JP2019031991A - Conical roller bearing - Google Patents

Abstract

To avoid increase in rotational torque of a conical roller bearing, and prevent deficiency of lubrication between a large flange part of an inner ring and a large end surface of a conical roller in operation start.SOLUTION: A holder 40 has an annular oil guide passage 49 configured to guide lubricant to a large-diameter side of the holder on an inner diameter surface 47 of a column part 43, and an oil hole part 50 penetrating to the oil guide passage 49 from a width surface 45 of a small-diameter side annular part 41. In the oil guide passage 49 and the oil hole part 50, lubricant is held by surface tension in resting of the holder 40, and the lubricant is supplied to a large end surface 32 of a conical roller 30 in operation start.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a tapered roller bearing.

  Tapered roller bearings may be used in applications that support rotating shafts of various mechanical devices such as automobile transmission shafts and differential shafts. For lubrication inside the bearing, an oil lubrication system in which liquid lubricating oil is supplied from the outside of the bearing is generally used. 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 contacts and guides the large end surface of the tapered roller during operation. Since the sliding contact portion between the large brim 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 if the lubricating oil is insufficient in the sliding contact portion.

  During operation, a sufficient amount of lubricating oil is supplied to the large brim portion and the large end face of the tapered roller. The lubricating oil adhering to the large brim portion or the large end surface of the tapered roller during operation gradually flows down due to gravity after the operation is stopped, but it 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. For example, when the time until the operation restarts is long, the lubricating oil may flow down from the large end face or the large brim portion of the tapered roller, and there may be a lack of lubricating oil 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 will decrease. The lubrication environment in the part becomes severe. When the amount of oil is reduced, in tapered roller bearings, the lubricating oil easily enters the bearing from between the cage and the inner ring due to the pump action that occurs inside the bearing during operation. Since it is easy to flow and come out of the bearing, the lubricating oil is difficult to reach the large brim portion.

  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 to 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, for example, it is conceivable to form an oil passage in the cage as in Patent Document 1 or 2 (Patent Documents 1 and 2).

  The oil passage of the tapered roller bearing disclosed in Patent Document 1 includes a hole that passes through the inside of the pillar portion from the width surface on the small diameter side of the cage to the width surface on the large diameter side of the cage. It faces the large collar part of the inner ring at the exit of the width surface. A part of the lubricating oil applied to the width surface on the small diameter side of the cage is guided to the width surface on the large diameter side by the oil passage and supplied to the vicinity of the large collar portion of the inner ring. According to this oil passage, the amount of oil supplied to the vicinity of the large collar portion of the inner ring can be increased while avoiding an increase in the shear resistance of the lubricating oil between the tapered roller and the circumferential side surface of the column portion during operation.

  The oil passage of the tapered roller bearing disclosed in Patent Document 2 is from a groove portion that communicates from the inner peripheral end portion of the small-diameter side annular portion of the cage through the inner diameter surface of the column portion to the vicinity of the large-diameter side annular portion of the cage. Therefore, it faces the large collar surface of the inner ring at the end of the groove near the large-diameter annular portion. A part of the lubricating oil flowing between the small-diameter side annular portion of the cage and the small-diameter side of the inner ring is guided to the large-diameter side annular portion by the oil passage and supplied to the vicinity of the large collar portion of the inner ring. According to this oil passage, during operation, while avoiding an increase in the shear resistance of the lubricating oil between the tapered roller and the circumferential side surface of the column portion, the small diameter side annular portion of the cage is changed from the small diameter side annular portion to the large diameter side annular portion inside the bearing. The flow of lubricating oil can be promoted, and the amount of oil supplied to the vicinity of the large collar portion of the inner ring can be increased.

JP 2016-23733 A JP-A-2015-102134

  However, since the tapered roller bearing of Patent Document 1 has a through hole shape in which the entire oil passage is inclined to a cone angle of a column portion and has a large hole diameter, the lubricating oil is not supplied to the oil passage after the operation is stopped. This causes a problem that the lubricating oil cannot be supplied to the vicinity of the large collar portion of the inner ring immediately after the start of operation.

