JP2018168982A - Conical roller bearing - Google Patents

Abstract

To avoid increase in rotational torque of a conical roller bearing, and prevent lubrication deficiency between a large flange part of an inner ring and a large end surface of a conical roller at the initial stage of operation resumption.SOLUTION: In a second annular part 42 on a large diameter side of a cage-shaped holder 40, at a connection part 48 connecting an inner peripheral part 46 and an outer peripheral part 47, an oil groove 49 is formed on a pocket inside surface 48a forming a pocket 43. The oil groove 49 penetrates from an outer diameter of the second annular part 42 to an inner diameter thereof, and is opposite to a large end surface 12 of a conical roller 10. Consequently, an interval between the oil groove 49 and the large end surface 12 expands to easily hold lubricant the interval, so that the lubricant easily adheres to the large end surface 12.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a tapered roller bearing.

  For example, tapered roller bearings are conventionally used in applications that support rotating shafts of various mechanical devices such as automobile transmission shafts and differential shafts. An oil lubrication method using a liquid lubricating oil is generally used for lubrication inside the bearing. As a method for supplying the lubricating oil, a splash lubrication method in which the lubricating oil is splashed onto the bearing by agitation of the lubricating oil accompanying the rotation of the gear during operation of the mechanical device, or a part of the bearing in the oil bath. An oil bath lubrication method that is soaked in water is common.

  The inner ring of the tapered roller bearing has a large collar portion that guides the large end face of the tapered roller during operation. Since the sliding contact portion between the large collar portion and the large end surface of the tapered roller is a sliding contact in the circumferential direction, there is a concern that seizure may occur due to insufficient or depletion of lubricating oil in the sliding contact portion. .

  During operation, a sufficient amount of lubricating oil is supplied to the large collar and the large end surfaces of the tapered rollers. The lubricating oil adhering to the large collar or the tapered end of the tapered roller during operation gradually flows down by gravity after the operation is stopped, but remains sufficiently in the sliding contact portion for a short time. For this reason, when the operation is resumed in a short time, there is no concern that a shortage of lubricating oil will occur. When the time until the operation is restarted is long, the lubricating oil flows down from the large end face and the large flange portion of the tapered roller, and the lubricating oil is insufficient at the sliding contact portion at the beginning of the operation.

  In addition, as the lubricating oil has a lower viscosity during operation or the amount of lubricating oil supplied into the bearing during operation decreases, the sliding contact between the large collar portion of the inner ring and the large end surface of the tapered roller becomes smaller. The lubrication environment in the part becomes severe. In tapered roller bearings, due to the pumping action that occurs inside the bearing during operation, lubricating oil tends to enter the bearing from between the cage and the inner ring, and the centrifugal force causes the inside of the bearing to flow toward the outer ring and easily escape to the outside of the bearing. . For this reason, if the amount of oil is reduced, the lubricating oil is difficult to reach the large collar.

  In particular, tapered roller bearings used for automobile transmissions or differentials have recently been required to reduce bearing rotational torque for the purpose of reducing the fuel consumption of automobiles. As a means for reducing the bearing rotational torque, it is effective to suppress the agitation resistance of the lubricating oil inside the bearing. For this reason, there is a tendency to use low-viscosity lubricating oil or reduce the amount of oil, and there is a concern that sufficient lubrication cannot be ensured at the sliding contact portion between the large collar portion of the inner ring and the large end surface of the tapered roller.

In response to this concern, in the tapered roller bearing disclosed in Patent Document 1, the pillar portion of the cage-shaped cage formed of resin has a plurality of groove-shaped oil guiding portions, and these oil guiding portions allow the above-described problem. The lubricating oil flowing inside the bearing is guided to the inner ring side by the pump action. Such tapered roller bearings can reduce the rotational torque of the bearing by reducing the weight of the cage. Furthermore, the oil guiding part can be used to slide the large collar part of the inner ring and the large end face of the tapered roller. Lubricating oil can be easily supplied.

JP 2008-45711 A

  However, in the tapered roller bearing disclosed in Patent Document 1, when the lubricating oil is supplied to the large end face or the large flange portion side of the tapered roller through the oil guiding portion of the column portion, the lubricating oil is transferred to the tapered roller. Touch the moving surface. That is, since the lubricating oil that collides with the rolling surface of the tapered roller that revolves during operation increases, the agitation resistance increases and the bearing rotational torque increases.

  In addition, when a plurality of oil guiding portions are formed in the pillar portion of the cage, the radial width of the pillar portion is increased. Along with this, the roller guide surface that contacts the tapered roller in the circumferential direction in the column portion also expands in the radial direction, so that the lubricating oil generated between the rolling surface of the tapered roller and the roller guide surface of the column portion. This increases the shear resistance, and this also increases the bearing rotational torque.

