JP2011208662A - Rolling bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rolling bearing for lengthening the service life of the bearing, by effectively utilizing base oil of grease sticking to a sealing device, in the rolling bearing with the sealing device of inner ring rotation lubricated by the grease.SOLUTION: This rolling bearing includes inner-outer rings 1 and 2, a plurality of rolling elements 3 interposed between the inner-outer rings 1 and 2 and the sealing device 5 arranged in the outer ring 2 and blocking up a bearing space between the inner-outer rings 1 and 2. In the rolling bearing, an annular ring-shaped base oil moving medium 6 constituted of a material for generating a capillary phenomenon and moving the base oil of the grease, is arranged on an inner wall surface of the sealing device 5, and an inner peripheral edge part of the base oil moving medium 6 is contacted with an inner diameter surface 1a of the inner ring 1.

Description

  The present invention relates to a rolling bearing with a grease lubricated sealing device.

  As lubrication methods for rolling bearings, there are grease lubrication and air-oil lubrication. Air oil lubrication is excellent in high-speed performance because the lubricating oil is forcibly supplied from the outside of the bearing to the race and the rolling elements. However, since an air oil supply device is required as ancillary equipment and a large amount of air is consumed, there are problems in terms of cost, noise, energy saving, and resource saving. There is also a problem of deteriorating the environment due to the scattering of oil.

On the other hand, grease lubrication is widely used because it is inferior in speed to air-oil lubrication but does not require additional equipment and is maintenance-free. If a sealing device is provided in the bearing used for this grease lubrication, it is possible to prevent the grease from being scattered to the outside of the bearing and to have an advantage that the influence on the surrounding environment is small.
However, since grease lubrication is performed only with the grease enclosed at the time of bearing assembly, high-speed operation leads to bearing life at an early stage due to deterioration of the grease due to heat generation of the bearing and loss of oil film on the raceway surface, especially the inner ring. There is a case.

  As an attempt to increase the speed of grease-lubricated bearings, the inner diameter surface of the cage and the outer diameter surface of the inner ring have a slope structure that increases in diameter toward the center side from the end surface, and oil mist is guided to the rolling element side by the pump action. There is a proposal (Patent Document 1).

JP 2006-161943 A

  In general, the grease-lubricated bearing including the proposed technique is used after the running-in operation because the grease encapsulated in the bearing assembly exists on the raceway surface of the raceway. At this time, the grease existing on the raceway surface is stepped on the rolling elements, a part of the grease is scraped to the end of the raceway surface, a part is scattered, and adheres to the inner wall surface of the sealing device provided at both ends of the bearing To do. Most of the base oil separated from the grease remaining on the raceway is supplied to the raceway surface and contributes to lubrication. However, grease adhered to the inner wall surface of the sealing device (hereinafter, this grease is referred to as “sealing device adhesion grease”). The contribution to lubrication is small. The service life of grease-lubricated bearings is often determined by the service life of the grease if the usage conditions are appropriate. Therefore, if the grease attached to the sealing device can be used more effectively, the service life of the bearing can be maintained with the same amount of grease filled as before. Can be extended.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a rolling bearing with a grease-lubricated inner ring rotating rolling bearing with a sealing device that effectively utilizes the base oil of grease attached to the sealing device to extend the life of the bearing.

  The rolling bearing according to the present invention is a rolling bearing comprising an inner and outer ring, a plurality of rolling elements interposed between the inner and outer rings, and a sealing device provided in the outer ring and closing a bearing space between the inner and outer rings. An annular base oil moving medium made of a material that causes capillary action is provided on the inner wall surface of the inner ring, and the inner peripheral edge of the base oil moving medium is in contact with the outer diameter surface of the inner ring. Features.

Grease is sealed in the bearing space between the inner and outer rings. The grease that was present on the raceway surface by the operation of the bearing is stepped on the rolling elements, part of the grease is scraped to the end of the raceway surface, and part of the grease is scattered on the inner wall surface of the sealing device provided at both ends of the bearing. Adhere to.
According to this configuration, the base oil moving medium for moving the base oil of the grease is provided on the inner wall surface of the sealing device, and the inner peripheral edge of the base oil moving medium is brought into contact with the outer diameter surface of the inner ring. Of the grease attached to the sealing device attached to the wall surface, only the base oil necessary for lubrication is attached to the outer surface of the inner ring through the base oil moving medium by capillary action. When the inner ring rotates, the base oil attached to the outer surface of the inner ring can contribute to lubrication by centrifugal force and surface tension. As a result, it is possible to extend the life of the conventional rolling bearing with a sealing device in which the same amount of grease is sealed.

