Rolling bearing and slinger member

Abstract

A rolling bearing with a bearing space (3) of which one side in the axial direction communicates with the outside of the bearing, the rolling bearing having: a slinger member (6) formed in an annular shape to cover an annular opening on the other side in the axial direction of the bearing space (3) while leaving an annular oil-passing gap (23) at a radially outer edge of the annular opening on the other side in the axial direction; and a plurality of protrusions (24) formed on an axially inner surface of the slinger member (6) at intervals in the circumferential direction such that an inter-protrusion gap (25) penetrating in the radial direction is formed between adjacent protrusions (24) in the circumferential direction.

Description

Rolling bearings and slinger components

[0001] The present invention relates to a rolling bearing and a slinger member used in the rolling bearing.

[0002] BACKGROUND ART Rolling bearings are often used as bearings for supporting rotating shafts in automobiles, industrial machines, and the like (for example, Patent Documents 1 and 2).

[0003] The rolling bearings in Patent Documents 1 and 2 have an outer ring, an inner ring disposed radially inward of the outer ring, a plurality of balls incorporated in an annular bearing space formed between the outer ring and the inner ring, and a cage that holds the plurality of balls. The cage has pockets formed in it to accommodate each ball.

[0004] The rolling bearings of Patent Documents 1 and 2 are used while lubricating the interior of the bearing with lubricating oil supplied from outside the bearing. For example, the rolling bearing of Patent Document 2 is used with an oil supply nozzle disposed adjacent to one axial side, and lubricating oil continuously supplied from the oil supply nozzle is introduced into the bearing space, allowing the bearing to rotate while lubricating the interior with the lubricating oil.

[0005] Incidentally, the rolling bearing as described above is, for example, calculated by the dmn value (ball pitch circle diameter dm (mm) × rotation speed n (min －１ When used in a high-speed rotation range where the RH (relative humidity) is 650,000 or more, the balls and cage rotate at high speed, causing the air in the bearing space between the outer and inner rings to move rapidly in the circumferential direction, creating an air curtain. This air curtain then prevents the flow of lubricating oil from outside the bearing into the bearing, resulting in a decrease in the amount of lubricating oil passing through the bearing, resulting in insufficient lubrication and cooling inside the bearing.

[0006] In particular, in recent years, in the field of electric vehicles such as EVs (battery electric vehicles) and HEVs (hybrid electric vehicles), the viscosity of lubricating oils used in the powertrains of electric vehicles has been reduced and the amount of oil used has been reduced in order to improve fuel economy and the output density of electric motors for driving, and the lubrication conditions for rolling bearings have become stricter.As a result, there is a problem that rolling bearings that support the rotating shaft of electric motors for driving, and rolling bearings that support the rotating shaft of reducers that slow down the rotation output from the electric motors, are prone to insufficient lubrication and cooling inside the bearings during high-speed rotation.

[0007] In response to the above problem, Patent Document 1 provides a retainer with an oil supply hole that penetrates the retainer and communicates with the pocket, and an oil capture protrusion that protrudes axially from the edge of the end opening on the opposite side of the oil supply hole that communicates with the pocket; the oil capture protrusion captures the lubricating oil supplied from outside the bearing and guides it to the oil supply hole, and the lubricating oil is introduced into the pocket of the retainer through the oil supply hole.

[0008] In response to the above problem, Patent Document 2 discloses a method in which an annular fixed plate is fixed to the outer ring to cover the annular opening on the other axial side of the bearing space between the outer ring and the inner ring (the side opposite to the side to which lubricating oil is supplied), and a suction pump is connected via a dedicated pipe to an oil suction hole formed in the fixed plate, and the lubricating oil inside the bearing is sucked up by the suction pump, thereby drawing the lubricating oil supplied from one axial side into the interior of the bearing.

[0009] JP 2022-164434 A JP 2022-163432 A

[0010] However, if an oil supply hole is formed that passes through the retainer in the axial direction, as in Patent Document 1, in order to ensure oil flow through the inside of the bearing during high-speed rotation, there are problems such as the strength of the retainer being reduced by the oil supply hole and the structure of the mold used to form the retainer being complicated, resulting in increased manufacturing costs.

[0011] Furthermore, as in Patent Document 2, if an annular fixed plate is provided to cover the annular opening of the bearing space between the outer ring and the inner ring, and a suction pump is connected via piping to an oil suction hole formed in the fixed plate, a suction pump and dedicated piping to connect the suction pump to the fixed plate are required, which poses a problem of increased overall costs.

[0012] The problem to be solved by the present invention is to provide a low-cost rolling bearing that can ensure oil permeability inside the bearing during high-speed rotation.

[0013] In order to solve the above problems, the present invention provides a rolling bearing having the following configuration: [Configuration 1] A rolling bearing comprising an outer ring, an inner ring arranged radially inside the outer ring, a plurality of rolling elements incorporated in an annular bearing space formed between the outer ring and the inner ring, and a cage for holding the plurality of rolling elements, wherein one axial side of the bearing space is connected to the outside of the bearing, the rolling bearing is characterized in that a slinger member is provided which is formed in an annular shape covering the annular opening on the other axial side of the bearing space, leaving an annular oil passage gap at the radial outer end of the opening, and which rotates integrally with the inner ring, and a plurality of convex portions are formed on the axially inner surface of the slinger member at intervals in the circumferential direction so that convex portion gaps are formed radially between circumferentially adjacent convex portions.

[0014] With this configuration, multiple convex portions are formed at circumferential intervals on the axially inner surface of the slinger member, and radially penetrating gaps are formed between adjacent convex portions. As the bearing rotates, the lubricating oil and air present in the convex portion gaps are displaced radially outward by the action of the centrifugal pump / centrifugal blower. The action of this centrifugal pump / centrifugal blower draws lubricating oil supplied from one axial side into the bearing and discharges it through the oil passage gap between the outer ring and the slinger member. This ensures oil permeability within the bearing even at high speeds. Furthermore, because there is no need to form an oil supply hole axially penetrating the cage or connect a suction pump via dedicated piping to ensure oil permeability, this configuration is low-cost.

[0015] [Configuration 2] The rolling bearing according to Configuration 1, wherein a front side surface of the protrusion in the slinger rotation direction is inclined radially outward and rearward in the slinger rotation direction.

