JP2021032354A - Conical roller bearing - Google Patents

Abstract

To provide a conical roller bearing capable of preventing lubricant from leaking out from an oil groove and preventing seizure even under a lubrication environment in which lubricant is supplied intermittently or under a lubrication environment in which an amount of lubricant is minute.SOLUTION: A holder 14 of a conical roller bearing 10 has a first gap S1 between an axial inner end surface 16a of a small diameter side annular part 16 and a small diameter side end surface 13c of a conical roller 13, and has a second gap S2 between an axial inner end surface 15a of a large diameter side annular part 15 and a large diameter side end surface 13b of the conical roller 13. The dimensions of the first gap S1 and the second gap S2 are set to 0.3 mm or less. The axial inner end surface 15a of the large diameter side annular part 15 is provided with an oil groove 20 for storing lubricant. The oil groove 20 is provided so that the large diameter side end surface 13b of the conical roller 13 and the axial inner end surface 15a of the large diameter side annular part 15 are housed in an overlapping region in a longitudinal direction of the conical roller 13.SELECTED DRAWING: Figure 1

Description

The present invention relates to a tapered roller bearing, and more particularly to a tapered roller bearing in which lubricating oil is supplied to the inside of the bearing.

In recent years, a mechanism for stopping the lubricating oil pump when the engine is stopped, such as the transmission of some hybrid vehicles, has appeared, which tends to cause a seizure problem of bearings. In addition, when the vehicle is towed, the lubricating oil pump does not operate and the tires spin, which may cause seizure of the bearings in the transmission. Therefore, there is a demand for bearings that can prevent seizure even in a lubricating environment in which the supply of lubricating oil is intermittent or in a lubricating environment in which a small amount of lubricating oil is used.

As the conventional tapered roller bearing 100, as shown in FIGS. 16 to 19, an outer ring 111 having an outer ring raceway surface 111a on the inner peripheral surface, an inner ring 112 having an inner ring raceway surface 112a on the outer peripheral surface, and an outer ring raceway surface 111a. It is known that a plurality of tapered rollers 113 provided so as to be rollable between the inner ring raceway surface 112a and a cage 114 for holding the plurality of tapered rollers 113 at substantially equal intervals in the circumferential direction ( For example, see Patent Document 1).

Further, the cage 114 includes a large-diameter annulus 115, a small-diameter annulus 116 coaxially arranged with the large-diameter annulus 115, and a large-diameter annulus 115 and a small-diameter annulus 116. The large-diameter annulus 115 and the small-diameter annulus 116 are between a plurality of pillars 117 provided at substantially equal intervals in the circumferential direction and pillars 117 adjacent to each other in the circumferential direction. It has a pocket 118, which is formed by being surrounded by a conical roller 113 and holds the conical roller 113 so as to be rollable. Further, the tapered roller 113 is provided on a rolling surface 113a provided on the peripheral surface of the tapered roller 113, a large-diameter side end surface 113b provided on the large-diameter side end portion of the tapered roller 113, and a small-diameter side end portion of the tapered roller 113. It has a small diameter side end surface 113c provided.

Japanese Patent No. 6354242

Then, in the tapered roller bearing 100 described in Patent Document 1, one oil groove 120 along the circumferential direction is formed on the axial inner end surface 115a of the large diameter side annular portion 115 of the cage 114 to obtain oil. In order to increase the amount of lubricating oil stored inside the groove 120, the radial width of the oil groove 120 is set to 1/3 of the radial width of the large diameter side annular portion 115. That is, for example, when the radial width of the large diameter side annular portion 115 is 9 mm, the radial width of the oil groove 120 is 3 mm. In this case, since the oil groove 120 alone cannot generate the capillary phenomenon and hold the lubricating oil, it is necessary to cover the oil groove 120 with the tapered roller 113 as described in Patent Document 1 above. there were.

