JP2022034794A - Resin-made retainer for tapered roller bearing, and tapered roller bearing - Google Patents

Abstract

To provide a resin-made retainer for a tapered roller bearing capable of preventing a quick temperature rise between a large end surface of a tapered roller and a large flange of an inner ring when the tapered roller bearing is to be started, and excellent in moldability.SOLUTION: In a resin-made retainer for a tapered roller bearing, a large diameter side rim 13, a small diameter side rim 14, and a plurality of pillars 15 are integrally molded by a resin composition. A large diameter side rim inner peripheral surface 23 is tilted in a tapered shape in which an inner diameter gradually increases as going away from a large end surface 11 of a tapered roller 6 to a retainer axial direction.SELECTED DRAWING: Figure 1

Description

The present invention relates to a resin cage for tapered roller bearings and a tapered roller bearing using the resin cage for tapered roller bearings.

Tapered roller bearings, which are bearings capable of simultaneously supporting radial loads and axial loads, are often used in automobile transmissions and differential mechanisms (for example, Patent Document 1).

The tapered roller bearings of Patent Document 1 include an outer ring having a conical outer ring raceway surface on the inner circumference, an inner ring having a conical inner ring raceway surface facing the inner diameter side of the outer ring raceway surface on the outer circumference, and an outer ring raceway surface and an inner ring. It has a plurality of tapered rollers incorporated at intervals in the circumferential direction between the raceway surfaces, and an annular cage for maintaining the circumferential spacing of the plurality of tapered rollers. On the outer circumference of the inner ring, a large brim is formed to guide the large end surface of the tapered roller. During bearing rotation, the large end face of the tapered roller and the large collar of the inner ring support part of the axial load through slippery contact.

Lubrication of the conical roller bearings includes a splash lubrication method that lubricates the bearing by splashes of lubricating oil that is splashed up by the rotation of the gear, a pressure feed lubrication method that directly supplies the lubricating oil pumped from the oil pump to the bearing, and oil. This is done by an oil bath lubrication method that uses the bearing with a part of the bearing immersed in the lubricating oil stored in the bath. Here, when the bearing is rotating, the lubricating oil is continuously supplied to the tapered roller bearing from the outside, but when the bearing is stopped, the lubricating oil is continuously supplied to the tapered roller bearing from the outside. Stop. Therefore, when the tapered roller bearing is stopped for a long time, most of the lubricating oil adhering to the tapered roller bearing flows down, and then when the tapered roller bearing is started, insufficient lubrication is likely to occur.

In particular, in recent years, in order to suppress energy loss caused by the stirring resistance of lubricating oil, there is a tendency to use low-viscosity lubricating oil or reduce the amount of lubricating oil in transmissions and differential mechanisms of automobiles. Therefore, when the tapered roller bearing is stopped for a long time, the amount of lubricating oil remaining in the tapered roller bearing tends to be too small, and then when the tapered roller bearing is started, the large end face of the tapered roller and the large flange of the inner ring There is a risk that the temperature will rise sharply between and.

Japanese Unexamined Patent Publication No. 2007-024168 International Publication No. 2011/062188

By the way, the figure of Patent Document 2 as a cage for tapered roller bearings capable of lubricating between the large end surface of the tapered rollers and the large flange of the inner ring even when the supply of lubricating oil to the tapered roller bearings from the outside is stopped. 5 and those shown in FIG. 11 are known.

The cage for tapered roller bearings of FIGS. 5 and 11 of Patent Document 2 has a large-diameter side rim extending in the circumferential direction of the cage along the large end faces of a plurality of tapered rollers arranged at intervals in the circumferential direction of the cage. The large-diameter side rim part and the small-diameter side rim part pass between the tapered rollers, the small-diameter side rim part extending in the circumferential direction of the cage along the small end faces of the plurality of tapered rollers, and the tapered rollers adjacent to each other in the circumferential direction of the cage. It has a plurality of pillars to be connected, and the large-diameter side rim portion, the small-diameter side rim portion, and the plurality of pillar portions each partition a plurality of pockets for accommodating a plurality of tapered rollers. The large-diameter rim portion extends from the large-diameter side pocket surface facing the large-end surface of each cone and the inner end of the large-diameter pocket surface in the radial direction of the cage in a direction away from the large-end surface of the cone. It has a large-diameter side rim inner peripheral surface facing inward in the radial direction of the cage, and an oil-retaining recess that opens across between the large-diameter side pocket surface and the large-diameter side rim inner peripheral surface.

In this tapered roller bearing cage, when the tapered roller bearing is rotating, a part of the lubricating oil flowing inside the bearing is stored in the oil retaining recess formed in the large diameter side rim of the cage, and then. When the bearing stops and starts rotating again, the lubricating oil flowing out of the oil-retaining recess lubricates between the large end surface of the tapered roller and the large flange of the inner ring.

By the way, in the tapered roller bearing cage of FIGS. 5 and 11 of Patent Document 2, the inner peripheral surface of the large-diameter rim facing inward in the radial direction of the cage of the large-diameter side rim is parallel to the axial direction of the cage. In order to guide the lubricating oil, which is formed in a cylindrical shape or adheres to the surface of the inner peripheral surface of the large diameter side rim, toward the large end surface of the tapered roller, from the large end surface of the tapered roller in the cage axial direction. It is formed in a tapered shape in which the inner diameter gradually decreases as the distance increases.

Here, the inventor of the present application noticed the following problem when he tried to manufacture a cage for tapered roller bearings as shown in FIGS. 5 and 11 of Patent Document 2 by resin molding using a mold. ..

That is, since the tapered roller bearing cage has a conical table shape in which the small diameter side rim portion is on the small diameter side and the large diameter side rim portion is on the large diameter side, this tapered roller bearing cage is used. In the case of manufacturing by resin molding using a mold, a female mold having a tapered cavity and a male mold having a tapered core are used. Here, as shown in FIGS. 5 and 11 of Patent Document 2, the inner peripheral surface of the rim on the large diameter side has a cylindrical shape parallel to the axial direction of the cage, or a tapered shape in which the inner diameter decreases as the distance from the large end surface of the tapered roller increases. In this case, it is difficult for the male mold to be removed from the molded product. Therefore, I noticed that there is a problem that the moldability deteriorates.

The problem to be solved by the present invention is for tapered roller bearings in which a rapid temperature rise is unlikely to occur between the large end surface of the tapered roller and the large flange of the inner ring when the tapered roller bearing is started, and the shapeability is excellent. It is to provide a resin cage.

