Rolling bearing with seal

Abstract

To provide a rolling bearing with a seal capable of preventing lubricant inside a bearing from becoming insufficient during high-speed rotation, and reducing agitation resistance of lubricant inside the bearing.SOLUTION: One of a pair of sealing members 7, 8 is an outer ring fixed sealing member 7 fixed to an inner periphery of an outer ring 2, and the other is an inner ring fixed sealing member 8 fixed to an outer periphery of an inner ring 3. Between the inner periphery of the outer ring fixed sealing member 7 and the outer periphery of the inner ring 3, an oil supply gap 23 is formed to introduce lubricant supplied from the outside of a bearing into a bearing space 4. Between the outer periphery of the inner ring fixed sealing member 8 and the inner periphery of the outer ring 2, an oil drain gap 29 is formed to discharge lubricant from the bearing space 4.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This invention relates to a sealed rolling bearing.

Background Art

[0002] As a bearing for supporting a rotating shaft of an automobile or an industrial machine, etc., a sealed rolling bearing is often used (for example, Patent Documents 1 and 2). The sealed rolling bearings of Patent Documents 1 and 2 include an outer ring, an inner ring disposed radially inward of 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 pair of seal members that respectively cover one end opening in the axial direction and the other end opening in the axial direction of the bearing space.

[0003] In the sealed rolling bearing of Patent Document 1, the pair of seal members are both outer ring fixed seal members fixed to the inner circumference of the outer ring, and a labyrinth gap is formed between the inner circumference of the outer ring fixed seal member and the outer circumference of the inner ring. This sealed rolling bearing lubricates the inside of the bearing by introducing lubricating oil supplied from the outside of the bearing into the bearing space through the labyrinth gap between the inner circumference of the outer ring fixed seal member and the outer circumference of the inner ring.

[0004] On the other hand, in the sealed rolling bearing of Patent Document 2, the pair of seal members are both inner ring fixed seal members fixed to the outer circumference of the inner ring, and a radial gap is formed between the outer circumference of the inner ring fixed seal member and the inner circumference of the outer ring. In this sealed rolling bearing, since the pair of seal members are inner ring fixed seal members that rotate integrally with the inner ring, the lubricating oil inside the bearing moves radially outward by centrifugal force and is discharged to the outside of the bearing through the radial gap between the outer circumference of the inner ring fixed seal member and the inner circumference of the outer ring. Therefore, it is difficult for the lubricating oil to stay inside the bearing, and the stirring resistance of the lubricating oil inside the bearing can be suppressed to a small value.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] By the way, in recent years, in the field of electric vehicles such as EVs (battery electric vehicles) and HEVs (hybrid electric vehicles), in order to reduce the size and weight of electric motors, the high-speed rotation of electric motors has been promoted.

[0007] When the sealed rolling bearing of Patent Document 1 is used for such high-speed rotation applications, the lubricating oil introduced from the labyrinth clearance between the inner circumference of the outer ring fixed seal member and the outer circumference of the inner ring tends to stay inside the bearing, and due to the stirring resistance of the lubricating oil staying inside the bearing, there is a problem that the rotational resistance of the bearing increases.

[0008] Therefore, in order to reduce the stirring resistance of the lubricating oil inside the bearing, it may be considered to use the sealed rolling bearing of Patent Document 2. However, when the sealed rolling bearing of Patent Document 2 is used for high-speed rotation applications, the lubricating oil inside the bearing is discharged to the outside of the bearing from the radial clearance between the outer circumference of the inner ring fixed seal member and the inner circumference of the outer ring by centrifugal force, so that the lubricating oil inside the bearing becomes insufficient, and there is a risk of abnormal heat generation, peeling damage, seizure, etc.

[0009] The problem to be solved by this invention is to provide a sealed rolling bearing in which the lubricating oil inside the bearing is less likely to be insufficient during high-speed rotation, and moreover, the stirring resistance of the lubricating oil inside the bearing can be suppressed to be small. [Means for Solving the Problems]

[0010] In order to solve the above problems, this invention provides a sealed rolling bearing having the following configuration. [Configuration 1] An outer ring, An inner ring disposed radially inward of the outer ring, A plurality of rolling elements incorporated in an annular bearing space formed between the outer ring and the inner ring, In a rolling bearing with seals having a pair of seal members that respectively cover one axial end opening and the other axial end opening of the bearing space, One of the pair of seal members is an outer ring fixed seal member fixed to the inner circumference of the outer ring, and the other is an inner ring fixed seal member fixed to the outer circumference of the inner ring, An oil discharge gap for discharging lubricating oil from the bearing space is formed between the outer circumference of the inner ring fixed seal member and the inner circumference of the outer ring, A rolling bearing with seals, characterized in that an oil supply gap for introducing lubricating oil supplied from outside the bearing into the bearing space is formed between the inner circumference of the outer ring fixed seal member and the outer circumference of the inner ring.

