JP2007321848A - Tapered roller bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tapered roller bearing into which lubricating oil flows, reduced in torque loss caused by the flowing resistance of the lubricating oil. <P>SOLUTION: A through-hole through which the lubricating oil flows is formed in the axial center of a tapered roller 4, and a cutout 10a is formed in a columnar portion 8 on the narrow side of a trapezoidal pocket 9 of a cage 5. Thus, the amount of the lubricating oil residing in the bearing is reduced to reduce the torque loss caused by the flowing resistance of the lubricating oil. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a tapered roller bearing in which torque loss due to flow resistance of lubricating oil is reduced.

  The tapered roller bearing is composed of an inner ring having small and large flanges on both sides of the raceway surface of the outer diameter surface, an outer ring having a raceway surface on the inner diameter surface, and a plurality of rows arranged between the raceways of the inner ring and the outer ring. The tapered rollers and a cage that holds and stores these tapered rollers in a pocket. The cage is linked to a small annular portion that is continuous on the small-diameter end surface side of the tapered roller and a large-diameter end surface side of the tapered roller. A base consisting of a large annular part and a plurality of pillars connecting these annular parts, the pocket is a narrow side where the small diameter side of the tapered roller is accommodated, and a wide side is the part which accommodates the large diameter side What was formed in the shape is used.

  A tapered roller bearing that supports a power transmission shaft such as a differential or a transmission of a self-propelled vehicle is used in a state where a lower part is immersed in an oil bath. Therefore, an oil bath lubrication state occurs in which the oil in the oil bath flows into the bearing as the lubricating oil as the shaft rotates. In the tapered roller bearing used for such an application, the lubricating oil flows into the bearing from the small diameter side of the tapered roller by a so-called pump action. Lubricating oil flowing from the outer diameter side of the cage passes along the raceway surface of the outer ring to the larger diameter side of the tapered roller. Lubricating oil flowing from the inner diameter side of the cage passes along the raceway surface of the inner ring to the larger diameter side of the tapered roller.

  Lubricating oil flows around the tapered roller from the roller small diameter side to the large diameter side. The tapered roller shears the flow of the lubricating oil so as to revolve between the raceway surfaces of the inner and outer rings in the circumferential direction. For this reason, stirring resistance due to the viscosity of the lubricating oil is generated.

On the other hand, in such a tapered roller bearing used for a portion where the lubricating oil flows from the outside, a notch is provided in the pocket of the cage so that the lubrication flows separately into the outer diameter side and the inner diameter side of the cage. There is one in which oil passes through the notches to improve the flow of lubricating oil inside the bearing (see Patent Documents 1 and 2). As shown in FIG. 8 (a), in Patent Document 1, a notch 10d is provided in the central portion of the column portion 8 between the pockets 9 of the cage 5, and foreign matter mixed in the lubricating oil is generated inside the bearing. So that it does not stay. Moreover, in what was described in patent document 2, as shown in FIG.8 (b), the notch 10e is provided in the small annular part 6 and the large annular part 7 of the axial direction both ends of the pocket 9 of the holder | retainer 5, and hold | maintained. The lubricating oil flowing in from the outer diameter side of the vessel is made easier to flow to the inner ring side. In addition, each dimension of the pocket 9 entered in each figure is the value used for the comparative example in the torque measurement test mentioned later.
In some cases, solid grease is fitted into a through hole formed in the axial center of the tapered roller for the purpose of improving the lubricity of the tapered roller bearing (see Patent Document 3).

JP-A-9-32858 (FIG. 3) JP-A-11-2011149 (FIG. 2) Japanese Patent Laid-Open No. 2004-176771 (FIG. 4)

  A tapered roller bearing has a larger rotational torque than a ball bearing. In particular, the tapered roller bearing has an action of drawing the lubricating oil into the bearing by a so-called pump action, and therefore, when used in the oil bath lubrication state, the ratio of the stirring resistance to the torque becomes large. In recent years, there has been a strong demand for energy saving and low fuel consumption as environmental measures, and for tapered roller bearings, it is desired to reduce the torque.

  On the other hand, in a tapered roller bearing in which the lubricating oil is divided into an outer diameter side and an inner diameter side of the cage and flows into the bearing, torque loss is reduced when the ratio of the lubricating oil flowing from the inner diameter side of the cage to the inner ring side increases. It turns out that it grows. The reason is considered as follows.

