Electrolytic corrosion resistant bearing

Abstract

[Problem] To provide an electrolytic corrosion resistant bearing capable of preventing the bearing from falling out of a metal cover covering rubber with insulating properties, and reliably maintaining insulating performance, and by extension, a electrolytic corrosion suppressing effect, over a long period. [Solution] An electrolytic corrosion resistant bearing 100 according to the present invention comprises an outer ring 110, an inner ring 120, and a rolling body (ball 130) that rolls between the outer ring and the inner ring, the electrolytic corrosion resistant bearing comprising: a metal cover 150 covering the outer side of the outer ring or the inner side of the inner ring; and rubber 160 disposed between the outer side of the outer ring and the metal cover or between the inner side of the inner ring and the metal cover. The metal cover has: a cylindrical part 152 along the outer circumferential surface of the outer ring or the inner circumferential surface of the inner ring; an annular part 154 that is bent from one end of the cylindrical part along an end face of one of either the outer ring or the inner ring by press molding; and a crimped part 156 that is bent from the other end of the cylindrical part along an end face of the other of either the outer ring or the inner ring by crimping.

Description

Electric corrosion-resistant bearing

[0001] The present invention relates to an electric corrosion-resistant bearing.

[0002] In recent years, with the development of electric cars (EVs) and hybrid cars (HVs), the number of high-voltage components installed in a single automobile has been increasing. When the current of these high-voltage components passes through the bearing, electric corrosion occurs on the surface of the rolling elements of the bearing, the raceway surfaces of the outer ring and the inner ring, which contributes to damage.

[0003] For example, in Patent Document 1, "an electric corrosion-preventing bearing including an inner ring, an outer ring, a plurality of rolling elements provided between the inner ring and the outer ring, and an annular electric corrosion-preventing member attached to one of the raceway rings of the inner ring and the outer ring and at least covering the cylindrical circumferential surface of the raceway ring, the electric corrosion-preventing member having a rubber or resin insulating material covering the circumferential surface and fixed to the circumferential surface, and a cover covering the insulating material and fixed to the insulating material" is disclosed.

[0004] Japanese Unexamined Patent Application Publication No. 2019-138467

[0005] In Patent Document 1, damage to the insulating material is prevented by covering the insulating material with a cover. However, in Patent Document 1, the cover is configured to cover the outer circumferential surface of the outer ring and one side surface of the outer ring and the inner ring. With such a configuration, since the other side surface of the outer ring and the inner ring is in an open state, there is a possibility that the bearing may fall off from the opening when an axial load is applied from the side surface direction of the cover.

[0006] In view of such problems, an object of the present invention is to provide an electric corrosion-resistant bearing that can prevent the bearing from falling off from a metal cover covering rubber having insulating properties, and can surely and continuously maintain the insulating performance and thus the electric corrosion suppression effect over a long period of time.

[0007] To solve the above problems, the corrosion-resistant bearing according to the present invention is a corrosion-resistant bearing comprising an outer ring, an inner ring, and rolling elements that roll between the outer ring and the inner ring, wherein the bearing comprises a metal cover that covers the outside of the outer ring or the inside of the inner ring, and rubber disposed between the outside of the outer ring and the metal cover, or between the inside of the inner ring and the metal cover, the metal cover having a cylindrical portion along the outer circumferential surface of the outer ring or the inner circumferential surface of the inner ring, an annular portion bent from one end of the cylindrical portion along one end face of the outer ring or the inner ring by press molding, and a crimped portion bent from the other end of the cylindrical portion along the other end face of the outer ring or the inner ring by crimping.

[0008] The corners of the outer or inner ring corresponding to the crimped portion should preferably have a chamfer formed that is eccentric with respect to the central axis.

[0009] According to the present invention, it is possible to provide a corrosion-resistant bearing that prevents the bearing from falling off the metal cover that covers the insulating rubber, and that can reliably maintain its insulating performance and, consequently, its corrosion suppression effect over a long period of time.

[0010] This is a diagram illustrating a corrosion-resistant bearing according to the first embodiment. This is a diagram illustrating the manufacturing process of the bearing. This is an overall view of the bearing according to the first embodiment. This is a diagram illustrating a corrosion-resistant bearing according to the second embodiment.

[0011] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings. The dimensions, shapes, materials, and other specific numerical values ​​shown in these embodiments are merely illustrative 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 or configuration are denoted by the same reference numerals to avoid redundant explanations, and elements not directly related to the present invention are not shown or described.

[0012] (First Embodiment) Figure 1 is a diagram illustrating a corrosion-resistant bearing according to the first embodiment (hereinafter simply referred to as "bearing 100"). As shown in Figure 1, the bearing 100 of the first embodiment is composed of an outer ring 110, an inner ring 120, and balls 130 which are rolling elements that roll between the outer ring 110 and the inner ring 120.

[0013] The ball 130 is held by the retainer 140. In the first embodiment, the ball 130 is used as an example of a rolling element, but the invention is not limited to this, and it is also possible to apply the present invention using rollers (not shown) as rolling elements.

[0014] A feature of the first embodiment is that the bearing 100 includes a metal cover 150 that covers the outside of the outer ring 110, and rubber 160 that is placed between the outside of the outer ring 110 and the metal cover 150. By placing the rubber 160 in this manner, insulation can be provided to the outer ring 110 and, consequently, the bearing 100. Note that an insulating resin may be used instead of rubber.

