Rolling bearing and rotary machine

Abstract

To increase a bearing rotation speed at which starvation occurs using a rolling bearing itself.SOLUTION: A rolling bearing 1 comprises an inward member 10 having a first raceway surface 11, an outward member 20 having a second raceway surface 21, a plurality of rolling elements 30, and a holder 40. The rolling bearing further comprises a shield 50 that protrudes from the outward member 20 toward the inward member 10 at a position spaced apart on one side in an axial direction with respect to the rolling elements 30 and the holder 40; and a slinger 60 that protrudes from the inward member 10 toward the outward member 20 at a position spaced apart on the other side in the axial direction with respect to the rolling elements 30 and the holder 40. A first oil vent port 71, which draws in oil, is formed between the shield 50 and the inward member 10. A second oil vent port 72, which discharges the oil drawn in through the first oil vent port 71, is formed between the slinger 60 and the outward member 20.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a rolling bearing and a rotary machine equipped with the same. [Background technology]

[0002] The rolling bearing comprises an inner member including a first raceway surface, an outer member including a second raceway surface, a plurality of rolling elements arranged between the raceway surfaces, and a cage that holds the rolling elements.

[0003] When a rolling bearing rotates at high speed, if there is a certain amount of oil at the entrance of the elastic fluid contact between the rolling elements and the raceway surface, there is sufficient lubrication, and the oil film thickness does not increase any further.It is known that if the amount of oil supplied to the rolling bearing is insufficient during high-speed rotation, the oil film thickness between the rolling elements and the raceway surface becomes thinner, a phenomenon known as starvation lubrication, and the rolling viscous resistance decreases (Non-Patent Documents 1 to 3).

[0004] When rotating a rolling bearing at high speed using an oil lubrication system, it is common to use an open bearing without seals or shields, as in the test examples in Non-Patent Documents 1 and 2, with the inner member located on the rotating part side of the rotating machine and the outer member located on the housing side of the rotating machine, and to provide the rotating machine with an oil supply unit that supplies oil to the side of the rolling bearing.

[0005] In the test examples of open bearings disclosed in Non-Patent Documents 1 and 2, it was shown that when the oil supply rate was 70 ml / min or 100 ml / min, sufficient lubrication was maintained up to the maximum bearing rotation speed of the test conditions, but when the oil supply rate was 40 ml / min, starvation occurred at bearing rotation speeds lower than the maximum bearing rotation speed of the test conditions.

[0006] In the air-oil lubrication system used in machine tool spindles, the oil supply unit can independently control the small amount of oil supplied with high precision, so by adjusting the amount of oil supplied according to the bearing rotation speed, it is possible to stabilize the starvation state to a degree that does not break the oil film between the rolling elements and the raceway surface, thereby actively reducing friction torque. Non-Patent Document 3 discloses a calculation method for theoretically estimating friction torque when the amount of oil supplied is small, as in the air-oil lubrication system. [Prior art documents] [Non-patent literature]

[0007] [Non-Patent Document 1] Toyama, "Lubrication Analysis of High-Speed ​​Deep Groove Ball Bearings (1st Report) -Evaluation of the Influence of Oil Supply Volume by Lubrication Visualization-", Tribology Conference 2023 Spring, Tokyo, Proceedings, pp. 240-244 [Non-patent document 2] Toyama, “Lubrication Analysis of High-Speed ​​Deep Groove Ball Bearings (2nd Report) -Evaluation of the Influence of Oil Supply Volume by Lubrication Visualization-”, Tribology Conference 2023 Spring, Tokyo, Proceedings, pp. 245-246 [Non-patent document 3] Fujiwara, "Estimation Method of Friction Torque of Air-Oil Lubricated Angular Contact Ball Bearings - Lubrication Analysis of High-Speed ​​Deep Groove Ball Bearings (1st Report) - Evaluation of the Influence of Oil Supply Volume by Lubrication Visualization -", NTN TECHNICAL REVIEW No.82(2014), pp.54-60 Summary of the Invention [Problem to be solved by the invention]

[0008] In today's world, where energy conservation is a major concern, low torque is required for rolling bearings, so the amount of oil supplied is limited to a small amount to suppress agitation resistance. When a small amount of oil is supplied to the sides of an open bearing, the small amount mixes with the atmosphere surrounding the bearing and enters the bearing, causing air curtains to form on both sides of the open bearing during high-speed rotation. Air curtains are a phenomenon in which a high-speed rotating cage and multiple rolling elements revolving at high speeds agitate the lubricating fluid, such as oil, causing it to swirl circumferentially and spread to the sides. If the force of the air curtain is strong, it becomes difficult for the oil supplied to the sides of the open bearing to penetrate the annular space of the rolling bearing, reducing the amount of oil contributing to lubrication and cooling of the rolling elements, resulting in starvation.

[0009] However, in applications where bearing failure tolerance is important, high-speed rotation under sufficient lubrication is sometimes required. Rotating machines equipped with an oil supply system capable of precisely controlling the amount of oil supplied, such as air-oil lubrication, can maintain sufficient lubrication by increasing the amount of oil supplied from the oil supply system based on control that takes into account increases in bearing rotation speed and the effects of air curtains. However, there are cases where adopting such an oil supply system with a control function is not possible. For example, in electric axle units (so-called e-axles) that integrate an electric motor, gear reducer, and inverter for vehicle drive, the rotational speeds of the motor shaft and the input shaft of the reducer and the second and subsequent transmission shafts of the reducer differ significantly during operation. Therefore, the desired amount of oil supplied differs between the rolling bearings supporting the high-speed shaft, such as the input shaft, and the rolling bearings supporting the second and subsequent transmission shafts. Installing a dedicated oil supply system with a control function for oil lubrication of the rolling bearings supporting the high-speed shaft would result in an increase in the size and complexity of the unit, making it unacceptable. In such an operating environment, it is not possible to meet the demand for higher rotational speeds by raising the bearing rotational speed at which starvation occurs (i.e., the upper limit of the bearing rotational speed at which sufficient lubrication can be maintained).

[0010] In view of the above background, an object of the present invention is to increase the bearing rotation speed at which starvation occurs without requiring an electric axle unit or the like to be larger or more complex. [Means for solving the problem]

[0011] In order to solve the above problems, the present invention employs Configuration 1, which is a rolling bearing comprising an inner member having a first raceway surface, an outer member having a second raceway surface, a plurality of rolling elements arranged between the first raceway surface and the second raceway surface, and a cage that holds the plurality of rolling elements, further comprising: a shield that protrudes from the inner diameter surface of the outer member toward the outer diameter surface of the inner member at a position spaced apart on one axial side from the rolling elements and the cage; and a slinger that protrudes from the outer diameter surface of the inner member toward the inner diameter surface of the outer member at a position spaced apart on the other axial side opposite to the one axial side from the rolling elements and the cage, wherein a first oil passage is formed between the shield and the inner member, and a second oil passage is formed between the slinger and the outer member.

