JP2020200944A - Tapered roller bearing - Google Patents

Abstract

To provide 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 stopped for a long time and the tapered roller bearing is to be started thereafter.SOLUTION: A tapered roller bearing includes a large diameter side annular portion 12 extending in the circumferential direction along a large end surface 11 of a plurality of tapered rollers 4, a small diameter side annular portion 13 extending in the circumferential direction along a small end surface 10 of the plurality of the tapered rollers 4, and a plurality of pillar portions 14 connecting the large diameter side annular portion 12 with the small diameter side annular portion 13. The large diameter side annular portion 12 includes a large diameter side pocket surface 16 confronting the large end surface 11 of each of the tapered rollers 4, and an oil retaining recession 20 opened across an inner peripheral surface of the large diameter side annular portion 12 and the large diameter side pocket surface 16. A surface facing the radial inner side of the inner surface of the oil retaining recession 20 is a tilt surface coming closer to the radial inner side as coming closer to the tapered roller 4.SELECTED DRAWING: Figure 1

Description

The present invention relates to 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.

Such tapered roller bearings include an outer ring, an inner ring coaxially arranged inside the outer ring, a plurality of tapered rollers incorporated between the outer ring and the inner ring at a circumferential interval, and the plurality of tapered rollers. An annular cage for holding the distance between the rollers in the circumferential direction is provided. The inner ring has a large collar that contacts the large end face of each 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 due to slippery contact.

Lubrication of the tapered roller bearing is performed by the splash of the lubricating oil that is flipped up by the rotation of the gear or the lubricating oil that is pumped from the oil pump. 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 supplied from the outside to the tapered roller bearing. Stop. Therefore, when the tapered roller bearing is stopped for a long period of 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 agitation 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 The amount of lubricating oil between the bearings is likely to be insufficient.

Therefore, in order to prevent such a shortage of lubricating oil, even when the supply of lubricating oil to the tapered roller bearing from the outside is stopped, the tapered roller that can lubricate between the large end surface of the tapered roller and the large flange of the inner ring. As the bearing, those described in FIGS. 11 to 14 of Patent Document 1 are known. The cage of the tapered roller bearings of FIGS. 11 to 14 of Patent Document 1 has a large-diameter annular portion extending in the circumferential direction along the large end surface of the tapered roller and a small diameter extending in the circumferential direction along the small end surface of the tapered roller. It has a side annular portion and a plurality of pillar portions connecting the large-diameter side annular portion and the small-diameter side annular portion, and a plurality of oil-retaining recesses are formed in the large-diameter side annular portion at intervals in the circumferential direction. ing. The oil retention recess is opened so as to straddle between the inner peripheral surface of the large diameter side annular portion and the large diameter side pocket surface. The large diameter side pocket surface is a surface facing the large end surface of the tapered roller.

In the tapered roller bearing of Patent Document 1, when lubricating oil is continuously supplied to the tapered roller bearing from the outside, a part of the lubricating oil is retained on the inner circumference of the large diameter side annular portion of the cage. When the lubricant is stored in the oil recess and then the supply of lubricating oil to the tapered roller bearing is stopped for some reason, the lubricating oil that flows out from the oil retention recess on the inner circumference of the large diameter side annular portion of the cage is used. Lubricate between the large end face of the tapered roller and the large collar of the inner ring.

U.S. Pat. No. 899,498

By the way, in the tapered roller bearing of Patent Document 1, the bottom surface of the oil-retaining recess (that is, the inner surface of the oil-retaining recess facing the inside in the radial direction) formed on the large-diameter annular portion of the cage is tapered. It is tilted so that it approaches the outer side in the radial direction as it approaches. That is, when the lubricating oil in the oil-retaining recess receives centrifugal force as the bearing rotates, the lubricating oil in the oil-retaining recess has a component force in the direction toward the large end surface of the tapered roller. The bottom surface of the recess is provided with an inclination in the radial direction as it approaches the tapered roller.

