Roller bearing

Abstract

To provide a roller bearing which can be extended in peeling resistant life and can be suppressed in the occurrence of damage when assembled in a machine.SOLUTION: The ratio of the hardness of a roller to the hardness of an inner ring and an outer ring is 1 or higher. Each of the plurality of rollers has a one-side chamfered part formed between a rolling surface and the one-axial-side end face, and an other-side chamfered part formed between the rolling surface and the other-axial-side end face. In a first connection part between the rolling surface and the one-side chamfered part, 15°≤θ1≤40°is established where a first angle θ1 is an angle formed between the rolling surface and the one-side chamfered part, and in a second connection part between the rolling surface and the other-side chamfered part, 15°≤θ2≤40°is established where a second angle θ2 is an angle formed between the rolling surface and the other-side chamfered part.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a roller bearing. [Background technology]

[0002] Among rolling bearings, roller bearings are suitable for supporting heavy loads and are used in a variety of rotating machines. Therefore, roller bearings are expected to have a long life when supporting heavy loads. As will be described later, the applicant has discovered that the rolling fatigue life of the raceway surface (hereinafter sometimes referred to as "flaking life") can be extended by making the rollers harder than the raceway rings.

[0003] The main types of roller bearings include cylindrical roller bearings such as rod roller bearings and needle roller bearings, tapered roller bearings, and self-aligning roller bearings. Patent Document 1 discloses an example of a cylindrical roller bearing, and Patent Document 2 discloses an example of a tapered roller bearing. Cylindrical roller bearings and tapered roller bearings are known as separable bearings. Separable bearings can be separated into an outer ring side and an inner ring side, and usually one of them is an assembly. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-251323 [Patent Document 2] Japanese Patent Application Laid-Open No. 2007-211833 Summary of the Invention [Problem to be solved by the invention]

[0005] Fig. 1 is a cross-sectional view showing a state in which a tapered roller bearing 1 is attached to a shaft 80 and a housing 90. Fig. 2 is a view for explaining the process of attaching the tapered roller bearing 1 to the shaft 80 and the housing 90. A method of assembling the tapered roller bearing 1 will be described with reference to Figs. 1 and 2.

[0006] The tapered roller bearing 1 comprises an inner ring 10 having an inner ring raceway surface 11 on its outer peripheral surface, an outer ring 20 having an outer ring raceway surface 21 on its inner peripheral surface, a plurality of rollers 30 arranged so as to roll freely between the inner ring raceway surface 11 and the outer ring raceway surface 21, and a retainer 40 that holds the plurality of rollers 30 so as to roll freely.

[0007] In the case of tapered roller bearing 1, it can be separated into outer ring 20 and an inner ring assembly consisting of inner ring 10, rollers 30, and cage 40. When these are mounted on a machine, outer ring 20 is attached to housing 90. The inner ring assembly is mounted on shaft 80, to which is attached a fixing member 50 consisting of a nut or the like that fixes inner ring 10. As shown in Figure 2, a shaft assembly 60 is formed by mounting the inner ring assembly and fixing member 50 on shaft 80. This shaft assembly 60 is inserted into housing 90 to be assembled into a machine.

[0008] Fig. 3 is a diagram showing a state in which the axis O80 of the shaft 80 is misaligned with respect to the axis O90 of the housing 90. Fig. 4 is a diagram showing a state in which the shaft 80 is tilted with respect to the housing 90. Here, if the axis O80 of the shaft 80 is radially misaligned with respect to the axis O90 of the housing 90 as shown in Fig. 3, or if there is an inclination at the angle of the axis O80 of the shaft 80 with respect to the axis O90 of the housing 90 as shown in Fig. 4, the rollers 30 located at the outermost radial position of the shaft assembly 60 will come into local contact with the outer ring raceway surface 21.

