Ball bearing

Abstract

An outer-diameter-side axial groove (24) is formed in a radially outer side surface (23) of the retainer claw portion (22), and an inner-diameter-side axial groove (26) is formed in a radially inner side surface (25) of the retainer claw portion (22), and the retainer claw portion (22) has a cross-sectional shape orthogonal to the axial direction that is an H shape that is open to the radially outer side and the radially inner side by the outer-diameter-side axial groove (24) and the inner-diameter-side axial groove (26).

Description

Technical Field

[0001] This invention relates to ball bearings. Background Technology

[0002] Ball bearings are mostly used as bearings to support rotating shafts in automobiles, construction machinery, etc. Typically, a ball bearing has: an inner ring, an outer ring coaxially disposed radially outside the inner ring, a plurality of balls disposed in an annular space between the inner and outer rings, and a retainer for holding the plurality of balls.

[0003] As a retainer, for example, as in Patent Document 1, a resin retainer (so-called crown retainer) is known. This resin retainer has a retainer annular portion that is adjacent to the passage area of ​​the ball and extends circumferentially, and a cantilever-beam-shaped retainer claw portion that extends axially from the retainer annular portion between circumferentially adjacent balls. The retainer claw portion has a ball guide surface that faces the surface of the ball and is formed as a concave spherical surface along the surface of the ball in a manner that holds the ball in place.

[0004] In addition, for example, as in Patent Document 2, sealed ball bearings are often used. In order to prevent foreign objects from entering the ball bearing from the outside or to prevent lubricants (lubricating oil, grease, etc.) from leaking from the inside of the ball bearing to the outside, an annular sealing member is used to block the axial end opening of the annular space formed between the inner and outer rings.

[0005] Patent Document 1: Japanese Patent No. 3035766

[0006] Patent Document 2: International Publication No. 2016 / 143786

[0007] In recent years, in the field of electric vehicles such as EVs (battery electric vehicles) and HEVs (hybrid electric vehicles), the pursuit of miniaturization and lightweighting of electric motors has led to advancements in high-speed rotation. The ball bearings that support the rotating shaft that powers this electric motor's rotation are often characterized by a dmn value (the pitch circle diameter of the ball, dm (mm), multiplied by the rotational speed, n (min)). －1 It was used under conditions exceeding 2 million.

[0008] The inventors of this application have studied the use of crown retainers in ball bearings that support high-speed rotating shafts of EVs, HEVs, etc.

[0009] However, it is understood that when using a crown-shaped cage in a high-speed rotating ball bearing, the centrifugal force acting on the cantilevered cage claws causes torsional deformation in the cage annulus, tilting the cage claws radially outward. Furthermore, the cage claws themselves also undergo radial outward deflection. This raises concerns about interference between the cage claws and the balls due to these deformations. If the cage claws interfere with the balls, it becomes a cause of overheating in the ball bearing.

[0010] In particular, when using bearings with crown retainers or sealed ball bearings, there is a concern that abnormal heat generation may occur due to the sliding resistance of the contact portion if the retainer annulus of the crown retainer comes into contact with the sealing component. Therefore, it is necessary to suppress the axial width dimension of the retainer annulus to prevent it from contacting the sealing component. Consequently, it is difficult to improve the rigidity of the retainer annulus, and torsional deformation is easily generated in the retainer annulus due to the centrifugal force acting on the retainer claws, making it easy for the retainer claws and balls to interfere.

[0011] Thus, when using a crown retainer in a sealed ball bearing, it becomes difficult to use the sealed ball bearing for high-speed rotation applications. Furthermore, when the space for bearing installation is limited and the width of the bearing needs to be minimized, it is difficult to avoid contact between the crown retainer and the sealing element. Therefore, it is sometimes necessary to abandon the use of sealed ball bearings and instead use open-type ball bearings with no sealing element and open at both ends axially. Summary of the Invention

[0012] The problem to be solved by the present invention is to provide a ball bearing that is less prone to deformation of the resin retainer due to centrifugal force when used at high speeds.

[0013] To address the aforementioned issues, the ball bearing in this invention employs the following structure.

[0014] A ball bearing, comprising:

[0015] Inner circle;

[0016] The outer ring is coaxially disposed radially outside the aforementioned inner ring;

[0017] Multiple balls are assembled in an annular space formed between the inner ring and the outer ring; and

[0018] A resin retainer holds the aforementioned multiple balls.

[0019] The aforementioned resin retainer has a retainer annular portion that is adjacent to the passage area of ​​the aforementioned balls and extends circumferentially, and a cantilever beam-shaped retainer claw portion that extends axially from the aforementioned retainer annular portion between the circumferentially adjacent aforementioned balls.

[0020] The aforementioned ball bearing is characterized in that,

[0021] An outer diameter side axial groove is formed on the radially outer surface of the retainer claw portion. This outer diameter side axial groove extends axially from the front end of the retainer claw portion toward the retainer annular portion.

[0022] An inner diameter-side axial groove is formed on the radially inner surface of the retainer claw portion, and the inner diameter-side axial groove extends axially from the front end of the retainer claw portion toward the retainer annular portion.

[0023] The retainer claw portion, by means of the axial groove on the outer diameter side and the axial groove on the inner diameter side, has a cross-sectional shape that is orthogonal to the axial direction, which is an H shape that opens to the radially outward and radially inward.

[0024] Accordingly, the cross-sectional shape of the retainer claw is H-shaped by the outer diameter axial groove formed on the radially outer side of the retainer claw and the inner diameter axial groove formed on the radially inner side of the retainer claw. This ensures the resistance to the second moment of cross-section of the retainer claw (the difficulty of deformation of the retainer claw relative to bending moment) and suppresses the mass of the retainer claw. Therefore, when used under high-speed rotation, it can also suppress torsional deformation of the retainer annulus due to centrifugal force on the retainer claw and suppress flexural deformation of the retainer claw itself towards the radially outward.

[0025] The following structure is preferred:

[0026] The axial length of the retainer claw is set to be greater than the radius of the ball.

[0027] The aforementioned retainer claw portion has a circumferentially opposing surface that is circumferentially opposite to the aforementioned ball.

[0028] The portion of the circumferentially opposed surface that receives the ball is formed in a planar shape such that the circumferentially opposed surface does not interfere with the ball when the retainer claw moves radially outward due to centrifugal force.

[0029] Accordingly, since the circumferential opposing surface of the retainer claw is planar, interference between the circumferential opposing surface of the retainer claw and the ball can be prevented when the retainer claw moves radially outward due to the centrifugal force acting on it. Furthermore, since the shear resistance of the lubricant generated between the circumferential opposing surface of the retainer claw and the ball is suppressed to a low level, heat generation in the ball bearing can also be suppressed.

[0030] The following structure is preferred:

[0031] The aforementioned retainer annular portion has an axially opposed surface that is axially opposite to the aforementioned ball.

[0032] The aforementioned circumferential opposing surfaces and the aforementioned axial opposing surfaces are connected in a concave arc shape in cross section.

[0033] Accordingly, since the circumferential opposing surfaces and the axial opposing surfaces are connected in a concave arc shape, the mass of the axial front end portion of the retainer claw can be minimized, and the cross-sectional area of ​​the axial root portion of the retainer claw can be ensured. Therefore, the deflection of the retainer claw caused by the centrifugal force acting on it can be effectively suppressed.

[0034] The preferred structure is as follows: the axial end of the axial groove on the outer diameter side, near the retainer ring portion, is sloping upwards in a concave arc shape to the outer periphery of the retainer ring portion.

[0035] Accordingly, since the axial end of the axial groove on the outer diameter side, near the retainer annulus, slopes upward in a concave arc shape, the mass of the axial front end of the retainer claw can be minimized, and the cross-sectional area of ​​the axial root of the retainer claw can be ensured. Therefore, the deflection of the retainer claw caused by the centrifugal force acting on it can be effectively suppressed.

[0036] Preferably, a guide surface for the retainer is formed on the inner circumference of the retainer annulus and is guided to slide in contact with the outer circumference of the inner ring.

[0037] Accordingly, by sliding contact between the retainer guide surface on the inner circumference of the retainer ring and the outer circumference of the inner ring, the resin retainer can be radially positioned.

[0038] The following structure is preferred:

[0039] Furthermore, it has an annular sealing member that blocks the axial end opening of the aforementioned annular space.

[0040] The aforementioned retainer annular portion has a retainer-side sliding contact surface, which is axially opposed to and in sliding contact with the aforementioned sealing member.

[0041] The aforementioned sealing component has a sealing-side sliding contact surface that slides in contact with the aforementioned retainer-side sliding contact surface.

[0042] One of the sliding contact surfaces on the retainer side and the sealing side has multiple axial protrusions formed at constant intervals along the circumference, with a cross-sectional shape that convexes axially.

[0043] Accordingly, since multiple axial protrusions with axially convex arc-shaped cross-sections are formed at constant intervals along the circumference on one of the sliding contact surfaces on the retainer side and the sealing side, an oil film based on the wedge-shaped film effect is formed between these axial protrusions and the sliding contact surface. This oil film achieves fluid lubrication between the axial protrusions and the sliding contact surface, thereby minimizing the contact resistance between the retainer and the sealing component. Therefore, abnormal heating due to sliding resistance at the contact portion between the retainer and the sealing component can be prevented. Furthermore, since the retainer annulus is configured to slide in contact with the sealing component, the axial thickness of the retainer annulus can be set to be larger, thereby improving the rigidity of the retainer annulus. Therefore, when used under high-speed rotation, torsional deformation of the retainer annulus caused by centrifugal force on the retainer claws can be suppressed, thereby preventing the retainer claws from tilting radially outward.

[0044] The preferred structure is as follows: the axial protrusion has a parallel top with a height that is constant radially along the axially protruding arc-shaped top in the circumferential cross-section, and an inclined top with a height that gradually decreases radially outward from the radially outer end of the parallel top.

[0045] Accordingly, when the bearing rotates at a low speed, resulting in a relatively small centrifugal force on the retainer claw, an oil film based on the wedge-shaped film effect can be formed between the parallel top of the axially protruding portion and the sliding contact surface. Furthermore, when the bearing rotates at a high speed, resulting in a relatively large centrifugal force on the retainer claw, an oil film based on the wedge-shaped film effect can be formed between the parallel top and inclined top of the axially protruding portion and the sliding contact surface, even under conditions of significant torsional deformation in the retainer annulus. Thus, an oil film based on the wedge-shaped film effect can be stably formed between the retainer and the sealing component regardless of the bearing's rotational speed.

[0046] Preferably, the cross-sectional shape of the inclined top, which is orthogonal to the circumference, forms an R-shape (arc shape) that is smoothly connected to the parallel top.

[0047] Therefore, since the inclined top and the parallel top are smoothly connected, when a wedge-shaped film based on the wedge effect is formed between the parallel top and the inclined top and the sliding contact surface, the oil film can be stably formed even when the retainer annulus has undergone relatively large torsional deformation.

[0048] Preferably, the plurality of axial protrusions are positioned at a position overlapping with the pitch circle of the ball or radially outward from the pitch circle of the ball.

[0049] Therefore, when the centrifugal force acting on the retainer claw causes torsional deformation in the retainer annular portion that causes the retainer claw to tilt toward the radially outward direction, it is possible to prevent the retainer-side sliding contact surface and the sealing-side sliding contact surface from contacting at a position that is radially offset to the outward than the axial protrusion due to the torsional deformation.

[0050] The preferred structure is as follows: the axial groove on the outer diameter side has a shape in which the position of the groove bottom gradually changes radially outward from one side of the front end of the retainer claw portion toward one side of the retainer annular portion.

[0051] Accordingly, since the position of the bottom of the axial groove on the outer diameter side gradually changes radially outward from the side of the front end of the retainer claw towards the side of the retainer annulus, the lubricant supplied to the axial groove on the outer diameter side is moved from the side of the front end of the retainer claw towards the side of the retainer annulus by the pump action, and is thus introduced into the area between the retainer annulus and the sealing component. Therefore, the sliding contact surface of one of the retainer-side sliding contact surfaces and the sealing-side sliding contact surface can be sufficiently lubricated between the sliding contact surface and the axial protrusion, effectively forming a wedge-shaped oil film.

