JP2010031901A - Tapered roller bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tapered roller bearing capable of reducing torque by restraining an increase in agitating resistance to lubricating oil of a rolling element, by optimizing an inflow quantity of the lubricating oil to the bearing inside. <P>SOLUTION: A cone side extension part 21e and a cup side extension part 22e are arranged on the first end side in the axial direction of a cup 22 and a cone 21, and a bearing ring side gap C is formed between an inner peripheral surface of a cup side flange part 22a formed on an inner peripheral surface of its cup side extension part 22e and an outer peripheral surface of the cone side extension part 21e. An outer peripheral surface of a small collar part 21s for regulating a position in the axial direction on the small end surface side of a tapered roller 23, is formed as an inclined face 21f inclining in the same direction as the outer peripheral surface of the tapered roller. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a tapered roller bearing.

JP 2005-69421 A WO2005 / 045269

  In a gear-type drive transmission unit for automobiles, a tapered roller bearing is employed at its main point (for example, a differential gear device forming a final reduction gear) (Patent Documents 1 and 2). The tapered roller bearing has an advantage that it can be used with a large capacity even though it is compact, and has an advantage that it is excellent in durability against an impact load due to gear engagement.

  The tapered roller bearing sucks lubricating oil from the small diameter side (first end side) into the rolling element holding space between the inner and outer rings and flows out from the large diameter side (second end side) by the pump action generated by the rotation of the bearing. It has become. However, if the amount of the lubricating oil sucked in is excessive or the outflow from the large diameter side is obstructed, the amount of lubricating oil staying in the rolling element holding space becomes excessive, and the stirring resistance of the lubricating oil by the rolling element becomes large. As a result, the rotational torque of the bearing increases, the efficiency of the unit d years after driving decreases, and the fuel consumption of the vehicle deteriorates. In order to solve this problem, Patent Documents 1 and 2 describe a cage-side flange by bending back a first end side end portion of the cage in an axial direction toward a corresponding end portion of the outer peripheral surface of the inner ring. A bearing has been proposed in which a gap is formed between the cage-side flange and the inner ring so as to restrict the inflow of lubricating oil.

  However, in the configuration of the bearing described above, it is difficult for the lubricating oil staying between the small end surface of the tapered roller and the cage side flange portion to be discharged out of the bearing, and the stirring resistance of the tapered roller against the lubricating oil is likely to increase. Thus, there is a drawback that the rotational torque of the bearing tends to increase.

  An object of the present invention is to provide a tapered roller bearing capable of promoting the discharge of lubricating oil to the outside of the bearing on the small end face side of the tapered roller and reducing the stirring resistance of the tapered roller with respect to the lubricating oil.

Means for Solving the Problems and Effects of the Invention

In order to solve the above problems, the tapered roller bearing of the present invention is
The outer ring and inner ring arranged opposite to each other in the radial direction are provided, and conical raceway surfaces that expand from the first end side to the second end side in the axial direction are formed on the inner peripheral surface of the outer ring and the outer peripheral surface of the inner ring, respectively. A plurality of tapered rollers that form rolling elements in the circumferential direction of rotation in a rolling element holding space formed between the conical raceway surfaces,
The outer ring and the inner ring are respectively formed with an outer ring side extending part and an inner ring side extending part extending in the axial direction to the first end side from the raceway surface of the tapered roller.
A circumferential outer ring side flange portion protruding radially inward is provided on the inner circumferential surface of the outer ring side extending portion, and an inner circumferential surface of the outer ring side flange portion and an outer circumferential surface of the inner ring side extending portion are provided. A raceway side gap is formed between
The second end in the axial direction of the tapered roller is formed in such a manner that a predetermined one end in the axial direction is a first end and the inner peripheral surface of the inner ring is adjacent to the second end side in the axial direction of the conical raceway surface. A large collar portion in the circumferential direction that regulates the position of the end side is formed to protrude,
The inner ring of the inner ring is adjacent to the first end side in the axial direction of the conical raceway surface, and a circumferential small flange that regulates the position of the first end side in the axial direction of the tapered roller is formed to protrude. And
The outer peripheral surface of the small collar portion is formed as an inclined surface inclined in the same direction as the outer peripheral surface of the tapered roller.