[0009] Localized contact during assembly can cause surface damage (scratches and plastic deformation). The inventors of the present application investigated bearing damage due to improper assembly in the market and found that the incidence of such damage is particularly high for so-called large bearings, bearings with an outer diameter exceeding 180 mm (as defined by Japanese Industrial Standards JIS B0104-1991). Large bearings are also heavy. According to a rolling bearing catalog published by the applicant, the bearing's weight alone exceeds approximately 3 kg. When the shaft 80 and other fixing members 50 are attached to the large bearing, the shaft assembly 60 becomes even heavier and has greater inertia. Therefore, the inventors of the present application found that misalignment or tilt of the shaft assembly 60 relative to the housing 90 can easily cause damage between the outer ring raceway surface 21 and the rolling surface 31 of the roller 30 due to the impact of a collision during machine assembly.

[0010] Furthermore, machines that use large bearings are large in size and weight. The shaft assembly 60 can be inserted into the housing 90 in either a vertical orientation, in which the axial centers of the housing 90 and bearing 1 face the direction of gravity, or a horizontal orientation, in which the axial centers of the housing 90 and bearing 1 face perpendicular to the direction of gravity. In large machines, the horizontal orientation is often used, as shown in FIG. 2. This is because many large machines are used horizontally, and it is time-consuming to convert the machine to a horizontal orientation after inserting the shaft assembly 60 into the housing 90 in a vertical orientation. Therefore, the shaft assembly 60 is often lifted by a crane or other device while in the horizontal orientation in which it is used, and the misalignment or inclination between the axial center O80 of the shaft 80 and the axial center O90 of the housing 90 is adjusted. The internal clearance of a bearing is on the order of several tens of micrometers to 0.1 mm, making it difficult to adjust with such high precision by lifting it with a crane. Such mechanical assembly conditions also contribute to the occurrence of scratches on the outer ring raceway surface 21 and the rolling surfaces 31 of the rollers 30.

[0011] As described above, in order to extend the flaking life, it is preferable to increase the hardness of the rollers 30, as will be described later. However, a harder roller 30 means an increased risk of scratches occurring on the mating part that comes into contact with the roller 30 (the outer ring raceway surface 21 in the case of the tapered roller bearing 1).

[0012] The present invention has been made in view of the above problems, and an object of the present invention is to provide a roller bearing that can extend the flaking life and suppress the occurrence of scratches when the bearing is assembled into a machine. [Means for solving the problem]

[0013] The above object of the present invention can be achieved by the following configuration. (1) an inner ring having an inner ring raceway on its outer circumferential surface; an outer ring having an outer ring raceway surface on its inner circumferential surface; a plurality of rollers provided rollably between the inner ring raceway surface and the outer ring raceway surface; A roller bearing comprising: a ratio of the hardness of the rollers to the hardness of the inner ring and the outer ring is 1 or greater, each of the rollers has a first side chamfered portion formed between the rolling surface and one axial end face, and an second side chamfered portion formed between the rolling surface and the other axial end face, At a first connection portion between the rolling surface and the one chamfered portion, when an angle formed between the rolling surface and the one chamfered portion is defined as a first angle θ1, 15°≦θ1≦40°; At a second connection portion between the rolling surface and the other side chamfered portion, when the angle formed by the rolling surface and the other side chamfered portion is defined as a second angle θ2, 15°≦θ2≦40°. Roller bearings. (2) At a third connection portion between the one axial end surface and the one side chamfered portion, when the angle formed by the one axial end surface and the one side chamfered portion is defined as a third angle θ3, 15°≦θ3≦40°, At a fourth connection portion between the other axial end surface and the other side chamfered portion, when the angle formed by the other axial end surface and the other side chamfered portion is defined as a fourth angle θ4, 15°≦θ4≦40°. (1) A roller bearing according to the present invention. (3) The cross-sectional shape of the one side chamfered portion is a single arc shape, The cross-sectional shape of the other side chamfered portion is a single arc shape. A roller bearing according to (1) or (2). (4) The cross-sectional shape of the one side chamfered portion is a first tapered portion connected to a first connection portion with the rolling surface and inclined toward an axis of the roller as it moves toward one side in the axial direction; a first arc portion having a single arc shape connected to the first tapered portion; a second tapered portion connected to the first arc portion, inclined toward the axis of the roller as it extends toward the one axial side, and connected to a third connection portion with the one axial side end surface; Including, The cross-sectional shape of the other side chamfered portion is a third tapered portion connected to the second connection portion with the rolling surface and inclined toward the axis of the roller as it moves toward the other axial side; a second arc portion having a single arc shape connected to the third tapered portion; a fourth tapered portion that is connected to the second arc portion, that inclines toward the axis of the roller as it extends toward the other axial side, and that is connected to a fourth connection portion with the other axial side end surface; Including, A roller bearing according to (1) or (2). [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a roller bearing that can extend the flaking life and suppress the occurrence of scratches when the bearing is mounted on a machine. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a cross-sectional view showing a tapered roller bearing mounted on a shaft and a housing. [Figure 2] FIG. 2 is a view for explaining the process of attaching the tapered roller bearing to the shaft and the housing. [Figure 3] FIG. 3 is a diagram showing a state in which the axis of the shaft is misaligned with the axis of the housing. [Figure 4] FIG. 4 is a diagram showing a state in which the shaft is tilted relative to the housing. [Figure 5] FIG. 5 is an enlarged view of the periphery of one side chamfer between the rolling surface of the roller and one axial end face. [Figure 6] FIG. 6 is an enlarged view of the periphery of the other side chamfer between the rolling surface of the roller and the other axial end face. [Figure 7] FIG. 7 is an enlarged view of the periphery of one side chamfer between the rolling surface of the roller and one axial end face of the roller in the modified example. [Figure 8] FIG. 8 is an enlarged view of the periphery of the other side chamfer between the rolling surface of the roller and the other axial end face of the roller in the modified example. DETAILED DESCRIPTION OF THE INVENTION