[0012] According to the above-mentioned configuration 1, when the rolling bearing rotates with the inner member rotating, the lubricating fluid such as oil that is agitated by the rolling elements and cage and flows toward one axial side is received by the shield, reducing the effect of an air curtain on the side surface on one axial side of the rolling bearing, making it easier for the oil supplied to one axial side of the rolling bearing to reach the first oil vent between the shield and the inner member. Meanwhile, on the other axial side of the rolling bearing, the slinger exerts a centrifugal force on the oil that has lubricated and cooled the rolling elements, promoting the discharge of the oil from the second oil vent between the outer member and the slinger and reducing the back pressure of the second oil vent relative to the first oil vent, making it easier for the oil to be sucked in through the first oil vent. By reducing the effect of the air curtain on one axial side of the rolling bearing while promoting oil discharge on the other axial side of the rolling bearing, it is possible to prevent oil from flowing back through the first oil vent, and to exert a centrifugal pumping action by drawing oil drawn in through the first oil vent toward the second oil vent, lubricating and cooling the rolling elements, etc., and discharging the oil from the second oil vent. Increasing the bearing rotational speed strengthens this centrifugal pumping action. In this way, if the rolling bearing is equipped with a shield and slinger that exerts an effective centrifugal pumping action at high rotational speeds, the bearing rotational speed at which starvation occurs can be increased by the rolling bearing itself, without requiring the electric axle unit, etc. to be larger or more complex.

[0013] In the above configuration 1, configuration 2 can be adopted in which the retainer has an annular portion extending circumferentially on the other axial side of the plurality of rolling elements, and the slinger has a side plate portion facing the side surface on the other axial side of the annular portion with an axial gap therebetween.

[0014] According to the above configuration 2, oil is caused to flow between the annular portion of the retainer and the side plate portion of the slinger, and centrifugal action is exerted on the oil from both areas to prevent it from escaping from this gap, thereby sending it to the second oil passage port.

[0015] In the above configuration 2, a configuration 3 can be adopted in which the slinger has a tubular plate portion fitted into the inner member so as to face the annular portion with a radial gap therebetween, the side plate portion protrudes radially outward from the other axial side of the tubular plate portion, and the radial gap between the tubular plate portion and the annular portion is smaller than the axial gap between the side surface of the other axial side of the annular portion and the side plate portion.

[0016] According to the above-mentioned configuration 3, oil is less likely to pass between the annular portion of the retainer and the cylindrical plate portion of the slinger, making it easier to supply oil to the rolling elements between the inner circumference of the retainer and the inner member, where the oil tends to become relatively diluted when the rolling bearing rotates at high speed.

[0017] In the above configurations 2 or 3, configuration 4 can be adopted in which the radial distance between the outer peripheral edge of the side plate portion and the outer member is set larger than the axial distance between the side surface on the other axial side of the annular portion and the side plate portion.

[0018] According to the above configuration 4, the oil that has passed between the annular portion of the cage and the side plate portion of the slinger can be easily discharged from the second oil passage port.

[0019] In the above configuration 4, a configuration 5 can be adopted in which the outer member has a shoulder portion facing the annular portion with a radial gap therebetween, and a notch portion provided at a position facing the side plate portion in the radial direction and having a larger diameter than the shoulder portion, and the side plate portion is provided with a smaller diameter than the shoulder portion.

[0020] According to the above configuration 5, the notch portion of the outer member can widen the second oil passage radially, thereby avoiding the need to reduce the diameter of the side plate portion of the slinger, and can make it easier for oil that passes between the outer member and the outer periphery of the retainer to flow toward the second oil passage.

[0021] In any one of the above configurations 1 to 5, a configuration 6 can be adopted in which the inner diameter of the shield is set to be equal to or smaller than the inner diameter of the cage.

[0022] According to the above-mentioned configuration 6, the entire retainer and most of the rolling elements are covered from one axial side by the shield, so that most of the oil that is stirred by the retainer and the rolling elements and flows toward one axial side can be received by the shield and prevented from flowing back into the first oil passage port.

[0023] In any one of the above configurations 1 to 6, a configuration 7 can be adopted in which the cage is provided at a position farther away from the shield in the other axial direction than the rolling elements.

[0024] According to the seventh aspect, a large space is provided between the shield and the rolling elements, so that oil can be diffused in the space between them and can easily reach the rolling elements.

[0025] In any one of the above configurations 1 to 7, a configuration 8 can be adopted in which the shield has a tip plate portion that is closest to the inner member in the shield, and an inner diameter side tapered plate portion that extends in a direction inclined radially outward from one axial side of the tip plate portion.

[0026] According to the above configuration 8, oil supplied to one axial side of the rolling bearing can easily enter the first oil port, and oil received by the shield can easily reach the rolling elements.

[0027] In any one of the above configurations 1 to 8, a configuration 9 can be adopted in which the cage is made of a resin member having an annular portion extending in the circumferential direction and multiple pairs of claw portions extending from the annular portion to one axial side so as to form a space that is open radially inward, radially outward, and to one axial side, the rolling elements are made of balls arranged in the space, and the spaces between the claw portions located between the rolling elements adjacent in the circumferential direction are recessed toward the other axial side, and when the minimum axial thickness from the recessed end face located furthest to the other axial side between the claw portions to the side surface of the cage on the other axial side is defined as a, the axial thickness from the bottom of a pocket located furthest to the other axial side in the space is defined as b, and the minimum distance between an imaginary plane passing through the centers of the multiple rolling elements and the recessed end face is defined as c, a>b and c>0 are satisfied.

[0028] According to the above configuration 9, deformation of the cage due to centrifugal force during high-speed rotation is suppressed, so that the rolling bearing can be made into a ball bearing suitable for high-speed rotation applications.

[0029] Configuration 10 can be adopted, which is a rotary machine comprising a rolling bearing according to any one of configurations 1 to 9 above, a rotating part supported by the rolling bearing, and an oil supply part that supplies oil to one axial side of the rolling bearing.