  In the tapered roller bearing of the present invention, an inner ring side extension part and an outer ring side extension part are provided on the first end side in the axial direction of the outer ring and the inner ring, and the outer ring side formed on the inner peripheral surface of the outer ring side extension part. A bearing ring side gap is formed between the inner peripheral surface of the flange portion and the outer peripheral surface of the inner ring side extending portion. The bearing ring side gap serves to adjust or regulate the amount of lubricating oil flowing from the first end side into the rolling element holding space. Since the outer peripheral surface of the small collar portion that restricts the axial position on the small end surface side of the tapered roller formed on the outer peripheral surface of the inner ring is formed as an inclined surface that is inclined in the same direction as the outer peripheral surface of the tapered roller. Lubricating oil staying between the small end face of the roller and the bearing ring side flange can be smoothly discharged from the bearing ring side gap along the inclined surface to the outside of the bearing. An increase in torque can be effectively suppressed. Further, the lubricating action of the tapered roller can be smoothly drawn toward the tapered roller along the outer peripheral surface of the inclined small flange portion.

  The rolling element holding space has a main body portion configured as a truncated cone-shaped shell body whose diameter increases from the first end side in the axial direction toward the second end side, and the tapered roller extends in the circumferential direction of the main body portion. A cage in which a plurality of pocket portions for accommodating and holding each of them is formed can be arranged. In this case, the retainer bends the first end side in the axial direction of the main body portion inward in the radial direction to form a retainer side flange portion, and the radially inner peripheral surface of the retainer side flange portion is small. The cage-side gap can be formed by facing the outer peripheral surface forming the inclined surface of the collar portion. By combining the bearing ring side gap and the cage side gap, the oil inflow amount to the rolling element side can be adjusted more finely. For example, even when the amount of lubricating oil supplied to the bearing itself is considerably large, excessive oil inflow to the rolling element side can be suppressed by the combined use of the bearing ring side gap and the cage side gap. In addition, the cage side flange portion is interposed between the rolling element and the bearing ring side flange portion, so that the oil sump space formed between the cage side flange portion and the rolling element is expanded, The fluctuation of the supplied oil inflow amount can be further reduced.

  On the other hand, the cage has a structure in which the first end side in the axial direction of the main body portion extends linearly toward the small collar portion in a cross section including the central axis, and is opposed to the outer peripheral surface forming the inclined surface of the small collar portion. That is, a structure in which the cage side flange portion is abolished can also be adopted. As a result, the discharge of the lubricating oil staying between the small end surface of the tapered roller and the bearing ring side flange portion is not hindered by the cage side flange portion, and the lubricating oil can be discharged more smoothly out of the bearing.

  In order to prevent the foreign matter from the outside of the bearing from entering the rolling element holding space while avoiding an excessive increase in the rotational torque of the bearing, it is desirable to form the bearing ring side gap as a labyrinth seal. The gap on the race ring side that forms the labyrinth seal prevents foreign matter from entering the rolling element holding space from the first end side, and even if the amount of lubricating oil supplied to the first end side becomes excessive, The gap interval is narrowed to such an extent that a labyrinth seal is formed to prevent intrusion, so that the inflow amount of lubricating oil is restricted to a relatively small amount. However, the lubricating oil passing through the bearing ring side gap is larger in the axial direction in the side edge portion on the first end side of the cage and the outer peripheral surface of the inner ring side extension portion than the bearing ring side gap. Since they are opposed to each other with a radial interval, they pass quickly between the cage and the inner ring side extension and are supplied to the cage. That is, while the amount of lubricating oil passing through the raceway side gap is suppressed, the amount of lubricating oil supplied to the rolling elements themselves is stabilized to a necessary and sufficient value, and no significant fluctuation occurs. As a result, it is possible to suppress the problem that the amount of lubricating oil swings to the excessive side and increases the stirring resistance of the rolling elements, and the problem that the amount of lubricating oil flowing into the bearing swings to the insufficient side and causes seizure or the like is less likely to occur. When the cage side gap is formed, the gap interval is set larger than the bearing ring side gap.

  The radial direction interval may be determined so that the labyrinth seal is not formed between the side edge portion on the first end side of the cage in the axial direction and the outer peripheral surface of the inner ring side extending portion. In other words, foreign matter or the like can enter the bearing sufficiently on the side of the gap on the race ring side where the labyrinth seal is formed, so that the space between the cage and the extension portion on the inner ring side does not form a labyrinth seal. You can zoom in and out. As a result, the lubricating oil passing through the bearing ring side gap can be more quickly guided to the rolling element side.