[0016] With this configuration, the front side of the convex portion in the direction of slinger rotation is inclined radially outward toward the rear in the direction of slinger rotation, so that when the bearing rotates, the lubricating oil and air present in the gaps between the convex portions are pushed outward in the circumferential direction by the front side of the convex portion in the direction of slinger rotation, thereby enhancing the effect of moving the lubricating oil and air in the gaps between the convex portions radially outward.

[0017] [Configuration 3] The rolling bearing according to Configuration 2, wherein the front side surface of the protrusion in the slinger rotation direction is formed in a curved shape that protrudes radially outward when viewed from the axial direction.

[0018] When this configuration is adopted, the inclination angle of the front side of the convex portion in the slinger rotation direction increases as it moves radially outward, making it possible to efficiently move the lubricating oil and air present in the gaps between the convex portions radially outward.

[0019] [Configuration 4] The rolling bearing according to any one of Configurations 1 to 3, wherein the shape of the convex portion as viewed from the axial direction is a circumferentially symmetrical mountain shape whose circumferential width gradually decreases radially outward.

[0020] When this configuration is adopted, the shape of the convex portion when viewed from the axial direction is circumferentially symmetrical, so that whether the slinger rotation direction is to the right or to the left, it is possible to obtain a centrifugal pump action and a centrifugal blower action due to the inclination of the side surface of the convex portion in front of the slinger rotation direction.

[0021] [Configuration 5] The rolling bearing according to Configuration 2 or 3, wherein a rear side surface of the protrusion in the direction of rotation of the slinger is inclined radially outward and rearward in the direction of rotation of the slinger.

[0022] When this configuration is adopted, the rear side of the convex portion in the direction of slinger rotation is inclined to the same side as the front side of the convex portion in the direction of slinger rotation, so the flow path area of ​​the gap between the convex portions is large, and it is possible to increase the flow rate of lubricating oil that moves radially outward through the gap between the convex portions.

[0023] [Configuration 6] A rolling bearing according to any one of Configurations 1 to 5, wherein the slinger member has a slinger main body that protrudes radially outward from the outer periphery of the inner ring so as to face the bearing space, the slinger main body is formed from an annular metal plate, and the convex portion is a portion that is press-formed from the metal plate so that the side surface opposite the bearing space is recessed in the axial direction and the side surface on the bearing space side protrudes in the axial direction.

[0024] When this configuration is adopted, the protrusion of the slinger member is formed by press molding of a metal plate, which makes it possible to reduce the manufacturing cost of the slinger member.

[0025] [Configuration 7] The rolling bearing according to any one of Configurations 1 to 5, wherein the slinger member has a slinger main body portion that protrudes radially outward relative to the outer periphery of the inner ring, the slinger main body portion has an annular metal plate and a resin molded portion fixed to the metal plate, and the convex portion is a portion formed by resin molding of the resin molded portion.

[0026] With this configuration, the convex portion of the slinger member is formed by resin molding, which allows for a high degree of freedom in the shape of the convex portion, and therefore the front side of the convex portion in the slinger rotation direction can be shaped to perform centrifugal pumping and centrifugal blowing functions particularly efficiently.

[0027] [Configuration 8] The rolling bearing according to Configuration 7, wherein a plurality of through holes are formed in the metal plate at intervals in the circumferential direction, and the resin molded portion has a shape that passes through the metal plate and passes through the plurality of through holes.

[0028] By adopting this configuration, the resin molded portion has portions that fit into the multiple through holes in the metal plate, thereby increasing the fixing strength of the resin molded portion to the metal plate. This makes it possible to reliably prevent the resin molded portion from coming off the metal plate due to centrifugal force acting during high-speed rotation. Here, it is preferable that the multiple protrusions are provided at circumferential positions corresponding to the multiple through holes. This makes it possible to reliably support the centrifugal force acting on the protrusions of the resin molded portion during high-speed rotation by the portions of the resin molded portion that fit into the through holes in the metal plate.

[0029] [Configuration 9] The rolling bearing according to any one of Configurations 1 to 8, wherein an annular shield member is provided at a radially inner end of the annular opening on one axial side of the bearing space, covering the annular opening on the one axial side, leaving a second oil gap at the radially inner end of the annular opening.

[0030]

[0003] This configuration allows for particularly effective lubrication of the interior of the bearing. Specifically, when the bearing rotates, lubricating oil supplied from outside the bearing into the bearing space tends to move radially outward due to centrifugal force. Meanwhile, because the contact area between the rolling elements and the inner ring is located at the innermost radial position within the bearing space, the contact area between the rolling elements and the inner ring is less susceptible to lubrication from outside the bearing than other areas. Therefore, by using an annular shield member to cover the annular opening on one axial side of the bearing space, leaving a second oil passage gap at the radially inner end of the annular opening on one axial side, the lubricating oil supplied from one axial side can be drawn into the bearing space from a position close to the contact area between the rolling elements and the inner ring. This makes it easier for the lubricating oil to reach the contact area between the rolling elements and the inner ring, thereby enabling particularly effective lubrication of the interior of the bearing.

[0031] [Configuration 10] The rolling bearing according to Configuration 9, wherein an oil guide portion having a funnel-shaped inner peripheral surface whose diameter gradually decreases toward the other axial side is formed at a radially inner end of the shield member.

[0032] When this configuration is adopted, the inner surface of the oil guide portion of the shield member is formed into a funnel shape that gradually narrows in diameter toward the other axial side, which smooths the flow of lubricating oil drawn into the bearing space from outside the bearing through the second oil gap, making it easier for the lubricating oil to reach the contact area between the rolling element and the inner ring.

[0033] It is more preferable to add the following configuration to the above configurations 1 to 10. The cage has a plurality of cage post portions extending in the axial direction between the rolling elements adjacent in the circumferential direction, and a cage annular portion connecting axial end portions of the plurality of cage post portions, the cage annular portion being disposed on one axial side of the rolling elements, and the axial distance between the convex portions and the rolling elements being set to be smaller than the axial width of the cage annular portion. By adding this configuration, it is possible to set the axial height of the convex portions high while preventing the convex portions from interfering with the cage, and to enhance the action of the centrifugal pump / centrifugal blower by the convex portions.

[0034] [Configuration 11] A rolling bearing according to any one of configurations 1 to 10, wherein the retainer has a plurality of retainer column portions extending axially between circumferentially adjacent rolling elements, and a retainer annular portion connecting axial ends of the plurality of retainer column portions, and the retainer annular portion is arranged between the plurality of rolling elements and the slinger member so as to axially face the tip end surfaces of the convex portions of the slinger member.

