JP2007120648A - Tapered roller bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To substantialize low torque without deteriorating the rigidity of a bearing. <P>SOLUTION: The tapered roller bearing comprises an inner ring 2, an outer ring 3, a plurality of tapered rollers 4 which are disposed between the inner ring 2 and the outer ring 3 and is capable of freely rolling the between those rings, and a retainer 5 circumferentially holding the tapered rollers 4 thereon at specified intervals. The retainer 5 comprises a small annular part 6 continuously formed on the small end face side of the tapered rollers 4, a large annular part 7 continuously formed on the large end face side of the tapered rollers 4, and a plurality of column parts 8 connecting the large and small annular parts 6, 7 to each other. A pocket 9 between the adjacent column parts 8 is formed in such a trapezoidal shape that its portion storing the small diameter side of the tapered rollers 4 is formed narrow and its portion storing the large diameter side of the tapered rollers 4 is formed wide. Cutout parts 10a, 10b, and 10c are provided to the column parts 8 on the narrow side of the pocket 9. The retainer 5 is in non-contact with the outer ring 3 in a neutral state, and in contact with the outer ring 3 when it is moved in the radial direction. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a tapered roller bearing and can be applied to a bearing that supports a power transmission shaft such as a differential of a self-propelled vehicle or a transmission.

  Tapered roller bearings consist of an inner ring with small and large collars on both sides of the raceway surface of the outer diameter surface, an outer ring with a raceway surface on the inner diameter surface, and a plurality of rows arranged between the raceway surfaces of the inner ring and the outer ring. And a retainer that holds and stores these tapered rollers in a pocket. The retainer is connected to a small annular portion that is continuous on the small diameter end surface side of the tapered roller, and is connected on the large diameter end surface side of the tapered roller. A base composed of a large annular portion and a plurality of column portions connecting these annular portions, wherein the pocket has a narrow side on the small diameter side of the tapered roller and a wide side on the large diameter side. What was formed in the shape is used.

  Tapered roller bearings that support power transmission shafts such as differentials and transmissions of self-propelled vehicles are used with the lower part immersed in an oil bath, and the oil in the oil bath flows into the bearing as lubricating oil as it rotates. . In tapered roller bearings used for such applications, the lubricating oil flows into the bearing from the small diameter side of the tapered roller, and the lubricating oil flowing from the outer diameter side of the cage flows along the raceway surface of the outer ring. The lubricating oil that passes to the larger diameter side and flows from the inner diameter side to the cage passes along the raceway surface of the inner ring to the larger diameter side of the tapered roller.

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, and the lubricating oil that flows into the outer diameter side and the inner diameter side of the cage is separated. There is one that passes through this notch and improves the flow of lubricating oil inside the bearing (see Patent Documents 1 and 2). In what is described in Patent Document 1, as shown in FIG. 11 (A), a notch 10d is provided in the center of the column portion 8 between the pockets 9 of the cage 5, and foreign matter mixed into 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 to FIG. 11 (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.
JP 09-32858 A JP-A-11-2011149 JP 09-096352 A JP-A-11-210765 JP 2003-343552 A

  As described above, in the tapered roller bearing in which the lubricating oil is divided into the outer diameter side and the inner diameter side of the cage and flows into the bearing, the torque increases 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 the loss increases. 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 large 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 flowing 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, when the ratio of the lubricating oil flowing from the inner diameter side to the inner ring side of the cage increases, the amount of the lubricating oil staying inside the bearing increases, and this staying lubricating oil becomes a flow resistance against the bearing rotation and generates torque. Loss is considered to increase.

  Therefore, it is necessary to reduce torque loss due to flow resistance of the lubricating oil in the tapered roller bearing in which the lubricating oil flows into the bearing. The above is a method for reducing the flow resistance of oil to reduce torque, but in order to significantly reduce torque, it is necessary to change the bearing specifications so that the rolling viscous resistance decreases. . However, in the conventional torque reduction method (see Patent Documents 3 to 5), torque reduction without reducing the rated load is possible, but the bearing rigidity is somewhat reduced.

  The main object of the present invention is to realize a low torque without reducing the bearing rigidity.

