JP2012233548A - Rolling bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rolling bearing which can reduce torque, can improve the intrusion resistance of foreign matters into a bearing, and can elongate the life of the bearing.SOLUTION: A seal groove 1b whose cross section is formed into a curved shape of a shape which is formed by connecting a curved line and a linear line is formed at a peripheral face at the side of a bearing space of an inner ring 1. The seal member 5 is fixed to an outer ring 2 at its base end and has a seal lip 7e at its tip. The tip of the seal lip 7e is composed of a high-wear material which has a cross section along the inner face of the seal groove 1b, and in which the whole face of a portion entering the seal groove 1b is brought into a non-contact state by being worn by the use of the bearing in a rotation state or brought into a light-contact state at a level at which contact pressure can be deemed zero.

Description

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

Since foreign matter such as gear wear powder is mixed in the transmission of an automobile, a contact-type sealing plate (seal member) is set in a conventional transmission bearing. When sealing the bearing space with such a contact-type seal member, foreign matter can be prevented from entering the bearing, but since a seal torque is generated, how to reduce the mechanical loss in promoting the fuel saving of the automobile. It was a problem.
Therefore, as shown in FIG. 9, the present applicant wears the lip portion 50 a of the seal member 50 using an easily wearable member by friction with the so-called seal land 51 a of the inner ring 51, so that the contact type is initially set in operation. A technique is proposed in which the sealing member 50 is in a non-contact state (Patent Document 1). When the seal member 50 reaches a non-contact state, the optimum clearance generated between the seal member 50 and the inner ring 51 allows oil to pass through the bearing, but prevents large foreign matter from entering.

JP 2010-19296 A

  In the conventional bearing, the labyrinth length of the clearance generated after the seal member 50 is worn is short, and the foreign matter penetration resistance is low. In the conventional example as shown in FIGS. 9 and 10, since only a part of the lip portion of the seal members 50 and 50A is in contact with the inner ring 51, a sufficient labyrinth length cannot be obtained, and the foreign matter penetration resistance is low. .

  An object of the present invention is to provide a rolling bearing capable of reducing the torque, improving the penetration resistance of the bearing against foreign matter, and extending the life of the bearing.

  The rolling bearing of the present invention is a rolling bearing comprising an inner and outer ring, 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. A seal groove having a cross-sectional shape connecting a curve or a curve and a straight line is provided on the bearing space side peripheral surface of one of the inner and outer rings, and the base end of the seal member is the other ring The tip of the seal lip has a cross-sectional shape along the inner surface of the seal groove, and the bearing is used in a rotating state. The entire surface of the entering portion is made of a high-abrasion material that wears out of contact and is light in contact so that the contact pressure can be regarded as zero.

  According to this configuration, the contact type seal member at the beginning of operation becomes a non-contact or light contact type seal member at the initial stage after operation due to wear. At this time, a minute optimum clearance is formed between the tip of the seal lip portion and the seal groove. This optimum clearance is smaller than the foreign material and allows oil to pass through, but cannot allow foreign material of such a size as to affect the bearing life. Further, the entire end of the seal lip portion wears in the seal groove along the cross-sectional shape of the seal groove of the one bearing ring. For this reason, the seal member of the present invention can ensure a large contact area between the seal lip and the race. Therefore, the seal member of the present invention can have a longer and more complex labyrinth structure than those in which only a part of the conventional lip portion is in contact with the inner ring or a flat seal land formed on the outer peripheral surface of the inner ring. . As a result, it is possible to reduce the torque, improve the penetration resistance of the bearing against foreign matter, and extend the life of the bearing.

  The seal lip portion may have a shape in contact with the one raceway in the radial direction and the axial direction. In this case, a long and complicated labyrinth structure can be easily and reliably formed.

The high wear material may be a rubber material or a resin material.
The high wear material may be a rubber material, and the seal member may be formed by vulcanization molding of the rubber material.
The high wear material may be a resin material, and the seal member may be formed by injection molding the resin material.