[0035] When this configuration is adopted, the retainer annular portion is positioned to face the tip surface of the convex portion of the slinger member, so that the retainer annular portion functions as a cover that prevents lubricating oil and air in the gap between the convex portions from escaping in the axial direction, making it possible to effectively generate the action of a centrifugal pump / centrifugal blower.

[0036] The present invention also provides a slinger member for use in the above-mentioned rolling bearing, having the following configuration: [Configuration 12] An annular slinger member having a slinger main body, characterized in that a plurality of convex portions are formed on a side surface of the slinger main body at intervals in the circumferential direction so that radially penetrating inter-convex portion gaps are formed between circumferentially adjacent convex portions.

[0037] [Configuration 13] The slinger member according to Configuration 12, further comprising a washer portion formed in the shape of an annular plate extending radially inward from the slinger body portion.

[0038] By adopting this configuration, even in the case of a rolling bearing in which a slinger member is not provided inside the inner ring, the slinger member can be attached externally to the inner ring so that the washer portion of the slinger member contacts the axial end face of the inner ring of the rolling bearing, thereby ensuring oil permeability inside the bearing when the rolling bearing rotates at high speeds.

[0039] [Configuration 14] The slinger member according to Configuration 13, wherein a plurality of claw pieces bent and raised in the axial direction are formed at intervals in the circumferential direction on the inner periphery of the washer portion.

[0040] By adopting this configuration, the washer portion of the slinger member is pressed against the axial end face of the inner ring, compressing the claws on the inner circumference of the washer portion in the axial direction, and the frictional force generated between the claws and the axial end face of the inner ring makes it possible to prevent the slinger member from rotating relative to the inner ring.

[0041] [Configuration 15] The slinger member according to Configuration 14, wherein a plurality of positioning pieces are formed on the inner periphery of the washer portion between adjacent claw pieces in the circumferential direction, the positioning pieces protruding radially inward beyond the tips of the claw pieces.

[0042] When this configuration is adopted, the positioning piece is fitted onto the outer periphery of the rotating shaft inserted into the inner ring, and this fitting makes it possible to position the slinger member in the radial direction.

[0043] The slinger members according to the above configurations 12 to 15 can adopt the configurations of the slinger members according to the above configurations 1 to 13, respectively.

[0044] In this invention, a rolling bearing means one having an outer ring, an inner ring, rolling elements, and a slinger member, and the slinger member does not necessarily have to be arranged on the outer periphery of the inner ring; the concept also includes one in which the slinger member and inner ring are arranged side by side in the axial direction, for example, one in which the slinger member is arranged in contact with the axial end face of the inner ring.

[0045] In the rolling bearing of this invention, a plurality of convex portions are formed at circumferential intervals on the axially inner surface of the slinger member, and radially penetrating convex gaps are formed between adjacent convex portions. As a result, when the bearing rotates, the lubricating oil and air present in the convex gaps are displaced radially outward by the action of a centrifugal pump / centrifugal blower. The action of this centrifugal pump / centrifugal blower draws lubricating oil supplied from one axial side into the bearing and discharges it through the oil passage gap between the outer ring and the slinger member. This ensures oil permeability within the bearing even at high speeds. Furthermore, because there is no need to form an oil supply hole axially penetrating the cage or connect a suction pump via dedicated piping to ensure oil permeability, the bearing is low-cost.

[0046] 10A cross-sectional view of the slinger member of FIG. 6 taken out and viewed from the axial direction; sectional view taken along line VIII-VIII of FIG. 7A cross-sectional view taken along line IX-IX of FIG. 7A cross-sectional view of the slinger member of FIG. 6 taken out and viewed from the axial direction; sectional view taken along line VIII-VIII of FIG. 7A cross-sectional view taken along line IX-IX of FIG. 7A cross-sectional view of the slinger member of FIG. 10A cross-sectional view taken along line XII-XII of FIG. 10A cross-sectional view of a modified example of the convex portion of FIG. 12 in which the circumferential side surface is linear; sectional view of another modified example of the convex portion of FIG. 12A cross-sectional view of the slinger member used in the rolling bearing of the sixth embodiment of the invention taken from the axial direction; sectional view taken along line XVI-XVI of FIG. 15A

[0047] Figure 1 shows a rolling bearing according to a first embodiment of the present invention. This rolling bearing has an outer ring 1, an inner ring 2 arranged coaxially radially inward of the outer ring 1, a plurality of rolling elements 4 mounted at intervals in the circumferential direction in an annular bearing space 3 formed between the outer ring 1 and the inner ring 2, a cage 5 that maintains the circumferential spacing of the plurality of rolling elements 4, and a slinger member 6 that rotates integrally with the inner ring 2. The bearing bore diameter of this rolling bearing (i.e., the bore diameter of the inner ring 2) is set in the range of 30 mm to 45 mm.

[0048] This rolling bearing is used while its interior is lubricated with lubricating oil supplied from outside the bearing. That is, in this rolling bearing, one axial end of the bearing space 3 (the left side in the figure) is open to the outside of the bearing, and the other axial end of the bearing space 3 (the left side in the figure) is in communication with the outside of the bearing. Lubricating oil is continuously supplied from one axial end (the left side in the figure) into the bearing space 3, and the bearing rotates while lubricating the inside of the bearing with that lubricating oil. Note that the outside of the bearing refers to space other than the bearing space 3.

[0049] Lubricating oil can be supplied to the rolling bearings by a variety of methods, including splash lubrication, in which the rotation of a gear (not shown) causes the lubricating oil to splash up and splash droplets of the lubricating oil onto the bearings; jet lubrication, in which lubricating oil pressurized from an oil pump (not shown) is sprayed from an oil supply nozzle; air-oil lubrication, in which lubricating oil is mixed with compressed air and the compressed air (oil air) is supplied; and circulating lubrication, in which oil is constantly circulated using an oil pump (not shown).

[0050] The axial direction is the direction parallel to the central axis of the outer ring 1 (central axis of the bearing), the radial direction is the direction perpendicular to the central axis of the outer ring 1, and the circumferential direction is the direction along the circumference that goes around the central axis of the outer ring 1. Furthermore, one axial side is the lubricating oil supply side along the axial direction (left side in the figure), and the other axial side is the lubricating oil discharge side along the axial direction (right side in the figure).