  Recently, the use of an aluminum housing that supports the outer ring of a tapered roller bearing has increased the amount of bearing misalignment, and the bearing rigidity has been reduced by reducing the amount of preload applied to the tapered roller bearing in order to reduce the bearing torque. As a result, the behavior of the tapered roller during operation becomes unstable, and there is a further concern about insufficient lubrication at the sliding contact portion between the large collar portion of the inner ring and the large end surface of the tapered roller.

  In addition, when the operation is restarted, the temperature of the lubricating oil is low, the viscosity of the lubricating oil supplied to the bearing is high, and the fluidity is poor, so that the lubricating oil particularly reaches between the large collar of the inner ring and the large end face of the tapered roller. This is a difficult condition, and there is a particular concern about insufficient lubrication at the sliding contact portion. This concern is particularly noticeable in cold regions (for example, in a cryogenic environment such as -40 ° C to -30 ° C).

  In view of the above-described background, the problem to be solved by the present invention is to prevent insufficient lubrication between the large collar portion of the inner ring and the large end surface of the tapered roller at the beginning of the operation while avoiding an increase in rotational torque of the tapered roller bearing. That is.

  To achieve the above object, the present invention provides a tapered roller having a small end surface, a large end surface and a rolling surface, a raceway surface provided on the outer periphery, and a large collar portion for guiding the large end surface of the tapered roller. An inner ring having a raceway surface provided on the inner circumference, and an outer ring disposed coaxially with the inner ring, and a cage formed of resin, wherein the cage is a first annular portion. And a second annular portion having a diameter larger than that of the first annular portion, and a plurality of column portions that divide the first annular portion and the second annular portion into pockets, and the tapered roller Is accommodated in the pocket in a posture in which the large end surface is directed toward the second annular portion, and penetrates from the outer diameter to the inner diameter in the pocket inner surface forming the pocket of the second annular portion. An oil groove is provided, and at least a part of the oil groove is formed of the tapered roller. It is obtained by adopting a configuration in which opposes the end face.

  According to the above configuration, the lubricating oil supplied from the outside during the bearing operation easily enters the oil groove from the inner diameter side or the outer diameter side of the second annular portion. Since at least a part of the oil groove passes through a region on the inner surface of the pocket that faces the large end surface of the tapered roller, the gap between the inner surface of the pocket and the large end surface of the tapered roller is widened in the facing region. The amount of lubricating oil adhering to the large end surface of the tapered roller near the inner surface of the pocket increases. Lubricating oil adhering to the large end surface of the tapered roller near the inner surface of the pocket is carried to the large collar portion of the inner ring as the tapered roller rotates about the central axis. Therefore, if the amount of lubricating oil adhering to the large end surface of the tapered roller near the pocket inner surface increases, the amount of lubricating oil supplied to the sliding contact portion between the large collar portion of the inner ring and the large end surface of the tapered roller also increases. This prevents insufficient lubrication between the large collar portion of the inner ring and the large end surface of the tapered roller even in an environment where the amount of lubricating oil becomes small as in the beginning of resumption of operation.

  Further, according to the above configuration, since the oil groove passes through the inner surface of the pocket of the second annular portion, there is no increase in lubricating oil that collides with the rolling surface of the tapered roller (that is, there is no increase in stirring resistance). This avoids an increase in the rotational torque of the tapered roller bearing.

  Furthermore, according to the above configuration, the oil groove on the inner surface of the pocket of the second annular portion and the large end surface of the tapered roller have a wide area between the inner surface of the pocket and the large end surface of the tapered roller. Compared to the case where there is no groove, the shear resistance of the lubricating oil generated between the inner surface of the pocket and the large end surface of the tapered roller is reduced. This also leads to a reduction in rotational torque of the tapered roller bearing.

  Preferably, all of the oil groove passes through a position facing the large end surface of the tapered roller. If it does in this way, the above-mentioned insufficient lubrication can be prevented by utilizing an oil groove without waste.

  In the present invention, the number of oil grooves per pocket is not limited.

  For example, the second annular portion has a plurality of the oil grooves for each of the pockets, and the plurality of oil grooves are symmetrical with respect to a virtual plane that bisects the pockets in the circumferential direction. Can be mentioned. If it does in this way, the above-mentioned insufficient lubrication can be similarly prevented regardless of the revolution direction of the tapered roller.

  In this invention, the oil groove may extend in a straight line in the radial direction, may be inclined, or may be bent. In any case, the larger the area in which the tapered roller's large end surface and the oil groove face each other in the direction of the central axis of the tapered roller, the more easily the lubricating oil adheres to the large end surface. For this reason, it is better that the oil groove is more opposed to a place where the circumference of the large end surface (a circumference around the central axis of the tapered roller) is large.

  For example, the oil groove extends in the direction of gradually approaching the column part from the outer diameter to the inner diameter of the second annular part. In this way, the oil groove can be prevented from moving away from the peripheral projection position of the large end surface of the tapered roller from the outer diameter to the inner diameter of the second annular portion, and the lubricating oil can be easily supplied to the large end surface. it can.

