Creep-resistant bearing

Abstract

The objective is to provide a creep-resistant bearing that can prevent rotational creep without adding any parts, and can suppress wear between the outer ring and the housing caused by rotational 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, the mating surface of the mating member to which the stationary ring is attached has lathe marks 114 remaining from when the mating surface was machined on a lathe.

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 so that the inner ring rotates together with the shaft, various creeps may occur. An example of this is circumferential creep.

[0003] FIG. 5 is a diagram for explaining circumferential creep. Circumferential creep occurs when the internal torque of the bearing 30a becomes larger than the outer diameter surface friction torque of the bearing 30a (at high rotation and light load) in a configuration where the outer ring 30 is loosely fitted into the housing 40 (clearance fit). It is a phenomenon in which the outer diameter surface of the outer ring 30 slides inside the housing 40.

[0004] [[ID=,20]]During the occurrence of circumferential creep, an oil film of lubricating oil is formed between the outer ring 30 and the housing 40, so almost no wear occurs. However, when a heavy load is applied during the occurrence of creep, the creep stops, and wear occurs on the contact surface between the outer ring 30 and the housing 40 at the moment the creep stops, which becomes a problem.

[0005] As one of the techniques for suppressing circumferential creep, there is a configuration in which an O-ring is fitted on the outer peripheral surface of the outer ring. For example, Patent Document 1 discloses "a rolling bearing including 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 be rollable between the outer ring raceway surface and the inner ring raceway surface, wherein at least one annular groove is formed over the entire circumference on the outer peripheral surface of the outer ring, an annular elastic body is mounted in the annular groove, and in a state where the outer ring is internally fitted and supported by an outer ring support portion, the crushing rate of the annular elastic body is set to 15% to 30%, and the hardness of the annular elastic body is set to HS70 or less."

Prior Art Documents

[0006] [Patent Document 1] Japanese Patent Publication No. 2015-215061 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] The annular elastic body, or so-called O-ring, used in Patent Document 1 has the effect of suppressing rotational creep, but it increases costs due to the addition of parts and increases the assembly process. Furthermore, O-rings have the disadvantage of being unsuitable for high-temperature environments.

[0008] In view of these problems, the present invention aims to provide a creep-resistant bearing that can prevent rotational creep without adding any parts and can suppress wear between the outer ring and the housing caused by rotational creep. [Means for solving the problem]

[0009] 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, the mating surface of the mating member to which the stationary ring is attached has lathe marks remaining from when the mating surface was machined on a lathe.

[0010] It is desirable that black scale be formed on the above-mentioned turn marks. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a creep-resistant bearing that can prevent rotational creep without adding any parts and can suppress wear between the outer ring and the housing caused by rotational creep. [Brief explanation of the drawing]

[0012] [Figure 1] This is a diagram illustrating the creep-resistant bearing according to this embodiment. [Figure 2] This diagram illustrates the manufacturing method for the outer ring of the bearing in this embodiment. [Figure 3] This is a diagram illustrating a conventional method for manufacturing the outer ring of a bearing. [Figure 4] This diagram illustrates a comparison between the outer ring of this embodiment and a conventional outer ring. [Figure 5] This is a diagram illustrating the phenomenon of "following creep." [Modes for carrying out the invention]

[0013] 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.

[0014] Figure 1 is a diagram illustrating a creep-resistant bearing (hereinafter referred to as bearing 100) according to this embodiment. To facilitate understanding, a part of bearing 100 is cut out to show its internal structure. As shown in Figure 1, 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.

[0015] In many cases, the bearing 100 has an outer ring 110 and an inner ring 120, one of which is used as a stationary ring and the other as a rotating ring, and rotational creep occurs in the clearance-fitted stationary ring. In this embodiment, an example is shown in which the outer ring 110 is a stationary ring clearance-fitted to a mating part, a housing (not shown), and the inner ring 120 is a rotating ring that holds the shaft (not shown).

[0016] As a feature of the bearing 100 of the present embodiment, on the outer ring 110, which is a fixed ring, on the fitting surface with the housing, that is, the outer peripheral surface 112, lathe marks 114 when the outer peripheral surface 112 (fitting surface) is machined with a lathe remain. On the lathe marks 114 on the outer peripheral surface 112 of the outer ring 110, the black skin generated by heat treatment (quenching and tempering) remains without being polished. Between the lathe marks 114, a polished surface 116 polished with a grindstone or the like is formed, and the fine lathe marks 114 and the fine polished surfaces 116 are arranged alternately. That is, the outer peripheral surface 112 of the outer ring 110 is composed of the lathe marks 114 and the polished surfaces 116.