  That is, the lubricating oil flowing from the outer diameter side of the cage to the outer ring side smoothly passes to the larger diameter side of the tapered roller along the raceway surface because there is no obstacle on the inner diameter surface of the outer ring. The lubricating oil that flows out from the inner diameter side of the cage to the inner ring side has a large flaw on the outer diameter surface of the inner ring, so when it passes along the raceway surface to the larger diameter side of the tapered roller It will be dammed up with a large spear and will easily stay inside the bearing. For this reason, if the ratio of the lubricating oil flowing from the inner diameter side of the cage to the inner ring side increases, the amount of lubricating oil staying inside the bearing increases, and this staying lubricating oil becomes a flow resistance against bearing rotation and becomes a torque loss. Is considered to increase.

  Accordingly, an object of the present invention is to reduce torque loss due to flow resistance of lubricating oil in a tapered roller bearing in which lubricating oil flows into the bearing.

  In order to solve the above-described problems, the present invention provides an inner ring having small and large flanges on both sides of a raceway surface of an outer diameter surface, an outer ring having a raceway surface on an inner diameter surface, and the inner ring and the outer ring. A plurality of tapered rollers arranged between the raceway surfaces, and a retainer that holds and holds these tapered rollers in a pocket, and the retainer is connected to the small-diameter end surface side of the tapered rollers, It consists of a large annular portion that is continuous on the large diameter end surface side of the tapered roller and a plurality of column portions that connect these annular portions, and the pocket is a narrow-side, large-diameter portion that houses the small diameter side of the tapered roller In the tapered roller bearing formed in a trapezoidal shape in which the portion for housing the side is the wide side, a through hole is formed in the axial center of the tapered roller, and the columnar portion on the narrow side of the trapezoidal pocket of the cage A configuration with notches was adopted.

  If a through-hole is formed in the axial center of a tapered roller, the pump action by a through-hole itself will arise with the revolution of a tapered roller. That is, the axis of the through-hole is inclined so that the roller large-diameter side is separated outward in the radial direction of the bearing. Therefore, the centrifugal force acting on the lubricating oil in the through-hole causes the large diameter from the roller small-diameter end in the through-hole. A lubricating oil flow toward the radial end is generated. By this pump action, the lubricating oil on the inner diameter side of the cage is sucked into the through hole from the small diameter side of the roller and discharged from the large diameter side of the roller. As described above, generally, the lubricating oil inside the cage is blocked by the inner ring large cage when it passes along the inner ring raceway surface to the larger diameter side of the tapered roller, and tends to stay in the bearing. The through hole of the tapered roller functions as a bypass of the lubricating oil having no such place, reducing the amount of the lubricating oil staying in the bearing and reducing the torque loss due to the flow resistance of the lubricating oil.

  In addition, by providing a notch in the narrow column of the trapezoidal pocket of the cage, lubricating oil flowing from the inner diameter side of the cage to the inner ring side can be used to reduce the narrow width of the pocket that houses the smaller diameter side of the tapered roller. Torque from the notch on the side to the outer ring side, reducing the amount of lubricating oil that reaches the main ring along the raceway surface of the inner ring, reducing the amount of lubricating oil remaining in the bearing, and torque due to the flow resistance of the lubricating oil Reduce loss.

  Since the present invention can be expected to reduce torque loss by both the roller through hole and the notch of the narrow side column portion, it is effective in reducing the energy consumption and fuel consumption of the transportation equipment in combination with the weight reduction of the tapered roller by the through hole. To promote.

  The through hole is a tapered hole that gradually increases in diameter from the roller small-diameter end side toward the large-diameter end side, or a small-diameter hole on the roller small-diameter end side and a large-diameter hole on the large-diameter end side. Can be configured. It is also possible to form a step portion in the middle of these through holes as required. By forming a spiral groove on the inner peripheral surface of the through hole, the pumping action of the through hole can be further enhanced with the rotation of the tapered roller.

  By providing a notch also in the narrow annular part on the narrow side of the trapezoidal pocket, the lubricating oil flowing from the inner diameter side of the cage to the inner ring side is released from the notch of the small annular part to the outer ring side, and the inner ring Thus, the amount of lubricating oil reaching the surface along the raceway surface can be reduced, and torque loss due to the flow resistance of the lubricating oil can be further reduced.

  By providing a notch in at least the column portion on the wide side of the trapezoidal pocket, the tapered roller can be brought into sliding contact with the column portion in a balanced manner.

