outer ring peripheral surface is prevented even when used under heavy load, rotating load, or light load conditions with oil or grease lubrication." [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6064783 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, one of the issues facing bearings used in electric cars (EVs) and hybrid cars (HVs) is the need to address noise and vibration (NV). Because EVs and other vehicles are quieter than engine-powered vehicles, bearing noise, which was not an issue in engine-powered vehicles, has become a significant issue. For this reason, bearings are required to have high NV characteristics in addition to creep resistance. However, the rolling bearing in Patent Document 1 does not mention NV characteristics, leaving room for further improvement.

[0006] In view of the above problems, the present invention has an object to provide a bearing that can ensure sufficient creep resistance and NV characteristics. [Means for solving the problem]

[0007] In order to solve the above problems, a typical configuration of a bearing according to the present invention is a bearing including a steel outer ring, a steel inner ring, and rolling elements that roll between them, characterized in that it has a resin or rubber coating covering the outer peripheral surface of the outer ring, and where the combined thickness of the outer ring and coating is H and the thickness of the coating is x, the following formula is satisfied: 0.05≦x / H≦0.3. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a bearing that can ensure sufficient creep resistance and NV characteristics. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram illustrating a bearing according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Dimensions, materials, and other specific values ​​shown in the embodiments are merely examples for facilitating understanding of the invention and, unless otherwise specified, do not limit the present invention. In this specification and drawings, elements having substantially the same functions and configurations are designated by the same reference numerals to avoid redundant explanation, and elements not directly related to the present invention are not shown or described.

[0011] Fig. 1 is a diagram illustrating a bearing 100 according to this embodiment. As shown in Fig. 1, the bearing 100 is a deep groove ball bearing, and includes a steel outer ring 110, a steel inner ring 120, and balls 130 as rolling elements that roll between them. The balls 130 are held in place by a cage 140.

[0012] In the bearing 100 of this embodiment, the outer peripheral surface 112 of the outer ring 110 is covered with a coating 150. This makes it possible to obtain high creep resistance in the bearing 100. The coating 150 can be made of resin or rubber, and when using resin, it is preferable to blend in an elastomer material.

[0013] In bearing 100 of this embodiment, resin grooves 116 are formed on the inner circumferential surface 114 of outer ring 110, and coating 150 extends from the outer circumferential surface 112 of outer ring 110 into resin grooves 116 on inner circumferential surface 114. This means that outer ring 110 is covered with coating 150 up to resin grooves 116 on inner circumferential surface 114. In other words, because outer ring 110 is covered with coating 150 not only on outer circumferential surface 112 but also on resin grooves 116 on inner circumferential surface 114, adhesion performance can be further improved.

[0014] A feature of bearing 100 of this embodiment is that, when the total thickness of outer ring 110 and coating 150 is H and the thickness of coating 150 is x, x / H is set to satisfy the formula "0.05≦x / H≦0.3." This makes it possible to reduce NV and ensure sufficient NV characteristics.

[0015] While the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such examples. It is clear that those skilled in the art can conceive of various modifications and alterations within the scope of the claims, and it is understood that such modifications and alterations naturally fall within the technical scope of the present invention. [Industrial Applicability]

[0016] The present invention can be used as a bearing including a steel outer ring, a steel inner ring, and rolling elements that roll between them. [Explanation of symbols]

[0017] 100... bearing, 110... outer ring, 112... outer peripheral surface, 114... inner peripheral surface, 116... resin groove, 120... inner ring, 130... ball, 140... cage, 150... coating

Claims

[Claim 1] A bearing comprising a steel outer ring, a steel inner ring, and rolling elements that roll between them, a resin or rubber coating covering the outer peripheral surface of the outer ring, When the total thickness of the outer ring and the coating is H and the thickness of the coating is x, the following equation is obtained: 0.05≦x / H≦0.3 A bearing characterized by satisfying the above.

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