However, as shown in FIG. 16, when the cage 114 is moved axially toward the large diameter side of the tapered roller 113, the large diameter side end surface 113b of the tapered roller 113 and the axial inner end surface of the large diameter side annular portion 115 are used. The gap with 115a became large, and the lubricating oil leaked from the oil groove 120 without the capillary phenomenon working.

Further, in the drawing of Patent Document 1, the large-diameter side end surface of the tapered roller is described as a flat surface, but as shown in FIGS. 16 to 18, the large-diameter side end surface 113b of the tapered roller 113 has a convex spherical shape. In addition to being formed in, a recess 113d may be formed in the center of the large-diameter side end surface 113b. In such a tapered roller 113, even if the axial gap between the tapered roller 113 and the cage 114 is reduced, the gap SP at the portion where the recess 113d of the tapered roller 113 and the oil groove 120 overlap (FIG. 19). Lubricating oil had leaked from (see).

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to prevent the lubricating oil from leaking from the oil groove, or in a lubricating environment where the supply of the lubricating oil is intermittent. It is an object of the present invention to provide tapered roller bearings capable of preventing seizure even in a lubricating environment in which a small amount of lubricating oil is used.

The above object of the present invention is achieved by the following configuration.
(1) An outer ring having an outer ring raceway surface on the inner peripheral surface, an inner ring having an inner ring raceway surface on the outer peripheral surface, and a plurality of tapered rollers provided so as to be rollable between the outer ring raceway surface and the inner ring raceway surface. A cage that holds the plurality of tapered rollers at substantially equal intervals in the circumferential direction is provided, and the cage has a large-diameter side annular portion and a small diameter arranged coaxially with the large-diameter side annular portion. The side annular portion, the large-diameter side annular portion, and the small-diameter side annular portion are connected in the axial direction, and a plurality of pillar portions provided at substantially equal intervals in the circumferential direction are adjacent to each other in the circumferential direction. A tapered roller bearing having a pocket formed between columns and holding the tapered roller so as to be rollable, wherein the cage is an axial inner end surface of the small diameter side annular portion and the tapered roller. The first gap is provided between the small diameter side end surface and the axial inner end surface of the large diameter side annular portion and the large diameter side end surface of the tapered roller. The size of the second gap is set to 0.3 mm or less, and at least one oil groove for storing lubricating oil is provided on the axial inner end surface of the large diameter side annular portion. A tapered roller bearing, characterized in that the large-diameter side end surface of the tapered roller and the axial inner end surface of the large-diameter side annular portion are provided so as to fit in a region where they overlap in the longitudinal direction of the tapered roller.
(2) The large-diameter end face of the tapered roller is provided around a circular recess formed in the center of the large-diameter end face and the recess, and is provided in the axial direction of the large-diameter ring portion. The oil groove has an annular contact surface that can contact the end surface, and the annular contact surface and the axial inner end surface of the large diameter side annular portion overlap each other in the longitudinal direction of the tapered roller. The tapered roller bearing according to (1), which is provided so as to fit in a region.
(3) The tapered roller bearing according to (2), wherein the oil groove is formed in an annular fan shape along the circumferential direction of the large diameter side annular portion.
(4) The pair of end connecting sides, which are both ends in the longitudinal direction of the oil groove, are formed in an arc shape that follows the outer peripheral edge of the annular contact surface of the tapered roller (3). ) Described in tapered roller bearings.
(5) The tapered roller bearing according to (2), wherein the oil groove is formed in an annular fan shape along the annular contact surface of the tapered roller.
(6) An oil storage recess for storing lubricating oil is formed at a position overlapping the recess of the tapered roller in the longitudinal direction of the tapered roller on the axial inner end surface of the large-diameter annular portion of the cage. The tapered roller bearing according to (5).
(7) The axial inner end surface of the large diameter side annular portion is formed in a concave spherical shape, the large diameter side end surface of the cone is formed in a convex spherical shape, and the inside of the large diameter side annular portion in the axial direction. The conical roller bearing according to (1), wherein the concave spherical radius of curvature SRy of the end face is set within ± 10% of the convex spherical radius of curvature Ra of the large diameter side end face of the cone. ..
(8) Any one of (1) to (7), wherein the lubricating oil is intermittently supplied to the inside of the bearing, or the lubricating oil inside the bearing is used in a lubricating environment in a small amount. Tapered roller bearings listed in 1.