However, when the tapered roller bearings stop for a long time, the lubricating oil in the oil-retaining recesses moves toward the tapered rollers due to the inclination of the bottom surface of the oil-retaining recesses, and the large end surface of the tapered rollers and the large-diameter annular ring of the cage. It gradually flows out through the gap between the parts. After that, when the tapered roller bearing is started, it may not be possible to sufficiently lubricate between the large end surface of the tapered roller and the large collar of the inner ring. As a result, there is a risk that the temperature will rise sharply between the large end face of the tapered roller and the large collar of the inner ring.

The problem to be solved by the present invention is to suppress a rapid temperature rise between the large end face of the tapered roller and the large flange of the inner ring when the tapered roller bearing is stopped for a long time and then the tapered roller bearing is started. It is to provide tapered roller bearings that can be used.

In order to solve the above problems, the present invention provides a tapered roller bearing having the following configuration.
An outer ring, an inner ring coaxially arranged inside the outer ring, a plurality of tapered rollers incorporated between the outer ring and the inner ring at a circumferential interval, and a circumferential distance between the plurality of tapered rollers. The inner ring has a large collar that contacts the large end surface of each tapered roller, and the cage is circumferentially along the large end surface of the plurality of tapered rollers. A large-diameter annular portion extending in the circumferential direction, a small-diameter annular portion extending in the circumferential direction along the small end faces of the plurality of tapered rollers, and a plurality of pillar portions connecting the large-diameter annular portion and the small-diameter annular portion. The large-diameter annular portion, the small-diameter annular portion, and the plurality of pillar portions each partition a plurality of pockets for accommodating the plurality of tapered rollers, and the large-diameter annular portion is each of the above. In a tapered roller bearing having a large-diameter side pocket surface facing the large end surface of the tapered roller and an oil-retaining recess that opens across the inner peripheral surface of the large-diameter annular portion and the large-diameter side pocket surface. A tapered roller bearing, wherein the surface of the inner surface of the oil-retaining recess that faces the inside in the radial direction is an inclined surface that approaches the inside in the radial direction as it approaches the tapered roller.

In this way, the bottom surface of the oil-retaining recess located below the axis (that is, the surface of the inner surface of the oil-retaining recess facing the inner side in the radial direction) is inclined upward as it approaches the tapered roller. Therefore, when the tapered roller bearing stops operating, the lubricating oil in the oil retaining recess located below the axis of the rotating shaft of the tapered roller bearing is less likely to flow out from the oil retaining recess. Further, when the tapered roller bearing rotates, the lubricating oil in the oil retaining recess moves to the tapered roller side along the inclination by centrifugal force, and the large end surface of the tapered roller can be lubricated. Therefore, when the tapered roller bearing is stopped for a long time and then the tapered roller bearing is started, it is possible to effectively prevent a rapid temperature rise between the large end surface of the tapered roller and the large collar of the inner ring.

It is preferable that a plurality of the oil-retaining recesses are provided side by side in the circumferential direction between the pillars adjacent to each other in the circumferential direction.

By doing so, it is possible to increase the area of the inner surface of the oil-retaining recess as compared with the case where one oil-retaining recess is provided between the pillars adjacent to each other in the circumferential direction. Therefore, the contact area between the lubricating oil in the oil-retaining recess and the inner surface of the oil-retaining recess increases, and the surface tension acting between the inner surface and the lubricating oil becomes large. This makes it easier to retain the lubricating oil in the oil retention recess.

When the tapered roller has a recess in the center of the large end surface, it is preferable that the oil retaining recesses are arranged on both sides of the recess.

In this way, when the tapered roller bearing is stopped, the lubricating oil held in the oil retaining recess can be prevented from flowing out to the recess on the large end surface of the tapered roller, and the tapered roller and the inner ring can be prevented from flowing out. It is possible to lubricate the large end face of tapered rollers while reducing friction with the large bearing.

Of the openings on the large diameter side pocket surface side of the oil retention recess, the opening area of the portion facing the large end surface is 50% or more of the opening area of the oil retention recess on the large diameter side pocket surface side. Is preferable.