[0016] The tapered roller bearing 1 according to this embodiment has the same configuration as the tapered roller bearing 1 described above with reference to Figures 1 and 2. That is, the tapered roller bearing 1 comprises an inner ring 10 having an inner ring raceway surface 11 on its outer peripheral surface, an outer ring 20 having an outer ring raceway surface 21 on its inner peripheral surface, a plurality of rollers 30 provided so as to roll freely between the inner ring raceway surface 11 and the outer ring raceway surface 21, and a cage 40 that holds the plurality of rollers 30 so as to roll freely. The tapered roller bearing 1 supports a shaft 80 so as to be rotatable relative to a housing 90.

[0017] The ratio of the hardness of the rollers 30 to the hardness of the inner ring 10 and the outer ring 20 is equal to or greater than 1. In other words, the hardness of the rollers 30 is equal to or greater than the hardness of the inner ring 10 and the outer ring 20.

[0018] Advances in steelmaking technology have significantly improved the cleanliness of bearing steel, reducing bearing life due to internal flaking. Instead, surface flaking, which occurs due to indentations caused by foreign particles trapped in the lubricant, has become a problem. Premature flaking under contaminated lubrication is known to be caused by tangential forces acting on the rolling surfaces between the inner and outer rings 10 and 20 and the rolling elements 4. Factors that affect tangential forces include the surface shape and surface roughness of the rolling surfaces. When rolling devices, such as rolling bearings, are used in environments where oil film formation at the rolling contact points is insufficient, protrusion interference due to surface roughness occurs between the two rolling surfaces. This protrusion interference increases the coefficient of friction and localized contact stress, which is known to cause surface damage and shorten the life of the rolling device. When the tangential forces acting on the raceways, such as due to minor slippage, increase, the inner and outer rings 10 and 20 are more likely to be damaged by rotation. Therefore, by making the surface hardness of the rollers 30 harder than the raceway surface and providing an appropriate hardness difference between the contacting members, the surface roughness is improved and damage to the rollers 30 can be minimized.