  The axial direction distance between the side circumferential surface located inside the bearing in the axial direction of the outer ring side flange portion and the side edge portion on the first end side of the cage is the axial width of the inner circumferential surface of the outer ring side flange portion. Can be set smaller. By making the axial direction distance between the outer ring side flange part and the cage smaller than the axial direction width of the inner peripheral surface of the outer ring side flange part forming the labyrinth seal part, it passes through the bearing ring side gap. The effect of promptly guiding the coming lubricating oil to the rolling element side can be further enhanced.

  The outer ring side flange portion can be provided at a position offset from the first end side end surface in the axial direction of the outer ring side extending portion by a certain depth in the axial direction. As a result of studies by the present inventor, when the bearing ring side gap is formed in the tapered roller bearing, the amount of oil flowing into the bearing is greatly affected by the gap (radial direction) of the bearing ring side gap and is held in the gap. It was found that the agitation shear resistance of the oil is more affected by the gap width (axial direction). Therefore, by offsetting the outer ring side flange part from the end face on the first end side, the thickness (inner peripheral surface width) of the outer ring side flange part that determines the axial width of the bearing ring side gap can be reduced and held in the bearing ring side gap. The effect of restricting the inflow of oil into the bearing can be achieved without any problem by adjusting the gap distance on the bearing ring side while reducing the amount of oil to be applied, and hence the stirring shear resistance.

  On the outer peripheral surface of the inner ring side extension portion, a first portion that forms an end ring side gap that forms a first end side end portion in the axial direction of the outer peripheral surface and faces the inner peripheral surface of the outer ring side flange portion, and an axial A second portion having a larger diameter than the first portion can be formed in the direction following the first portion on the inner side of the directional bearing. Then, the step gap surface connecting the first portion and the second portion in the radial direction is opposed to the front end portion of the side peripheral surface located inside the bearing of the outer ring side flange portion in the axial direction, thereby assisting the auxiliary gap. Can be formed. By forming an auxiliary gap in the axial direction following the radial ring-side gap in the radial direction, the gap that restricts the inflow of oil is formed in a staircase as a whole, and foreign matter from the outside of the bearing is caused by rolling elements. The effect of entering the holding space can be enhanced.

  In this case, it is desirable that the auxiliary gap is formed smaller than the bearing ring side gap. As described above, the bearing ring side gap is reduced in the axial width due to the offset of the outer ring side flange portion, and the friction shear resistance on the inner surface of the gap and thus the rotational torque of the bearing can be reduced. Also, the effect of restricting oil inflow can be enhanced by narrowing the interval. In addition, since the facing direction of the bearing ring side gap is the radial direction, the auxiliary gap is the axial direction of the auxiliary gap, so the gap interval of the auxiliary gap formed on the extension inside the axial direction of the bearing ring side gap is By reducing the size, the amount of oil retained in the auxiliary gap can be reduced, and the increase in the agitation shear resistance and hence the bearing rotational torque can be kept small.

  Next, in the rolling element holding space, a cage in which a plurality of pocket portions for accommodating and holding the rolling elements in a rollable manner is formed in the circumferential direction can be arranged. A cage side flange portion projecting radially inward toward the outer peripheral surface of the inner ring side extension portion can be formed on the side edge on the first end side of the cage in the axial direction. A cage side gap can be formed between the inner peripheral surface and the outer peripheral surface of the inner ring side extending portion. By combining the bearing ring side gap and the cage side gap, the oil inflow amount to the rolling element side can be adjusted more finely. For example, even when the amount of lubricating oil supplied to the bearing itself is considerably large, excessive oil inflow to the rolling element side can be suppressed by the combined use of the bearing ring side gap and the cage side gap. In addition, the cage side flange portion is interposed between the rolling element and the bearing ring side flange portion, so that the oil sump space formed between the cage side flange portion and the rolling element is expanded, The fluctuation of the supplied oil inflow amount can be further reduced.

  In this case, it is desirable to set the axial direction width of the inner peripheral surface of the bearing ring side flange portion smaller than the axial direction width of the inner peripheral surface of the cage side flange portion. As a result, the cage flange portion is held in the cage gap by reducing the axial width of the cage side flange portion more than the bearing ring side flange portion while supplementarily enhancing the effect of regulating the oil inflow amount. The amount of oil to be reduced can be reduced, and the increase in the stirring shear resistance and hence the bearing rotational torque can be suppressed.

