JP2011141000A - Rolling bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rolling bearing capable of preventing entering of foreign matter into the bearing, and capable of early reducing seal torque. <P>SOLUTION: This rolling bearing includes inner-outer rings 1 and 2, a plurality of rolling elements 3 and a seal member 5. The seal member 5 is a contact seal whose base end is fixed to the outer ring 2 and seal lip part 15 contacts with the inner ring 1. The seal lip part 15 is composed of a body part 15a and a tip part 15b contacting with the inner ring 1 by projecting from the inner peripheral edge of this body part 15a. A construction material of at least the tip part 15b is a high abrasion material of becoming noncontact by being abraded or becoming light contact of a degree of regarding contact pressure as zero by using the bearing in a rotational state. A seal contact surface MS contacting with the seal lip part 15 in the inner ring 1 is formed as a machining surface. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

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

Foreign matter such as gear abrasion powder is mixed in the transmission of the automobile. For this reason, a conventional bearing used in an automobile transmission is a rolling bearing having a contact-type seal member that seals a bearing space formed between inner and outer rings, and foreign matters enter the bearing by the seal member. Is preventing.
When the bearing space is sealed with such a contact type seal member, foreign matter can be prevented from entering the bearing, but the mechanical loss due to the seal torque is large, which is a problem in promoting the fuel saving of the automobile. .
In such a rolling bearing, shot peening is applied to the surface where the seal lip portion is in sliding contact, for example, the inner wall surface of the seal groove of the bearing rotating ring, and the maximum roughness Ry of the contact surface is reduced to 2.5 μm or less, and the seal torque Has been proposed (Patent Document 1).

JP 2007-107588 A

  In the rolling bearing in which the seal torque is reduced by the shot peening described above, the torque reduction effect is limited. If a non-contact seal is used, the seal torque can be reduced to zero, but reducing the seal clearance to the extent that foreign matter such as wear particles from the gears can be prevented is due to assembly errors, processing errors, thermal expansion differences, etc. It is difficult to realize.

  An object of the present invention is to provide a rolling bearing capable of preventing foreign matters from entering the bearing and reducing the sealing torque at an early stage.

A rolling bearing according to a first aspect of the present invention includes inner and outer rings, a plurality of rolling elements interposed between raceway surfaces of the inner and outer rings, and a seal member that seals a bearing space formed between the inner and outer rings. In the rolling bearing, the seal member is a contact seal in which a base end is fixed to the outer ring and a seal lip portion is in contact with the inner ring, and the seal lip portion protrudes from a main body portion and an inner peripheral edge of the main body portion. The tip portion is in contact with the inner ring, and at least the tip portion is made of a material that is worn out of contact with the bearing when it is used in a rotating state. The seal contact surface that is a wear material and contacts the seal lip portion of the inner ring is a wear promoting treatment surface that promotes wear of the seal lip portion.
The “high wear material” is a material that easily wears.

  According to this configuration, the material of the tip portion of the seal lip portion is made of a high wear material as described above, and the seal contact surface of the inner ring is a wear promoting treatment surface that promotes wear of the seal lip portion. The seal member which is a contact type becomes a non-contact or light contact type seal member due to wear. Therefore, the seal torque can be sufficiently and quickly reduced by wearing the tip portion of the seal lip portion. In addition, due to the wear of the seal member, a minute gap serving as an optimal non-contact seal gap or a light contact seal gap is formed between the seal lip portion and the inner ring. Therefore, although the lubricating oil can pass through, it is possible to prevent the entry of foreign matters having a large particle size that affect the bearing life. Therefore, it is possible to reliably prevent foreign matter from entering the bearing and sufficiently reduce the sealing torque.

The surface roughness of the seal contact surface in the inner ring is set to Ra 6.3 μm or less.
The wear promoting treatment surface may be one in which the seal contact surface of the inner ring is subjected to laser marking or knurling. When laser marking is applied to the seal contact surface, minute protrusions are formed in the vicinity of the laser irradiation portion. For this reason, wear of the tip portion of the seal lip portion is promoted.