[0030] According to the above configuration 10, oil can be sucked in from the first oil port when the rolling bearing is rotating at high speed, so that the bearing rotation speed at which starvation occurs can be increased and the rotating part can be operated at high speed without providing an oil supply section that can precisely control the amount of oil supplied. [Effects of the Invention]

[0031] As described above, by adopting the above configuration 1, the present invention increases the bearing rotation speed at which starvation occurs without requiring an electric axle unit or the like to be larger or more complicated. [Brief explanation of the drawings]

[0032] [Figure 1] FIG. 1 is a longitudinal sectional front view showing a main part of a rolling bearing according to an embodiment of the present invention and a rotary machine including the same; [Figure 2] Left side view of the cage in Figure 1 [Figure 3] Cross section of line III-III in Figure 2 DETAILED DESCRIPTION OF THE INVENTION

[0033] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A rolling bearing and a rotary machine according to an embodiment of the present invention will be described with reference to the accompanying drawings.

[0034] The rotating machine shown in Figure 1 comprises a housing 100, a rotating part 101 that rotates relative to the housing 100, a rolling bearing 1 that supports the rotating part 101 so that it can rotate freely relative to the housing 100, and an oil supply part 102 that supplies oil to the rolling bearing 1.

[0035] The rolling bearing 1 comprises an inner member 10, an outer member 20 surrounding the inner member 10, a plurality of rolling elements 30 housed between the inner member 10 and the outer member 20, a cage 40 that holds these rolling elements 30, a shield 50 attached to the outer member 20, and a slinger 60 attached to the inner member 10. The inner diameter of the rolling bearing 1 can be in the range of 30 mm to 45 mm, for example.

[0036] The rolling elements 30 , the cage 40 , the shield 50 and the slinger 60 are arranged in an annular space 70 formed by the outer periphery of the inner member 10 and the inner periphery of the outer member 20 .

[0037] Here, the direction along the central axis of the rolling bearing 1 is referred to as the "axial direction," the direction perpendicular to the central axis is referred to as the "radial direction," and the direction in which the circumference centered on the central axis of the bearing extends is referred to as the "circumferential direction." In the radial direction, the side closer to the central axis of the bearing is referred to as the "radially inner side," and conversely, the side away from the central axis is referred to as the "radially outer side." In Figure 1, the axial direction corresponds to the left-right direction, and the radial direction corresponds to the up-down direction.

[0038] The housing 100 is made of a casing that is stationary relative to the rotating part 101. The rotating part 101 is made of a shaft that is rotated by input torque. For example, if the rotating machine is an electric axle unit for driving a vehicle, the rotating part 101 can be a motor shaft or a transmission shaft of a reducer, and the housing 100 can be a motor case or a reducer case.

[0039] The oil supply unit 102 supplies oil to one axial side of the rolling bearing 1. It reaches the outer periphery of the end of the inner member 10 on one axial side. In the illustrated example, splash lubrication is assumed, and a tube is used as the oil supply unit 102, which drops oil toward one axial side of the rolling bearing 1. If oil bath lubrication is used, an oil bath can be used as the oil supply unit, storing oil at an oil level that submerges the lower part of the rolling element 30, located at the lowest position in the orbital trajectory of the rolling element 30. The oil supply unit 102 may supply oil in liquid form, as in oil bath lubrication or splash lubrication, or in mist form, as in drop lubrication or spray lubrication. In FIG. 1, the movement of oil is schematically indicated by arrows without a reference symbol. The atmosphere surrounding the rolling bearing 1 is generally air. The amount of oil supplied from the oil supply portion 102 is small, and the oil and the atmosphere mix together and enter the annular space 70 to become a lubricating fluid that contributes to lubrication and cooling of the rolling elements 30 and the like.

[0040] The inner member 10 is made of a raceway ring including a first raceway surface 11 and a shoulder portion 12 on its outer periphery that defines the outer diameter of the inner member 10. The inner diameter surface of the inner member 10 is fitted into the rotating portion 101.

[0041] The outer member 20 is made of a raceway ring including, on its inner circumference, a second raceway surface 21, a shoulder portion 22 that defines the inner diameter of the outer member 20, a full circumferential groove portion 23 formed at a position spaced apart from the second raceway surface 21 on one side in the axial direction, and a notch portion 24 provided at a position spaced apart from the second raceway surface 21 on the other side in the axial direction and with a larger diameter than the shoulder portion 22. The outer diameter surface of the outer member 20 is fitted into the housing 100.

[0042] The rolling elements 30 are balls that roll on the first raceway surface 11 and the second raceway surface 21 .

[0043] The rolling bearing 1 is configured as a deep groove ball bearing.

[0044] The maximum rotational speed of the rolling bearing 1 accompanying the rotation of the rotating part 101 is set to a dmn value of 650,000 or more. Here, the dmn value is [{outer diameter of the rolling bearing (mm) + inner diameter of the rolling bearing (mm)} / 2] × rotation speed n (min -1 ) The outer diameter of the rolling bearing 1 is determined by the outer diameter surface of the outer member 20. The inner diameter of the rolling bearing 1 is determined by the inner diameter surface of the inner member 10. The rotation speed n is determined by the number of rotations per minute of the inner member 10.

[0045] 1 and 2, the cage 40 is made of a resin member having a seamless annular portion 41 extending circumferentially at a position on the other axial side (the right side in FIG. 1) opposite one axial side of the plurality of rolling elements 30, and multiple pairs of claw portions 42, 43 extending from the annular portion 41 toward one axial side. The pair of claw portions 42, 43 extend from the annular portion 41 so as to form spaces 44 that are open radially inward, radially outward, and toward one axial side (the left side in FIG. 1). The spaces 44 are arranged at multiple locations around the circumference of the cage 40 at equal intervals.

[0046] As shown in FIGS. 1 to 3, the rolling elements 30 are arranged in spaces 44. One space 44 is formed by the opposing portions of a pair of claw portions 42, 43 that face each other in the circumferential direction with the rolling elements 30 interposed therebetween, and by a part of the annular portion 41. The pair of claw portions 42, 43 have tip portions that are located on one axial side of the center of the rolling elements 30. The minimum width of an opening formed in the side surface on one axial side of the cage 40 by the tip portions of this pair of claw portions 42, 43 is smaller than the diameter of the rolling elements 30. The rolling elements 30 are arranged in the space by being forced to pass between the tip portions of the pair of claw portions 42, 43.