[0019] The rollers 30 have a hardness of HRC 61.1 or more and a retained austenite content of 31 vol% or less. Furthermore, it is preferable that the rollers 30 have a surface residual compressive stress of 100 MPa or less. Regarding the relationship between the amount of retained austenite and the rate of dimensional change, the greater the initial amount of retained austenite, the greater the dimensional change tends to be. As the amount of retained austenite increases, the gaps between the rollers 30 and the inner ring 10 and the outer ring 20 become narrower, which can lead to seizure and shorten the bearing life. Therefore, by setting the upper limit of the amount of retained austenite to 31 vol%, dimensional stability is improved and the occurrence of increases in surface pressure and seizure due to dimensional changes over time can be suppressed, thereby improving the flaking life of the tapered roller bearing 1. Furthermore, by setting the hardness of the rollers 30 to HRC 61.1 or more, they can be made harder than the inner ring 10 and the outer ring 20.

[0020] There are no particular restrictions on the manufacturing method, materials, etc. of the inner ring 10 and the outer ring 20, as long as they satisfy the hardness ratio with respect to the rollers 30. Preferably, the inner ring 10, the outer ring 20, and the rollers 30 are made of the same material, SUJ2 or SUJ3, which is a high-carbon chromium bearing steel specified in JIS G4805.

[0021] 1 and 2 may be referred to as the one axial side, and the left side in Figures 1 and 2 may be referred to as the other axial side. Roller 30 has one axial side end face 33 and the other axial side end face 35. Figure 5 is an enlarged view of the area around one side chamfered portion 37 between rolling surface 31 and one axial side end face 33 of roller 30. Figure 6 is an enlarged view of the area around the other side chamfered portion 39 between rolling surface 31 and other axial side end face 35 of roller 30.

[0022] As shown in Figures 5 and 6, each of the rollers 30 of the tapered roller bearing 1 has a one-side chamfered portion 37 formed between the rolling surface 31 and one axial side end face 33, and an other-side chamfered portion 39 formed between the rolling surface 31 and the other axial side end face 35.

[0023] 3 and 4, even if the axis O80 of the shaft 80 is misaligned or inclined with respect to the axis O90 of the housing 90 when the shaft assembly 60 is inserted into the housing 90, it is thought that the misalignment or inclination can be corrected by enlarging the one side chamfered portion 37 and the other side chamfered portion 39 of the roller 30. In other words, by providing large one side chamfered portion 37 and the other side chamfered portion 39 near the edges between the rolling surface 31 and the one axial end face 33 and the other axial end face 35, these one side chamfered portion 37 and the other side chamfered portion 39 will guide the outer ring raceway surface 21, making it possible to correct and eliminate the misalignment or inclination.

[0024] However, if the one side chamfer 37 and the other side chamfer 39 of the roller 30 are made too large, the contact area between the rolling surface 31 and the outer ring raceway surface 21 will decrease. This will tend to increase the contact surface pressure between the outer ring raceway surface 21 and the roller 30 during operation, which will increase the probability of edge load occurring.

[0025] With regard to the size of the chamfer of roller 30, Japanese Industrial Standard JIS B1506:2005 specifies the minimum chamfer value (see Appendix 3) and the allowable limit value of the chamfer dimension (see Appendix 8) for cylindrical rollers. However, the standard does not specify the size for tapered roller bearings. Furthermore, the chamfer dimension specifications specified in the standard are based on the assumption that they are applied to standard rolling bearings, and do not explicitly state whether they are appropriate when the hardness of roller 30 is equal to or greater than the hardness of inner ring 10 and outer ring 20, as in this embodiment.

[0026] Meanwhile, the inventors of the present application have found that not only the roller chamfer dimensions but also the chamfer shape are important in preventing scratches (especially indentations due to plastic deformation) on the outer ring raceway surface 21 caused by the roller chamfers during machine assembly. However, in Appendix 3 of JIS B1506:2005, Note 5 simply states that the chamfer shape must not extend beyond the contour shape corresponding to the minimum chamfer dimensions. In other words, even if JIS B1506:2005 is referenced, it is not possible to design a roller chamfer shape that will prevent indentations from being generated on the outer ring raceway surface when the roller hardness is improved.

[0027] To function as a bearing (to rotate smoothly and operate for long periods of time), the rolling surfaces of rollers are generally ground and sometimes super-finished. Both axial end surfaces of rollers are also generally ground and sometimes super-finished in structures where they come into contact with the flanges of the inner and outer rings, or with circular components called guide rings that are incorporated into the bearing and help align the rollers.