In this way, since 50% or more of the opening on the large diameter side pocket surface side of the oil retention recess faces the large end surface of the tapered roller, oil retention is performed through the opening on the large diameter side pocket surface side of the oil retention recess. Most of the lubricating oil that flows out of the recess can be efficiently adhered to the large end surface of the tapered roller, and the large end surface of the tapered roller can be effectively lubricated.

The inclination angle of the inclined surface with respect to the direction parallel to the axis of the cage is preferably 10 degrees or less.

By doing so, the lubricating oil in the oil retaining recess preferably lubricates the large end surface during the rotation of the tapered roller bearing, and is suitably held in the oil retaining recess when the tapered roller bearing is stopped. can do. In addition, it is within the range that can be dealt with by removing the mold during resin molding.

It is preferable that the cross-sectional shape orthogonal to the axis of the cage of the oil retention recess is square.

By doing so, the lubricating oil is held in the corner portion of the cross section of the oil-retaining recess due to the surface tension of the lubricating oil, so that the lubricating oil is easily held in the oil-retaining recess.

The oil-retaining recess is preferably located inside the peripheral edge of the large end surface so as not to protrude outside the region facing the large end surface of each tapered roller.

By forming the oil-retaining recess in the above-described manner, the lubricating oil held in the oil-retaining recess can be effectively supplied to the roller large end surface, and between the roller large end surface and the inner ring large flange surface. An effect that contributes to lubrication can be obtained.

When the inner ring has a small collar facing the small end surface of each tapered roller and the cage is integrally formed of the resin composition, an elastomer is added to the resin material as the resin composition. It is preferable to use a plastic one.

That is, the tapered roller bearing can be assembled as follows. First, insert a tapered roller into each pocket of the cage. Next, the inner ring is inserted into the cage in which the tapered rollers are housed in each pocket. At this time, the tapered roller needs to get over the small collar of the inner ring, but the tapered roller cannot get over the small collar with the same dimensional relationship because the movement of the tapered roller is restricted by the cage in the radial direction. .. Therefore, when the cage is integrally formed of a resin composition in order to allow the tapered roller to get over the small collar, the tapered roller receives the small collar from the small collar when the tapered roller rides on the small collar. The cage is elastically deformed by the force. Here, if an elastomer is added to the resin material as the resin composition for forming the cage, the elasticity of the cage is increased, so that the inner ring is placed in the cage in which the tapered rollers are housed in each pocket. The work of inserting is facilitated, and the assemblability of the tapered roller bearing can be improved.

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

In this way, the decrease in toughness and strength of the cage 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 achieve both the toughness and strength of the cage and the assembling property of the tapered roller bearings.

When the tapered roller bearing of the present invention is used, the bottom surface of the oil-retaining recess located below the axis (that is, the surface of the inner surface of the oil-retaining recess facing the inner side in the radial direction) is inclined upward as it approaches the tapered roller. Will be done. Therefore, when the tapered roller bearing stops operating, the lubricating oil in the oil retaining recess located below the axis of the rotating shaft of the tapered roller bearing is less likely to flow out from the oil retaining recess. Further, when the tapered roller bearing rotates, the lubricating oil in the oil retaining recess moves to the tapered roller side along the inclination by centrifugal force, and the large end surface can be lubricated. Therefore, when the tapered roller bearing is stopped for a long time and then the tapered roller bearing is started, it is possible to effectively prevent a rapid temperature rise between the large end surface of the tapered roller and the large collar of the inner ring.

Cross-sectional view of the tapered roller bearing according to the embodiment of the present invention along the axial plane. Perspective view of the cage shown in FIG. Enlarged view of the vicinity of the oil retention recess in FIG. Partial cross-sectional view of the cage shown in FIG. 1 as viewed from the large end surface side of the tapered rollers. Partially enlarged view showing details of the vicinity of the oil retention recess of FIG. The figure which shows an example of the transmission using the tapered roller bearing shown in FIG. The figure which shows an example of the differential mechanism using the tapered roller bearing shown in FIG.