  A rolling bearing according to a second aspect of the present invention includes inner and outer rings, a plurality of rolling elements interposed between the raceway surfaces of the inner and outer rings, and a seal member that seals a bearing space formed between the inner and outer rings. In the rolling bearing, the seal member is a contact seal in which a base end is fixed to the outer ring and a seal lip portion is in contact with the inner ring, and the seal lip portion protrudes from a main body portion and an inner peripheral edge of the main body portion. The tip portion is in contact with the inner ring, and at least the tip portion is made of a material that is worn out of contact with the bearing when it is used in a rotating state. A seal contact surface that is a wear material and contacts the seal lip portion of the inner ring is a turning surface.

  According to this configuration, since the material of the tip portion of the seal lip portion is a high wear material as described above, and the seal contact surface of the inner ring is a turning surface, the seal member that was a contact type at the initial stage of operation, It becomes a non-contact or light contact type seal member due to wear. Therefore, the seal torque can be sufficiently and quickly reduced by wearing the tip portion of the seal lip portion. Since it is not necessary to polish at least the seal contact surface of the inner ring after turning, the number of processes can be reduced, and thus the manufacturing cost can be reduced. In addition, similarly to the first invention, it is possible to reliably prevent foreign matter from entering the bearing and sufficiently reduce the sealing torque.

  A seal groove may be provided on the outer periphery of the inner ring, and an inner surface of the seal groove may be the seal contact surface. The sealing effect is enhanced by bringing the sealing lip portion into contact with the sealing groove of the inner ring. Therefore, even if a non-contact seal is formed due to wear of the seal lip portion, reliable sealing performance is ensured.

  The seal lip portion of the seal member may be shaped to contact the inner ring in the radial direction. In this case, after the seal lip part comes into contact in the radial direction by the operation of the bearing and wears to a non-contact state or a light contact state, the seal lip part is adsorbed even if the bearing space becomes negative pressure. Can be eliminated or reduced.

  The front end portion of the seal lip portion may protrude from the inner surface side edge, which is a part of the axial thickness of the inner peripheral edge of the main body portion, toward the inner diameter side so as to contact the inner ring. In this case, the rigidity of the seal member can be increased as compared with the case where the tip portion of the seal lip portion is provided on the outside in the axial direction or in the middle. As a result, the seal lip portion is unlikely to warp outward in the axial direction, and a strong contact force can be applied to the seal lip portion. Therefore, the seal torque can be sufficiently and quickly reduced by wearing the tip portion of the seal lip portion.

  The seal lip portion of the seal member may be shaped to contact the inner ring in the axial direction. When the seal lip portion is in axial contact, it is easy to reduce the contact pressure during contact.

  The rolling bearing of the present invention may be a transmission bearing used for supporting a transmission drive transmission shaft for an automobile. The transmission drive transmission shaft may be any shaft such as an input shaft, an output shaft, and an intermediate transmission shaft. In this case, foreign matter such as gear wear powder in the transmission can be prevented from entering the bearing. Since it is possible to reduce the seal torque, it is possible to save the fuel consumption of the automobile.

A first rolling bearing according to the present invention includes a rolling member including inner and outer rings, a plurality of rolling elements interposed between raceway surfaces of the inner and outer rings, and a seal member that seals a bearing space formed between the inner and outer rings. In the bearing, the seal member is a contact seal having a base end fixed to the outer ring and a seal lip portion contacting the inner ring, and the seal lip portion protrudes from a main body portion and an inner peripheral edge of the main body portion. A high-abrasion material that is at least in contact with the surface and is made of at least the material of the front-end portion that wears out of contact with the rotation of the bearing in a rotating state or is light in contact so that the contact pressure can be regarded as zero. It is.
The seal contact surface with which the seal lip portion is in contact with the inner ring is a wear promoting treatment surface that promotes wear of the seal lip portion, thereby preventing foreign matter from entering the bearing and reducing the seal torque at an early stage. be able to.

  In the second rolling bearing of the present invention, the material of the tip portion of the seal lip portion is made of a high wear material, and the seal contact surface with which the seal lip portion of the inner ring contacts is a turning surface. While preventing intrusion of foreign matter, it is possible to reduce the seal torque at an early stage.

