WO2022225086A1

WO2022225086A1 - Load-variable rolling bearing, and rolling element for load-variable rolling bearing

Info

Publication number: WO2022225086A1
Application number: PCT/KR2021/005161
Authority: WO
Inventors: 이영근; 신현의
Original assignee: 이영근; 신현의
Priority date: 2021-04-23
Filing date: 2021-04-23
Publication date: 2022-10-27
Also published as: CN117083466A; DE112021006741T5; JP2024514680A

Abstract

The present invention relates to a load-variable rolling bearing (100) and a rolling element (130) for the load-variable rolling bearing, the rolling bearing comprising: a ring-shaped outer race (110) having an outer raceway (111) recessed at the inner diameter surface thereof; a ring-shaped inner race (120) having an inner raceway (121) recessed at the outer diameter surface thereof; and a plurality of rolling elements (130) aligned between the outer raceway (111) and the inner raceway (121) in the circumferential direction, wherein the rolling element (130) includes a cylindrical rolling element variable contact part (133), and rolling element spherical parts (131) provided on both sides of the rolling element variable contact part (133) and formed as a convex spherical surface, the outer raceway (111) includes outer raceway spherical contact parts (111-1) having a cross section formed in a concave circular arc shape, and a cylindrical outer raceway variable contact part (111-3) positioned to be adjacent to the outer raceway spherical contact parts (111-1) in the axial direction, the inner raceway (121) includes inner raceway spherical contact parts (121-1) having a cross section formed in a concave circular arc shape, and a cylindrical inner raceway variable contact part (121-3) positioned to be adjacent to the inner raceway spherical contact parts (121-1) in the axial direction, the rolling element spherical part (131) is positioned between the outer raceway spherical contact part (111-1) and the inner raceway spherical contact part (121-1), and the rolling element variable contact part (133) is positioned between the outer raceway variable contact part (111-3) and the inner raceway variable contact part (121-3).

Description

Rolling elements for variable load rolling bearings and variable load rolling bearings

The present invention relates to a variable load type rolling bearing and a rolling element for a variable load type rolling bearing, and more particularly, to a rolling element for a variable load type rolling bearing and a variable load type rolling bearing in which the rated capacity of the bearing is varied by an external force applied to the bearing. it's about

A ball bearing refers to a bearing that uses a ball as a rolling element between an inner ring and an outer ring to drive the bearing, and a retainer (aka, cage) that maintains the circumferential distance between the rolling elements is installed in a general ball bearing.

1 is a partially cut-away perspective view of a ball bearing 1 of the prior art. Referring to FIG. 1 , the conventional ball bearing 1 has a ring-shaped outer ring 10 in which an outer ring raceway 11 is formed on the inner diameter side so as to be driven in contact with a ball 30 which is a rolling element, and the ball 30 is in contact. A ring-shaped inner ring 20 in which an inner raceway 21 is formed on the outer diameter side to be driven by It consists of a plurality of rolling balls 30 and a retainer 40 installed between the outer ring 10 and the inner ring 20 so as to maintain a circumferential distance between the balls 30 .

The rated capacity (static load rating, dynamic load rating), which is the support capacity of rolling bearings such as ball bearings against external loads, depends on the number of rolling elements and the size of rolling elements (ball diameter, roller diameter in the case of roller bearings). ) will vary depending on

Since the ball bearing of the form shown in FIG. 1 has a spherical rolling element, the contact area of the rolling element is smaller than that of a roller bearing such as a tapered roller bearing disclosed in Korean Patent Application Laid-Open No. 10-2009-0041103. Although the contact resistance is small and the rotational torque is low, the bearing capacity for the load acting on the bearing is smaller than that of the roller bearing.

Therefore, in the conventional automobile transmission, etc., the tapered roller bearing known in Korean Patent Laid-Open No. 10-2009-0041103 has been used. Ball bearings are used. When the load applied to the bearing is variable, such as in a transmission, since the bearing must be designed according to a large load, there is a problem in that a bearing having an unnecessarily large size is installed compared to the operation.

For example, the transmission has a characteristic that the load acting on the bearing is large at the low stage (for example, 1st to 3rd gear) and the load acting on the bearing at the high stage (5th gear or more) is very small. It is less than 10%, and it is mainly operated over 90% in high stages. The bearing installed in the transmission has an operating rate of less than 10%, but since it must be designed for the low stage with a large load, bearings with unnecessarily large rated capacity are used at the high stage where more than 90% of the operation is performed. In addition, there was a big problem in the weight and rotational torque of the bearing to be used at a high stage.