In order to solve the above problems, the present invention provides a resin cage for tapered roller bearings having the following configuration.
A large-diameter rim portion extending in the circumferential direction of the cage along the large end faces of multiple tapered rollers arranged at intervals in the circumferential direction of the cage.
The small diameter side rim portion extending in the circumferential direction of the cage along the small end faces of the plurality of tapered rollers, and the rim portion on the small diameter side.
It has a plurality of pillar portions that connect the large-diameter side rim portion and the small-diameter side rim portion through between the tapered rollers adjacent to each other in the circumferential direction of the cage.
The large-diameter side rim portion, the small-diameter side rim portion, and the plurality of pillar portions each partition a plurality of pockets for accommodating the plurality of tapered rollers.
The large-diameter side rim portion, the small-diameter side rim portion, and the plurality of pillar portions are integrally molded with the resin composition.
The large-diameter side rim portion is away from the large-diameter side pocket surface facing the large end surface of each tapered roller and the inner end of the large-diameter side pocket surface in the radial direction of the cage, in a direction away from the large end surface of the tapered roller. Tapered roller bearing with an inner peripheral surface of the large-diameter rim that extends inward in the radial direction of the cage and an oil-retaining recess that opens across the large-diameter pocket surface and the inner peripheral surface of the large-diameter rim. In a resin cage for
The inner peripheral surface of the large-diameter rim is made of a resin for tapered roller bearings, characterized in that the inner peripheral surface of the tapered roller is inclined in a tapered shape in which the inner diameter gradually increases as the distance from the large end surface of the tapered roller increases in the axial direction of the cage. Cage.

In this way, the inner peripheral surface of the large-diameter rim is formed with a tapered shape in which the inner diameter gradually increases as the inner peripheral surface of the tapered roller moves away from the large end surface of the tapered roller in the axial direction of the cage, so that it has a tapered cavity. When resin-molding a resin cage for tapered roller bearings using a female mold and a male mold with a tapered core, the male mold can be easily removed from the resin cage for tapered roller bearings, and the moldability is easy to form. Is excellent.

Further, when the tapered roller bearing is rotating, a part of the lubricating oil flowing inside the bearing is stored in the oil-retaining recess formed in the large-diameter side rim portion of the resin cage for the tapered roller bearing, and then. When the bearing stops and then starts rotating again, the lubricating oil flowing out of the oil-retaining recess can lubricate between the large end face of the tapered roller and the large flange of the inner ring. Therefore, when the tapered roller bearing is started, a rapid temperature rise is unlikely to occur between the large end surface of the tapered roller and the large flange of the inner ring.

The inclination angle θ of the inner peripheral surface of the large-diameter rim with respect to the cage axial direction is preferably set in the range of 0 ° <θ≤10 °.

When the inclination angle θ is set to 10 ° or less, a resin cage for tapered roller bearings is resin-molded using a female type with a tapered cavity and a male type with a tapered core, and for tapered roller bearings. When the male mold and the female mold are separated from the resin cage, it is possible to prevent the resin cage for tapered roller bearings from sticking to the female mold. Further, when the inclination angle θ is set to be larger than 0 °, excellent formability can be ensured.

The oil-retaining recess has a cross section orthogonal to the circumferential direction of the cage, and the inner surface of the oil-retaining recess holds the middle position of the large-diameter side pocket surface in the cage radial direction and the inner peripheral surface of the large-diameter rim. It is preferable to form it so as to have an L-shaped cross section that is bent and connected to the intermediate position in the axial direction.

In this way, the oil retaining recess is configured to be non-penetrating in the axial direction of the cage, so that the lubricating oil that flows inside the bearing from the small diameter side to the large diameter side due to the pumping action during bearing rotation is used for tapered roller bearings. It is possible to reliably collect the oil in the oil-retaining recess formed in the large-diameter side rim portion of the resin cage. Therefore, when the tapered roller bearing is started, it is possible to effectively lubricate between the large end surface of the tapered roller and the large flange of the inner ring.

On the inner peripheral surface of the large-diameter rim, the inner surface of the oil-retaining recess is located far from the large end surface of the tapered roller in the circumferential direction of the cage with respect to the position where the inner surface of the oil-retaining recess is connected to the inner peripheral surface of the large-diameter rim. It is preferable to form a convex portion that extends continuously over the entire circumference.

In this way, a resin cage for tapered roller bearings is resin-molded using a female mold with a tapered cavity and a male mold with a tapered core, and the resin cage for tapered roller bearings is male. When the mold and female mold are separated, the male mold is caught on the convex part of the inner peripheral surface of the large diameter side rim and pulls the resin cage for tapered roller bearings in the axial direction of the cage, so it is made of resin for tapered roller bearings. It is possible to prevent the cage from sticking to the female mold.

Further, the convex portion is located on the side far from the large end surface of the conical roller with respect to the position where the inner surface of the oil retaining recess is connected to the inner peripheral surface of the large diameter side rim, and is continuous over the entire circumference in the circumferential direction of the cage. When the lubricating oil that flows from the small diameter side to the large diameter side is received in the oil retention recess due to the pumping action during the rotation of the bearing, the lubricating oil that overflows from the oil retention recess is collected by the convex portion. It can be dammed and held on the inner peripheral surface of the large diameter side rim. Therefore, when the tapered roller bearing is started, it is possible to particularly effectively lubricate the space between the large end surface of the tapered roller and the large flange of the inner ring.

It is preferable to set the height of the convex portion in the cage radial direction with respect to the root of the convex portion on the side close to the large end surface of the tapered roller to 1.0 mm or less.

In this way, when the resin cage for tapered roller bearings is resin-molded using a female mold with a tapered cavity and a male mold with a tapered core, the male mold is used as a resin for tapered roller bearings. It is possible to reliably release the mold from the cage.

It is preferable that the convex portion is formed so that the cross-sectional shape orthogonal to the circumferential direction of the cage is arcuate.

In this way, when the resin cage for tapered roller bearings is resin-molded using a female mold with a tapered cavity and a male mold with a tapered core, the male mold is used as a resin for tapered roller bearings. It is possible to smoothly release the mold from the cage.

As the resin composition, it is preferable to use a resin material to which an elastomer is added.

In this way, the flexibility of the resin cage for tapered roller bearings increases, so a female type with a tapered cavity and a male type with a tapered core are used to make a resin cage for tapered roller bearings. Is molded into resin, and when the male and female molds are separated from the resin cage for tapered roller bearings, the molds can be smoothly released. In addition, when assembling the bearing, the cage is incorporated while expanding its diameter, so that the flexibility is increased and the assembling property is improved.