[0047] The annular portion 41 is disposed facing the shoulder portion 22 on the other axial side of the outer member 20 with a radial gap therebetween. A side surface 45 on the other axial side of the annular portion 41 is flat and extends radially, and is located furthest on the other axial side of the cage 40. The claw portions 42, 43 are located furthest on the one axial side of the cage 40. The axial length of the claw portions 42, 43 from the full-circumferential resin portion forming the annular portion 41 is shorter than that of the rolling element 30.

[0048] The cage 40 is guided in the radial and axial directions by the plurality of rolling elements 30. Therefore, as shown in FIG. 1, the cage 40 is arranged in a state where it does not contact the inner member 10, the outer member 20, the shield 50, and the slinger 60.

[0049] Most of the cage surface that forms the space 44 follows an imaginary spherical surface and serves as a guide surface that can come into contact with the rolling elements 30. The geometric center O of the space 44 is the center of the imaginary spherical surface. In the illustration, the center O of the space 44 coincides with the center of the rolling elements 30. In addition, in FIG. 3, the up-down direction corresponds to the axial direction, and the left-right direction corresponds to the circumferential direction.

[0050] As shown in Figure 3, the claw portions 42, 43 include an oil inlet passage 44a facing the space 44. The oil inlet passage 44a is a flow path that forms a groove space between the rolling element 30 and the oil inlet passage 44a, into which the rolling element 30 cannot enter. During operation of the rolling bearing 1, oil enters between the oil inlet passage 44a and the rolling element 30, promoting lubrication and cooling of the rolling element 30 and its surroundings.

[0051] The oil inlet passage 44a is located on an imaginary plane that passes through the centers of the multiple rolling elements 30. Because the rotation speed of the rolling elements 30 is fastest on or near this imaginary plane, it is preferable to provide the oil inlet passage 44a to promote lubrication.

[0052] As shown in FIGS. 2 and 3 , the cage 40 has a recessed shape toward the other axial direction between two claw portions 42, 43 located between adjacent rolling elements 30 in the circumferential direction. Here, the minimum axial thickness from the recessed end surface 46, which is located farthest toward the other axial direction between the two claw portions 42, 43, to the side surface of the cage 40 on the other axial side is defined as a. The axial thickness from the pocket bottom P, which is located farthest toward the other axial side in the space 44, to the side surface of the cage 40 on the other axial side is defined as b. The minimum distance between the recessed end surface 46 and an imaginary plane passing through the centers of the rolling elements 30 is defined as c. The cage 40 satisfies a > b and c > 0. This ensures the ring strength of the cage 40 while reducing the mass of the claw portions 42, 43 and thereby reducing the centrifugal force acting on the claw portions 42, 43. This ultimately suppresses deformation of the cage 40 during high-speed rotation and prevents interference between the claw portions 42, 43 and other components, such as the rolling elements 30.

[0053] The resin material forming the cage 40 may be, for example, one containing polyether ether ketone (PEEK) or polyphenylene sulfide (PPS) as a primary component, or a composite material in which reinforcing fibers such as carbon or glass are mixed with an appropriate matrix resin. The axial thicknesses a, b, and c may be determined so that a > b and c > 0 are satisfied depending on the strength of the resin material forming the cage 40. For example, when polyamide resin is used as the primary component of the resin material, setting the axial thickness b to 1 / 70 to 1 / 30 of the cage PCD can ensure rigidity at the relatively thin pocket bottom P and effectively prevent deformation during high-speed rotation. In this case, when the welds generated during injection molding of the cage 40 are located at the minimum axial thickness a, setting the minimum axial thickness a to 1 / 62 to 1 / 26 of the cage PCD can ensure strength at the welds. The cage PCD refers to the diameter of an imaginary circle extending circumferentially through the center O of each space 44.

[0054] 1, the shield 50 protrudes from the inner diameter surface of the outer member 20 toward the outer diameter surface of the inner member 10 at a position spaced apart on one axial side from the rolling elements 30 and the cage 40. A first oil passage port 71 is formed between the shield 50 and the inner member 10. The first oil passage port 71 is a space through which oil can pass between the shield 50 and the inner member 10, and serves as an inlet for sucking a lubricating fluid such as oil that has reached the gap between the shield 50 and the inner member 10 from one axial side of the annular space 70 into a spatial region in the annular space 70 that is closer to the rolling elements 30 than the shield 50.

[0055] When the inner member 10 rotates and the rolling bearing 1 rotates, the lubricating fluid such as oil is agitated by the rolling elements 30 and the cage 40, and the lubricating fluid such as oil that flows toward one axial side of the rolling elements 30 and the cage 40 is received by the shield 50, thereby reducing the effect of the air curtain on the side surface on one axial side of the rolling bearing 1. This makes it easier for the oil supplied from the oil supply part 102 to the rolling bearing 1 toward one axial side to reach the first oil vent port 71.

[0056] The slinger 60 protrudes from the outer diameter surface of the inner member 10 toward the inner diameter surface of the outer member 20 at a position spaced apart on the other axial side from the rolling elements 30 and the cage 40. A second oil passage port 72 is formed between the slinger 60 and the outer member 20. The second oil passage port 72 is a space through which oil can pass between the slinger 60 and the outer member 20, and serves as an outlet for discharging lubricating fluid such as oil that has been sucked in through the first oil passage port 71 and has reached the other axial side of the rolling elements 30 and the cage 40 in the annular space 70 to the outside of the annular space 70.

[0057] The slinger 60 exerts a centrifugal action on the lubricating fluid such as oil in the annular space 70, which promotes the discharge of the lubricating fluid such as oil from the second oil vent port 72. As a result, the back pressure of the second oil vent port 72 relative to the first oil vent port 71 is reduced. The pressure difference between the first oil vent port 71 and the second oil vent port 72 causes the lubricating fluid such as oil that has lubricated and cooled the rolling elements 30, etc., to be drawn toward the second oil vent port 72, making it easier for oil supplied from the oil supply unit 102 and the atmosphere to be drawn through the first oil vent port 71.

[0058] The shield 50 and the slinger 60 are each formed from a single metal plate. In this example, a steel plate is used as the metal plate. For example, an SPC material specified in the JIS standard can be used as the steel plate.

[0059] The shield 50 is composed of a curled plate portion 51 held in the circumferential groove portion 23 of the outer member 20, a tip plate portion 52 that is closest to the shoulder portion 12 on one axial side of the inner member 10 within the shield 50, an inner diameter side tapered plate portion 53 that extends in a direction inclined radially outward from one axial side of the tip plate portion 52, an intermediate plate portion 54 that extends radially from the inner diameter side tapered plate portion 53, and an outer diameter side tapered plate portion 55 that extends from the inner diameter side of the curled plate portion 51 in a direction inclined axially to one side to the intermediate plate portion 54.