FIG. 1 shows a tapered roller bearing 1 according to an embodiment of the present invention. The tapered roller bearing 1 includes an outer ring 2, an inner ring 3 coaxially arranged inside the outer ring 2, and a plurality of tapered rollers 4 incorporated between the outer ring 2 and the inner ring 3 at intervals in the circumferential direction. It has an annular cage 5 that holds a plurality of tapered rollers 4 in the circumferential direction. The tapered roller bearing 1 has a size used for automobiles, and as a specific example, the inner diameter of the inner ring 3 is 40 mm or less (may be 35 mm or less), and the following examples are shown.

A tapered outer ring raceway surface 6 is formed on the inner circumference of the outer ring 2. On the outer circumference of the inner ring 3, there are a tapered inner ring raceway surface 7 that faces the outer ring raceway surface 6 in the radial direction, a small collar 8 located on the small diameter side of the inner ring raceway surface 7, and a large diameter side of the inner ring raceway surface 7. A large diameter 9 is formed. The tapered roller 4 is in rolling contact with the outer ring raceway surface 6 and the inner ring raceway surface 7.

The small collar 8 is formed so as to project from the inner ring raceway surface 7 toward the outer diameter side so as to face the small end surface 10 of the tapered roller 4. The small collar 8 regulates the tapered roller 4 from moving to the small diameter side of the inner ring raceway surface 7 and prevents the tapered roller 4 from falling off from the inner ring raceway surface 7. The large collar 9 is formed so as to project from the inner ring raceway surface 7 toward the outer diameter side so as to face the large end surface 11 of the tapered roller 4. When the bearing rotates, the large end surface 11 of the tapered roller 4 and the large collar 9 of the inner ring 3 support a part of the axial load by contact with slip.

As shown in FIGS. 1 and 2, the cage 5 has a large-diameter annular portion 12 extending in the circumferential direction along the large end surface 11 of each tapered roller 4 and a circumferential direction along the small end surface 10 of each tapered roller 4. It has a small diameter side annular portion 13 extending in the circumferential direction, and a plurality of pillar portions 14 connecting the large diameter side annular portion 12 and the small diameter side annular portion 13 through between the tapered rollers 4 adjacent to each other in the circumferential direction.

The large-diameter annular portion 12, the small-diameter annular portion 13, and the plurality of pillar portions 14 partition a plurality of pockets 15 for accommodating the plurality of tapered rollers 4, respectively. Here, the large diameter side annular portion 12 and the small diameter side annular portion 13 partition both ends of the pocket 15 in the cage axial direction, and the pillar portion 14 partitions both ends of the pocket 15 in the cage circumferential direction. The large diameter side annular portion 12 is formed with a large diameter side pocket surface 16 facing the large end surface 11 of the tapered roller 4, and the small diameter side annular portion 13 is formed with a small diameter side pocket facing the small end surface 10 of the tapered roller 4. The surface 17 is formed. The large-diameter side pocket surface 16 is formed so as to be inclined with respect to the axially perpendicular direction (vertical direction in the figure) of the cage 5 so as to be in surface contact with the large end surface 11 of the tapered rollers 4. The pillar portion 14 has a roller guide surface that contacts the outer circumference of the tapered roller 4 at a position facing the outer circumference of the tapered roller 4.

A plurality of oil retention recesses 20 are formed on the inner circumference of the large diameter side annular portion 12 at intervals in the circumferential direction of the cage. The oil retention recess 20 is formed so as to straddle the inner circumference of the large diameter side annular portion 12 and the large diameter side pocket surface 16. That is, the oil retention recess 20 is formed by opening in the inner circumference of the large diameter side annular portion 12 and opening in the large diameter side pocket surface 16. The opening portion of the oil retention recess 20 to the inner circumference of the large diameter side annular portion 12 has a rectangular shape when viewed from the inside in the radial direction of the cage. The opening portion of the oil retention recess 20 to the large diameter side pocket surface 16 has a rectangular shape when viewed in the axial direction.

