Thrust self-aligning roller bearing

Abstract

The objective is to provide a thrust self-aligning roller bearing that can reduce contact stress on the rollers when they come into contact with the inner and outer rings, making it less likely to cause oil film breakdown and ultimately improving lubrication life. [Solution] The thrust self-aligning roller bearing (bearing 100) according to the present invention is a thrust self-aligning roller bearing comprising an inner ring 110, an outer ring 120, and rollers 130 that roll between the inner ring and the outer ring, wherein the rollers 130 are cylindrical members of the shape of a bale, with a smaller diameter on the inner circumference side of the bearing and a larger diameter on the outer circumference side of the bearing, and have a rolling surface 132, an end face (large diameter side end face 134a, small diameter side end face 134b), and a chamfered portion 136 arranged between them, and the chamfered portion 136 has a recess 138 that communicates with the rolling surface 132 and the end face.

Description

Technical Field

[0001] The present invention relates to a thrust self-aligning roller bearing including an inner ring, an outer ring, and rollers that roll between the inner ring and the outer ring.

Background Art

[0002] As one of the bearings used in industrial equipment and the like, a thrust self-aligning roller bearing is known. Although it is not a thrust bearing, as an automatic self-aligning roller bearing, for example, Patent Document 1 discloses "an outer ring having a spherical raceway surface on the inner peripheral surface, an inner ring having a plurality of rows of raceway surfaces facing the outer ring raceway surface on the outer peripheral surface, a plurality of rollers rotatably arranged on the plurality of rows of raceway surfaces, and a cage for holding the rollers at equal intervals in the rolling direction (double-row automatic self-aligning roller bearing)".

[0003] The automatic self-aligning roller bearing of Patent Document 1 is characterized in that "the rollers are formed in a drooping shape such that the clearance between the outer ring and the inner ring of the roller raceway surface increases toward the ends of the rollers between the rolling surface and the chamfers at both axial ends". According to Patent Document 1, "by forming the drooping shape, it is possible to relieve the edge load generated between the rollers and the outer ring and the inner ring, and prevent the reduction of the bearing life due to the occurrence of peeling."

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Self-aligning thrust roller bearings have the largest load capacity among thrust bearings. Therefore, they can extend the rated life of the bearing. However, in reality, the maximum external force is limited by the influence of the lubricant. For example, grease, as a lubricant, experiences lubrication failure due to oil film breakdown (oil film breakdown) in a region below the static load stress (4000 MPa). To prevent oil film breakdown, it is necessary to further reduce the contact stress between the raceway surfaces and flanges of the inner and outer rings.

[0006] In view of these problems, the present invention aims to provide a thrust self-aligning roller bearing that can reduce the contact stress on the rollers when they come into contact with the inner and outer rings, making it less likely to cause oil film breakdown and thus improving the lubrication life. [Means for solving the problem]

[0007] To solve the above problems, a typical configuration of the thrust self-aligning roller bearing according to the present invention is a thrust self-aligning roller bearing comprising an inner ring, an outer ring, and rollers that roll between the inner and outer rings, wherein the rollers are cylindrical members with a smaller diameter on the inner circumference side of the bearing and a larger diameter on the outer circumference side of the bearing, and have a rolling surface, an end surface, and a chamfered portion arranged between them, and the chamfered portion is formed in a recess that communicates with the rolling surface and the end surface.

[0008] The chamfered portion may have multiple recesses formed therein.

[0009] The above-mentioned multiple recesses should preferably be arranged at equal intervals in the circumferential direction. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a thrust self-aligning roller bearing that can reduce the contact stress on the rollers when they come into contact with the inner or outer ring, making it less likely to cause oil film breakdown and thus improving the lubrication life. [Brief explanation of the drawing]

[0011] [Figure 1]This diagram illustrates the thrust self-aligning roller bearing according to this embodiment. [Figure 2] This is a perspective from that time. [Figure 3] This diagram illustrates the relationship between the path of the roller's rolling surface and the roller pressure. [Figure 4] This figure illustrates another example of bearing rollers in this embodiment. [Modes for carrying out the invention]

[0012] 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.

[0013] Figure 1 is a diagram illustrating a thrust self-aligning roller bearing (hereinafter referred to as bearing 100) according to this embodiment. As shown in Figure 1, bearing 100 comprises an inner ring 110, an outer ring 120, and rollers 130 that roll between them. The inner ring 110 has a flange portion 114 that protrudes toward the rollers 130 from the inner ring raceway surface 112.

[0014] The roller 130 is a rolling element that rolls between the inner ring raceway surface 112 of the inner ring 110 and the outer ring raceway surface 122 of the outer ring 120 as the bearing 100 rotates. The roller 130 is a cylindrical member with a barrel shape, and its diameter is smaller on the inner side of the bearing 100 and larger on the outer side of the bearing 100.

[0015] Each roller 130 has a rolling surface 132, two end faces (a large-diameter end face 134a and a small-diameter end face 134b), and a chamfered portion 136 positioned between the rolling surface 132 and the end faces. The rolling surface 132 is the outer circumferential surface facing the inner ring raceway surface 112 of the inner ring 110 and the outer ring raceway surface 122 of the outer ring 120.