The present invention has been proposed to solve the problems of the prior art as described above, and it is an object of the present invention to provide a variable load type rolling bearing and a rolling element for variable load type rolling bearing in which the rated capacity of the bearing is varied according to an external force under a variable load environment. do.

For the above purpose, the present invention provides a ring-shaped outer ring in which an outer raceway is concavely formed on the inner surface, a ring-shaped inner ring in which an inner raceway is concavely formed on the outer surface, and a circumferential direction between the outer raceway and the inner raceway. a plurality of rolling elements aligned along; The rolling element includes a cylindrical rolling element variable contact portion and a rolling element spherical surface portion provided on both sides of the rolling element variable contact portion and formed as a convex spherical surface; The outer ring raceway includes an outer ring raceway surface contact portion formed in a concave arc shape in cross section, and a cylindrical outer ring raceway variable contact portion positioned adjacent to the outer ring raceway surface contact portion in the axial direction; the inner ring raceway includes an inner ring raceway surface contact portion formed in a concave arc shape in cross section, and a cylindrical inner ring raceway variable contact portion adjacent to the inner ring raceway surface contact portion in the axial direction; The rolling body spherical surface portion is located between the outer ring raceway surface contact portion and the inner ring raceway surface contact portion, and the rolling element variable contact portion is located between the outer ring raceway variable contact portion and the inner ring raceway variable contact portion.

In the above, the outer ring raceway surface contact portion is provided with two spaced apart in the axial direction, and the inner ring raceway surface contact portion is provided with two inner ring raceway surface contact portions spaced apart in the axial direction; The outer ring raceway variable contact portion is located between the outer ring raceway surface contact portion; the inner race variable contact portion is located between the inner race track surface contact portions, and is spaced apart from the outer race variable contact portion in a radial direction; The outer ring raceway surface contact portion and the inner ring raceway surface contact portion face each other in a diagonal direction.

In the above, when the bearing is assembled, the rolling element spherical surface portion is in contact with the outer ring raceway surface contact portion and the inner ring raceway surface contact portion on both sides before the rolling element variable contact portion comes into contact with the outer ring raceway variable contact portion and the inner ring raceway variable contact portion on both sides. characterized.

In the above, when the bearing is assembled, the rolling element spherical surface portion is in contact with the outer ring raceway surface contact portion and the inner ring raceway surface contact portion on both sides, and the rolling element variable contact portion is spaced apart from the outer ring raceway variable contact portion and the inner ring raceway variable contact portion on both sides. do.

In the above, it is characterized in that the outer ring track variable contact portion and the inner ring track variable contact portion are formed in the form of a crowning protruding center in the axial direction.

In the above, the rolling element variable contact portion is characterized in that the longitudinal center is formed in the form of a protruding crowning.

In the above, a concave outer ring undercut portion extending in the circumferential direction is formed between the outer ring raceway surface contact portion and the outer ring raceway variable contact portion, and a concave inner ring undercut extending along the circumferential direction between the inner ring raceway surface contact portion and the inner ring raceway variable contact portion. It is characterized in that the addition is formed.

1 is a partially cut-away perspective view showing a ball bearing according to the prior art,

2 is a half cross-sectional view of a load variable type rolling bearing according to the present invention;

3 is an enlarged view of part "A" of FIG. 2,

4 is an enlarged view of part "B" of FIG. 2,

5 is a cross-sectional view showing a rolling element provided in the load variable type rolling bearing of the present invention.

Hereinafter, a variable load type rolling bearing and a rolling element for a load variable type rolling bearing according to the present invention will be described in detail with reference to the accompanying drawings.

2 is a half cross-sectional view of a variable load type rolling bearing according to the present invention, FIG. 3 is an enlarged view of part “A” of FIG. 2 , FIG. 4 is an enlarged view of part “B” of FIG. 2 , and FIG. 5 is this view It is a cross-sectional view showing a rolling element provided in the invention variable load type rolling bearing.

In the following description, the horizontal direction in FIG. 2 will be described as the axial direction. A vertical direction in FIG. 2 is a radial direction.

