Rolling bearing

Abstract

To provide a rolling bearing capable of preventing warpage of a seal member.SOLUTION: A ball bearing 1 includes an outer ring 100, an inner ring 120 arranged to face the outer ring 100, a plurality of balls 130 disposed between the outer ring 100 and the inner ring 120, and a resin-made seal member 140 attached to the outer ring 100 and covering between the outer ring and the inner ring. The outer ring 100 includes a raceway groove 101 on which the ball 130 rolls, a peripheral groove 110 provided on the axial outer side relative to the raceway groove 101, and a shoulder 115 provided on the axial outer side relative to the peripheral groove 110 and protruding to the inner ring 120 side. The seal member 140 includes a head 146 fitted to the peripheral groove 110, a step 150 provided on the axial outer side and the inner ring 120 side relative to the head 146, and a step surface 151 continuous with the step 150 and abutted to the shoulder 115 in the radial direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a rolling bearing having an improved resin seal member mounted between an outer ring and an inner ring. [Background technology]

[0002] Generally, rolling bearings are fitted with seals to prevent leakage of grease filled in the raceway grooves and to prevent the intrusion of water and dust from the outside. One example of a seal is a ring-shaped resin member, with its outer periphery fitted into a circumferential groove formed in the outer ring, for example, and its inner periphery held close to the inner ring. An example of a rolling bearing fitted with such a seal is disclosed in Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 8-135668 DISCLOSURE OF THE INVENTION [Problem to be solved by the invention]

[0004] When a seal member is fitted into the circumferential groove of the outer ring, pressure from the circumferential groove acts on the outer periphery of the seal member, which can cause the inner periphery to warp axially outward. When the rolling bearing rotates and heats up, the seal member thermally expands, causing further warping. Warping of the inner periphery of the seal member not only increases the gap with the inner ring, impairing its function as a seal member, but also risks the seal member protruding from the end face of the rolling bearing and interfering with other components.

[0005] The present invention has been made to solve the problems associated with conventional rolling bearings as described above, and has an object to provide a rolling bearing that can prevent warping of the seal member. [Means for solving the problem]

[0006] The present invention is a rolling bearing comprising a first raceway, a second raceway arranged opposite the first raceway, a plurality of rolling elements arranged between the first raceway and the second raceway, and a sealing member made of resin attached to the first raceway and covering the space between the first raceway and the second raceway, wherein the first raceway has a raceway groove in which the rolling elements roll, a circumferential groove provided axially outward from the raceway groove, and a shoulder provided axially outward from the circumferential groove and protruding toward the second raceway, and the sealing member has a head that engages with the circumferential groove, a step provided axially outward from the head and on the second raceway, and a stepped surface that is continuous with the step and abuts the shoulder radially.

[0007] According to the present invention, the stepped surface abuts against the shoulder of the first bearing ring in the radial direction, so that even if the head tries to rotate, it is blocked by the shoulder, and warping of the seal member can be prevented. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1A is a cross-sectional view showing a ball bearing according to an embodiment of the present invention, and FIG. 1B is an enlarged view of a portion indicated by arrow B in FIG. [Figure 2] FIG. 2 is an enlarged cross-sectional view of a main part of the sealing member according to the embodiment. [Figure 3] FIG. 3 is a cross-sectional view showing a modification of FIG. 2. DETAILED DESCRIPTION OF THE INVENTION

[0009] 1. Ball bearing structure A ball bearing according to an embodiment of the present invention will now be described. Fig. 1 is a cross-sectional view showing a ball bearing 1 according to the embodiment. In the following description, the direction of the center line of the ball bearing 1 will be referred to as the "axial direction," and the direction perpendicular to the axial direction will be referred to as the "radial direction." Furthermore, the direction of rotation around the axial direction will be referred to as the "circumferential direction."

[0010] 1, the ball bearing 1 is generally composed of an outer ring (first raceway) 100, an inner ring 120 (second raceway) disposed opposite the outer ring 100, a plurality of balls (rolling elements) 130 disposed between the outer ring 100 and the inner ring 120, a seal member 140 attached to the outer ring 100 to seal the gap between the outer ring 100 and the inner ring 120, and a cage 160 that holds the balls 130 at equal intervals in the circumferential direction. Each component will be described in detail below.

[0011] The outer ring 100 is annular and made of, for example, bearing steel, and has a raceway groove 101 with an arc-shaped cross section formed around the entire circumference on its inner peripheral surface. Axially outward from the raceway groove 101, a chamfered portion 102 is formed which widens outward in the axial direction.