  The inner peripheral surface of the outer ring side flange portion can be formed as a cut finish surface. Since the thin cage having a large number of pockets is manufactured by punching, the gap forming method using the cage disclosed in Patent Documents 1 and 2 is punched with a rough forming accuracy on the gap forming surface on the cage side. From the viewpoint of preventing interference between the cage and the inner ring, the gap formed between the cage and the inner ring is more than necessary. I had to set it large. However, in the present invention, since the gap is formed by using the outer ring side flange portion that can be integrally formed as a part of the outer ring by forging and cutting, the inner peripheral surface of the outer ring side flange portion is a cutting surface with good formation accuracy. By this, the space | interval of the outer ring | wheel side flange part can be shortened more, the oil inflow control effect improves, and the dispersion | variation between individual bearings can also be reduced.

  Due to the side circumferential surface on the first end side in the axial direction of the outer ring side flange portion and the inner circumferential surface end portion of the outer ring side extending portion on the first end side, the end surface on the first end side of the outer ring has a circumferential direction. A spot-like recess can be formed. Since this concave portion can function as a lubricating oil retention portion in the raceway side gap, even if the amount of lubricating oil supplied to the bearing first end side fluctuates, the lubricating oil is pooled in the concave portion. The amount of lubricating oil supplied to the bearing ring side gap can be stabilized.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows the internal structure of a differential gear device that is one of the objects to which the present invention is applied. The differential gear device 3 is applied to the final reduction gear portion of the transmission unit in an FR (front engine rear wheel drive) type automobile, and is forward of the vehicle via a long propeller shaft 1 at the front and rear (right side in FIG. 1). Power from an engine (not shown) mounted on the drive shaft 2 is transmitted to the drive shaft 2 via the differential gear device 3 to rotate left and right rear wheels (drive wheels; not shown). . The rotation of the propeller shaft 1 is transmitted to the pinion shaft 31 (a member included in the liquid lubrication mechanism 30 described later) through the companion flange 38. The pinion shaft 31 is supported in a case 34 by a pair of tapered roller bearings 10 and 20.

  These tapered roller bearings 10 and 20 have a constant facing distance through a cylindrical spacer 39 fitted on the pinion shaft 31 such that the first end side (the smaller diameter side of the raceway surface) faces in the axial direction. Mounted on the pinion shaft 31. The inner rings 11, 21 rotate integrally with the pinion shaft 31, while the outer rings 12, 22 are fixed to the bearing housing portion 35 in the case 34 so as not to rotate.

  The tapered roller bearings 10 and 20 are both configured as the tapered roller bearing of the present invention, and have the same configuration except that the bearing dimensions are different. As shown in FIG. 2, the outer rings 12 and 22 and the inner rings 11 and 21 are opposed to each other in the radial direction, and the annular rolling element holding space between the outer rings 12 and 22 and the inner rings 11 and 21 is used. A plurality of tapered rollers 13 and 23 as rolling elements arranged in the circumferential direction of rotation are provided. Conical raceway surfaces that increase in diameter from the first end side in the axial direction toward the second end side are formed on the inner peripheral surfaces of the outer rings 12 and 22 and the outer peripheral surfaces of the inner rings 11 and 21, respectively. The tapered rollers 13 and 23 are disposed between them.

  In the inner peripheral surfaces of the inner rings 11 and 21, adjacent to the second end side in the axial direction of the conical raceway surface, a circumferential direction that regulates the position of the second end side in the axial direction of the tapered rollers 13 and 23. The large collar portions 11b and 21b are formed to protrude. In addition, circumferential small ribs 11s and 21s that project the conical roller surface adjacent to the first end in the axial direction and restrict the position of the tapered rollers 13 and 23 in the axial direction are formed to protrude. Has been. The inner rings 11 and 21 and the outer rings 12 and 22 are formed by forging and cutting of a steel material.

  On the other hand, in each rolling element holding space, cages 14 and 24 are arranged in which a plurality of pocket portions 24p for accommodating and holding the tapered rollers 13 and 23 so as to roll are formed in the circumferential direction. The cages 14 and 24 are formed by punching the outer shape and the pocket portion 24p using a steel plate as a raw material, and further, press working in a drawing form in the axial direction including bending back of the cage-side flange portions 14a and 24a described later. The outer surface is not cut.

  The outer rings 12 and 22 and the inner rings 11 and 21 of the tapered roller bearings 10 and 20 have outer ring side extending portions 12e and 22e extending in the axial direction to the first end side from the raceway surfaces of the tapered rollers 13 and 23, respectively. And inner ring side extension parts 11e and 21e are formed, respectively. In addition, outer circumferential side outer ring side flange portions 12a and 22a projecting radially inward are provided on the inner circumferential surfaces of the outer ring side extending portions 12e and 22e, and the inner circumferential surfaces of the outer ring side flange portions 12a and 22a. And raceway side gaps A and C are formed between the outer peripheral surfaces of the inner ring side extending portions 11e and 21e. Also, cage side flange portions 14a and 24a projecting radially inward toward the outer peripheral surface of the inner ring side extending portions 11e and 21e are formed on the side edge on the first end side of the cage 24, and the cage Cage-side gaps B and D are formed between the inner peripheral surface of the container-side flange portions 14a and 24a and the outer peripheral surface of the inner ring gavel portions 11s and 21s.

