JP2007120606A - Tapered roller bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent increase in the load capacity and damage of a raceway surface due to excess surface pressure by increasing the number of rollers, substantialize low torque without deteriorating the rigidity of a bearing, and suppress the occurrence of dragging torque. <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 outer diameter of the retainer 5 is set to a size to form a clearance between the outer peripheral face of the retainer and the outer ring raceway surface during rotation of a bearing when the retainer center moves to the axial center. A tapered face 5d where the external-diameter face of the tapered rollers 4 slidingly contacts on both side of the inner-diameter face of a column part 5c formed between pockets 5e is provided. A length of the tapered face 5d in the width direction is set to 5% or more and less than 11% of the average diameter of the tapered rollers 4. The roller factor γ is set to 0.94 or more. <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.

  FIG. 5 shows an example of the configuration of an automobile transmission. 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, meshes 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.

  FIG. 6 shows an example of the configuration of the automobile differential. 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.

  The tapered roller bearing that can be used in the transmission and the differential has an outer ring having a conical raceway surface, a conical raceway surface, and a small flange portion and a large diameter side end portion at a small diameter side end portion of the raceway surface. An inner ring having a large collar portion, a plurality of tapered rollers arranged to roll between the raceway surface of the outer ring and the raceway surface of the inner ring, and a cage for holding the tapered rollers at equal intervals in the circumferential direction. I have.

  In such a tapered roller bearing, tapered surfaces on which the outer diameter surfaces of the tapered rollers are slidably contacted are provided on both sides of the inner diameter surface of the column portion, so that contact wrinkles are not generated on the outer diameter surface of the tapered rollers. Conventionally, the length of the tapered surface in the width direction is 11% to 20% of the average diameter of the tapered rollers.

  As described above, in the differential and the transmission, the tapered roller bearing rotates with the lower part immersed in the oil bath of this lubricating oil. As described above, in the tapered roller bearing used in the oil bath lubricated state, the wedge space formed by these surfaces is also formed between the outer diameter surface of the tapered roller 4 and the tapered surface of the columnar inner diameter surface of the cage 5. Lubricated with lubricating oil.

  Therefore, when the length dimension L in the width direction of the tapered surface of the cage is 11% to 20% of the average diameter of the tapered roller, it is between the outer diameter surface of the tapered roller and the tapered surface of the columnar inner diameter surface. A relatively large wedge space is formed, and a large amount of lubricating oil enters the wedge space. Since the amount of lubricating oil entering the interface between the outer diameter surface of the roller and the tapered surface of the cage is limited from this wedge space, if a large amount of lubricating oil enters the wedge space in this way, There is a problem that there is no escape space and there is resistance to rotation of the bearing, and torque loss increases. Further, in the tapered roller bearing that flows into the bearing as described above, the flow resistance of the lubricating oil with respect to the rotation of the cage also causes a torque loss that cannot be ignored.

Therefore, it is necessary to reduce torque loss due to the flow resistance of the lubricating oil in the tapered roller bearing in which the lubricating oil flows into the bearing. That is, it is necessary to reduce the oil flow resistance in order to reduce the torque. However, in order to significantly reduce the torque, it is necessary to change the bearing specifications so that the rolling viscous resistance is reduced. However, with the conventional torque reduction technique (see Patent Documents 1 to 3), it is possible to reduce the torque without reducing the rated load, but the bearing rigidity is somewhat reduced.
JP 09-096352 A Japanese Patent Laid-Open No. 11-0210765 JP 2003-343552 A JP 2003-28165 A

  On the other hand, low-viscosity oil tends to be used for automobile transmissions in recent years for the purpose of AT / CVT mission and fuel efficiency reduction. When unfavorable conditions such as high, low oil volume, preload loss occur, etc., surface origin separation due to poor lubrication may occur on the raceway surface of the inner ring with high surface pressure. .

  As a countermeasure for short life due to this surface-origin separation, reduction of the maximum surface pressure is a direct and effective solution. In order to reduce the maximum surface pressure, the bearing dimensions are changed, or if the bearing dimensions are not changed, the number of rollers of the bearing is increased. In order to increase the number of rollers without reducing the roller diameter, the pocket interval of the cage must be narrowed. For this purpose, it is necessary to enlarge the pitch circle of the cage and bring it closer to the outer ring side as much as possible.