According to the present invention, since the oil groove for storing the lubricating oil is provided on the axial inner end surface of the large diameter side annular portion of the cage, the lubricating oil is not supplied to the bearing and the amount of the lubricating oil in the bearing becomes small. Even so, the lubricating oil stored in the oil groove is supplied to the large-diameter side end face of the cone. Therefore, seizure of the bearing can be prevented even in a lubricating environment in which the supply of lubricating oil is intermittent or in a lubricating environment in which a small amount of lubricating oil is used. Further, since the oil groove is provided so that the large-diameter side end surface of the tapered roller and the axial inner end surface of the large-diameter annulus portion of the cage overlap in the longitudinal direction of the tapered roller, the conical groove is provided. The lid is closed by the large diameter side end face of the roller. Therefore, it is possible to prevent the lubricating oil from leaking from the oil groove.

It is sectional drawing explaining one Embodiment of the tapered roller bearing which concerns on this invention. It is a top view which looked at the cage and the tapered roller from the outside in the radial direction. It is a schematic view which looked at the cage shown in FIG. 1 from the inside in the radial direction. It is a schematic diagram which shows the positional relationship between an oil groove and a large diameter side end face of a tapered roller. It is a schematic diagram explaining the 1st modification of a cage. It is a schematic diagram explaining the 2nd modification of a cage. It is a schematic diagram explaining the 3rd modification of a cage. It is a schematic diagram explaining the 4th modification of a cage. It is a schematic diagram explaining the 5th modification of a cage. It is a schematic diagram explaining the 6th modification of a cage. It is sectional drawing explaining the 7th modification of a cage. It is a schematic diagram corresponding to FIG. 4 of the cage of the 7th modification. It is sectional drawing explaining the 8th modification of the cage. It is sectional drawing explaining the lubrication to a bearing by a lubricating oil pump. It is sectional drawing explaining the lubrication to a bearing by the bouncing of a gear. It is sectional drawing explaining when the cage moves in the axial direction to the large diameter side of a tapered roller in the conventional tapered roller bearing. It is sectional drawing explaining when the cage shown in FIG. 16 moved in the axial direction to the small diameter side of a tapered roller. 16 is a plan view of the cage and tapered rollers shown in FIG. 16 as viewed from the outside in the radial direction. It is a schematic diagram which shows the contact positional relationship between the oil groove shown in FIG. 16 and the end face on the large diameter side of a tapered roller.

Hereinafter, an embodiment of a tapered roller bearing according to the present invention will be described in detail with reference to the drawings.

As shown in FIG. 1, the tapered roller bearing 10 of the present embodiment has an outer ring 11 having an outer ring raceway surface 11a on the inner peripheral surface, an inner ring 12 having an inner ring raceway surface 12a on the outer peripheral surface, and an outer ring raceway surface 11a and an inner ring. A plurality of tapered rollers 13 provided so as to be rollable between the raceway surface 12a and a cage 14 for holding the plurality of tapered rollers 13 at substantially equal intervals in the circumferential direction are provided. In the present embodiment, the lubricating oil circulating inside the housing H (see FIG. 14) is appropriately supplied to the inside of the bearing by the lubricating oil pump P (see FIG. 14) or the like.

The inner ring 12 has a large collar portion 12b provided at the large diameter side end portion of the inner ring 12 and a small collar portion 12c provided at the small diameter side end portion of the inner ring 12. The outer peripheral surface of the inner ring 12 is formed in a substantially conical shape.