(A) is sectional drawing of the rolling bearing which concerns on one Embodiment of this invention, (B) is principal part sectional drawing which expands and shows the sealing member etc. of the rolling bearing. (A) is an enlarged cross-sectional view showing a state before wear when the seal lip portion of the seal member is in contact with the inner ring, and (B) is a view between the seal lip portion and the inner ring due to wear of the seal lip portion. It is an expanded sectional view which shows the state in which the optimal micro clearance gap was formed. It is a graph which shows the time-dependent change of the rotational torque and bearing temperature of the rolling bearing. It is an expanded sectional view of the principal part of the rolling bearing which concerns on other embodiment of this invention. It is an expanded sectional view of the principal part of the rolling bearing which concerns on other embodiment of this invention. It is an expanded sectional view of the principal part of the rolling bearing which concerns on other embodiment of this invention. It is a figure which shows the example which used the bearing for transmissions concerning embodiment of this invention for a continuously variable transmission.

An embodiment of the present invention will be described with reference to FIGS.
The rolling bearing according to this embodiment is, for example, a bearing used in an automobile transmission or the like, and a plurality of rolling elements are provided between the raceway surfaces 1a and 2a of the inner and outer rings 1 and 2 as shown in FIG. 3 is interposed. The inner and outer rings 1 and 2 and the rolling element 3 are made of, for example, high carbon chrome bearing steel such as SUJ2, martensitic stainless steel, or the like. However, it is not limited to these steels. This rolling bearing has a cage 4 that holds the plurality of rolling elements 3, and both ends of an annular bearing space formed between the inner and outer rings 1 and 2 are sealed with seal members 5, respectively. Grease is initially sealed in the bearing. The rolling bearing of this example is a deep groove ball bearing in which the rolling elements 3 are balls, 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. However, it is also possible to apply an angular ball bearing as a rolling bearing. It is also possible to use an outer ring rotating type in which the inner ring 1 is a fixed ring and the outer ring 2 is a rotating ring.

  The cage 4 is formed by combining two annular holding plates having hemispherical bulging portions arranged at predetermined intervals along the circumferential direction. Each annular holding plate is, for example, a cold-worked steel strip press product. Each annular holding plate has a hemispherical bulging portion disposed along the circumferential direction and a flat portion between adjacent hemispherical bulging portions. In a state where these annular holding plates are combined, the flat portions are overlapped, and the flat portions are connected via a fixing tool such as a rivet. However, the fixing tool is omitted, a claw-like engaging part is provided on one flat part, an engaged part is provided on the other flat part, and the flat part is connected by engaging the engaging part with the engaged part. You may let them. By connecting the flat portions, the hemispherical bulge portions face each other to form a ring-shaped pocket Pt.

The seal member 5 and the like will be described.
As shown in FIG. 1, a seal attachment groove 2 b for fitting and fixing the seal member 5 is formed on the inner peripheral surface of the outer ring 2. A seal groove 1c is formed on the outer periphery of the inner ring 1, and a seal lip portion 15 contacts the inner surface of the seal groove 1c in the radial direction. The inner surface of the seal groove 1c is a wear promoting treatment surface that promotes wear of the seal lip portion 15, specifically, a surface formed by turning (turning surface), and no additional processing such as polishing is performed after the turning. . By the turning process, the surface roughness of the seal contact surface MS in the inner ring 1 is set to Ra 6.3 μm or less.
The seal contact surface MS with which the seal lip portion 15 in the inner ring 1 contacts is particularly a turning surface, so that wear of the tip portion 15b of the seal lip portion 15 can be promoted as will be described later.
The seal member 5 includes an annular cored bar 6 and an elastic member 7 that is integrally fixed to the cored bar 6. The entire seal member 5 is formed, for example, by vulcanization molding of a rubber material, and the cored bar 6 is bonded to the elastic member 7 at the time of vulcanization molding.

  The metal core 6 has a cylindrical portion 8, a standing plate portion 9, and an inclined portion 10 sequentially from the outer diameter side. The upright plate portion 9 is disposed substantially parallel to the end surface on the axially inner side of the bearing from the end surfaces of the inner and outer rings 1 and 2. The cylindrical portion 8 is connected to the base end of the standing plate portion 9, and the standing plate portion 9 and the cylindrical portion 8 form an L-shaped cross section. The elastic member outer peripheral portion 11 of the elastic member 7 provided mainly on the outer peripheral surface of the cylindrical portion 8 is fitted and fixed to the seal mounting groove 2 b of the outer ring 2. An inclined portion 10 that is slightly inclined inward in the axial direction as it goes toward the inner diameter side is connected to the inner peripheral end of the upright plate portion 9.