As shown in FIG. 2, the variable load rolling bearing 100 according to the present invention has a ring-shaped outer ring 110 in which the outer raceway 111 is concavely formed on the inner surface, and the inner raceway 121 is concave on the outer surface. A ring-shaped inner ring 120 is formed, and a plurality of rolling elements 130 are arranged along the circumferential direction between the outer ring track 111 and the inner ring track 121 . Reference numeral 140 denotes a cage for maintaining the circumferential spacing of the rolling elements 130 . The variable load rolling bearing 100 according to the present invention may further include a cage 140 . The cage 140 has a ring shape, and is spaced apart along the circumferential direction to form a plurality of pockets in which the rolling elements 130 are accommodated. Although not shown in FIG. 2 , a seal (not shown) for sealing may be provided in the openings formed on both sides in the axial direction between the inner ring 120 and the outer ring 110 .

The rolling element 130 is provided on both sides of the cylindrical rolling element variable contact portion 133 and the longitudinal direction (transverse direction in FIG. 5) of the rolling element variable contact portion 133, and the rolling element spherical surface portion 131 formed as a convex spherical surface. include

5, the rolling element 130 is formed in a cylindrical shape with a part removed from the sphere. The diameter (H) of the rolling element variable contact portion 133 may be formed in the range of 80% to 95% of the value (2×R) multiplied by the radius of curvature of the spherical rolling element spherical surface portion 131 . As the rolling element variable contact portion 133 is formed on the rolling element 130, a larger number (for example, one or two) of the rolling element 130 is assembled to the bearing when necessary compared to the spherical rolling element. can be

The rolling element variable contact portion 133 may be formed in a cylindrical shape, and may be formed in the form of a crowning protruding outward. Since the specific form of the crowning is a conventionally known technique, a description thereof will be omitted.

The rolling element spherical surface portion 131 is provided with a spherical surface in a form in which the diameter decreases from the portion connected to the rolling element variable contact portion 133 .

The rolling element 130 is manufactured in the form of a sphere having a sphericity of 3 μm or less, and the cylindrical rolling element variable contact portion 133 may be formed by grinding the middle part while chucking and rotating both sides of the sphere, The cylindrical rolling element may form the variable contact portion 133 by passing the sphere between the rubber grindstone (for rotational driving) and the grinding grindstone (for grinding processing).

The cylindrical rolling element variable contact portion 133 is formed in a cylindrical shape from which a part of the sphere is removed, so that the centers of curvature of the rolling element spherical surface portions 131 on both sides coincide with each other.

The outer ring track 111 includes an outer ring track surface contact portion 111-1 and an outer ring track variable contact portion 111-3. The outer ring raceway surface contact portion 111-1 extends along the circumferential direction and has a cross-sectional shape in the form of a concave arc as shown in FIG. 2 .

The outer ring track variable contact portion 111-3 is adjacent to the outer ring track surface contact portion 111-1 in the axial direction to form a concave bottom of the outer ring track 111 . The outer ring raceway surface contact portion 111-1 is provided with two spaced apart in the axial direction, and the outer ring raceway variable contact portion 111-3 is located between the outer ring raceway surface contact portion 111-1 and the outer ring raceway 111. form the bottom of

The outer ring track variable contact portion 111-3 is formed in a cylindrical shape. The outer ring track variable contact portion 111-3 may be formed in a convex crowning shape. When the outer ring track variable contact part 111-3 is formed in a crowning shape, an external force acts on the bearing, and when the outer ring track variable contact part 111-3 and the rolling element come into contact with the variable contact part 133, the contact stress from the center Concentration can be prevented.

The radius of curvature of the arc of the cross section shown in FIG. 2 of the outer ring raceway surface contact portion 111-1 is greater than the radius of curvature R of the rolling element spherical surface portion 131 . The radius of curvature of the outer ring raceway surface contact portion 111-1 is formed in the range of 102 to 200% of the radius of curvature of the rolling element spherical surface portion 131 .

When the bearing is assembled to the shaft and the housing (not shown) (when the bearing is assembled and the inner ring or outer ring is press-fitted to the shaft or housing), as shown in FIG. At the intermediate point, the rolling element spherical surface portion 131 contacts the outer ring raceway surface contact portion 111-1 (reference numeral P1 in FIG. 2 ). With the outer ring raceway variable contact portion 111-3 interposed therebetween, the outer ring raceway surface contact portion 111-1 and the rolling element spherical surface portion 131 are in contact on both sides in the axial direction.