  The total area of the notches provided on the narrow side of the trapezoidal pocket is larger than the total area of the notches provided on the wide side of the trapezoidal pocket. It is possible to further reduce the torque loss due to the flow resistance of the lubricating oil by reducing the amount of the lubricating oil reaching the maximum.

  A radially inward flange opposite to the outer diameter surface of the small ring of the inner ring is provided on the outer side in the axial direction of the small annular portion of the cage, and the inner diameter surface of the flange of the small annular portion opposed to the inner ring By reducing the clearance between the outer diameter surface of the inner ring and the outer diameter of the inner ring from 2.0% or less, the amount of lubricating oil flowing from the inner diameter side of the cage to the inner ring side is reduced, Torque loss due to the flow resistance of the lubricating oil can be further reduced.

  At least the surface of the tapered roller is provided with an infinite number of minute concave recesses, the surface roughness parameter Ryni of the surface provided with the recesses is 0.4 μm ≦ Ryni ≦ 1.0 μm, and the Sk value is Even if the amount of lubricating oil staying inside the bearing is reduced by sufficiently retaining the lubricating oil on the surface of the tapered roller by setting it to −1.6 or less, the contact portion between the tapered roller and the inner and outer rings is sufficiently lubricated. be able to.

  The parameter Ryni is the average value of the maximum height for each reference length, that is, the reference length is extracted from the roughness curve in the direction of the average line, and the interval between the peak line and the valley bottom line of the extracted part is determined by the roughness curve. It is a value measured in the direction of the vertical magnification (ISO 4287: 1997). The Sk value is a value representing the degree of distortion of the roughness curve, that is, the asymmetry of the roughness unevenness distribution (ISO 4287: 1997), and the Sk value is close to 0 in a symmetric distribution such as a Gaussian distribution. When the concave and convex portions are deleted, a negative value is obtained. Conversely, when the concave portions are deleted, a positive value is obtained. The Sk value can be controlled by selecting the rotational speed of the barrel polishing machine, the processing time, the amount of workpiece input, the type and size of the polishing tip, etc. By setting the Sk value to −1.6 or less, Lubricating oil can be held evenly in innumerable minute concave recesses.

  Each tapered roller bearing described above is suitable for supporting a power transmission shaft of a self-propelled vehicle.

  Since the tapered roller bearing of the present invention has a through-hole formed in the roller shaft center, a pumping action is produced in which the lubricating oil is sucked from the through-hole inlet on the small roller diameter side and discharged from the through-hole outlet on the large roller diameter side. This pumping action increases the amount of lubricating oil that passes through the roller's through hole, and tends to stay in the bearing by bypassing the lubricating oil that was dammed by the inner ring ridge and tends to stay inside the bearing. Further, the amount of lubricating oil passing between the rollers inside the cage can be reduced, and the stirring resistance of the lubricating oil when the tapered roller revolves can be reduced. As a result, the torque of the tapered roller bearing can be reduced, and energy saving and fuel consumption reduction of transportation equipment such as automobiles can be promoted.

  In addition, since the notch is provided in the narrow pillar portion of the trapezoidal pocket of the cage, the lubricant that flows from the inner diameter side of the cage to the inner ring side is used to reduce the narrow width of the pocket that stores the smaller diameter side of the tapered roller. Torque from the notch on the side to the outer ring side, reducing the amount of lubricating oil that reaches the main ring along the raceway surface of the inner ring, reducing the amount of lubricating oil remaining in the bearing, and torque due to the flow resistance of the lubricating oil Loss can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, the tapered roller bearing 1 includes a plurality of tapered rollers 4 held in a cage 5 between the raceways 2 a and 3 a of the inner ring 2 and the outer ring 3. The movement in the axial direction is restricted by the small rod 2b and the large rod 2c provided on both sides of the raceway surface 2a of the inner ring 2.

As shown in FIGS. 2 (A) to 2 (E), the tapered roller used in the tapered roller bearing of the present invention has a through hole formed in the roller shaft center. The through-holes may be configured with a uniform diameter over the entire length, but in order to enhance the pumping action of the through-holes, different diameter through-holes having a small diameter on the roller small diameter side and a large diameter on the roller large diameter side as follows It is good to do. As a result, the amount of lubricating oil in the through hole is increased, and the centrifugal force acting on the lubricating oil is increased as the roller revolves. Both ends of the through hole are preferably formed so as to open on the inner diameter side of the cage. If a part of both end openings of the through hole enter the cage pocket, the flow of the lubricating oil may be hindered.