The elastic member 7 mainly has an elastic member outer peripheral portion 11, a cover portion 12, an inclined cover portion 13, and an elastic member inner peripheral portion 14.
The outer surface of the upright plate portion 9 in the cored bar 6 is covered with a uniform thin-walled cover portion 12. The inclined portion 10 is provided with an inclined cover portion 13 that is thicker than the cover portion 12. The inclined cover portion 13 covers the inner and outer surfaces of the inclined portion 10.
The inner surface of the inclined portion 10 of the inclined cover portion 13 is slightly inclined inward in the axial direction as it goes toward the inner diameter side. Therefore, the inner surface portion 13a constituting the inner surface of the inclined covering portion 13 has a uniform axial thickness along the radial direction. In addition, the outer surface of the inclined portion 10 of the inclined cover portion 13 is connected to the cover portion 12 in the same plane without a step. Therefore, the outer surface portion 13b constituting the outer surface of the inclined covering portion 13 is formed so that the axial thickness gradually increases toward the inner diameter side. The inner surface and outer surface portions 13a and 13b can increase the rigidity of the inclined cover portion 13 as a whole.

As shown in FIGS. 1B and 2A, an elastic member inner peripheral portion 14 is connected to the inner peripheral edge of the inclined covering portion 13 of the elastic member 7. The elastic member inner peripheral portion 14 extends to the inner diameter side of the inner peripheral edge of the inclined portion 10 in the cored bar 6.
The portion above the two-dot chain line in FIG. 2A and below the inclined cover portion 13 is the outer peripheral portion 14a of the elastic member inner peripheral portion 14, and the inner peripheral portion of the elastic member inner peripheral portion 14, that is, A portion below the two-dot chain line in FIG. 1 and 2A, the tip portion 15b of the seal lip portion 15 represents a natural state, and the tip portion 15b is taken into the inner ring 1 in an initial state before actual bearing operation. 2A, the tip portion 15b of the seal lip portion 15 is in pressure contact with the seal groove 1c of the inner ring 1 in an elastically deformed state.

  In the elastic member 7, the outer peripheral portion 14 a of the elastic member inner peripheral portion 14 is a portion that integrally connects the inclined covering portion 13 and the seal lip portion 15. The outer surface of the outer peripheral portion 14a is inclined inward in the axial direction toward the inner diameter side. The inner surface of the outer peripheral portion 14 a is connected to the inner peripheral edge of the inner surface of the inner surface portion 13 a in the inclined cover portion 13, and is connected to the inner surface of the seal lip portion 15 on the same surface without a step so as to be flat. In this example, the radial height H 1 of the outer peripheral portion 14 a of the elastic member inner peripheral portion 14 is shorter than the radial height H 2 of the seal lip portion 15. With the shape of the outer peripheral portion 14a and the inclined cover portion 13 described above, the rigidity of the radially inner peripheral portion of the seal member 5 can be reliably increased.

The seal member 5 is a contact seal in which the seal lip portion 15 is in contact with the seal groove 1 c of the inner ring 1. In this example, the initial contact force of the seal lip portion 15 with respect to the inner ring 1 is defined as 11 N or more.
The seal lip portion 15 includes a main body portion 15a and the tip portion 15b. Among these, the tip portion 15b is provided to protrude from the inner surface side edge of the inner peripheral edge of the main body portion 15a toward the inner diameter side. In other words, the tip end portion 15b protrudes from the inner surface side edge, which is a part of the axial thickness at the inner peripheral edge of the main body portion 15a, to the inner diameter side and contacts the bottom surface of the seal groove 1c of the inner ring 1 in the radial direction. The shape to be. An axial thickness of the seal lip portion 15 is formed thinner than an axial thickness of the outer peripheral portion 14a, and an axial thickness of the tip portion 15b is formed thinner than an axial thickness of the main body portion 15a. . Thereby, the contact force from the inner ring 1 can be concentrated and applied to the tip portion 15 b of the seal lip portion 15. Further, the radial height H of the elastic member inner peripheral portion 14 is set to be equal to or less than the axial thickness t1 of the main body portion 15a of the seal lip portion 15.

  The material of at least the tip portion 15b of the seal lip portion 15 is a high-abrasion material that is lightly contacted so that it can be worn out of contact or contact pressure can be regarded as zero when the bearing is used in a rotating state. is there. The high wear material may be provided only on the tip portion 15b of the seal lip portion 15 or across the tip portion 15b and the main body portion 15a. This high wear material is selected from a specific type depending on the compatibility with the bearing operating temperature and the lubricating oil. The high wear material is made of, for example, a high wear rubber material. For example, 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.