  As an example in which the cage is brought into contact with the inner surface of the outer ring, there is a tapered roller bearing shown in FIG. 7 (see Patent Document 4). The tapered roller bearing 61 guides the cage 62 by sliding the outer peripheral surface of the small-diameter side annular portion 62 a and the outer peripheral surface of the large-diameter side annular portion 62 b with the inner surface of the outer ring 63. In order to suppress drag torque on the outer diameter surface of the portion 62c, a recess 64 is formed to maintain a non-contact state between the outer diameter surface of the column portion 62c and the raceway surface 63a of the outer ring 63. As shown in detail in FIG. 7, the retainer 62 has a small-diameter-side annular portion 62a, a large-diameter-side annular portion 62b, and a small-diameter-side annular portion 62a and a large-diameter-side annular portion 62b connected in the axial direction to the outer diameter surface. And a plurality of column parts 62c in which recesses 64 are formed. A plurality of pockets 66 are provided between the column portions 62c for accommodating the tapered rollers 65 in a rollable manner. The small-diameter-side annular portion 62a is provided with a flange portion 62d that extends integrally on the inner-diameter side.

  In the tapered roller bearing 61 described in Patent Document 4, since the recess 64 is provided in the column portion 62 c of the cage 62, the plate thickness is inevitably thinned and the rigidity of the cage 62 is reduced, and the stress at the time of assembling the bearing 61 is reduced. Due to this, there is a possibility that the cage 62 is deformed or the cage 62 is deformed while the bearing 61 is rotating. Further, since the outer peripheral surface of the small-diameter side annular portion 62a and the outer peripheral surface of the large-diameter side annular portion 62b of the cage 62 are in sliding contact with the inner surface of the outer ring 63, there is a problem that the torque is increased accordingly.

On the other hand, a conventional typical tapered roller bearing with a cage other than the tapered roller bearing described in Patent Document 1 avoids contact between the outer ring 71 and the cage 72 as shown in FIG. In order to secure the width and to obtain the appropriate column strength and smooth rotation of the cage 72, the roller coefficient γ (roller filling rate) defined by the following formula is usually required to be 0.94 or less ( Patent Document 2).
Roller coefficient γ = (Z · DA) / (π · PCD) ≦ 0.94
Here, Z: number of rollers, DA: roller average diameter, PCD: roller pitch circle diameter In FIG. 8, 73 is a tapered roller, 74 is a column surface, 75 is an inner ring, and θ is a window angle.

  If an attempt is made to simply increase the roller filling rate while keeping the pocket size of the cage 72 as it is, the column 72a of the cage 72 becomes thin, and sufficient column strength cannot be ensured. On the other hand, when the cage diameter is changed (diameter is increased) in a direction in which the gap between the cage and the outer ring is reduced in order to secure the column strength, as described in Patent Document 4, the outer ring contact of the cage is performed. This may promote wear at the part and increase drag torque.

  The object of the present invention is to increase the number of rollers to prevent an early breakage due to an increase in load capacity and excessive surface pressure of the raceway surface, and to realize a reduction in torque without reducing bearing rigidity. An object of the present invention is to provide a tapered roller bearing capable of suppressing the generation of drag torque.

  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 cone having a retainer having a pocket for holding the tapered rollers at predetermined circumferential intervals. In a roller bearing, when the outer diameter of the cage is moved in the radial direction, the outer circumferential surface of the cage comes into contact with the outer ring raceway surface, but the cage center moves to the shaft center during rotation of the bearing. A dimension is formed so that a gap is formed between the outer peripheral surface and the outer ring raceway surface, and tapered surfaces are provided on both sides of the inner diameter surface of the column portion formed between the pockets so that the outer diameter surface of the tapered roller is in sliding contact. The length of the tapered surface in the width direction is 5% or more and less than 11% of the average diameter of the tapered rollers, and the roller coefficient γ is 0.94 or more.

  In the state where the cage is located at the center of the shaft, there is a clearance between the outer diameter of the cage and the outer ring raceway surface, so that contact between the outer ring and the cage hardly occurs during the bearing operation.

By making the cage dimensions such that contact between the outer ring and the cage is avoided only during rotation, the roller coefficient γ can be made γ> 0.94.

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 a conventional typical tapered roller bearing with a cage, the roller coefficient γ is usually designed to be 0.94 or less, so that the roller coefficient γ exceeds 0.94, This means that the roller filling rate and thus the bearing rigidity is high.