It is preferable to further add a fiber reinforcing material to the resin material.

In this way, the decrease in strength of the resin cage for tapered roller bearings due to the addition of the elastomer to the resin material can be compensated for by the fiber reinforced material. Therefore, it is possible to realize the formability and assembling property of the resin cage for tapered roller bearings and the strength of the resin cage for tapered roller bearings.

Further, in the present invention, as the tapered roller bearing using the resin cage for the tapered roller bearing described above, the one having the following configuration is also provided.
An outer ring with a conical outer ring raceway surface on the inner circumference,
An inner ring having a conical inner ring raceway surface facing the inner diameter side of the outer ring raceway surface on the outer circumference,
A plurality of tapered rollers incorporated at intervals in the circumferential direction between the outer ring raceway surface and the inner ring raceway surface,
The resin cage for tapered roller bearings, which holds the distance between the plurality of tapered rollers in the circumferential direction, is provided.
The inner ring is a tapered roller bearing having a large collar that contacts the large end surface of each tapered roller.

It is preferable that the oil retaining recess is arranged so as to fit within the region of the large diameter side pocket surface facing the large end surface of the tapered roller so as not to protrude outward from the region facing the large end surface of the tapered roller.

By doing so, it is possible to prevent the lubricating oil accumulated in the oil retaining recess from falling from the outside of the large end surface of the tapered roller and being washed away, so that the large end surface of the tapered roller and the large diameter side rim portion can be prevented. It is possible to effectively hold the lubricating oil between the oil retaining recess and the oil retaining recess.

When the tapered roller has a circular recess in the center of the large end surface, it is preferable to provide two oil-retaining recesses on both sides of the cage peripheral direction sandwiching the circular recess for one pocket.

By doing so, the oil-retaining recesses are arranged on both sides in the circumferential direction of the cage sandwiching the circular recess, so that the lubricating oil collected in the oil-retaining recess is conical with the large-diameter side pocket surface of the large-diameter side rim portion. It is possible to prevent the roller from falling from between the circular recess on the large end surface of the roller and being washed away. Therefore, it is possible to effectively hold the lubricating oil between the large end surface of the tapered roller and the oil-retaining recess of the large-diameter side rim portion.

Of the openings on the large-diameter side pocket surface side of the oil-retaining recess, the opening area facing the annular portion of the large end surface of each conical roller excluding the circular recess is the large diameter of the oil-retaining recess. It is preferable that the opening area on the side pocket surface side is 50% or more.

By doing so, it is effective to prevent the lubricating oil accumulated in the oil retaining recess from falling from between the large diameter pocket surface of the large diameter side rim and the circular recess on the large end surface of the tapered roller and being washed away. can do.

The two oil-retaining recesses on both sides of the circular recess in the circumferential direction of the cage each have a polygonal shape having two or more corners where adjacent inner surfaces of the oil-retaining recess intersect with each other when viewed in the axial direction of the cage. It is preferable to form in.

In this way, at the corners of the oil-retaining recess, the lubricating oil comes into contact with each of the adjacent inner surfaces of the oil-retaining recess, so that the surface tension of the lubricating oil makes it easier for the lubricating oil to be held in the oil-retaining recess. .. Therefore, if a polygonal oil-retaining recess having two or more corners is adopted, the lubricating oil in the oil-retaining recess is suppressed from flowing out from the oil-retaining recess due to its own weight while the bearing is stopped, and the bearing is long-term. Lubricating oil can be reliably kept in the oil-retaining recess even when the oil is stopped for a long time. As a result, when the tapered roller bearing is started, it is possible to reliably lubricate between the large end surface of the tapered roller and the large flange of the inner ring.

The resin cage for tapered roller bearings of the present invention is formed by inclining the inner peripheral surface of the rim on the large diameter side in a tapered shape in which the inner diameter gradually increases as the distance from the large end surface of the tapered rollers increases in the axial direction of the cage. Therefore, when resin-molding a resin cage for tapered roller bearings using a female mold with a tapered cavity and a male mold with a tapered core, the resin cage for tapered roller bearings is replaced with a male mold. Is easy to remove from the mold and has excellent moldability. Further, when the tapered roller bearing is rotating, a part of the lubricating oil flowing inside the bearing is stored in the oil-retaining recess formed in the large-diameter side rim portion of the resin cage for the tapered roller bearing, and then. When the bearing stops and then starts rotating again, the lubricating oil flowing out of the oil-retaining recess can lubricate between the large end face of the tapered roller and the large flange of the inner ring. Therefore, when the tapered roller bearing is started, a rapid temperature rise is unlikely to occur between the large end surface of the tapered roller and the large flange of the inner ring.

Cross-sectional view along the axial plane of a tapered roller bearing incorporating a resin cage for tapered roller bearings according to the first embodiment of the present invention. Enlarged cross-sectional view of the vicinity of the oil retention recess in FIG. A perspective view of the resin cage for tapered roller bearings shown in FIG. 1 as viewed from the small diameter side. A perspective view of the resin cage for tapered roller bearings shown in FIG. 1 as viewed from the small diameter side in the axial direction of the cage. The figure which shows the modification which reduced the oil-retaining recess of the resin cage for a tapered roller bearing shown in FIG. 4 to one. The figure which shows the state which the lubricating oil is held in the corner part of the oil-retaining recess of the resin cage for a tapered roller bearing shown in FIG. The figure which shows the state which the male mold and the female mold which injection-molded the resin cage for tapered roller bearing shown in FIG. 1 are closed. The figure which shows the state which opened the male mold and the female mold shown in FIG. 7, and separated the male mold and the female mold from the resin cage for tapered roller bearings. The figure which shows the resin cage for the tapered roller bearing of the 2nd Embodiment of this invention corresponding to FIG. (A) is a diagram showing a modified example of the convex portion shown in FIG. 9, and (b) is a diagram showing another modified example of the convex portion shown in FIG. The figure which shows the state which the male mold and the female mold which injection-molded the resin cage for tapered roller bearings shown in FIG. 9 are closed. The figure which shows the state which the female mold shown in FIG. 11 is released from the resin cage for a tapered roller bearing. The figure which shows the analysis result of the oil retention amount of the oil retention recess at the time of bearing stop when one oil retention recess is provided for one pocket. The figure which shows the analysis result of the oil retention amount of the oil retention recess at the time of bearing stop when two oil retention recesses are provided for one pocket.