The tapered roller 13 is provided on a rolling surface 13a provided on the peripheral surface of the tapered roller 13, a large-diameter side end surface 13b provided on the large-diameter side end of the tapered roller 13, and a small-diameter side end of the tapered roller 13. It has a small diameter side end surface 13c. Further, the large-diameter side end surface 13b is formed in a convex spherical shape having a radius of curvature Ra, and a circular recess 13d is formed in the central portion thereof. The center of the convex spherical surface is located on the rotation axis of the tapered roller 13.

The cage 14 is made of synthetic resin and is injection-molded by an axial draw. The large-diameter ring portion 15 and the small-diameter annulus 16 arranged coaxially with the large-diameter annulus 15 are large. The radial side annular portion 15 and the small diameter side annular portion 16 are connected in the axial direction, and are large between a plurality of pillar portions 17 provided at substantially equal intervals in the circumferential direction and pillar portions 17 adjacent to each other in the circumferential direction. It is formed by being surrounded by a radial side annular portion 15 and a small diameter side annular portion 16, and has a pocket 18 for holding a conical roller 13 so as to be rollable.

Further, the cage 14 has a first gap S1 between the axial inner end surface 16a of the small diameter side annular portion 16 of the cage 14 and the small diameter side end surface 13c of the tapered roller 13. Further, the cage 14 has a second gap S2 between the axial inner end surface 15a of the large diameter side annular portion 15 of the cage 14 and the large diameter side end surface 13b of the tapered roller 13. Further, in the present embodiment, the roller axial dimension D1 of the first gap S1 and the roller axial dimension D2 of the second gap S2 are set to 0.3 mm or less, respectively. The roller axis direction dimensions D1 and D2 are dimensions along the central axis (rotation axis) direction of the tapered roller 13.

Further, the surface of the axial inner end surface (hereinafter, also simply referred to as “pocket surface”) 15a of the large diameter side annular portion 15 of the cage 14 is roughly formed, and the specific surface roughness of the pocket surface 15a is formed. (Arithmetic mean roughness) is set to 3 μm to 20 μm.

The roughness of the pocket surface 15a of the large-diameter annular portion 15 functions to guide the lubricating oil stored in the oil groove 20, which will be described later, to the tapered rollers 13. Thereby, the oil retention capacity and the oil supply capacity of the pocket surface 15a can be enhanced. Further, it is preferable that the inner surface of the oil groove 20, which will be described later, is also roughly formed in order to enhance the oil retention capacity. Further, since the pocket surface 15a is substantially perpendicular to the die-cutting direction during molding of the cage, even if the pocket surface 15a is roughly formed, it does not hinder the mold release after molding. The surface roughness of the pocket surface 15a may be set for all pockets 18 or for some pockets 18.

The pocket surface 15a of the large diameter side annular portion 15 is formed in a concave spherical shape having a radius of curvature SRy. The concave spherical radius of curvature SRy of the pocket surface 15a is set within ± 10% of the convex spherical radius of curvature Ra of the large diameter side end surface 13b of the cone 13 (0.9Ra ≦ SRy ≦ 1). .1Ra). As a result, the degree of adhesion between the pocket surface 15a and the large diameter side end surface 13b of the tapered roller 13 is improved, so that a high oil retention and refueling effect can be obtained. However, if SRy is matched with Ra (SRy = Ra) and hits the entire surface, the frictional resistance increases. Therefore, the optimum state is that the radius of curvature is slightly shifted so that the SRy is not completely adhered.

Further, as shown in FIGS. 1 to 4, one oil groove 20 for storing lubricating oil is formed on the pocket surface 15a of the large diameter side annular portion 15 of the cage 14. The oil groove 20 is a bottomed groove, and is formed in each pocket 18 in an annular fan shape along the circumferential direction of the large diameter side annular portion 15. The oil groove 20 may be provided for all the pockets 18 or may be provided for some of the pockets 18. Further, the number of oil grooves 20 is not limited to one, and may be two or more.