[0011] When this configuration is adopted, since the inner ring fixed seal member rotates integrally with the inner ring, the lubricating oil inside the bearing moves radially outward by centrifugal force and is discharged to the outside of the bearing through the oil discharge gap between the outer circumference of the inner ring fixed seal member and the inner circumference of the outer ring. Therefore, it is difficult for the lubricating oil to stay inside the bearing, and it is possible to significantly suppress the stirring resistance of the lubricating oil inside the bearing.

[0012] Also, since the outer ring fixed seal member does not rotate even when the inner ring rotates, as the lubricating oil inside the bearing is discharged from the oil discharge gap by centrifugal force, the lubricating oil supplied from outside the bearing can be drawn into the bearing through the oil supply gap between the inner circumference of the outer ring fixed seal member and the outer circumference of the inner ring. Therefore, it is difficult for the lubricating oil inside the bearing to be insufficient during high-speed rotation, and the inside of the bearing can be stably lubricated.

[0013] Furthermore, the lubricating oil inside the bearing is discharged to the outside of the bearing through the oil drainage gap between the outer circumference of the inner ring fixing seal member and the inner circumference of the outer ring, and the lubricating oil supplied from the outside of the bearing is drawn into the bearing through the oil supply gap between the inner circumference of the outer ring fixing seal member and the outer circumference of the inner ring. Since these two actions occur simultaneously, the lubricating oil inside the bearing is constantly replaced, and heat exchange inside the bearing is smooth. Therefore, it is possible to effectively suppress the temperature rise during high-speed rotation.

[0014] [Configuration 2] The outer ring fixing seal member has a rubber seal lip provided with a plurality of convex portions that are slidably in contact with the outer circumference of the inner ring with an oil film therebetween, and are provided at intervals in the circumferential direction. The oil supply gap is the gap formed between the adjacent convex portions in the circumferential direction. The sealed rolling bearing according to Configuration 1.

[0015] When this configuration is adopted, since the oil supply gap is the gap formed between the convex portions adjacent to each other in the circumferential direction of the seal lip, by adjusting the height of the convex portion of the seal lip, the gap dimension of the oil supply gap can be accurately controlled. Therefore, the gap dimension of the oil supply gap can be set small, and it is possible to effectively prevent foreign matter from entering the bearing from the outside of the bearing through the oil supply gap.

[0016] [Configuration 3] On the outer circumference of the inner ring, a cylindrical seal sliding contact surface is formed that extends axially from the portion where the seal lip is slidably in contact and connects to the axial end surface of the inner ring. The sealed rolling bearing according to Configuration 2.

[0017] When this configuration is adopted, since the seal sliding contact surface on the outer circumference of the inner ring is cylindrical and extends axially from the portion where the seal lip is slidably in contact and connects to the axial end surface of the inner ring, compared with the case where the seal lip is slidably in contact with the inner surface of the concave groove, the oil supply gap between the seal lip and the inner ring is in a state of being largely exposed to the outside of the bearing. Therefore, it is possible to smoothly introduce the lubricating oil supplied from the outside of the bearing into the oil supply gap.

[0018] [Configuration 4] On the outer periphery of the inner ring, a cylindrical seal fixing surface is formed into which the radially inner end of the inner ring fixing seal member is fitted and fixed. The seal-attached rolling bearing according to Configuration 3 in which the shape of the inner ring is symmetric with respect to a plane perpendicular to the axis by making the seal fixing surface and the seal sliding contact surface symmetric with the same outer diameter.

[0019] When this configuration is adopted, when manufacturing the inner ring, the seal fixing surface and the seal sliding contact surface can be processed in the same process, so the cost is low. Also, when assembling the rolling bearing, it is not necessary to distinguish the front and back directions of the inner ring, so the workability is excellent.

[0020] [Configuration 5] The seal-attached rolling bearing according to any one of Configurations 1 to 4, wherein a metal shield plate that is non-contact with the inner periphery of the outer ring is used as the inner ring fixing seal member.