  Further, the tapered roller bearing disclosed in Patent Document 2 has a narrow gap between the small-diameter-side annular portion and the small-diameter side of the inner ring, and between the small-diameter-side annular portion and the small-diameter side of the outer ring. It is possible to reduce the agitation resistance inside the bearing because it restricts the inflow of lubricating oil. However, in automobile transmissions, etc., which tend to reduce the amount of oil, the amount of oil inside the bearing becomes very small, and the column part Even if the flow of the lubricating oil is promoted by the oil passage on the inner diameter surface of the inner ring, there is a possibility of insufficient lubrication at the sliding contact portion between the large collar portion of the inner ring and the tapered roller.

  Recently, the use of aluminum housing as a housing to support the outer ring of tapered roller bearings for weight reduction has increased the amount of bearing misalignment, and to tapered roller bearings to reduce bearing rotational torque. Due to the reduction in bearing rigidity associated with reducing the preload of the roller, the behavior of the tapered roller becomes unstable during bearing operation, and there is a further concern about insufficient lubrication at the sliding portion of the inner ring collar and the tapered end of the tapered roller. ing.

  In addition, when the temperature of the lubricating oil is low, the viscosity of the lubricating oil supplied into the bearing is high and its fluidity is poor, which makes it difficult for the lubricating oil to reach between the large collar portion of the inner ring and the large end face of the tapered roller. There is a particular concern about insufficient lubrication at the sliding contact portion.

  In view of the above background, the problem to be solved by the present invention is to prevent 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 at the start of operation while avoiding an increase in rotational torque. To provide a tapered roller bearing suitable for the purpose.

  To achieve the above object, the present invention comprises an inner ring, an outer ring, a plurality of tapered rollers interposed between the inner ring and the outer ring, and a resin cage that holds the tapered rollers, The inner ring includes a raceway surface on which the tapered roller rolls, and a large brim portion that is provided on a large diameter side of the raceway surface and is in sliding contact with the large end surface of the tapered roller, and the cage includes the inner ring. An annular portion located between the small-diameter side of the outer ring and the small-diameter side of the outer ring, and a plurality of pillars extending from the annular portion to the large-diameter side of the inner ring and the large-diameter side of the outer ring, A width surface exposed in the axial direction from between a small diameter side of the inner ring and a small diameter side of the outer ring, and an inner diameter surface of the pillar portion facing the raceway surface of the inner ring includes a large diameter side of the cage A groove-shaped oil guiding path for guiding lubricating oil is formed, and the cage has the width of the annular portion. An oil hole through which the lubricating oil flows is formed through the oil guiding path, and the lubricating oil is held in the oil guiding path and the oil hole by surface tension when the cage is stationary. It is a tapered roller bearing that is possible.

  According to the above configuration, during the operation of the bearing, the external lubricating oil is sucked from the small diameter side of the inner ring and the outer ring to the bearing inner side by the pump action inside the bearing. A part of the sucked lubricating oil easily enters the oil hole that opens in the width surface of the annular portion of the cage, and flows out through the oil hole to the oil guide path on the inner diameter surface of the column. The spilled lubricating oil flows through the groove-shaped oil guiding path by the above-described pump action and centrifugal action. Since the lubricating oil flowing through the oil guide path is guided to the large diameter side of the cage, the lubricating oil is easily supplied to the sliding contact portion between the large collar portion of the inner ring and the large end surface of the tapered roller. Insufficient lubrication is prevented. Here, since the lubricating oil flowing through the oil guide portion on the inner diameter surface of the oil hole and the column portion penetrating the inside of the cage is not subjected to shear from the tapered roller, it does not cause an increase in rotational torque. After the operation is stopped, the lubricating oil is held by the surface tension in the oil guide path and the oil hole of the stationary cage. For this reason, at the start of operation, the lubricating oil remaining in the oil guide path and the oil hole portion is supplied to the sliding contact portion at an early stage. This prevents insufficient lubrication at the sliding contact portion at the start of operation.