  2A is an enlarged cross-sectional view of the main part in a state in which the seal lip portion is in contact with the bottom surface of the seal groove of the inner ring, and FIG. 2B is a wear of the tip portion of the seal lip portion using the bearing in a rotating state. It is an expanded sectional view of the important section of the state made to do. For example, when the bearing is used for 1 hour to several hours, which is about the time of running-in in a rotating state, the tip portion 15 b of the seal lip portion 15 of the seal member 5 is worn. That is, the seal member 5 changes from the state of FIG. 2A to the state of FIG.

The seal mold for molding the seal member 5 has an upper mold and a lower mold. A cavity for molding the seal member 5 is formed in a state where the upper mold and the lower mold are combined. The seal mold is formed with a gate for injecting the material of the elastic member 7 into the cavity.
The tip portion 15b 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 not applied are molded by the seal mold, for example, by two-color molding. That is, after the other portion of the elastic member 7 on the primary side is molded, the high wear rubber material is poured into the cavity of the tip portion 15b of the seal lip portion 15 on the secondary side, and the elastic member 7 is molded integrally. In this way, the tip end portion 15b of the seal lip portion 15 on the secondary side in the same seal mold is molded integrally with the other portions.

  According to the rolling bearing described above, the material of the tip portion 15b of the seal lip portion 15 is made of a high wear material as described above, and the seal contact surface MS of the inner ring 1 is a turning surface. The seal member 5 which has been changed into a non-contact or light contact type seal member 5 due to wear. Therefore, the seal torque can be reduced sufficiently and quickly by wearing the tip portion 15b of the seal lip portion 15. Since it is not necessary to polish at least the seal contact surface MS of the inner ring 1 after turning, the number of steps can be reduced, and thus the manufacturing cost can be reduced. Further, due to the wear of the seal member 5, as shown in FIG. 2B, a minute gap δ is formed between the seal lip portion 15 and the inner ring 1 as an optimum non-contact seal gap or light contact seal gap. Is done. Therefore, although the lubricating oil can pass through, it is possible to prevent the entry of foreign matters having a large particle size that affect the bearing life. Therefore, it is possible to reliably prevent foreign matter from entering the bearing and sufficiently reduce the sealing torque.

  In this example, the sealing effect is enhanced by bringing the sealing lip portion 15 into contact with the sealing groove 1c of the inner ring 1. For this reason, even if the seal lip portion 15 is worn and becomes a non-contact seal, reliable sealing performance is ensured. The seal lip portion 15 is shaped to contact the bottom surface of the seal groove 1c of the inner ring 1 in the radial direction. In this case, after the seal lip portion 15 is contacted in the radial direction by the operation of the bearing and is worn to the non-contact state or the light contact state, the seal lip portion 15 is adsorbed even if the bearing space becomes negative pressure. Can be eliminated or reduced.

  Further, since the tip end portion 15b of the seal lip portion 15 is provided on the inner side in the axial direction of the main body portion 15a of the seal lip portion 15, the rigidity of the seal member 5 can be increased as compared with the conventional one. As a result, the seal lip portion 15 does not easily warp outward in the axial direction, and a strong contact force can be applied to the seal lip portion 15. Therefore, the seal torque can be reduced sufficiently and quickly by wearing the tip portion 15b of the seal lip portion 15.

  In the seal member 5, the radial height H of the elastic member inner peripheral portion 14 is set to be equal to or less than the axial thickness t 1 of the main body portion 15 a of the seal lip portion 15. Therefore, the radial height of the elastic member inner peripheral portion 14 having a low rigidity among the elastic members 7 can be made shorter than that of the prior art. Therefore, the rigidity of the seal member 5 can be increased as compared with the conventional one, and a strong contact force can be applied to the seal lip portion 15. Therefore, the tip portion 15b of the seal lip portion 15 can be more reliably worn.