On the outer diameter surface of the inner ring, a slope that becomes larger as it approaches the raceway surface side from the end surface side, and an inner peripheral edge portion of the base oil moving medium contacts may be provided. In this case, when the inner ring rotates, the base oil adhering to the outer surface of the inner ring moves to the large diameter side, that is, the raceway side of the inner ring while adhering to the inclined surface due to centrifugal force and surface tension. Hereinafter, the flow of the base oil due to the centrifugal force and the surface tension is referred to as “attachment flow”.
The grease attached to the sealing device contributes to the lubrication of the bearing by the above two actions, that is, the action of capillary action and the action of the attached flow. When the running-in operation of the bearing is performed, the base oil of the grease attached to the sealing device is supplied to the outer diameter surface of the inner ring through the base oil moving medium by the action of capillary action. The base oil supplied to the outer surface of the inner ring moves to the center of the bearing due to the attached flow and contributes to lubrication.

  The slope angle of the slope of the outer diameter surface in the inner ring may be an angle at which the base oil flows to the raceway surface side by centrifugal force when the bearing is rotated at an allowable rotational speed or a use rotational speed of the bearing. The “allowable rotational speed” is a value described in a catalog of rolling bearings and is determined according to the bearing dimensions. The centrifugal force acting on the grease varies depending on the rotation speed. Specifically, the higher the rotational speed, the greater the centrifugal force acting on the grease adhering to the slope, and the base oil supplied to the outer surface of the inner ring is more likely to move to the center of the bearing, which increases lubrication. Contribute.

The base oil moving medium and the slope of the outer diameter surface of the inner ring may be provided only on one side or both sides of the bearing.
When the slope angle of the outer surface of the inner ring is α, the pitch diameter of the bearing is dm (mm), and the rotational speed is n (min ⁻¹ ), the slope angle α is given by the following equation. May be.
α ≧ 0.056 · dm · n · 10 ⁻⁴ −2
This equation is based on the results of experiments conducted using a pseudo inner ring with an inner diameter of 70 mm and a 100 mm bearing with slopes. The oil was attached to the slope of the inner ring (angle changed) using air oil, and the presence or absence of attached flow was observed visually.
As a way of thinking about the flow of adhesion on the slope, if oil adheres to the slope, there is no difference between the oil of air oil and the base oil of grease.

The sealing device may be a seal formed by reinforcing an elastic body with a core metal, or a shield made of a steel plate.
The entire circumference of the inner peripheral edge of the base oil moving medium may be in contact with the outer diameter surface of the inner ring. In this case, the amount of movement of the base oil per unit time that moves from the grease attached to the sealing device to the outer surface of the inner ring can be increased. As a result, it is possible to use the rolling bearing at high speed and at medium and high loads.

  A part of the inner peripheral edge of the base oil moving medium may be in contact with the outer diameter surface of the inner ring. By limiting the contact portion of the base oil moving medium with the inner ring outer diameter surface in this way, the amount of base oil movement per unit time moving from the sealing device-attached grease to the inner ring outer diameter surface is reduced. Thereby, base oil can be utilized for a long time. In this way, by changing the length of the contact portion, the amount of oil adhering to the slope can be adjusted, and the life can be extended according to the operating conditions.

The material of the base oil transfer medium may be at least one of Japanese paper, woven fabric (including non-woven fabric), and leather in which capillary action occurs.
The sealing device may not be in contact with the outer diameter surface of the inner ring. For example, in a machine tool bearing, a general industrial machine motor bearing, or the like for which low torque is desired from the viewpoint of low heat generation and energy saving, the sealing device may be non-contact.
The sealing device may be in contact with the outer diameter surface of the inner ring. For example, in the case of railway vehicle bearings, automobile bearings, windmill bearings, etc. that place importance on dustproof and waterproof properties, the sealing device may be in contact.

