JP2021143765A - Conical roller bearing - Google Patents

Abstract

To prevent insufficient lubrication between a large flange part of an inner ring and a large end surface of a conical roller at the beginning of restarting operation, while avoiding increase of rotation torque of a conical roller bearing.SOLUTION: In a second annular part 42 on a large diameter side of a cage-shaped holder 40, an oil groove 49 is formed on a pocket inside surface 48a forming a pocket 43, at a connection part 48 connecting an inner peripheral part 46 and an outer peripheral part 47. The oil groove 49 faces a large end surface 12 of a conical roller 10, and approaches a pillar part 44 on the side closer to itself as it approaches the inner peripheral part 46 of the second annular part 42. Consequently, lubricant is held between the oil groove 49 and the large end surface 12, and easily adheres to the large end surface 12.SELECTED DRAWING: Figure 1

Description

The present invention relates to tapered roller bearings.

For example, tapered roller bearings have been conventionally used in applications for supporting rotating shafts of various mechanical devices such as transmission shafts of automobiles and differential shafts. An oil lubrication method that uses liquid lubricating oil is generally used for lubrication inside the bearing. The lubricating oil can be supplied by a splash lubrication method in which the lubricating oil is splashed onto the bearing by stirring the lubricating oil accompanying the rotation of the gear during operation of the mechanical device, or a part of the bearing in an oil bath. The oil bath lubrication method of immersing in water is common.

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

During operation, a sufficient amount of lubricating oil is supplied to the large collar and the large end face of the tapered roller. Lubricating oil adhering to the large collar or the large end surface of the tapered roller during operation gradually flows down due to gravity after the operation is stopped, but for a short time, it remains sufficiently in the sliding contact portion. Therefore, if the operation is restarted in a short time, there is no concern that the lubricating oil will be insufficient. If it takes a long time to restart the operation, the lubricating oil will flow down from the large end surface and the large flange of the tapered roller, and at the beginning of the restart of the operation, the lubricating oil will be insufficient at the sliding contact portion.

Further, the lower the viscosity of the lubricating oil during operation, or the smaller the amount of lubricating oil supplied to the inside of the bearing during operation, the more the large flange of the inner ring and the large end surface of the tapered roller are in sliding contact. The lubrication environment in the part becomes severe. In tapered roller bearings, the pumping action that occurs inside the bearing during operation makes it easier for lubricating oil to enter the inside of the bearing from between the cage and the inner ring, and centrifugal force causes the inside of the bearing to flow toward the outer ring side and escape to the outside of the bearing. .. Therefore, if the amount of oil is reduced, it becomes difficult for the lubricating oil to reach the large collar.

In particular, for tapered roller bearings used in automobile transmissions or differentials, reduction of bearing rotation torque has been required in recent years for the purpose of reducing fuel consumption of automobiles. As a means for reducing the bearing rotation torque, it is effective to suppress the stirring 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 flange 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 guide portions, and these oil guide portions are described above. Lubricating oil flowing inside the bearing is guided to the inner ring side by the pumping action of. In such a tapered roller bearing, the bearing rotation torque can be reduced by reducing the weight of the cage, and further, the oil guide portion makes the sliding contact portion between the large flange portion of the inner ring and the large end surface of the tapered roller. Lubricating oil can be easily supplied.

Japanese Unexamined Patent Publication No. 2008-45711

However, in the tapered roller bearing disclosed in Patent Document 1, when the lubricating oil is supplied to the large end surface or the large flange side of the tapered roller through the oil guide portion of the column portion, the lubricating oil is rolled by the tapered roller. Contact the moving surface. That is, since the amount of lubricating oil that collides with the rolling surface of the tapered roller that revolves during operation increases, there is a problem that the stirring resistance increases and the bearing rotation torque increases.

Further, when a plurality of oil guide portions are formed on the pillar portion of the cage, the radial width of the pillar portion becomes large. Along with this, the roller guide surface that comes into contact with the tapered rollers in the circumferential direction also expands in the radial direction, so that the lubricating oil generated between the rolling surface of the tapered rollers and the roller guide surface of the column portion. The shear resistance of the bearing increases, which also causes an increase in bearing rotation torque.