  Here, FIG. 3 is a graph showing temporal changes in the rotational torque and the bearing temperature of the rolling bearing according to the embodiment of the present invention. Within a few minutes after the start of bearing operation, the tip end portion 15b of the seal lip portion 15 is worn, allowing the passage of lubricating oil and forming an optimal labyrinth gap that can prevent the entry of foreign matter having a large particle size that affects the bearing life. The As a result, as shown in FIG. 3, the seal torque, which has occupied most of the bearing torque, becomes zero, thereby realizing a rolling bearing in which the rotational torque is greatly reduced to about 0.1 N · m. Is possible. Along with this, the self-heating of the bearing has also decreased to about 50 ° C. or less. The bearing temperature in this case refers to the temperature of the outer ring 2. By reducing the self-temperature rise of the bearing at an early stage, it is possible to select oil having a lower viscosity than conventional oil. If this bearing is used in a transmission, the loss of the entire transmission can be reduced.

  Hereinafter, other embodiments of the present invention will be described. In the following description, the same reference numerals are given to the portions corresponding to the matters described in the preceding forms in each embodiment, and the overlapping description is omitted. When only a part of the configuration is described, the other parts of the configuration are the same as those described in the preceding section. Not only the combination of the parts specifically described in each embodiment, but also the embodiments can be partially combined as long as the combination does not hinder.

  As shown in FIG. 4, the tip portion 15b of the seal lip portion 15 is made of a high wear material as described above, and the inner ring seal groove 1c is a turning surface. The inner ring 1 may have a shape in contact with the axial direction. In this case, when the tip portion 15b of the seal lip portion 15 is in axial contact with the inner surface 1ca of the seal groove 1c, it is easy to reduce the contact pressure at the time of contact.

  As shown in FIG. 5, the seal contact surface MS with which the tip portion 15b of the seal lip portion 15 contacts the inner ring 1 may be the outer diameter surface 1b of the inner ring 1, and the outer diameter surface 1b may be a turning surface. In this case, the total length of the seal member can be shortened compared to the configuration in which the inner ring seal groove in FIG. 1 is used as the seal contact surface. Accordingly, it is possible to increase the rigidity of the seal member 5 as compared with the seal member corresponding to the inner ring seal groove 1c, and to apply a strong contact force to the seal lip portion 15 by operating the bearing. Thereby, the front-end | tip part 15b of the seal lip part 15 can be more reliably worn out early.

  In the configuration of FIG. 6, the inner ring seal groove 1 c is a turning surface, and the radial height H of the elastic member inner peripheral portion 14 is larger than the axial thickness t 1 of the main body portion 15 a of the seal lip portion 15. . Since the tip end portion 15b of the seal lip portion 15 is provided on the inner side in the axial direction of the main body portion 15a, the rigidity of the seal member 5 is increased as compared with the conventional one, thereby making it difficult for the seal lip portion 15 to warp outward in the axial direction. A strong contact force can be applied to the portion 15.

  In each of the above-described embodiments, the wear promoting treatment surface in the inner ring is a turning surface, but is not limited to a turning surface. For example, the wear promoting treatment surface may be a surface that has been subjected to laser marking or knurling on the seal contact surface of the inner ring. When laser marking is applied to the seal contact surface, minute protrusions are formed in the vicinity of the laser irradiation portion. For this reason, wear of the tip portion of the seal lip portion is promoted.

FIG. 7 is a diagram showing an example in which a transmission bearing is used in a continuously variable transmission (CVT). The transmission bearing BR1 including the rolling bearing according to any of the above-described embodiments is a gear that changes the rotation of the input shaft 22 in a stepless manner and transmits the rotation to the rotation of the output shaft 23.
In FIG. 7, the input shaft 22 is rotationally driven via a torque converter 24 and a planetary mechanism unit 25 by a drive source such as an engine. A driving pulley 26 that rotates synchronously with the input shaft 22 is provided on the input shaft 22, and the groove width of the driving pulley 26 is controlled by a driving actuator 27 so as to be freely expanded and contracted. A driven pulley 28 that rotates synchronously with the output shaft 23 is provided on the output shaft 23, and the groove width of the driven pulley 28 is controlled by a driven actuator 29 so as to be freely expanded and contracted.

  The driven pulley 28 and the driving pulley 26 are rotated at a speed corresponding to each diameter via an endless belt 30 spanned by a diameter corresponding to the selected groove width, and are input to the input shaft 22. The transmitted power is transmitted from the driving pulley 26 to the driven pulley 28 via the endless belt 30. The power transmitted to the driven pulley 28 is transmitted from the output shaft 23 to the drive wheels via the reduction gear train 30 and the differential 31. A deep groove ball bearing is used as the transmission bearing BR1 for rotatably supporting the input shaft 22 and the output shaft 23.