  For example, the oil guide passage has a terminal portion having a shape in which the groove width is increased toward the larger diameter side of the cage, and the pillar portion is a lubricating oil guided to the terminal portion of the oil guide passage. It is good to have the open end which can supply to the said big end surface of the said tapered roller. In this way, the lubricating oil is easily diffused in the circumferential direction by the terminal portion of the oil guide path, and the lubricating oil that has flowed out from the terminal portion is easily supplied from the open end portion of the column portion to the large end surface of the tapered roller, Lubricating oil adhering to the large end surface is easily supplied to the sliding contact portion with the large collar portion of the inner ring by the rotation of the tapered roller.

  In the present invention, as described above, more lubrication is provided to the large end surface of the tapered roller by the oil hole portion opened in the annular portion on the small diameter side of the cage and the oil guide path formed in the inner diameter surface of the column portion. Oil is supplied and seizure resistance is improved. For this reason, by reducing the gap between the annular portion on the small diameter side of the cage and the small diameter side of the inner ring and the small diameter side of the outer ring and restricting the flow of lubricating oil into the bearing, the stirring resistance is reduced. However, the sliding contact portion between the large collar portion of the inner ring and the large end surface of the tapered roller can be sufficiently lubricated.

  For example, the inner ring further includes a small brim portion provided on the small diameter side of the raceway surface of the inner ring and surrounded by the annular portion of the retainer, and between the small brim portion and the annular portion. The gap is set to a dimension of 1.5% or less with respect to the outer diameter of the small brim portion. If it does in this way, it can control that lubricating oil outside a bearing flows into the inside of a bearing from between the small diameter side of an inner ring and the annular part of a cage, and can reduce stirring resistance.

  For example, the gap between the annular portion of the cage and the small diameter side of the outer ring is set to a size of 2.0% or less with respect to the small diameter side inner diameter of the outer ring. If it does in this way, it can suppress that lubricating oil outside a bearing flows in into the inside of a bearing from between the small diameter side of an outer ring and the annular part of a cage, and can reduce stirring resistance.

  The oil guide path and the oil hole portion may have any shape in which the lubricating oil remains in the oil guide path and the oil hole portion while the cage is in a stationary state after the operation is stopped.

  For example, all of the oil hole portions of the cage have a shape along the axial direction. This makes it difficult for the lubricating oil to flow down the oil hole when the operation is stopped, so that the lubricating oil tends to remain in the oil hole.

  For example, the oil hole portion of the cage has a shape that increases toward the larger diameter side of the cage. If it does in this way, the capacity | capacitance of an oil hole part can be increased and more lubricating oil can be hold | maintained in an oil hole part.

  For example, the entire oil guide path of the cage has a shape in which the groove width is increased toward the larger diameter side of the cage. If it does in this way, the capacity | capacitance of an oil guideway can be increased and more lubricating oil can be hold | maintained in an oil guideway.

  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. For example, it is suitable for supporting a transmission shaft for an automobile or a rotating shaft of a differential. 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 start of 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 prevents 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 at the start of operation while avoiding an increase in rotational torque of the tapered roller bearing. As a result, the seizure resistance can be improved when using a low-viscosity lubricating oil or reducing the amount of oil.

Sectional drawing which shows the tapered roller bearing which concerns on 1st embodiment of this invention The partial enlarged view which shows an external appearance when the oil guide path of the cage | basket of FIG. 1 is seen from radial inside. Partial sectional view showing a cage according to a second embodiment of the present invention The figure which shows the metal mold | die part which shape | molds the cage | basket part of FIG. The partial enlarged view which shows the oil guide path of the holder | retainer which concerns on 3rd embodiment of this invention similarly to FIG. Sectional drawing which shows an example of the differential for motor vehicles incorporating the tapered roller bearing which concerns on this invention Sectional drawing which shows an example of the transmission for motor vehicles incorporating the tapered roller bearing which concerns on this invention

  Hereinafter, a tapered roller bearing according to a first embodiment of the present invention will be described with reference to FIGS. 1 and 2 of the accompanying drawings.

