JP6522357B2 - Rolling bearing - Google Patents

Description

  The present invention relates to a rolling bearing used, for example, in a transmission of an automobile.

  In the transmission of an automobile, foreign matter such as gear wear powder is mixed, so that the conventional transmission bearing is provided with a contact type sealing plate (seal member) to prevent foreign matter from entering the bearing space. When the bearing space is sealed with such a contact type seal member, entry of foreign matter into the bearing space can be prevented, but a seal torque is generated. A bearing for a transmission is required to have both sealing performance to prevent foreign matter from entering the bearing space and low friction performance to suppress the seal torque due to the frictional resistance between the seal member and the rotation-side race.

  Therefore, by applying a shot-peel treatment to the sliding contact surface on which the seal lip portion of the seal member in the rotation-side raceway comes in sliding contact, lubricating oil is held on the sliding contact surface to form a fluid film, and sealing performance is ensured. At the same time, it has been proposed to reduce the seal torque (for example, Patent Document 1).

  In addition, the seal lip is made of a highly wearable material that is easy to wear, and the tip of the seal lip is abraded during the initial operation of the bearing to form an optimum labyrinth clearance between the seal lip and the rotating race. It is proposed to do (for example, patent document 2). At the time of actual use after the completion of wear, the labyrinth gap prevents foreign matter from entering and the seal member becomes a noncontact seal, so that the seal torque is suppressed to a low level, and the effect of reducing the fuel consumption of the vehicle can be expected.

Unexamined-Japanese-Patent No. 2007-107588 JP, 2013-36493, A

  In the configuration of Patent Document 1, the torque reduction effect is limited, and a satisfactory torque reduction effect can not be obtained. Further, although the configuration of Patent Document 2 can obtain a satisfactory torque reduction effect after the completion of wear, the time until the completion of wear may vary depending on the use environment in the transmission. Therefore, it is difficult to adjust the time of break-in operation before and after shipment, and it is necessary to take longer time of break-in operation.

  An object of the present invention is to provide a rolling bearing which is excellent in sealing performance, good in low friction performance, and can shorten the time until the seal lip portion is appropriately worn.

The rolling bearing according to the present invention seals the bearing space formed between the inner and outer rings, the inner ring which is a rotating ring, the outer ring which is a fixed ring, a plurality of rolling elements interposed between the raceway surfaces of these inner and outer rings The seal member has a seal lip portion whose outer diameter end is fixed to the outer ring and which is in contact with the outer peripheral surface of the inner ring with an interference at the inner diameter end side, and the seal lip portion The tip portion in contact with the outer peripheral surface of at least the inner ring is worn by using the bearing in a rotating state so that it is not in contact with the outer peripheral surface of the inner ring or the light contact can be regarded as zero contact pressure made made of a high wear material, the seal to promote the wear of the lip, before SL on the surface in contact with the outer peripheral surface of the inner ring of the seal lip portion, wherein said inner ring by a centrifugal force accompanying the rotation of the inner ring seal lip portion And the intervening oil between Ring-shaped oil groove for guiding the provided et al is, the oil groove to induce oil, characterized in that to a state close to zero or zero oil film between the inner ring and the seal lip portion.

  According to this configuration, the tip portion of at least the seal lip portion in contact with the outer peripheral surface of the inner ring is made of a high wear material, so that the tip portion of the seal lip portion wears early by using the bearing in a rotating state. In order to wear the seal lip, it is advantageous that the smaller the amount of oil present between the inner ring and the seal lip, the higher the coefficient of friction. If an annular oil groove is provided on the surface in contact with the outer peripheral surface of the inner ring of the seal lip as in this configuration, the oil present between the inner ring and the seal lip by the centrifugal force accompanying the rotation of the inner ring The amount of oil guided to the oil groove and interposed between the inner ring and the seal lip decreases. The oil present between the inner ring and the seal lip flows from the side of the seal lip to the outer diameter side by centrifugal force, but the contact surface between the inner ring and the seal lip has a certain width, so The oil in the middle in the width direction is difficult to escape to the side. Such oil also flows to the oil groove when the oil groove is present. As a result, the oil film between the inner ring and the seal lip becomes zero or nearly zero. As a result, the coefficient of friction between the inner ring and the seal lip increases, wear of the seal lip is further promoted, and the tip of the seal lip does not contact or lightly contact the outer peripheral surface of the inner ring. Time is reduced.