[0021] When this configuration is adopted, since the inner ring fixing seal member is non-contact with the inner periphery of the outer ring, it is possible to greatly suppress the rotational resistance of the bearing.

[0022] [Configuration 6] The seal-attached rolling bearing according to any one of Configurations 1 to 5, wherein the inner ring fixing seal member has a fitting cylinder portion that fits onto the outer periphery of the inner ring, an annular plate portion that rises radially outward from the fitting cylinder portion, and a flange bending portion that is bent axially inward at the radially outer end of the annular plate portion.

[0023] When this configuration is adopted, since the inner ring fixing seal member has a flange bending portion formed by bending axially inward at the radially outer end of the annular plate portion, when the lubricating oil drawn into the bearing from the oil supply gap between the inner periphery of the outer ring fixing seal member and the outer periphery of the inner ring moves radially outward by centrifugal force, a part of the lubricating oil can be received by the flange bending portion of the inner ring fixing seal member before reaching the oil drain gap between the outer periphery of the inner ring fixing seal member and the inner periphery of the outer ring and retained inside the bearing. Therefore, it is possible to prevent the lubricating oil drawn into the bearing from the oil supply gap from being excessively discharged from the oil drain gap.

[0024] [Configuration 7] A circumferential groove extending in the circumferential direction is formed on the inner circumference of the outer ring at a position corresponding to the inner ring fixing seal member. The sealed rolling bearing according to Configuration 6, wherein at least a part of the edge bending portion of the inner ring fixing seal member is accommodated in the circumferential groove.

[0025] When this configuration is adopted, since at least a part of the edge bending portion of the inner ring fixing seal member is accommodated in the circumferential groove formed on the inner circumference of the outer ring, the lubricating oil inside the bearing that moves along the inner circumference of the outer ring toward the inner ring fixing seal member side can be efficiently received by the edge bending portion. Therefore, it is possible to effectively prevent the lubricating oil inside the bearing from being excessively discharged from the oil drain gap.

[0026] [Configuration 8] A seal fixing groove into which the radially outer end of the outer ring fixing seal member is fitted and fixed is formed on the inner circumference of the outer ring. The sealed rolling bearing according to Configuration 7, wherein the outer ring is symmetric with respect to a plane perpendicular to the axis by making the cross-sectional shape of the seal fixing groove and the cross-sectional shape of the circumferential groove symmetric.

[0027] When this configuration is adopted, when manufacturing the outer ring, the seal fixing groove and the circumferential groove can be processed in the same process, so the cost is low. Also, when assembling the rolling bearing, it is not necessary to distinguish between the front and back directions of the outer ring, so the workability is excellent.

[0028] [Configuration 9] The sealed rolling bearing according to any one of claims 1 to 8, wherein grease is enclosed in the bearing space.

[0029] When this configuration is adopted, it is possible to ensure the lubrication inside the bearing until lubricating oil is supplied from the outside of the bearing at the initial stage of use of the bearing.

Advantages of the Invention

[0030] In the sealed rolling bearing of the present invention, since the inner ring fixed seal member rotates integrally with the inner ring, the lubricating oil inside the bearing moves radially outward by centrifugal force and is discharged from the bearing to the outside through the oil drainage gap between the outer periphery of the inner ring fixed seal member and the inner periphery of the outer ring. Therefore, it is difficult for the lubricating oil to stay inside the bearing, and the stirring resistance of the lubricating oil inside the bearing can be suppressed to a small level.

[0031] Also, since the outer ring fixed seal member does not rotate even when the inner ring rotates, as the lubricating oil inside the bearing is discharged from the oil drainage gap by centrifugal force, the lubricating oil supplied from the outside of the bearing can be drawn into the bearing through the oil supply gap between the inner periphery of the outer ring fixed seal member and the outer periphery of the inner ring. Therefore, it is difficult for the lubricating oil inside the bearing to be insufficient during high-speed rotation, and the inside of the bearing can be stably lubricated.

[0032] Furthermore, since the action of the lubricating oil inside the bearing being discharged from the bearing to the outside through the oil drainage gap between the outer periphery of the inner ring fixed seal member and the inner periphery of the outer ring and the action of the lubricating oil supplied from the outside of the bearing being drawn into the bearing through the oil supply gap between the inner periphery of the outer ring fixed seal member and the outer periphery of the inner ring occur simultaneously, the lubricating oil inside the bearing is always replaced, and the heat exchange inside the bearing is smooth. Therefore, it is possible to effectively suppress the temperature rise during high-speed rotation.