[0052] Alternatively, the following structure can be adopted: the axial groove on the inner diameter side has a shape in which the position of the groove bottom gradually changes radially inward from one side of the front end of the retainer claw portion toward one side of the retainer annular portion.

[0053] The preferred structure is as follows: the axial end of the annular space opposite to the axial end of the side blocked by the sealing member is left open without a sealing member, so that the annular space can receive lubricant supplied from the outside.

[0054] Accordingly, the sliding contact surface of one of the retainer-side sliding contact surfaces and the sealing-side sliding contact surface can be fully lubricated between the sliding contact surface and the axial protrusion, thereby reliably forming an oil film based on a wedge-shaped film.

[0055] The following structure is preferred:

[0056] The axial length of the retainer claw is set to be greater than the radius of the ball.

[0057] When the retainer claw portion has a circumferentially opposing surface that is circumferentially opposite to the ball,

[0058] The portion of the circumferentially opposed surface that receives the ball in the circumferential direction is formed into a straight line shape that does not have a circumferential inclination but extends straight along the axial direction, so that no axial component force is generated when the ball is received.

[0059] Therefore, since no axial force is generated in the retainer claw when the ball is received by the retainer claw, it is possible to prevent the retainer from being forcefully pressed against the sealing component in the axial direction. Thus, the sliding resistance at the contact portion between the retainer and the sealing component can be effectively suppressed.

[0060] The following structure is preferred:

[0061] When the aforementioned axial protrusion is formed on the aforementioned sliding contact surface of the sealing side.

[0062] The aforementioned sealing component has an annular core and a rubber material vulcanized and bonded to the surface of the core.

[0063] The aforementioned axial protrusions are formed from the aforementioned rubber material.

[0064] Therefore, it is possible to form axial protrusions with high dimensional accuracy at low cost.

[0065] Preferably, the axial groove on the inner diameter side is formed to extend axially through the radial inner surface of the retainer claw and the guide surface of the retainer.

[0066] Accordingly, the lubricant supplied to the radially inner region of the retainer claw is introduced into the region between the retainer annulus and the sealing member through the axial groove on the inner diameter side. Therefore, the sliding contact surface of one of the retainer-side sliding contact surfaces and the sealing-side sliding contact surface, along with the axial protrusion, can be adequately lubricated, effectively forming a wedge-shaped oil film.

[0067] The following structure is preferred:

[0068] When a retainer guide surface is formed on the inner circumference of the retainer annulus and is guided to slide in contact with the outer circumference of the inner ring, the retainer guide surface is formed.

[0069] The aforementioned retainer annular portion has a chamfered portion that obliquely connects the retainer-side sliding contact surface and the retainer-guided surface in a cross-section orthogonal to the circumferential direction.

[0070] Accordingly, by utilizing the effect of centrifugal force, lubricant that has been introduced from the radially inner region of the retainer claw through the axial groove on the inner diameter side into the region between the retainer annulus and the sealing component can be smoothly guided along the chamfer to the retainer-side sliding contact surface.

[0071] The following structure can be adopted:

[0072] The outer ring has an outer ring track groove for the rolling contact of the balls, and a pair of outer ring groove shoulders located on both sides of the outer ring track groove along its axial direction.

[0073] The axial length of the retainer claw is set to be greater than the axial width of the outer ring track groove.

[0074] A root-side guide surface is formed on the radially outer side of the aforementioned retainer annular portion, which slides in contact with one of the outer ring groove shoulders of the aforementioned pair of outer ring groove shoulders.

[0075] A front-side guide surface is formed on the radially outer side of the axial end of the aforementioned retainer claw portion, which slides in contact with the outer ring groove shoulder of the other of the aforementioned pair of outer ring groove shoulders.

[0076] The circumferential cross-sectional shape of the aforementioned root-side guided surface and the aforementioned front-side guided surface is formed as an arc protruding radially outward.

[0077] Accordingly, since the circumferential cross-sectional shape of the root-side guided surface is formed as an arc protruding radially outward, an oil film based on the wedge-shaped film effect is formed between the root-side guided surface and one of the outer ring groove shoulders. This oil film creates a fluid lubrication state between the root-side guided surface and the outer ring groove shoulder, thereby minimizing the contact resistance between the retainer and the outer ring. Similarly, since the circumferential cross-sectional shape of the front-end guided surface is formed as an arc protruding radially outward, an oil film based on the wedge-shaped film effect is formed between the front-end guided surface and the other outer ring groove shoulder. This oil film also creates a fluid lubrication state between the front-end guided surface and the outer ring groove shoulder, thereby minimizing the contact resistance between the retainer and the outer ring. Therefore, abnormal heating due to sliding resistance at the contact portion between the retainer and the outer ring can be prevented. Furthermore, since one of the outer ring groove shoulders supports the retainer annulus from the radially outer side, and the other outer ring groove shoulder supports the axial end of the front end of the retainer claw from the radially outer side, the retainer claw is less prone to flexing deformation towards the radially outer side. Therefore, even when used under high-speed rotation, torsional deformation of the retainer annulus due to centrifugal force on the retainer claw can be suppressed, and flexing deformation of the retainer claw itself towards the radially outer side can also be suppressed.

[0078] Preferably, an R-shaped chamfer (circular chamfer) is applied to the axial end edge of the root-side guided surface away from the retainer claw portion and the axial end edge of the front-side guided surface away from the retainer annular portion.

[0079] Accordingly, an oil film based on the wedge-shaped film effect can be effectively formed between the root-side guided surface and the outer ring groove shoulder of one side, and an oil film based on the wedge-shaped film effect can also be effectively formed between the front-side guided surface and the outer ring groove shoulder of the other side.

[0080] Preferably, a recess is formed between the root-side guided surface and the front-side guided surface on the radially outer side of the retainer claw portion. The recess has an axial width that is wider than the axial width of the outer ring track groove and extends circumferentially.

[0081] Accordingly, it is possible to prevent the boundary portions of the outer ring groove shoulder and the outer ring track groove from sliding into contact with the radially outer surface of the retainer annulus or the radially outer surface of the retainer claw. Therefore, it is possible to prevent localized wear on the radially outer surface of the retainer annulus or the radially outer surface of the retainer claw at the positions corresponding to the boundary portions of the outer ring groove shoulder and the outer ring track groove.

[0082] In addition, to solve the above-mentioned problems, the present invention also provides a ball bearing with the following structure.

[0083] A ball bearing, comprising:

[0084] Inner circle;

[0085] The outer ring is coaxially disposed radially outside the aforementioned inner ring;

[0086] Multiple balls are assembled in an annular space formed between the inner ring and the outer ring;

[0087] An annular sealing member that blocks one end opening of the annular space along its axial direction; and

[0088] A resin retainer holds the aforementioned multiple balls.

[0089] The aforementioned resin retainer has a retainer annular portion extending circumferentially in the region where the ball passes through and the sealing member is axially clamped, and a cantilever-beam-shaped retainer claw portion extending axially from the retainer annular portion between the circumferentially adjacent balls.

[0090] The aforementioned ball bearing is characterized in that,

[0091] The aforementioned retainer annular portion has a retainer-side sliding contact surface, which is axially opposed to and in sliding contact with the aforementioned sealing member.

[0092] The aforementioned sealing component has a sealing-side sliding contact surface that slides in contact with the aforementioned retainer-side sliding contact surface.

[0093] One of the sliding contact surfaces on the retainer side and the sealing side has multiple axial protrusions formed at constant intervals along the circumference, with a cross-sectional shape that convexes axially.

[0094] Accordingly, since multiple axial protrusions with axially convex arc-shaped cross-sections are formed at constant intervals along the circumference on one of the sliding contact surfaces on the retainer side and the sealing side, an oil film based on the wedge-shaped film effect is formed between these axial protrusions and the sliding contact surface. This oil film achieves fluid lubrication between the axial protrusions and the sliding contact surface, thereby minimizing the contact resistance between the retainer and the sealing component. Therefore, abnormal heating due to sliding resistance at the contact portion between the retainer and the sealing component can be prevented. Furthermore, since the retainer annulus is configured to slide in contact with the sealing component, the axial thickness of the retainer annulus can be set to be larger, thereby improving the rigidity of the retainer annulus. Therefore, when used under high-speed rotation, torsional deformation of the retainer annulus caused by centrifugal force on the retainer claws can be suppressed, thereby preventing the retainer claws from tilting radially outward.

[0095] The following structure is preferred:

[0096] The axial length of the retainer claw is set to be greater than the radius of the ball.

[0097] The aforementioned retainer claw portion has a circumferentially opposing surface that is circumferentially opposite to the aforementioned ball.

[0098] The portion of the circumferentially opposed surface that receives the ball in the circumferential direction is formed into a straight line shape that does not have a circumferential inclination but extends straight along the axial direction, so that no axial component force is generated when the ball is received.

[0099] Therefore, since no axial force is generated in the retainer claw when the ball is received by the retainer claw, it is possible to prevent the retainer from being forcefully pressed against the sealing component in the axial direction. Thus, the sliding resistance at the contact portion between the retainer and the sealing component can be effectively suppressed.

[0100] Preferably, the circumferential opposing surface extends parallel to the straight line connecting the center of the retainer annular portion and the center of the retainer claw portion, so that when the retainer claw portion moves radially outward due to centrifugal force, the circumferential opposing surface does not interfere with the ball.

[0101] Accordingly, interference between the circumferential opposing surface of the retainer claw and the ball can be prevented when the retainer annular portion and the retainer claw portion are deformed by the centrifugal force acting on the retainer claw portion, and the retainer claw portion moves radially outward along with the deformation.

[0102] The preferred structure is as follows: the axial protrusion has a parallel top with a height that is constant radially along the axially protruding arc-shaped top in the circumferential cross-section, and an inclined top with a height that gradually decreases radially outward from the radially outer end of the parallel top.

[0103] Accordingly, when the bearing rotates at a low speed, resulting in a relatively small centrifugal force on the retainer claw, an oil film based on the wedge-shaped film effect can be formed between the parallel top of the axially protruding portion and the sliding contact surface. Furthermore, when the bearing rotates at a high speed, resulting in a relatively large centrifugal force on the retainer claw, an oil film based on the wedge-shaped film effect can be formed between the parallel top and inclined top of the axially protruding portion and the sliding contact surface, even under conditions of significant torsional deformation in the retainer annulus. Thus, an oil film based on the wedge-shaped film effect can be stably formed between the retainer and the sealing component regardless of the bearing's rotational speed.

[0104] Preferably, the cross-sectional shape of the inclined top, which is orthogonal to the circumference, forms an R-shape that is smoothly connected to the parallel top.

[0105] Therefore, since the inclined top and the parallel top are smoothly connected, when a wedge-shaped film based on the wedge effect is formed between the parallel top and the inclined top and the sliding contact surface, the oil film can be stably formed even when the retainer annulus has undergone relatively large torsional deformation.

[0106] Preferably, the plurality of axial protrusions are positioned at a position overlapping with the pitch circle of the ball or radially outward from the pitch circle of the ball.

[0107] Therefore, when the centrifugal force acting on the retainer claw causes torsional deformation in the retainer annular portion that causes the retainer claw to tilt toward the radially outward direction, it is possible to prevent the retainer-side sliding contact surface and the sealing-side sliding contact surface from contacting at a position that is radially offset to the outward than the axial protrusion due to the torsional deformation.

[0108] The following structure is preferred:

[0109] When the aforementioned axial protrusion is formed on the aforementioned sliding contact surface of the sealing side.

[0110] The aforementioned sealing component has an annular core and a rubber material vulcanized and bonded to the surface of the core.

[0111] The aforementioned axial protrusions are formed from the aforementioned rubber material.

[0112] Therefore, it is possible to form axial protrusions with high dimensional accuracy at low cost.

[0113] Preferably, a guide surface for the retainer is formed on the inner circumference of the retainer annulus and is guided to slide in contact with the outer circumference of the inner ring.

[0114] Accordingly, by sliding contact between the retainer guide surface on the inner circumference of the retainer ring and the outer circumference of the inner ring, the resin retainer can be radially positioned.

[0115] Preferably, an inner diameter side axial groove is provided on the inner circumference of the above-mentioned resin retainer. The inner diameter side axial groove is formed to extend axially through the radial inner surface of the retainer claw and the guide surface of the retainer.