FIG. 2A shows a through hole formed by a tapered hole 4a that gradually increases in diameter from the roller small diameter side toward the large diameter side. By setting the tapered hole 4a to have a larger diameter on the larger diameter side of the roller, the amount of lubricating oil inside the tapered hole 4a where the centrifugal force acts is increased and the pump action is strengthened.

FIG. 2B shows a through hole formed by a tapered hole 4b whose diameter gradually increases from the roller small diameter end toward the large diameter end. An inclined step 4b ₃ is formed in the middle of the through hole. One side of the inclined step portion 4b ₃ is the large diameter tapered hole 4b ₁ and the other side is the small diameter tapered hole 4b ₂ . Since this through hole can further increase the amount of lubricating oil in the through hole as compared with FIG. 2A, the pumping action of the through hole can be further enhanced.

FIG. 2C shows a through hole formed by a stepped hole 4c. The stepped hole 4c is a through hole in which two types of large and small uniform diameter holes 4c ₁ and 4c ₂ are made continuous from the roller small diameter end to the large diameter end. Uniform diameter hole 4c ₁ Gakoro large diameter side of the large diameter, is formed in the uniform diameter hole 4c ₂ Gakoro small diameter end side of the small diameter. Large and small holes 4c ₁ and 4c ₂ are connected at the center in the roller axial direction, and a radial step 4c ₃ is formed here.

FIG. 2D is a through-hole formed by a stepped hole 4d in which two types of large and small uniform diameter holes 4d ₁ and 4d ₂ are continuous from the small-diameter end to the large-diameter end as in (C). holes _4d 1, 4d ₂ stepped portion 4d ₃ of the portion connected with Gakoro axial center is inclined. That is, a tapered step portion 4d ₃ having a gradually increased diameter from the small diameter hole 4d ₂ to the large diameter hole 4d ₁ is formed.

FIG. 2E shows a through hole formed by a grooved tapered hole 4e that gradually increases in diameter from the roller small diameter end toward the large diameter end. The grooved through-hole 4e is roller toward the small diameter end to the large diameter end is obtained by forming a spiral groove 4e ₂ on the inner peripheral surface of the tapered hole 4e ₁ was gradually diverging. The direction in which the spiral groove 4e ₂ is formed is preferably a direction that promotes the flow of the lubricating oil in the through hole as the tapered roller rotates.

  In any tapered roller, the tapered roller axis is inclined so that the larger diameter side is away from the center of the bearing, so that the lubricating oil flows from the small diameter side inlet of the roller along with the revolution movement of the tapered roller. It flows out from the exit. Such a tendency of the lubricating oil to flow is reinforced by a shape in which the inner diameter of the through hole expands and changes from the small diameter end toward the large diameter end. Since the inlet and outlet of the through hole are opened on the inner diameter side of the cage, the tendency of the lubricating oil from the smaller diameter side to the larger diameter side on the cage inner diameter side is reinforced. Lubricating oil coming out of the through-hole outlet once flows out of the bearing and then flows into the small diameter side inlet of the tapered roller again.

  As shown in FIG. 3, the cage 5 includes a small annular portion 6 that is continuous on the small diameter end surface side of the tapered roller 4, a large annular portion 7 that is continuous on the large diameter end surface side of the tapered roller 4, and these small annular portions 6. And a plurality of column portions 8 that connect the large annular portion 7, and a trapezoidal pocket 9 in which the portion storing the small diameter side of the tapered roller 4 is the narrow side and the portion storing the large diameter side is the wide side. Is formed. On the narrow side and wide side of the pocket 9, two notches 10a and 10b are provided in the pillars 8 on both sides, respectively, and the notches 10a and 10b have a depth of 1.0 mm. The width is 4.6 mm.

  FIGS. 4A and 4B show modifications of the cage 5. In the modification shown in FIG. 4A, the small annular portion 6 on the narrow side of the pocket 9 is also provided with a notch 10c, and the total area of the three notches 10a and 10c on the narrow side is the wide side. This is wider than the total area of the two notches 10b. The notch 10c has a depth of 1.0 mm and a width of 5.7 mm.

  In the modification shown in FIG. 4B, the depth of each notch 10a of the narrow column 8 is 1.5 mm, which is deeper than each notch 10b of the wide column 8. The total area of the notches 10a on the width side is wider than the total area of the notches 10b on the wide side.