Recently, the adoption of an aluminum housing that supports the outer ring of the tapered roller bearing has increased the amount of misalignment of the bearing, and the reduction of the preload applied to the tapered roller bearing to reduce the bearing rotation torque has reduced the bearing rigidity. As a result, the behavior of the tapered rollers during operation becomes unstable, and there is a growing concern about insufficient lubrication between the large bearing of the inner ring and the sliding contact portion of the large end face of the tapered rollers.

In addition, at the beginning of restarting the operation, the temperature of the lubricating oil is low, the viscosity of the lubricating oil supplied to the inside of the bearing is high, and the fluidity is poor. It becomes a difficult condition, and there is a particular concern about insufficient lubrication at the sliding contact portion. This concern is especially pronounced in cold regions (eg, in cryogenic environments such as -40 ° C to -30 ° C).

In view of the above 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 initial stage of restarting the operation while avoiding an increase in the rotational torque of the tapered roller bearing. That is.

In order to achieve the above problems, the present invention presents a tapered roller having a small end surface, a large end surface, and a rolling surface, a raceway surface provided on the outer circumference, and a large flange portion for guiding the large end surface of the tapered roller. The cage includes an inner ring having a The tapered roller has a second annular portion having a diameter larger than that of the first annular portion, and a plurality of pillar portions that divide the first annular portion and the second annular portion into pockets. Is housed in the pocket with the large end surface facing the second annular portion side, and penetrates from the outer diameter to the inner diameter of the inner side surface of the pocket forming the pocket in the second annular portion. An oil groove is provided, and at least a part of the oil groove is opposed to the large end surface of the tapered roller.

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 facing the large end surface of the tapered roller, in the opposite region, the space between the inner surface of the pocket and the large end surface of the tapered roller is widened, and lubricating oil is provided. The amount of lubricating oil that adheres 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 and from the large collar of the inner ring as it rotates around the central axis of the tapered roller. Therefore, if the amount of lubricating oil adhering to the large end surface of the tapered roller increases near the inner surface of the pocket, 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 of the inner ring and the large end face of the tapered roller even in an environment where the amount of lubricating oil is small, such as when the operation is restarted.

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 the lubricating oil that collides with the rolling surface of the tapered roller (that is, there is no increase in stirring resistance). As a result, an increase in the rotational torque of the tapered roller bearing can be avoided.

Further, according to the above configuration, in the region where the oil groove on the inner surface of the pocket of the second annular portion and the large end surface of the tapered roller are opposed to each other, the space between the inner surface of the pocket and the large end surface of the tapered roller becomes wider, so that oil is used. 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 as compared with the case where there is no groove. This also leads to a reduction in the rotational torque of the tapered roller bearings.

Preferably, the entire oil groove may pass through a position facing the large end surface of the tapered roller. In this way, the oil groove can be utilized without waste and the above-mentioned insufficient lubrication can be prevented.

In the present invention, the number of oil grooves in each pocket does not matter.

For example, the second annular portion has a plurality of the oil grooves for each pocket, and the plurality of oil grooves have a symmetrical shape with a virtual plane that bisects the pocket in the circumferential direction as a boundary. Can be mentioned. In this way, the above-mentioned insufficient lubrication can be similarly prevented regardless of the direction of revolution of the tapered rollers.

In the present invention, the oil groove may extend in a straight line in the radial direction, may be inclined, or may be curved. In any case, the larger the area where the large end surface of the tapered roller and the oil groove face each other in the central axis direction of the tapered roller, the easier it is for the lubricating oil to adhere to the large end surface. Therefore, it is appropriate that the oil groove faces a large portion of the large end surface having a large peripheral length (peripheral length around the central axis of the tapered roller).

For example, the oil groove extends in a direction gradually approaching the pillar portion from the outer diameter of the second annular portion toward the inner diameter. By doing so, it is possible to prevent the oil groove from moving from the outer diameter to the inner diameter of the second annular portion from the peripheral projection position of the large end surface of the tapered roller, and to facilitate the supply of lubricating oil to the large end surface. can.

Further, 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 bearing operation, the direction in which the large end surface of the tapered roller rotates around the central axis of the tapered roller and the direction in which the lubricating oil flows through the oil groove are close to each other, so that the side surface of the oil groove is straight. Compared to the case of the shape, the lubricating oil is caught in the rotating large end surface and easily reaches the large bearing portion of the inner ring. Therefore, the lubricating oil is supplied to the sliding contact portion between the large bearing portion and the large end surface. It can be made easier.