The seal member has an annular cored bar and an elastic member that covers the whole or a part of the cored bar, and the elastic member is an inner peripheral part of the elastic member that extends to the inner diameter side of the inner peripheral edge of the cored bar. The inner peripheral portion of the inner peripheral portion of the elastic member may be the tip portion of the seal lip portion.
When the elastic member is configured to cover the entire cored bar, a part of the elastic member provided at the base end of the seal member is fixed to the other race ring while being elastically deformed. Thereby, the sealing performance of the other bearing ring and the base end of the seal member can be further improved. In the case where the elastic member covers a part of the core metal, for example, the core metal part at the base end of the seal member is directly fixed to the other race ring by caulking or the like, for example. In this case, the rigidity of the seal member can be increased as compared with the elastic member covering the entire core bar, and a strong contact force can be applied to the distal end portion of the seal lip portion. Therefore, the tip end portion of the seal lip portion can be worn early.

The seal member may be formed by vulcanization molding or injection molding of an elastic member on the whole or a part of the core metal.
The high wear material may be a solid lubricant, non-woven fabric, or mild steel.
The rolling bearing may be used for an automobile transmission. In this case, the front end of the seal lip portion is worn along the cross-sectional shape of the seal groove of the bearing ring, so that the entire surface of the seal groove is worn, so that a long and complicated labyrinth structure can be obtained. Foreign matter such as gear wear powder in the transmission can be prevented from entering the bearing. Further, since the sealing torque can be reduced, the fuel consumption of the automobile can be reduced.

  The rolling bearing of the present invention is a rolling bearing comprising an inner and outer ring, 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. A seal groove having a cross-sectional shape connecting a curve or a curve and a straight line is provided on the bearing space side peripheral surface of one of the inner and outer rings, and the base end of the seal member is the other ring The tip of the seal lip has a cross-sectional shape along the inner surface of the seal groove, and the bearing is used in a rotating state. The entire surface is made of high wear material that wears out of contact and becomes light contact so that the contact pressure can be assumed to be zero. To improve bearing performance and extend the life of bearings Rukoto is possible.

It is sectional drawing of the rolling bearing which concerns on 1st Embodiment of this invention. (A) is an enlarged sectional view near the seal member of the rolling bearing, and (B) is an enlarged sectional view near the seal lip portion of the seal member. (A) is an enlarged cross-sectional view of a main part in a state where the seal lip part is in contact with the seal groove of the inner ring, and (B) is a main part in a state where the tip part of the seal lip part is worn by using the bearing in a rotating state. It is an expanded sectional view. It is sectional drawing of the seal molding die of the seal member. It is sectional drawing of the form which changed the seal member partially. It is sectional drawing of the sealing member of the rolling bearing which concerns on other embodiment of this invention. It is an expanded sectional view near a seal lip portion of a seal member of a rolling bearing according to still another embodiment of the present invention. It is a figure which shows schematically the example which used the rolling bearing which concerns on either embodiment of this invention for the transmission. It is sectional drawing of the principal part of the rolling bearing of a prior art example. It is sectional drawing of the rolling bearing of another prior art example.

A first embodiment of the present invention will be described with reference to FIGS.
The rolling bearing according to this embodiment is used, for example, in an automobile transmission. The following description also includes a description of a method for manufacturing a rolling bearing. As shown in FIG. 1, in this rolling bearing, a plurality of rolling elements 3 are interposed between raceway surfaces 1a, 2a of inner and outer rings 1, 2, which are raceways. 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. A cage 4 for holding the rolling elements 3 is provided, 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. This rolling bearing is a deep groove ball bearing in which the rolling element 3 is a ball, and in this example, 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, an angular ball bearing can also be applied as a bearing with a seal. 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.