  The tapered roller bearing shown in FIG. 1 includes an inner ring 10, an outer ring 20, a plurality of tapered rollers 30 interposed between the inner ring 10 and the outer ring 20, and a cage 40 that holds the plurality of tapered rollers 30. .

  In FIG. 1, the central axes (not shown) of the inner ring 10, the outer ring 20, and the cage 40 are coaxial. The axis which becomes the coaxial rotation center is a bearing central axis (not shown) of the tapered roller bearing. 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”. FIG. 1 shows a cross section on a virtual axial plane including a bearing central axis (not shown) of a tapered roller bearing.

  The inner ring 10 is composed of an annular raceway that is continuous in the entire circumference in the circumferential direction, and has a conical raceway surface 11, a large brim portion 12, and a small brim portion 13 on the outer circumference thereof. The outer diameter of the small brim portion 13 located on the small diameter side with respect to the raceway surface 11 is smaller than the outer diameter of the large brim portion 12 located on the large diameter side with respect to the raceway surface 11. The large collar portion 12 guides the tapered roller 30 in the circumferential direction and receives an axial load from the tapered roller 30. The small collar portion 13 supports the tapered roller 30 so as not to be separated from the inner ring 10 in an assembly constituted by the inner ring 10, the cage 40, and the plurality of tapered rollers 30.

  Here, in consideration of the positional relationship in the axial direction, when the axial position on the raceway surface 11 having the average diameter of the raceway surface 11 of the inner ring 10 is a boundary, among both side surfaces that define the width of the inner ring 10, The inner ring portion that exists in the axial direction from the side surface with the smaller outer diameter (left side surface in the figure) to the boundary is called the small diameter side of the inner ring 10, and the side surface with the larger outer diameter (right side surface in the figure) The inner ring portion existing in the axial range from the boundary to the boundary is referred to as the large diameter side of the inner ring 10.

  The outer ring 20 is formed of an annular raceway that is continuous in the entire circumference, and has a conical raceway surface 21 on the inner circumference thereof. The outer ring 20 is disposed coaxially with the inner ring 10.

  Here, considering the positional relationship in the axial direction, when the axial position on the raceway surface 21 having the average diameter of the raceway surface 21 of the outer ring 20 is a boundary, The outer ring portion existing in the axial range from the side surface with the smaller inner diameter (left side surface in the figure) to the boundary is referred to as the small diameter side of the outer ring 20, and the side surface with the larger inner diameter (right side surface in the figure) The outer ring portion existing in the axial range up to the boundary is referred to as the large diameter side of the outer ring 20.

  The tapered roller 30 includes a rolling element having a small end surface 31, a large end surface 32, and a rolling surface 33. The diameter of the small end surface 31 is smaller than the diameter of the large end surface 32. The rolling surface 33 is formed in a conical shape that can come into line contact with the raceway surface 11 of the inner ring 10 and the raceway surface 21 of the outer ring 20. The rolling surface 33 is connected to the small end surface 31 and the large end surface 32 through a chamfered portion. The small end surface 31 is supported by the small brim portion 13 of the inner ring 10. The large end surface 32 is in sliding contact with the large collar portion 12 of the inner ring 10 and is guided in the circumferential direction by the large collar portion 12.

  The large end surface 32 of the tapered roller 30 and the large collar portion 12 of the inner ring 10 are brought into contact with each other by preloading. During the bearing operation, the tapered roller 30 is interposed between the raceway surface 11 of the inner ring 10 and the raceway surface 21 of the outer ring 20 on the rolling surface 33 and revolves between the raceway surfaces 11 and 21 while rotating.

  Friction portions between the tapered roller 30 that contacts the inside of the bearing surrounded by the outer periphery of the inner ring 10 and the inner periphery of the outer ring 20 and the inner ring 10 and the outer ring 20 are lubricated by lubricating oil supplied from the outside of the bearing. . The lubricating oil supply method is the above-described splash lubrication method or oil bath lubrication method.