  Returning to FIG. 1, the lubricating oil L is supplied from the first end side to the rolling element holding spaces by the liquid lubrication mechanism 30 to the tapered roller bearings 10 and 20 on the pinion shaft 31. The liquid lubrication mechanism 30 includes the pinion shaft 31, a pinion gear 32 attached to one end of the pinion shaft 31, and a lower edge portion immersed in the lubricating oil L in the differential case 34 and the pinion gear 32. And a ring gear 33 that meshes and is rotationally driven to lift up the lubricating oil L.

  Further, a companion flange 38 (connection joint) for connecting the propeller shaft 1 and the pinion shaft 31 is fastened to the other end of the pinion shaft 31 by a nut 38a screwed in the axial direction from the corresponding end face to the pinion shaft 31. Has been. A sliding oil seal 36 is inserted between the inner peripheral surface of the bearing housing portion 35 and the companion flange 38. Further, an annular deflector 37 (protective member) covering the oil seal 36 is fixed to the companion flange 38 so as to be integrally rotatable.

  The lubricating oil L bounced up by the ring gear 33 passes through an oil supply passage 35 a along the inner wall surface of the bearing housing portion 35, and the first end in the axial direction of the inner rings 11, 21 with respect to the pair of tapered roller bearings 10, 20. Supplied from the side. The lubricating oil L supplied from the first end side in each of the tapered roller bearings 10 and 20 is drawn into the bearing spirally along the rolling surface by a pump action generated as the tapered rollers 13 and 23 rotate. Each is discharged from the second end side.

  At this time, the operations and effects of the raceway side gaps A and C and the cage side gaps B and D are exactly the same for the tapered roller bearings 10 and 20, and hence the tapered rollers on the side closer to the ring gear 33 will be described below. The bearing 20 will be described as a representative. FIG. 3 is an enlarged view thereof. The bearing ring side gap C formed between the inner peripheral surface of the outer ring side flange portion 22a and the outer peripheral surface of the inner ring side extending portion 21e is an inflow of the lubricating oil L from the first end side to the rolling element holding space. It plays a role in regulating the quantity. The outer ring side flange portion 22a is integrally formed in a continuous annular shape along the circumferential direction of the outer ring as a part of the outer ring 22 by forging and cutting. The inner peripheral surface of the flange portion 22e is a cutting surface with good formation accuracy together with the outer peripheral surface of the inner ring side extending portion 21e. In addition, the raceway side gap C forms a labyrinth seal in order to prevent foreign matters from the outside of the bearing from entering the rolling element holding space while avoiding an excessive increase in the rotational torque of the bearing.

  The outer peripheral surface of the inner ring side extending portion 21e forms a first end side end portion in the axial direction of the outer peripheral surface, and forms a raceway ring side gap C facing the inner peripheral surface of the outer ring side flange portion 22a. A first portion and a second portion formed on the inner side of the axial direction bearing and having a diameter larger than the first portion in a form following the first portion. Specifically, the outer peripheral surface of the small flange portion 21s is the second portion, and is located on the side closer to the first end (outside of the bearing) than the small flange portion 21s in the axial direction of the inner ring side extending portion 21e. The outer peripheral surface of the part forms the first part. The outer peripheral surface of the small flange portion 21 s is an inclined surface 21 f that is inclined in the same direction as the outer peripheral surface of the tapered roller 23.

  The first portion and the second portion are connected stepwise in the radial direction by the stepped surface, and the tip of the side peripheral surface located inside the bearing of the outer ring side flange portion 22a is the stepped surface in the axial direction. Auxiliary gap F is formed by facing. The interval (axial direction) λ of the auxiliary gap F is set to be smaller than the interval (radial direction) g1 of the bearing ring side gap C. Further, the inner peripheral surface of the cage side flange portion 24a is opposed to the outer peripheral surface (second portion) of the small collar portion 21s to form a cage side gap D. The cage 24 has a side edge portion on the first end side in the axial direction, that is, the main body portion 24m excluding the cage-side flange portion 24a has a diameter increased from the first end side in the axial direction toward the second end side. It is configured as a frustoconical shell.