In the present invention, the width of the oil groove may be constant or may change. In addition, the width of the oil groove takes into consideration the required lubrication performance at the sliding contact portion between the large end surface of the tapered roller and the large flange portion of the inner ring, the mechanical strength of the second annular portion, the difficulty of forming the oil groove, and the like. It may be decided appropriately.

For example, the oil groove may have a constant width from the outer diameter to the inner diameter of the second annular portion.

For example, the width of the oil groove may be less than half the maximum diameter of the tapered roller.

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

For example, the pillar portion has a roller guide surface that comes into contact with 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. Is mentioned. In this way, the shear resistance of the lubricating oil between the roller guide surface of the column portion and the rolling surface of the tapered roller can be suppressed as compared with the cage of Patent Document 1.

The tapered roller bearing according to the present invention is suitable for supporting a rotating shaft included in a power transmission path of an automobile, and is suitable for supplying lubricating oil from the outside to the inside of the bearing by a splash or oil bath lubrication method. be. The tapered roller bearing according to the present invention can prevent insufficient lubrication between the large flange of the inner ring and the large end face of the tapered roller at the initial stage of restarting operation, while avoiding an increase in the 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 the reduction of the amount of oil, which in turn reduces the power loss of the automobile and contributes to the reduction of fuel consumption.

According to the present invention, by adopting the above configuration, the amount of lubricating oil adhering to the large end surface of the tapered roller is increased in the oil groove provided on the inner surface of the pocket of the second annular portion of the cage, and the inner surface of the pocket and the large end surface of the tapered roller are increased. Since it is possible to reduce the shear resistance of the lubricating oil generated between and, while avoiding an increase in the rotational torque of the tapered roller bearings, between the large collar of the inner ring and the large end face of the tapered rollers at the beginning of operation restart. It is possible to prevent insufficient lubrication.

A cross-sectional view showing a tapered roller bearing according to the first embodiment of the present invention as a cut surface of the line I-I in FIG. Partial cross-sectional view showing the cage of FIG. 1 with a cut surface of line II-II in FIG. Partial perspective view showing the appearance of the cage of FIG. Partial plan view showing the appearance of the cage 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 cross-sectional view of the cage according to the fourth embodiment of the present invention. Sectional drawing which shows an example of the differential for automobiles which incorporated the tapered roller bearing which concerns on embodiment of this invention. Sectional drawing which shows an example of the transmission for automobiles which incorporated the tapered roller bearing which concerns on embodiment of this invention.

Hereinafter, the tapered roller bearing according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 4 of the attached drawings.

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. Note that FIG. 1 shows a cross section of the tapered roller bearing 1 on a virtual axial plane including the bearing central axis (not shown), and the position of the cross section is a position passing through the line II shown in FIG. 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 center of rotation of the coaxial cable is the bearing center 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 left-right direction in FIG. Further, the direction perpendicular to the bearing center axis is simply referred to as "diameter direction", and this radial direction corresponds to the vertical direction in FIG. Further, 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 raceway ring having a conical raceway surface 21 on the outer circumference thereof and a large flange portion 22 which is higher in the radial direction than the large diameter side of the raceway surface 21. The large collar portion 22 is a continuous portion all around the circumference along the circumferential direction.

The outer ring 30 is a raceway ring having a conical raceway surface 31 on the inner circumference thereof.

The tapered roller 10 is a rolling element having a small end surface 11, a large end surface 12, and a conical rolling surface 13 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 of the tapered roller 10 on the small diameter side, 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 side surface of the tapered roller 10 on the large diameter side, 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, and hereinafter, this direction is simply referred to as "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 surface 12 of the tapered roller 10 and the large flange portion 22 of the inner ring 20 are brought into contact with each other in the roller center axis direction due to the preload on the tapered roller bearing 1. During 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 while rotating. Roll on surfaces 21 and 31 (revolution of 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 each 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 first annular portion 41 and the second annular portion 42 into pockets 43. It has a plurality of pillar portions 44.

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

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

The second annular portion 42 is a cage portion 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 rollers 10. The pillar portion 44 is a cage portion extending between the first annular portion 41 and the second annular portion 42 so as to separate the adjacent pockets 43 and 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 arranged 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 housed in the pocket 43 with the large end surface 12 facing the second annular portion 42 side.