  As shown in FIG. 1, a radially inward flange 11 facing the outer diameter surface of the small collar 2b of the inner ring 2 is provided on the outer side in the axial direction of the small annular portion 6 of the cage 5. As shown in FIG. 6, the gap δ between the inner diameter surface of the flange 11 of the small annular portion 6 and the outer diameter surface of the small flange 2b of the inner ring 2 is 2.0, which is the outer diameter dimension of the small flange 2b. % Is set narrowly.

  Although not shown in the drawings, the entire surface of the tapered roller 4 is provided with an infinite number of minute concave recesses, and the surface roughness parameter Ryni of the surface provided with these recesses is 0.4 μm ≦ Ryni ≦. It is set to 1.0 μm and the Sk value is −1.6 or less.

  FIG. 5 shows a differential of an automobile using the tapered roller bearing 1 described above. The differential is connected to a propeller shaft (not shown), and a drive pinion 22 inserted through the differential case 21 is engaged with a ring gear 24 attached to the differential gear case 23 and attached to the inside of the differential gear case 23. The pinion gear 25 thus engaged is engaged with a side gear 26 connected to a drive shaft (not shown) inserted through the differential gear case 23 from the left and right, and the driving force of the engine is transmitted from the propeller shaft to the left and right drive shafts. It is like that. In this differential, a drive pinion 22 that is a power transmission shaft and a differential gear case 23 are supported by a pair of tapered roller bearings 1a and 1b, respectively.

  Lubricating oil is stored in the differential case 21 and sealed with seal members 27a, 27b, and 27c, and the tapered roller bearings 1a and 1b are immersed in the oil bath of the stored lubricating oil. Rotate with.

  When the tapered roller bearings 1a and 1b rotate at high speed and the lower part is immersed in an oil bath, the lubricating oil in the oil bath is removed from the cage 5 from the small diameter side of the tapered roller 4 as shown by arrows in FIG. Lubricating oil that flows into the bearing is divided into a radial side and an internal diameter side, and flows into the outer ring 3 from the outer diameter side of the cage 5, passes along the raceway surface 3 a of the outer ring 3 to the larger diameter side of the tapered roller 4. Out of the bearing. On the other hand, the lubricating oil flowing from the inner diameter side of the cage 5 to the inner ring 2 side is retained because the gap δ between the flange 11 of the small annular portion 6 of the cage 5 and the small flange 2b of the inner ring 2 is set narrow. Much less than the lubricating oil flowing in from the outer diameter side of the vessel 5 and most of the lubricating oil flowing in from the gap δ passes through the notch 10a provided in the column 8 on the narrow side of the pocket 9. Then, it moves to the outer diameter side of the cage 5. Therefore, the amount of the lubricating oil that reaches the large collar 2c along the raceway surface 2a of the inner ring 2 is very small, and the amount of the lubricating oil staying inside the bearing can be reduced.

  As examples, a tapered roller bearing (Example 1) using the cage shown in FIG. 3 and a tapered roller bearing (Example 2) using the cage shown in FIG. 4A were prepared. Further, as comparative examples, a tapered roller bearing (Comparative Example 1) using a cage having no notch in the pocket and a tapered roller bearing (Comparative Example) using the cage shown in FIGS. 8 (a) and 8 (b). 2, 3) were prepared.

  Each tapered roller bearing has an outer diameter of 100 mm, an inner diameter of 45 mm, and a width of 27.25 mm, and the portions other than the pocket notch are the same. In either case, a tapered hole 4a is formed in a common specification as shown in FIG.

About the tapered roller bearing of the said Example and the comparative example, the torque measurement test using the vertical torque tester was done. The test conditions are as follows.
・ Axial load: 300kgf
・ Rotation speed: 300-2000 rpm (100 rpm pitch)
・ Lubrication conditions: Oil bath lubrication (lubricating oil: 75W-90)

  FIG. 7 shows the results of the torque measurement test. The vertical axis of the graph in FIG. 7 represents the torque reduction rate with respect to the torque of Comparative Example 1 using a cage that has no notch in the pocket. The comparative example 2 in which a notch is provided in the central part of the pocket column part and the comparative example 3 in which a notch is provided in the small annular part and the large annular part of the pocket also show a torque reducing effect, but the narrow side of the pocket In Example 1, in which a notch is provided in the column portion, a torque reduction effect superior to those of the comparative examples is recognized, a notch is provided in the narrow annular portion, and the notch on the narrow side is provided. In Example 2 in which the total area is wider than that on the wide side, a further excellent torque reduction effect is recognized.