  As another example, the oil groove may have a curved groove side surface that bends in the rotation direction of the tapered roller. In this way, during the operation of the bearing, the direction in which the large end surface of the tapered roller rotates around the central axis of the tapered roller and the direction of the flow of the lubricating oil through the oil groove are close to each other. Compared to the case of the shape, the lubricating oil is caught in the rotating large end surface and easily reaches the large collar portion of the inner ring, so the lubricating oil is supplied to the sliding contact portion between the large collar portion and the large end surface. Can be made easier.

  In the present invention, the width of the oil groove may be constant or may vary. The width of the oil groove also takes into account the required lubrication performance at the sliding contact portion between the large end surface of the tapered roller and the large collar portion of the inner ring, the mechanical strength of the second annular portion, the difficulty of forming the oil groove, and the like. May be determined as appropriate.

  For example, the oil groove has a certain width from the outer diameter to the inner diameter of the second annular portion.

  For example, the width of the oil groove is less than or equal to half the maximum diameter of the tapered roller.

  In this invention, since the oil groove is only formed on the pocket inner surface of the second annular portion, it is not necessary to set the radial width of the column portion as wide as the cage of Patent Document 1.

  For example, the column portion has a roller guide surface that contacts the rolling surface of the tapered roller in the circumferential direction, and the radial width of the roller guide surface is 1/3 or less of the minimum diameter of the rolling surface. It is mentioned that. If it does in this way, compared with the holder | retainer of patent document 1, the shear resistance of the lubricating oil between the roller guide surface of a pillar part and the rolling surface of a tapered roller can be suppressed.

  The tapered roller bearing according to the present invention is suitable for use in supporting a rotating shaft included in a power transmission path of an automobile, and for supplying lubricating oil from the outside to the inside of the bearing by splashing or oil bath lubrication. is there. The tapered roller bearing according to the present invention can prevent insufficient lubrication between the large collar portion of the inner ring and the large end surface of the tapered roller at the beginning of the operation while avoiding an increase in rotational torque of the tapered roller bearing as described above. Therefore, it is possible to cope with the use of low-viscosity lubricating oil and a reduction in the amount of oil, which in turn can contribute to lower fuel consumption by reducing the power loss of the automobile.

  By adopting the above configuration, the present invention increases the amount of lubricating oil adhering to the large end surface of the tapered roller at the oil groove of the pocket inner surface of the second annular portion of the cage, thereby increasing the pocket inner surface and the large end surface of the tapered roller. It is possible to reduce the shear resistance of the lubricating oil generated between the inner ring and the gap between the large collar of the inner ring and the large end face of the tapered roller at the beginning of the operation while avoiding an increase in the rotational torque of the tapered roller bearing. Insufficient lubrication can be prevented.

Sectional drawing which shows the tapered roller bearing which concerns on 1st embodiment of this invention by the cut surface of the II line | wire in FIG. 1 is a partial cross-sectional view showing the cage of FIG. 1 taken along the line II-II in FIG. The fragmentary perspective view which shows the external appearance of the holder | retainer of FIG. The partial top view which shows the external appearance of the holder | retainer of FIG. Partial sectional view of the cage according to the second embodiment of the present invention Partial sectional view of the cage according to the third embodiment of the present invention Partial sectional view of a cage according to a fourth embodiment of the present invention Sectional drawing which shows an example of the differential for motor vehicles incorporating the tapered roller bearing which concerns on embodiment of this invention Sectional drawing which shows an example of the transmission for motor vehicles incorporating the tapered roller bearing which concerns on embodiment of this invention

  Hereinafter, a tapered roller bearing according to a first embodiment of the present invention will be described with reference to FIGS.

  The tapered roller bearing 1 shown in FIG. 1 includes a predetermined number of tapered rollers 10, an inner ring 20, an outer ring 30, and a cage 40. FIG. 1 shows a cross section of the tapered roller bearing 1 on a virtual axial plane including a bearing central axis (not shown), and the position of the cross section is a position passing through the line I-I shown in FIG. It is. FIG. 2 shows a cross section on a virtual radial plane orthogonal to the central axis of the tapered roller 10 in FIG. 1, and the position of the cross section is a position passing through the line II-II shown in FIG.

  The central axes (not shown) of the inner ring 20, the outer ring 30, and the cage 40 are coaxial. The axis that serves as the coaxial rotation center is the bearing central axis (not shown) of the tapered roller bearing 1. Hereinafter, the direction along the bearing central axis (not shown) is simply referred to as “axial direction”, and this axial direction corresponds to the horizontal direction in FIG. A direction perpendicular to the bearing central axis is simply referred to as a “radial direction”, and this radial direction corresponds to the vertical direction in FIG. The circumferential direction around the bearing central axis (not shown) is simply referred to as “circumferential direction”.