[0016] The large-diameter side end face 134a is the end face on the outer peripheral side of the bearing 100, and the small-diameter side end face 134b is the end face on the inner peripheral side of the bearing 100. The chamfer portion 136 of the present embodiment is formed by chamfering the corner formed by the rolling surface 132 and the large-diameter side end face 134a.

[0017] The roller 130 is held by the cage 140. Specifically, a part of the large-diameter side end face 134a of the roller 130 is covered by the flange portion 114 of the inner ring 110. Thereby, the roller 130 is guided by the inner ring 110 on the guide surface 116 of the flange portion 114 while being held by the cage 140.

[0018] FIG. 2 is a perspective view of the roller 130. As a feature of the bearing 100 of the present embodiment, as shown in FIG. 2, a concave portion 138 communicating with the rolling surface 132 and the large-diameter side end face 134a, which is an end face, is formed in the chamfer portion 136 on the large-diameter side of the roller 130. [[ID=十一]]

[0019] FIG. 3 is a diagram for explaining the relationship between the path of the rolling surface of the roller and the contact pressure of the roller. FIG. 3(a) is a diagram showing the variation of the contact pressure of the roller on the ridge line r1 including the concave portion of the roller 130 (hereinafter referred to as an example). FIG. 3(b) is a diagram showing the variation of the contact pressure of the roller on the ridge line r2 without the concave portion of the roller 130 (hereinafter referred to as a comparative example).

[0020] In the comparative example (ridge line r2 without a concave portion), as shown in FIG. 3(b), the contact pressure of the roller gradually increases from the large-diameter side toward the small-diameter side and decreases at the position corresponding to the chamfer portion. When passing the position corresponding to the chamfer portion 136, the contact pressure of the roller significantly increases. In the comparative example, at about 25 mm of the path (the position corresponding to the broken line L shown in FIG. 2), the contact pressure of the roller becomes the maximum. The maximum value at this time is about 700 MPa.

[0021] On the other hand, in the example (ridge line r1 with a concave portion) as well, as shown in FIG. 3(a), the contact pressure of the roller gradually increases from the large-diameter side toward the small-diameter side and decreases at the concave portion 138 (the position corresponding to the chamfer portion 136). And when passing the concave portion 138, the contact pressure of the roller significantly increases.

[0022] However, the maximum value of the surface pressure in the embodiment is about 600 MPa, which is lower than the maximum value of the comparative example. That is, when the contact point approaches the ridge line r1 including the concave portion 138 while the roller 130 is rolling, the maximum value of the contact stress of the roller is spot-reduced.

[0023] By providing a stress reduction portion on the rolling surface 132 in this way, even if a stress causing oil film breakdown is applied, the oil film thickness is restored at the stress reduction portion. Therefore, it is difficult to cause oil film breakdown, and the lubrication life can be improved. As a result, the replacement frequency of the bearing 100 due to breakage can be reduced, contributing to cost reduction. Also, since it is difficult to cause oil film breakdown, the lubrication life can be improved.

[0024] In addition, since the concave portion 138 communicates with the rolling surface 132 and the large-diameter side end surface 134a, the lubricant is easily supplied to the rolling surface 132 through the concave portion 138. From this, it is possible to make it difficult to cause oil film breakdown of the rolling surface 132 and also improve the lubrication life.

[0025] (Another example of the roller) FIG. 4 is a diagram for explaining another example of the roller of the bearing of the present embodiment. The roller 130 shown in FIG. 2 has one concave portion 138 formed in the chamfer portion 136, whereas the roller 130a shown in FIG. 4 has a plurality of concave portions 138 formed in the chamfer portion 136. Specifically, in FIG. 4, five concave portions 138 are shown in the chamfer portion 136. According to such a configuration, it is possible to increase the stress reduction portions on the contact surfaces between the inner ring 110 and the outer ring 120 and the roller 130, and further improve the lubrication life.

[0026] Furthermore, in 130a shown in FIG. 4, the plurality of concave portions are arranged at equal intervals in the circumferential direction of the roller 130. Since the stress reduction portions are at equal intervals, it is possible to make it even more difficult to cause oil film breakdown and further enhance the above-described effects.

[0027] 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 these examples. It will be obvious 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. [Industrial applicability]

[0028] The present invention can be used as a thrust self-aligning roller bearing comprising an inner ring, an outer ring, and rollers that roll between the inner and outer rings. [Explanation of Symbols]

[0029] 100...bearing, 110...inner ring, 112...inner ring raceway surface, 114...flange, 120...outer ring, 122...outer ring raceway surface, 130...roller, 132...rolling surface, 134a...large diameter end face, 134b...small diameter end face, 136...chamfered portion, 138...recess, 140...cage

Claims

1. In a thrust self-aligning roller bearing comprising an inner ring, an outer ring, and rollers that roll between the inner ring and the outer ring, The aforementioned time, A cylindrical member shaped like a rice bale, with a smaller diameter on the inner circumference side of the bearing and a larger diameter on the outer circumference side of the bearing, It has a rolling surface, an end face, and a chamfered portion positioned between them, A thrust self-aligning roller bearing characterized in that a recess is formed in the chamfered portion, communicating with the rolling surface and the end surface.

2. The thrust self-aligning roller bearing according to claim 1, characterized in that a plurality of recesses are formed in the chamfered portion.

3. The thrust self-aligning roller bearing according to claim 2, characterized in that the plurality of recesses are arranged at equal intervals in the circumferential direction.

Images