Brief Description of the Drawings

[0033]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Embodiments for Carrying Out the Invention

[0034] Fig. 1 shows a sealed rolling bearing 1 according to an embodiment of the present invention. This sealed rolling bearing 1 includes an outer ring 2, an inner ring 3 coaxially disposed radially inward of the outer ring 2, a plurality of rolling elements 5 incorporated in an annular bearing space 4 formed between the outer ring 2 and the inner ring 3 with a circumferential interval therebetween, a cage 6 for holding the circumferential interval of the plurality of rolling elements 5, and a pair of seal members 7, 8 for covering respectively one axial end opening and the other axial end opening of the bearing space 4. The pair of seal members 7, 8 includes an outer ring fixing seal member 7 fixed to the inner circumference of the outer ring 2 and an inner ring fixing seal member 8 fixed to the outer circumference of the inner ring 3. The bearing space 4 is filled with grease for initial lubrication.

[0035] On the inner circumference of the outer ring 2, there are formed an outer ring raceway groove 9 with which the rolling elements 5 are in rolling contact, a pair of outer ring shoulders 10 positioned axially outside the outer ring raceway groove 9, a seal fixing groove 11 positioned axially outside one of the pair of outer ring shoulders 10 (the left outer ring shoulder 10 in the figure), and a circumferential groove 12 positioned axially outside the other of the pair of outer ring shoulders 10 (the right outer ring shoulder 10 in the figure). The outer ring raceway groove 9 is an arc groove having a concave arc-shaped cross section along the surface of the rolling element 5, and is formed by extending circumferentially at the axial center of the inner circumference of the outer ring 2. The pair of outer ring shoulders 10 are embankment-shaped portions extending circumferentially on both sides sandwiching the outer ring raceway groove 9 in the axial direction. The radially outer end of the outer ring fixing seal member 7 is fitted and fixed in the seal fixing groove 11.

[0036] On the outer circumference of the inner ring 3, there are formed an inner ring raceway groove 13 with which the rolling elements 5 are in rolling contact, a pair of inner ring shoulders 14 positioned axially outside the inner ring raceway groove 13, a seal sliding contact surface 15 (see FIG. 2) positioned axially outside one of the pair of inner ring shoulders 14 (the left inner ring shoulder 14 in the figure), and a seal fixing surface 16 positioned axially outside the other of the pair of inner ring shoulders 14 (the right inner ring shoulder 14 in the figure). The inner ring raceway groove 13 is an arc groove having a concave arc-shaped cross section along the surface of the rolling element 5, and is formed by extending circumferentially at the axial center of the outer circumference of the inner ring 3. The pair of inner ring shoulders 14 are embankment-shaped portions extending circumferentially on both sides sandwiching the inner ring raceway groove 13 in the axial direction. The radially inner end of the inner ring fixing seal member 8 is fitted and fixed in the seal fixing surface 16.

[0037] The rolling elements 5 are radially sandwiched between the outer ring raceway groove 9 and the inner ring raceway groove 13. This sealed rolling bearing 1 is a deep groove ball bearing. That is, the outer ring raceway groove 9 is an arc groove symmetric with respect to the axial center of the outer ring 2, and the inner ring raceway groove 13 is also an arc groove symmetric with respect to the axial center of the inner ring 3.

[0038] As shown in FIG. 2, the outer ring fixed seal member 7 is composed of an annular plate-shaped core metal 17 and a rubber 18 vulcanized and adhered to the core metal 17. The core metal 17 is formed by press-forming a steel plate such as a cold-rolled steel plate or a stainless steel plate. The rubber 18 has an outer peripheral rubber portion 19 extending radially outward from the radially outer end of the core metal 17, an outer surface rubber portion 20 covering the entire axially outer side surface of the core metal 17, and a seal lip 21 extending radially inward from the radially inner end of the core metal 17.

[0039] The outer peripheral rubber portion 19 is fitted into the seal fixing groove 11 on the inner circumference of the outer ring 2. The seal lip 21 is in sliding contact with the seal sliding contact surface 15 on the outer circumference of the inner ring 3. The seal sliding contact surface 15 is a cylindrical surface that extends axially with a constant outer diameter from the portion where the seal lip 21 is in sliding contact and connects to the axially end face 22 of the inner ring 3. An oil supply gap 23 for introducing lubricating oil supplied from outside the bearing into the bearing space 4 is formed between the inner circumference of the seal lip 21 and the seal sliding contact surface 15.