  The inner ring 20 shown in FIG. 1 is a race ring having a conical raceway surface 21 on its outer periphery and a large flange portion 22 that is higher in the radial direction than the large diameter side of the raceway surface 21. The large collar portion 22 is an all-round continuous portion along the circumferential direction.

  The outer ring 30 is a race ring having a conical raceway surface 31 on its inner periphery.

  The tapered roller 10 is a rolling element having a small end surface 11, a large end surface 12, and a rolling surface 13 formed in a tapered shape corresponding to the raceway surface 21 of the inner ring 20 and the raceway surface 31 of the outer ring 30. . The small end surface 11 is a side surface on the small diameter side of the tapered roller 10 and is a surface portion that does not roll on the raceway surface 21 of the inner ring 20 and the raceway surface 31 of the outer ring 30. The large end surface 12 is a large-diameter side surface of the tapered roller 10 and is a surface portion that does not roll on the raceway surface 21 of the inner ring 20 and the raceway surface 31 of the outer ring 30. The side surface of the tapered roller 10 is a surface portion of the tapered roller 10 exposed in the central axis direction of the tapered roller 10.

  Here, the central axis direction of the tapered roller 10 refers to a linear direction in which the central axis CL extends. Hereinafter, this direction is simply referred to as a “roller central axis direction”. Further, the circumferential direction around the central axis CL of the tapered roller 10 is simply referred to as “roller circumferential direction”.

  The large end face 12 of the tapered roller 10 and the large collar portion 22 of the inner ring 20 are brought into contact with the tapered roller bearing 1 in the direction of the center axis of the roller. During the bearing operation, the tapered roller 10 is interposed between the raceway surface 21 of the inner ring 20 and the raceway surface 31 of the outer ring 30 on the rolling surface 13, and rotates around the central axis CL of the tapered roller 10. Roll on the surfaces 21 and 31 (revolution of the tapered roller 10). At this time, the large end surface 12 of the tapered roller 10 slides in the circumferential direction with respect to the large collar portion 22 of the inner ring 20, and the large collar portion 22 guides the large end surface 12 in the circumferential direction.

  The tapered roller 10, the inner ring 20 and the outer ring 30 are integrally formed of steel, for example, bearing steel.

  The cage 40 divides the first annular portion 41, the second annular portion 42 having a larger diameter than the first annular portion 41, and the pockets 43 between the first annular portion 41 and the second annular portion 42. A plurality of column portions 44.

  The cage 40 is integrally formed of synthetic resin. The synthetic resin may be, for example, a fiber reinforced resin containing reinforced fibers. The cage 40 is formed by a mold that is divided into two in the axial direction.

  The first annular portion 41 is a cage portion that is continuous in the circumferential direction on the small diameter side of the cage 40.

  The second annular portion 42 is a cage portion that is continuous in the circumferential direction on the large diameter side of the cage 40. The outer diameter of the second annular portion 42 is larger than the outer diameter of the first annular portion 41.

  The pocket 43 is a space formed in the cage 40 for accommodating the tapered roller 10. The pillar portion 44 is a cage portion that extends between the first annular portion 41 and the second annular portion 42 so as to separate the adjacent pockets 43, 43 in the circumferential direction. The number of pockets 43 in the cage 40 is the same as the total number of tapered rollers 10 disposed between the raceway surface 21 of the inner ring 20 and the raceway surface 31 of the outer ring 30.

  The tapered roller 10 is accommodated in the pocket 43 in such a posture that the large end surface 12 faces the second annular portion 42 side.

  The cage 40 rotates while maintaining a predetermined interval in the circumferential direction between the tapered rollers 10 during the bearing operation. The cage 40 is of a so-called rolling element guide type that is guided in the radial direction by the tapered roller 10.

  In FIG. 1, in order to show the size of the radial pocket clearance δ set between the cage 40 and the tapered roller 10, the outer ring 30 is separated from the tapered roller 10 in the radial direction by an amount corresponding to the pocket clearance δ. It is drawn at the position. Of course, the raceway surface 31 of the outer ring 30 contacts the rolling surface 13 of the tapered roller 10 during the bearing operation. The range in which the cage 40 can freely move in the radial direction relative to the tapered roller 10 accommodated in the pocket 43 corresponds to the pocket clearance δ in the radial direction.

  The column portion 44 has a roller guide surface 45 that contacts the rolling surface 13 of the tapered roller 10 in the circumferential direction. The roller guide surface 45 can come into contact with the rolling surface 13 of the tapered roller 10 in the circumferential direction within the aforementioned pocket clearance δ. The radial width W1 of the roller guide surface 45 is preferably 1/3 or less of the minimum diameter D1 of the rolling surface 13 thereof. The radial width W1 of the roller guide surface 45 is such that the contact position on the column portion 44 that is in contact with the rolling surface 13 of the tapered roller 10 on the innermost side in the radial direction and the rolling surface 13 of the tapered roller 10 on the outermost radial direction. It is a distance in the radial direction between the contact position on the pillar portion 44 that comes into contact.