The cage 40 rotates while the column portion 44 keeps the circumferential distance between the tapered rollers 10 predetermined during the bearing operation. The cage 40 is of a so-called rolling element guidance system in which the cage 40 is guided in the radial direction by the tapered rollers 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 a considerable amount corresponding to the pocket clearance δ. It is drawn in the correct position. Of course, during the bearing operation, the raceway surface 31 of the outer ring 30 comes into contact with the rolling surface 13 of the tapered rollers 10. The range in which the cage 40 can move freely in the radial direction relative to the tapered roller 10 housed in the pocket 43 corresponds to the pocket clearance δ in the radial direction.

The pillar portion 44 has a roller guide surface 45 that comes into contact with the rolling surface 13 of the tapered roller 10 in the circumferential direction. The roller guide surface 45 may come into contact with the rolling surface 13 of the tapered roller 10 in the circumferential direction within the range of the pocket clearance δ described above. 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. The radial width W1 of the roller guide surface 45 is the contact position on the pillar portion 44 that comes into contact with the rolling surface 13 of the tapered roller 10 in the most radial direction, and the rolling surface 13 of the tapered roller 10 and the outermost radial width. It is a radial distance from the contact position on the column portion 44 in contact.

The second annular portion 42 has 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 all-around surface portion that surrounds the large flange portion 22 of the inner ring 20. The outer peripheral portion 47 of the second annular portion 42 is an all-around surface portion along the inner peripheral portion 46 in the circumferential direction. The connecting portion 48 of the second annular portion 42 has a pocket inner side surface 48a forming 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 48a has an oil groove 49 penetrating from the outer diameter of the second annular portion 42 to the inner diameter (from the outer peripheral portion 47 to the inner peripheral portion 46). As shown in FIGS. 2 to 4, all of the oil grooves 49 are open toward the pocket 43 side in the axial direction and are recessed in the axial direction. Such a shape of the oil groove 49 is preferable in that it can be transferred to one of the molds divided into two in the axial direction and does not include an undercut portion.

The oil groove 49 is composed of 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 49a, 49b, and 49c are groove inner surface portions for providing the depth of the oil groove 49.

In the illustrated example, the depth is constant for all of the oil grooves 49, but the depth of the oil grooves may be changed. It may be composed of 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 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.

FIG. 2 shows a virtual plane Pax that bisects the pocket 43 in the circumferential direction. The virtual plane Pax is a virtual plane including the bearing central axis (not shown), and passes through the center of the inner side surface of the pocket 48a in the circumferential direction. When the central axis CL of the tapered roller 10 shown in FIG. 1 is projected on the second annular portion 42 in the direction of the roller central axis at the position where the central axis CL of the tapered roller 10 is on the virtual plane Pax of FIG. 2, the large end surface 12 of the tapered roller 10 is projected onto the second annular portion 42. The projection position of the periphery of 12 is shown by a two-dot chain line in FIG. 2, and the two-dot chain line is designated by reference numeral 12. The maximum peripheral length of the large end surface 12 in the roller circumferential direction is on the peripheral edge indicated by the alternate long and short dash line.

As can be seen from the fact that the entire oil groove 49 is contained inside the alternate long and short dash line, the entire oil groove 49 faces the large end surface 12 of the tapered roller 10. In other words, all of the oil grooves 49 are provided at positions facing the large end surface 12 in the direction of the roller center axis.

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) in a direction gradually approaching the pillar portion 44. There is. Therefore, as compared with the case where the oil groove extending straight along the virtual plane Pax is adopted, the oil groove 49 is projected on the periphery of the large end surface 12 from the outer peripheral portion 47 to the inner peripheral portion 46 of the second annular portion 42. It is suppressed from moving away from the position (on the two-point chain line).

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 side surface 48a.

The plurality of oil grooves 49 have a symmetrical shape with the virtual plane Pax as a boundary. The distance between the virtual plane Pax and the oil grooves 49 existing on both sides in the circumferential direction with respect to the virtual plane Pax gradually increases from the outer peripheral portion 47 to the inner peripheral portion 46 of the second annular portion 42. .. That is, the closer each oil groove 49 is to the inner peripheral portion 46, the closer to the pillar portion 44 on the side closer to itself among the pillar portions 44 located on both sides in the circumferential direction of the pocket 43, so that the large end surface 12 It is suppressed from moving away from the peripheral projection position (on the two-point chain line) of.