When accelerating the output shaft 23 relative to the input shaft 22, the endless belt 30 is stretched by reducing the groove width of the driving pulley 26 and increasing the groove width of the driven pulley 28. The diameter of the portion is larger at the driving pulley 26 portion and smaller at the driven pulley 28 portion, and the output shaft 23 is accelerated relative to the input shaft 22.
When the output shaft 23 is decelerated with respect to the input shaft 22, the groove spanned on the endless belt 30 is increased by increasing the groove width of the driving pulley 26 and decreasing the groove width of the driven pulley 28. Is reduced at the drive pulley 26 portion and increased at the driven pulley 28 portion, and the output shaft 23 is decelerated with respect to the input shaft 22.
According to this configuration, foreign matter such as gear wear powder in the transmission can be prevented from entering the bearing. Since it is possible to reduce the seal torque, it is possible to save the fuel consumption of the automobile.

In the present embodiment, an example in which a bearing including a seal member unique to the present application is used in a continuously variable transmission is shown, but it can be used in a manual transmission and an automatic transmission.
When the transmission bearing is an outer ring rotating type, a seal member can be fitted and fixed to the outer peripheral surface of the inner ring, and the seal lip portion unique to the present invention can be brought into contact with the outer ring seal groove and worn.
Instead of forming a seal member by vulcanization molding of a rubber material, a seal member may be formed by injection molding of a resin material. The rolling bearing according to each embodiment may be a full ball bearing without a cage.

DESCRIPTION OF SYMBOLS 1 ... Inner ring 1b ... Outer diameter surface 2 ... Outer ring 1a, 2a ... Raceway surface 3 ... Rolling element 5 ... Seal member 15 ... Seal lip part 15a ... Body part 15b ... Tip part MS ... Seal contact surface

Claims (9)

In a rolling bearing comprising an inner and outer ring, a plurality of rolling elements interposed between raceway surfaces of the inner and outer rings, and a seal member that seals a bearing space formed between the inner and outer rings,
The seal member is a contact seal in which a base end is fixed to an outer ring and a seal lip portion is in contact with an inner ring, and the seal lip portion protrudes from an inner peripheral edge of the main body portion and contacts the inner ring. The material of at least the tip portion is a high wear material that wears out of contact and becomes non-contact or uses light contact so that the contact pressure can be regarded as zero when the bearing is used in a rotating state.
A rolling bearing characterized in that a seal contact surface with which the seal lip portion of the inner ring contacts is a wear promoting treatment surface that promotes wear of the seal lip portion.   The rolling bearing according to claim 1, wherein the surface roughness of the seal contact surface of the inner ring is Ra 6.3 µm or less.   3. The rolling bearing according to claim 1, wherein the wear promoting treatment surface is obtained by performing laser marking or knurling on the seal contact surface of the inner ring. In a rolling bearing comprising an inner and outer ring, a plurality of rolling elements interposed between raceway surfaces of the inner and outer rings, and a seal member that seals a bearing space formed between the inner and outer rings,
The seal member is a contact seal in which a base end is fixed to an outer ring and a seal lip portion is in contact with an inner ring, and the seal lip portion protrudes from an inner peripheral edge of the main body portion and contacts the inner ring. The material of at least the tip portion is a high wear material that wears out of contact and becomes non-contact or uses light contact so that the contact pressure can be regarded as zero when the bearing is used in a rotating state.
A rolling bearing, wherein a seal contact surface with which the seal lip portion of the inner ring contacts is a turning surface.   5. The rolling bearing according to claim 1, wherein a seal groove is provided on an outer periphery of the inner ring, and an inner surface of the seal groove serves as the seal contact surface.   The rolling bearing according to any one of claims 1 to 5, wherein a seal lip portion of the seal member is in a shape in contact with the inner ring in a radial direction.   The rolling bearing according to claim 6, wherein the tip end portion of the seal lip portion protrudes from the inner surface side edge, which is a part of the axial thickness of the inner peripheral edge of the main body portion, toward the inner diameter side to come into contact with the inner ring. .   The rolling bearing according to any one of claims 1 to 5, wherein a seal lip portion of the seal member is in a shape contacting with an inner ring in an axial direction.   9. The rolling bearing according to claim 1, wherein the bearing is a transmission bearing used for supporting a transmission drive transmission shaft for an automobile.

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