  The second annular portion 42 includes an inner peripheral portion 46, an outer peripheral portion 47, and a connecting portion 48 that connects the inner peripheral portion 46 and the outer peripheral portion 47. The inner peripheral portion 46 of the second annular portion 42 is an entire peripheral surface portion surrounding the large collar portion 22 of the inner ring 20. The outer peripheral portion 47 of the second annular portion 42 is an entire peripheral surface portion along the circumferential direction of the inner peripheral portion 46. The connecting portion 48 of the second annular portion 42 has a pocket inner side surface 48 a that forms the pocket 43. The pocket inner side surface 48a of the second annular portion 42 is formed for each pocket 43, and has the same shape.

  The pocket inner side surface 48 a has an oil groove 49 that penetrates from the outer diameter to the inner diameter (from the outer peripheral portion 47 to the inner peripheral portion 46) of the second annular portion 42. As shown in FIGS. 2 to 4, the entire oil groove 49 is open toward the pocket 43 in the axial direction and is recessed in the axial direction. Such a shape of the oil groove 49 is preferable in that it can be transferred by one of the dies divided in the axial direction and does not include an undercut portion.

  The oil groove 49 includes groove side surfaces 49a and 49b facing in the circumferential direction, and a groove bottom portion 49c along the radial direction. The groove side surfaces 49 a, 49 b and 49 c are groove inner surface portions for providing the oil groove 49 with a depth.

  In the illustrated example, the depth of the oil groove 49 is made constant throughout, but the depth of the oil groove may vary. For example, the oil groove has a cross-sectional shape along the circumferential direction, that is, a cross section along the circumferential direction. It may be constituted by a pair of groove side surfaces forming a V shape.

  The oil groove 49 has a constant width W2 from the outer diameter (outer peripheral portion 47) to the inner diameter (inner peripheral portion 46) of the second annular portion 42. The width W2 of the oil groove 49 is the shortest distance between an arbitrary point on the edge of the groove side surface 49a and the edge of the groove side surface 49b.

  The width W2 of the oil groove 49 is less than or equal to half of the maximum diameter D2 of the tapered roller 10. The maximum diameter D2 of the tapered roller 10 is the maximum diameter of the rolling surface 13.

  A virtual plane Pax that bisects the pocket 43 in the circumferential direction is shown in FIG. The virtual plane Pax is a virtual plane including a bearing center axis (not shown) and passes through the center in the circumferential direction of the pocket inner side surface 48a. When the central axis CL of the tapered roller 10 shown in FIG. 1 is on the virtual plane Pax in FIG. The projection position of the periphery of 12 is shown by a two-dot chain line in FIG. The maximum circumferential length of the large end surface 12 in the roller circumferential direction is on the periphery indicated by a two-dot chain line.

  As can be seen from the fact that the entire oil groove 49 is accommodated inside the two-dot chain line, the entire oil groove 49 faces the large end face 12 of the tapered roller 10. In other words, the entire oil groove 49 is provided at a position facing the large end surface 12 in the roller central axis direction.

  As shown in FIGS. 2 and 3, the oil groove 49 extends from the outer diameter (outer peripheral portion 47) of the second annular portion 42 toward the inner diameter (inner peripheral portion 46) and gradually approaches the column portion 44. Yes. For this reason, the oil groove 49 is projected from the outer peripheral portion 47 of the second annular portion 42 toward the inner peripheral portion 46 in the peripheral projection of the large end surface 12 as compared with the case where the oil groove extending straight along the virtual plane Pax is adopted. Moving away from the position (on the two-dot chain line) is suppressed.

  The second annular portion 42 has a plurality of oil grooves 49 for each pocket 43. In the illustrated example, two oil grooves 49 are included in the pocket inner surface 48a.

  The plurality of oil grooves 49 are symmetrical with respect to the virtual plane Pax. Each distance between the virtual plane Pax and each oil groove 49 existing on both sides in the circumferential direction with the virtual plane Pax as a boundary gradually increases from the outer peripheral portion 47 of the second annular portion 42 toward the inner peripheral portion 46. . In other words, the greater the oil groove 49 is, the closer to the inner peripheral portion 46, the closer to the pillar portion 44 closer to itself among the pillar portions 44 located on both sides in the circumferential direction of the pocket 43. The distance from the peripheral projection position (on the chain double-dashed line) is suppressed.