As shown in FIG. 3, the inner surface of the oil-retaining recess 20 is composed of a bottom surface 21 facing inward in the radial direction and an inner wall surface 22 that rises radially inward from the peripheral edge of the bottom surface 21 and reaches the opening edge of the oil-retaining recess 20. .. The bottom surface 21 is an inclined surface that approaches inward in the radial direction as it approaches the tapered roller. That is, the oil retention recess 20 gradually becomes deeper in the radial direction as it moves away from the opening of the large diameter side pocket surface 16 in the axial direction. The inclination angle θ of the bottom surface 21 with respect to the direction parallel to the axis of the cage 5 is larger than 0 degrees and 10 degrees or less (preferably 5 degrees or more and 10 degrees or less).

As shown in FIG. 5, the inner wall surface 22 includes a pair of facing surfaces 24 facing each other in the circumferential direction of the cage, and a connecting surface 25 connecting one ends of the facing surfaces 24 to each other. The connecting surface 25 is an upright surface that faces the large end surface 11 of the tapered rollers 4 in the axial direction. The facing surface 24 and the connecting surface 25 intersect directly or through a corner R having a small radius of curvature (for example, a corner R having a radius of curvature of 0.5 mm or less). The facing surface 24 and the bottom surface 21 also intersect directly or via a corner R having a small radius of curvature (for example, a corner R having a radius of curvature of 0.5 mm or less). The connecting surface 25 and the bottom surface 21 also intersect directly or via a corner R having a small radius of curvature (for example, a corner R having a radius of curvature of 0.5 mm or less). The cross-sectional shape of the oil-retaining recess 20 orthogonal to the axis of the cage 5 is square, and the cross-sectional shape of the oil-retaining recess 20 orthogonal to the radial direction is also square. Therefore, a concave corner portion 26 is formed between the bottom surface 21 and the facing surface 24, and a concave corner portion 27 is also formed between the bottom surface 21 and the connecting surface 25, and between the facing surface 24 and the connecting surface 25. The concave corner 28 is formed.

Here, the depth of the oil retention recess 20 (that is, the distance from the deepest portion of the oil retention recess 20 to the inner diameter surface of the large diameter side annular portion 12) is 0.2 to 2.0 mm (preferably 0.3). ~ 1.0 mm), or 0.2 <h / H <0.7 in relation to H and h shown in FIG. At the lower limit of h / H, the oil retention effect is too small, and at the upper limit, there is concern about insufficient strength.

The tapered roller 4 has a recess 11a in the center of the large end surface 11. The large end surface 11 is composed of a recess 11a and an annular surface 11b that surrounds the recess 11a. The annular surface 11b is a surface that is pressed against the large collar 9. The annular surface 11b is a spherical surface having a sufficiently large radius of curvature (at least a radius of curvature larger than the radius of the inner ring 3). The oil retention recesses 20 are arranged on both sides of the recesses 11a. The recess 11a is formed so as to open on the large end surface 11 and enter the small end surface side of the tapered roller in the axial direction from the opening.

A plurality of oil retention recesses 20 are provided side by side in the circumferential direction between the pillar portions 14 adjacent to each other in the circumferential direction. That is, a plurality of oil retention recesses 20 are provided for each large diameter side pocket surface 16. As an example of such an oil retention recess 20, FIGS. 4 and 5 show a mode in which two locations are provided for each of the large diameter side pocket surfaces 16. The two oil-retaining recesses 20 are arranged apart from each other on both sides of the cage 5 in the circumferential direction with respect to the center of the large-diameter side pocket surface 16. That is, the oil retention recesses 20 are provided one by one in the left and right directions shown in the recess 11a. The oil retention recess 20 is arranged outside the recess 11a so as to face only the portion of the annular surface 11b, not the recess 11a of the large end surface 11.