[0017] FIG. 2 is a diagram for explaining a method of manufacturing the outer ring 110 of the bearing 100 of the present embodiment. FIG. 3 is a diagram for explaining a method of manufacturing the outer ring 30 of a conventional bearing.

[0018] In the method of manufacturing the outer ring 30 of a conventional bearing, first, as shown in FIG. 3(a), the outer peripheral surface 32 (fitting surface) of the outer ring 30 is turned by a turning tool 10 to a dimension with a grinding allowance. As a result, lathe marks 34 are formed on the outer peripheral surface 32 of 30. After heat treatment, as shown in FIG. 3(b), the outer peripheral surface 32 of the outer ring 30 is polished to the finish dimension by a grindstone 20. The outer ring 30 thus formed has the lathe marks 34 on the outer peripheral surface 32 removed by polishing and becomes flat.

[0019] In the method of manufacturing the outer ring 110 of the bearing 100 of the present embodiment, first, as shown in FIG. 2(a), the turning groove bottom dimension of the outer peripheral surface 112 (fitting surface) of the outer ring 110 is turned by a turning tool 10 to a depth exceeding the finish dimension, and the unevenness of the lathe marks 114 is set to straddle the finish dimension. As a result, lathe marks 114 are formed on the outer peripheral surface 112 of the outer ring 110.

[0020] After that, when the outer ring 110 is heat-treated, as shown in FIG. 2(b), the outer peripheral surface 112 of the outer ring 110 is polished to the finish dimension by a grindstone 20. The outer ring 110 thus formed has the lathe marks 114 remaining between the polished surfaces 116 formed by polishing on the outer peripheral surface 112. Also, since heat treatment is performed before the polishing process, the black skin of the heat treatment remains on the remaining lathe marks 114.

[0021] FIG. 4 is a diagram for comparatively explaining the outer ring 110 of the present embodiment and the conventional outer ring 30. FIG. 4(a) is a diagram illustrating a state in which the outer ring 110 of the present embodiment is fixed to the housing 40. FIG. 4(b) is a diagram illustrating a state in which the conventional outer ring 30 is fixed to the housing 40.

[0022] As illustrated in FIG. 4(b), since the outer peripheral surface 32 of the conventional outer ring 30 is flat, an oil film 50 of lubricating oil is likely to be formed between the outer peripheral surface 32 and the housing 40. Then, circumferential creep occurs, and wear between the outer ring 30 and the housing 40 occurs when a high load is applied and the creep stops.

[0023] On the other hand, the outer ring 110 of the bearing 100 of the present embodiment has lathe marks 114 remaining on the outer peripheral surface 112. Therefore, the oil film is broken by the lathe marks 114, and the polished surface 116 can be brought into contact with the housing 40. As a result, since the frictional resistance between the outer peripheral surface 112 of the outer ring 110 and the housing 40 increases, the occurrence of circumferential creep can be prevented. Thus, according to the bearing 100 of the present embodiment, circumferential creep can be prevented without adding components, and wear between the outer ring 110 and the housing 40 due to the stop of circumferential creep can be suppressed.

[0024] As described above, the preferred embodiments of the present invention have been described with reference to the accompanying drawings. Needless to say, the present invention is not limited to such examples. It is obvious that those skilled in the art can conceive of various modification examples or correction examples within the scope described in the claims, and it is naturally understood that they also belong to the technical scope of the present invention.

Industrial Applicability

[0025] The present invention can be used as an anti-creep bearing.

Explanation of Reference Numerals

[0026] 10... Turning tool, 20... Grinding wheel, 30... Outer ring, 30a... Bearing, 32... Outer surface, 34... Turning marks, 40... Housing, 50... Oil film, 100... Bearing, 110... Outer ring, 112... Outer surface, 114... Turning marks, 116... Polished surface, 120... Inner ring, 130... Ball

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, the mating surface of the fixed ring with the mating member to which it is attached has lathe marks remaining from when the mating surface was machined on a lathe.

2. A creep-resistant bearing characterized by the formation of a black scale on the aforementioned turn marks.

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