[0040] As shown in FIG. 3, on the inner circumference of the seal lip 21, a plurality of convex portions 24 provided at intervals in the circumferential direction and a lip inner circumferential surface 25 connecting between the circumferentially adjacent convex portions 24 are formed. Each convex portion 24 is arranged at an equal pitch over the entire inner circumference of the seal lip 21. The height of each convex portion 24 (the distance from the lip inner circumferential surface 25 to the seal sliding contact surface 15 in a state where the tip of the convex portion 24 is in contact with the seal sliding contact surface 15) is set to 0.1 mm or less. Each convex portion 24 is formed to extend in a direction intersecting the circumferential direction (for example, a direction perpendicular to the circumferential direction (a direction perpendicular to the paper surface in the figure)). The oil supply gap 23 is a gap formed between the circumferentially adjacent convex portions 24.

[0041] Each convex portion 24 is formed such that its cross-sectional shape along the circumferential direction is a convex arc shape, and it is configured to be in sliding contact with the seal sliding contact surface 15 via an oil film due to the wedge film effect. That is, when the seal sliding contact surface 15 on the outer periphery of the inner ring 3 moves in the circumferential direction with respect to each convex portion 24, the lubricating oil existing between the convex portions 24 adjacent to each other in the circumferential direction is introduced between the convex portion 24 and the seal sliding contact surface 15 along the surface of each convex portion 24. At this time, due to the wedge film effect, the lubrication state between each convex portion 24 and the seal sliding contact surface 15 becomes a fluid lubrication state, and it is possible to keep the sliding resistance (seal torque) of the seal lip 21 low.

[0042] As shown in FIG. 4, the inner ring fixed seal member 8 is a metal shield plate formed by press-molding a metal plate (for example, a steel plate), and is provided in non-contact with the inner periphery of the outer ring 2. The inner ring fixed seal member 8 has a fitting cylinder portion 26 that fits onto the outer periphery of the inner ring 3, an annular plate portion 27 that rises radially outward from the fitting cylinder portion 26, and an edge bending portion 28 that is bent axially inward (left side in the figure) at the radially outer end of the annular plate portion 27.

[0043] The fitting cylinder portion 26 is fixed by fitting with a clamping allowance onto the seal fixing surface 16 on the outer periphery of the inner ring 3. The seal fixing surface 16 is a cylindrical surface that extends axially with a constant outer diameter and is connected to the axial end surface 22 of the inner ring 3. The seal fixing surface 16 has a symmetric shape with the same outer diameter as the seal sliding contact surface 15 (see FIG. 2), and thus, as shown in FIG. 1, the inner ring 3 has a symmetric shape with respect to a virtual plane perpendicular to the axis passing through the axial center of the inner ring 3.

[0044] The circumferential groove 12 on the inner periphery of the outer ring 2 extends in the circumferential direction at a position corresponding to the inner ring fixed seal member 8, and at least a part (all in the figure) of the edge bending portion 28 is accommodated therein. The edge bending portion 28 is a cylindrical portion that extends axially inward from the radially outer end of the annular plate portion 27, and its inner diameter is larger than the inner diameter of the outer ring shoulder 10. An oil discharge gap 29 for discharging lubricating oil from the bearing space 4 is formed between the outer periphery of the edge bending portion 28 and the inner periphery of the outer ring 2. The oil discharge gap 29 is an annular minute gap (see FIG. 11).

[0045] The cross-sectional shape of the circumferential groove 12 is symmetrical with the cross-sectional shape of the seal fixing groove 11 (see FIG. 3), and thus, as shown in FIG. 1, the outer ring 2 has a symmetrical shape with respect to the virtual plane perpendicular to the axis passing through the axial center of the outer ring 2.

[0046] As shown in FIG. 12, this sealed rolling bearing 1 is used for the application of supporting a rotating shaft 34 rotatably in a state of being attached to a fixed housing 33. The rotating shaft 34 is, for example, a rotating shaft to which the rotation of an electric motor of an electric vehicle is input, or a rotating shaft of a hybrid electric vehicle that uses an electric motor as an auxiliary driving force of an engine. The housing 33 is provided with a lubricating oil supply passage 35 for supplying lubricating oil to the sealed rolling bearing 1 from one axial side.