The oil-retaining recess 20 is located inside the peripheral edge of the large end surface 11 so as not to protrude outside the region of the tapered roller 4 facing the large end surface 11. That is, as shown in FIG. 4, in a plan view from the large end surface 11 side, all the regions inside the opening edge of the oil retention recess 20 are located inside the peripheral edge of the large end surface 11. Further, the oil retention recess 20 is provided so as not to protrude inside the opening edge of the recess 11a. That is, in a plan view from the large end surface 11 side, all the regions inside the opening edge of the oil retention recess 20 are located outside the opening edge of the recess 11a.

Here, the large-diameter side annular portion 12 has a weld line L (a portion where the resin joins when the cage 5 is resin-molded). Specifically, by providing the weld line L between the adjacent oil retention recesses 20, the large diameter side annular portion 12 is sufficiently sufficient as compared with the configuration in which the weld line L is provided at a position where the weld line L overlaps the oil retention recess 20. It is possible to secure a large wall thickness and to provide the oil retention recess 20 without causing a large decrease in strength.

The cage 5 is made of synthetic resin and is integrally formed seamlessly. That is, the large diameter side annular portion 12, the small diameter side annular portion 13, and the plurality of pillar portions 14 constituting the cage 5 are seamlessly and integrally formed of the resin composition. As the resin composition constituting the cage 5, it is possible to use a resin composition made 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) can be adopted as the resin material that is the base of the resin composition. As the polyamide, polyamide 66 (PA66), polyamide 46 (PA46), polynonamethylene terephthalamide (PA9T) and the like can be used. When polyamide is used, since the polyamide has a relatively high lipophilicity, the lubricating oil easily fits into the inner surface of the oil-retaining recess 20, and the surface tension of the lubricating oil can effectively hold the lubricating oil in the oil-retaining recess 20. It will be possible. Instead of polyamide, polyphenylene sulfide (PPS), polyetheretherketone (PEEK), or the like can also be used. 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). it can. The combination of types of resin material, elastomer, and fiber reinforced material can be freely selected as appropriate.

FIG. 6 shows a structural diagram of a part of the tapered roller bearing 1 when it is arranged in the transmission 30 of an automobile.

In particular, in recent years, in order to suppress energy loss caused by agitation 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 1 is stopped for a long time, the amount of lubricating oil remaining in the tapered roller bearing 1 tends to be too small, and then when the tapered roller bearing 1 is started, the large end surface 11 of the tapered roller 4 There is a possibility that a rapid temperature rise will occur between the inner ring 3 and the large bearing 9 of the inner ring 3.

In response to this problem, in the tapered roller bearing 1 of this embodiment, lubricating oil is introduced into the oil retaining recess 20 when the tapered roller bearing 1 is rotating. Here, as described above, the bottom surface 21 of the oil retention recess 20 is inclined inward in the radial direction as it approaches the tapered roller 4. Therefore, when the tapered roller bearing 1 is stopped, a force acts on the lubricating oil in the oil retaining recess 20 in the direction of flowing into the inner part of the oil retaining recess 20 along the inclination of the bottom surface 21 by gravity. Therefore, even if the oil is stopped for a long time, the lubricating oil is stored in the oil retention recess 20 and is unlikely to flow out from the oil retention recess 20. After that, when the tapered roller bearing 1 is started, a centrifugal force acts on the lubricating oil in the oil retaining recess 20. Then, the lubricating oil moves to the tapered roller 4 side along the inclination of the bottom surface 21, flows out from the oil retention recess 20, and is supplied to the large end surface 11 of the tapered roller 4. Therefore, when the tapered roller bearing 1 is stopped for a long time and then the tapered roller bearing 1 is started, a rapid temperature rise between the large end surface 11 of the tapered roller 4 and the large flange 9 of the inner ring 3 is effectively prevented. can do.

Further, in the tapered roller bearing 1, the oil-retaining recesses 20 are arranged on both sides of the tapered roller 4 so as to sandwich the recesses 11a of the large end surface 11, so that the oil-retaining recesses when the tapered roller bearing 1 is stopped. It is possible to prevent the lubricating oil held in the tapered roller 4 from flowing out into the recess 11a of the large end surface 11 of the tapered roller 4, and the tapered roller 4 while reducing the friction between the tapered roller 4 and the large flange 9 of the inner ring 3. It is possible to lubricate the large end surface 11 (particularly the annular surface 11b) of the rollers 4.