The outer ring raceway variable contact part 111-3, which is in contact with the outer ring raceway surface contact part 111-1 and the rolling body spherical surface part 131 on both sides in the axial direction, and is located between the outer ring raceway surface contact part 111-1, is a rolling element variable contact part. (133) and a minute gap (Do; for example, 100㎛) are spaced apart.

Since the radius of curvature of the outer ring raceway surface contact portion 111-1 is larger than the radius of curvature of the rolling body spherical surface portion 131, the distance between the outer ring raceway surface contact portion 111-1 and the rolling element spherical surface portion 131 is large on both sides. do.

A concave outer ring undercut portion 111-5 extending in the circumferential direction is formed between the outer ring raceway surface contact portion 111-1 and the outer ring raceway variable contact portion 111-3. By forming the outer ring undercut portion 111-5, interference with the rolling element 130 is prevented, and superfinishing processing of the outer ring raceway surface contact portion 111-1 and the outer ring raceway variable contact portion 111-3 This can be done smoothly.

In FIG. 3 , reference numeral Go denotes an interval between the outer ring raceway surface contact portion 111-1 and the rolling element spherical surface portion 131 . When the bearing is assembled, the outer ring raceway surface contact portion 111-1 and the rolling element spherical surface portion 131 are in contact with the middle point P1 of the arc of the outer ring raceway surface contact portion 111-1 in the axial direction, and are spaced apart as the distance from the intermediate point increases. The distance Go increases.

The inner ring raceway 121 includes an inner ring raceway surface contact portion 121-1 and an inner ring raceway variable contact portion 121-3. The inner ring raceway surface contact portion 121-1 extends along the circumferential direction and has a cross-sectional shape in the form of a concave arc as shown in FIG. 2 .

The inner ring raceway variable contact portion 121-3 is adjacent to the inner ring raceway surface contact portion 121-1 in the axial direction to form a concave bottom of the inner ring raceway 121 . The inner ring raceway surface contact portion 121-1 is provided with two spaced apart in the axial direction, and the inner ring raceway variable contact portion 121-3 is located between the inner ring raceway surface contact portion 121-1, and the inner ring raceway 121 form the bottom of

The inner race variable contact part 121-3 faces the outer race variable contact part 111-3, and is spaced apart from the outer race variable contact part 111-3 in a radial direction inward.

The inner ring raceway surface contact portion 121-1 faces the outer ring raceway surface contact portion 111-1 in a diagonal direction.

The inner ring track variable contact portion 121-3 is formed in a cylindrical shape. The cross-sectional shape of the inner ring track variable contact portion 121-3 may be formed in the form of a convex crowning center in the axial direction. Since the inner race variable contact part 121-3 is formed in a crowning shape, when the inner race variable contact part 121-3 and the rolling element come into contact with the variable contact part 133, the contact stress concentration can be prevented by contacting from the center. .

The radius of curvature of the arc cross section of the inner ring raceway surface contact portion 121-1 shown in FIG. 2 is greater than the radius of curvature of the rolling element spherical surface portion 131 . The radius of curvature of the inner ring raceway surface contact portion 121-1 is formed in the range of 102 to 200% of the radius of curvature of the rolling element spherical surface portion 131 . When the bearing is assembled, the rolling element spherical surface portion 131 contacts the inner ring raceway surface contact portion 121-1 at the midpoint of the arc of the inner ring raceway surface contact portion 121-1 as shown in FIG. Reference number P2). With the inner ring raceway variable contact portion 121-3 interposed therebetween, the inner ring raceway surface contact portion 121-1 and the rolling element spherical surface portion 131 are in contact on both sides in the axial direction.

The inner ring raceway variable contact part 121-3, which is in contact with the inner ring raceway surface contact part 121-1 and the rolling body spherical surface part 131 on both sides in the axial direction, and is located between the inner ring raceway surface contact part 121-1, is the rolling body variable The contact portion 133 is spaced apart from each other by a minute distance (Di; for example, 100 μm). The gap between the inner ring raceway surface contact portion 121-1 and the rolling element spherical surface portion 131 is formed to be large on both sides.

A concave inner ring undercut portion 121-5 extending in the circumferential direction is formed between the inner ring raceway surface contact portion 121-1 and the inner ring raceway variable contact portion 121-3. By forming the inner ring undercut portion 121-5, interference with the rolling element 130 is prevented, and the super-finishing process of the inner ring raceway surface contact portion 121-1 and the inner ring raceway variable contact portion 121-3 is smooth. can be done

In FIG. 4 , reference numeral Gi denotes an interval between the inner ring raceway surface contact portion 121-1 and the rolling element spherical surface portion 131 . When the bearing is assembled, the inner ring raceway surface contact portion 121-1 and the rolling element spherical surface portion 131 come in contact with the middle point P2 of the arc of the inner ring raceway surface contact portion 121-1, and spaced apart from the center point ( Gi) increases.