  By making the length dimension of the tapered surface in the width direction less than 11% (preferably 9% or less) of the average diameter of the tapered roller, a very large wedge space is formed between the outer diameter surface of the tapered roller and the tapered surface. Not formed. If the length dimension in the width direction of the tapered surface is less than 5% of the average diameter of the tapered roller, the elastic contact area between the outer diameter surface of the tapered roller and the tapered surface may be larger than the width of the tapered surface. The length dimension of the tapered surface in the width direction is preferably 5% or more of the average diameter of the tapered rollers.

  The thickness of the column portion is 5% or more and less than 17% of the average diameter of the tapered rollers. Thereby, the thickness of a pillar part can be made thin and the flow resistance of the lubricating oil with respect to rotation of a holder | retainer can be made small. If the thickness dimension of the column part is less than 5% of the average diameter of the tapered roller, the rigidity of the cage cannot be sufficiently secured. Therefore, the thickness dimension of the column part is set to 5% or more of the average diameter of the tapered roller. Is preferred.

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

  In the tapered roller bearing of the present invention, there is a clearance between the outer diameter of the cage and the outer ring raceway surface in a state where the cage is located at the center of the shaft, so that there is almost no contact between the outer ring and the cage during the bearing operation. It does not occur, and an increase in drag torque due to contact and wear can be suppressed.

  Since the length dimension of the tapered surface in the width direction is 5% or more and less than 11% (preferably 9% or less) of the average diameter of the tapered roller, there is not much space between the outer diameter surface of the tapered roller and the tapered surface. A large wedge space is not formed. For this reason, the amount of lubricating oil entering the wedge space can be reduced, and torque loss due to the absence of the escape space for the lubricating oil can be reduced.

  FIG. 10 shows the rigidity ratio (− ● −) and torque ratio (− ◯ −) when the tapered roller pitch diameter (PCD) is changed in the tapered roller bearing. As shown in FIG. 10, when the PCD is reduced, the torque of the bearing is greatly reduced, but the bearing rigidity is not reduced so much as a result of calculating and confirming the amount of elastic deformation of the tapered roller. Therefore, the torque can be reduced without reducing the rigidity by reducing the PCD while decreasing or increasing the number of rollers.

  In the present invention, the PCD can be reduced while increasing the number of rollers by making the roller coefficient γ exceed 0.94. Thereby, low torque can be realized without reducing the bearing rigidity. In addition, increasing the number of rollers not only increases the load capacity, but also reduces the maximum surface pressure of the raceway surface, thus preventing surface-origin separation with an extremely short life under severe lubrication conditions. be able to.

  In addition, by setting the thickness of the column portion to 5% or more and less than 17% of the average diameter of the tapered rollers, the thickness of the column portion is reduced, and the flow resistance of the lubricating oil to the rotation of the cage is reduced. Thus, torque loss can be further reduced.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. The tapered roller bearing 1 according to this embodiment 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 be freely rollable. The tapered roller 4 is accommodated in a pocket 5 e formed in the cage 5. Each tapered roller 4 is restricted from moving in the axial direction 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 cage 5 is made of an iron plate and can be used without worrying about material deterioration (oil resistance) due to immersion in oil. The cage 5 may be integrally formed with a super engineering plastic such as PPS, PEEK, PA, PPA, or PAI instead of the steel plate. Resin cages are lighter in weight than steel plates, are self-lubricating, and have a low coefficient of friction. Therefore, in combination with the effect of lubricating oil in the bearing, contact with the outer ring It is possible to suppress the occurrence of wear due to. Further, since the resin cage is light and has a small coefficient of friction, it is suitable for reducing torque loss and cage wear at the time of starting 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), poly1,4-cyclohexanedimethylene terephthalate (PCT), polyamide 46 (PA46), polyamide 6T (PA6T), polyamide 9T (PA9T), polyamide 11,12 (PA11,12), fluororesin, polyphthalamide (PPA)

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.