FIG. 1 shows a tapered roller bearing using the resin cage 1 for tapered roller bearings according to the first embodiment of the present invention. This tapered roller bearing has an outer ring 3 having a conical outer ring raceway surface 2 on the inner circumference, an inner ring 5 having a conical inner ring raceway surface 4 on the outer circumference, and a circumference between the outer ring raceway surface 2 and the inner ring raceway surface 4. A plurality of tapered rollers 6 incorporated at intervals in the direction and a resin cage 1 for tapered roller bearings (hereinafter, simply referred to as "resin cage 1") for maintaining the distance between the plurality of tapered rollers 6. Have.

The inner ring 5 is coaxially arranged inside the outer ring 3. On the outer periphery of the inner ring 5, an inner ring raceway surface 4, a small collar 7 located on the small diameter side of the inner ring raceway surface 4, and a large collar 8 located on the large diameter side of the inner ring raceway surface 4 are formed. The inner ring raceway surface 4 faces the inner diameter side of the outer ring raceway surface 2. The tapered roller 6 is in rolling contact with the outer ring raceway surface 2 and the inner ring raceway surface 4. During bearing rotation, each tapered roller 6 revolves around the axis of the inner ring 5 (that is, the axis of the resin cage 1) between the outer ring raceway surface 2 and the inner ring raceway surface 4 while rotating on its axis.

The plurality of tapered rollers 6 are spaced from each other in the circumferential direction of the resin cage 1 and are centered on the virtual cone surface (pitch cone) centered on the axis of the annular resin cage 1 (center line of each tapered roller 6). (Not shown) is located. The tapered roller 6 has a conical rolling surface 9, a small end surface 10 connected to the small diameter side of the rolling surface 9, and a large end surface 11 connected to the large diameter side of the rolling surface 9. A circular recess 12 (see FIG. 4) is formed in the center of the large end surface 11. The rolling surface 9 is a portion of the surface of the tapered rollers 6 that rolls into contact with the outer ring raceway surface 2.

The small collar 7 is formed so as to project radially outward from the inner ring raceway surface 4 so as to face the small end surface 10 of the tapered roller 6. The small collar 7 regulates the tapered roller 6 from moving to the small diameter side, and prevents the tapered roller 6 from falling off from the inner ring raceway surface 4. The large collar 8 is formed so as to project radially outward from the inner ring raceway surface 4 so as to face the large end surface 11 of the tapered roller 6. When the bearing rotates, the large end surface 11 of the tapered rollers 6 and the large flange 8 of the inner ring 5 support a part of the axial load by contact with slip.

The resin cage 1 has a large diameter side rim portion 13 extending in the circumferential direction of the cage along the large end surface 11 of each tapered roller 6 and a small diameter side extending in the circumferential direction of the cage along the small end surface 10 of each tapered roller 6. It has a rim portion 14 and a plurality of pillar portions 15 connecting the large diameter side rim portion 13 and the small diameter side rim portion 14 through between the tapered rollers 6 adjacent to each other in the circumferential direction of the cage.

The large-diameter side rim portion 13, the small-diameter side rim portion 14, and the plurality of pillar portions 15 partition a plurality of pockets 16 for accommodating the plurality of tapered rollers 6, respectively. Here, the large-diameter side rim portion 13 and the small-diameter side rim portion 14 partition both ends of the pocket 16 in the cage axial direction, and the pillar portion 15 partitions both ends of the pocket 16 in the cage circumferential direction. The large-diameter side rim portion 13 is formed with a large-diameter side pocket surface 17 facing the large end surface 11 of the tapered roller 6, and the small-diameter side rim portion 14 is formed with a small-diameter side pocket facing the small end surface 10 of the tapered roller 6. The surface 18 is formed.

The large-diameter side pocket surface 17 is formed so as to be inclined with respect to the cage radial direction (vertical direction in the figure) so as to face parallel to the large end surface 11 of the tapered rollers 6. The small diameter side pocket surface 18 is also formed so as to be inclined with respect to the cage radial direction (vertical direction in the figure) so as to face the small end surface 10 of the tapered roller 6 in parallel.

The pillar portion 15 is formed with a roller guide surface 19 that guides the rolling surface 9 on the outer circumference of the tapered roller 6, and a triangular recess 20 located at the end of the pillar portion 15 on the side of the large diameter side rim portion 13. ing. The triangular recess 20 is a recess recessed in the circumferential direction of the cage with respect to the roller guide surface 19. As shown in FIGS. 7 and 8, the triangular recess 20 forms the large-diameter side pocket surface 17 of the female mold 22 when the resin cage 1 is resin-molded using the male mold 21 and the female mold 22. This is the part through which the part passes.

As shown in FIG. 1, the triangular recess 20 has a corner portion where the large diameter side pocket surface 17 and the pillar portion 15 intersect as one side when viewed in the circumferential direction of the resin cage 1, and the small diameter side rim portion from that one side. It is a triangular recess whose width in the radial direction of the cage gradually decreases as it approaches 14. When viewed in the circumferential direction of the resin cage 1, one side of the triangular recess 20 on the outer side in the radial direction coincides with the outer circumference of the resin cage 1, and one side of the triangular recess 20 on the inner side in the circumferential direction is the cage shaft. It extends parallel to the direction or inclined in the direction of the cage axis from the large diameter side to the small diameter side toward the axis of the cage.

The large-diameter side rim portion 13, the small-diameter side rim portion 14, and the plurality of pillar portions 15 constituting the cage are seamlessly and integrally formed of a resin composition. As the resin composition forming the cage, it is possible to use a resin composition consisting of only a resin material, but here, a resin material to which an elastomer and a fiber reinforced material are added is used.

Polyamide (PA) or super engineering plastic can be adopted as the resin material as the base of the resin composition. As the polyamide, polyamide 66 (PA66), polyamide 46 (PA46), polynonamethylene terephthalamide (PA9T) and the like can be used. Further, as the super engineering plastic, polyphenylene sulfide (PPS) can be adopted. When PPS is used as the base resin material of the resin composition forming the resin cage 1, PPS is preferable because it is excellent in heat resistance, oil resistance, and low water absorption. The elastomer added to the resin material is, for example, a thermoplastic elastomer.

As the fiber reinforcing material added to the resin material, glass fiber, carbon fiber, aramid fiber and the like can be adopted. When glass fiber is used as the fiber reinforcing material, the content of the glass fiber in the fiber reinforcing material may be 10 to 50% by weight (preferably 20 to 40% by weight, more preferably 25 to 35% by weight). can. The combination of types of resin material, elastomer, and fiber reinforced material can be freely selected as appropriate.