[0047] As shown in FIG. 1, in this sealed rolling bearing 1, since the inner ring fixed seal member 8 rotates integrally with the inner ring 3, the lubricating oil inside the bearing moves radially outward by centrifugal force and is discharged to the outside of the bearing from the oil discharge gap 29 between the outer periphery of the inner ring fixed seal member 8 and the inner periphery of the outer ring 2. Therefore, it is difficult for the lubricating oil to stay inside the bearing, and it is possible to greatly suppress the stirring resistance of the lubricating oil inside the bearing.

[0048] Also, since the outer ring fixed seal member 7 does not rotate even when the inner ring 3 rotates, as the lubricating oil inside the bearing is discharged from the oil discharge gap 29 by centrifugal force, the lubricating oil supplied from the outside of the bearing can be drawn into the bearing from the oil supply gap 23 between the inner periphery of the outer ring fixed seal member 7 and the outer periphery of the inner ring 3. Therefore, it is difficult for the lubricating oil inside the bearing to be insufficient during high-speed rotation, and the inside of the bearing can be stably lubricated.

[0049] Furthermore, since the lubricating oil inside the bearing is discharged to the outside of the bearing from the oil drainage gap 29 between the outer circumference of the inner ring fixing seal member 8 and the inner circumference of the outer ring 2, and the lubricating oil supplied from the outside of the bearing is drawn into the bearing from the oil supply gap 23 between the inner circumference of the outer ring fixing seal member 7 and the outer circumference of the inner ring 3 at the same time, the lubricating oil inside the bearing is constantly replaced, and the heat exchange inside the bearing is smooth. Therefore, it is possible to effectively suppress the temperature rise during high-speed rotation.

[0050] Also, as shown in FIG. 3, in this sealed rolling bearing 1, since the oil supply gap 23 is a gap formed between the convex portions 24 adjacent to each other in the circumferential direction of the seal lip 21, the gap dimension of the oil supply gap 23 can be accurately controlled by adjusting the height of the convex portion 24 of the seal lip 21. Therefore, the gap dimension of the oil supply gap 23 can be set small, and it is possible to effectively prevent foreign matter from entering the bearing from the outside of the bearing through the oil supply gap 23.

[0051] Also, as shown in FIG. 2, in this sealed rolling bearing 1, since the seal sliding contact surface 15 on the outer circumference of the inner ring 3 is cylindrical and extends in the axial direction from the portion where the seal lip 21 makes sliding contact and connects to the axial end face 22 of the inner ring 3, the oil supply gap 23 between the seal lip 21 and the inner ring 3 is in a state of being largely exposed to the outside of the bearing as compared with the case where the seal lip 21 is in sliding contact with the inner surface of the concave groove. Therefore, it is possible to smoothly introduce the lubricating oil supplied from the outside of the bearing into the oil supply gap 23.

[0052] In addition, as shown in Fig. 4, in this sealed rolling bearing 1, since the inner ring fixed seal member 8 has a bent edge portion 28 formed by bending axially inward at the radially outer end of the annular plate portion 27, as shown in Fig. 1, when the lubricating oil drawn into the bearing from the oil supply gap 23 between the inner circumference of the outer ring fixed seal member 7 and the outer circumference of the inner ring 3 moves radially outward by centrifugal force, as shown in Fig. 4, before a part of the lubricating oil reaches the oil drainage gap 29 between the outer circumference of the inner ring fixed seal member 8 and the inner circumference of the outer ring 2, it can be received by the bent edge portion 28 of the inner ring fixed seal member 8 and retained inside the bearing. Therefore, it is possible to prevent the lubricating oil drawn into the bearing from the oil supply gap 23 shown in Fig. 1 from being excessively discharged from the oil drainage gap 29.

[0053] In addition, as shown in Fig. 4, in this sealed rolling bearing 1, since at least a part of the bent edge portion 28 of the inner ring fixed seal member 8 is accommodated in the circumferential groove 12 formed on the inner circumference of the outer ring 2, the lubricating oil inside the bearing moving along the inner circumference of the outer ring shoulder 10 to the side of the inner ring fixed seal member 8 (the right side in the figure) can be efficiently received by the bent edge portion 28. Therefore, it is possible to effectively prevent the lubricating oil inside the bearing from being excessively discharged from the oil drainage gap 29.

[0054] In addition, in this sealed rolling bearing 1, as shown in Fig. 4, by making the seal fixing surface 16 shown in Fig. 4 and the seal sliding contact surface 15 shown in Fig. 2 have a symmetrical shape with the same outer diameter, the shape of the inner ring 3 shown in Fig. 1 is symmetrical with respect to the plane perpendicular to the axis. Therefore, when manufacturing the inner ring 3, the seal fixing surface 16 and the seal sliding contact surface 15 can be machined in the same process, which is low-cost. Also, when assembling the rolling bearing 1, there is no need to distinguish the front and back directions of the inner ring 3, so the workability is excellent.