[0116] Accordingly, the lubricant supplied to the radially inner region of the retainer claw is introduced into the region between the retainer annulus and the sealing member through the axial groove on the inner diameter side. Therefore, the sliding contact surface of one of the retainer-side sliding contact surfaces and the sealing-side sliding contact surface, along with the axial protrusion, can be adequately lubricated, effectively forming a wedge-shaped oil film.

[0117] The preferred structure is as follows: the retainer annular portion has a chamfered portion, which obliquely connects the retainer side sliding contact surface and the retainer guided surface in a cross section orthogonal to the circumferential direction.

[0118] Accordingly, by utilizing the effect of centrifugal force, lubricant that has been introduced from the radially inner region of the retainer claw through the axial groove on the inner diameter side into the region between the retainer annulus and the sealing component can be smoothly guided along the chamfer to the retainer-side sliding contact surface.

[0119] The following structure is preferred:

[0120] An axial groove extending axially from the front end of the retainer claw portion toward the retainer annular portion is formed on the radially outer side of the aforementioned retainer claw portion.

[0121] The aforementioned outer diameter side axial groove has a shape in which the position of the groove bottom gradually changes radially outward from one side of the front end of the aforementioned retainer claw portion toward one side of the aforementioned retainer annular portion.

[0122] Accordingly, since the position of the bottom of the axial groove on the outer diameter side gradually changes radially outward from the side of the front end of the retainer claw towards the side of the retainer annulus, the lubricant supplied to the axial groove on the outer diameter side is moved from the side of the front end of the retainer claw towards the side of the retainer annulus by the pump action, and is thus introduced into the area between the retainer annulus and the sealing component. Therefore, the sliding contact surface of one of the retainer-side sliding contact surfaces and the sealing-side sliding contact surface can be sufficiently lubricated between the sliding contact surface and the axial protrusion, effectively forming a wedge-shaped oil film.

[0123] The preferred structure is as follows: the axial end of the annular space opposite to the axial end of the side blocked by the sealing member is left open without a sealing member, so that the annular space can receive lubricant supplied from the outside.

[0124] Accordingly, the sliding contact surface of one of the retainer-side sliding contact surfaces and the sealing-side sliding contact surface can be fully lubricated between the sliding contact surface and the axial protrusion, thereby reliably forming an oil film based on a wedge-shaped film.

[0125] In addition, to solve the above-mentioned problems, the present invention also provides a ball bearing with the following structure.

[0126] A ball bearing, comprising:

[0127] Inner circle;

[0128] The outer ring is coaxially disposed radially outside the aforementioned inner ring;

[0129] Multiple balls are assembled in an annular space formed between the inner ring and the outer ring; and

[0130] A resin retainer holds the aforementioned multiple balls.

[0131] The outer ring has an outer ring track groove for the rolling contact of the balls, and a pair of outer ring groove shoulders located on both sides of the outer ring track groove along its axial direction.

[0132] The aforementioned resin retainer has a retainer annular portion that is adjacent to the passage area of ​​the aforementioned balls and extends circumferentially, and a cantilever beam-shaped retainer claw portion that extends axially from the aforementioned retainer annular portion between the circumferentially adjacent aforementioned balls.

[0133] The aforementioned ball bearing is characterized in that,

[0134] The axial length of the retainer claw is set to be greater than the axial width of the outer ring track groove.

[0135] A root-side guide surface is formed on the radially outer side of the aforementioned retainer annular portion, which slides in contact with one of the outer ring groove shoulders of the aforementioned pair of outer ring groove shoulders.

[0136] A front-side guide surface is formed on the radially outer side of the axial end of the aforementioned retainer claw portion, which slides in contact with the outer ring groove shoulder of the other of the aforementioned pair of outer ring groove shoulders.

[0137] The circumferential cross-sectional shape of the aforementioned root-side guided surface and the aforementioned front-side guided surface is formed as an arc protruding radially outward.

[0138] Accordingly, since the circumferential cross-sectional shape of the root-side guided surface is formed as an arc protruding radially outward, an oil film based on the wedge-shaped film effect is formed between the root-side guided surface and one of the outer ring groove shoulders. This oil film creates a fluid lubrication state between the root-side guided surface and the outer ring groove shoulder, thereby minimizing the contact resistance between the retainer and the outer ring. Similarly, since the circumferential cross-sectional shape of the front-end guided surface is formed as an arc protruding radially outward, an oil film based on the wedge-shaped film effect is formed between the front-end guided surface and the other outer ring groove shoulder. This oil film also creates a fluid lubrication state between the front-end guided surface and the outer ring groove shoulder, thereby minimizing the contact resistance between the retainer and the outer ring. Therefore, abnormal heating due to sliding resistance at the contact portion between the retainer and the outer ring can be prevented. Furthermore, since one of the outer ring groove shoulders supports the retainer annulus from the radially outer side, and the other outer ring groove shoulder supports the axial end of the front end of the retainer claw from the radially outer side, the retainer claw is less prone to flexing deformation towards the radially outer side. Therefore, even when used under high-speed rotation, torsional deformation of the retainer annulus due to centrifugal force on the retainer claw can be suppressed, and flexing deformation of the retainer claw itself towards the radially outer side can also be suppressed.

[0139] The following structure is preferred:

[0140] The aforementioned retainer claw portion has a circumferentially opposing surface that is circumferentially opposite to the aforementioned ball.

[0141] The portion of the circumferentially opposed surface that receives the ball in the circumferential direction is formed into a planar shape that extends parallel to the straight line connecting the center of the retainer annular portion and the center of the retainer claw portion, so that when the retainer claw portion moves radially outward due to centrifugal force, the circumferentially opposed surface does not interfere with the ball.

[0142] Accordingly, since the circumferential opposing surface of the retainer claw is planar, interference between the circumferential opposing surface of the retainer claw and the ball can be prevented when the retainer claw moves radially outward due to the centrifugal force acting on it. Furthermore, since the shear resistance of the lubricant generated between the circumferential opposing surface of the retainer claw and the ball is suppressed to a low level, heat generation in the ball bearing can also be suppressed.

[0143] Preferably, an R-shaped chamfer is applied to the axial end edge of the root-side guided surface away from the retainer claw portion and the axial end edge of the front-side guided surface away from the retainer annular portion.

[0144] Accordingly, an oil film based on the wedge-shaped film effect can be effectively formed between the root-side guided surface and the outer ring groove shoulder of one side, and an oil film based on the wedge-shaped film effect can also be effectively formed between the front-side guided surface and the outer ring groove shoulder of the other side.

[0145] Preferably, a recess is formed between the root-side guided surface and the front-side guided surface on the radially outer side of the retainer claw portion. The recess has an axial width that is wider than the axial width of the outer ring track groove and extends circumferentially.

[0146] Accordingly, it is possible to prevent the boundary portions of the outer ring groove shoulder and the outer ring track groove from sliding into contact with the radially outer surface of the retainer annulus or the radially outer surface of the retainer claw. Therefore, it is possible to prevent localized wear on the radially outer surface of the retainer annulus or the radially outer surface of the retainer claw at the positions corresponding to the boundary portions of the outer ring groove shoulder and the outer ring track groove.

[0147] Preferably, an oil accumulation groove is formed on the radially inner side of the retainer claw portion, and the oil accumulation groove extends axially from the front end of the retainer claw portion toward the retainer annular portion.

[0148] Accordingly, the lubricant that is dispersed to the outer diameter side due to centrifugal force can be stored in the oil storage tank, and the lubricant can be supplied to the inner ring.

[0149] The following structure is preferred:

[0150] Furthermore, it has an annular sealing member that blocks the axial end opening of the aforementioned annular space.

[0151] The aforementioned retainer annular portion has a retainer-side sliding contact surface, which is axially opposed to and in sliding contact with the aforementioned sealing member.

[0152] The aforementioned sealing component has a sealing-side sliding contact surface that slides in contact with the aforementioned retainer-side sliding contact surface.

[0153] One of the sliding contact surfaces on the retainer side and the sealing side has multiple axial protrusions formed at constant intervals along the circumference, with a cross-sectional shape that convexes axially.

[0154] Accordingly, since multiple axial protrusions with axially convex arc-shaped cross-sections are formed at constant intervals along the circumference on one of the sliding contact surfaces on the retainer side and the sealing side, an oil film based on the wedge-shaped film effect is formed between these axial protrusions and the sliding contact surface. This oil film achieves fluid lubrication between the axial protrusions and the sliding contact surface, thereby minimizing the contact resistance between the retainer and the sealing component. Therefore, abnormal heating due to sliding resistance at the contact portion between the retainer and the sealing component can be prevented. Furthermore, since the retainer annulus is designed to slide in contact with the sealing component, the axial thickness of the retainer annulus can be set to be larger, thereby improving the rigidity of the retainer annulus. Therefore, when used under high-speed rotation, torsional deformation of the retainer annulus caused by centrifugal force on the retainer claw can be suppressed.

[0155] The preferred structure is as follows: the axial protrusion has a parallel top with a height that is constant radially along the axially protruding arc-shaped top in the circumferential cross-section, and an inclined top with a height that gradually decreases radially outward from the radially outer end of the parallel top.

[0156] Accordingly, when the bearing rotates at a low speed, resulting in a relatively small centrifugal force on the retainer claw, an oil film based on the wedge-shaped film effect can be formed between the parallel top of the axially protruding portion and the sliding contact surface. Furthermore, when the bearing rotates at a high speed, resulting in a relatively large centrifugal force on the retainer claw, an oil film based on the wedge-shaped film effect can be formed between the parallel top and inclined top of the axially protruding portion and the sliding contact surface, even under conditions of significant torsional deformation in the retainer annulus. Thus, an oil film based on the wedge-shaped film effect can be stably formed between the retainer and the sealing component regardless of the bearing's rotational speed.

[0157] Preferably, the cross-sectional shape of the inclined top, which is orthogonal to the circumference, forms an R-shape that is smoothly connected to the parallel top.

[0158] Therefore, since the inclined top and the parallel top are smoothly connected, when a wedge-shaped film based on the wedge effect is formed between the parallel top and the inclined top and the sliding contact surface, the oil film can be stably formed even when the retainer annulus has undergone relatively large torsional deformation.

[0159] Preferably, the plurality of axial protrusions are positioned at a position overlapping with the pitch circle of the ball or radially outward from the pitch circle of the ball.

[0160] Therefore, when the centrifugal force acting on the retainer claw causes torsional deformation in the retainer annular portion that causes the retainer claw to tilt toward the radially outward direction, it is possible to prevent the retainer-side sliding contact surface and the sealing-side sliding contact surface from contacting at a position that is radially offset to the outward than the axial protrusion due to the torsional deformation.

[0161] The preferred structure is as follows: the axial end of the annular space opposite to the axial end of the side blocked by the sealing member is left open without a sealing member, so that the annular space can receive lubricant supplied from the outside.

[0162] Accordingly, the root-side guided surface and the front-side guided surface can be fully lubricated, and an oil film based on a wedge-shaped film can be reliably formed.

[0163] The ball bearings described above are particularly suitable for use as bearings for electric motors in electric vehicles or for transmissions in electric vehicles that reduce the rotation of the electric motor.

[0164] When the ball bearing of the present invention is used under high-speed rotation, it is difficult for the resin retainer to deform due to centrifugal force. Attached Figure Description

[0165] Figure 1 This is a cross-sectional view showing the ball bearing according to the first embodiment of the present invention.

[0166] Figure 2 It is along Figure 1 A sectional view along line II-II.

[0167] Figure 3 It is along Figure 1 A cross-sectional view along line III-III.

[0168] Figure 4 yes Figure 1 An enlarged cross-sectional view of the area near the resin retainer of the ball bearing.

[0169] Figure 5 Viewed from one side of the retainer claw Figure 1 The three-dimensional image obtained from the retainer.

[0170] Figure 6 It is an enlarged representation Figure 1 The diagram shows the area near the sealing lip of the sealing component.

[0171] Figure 7 It is along Figure 6 A sectional view along line VII-VII.

[0172] Figure 8 It was assembled Figure 1 A simplified diagram of a ball bearing-type transmission for electric vehicles.