FIG. 4 is a schematic view showing the positional relationship between the oil groove 20 and the large diameter side end surface 13b of the tapered roller 13. The large-diameter side end surface 13b of the tapered roller 13 has a circular recess 13d formed in the center of the large-diameter side end surface 13b and an annular contact surface provided around the recess 13d and capable of contacting the pocket surface 15a. It has 13e and. The oil groove 20 is accommodated in a region where the large-diameter side end surface 13b of the tapered roller 13 and the pocket surface 15a overlap in the longitudinal direction of the tapered roller 13 (a region where the tapered roller 13 overlaps when viewed in the longitudinal direction). Provided. More specifically, the oil groove 20 is provided so as to fit in a region where the annular contact surface 13e and the pocket surface 15a overlap in the longitudinal direction of the tapered rollers 13. As a result, the oil groove 20 is covered with the annular contact surface 13e (large diameter side end surface 13b) of the tapered rollers 13, so that it is possible to prevent the lubricating oil from leaking from the oil groove 20.

Further, the diameter of the recess 13d of the present embodiment is formed to be smaller than the recess of a general tapered roller. In other words, the diameter of the recess 13d of the present embodiment is set so that the recess 13d and the oil groove 20 do not overlap in the longitudinal direction of the tapered roller 13, including the amount of movement in the radial direction of the cage 14. There is.

Further, as shown in FIG. 4, in the present embodiment, the oil groove 20 is formed in an annular fan shape, and the pair of end connecting sides 21 which are both ends in the longitudinal direction of the oil groove 20 are tapered rollers 13. It is formed in an arc shape that follows the outer peripheral edge of the annular contact surface 13e. As a result, the capacity for storing the lubricating oil in the oil groove 20 can be increased. Further, the oil groove 20 formed by the axial draw extends in the same direction (axial direction) as the central axis of the cage 14, which is the direction in which the molding die moves (releases) during injection molding.

The cage 14 is made of synthetic resin and can be injection molded by, for example, an axial draw. The surface roughness of the pocket surface 15a of the large diameter side annular portion 15 and the oil groove 20 can also be formed at the same time by this injection molding. In this case, it is not necessary to add a processing process, special molding such as two-color molding (double molding), and bonding of a separately manufactured oil-retaining member. Therefore, the seizure resistance can be improved without increasing the manufacturing cost.

The material of the cage 14 is not particularly limited, and examples thereof include a general cage resin material such as nylon. The synthetic resin of the cage 14 may contain fibers as a reinforcing agent.

As described above, according to the tapered roller bearing 10 of the present embodiment, the bearing 10 is provided with an oil groove 20 for storing lubricating oil on the pocket surface 15a of the large diameter side annular portion 15 of the cage 14. Even if the lubricating oil is not supplied and the amount of the lubricating oil in the bearing 10 becomes small, the lubricating oil stored in the oil groove 20 is supplied to the large-diameter side end surface 13b of the tapered roller 13. Therefore, seizure of the bearing 10 can be prevented even in a lubricating environment in which the supply of lubricating oil is intermittent or in a lubricating environment in which a small amount of lubricating oil is used. Further, since the oil groove 20 is provided so as to fit in the region where the annular contact surface 13e of the tapered roller 13 and the pocket surface 15a overlap in the longitudinal direction of the tapered roller 13, the annular contact surface 13e of the tapered roller 13 is provided in the oil groove 20. The contact surface 13e of the lid is closed. Therefore, it is possible to prevent the lubricating oil from leaking from the oil groove 20.

Further, according to the tapered roller bearing 10 of the present embodiment, the oil groove 20 is formed along the circumferential direction, and the direction of action of the centrifugal force during the rotation of the bearing and the formation direction of the oil groove 20 are orthogonal to each other. It is possible to prevent the lubricating oil contained in the bearing from scattering due to centrifugal force.