  After the completion of wear, the tip portion of the seal lip portion is in non-contact or in light contact with the outer peripheral surface of the inner ring, so that almost no seal torque is generated. A fine gap between the tip of the seal lip and the outer peripheral surface of the inner ring after the completion of wear acts as a labyrinth gap to prevent foreign matter from entering the bearing space.

In the present invention, the seal lip portion may be made of a rubber material.
The seal member is fixed to the outer ring so that the tip end portion of the seal lip portion contacts the outer peripheral surface of the inner ring in a state of having an interference by utilizing the elasticity of the seal lip portion made of a rubber material. As the tip of the seal lip wears as the inner ring rotates, the seal lip returns to the normal posture, and when wear is complete, it is optimal between the tip of the seal lip and the outer peripheral surface of the inner ring Labyrinth clearance is formed.

When the seal member has an annular core metal and a rubber material integrally fixed to the core metal and partially or entirely forming the seal lip portion, the rubber material is vulcanized on the entire core metal. It may be fixed by molding, and the rubber material may be fixed by vulcanization molding only to the inner diameter portion of the core metal.
In the former case, the sealing performance between the outer ring and the outer diameter end of the seal member can be improved by fittingly fixing the outer diameter end of the seal member in a state of being elastically deformed in the seal attachment groove provided in the outer ring. In the latter case, the amount of rubber used can be reduced.

In the present invention, the tip end portion of the seal lip may be in radial contact with the outer peripheral surface of the inner ring.
When in radial contact, the depth direction of the oil groove is the outer diameter direction, so the oil present between the inner ring and the seal lip portion is likely to be guided to the oil groove by the centrifugal force accompanying the rotation of the inner ring. As a result, the coefficient of friction between the inner ring and the seal lip increases, and wear of the seal lip is promoted.

In the present invention, the outer peripheral surface of the inner ring may have an annular step surface facing in the axial direction, and the tip end portion of the seal lip may be in axial contact with the step surface.
In the case of axial contact, the depth direction of the oil groove is the axial direction, but the oil present between the inner ring and the seal lip due to the centrifugal force accompanying the rotation of the inner ring is on the outer diameter edge of the oil groove It is gathered up and guided to the inside of the oil groove along the wall surface on the outer diameter side of the oil groove. As a result, the coefficient of friction between the inner ring and the seal lip increases, and wear of the seal lip is promoted.

  The rolling bearing may be used for a transmission of a car. In this case, since the optimum labyrinth clearance is formed by the operation of the bearing, it is possible to prevent foreign matter such as wear powder of the gear in the transmission from intruding into the bearing. In addition, the torque generated by the seal member is reduced, and the fuel consumption of the automobile can be improved.

The rolling bearing according to the present invention seals the bearing space formed between the inner and outer rings, the inner ring which is a rotating ring, the outer ring which is a fixed ring, a plurality of rolling elements interposed between the raceway surfaces of these inner and outer rings The seal member has a seal lip portion whose outer diameter end is fixed to the outer ring and which is in contact with the outer peripheral surface of the inner ring with an interference at the inner diameter end side, and the seal lip portion The tip portion in contact with the outer peripheral surface of at least the inner ring is worn by using the bearing in a rotating state so that it is not in contact with the outer peripheral surface of the inner ring or the light contact can be regarded as zero contact pressure made made of a high wear material, the seal to promote the wear of the lip, before SL on the surface in contact with the outer peripheral surface of the inner ring of the seal lip portion, wherein said inner ring by a centrifugal force accompanying the rotation of the inner ring seal lip portion And the intervening oil between Ring-shaped oil groove for guiding the provided et al is, the oil groove to induce oil, in order to a state close to zero or zero oil film between the inner ring and the seal lip portion, excellent sealing performance And, the low friction performance is good, and the time until the seal lip portion wears appropriately can be shortened.

It is a sectional view of a rolling bearing concerning one embodiment of this invention. (A) is an expanded sectional view of seal part vicinity of the rolling bearing, (B) is the elements on larger scale of seal lip part vicinity of the seal member. (A) Sectional drawing which shows the state before wear of the front-end | tip part of the same seal lip part, (B) is sectional drawing which shows the state after completion | finish of wear. It is sectional drawing of the seal | sticker mold of the same sealing member. It is sectional drawing of seal | sticker member vicinity of the rolling bearing which concerns on different embodiment of this invention. It is sectional drawing of seal lip part vicinity of the rolling bearing which concerns on another embodiment which concerns on this invention. It is the schematic of the example which used the rolling bearing shown in FIG. 1 for a transmission.