[0173] Figure 9 This is a cross-sectional view showing the ball bearing according to the second embodiment of the present invention.

[0174] Figure 10 Is with Figure 2 Correspondingly represent Figure 9 A diagram of a ball bearing.

[0175] Figure 11 Is with Figure 3 Correspondingly represent Figure 9 A diagram of a ball bearing.

[0176] Figure 12 yes Figure 9 An enlarged cross-sectional view of the vicinity of the sealing component of the ball bearing.

[0177] Figure 13 It is along Figure 12 A cross-sectional view of line XIII-XIII.

[0178] Figure 14 Viewed from one side of the retainer claw Figure 9 The three-dimensional image obtained from the retainer.

[0179] Figure 15 Viewed from one side of the retainer annulus Figure 9 The three-dimensional image obtained from the retainer.

[0180] Figure 16 Viewed from one side of the retainer annulus Figure 9 The side view obtained from the retainer.

[0181] Figure 17 It means Figure 16 Side view of a modified example of the retainer shown.

[0182] Figure 18 Is with Figure 12 The diagram correspondingly shows the ball bearing of the third embodiment of the present invention.

[0183] Figure 19 It is along Figure 18 A cross-sectional view of the XIX-XIX line.

[0184] Figure 20 This is observed from one side of the sliding contact surface on the sealing side. Figure 19 The diagram shows the axial protrusion.

[0185] Figure 21 Is with Figure 1 The diagram correspondingly shows the ball bearing of the fourth embodiment of the present invention.

[0186] Figure 22 Is with Figure 2 Correspondingly represent Figure 21 A diagram of a ball bearing.

[0187] Figure 23 Is with Figure 3 Correspondingly represent Figure 21 A diagram of a ball bearing.

[0188] Figure 24 yes Figure 21 An enlarged cross-sectional view of the area near the resin retainer of the ball bearing.

[0189] Figure 25 yes Figure 23 A magnified view of a portion of the retainer shown.

[0190] Figure 26 Viewed from one side of the retainer claw Figure 21 The three-dimensional image obtained from the retainer.

[0191] Figure 27 This is a cross-sectional view showing the ball bearing according to the fifth embodiment of the present invention.

[0192] Figure 28 It is along Figure 27 A cross-sectional view of the XXVIII-XXVIII line.

[0193] Figure 29 It is along Figure 27 A cross-sectional view of the XXIX-XXIX line.

[0194] Figure 30 Viewed from one side of the retainer claw Figure 27 The three-dimensional image obtained from the retainer.

[0195] Figure 31 Viewed from one side of the retainer annulus Figure 27 The three-dimensional image obtained from the retainer.

[0196] Figure 32 This is a cross-sectional view showing the ball bearing according to the sixth embodiment of the present invention.

[0197] Figure 33 It is along Figure 32 A sectional view of line XXXIII-XXXIII.

[0198] Figure 34 It is along Figure 32 A sectional view of line XXXIV-XXXIV.

[0199] Figure 35 yes Figure 32 An enlarged sectional view of the vicinity of the retainer annulus of the ball bearing.

[0200] Figure 36 It is along Figure 35 A sectional view of the XXXVI-XXXVI line.

[0201] Figure 37 Viewed from one side of the retainer claw Figure 32 The three-dimensional image obtained from the retainer.

[0202] Figure 38 This is a cross-sectional view showing the ball bearing according to the seventh embodiment of the present invention.

[0203] Figure 39 It is along Figure 38 A cross-sectional view of the XXXIX-XXXIX line.

[0204] Figure 40 It is along Figure 38 A cross-sectional view of the XL-XL line.

[0205] Figure 41 Viewed from one side of the retainer claw Figure 38 The three-dimensional image obtained from the retainer.

[0206] Figure 42 This is a cross-sectional view showing the ball bearing according to the eighth embodiment of the present invention.

[0207] Figure 43 It is along Figure 42 A cross-sectional view of the XLIII-XLIII line.

[0208] Figure 44 It is along Figure 42 A cross-sectional view of the XLIV-XLIV line.

[0209] Figure 45 Viewed from one side of the retainer claw Figure 42 The three-dimensional image obtained from the retainer.

[0210] Figure 46 This is an enlarged cross-sectional view of the vicinity of the retainer annulus portion of the ball bearing according to the ninth embodiment of the present invention.

[0211] Figure 47 It is along Figure 46 A sectional view of the XLVII-XLVII line.

[0212] Figure 48 This is an enlarged cross-sectional view of the vicinity of the retainer annulus portion of the ball bearing according to the 10th embodiment of the present invention.

[0213] Figure 49 It is along Figure 48 A cross-sectional view of the XLIX-XLIX line. Detailed Implementation

[0214] Figure 1 The ball bearing 1 represents a first embodiment of the present invention. The ball bearing 1 includes: an inner ring 2; an outer ring 3 coaxially disposed radially outside the inner ring 2; a plurality of balls 5 circumferentially spaced and assembled within an annular space 4 formed between the inner ring 2 and the outer ring 3; an annular sealing member 6 blocking one end opening of one of the axial end openings of the annular space 4; and a resin retainer 7 (hereinafter referred to as "retainer 7") maintaining the circumferential spacing of the plurality of balls 5. The ball bearing 1 is a sealed ball bearing having the sealing member 6.

[0215] An inner ring 2 has an inner ring track groove 8 for rolling contact of the ball 5, a pair of inner ring groove shoulders 9 located axially outside the inner ring track groove 8, and a sliding recess 10 located axially outside the inner ring groove shoulders 9. The inner ring track groove 8 is an arcuate groove with a concave arcuate cross-section along the surface of the ball 5, extending circumferentially at the axial center of the outer circumference of the inner ring 2. The pair of inner ring groove shoulders 9 are dam-like portions that axially sandwich the inner ring track groove 8 and extend circumferentially on both sides. The sliding recess 10 is a circumferentially extending recess formed adjacent to the axially outside of the inner ring groove shoulders 9. The sealing lip 11 of the sealing member 6, located at the inner diameter end, slides in contact with the inner surface of the sliding recess 10. In the figure, the surface of the inner surface of the sliding recess 10 for sliding contact with the sealing lip 11 is a cylindrical surface with a constant outer diameter along the axial direction.

[0216] The outer ring 3 has an outer ring track groove 12 for the rolling contact of the ball 5, a pair of outer ring groove shoulders 13 located axially outside the outer ring track groove 12, and a sealing and fixing groove 14 located axially outside the outer ring groove shoulders 13. The outer ring track groove 12 is an arcuate groove with a concave arcuate cross-section along the surface of the ball 5, and is formed extending circumferentially at the axial center of the inner circumference of the outer ring 3. The pair of outer ring groove shoulders 13 are dam-like portions that extend circumferentially on both sides of the outer ring track groove 12 in the axial direction. The sealing and fixing groove 14 is a groove extending circumferentially adjacent to the axially outside of the outer ring groove shoulders 13. The fitting portion 15 of the sealing member 6, located at the outer diameter side end, is fitted and fixed into the sealing and fixing groove 14.

[0217] The ball 5 is held radially between the outer ring groove 12 and the inner ring groove 8. The axial width of the outer ring groove 12 is greater than half the diameter of the ball 5. Similarly, the axial width of the inner ring groove 8 is also greater than half the diameter of the ball 5. The ball 5 is a steel ball. Ceramic balls can also be used as the ball 5.

[0218] like Figure 4As shown, the sealing member 6 is an annular component formed by vulcanizing and bonding a rubber material 17 (e.g., nitrile rubber, acrylic rubber, etc.) to the surface of an annular core 16. The sealing member 6 has a fitting portion 15 that engages with the sealing groove 14, an annular plate portion 18 extending radially inward from the fitting portion 15, and a sealing lip 11 that slides in contact with the inner surface of the sliding recess 10. The core 16 has an annular plate-shaped flange portion 19 and a cylindrical portion 20 that bends axially inward along the radially outer end of the flange portion 19. The flange portion 19 is embedded in the annular plate portion 18 of the sealing member 6, and the cylindrical portion 20 is embedded in the fitting portion 15 of the sealing member 6.

[0219] like Figure 1 As shown, the sealing member 6 is provided only on one of the end openings on both sides of the axial direction of the annular space 4. That is, the axial end of the annular space 4 opposite to the side blocked by the sealing member 6 (right side in the figure) (left side in the figure) is open without the sealing member 6, so that the annular space 4 can receive lubricating oil supplied from the outside.

[0220] The retainer 7 has a retainer annular portion 21 that is adjacent to the passage area of ​​the ball 5 and extends circumferentially, and a retainer claw portion 22 that extends axially from the retainer annular portion 21 between the circumferentially adjacent balls 5. The retainer annular portion 21 and the retainer claw portion 22 are formed as a seamless integral piece from a resin composition. The resin composition forming the retainer annular portion 21 and the retainer claw portion 22 can also be a resin composition made of resin material only, but here, a resin composition in which fiber reinforcing material is added to the resin material is used. The retainer 7 is preferably manufactured by injection molding. The retainer annular portion 21 extends circumferentially in the area where it is axially sandwiched between the passage area of ​​the ball 5 and the sealing member 6.

[0221] The resin material used as the base for the resin composition can be polyamide (PA) or super engineering plastic. As a polyamide, polyamide 46 (PA46), polyamide 66 (PA66), and poly(terephthalamide nonadiamine) (PA9T) can be used. As a super engineering plastic, polyetheretherketone (PEEK) and polyphenylene sulfide (PPS) can be used. As a fiber reinforcing material added to the resin material, glass fiber, carbon fiber, and aramid fiber can be used.

[0222] The retainer claw portion 22 is formed as a cantilever beam, with one axial end serving as a fixed end fixed to the retainer annular portion 21 and the other axial end serving as a free end. The axial length of the retainer claw portion 22 is set to be greater than the radius of the ball 5. The retainer claw portion 22 has a constant shape with its radial thickness remaining unchanged in the axial direction.

[0223] like Figure 2 , Figure 4As shown, an outer diameter axial groove 24 extending axially from the front end of the retainer claw portion 22 toward the retainer annular portion 21 is formed on the radially outer surface 23 of the retainer claw portion 22. Additionally, an inner diameter axial groove 26 extending axially from the front end of the retainer claw portion 22 toward the retainer annular portion 21 is formed on the radially inner surface 25 of the retainer claw portion 22. Figure 2 As shown, the outer diameter side axial groove 24 has a groove width that is more than half the circumferential width of the front end of the retainer claw portion 22. Similarly, the inner diameter side axial groove 26 also has a groove width that is more than half the circumferential width of the front end of the retainer claw portion 22. Furthermore, the retainer claw portion 22, thanks to the outer diameter side axial groove 24 and the inner diameter side axial groove 26, has an H-shaped cross-sectional shape orthogonal to the axial direction, opening radially outward and radially inward. Additionally, the outer diameter side axial groove 24 and the inner diameter side axial groove 26 are formed to open towards the front end of the retainer claw portion 22 so that the shape of the retainer claw portion 22 when viewed axially from the front end side is H-shaped.

[0224] The retainer claw 22 has a circumferentially opposing surface 27 that is circumferentially opposite to the ball 5. The portion of the circumferentially opposing surface 27 that receives the ball 5 is formed in a planar shape that extends in a manner that prevents interference with the ball 5 when the retainer claw 22 moves radially outward due to centrifugal force. In the figure, the circumferentially opposing surface 27 is a plane extending parallel to an imaginary straight line connecting the center of the retainer annulus 21 and the center of the retainer claw 22 (a plane that extends in a manner that the circumferential width of the retainer claw 22 remains constant along the radial direction) when viewed axially. The center of the retainer annulus 21 is located at the same position as the center of the inner ring 2 or the center of the outer ring 3. Furthermore, the center of the retainer claw 22, when viewed axially, is located at the midpoint between a pair of circumferentially opposing surfaces 27 on either side of the retainer claw 22.

[0225] The spacing between circumferentially adjacent retainer claws 22 (i.e., the spacing between circumferentially opposed surfaces 27) is preferably set to be 1.02 to 1.11 times the diameter of the ball 5 on the pitch circle of the ball 5. Accordingly, vibration of the retainer 7 can be reduced.