[0051] The inner circumference of the outer ring 1 is formed with an outer ring raceway groove 7 with which the rolling elements 4 roll and make contact, and a pair of outer ring shoulder surfaces 8, 9 adjacent to one axial side and the other axial side of the outer ring raceway groove 7. The outer ring shoulder surfaces 8, 9 are cylindrical surfaces with a constant inner diameter along the axial direction. The cross-sectional shape of the outer ring 1 is symmetrical with respect to an imaginary axis-perpendicular plane passing through the axial center of the outer ring 1.

[0052] The outer periphery of the inner ring 2 is formed with an inner ring raceway groove 10 with which the rolling elements 4 roll, a pair of inner ring shoulder surfaces 11, 12 adjacent to one axial side and the other axial side of the inner ring raceway groove 10, an annular recess 13 adjacent to the inner ring shoulder surface 11 on one axial side (left side in the figure) of the pair of inner ring shoulder surfaces 11, 12, and a slinger fitting recess 14 adjacent to the inner ring shoulder surface 12 on the other axial side (right side in the figure) of the pair of inner ring shoulder surfaces 11, 12. The inner ring shoulder surfaces 11, 12 are cylindrical surfaces with a constant outer diameter along the axial direction.

[0053] The slinger fitting recess 14 is a recess with a cylindrical outer periphery whose outer diameter is smaller than that of the inner race shoulder surface 12. A tubular portion 22 (described later) of the slinger member 6 is fitted and fixed in the slinger fitting recess 14. One axial end (the left side in the figure) of the tubular portion 22 of the slinger member 6 engages with a step between the inner race shoulder surface 12 and the slinger fitting recess 14, and this engagement positions the slinger member 6 in the axial direction. The radial depth of the slinger fitting recess 14 relative to the inner race shoulder surface 12 corresponds to the radial thickness of the tubular portion 22 of the slinger member 6 (specifically, 0.5 to 1.5 times the radial thickness of the tubular portion 22 of the slinger member 6).

[0054] The annular recess 13 has the same shape as the slinger fitting recess 14, which makes the cross-sectional shape of the inner ring 2 symmetrical with respect to an imaginary axis-perpendicular plane passing through the axial center of the inner ring 2. The annular recess 13 is formed continuously from the inner ring raceway surface to an end face 16 on one axial side (left side in the figure) of the inner ring 2, and the slinger fitting recess 14 is also formed continuously from the inner ring raceway surface to an end face 17 on the other axial side (right side in the figure) of the inner ring 2. The end faces 16, 17 on both axial sides of the inner ring 2 are flat surfaces perpendicular to the axial direction.

[0055] Here, a slinger fitting recess 14 is formed on the outer periphery of the inner ring 2, and the slinger member 6 is fitted into this slinger fitting recess 14, but instead of forming a slinger fitting recess 14 on the outer periphery of the inner ring 2, the inner ring shoulder surface 12 may be formed continuously from the inner ring raceway groove 10 to the end face 17 on the other axial side of the inner ring 2 (the right side in the figure), and the slinger member 6 may be fitted into the outer periphery of this inner ring shoulder surface 12.

[0056] The rolling elements 4 are sandwiched radially between the outer ring raceway groove 7 and the inner ring raceway groove 10. In this embodiment, the rolling elements 4 are balls. The outer ring raceway groove 7 is an arc groove having a concave arc cross section that conforms to the surface of the rolling elements 4, and the inner ring raceway groove 10 is also an arc groove having a concave arc cross section that conforms to the surface of the rolling elements 4.

[0057] The cage 5 has a plurality of cage post portions 18 extending axially between circumferentially adjacent rolling elements 4, and a cage annular portion 19 connecting the ends of the plurality of cage post portions 18 on one axial side (left side in the figure). The cage annular portion 19 is disposed on one axial side relative to the rolling elements 4. The cage post portions 18 are formed in a cantilever shape with their ends on one axial side (left side in the figure) fixed to the cage annular portion 19 as a fixed end and their ends on the other axial side (right side in the figure) as a free end. Pockets 20 that accommodate the rolling elements 4 are formed between circumferentially adjacent cage post portions 18 with the rolling elements 4 sandwiched therebetween. The inner surfaces of the pockets 20 are concave spherical surfaces that conform to the surfaces of the rolling elements 4.

[0058] Each cage post portion 18 and the cage annular portion 19 are seamlessly formed from a resin composition containing a resin material and a fiber reinforcement added thereto. Examples of resin materials that make up the resin composition include polyamide resin (PA), polyether ether ketone resin (PEEK), and polyphenylene sulfide resin (PPS). Examples of polyamide resin (PA) that can be used include polyamide 46 (PA46), polyamide 66 (PA66), and polynonamethylene terephthalamide (PA9T). Examples of fiber reinforcement added to the resin material include glass fiber, carbon fiber, and aramid fiber. The fiber reinforcement is blended in at a ratio of 10 to 50 weight % of the resin composition that forms the cage 5.

[0059] The slinger member 6 has an annular slinger body 21 that protrudes radially outward from the outer periphery of the inner ring 2 so as to face the bearing space 3, and a tubular portion 22 that extends from the radially inner end of the slinger body 21 to one axial side (left side in the figure). The slinger body 21 covers the annular opening on the other axial side of the bearing space 3, leaving an annular oil gap 23 at the radially outer end of the annular opening on the other axial side (right side in the figure) of the bearing space 3. The oil gap 23 is formed in an annular shape that extends continuously around the entire circumference between the outer ring 1 and the slinger member 6.

[0060] A plurality of protrusions 24 are formed at intervals in the circumferential direction on the side surface on one axial side (the left side in the figure) of the slinger body 21, i.e., on the axially inner surface of the slinger body 21 (the surface facing the bearing space 3). The axially inner surface refers to the side closer to the rolling elements 4. As shown in Figure 2, a radially penetrating inter-protrusion gap 25 is formed between adjacent protrusions 24 in the circumferential direction.

[0061] As shown in Figure 2, when viewed from the axial direction, the convex portion 24 has a circumferentially symmetrical mountain shape whose circumferential width gradually decreases radially outward. Both side surfaces 26 on both circumferential sides of the convex portion 24 are inclined surfaces that are inclined in a direction in which the circumferential width of the convex portion 24 decreases radially outward. As a result, whether the slinger member 6 rotates clockwise or counterclockwise, the inclination of the side surface 26 on the front side of the convex portion 24 in the slinger rotation direction is inclined radially outward toward the rear side of the slinger rotation direction. The number of convex portions 24 is preferably three or more, and more preferably six or more.