[0055] In addition, as shown in Fig. 1, in this sealed rolling bearing 1, as the inner ring fixed seal member 8, a metal shield plate that is non-contact with the inner circumference of the outer ring 2 is adopted, so it is possible to greatly suppress the rotational resistance of the bearing.

[0056] In addition, in this sealed rolling bearing 1, by making the cross-sectional shape of the seal fixing groove 11 shown in FIG. 2 symmetric with the cross-sectional shape of the circumferential groove 12 shown in FIG. 4, the shape of the outer ring 2 shown in FIG. 1 is symmetric with respect to the plane perpendicular to the axis. Therefore, when manufacturing the outer ring 2, the seal fixing groove 11 and the circumferential groove 12 can be machined in the same process, which is low-cost. Also, when assembling the rolling bearing 1, it is not necessary to distinguish the front and back directions of the outer ring 2, so the workability is excellent.

[0057] In the above embodiment, as shown in FIG. 4, as the edge bending portion 28 formed by bending inward in the axial direction at the radially outer end of the annular plate portion 27, a cylindrical shape extending with a constant diameter from the radially outer end of the annular plate portion 27 toward the inner side in the axial direction was taken as an example for explanation. However, as shown in FIG. 5, a frustum-shaped structure whose diameter gradually increases from the radially outer end of the annular plate portion 27 toward the inner side in the axial direction may be adopted. In FIG. 5, the radially outer portion of the edge bending portion 28 is accommodated in the circumferential groove 12 on the inner circumference of the outer ring 2. Even if the configuration shown in FIG. 5 is adopted, the lubricating oil inside the bearing that moves along the inner circumference of the outer ring shoulder 10 to the side of the inner ring fixing seal member 8 (the right side in the figure) can be efficiently received by the edge bending portion 28. Therefore, it is possible to effectively prevent the lubricating oil inside the bearing from being excessively discharged from the oil drain gap 29.

[0058] As the edge bending portion 28 formed by bending axially inward at the radially outer end of the annular plate portion 27, as shown in FIG. 6, a crank-shaped cross-section composed of a cylindrical portion 36 and an annular plate portion 37 extending radially outward from the tip of the cylindrical portion 36 may be adopted. As shown in FIG. 7, a frustum-shaped one with a diameter gradually decreasing axially inward from the radially outer end of the annular plate portion 27 may be adopted. As shown in FIG. 8, a configuration connecting to a cylindrical portion 39 via a frustum portion 38 from the radially outer end of the annular plate portion 27 may be adopted. As shown in FIG. 9, a configuration connecting to a cylindrical portion 41 via an R portion 40 with an arcuate cross-section from the radially outer end of the annular plate portion 27 may be adopted. In any of the modified examples shown in FIGS. 6 to 9, since at least a part of the edge bending portion 28 is accommodated in the circumferential groove 12 on the inner circumference of the outer ring 2, the lubricating oil inside the bearing that moves along the inner circumference of the outer ring shoulder 10 to the side of the inner ring fixing seal member 8 (the right side in the figure) can be efficiently received by the edge bending portion 28. Compared with the case where all of the edge bending portion 28 is arranged outside the circumferential groove 12 as shown in FIG. 10, it is possible to effectively prevent the lubricating oil inside the bearing from being excessively discharged from the oil drainage gap 29.

[0059] In the above embodiment, as an example of the outer ring fixing seal member 7, one in which rubber 18 is vulcanized and adhered to the core metal 17 is cited. However, as the outer ring fixing seal member 7, a shield plate formed by press-forming a metal plate (for example, a configuration in which the inner diameter side and the outer diameter side of the inner ring fixing seal member 8 in the above embodiment are interchanged) may be adopted. In this case, the inner circumference of the outer ring fixing seal member 7 does not slidably contact the outer circumference of the inner ring 3, and a configuration can be adopted in which an annular oil supply gap 23 is formed between the inner circumference of the outer ring fixing seal member 7 and the outer circumference of the inner ring 3.

[0060] Also, in the above embodiment, as an example of the inner ring fixing seal member 8, one in which a shield plate formed by press-forming a metal plate is adopted is cited. However, as the inner ring fixing seal member 8, one in which rubber is vulcanized and adhered to a core metal may be adopted. In this case, as the inner ring fixing seal member 8, for example, a configuration in which the inner diameter side and the outer diameter side of the outer ring fixing seal member 7 in the above embodiment are interchanged may be adopted, and the gap between the adjacent convex portions 24 in the circumferential direction can be used as the oil drainage gap 29.