The small diameter side rim portion 14 has an inward flange shape that intersects the pitch cone from the connection position with the pillar portion 15 and extends inward in the radial direction of the cage. The pitch cone is a virtual cone surface composed of a locus through which the rotation axis of the tapered roller 6 passes when the tapered roller 6 revolves while rotating between the outer ring 3 and the inner ring 5.

As shown in FIG. 2, the large-diameter side rim portion 13 extends from the large-diameter side pocket surface 17 and the inner end in the cage radial direction of the large-diameter side pocket surface 17 in a direction away from the large end surface 11 of the cone 6. It has a large-diameter side rim inner peripheral surface 23 and an oil-retaining recess 24 that opens across between the large-diameter side pocket surface 17 and the large-diameter side rim inner peripheral surface 23. The large-diameter side rim inner peripheral surface 23 is a surface of the large-diameter side rim portion 13 facing inward in the radial direction of the cage. The large diameter side rim inner peripheral surface 23 faces the outer peripheral surface of the large collar 8 in the radial direction of the cage.

The large-diameter side rim inner peripheral surface 23 is formed so as to be inclined in a tapered shape in which the inner diameter gradually increases as the distance from the large end surface 11 of the tapered roller 6 in the cage axial direction increases. The inclination angle θ of the large diameter side rim inner peripheral surface 23 with respect to the cage axial direction is set in the range of 0 ° <θ≤10 ° (at least 0 ° <θ≤20 °). The large-diameter side rim inner peripheral surface 23 is a conical surface extending linearly in a cross section orthogonal to the cage peripheral direction. The end of the tapered roller 6 on the inner peripheral surface of the large diameter side rim 23 on the side close to the large end surface 11 is the side close to the large diameter side rim portion 13 on one side of the triangular recess 20 of the pillar portion 15 on the inner side in the circumferential direction. It is in a position aligned with the end in the radial direction of the cage.

As shown in FIG. 2, the oil-retaining recess 24 has an inner surface of the oil-retaining recess 24 at an intermediate position in the cage radial direction of the large-diameter side pocket surface 17 and a large-diameter side in a cross section orthogonal to the circumferential direction of the cage. The inner peripheral surface of the rim 23 is formed so as to have an L-shaped cross section that is bent and connected to the intermediate position in the axial direction of the cage. The inner surface of the oil retaining recess 24 is inward in the radial direction of the cage from the inner bottom surface 25 facing inward in the radial direction of the cage and the end of the inner bottom surface 25 on the side far from the large end surface 11 of the tapered rollers 6 in the axial direction of the cage. It has an inner wall surface 26 that stands up to reach the inner peripheral surface 23 of the large diameter side rim. Although the inner bottom surface 25 extends parallel to the cage axial direction in the figure, it may be inclined with an inclination angle of 10 ° or less with respect to the cage axial direction. The inner wall surface 26 extends parallel to the radial direction of the cage.

As shown in FIG. 3, two oil retention recesses 24 are provided for each pocket 16 apart from each other in the circumferential direction of the cage. When the lubricating oil is received in the oil-retaining recess 24, the surface tension of the lubricating oil causes the lubricating oil in the oil-retaining recess 24 to stay in the oil-retaining recess 24 even if an external force such as gravity acts on the lubricating oil. A force (hereinafter referred to as a holding force F1) acts. When the holding force F1 is larger than the gravity F2 acting on the lubricating oil, the lubricating oil is effectively held in the oil holding recess 24. The holding force F1 is calculated by the following formula.
F1 = γ × L × cosθ
Here, L is the wettling length (total length of the inner surface of the oil retaining recess 24 in contact with the lubricating oil), and θ is the contact angle of the lubricating oil with respect to the resin composition constituting the resin cage 1.
On the other hand, the gravity F2 acting on the lubricating oil is calculated by the following formula.
F2 = g × ρ × V
Here, g is the gravitational acceleration (standard acceleration of free fall), ρ is the density of the lubricating oil, and V is the volume of the lubricating oil.
For example, the surface tension of the lubricating oil γ = 30 (mN / m), the contact angle θ = 18.5 (°), the wettling length L = 2.8 × 10 ^-3 (m), and the lubricating oil density ρ = 0. When .850 (g / cm ³ ) and the lubricating oil volume V = 0.49 (mm ³ ), F1 = 8.0 × ^10-5 N. At this time, the gravity F2 acting on the lubricating oil is F2 = 4.0 × ^10-6N . Therefore, F1 ≧ F2, and the lubricating oil in the oil-retaining recess 24 is held in the oil-retaining recess 24 by surface tension. The oil-retaining recess 24 can be formed so that the volume of each of the oil-retaining recesses 24 is 3.00 (mm ³ ) or less.

As shown in FIG. 4, both of the two oil retention recesses 24 are regions of the large diameter side pocket surface 17 facing the large end surface 11 of the tapered roller 6 (the large end surface 11 of the tapered roller 6 shown by the chain line in the figure). The tapered roller 6 is arranged so as to be contained in the region facing the large end surface 11 of the tapered roller 6 so as not to protrude outward from the region inside the roller. Here, the large end surface 11 is a surface including a chamfered portion 27 (see FIG. 2) on the outer periphery of the end portion on the large diameter side of the tapered roller 6.

Further, the two oil-retaining recesses 24 are arranged on both sides of the circular recess 12 in the circumferential direction of the cage so as to sandwich the circular recess 12 between the two oil-retaining recesses 24. The circular recess 12 is the entire portion (including a chamfered portion formed along the peripheral edge of the circular recess 12) recessed from the annular planar portion of the large end surface 11 toward the inner diameter side.

Of the openings on the large-diameter side pocket surface 17 side of the oil-retaining recess 24, the annular portion excluding the circular recess 12 of the large end surface 11 of each conical roller 6 (inside and inside of the outer circle shown by the chain line in the figure). The opening area facing the circle (the portion outside the circle) is 50% or more (preferably 60% or more, more preferably 80% or more) of the opening area on the large diameter side pocket surface 17 side of the oil retaining recess 24. 100%). In the figure, the two oil-retaining recesses 24 are arranged so that there is no portion of the large-diameter side pocket surface 17 that enters the region facing the circular recess 12 (the part of the inner circle shown by the chain line in the figure). There is.