[0060] The shield 50 is attached to the outer member 20 by caulking the curled plate portion 51 into the circumferential groove portion 23 of the outer member 20 .

[0061] The tip plate portion 52 is arranged to face the shoulder portion 12 on one axial side of the inner member 10 with a radial gap therebetween. The inner periphery of the tip plate portion 52 defines the inner diameter of the shield 50. The inner diameter of the shield 50 is set to be equal to or smaller than the inner diameter of the cage 40. Therefore, the entire cage 40 is covered from one axial side by the shield 50. When the rolling bearing 1 rotates, most of the lubricating fluid such as oil that is agitated by the rolling elements 30 and the cage 40 and flows toward one axial side is received by the shield 50.

[0062] The inner diameter side tapered plate portion 53 extends in a direction inclined radially outward from the tip plate portion 52, which defines the inner diameter of the shield 50, toward one axial side, so that the space between the inner diameter side tapered plate portion 53 and the shoulder portion 12 is larger than the space between the tip plate portion 52 and the shoulder portion 12 on one axial side of the inner member 10. Therefore, oil supplied from the oil supply portion 102 can easily enter the first oil vent port 71 from between the inner diameter side tapered plate portion 53 and the shoulder portion 12.

[0063] The tip plate portion 52 is cylindrical and extends circumferentially with a certain length in the axial direction from the inner diameter side tapered plate portion 53. Therefore, the lubricating fluid such as oil that enters the first oil passage port 71 is likely to flow along the inner periphery of the tip plate portion 52 and the shoulder portion 12 toward the rolling elements 30.

[0064] The distance between the shield 50 and the cage 40 is greater than the distance between the shield 50 and the rolling elements 30. By disposing the annular portion 41 on the other axial side of the rolling elements 30, the cage 40 is located farther axially from the shield 50 than the rolling elements 30. Since the annular portion 41 is not present between the shield 50 and the rolling elements 30, the space between the shield 50 and the rolling elements 30 is relatively wide. Therefore, lubricating fluid such as oil sucked through the first oil vent 71 enters and diffuses into the relatively wide space between the shield 50 and the rolling elements 30, making it easier to reach the rolling elements 30. Furthermore, the flow rate of the agitated lubricating fluid such as oil toward the other axial side is reduced due to the annular portion 41, and the flow rate toward one axial side in the relatively wide space is increased. When the lubricating fluid such as oil flowing toward one axial side is received by the shield 50, it changes direction and diffuses into the relatively wide space. When lubricating fluid such as oil received by the shield 50 flows toward the outer member 20, it is guided by the outer diameter side tapered plate portion 55, making it easier to reach the rolling elements 30. Furthermore, when lubricating fluid such as oil received by the shield 50 flows toward the inner member 10, it combines with lubricating fluid such as oil that enters the relatively large space between the shield 50 and the rolling elements 30 from the first oil passage port 71, and is guided by the inner diameter side tapered plate portion 53 and the tip plate portion 52, making it easier to reach the rolling elements 30.

[0065] The slinger 60 is composed of a cylindrical plate portion 61 fitted to the outer periphery of the other axial side of the inner member 10, and a side plate portion 62 protruding radially outward from the other axial side of the cylindrical plate portion 61.

[0066] The slinger 60 is attached to the inner member 10 by press-fitting the cylindrical plate portion 61 into the inner member 10 .

[0067] The cylindrical plate portion 61 is disposed facing the inner periphery of the annular portion 41 with a gap therebetween in the radial direction. The side plate portion 62 is disposed facing the side surface 45 on the other axial side of the annular portion 41 with a gap therebetween in the axial direction.

[0068] Because the cylindrical plate portion 61 is positioned between the inner member 10 and the annular portion 41, the radial distance g1 between the cylindrical plate portion 61 and the annular portion 41 is narrower than the radial distance between the annular portion 41 and the inner member 10. Lubricating fluid such as oil that attempts to enter between the annular portion 41 and the cylindrical plate portion 61 from near the rolling elements 30 is obstructed by the cylindrical plate portion 61, making it difficult for it to pass between the annular portion 41 and the cylindrical plate portion 61. When the rolling bearing 1 rotates at high speed, the centrifugal action is strong, in which lubricating fluid such as oil that comes into contact with the outer periphery of the cage 40, the outer periphery of the inner member 10, the slinger 60, etc. is sent radially outward by centrifugal force, so the lubricating fluid such as oil is unevenly distributed toward the outer member 20, and the oil tends to become diluted between the cage 40 and the inner member 10. Therefore, it becomes difficult for lubricating fluid such as oil to pass between the annular portion 41 and the cylindrical plate portion 61 from the vicinity of the rolling element 30, which is advantageous for lubrication and cooling of the rolling element 30 and the first raceway surface 11.

[0069] A radial distance g1 between the cylindrical plate portion 61 and the annular portion 41 is set smaller than an axial distance g2 between the side surface 45 on the other axial side of the annular portion 41 and the side plate portion 62. Therefore, the flow path cross-sectional area between the side surface 45 on the other axial side of the annular portion 41 and the side plate portion 62 is larger than the flow path cross-sectional area between the cylindrical plate portion 61 and the annular portion 41.

[0070] The entire amount of lubricating fluid, such as oil, that has passed between the cylindrical plate portion 61 and the annular portion 41 toward the other axial side enters the gap between the side plate portion 62 and the side surface 45 on the other axial side of the annular portion 41. At this time, the lubricating fluid is guided by the side plate portion 62, changing its flow direction radially outward. Furthermore, when the lubricating fluid, such as oil, moves from the gap between the cylindrical plate portion 61 and the annular portion 41, which has a relatively narrow flow passage cross section, to the gap between the side plate portion 62 and the side surface 45 on the other axial side of the annular portion 41, which has a relatively wide flow passage cross section, the velocity of the lubricating fluid moving radially outward increases as the pressure decreases. This increase in velocity makes it easier for the lubricating fluid, such as oil, that has passed between the side plate portion 62 and the side surface 45 on the other axial side of the annular portion 41 to be discharged from the second oil vent port 72.

[0071] Furthermore, between the side surface 45 on the other axial side of the annular portion 41 and the side plate portion 62, lubricating fluid such as oil that comes into contact with the side surface 45 or the side plate portion 62 is sent radially outward by centrifugal force. The lubricating fluid such as oil that comes into contact with the side surface 45 or the side plate portion 62 cannot escape from between the side surface 45 and the side plate portion 62, and centrifugal action is exerted by both portions 45, 62 to the second oil vent port 72 that is thrown out radially outward from the side surface 45 or the side plate portion 62.