  The axial width t1 of the inner peripheral surface of the bearing ring side flange portion 22a is set smaller than the axial width t2 of the inner peripheral surface of the cage side flange portion 24a. Further, the axial direction distance μ between the side peripheral surface of the outer ring side flange portion 22a located outside the bearing in the axial direction and the stepped surface is determined by the inner peripheral surface of the outer ring side flange portion 22a and the cage side flange portion 24a. Is set smaller than either of the axial widths t1 and t2.

  An interval (radial direction) g1 of the bearing ring side gap C is, for example, not less than 0.5 mm and not more than 0.7 mm (for example, 0.63 mm). Further, the interval (axial direction) λ of the auxiliary gap F is, for example, not less than 0.2 mm and not more than 0.6 mm (for example, 0.4 mm). Each is appropriately set within the above numerical range so that λ <g1. Moreover, the overlap amount ε in the radial direction between the distal end portion of the cage side flange portion 22a and the small flange portion 21s is 0.6 mm or greater and 1.0 mm or less.

  On the other hand, the distance between the cage side gaps D, that is, the radial facing distance g2 between the side edge portion on the first end side of the cage 24 and the outer peripheral surface of the inner ring side extending portion 21e in the axial direction (the small flange portion 21s). Is defined as a value at a position where the interval is the smallest since the inner peripheral surface of the inner surface is inclined) is set to be larger than the interval of the bearing ring side gap C.

  Since the outer peripheral surface of the small flange portion 21s that regulates the axial position on the small end surface side of the tapered roller 23 is formed as an inclined surface 21f that is inclined in the same direction as the outer peripheral surface of the tapered roller, the small end surface of the tapered roller 23 and the track Lubricating oil L staying in contact with the wheel-side flange portion 22a can be smoothly discharged from the bearing ring-side gap C along the inclined surface 21f to the outside of the bearing, and the stirring resistance of the tapered roller 23 against the lubricating oil L and the bearing rotation An increase in torque can be effectively suppressed. Further, the pumping action of the tapered roller 23 allows the lubricating oil L to be smoothly drawn toward the tapered roller 23 along the outer peripheral surface of the inclined small flange portion 21s.

  In addition, by combining the auxiliary gap F with the raceway side gap C and forming the entire gap in a step shape, the sealing performance between the inner and outer rings 22 and 23 (particularly, the entry and blocking performance of foreign matter or the like) is improved. Further, by reducing the interval λ of the auxiliary gap F formed on the inner extension in the axial direction of the bearing ring side gap C to be smaller than the interval g1 of the bearing ring side gap C, the auxiliary gap F is held. The amount of oil to be reduced can be reduced, and the increase in the stirring shear resistance and thus the bearing rotational torque is suppressed.

  Furthermore, by combining the bearing ring side gap C and the cage side gap D, the oil inflow amount to the rolling element 23 side can be adjusted more finely. For example, even when the amount of lubricating oil supplied to the bearing itself is considerably large, the combined use of the bearing ring side gap C and the cage side gap D can suppress excessive oil inflow to the rolling element 23 side. it can. In the present embodiment, the cage-side flange portion 24a is set such that the axial direction width t2 of the inner peripheral surface is larger than the axial direction width t1 of the inner peripheral surface of the race ring-side flange portion 22a. While assisting the restriction of the oil inflow amount in cooperation with the side gap C, the amount of oil retained in the cage side gap D on the oil inlet side is reduced, and the stirring shear resistance and thus the bearing rotational torque are reduced. Contributes to increase control. For example, the axial width t2 of the cage flange portion 24a is set to 1.5 to 2.0 mm, and the axial width t1 of the bearing ring side flange 22a is set to 0.8 to 1.4 mm.

  Since the inner peripheral surface of the outer ring side flange portion 22a is a cutting surface with good forming accuracy together with the outer peripheral surface of the inner ring side extending portion 21e, the gap g1 of the race ring gap C can be further reduced, and the oil inflow restriction is achieved. The effect is improved. Moreover, the variation between the individual bearings of the gap g1 is also suppressed. Furthermore, the gap g2 of the cage-side gap D tends to fluctuate due to the play in the radial direction of the cage 24 in the rolling element holding space, whereas the inner ring-side extending portion 21e that forms the bearing ring-side gap C. The outer peripheral surface of the inner ring 22 has a constant position in the radial direction, coupled with the inner ring 22 and the outer ring 21 being assembled in a form in which a preload is applied in the axial direction via the rolling elements 23. As a result, the gap g1 of the bearing ring side gap C hardly changes during rotation of the bearing, and the supply amount of the lubricating oil L can be kept stable.