As shown in FIG. 4, the two oil-retaining recesses 24 on both sides in the circumferential direction of the cage that sandwich the circular recess 12 are the corner angles where the adjacent inner surfaces of the oil-retaining recesses 24 intersect each other when viewed in the cage axial direction. It is formed in a polygonal shape (square shape in the figure) having two or more portions 28 (two in the figure).

As shown in FIGS. 7 and 8, the resin cage 1 can be manufactured by resin molding using a male mold 21 and a female mold 22 that can be separated in the axial direction of the cage. The male mold 21 is a mold having a tapered core 29 that forms a surface of the pillar portion 15 of the resin cage 1 that faces inward in the radial direction, and the female mold 22 is a pillar portion 15 of the resin cage 1. A mold having a tapered cavity 30 for forming a surface facing outward in the radial direction of the cage. Here, the small diameter side pocket surface 18 and the guide surface 19 of the resin cage 1 shown in FIG. 1 are molded by the male mold 21, and the large diameter side rim inner peripheral surface 23 shown in FIG. 2 is also molded by the male mold 21. To. On the other hand, the large-diameter side pocket surface 17 and the triangular recess 20 of the resin cage 1 shown in FIG. 1 are formed by a female mold 22.

In recent years, in order to suppress energy loss caused by the stirring resistance of lubricating oil, there is a tendency to use low-viscosity lubricating oil or reduce the amount of lubricating oil in transmissions and differential mechanisms of automobiles. Therefore, when tapered roller bearings are used in automobile transmissions and differential mechanisms, the amount of lubricating oil remaining in the tapered roller bearings tends to be too small when the tapered roller bearings stop for a long period of time. At the time of starting, there is a possibility that the temperature between the large end surface 11 of the tapered roller 6 and the large bearing 8 of the inner ring 5 shown in FIG. 1 rises sharply.

In response to this problem, in the tapered roller bearing of this embodiment, when the tapered roller bearing is rotating, a part of the lubricating oil flowing inside the bearing is formed on the large diameter side rim portion 13 of the resin cage 1. When the bearing is temporarily stopped and the bearing starts to rotate again, the lubricating oil that flows out from the oil-retaining recess 24 is used to supply the large end surface 11 of the tapered roller 6 and the large flange of the inner ring 5. It is possible to lubricate between the eight. Therefore, when the tapered roller bearing is started, a rapid temperature rise is unlikely to occur between the large end surface 11 of the tapered roller 6 and the large flange 8 of the inner ring 5.

Further, since the resin cage 1 is formed so that the inner peripheral surface 23 of the large diameter side rim is inclined in a tapered shape in which the inner diameter gradually increases as the inner peripheral surface 23 of the conical roller 6 moves away from the large end surface 11 of the cone 6 in the cage axial direction. As shown in FIGS. 7 and 8, when the resin cage 1 is resin-molded using the female mold 22 and the male mold 21, the male mold 21 is easily released from the resin cage 1 and has excellent moldability. ing.

Further, as shown in FIG. 2, in this resin cage 1, the inclination angle θ of the large diameter side rim inner peripheral surface 23 with respect to the cage axial direction is set to 10 ° or less (at least 20 ° or less). As shown in FIGS. 7 and 8, when the resin cage 1 is resin-molded using the female mold 22 and the male mold 21, and the male mold 21 and the female mold 22 are separated from the resin cage 1, the resin is formed. It is possible to prevent the cage 1 from sticking to the female mold 22.

Further, as shown in FIG. 2, the resin cage 1 forms an oil-retaining recess 24 so as to have an L-shaped cross section in a cross section orthogonal to the circumferential direction of the cage, and the oil-retaining recess 24 is a cage shaft. Since the structure is non-penetrating in the direction, the lubricating oil that flows from the small diameter side to the large diameter side inside the bearing due to the pumping action during bearing rotation is formed on the large diameter side rim portion 13 of the resin cage 1. It is possible to reliably receive and store the oil in the oil recess 24. Therefore, when the tapered roller bearing is started, it is possible to effectively lubricate between the large end surface 11 of the tapered roller 6 and the large flange 8 of the inner ring 5.

Further, since the resin cage 1 is formed of a resin composition obtained by adding an elastomer to a resin material, the resin cage 1 has high flexibility. Therefore, when the resin cage 1 is resin-molded using the female mold 22 and the male mold 21, and the male mold 21 and the female mold 22 are released from the resin cage 1, the mold can be smoothly released.

Further, since the resin cage 1 further adds a fiber reinforcing material to the resin material, it is possible to compensate for the decrease in strength of the resin cage 1 due to the addition of the elastomer to the resin material with the fiber reinforcing material. be. Therefore, it is possible to realize the moldability and assembling property of the resin cage 1 and the strength of the resin cage 1.

Further, as shown in FIG. 4, the tapered roller bearing has the large end surface 11 of the tapered roller 6 so as not to protrude outward from the region of the large diameter side pocket surface 17 facing the large end surface 11 of the tapered roller 6. Since the oil-retaining recess 24 is arranged so as to fit in the facing region, it is necessary to prevent the lubricating oil collected in the oil-retaining recess 24 from falling from the outside of the large end surface 11 of the tapered roller 6 and being washed away. Can be done. Therefore, it is possible to effectively hold the lubricating oil between the large end surface 11 of the tapered roller 6 and the oil retaining recess 24 of the large diameter side rim portion 13.

Further, as shown in FIG. 4, the tapered roller bearing is provided with two oil-retaining recesses 24 on both sides in the circumferential direction of the cage sandwiching the circular recess 12 for each pocket 16, so that the oil-retaining recess 24 is provided. It is possible to prevent the lubricating oil accumulated in the tapered roller 6 from falling from between the large diameter side pocket surface 17 of the large diameter side rim portion 13 and the circular recess 12 of the large end surface 11 of the tapered roller 6 and being washed away. Therefore, it is possible to effectively hold the lubricating oil between the large end surface 11 of the tapered roller 6 and the oil retaining recess 24 of the large diameter side rim portion 13.

Further, in the tapered roller bearing, as shown in FIG. 4, the circular recess 12 in the large end surface 11 of each tapered roller 6 is removed from the opening on the large diameter side pocket surface 17 side of the oil retaining recess 24. The opening area facing the annular portion is 50% or more (preferably 60% or more, more preferably 80% or more, 100% in FIG. 4) of the opening area on the large diameter side pocket surface 17 side of the oil retaining recess 24. Therefore, it is effective that the lubricating oil accumulated in the oil-retaining recess 24 falls from between the large-diameter side pocket surface 17 of the large-diameter side rim portion 13 and the circular recess 12 of the large end surface 11 of the tapered roller 6 and is washed away. Can be prevented.