  The present invention solves the problem by reducing the PCD without decreasing or increasing the number of rollers. FIG. 12 shows the rigidity ratio (-●-) and torque ratio (-o-) when the roller pitch diameter (PCD) is changed in the tapered roller bearing. As shown in FIG. 12, when the PCD is reduced, the bearing torque is significantly reduced, but the bearing rigidity is not reduced so much as a result of calculating and confirming the elastic deformation amount of the roller. Therefore, the torque can be reduced without reducing the rigidity by reducing the PCD while decreasing or increasing the number of rollers.

  The tapered roller bearing of the present invention includes an inner ring, an outer ring, a plurality of tapered rollers arranged to roll between the inner ring and the outer ring, and a cage that holds the tapered rollers at a predetermined circumferential interval. The roller coefficient γ exceeds 0.94, and the cage includes a small annular portion that is continuous on the small end surface side of the tapered roller, a large annular portion that is continuous on the large end surface side of the tapered roller, and a plurality of portions that connect these annular portions. A trapezoidal pocket is formed between the adjacent pillars. The trapezoidal pocket has a narrow side on the small diameter side and a wide side on the large diameter side. A notch is provided in the column on the width side, and the cage is in non-contact with the outer ring in the neutral state and contacts with the outer ring when moved in the radial direction.

  The roller coefficient γ (roller filling ratio) is a parameter represented by (number of rollers × roller average diameter) / (π × PCD). When the average roller diameter is constant, the larger the value of γ, the greater the number of rollers. It means that there are many. In the conventional typical tapered roller bearing with a cage, the roller coefficient γ is usually designed to be 0.94 or less, whereas the roller coefficient γ exceeds 0.94. This means that the roller filling rate and thus the bearing rigidity is high.

  Moreover, the following effect | action is acquired by providing a notch in the column part by the side of the narrow side of the trapezoid shaped pocket of a holder | retainer. That is, the lubricating oil flowing from the inner diameter side of the cage to the inner ring side can be quickly released to the outer ring side through this notch. As a result, the amount of lubricating oil reaching the large collar along the raceway surface of the inner ring is reduced, and the amount of lubricating oil staying inside the bearing is reduced. Therefore, torque loss due to the flow resistance of the lubricating oil is reduced.

  According to a second aspect of the present invention, in the tapered roller bearing according to the first aspect, a notch is also provided in the small annular portion on the narrow side of the pocket. By adopting such a configuration, the lubricating oil flowing from the inner diameter side of the cage to the inner ring side can be released from the notch to the outer ring side. Accordingly, the amount of lubricating oil reaching the large collar along the raceway surface of the inner ring is reduced, and torque loss due to the flow resistance of the lubricating oil is further reduced.

  According to a third aspect of the present invention, in the tapered roller bearing according to any one of the first to third aspects, a notch is provided in at least a column portion on the wide side of the pocket. By adopting such a configuration, the tapered roller can be brought into contact with the column portion in a balanced manner.

  According to a fourth aspect of the present invention, in the tapered roller bearing of the third aspect, the total area of the notches provided on the narrow side of the pocket is made wider than the total area of the notches provided on the wide side of the pocket. It is what. By adopting such a configuration, 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 large collar along the raceway surface of the inner ring.

  According to a fifth aspect of the present invention, in the tapered roller bearing according to any one of the first to fourth aspects, a radially inwardly facing outer diameter surface of the small collar of the inner ring is provided on the outer side in the axial direction of the small annular portion of the cage. A collar is provided, and the upper limit of the clearance between the inner diameter surface of the collar and the outer diameter surface of the small collar of the inner ring is set to 2.0% of the outer diameter dimension of the small collar. By adopting such a configuration, the amount of lubricating oil flowing from the inner diameter side of the cage to the inner ring side can be reduced, and torque loss due to the flow resistance of the lubricating oil can be further reduced.

  According to a sixth aspect of the present invention, in the tapered roller bearing according to any one of the first to fifth aspects, an infinite number of minute concave concaves are randomly provided on at least the surface of the tapered roller, and the surface roughness of the surface provided with the concaves is provided. The parameter Ryni is 0.4 μm ≦ Ryni ≦ 1.0 μm, and the Sk value is −1.6 or less. By adopting such a configuration, the contact between the tapered roller and the inner and outer rings can be sufficiently lubricated even if the lubricant is evenly retained on the surface of the tapered roller and the amount of lubricant remaining in the bearing is reduced. can do.