An embodiment of the present invention will be described in conjunction with FIGS.
As shown in FIG. 1, this rolling bearing comprises inner and outer races 1 and 2 which are races, a plurality of rolling elements 3 interposed between the raceways 1a and 2a of the inner and outer races 1 and 2 and these rolling elements A holder 4 for holding the bearing 3 and two seal members 5 for sealing both ends of an annular bearing space S formed between the inner and outer rings 1 and 2 are provided. Grease is initially sealed in the bearing space S. This rolling bearing is a deep groove ball bearing in which the rolling element 3 is a ball, and is an inner ring rotating type in which the inner ring 1 is a rotating ring and the outer ring 2 is a fixed ring.

  As shown in FIG. 2 (A), the outer diameter end of the seal member 5 is provided on the inner peripheral surface of the outer ring 2 and fitted and fixed to the seal mounting groove 2b. Is in radial contact with the cylindrical outer peripheral surface 1b. The seal member 5 has an annular core metal 6 and an elastic member 7 integrally fixed to the core metal 6. The seal metal body 8 is constituted by the core metal 6 and the elastic member 7 mainly, and the seal lip portion 9 is constituted by the remaining portion of the elastic member 7, in this example, the inner diameter end side portion of the elastic member 7. . In this example, the elastic member 7 is provided so as to cover the entire core metal 6 except for the inner side surface of the post plate 6 b of the core metal 6. The seal member 5 is formed by, for example, vulcanizing a rubber material, and the metal core metal 6 is adhered to the elastic member 7 at the time of the vulcanization molding.

  The cored bar 6 has a cylindrical portion 6a, an upright plate portion 6b, and an inclined portion 6c sequentially from the outer diameter side. The upstanding plate portion 6 b is disposed axially inward of the end faces of the inner and outer rings 1, 2 in a direction substantially parallel to the end faces. The cylindrical portion 6a is connected to the outer diameter end of the standing plate portion 6b, and the standing plate portion 6b and the cylindrical portion 6a form an L-shaped cross section. The outer diameter end of the seal member 5 formed of the cylindrical portion 6a and the outer peripheral portion 7a (a part of the elastic member 7) provided on the outer peripheral surface of the cylindrical portion 6a is the outer diameter end of the seal member main body 8. The outer diameter end of the seal member main body 8 is fitted and fixed to the seal attachment groove 2b. At this time, the outer peripheral portion 7a is fixed to the seal attachment groove 2b in a state of being elastically deformed, and the sealability between the outer ring 2 and the outer diameter end of the seal member main body 8 is further enhanced. At the inner diameter end of the upstanding plate portion 6b, an inclined portion 6c which is inclined inward in the axial direction toward the inner diameter side is connected.

  The outer surface of the upstanding plate portion 6b of the cored bar 6 is covered with a covering portion 7b of uniform thin-walled shape, and the inner and outer surfaces of the inclined portion 6c are covered with covering portions 7c and 7d, respectively. The inner diameter end of the cover portions 7 c and 7 d is the inner diameter end of the seal member main body 8. A seal lip portion 9 in contact with the outer peripheral surface of the inner ring 1 is provided at the inner diameter end of the seal member main body 8. The elastic member 7 has the outer peripheral portion 7 a, cover portions 7 b, 7 c, 7 d and a seal lip portion 9.

  As shown in FIG. 2 (B) which is a partially enlarged view of FIG. 2 (A), the seal lip portion 9 has a proximal end portion 10, an intermediate portion 11 and a distal end portion 12 which continue in order from the outer diameter side to the inner diameter side. Have. These portions 10, 11, 12 are integrally formed. In the same figure, although it is illustrated that the tip portion 12 bites into the outer peripheral surface 1b of the inner ring 1, in fact, the tip portion 12 is tightened against the outer peripheral surface 1b of the inner ring 1 in a seal mounted state. It is in contact with the state of holding δ.

  The base end portion 10 is a portion connected to the seal member main body 8 and extends to the inner diameter side at substantially the same angle as the inclined portion 6 c of the core metal 6. That is, the inner surface on the bearing space S side and the outer surface on the opposite side in the proximal end portion 10 are formed in a cross-sectional shape that is inclined so as to reach the inner side in the axial direction toward the inner diameter side. Further, the proximal end portion 10 has a cross-sectional shape which becomes thinner toward the inner diameter side, that is, the distal end portion 12. In addition, the said cross section is a cross section cut and seen in the plane containing a bearing axial center.