  The cage 5 includes a small-diameter-side annular portion 5a, a large-diameter-side annular portion 5b, and a plurality of column portions 5c that connect the small-diameter-side annular portion 5a and the large-diameter-side annular portion 5b in the axial direction. A plurality of pockets 5e are formed between the column portions 5c adjacent to each other in the circumferential direction so as to accommodate the tapered rollers 4 in a rollable manner. As shown in FIG. 4B, the retainer 5 is provided with column surfaces (taper surfaces) 5d on which the outer diameter surfaces of the tapered rollers 4 are in sliding contact with both sides of the inner diameter surface of the column portion 5c.

  The diameter of the cage of the tapered roller bearing according to the present invention is such that the cage 5 is moved to the axial small diameter side as shown in FIG. 2 (B), and then is moved downward in the radial direction as shown in FIG. 3 (A). The outer ring 3 and the cage 5 come into contact with each other, but when the bearing rotates and the cage 5 is centered as shown in FIG. 3C, the cage 5 and the outer ring 3 leave a predetermined gap in the entire circumferential direction. The dimensions are set so that they do not touch each other. That is, when the cage 5 is arranged at the center of the shaft and the cage 5 is close to the small diameter side as shown in FIG. 2B, a gap is formed between the cage 5 and the outer ring 3. When moved radially from the center, the outer ring 3 and the cage 5 are set to contact dimensions.

  As a result, the outer ring 3 and the cage 5 are in contact with each other in the initial stage of operation, but are not in contact with each other during operation, so that an increase in drag torque and wear due to contact can be suppressed. In the case of a steel plate cage, the bottom expansion and caulking work is necessary. However, in the case of a resin cage, it is not necessary, so it is easy to ensure the dimensional accuracy required for the invention. Here, “bottom opening” means that when the cage 5 incorporating the roller is assembled to the inner ring, the diameter of the pillar portion on the smaller diameter side of the cage 5 is greatly expanded so that the roller gets over the inner ring gavel. The “caulking work” means that the pillar portion of the small diameter portion of the cage 5 that has been greatly expanded as described above is pushed from the outside with a mold and returned to its original state.

  As shown in FIG. 4, the cage 5 is provided with tapered surfaces 5d on both sides of the inner diameter surface of the column portion 5c so that the outer diameter surfaces of the tapered rollers 4 are in sliding contact with each other. The length of the tapered surface 5d in the width direction is provided. The dimension L is 5% or more of the average diameter D of the tapered rollers 4 and less than 11% (preferably 9% or less). By setting the length dimension L in the width direction of the tapered surface 5d to less than 11% of the average diameter of the tapered roller 4, a very large wedge space is not formed between the outer diameter surface of the tapered roller 4 and the tapered surface 5d. . When the length dimension L in the width direction of the tapered surface 5d is less than 5% of the average diameter of the tapered roller, the elastic contact region between the outer diameter surface of the tapered roller 4 and the tapered surface 5d is larger than the width of the tapered surface 5d. Since there exists a possibility, it is preferable that the length dimension L of the taper surface 5d in the width direction shall be 5% or more of the average diameter of the tapered roller 4. In this embodiment, the length dimension L in the width direction of the tapered surface 5d is 7% of the average diameter D of the tapered rollers 4.

  Further, the thickness dimension T of the column part 5c is set to 5% or more and less than 17% of the average diameter D of the tapered rollers 4. Thereby, the flow resistance of the lubricating oil with respect to the rotation of the cage 5 can be reduced. In addition, if the thickness dimension T of the column part 5c is less than 5% of the average diameter of the tapered roller, the rigidity of the cage 5 cannot be sufficiently secured. Therefore, the thickness dimension T of the column part 5c is equal to the average diameter of the tapered roller 4. 5% or more is preferable. In this embodiment, the thickness dimension T of the column part 5 c is 10% of the average diameter D of the tapered rollers 4.

  In the tapered roller bearing of the present invention, there is a clearance between the outer diameter of the cage and the outer raceway surface when the cage 5 is located at the center of the shaft. Contact hardly occurs, and an increase in drag torque and wear due to contact can be suppressed.

  Since the length dimension L in the width direction of the tapered surface 5d is 5% or more and less than 11% (preferably 9% or less) of the average diameter of the tapered roller 4, the outer diameter surface of the tapered roller 4 and the tapered surface 5d are reduced. A large wedge space is not formed between the two. For this reason, the amount of lubricating oil entering the wedge space can be reduced, and torque loss due to the absence of the escape space for the lubricating oil can be reduced.