Further, according to the tapered roller bearing 10 of the present embodiment, the amount of lubricating oil can be significantly reduced, so that the stirring resistance of the lubricating oil can be reduced. Further, for example, if the structure is such that even a small amount of lubricating oil can be supplied by splashing with gears (see FIG. 15), the lubricating oil pump and the oil supply passage can be eliminated, thereby making the entire lubrication system lightweight and compact. , Cost reduction can be achieved.

Further, according to the tapered roller bearing 10 of the present embodiment, the bearing is prevented from seizure even in a lubricating environment where lubricating oil is intermittently supplied into the bearing or the amount of lubricating oil in the bearing is very small. Performance and lubrication effect can be maintained for a long period of time. Therefore, the tapered roller bearing 10 of the present embodiment can be suitably used for a mechanism such as a transmission of some hybrid vehicles in which the lubricating oil pump is temporarily stopped when the engine is stopped, and also for an automobile. It is possible to cope with a situation where it is difficult to supply a sufficient amount of lubricating oil because the lubricating oil pump does not operate when the vehicle is towed.

Here, a lubrication environment in which the amount of lubricating oil in the present specification is very small will be described. For example, in the case of a transmission such as an automobile, there are generally two methods of supplying lubricating oil: pumping the lubricating oil by the lubricating oil pump P shown in FIG. 14 and splashing the lubricating oil by the gear G shown in FIG. Known for.

As a structure for pumping lubricating oil by the lubricating oil pump P, as shown in FIG. 14, the outer ring 11 of the tapered roller bearing 10 is fitted inside the housing H, and the inner ring 12 is fitted outside the rotating shaft A, and the housing. A structure is generally known in which a lubrication passage R communicating with the bearing 10 is provided in H, and a lubricating oil pump P is connected to the lubrication passage R. In the case of this structure, the lubricating oil pumped from the lubricating oil pump P is supplied to the bearing 10 via the oil supply passage R.

Further, as a structure in which the lubricating oil is splashed by the gear G, as shown in FIG. 15, the outer ring 11 of the tapered roller bearing 10 is fitted inside the housing H, and the inner ring 12 is fitted outside the rotating shaft A to rotate. A structure in which a gear G is provided on the shaft A adjacent to the inner ring 12 is generally known. In the case of this structure, the lubricating oil adhering to the gear G is scattered by the centrifugal force accompanying the rotation of the shaft, and the scattered lubricating oil is adhering to the bearing 10 and refueled.

In the above two types of structures, an amount of lubricating oil of about 50 cc / min to 1000 cc / min is supplied in order to prevent seizure of the bearing. If the amount of the lubricating oil is less than 10 cc / min, heat generation and seizure are likely to occur due to insufficient oil film due to the lack of lubricating oil, and seizure occurs at 0 cc / min (non-lubricated oil). The present invention corresponds to a dilute lubricated state rather than a non-lubricated state, and has a great effect in a lubricating environment in which a small amount of lubricating oil is used, specifically, in a dilute lubricated state of about 0.01 cc / min to 10 cc / min. Demonstrate.

Next, the environment in which the lubricating oil in the present specification is intermittently supplied will be described. For example, in a hybrid vehicle, there is a mode in which the vehicle runs on an electric motor with the engine stopped. In this mode, in the structure of only the lubricating oil pump directly connected to the engine, running is performed in a state where the lubricating oil is not supplied to the bearings. For this reason, a non-lubricated running state occurs for up to several minutes, but the bearing must not seize during this period. There is a need to extend this electric running time with the evolution of batteries. At present, in order to prevent seizure, there are some models that control the operation of the lubricating oil pump by rotating the engine at regular intervals. To solve this problem, it is necessary to add an electric lubricating oil pump to the system or to adopt a non-lubricating and seizure-resistant bearing as in the present invention. In the present invention, since the time until seizure is related to the amount of lubricating oil stored in the oil groove, it is possible to significantly extend the non-lubricating application time from several tens of minutes to several hours by increasing the amount of lubricating oil. It is possible. The increase in the amount of lubricating oil can be dealt with, for example, by increasing the number of oil grooves or increasing the depth of the oil grooves.