The tapered roller bearing 1 is used in a splash or oil bath lubrication system. During the bearing operation, the lubricating oil supplied from the outside easily enters the oil grooves 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 the region on the inner side surface 48a of the pocket facing the central axial direction at the large end surface 12 of the tapered roller 10, in the facing region of the oil groove 49, the inner portion 48a of the pocket and the large end surface The space between the 12 and the 12 is widened, and a large amount of lubricating oil (indicated by a dot pattern in FIG. 1) is easily held. As a result, the amount of the lubricating oil adhering to the large end surface 12 increases near the inner side surface 48a of the pocket. .. Moreover, the higher the viscosity of the lubricating oil as at the beginning of restarting the operation, the easier it is for the lubricating oil to be held between the large end surface 12 and the oil groove 49. The lubricating oil adhering to the large end surface 12 near the inner side surface 48a of the pocket is carried between the large flange portion 22 of the inner ring 20 as the tapered roller 10 rotates in the circumferential direction. Therefore, the amount of lubricating oil supplied to the sliding contact portion between the large flange portion 22 and the large end surface 12 also increases. As a result, insufficient lubrication between the large flange portion 22 and the large end surface 12 can be prevented even in an environment where the amount of lubricating oil supplied to the tapered roller bearing 1 is small as in the initial operation restart.

Further, since the oil groove 49 passes through the inner side surface 48a of the pocket of the second annular portion 42, there is no increase in the 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 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 face each other, the space between the pocket inner side surface 48a and the large end surface 12 becomes wider, so that the pocket inner side surface 48a and the large end surface 12 are compared with those without the oil groove 49. The shear resistance of the lubricating oil generated during this period is reduced. This also leads to a reduction in the rotational torque of the tapered roller bearing 1.

As described above, in the tapered roller bearing 1, the amount of lubricating oil adhering to the large end surface 12 of the tapered roller 10 is increased in the oil groove 49 included in the pocket inner side surface 48a of the second annular portion 42 of the cage 40 to increase the amount of the lubricating oil 20. It is possible to increase the amount of lubricating oil supplied to the sliding contact portion between the large flange portion 22 and the large end surface 12, and the shear resistance of the lubricating oil generated between the inner side surface 48a of the pocket and the large end surface 12. Since it is possible to reduce the amount, it is possible to prevent insufficient lubrication between the large flange portion 22 and the large end surface 12 at the initial stage of restarting the operation while avoiding an increase in the bearing rotation torque.

Further, in this tapered roller bearing 1, since all of the oil grooves 49 pass through a position facing the large end surface 12 in the direction of the roller center axis, the oil grooves 49 can be utilized without waste to prevent the above-mentioned insufficient lubrication. Can be done.

Further, 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 in the rotation direction between the oil groove 49 and the large end surface 12. Depending on the rotation direction of the tapered roller 10, the lubricating oil is dragged toward the large flange 22 side of the inner ring 20 in the oil groove 49 on one side in the circumferential direction with the virtual plane Pax as a boundary, 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 these oil grooves 49 have a symmetrical shape with the virtual plane Pax that divides the pocket 43 into two equal parts in the circumferential direction as a boundary. Therefore, there is no difference in the holding and supply performance of the lubricating oil by the plurality of oil grooves 49 regardless of the revolving direction of the tapered roller 10 (see FIG. 2), and similarly, the above-mentioned insufficient lubrication is prevented. be able to.

Further, in the tapered roller bearing 1, since the oil groove 49 extends from the outer peripheral portion 47 of the second annular portion 42 toward the inner peripheral portion 46 in a direction gradually approaching the pillar portion 44, the oil groove 49 is inside from the outer peripheral portion 47. It is possible to prevent the oil groove 49 from moving toward the peripheral portion 46 from the peripheral projection position (on the two-point chain line in FIG. 2) of the large end surface 12, so that 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 comes into 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 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 is shown in which all of the oil grooves 49 pass through a position facing the large end surface 12 in the roller center axis direction, but at least a part of the oil grooves is changed so as to pass through the facing positions. However, even with such a change, it is possible to increase the amount of lubricating oil adhering to the large end surface 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. Note that FIG. 5 shows a cross section of the column portion 44 on a virtual radial plane perpendicular to the bearing central axis (not shown), and shows the appearance of the vicinity of the pocket 51 of the second annular portion 50 as viewed from the axial direction. There is.