[0028] Therefore, even if the chamfer shape of the roller is formed in a process prior to grinding (such as turning or header machining), the angle at the intersection (edge) of the ground surface and chamfer will be larger than it was at the time of forming because the rolling surface and both axial end faces are ground. This is because there is a grinding allowance. One approach is to form the chamfer so that the intersection of the ground surface and chamfer has a smooth angle after grinding, taking into account the grinding allowance, but the amount of allowance will vary depending on variations in the roller dimensions before grinding. Furthermore, since a bearing contains multiple rollers (usually a dozen or several tens), minimizing variations in the dimensions and shapes of the rollers within the bearing is extremely important for the bearing's functionality.

[0029] JIS B0701 specifies two common chamfering methods: "chamfering," which processes the corners of machined products at a 45° angle, and "rounding," which processes the corners with a single arc. When the former "chamfering" method is applied to rollers, the angle between the roller rolling surface and the chamfer is constant at 45°. During machine assembly, the edge at the intersection of the chamfer and the rolling surface comes into contact with the raceway, making indentations more likely to occur. When the latter "rounding" method is applied to rollers, the "rounding" is created during the cutting process and then ground. A machining allowance is required during grinding, and if there is variation in the roller diameter after cutting, for example, this machining allowance will vary when finishing to the order of microns during grinding. As a result, the angle θ between the generatrix of the rounding and the rolling surface at the intersection of the rolling surface and the "rounding" becomes greater than 0°, and this value varies depending on the machining allowance. The smaller the angle θ between the generatrix of the "radius" and the rolling surface, the easier it is for the "radius" of the roller chamfer to come into contact with the raceway surface during machine assembly, and the greater the effectiveness in preventing the formation of indentations. However, setting θ too small increases the variation in θ due to grinding allowance. Taking these factors into consideration, the inventors have found that the optimal value for θ is 15 to 40°, as described below.

[0030] In this embodiment, as shown in FIG. 5 , when the angle formed between the rolling surface 31 and the one side chamfered portion 37 at a first connection portion P1 between the rolling surface 31 and the one side chamfered portion 37 is defined as a first angle θ1, the first angle θ1 satisfies the following criteria: 15°≦θ1≦40°. The first angle θ1 can also be defined as the angle formed between the rolling surface 31 and the generatrix of the one side chamfered portion 37 at the first connection portion P1 (see the dashed line in FIG. 5 ). Furthermore, when the angle formed between the one axial end surface 33 and the one side chamfered portion 37 at a third connection portion P3 between the one axial end surface 33 and the one side chamfered portion 37 is defined as a third angle θ3, the third angle θ3 satisfies the following criteria: 15°≦θ3≦40°. The third angle θ3 can also be defined as the angle formed between the one axial end surface 33 and the generatrix of the one side chamfered portion 37 at the third connection portion P3 (see the dashed line in FIG. 5 ).

[0031] As shown in FIG. 6 , when the angle between the rolling surface 31 and the other side chamfered portion 39 at a second connection portion P2 between the rolling surface 31 and the other side chamfered portion 39 is defined as a second angle θ2, the second angle θ2 satisfies the following relationship: 15°≦θ2≦40°. The second angle θ2 can also be defined as the angle between the rolling surface 31 and the generatrix of the other side chamfered portion 39 at the second connection portion P2 (see the dashed line in FIG. 6 ). When the angle between the other axial end surface 35 and the other side chamfered portion 39 at a fourth connection portion P4 between the other axial end surface 35 and the other side chamfered portion 39 is defined as a fourth angle θ4, the fourth angle θ4 satisfies the following relationship: 15°≦θ4≦40°. The fourth angle θ4 can also be defined as the angle between the other axial end surface 35 and the generatrix of the other side chamfered portion 39 at the fourth connection portion P4 (see the dashed line in FIG. 6 ).