  As shown in FIG. 2A, a seal mounting groove 2b for fitting and fixing the seal member 5 is formed on the inner peripheral surface of the outer ring. In the inner ring 1, a seal groove 1 b including a circumferential groove is formed at a position corresponding to the inner peripheral portion of each seal member 5. The seal member 5 includes an annular cored bar 6 and an elastic member 7 that is integrally fixed to the cored bar 6. In this example, the elastic member 7 is provided so as to cover the entire core bar 6 except for the inner surface of the standing plate portion 6 b of the core bar 6. The 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 cored bar 6 has a cylindrical part 6a, a standing plate part 6b, and an inclined part 6c in order from the outer diameter side. The upright plate portion 6b is arranged substantially parallel to the end surface on the axially inner side than the end surfaces of the inner and outer rings 1 and 2. The cylindrical portion 6a is connected to the base 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 base end of the seal member 5 composed 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 fitted and fixed to the seal mounting groove 2b of the outer ring 2. It becomes a fitting part. An inclined portion 6c that is inclined inward in the axial direction toward the inner diameter side is connected to the tip of the upright plate portion 6b.

  The outer surface of the standing plate portion 6b in the cored bar 6 is covered with a uniform thin-walled cover portion 7b, and the inner and outer surfaces of the inclined portion 6c are covered with cover portions 7c and 7d, respectively. A seal lip portion 7e is provided at the inner diameter side tip of the cover portions 7c and 7d. The elastic member 7 includes the outer peripheral portion 7a, cover portions 7b, 7c, and 7d, and a seal lip portion 7e (described later).

  As shown in FIG. 2B, the seal groove 1b is provided on the bearing space side peripheral surface of the inner ring 1, that is, the inner ring outer peripheral surface, and the cross-sectional shape of the seal groove 1b is a shape that connects a curve and a straight line. Yes. The seal groove 1 b has an inner inclined surface 8 connected to the inner ring outer diameter surface 1 c, a groove bottom surface 9 following the inner inclined surface 8, and an outer inclined surface 10 following the groove bottom surface 9. Of these, the inner inclined surface 8 and the outer inclined surface 10 were each cut by a plane including the bearing axial direction, and the cross-sectional shape was a straight line, and the groove bottom surface 9 was viewed by cutting the plane including the bearing axial direction. The cross-sectional shape is a curve that is recessed toward the inner diameter side.

  The inner inclined surface 8 is formed in a shape that is inclined outward in the axial direction from the outer diameter side toward the inner diameter side. The outer inclined surface 10 is formed in a shape that is inclined outward in the axial direction from the inner diameter side toward the outer diameter side. The groove bottom surface 9 connects the inner diameter side edge portion of the inner inclined surface 8 and the inner diameter side edge portion of the outer inclined surface 10, and is formed in a substantially V-shaped cross section as the entire seal groove 1b.

As shown in FIG. 2B, the seal lip portion 7e has a lip base end portion 7ea and a tip end portion 7eb sequentially from the outer diameter side. The elastic member 7 includes an elastic member inner peripheral portion 11 that extends to the inner diameter side from the inner peripheral edge of the inclined portion 6c of the cored bar 6. The outer peripheral portion 11a of the elastic member inner peripheral portion 11 is used as the lip base end of the seal lip portion 7e. The inner peripheral part 11b of the elastic member inner peripheral part 11 is used as the tip part 7eb of the seal lip part 7e.
The front end portion 7eb of the seal lip portion 7e protrudes from the inner peripheral edge of the lip base end portion 7ea and slides into the inner grooved surface 8, the groove bottom surface 9, and the outer inclined surface 10 respectively. Touch. That is, the front end portion 7eb of the seal lip portion 7e includes an inner inclined portion 12 facing the inner inclined surface 8, a bottom portion 13 connected to the inner inclined portion 12 and facing the groove bottom surface 9, and an outer inclined surface 10 connected to the bottom portion 13. And an outer inclined portion 14 facing the surface.