A part of the grease sealed in the bearing space between the inner and outer rings may be attached to the inner wall surface of the sealing device. Due to the operation of the bearing, the grease base oil scattered and adhered from the end of the raceway surface to the inner surface of the outer ring is connected to the grease base oil adhered to the inner wall surface of the sealing device. As a result, the base oil in the grease attached to the sealing device can be smoothly supplied to the outer surface of the inner ring. As described above, after a part of the base oil of the grease existing on the inner wall surface of the sealing device that hardly contributes to lubrication adheres to the outer surface of the inner ring through the base oil moving medium, it contributes to the lubrication of the bearing. . This makes it possible to extend the life of the bearing with the same amount of grease filled as before. In addition, since the amount of grease charged in the vicinity of the raceway surface can be reduced, the initial break-in operation time can be shortened.
The rolling bearing may be used for a machine tool.
The rolling bearing may support the motor rotor.
The rolling bearing may be used for an automobile.
The rolling bearing may be used for a wind turbine.

  The rolling bearing according to the present invention is a rolling bearing comprising an inner and outer ring, a plurality of rolling elements interposed between the inner and outer rings, and a sealing device provided in the outer ring and closing a bearing space between the inner and outer rings. An annular base oil moving medium made of a material that causes capillary action is provided on the inner wall surface of the inner ring, and the inner peripheral edge of the base oil moving medium is brought into contact with the outer diameter surface of the inner ring. In rolling bearings with a sealing device for inner ring rotation to be lubricated, the base oil of grease attached to the sealing device can be effectively used to extend the life of the bearing.

It is sectional drawing of the rolling bearing which concerns on one Embodiment of this invention. It is an expanded sectional view of the principal part of the rolling bearing. (A) is sectional drawing of the rolling bearing which concerns on other embodiment of this invention, (B) is a side view which shows only the inner peripheral part of the base oil moving medium of the rolling bearing from an axial direction. It is a side view which shows only the inner peripheral part of the base oil moving medium of the rolling bearing which concerns on other embodiment of this invention from an axial direction. It is sectional drawing of the rolling bearing which concerns on other embodiment of this invention. It is sectional drawing of the rolling bearing which concerns on other embodiment of this invention. It is sectional drawing of the rolling bearing which concerns on other embodiment of this invention.

An embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 1, the rolling bearing according to this embodiment includes an inner ring 1, an outer ring 2, a plurality of rolling elements 3, a cage 4, a sealing device 5, and a base oil moving medium 6. An angular ball bearing is applied to the rolling bearing of this example, and it is an inner ring rotating type. However, the rolling bearing is not limited to the angular ball bearing. As the rolling bearing, for example, a deep groove ball bearing, a cylindrical roller bearing, or a tapered roller bearing can be applied. The rolling element 3 consists of a ball. The plurality of rolling elements 3 are interposed between the inner and outer rings 1 and 2 and are rotatably held by the cage 4. Both ends of the bearing space between the inner and outer rings 1, 2 are closed by sealing devices 5, 5, and grease is sealed inside the bearing.
The cage 4 is an outer ring guide type guided on the inner peripheral surface of the outer ring and is formed in a ring shape. Pockets Pt for holding the rolling elements 3 are formed in the cage 4 at regular intervals in the circumferential direction. Each pocket Pt is formed in a cylindrical hole shape that penetrates the cage 4 inward and outward in the radial direction.

The sealing device and the like will be described.
As shown in FIGS. 1 and 2, shields made of steel plates are attached to both sides of the outer ring 2 as a sealing device 5, and this bearing is a sealed type rolling bearing. Sealing device fixing grooves 2 a that are recessed radially outward from the inner diameter of the outer ring are formed at both ends of the inner diameter surface of the outer ring 2. The outer diameter surfaces 1a on both sides of the inner ring 1 are provided with slopes (described later) that become larger in diameter as they approach the raceway surface 1b side from the end surface side and contact the inner peripheral edge portion 6a of the base oil moving medium 6.
As shown in FIG. 2, a radially outer base end 8 of the sealing device 5 is fixed to the sealing device fixing groove 2a. The radially inner tip 9 of the sealing device 5 is formed in a substantially L-shaped cross section toward the inside of the bearing toward the tip, and a predetermined small distance gap so as not to contact the outer diameter surface 1a of the inner ring 1. δ is formed. This gap δ is set to such a size that a sealing effect can be obtained. Thus, in this example, the sealing device 5 is not in contact with the outer diameter surface 1a of the inner ring 1.