  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 distance between the peak line and the bottom line of the extracted part is set to the vertical line of the roughness curve. It is a value measured in the direction of 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 workpiece input amount, the type and size of the polishing tip, etc., and by setting the Sk value to −1.6 or less, Lubricating oil can be evenly retained in the infinite number of minute concave recesses.

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

  According to this invention, a reduction in torque can be realized without reducing the bearing rigidity. That is, by providing a notch that cuts from the outer diameter side to the inner diameter side in the narrow column of the trapezoidal pocket of the cage, the lubricating oil that has flowed from the inner diameter side to the inner ring side of the cage is removed. Through the outer ring, the amount of lubricating oil reaching the large brim along the raceway surface of the inner ring is reduced, the amount of lubricating oil staying inside the bearing is reduced, and the flow resistance of the lubricating oil is reduced. Torque loss due to is reduced.

  By setting the roller coefficient γ to exceed 0.94, it is possible to prevent a decrease in rigidity. In addition, setting the roller coefficient to exceed 0.94 not only increases the load capacity, but also reduces the maximum surface pressure of the raceway surface of the tapered roller bearing. It is possible to prevent surface starting point peeling with a short life.

  Embodiments of the present invention will be described below with reference to the drawings.

  A tapered roller bearing 1 according to the embodiment shown in FIG. 1 includes an inner ring 2, an outer ring 3, a tapered roller 4, and a cage 5. The inner ring 2 has a conical track surface 2a on the outer periphery, and the outer ring 3 has a conical track surface 3a on the inner periphery. A plurality of tapered rollers 4 are interposed between the raceway surface 2a of the inner ring 2 and the raceway surface 3a of the outer ring 3 so as to roll freely. Each tapered roller 4 is accommodated in a pocket formed in the cage 5, and movement in the axial direction is restricted by a small brim 2 b and a large brim 2 c provided on both sides of the raceway surface 2 a of the inner ring 2.

The tapered roller bearing 1 has a roller coefficient γ of γ> 0.94. The roller coefficient γ represents the filling rate of the roller and is defined by the following equation.
Roller coefficient γ = (Z · DA) / (π · PCD)
here,
Z: Number of rollers
DA: Roller average diameter,
PCD: Roller pitch diameter.

  For comparison, referring to the prior art, as shown in FIG. 13, in a typical tapered roller bearing with a cage in which the cage is spaced from the outer ring, the window angle is about 50 ° at most. is there. In order to avoid the contact between the outer ring 71 and the cage 72 as shown in FIG. 13 and to secure the column width of the cage 72 and to obtain the appropriate column strength and smooth rotation of the cage 72, the roller coefficient γ Is normally designed to be 0.94 or less. In FIG. 13, reference numerals 73, 74, and 75 denote a tapered roller, a column surface, and an inner ring, respectively, and reference sign θ denotes a window angle.

  Although not shown in the figure, the entire surface of the tapered roller 4 is provided with an infinite number of minute concave concaves. The surface provided with the depression has a surface roughness parameter Ryni of 0.4 μm ≦ Ryni ≦ 1.0 μm and an Sk value of −1.6 or less.

  As shown in FIG. 1B, the cage 5 includes a small annular portion 6 that is continuous on the small end face side of the tapered roller 4, a large annular portion 7 that is continuous on the large end face side of the tapered roller 4, and these small annular portions. 6 and a plurality of pillars 8 that connect the macro-annular part 7. And as shown to FIG. 1 (A), the pocket 9 is formed between the pillar parts 8 which adjoined. The window angle θ of the cage 5 is, for example, in the range of 25 ° to 50 °. The window angle θ refers to an angle formed by the side surface of the column portion 8 that is in contact with the rolling surface of the tapered roller 4 (see FIG. 1A).