In the second embodiment, there is only one oil groove 53 for each pocket 51, and the difference in the revolution direction of the tapered rollers causes a difference in the holding and supply performance of the lubricating oil by the oil groove 53, but the second annular portion 50 It is suitable when the reduction in the amount of wall material can be suppressed and the bearing rotation direction is limited to one direction.

A third embodiment of the present invention will be described with reference to FIG. Note that FIG. 6 shows a cross section and an appearance similar to those in FIG. 5, although the cutting position is different from that of 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 peripheral edge of the large end surface 12 of the tapered roller (indicated by the alternate long and short dash line in the figure). That is, the center of curvature of the groove side surface 61a on one side is on the side 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 groove side surface 61b on the opposite side is also the same.

When the large end surface 12 rotates in the roller circumferential direction during bearing operation, the direction of the lubricating oil flowing through the oil groove 61 is the roller due to the groove side surfaces 61a and 61b of the oil groove 61 that bends in the same direction as the rotation direction of the roller 10. Since the oil groove is closer to the rotation direction of 10, the lubricating oil of the oil groove 61 is caught in the rotating large end surface 12 as compared with the first embodiment or the second embodiment in which the groove side surface of the oil groove is linear, and the inner ring. It becomes easier to reach the large bearing (see Fig. 1). Therefore, in the third embodiment, it is possible to make it easier to supply the lubricating oil to the sliding contact portion between the large end surface 12 and the large flange portion of the inner ring.

The groove side surfaces 61a and 61b may have a single arcuate surface shape or a composite curved surface shape in which a plurality of arcuate surfaces are smoothly connected. Further, in the illustrated example, the groove side surfaces 61a and 61b on both sides of the oil groove 61 are curved, but considering the adhesion to the large end surface 12, at least the groove side surface 61a on the side close to the peripheral edge of the large end surface 12 is curved. It is preferably shaped, and only one side may be curved.

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

As shown in FIG. 7, in the second annular portion 70 of the fourth embodiment, the width W2 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 groove side surface 71b on the opposite side extends toward the groove side surface 71a with respect to the direction in which the groove side surface 71a on one side extends.

When the large end surface of the tapered roller (see FIG. 1) rotates in the roller circumferential direction during bearing operation, the lubricating oil existing between the oil groove 71 and the large end surface is released in the rotation direction, for example, the clock in FIG. It is sheared in the clockwise direction. 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 gradually decreases toward the inner peripheral surface of the second annular portion 70, it becomes difficult for the lubricating oil to flow out from the oil groove 71 to the inner ring side. Therefore, in the fourth embodiment, the lubricating oil can be more easily held between the oil groove 71 and the large end surface (see FIG. 1).

The tapered roller bearing according to the above-described embodiment is preferably used as a tapered roller bearing for an automobile. 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 applications. An example of using the tapered roller bearing described above will be described with reference to FIGS. 8 and 9. FIG. 8 shows an example of an automobile differential.

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

Another use example of the tapered roller bearing described above 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-speed transmission that changes the gear ratio stepwise, and is described above as rolling bearings 203 to 208 that rotatably support the rotating shafts (for example, the input shaft 201 and the output shaft 202). The tapered roller bearing according to any one of the embodiments of the above is provided. The transmission shown is an input shaft 201 into which the rotation of the engine is input, an output shaft 202 provided in parallel with the input shaft 201, and a plurality of gear trains 209 to 212 for transmitting 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 used by selectively engaging the clutch, and changes the gear ratio of rotation 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 the differential gear or the like. The input shaft 201 and the output shaft 202 are rotatably supported by the corresponding tapered roller bearings 203 and 204 or the tapered roller bearings 205 and 206, respectively. Further, in this transmission, the lubricating oil is splashed on the side surfaces of the tapered roller bearings 203 to 208 due to the splashing of the lubricating oil (transmission 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. 1 to 7. Therefore, while avoiding an increase in bearing rotation torque due to stirring resistance and shear resistance of the lubricating oil supplied to the inside of the bearing by splashing in the transmission or differential or by the oil bath lubrication method, the large flange and cone of the inner ring at the beginning of operation restart. 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 the reduction of the amount of oil, which in turn reduces the power loss of the automobile and contributes to lower fuel consumption. be able to.