  An intermediate portion 10 connected to the base end portion 8 of the sealing device 5 includes an inclined portion 10a and a standing plate portion 10b. In other words, in the sealing device 5, the inclined portion 10 a that is inclined toward the bearing outer side as it goes inward in the radial direction is connected to the inner peripheral edge portion of the base end portion 8, and the upright plate portion 10 b is connected to the inner peripheral edge portion of the inclined portion 10 a. The upright plate portion 10b is provided along a plane perpendicular to the bearing axial direction, and the distal end portion 9 is connected to the inner peripheral edge portion of the upright plate portion 10b.

An annular base oil moving medium 6 made of a material that causes capillary action is provided on the inner wall surface of the sealing device 5. Of the inner wall surface of the sealing device 5, the base oil moving medium 6 is fixed over the inner peripheral portion of the base end portion 8, the inclined portion 10a, and the upright plate portion 10b. The entire circumference of the inner peripheral edge 6 a of the base oil moving medium 6 is brought into contact with the outer diameter surface 1 a of the inner ring 1. Specifically, the inner peripheral edge 6a of the base oil moving medium 6 is held by the tip 9 having a substantially L-shaped cross section that is inclined inward of the bearing toward the tip. As a material of the base oil moving medium 6, for example, at least one of Japanese paper, woven fabric (including non-woven fabric), and leather is applied.
Further, a part of the grease sealed in the bearing space between the inner and outer rings 1 and 2 is attached to the inner wall surface of the sealing device 5. The grease adhered to the inner wall surface is referred to as “sealing device adhesion grease Gr”. In this example, the sealing device adhesion grease Gr is adhered to the inner wall surface of the sealing device 5 by the operation of the bearing. However, as will be described later, the sealing device adhesion grease Gr is adhered to the inner wall surface of the sealing device 5 when the bearing is assembled. You may let them.

The inclined surface is provided on the outer diameter surface 1 a of the inner ring 1. In this example, the entire outer diameter surface 1a is a slope, but a part of the outer diameter surface 1a of the inner ring 1 may be a slope.
Since the centrifugal force acting on the grease varies depending on the rotational speed, the inclination angle of the outer diameter surface 1a of the inner ring 1 with respect to the axial direction L1 is preferably set in accordance with the allowable rotational speed of the bearing or the used rotational speed. At that time, when the inclination angle of the outer surface 1a of the inner ring 1 is α, the pitch circle diameter of the bearing is dm (mm) (FIG. 1), and the rotational speed is n (min ⁻¹ ), the following equation is used. When the inclination angle α is given, the base oil attached to the slope of the inner ring 1 moves to the raceway surface 1b and contributes to lubrication, which is more preferable.

α ≧ 0.056 · dm · n · 10 ⁻⁴ −2
Here, a value obtained by multiplying the pitch circle diameter dm (mm) by the rotational speed n (min ⁻¹ ) is referred to as a dmn value.

The grease existing on the raceway surface by the operation of the bearing is stepped on the rolling element 3, a part of the grease is scraped to the end of the raceway surface, and part of the grease is scattered, and the inside of the sealing device 5 provided at both ends of the bearing Adhere to the wall. According to the rolling bearing described above, the base oil moving medium 6 is provided on the inner wall surface of the sealing device 6, and the inner peripheral edge 6 a of the base oil moving medium 6 is brought into contact with the outer diameter surface 1 a of the inner ring 1. Only the base oil necessary for lubrication is attached to the outer diameter surface 1a of the inner ring 1 through the base oil moving medium 6 by a capillary phenomenon, among the sealing device adhesion grease Gr adhering to the inner wall surface. When the inner ring 1 rotates, the base oil adhering to the outer diameter surface 1a of the inner ring 1 moves to the raceway surface 1b side of the inner ring 1 while adhering to the slope due to centrifugal force and surface tension.
As described above, the adhesion device-attached grease Gr contributes to the lubrication of the bearing by the two actions, that is, the action of the capillary phenomenon and the action of the attached flow.

  When a part of the grease sealed in the bearing space is attached to the inner wall surface of the sealing device 5 at the time of bearing assembly, the grease is scattered and attached from the end of the raceway surface to the inner diameter surface of the outer ring 2 by the operation of the bearing. This base oil is connected to the base oil of the grease adhered to the inner wall surface of the sealing device 5. As a result, the base oil in the grease attached to the sealing device can be smoothly supplied to the inner ring outer diameter surface 1a. As described above, after a part of the base oil of the grease that has hardly contributed to the lubrication conventionally adheres to the outer diameter surface 1a of the inner ring 1 through the base oil moving medium 6, it contributes to the lubrication of the bearing. This makes it possible to extend the life of the bearing with the same amount of grease filled as before. In addition, since the amount of grease sealed in the vicinity of the raceway surface can be reduced, the initial break-in operation time can be shortened.