Further, in the tapered roller bearing 1, the opening area of the portion of the opening on the large diameter side pocket surface 16 side of the oil retention recess 20 facing the large end surface 11 is the large diameter side pocket surface 16 side of the oil retention recess 20. Since it is 50% or more (preferably 70% or more, more preferably 90% or more) of the opening area of the oil retaining recess 20, it flows out of the oil retaining recess 20 through the opening on the large diameter side pocket surface 16 side of the oil retaining recess 20. Most of the lubricating oil can be efficiently adhered to the large end surface 11 of the tapered roller 4 (particularly, the annular surface 11b), and the large end surface 11 of the tapered roller 4 can be effectively lubricated.

Further, in the tapered roller bearing 1, since the inclination angle θ of the bottom surface 21 of the oil retaining recess 20 is set to 10 degrees or less, the lubricating oil in the oil retaining recess 20 is conical during the rotation of the tapered roller bearing 1. It smoothly flows toward the large end surface 11 of the roller 4, and the large end surface 11 of the tapered roller 4 can be effectively lubricated. Further, since the inclination angle θ of the bottom surface 21 of the oil retention recess 20 is set to be larger than 0 degrees, preferably 5 degrees or more, the lubricating oil is surely supplied into the oil retention recess 20 when the tapered roller bearing 1 is stopped. It is possible to hold it in.

Further, as described above, the cross-sectional shape of the oil-retaining recess 20 orthogonal to the axis of the cage 5 is square, and the cross-sectional shape orthogonal to the radial direction of the oil-retaining recess 20 is also square, inside the oil-retaining recess 20. A plurality of corners 26, 27, 28 are formed in the. Therefore, the surface tension acting between the inner surface of the oil-retaining recess 20 and the lubricating oil is larger than that of the oil-retaining recess in which these cross-sectional shapes are circular and the corners 26, 27, and 28 are not formed. It becomes. Therefore, the surface tension effectively acts on the lubricating oil held in the oil retaining recess 20, and the lubricating oil is easily held in the oil retaining recess 20.

Further, in the tapered roller bearing 1, the oil retaining recess 20 is arranged inside the peripheral edge of the large end surface 11 so as not to protrude to the outside of the region facing the large end surface 11 of each tapered roller 4, so that the tapered roller bearing 1. When the roller bearing 1 is stopped, it is possible to effectively prevent the lubricating oil held in the oil retaining recess 20 from flowing out of the oil retaining recess 20 through the outside of the large end surface 11. There is.

The tapered roller bearing 1 can also be used as a rolling bearing that rotatably supports the input shaft of the differential mechanism 40 shown in FIG. 7.

The above-mentioned tapered roller bearing 1 can be assembled as follows. First, the tapered roller 4 is inserted into each pocket 15 of the cage 5. Next, the inner ring 3 is inserted into the cage 5 in which the tapered rollers 4 are housed in the respective pockets 15. At this time, the tapered roller 4 needs to get over the small collar 8 of the inner ring 3, but since the tapered roller 4 is restricted from moving outward in the radial direction by the cage 5, the small collar 4 has the same dimensional relationship. I can't get over 8. Therefore, in order for the tapered roller 4 to get over the small collar 8, the cage 5 is elastically deformed by the force in the diameter-expanding direction that the tapered roller 4 receives from the small collar 8 when the tapered roller 4 rides on the small collar 8. It becomes. Here, in the above embodiment, as the resin composition forming the cage 5, a resin material to which an elastomer is added is used, so that the cage 5 has high elasticity and is tapered in each pocket 15. The work of inserting the inner ring 3 into the cage 5 in which the rollers 4 are housed is easy, and it is possible to obtain excellent assemblability of the tapered roller bearing 1.