  The outer diameter of the cage 5 is determined by moving the cage 5 from the state of FIG. 2 (A) to the axial smaller diameter side as shown by the arrow in FIG. 2 (B), and then FIG. 3 (A). When the outer ring 3 and the cage 5 are brought into contact with each other and the bearing is rotated and the cage 5 is centered as shown in FIG. 3C, the cage 5 and the outer ring 3 are moved. Is set to a dimension such that there is no contact with a predetermined clearance all around. In other words, such a dimension means that the clearance between the retainer 5 and the outer ring 3 is such that the retainer 5 is disposed at the axial center and the retainer 5 is close to the small diameter side as shown in FIG. Although it exists, the outer ring 3 and the cage 5 are in contact with each other when the cage 5 is moved in the radial direction from the axial center. As a result, the outer ring 3 and the cage 5 are in contact at the initial stage of operation (FIG. 3 (B)), but are not in contact during operation (FIG. 3 (C)). Can be suppressed. In the case of an iron plate cage, it is necessary to spread the bottom and caulk, but in the case of a resin cage, it is not necessary, and it is easy to ensure the required dimensional accuracy. Here, “bottom opening” means that when the cage 5 incorporating the roller is assembled to the inner ring, the diameter of the column portion on the small diameter side of the cage 5 is greatly expanded so that the roller can get over the small brim of the inner ring. . “Caulking operation” refers to pushing the column portion of the small-diameter portion of the cage 5 greatly expanded as described above by pushing it with a mold from the outside.

  As shown in FIG. 4, the pocket 9 of the cage 5 is trapezoidal, and the portion for storing the small diameter side of the tapered roller 4 is the narrow side, and the portion for storing the large diameter side is the wide side. On the narrow side and wide side of the pocket 9, two notches 10 a and 10 b that are cut from the outer diameter side to the inner diameter side are provided in each of the column portions 8 on both sides. Each notch 10a, 10b has a depth of 1.0 mm and a width of 4.6 mm. The notches 10a and 10b illustrated in the drawings are in the form of grooves cut through in the radial direction of the cage 5, but the inner diameter side and the outer diameter side of the cage 5 are connected to make the lubricating oil smooth. As long as the passage can be allowed, the shape and dimensions are arbitrary.

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

  In the modification shown in FIG. 6, the depth of each notch 10a of the narrow-side column portion 8 is 1.5 mm, which is deeper than each notch 10b of the wide-side column portion 8, and each notch on the narrow side. The total area of 10a is wider than the total area of the notches 10b on the wide side.

  As shown in FIG. 7, a radially inward flange 11 is provided on the outer side in the axial direction of the small annular portion 6 of the cage 5 so as to face the outer diameter surface of the small collar 2b of the inner ring 2. The clearance δ between the inner diameter surface of 11 and the outer diameter surface of the small collar 2b of the inner ring 2 is set narrowly to 2.0% or less of the outer diameter dimension of the small collar 2b.

The cage 5 is integrally formed with a super engineering plastic such as PPS, PEEK, PA, PPA, or PAI. By using engineering plastics with excellent mechanical strength, oil resistance and heat resistance for the cage, the cage weight is lighter, self-lubricating, and the coefficient of friction is smaller than that of steel plate cages. Therefore, in combination with the effect of the lubricating oil present in the bearing, it becomes possible to suppress the occurrence of wear due to contact with the outer ring. In addition, these resins are lighter and have a smaller coefficient of friction than steel plates, and are therefore suitable for reducing torque loss and cage wear at the start of the bearing.

  Engineering plastics include general purpose engineering plastics and super engineering plastics. Typical examples are listed below, but these are examples of engineering plastics, and engineering plastics are not limited to the following.

[General-purpose engineering plastics] Polycarbonate (PC), polyamide 6 (PA6), polyamide 66 (PA66), polyacetal (POM), modified polyphenylene ether (m-PPE), polybutylene terephthalate (PBT), GF reinforced polyethylene terephthalate (GF) -PET), ultra high molecular weight polyethylene (UHMW-PE)

[Super Engineering Plastics] Polysulfone (PSF), Polyethersulfone (PES), Polyphenylene sulfide (PPS), Polyarylate (PAR), Polyamideimide (PAI), Polyetherimide (PEI), Polyetheretherketone ( PEEK), liquid crystal polymer (LCP), thermoplastic polyimide (TPI), polybenzimidazole (PBI), polymethylbenten (TPX), poly 1,4-cyclohexanedimethylene terephthalate (PCT), polyamide 46 (PA46), polyamide 6T (PA6T), polyamide 9T (PA9T), polyamide 11,12 (PA11,12), fluororesin, polyphthalamide (PPA)

  If necessary, a glass fiber or carbon fiber blended with these resin materials or other engineering plastics may be used for strength enhancement.