[0072] If the axial distance g2 between the side surface 45 on the other axial side of the annular portion 41 and the side plate portion 62 is too wide, the flow of lubricating fluid such as oil will be disturbed between the side surface 45 and the side plate portion 62, reducing the efficiency of sending the lubricating fluid such as oil by centrifugal force. For this reason, the axial distance g2 is set to, for example, 1 mm or more and 3 mm or less.

[0073] A radial distance g3 between the outer peripheral edge of the side plate portion 62 and the outer member 20 is set larger than an axial distance g2 between the side surface 45 on the other axial side of the annular portion 41 and the side plate portion 62. Therefore, the flow path cross-sectional area between the outer peripheral edge of the side plate portion 62 and the outer member 20 is larger than the flow path cross-sectional area between the side surface 45 on the other axial side of the annular portion 41 and the side plate portion 62.

[0074] When a lubricating fluid such as oil that has passed radially outward between the side plate portion 62 and the side surface 45 on the other axial side of the annular portion 41 moves from the gap between the side plate portion 62 and the side surface 45 on the other axial side of the annular portion 41, which has a relatively narrow flow passage cross section, to the gap between the outer peripheral edge of the side plate portion 62, which has a relatively wide flow passage cross section, and the outer member 20, the velocity of the lubricating fluid that moves radially outward increases as the pressure decreases. For this reason, the lubricating fluid such as oil that has passed radially outward between the side plate portion 62 and the side surface 45 on the other axial side of the annular portion 41 is more likely to be discharged from the second oil vent port 72.

[0075] The cutout portion 24 of the outer member 20 is provided with a diameter larger than that of the shoulder portion 22 at a position radially opposite the side plate portion 62, and therefore the second oil vent port 72 is provided wider radially outward, thereby avoiding the need to reduce the outer diameter of the side plate portion 62. Accordingly, the space axially opposite the side plate portion 62 and the side surface 45 on the other axial side of the annular portion 41 is expanded radially outward, which is advantageous for strengthening the centrifugal action described above.

[0076] Because the annular portion 41 faces the shoulder portion 22 of the outer member 20 with a radial gap therebetween and the side plate portion 62 has a smaller diameter than the shoulder portion 22, lubricating fluid such as oil flowing from the vicinity of the rolling elements 30 toward the other axial side between the shoulder portion 22 and the outer periphery of the cage 40 can reach the second oil vent 72 without colliding with the side plate portion 62 in the axial direction. As a result, the lubricating fluid such as oil that has passed between the outer member 20 and the outer periphery of the cage 40 is more likely to head toward the second oil vent 72. Consequently, the lubricating fluid such as oil present near the second oil vent 72 is more likely to be discharged from the second oil vent 72. In the illustrated example, the outer diameter of the side plate portion 62 is set to be equal to the outer diameter of the annular portion 41 in order to maximize the centrifugal action between the side surface 45 on the other axial side of the annular portion 41 and the side plate portion 62.

[0077] Lubricating fluid such as oil that has passed between the side surface 45 on the other axial side of the annular portion 41 and the side plate portion 62 joins with lubricating fluid such as oil that has passed between the annular portion 41 and the shoulder portion 22 to the other axial side, and is discharged from the second oil vent port 72. When the rolling bearing 1 is rotating at high speed, if the force of the lubricating fluid such as oil that has passed between the side surface 45 and the side plate portion 62 is strong, it may reach the notch portion 24. The lubricating fluid such as oil that has reached this point collides with the notch portion 24 and spreads, heading toward the second oil vent port 72, or is guided by the notch portion 24 and turns counterclockwise in the figure between the notch portion 24 and the outer periphery of the annular portion 41, heading toward the second oil vent port 72. Even if a lubricating fluid such as oil hits the notch 24, the notch 24 forms a radial step with respect to the shoulder 22, so that the lubricating fluid is prevented from moving between the shoulder 22 and the outer periphery of the annular portion 41.

[0078] The side surface on the other axial side of the side plate portion 62 comes into contact with the atmosphere surrounding the rolling bearing 1. When the inner member 10 rotates, causing the rolling bearing 1 to rotate, the atmosphere in contact with the side surface on the other axial side of the side plate portion 62 is sent radially outward by centrifugal force. This flow blows and reduces the pressure of the fluid present near the second oil vent port 72 outside the annular space 70, thereby encouraging the discharge of lubricating fluid such as oil from the second oil vent port 72.

[0079] When the rolling bearing 1 is configured as a ball bearing, whether or not there is sufficient lubrication between the rolling element 30 and the raceway surfaces 11, 12 when the amount of oil sucked in from the first oil port 71 is small can be examined, for example, using the test results shown in Non-Patent Documents 1 and 2 and the reduction in rolling viscous resistance φr based on the knowledge of the method for estimating friction torque shown in Non-Patent Document 3.

[0080] Here, the reduction in rolling viscous resistance φr is a value calculated by the following formula 1.

number

[0081] According to the test examples in Non-Patent Documents 1 and 2, sufficient lubrication was maintained up to the maximum speed under test conditions with oil supply rates of 70 ml / min and 100 ml / min, while starvation occurred at speeds lower than the maximum under test conditions with an oil supply rate of 40 ml / min. The reduction in rolling viscous resistance φr under each test condition was calculated as φr = 0.288 under the test condition with an oil supply rate of 40 ml / min, φr = 0.505 under the test condition with an oil supply rate of 70 ml / min, and φr = 0.721 under the test condition with an oil supply rate of 100 ml / min. Therefore, it is believed that sufficient lubrication can be maintained when φr ≧ 0.505 is satisfied.

[0082] That is, the amount of oil sucked in from the first oil inlet 71 is taken as the value of k, the dynamic viscosity of the oil in the usage environment as the value of ν, the passage period of the rolling element 30 when the rolling bearing 1 has the desired dmn value in the usage environment as the value of T, and the major axis radius of the contact ellipse at the contact point between the rolling element 30 and the first raceway surface 11 or the second raceway surface 21 in the usage environment as the value of a, and φr is calculated; for example, if φr≧0.505 is satisfied when the dmn value of the rolling bearing 1 is a predetermined value of 650,000 or more, it is considered that sufficient lubrication can be maintained at that predetermined value.