[0226] like Figure 3 , Figure 5 As shown, the portion of the circumferentially opposed surface 27 that receives the ball 5 in the circumferential direction, viewed radially, is a straight line extending axially without any circumferential inclination, so that no axial component force is generated when the ball 5 is received. The retainer annular portion 21 has an axially opposed surface 28 that is axially opposed to the ball 5. The circumferentially opposed surface 27 and the axially opposed surface 28 are connected in a concave arc shape. In the figure, the surface connecting the circumferentially opposed surface 27 and the axially opposed surface 28 is a single R (circular arc) surface (a locally cylindrical surface with a constant radius of curvature).

[0227] like Figure 4 As shown, the axial end of the outer diameter side axial groove 24, near the retainer annulus 21, slopes upwards in a concave arc shape to the outer circumference of the retainer annulus 21. The axial end of the inner diameter side axial groove 26, near the retainer annulus 21, also slopes upwards to the inner circumference of the retainer annulus 21. A retainer guided surface 29 is formed on the inner circumference of the retainer annulus 21, which slides in contact with the inner ring groove shoulder 9 on the outer circumference of the inner ring 2 and is guided thereto. The retainer guided surface 29 is an annular surface that slides directly in contact with the inner ring groove shoulder 9. If the sliding gap between the retainer guided surface 29 and the inner ring groove shoulder 9 is set to 0.22 mm or less, the vibration of the retainer 7 can be reduced. The upwardly sloping portion of the inner diameter side axial groove 26 towards the inner circumference of the retainer annulus 21 opens towards the retainer guided surface 29.

[0228] like Figure 6 , Figure 7 As shown, a plurality of protrusions 30 are provided circumferentially at intervals on the inner diameter side end of the sealing lip 11, which slide in contact with the sliding recesses 10 on the outer periphery of the inner ring 2. The protrusions 30 are formed to extend in a direction orthogonal to the circumferential direction. For example... Figure 7 As shown, each protrusion 30 has a convex arc-shaped cross-sectional shape.

[0229] like Figure 8 As shown, the ball bearing 1 described above can be used as a bearing for an electric vehicle transmission 32 that reduces the rotation of the electric motor 31 in electric vehicles such as EVs (battery electric vehicles) and HEVs (hybrid electric vehicles). This electric vehicle transmission 32 bearing rotates at a wide range of speeds from low to high during vehicle operation. When the bearing rotates at its highest speed, the dmn value (pitch circle diameter of the ball 5 (mm) × rotational speed (min)) is... －1 It was used under conditions exceeding 2 million.

[0230] Figure 8 The transmission shown includes: a stator 33 of an electric motor 31, a rotor 34 of the electric motor 31, a rotating shaft 35 connected to the rotor 34, a ball bearing 1 supporting the rotating shaft 35 for rotatability, a second rotating shaft 36 and a third rotating shaft 37 arranged parallel to the rotating shaft 35, a first gear train 38 transmitting the rotation of the rotating shaft 35 to the second rotating shaft 36, and a second gear train 39 transmitting the rotation of the second rotating shaft 36 to the third rotating shaft 37. The stator 33 is an annular stationary component, and the rotor 34, which serves as a rotating component, is disposed inside the stator 33. When the stator 33 is energized, the rotor 34 rotates due to the electromagnetic force acting between the stator 33 and the rotor 34, and the rotation of the rotor 34 is input to the rotating shaft 35.

[0231] like Figure 5 As shown, the ball bearing 1, by means of an outer diameter side axial groove 24 formed on the radially outer surface 23 of the retainer claw 22 and an inner diameter side axial groove 26 formed on the radially inner surface 25 of the retainer claw 22, makes the cross-sectional shape of the retainer claw 22 H-shaped. Therefore, it can ensure the cross-sectional second moment of the retainer claw 22 (the difficulty of deformation of the retainer claw 22 relative to the bending moment) and suppress the mass of the retainer claw 22. Therefore, when used under high-speed rotation, it can also suppress torsional deformation of the retainer annulus 21 caused by the centrifugal force on the retainer claw 22, and suppress flexural deformation of the retainer claw 22 itself toward the radially outward. Furthermore, through data analysis conducted by the inventors, it was determined that the retainer claw portion 22 with the outer diameter side axial groove 24 and the inner diameter side axial groove 26 formed can reduce the deformation of the retainer claw portion 22 caused by centrifugal force to at least 77% compared with the retainer claw portion 22 without the outer diameter side axial groove 24 and the inner diameter side axial groove 26 formed.

[0232] In addition, such as Figure 2 As shown, for this ball bearing 1, the portion of the circumferentially opposed surface 27 that receives the ball 5 is a planar shape extending parallel to the straight line connecting the center of the cage annular portion 21 and the center of the cage claw portion 22. Therefore, when the cage claw portion 22 moves radially outward due to the centrifugal force acting on the cage claw portion 22, interference between the circumferentially opposed surface 27 of the cage claw portion 22 and the ball 5 can be prevented. In addition, since the shear resistance of the lubricating oil generated between the circumferentially opposed surface 27 of the cage claw portion 22 and the ball 5 is suppressed to a low level, the heat generation of the ball bearing 1 can also be suppressed.

[0233] In addition, such as Figure 5 As shown, for this ball bearing 1, the circumferential opposing surface 27 and the axial opposing surface 28 are connected in a concave arc shape, thus reducing the mass of the axial front end portion of the retainer claw portion 22 and ensuring the cross-sectional area of ​​the axial root portion of the retainer claw portion 22. Therefore, the deflection of the retainer claw portion 22 caused by the centrifugal force acting on it can be effectively suppressed.

[0234] In addition, such as Figure 4As shown, for this ball bearing 1, the axial end of the outer diameter side axial groove 24 near the cage annulus 21 slopes upward in a concave arc shape. This reduces the mass of the axial front end of the cage claw 22 and ensures a smaller cross-sectional area at the axial root of the cage claw 22. Furthermore, since the axial end of the inner diameter side axial groove 26 near the cage annulus 21 also slopes upward to the inner circumference of the cage annulus 21, the cross-sectional area at the axial root of the cage claw 22 is ensured more effectively. Therefore, deflection of the cage claw 22 due to centrifugal force acting on it can be effectively suppressed.

[0235] In addition, such as Figure 4 As shown, for the ball bearing 1, a cage guide surface 29 is formed on the inner circumference of the cage annulus 21 and is guided to slide in contact with the outer circumference of the inner ring 2. Therefore, the cage 7 can be radially positioned by the sliding contact between the cage guide surface 29 on the inner circumference of the cage annulus 21 and the outer circumference of the inner ring 2.

[0236] Figures 9-16 The ball bearing 1 represents the second embodiment. The same reference numerals are used for the parts corresponding to the first embodiment, and descriptions are omitted.

[0237] like Figure 10 As shown, the portion of the circumferentially opposing surface 27 of the retainer claw portion 22 that receives the ball 5 in the circumferential direction has a planar shape that extends parallel to the imaginary straight line connecting the center of the retainer annular portion 21 and the center of the retainer claw portion 22 when viewed from the axial direction, so that the circumferentially opposing surface 27 does not interfere with the ball 5 when the retainer claw portion 22 moves radially outward due to centrifugal force.

[0238] like Figure 11 As shown, the portion of the circumferentially opposed surface 27 that receives the ball 5 in the circumferential direction, when viewed radially, does not have a circumferential inclination but extends straight along the axial direction so as not to generate an axial component force when receiving the ball 5.

[0239] like Figure 12 As shown, the retainer claw portion 22 has a front-end tapering shape where the radial thickness gradually decreases from the side near the retainer annulus portion 21 (root side) towards the side away from the retainer annulus portion 21 (front end side). The axial thickness of the retainer annulus portion 21 is approximately the same size as the axial spacing between the ball 5 and the sealing member 6 (specifically, more than 95% and less than 100% of the axial spacing between the ball 5 and the sealing member 6). The retainer annulus portion 21 has a retainer-side sliding contact surface 40 that is axially opposed to and slides in contact with the sealing member 6, and the sealing member 6 has a sealing-side sliding contact surface 41 that slides in contact with the retainer-side sliding contact surface 40.

[0240] like Figure 13 As shown, a plurality of axial protrusions 42 are formed at constant intervals along the circumference of the sliding contact surface 40 on the retainer side. Each axial protrusion 42 is formed with a cross-sectional shape that protrudes axially in an arc shape along the circumference. In addition, the axial height of the axial protrusion 42 is set to less than 5% of the circumferential width dimension of the axial protrusion 42. In the figure, the axial height of the axial protrusion 42 is exaggerated for easy understanding of its existence. On the other hand, the sliding contact surface 41 on the sealing side is a circular plane perpendicular to the axial direction and does not have axial protrusions 42 formed thereon.

[0241] like Figure 12 As shown, the axial protrusion 42 is positioned either overlapping the pitch circle of the ball 5 (an imaginary circle connecting the centers of the plurality of balls 5) or radially outward from the pitch circle of the ball 5. Here, "the axial protrusion 42 is positioned overlapping the pitch circle of the ball 5" means that the imaginary cylindrical surface passing through the pitch circle of the ball 5 is located at the position where the axial protrusion 42 passes. "The axial protrusion 42 is positioned radially outward from the pitch circle of the ball 5" means that the entire axial protrusion 42 is located radially outward from the imaginary cylindrical surface passing through the pitch circle of the ball 5. In the figure, the axial protrusion 42 is positioned radially outward from the pitch circle of the ball 5.

[0242] like Figure 12 , Figure 15 As shown, the axial protrusion 42 has a parallel top 43, a first inclined top 44, and a second inclined top 45. The parallel top 43 is the portion of the axially convex arc-shaped top in the circumferential cross-section where the height is constant radially. The first inclined top 44 is the portion of the axially convex arc-shaped top in the circumferential cross-section where the height gradually decreases radially outward from the radially outer end of the parallel top 43. The second inclined top 45 is the portion of the axially convex arc-shaped top in the circumferential cross-section where the height gradually decreases radially inward from the radially inner end of the parallel top 43. Figure 12 As shown, the cross-sectional shape of the first inclined top 44, which is orthogonal to the circumference, becomes an R-shape that smoothly connects with the parallel top 43. The second inclined top 45, which is also orthogonal to the circumference, becomes an R-shape that smoothly connects with the parallel top 43.

[0243] like Figure 16 As shown, the retainer's guided surface 29 is an annular surface that directly slides in contact with the inner ring groove shoulder 9. (As shown...) Figure 17 As shown, the retainer's guided surface 29 can also form an annular surface with a plurality of convex arc-shaped protrusions 46 spaced circumferentially and projecting radially inward. If the sliding gap between the protrusions 46 and the inner ring 2 is set to a size of 0.22 mm or less, the vibration of the retainer 7 can be reduced.

[0244] like Figure 12 As shown, the inner diameter side axial groove 26 of the radial inner surface 25 of the retainer claw portion 22 is formed to axially penetrate the radial inner surface 25 of the retainer claw portion 22 and the retainer guided surface 29. Figure 10 As shown, the inner diameter side axial groove 26 has a groove width that is more than half the circumferential width of the front end of the retainer claw portion 22.

[0245] like Figure 12 As shown, the retainer annular portion 21 has a chamfered portion 47 that obliquely connects the retainer-side sliding contact surface 40 and the retainer guided surface 29 in a cross-section orthogonal to the circumferential direction. With this chamfered portion 47, the axial width of the radially inner end of the retainer annular portion 21 is less than half the axial width of the portion with the largest axial width of the retainer annular portion 21. Furthermore, the retainer annular portion 21 has a chamfered portion 48 that obliquely connects the retainer-side sliding contact surface 40 and the outer circumferential surface of the retainer annular portion 21 in a cross-section orthogonal to the circumferential direction.

[0246] The outer diameter side axial groove 24 of the radially outer surface 23 of the retainer claw portion 22 has a shape in which the position of the groove bottom gradually changes radially outward from one side of the front end of the retainer claw portion 22 toward one side of the retainer annular portion 21. For example... Figure 11 , Figure 14 As shown, the axial groove 24 on the outer diameter side has a groove width that is more than half the circumferential width of the front end of the retainer claw portion 22. In addition, an axial cutout 49 is formed on the outer periphery of the retainer annular portion 21 at a position corresponding to the axial groove 24 on the outer diameter side.