Further, in the tapered roller bearing, as shown in FIG. 6, the two oil-retaining recesses 24 on both sides in the circumferential direction of the cage sandwiching the circular recess 12 are the oil-retaining recesses 24, respectively, when viewed in the axial direction of the cage. Since it is formed in a polygonal shape having two or more corner portions 28 where the adjacent inner surfaces of the above intersect with each other, the holding power of the lubricating oil in the oil retaining recess 24 is high.

That is, in the corner portion 28 of the oil-retaining recess 24, the lubricating oil comes into contact with each of the adjacent inner surfaces of the oil-retaining recess 24, so that the lubricating oil is easily held in the oil-retaining recess 24 due to the surface tension of the lubricating oil. Become. Therefore, as shown in FIG. 6, when the polygonal oil-retaining recess 24 having two or more corner portions 28 is adopted, the lubricating oil in the oil-retaining recess 24 is removed from the oil-retaining recess by its own weight while the bearing is stopped. It is possible to suppress the outflow and surely keep the lubricating oil in the oil retaining recess 24 even when the bearing is stopped for a long period of time. As a result, when the tapered roller bearing is started, it is possible to reliably lubricate between the large end surface 11 of the tapered roller 6 and the large flange 8 of the inner ring 5. For example, as shown in FIG. 5, if there is only one oil retaining recess 24 per pocket 16, there are only two corner portions 28 per pocket 16, whereas as shown in FIG. 6, 1 If there are two oil-retaining recesses 24 per pocket 16, four corners 28 can be secured for each pocket 16, so that the total amount of lubricating oil held in the oil-retaining recesses 24 per pocket 16. Can be increased.

FIG. 9 shows the resin cage 1 of the second embodiment. The only difference is that the convex portion 31 is added as compared with the first embodiment, and the other configurations are the same as those of the first embodiment. Therefore, the parts corresponding to the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

On the inner peripheral surface of the large-diameter rim 23, the inner surface of the oil-retaining recess 24 is located far from the large end surface 11 of the tapered roller 6 with respect to the position where the inner surface of the oil-retaining recess 24 is connected to the inner peripheral surface of the large-diameter rim. A convex portion 31 extending continuously over the entire circumference is formed.

The height h in the cage radial direction of the convex portion 31 with respect to the root of the tapered roller 6 on the side close to the large end surface 11 of the convex portion 31 is set to 1.0 mm or less (at least 2.0 mm or less).

The convex portion 31 is formed so that the cross-sectional shape orthogonal to the circumferential direction of the cage is an arc shape.

In this resin cage 1, as shown in FIGS. 11 and 12, the resin cage 1 is resin-molded using the female mold 22 and the male mold 21, and the male mold 21 and the female mold 22 are separated from the resin cage 1. When molding, the male mold 21 is caught on the convex portion 31 of the inner peripheral surface 23 of the large diameter side rim and pulls the resin cage 1 in the cage axial direction, so that the situation where the resin cage 1 sticks to the female mold 22 is prevented. can do. The resin cage 1 shown in FIG. 12 is released from the male mold 21 by using an extrusion pin (not shown) incorporated in the male mold 21.

Further, in this resin cage 1, the convex portion 31 is located on the side far from the large end surface 11 of the conical roller 6 with respect to the position where the inner surface of the oil retaining recess 24 is connected to the inner peripheral surface 23 of the large diameter side rim. In addition, since it extends continuously over the entire circumference in the circumferential direction of the cage, when the lubricating oil flowing from the small diameter side to the large diameter side is received in the oil retaining recess 24 by the pumping action during bearing rotation, The lubricating oil overflowing from the oil retention recess 24 can be blocked by the convex portion 31 and held on the inner peripheral surface 23 of the large diameter side rim. Therefore, when the tapered roller bearing is started, it is possible to particularly effectively lubricate between the large end surface 11 of the tapered roller 6 and the large flange 8 of the inner ring 5.

Further, since the height h of the convex portion 31 in the cage radial direction is set to 1.0 mm or less in this resin cage 1, the female mold 22 and the male mold 21 are set as shown in FIGS. 11 and 12. When the resin cage 1 is resin-molded using the above, the male mold 21 can be reliably released from the resin cage 1.

The convex portion 31 may have a rectangular cross-sectional shape as shown in FIG. 10 (a) or a trapezoidal cross-sectional shape as shown in FIG. 10 (b). As shown in FIG. 9, when an arcuate cross-sectional shape is adopted, as shown in FIGS. 11 and 12, when the resin cage 1 is resin-molded using the female mold 22 and the male mold 21, the male mold 1 is formed. The mold 21 can be smoothly separated from the resin cage 1.

Compared with the case where one oil-retaining recess 24 is provided for each pocket 16, it is more effective to provide two oil-retaining recesses 24 for each pocket 16 as in the above embodiment. The following analysis was performed to confirm that it was possible to retain.

<Analysis conditions>
Unsteady fluid analysis by multiphase flow (VOF) Bearing size: φ34 mm × φ62 mm × 16 mm
Bearing rotation speed: 6000 rpm
Temperature: 120 ° C constant Lubricating oil: ATF (kinematic viscosity at 120 ° C is 3.90 mm ² / sec)
Inflow condition: Oil supply amount: 100 mL / min (oil flows in from the side of the outer ring small diameter side end face)
9.6 mm to 49.6 mm from the end face on the small diameter side of the outer ring is filled with oil.
Outflow condition: Pressure Outlet Initial condition: Air, 0m / s, 0MPa (gauge pressure)

<Analysis content>
1. 1. Rotate the bearing to allow the lubricating oil to flow in.
2. 2. After 0.5 seconds from the start of rotation, the rotation of the bearing is stopped, and the state is allowed to reach a steady state where the flow of lubricating oil disappears.
3. 3. In a steady state where the flow of lubricating oil has stopped to complete, check the amount of residual oil in the oil retention recess (after 2.5 seconds).