  The middle portion 11 is a portion connecting the proximal end portion 10 and the distal end portion 12 and has a smaller axial thickness than the proximal end portion 10 and the distal end portion 12. Thereby, the entire cross-sectional shape of the seal lip 9 is a shape that is narrowed in the axial direction at the intermediate portion 11 which is the intermediate portion in the radial direction. Further, the seal lip 9 has a V-shaped bent shape bent at the intermediate portion 11 so that the relief recess 13 is formed on the outer surface with respect to the bearing space S.

  The distal end portion 12 has a shape that is wide in the axial direction and connected to the intermediate portion 11 at the axially inner portion, and is provided with an axial protrusion 12 a that protrudes axially outward from the outer diameter end. The inner peripheral surface of the tip portion 12, that is, the surface facing the outer peripheral surface 1b of the inner ring 1 has a cross-sectional shape in which the outer shape is a curved line in which the central portion in the axial direction bulges to the inner diameter side. A plurality (for example, three) of annular oil grooves 14 are provided side by side at equal intervals. In the case of the illustrated example, each oil groove 14 has a shape in which the width is slightly narrowed toward the bottom, and the bottom surface is a cylindrical surface. Although the depths of the oil grooves 14 are different from each other, the radial position of the bottom surface is the same.

  The tip portion 12 is made of a highly wearable material that wears and becomes noncontact with the inner ring 1 or a light contact with which the contact pressure can be regarded as zero by using the bearing in a rotating state. The high wear material is made of, for example, a high wear rubber material. A resin material, a solid lubricant, a non-woven fabric, a mild steel or the like may be applied as another material constituting the high wear material. In this example, only the tip portion 12 is made of a high wear material, but is not limited to this example. For example, the tip portion 12 and the middle portion 11 may be made of a high wear material, or the entire seal lip 9 covering the tip portion 12, the middle portion 11, and the base portion 10 may be made of a high wear material. .

  In a state where the seal member 5 is incorporated in the bearing, the inner peripheral surface of the tip member 12 is in radial contact with the outer peripheral surface 1 b of the inner ring 1 by elastically deforming the tip portion 12 by an amount of interference δ. By rotating the inner ring 1 in this state, the tip end portion 12 of the seal lip portion 9 is abraded.

Explain the mechanism of wear.
As described above, when the tip portion 12 contacts the outer peripheral surface 1 b of the inner ring 1, the tip portion 12 has a reaction force to the inner ring 1, that is, a pressing force when the tip portion 12 contacts the outer peripheral surface 1 b of the inner ring 1. Works. In other words, by forming the seal lip 9 in a V-shaped bent shape bent at the intermediate portion 11 so that the seal lip 9 is released on the outer surface with respect to the bearing space S and the recess 13 is generated, the seal lip 9 is an intermediate portion It becomes like a spring that bends at 11, giving a constant radial pressing force. That is, due to the elastic deformation of the seal lip portion 9, the tip portion 12 is pressed against the outer peripheral surface 1b of the inner ring 1 with a constant pressing force, whereby the wear progresses stably. As the wear of the tip portion 12 progresses, the wear of the tip portion 12 proceeds continuously because the bending of the intermediate portion 11 tries to return to the state before the seal member is assembled to follow it.

  Because the tip portion 12 of the seal lip 9 is made of a high wear material, the tip portion 12 wears early. In addition, by providing the oil groove 14 on the inner circumferential surface of the tip portion 12, wear is promoted for the reason described later. From these things, the time until the tip portion 12 of the seal lip 9 becomes noncontact or light contact with the outer peripheral surface 1b of the inner ring 1 is shortened.

The reason why the wear is promoted when the oil groove 14 is provided will be described.
In order to wear the tip portion 12 of the seal lip portion 9, it is advantageous that the smaller the amount of oil interposed between the inner ring 1 and the tip portion 12, the higher the coefficient of friction. When the oil groove 14 is provided on the inner peripheral surface of the tip portion 12, the centrifugal force accompanying the rotation of the inner ring 1 causes the space between the inner ring 1 and the tip portion 12 as shown by the arrow in FIG. The intervening oil is guided to the oil groove 14 to reduce the amount of oil interposed between the inner ring 1 and the tip portion 12. The oil present between the inner ring 1 and the seal lip 9 flows outward from the side of the seal lip 9 by centrifugal force, but the contact surface between the inner ring 1 and the seal lip 9 has a certain width. Therefore, the oil in the middle portion in the width direction of the contact surface is difficult to escape to the side surface. Such oil also flows to the oil groove 14 when the oil groove 14 is present. As a result, the oil film between the inner ring 1 and the tip portion 12 becomes zero or nearly zero. As a result, the coefficient of friction between the inner ring 1 and the tip portion 12 is increased, and wear of the tip portion 12 is further promoted.