  As shown in FIG. 3A, the cross-sectional shape of the seal lip portion 7e as viewed by cutting the inner inclined portion 12, the bottom portion 13 and the outer inclined portion 14 along a plane including the bearing axial direction is the seal groove 1b. In the assembled state before using this bearing, the seal groove 1b is formed with a constant allowance δa. In other words, when the bearing is assembled, the inner inclined portion 12, the bottom portion 13, and the outer inclined portion 14 of the seal lip portion 7e are respectively the inner inclined surface 8, the groove bottom surface 9, and the outer inclined surface 10 of the seal groove 1b. It is provided so as to be located slightly inward in the radial direction (indicated by a two-dot chain line in FIG. 3A). As a result, the seal lip portion 7e is elastically deformed, and the inner inclined portion 12, the bottom portion 13, and the outer inclined portion 14 of the seal lip portion 7e are in close contact with the inner inclined surface 8, the groove bottom surface 9, and the outer inclined surface 10, respectively. It comes to contact. The inner inclined portion 12 contacts the inner inclined surface 8 in the axial direction, the bottom portion 13 contacts the groove bottom surface 9 in the radial direction, and the outer inclined portion 14 contacts the outer inclined surface 10 in the axial direction.

  As shown in FIG. 3B, the tip portion 7eb of the seal lip portion 7e is worn out of contact with the entire surface of the seal groove 1b by using this bearing in a rotating state. It is made of a high-abrasion material that provides light contact with a contact pressure of zero. As the tip end 7eb of the seal lip 7e wears in this way, a minute optimum clearance is formed which is connected to the inside and outside of the bearing, and between the inner inclined portion 12 of the seal lip 7e and the inner inclined surface 8 of the seal groove 1b. The clearance δ1, the clearance δ2 between the bottom portion 13 and the groove bottom surface 9, and the clearance δ3 between the outer inclined portion 14 and the outer inclined surface 10 communicate with each other with uniform dimensions. In this example, the high wear material is provided only at the tip 7eb, but is not limited to this example. For example, a high wear material may be provided on the entire seal lip portion 7e extending from the distal end portion 7eb and the lip base end portion 7ea. The high wear material is made of, for example, a high wear rubber material. As other materials constituting the high wear material, a resin material, a solid lubricant, a nonwoven fabric, mild steel, or the like may be applied. When the resin material is used, the seal member 5 can be formed by injection molding the resin material using an injection mold not shown.

  As shown in FIG. 4, the seal mold 15 for molding the seal member 5 includes, for example, two molds 16 and 17 that are combined. One of the molds 16, 17 has an annular cavity portion 18 that molds the inner surface portion of the seal member 5, and the other mold 17 serves as an outer surface portion of the seal member 5. It has an annular cavity portion 19 to be molded. In a state where these two molds 16 and 17 are combined with each other, a cavity 20 for molding the seal member 5 is formed. In the seal mold 15, annular gates 21 a and 21 b for injecting the material of the elastic member 7 into the cavity 20 are provided adjacent to the outer peripheral portion and the inner peripheral portion of the cavity 20.

  The tip portion 7eb of the seal lip portion 7e to which the high wear rubber material is applied and the other portion of the elastic member 7 to which the rubber material is applied are molded by the seal molding die 15 by, for example, two-color molding. . First, a rubber material is injected from the gate 21a adjacent to the outer peripheral side portion of the cavity 20, and a portion other than the tip portion 7eb in the elastic member 7 on the primary side is molded. Next, a high wear rubber material is poured from the gate 21b adjacent to the inner peripheral side portion of the cavity 20, and the tip portion 7eb of the seal lip portion 7e on the secondary side is molded. A high wear rubber material is poured from the gate 21b adjacent to the inner peripheral portion of the cavity 20 to form the tip portion 7ea of the seal lip portion 7e, and then the rubber material is applied from the gate 21a adjacent to the outer peripheral portion of the cavity 20. It may be injected and a part other than the tip part 7eb may be formed. In any case, the tip part 7eb made of a high wear rubber material and the other part made of a rubber material can be integrally molded by the same seal molding die 15.