Further, since the tapered roller bearing 1 employs a resin composition obtained by adding an elastomer to a resin material and further adding a fiber reinforced material as a resin composition forming the cage 5, the cage by adding the elastomer. It is possible to compensate for the decrease in toughness / strength of 5 with a fiber reinforcing material. Therefore, it is possible to achieve both the toughness and strength of the cage 5 and the assembling property of the tapered roller bearing 1.

Although the embodiments of the present invention have been described, the scope of the present invention is not limited to the above embodiments, and various modifications can be applied.

In the above embodiment, as shown in FIGS. 2, 4 and 5, two oil retention recesses 20 are provided for each large diameter side pocket surface 16, but the oil retention recesses 20 are provided for each large diameter side pocket surface 16. It may be provided at three or more places, one place at a time, and a different number of oil retention recesses 20 may be provided for each large diameter side pocket surface 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 2 Outer ring 3 Inner ring 4 Tapered roller 5 Cage 8 Small collar 9 Large collar 10 Small end surface 11 Large end surface 11a Recess 12 Large diameter side annular part 13 Small diameter side annular part 14 Pillar part 15 Pocket 16 Large diameter side pocket surface 20 Oil retention recess 21 Bottom surface (the inner surface of the oil retention recess facing the inside in the radial direction)

Claims (9)

With the outer ring
An inner ring coaxially arranged inside the outer ring and
A plurality of tapered rollers incorporated between the outer ring and the inner ring at intervals in the circumferential direction.
An annular cage for holding the circumferential spacing of the plurality of tapered rollers is provided.
The inner ring has a large collar that contacts the large end face of each tapered roller.
The cage includes a large-diameter annular portion extending in the circumferential direction along the large end faces of the plurality of tapered rollers, a small-diameter annular portion extending in the circumferential direction along the small end faces of the plurality of tapered rollers, and the large annular portion. It has a radial ring portion and a plurality of pillar portions connecting the small diameter side annular portion.
The large-diameter annular portion, the small-diameter annular portion, and the plurality of pillar portions partition a plurality of pockets for accommodating the plurality of tapered rollers.
The large-diameter annular portion is held so as to open across between the large-diameter pocket surface facing the large end surface of each tapered roller, the inner peripheral surface of the large-diameter annular portion, and the large-diameter pocket surface. In tapered roller bearings with oil recesses
A tapered roller bearing, wherein a surface of the inner surface of the oil-retaining recess that faces the inner side in the radial direction is an inclined surface that approaches the inner side in the radial direction as the roller approaches the tapered roller. The tapered roller bearing according to claim 1, wherein a plurality of the oil-retaining recesses are provided side by side in the circumferential direction between the pillars adjacent to each other in the circumferential direction. The tapered roller has a recess in the center of the large end surface.
The tapered roller bearing according to claim 1 or 2, wherein the oil retaining recess is arranged on both sides of the recess. Of the openings on the large-diameter side pocket surface side of the oil-retaining recess, the opening area of the portion facing the large end surface is 50% or more of the opening area of the oil-retaining recess on the large-diameter side pocket surface side. The tapered roller bearing according to any one of claims 1 to 3. The tapered roller bearing according to any one of claims 1 to 4, wherein the inclination angle of the inclined surface with respect to the direction parallel to the axis of the cage is 10 degrees or less. The tapered roller bearing according to any one of claims 1 to 5, wherein the cross-sectional shape orthogonal to the axis of the cage of the oil-retaining recess is square. The tapered roller bearing according to any one of claims 1 to 6, wherein the oil retaining recess is located inside the peripheral edge of the large end surface so as not to protrude outside the region facing the large end surface of each tapered roller. .. The inner ring has a small collar facing the small end surface of each tapered roller.
The tapered roller bearing according to any one of claims 1 to 7, wherein the cage is integrally formed of a resin composition, and the resin composition is a resin material to which an elastomer is added. The tapered roller bearing according to claim 8, wherein a fiber reinforcing material is further added to the resin material.

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