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

  As shown in FIGS. 1 and 2, the retainer 40 is constant in the circumferential direction between the small-diameter-side annular portion 41, the large-diameter-side annular portion 42, and the small-diameter-side annular portion 41 and the large-diameter-side annular portion 42. It has a plurality of column parts 43 divided into intervals, and is formed of an annular bearing part that can accommodate the tapered roller 30 in a squirrel-cage pocket 44. In addition, although the cage 40 illustrated the cage-type cage, the cage 40 may be changed to a so-called comb-shaped cage that does not have the large-diameter side annular portion.

  Here, in consideration of the axial positional relationship, when the axial position that bisects the length of the axial column 43 is a boundary, the cage 40 extends from the leftmost end in the figure to the boundary. The cage portion existing in the axial range is called the small diameter side of the cage 40, and the cage portion existing in the axial range from the rightmost end of the cage 40 to the boundary is the large diameter of the cage 40. The side.

  The number of pockets 44 in the cage 40 is the same as the total number of tapered rollers 30 disposed between the raceway surface 11 of the inner ring 10 and the raceway surface 21 of the outer ring 20. The tapered roller 30 is accommodated in the pocket 44 in a posture in which the large end surface 32 faces the large diameter side of the cage 40.

  The cage 40 rotates while maintaining a predetermined interval in the circumferential direction between the tapered rollers 30 during the bearing operation. The cage 40 is usually of a so-called rolling element guide type that is guided in the radial direction by the tapered roller 30.

  The small diameter side annular portion 41 of the retainer 40 is located between the small diameter side of the inner ring 10 and the small diameter side of the outer ring 20. The small diameter side annular portion 41 surrounds the small collar portion 13 of the inner ring 10. The large diameter side annular portion 42 of the cage 40 surrounds the large collar portion 12 on the large diameter side of the inner ring 10. The outer diameter of the large-diameter side annular portion 42 is larger than the outer diameter of the small-diameter side annular portion 41. The pillar portion 43 of the cage 40 extends from the small-diameter side annular portion 41 to the large-diameter side of the inner ring 10 and the large-diameter side of the outer ring 20.

  The small-diameter-side annular portion 41 has a width surface 45 that is exposed in the axial direction from between the small-diameter side of the inner ring 10 and the small-diameter side of the outer ring 20. The large-diameter-side annular portion 42 has a width surface 46 that is exposed in the axial direction at a position surrounding the large collar portion 12 of the inner ring 10. Each of the width surfaces 45 and 46 has a planar shape along the radial direction, and has two side surfaces that define the width of the cage 40.

  A gap δi is set between the small-diameter side annular portion 41 of the cage 40 and the small collar portion 13 of the inner ring 10. The small-diameter-side annular portion 41 has a shape protruding radially inward from a region overlapping the column portion 43 in the axial direction in order to narrow the gap δi. The dimension of the gap δi is set to 1.5% or less with respect to the outer diameter of the small brim portion 13. Thereby, the lubricating oil outside the bearing is less likely to flow between the small diameter side of the inner ring 10 and the cage 40 through the gap δi. The outer diameter of the small brim portion 13 corresponds to the protruding height in the radial direction of the small brim portion 13 with respect to the raceway surface 11.

Further, a gap δo is set between the small-diameter-side annular portion 41 of the cage 40 and the small-diameter side of the outer ring 20. The small-diameter side annular portion 41 and the column portion 43 have a series of outer diameter surface portions along the raceway surface 21 of the outer ring 20 in order to narrow the gap δo. The dimension of the gap δo is set to 2.0% or less with respect to the inner diameter of the outer ring 20 on the small diameter side. Thereby, the lubricating oil outside the bearing is less likely to flow between the small diameter side of the outer ring 20 and the cage 40 through the gap δo. The inner diameter on the small diameter side of the outer ring 20 corresponds to the smallest inner diameter in the inner peripheral portion of the outer ring 20 that faces the small diameter side annular portion 41 in the radial direction.