[0247] like Figure 11 , Figure 14 As shown, a claw tip oil passage 50 is formed on both circumferential sides (the shoulders of the outer diameter side axial groove 24) of the front end of the radially outer surface 23 of the retainer claw portion 22, extending circumferentially through the shoulders of the outer diameter side axial groove 24. The claw tip oil passage 50 is a stepped cut that rises from the side away from the retainer annulus portion 21 toward the side closer to the retainer annulus portion 21. By providing this claw tip oil passage 50, the lubrication performance of the ball 5 can be improved.

[0248] like Figure 13 As shown, the ball bearing 1 has a plurality of axial protrusions 42 formed at constant intervals along the circumferential direction on the sliding contact surface 40 on the cage side. These protrusions have an axially convex arc shape in cross-section. Therefore, an oil film based on the wedge-shaped film effect is formed between the axial protrusions 42 and the sliding contact surface 41 on the sealing side. Through this oil film, the axial protrusions 42 and the sliding contact surface 41 on the sealing side are in a fluid lubrication state, thereby minimizing the contact resistance between the cage 7 and the sealing member 6. Therefore, abnormal heat generation due to the sliding resistance of the contact portion between the cage 7 and the sealing member 6 can be prevented.

[0249] Here, the lubrication state between sliding contact surfaces is distinguished into boundary lubrication state and fluid lubrication state. Boundary lubrication state refers to the state characterized by multiple molecular layers (10) of lubricating oil adsorbed on each sliding contact surface. －5 ~10 －6 The sliding contact surface is lubricated by an oil film (approximately 10 mm thick), resulting in direct contact between the fine unevenness of the sliding contact surface. On the other hand, fluid lubrication refers to the formation of an oil film (e.g., 10 mm thick) between the sliding contact surfaces using the wedge-shaped film effect. －3 ~10 －1 The oil film (approximately mm) creates a state where the sliding contact surfaces do not directly contact each other (only indirect contact occurs via the oil film). If a wedge-shaped film effect is generated, resulting in fluid lubrication, the sliding resistance is almost zero, thus enabling operation at previously impossible high circumferential speeds.

[0250] In addition, such as Figure 12 As shown, for this ball bearing 1, the retainer annulus 21 is configured to slide in contact with the sealing member 6. Therefore, the axial thickness of the retainer annulus 21 is set to be relatively large, thereby improving the rigidity of the retainer annulus 21. Thus, when used under high-speed rotation, torsional deformation of the retainer annulus 21 caused by centrifugal force on the retainer claw 22 can be suppressed, thereby preventing the retainer claw 22 from tilting radially outward.

[0251] In addition, the ball bearing 1 can also be installed in a position where the space for the bearing is narrow and the width of the bearing needs to be minimized (i.e., a position where previously it was necessary to abandon the use of sealed ball bearings and to use open-type ball bearings with open ends in the axial direction without the sealing component 6).

[0252] In addition, such as Figure 11 As shown, for this ball bearing 1, the portion of the circumferentially opposed surface 27 that receives the ball 5 in the circumferential direction forms a straight line shape that extends axially without any circumferential inclination. Therefore, when the ball 5 is received by the retainer claw portion 22, no axial component force is generated in the retainer claw portion 22. Thus, it is possible to prevent the retainer 7 from being forcefully pressed against the sealing member 6 in the axial direction, thereby effectively suppressing the sliding resistance of the contact portion between the retainer 7 and the sealing member 6.

[0253] In addition, such as Figure 12As shown, the ball bearing 1 employs an axial protrusion 42 with a parallel top 43 and a first inclined top 44. Therefore, when the bearing rotates at a low speed, and the centrifugal force on the retainer claw 22 is relatively small, an oil film based on the wedge-shaped film effect can be formed between the parallel top 43 of the axial protrusion 42 and the sliding contact surface 41 on the sealing side. Furthermore, when the bearing rotates at a high speed, and the centrifugal force on the retainer claw 22 is relatively large, even with significant torsional deformation of the retainer annular portion 21, an oil film based on the wedge-shaped film effect can be formed between the parallel top 43 and the first inclined top 44 of the axial protrusion 42 and the sliding contact surface 41 on the sealing side. In this way, an oil film based on the wedge-shaped film effect can be stably formed between the retainer 7 and the sealing member 6 regardless of the bearing's rotational speed.

[0254] In addition, such as Figure 12 As shown, for the ball bearing 1, the cross-sectional shape of the first inclined top 44 orthogonal to the circumference is R-shaped. The first inclined top 44 is smoothly connected to the parallel top 43. Therefore, when the retainer annular portion 21 has a relatively large torsional deformation, when an oil film based on the wedge film effect is formed between the parallel top 43 and the first inclined top 44 and the sealing side sliding contact surface 41, the oil film can be stably formed.

[0255] In addition, such as Figure 12 As shown, for this ball bearing 1, an inner diameter side axial groove 26 (inner diameter side oil groove) is provided on the inner circumference of the cage 7. Therefore, lubricating oil supplied to the radially inner region of the cage claw portion 22 is introduced into the region between the cage annular portion 21 and the sealing member 6 through the inner diameter side axial groove 26. Thus, the area between the sealing side sliding contact surface 41 and the axial protrusion 42 can be sufficiently lubricated, and a wedge-shaped oil film can be effectively formed.

[0256] In addition, such as Figure 12 As shown, the ball bearing 1 employs a retainer annular portion 21 having a chamfered portion 47 that obliquely connects the retainer-side sliding contact surface 40 and the retainer guided surface 29 in a cross-section orthogonal to the circumferential direction. Therefore, by utilizing the action of centrifugal force, lubricating oil that is guided from the radially inner region of the retainer claw portion 22 through the inner diameter side axial groove 26 into the region between the retainer annular portion 21 and the sealing member 6 can be smoothly guided along the chamfered portion 47 to the retainer-side sliding contact surface 40.

[0257] In addition, such as Figure 12As shown, for the ball bearing 1, the axial protrusion 42 is positioned at a position overlapping with the pitch circle of the ball 5 or radially outward from the pitch circle of the ball 5. Therefore, when the centrifugal force acting on the retainer claw portion 22 causes torsional deformation in the retainer annular portion 21 in a direction that causes the retainer claw portion 22 to tilt radially outward, it can prevent the retainer-side sliding contact surface 40 and the sealing-side sliding contact surface 41 from contacting at a position radially outward from the axial protrusion 42 due to the torsional deformation.

[0258] In addition, such as Figure 12 As shown, for this ball bearing 1, the position of the bottom of the outer diameter side axial groove 24 (outer diameter side oil groove) gradually changes radially outward from the side of the front end of the retainer claw portion 22 toward the side of the retainer annulus portion 21. Therefore, the lubricating oil supplied to the outer diameter side axial groove 24 moves from the side of the front end of the retainer claw portion 22 toward the side of the retainer annulus portion 21 by the action of a pump, and is thus introduced into the area between the retainer annulus portion 21 and the sealing member 6. Therefore, the sliding contact surface 41 on the sealing side and the axial protrusion 42 can be sufficiently lubricated, and a wedge-shaped oil film can be effectively formed.

[0259] Furthermore, for the ball bearing 1, the axial end of the annular space 4 opposite to the axial end of the side blocked by the sealed component 6 is open, so that the sliding contact surface 41 on the sealing side and the axial protrusion 42 can be fully lubricated, and an oil film based on a wedge-shaped film can be reliably formed.

[0260] Figure 18 The ball bearing 1 represents the third embodiment. In the second embodiment, an axial protrusion 42 is provided on the retainer-side sliding contact surface 40, which is both the retainer-side sliding contact surface 40 and the sealing-side sliding contact surface 41. In contrast, the third embodiment differs in that an axial protrusion 42 is provided on the sealing-side sliding contact surface 41; otherwise, the structure is the same. Therefore, the same reference numerals are used for the parts corresponding to those in the second embodiment, and descriptions are omitted.

[0261] like Figure 19 As shown, a plurality of axial protrusions 42 are formed at constant intervals along the circumference of the sliding contact surface 41 on the sealing side. The axial protrusions 42 are molded from the rubber material 17 constituting the sealing member 6. Each axial protrusion 42 is formed with a cross-sectional shape along the circumference that is an arc protruding axially. In addition, the axial height of the axial protrusion 42 is set to less than 5% of the circumferential width dimension of the axial protrusion 42. In the figure, the axial height of the axial protrusion 42 is exaggerated for easy understanding of its existence. On the other hand, the sliding contact surface 40 on the retainer side is a circular plane perpendicular to the axial direction and does not have axial protrusions 42 formed thereon.

[0262] like Figure 18As shown, the axial protrusion 42 is positioned at a position that overlaps with the pitch circle of the ball 5 (an imaginary circle connecting the centers of the plurality of balls 5) or is radially outward from the pitch circle of the ball 5.

[0263] like Figure 18 , Figure 20 As shown, the axial protrusion 42 has a parallel top 43, a first inclined top 44, and a second inclined top 45. The parallel top 43 is the portion of the axially convex arc-shaped top in the circumferential cross-section where the height is constant radially. The first inclined top 44 is the portion of the axially convex arc-shaped top in the circumferential cross-section where the height gradually decreases radially outward from the radially outer end of the parallel top 43. The second inclined top 45 is the portion of the axially convex arc-shaped top in the circumferential cross-section where the height gradually decreases radially inward from the radially inner end of the parallel top 43. Figure 18 As shown, the cross-sectional shape of the first inclined top 44, which is orthogonal to the circumference, becomes an R-shape that smoothly connects with the parallel top 43. The second inclined top 45, which is also orthogonal to the circumference, becomes an R-shape that smoothly connects with the parallel top 43.

[0264] like Figure 19 As shown, for this ball bearing 1, multiple axial protrusions 42, with an axially convex arc shape in cross-section, are formed at constant intervals along the circumferential direction on the sliding contact surface 41 of the sealing side. Therefore, an oil film based on the wedge-shaped film effect is formed between these axial protrusions 42 and the sliding contact surface 40 of the cage side. Through this oil film, the axial protrusions 42 and the sliding contact surface 40 of the cage side are in a fluid lubrication state, thereby minimizing the contact resistance between the cage 7 and the sealing member 6. Therefore, abnormal heat generation due to the sliding resistance of the contact portion between the cage 7 and the sealing member 6 can be prevented.

[0265] In addition, such as Figure 18 As shown, the ball bearing 1 employs an axial protrusion 42 with a parallel top 43 and a first inclined top 44. Therefore, when the bearing rotates at a low speed, and the centrifugal force on the retainer claw portion 22 is relatively small, an oil film based on the wedge-shaped film effect can be formed between the parallel top 43 of the axial protrusion 42 and the retainer-side sliding contact surface 40. Furthermore, when the bearing rotates at a high speed, and the centrifugal force on the retainer claw portion 22 is relatively large, even with significant torsional deformation of the retainer annular portion 21, an oil film based on the wedge-shaped film effect can be formed between the parallel top 43 and the first inclined top 44 of the axial protrusion 42 and the retainer-side sliding contact surface 40. In this way, an oil film based on the wedge-shaped film effect can be stably formed between the retainer 7 and the sealing member 6 regardless of the bearing's rotational speed.

[0266] In addition, such as Figure 18As shown, for the ball bearing 1, the cross-sectional shape of the first inclined top 44 orthogonal to the circumferential direction is R-shaped. The first inclined top 44 is smoothly connected to the parallel top 43. Therefore, when the retainer annular portion 21 has a relatively large torsional deformation, when an oil film based on the wedge film effect is formed between the parallel top 43 and the first inclined top 44 and the retainer side sliding contact surface 40, the oil film can be stably formed.

[0267] In addition, such as Figure 18 As shown, the ball bearing 1 has an inner diameter side axial groove 26 on the inner circumference of the retainer 7. Therefore, lubricating oil supplied to the radially inner region of the retainer claw portion 22 is guided through the inner diameter side axial groove 26 into the region between the retainer annular portion 21 and the sealing member 6. Thus, sufficient lubrication is achieved between the retainer-side sliding contact surface 40 and the axial protrusion 42, effectively forming a wedge-shaped oil film.

[0268] Other effects are the same as in the first and second embodiments.