The effect will be described.
According to this configuration, as shown in FIG. 3 (A), the seal member 5 that was a contact type at the beginning of operation is not contacted or lightly contacted at the initial stage after operation as shown in FIG. 3 (B) due to wear. This is a type of seal member 5. At this time, minute optimum clearances δ1, δ2, and δ3 are formed between the tip portion 7eb of the seal lip portion 7e and the seal groove 1b. These optimum clearances δ1, δ2, and δ3 are smaller than foreign materials and allow oil to pass therethrough, but foreign materials having a size that affects the bearing life cannot pass. Further, the entire end portion 7eb of the seal lip portion 7e is worn along the cross-sectional shape of the seal groove 1b. For this reason, the seal member 5 of the present embodiment can ensure a large contact area between the seal lip 7 e and the inner ring 1. Therefore, the seal member 5 can have a labyrinth structure that is longer and more complicated than a conventional member in which only a part of the lip portion is in contact with the inner ring or a flat seal land formed on the outer peripheral surface of the inner ring. As a result, low torque can be achieved, and the foreign matter penetration resistance of the bearing can be improved, and the life of the bearing can be extended.

Of the seal lip portion 7e, the inner inclined portion 12 contacts the inner inclined surface 8 in the axial direction, the bottom portion 13 contacts the groove bottom surface 9 in the radial direction, and the outer inclined portion 14 contacts the outer inclined surface 10. It contacts in the axial direction. As described above, the seal lip portion 7e has a shape in contact with the seal groove 1b in the radial direction and the axial direction, so that a long and complicated labyrinth structure can be easily and reliably formed simply by rotating the bearing. can do.
In this example, since the elastic member 7 covers the entire core bar 6, a part of the elastic member 7 provided at the base end of the seal member 5 is fixed in an elastically deformed state in the outer ring seal groove 2b. Thereby, the sealing performance of the outer ring | wheel 2 and the base end of the sealing member 5 can be improved more.

  As a form in which the seal member 5 is partially changed, as shown in FIG. 5, a configuration in which the rigidity of the seal lip portion 7e is increased may be employed. That is, in the example of FIG. 5, the radial dimension L1 of the lip base end 7ea of the seal lip 7e is formed to be relatively shorter than the radial dimension L2 of the distal end 7eb. Moreover, the thickness of the cover parts 7c and 7d which respectively cover the inner and outer surfaces of the inclined part 6c of the metal core 6 among the elastic members 7 is formed uniformly. By using the bearing including the seal member 5A in a rotating state, the tip end portion 7eb of the seal lip portion 7e is brought into the seal groove 1b (see FIG. 2A) due to the rigidity of the inclined portion 6c of the core metal 6. The entire surface of the entering part wears earlier than that of FIG.

  As shown in FIG. 6, you may comprise so that the elastic member 7 of a sealing member may cover a part of 6 A of metal cores. The metal core 6A includes a bent portion 6Aa, a cylindrical portion 6Ab, a first standing plate portion 6Ac, a first inclined portion 6Ad, a second standing plate portion 6Ae, and a second inclined portion 6Af. The elastic member 7 covers the inner diameter side portion of the second upright plate portion 6Ae and the second inclined portion 6Af. The bent portion 6Aa and the cylindrical portion 6Ab are caulked and fixed to the outer ring seal groove 2b (see FIG. 2A). Other configurations are the same as those in FIG. In this case, the rigidity of the seal member 5B can be increased more than that in which the elastic member 7 covers the entire core, and a strong contact force can be applied to the tip end portion 7eb of the seal lip portion 7e. Therefore, the tip end portion 7eb of the seal lip portion 7e can be worn early.