[0015] The metal cover 150 has a cylindrical portion 152, an annular portion 154, and a crimped portion 156. The cylindrical portion 152 is cylindrical in shape and is the part that follows the outer circumferential surface 112 of the outer ring 110. The annular portion 154 is an annular in shape and is the part that is bent from one end of the cylindrical portion 152 along one end face 114 of the outer ring 110 by press molding. The crimped portion 156 is the part that is bent from the other end of the cylindrical portion 152 along the other end face 116 of the outer ring 110 by crimping. More specifically, the crimped portion 156 is crimped along the chamfer 118 of the end face 116.

[0016] Figure 2 is a diagram illustrating the manufacturing process of the bearing 100. When manufacturing the bearing 100, first, as shown in Figure 2(a), a metal cover 150 with rubber 160 on its inner surface is attached to the outer ring 110. Next, as shown in Figure 2(b), the other end 152a of the cylindrical portion 152 of the metal cover 150 is crimped and bent along the chamfer 118 of the other end face 116 of the outer ring 110 using a roller 10. This forms a crimped portion 156, as shown in Figure 2(c).

[0017] With the above configuration, the crimped portion 156 is caught on the chamfer 118 of the outer ring. Therefore, it is possible to prevent the bearing 100 from falling off the metal cover 150 that covers the insulating rubber 160, and to reliably maintain the insulating performance and, consequently, the anti-corrosion effect over a long period of time.

[0018] Figure 3 is an overall view of the bearing 100 according to the first embodiment. Figure 3(a) is a front view of the bearing 100. Figure 3(b) is a cross-sectional view taken along line A-A in Figure 3(a). For ease of understanding, the metal cover 150 and rubber 160 of the bearing 100 are not shown in Figure 3(a).

[0019] As illustrated in Figure 3, the chamfer 118 at the corner of the outer ring 110 of the bearing 100 that corresponds to the crimped portion 156 of the metal cover 150 is eccentric with respect to the central axis.

[0020] In the first embodiment, the rotation center (not shown) of the tool used to chamfer the corners of the outer ring 110 is offset from the center of the outer ring 110 during machining. As a result, the amount of material removed changes in the circumferential direction, so the central axis X0 of the outer diameter of the outer ring 110 (i.e., the outer circumference circle 118a of the chamfer 118) and the central axis X1 of the inner circumference circle 118b of the chamfer 118 are offset by C1.

[0021] As in the bearing 100 of the first embodiment, by forming an eccentric chamfer 118 with respect to the central axis and crimping the metal cover 150 thereto, the rotation of the metal cover 150 relative to the outer ring 110 can be effectively prevented. As a result, even if the rubber 160 shrinks in volume due to aging or other factors and the crimping becomes weaker, the metal cover 150 will rotate together with the outer ring 110, and the metal cover 150 and the outer ring 110 will not rotate relative to each other. Therefore, it is possible to maintain good insulation performance over the long term.

[0022] (Second Embodiment) Figure 4 is a diagram illustrating a corrosion-resistant bearing (hereinafter simply referred to as "bearing 100a") according to the second embodiment. In the second embodiment, the same components as those described in the previously described embodiment are denoted by the same reference numerals and their descriptions are omitted.

[0023] In the bearing 100 of the first embodiment, the outside of the outer ring 110 is covered by a metal cover 150, and rubber 160 is placed between the outside of the outer ring 110 and the metal cover 150. In contrast, in the bearing 100a of the second embodiment, the inside of the inner ring 120 is covered by a metal cover 170, and rubber 180 is placed between the inside of the inner ring 120 and the metal cover 170.

[0024] The metal cover 170 has a cylindrical portion 172, an annular portion 174, and a crimped portion 176. The cylindrical portion 172 is cylindrical in shape and is the part that follows the inner circumferential surface 122 of the inner ring 120. The annular portion 174 is an annular in shape and is the part that is bent from one end of the cylindrical portion 172 along one end face 124 of the inner ring 120 by press molding. The crimped portion 176 is the part that is bent from the other end of the cylindrical portion 172 along the chamfer 128 of the other end face 126 of the inner ring by crimping.

[0025] According to the configuration of the bearing 100a of the second embodiment, the inner ring 120 can obtain the same effect as the outer ring 110 of the bearing 100 of the first embodiment.

[0026] 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 such examples. It will be clear 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.

[0027] This invention can be used as a corrosion-resistant bearing.

[0028] 10...Roller, 100...Bearing, 100a...Bearing, 110...Outer ring, 112...Outer circumference, 114...End face, 116...End face, 118...Chamfer, 120...Inner ring, 122...Inner circumference, 124...End face, 126...End face, 128...Chamfer, 130...Ball, 140...Cage, 150, 170...Metal cover, 152, 172...Cylindrical part, 152a...Other end, 154, 174...Ring part, 156, 176...Crimped part, 160, 180...Rubber

Claims

1. A corrosion-resistant bearing comprising an outer ring, an inner ring, and rolling elements that roll between the outer ring and the inner ring, wherein the bearing comprises a metal cover that covers the outside of the outer ring or the inside of the inner ring, and rubber disposed between the outside of the outer ring and the metal cover, or between the inside of the inner ring and the metal cover, the metal cover having a cylindrical portion along the outer circumferential surface of the outer ring or the inner circumferential surface of the inner ring, an annular portion bent from one end of the cylindrical portion by press molding along one end face of the outer ring or the inner ring, and a crimped portion bent from the other end of the cylindrical portion by crimping along the other end face of the outer ring or the inner ring.

2. The corrosion-resistant bearing according to claim 1, characterized in that the corner of the outer ring or the inner ring corresponding to the crimped portion has a chamfer formed that is eccentric with respect to the central axis.

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