  When the tip end portion 12 of the seal lip 9 wears to a non-contact or light contact with the outer peripheral surface 1 b of the inner ring 1, the reaction force of the seal lip portion 3 against the inner ring 1 approaches “zero”. Wear is complete. After the completion of wear, as shown in FIG. 3 (B), a minute labyrinth gap δs is formed between the tip portion 12 and the front wheel 1. The labyrinth gap δs is not necessarily formed uniformly over the entire circumference, and may be formed only in a part of the circumferential direction.

The following effects can be obtained by forming the labyrinth gap δs.
(1) The seal torque is reduced.
(2) The self-heating of the bearing is lower than that of the conventional product.
(3) By lowering the self-heating of the bearing, it is possible to select an oil having a viscosity lower than that of the oil conventionally used.
(4) It can be expected to reduce the overall loss of the transmission.
(5) Due to the labyrinth clearance δs, it is possible to prevent foreign matter having a large particle diameter that affects the bearing life from intruding into the bearing.

  As shown in FIG. 4, the seal mold 20 for molding the seal member 5 has, for example, two molds 21 and 22 combined. One of the molds 21 and 22 has an annular cavity portion 23 for molding the inner surface portion of the seal member 5, and the other mold 22 has an outer surface portion of the seal member 5. It has an annular cavity portion 24 to be molded. A cavity 25 for molding the sealing member 5 is formed in a state where the two molds 21 and 22 are combined with each other. In the seal mold 20, annular gates 26 and 27 for injecting the material of the elastic member 7 into the cavity 25 are provided adjacent to the outer peripheral side portion and the inner peripheral side portion of the cavity 25, respectively.

  The tip portion 12 of the seal lip 9 to which the high wear rubber material is applied and the other portion of the elastic member 7 to which the high wear rubber material is applied are formed by the seal molding die 20, for example, by two-color molding It is molded. First, a rubber material which is not highly worn is injected from the gate 26 adjacent to the outer peripheral side portion of the cavity 25, and the other portion of the elastic member 7 to be the primary side is formed. Next, high wear rubber material is poured from the gate 27 adjacent to the inner peripheral side portion of the cavity 25 to form the tip end portion 12 of the seal lip portion 9 which becomes the secondary side. After the high wear rubber material is first poured from the gate 27 adjacent to the inner peripheral side portion of the cavity 25 to form the projecting portion 12, the rubber material not high wear is used from the gate 26 adjacent to the outer peripheral side portion of the cavity 25. It may be injected and a portion other than the tip portion 12 may be formed. In any case, the same seal molding die 20 can integrally form the tip portion 12 made of a high wear rubber material and the other part made of a non-high wear rubber material.

  FIG. 5 shows another example of the seal member. Similar to the seal member 5 of FIG. 1, the seal member 5 includes an annular core metal 6 and an elastic member 7 made of a rubber material integrally fixed to the core metal 6, but the seal member of FIG. Unlike 5, the elastic member 7 is fixed by vulcanization molding only to the inner diameter portion of the core metal 6. A portion on the inner diameter side of the core metal 6 in the elastic member 7 fixed to the inner diameter portion of the core metal 6 becomes a seal lip portion 9. The metal core 6 has a mounting portion 6 d extending outward from the axially inner end of the cylindrical portion 6 a, and the mounting portion 6 d is fitted and fixed to the seal mounting groove 2 b of the outer ring 2. As described above, if the rubber material is used only at a place necessary to form the seal lip portion 9, the amount of the rubber material used can be reduced.

  FIG. 6 shows another example of the seal member. As shown in the drawing, an annular step surface 1c facing in the axial direction is provided on the outer peripheral surface 1b of the inner ring 1, and the tip portion 12 of the seal lip portion 9 of the seal member 5 is in axial contact with this step surface 1c. In this case, the oil groove 14 is provided on the surface in contact with the step surface 1c, that is, the surface facing the inner side in the axial direction of the tip portion 12. Unlike in the case of radial contact, the depth direction of oil groove 14 is the axial direction, but the oil present between inner ring 1 and tip portion 12 by the centrifugal force accompanying the rotation of inner ring 1 is the outer diameter of oil groove 14 It gathers to the side edge and is guided to the inside of the oil groove 14 along the outer diameter side wall surface of the oil groove 14. In the case of the example of the figure, the depth direction of the oil groove 14 is an axial direction which is slightly inclined toward the outer diameter side, so it is easy to be guided into the oil groove 14. As a result, the amount of oil present between the inner ring 1 and the tip portion 12 is reduced, and the friction coefficient between the inner ring 1 and the tip portion 12 is increased, so that the wear of the tip portion 12 is promoted.