Two of the outer ring raceway surface contact parts 111-1 are provided to be spaced apart in the axial direction, and two inner ring raceway surface contact parts 121-1 are provided to be spaced apart from each other in the axial direction. The outer ring raceway variable contact portion 111-3 is located between the outer ring raceway surface contact portions 111-1, and the inner ring raceway variable contact portion 121-3 is located between the inner ring raceway surface contact portion 121-1, and the The outer ring raceway variable contact portion 111-3 is spaced apart from each other in the radial direction, and the outer ring raceway surface contact portion 111-1 and the inner ring raceway surface contact portion 121-1 face each other in a diagonal direction.

When a load is applied to the bearing during operation, for example, when a radial load is applied to a shaft (not shown) inserted into the inner ring 120 , some rolling elements 130 are pressed by the outer ring 110 to change the inner ring trajectory. The distance Di between the contact part 121-3 and the rolling element variable contact part 133 and the distance Do between the outer ring track variable contact part 111-3 and the rolling element variable contact part 133 are reduced, and the load In accordance with the increase of the inner ring track variable contact portion 121-3 and the rolling element variable contact portion 133 come into contact, and the outer ring track variable contact portion 111-3 and the rolling element variable contact portion 133 come into contact with each other.

When a large load is applied to the bearing, the inner ring 120 of the bearing is in contact with the inner ring raceway surface contact portion 121-1 and the rolling element spherical surface portion 131, and in addition, the inner ring raceway variable contact portion 121-3 and the rolling element variable contact portion ( 133) is in contact, and the outer ring 110 is in contact with the outer ring raceway surface contact portion 111-1 and the rolling body spherical surface portion 131, in addition to the outer ring raceway variable contact portion 111-3 and rolling element variable contact portion 133 It works while being in contact with it, so the rated load increases.

For example, in the transmission, at a high stage where a large load is not applied to the bearing, the inner ring 120 does not have the inner ring raceway variable contact portion 121-3 in contact with the rolling element variable contact portion 133, and the inner ring raceway surface contact portion 121-1). In the state in which the rolling element spherical surface part 131 is in contact, and the outer ring 110, the outer ring raceway variable contact part 111-3 does not contact the rolling element variable contact part 133, and the outer ring raceway surface contact part 111-1 and The rolling element spherical surface part 131 rotates in a contact state, and rotates in a four-point contact state (P1, P2).

In the lower stage where a large load is applied to the bearing, the inner ring 120 has the inner ring raceway variable contact portion 121-3 in contact with the rolling element variable contact portion 133, and the inner ring raceway surface contact portion 121-1 also has the rolling element spherical surface portion 131. In the state in which the outer ring 110 is in contact, the outer ring track variable contact portion 111-3 is in contact with the rolling element variable contact portion 133, and the outer ring track surface contact portion 111-1 is also in contact with the rolling element spherical surface portion 131 rotate in Therefore, when a large load such as a low-speed operation of the transmission is applied, the load-bearing capacity is increased, and in a state of a small load such as a high-speed operation, the four-point contact rotation causes the rolling elements inside and outside the radial direction to contact and rotate in contact with the variable contact portion 133. The rotational torque is reduced compared to the case where unnecessary torque increase or a decrease in efficiency (fuel efficiency, etc.) due to the use of a large bearing is prevented. Since the rated capacity is increased for high loads in a variable load environment, large loads can be supported without increasing the bearing size (rolling body size, etc.).

The gap Di between the inner ring raceway surface contact portion 121-1 and the rolling element spherical surface portion 131 or the distance Do between the outer ring raceway variable contact portion 111-3 and the rolling element variable contact portion 133 is a bearing It is manufactured by setting it according to the magnitude of the variable load acting on it.

Although the insulation is shown in FIG. 2 for explaining the present invention, the present invention is not limited thereto, and the present invention also includes two or more double rows.

In the present invention, the initial torque is not large and the load capacity can be increased.