  The tapered roller bearing 1 is used in a splashing or oil bath lubrication system. During the operation of the bearing, the lubricating oil supplied from the outside easily enters the oil groove 49 from the inner diameter side or the outer diameter side of the second annular portion 42 (see FIGS. 1 and 2). Since all of these oil grooves 49 pass through a region on the pocket inner side surface 48a facing the central axis in the large end surface 12 of the tapered roller 10, the pocket inner side portion 48a and the large end surface are opposed to the region facing the oil groove 49. 12, the amount of lubricating oil (indicated by a dot pattern in FIG. 1) is easily retained, and as a result, the amount of lubricating oil adhering to the large end surface 12 near the pocket inner side surface 48a increases. . In addition, as the viscosity of the lubricating oil is higher as at the beginning of the resumption of operation, the lubricating oil is more easily held between the large end surface 12 and the oil groove 49. Lubricating oil adhering to the large end surface 12 near the pocket inner side surface 48 a is carried to the large collar portion 22 of the inner ring 20 as the tapered roller 10 rotates in the circumferential direction of the roller. Therefore, the amount of lubricating oil supplied to the sliding contact portion between the large collar portion 22 and the large end surface 12 also increases. As a result, insufficient lubrication between the large collar portion 22 and the large end face 12 is prevented even in an environment where the amount of lubricating oil supplied to the tapered roller bearing 1 is small, as in the beginning of resumption of operation.

  Further, since the oil groove 49 passes through the pocket inner side surface 48a of the second annular portion 42, there is no increase in lubricating oil that collides with the rolling surface 13 of the tapered roller 10 (that is, there is no increase in stirring resistance). The increase in the rotational torque of the tapered roller bearing 1 can be avoided.

  Further, in the region where the oil groove 49 and the large end surface 12 are opposed, the space between the pocket inner side surface 48a and the large end surface 12 becomes wider. Therefore, compared with the case where there is no oil groove 49, the pocket inner side surface 48a and the large end surface 12 The shear resistance of the lubricating oil generated during this period is reduced. This also leads to a reduction in rotational torque of the tapered roller bearing 1.

  Thus, the tapered roller bearing 1 increases the amount of lubricating oil adhering to the large end surface 12 of the tapered roller 10 by the oil groove 49 provided in the pocket inner surface 48a of the second annular portion 42 of the retainer 40 to increase the inner ring 20. It is possible to increase the amount of lubricating oil supplied to the sliding contact portion between the large collar portion 22 and the large end surface 12, and to reduce the shear resistance of the lubricating oil generated between the pocket inner side surface 48 a and the large end surface 12. Since reduction can be achieved, insufficient lubrication between the large collar portion 22 and the large end face 12 at the beginning of resumption of operation can be prevented while avoiding an increase in bearing rotational torque.

  Further, in the tapered roller bearing 1, since all of the oil groove 49 passes through the position facing the large end surface 12 in the roller central axis direction, the oil groove 49 can be used without waste to prevent the above-described insufficient lubrication. Can do.

  When the tapered roller 10 rolls in the revolution direction and the large end surface 12 rotates in the roller circumferential direction, the lubricating oil is sheared between the oil groove 49 and the large end surface 12 in the rotation direction. According to the rotational direction of the tapered roller 10, in the oil groove 49 on one side in the circumferential direction with the imaginary plane Pax as a boundary, the lubricating oil is dragged toward the large flange portion 22 side of the inner ring 20, and the oil on the other side in the opposite circumferential direction In the groove 49, the lubricating oil is dragged toward the outer ring 30 side. In the tapered roller bearing 1, the second annular portion 42 has a plurality of oil grooves 49 for each pocket 43, and the oil grooves 49 are symmetrical with respect to a virtual plane Pax that bisects the pocket 43 in the circumferential direction. (See FIG. 2), there is no difference in the retention and supply performance of the lubricating oil by the plurality of oil grooves 49 regardless of the revolution direction of the tapered roller 10, and similarly the above-described lack of lubrication is prevented. be able to.

  Further, the tapered roller bearing 1 has an oil groove 49 extending from the outer peripheral portion 47 of the second annular portion 42 toward the inner peripheral portion 46 in a direction of gradually approaching the column portion 44. The oil groove 49 can be prevented from moving away from the peripheral projection position (on the two-dot chain line in FIG. 2) of the large end surface 12 toward the peripheral portion 46, and the lubricating oil can be easily supplied to the large end surface 12.

  Further, the tapered roller bearing 1 has a roller guide surface 45 in which the column portion 44 is in contact with the rolling surface 13 of the tapered roller 10 in the circumferential direction, and the radial width W1 of the roller guide surface 45 is that of the rolling surface 13. Since it is 1/3 or less of the minimum diameter, the shear resistance of the lubricating oil between the roller guide surface 45 and the rolling surface 13 can be suppressed.

  In the first embodiment, an example in which all of the oil groove 49 passes through the position facing the large end surface 12 in the roller central axis direction is shown. However, the oil groove 49 is changed so that at least a part of the oil groove passes through the facing position. Even if such a change is made, it is possible to increase the amount of lubricating oil adhering to the large end face 12.