[0062] As shown in Figure 1, the slinger body 21 is formed from an annular metal plate (such as a steel plate), and the tubular portion 22 is formed integrally with the slinger body 21. The protrusion 24 is formed by press-forming the metal plate so that the side of the slinger body 21 opposite the bearing space 3 (the right side in the figure) is recessed in the axial direction, and the side of the slinger body 21 facing the bearing space 3 (the left side in the figure) protrudes in the axial direction. The axial distance between the tip surface 27 of the protrusion 24 and the rolling elements 4 is smaller than the axial width of the bottom of the pocket 20 in the cage annular portion 19. The tip surface 27 of the protrusion 24 is formed into a flat surface perpendicular to the axial direction.

[0063] This rolling bearing can be used as a bearing for supporting the rotating shaft of an electric motor for driving electric vehicles such as EVs (battery electric vehicles) and HEVs (hybrid electric vehicles), or as a bearing for supporting the rotating shaft of a reducer that reduces the rotation output from the electric motor. Bearings used for such applications have a dmn value (ball pitch circle diameter dm (mm) × rotation speed n (min －１ )) is used in the high speed rotation range where the rpm is 650,000 or more, and in recent years, there has been a trend toward lower viscosity and less oil volume supplied to the bearings, which means that the lubrication conditions are very severe and there is a problem that the lubrication and cooling inside the bearings are likely to be insufficient.

[0064] To address this issue, the rolling bearing of the above embodiment has multiple convex portions 24 formed at circumferential intervals on the axially inner surface of the slinger member 6, as shown in FIGS. 1 and 2 . Radially penetrating convex portion gaps 25 (see FIG. 2 ) are formed between adjacent convex portions 24 in the circumferential direction. As a result, when the bearing rotates, the lubricating oil and air present in the convex portion gaps 25 move radially outward by the action of the centrifugal pump / centrifugal blower. As shown by the arrow in FIG. 3 , the action of the centrifugal pump / centrifugal blower draws lubricating oil supplied from one axial side (the left side in the drawing) into the bearing and discharges it through the oil passage gap 23 between the outer ring 1 and the slinger member 6. This ensures oil permeability within the bearing during high-speed rotation. Furthermore, because there is no need to form an oil supply hole axially penetrating the cage 5 or connect a suction pump via dedicated piping to ensure oil permeability, costs are low.

[0065] 2, in this rolling bearing, the front side surface 26 of the convex portion 24 in the slinger rotation direction is inclined radially outward and rearward in the slinger rotation direction, so that when the bearing rotates, the lubricating oil and air present in the gaps 25 between the convex portions are pushed outward in the circumferential direction by the front side surface 26 of the convex portion 24 in the slinger rotation direction. This makes it possible to enhance the effect of moving the lubricating oil and air in the gaps 25 radially outward.

[0066] Furthermore, as shown in Figure 2, the shape of the protrusion 24 when viewed from the axial direction of this rolling bearing is circumferentially symmetrical, so that whether the slinger rotates to the right or left, it is possible to obtain a pumping action and a blower action due to the inclination of the side surface 26 of the protrusion 24 on the front side in the slinger rotation direction.

[0067] Furthermore, as shown in FIG. 1, in this rolling bearing, the protrusion 24 of the slinger member 6 is formed by press molding of a metal plate, so that the manufacturing cost of the slinger member 6 can be kept low.

[0068] Furthermore, as shown in Figure 3, in this rolling bearing, the retainer annular portion 19 is positioned on one axial side (the left side in the figure) of the rolling elements 4, i.e., on the opposite side from the slinger member 6, and the axial distance between the tip surface 27 of the convex portion 24 and the rolling elements 4 is set to be smaller than the axial width of the retainer annular portion 19.This makes it possible to set the axial height of the convex portion 24 high while avoiding interference of the convex portion 24 with the retainer 5, and to enhance the effect of the centrifugal pump / centrifugal blower by the convex portion 24.

[0069] 4 shows a second embodiment of the present invention. The second embodiment differs from the first embodiment only in that the arrangement of the cage annular portion 19 of the cage 5 is changed and a shield member 30 is added, but the other configurations are basically the same. Therefore, parts corresponding to those in the first embodiment are given the same reference numerals and descriptions thereof will be omitted.

[0070] A shield member 30 is provided in the annular opening on one axial side (left side in the figure) of the bearing space 3. The shield member 30 is formed in an annular shape that covers the annular opening on one axial side of the bearing space 3, leaving a second oil passage gap 31 at the radially inner end of the annular opening on one axial side (left side in the figure) of the bearing space 3. The end of the bearing space 3 on one axial side (left side in the figure) communicates with the outside of the bearing via the second oil passage gap 31. The second oil passage gap 31 is an annular gap that extends continuously around the entire circumference between the shield member 30 and the inner ring 2. The radially outer end of the shield member 30 is fitted into and fixed in a shield groove 32 formed in the inner circumference of the outer ring 1 at one axial end.

[0071] An oil guide portion 33 having a funnel-shaped inner peripheral surface whose diameter gradually decreases toward the other axial side (the right side in the drawing) is formed at the radially inner end of the shield member 30. In the drawing, the oil guide portion 33 having a funnel-shaped inner peripheral surface is shown as having a linear cross section whose inner diameter gradually decreases toward the other axial side (the right side in the drawing), but it is also possible to use an oil guide portion having an arc-shaped cross section whose inner diameter gradually decreases toward the other axial side (the right side in the drawing).

[0072] The cage annular portion 19 is disposed on the other axial side (right side in the figure) of the rolling elements 4. The cage post portions 18 are formed in a cantilever shape with their ends on the other axial side (right side in the figure) fixed to the cage annular portion 19 as a fixed end and their ends on one axial side (left side in the figure) as a free end. The cage annular portion 19 is disposed between the rolling elements 4 and the slinger member 6 so as to axially face the tip surfaces 27 of the protrusions 24 of the slinger member 6. The surface of the cage annular portion 19 facing the tip surfaces 27 of the protrusions 24 is formed as a flat surface perpendicular to the axial direction. The axial distance between the tip surfaces 27 of the protrusions 24 of the slinger member 6 and the cage annular portion 19 can be set to 0.5 mm or less.