[0269] Figures 21-26 The ball bearing 1 is indicated by the fourth embodiment. Compared to the third embodiment, the fourth embodiment adds a sealing member 61, and the shape of the retainer 7 is partially different, but the other structures are the same. Therefore, the same reference numerals are used for the parts corresponding to those in the third embodiment, and descriptions are omitted.

[0270] like Figure 21 As shown, a sealing member 6 is provided at one end opening of the annular space 4 on both sides of the axial direction, and a sealing member 61 is also provided at the other end opening. Lubricant is sealed in the annular space 4 between the sealing member 6 and the sealing member 61.

[0271] like Figure 22 , Figure 23 As shown, the retainer claw 22 has a circumferentially opposing surface 27 that is circumferentially opposite to the ball 5. The portion of the circumferentially opposing surface 27 that receives the ball 5 is formed in a planar shape such that the circumferentially opposing surface 27 does not interfere with the ball 5 when the retainer claw 22 moves radially outward due to centrifugal force. Figure 22 As shown, the circumferential opposing surface 27 is a plane that, when viewed axially, gradually approaches the imaginary straight line connecting the center of the retainer annular portion 21 and the center of the retainer claw portion 22 from the radially outer side toward the radially inner side (a plane that extends in such a way that the circumferential width of the retainer claw portion 22 gradually decreases from the radially outer side toward the radially inner side).

[0272] like Figure 24As shown, a stepped portion 62 is provided in the retainer annular portion 21, which rises radially outward from the radially outer side of the root of the retainer claw portion 22. By providing this stepped portion 62, when the lubricant sealed in the annular space 4 moves along the axial groove 24 on the outer diameter side towards one side of the retainer annular portion 21, a portion of the lubricant can be received by the stepped portion 62 and returned to one side of the ball 5.

[0273] like Figure 25 As shown, the circumferential opposing surface 27 and the axial opposing surface 28 are connected by a composite R-shaped surface. In the figure, the surface connecting the circumferential opposing surface 27 and the axial opposing surface 28 is composed of a partially cylindrical front end R-face 63 connected to the circumferential opposing surface 27 and having a radius of curvature R2 smaller than the radius R1 of the ball 5, a partially cylindrical root R-face 64 connected to the axial opposing surface 28 and having a radius of curvature R3 larger than the radius R1 of the ball 5, and an intermediate R-face 65 that smoothly connects the front end R-face 63 and the root R-face 64.

[0274] The ball bearing 1 has the same effect as in the third embodiment.

[0275] Figures 27-31 This refers to the ball bearing 1 in the fifth embodiment. The fifth embodiment is equivalent to omitting the second embodiment. Figures 9-17 The embodiment shown is an embodiment of the claw tip oil passage 50. Therefore, the same reference numerals are used for the parts corresponding to the second embodiment, and the description is omitted.

[0276] Figures 32-37 The ball bearing 1 represents the sixth embodiment of the present invention. The same reference numerals are used for parts corresponding to the above embodiments, and descriptions are omitted.

[0277] The retainer claw portion 22 is formed as a cantilever beam, with one axial end serving as a fixed end fixed to the retainer annular portion 21 and the other axial end serving as a free end. The axial length of the retainer claw portion 22 is set to be greater than the axial width of the outer ring track groove 12. The retainer claw portion 22 has a constant shape with its radial thickness not changing in the axial direction.

[0278] like Figure 32 , Figure 37 As shown, on the radially outer surface of the retainer annular portion 21, a root-side guided surface 51 is formed at a position corresponding to the root of the retainer claw portion 22, which slides in contact with one of the outer ring groove shoulders 13 of the pair of outer ring groove shoulders 13. Additionally, on the radially outer surface of the axial end of the front end of the retainer claw portion 22, a front end-side guided surface 52 is formed, which slides in contact with the other of the outer ring groove shoulders 13 of the pair of outer ring groove shoulders 13.

[0279] like Figure 36As shown, the circumferential cross-sectional shape of the root-side guided surface 51 is formed as an arc protruding radially outward. Here, "protruding radially outward" means having a shape that protrudes radially outward relative to a circle concentric with the retainer annular portion 21. The front-end guided surface 52 (see reference...) Figure 37 The cross-sectional shape along the circumferential direction is also formed as an arc protruding radially outward. The cross-section along the circumferential direction of the root-side guided surface 51 and the cross-section along the circumferential direction of the front-end guided surface 52 have the same shape. The radius of curvature of the cross-sections along the circumferential direction of the root-side guided surface 51 and the front-end guided surface 52 can be set to be smaller than 1 / 2 of the radius of the inner diameter of the outer ring groove shoulder 13 and larger than 1 / 10 of the radius of the inner diameter of the outer ring groove shoulder 13.

[0280] like Figure 37 As shown, in this embodiment, the root-side guided surface 51 and the front-side guided surface 52 are a series of surfaces that are straight and continuous in the axial direction in such a way that no recess is generated between the root-side guided surface 51 and the front-side guided surface 52.

[0281] like Figure 34 As shown, the axial end edge 53 of the root-side guided surface 51, on the side away from the retainer claw 22, is chamfered with an R-shape. Here, as... Figure 35 As shown, an R-shaped chamfer refers to a corner shape that gives a cross-sectional shape orthogonal to the circumferential direction a convex arc shape. For example... Figure 34 As shown, the axial end edge 54 of the front end side of the guide surface 52, which is away from the retainer annular portion 21, is also chamfered with an R.

[0282] like Figure 36 As shown, for this ball bearing 1, the circumferential cross-sectional shape of the root-side guided surface 51 is formed as an arc protruding radially outward. Therefore, an oil film based on the wedge-shaped film effect is formed between the root-side guided surface 51 and one of the outer ring groove shoulders 13. Through this oil film, the root-side guided surface 51 and the outer ring groove shoulder 13 are in a fluid lubrication state, thereby minimizing the contact resistance between the retainer 7 and the outer ring 3. Similarly, Figure 32 The front-end guided surface 52 shown is also formed in a radially outward protruding arc shape along its circumferential cross-sectional shape. Therefore, an oil film based on the wedge-shaped film effect is formed between the front-end guided surface 52 and the outer ring groove shoulder 13 (the outer ring groove shoulder 13 on the left). Through this oil film, the front-end guided surface 52 and the outer ring groove shoulder 13 are in a fluid lubrication state, thereby minimizing the contact resistance between the retainer 7 and the outer ring 3. Therefore, abnormal heat generation due to the sliding resistance of the contact portion between the retainer 7 and the outer ring 3 can be prevented.

[0283] In addition, such as Figure 32As shown, for this ball bearing 1, one of the outer ring groove shoulders 13 (the right outer ring groove shoulder 13) supports the cage annulus 21 radially outward, and the other outer ring groove shoulder 13 (the left outer ring groove shoulder 13) supports the axial end of the front end of the cage claw 22 radially outward. Therefore, the cage claw 22 is unlikely to flex radially outward. Thus, when used at high speeds, torsional deformation of the cage annulus 21 due to centrifugal force on the cage claw 22 can be suppressed, and flexural deformation of the cage claw 22 itself radially outward can also be suppressed.

[0284] In addition, such as Figure 34 As shown, for this ball bearing 1, the axial end edge 53 of the root-side guided surface 51 away from the cage claw portion 22 and the axial end edge 54 of the front-side guided surface 52 away from the cage annular portion 21 are chamfered with a radius (R), thus enabling... Figure 32 An oil film based on the wedge film effect is effectively formed between the root-side guided surface 51 and one of the outer ring groove shoulders 13 (the outer ring groove shoulder 13 on the right side), and an oil film based on the wedge film effect is also effectively formed between the front-side guided surface 52 and the other outer ring groove shoulder 13 (the outer ring groove shoulder 13 on the left side).

[0285] In addition, such as Figure 33 As shown, for this ball bearing 1, the portion of the circumferentially opposed surface 27 that receives the ball 5 is a planar shape extending parallel to the straight line connecting the center of the cage annular portion 21 and the center of the cage claw portion 22. Therefore, interference between the circumferentially opposed surface 27 of the cage claw portion 22 and the ball 5 can be prevented when the cage claw portion 22 moves radially outward due to the centrifugal force acting on it. Furthermore, since the shear resistance of the lubricating oil generated between the circumferentially opposed surface 27 of the cage claw portion 22 and the ball 5 is suppressed to a low level, heat generation in the ball bearing 1 can also be suppressed.

[0286] Furthermore, for the ball bearing 1, the axial end of the annular space 4 opposite to the axial end of the side blocked by the sealed component 6 is open, so the root-side guided surface 51 and the front-side guided surface 52 can be fully lubricated, and an oil film based on a wedge-shaped film can be reliably formed.

[0287] Figures 38-41 The ball bearing 1 represents the seventh embodiment. The seventh embodiment and the sixth embodiment ( Figures 32-37 The only difference in the embodiment shown is the addition of an oil storage tank 55; otherwise, the structure is the same as in the sixth embodiment. Therefore, the same reference numerals are used for the parts corresponding to those in the sixth embodiment, and descriptions are omitted.

[0288] like Figure 38 , Figure 40 As shown, an oil accumulation groove 55 is formed on the radially inner side of the retainer claw portion 22, extending axially from the front end of the retainer claw portion 22 toward the retainer annular portion 21. Figure 38 As shown, the oil accumulation groove 55 is located radially opposite to the inner ring groove shoulder 9 on the side near the retainer annular portion 21 of the pair of inner ring groove shoulders 9, and slopes upward to the radially inner side of the retainer 7. That is, the oil accumulation groove 55 is a groove that does not penetrate axially. Alternatively, the oil accumulation groove 55 can also be formed to penetrate the radially inner side of the retainer 7 axially.

[0289] like Figure 39 , Figure 41 As shown, the oil accumulation groove 55 is formed at the circumferential center of the radially inner side surface of the retainer claw portion 22. The oil accumulation groove 55 has a semi-circular cross-sectional shape. The oil accumulation groove 55 may also have a triangular cross-sectional shape or a quadrilateral cross-sectional shape.

[0290] The ball bearing 1 of this embodiment can store the lubricating oil that is scattered to the outer diameter side due to centrifugal force in the oil storage tank 55 and supply the lubricating oil to the inner ring 2.

[0291] Furthermore, the ball bearing 1 in this embodiment has the same effect as that in the sixth embodiment.

[0292] Figures 42-45 The ball bearing 1 represents the eighth embodiment. The eighth embodiment and the seventh embodiment ( Figures 38-41 The only difference in the embodiment shown is the addition of a recessed portion 56; otherwise, the structure is the same as in the 7th embodiment. Therefore, the same reference numerals are used for the parts corresponding to those in the 7th embodiment, and descriptions are omitted.

[0293] like Figure 45 As shown, a retraction recess 56 is formed in the portion between the root-side guided surface 51 and the front-side guided surface 52 on the radially outer surface of the retainer claw portion 22. That is, the radially outer surface of the retainer claw portion 22 becomes a surface with a stepped difference, in which the root-side guided surface 51, the retraction recess 56, and the front-side guided surface 52 are arranged sequentially along the axial direction.

[0294] like Figure 42 , Figure 43 As shown, the recess 56 has an axial width wider than the outer ring track groove 12 and extends circumferentially. Here, as... Figure 42As shown, the recess 56 is configured to cover the axial width of the outer ring track groove 12 across its entire width. Specifically, the end of the recess 56 on one side of the root-side guided surface 51 is positioned offset from the boundary portion of one of the outer ring groove shoulders 13 (the outer ring groove shoulder 13 near the retainer annulus 21) with the outer ring track groove 12 towards that one outer ring groove shoulder 13. Furthermore, the end of the recess 56 on one side of the front-side guided surface 52 is positioned offset from the boundary portion of the other outer ring groove shoulder 13 (the outer ring groove shoulder 13 away from the retainer annulus 21) with the outer ring track groove 12 towards that other outer ring groove shoulder 13. The axial ends of the recess 56 slope upwards at both ends towards the root-side guided surface 51 and the front-side guided surface 52.

[0295] like Figure 43 As shown, the recess 56 is recessed relative to the root-side guided surface 51 (or the front-side guided surface 52) in such a way that it has an inner surface that is recessed radially inward relative to the root-side guided surface 51 (or the front-side guided surface 52). In the figure, the inner surface of the recess 56 is a flat surface orthogonal to the radial direction.