  In the present invention, the PCD can be reduced while increasing the number of rollers by making the roller coefficient γ exceed 0.94. For this reason, a reduction in torque can be realized without reducing the bearing rigidity. Also, by increasing the number of rollers, not only the load capacity is increased, but the maximum surface pressure of the inner and outer ring raceway surfaces can be reduced by increasing the number of rollers without impairing the torque characteristics of the bearing. Even when adverse conditions such as a small amount of oil and occurrence of preload loss result in severe lubrication conditions, it is possible to prevent surface-origin separation having an extremely short life, particularly on the inner ring raceway surface.

  In addition, by setting the thickness of the column portion to 5% or more and less than 17% of the average diameter of the tapered rollers, the thickness of the column portion is reduced, and the flow resistance of the lubricating oil to the rotation of the cage is reduced. Thus, torque loss can be further reduced.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and can be variously modified. For example, in the embodiments, it has been described that super engineering plastics such as PPS, PEEK, PA, PPA, PAI can be used for the cage material. However, if necessary, these resin materials or other engineering plastics may be used for strength enhancement. A blend of glass fiber or carbon fiber may be used.

  The tapered roller bearing 1 according to the present invention can be used for automobile transmissions and differentials, but can also be used for applications other than automobile gear devices.

  Tapered roller bearing (Example) using a cage whose length L of the tapered surface is 7% of the average diameter D of the tapered roller, and 13% of the average diameter D of the tapered roller having a tapered surface length L A tapered roller bearing (comparative example) using the conventional cage described above was prepared. Each tapered roller bearing had an outer diameter of 100 mm, an inner diameter of 45 mm, and a width of 27.25 mm. Further, the thickness T of the column portion of the cage was set to 13% of the average diameter D of the tapered roller in the example and 17% in the comparative example.

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. 9 shows the results of the torque measurement test. The vertical axis of the graph of FIG. 9 represents the torque reduction rate of the embodiment with respect to the torque of the comparative example. In the example in which the length L of the tapered surface is as small as 7% of the average diameter D of the tapered roller, a remarkable torque reduction effect is recognized from low speed rotation to high speed rotation, and even at the maximum rotation speed of 2000 rpm of the test. A torque reduction rate of 12.0% is obtained. The torque reduction effect of this embodiment includes the effect of reducing the flow resistance of the lubricating oil against the rotation of the cage by reducing the thickness dimension T of the column portion.

(A) is a fragmentary sectional view of the tapered roller bearing of the present invention, and (B) is a longitudinal sectional view of the roller bearing. (A) is sectional drawing of the holder | retainer before an axial direction movement, (B) is sectional drawing of the holder | retainer after movement. (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. Is 1 shows the cage of FIG. 1, (A) is a developed plan view, and (B) is a sectional view taken along line XX of (A). It is a fragmentary sectional view of the transmission of a car. It is sectional drawing which shows the differential of a motor vehicle. It is a fragmentary sectional view of the conventional tapered roller bearing. It is sectional drawing of the conventional tapered roller bearing which brought the cage | basket toward the outer ring | wheel side. It is a graph which shows the result of a torque measurement test. It is a diagram showing the change of a rigidity ratio and a torque ratio when changing a tapered roller pitch diameter (PCD) in a tapered roller bearing.

Explanation of symbols

1 Bearing 2 Inner ring 2a Raceway surface 3a Raceway surface 3 Outer ring 4 Tapered roller 5 Cage 5d Tapered surface 5e Pocket

Claims (3)

In a tapered roller bearing comprising 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 having a pocket for holding the tapered rollers at predetermined circumferential intervals,
When the outer diameter of the cage is moved in the radial direction, the outer circumferential surface of the cage comes into contact with the outer ring raceway surface. The tapered surface has a dimension that allows a clearance to be formed between the tapered surface and a tapered surface on which the outer diameter surface of the tapered roller is in sliding contact with both sides of the inner diameter surface of the column portion formed between the pockets. A tapered roller bearing characterized in that the length dimension in the width direction is 5% or more and less than 11% of the average diameter of the tapered rollers, and the roller coefficient γ is 0.94 or more. The tapered roller bearing according to claim 1, wherein a thickness dimension of the column portion is 5% or more and less than 17% of an average diameter of the tapered roller. The tapered roller bearing according to claim 1 or 2, wherein a power transmission shaft of the self-propelled vehicle is supported.

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