  As shown in FIG. 7, the cross-sectional shape of the seal groove 1b of the inner ring 1 may be a cross-sectional arc shape formed of a curve. FIG. 7 is an enlarged cross-sectional view of a main part in a state where the tip of the seal lip 7e is worn by using the bearing in a rotating state. In this case, the cross-sectional shape of the tip portion 7eb of the seal lip portion 7e is a cross-sectional arc shape similar to the cross-sectional shape of the seal groove 1b. In this case as well, the labyrinth structure can be longer and more complex than the conventional structure, which can reduce the torque and improve the resistance to foreign matter penetration of the bearing, thereby extending the life of the bearing. It becomes possible.

  FIG. 8 is a schematic view showing an example in which the rolling bearing according to any of the embodiments is incorporated in a transmission of an automobile. The figure is an example of an automatic transmission. The outer rings of the rolling bearings BR1 and BR1 are fitted to both ends of the case 22 in the axial direction, and both ends of the main shaft 23 are rotatably supported by the inner rings of the bearings BR1 and BR1. A counter shaft 24 is provided in the case 22 in parallel with the main shaft 23. The counter shaft 24 has a gear portion that meshes with the gear portion of the main shaft 23 and is rotatably supported by the case 22 via a bearing.

When the rolling bearings BR1 and BR1 are incorporated in an automobile transmission in this way, foreign matters such as gear wear powder in the transmission can be reliably prevented from entering the bearing, and after the start of use, Torque reduction can be achieved at an earlier stage. Since it is possible to reduce the seal torque, it is possible to save the fuel consumption of the automobile. Further, since the manufacturing cost of the rolling bearing can be reduced, the cost of the entire transmission can be reduced.
Note that the rolling bearing according to any of the embodiments may be used in a continuously variable transmission or a manual transmission.

DESCRIPTION OF SYMBOLS 1 ... Inner ring 1b ... Seal groove 2 ... Outer ring 1a, 2a ... Raceway surface 3 ... Rolling element 5 ... Seal member 6 ... Core metal 7 ... Elastic member 7e ... Seal lip part 7eb ... Tip part

Claims (9)

In a rolling bearing comprising an inner and outer ring, 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,
A seal groove having a cross-sectional shape connecting a curved line or a straight line is provided on the bearing space side peripheral surface of one of the inner and outer rings.
The seal member has a base end fixed to the other race ring and a seal lip portion at the tip.
The tip of the seal lip has a cross-sectional shape along the inner surface of the seal groove, and when the bearing is used in a rotating state, the entire surface of the portion that enters the seal groove is worn and contactless. A rolling bearing characterized in that it is made of a highly wearable material that has a light contact with which contact pressure can be regarded as zero.   The rolling bearing according to claim 1, wherein the seal lip portion has a shape in contact with the one raceway in a radial direction and an axial direction.   The rolling bearing according to claim 1 or 2, wherein the high wear material is a rubber material or a resin material.   4. The rolling bearing according to claim 3, wherein the high wear material is a rubber material, and the seal member is formed by vulcanization molding of the rubber material.   4. The rolling bearing according to claim 3, wherein the high wear material is a resin material, and the seal member is formed by injection molding the resin material.   6. The sealing member according to claim 1, wherein the sealing member includes an annular cored bar and an elastic member that covers all or a part of the cored bar, and the elastic member includes the cored bar. A rolling bearing including an inner peripheral portion of an elastic member extending to an inner diameter side of the inner peripheral edge, and an inner peripheral portion of the inner peripheral portion of the elastic member as the tip end portion of the seal lip portion.   7. The rolling bearing according to claim 6, wherein the seal member is formed by vulcanization molding or injection molding of an elastic member on the whole or a part of the core metal.   The rolling bearing according to any one of claims 1 to 7, wherein the high wear material is a solid lubricant, a nonwoven fabric, or mild steel.   9. The rolling bearing according to claim 1, wherein the rolling bearing is used for a transmission of an automobile.

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