Claims

A ring-shaped outer ring 110 in which the outer ring raceway 111 is concavely formed on the inner diameter surface, a ring-shaped inner ring 120 in which the inner ring raceway 121 is concavely formed on the outer diameter surface, and the outer ring raceway 111 and the inner ring a plurality of rolling elements 130 arranged in a circumferential direction between the raceways 121;

The rolling element 130 includes a cylindrical rolling element variable contact portion 133 and a rolling element spherical surface portion 131 provided on both sides of the rolling element variable contact portion 133 and formed as a convex spherical surface;

The outer ring raceway 111 has an outer ring raceway surface contact portion 111-1 formed in a concave arc shape in cross section, and a cylindrical outer ring raceway variable contact portion located adjacent to the outer ring raceway surface contact portion 111-1 in the axial direction ( 111-3);

The inner ring raceway 121 includes an inner ring raceway surface contact portion 121-1 formed in the shape of a concave arc in cross section, and a cylindrical inner ring raceway variable contact portion located adjacent to the inner ring raceway surface contact portion 121-1 in the axial direction ( 121-3);

The rolling body spherical surface part 131 is located between the outer ring raceway surface contact part 111-1 and the inner ring raceway surface contact part 121-1, and the rolling element variable contact part 133 includes the outer ring raceway variable contact part 111-3 and the inner ring. Load variable type rolling bearing (100), characterized in that it is located between the track variable contact portion (121-3).
According to claim 1, wherein the outer ring raceway surface contact portion (1111-1) is provided with two spaced apart in the axial direction, the inner ring raceway surface contact portion (121-1) is provided with two spaced apart in the axial direction; The outer ring raceway variable contact portion 111-3 is located between the outer ring raceway surface contact portion 111-1; The inner race variable contact portion 121-3 is located between the inner ring raceway surface contact portion 121-1, and is spaced apart from the outer race variable contact portion 111-3 in the radial direction;

The load variable rolling bearing (100), characterized in that the outer ring raceway surface contact portion (111-1) and the inner ring raceway surface contact portion (121-1) face each other in a diagonal direction.
According to claim 1 or 2, before the rolling body variable contact portion (133) is in contact with the outer ring track variable contact portion (111-3) and the inner ring track variable contact portion (121-3) on both sides when assembling, the rolling element Load variable type rolling bearing (100), characterized in that the spherical surface portion (131) is in contact with the outer ring raceway surface contact portion (111-1) and the inner ring raceway surface contact portion (121-1) on both sides.
The rolling element according to claim 1 or 2, wherein when the bearing is assembled, the rolling element spherical surface portion 131 is in contact with the outer ring raceway surface contact portion 111-1 and the inner ring raceway surface contact portion 121-1 on both sides, and the rolling element The variable contact portion 133 is spaced apart from the outer ring track variable contact portion 111-3 and the inner ring track variable contact portion 121-3 on both sides.
[3] The load-variable cloud according to claim 1 or 2, wherein the outer race variable contact part (111-3) and the inner race variable contact part (121-3) are formed in the form of a crowning protruding from the center in the axial direction. bearing (100).
[Claim 3] The variable load rolling bearing (100) according to claim 1 or 2, wherein the rolling element variable contact portion (133) is formed in the form of a protruding central portion in the longitudinal direction.
[Claim 3] The outer ring undercut portion (111-5) which is concave and extends in the circumferential direction is formed between the outer ring raceway surface contact part (111-1) and the outer race race variable contact part (111-3) according to claim 1 or 2 and a concave inner ring undercut portion 121-5 extending in the circumferential direction is formed between the inner ring raceway surface contact portion 121-1 and the inner ring raceway variable contact portion 121-3. (100).
A rolling element for a variable load type rolling bearing comprising:

The cylindrical rolling element includes a variable contact portion 133 and a rolling element spherical surface portion 131 provided on both sides of the variable contact portion 133 and formed in a convex spherical shape; The rolling element spherical surface portion 131 is a rolling element for variable load rolling bearing, characterized in that it is provided with a spherical surface in a form in which the diameter decreases from the portion connected to the rolling element variable contact portion 133 .
The method of claim 8, wherein the spherical surface is made of a spherical surface with a sphericity of 3㎛ or less, the cylindrical rolling element variable contact portion 133 is formed in a cylindrical shape with a part of the sphere removed, so that the centers of curvature of the rolling element spherical surface portions 131 on both sides are each other. Rolling elements 130 for variable load rolling bearings, characterized in that they coincide.