[0012] A circumferential groove 110 is formed in the chamfered portion 102, recessed radially outward from the axially outer end. The circumferential groove 110 has a circular surface 113 with an arc-shaped cross section extending from an inner end 111 on the axial and radial inner side to an outer end 112 on the axial and radial outer side. An outer tapered surface 114 with a linear cross section whose diameter decreases axially outward is formed axially outward from the outer end 112. An inner surface 116 is formed radially inward from the inner end 111. The portion from the inner surface 116 to the outer tapered surface 114 constitutes the circumferential groove 110. A shoulder 115 extending substantially parallel to the axial direction is formed axially outward from the outer tapered surface 114. In this embodiment, the inner surface 116 is slightly inclined axially inward with respect to the radial direction; however, the inner surface 116 may be substantially parallel to the radial direction.

[0013] FIG. 2 is a cross-sectional view showing details of the seal member 140. The seal member 140 is formed in an annular shape from a resin selected from the group consisting of aliphatic polyamides such as nylon 66 and nylon 46, semi-aromatic polyamides such as PA4T, PA6T, PA9T, and PA10T, polyimide resins such as polyamideimide and polyimide, polyarylether resins such as polyetheretherketone, aromatic polyester resins such as polybutylene terephthalate, fluorine-containing resins such as polytetrafluoroethylene, sulfur-containing novolac resins such as polyphenylene sulfide, and polyolefin resins such as polyethylene and polypropylene. The seal member 140 includes an annular portion 141 having a uniform thickness along the radial direction. As shown in FIG. 1A, a first ridge 142 projecting axially inward is formed on the radially inner side of the annular portion 141, and a flange portion 143 is formed on the radially inner side of the first ridge 142.

[0014] Meanwhile, second ridges (ridges) 144 that protrude axially inward are formed on the radially outer side of the annular portion 141, and annular grooves 145 that have a generally V-shaped cross section and are recessed axially outward are formed on the radially outer side of the second ridges 144. A head 146 is formed on the radially outer side of the annular groove 145. A flat end surface 147 that is generally parallel to the radial direction is formed on the head 146 at a location adjacent to the annular groove 145. The flat end surface 147 has a small gap with respect to the inner surface 116.

[0015] The head 146 has a circular surface 148 with an arc-shaped cross section extending from an inner end 146a located at the end of the flat end surface 147 to an outer end 146b on the axial and radial outer side. This circular surface 148 matches the shape of the circular surface 113 of the circumferential groove 110 and is in close contact with the circular surface 113. An inclined surface 149 with a linear cross section whose diameter decreases as it extends axially outward is formed on the axially outer side of the outer end 146b. A step 150 recessed radially inward is formed on the axially outer side of the inclined surface 149.

[0016] The step portion 150 is formed by a step surface 151, which is an outer peripheral surface that is approximately parallel to the axial direction, and a tapered surface 151a that faces axially outward and whose diameter decreases as it approaches axially inward. The step surface 150 abuts against the shoulder portion 115 of the outer ring 100.

[0017] Next, inner ring 120 is annular and made of, for example, bearing steel, and has raceway grooves 121 with an arc-shaped cross section formed around the entire circumference on its outer surface. A chamfered portion 122 that widens axially outward is formed axially outward from raceway groove 121. A recessed portion 123 that is recessed radially inward is formed axially outward from chamfered portion 122. A plurality of balls 130 are held between raceway groove 121 and raceway groove 101 of outer ring 100 at equal intervals in the circumferential direction by a cage 160 made of resin or metal.

[0018] 2. Effect Seal member 140 configured as described above is fitted into circumferential groove 110 of outer ring 100. When fitting, head 146 of seal member 140 is elastically deformed inward in annular groove 145 to fit into circumferential groove 110. As a result, seal member 140 lies between outer ring 100 and inner ring 120. In this state, the inner circumferential surface of flange portion 143 of seal member 140 is positioned adjacent to recess 123 of inner ring 120, and first ridge 142 of seal member 140 is positioned adjacent to chamfered portion 122 of inner ring 120. A labyrinth structure is formed in this way, which prevents leakage of grease filled between outer ring 100 and inner ring 120 and prevents intrusion of water and dust from the outside.

[0019] 3.Effects When the seal member 140 is fitted into the circumferential groove 110 of the outer ring 100, the relationship between the various parts around the head 146 of the seal member 140 and the various parts around the circumferential groove 110 is as follows, as shown in FIG. 1(B).

[0020] (1) The inner end 146 a of the head 146 abuts against the inner end 111 of the circumferential groove 110 . (2) The circular surface 148 of the head 146 is in close contact with the circular surface 113 of the circumferential groove 110 . (3) The outer end 146 b of the head 146 abuts against the outer end 112 of the circumferential groove 110 . (4) The inclined surface 149 of the head 146 abuts against the tapered surface 114 of the circumferential groove 110 . (5) The step surface 151 adjacent to the head 146 abuts against the shoulder 115 adjacent to the circumferential groove 110 .