  A second embodiment of the present invention will be described with reference to FIG. In the following, only the differences from the first embodiment will be described, and the same names will be used for the components corresponding to the first embodiment.

  As shown in FIG. 5, the second annular portion 50 of the second embodiment has only one oil groove 53 for each pocket 51. FIG. 5 shows a cross section of the column portion 44 on a virtual radial plane perpendicular to the bearing center axis (not shown), and shows an appearance of the vicinity of the pocket 51 of the second annular portion 50 viewed from the axial direction. Yes.

  In the second embodiment, there is only one oil groove 53 for each pocket 51, and the difference in the retention and supply performance of the lubricating oil by the oil groove 53 is caused by the difference in the revolution direction of the tapered roller. This is suitable when the bearing rotation direction is limited to one direction.

  A third embodiment of the present invention will be described with reference to FIG. FIG. 6 shows the same cross section and appearance, although the cutting position is different from FIG.

  As shown in FIG. 6, the second annular portion 60 of the third embodiment has an oil groove 61 extending in an arc shape. The oil groove 61 has curved groove side surfaces 61a and 61b that bend to the same side as the periphery (indicated by a two-dot chain line in the drawing) of the large end surface 12 of the tapered roller. That is, the center of curvature of the groove side surface 61a on one side is closer to the center of the large end surface 12 with the groove side surface 61a as a boundary. The center of curvature of the opposite groove side surface 61b is also the same.

  When the large end surface 12 rotates in the roller circumferential direction during the bearing operation, the flow direction of the lubricating oil passing through the oil groove 61 is changed by the groove side surfaces 61a and 61b of the oil groove 61 that bend in the same direction as the rotation direction of the roller 10. Therefore, the lubricating oil in the oil groove 61 is wound around the rotating large end surface 12 as compared with the first embodiment or the second embodiment in which the oil groove has a linear shape. It will be easy to reach the vase (see Fig. 1). For this reason, 3rd embodiment can make it easier to supply lubricating oil to the sliding contact part of the said big end surface 12 and the large collar part of an inner ring | wheel.

  The groove side surfaces 61a and 61b may have a single arc surface shape or a complex curved surface shape in which a plurality of arc surfaces are smoothly connected. In the illustrated example, the groove side surfaces 61 a and 61 b on both sides of the oil groove 61 are curved. However, considering the adhesion to the large end surface 12, at least the groove side surface 61 a near the periphery of the large end surface 12 is curved. Preferably, only one side may be curved.

  A fourth embodiment of the present invention will be described with reference to FIG. 7 shows the same cross section and appearance, although the cutting position is different from FIG.

  As shown in FIG. 7, in the second annular portion 70 of the fourth embodiment, the width W <b> 2 of the oil groove 71 gradually decreases toward the inner peripheral surface of the second annular portion 70. This width change is realized by inclining the direction in which the opposite groove side surface 71b extends to the groove side surface 71a side with respect to the direction in which the groove side surface 71a on one side extends.

  When the large end surface (see FIG. 1) of the tapered roller rotates in the roller circumferential direction during the bearing operation, the lubricating oil existing between the oil groove 71 and the large end surface is in the rotation direction, for example, the clock in FIG. Sheared around. Then, in the oil groove 71 on the right side in FIG. 7, the lubricating oil is dragged in the clockwise direction toward the inner peripheral surface side (that is, the inner ring side) of the second annular portion 70. Since the width W2 of the oil groove 71 is gradually reduced toward the inner peripheral surface of the second annular portion 70, the lubricating oil hardly flows out from the oil groove 71 to the inner ring side. Therefore, 4th embodiment can make it easier to hold | maintain lubricating oil between the oil groove 71 and the said big end surface (refer FIG. 1).

  The tapered roller bearing according to the above-described embodiment is preferably used as a tapered roller bearing for automobiles. Specifically, the tapered roller bearing according to the above-described embodiment is used to support a rotating shaft of a power transmission device of an automobile, and supplies lubricating oil from the outside to the inside of the bearing by splashing or oil bath lubrication. Suitable for use. The usage example of the above-mentioned tapered roller bearing will be described with reference to FIGS. FIG. 8 shows an example of an automobile differential.

  The differential shown in FIG. 8 has a drive pinion 104 rotatably supported by two tapered roller bearings 102 and 103 with respect to the housing 101, a ring gear 105 meshing with the drive pinion 104, and the ring gear 105 attached thereto. A differential gear case 107 rotatably supported with respect to the housing 101 by a tapered roller bearing 106, a pinion 108 disposed in the differential gear case 107, and a pair of side gears 109 meshing with the pinion 108 These are housed in a housing 101 in which gear oil is enclosed. This gear oil also serves as a lubricating oil for the tapered roller bearings 102, 103, and 106, and is supplied to the bearing side surface by splashing or oil bath lubrication. Each tapered roller bearing 102, 103, 106 corresponds to any of the above-described embodiments.