In addition, a passenger car may be towed as an auxiliary vehicle in the event of a breakdown or at a destination of a large vehicle such as a camper. In such a case, it is possible to prevent idling by mounting the drive wheels of the vehicle on a trolley or the like, but in reality, there are cases where the drive wheels are towed while idling. In this case, there is no drive transmission and the bearing is lightly loaded because of no-load idling. However, in the case of tapered roller bearings, preload is generally applied and the load for the preload is always applied. In this idling state, the engine and the electric lubricating oil pump do not operate, and the lubricating oil pump is stopped, so that the bearings are liable to seize. As a countermeasure for this, some models have devised a drive device so that splash refueling occurs. In the present invention, even if the lubricating oil pump is stopped, the bearing can be refueled until the lubricating oil stored in the oil groove is exhausted. Can be greatly improved.

In addition, when starting in an extremely cold environment, the lubricating oil freezes, and a phenomenon occurs in which neither lubrication by the lubricating oil pump nor refueling by splashing occurs temporarily. In this case, the lubrication must be covered by a small amount of oil adhering to the bearing itself until the frozen lubricating oil warms and melts. Further, in the present invention, since the frozen lubricating oil is stored in the oil groove, it is lubricated while gradually melting as the bearing generates heat, so that the seizure resistance can be dramatically improved.

Next, as a first modification of the present embodiment, as shown in FIG. 5, the pair of end connecting sides 21 of the oil groove 20 may be formed in a linear shape along the radial direction.

Further, as a second modification of the present embodiment, as shown in FIG. 6, the pair of end connecting sides 21 of the oil groove 20 may be formed in a semicircular shape.

Further, as a third modification of the present embodiment, as shown in FIG. 7, by bringing the outer diameter side side surface of the oil groove 20 closer to the outer peripheral surface of the large diameter side annular portion 15, the circumferential direction of the oil groove 20 The radial width D3 of the intermediate portion may be increased (formed in a substantially crescent shape). As a result, the capacity for storing the lubricating oil in the oil groove 20 can be further increased. The radial width D3 of the oil groove 20 is a width in a direction orthogonal to the extending direction of the oil groove 20.

Further, as a fourth modification of the present embodiment, as shown in FIG. 8, it is not necessary to form the recess 13d on the large diameter side end surface 13b of the tapered roller 13.

Further, as a fifth modification of the present embodiment, as shown in FIG. 9, an arc-shaped chamfer Rx may be applied to the corner portion on the inner diameter side of the pair of end connecting sides 21 of the oil groove 20.

Further, as a sixth modification of the present embodiment, as shown in FIG. 10, a linear chamfer Cx may be applied to the corner portion on the inner diameter side of the pair of end connecting sides 21 of the oil groove 20.

Further, as a seventh modification of the present embodiment, as shown in FIGS. 11 and 12, the oil groove 20 may be formed in an annular fan shape along the annular contact surface 13e of the tapered rollers 13. Further, in this modification, a semicircular oil storage recess 30 for storing lubricating oil is formed at a position where the recess 13d of the tapered roller 13 and the concave roller 13 overlap in the longitudinal direction on the pocket surface 15a of the cage 14. .. The oil storage recess 30 is formed smaller than the recess 13d. The oil storage recess 30 is also open on the inner peripheral surface of the large diameter side annular portion 15. According to this modification, the lubricating oil stored in the oil storage recess 30 in addition to the oil groove 20 can supply a large amount of lubricating oil to the momentary shortage of lubricating oil, further improving the seizure resistance of the bearing 10. Can be improved. Further, as an eighth modification of the present embodiment, as shown in FIG. 13, the oil storage recess 30 may be formed larger than the recess 13d.

The present invention is not limited to those exemplified in the above embodiments, and can be appropriately modified without departing from the gist of the present invention.