[0073] The rolling bearing of this embodiment is provided with an annular shield member 30 that covers the annular opening on one axial side (the left side in the figure) of the bearing space 3, leaving the second oil passage gap 31 at the radially inner end, and therefore it is possible to lubricate the interior of the bearing particularly effectively. That is, when the bearing rotates, lubricating oil supplied to the bearing space 3 from outside the bearing tends to move radially outward due to the action of centrifugal force, but on the other hand, the contact area between the rolling elements 4 and the inner ring 2 is located at the radially innermost part of the bearing space 3, and therefore the contact area between the rolling elements 4 and the inner ring 2 is less likely to be reached by lubricating oil supplied from outside the bearing than other parts. 4, if an annular shield member 30 is used to cover the annular opening on one axial side of the bearing space 3 (the left side in the figure), leaving a second oil passage gap 31 at the radially inner end, then, as shown by the arrow in the figure, when lubricating oil supplied from one axial side is drawn into the bearing space 3, it can be drawn in from a position close to the contact area between the rolling elements 4 and the inner ring 2. This makes it easier for the lubricating oil to reach the contact area between the rolling elements 4 and the inner ring 2, making it possible to particularly effectively lubricate the inside of the bearing. Furthermore, providing the shield member 30 can also prevent the lubricating oil from colliding with the rolling elements 4 and the cage 5, thereby preventing excessive stirring resistance from occurring.

[0074] Furthermore, this rolling bearing has an oil guide portion 33 at the radially inner end of the shield member 30, which has a funnel-shaped inner surface that gradually narrows in diameter towards the other axial side (the right side in the figure).This ensures a smooth flow of lubricating oil drawn into the bearing space 3 from outside the bearing through the second oil passage gap 31, making it easy for the lubricating oil to reach the contact area between the rolling element 4 and the inner ring 2.

[0075] Furthermore, in this rolling bearing, the retainer annular portion 19 is disposed so as to face the tip end surface 27 of the convex portion 24 of the slinger member 6, so that the retainer annular portion 19 functions as a cover that prevents the lubricating oil and air in the gap 25 between the convex portions (see FIG. 2) from escaping in the axial direction, making it possible to effectively generate the action of a centrifugal pump and centrifugal blower. In addition, the same effects as those of the first embodiment are achieved.

[0076] 5 shows a third embodiment of the present invention. The third embodiment differs from the second embodiment only in that the configuration of the cage 5 is changed and that the shield member 30 is attached to the outer ring 1 externally rather than inside the outer ring 1, but otherwise the configuration is basically the same. Therefore, parts corresponding to those in the second embodiment are given the same reference numerals and descriptions thereof will be omitted.

[0077] The cage 5 is a corrugated cage formed by joining a first annular member 34 provided on one axial side (left side in the figure) of the rolling elements 4 and a second annular member 35 provided on the other axial side (right side in the figure) of the rolling elements 4 with rivets (not shown). The first annular member 34 is an annular member in which arc-shaped pocket wall portions 36 along the outer periphery of the rolling elements 4 and flat plate portions (not shown) perpendicular to the axial direction are formed alternately in the circumferential direction. The second annular member 35 has the same configuration as the first annular member 34. The first annular member 34 and the second annular member 35 are formed by press-forming steel plate.

[0078] The shield member 30 is formed in an annular shape that covers the annular opening on one axial side of the bearing space 3, leaving a second oil passage gap 31 at the radially inner end of the annular opening on one axial side (left side in the figure) of the bearing space 3. The shield member 30 has a shield main body portion 37 that protrudes radially inward relative to the inner periphery of the outer ring 1 so as to face the bearing space 3, and an annular plate-shaped shield outer edge portion 38 that extends radially outward from the shield main body portion 37. The side surface of the shield outer edge portion 38 contacts the end face of the outer ring 1 on one axial side (left side in the figure). The outer periphery of the shield outer edge portion 38 is fitted into the inner periphery of a housing 39 that accommodates the outer ring 1. This fit positions the shield member 30 radially relative to the outer ring 1. An oil guide portion 33 is formed at the radially inner end of the shield main body portion 37. The rolling bearing of this embodiment achieves the same effects as the second embodiment.

[0079] 6 to 9 show a fourth embodiment of the present invention. The fourth embodiment is different from the first embodiment only in the configuration of the slinger member 6, and the other configurations are basically the same. Therefore, parts corresponding to those in the first embodiment are given the same reference numerals, and descriptions thereof will be omitted.

[0080] As shown in Figure 6, the slinger member 6 has a slinger main body portion 21 that protrudes radially outward from the outer periphery of the inner ring 2 so as to face the bearing space 3, and a washer portion 40 formed in the shape of an annular plate that extends radially inward from the slinger main body portion 21.

[0081] As shown in FIG. 7 , the slinger body 21 is formed with a plurality of protrusions 24 spaced apart in the circumferential direction. A radially extending inter-protrusion gap 25 is formed between adjacent protrusions 24 in the circumferential direction. When viewed from the axial direction, the protrusions 24 have a circumferentially symmetrical mountain shape whose circumferential width gradually decreases radially outward. Each of the side surfaces 26 on both circumferential sides of the protrusion 24 is an inclined surface that slopes in a direction in which the circumferential width of the protrusion 24 decreases radially outward. As a result, whether the slinger member 6 rotates clockwise or counterclockwise, the inclination direction of the front side surface 26 of the protrusion 24 in the slinger rotation direction is inclined radially outward toward the rear of the slinger rotation direction. When viewed from the axial direction, the front side surface 26 of the protrusion 24 in the slinger rotation direction is curved and convex radially outward, so that the angle of inclination with respect to the radial direction gradually increases radially outward.

[0082] 7 and 9, a plurality of claws 41 bent in the axial direction are formed at intervals in the circumferential direction on the inner periphery of the washer portion 40. The washer portion 40 is pressed in the axial direction against the end face 17 on the other axial side (the right side in the drawing) of the inner ring 2 shown in Fig. 6, and this pressing force compresses the claws 41 shown in Fig. 9 in the axial direction, and the frictional force generated between the claws 41 and the axial end face 17 of the inner ring 2 prevents the slinger member 6 from rotating relative to the inner ring 2.