  FIG. 7 is a schematic view showing an example in which the rolling bearing of FIG. 1 is incorporated into a transmission of a car. The figure is an example of an automatic transmission. The outer rings of the rolling bearings BR1 and BR1 are fitted to both axial ends of the case 43, and both ends of the main shaft 44 are rotatably supported by the inner rings of the bearings BR1 and BR1. The case 43 is provided with a countershaft 45 in parallel with the main shaft 44. The counter shaft 45 has a gear portion engaged with the gear portion of the main shaft 44, and is rotatably supported by the case 23 via a bearing. During operation, oil lubrication is performed by the lubricating oil stored in the case 43.

Thus, when the rolling bearings BR1 and BR1 are incorporated into a transmission of an automobile, it is possible to reliably prevent foreign matter such as wear powder of gears in the transmission from intruding into the bearing and at the seal lip portion. Regardless of the interference, the seal member can be worn sufficiently and reliably to reduce the torque. Since the torque generated by the seal member can be reduced, the fuel consumption of the vehicle can be reduced.
The rolling bearing according to any of the embodiments may be used for a continuously variable transmission or a manual transmission.

  As mentioned above, although the form for implementing this invention based on the Example was demonstrated, the embodiment disclosed here is an illustration and restrictive at no points. The scope of the present invention is indicated not by the above description but by the claims, and is intended to include all the modifications within the meaning and scope equivalent to the claims.

DESCRIPTION OF SYMBOLS 1 ... Inner ring 1a ... Raceway surface 1b ... Outer peripheral surface 1c ... Step surface 2 ... Outer ring 2a ... Raceway surface 3 ... Rolling element 5 ... Seal member 6 ... Core metal 7 ... Elastic member (rubber material)
9: seal lip portion 12: tip portion 14: oil groove S: bearing space δ: interference

Claims (7)

Rolling comprising an inner ring which is a rotating ring, an outer ring which is a fixed ring, a plurality of rolling elements interposed between raceways of these inner and outer rings, and a seal member which seals a bearing space formed between the inner and outer rings. In bearings,
The seal member has a seal lip portion whose outer diameter end is fixed to the outer ring and which contacts the outer peripheral surface of the inner ring with an interference on the inner diameter end side, and at least the outer periphery of the inner ring of the seal lip portion The tip portion in contact with the surface is made of a high wear material that wears by using the bearing in a rotating state and does not make contact with the outer peripheral surface of the inner ring or makes light contact such that the contact pressure can be regarded as zero. the order to promote the wear of the seal lip portion, the surface in contact with the outer peripheral surface of the inner ring before Symbol seal lip portion, interposed between the inner ring and the seal lip portion in the centrifugal force accompanying the rotation of the inner ring ring-shaped oil groove provided we are to induce oil, and the oil groove to induce oil, characterized in that a state close to zero or zero oil film between the inner ring and the seal lip portion Rolling bearings.   The rolling bearing according to claim 1, wherein the seal lip portion is made of a rubber material.   3. The rolling bearing according to claim 2, wherein the seal member includes an annular core metal and a rubber material integrally fixed to the core metal and partially or entirely forming the seal lip portion, the core A rolling bearing in which the rubber material is fixed by vulcanization molding to the whole of gold.   3. The rolling bearing according to claim 2, wherein the seal member includes an annular core metal and a rubber material integrally fixed to the core metal and partially or entirely forming the seal lip portion, the core A rolling bearing in which the rubber material is fixed by vulcanization molding only to an inner diameter portion of gold.   The rolling bearing according to any one of claims 1 to 4, wherein the tip end portion of the seal lip portion is in radial contact with an outer peripheral surface of the inner ring.   The rolling bearing according to any one of claims 1 to 4, wherein the outer peripheral surface of the inner ring has an annular step surface facing in the axial direction, and the tip portion of the seal lip portion is the step surface. Rolling bearing in axial contact.   The rolling bearing according to any one of claims 1 to 6, which is used in a transmission of an automobile.

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