[0061] The embodiments disclosed this time should be considered as illustrative in all aspects and not restrictive. The scope of the present invention is shown not by the above description but by the claims, and it is intended that all modifications within the meaning and scope equivalent to the claims be included.

Explanation of Signs

[0062] 1 Sealed rolling bearing 2 Outer ring 3 Inner ring 4 Bearing space 5 Rolling element 7 Outer ring fixed seal member 8 Inner ring fixed seal member 11 Seal fixing groove 12 Circumferential groove 15 Seal sliding contact surface 16 Seal fixing surface 21 Seal lip 22 Axial end face 23 Oil supply gap 24 Protrusion 26 Fitting cylinder part 27 Annular plate part 28 Edge bending part 29 Oil drainage gap

Claims

1. An outer ring (2), an inner ring (3) disposed radially inside the outer ring (2), a plurality of rolling elements (5) incorporated in an annular bearing space (4) formed between the outer ring (2) and the inner ring (3), In a rolling bearing with seals having a pair of seal members (7, 8) that respectively cover one axial end opening and the other axial end opening of the bearing space (4), one of the pair of seal members (7, 8) is an outer ring fixed seal member (7) fixed to the inner circumference of the outer ring (2), and the other is an inner ring fixed seal member (8) fixed to the outer circumference of the inner ring (3), An oil supply gap (23) for introducing lubricating oil supplied from outside the bearing into the bearing space (4) is formed between the inner circumference of the outer ring fixed seal member (7) and the outer circumference of the inner ring (3), A rolling bearing with seals, characterized in that an oil drain gap (29) for discharging lubricating oil from the bearing space (4) is formed between the outer circumference of the inner ring fixed seal member (8) and the inner circumference of the outer ring (2).

2. The outer ring fixed seal member (7) has a rubber seal lip (21) provided with a plurality of convex portions (24) that are in sliding contact with the outer circumference of the inner ring (3) via an oil film at intervals in the circumferential direction, The rolling bearing with seals according to claim 1, wherein the oil supply gap (23) is a gap formed between the adjacent convex portions (24) in the circumferential direction.

3. On the outer circumference of the inner ring (3), a cylindrical seal sliding contact surface (15) that extends axially from the portion where the seal lip (21) is in sliding contact and connects to the axial end surface (22) of the inner ring (3) is formed. The rolling bearing with seals according to claim 2.

4. On the outer circumference of the inner ring (3), a cylindrical seal fixing surface (16) into which the radially inner end of the inner ring fixed seal member (8) is fitted and fixed is formed, The rolling bearing with seals according to claim 3, wherein the seal fixing surface (16) and the seal sliding contact surface (15) have a symmetrical shape with the same outer diameter, making the shape of the inner ring (3) symmetrical with respect to a plane perpendicular to the axis.

5. The rolling bearing with seals according to any one of claims 1 to 4, wherein a metal shield plate that is non-contact with the inner circumference of the outer ring (2) is used as the inner ring fixed seal member (8).

6. The inner ring fixing seal member (8) includes a fitting cylinder portion (26) that fits onto the outer circumference of the inner ring (3), an annular plate portion (27) that rises radially outward from the fitting cylinder portion (26), and an edge bending portion (28) formed by bending axially inward at the radially outer end of the annular plate portion (27). The sealed rolling bearing according to any one of claims 1 to 4.

7. On the inner circumference of the outer ring (2), a circumferential groove (12) extending in the circumferential direction is formed at a position corresponding to the inner ring fixing seal member (8). The sealed rolling bearing according to claim 6, wherein at least a part of the edge bending portion (28) of the inner ring fixing seal member (8) is accommodated in the circumferential groove (12).

8. On the inner circumference of the outer ring (2), a seal fixing groove (11) into which the radially outer end of the outer ring fixing seal member (7) fits and is fixed is formed. The sealed rolling bearing according to claim 7, wherein the cross-sectional shape of the seal fixing groove (11) and the cross-sectional shape of the circumferential groove (12) are symmetric, so that the shape of the outer ring (2) is symmetric with respect to a plane perpendicular to the axis.

9. The sealed rolling bearing according to any one of claims 1 to 4, wherein grease is encapsulated in the bearing space (4).

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