The embodiments disclosed this time should be considered to be exemplary in all respects and not restrictive. Therefore, the scope of the present invention is indicated by the scope of claims rather than the above description, and it is intended that all modifications within the meaning and scope equivalent to the scope of claims are included.

10 Tapered roller 11 Small end surface 12 Large end surface 13 Rolling surface 20 Inner ring 21 Track 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 Pillar part 45 Roller guide surface 46 Inner circumference 47 Outer circumference 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 Bearings

Claims (9)

Tapered roller bearings with a small end face, a large end face, and a rolling surface,
An inner ring having a raceway surface provided on the outer circumference and a large flange portion for guiding the large end surface of the tapered roller.
An outer ring having a raceway surface provided on the inner circumference and arranged coaxially with the inner ring,
With a cage made of resin,
With
The cage has a plurality of pillars that divide the first annular portion, the second annular portion having a diameter larger than that of the first annular portion, and the first annular portion and the second annular portion into pockets. Has a part and
The tapered roller is housed in the pocket with the large end surface facing the second annular portion side.
A plurality of oil grooves passing through positions facing the large end surface of the tapered roller in the central axial direction are provided on the inner surface of the pocket forming the pocket in the second annular portion.
The oil grooves are present on both sides in the circumferential direction with the virtual plane that bisects the pocket in the circumferential direction, and each of these oil grooves approaches the inner peripheral portion of the second annular portion. A tapered roller bearing characterized in that it approaches the pillar portion on the side closer to itself among the pillar portions located on both sides in the circumferential direction of the pocket. The tapered roller bearing according to claim 1, wherein all of the oil grooves face the large end surface of the tapered roller. The second annular portion has a plurality of oil grooves for each pocket.
The tapered roller bearing according to claim 1 or 2, wherein the plurality of oil grooves have a symmetrical shape with a virtual plane that bisects the pocket in the circumferential direction as a boundary. The tapered roller bearing according to any one of claims 1 to 3, wherein the oil groove has a curved groove side surface that bends in the direction of rotation of the tapered roller. Tapered roller bearings with a small end face, a large end face, and a rolling surface,
An inner ring having a raceway surface provided on the outer circumference and a large flange portion for guiding the large end surface of the tapered roller.
An outer ring having a raceway surface provided on the inner circumference and arranged coaxially with the inner ring,
With a cage made of resin,
With
The cage has a plurality of pillars that divide the first annular portion, the second annular portion having a diameter larger than that of the first annular portion, and the first annular portion and the second annular portion into pockets. Has a part and
The tapered roller is housed in the pocket with the large end surface facing the second annular portion side.
An oil groove is provided on the inner surface of the pocket forming the pocket of the second annular portion so as to pass through a position facing the central axial direction of the large end surface of the tapered roller.
The oil groove is a tapered roller bearing characterized by having a curved groove side surface that bends in the direction of rotation 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 the outer diameter to the inner diameter of the second annular portion. The tapered roller bearing according to any one of claims 1 to 6, wherein the width of the oil groove is not more than half the maximum diameter of the tapered rollers. The pillar portion has a roller guide surface that comes into contact with 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. The tapered roller bearing according to any one of claims 1 to 7. Tapered roller bearings with a small end face, a large end face, and a rolling surface,
An inner ring having a raceway surface provided on the outer circumference and a large flange portion for guiding the large end surface of the tapered roller.
An outer ring having a raceway surface provided on the inner circumference and arranged coaxially with the inner ring,
With a cage made of resin,
With
The cage has a plurality of pillars that divide the first annular portion, the second annular portion having a diameter larger than that of the first annular portion, and the first annular portion and the second annular portion into pockets. Has a part and
The tapered roller is housed in the pocket with the large end surface facing the second annular portion side.
A plurality of oil grooves opening on the inner diameter side of the pocket are provided on the inner side surface of the pocket forming the pocket in the second annular portion.
A tapered roller bearing characterized in that the opening of the oil groove is located close to the pillar portion located on both sides in the circumferential direction of the pocket, and the oil groove extends from the opening toward the center in the circumferential direction of the pocket.

Images