10 Tapered roller bearing 11 Outer ring 11a Outer ring raceway surface 12 Inner ring 12a Inner ring raceway surface 13 Tapered roller 13a Rolling surface 13b Large diameter side end surface 13c Small diameter side end surface 13d Recess 13e Circular contact surface 14 Cage 15 Large diameter side annular part 15a Axial inner end surface (pocket surface)
16 Small diameter side annular part 16a Axial inner end surface 17 Pillar part 18 Pocket 20 Oil groove 21 End connection side 30 Oil storage recess S1 1st gap S2 2nd gap D1 Roller axial dimension of 1st gap D2 2nd gap Roller axis direction dimension Ra Radius of curvature of the large diameter side end face of the cone SRy Radius of curvature of the pocket surface

Claims (8)

An outer ring having an outer ring raceway surface on an inner peripheral surface, an inner ring having an inner ring raceway surface on an outer peripheral surface, a plurality of tapered rollers provided so as to be rollable between the outer ring raceway surface and the inner ring raceway surface, and the plurality of tapered rollers. It is equipped with a cage that holds the tapered rollers at approximately equal intervals in the circumferential direction.
The cage has a large diameter side annular portion, a small diameter side annular portion coaxially arranged with the large diameter side annular portion, and the large diameter side annular portion and the small diameter side annular portion as axes. A cone having a plurality of pillars connected in the direction and provided at substantially equal intervals in the circumferential direction, and a pocket formed between the pillars adjacent to each other in the circumferential direction and holding the tapered rollers so as to be rollable. Roller bearings
The cage has a first gap between the axial inner end surface of the small diameter side annular portion and the small diameter side end surface of the tapered roller, and the axial inner end surface of the large diameter side annular portion and the conical roller. It has a second gap between it and the end face on the large diameter side of the roller.
The dimensions of the first gap and the second gap are set to 0.3 mm or less, respectively.
At least one oil groove for storing lubricating oil is provided on the axial inner end surface of the large-diameter ring portion.
The tapered roller is provided so that the large-diameter side end surface of the tapered roller and the axial inner end surface of the large-diameter annulus portion are accommodated in a region where the tapered roller overlaps in the longitudinal direction. bearing. The large-diameter side end face of the tapered roller is provided around the circular recess formed in the center of the large-diameter end face and the concave portion, and is in contact with the axial inner end surface of the large-diameter annular portion. With a possible annular contact surface,
The oil groove is provided so as to fit in a region where the annular contact surface and the axial inner end surface of the large diameter side annular portion overlap in the longitudinal direction of the tapered roller. Described tapered roller bearings. The tapered roller bearing according to claim 2, wherein the oil groove is formed in an annular fan shape along the circumferential direction of the large diameter side annular portion. The third aspect of claim 3, wherein the pair of end connecting sides, which are both ends in the longitudinal direction of the oil groove, are formed in an arc shape that follows the outer peripheral edge of the annular contact surface of the tapered roller. Tapered roller bearings. The tapered roller bearing according to claim 2, wherein the oil groove is formed in an annular fan shape along the annular contact surface of the tapered roller. An oil storage recess for storing lubricating oil is formed at a position overlapping the recess of the tapered roller in the longitudinal direction of the tapered roller on the axial inner end surface of the large-diameter annular portion of the cage. The tapered roller bearing according to claim 5. The axial inner end surface of the large diameter side annular portion is formed in a concave spherical shape, and the large diameter side end surface of the tapered roller is formed in a convex spherical shape.
The concave spherical radius of curvature SRy of the axially inner end surface of the large diameter side annular portion is set within ± 10% of the convex spherical radius of curvature Ra of the large diameter side end surface of the tapered roller. The tapered roller bearing according to claim 1. The tapered roller according to any one of claims 1 to 7, wherein the lubricating oil is intermittently supplied to the inside of the bearing, or the lubricating oil inside the bearing is used in a lubricating environment in a small amount. Roller bearing.

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