Since the entire circumference of the inner peripheral edge 6a of the base oil moving medium 6 is brought into contact with the outer diameter surface 1a of the inner ring 1, the base oil movement per unit time moves from the sealing device-attached grease Gr to the outer diameter surface 1a of the inner ring 1. The amount can be increased. As a result, it is possible to use the rolling bearing at high speed and at medium and high loads.
Of the inner wall surface of the sealing device 5, the base oil moving medium 6 is fixed over the inner peripheral portion of the base end portion 8, the inclined portion 10a, and the upright plate portion 10b. Furthermore, since the inner peripheral edge 6a of the base oil moving medium 6 is inclined toward the inside of the bearing toward the tip, and is held by the tip 9 having a substantially L-shaped cross section, the sealing device adhesion grease Gr is removed from the inclined portion. 10a, the standing plate portion 10b, and the tip end portion 9 can be stably attached in an annular groove surrounded by a substantially concave cross section. Without providing a complicated structure, only the base oil can be gradually supplied from the sealing device-attached grease Gr stably attached in the annular groove.
Since the sealing device 5 is not in contact with the outer diameter surface 1a of the inner ring 1, the rolling bearing is used, for example, as a machine tool bearing or a general industrial machine motor bearing in which low torque is desired from the viewpoint of low heat generation and energy saving. It can be used suitably.

Another embodiment of the present invention will be described.
In the following description, the same reference numerals are given to the portions corresponding to the matters described in the preceding forms in each embodiment, and the overlapping description is omitted. When only a part of the configuration is described, the other parts of the configuration are the same as those described in the preceding section. Not only the combination of the parts specifically described in each embodiment, but also the embodiments can be partially combined as long as the combination does not hinder.

As shown in FIGS. 3A and 3B, a part of the inner peripheral edge 6 a of the base oil moving medium 6 may be brought into contact with the outer diameter surface 1 a of the inner ring 1. FIG. 3B is a side view showing only the inner peripheral edge 6a of the base oil moving medium 6 of the rolling bearing of FIG. 3A from the axial direction.
The inner peripheral edge 6a of the base oil moving medium 6 is provided with a recessed portion 6aa that is recessed radially outward at regular intervals in the circumferential direction. The inner peripheral edge portion 6a is provided with a concave shape portion 6aa and a convex shape portion 6ab adjacent to each other in the circumferential direction, and among these, a plurality (eight in this example) of the convex shape portions 6ab are arranged on the outer diameter surface of the inner ring 1. It is made to contact 1a. In this way, by limiting the contact portion of the base oil moving medium 6 with the inner ring outer diameter surface 1a, the amount of base oil movement per unit time moving from the sealing device adhesion grease Gr to the inner ring outer diameter surface 1a is reduced. . Thereby, base oil can be utilized for a long time.

  FIG. 4 is a side view showing only the inner peripheral edge portion of the base oil moving medium of a rolling bearing according to still another embodiment from the axial direction. As shown in the figure, in the inner peripheral edge 6a of the base oil moving medium 6, the intermediate part in the range of 180 degrees in the circumferential direction may be the concave part 6aa, and the remaining intermediate part may be the convex part 6ab. Also in this case, the base oil can be used for a longer time because the amount of base oil movement per unit time moving from the sealing device-attached grease Gr to the inner ring outer diameter surface 1a is reduced as in FIG.