[0032] The cross-sectional shapes of both the first chamfered portion 37 and the second chamfered portion 39 are single arc shapes. As shown in Fig. 5, the cross section of the first chamfered portion 37 is a single arc with a radius of curvature R1, and as shown in Fig. 6, the cross section of the second chamfered portion 39 is a single arc with a radius of curvature R2. There are no particular restrictions on the relationship between the radii of curvature R1 and R2.

[0033] By using this shape, it is possible to prevent the angles θ1 to θ4 formed by the intersections (first to fourth connection portions P1 to P4) of the grinding surfaces (rolling surface 31, one axial end face 33, other axial end face 35) and the chamfers (one side chamfer portion 37, other side chamfer portion 39) due to variations in grinding allowance from becoming too small or too large, and even if the hardness of the rollers is improved, the risk of indentations occurring on the outer ring raceway surface 21 during machine assembly can be reduced.

[0034] Fig. 7 is an enlarged view of the periphery of one side chamfered portion 37 between rolling surface 31 and one axial end face 33 of roller 30 in the modified example. Fig. 8 is an enlarged view of the periphery of the other side chamfered portion 39 between rolling surface 31 and the other axial end face 35 of roller 30 in the modified example.

[0035] 7, the cross-sectional shape of one side chamfered portion 37 includes a first tapered portion 37a that connects to a first connection portion P1 with the rolling surface 31 and inclines toward the axis of roller 30 as it extends to one axial side, a first arc-shaped portion 37b that connects to first tapered portion 37a, and a second tapered portion 37c that connects to first arc-shaped portion 37b and inclines toward the axis of roller 30 as it extends to one axial side and connects to a third connection portion P3 with one axial side end face 33. The cross section of first arc-shaped portion 37b consists of a single arc with a radius of curvature R1.

[0036] In this modified example, at a first connection portion P1 between the rolling surface 31 and the one side chamfered portion 37, the angle formed between the rolling surface 31 and the first tapered portion 37a of the one side chamfered portion 37 is a first angle θ1, and at a third connection portion P3 between the one axial end surface 33 and the one side chamfered portion 37, the angle formed between the one axial end surface 33 and the second tapered portion 37c of the one side chamfered portion 37 is a third angle θ3. The angles are 15°≦θ1≦40° and 15°≦θ3≦40°.

[0037] As shown in FIG. 8 , the cross-sectional shape of the other side chamfered portion 39 includes a third tapered portion 39a that connects to the second connection portion P2 with the rolling surface 31 and inclines toward the axis of the roller 30 as it extends toward the other axial side, a second arc portion 39b that has a single arc shape and connects to the third tapered portion 39a, and a fourth tapered portion 39c that connects to the second arc portion 39b and inclines toward the axis of the roller 30 as it extends toward the other axial side and connects to a fourth connection portion P4 with the other axial side end face 35, The cross section of the second arcuate portion 39b is formed by a single arcuate portion with a curvature radius R2.

[0038] In this modified example, at a second connection portion P2 between the rolling surface 31 and the other side chamfered portion 39, the angle formed by the rolling surface 31 and the third tapered portion 39a of the other side chamfered portion 39 is a second angle θ2, and at a fourth connection portion P4 between the other axial side end surface 35 and the other side chamfered portion 39, the angle formed by the other axial side end surface 35 and the fourth tapered portion 39c of the other side chamfered portion 39 is a fourth angle θ4. The angles are 15°≦θ2≦40° and 15°≦θ4≦40°.

[0039] In this way, by defining the generatrix shapes of the one-side chamfered portion 37 and the other-side chamfered portion 39 at the first connection portion P1 to the fourth connection portion P4 as linear shapes by the first tapered portion 37a to the fourth tapered portion 39c, it is possible to make constant the angles θ1 to θ4 formed by the intersections (first to fourth connection portions P1 to P4) of the grinding surfaces (rolling surface 31, one axial end face 33, and the other axial end face 35) and the chamfers (one-side chamfered portion 37, the other-side chamfered portion 39). However, this is a suitable method for a relatively large roller 30. If the roller 30 is small, the chamfer dimensions will also be small. Therefore, if the position at which the first arc portion 37b and the second arc portion 39b, which are made of a single arc, are formed is shifted, there is a possibility that the first tapered portion 37a to the fourth tapered portion 39c, which are the linear chamfered portions, will disappear during grinding.