  Another example of use of the above tapered roller bearing will be described with reference to FIG. FIG. 9 shows an example of an automobile transmission.

  The transmission shown in FIG. 9 is a multi-stage transmission that changes the gear ratio step by step. The rolling bearings 203 to 208 that rotatably support the rotation shafts (for example, the input shaft 201 and the output shaft 202) are described above. The tapered roller bearing according to any one of the embodiments is provided. The illustrated transmission includes an input shaft 201 to which engine rotation is input, an output shaft 202 provided in parallel with the input shaft 201, and a plurality of gear trains 209 to 212 that transmit the rotation from the input shaft 201 to the output shaft 202. And a clutch (not shown) incorporated between each of the gear trains 209 to 212 and the input shaft 201 or the output shaft 202. The transmission switches the gear trains 209 to 212 to be used by selectively engaging a clutch, and changes the transmission gear ratio transmitted from the input shaft 201 to the output shaft 202. The rotation of the output shaft 202 is output to the output gear 213, and the rotation of the output gear 213 is transmitted to a differential gear or the like. The input shaft 201 and the output shaft 202 are rotatably supported by corresponding tapered roller bearings 203 and 204 or tapered roller bearings 205 and 206, respectively. In this transmission, the lubricating oil is applied to the side surfaces of the tapered roller bearings 203 to 208 by splashing of the lubricating oil (mission oil) accompanying the rotation of the gear.

  The tapered roller bearings 102, 103, 106, 203 to 208 illustrated in FIGS. 8 and 9 use any of the tapered roller bearings shown in FIGS. Therefore, while avoiding an increase in bearing rotation torque due to the agitation resistance and shear resistance of the lubricating oil supplied to the inside of the bearing by splashing or oil bath lubrication in the transmission or differential, the inner ring large collar and cone Since it is possible to prevent insufficient lubrication between the large end faces of the rollers, it is possible to cope with the use of low-viscosity lubricating oil and a reduction in the amount of oil, which in turn contributes to lower fuel consumption by reducing the power loss of automobiles. be able to.

  It should be thought that embodiment disclosed this time is an illustration and restrictive at no points. Accordingly, the scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 10 Tapered roller 11 Small end surface 12 Large end surface 13 Rolling surface 20 Inner ring 21 Raceway surface 22 Large collar part 30 Outer ring 40 Cage 41 First annular part 42, 50, 60, 70 Second annular part 43, 51 Pocket 44 Column part 45 Roller guide surface 46 Inner peripheral portion 47 Outer peripheral portion 48 Connecting portion 48a Pocket inner side surface 49, 53, 61, 71 Oil groove 49a, 49b, 61a, 61b, 71a, 71b Groove side surface 1, 102, 103, 106, 203- 208 Tapered roller bearing

Claims (8)

A tapered roller having a small end surface, a large end surface and a rolling surface;
An inner ring having a raceway surface provided on the outer periphery and a large collar portion for guiding the large end surface of the tapered roller;
An outer ring having a raceway surface provided on the inner periphery, and disposed coaxially with the inner ring;
A cage formed of resin;
With
The cage includes a first annular portion, a second annular portion having a diameter larger than that of the first annular portion, and a plurality of columns that divide the first annular portion and the second annular portion into pockets. And
The tapered roller is accommodated in the pocket in a posture in which the large end surface is directed to the second annular portion side;
An oil groove penetrating from the outer diameter to the inner diameter is provided on the inner surface of the pocket forming the pocket in the second annular portion,
A tapered roller bearing, wherein at least a part of the oil groove is opposed to the large end surface of the tapered roller.   The tapered roller bearing according to claim 1, wherein all of the oil grooves are opposed to the large end surface of the tapered roller. The second annular portion has a plurality of the oil grooves for each pocket,
The tapered roller bearing according to claim 1 or 2, wherein the plurality of oil grooves are symmetrical with respect to a virtual plane that bisects the pocket in the circumferential direction.   4. The tapered roller bearing according to claim 1, wherein the oil groove extends in a direction of gradually approaching the column portion from the outer diameter to the inner diameter of the second annular portion. 5.   The tapered roller bearing according to any one of claims 1 to 4, wherein the oil groove has a curved groove side surface that bends in a rotating direction of the tapered roller.   The tapered roller bearing according to any one of claims 1 to 5, wherein the oil groove has a constant width from an outer diameter to an inner diameter of the second annular portion.   The tapered roller bearing according to any one of claims 1 to 6, wherein a width of the oil groove is not more than half of a maximum diameter of the tapered roller.   The column portion has a roller guide surface that is in circumferential contact with the rolling surface of the tapered roller, and the radial width of the roller guide surface is equal to or less than 1/3 of the minimum diameter of the rolling surface. The tapered roller bearing according to any one of claims 1 to 7.

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