  FIG. 9 shows an example of the configuration of an automobile differential that can use the tapered roller bearing of the present invention. This differential is connected to a propeller shaft (not shown), and a drive pinion 22 inserted into the differential case 21 meshes with a ring gear 24 attached to the differential gear case 23, and a pinion gear 25 attached to the inside of the differential gear case 23. However, the drive gear of the engine is transmitted from the propeller shaft to the left and right drive shafts by meshing with the side gear 26 coupled to the drive shaft (not shown) inserted into the differential gear case 23 from the left and right. 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.

  The differential case 21 is sealed with seal members 27a, 27b, and 27c, and the lubricating oil is stored inside. Each tapered roller bearing 1a, 1b rotates with its lower part immersed in this lubricating oil bath. When each tapered roller bearing 1a, 1b rotates at high speed and its lower part is immersed in an oil bath, the lubricating oil in the oil bath is drawn from the small diameter side of the tapered roller 4 to the outer diameter of the cage 5 as shown by arrows in FIG. The lubricating oil that flows into the bearing divided into the inner diameter side and the inner 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 far less than the lubricating oil flowing from the outer diameter side of the cage 5, and most of the lubricating oil flowing from this clearance δ is Then, it passes through the notch 10 a provided in the column portion 8 on the narrow side of the pocket 9 and 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 becomes very small, and the amount of the lubricating oil staying inside the bearing can be reduced.

  FIG. 10 exemplifies a configuration of an automobile transmission that can use the tapered roller bearing of the present invention. This transmission is of a synchronous mesh type, and in the figure the left direction is the engine side and the right direction is the drive wheel side. A tapered roller bearing 43 is interposed between the main shaft 41 and the main drive gear 42. In this example, the outer ring raceway surface of the tapered roller bearing 43 is directly formed on the inner periphery of the main drive gear 42. The main drive gear 42 is rotatably supported with respect to the casing 45 by a tapered roller bearing 44. A clutch gear 46 is engaged and connected to the main drive gear 42, and a synchronization mechanism 47 is disposed in the vicinity of the clutch gear 46.

  The synchronizer 47 includes a sleeve 48 that moves in the axial direction (left and right in the figure) by the operation of a selector (not shown), a synchronizer key 49 that is mounted on the inner periphery of the sleeve 48 so as to be axially movable, A hub 50 engaged and connected to the outer periphery of the shaft 41, a synchronizer ring 51 slidably mounted on the outer periphery (cone portion) of the clutch gear 46, and a synchronizer key 49 are elastically attached to the inner periphery of the sleeve 48. A pressing pin 52 and a spring 53 are provided.

  In the state shown in the figure, the sleeve 48 and the synchronizer key 49 are held in the neutral position by the pressing pin 52. At this time, the main drive gear 42 idles with respect to the main shaft 41. On the other hand, when the sleeve 48 is moved to the left side in the axial direction, for example, by the operation of the selector, the synchronizer key 49 is moved to the left side in the axial direction following the sleeve 48, and the synchronizer ring 51 is moved to the clutch gear 46. Press against the inclined surface of the cone. As a result, the rotational speed of the clutch gear 46 decreases, and conversely, the rotational speed on the synchro mechanism 47 side is increased. When the rotational speeds of the two are synchronized, the sleeve 48 further moves to the left in the axial direction, engages with the clutch gear 46, and the main shaft 41 and the main drive gear 42 are connected via the sync mechanism 47. . Thereby, the main shaft 41 and the main drive gear 42 rotate synchronously.