[0083] 7, a plurality of positioning pieces 42 that protrude radially inward beyond the tips of the claw pieces 41 are formed between adjacent claw pieces 41 on the inner periphery of the washer portion 40. As shown in FIG. 6, the positioning pieces 42 are fitted onto the outer periphery of a rotating shaft 43 that is inserted into the inner ring 2, and this fitting positions the slinger member 6 in the radial direction.

[0084] As shown in Figure 7, in the rolling bearing of this embodiment, the convex portion 24 is configured so that the inclination angle of the front side surface 26 of the convex portion 24 in the slinger rotation direction increases as it moves radially outward, making it possible to efficiently move the lubricating oil and air present in the gaps 25 between the convex portions radially outward.

[0085] 6, the rolling bearing of this embodiment uses a slinger member 6 having a washer portion 40 that contacts the axial end face 17 of the inner ring 2, so even in a rolling bearing that does not have a slinger member 6 provided on the outer periphery of the inner ring 2, by attaching the slinger member 6 to the outside of the inner ring 2, it is possible to ensure oil permeability inside the bearing when the rolling bearing rotates at high speed. In addition, the same effects as those of the first embodiment are achieved.

[0086] 10 to 12 show a fifth embodiment of the present invention. The fifth embodiment is different from the first embodiment only in the configuration of the slinger member 6, and the other configurations are basically the same. Therefore, parts corresponding to those in the first embodiment are given the same reference numerals, and descriptions thereof will be omitted.

[0087] 11 , the slinger member 6 has a slinger main body 21 that protrudes radially outward from the outer periphery of the inner ring 2 so as to face the bearing space 3, and a tubular portion 22 that is fitted onto and fixed to the outer periphery of the inner ring 2. The slinger main body 21 has an annular metal plate 44 and a resin molded portion 45 that is fixed to the metal plate 44. The protruding portion 24 is formed by resin molding the resin molded portion 45.

[0088] The resin molded portion 45 is fixed to the metal plate 44 by insert molding of resin. That is, the metal plate 44 is set inside a mold for molding the resin molded portion 45, and the mold is closed to injection mold the resin molded portion 45, thereby fixing the resin molded portion 45 to the surface of the metal plate 44. As the resin material for forming the resin molded portion 45, a resin composition similar to the resin composition for forming the cage 5 of the first embodiment can be used.

[0089] A plurality of through holes 46 are formed in the metal plate 44 at intervals in the circumferential direction, and the resin molded portion 45 has a shape that penetrates the metal plate 44 through these through holes 46. The resin molded portion 45 has an annular inner surface annular portion 47 fixed to a side surface on one axial side (left side in the figure) of the metal plate 44, an annular outer surface annular portion 48 fixed to a side surface on the other axial side (right side in the figure) of the metal plate 44, and a connecting portion 49 that passes through the through holes 46 of the metal plate 44 and connects the inner surface side annular portion 47 and the outer surface side annular portion 48. The protrusion 24 is formed integrally with the inner surface side annular portion 47.

[0090] As shown in FIG. 12 , each protrusion 24 is provided at a circumferential position corresponding to the plurality of through holes 46. When viewed from the axial direction, the protrusion 24 has a circumferentially symmetrical mountain shape whose circumferential width gradually decreases radially outward. Here, the side surfaces 26 on both circumferential sides of the protrusion 24 are inclined in a direction in which the circumferential width of the protrusion 24 decreases radially outward. As a result, whether the slinger member 6 rotates clockwise or counterclockwise, the inclination direction of the front side surface 26 of the protrusion 24 in the slinger rotation direction is inclined radially outward toward the rear of the slinger rotation direction. When viewed from the axial direction, the front side surface 26 of the protrusion 24 in the slinger rotation direction is formed in a curved shape that convexly extends radially outward, so that the inclination angle with respect to the radial direction gradually increases radially outward. The cross-sectional shape of the protrusion 24 perpendicular to the axial direction is formed in a uniform columnar shape along the axial direction.

[0091] As shown in Figure 11, in the rolling bearing of this embodiment, the convex portion 24 of the slinger member 6 is formed by resin molding, which allows for a high degree of freedom in the shape of the convex portion 24. Therefore, as shown in Figure 12, the front side surface 26 of the convex portion 24 in the slinger rotation direction can be shaped to provide a pumping action and a blowing action particularly efficiently.

[0092] 11, in this rolling bearing, the resin molded portion 45 has portions (connecting portions 49) that fit into the multiple through holes 46 of the metal plate 44, so that the resin molded portion 45 is highly firmly fixed to the metal plate 44. This makes it possible to reliably prevent the resin molded portion 45 from coming off the metal plate 44 due to centrifugal force acting during high-speed rotation.

[0093] 12, in this rolling bearing, the convex portions 24 of the resin molded portion 45 are arranged at circumferential positions of the through holes 46 of the metal plate 44, so that the centrifugal force that the convex portions 24 of the resin molded portion 45 receive during high-speed rotation can be reliably supported by the portions of the resin molded portion 45 that fit into the through holes 46 of the metal plate 44. In addition, the same effects as those of the first embodiment are achieved.

[0094] In this embodiment, as shown in Fig. 12, the front side surface 26 of the protrusion 24 in the slinger rotation direction is formed in a curved shape that convexes radially outward when viewed from the axial direction, but as shown in Fig. 13, the front side surface 26 of the protrusion 24 in the slinger rotation direction may also be formed in a straight line when viewed from the axial direction. In Fig. 13, the shape of the protrusion 24 when viewed from the axial direction is a circumferentially symmetrical mountain shape whose circumferential width gradually decreases radially outward. Furthermore, both side surfaces 26 on both circumferential sides of the protrusion 24 are inclined surfaces that are inclined in a direction in which the circumferential width of the protrusion 24 decreases radially outward.

[0095] It is also possible to employ protrusions 24 having a shape as shown in Fig. 14. In this case as well, gaps 25 are formed between circumferentially adjacent protrusions 24, penetrating in the radial direction, and therefore, when the bearing rotates, the lubricating oil and air present in the gaps 25 can be moved radially outward by the action of a centrifugal pump or centrifugal blower.