[0021] In this way, in ball bearing 1 having the above configuration, head 146 of seal member 140 is engaged with and supported in circumferential groove 110 due to the above (1) to (4). Here, even if a moment acts on head 146 due to stress from circumferential groove 110 and head 146 tries to rotate, shoulder 115 presses step surface 151, preventing head 146 from rotating. Therefore, warping of seal member 140 is prevented.

[0022] In particular, in the above embodiment, the contour of the circular surface portion 148 of the head portion 146 matches the circular surface portion 113 of the circumferential groove 110, so that the two are in close contact with each other, and the sealing member 140 can be firmly held in the circumferential groove 110.

[0023] Furthermore, since the inclined surface 149 of the head 146 is in contact with the tapered surface 114 of the circumferential groove 110, even if the head 146 tries to rotate, the inclined surface 149 is pressed against the tapered surface 114, and the rotation of the head 146 is more effectively prevented.

[0024] 4. Example of changes The present invention is not limited to the above-described embodiment, and various modifications can be made as follows. i) In the above embodiment, the circumferential groove 110 is formed in the outer ring 100, but it may be formed in the inner ring 120. In that case, the head 146 is formed on the inner ring 120 side of the seal member 140.

[0025] ii) In the above embodiment, the head 146 is formed with a circular surface 148 that has the same contour as the circular surface 113 of the circumferential groove 110, but the present invention is not limited to such a configuration. For example, as shown in FIG. 3, instead of the circular surface 148, an inclined surface 148a can be formed extending from the inner end 146a to the outer end 146b. Even in such a configuration, the head 148 is firmly supported by the circumferential groove 110, the tapered surface 114, and the shoulder 115 at three points: the inner end 146a, the inclined surface 149, and the stepped surface 151. In other words, it is sufficient that the head 148 is supported at three points, including the stepped surface 151.

[0026] iii) The present invention is not limited to ball bearings as in the above embodiment, but can be applied to all rolling bearings such as roller bearings. [Explanation of symbols]

[0027] 1...ball bearing, 100...outer ring (first raceway ring), 101...raceway groove, 102...chamfered portion, 110...circumferential groove, 111...inner end portion, 112...outer end portion, 113...circular surface portion, 114...outer tapered surface, 115...shoulder portion, 116...inner surface, 120...inner ring (second raceway ring), 121...raceway groove, 122...chamfered portion, 123...recess, 130...ball (rolling element), 140 ...Sealing member, 141...annular portion, 142...first ridge, 143...flange portion, 144...second ridge (ridge), 145...annular groove, 146...head portion, 147...flat end surface, 146a...inner end portion, 146b...outer end portion, 148...circular surface portion, 149...inclined surface, 150...step portion, 151...step surface, 151a...tapered surface, 152...inclined surface, 160...retainer.

Claims

1. a first bearing ring and a second bearing ring disposed opposite the first bearing ring; a plurality of rolling elements disposed between the first bearing ring and the second bearing ring; a sealing member made of resin that is attached to the first bearing ring and covers the gap between the first bearing ring and the second bearing ring; Equipped with The first bearing ring is a raceway groove in which the rolling elements roll; a circumferential groove provided axially outward of the raceway groove; a shoulder portion provided axially outward of the circumferential groove and protruding toward the second bearing ring; Equipped with The sealing member is a head portion that engages with the circumferential groove; a step portion provided axially outward from the head portion and on the second bearing ring side; a rolling bearing comprising a stepped surface that is continuous with the step portion and that abuts against the shoulder portion in the radial direction;

2. 2. The rolling bearing according to claim 1, wherein at least an outer end and an inner end of said head in the axial direction are in contact with said circumferential groove.

3. 3. A rolling bearing according to claim 2, wherein a cross-sectional profile from said outer end to said inner end coincides with a cross-sectional profile of said circumferential groove.

4. 3. The rolling bearing according to claim 2, wherein a cross-sectionally linearly inclined surface is formed between the outer end and the inner end, the diameter of which decreases axially inward.

5. 4. A rolling bearing according to claim 2 or 3, wherein a cross-sectionally linear inclined surface whose diameter decreases as it extends axially outward is formed on the axially outer side of the outer end portion, and a tapered surface against which the inclined surface abuts is formed in the circumferential groove.

6. 4. A rolling bearing according to claim 2, wherein a flat end face facing the axial direction is formed on the radially inner side of said inner end portion, said flat end face being spaced apart from said circumferential groove.

7. 3. A rolling bearing according to claim 1, wherein a ridge protruding axially inward is provided on the radially inner side of said head, and an annular groove recessed axially outward is provided between said ridge and said head.

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