<Analysis result>
FIG. 13 shows the analysis result when one oil retention recess 24 is provided for each pocket 16 as shown in FIG. 5, and two oil retention recesses 24 are provided for each pocket 16 as shown in FIG. The analysis result of the case is shown in FIG. From these analysis results, it can be seen that a large amount of lubricating oil remains in the corner portion 28 of the oil retaining recess 24 in the steady state where the flow of the lubricating oil disappears. Further, when two oil retention recesses 24 were provided for one pocket 16, the total amount of residual oil in the two oil retention recesses was 0.248 mm ³ in the analysis result shown in FIG. The amount of residual oil was approximately twice the amount of residual oil in the analysis result shown in FIG. 13 when one oil retention recess 24 was provided for each pocket 16. From these analysis results, it is better to provide two oil retention recesses 24 per pocket 16 as in the above embodiment, as compared with the case where one oil retention recess 24 is provided per pocket 16. Since the number of corner portions 28 of the oil retention recess 24 is large, it can be confirmed that the lubricating oil can be effectively held in the oil retention recess 24 per pocket 16.

It should be considered that the embodiments disclosed this time are exemplary in all respects and not restrictive. The scope of the present invention is shown by the scope of claims rather than the above description, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

1 Tapered roller bearing resin cage 2 Outer ring raceway surface 3 Outer ring 4 Inner ring raceway surface 5 Inner ring 6 Tapered roller 8 Large collar 10 Small end surface 11 Large end surface 12 Circular recess 13 Large diameter side rim part 14 Small diameter side rim part 15 Pillar part 16 Pocket 17 Large-diameter side pocket surface 23 Large-diameter side rim inner peripheral surface 24 Oil-retaining recess 28 Corner corner 31 Convex portion θ Inclined angle h Height

Claims (13)

A large diameter side rim portion (13) extending in the circumferential direction of the cage along the large end faces (11) of a plurality of tapered rollers (6) arranged at intervals in the circumferential direction of the cage.
The small diameter side rim portion (14) extending in the circumferential direction of the cage along the small end surface (10) of the plurality of tapered rollers (6),
It has a plurality of pillar portions (15) that connect the large diameter side rim portion (13) and the small diameter side rim portion (14) through between the tapered rollers (6) adjacent to each other in the circumferential direction of the cage. ,
The large-diameter side rim portion (13), the small-diameter side rim portion (14), and the plurality of pillar portions (15) partition a plurality of pockets (16) for accommodating the plurality of tapered rollers (6), respectively. ,
The large-diameter side rim portion (13), the small-diameter side rim portion (14), and the plurality of pillar portions (15) are integrally molded with the resin composition.
The large diameter side rim portion (13) has a holder diameter of the large diameter side pocket surface (17) facing the large end surface (11) of each tapered roller (6) and the large diameter side pocket surface (17). The large diameter side rim inner peripheral surface (23) extending from the inner end in the direction toward the large end surface (11) of the tapered roller (6) and facing inward in the radial direction of the cage, and the large diameter side pocket surface (17). ) And the oil-retaining recess (24) that opens across the inner peripheral surface (23) of the large-diameter side rim.
The inner peripheral surface (23) of the large diameter side rim is formed so as to be inclined in a tapered shape in which the inner diameter gradually increases as the inner peripheral surface (23) of the tapered roller (6) moves away from the large end surface (11) of the tapered roller (6) in the axial direction of the cage. A characteristic resin cage for tapered roller bearings. The resin cage for tapered roller bearings according to claim 1, wherein the inclination angle θ of the large-diameter side rim inner peripheral surface (23) with respect to the cage axial direction is set in the range of 0 ° <θ≤10 °. .. The oil-retaining recess (24) has an inner surface of the oil-retaining recess (24) at an intermediate position in the cage radial direction of the large-diameter side pocket surface (17) in a cross section orthogonal to the circumferential direction of the cage. The tapered roller bearing according to claim 1 or 2, which is formed so as to have an L-shaped cross section that is bent and connected to the intermediate position of the inner peripheral surface (23) of the large diameter side rim in the cage axial direction. Resin cage. On the inner peripheral surface (23) of the large diameter side rim, the tapered roller (6) is located at a position where the inner surface of the oil retaining recess (24) is connected to the inner peripheral surface (23) of the large diameter side rim. The resin cage for tapered roller bearings according to claim 3, wherein a convex portion (31) extending continuously over the entire circumference in the circumferential direction of the cage is formed on the side far from the large end surface (11). The height (h) of the convex portion (31) in the cage radial direction with respect to the root of the convex portion (31) on the side close to the large end surface (11) of the tapered roller (6) is set to 1.0 mm or less. The resin cage for tapered roller bearings according to claim 4. The resin cage for tapered roller bearings according to claim 4 or 5, wherein the convex portion (31) is formed so that the cross-sectional shape orthogonal to the circumferential direction of the cage is arcuate. The resin cage for tapered roller bearings according to any one of claims 1 to 6, wherein the resin composition is a resin material to which an elastomer is added. The resin cage for tapered roller bearings according to claim 7, wherein a fiber reinforced material is further added to the resin material. An outer ring (3) having a conical outer ring raceway surface (2) on the inner circumference,
An inner ring (5) having a conical inner ring raceway surface (4) facing the inner diameter side of the outer ring raceway surface (2) on the outer circumference.
A plurality of tapered rollers (6) incorporated at intervals in the circumferential direction between the outer ring raceway surface (2) and the inner ring raceway surface (4).
The resin cage (1) for tapered roller bearings according to any one of claims 1 to 8 for maintaining the circumferential spacing of the plurality of tapered rollers (6) is provided.
The inner ring (5) is a tapered roller bearing having a large collar (8) in contact with the large end surface (11) of each tapered roller (6). The oil retaining recess (24) is formed in the tapered roller (6) so as not to protrude outward from the region of the large diameter side pocket surface (17) facing the large end surface (11) of the tapered roller (6). The tapered roller bearing according to claim 9, which is arranged so as to be contained in a region facing the large end surface (11). The tapered roller (6) has a circular recess (12) in the center of the large end surface (11), and the oil retaining recess (24) has the circular recess (12) for one pocket (16). The tapered roller bearing according to claim 9 or 10, which is provided on both sides of the cage in the circumferential direction. An annular portion of the opening on the large-diameter side pocket surface (17) side of the oil-retaining recess (24) excluding the circular recess (12) of the large end surface (11) of each tapered roller (6). The tapered roller bearing according to claim 11, wherein the opening area facing the oil retaining recess (24) is 50% or more of the opening area on the large diameter side pocket surface (17) side. The two oil-retaining recesses (24) on both sides of the circular recess (12) in the circumferential direction of the cage are the corners where the adjacent inner surfaces of the oil-retaining recesses (24) intersect each other when viewed in the axial direction of the cage. The tapered roller bearing according to claim 11 or 12, which is formed in a polygonal shape having two or more corners (28).

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