  In addition, the torque reduction rate at 2000 rpm, which is the maximum rotation speed of the test, was 9.5% in Example 1 and 11.5% in Example 2, which was excellent even under high-speed rotation conditions such as in differentials and transmissions. A torque reduction effect can be obtained. In addition, the torque reduction rate in the rotational speed 2000rpm of the comparative example 2 and the comparative example 3 is 8.0% and 6.5%, respectively.

The longitudinal cross-sectional view which shows embodiment of a tapered roller bearing. (A)-(E) are longitudinal cross-sectional views of a tapered roller. The expanded top view of the holder | retainer of FIG. (A), (B) is an expansion | deployment top view which shows the modification of FIG. 2, respectively. The cross-sectional view which shows the differential which uses the tapered roller bearing of FIG. Sectional drawing which shows the flow of the lubricating oil to the inside of the bearing of the tapered roller bearing of FIG. The graph which shows the result of a torque measurement test. (A), (B) is an expansion | deployment top view which shows the conventional holder | retainer, respectively.

Explanation of symbols

1, 1a, 1b Tapered roller bearing 2 Inner ring 2a Raceway surface 2b Small flange 2c Large bowl 3 Outer ring 3a Raceway surface 4 Tapered roller 4b Tapered hole 4b Stepped hole 4d Stepped hole 4e Grooved taper hole 5 Cage 6 Small annular portion 7 Large annular portion 8 Column portion 9 Pocket 10a, 10b, 10c Notch 11 鍔 21 Differential case 22 Drive pinion 23 Differential gear case 24 Ring gear 25 Pinion gear 26 Side gear 27a, 27b, 27c Seal member

Claims (11)

  An inner ring provided with small and large ridges on both sides of the raceway surface of the outer diameter surface, an outer ring provided with a raceway surface on the inner diameter surface, a plurality of tapered rollers arranged between the raceways of the inner ring and the outer ring, And a retainer for storing and holding these tapered rollers in a pocket, wherein the retainer includes a small annular portion that is continuous on the small diameter end surface side of the tapered roller, and a large annular portion that is continuous on the large diameter end surface side of the tapered roller. And a plurality of pillars connecting these annular portions, and the pocket has a trapezoidal shape in which the portion storing the small diameter side of the tapered roller is the narrow side and the portion storing the large diameter side is the wide side. In the tapered roller bearing formed, the tapered roller bearing is characterized in that a through-hole is formed in the axial center of the tapered roller, and a notch is provided in a narrow column of the trapezoidal pocket of the cage. .   2. The tapered roller bearing according to claim 1, wherein the through-hole is a tapered hole that gradually increases in diameter from the small-diameter end side toward the large-diameter end side.   2. The tapered roller bearing according to claim 1, wherein the through-hole is composed of at least two different diameter holes, a small diameter hole on the roller small diameter end side and a large diameter hole on the large diameter end side.   The tapered roller bearing according to any one of claims 1 to 3, wherein a step portion is formed in the middle of the through hole.   The tapered roller bearing according to any one of claims 1 to 4, wherein a spiral groove is formed on an inner peripheral surface of the through hole.   The tapered roller bearing according to any one of claims 1 to 5, wherein a notch is provided also in a small annular portion on a narrow side of the trapezoidal pocket.   The tapered roller bearing according to any one of claims 1 to 6, wherein a notch is provided in at least a column part on the wide side of the trapezoidal pocket.   The tapered roller bearing according to claim 7, wherein a total area of the notches provided on the narrow side of the trapezoidal pocket is wider than a total area of the notches provided on the wide side of the trapezoidal pocket.   A radially inward flange opposite to the outer diameter surface of the small ring of the inner ring is provided on the outer side in the axial direction of the small annular portion of the cage, and the inner diameter surface of the flange of the small annular portion opposed to the inner ring The tapered roller bearing according to any one of claims 1 to 8, wherein a clearance with the outer diameter surface of the small collar is 2.0% or less of an outer diameter dimension of the small collar of the inner ring.   At least the surface of the tapered roller is provided with an infinite number of minute concave recesses, the surface roughness parameter Ryni of the surface provided with the recesses is 0.4 μm ≦ Ryni ≦ 1.0 μm, and the Sk value is The tapered roller bearing according to any one of claims 1 to 9, which is set to -1.6 or less.   The tapered roller bearing according to any one of claims 1 to 10, wherein the tapered roller bearing supports a power transmission shaft of a self-propelled vehicle.

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