[0096] Figures 15 and 16 show a sixth embodiment of the present invention. In the sixth embodiment, the shape of the convex portion 24 of the slinger member 6 is asymmetric in the circumferential direction, as compared with the fifth embodiment. That is, in the above-described embodiments, the shape of the convex portion 24 is symmetrical in the circumferential direction so that the inclination of the side surface 26 of the convex portion 24 on the front side in the slinger rotation direction can provide centrifugal pumping and centrifugal blowing effects regardless of whether the slinger rotation direction is clockwise or counterclockwise. However, in this embodiment, when the slinger rotation direction is predetermined, the shape of the convex portion 24 is asymmetric in the circumferential direction, as shown in Figure 15, thereby further improving the efficiency of the centrifugal pumping and centrifugal blowing effects. Parts corresponding to those in the fifth embodiment are designated by the same reference numerals, and their description will be omitted.

[0097] The side surface 26 of the protrusion 24 on the front side in the slinger rotation direction (left side in the drawing) is inclined radially outward toward the rear side in the slinger rotation direction (right direction in the drawing). In addition, the side surface 50 of the protrusion 24 on the rear side in the slinger rotation direction (right side in the drawing) is also inclined radially outward toward the rear side in the slinger rotation direction (right direction in the drawing).

[0098] In the rolling bearing of this embodiment, the rear side surface 50 of the convex portion 24 in the slinger rotation direction is inclined to the same side as the front side surface 26 of the convex portion 24 in the slinger rotation direction, so the flow path area of ​​the convex portion gap 25 is large, making it possible to increase the flow rate of lubricating oil that moves radially outward through the convex portion gap 25. In addition, the same effects as those of the fifth embodiment are achieved.

[0099] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims.

[0100] REFERENCE SIGNS LIST 1 outer ring 2 inner ring 3 bearing space 4 rolling element 5 cage 6 slinger member 18 cage post portion 19 cage annular portion 21 slinger main body portion 23 oil passage gap 24 convex portion 25 gap between convex portions 26 side surface 27 tip surface 30 shield member 31 second oil passage gap 33 oil guide portion 40 washer portion 41 hook piece 42 positioning piece 44 metal plate 45 resin molded portion 46 through hole 50 side surface

Claims

1. A rolling bearing comprising: an outer ring (1); an inner ring (2) arranged radially inward of the outer ring (1); a plurality of rolling elements (4) incorporated in an annular bearing space (3) formed between the outer ring (1) and the inner ring (2); and a cage (5) for holding the plurality of rolling elements (4), wherein one axial side of the bearing space (3) is connected to the outside of the bearing; a slinger member (6) formed in an annular shape that covers the annular opening on the other axial side of the bearing space (3), leaving an annular oil passage gap (23) at the radial outer end of the annular opening on the other axial side, and rotating integrally with the inner ring (2); and a plurality of convex portions (24) formed at circumferential intervals on the axial inner surface of the slinger member (6) so that convex portion gaps (25) that penetrate radially are formed between circumferentially adjacent convex portions (24).

2. A rolling bearing according to claim 1, wherein the front side surface (26) of the protrusion (24) in the direction of rotation of the slinger is inclined radially outward and rearward in the direction of rotation of the slinger.

3. A rolling bearing according to claim 2, wherein the front side surface (26) of the convex portion (24) in the slinger rotation direction is formed in a curved shape that convexly extends radially outward when viewed from the axial direction.

4. A rolling bearing according to any one of claims 1 to 3, wherein the shape of the convex portion (24) when viewed from the axial direction is a circumferentially symmetrical mountain shape whose circumferential width gradually decreases toward the radially outer side.

5. A rolling bearing according to claim 2 or 3, wherein the rear side surface (50) of the convex portion (24) in the direction of rotation of the slinger is inclined radially outward and rearward in the direction of rotation of the slinger.

6. A rolling bearing as claimed in any one of claims 1 to 5, wherein the slinger member (6) has a slinger main body (21) that protrudes radially outward relative to the outer periphery of the inner ring (2), the slinger main body (21) is formed from an annular metal plate, and the convex portion (24) is a portion formed by pressing the metal plate so that the side surface opposite the bearing space (3) is recessed in the axial direction and the side surface on the bearing space (3) side protrudes in the axial direction.

7. A rolling bearing as described in any one of claims 1 to 5, wherein the slinger member (6) has a slinger main body (21) that protrudes radially outward relative to the outer periphery of the inner ring (2), the slinger main body (21) has an annular metal plate (44) and a resin molded portion (45) fixed to the metal plate (44), and the convex portion (24) is a portion formed by resin molding of the resin molded portion (45).

8. A rolling bearing as set forth in claim 7, wherein a plurality of through holes (46) are formed in the metal plate (44) at intervals in the circumferential direction, and the resin molded portion (45) has a shape that passes through the metal plate (44) through the plurality of through holes (46).

9. A rolling bearing as described in any one of claims 1 to 8, in which an annular shield member (30) is provided at the radial inner end of the annular opening on one axial side of the bearing space (3), covering the annular opening on one axial side, leaving a second oil passage gap (31).

10. A rolling bearing as described in claim 9, wherein an oil guide portion (33) having a funnel-shaped inner peripheral surface whose diameter gradually decreases toward the other axial side is formed at the radially inner end of the shield member (30).

11. A rolling bearing as described in any one of claims 1 to 10, wherein the retainer (5) has a plurality of retainer column portions (18) extending axially between the rolling elements (4) adjacent in the circumferential direction, and a retainer annular portion (19) connecting the axial ends of the plurality of retainer column portions (18), and the retainer annular portion (19) is arranged between the plurality of rolling elements (4) and the slinger member (6) so as to axially face the tip surface (27) of the convex portion (24) of the slinger member (6).

12. A slinger member (6) having an annular slinger body (21), characterized in that a plurality of convex portions (24) are formed on the side surface of the slinger body (21) at intervals in the circumferential direction so that radially penetrating inter-convex portion gaps (25) are formed between adjacent convex portions (24) in the circumferential direction.

13. A slinger member (6) according to claim 12, further comprising a washer portion (40) formed in the shape of an annular plate extending radially inward from the slinger body portion (21).

14. A slinger member (6) as described in claim 13, wherein a plurality of claw pieces (41) bent in the axial direction are formed at intervals in the circumferential direction on the inner circumference of the washer portion (40).

15. A slinger member (6) as described in claim 14, in which a plurality of positioning pieces (42) protruding radially inward beyond the tips of the claw pieces (41) are formed on the inner circumference of the washer portion (40) between adjacent claw pieces (41) in the circumferential direction.

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