  Hereinafter, various deformation | transformation aspects of the tapered roller bearing 20 concerning one Embodiment of this invention are demonstrated. In FIG. 3, the axial direction width t1 of the inner peripheral surface of the outer ring side flange portion 22a is set larger than the axial direction width t2 of the inner peripheral surface of the cage side flange portion 24a, but in FIG. The thickness of the cage flange portion 24a is reduced so that is substantially equal to t2 or smaller than t2. Thereby, the axial direction width t1 of the bearing ring side gap C is reduced, and the stirring shear resistance of the lubricating oil in the bearing ring side gap C becomes smaller. As a result, it is possible to further reduce the rotational torque of the bearing.

  In the configuration of FIG. 5, the outer peripheral surface of the inner ring side extending portion 21 e is formed as a continuous cylindrical surface in which the portion that forms the bearing ring side gap C and the portion that forms the cage side gap D have the same outer diameter. Yes. Therefore, the auxiliary gap F formed in FIG. 3 is omitted. The first end side edge of the inner ring side raceway surface has a smaller diameter than the continuous cylindrical surface, so that it is recessed in the radial direction to form a small flange portion 21s. Lubricating oil that has passed through the bearing ring side gap C is quickly guided to the cage-side gap D having a large interval in a form that advances straight in the axial direction, so that the space between the outer ring-side flange portion 22a and the cage 24 ( It is difficult for excess lubricating oil to stay in the (oil sump space) 28, and the effect of reducing the stirring resistance of the lubricating oil by the tapered rollers 23 is enhanced. In FIG. 5, in order to make the outlet of the bearing ring side gap C approach the inlet of the cage side gap D and further enhance the above effect, the side peripheral surface of the outer ring side flange portion 22a located inside the bearing in the axial direction. And the axial direction distance ν between the outer peripheral side flange portion 24a and the inner peripheral surface of the outer ring side flange portion 22a and the inner periphery of the retainer side flange portion 24a. The surface (the cage side gap D) is set to be smaller than each of the axial widths t1 and t2.

  FIG. 6 shows a configuration in which the outer ring side flange portion 22a forming the bearing ring side gap C is offset by a certain depth d from the first end side end surface in the axial direction of the outer ring side extending portion 22e in the configuration of FIG. The aspect provided is shown. An outer ring side flange portion 22a has a side circumferential surface on the first end side in the axial direction and an inner circumferential surface end portion of the outer ring side extending portion 22e on the first end side. A counterbore 25 in the circumferential direction is formed.

  In the bearing ring side gap C, the cross-sectional area of the lubricating oil L decreases as the axial distance g1 decreases. Therefore, the inflow restriction effect of the lubricating oil L in the raceway side gap C can be enhanced by setting the axial direction gap g1 to be appropriately small. On the other hand, when the axial direction width t1 of the inner peripheral surface of the outer ring side flange portion 22a (that is, the axial direction width of the bearing ring side gap C) becomes extremely large, the amount of the lubricating oil L held in the bearing ring side gap C is reduced. This increases the stirring shear resistance of the lubricating oil L, leading to an increase in the rotational torque of the bearing.

  However, in the embodiment of FIG. 6, the thickness of the outer ring side flange portion 22a that forms the bearing ring side gap C (in FIG. 3, the thickness of the outer ring side flange portion 22a is substantially constant in the radial direction, and the inner circumferential surface width t1. Is adjusted in the reduction direction by the offset depth d of the outer ring side flange portion 22a from the end surface on the first end side. That is, the axial width t1 of the bearing ring side gap C is reduced, the agitating shear resistance of the lubricating oil L in the bearing ring side gap C and the bearing rotational torque are reduced, and the adjustment of the interval g1 of the bearing ring side gap C is performed. The effect of regulating the inflow of the lubricating oil L into the bearing is also achieved without problems.

  Moreover, since the recessed part 25 is formed in the outer ring side flange part 22a, it functions as a lubricating oil retention part in the bearing ring side gap C, and the lubricating oil to the bearing first end side by the liquid lubricating mechanism 30 (FIG. 1). Even if the supply amount of L fluctuates, a certain amount of the lubricating oil L is retained in the recess 25, which contributes to the suppression of fluctuations in the amount of lubricating oil passing through the bearing ring side gap C. Also in FIG. 6, the interval λ of the auxiliary gap F is set to be smaller than the interval g1 of the bearing ring side gap C.