  Tapered roller bearings (Example 1) using the cage shown in FIG. 4 and tapered roller bearings (Example 2) using the cage shown in FIG. 5 were prepared. Moreover, as a comparative example, a tapered roller bearing (Comparative Example 1) using a cage without a notch in the pocket and a tapered roller bearing (Comparative Example) using the cage shown in FIGS. 11 (A) and 11 (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.

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

  FIG. 8 shows the test results. The vertical axis of the graph in the figure represents the torque reduction rate with respect to the torque of Comparative Example 1 using a cage with no notch in the pocket. Although the comparative example 2 which provided the notch in the center part of the pocket | column part of a pocket and the comparative example 3 which provided the notch in the small annular part and the large annular part of a pocket also show a torque reduction effect, the narrow part of a pocket In Example 1 in which a notch is provided in the column on the side, a torque reduction effect superior to those of the comparative examples is recognized, and a notch on the narrow side is provided with a notch in the small annular portion on the narrow side. In Example 2 in which the total area of these 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.

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

(A) is a cross-sectional view of a tapered roller bearing showing an embodiment of the present invention, and (B) is a vertical cross-sectional view of the bearing. (A) is a sectional view of the cage before moving in the axial direction, (B) is a sectional view of the cage after moving. (A) is a side view of the cage of the tapered roller bearing at rest, (B) is a side view of the cage of the tapered roller bearing at the initial stage of rotation, and (C) is a side view of the cage of the tapered roller bearing during rotation. Fig. 1 is a developed plan view of a cage in the tapered roller bearing of Fig. 1. An expanded plan view similar to FIG. 4 showing a modification of the cage An expanded plan view similar to FIG. 4 showing another modification of the cage Partial enlarged view of FIG. Diagram showing results of bearing life test Cross section of a typical automobile differential Cross section of a typical automobile transmission (A) is a development plan view of a cage showing a conventional technique, (B) is a development plan view of a cage showing a conventional technique. Diagram showing changes in stiffness ratio (-●-) and torque ratio (-○-) when changing the roller pitch diameter (PCD) in tapered roller bearings Partial cross-sectional view of tapered roller bearing showing conventional technology

1, 1a, 1b Tapered roller bearing 2 Inner ring 2a Raceway surface 2b Small brim 2c Large brim 3 Outer ring 3a Raceway 4 Tapered roller 5 Cage 6 Small ring part 7 Large ring part 8 Pillar part 9 Pocket 10a, 10b, 10c Notch 11 collar

Claims (7)

  An inner ring, an outer ring, a plurality of tapered rollers arranged to roll between the inner ring and the outer ring, and a cage for holding the tapered rollers at a predetermined circumferential interval, and a roller coefficient γ of 0.94 The retainer is composed of a small annular portion that is continuous on the small end surface side of the tapered roller, a large annular portion that is continuous on the large end surface side of the tapered roller, and a plurality of column portions that connect these annular portions. A trapezoidal pocket is formed between the pillars, where the part that houses the small diameter side of the tapered roller is the narrow side and the part that accommodates the large diameter side is the wide side, and is cut out in the column part on the narrow side of the pocket A tapered roller bearing in which the cage is in non-contact with the outer ring in the neutral state and contacts with the outer ring when moved in the radial direction.   The tapered roller bearing according to claim 1, wherein a notch is also provided in the small annular portion on the narrow side of the pocket.   The tapered roller bearing according to claim 1, wherein a notch is provided in at least a column part on the wide side of the pocket.   The tapered roller bearing according to claim 3, wherein the total area of the notches provided on the narrow side of the pocket is wider than the total area of the notches provided on the wide side of the pocket.   Provided radially inwardly facing the outer diameter surface of the small collar of the inner ring on the outer side in the axial direction of the small annular portion of the cage, between the inner diameter surface of the collar and the outer diameter surface of the small collar of the inner ring The tapered roller bearing according to any one of claims 1 to 4, wherein the upper limit of the clearance is 2.0% of the outer diameter of the small collar.   At least the surface of the tapered roller is provided with an infinite number of minute concave concaves, the surface roughness parameter Ryni of the surface provided with the concaves 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 5, wherein the tapered roller bearing is 1.6 or less.   The tapered roller bearing according to any one of claims 1 to 6, which supports a power transmission shaft of a self-propelled vehicle.

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