[0083] The rolling bearing 1 shown in Figures 1 to 3 is as described above, and comprises an inner member 10 having a first raceway surface 11, an outer member 20 having a second raceway surface 21, a plurality of rolling elements 30 arranged between the first raceway surface 11 and the second raceway surface 21, and a cage 40 that holds the plurality of rolling elements 30.

[0084] This rolling bearing 1 further comprises, in particular, a shield 50 that protrudes from the inner diameter surface of the outer member 20 toward the outer diameter surface of the inner member 10 at a position spaced apart on one axial side (left side in FIG. 1 ) relative to the rolling elements 30 and the cage 40, and a slinger 60 that protrudes from the outer diameter surface of the inner member 10 toward the inner diameter surface of the outer member 20 at a position spaced apart on the other axial side (right side in FIG. 1 ) relative to the rolling elements 30 and the cage 40, and a first oil vent 71 that draws in oil is formed between the shield 50 and the inner member 10, and a second oil vent 72 that discharges the oil drawn in from the first oil vent 71 is formed between the slinger 60 and the outer member 20. As a result, when the rolling bearing 1 rotates with the inner member 10 rotating, the lubricating fluid such as oil that is stirred by the rolling elements 30 and retainer 40 and flows toward one axial side is received by the shield 50, reducing the effect of the air curtain on the side surface on one axial side of the rolling bearing 1, making it easier for the oil supplied to one axial side of the rolling bearing 1 to reach the first oil passage port 71, while on the other axial side of the rolling bearing 1, a centrifugal action is exerted by the slinger 60 on the oil that has lubricated and cooled the rolling elements 30, promoting the discharge of the oil from the second oil passage port 72, and ultimately reducing the back pressure of the second oil passage port 72 on the first oil passage port 71, making it easier to suck the oil through the first oil passage port 71. This rolling bearing 1 prevents oil from flowing back through the first oil port 71 by reducing the effect of these air curtains and by suppressing the back pressure of the second oil port 72 relative to the first oil port 71, thereby exerting a centrifugal pumping action by drawing oil drawn in through the first oil port 71 toward the second oil port 72 and discharging the oil that has lubricated and cooled the rolling elements 30 and the like from the second oil port 72. Increasing the dmn value (bearing rotational speed) of this rolling bearing 1 strengthens its centrifugal pumping action. In this way, because this rolling bearing 1 is equipped with the shield 50 and slinger 60 to exert an effective centrifugal pumping action during high-speed rotation, the bearing rotational speed at which starvation occurs can be increased without requiring an electric axle unit or other unit to be larger or more complex.

[0085] In addition, in this rolling bearing 1, the retainer 40 has an annular portion 41 that extends circumferentially on the other axial side relative to the multiple rolling elements 30, and the slinger 60 has a side plate portion 62 that faces the side surface 45 on the other axial side of the annular portion 41 with an axial gap between them, so that oil can flow into the space between the annular portion 41 and the side plate portion 62, and a centrifugal action can be exerted on the oil from both portions 45, 62 to prevent it from escaping from this space, and the oil can be sent to the second oil inlet 72.

[0086] In addition, this rolling bearing 1 has a tubular plate portion 61 fitted into the inner member 10 so that the slinger 60 faces the annular portion 41 with a radial gap between them, and the side plate portion 62 protrudes radially outward from the other axial side of the tubular plate portion 61.The radial gap g1 between the tubular plate portion 61 and the annular portion 41 is smaller than the axial gap g2 between the side surface 45 on the other axial side of the annular portion 41 and the side plate portion 62, making it difficult for oil to pass between the annular portion 41 and the tubular plate portion 61, and making it easier to supply oil to the rolling elements 30 between the inner circumference of the retainer 40 and the inner member 10, where the oil is likely to become relatively diluted when the rolling bearing 1 rotates at high speed.

[0087] In addition, in this rolling bearing 1, the radial distance g3 between the outer peripheral edge of the side plate portion 62 and the outer member 20 is set to be larger than the axial distance g2 between the side surface 45 on the other axial side of the annular portion 41 and the side plate portion 62, making it easier to discharge oil that has passed between the side surface 45 on the other lateral side of the annular portion 41 and the side plate portion 62 from the second oil passage port 72.

[0088] In addition, this rolling bearing 1 has a shoulder portion 22 in which the outer member 20 faces the annular portion 41 at a radial distance, and a notch portion 24 that is provided at a position radially opposite the side plate portion 62 and has a larger diameter than the shoulder portion 22.Since the side plate portion 62 is provided with a smaller diameter than the shoulder portion 22, the notch portion 24 radially widens the second oil passage 72, preventing the side plate portion 62 from becoming smaller in diameter, and makes it easier for oil that has passed between the outer member 20 and the outer periphery of the retainer 40 to flow toward the second oil passage 72.

[0089] Furthermore, in this rolling bearing 1, the inner diameter of the shield 50 is set to be equal to or smaller than the inner diameter of the retainer 40, so that the entire retainer 40 and most of the multiple rolling elements 30 are covered from one axial side by the shield 50, and most of the oil that is stirred by the retainer 40 and the rolling elements 30 and flows toward one axial side is received by the shield 50, preventing it from flowing back into the first oil passage 71.

[0090] Furthermore, in this rolling bearing 1, the retainer 40 is positioned further away from the shield 50 in the other axial direction than the rolling element 30, which provides a wider space between the shield 50 and the rolling element 30, allowing oil to diffuse in the space between the two, 50 and 30, making it easier for the oil to reach the rolling element 30.

[0091] Furthermore, in this rolling bearing 1, the shield 50 has a tip plate portion 52 that is closest to the inner member 10 within the shield 50, and an inner diameter side tapered plate portion 53 that extends in a direction inclined radially outward from one axial side of the tip plate portion 52, making it easier for oil supplied to one axial side of the rolling bearing 1 to enter the first oil passage port 71 and making it easier for the oil received by the shield 50 to reach the rolling element 30.