[0296] like Figure 42 As shown, in this embodiment, the ball bearing 1 has a recess 56 formed between the root-side guided surface 51 and the front-side guided surface 52. This prevents the boundary portions of the outer ring groove shoulder 13 and the outer ring track groove 12 from sliding into contact with the radially outer surface of the retainer annulus 21 or the radially outer surface of the retainer claw 22. Therefore, it prevents localized wear on the radially outer surface of the retainer annulus 21 or the radially outer surface of the retainer claw 22 at positions corresponding to the boundary portions of the outer ring groove shoulder 13 and the outer ring track groove 12.

[0297] Furthermore, the ball bearing 1 in this embodiment has the same effect as in the 6th and 7th embodiments.

[0298] Figure 46 , Figure 47 This refers to the ball bearing 1 of the 9th embodiment. The 9th embodiment is equivalent to the 6th embodiment ( Figures 32-37 The embodiment shown includes an additional sliding contact structure between the retainer 7 and the sealing member 6 as in the second embodiment. Figure 12 This is an embodiment of the sliding contact structure between the retainer-side sliding contact surface 40 and the sealing-side sliding contact surface 41. Therefore, the same reference numerals are used to denote the parts corresponding to the above embodiments, and the description is omitted.

[0299] Figure 48 , Figure 49This refers to the ball bearing 1 of the tenth embodiment. The tenth embodiment is equivalent to the sixth embodiment ( Figures 32-37 The embodiment shown includes an additional sliding contact structure between the retainer 7 and the sealing member 6 as in the third embodiment. Figure 18 This is an embodiment of the sliding contact structure between the retainer-side sliding contact surface 40 and the sealing-side sliding contact surface 41. Therefore, the same reference numerals are used to denote the parts corresponding to the above embodiments, and the description is omitted.

[0300] In the above embodiments, an oil-lubricated ball bearing 1 using lubricating oil as a lubricant to lubricate the interior of the bearing was illustrated. However, the present invention can also be applied to a grease-lubricated ball bearing 1 using grease as a lubricant to lubricate the interior of the bearing. Grease is a semi-solid lubricant comprising lubricating oil and a thickener dispersed in the lubricating oil.

[0301] The embodiments disclosed herein should be considered illustrative rather than limiting in all respects. The scope of the invention is defined by the claims rather than the foregoing description, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0302] Explanation of reference numerals in the attached figures

[0303] 1…ball bearing; 2…inner ring; 3…outer ring; 4…annular space; 5…ball; 6…sealing component; 7…resin retainer; 12…outer ring raceway; 13…outer ring raceway shoulder; 16…core; 17…rubber material; 21…retainer annular portion; 22…retainer claw portion; 23…radial outer surface; 24…outer diameter side axial groove; 25…radial inner surface; 26…inner diameter side axial groove; 27…circumferential opposing surfaces; 28…shaft 29… Retainer guided surface; 31… Electric motor; 32… Transmission for electric vehicles; 40… Retainer side sliding contact surface; 41… Sealing side sliding contact surface; 42… Axial protrusion; 43… Parallel top; 44… First inclined top; 47… Chamfer; 51… Root side guided surface; 52… Front end side guided surface; 53… Axial end edge; 54… Axial end edge; 55… Oil accumulation groove; 56… Recessed recess.

Claims

1. A ball bearing comprising: Inner circle (2); Outer ring (3), which is coaxially disposed on the radially outer side of the inner ring (2); Multiple balls (5) are assembled in an annular space (4) formed between the inner ring (2) and the outer ring (3); An annular sealing member (6) that blocks one end opening of the annular space (4) in the axial direction; and A resin retainer (7) holds the plurality of balls (5). The resin retainer (7) has a retainer annular portion (21) extending circumferentially in the region where the ball (5) passes through and is axially clamped by the sealing member (6), and a cantilevered retainer claw portion (22) extending axially from the retainer annular portion (21) between the circumferentially adjacent balls (5). The ball bearing is characterized in that... The retainer annular portion (21) has a retainer-side sliding contact surface (40), which is axially opposed to and in sliding contact with the sealing member (6). The sealing component (6) has a sealing-side sliding contact surface (41) that slides in contact with the retainer-side sliding contact surface (40). On one of the sliding contact surfaces (40) on the retainer side and the sliding contact surface (41) on the sealing side, a plurality of axial protrusions (42) with an axially convex arc shape in cross-section along the circumferential direction are formed at constant intervals. The axial protrusion (42) has a parallel top (43) with a height that is constant radially along the axially convex arcuate top in the circumferential section, and an inclined top (44) with a height that gradually decreases radially outward from the radially outer end of the parallel top (43) with the height of the axially convex arcuate top in the circumferential section.

2. The ball bearing according to claim 1, characterized in that, The axial length of the retainer claw (22) is set to be greater than the radius of the ball (5). The retainer claw (22) has a circumferentially opposing surface (27) that is circumferentially opposite to the ball (5). The portion of the circumferentially opposed surface (27) that receives the ball (5) in the circumferential direction forms a straight line shape that does not have a circumferential inclination but extends straight along the axial direction, so that no axial component force is generated when the ball (5) is received.

3. The ball bearing according to claim 2, characterized in that, The portion of the circumferentially opposed surface (27) that receives the ball (5) extends parallel to the straight line connecting the center of the retainer annular portion (21) and the center of the retainer claw portion (22), so that the circumferentially opposed surface (27) does not interfere with the ball (5) when the retainer claw portion (22) moves radially outward due to centrifugal force.

4. The ball bearing according to any one of claims 1 to 3, characterized in that, The circumferentially orthogonal cross-sectional shape of the inclined top (44) is an R-shape that is smoothly connected to the parallel top (43).

5. The ball bearing according to any one of claims 1 to 3, characterized in that, The plurality of axial protrusions (42) are positioned at a position that overlaps with the pitch circle of the ball (5) or is radially outward from the pitch circle of the ball (5).

6. The ball bearing according to any one of claims 1 to 3, characterized in that, The axial protrusion (42) is formed on the sliding contact surface (41) on the sealing side. The sealing component (6) has an annular core (16) and a rubber material (17) vulcanized and bonded to the surface of the core (16). The axial protrusion (42) is formed of the rubber material (17).

7. The ball bearing according to any one of claims 1 to 3, characterized in that, A retainer guide surface (29) is formed on the inner periphery of the retainer annular portion (21) and is guided to slide in contact with the outer periphery of the inner ring (2).

8. The ball bearing according to claim 7, characterized in that, An inner diameter side axial groove (26) is provided on the inner circumference of the resin retainer (7). The inner diameter side axial groove (26) is formed to penetrate the radial inner surface (25) of the retainer claw (22) and the retainer guided surface (29) in the axial direction.

9. The ball bearing according to claim 7, characterized in that, The retainer annular portion (21) has a chamfered portion (47) that obliquely connects the retainer-side sliding contact surface (40) and the retainer guided surface (29) in a cross-section orthogonal to the circumferential direction.

10. The ball bearing according to any one of claims 1 to 3, characterized in that, An axial groove (24) extending axially from the front end of the retainer claw portion (22) toward the retainer annular portion (21) is formed on the radially outer side (23). The outer diameter side axial groove (24) has a shape in which the position of the groove bottom gradually changes radially outward from one side of the front end of the retainer claw (22) toward one side of the retainer annular portion (21).

11. The ball bearing according to any one of claims 1 to 3, characterized in that, The axial end of the annular space (4) opposite to the axial end blocked by the sealing member (6) is open without the sealing member (6) so that the annular space (4) can receive lubricant supplied from the outside.

12. The ball bearing according to any one of claims 1 to 3, characterized in that, The bearing is used in the electric motor (31) of an electric vehicle, or in the transmission (32) of an electric vehicle that reduces the rotation of the electric motor (31).

13. A ball bearing comprising: Inner circle (2); Outer ring (3), which is coaxially disposed on the radially outer side of the inner ring (2); Multiple balls (5) are assembled in an annular space (4) formed between the inner ring (2) and the outer ring (3); An annular sealing member (6) that blocks one end opening of the annular space (4) in the axial direction; and A resin retainer (7) holds the plurality of balls (5). The resin retainer (7) has a retainer annular portion (21) extending circumferentially in the region where the ball (5) passes through and is axially clamped by the sealing member (6), and a cantilevered retainer claw portion (22) extending axially from the retainer annular portion (21) between the circumferentially adjacent balls (5). The ball bearing is characterized in that... The retainer annular portion (21) has a retainer-side sliding contact surface (40), which is axially opposed to and in sliding contact with the sealing member (6). The sealing component (6) has a sealing-side sliding contact surface (41) that slides in contact with the retainer-side sliding contact surface (40). On one of the sliding contact surfaces (40) on the retainer side and the sliding contact surface (41) on the sealing side, a plurality of axial protrusions (42) with an axially convex arc shape in cross-section along the circumferential direction are formed at constant intervals. An axial groove (24) extending axially from the front end of the retainer claw portion (22) toward the retainer annular portion (21) is formed on the radially outer side (23). The outer diameter side axial groove (24) has a shape in which the position of the groove bottom gradually changes radially outward from one side of the front end of the retainer claw (22) toward one side of the retainer annular portion (21).

14. The ball bearing according to claim 13, characterized in that, The axial length of the retainer claw (22) is set to be greater than the radius of the ball (5). The retainer claw (22) has a circumferentially opposing surface (27) that is circumferentially opposite to the ball (5). The portion of the circumferentially opposed surface (27) that receives the ball (5) in the circumferential direction forms a straight line shape that does not have a circumferential inclination but extends straight along the axial direction, so that no axial component force is generated when the ball (5) is received.

15. The ball bearing according to claim 14, characterized in that, The portion of the circumferentially opposed surface (27) that receives the ball (5) extends parallel to the straight line connecting the center of the retainer annular portion (21) and the center of the retainer claw portion (22), so that the circumferentially opposed surface (27) does not interfere with the ball (5) when the retainer claw portion (22) moves radially outward due to centrifugal force.

16. The ball bearing according to any one of claims 13 to 15, characterized in that, The axial protrusion (42) has a parallel top (43) with a height that is constant radially along the axially convex arcuate top in the circumferential section, and an inclined top (44) with a height that gradually decreases radially outward from the radially outer end of the parallel top (43) with the height of the axially convex arcuate top in the circumferential section. The circumferentially orthogonal cross-sectional shape of the inclined top (44) is an R-shape that is smoothly connected to the parallel top (43).

17. The ball bearing according to any one of claims 13 to 15, characterized in that, The plurality of axial protrusions (42) are positioned at a position that overlaps with the pitch circle of the ball (5) or is radially outward from the pitch circle of the ball (5).

18. The ball bearing according to any one of claims 13 to 15, characterized in that, The axial protrusion (42) is formed on the sliding contact surface (41) on the sealing side. The sealing component (6) has an annular core (16) and a rubber material (17) vulcanized and bonded to the surface of the core (16). The axial protrusion (42) is formed of the rubber material (17).

19. The ball bearing according to any one of claims 13 to 15, characterized in that, A retainer guide surface (29) is formed on the inner periphery of the retainer annular portion (21) and is guided to slide in contact with the outer periphery of the inner ring (2).

20. The ball bearing according to claim 19, characterized in that, An inner diameter side axial groove (26) is provided on the inner circumference of the resin retainer (7). The inner diameter side axial groove (26) is formed to penetrate the radial inner surface (25) of the retainer claw (22) and the retainer guided surface (29) in the axial direction.

21. The ball bearing according to claim 19, characterized in that, The retainer annular portion (21) has a chamfered portion (47) that obliquely connects the retainer-side sliding contact surface (40) and the retainer guided surface (29) in a cross-section orthogonal to the circumferential direction.

22. The ball bearing according to any one of claims 13 to 15, characterized in that, The axial end of the annular space (4) opposite to the axial end blocked by the sealing member (6) is open without the sealing member (6) so that the annular space (4) can receive lubricant supplied from the outside.

23. The ball bearing according to any one of claims 13 to 15, characterized in that, The bearing is used in the electric motor (31) of an electric vehicle, or in the transmission (32) of an electric vehicle that reduces the rotation of the electric motor (31).

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