[0040] The present invention is not limited to the above-described embodiment and can be modified in various ways. For example, the present invention can be applied to any roller bearing other than tapered roller bearings, such as cylindrical roller bearings and self-aligning roller bearings.

[0041] Although a self-aligning roller bearing is not a separable bearing, when the bearing is handled alone, the inner ring side may tilt significantly relative to the outer ring, causing the rollers to come off the outer ring raceway surface.When returning this to its original position, the chamfered portion of the roller comes into contact with the end of the outer ring raceway surface, so it is preferable to adopt a configuration similar to that of the tapered roller bearing 1 in the embodiment described above. [Explanation of symbols]

[0042] 1. Tapered roller bearings (roller bearings) 10. Inner Circle 11 Inner ring raceway surface 20 outer ring 21 Outer ring raceway Around 30 31 Rolling surface 33 End face on one side in the axial direction 35 End surface on the other side in the axial direction 37 One side chamfer 37a First tapered section 37b First arc 37c Second tapered section 39 Other side chamfer 39a Third tapered section 39b Second arc 39c Fourth tapered section 40 Retainer 50 Fixing member 60 shaft assembly 80 shaft 90 Housing O80 Shaft centerline O90 Housing axis P1 First connection part P2 Second connection part P3 Third connection part P4 Fourth connection R1 Radius of curvature of one side chamfer R2 Radius of curvature of the other side chamfer θ1 First angle θ2 Second angle θ3 third angle θ4 Quadrilateral degree

Claims

1. an inner ring having an inner ring raceway surface on its outer circumferential surface; an outer ring having an outer ring raceway surface on its inner circumferential surface; a plurality of rollers provided rollably between the inner ring raceway surface and the outer ring raceway surface; A roller bearing comprising: a ratio of the hardness of the rollers to the hardness of the inner ring and the outer ring is 1 or greater, each of the rollers has a first side chamfered portion formed between the rolling surface and one axial end face, and an second side chamfered portion formed between the rolling surface and the other axial end face, At a first connection portion between the rolling surface and the one chamfered portion, when an angle formed between the rolling surface and the one chamfered portion is defined as a first angle θ1, 15°≦θ1≦40°; At a second connection portion between the rolling surface and the other side chamfered portion, when an angle formed between the rolling surface and the other side chamfered portion is defined as a second angle θ2, 15°≦θ2≦40°. Roller bearings.

2. at a third connection portion between the one axial end surface and the one side chamfered portion, when an angle formed between the one axial end surface and the one side chamfered portion is defined as a third angle θ3, 15°≦θ3≦40°; At a fourth connection portion between the other axial end surface and the other side chamfered portion, when the angle formed by the other axial end surface and the other side chamfered portion is defined as a fourth angle θ4, 15°≦θ4≦40°.

2. A roller bearing according to claim 1.

3. a cross-sectional shape of the one side chamfered portion is a single arc shape, The cross-sectional shape of the other side chamfered portion is a single arc shape.

3. A roller bearing according to claim 1 or 2.

4. The cross-sectional shape of the one side chamfered portion is a first tapered portion connected to a first connection portion with the rolling surface and inclined toward an axis of the roller as it moves toward one side in the axial direction; a first arc portion having a single arc shape connected to the first tapered portion; a second tapered portion connected to the first arc portion, inclined toward the axis of the roller as it extends toward the one axial side, and connected to a third connection portion with the one axial side end surface; Including, The cross-sectional shape of the other side chamfered portion is a third tapered portion connected to the second connection portion with the rolling surface and inclined toward the axis of the roller as it moves toward the other axial side; a second arc portion having a single arc shape connected to the third tapered portion; a fourth tapered portion that is connected to the second arc portion, that inclines toward the axis of the roller as it extends toward the other axial side, and that is connected to a fourth connection portion with the other axial side end surface; Including, 3. A roller bearing according to claim 1 or 2.

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