[0092] In addition, in this rolling bearing 1, the cage 40 is made of a resin member having an annular portion 41 extending in the circumferential direction and multiple pairs of claw portions 42, 43 extending from the annular portion 41 toward one axial side so as to form a space 44 that is open radially inward, radially outward, and toward one axial side, the rolling elements 30 are made of balls arranged in the space 44, the spaces between the claw portions 42, 43 located between adjacent rolling elements 30 in the circumferential direction are recessed toward the other axial side, and a recessed end surface 46 located nearest to the other axial side between the claw portions 42, 43 extends from the other axial side of the cage 40. When the minimum axial thickness from the pocket bottom P located furthest to the other axial side of the retainer 40 (side surface 45 on the other axial side of the annular portion 41) is a, the axial thickness from the pocket bottom P located furthest to the other axial side of the retainer 40 in the space 44 (side surface 45 on the other axial side of the annular portion 41) is b, and the minimum distance between an imaginary plane passing through the centers of the multiple rolling elements 30 and the concave end surface 46 is c, since a > b and c > 0 are satisfied, deformation of the retainer 40 due to centrifugal force during high-speed rotation is suppressed, and the rolling bearing 1 can be made into a ball bearing suitable for high-speed rotation applications.

[0093] Furthermore, the rotating machine according to the embodiment comprises a rolling bearing 1, a rotating part 101 supported by the rolling bearing 1, and an oil supply part 102 that supplies oil to one axial side of the rolling bearing 1, and therefore oil can be sucked in from the first oil inlet 71 when the rolling bearing 1 rotates at high speed. This means that the bearing rotation speed at which starvation occurs can be increased and the rotating part 101 can be operated at high speeds without having to provide an oil supply part that can precisely control the amount of oil supplied.

[0094] In this embodiment, an example has been shown in which the space from the first oil vent port 71 to the rolling elements 30 passes directly in the axial direction, but a circumferential groove may be formed on the outer periphery of one axial end of the inner member, and a labyrinth gap may be formed between the circumferential groove and the tip plate portion of the shield. Also, although an example has been shown in which the shield 50 is made of a metal plate, it may also be a seal having an elastomer seal lip, and for example, a non-contact seal may be configured in which the seal lip is arranged so as to form a labyrinth gap between the seal lip and the circumferential groove of the inner member as described above, or the core metal of the seal may have a shape corresponding to that of the shield 50.

[0095] It is also possible to position the annular portion of the cage on one axial side relative to the rolling elements. In this case, the annular portion prevents lubricating fluid, such as oil, stirred by the rolling elements from moving toward the first oil vent, which is advantageous in reducing the effect of the air curtain. However, this is disadvantageous in that the annular portion prevents oil drawn from the first oil vent from reaching the rolling elements, and the increased distance between the slinger and the cage makes it difficult for the lubricating fluid, such as oil, to move toward the second oil vent, even if the slinger exerts a centrifugal force on the lubricating fluid, thereby weakening the centrifugal pumping effect. Therefore, the position of the annular portion of the cage relative to the rolling elements can be determined by taking these advantages and disadvantages into consideration.

[0096] Furthermore, the present invention can be applied to angular contact ball bearings and roller bearings in addition to deep groove ball bearings.

[0097] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0098] 1. Rolling bearings 10 Inner member 11 First orbital plane 20 Outer member 21 Second orbital plane 22 Shoulder 24 Notch 30 rolling elements 40 Retainer 41 Circular section 42, 43 Claws 44 Space 45 Side surface on the other side in the axial direction 46 Concave end face 50 Shield 52 Tip plate 53 Inner diameter tapered plate 60 Slinger 61 Cylinder plate part 62 Side plate part 71 First oil outlet 72 Second oil vent 101 Rotating part 102 Fuel Station

Claims

1. A rolling bearing comprising an inner member having a first raceway surface, an outer member having a second raceway surface, a plurality of rolling elements arranged between the first raceway surface and the second raceway surface, and a cage that holds the plurality of rolling elements, a shield protruding from the inner diameter surface of the outer member toward the outer diameter surface of the inner member at a position spaced apart on one axial side relative to the rolling elements and the cage, and a slinger protruding from the outer diameter surface of the inner member toward the inner diameter surface of the outer member at a position spaced apart on the other axial side opposite to the one axial side relative to the rolling elements and the cage, a first oil vent port is formed between the shield and the inner member, A rolling bearing characterized in that a second oil passage port is formed between the slinger and the outer member.

2. the cage has an annular portion extending circumferentially on the other axial side of the plurality of rolling elements, 2. The rolling bearing according to claim 1, wherein the slinger has a side plate portion that faces a side surface on the other axial side of the annular portion with an axial gap therebetween.

3. the slinger has a cylindrical plate portion fitted to the inner member so as to face the annular portion with a gap therebetween in the radial direction, the side plate portion protrudes radially outward from the other axial side of the cylindrical plate portion, 3. The rolling bearing according to claim 2, wherein the radial distance between the cylindrical plate portion and the annular portion is smaller than the axial distance between the side surface of the annular portion on the other axial side and the side plate portion.

4. 4. A rolling bearing as described in claim 2 or 3, wherein the radial distance between the outer peripheral edge of the side plate portion and the outer member is set larger than the axial distance between the side surface on the other axial side of the annular portion and the side plate portion.

5. the outer member has a shoulder portion facing the annular portion with a gap therebetween in the radial direction, and a notch portion provided at a position facing the side plate portion in the radial direction and having a diameter larger than that of the shoulder portion, 5. A rolling bearing according to claim 4, wherein the outer diameter of the side plate portion is smaller than that of the shoulder portion.

6. 4. The rolling bearing according to claim 1, wherein the inner diameter of the shield is equal to or smaller than the inner diameter of the cage.

7. 4. The rolling bearing according to claim 1, wherein the cage is provided at a position farther away from the shield in the axial direction than the rolling elements.

8. 4. A rolling bearing according to claim 1, wherein the shield has a tip plate portion that is closest to the inner member within the shield, and an inner diameter side tapered plate portion that extends in a direction inclined radially outward from one axial side of the tip plate portion.

9. the cage is made of a resin member having an annular portion extending in a circumferential direction and a plurality of pairs of claw portions extending from the annular portion toward one axial side so as to form spaces that are open radially inward, radially outward, and toward one axial side, the rolling elements are balls arranged in the space, 4. The rolling bearing according to claim 1, wherein the spaces between the claw portions located between the rolling elements adjacent in the circumferential direction are recessed toward the other axial side, and wherein a is the minimum axial thickness from the recessed end face located furthest to the other axial side between the claw portions to the side surface of the cage on the other axial side, b is the axial thickness from the bottom of a pocket located furthest to the other axial side in the space to the side surface of the cage on the other axial side, and c is the minimum distance between an imaginary plane passing through the centers of the multiple rolling elements and the recessed end face, such that a > b and c > 0 are satisfied.

10. A rotary machine comprising: a rolling bearing according to any one of claims 1 to 3; a rotating part supported by said rolling bearing; and an oil supply part that supplies oil to one axial side of said rolling bearing.

Images