Instead of the configuration in which the outer diameter surface 1a of the inner ring 1 is an inclined surface, the outer diameter surfaces 1a on both sides of the inner ring 1 may be flat surfaces parallel to the axial direction as shown in FIG. In this case, only the base oil necessary for lubrication in the sealer-attached grease Gr can be adhered to the outer diameter surface 1a of the inner ring 1 via the base oil moving medium 6 by capillary action, thereby contributing to lubrication.
As shown in FIG. 6, as the sealing device 5, a seal formed by reinforcing an elastic body 5a with a cored bar 5b may be applied. In the example of FIG. 6, an annular seal groove 1 c that contacts the seal lip 5 c is formed on the outer diameter surface 1 a of the inner ring 1, and a contact seal is used as a seal. Further, a deep groove ball bearing is applied as the rolling bearing, and an iron plate corrugated cage is applied as the cage 4.
As shown in FIG. 7, a seal may be applied as the sealing device 5, and the outer diameter surface 1a of the inner ring 1 may be a flat surface parallel to the axial direction as in FIG.
For example, in railway vehicle bearings, automobile bearings, wind turbine bearings, etc. that place importance on dustproof and waterproof properties, the sealing device 5 is preferably a contact type as shown in FIGS.

Depending on use conditions, the sealing device and the base oil moving medium may be provided only on one side of the bearing. In this case, a slope may be provided only on the inner ring outer diameter surface on one side where the base oil moving medium is provided.
Although the contact seal is used in FIGS. 6 and 7, a non-contact seal can be applied.
The rolling bearing of each embodiment can be configured without a cage.

DESCRIPTION OF SYMBOLS 1 ... Inner ring 1a ... Outer surface 2 ... Outer ring 3 ... Rolling element 5 ... Sealing device 6 ... Base oil moving medium 6a ... Inner peripheral edge

Claims (17)

In a rolling bearing comprising an inner and outer ring, a plurality of rolling elements interposed between the inner and outer rings, and a sealing device provided in the outer ring and closing a bearing space between the inner and outer rings,
An annular base oil moving medium made of a material that causes capillary action is provided on the inner wall surface of the sealing device, and the inner peripheral edge of the base oil moving medium is brought into contact with the outer diameter surface of the inner ring. A rolling bearing characterized by that.   The rolling bearing according to claim 1, wherein an outer diameter surface of the inner ring is provided with an inclined surface that becomes larger in diameter as it approaches the raceway surface side from the end surface side, and to contact the inner peripheral edge of the base oil moving medium.   3. The angle at which the base oil flows to the raceway surface side by a centrifugal force when the slope angle of the slope of the outer diameter surface of the inner ring is rotated at an allowable rotational speed or a use rotational speed of the bearing. Rolling bearing.   The rolling bearing according to claim 2 or 3, wherein the base oil moving medium and the outer surface of the inner ring are provided with slopes on only one side or both sides of the bearing. 5. The slope angle of the outer diameter surface of the inner ring is α, the pitch circle diameter of the bearing is dm (mm), and the rotational speed is n (min ⁻¹ ) in any one of claims 2 to 4. Rolling bearings where the slope angle α is given by:
α ≧ 0.056 · dm · n · 10 ⁻⁴ −2   6. The rolling bearing according to claim 1, wherein the sealing device is a seal formed by reinforcing an elastic body with a cored bar or a shield made of a steel plate.   7. A rolling bearing according to claim 1, wherein the entire circumference of the inner peripheral edge of the base oil moving medium is brought into contact with the outer diameter surface of the inner ring.   The rolling bearing according to any one of claims 1 to 6, wherein a part of the inner peripheral edge of the base oil moving medium is brought into contact with the outer diameter surface of the inner ring.   The rolling bearing according to any one of claims 1 to 8, wherein the base oil moving medium is made of at least one of Japanese paper, a woven fabric including a non-woven fabric, and a leather in which a capillary phenomenon occurs.   The rolling bearing according to any one of claims 1 to 9, wherein a sealing device is not in contact with an outer diameter surface of the inner ring.   The rolling bearing according to any one of claims 1 to 9, wherein a sealing device is brought into contact with an outer diameter surface of the inner ring.   The rolling bearing according to any one of claims 1 to 11, wherein a part of grease sealed in a bearing space between the inner and outer rings is attached to an inner wall surface of the sealing device.   The rolling bearing according to any one of claims 1 to 10, and 12, wherein the rolling bearing is used for a machine tool.   The rolling bearing according to claim 1, wherein the rolling bearing supports a motor rotor.   The rolling bearing according to any one of claims 1 to 9, 11, and 12, wherein the rolling bearing is used for a railway vehicle.   The rolling bearing according to any one of claims 1 to 9, 11, and 12, wherein the rolling bearing is used in an automobile.   The rolling bearing according to any one of claims 1 to 9, 11, and 12, wherein the rolling bearing is used for a wind turbine.