  FIG. 7 is a cross-sectional view including the central axis in the configuration of FIG. 3 in which the first end portion 24e in the axial direction of the main body portion of the retainer 24 is linearly extended toward the small flange portion 21s. This shows a structure that faces the outer peripheral surface 21f forming an inclined surface of 21s, that is, a structure in which the cage side flange portion is abolished. By omitting the cage side flange portion 24a, the drainage of the lubricating oil L staying between the small end surface of the tapered roller 23 and the race ring side flange portion 22a is not hindered by the cage side flange portion, and the cage 24 Since the gap g2 between the first end side portion 24e and the small flange portion 21s increases, the lubricating oil L can be discharged more smoothly to the outside of the bearing. Further, the pulling-in L of the lubricating oil L toward the tapered roller 23 can be performed more smoothly.

The principal part sectional drawing which shows an example of the differential gear apparatus used as the application object of this invention. The half sectional view which expands and shows the bearing part of FIG. The half sectional view which expands and shows one tapered roller bearing of FIG. 2 which makes one Example of the tapered roller bearing of this invention. FIG. 4 is a half sectional view showing a first modification of the tapered roller bearing of FIG. 3. The half sectional view showing the second modification similarly. The half sectional view showing the third modification similarly. The half sectional view showing the 4th modification similarly.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,20 Tapered roller bearing 11,21 Inner ring 11e, 21e Inner ring side extension part 12,22 Outer ring 12e, 22e Outer ring side extension part 12a, 22a Outer ring side flange part 13,23 Taper roller A, C Track ring side gap 14 , 24 Cage 14a, 24a Cage side flange D Cage side gap F Auxiliary gap

Claims (4)

A conical raceway surface having an outer ring and an inner ring arranged opposite to each other in the radial direction, and expanding in diameter from the first end side to the second end side in the axial direction on the inner peripheral surface of the outer ring and the outer peripheral surface of the inner ring, respectively. A plurality of tapered rollers that form rolling elements in the rotational circumferential direction in a rolling element holding space formed between the conical raceway surfaces,
The outer ring and the inner ring are respectively formed with an outer ring side extending part and an inner ring side extending part extending in the axial direction to the first end side from the raceway surface of the tapered roller, respectively.
A circumferential outer ring side flange portion protruding radially inward is provided on the inner circumferential surface of the outer ring side extending portion, and the outer circumferential surface of the outer ring side flange portion and the inner ring side extending portion are provided. A ring-side gap is formed between
One end predetermined in the axial direction is a first end, and the inner circumferential surface of the inner ring is adjacent to the second end side of the conical raceway surface in the axial direction, and the axial direction of the tapered roller A large collar portion in the circumferential direction that regulates the position of the second end side in the projection is formed,
An inner circumferential surface of the inner ring is adjacent to the first end side in the axial direction of the conical raceway surface, and a circumferential edge for regulating the position of the first end side in the axial direction of the tapered roller. The part is formed to protrude,
A tapered roller bearing, wherein an outer peripheral surface of the small flange portion is formed as an inclined surface inclined in the same direction as the outer peripheral surface of the tapered roller.   The rolling element holding space has a main body configured as a truncated cone-shaped shell that expands from the first end side in the axial direction toward the second end side, and the cone is formed in the circumferential direction of the main body portion. A cage in which a plurality of pocket portions are formed to accommodate and hold the rollers in a rollable manner is disposed, and the cage has a first end side in the axial direction bent inward in the radial direction. And forming a cage-side gap so that a radially inner circumferential surface of the cage-side flange portion faces an outer circumferential surface forming the inclined surface of the small flange portion. The tapered roller bearing according to Item 1.   The rolling element holding space has a main body configured as a truncated cone-shaped shell that expands from the first end side in the axial direction toward the second end side, and the cone is formed in the circumferential direction of the main body portion. A cage in which a plurality of pocket portions for accommodating and holding the rollers in a rollable manner is disposed, and the cage has a first end side in the axial direction of the main body portion in a cross section including a central axis. 2. The tapered roller bearing according to claim 1, wherein the tapered roller bearing extends linearly toward the side of the collar and faces the outer peripheral surface forming the inclined surface of the collar. The bearing ring side gap forms a labyrinth seal,
The side edge portion on the first end side of the retainer in the axial direction and the outer peripheral surface of the inner ring side extension portion are arranged to face each other with a radial interval larger than the gap on the race ring side. The tapered roller bearing according to claim 3.

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