  The column portion 43 includes a part of the cage 40 that connects the small-diameter side annular portion 41 and the large-diameter side annular portion 42. The column portion 43 has an inner diameter surface 47 that faces the raceway surface 11 of the inner ring 10 in the radial direction, and a pair of circumferential side surfaces 48 that face the tapered roller 30 adjacent to the column portion 43 in the circumferential direction. All of the column portions 43 are located closer to the outer ring 20 than the pitch circle diameter of the tapered rollers 30.

  The circumferential side surface 48 of the column part 43 has a roller guide region that can contact the rolling surface 33 of the tapered roller 30 in the circumferential direction. Of the circumferential side surface 48 of the column part 43, the radial width of the region that can contact the rolling surface 33 of the tapered roller 30 in the circumferential direction is 1/3 or less of the minimum diameter of the rolling surface 33. preferable. Thereby, the shear resistance of the lubricating oil between the rolling surface 33 of the tapered roller 30 and the circumferential side surface 48 of the column part 43 is suppressed. In addition, this radial direction width | variety is on the contact position on the pillar part 43 which contacts the rolling surface 33 of the tapered roller 30 on the innermost radial direction, and on the pillar part 43 which contacts the rolling surface 33 on the outermost radial direction. It corresponds to the distance in the radial direction between the contact position.

  The inner diameter surface 47 of the column portion 43 faces the tapered roller 30 in the circumferential direction only at the inner diameter edge e that is a boundary with the circumferential side surface 48. The inner diameter surface 47 of the column portion 43 has a shape inclined toward the outer ring 20 toward the larger diameter side of the cage 40.

  The inner diameter surface 47 of the column part 43 has a groove-shaped oil guide path 49 that guides the lubricating oil to the larger diameter side of the cage 40. The retainer 40 further includes an oil hole portion 50 penetrating from the width surface 45 of the small diameter side annular portion 41 to the oil guide path 49. As will be described later, lubricating oil flows into the oil hole portion 50 from the outside of the bearing, and the lubricating oil flows to the oil guide path 49.

  The oil guide path 49 of the pillar portion 43 communicates from the small diameter side to the large diameter side of the pillar portion 43 through the circumferential central portion of the inner diameter surface 47. Most of the oil guide path 49 continues from the starting end located on the small diameter side of the column part 43 to the large diameter side of the column part 43 with a constant groove width w1, and has a constant depth from the inner diameter edge e of the inner diameter surface 47. Have

  The oil guide path 49 has a terminal portion 51 having a shape in which the groove width is increased toward the larger diameter side of the cage 40. The end portion 51 of the oil guide path 49 has a groove width w2 that is larger than the groove width w1, and is gradually separated in the circumferential direction toward the larger diameter side of the cage 40 and gradually becomes shallower. The end portion 51 of the oil guide path 49 is located closer to the small-diameter side annular portion 41 than the large end surface 32 of the tapered roller 30, and the end of the column portion 43 on the large-diameter side (the connection portion with the large-diameter side annular portion 42). ) Not reached.

  The lubricating oil that has entered the oil guide path 49 flows through the oil guide path 49 toward the larger diameter side of the cage 40 and reaches the end portion 51. The flow direction of the lubricating oil guided to the end portion 51 of the oil guide path 49 gradually becomes closer to the circumferential direction. For this reason, the end portion 51 of the oil guide path 49 makes it easier for the lubricating oil to diffuse in the circumferential direction.

  The column portion 43 has an open end portion 52 having a shape opened in the circumferential direction between the terminal end portion 51 of the oil guide path 49 and the end on the large diameter side of the column portion 43. The open end 52 of the pillar 43 has a shape that is open on both sides in the circumferential direction.

  Since the lubricating oil guided to the terminal end portion 51 of the oil guide path 49 is changed in the flow direction toward the tapered roller 30 side, it goes from the open end portion 52 of the column portion 43 to the vicinity of the large end surface of the tapered roller 30, A part of the lubricating oil is supplied to the large end surface 32 of the tapered roller 30. The lubricating oil adhering to the large end surface 32 of the tapered roller 30 is easily supplied to the sliding contact portion with the large collar portion 12 of the inner ring 10 by the rotation of the tapered roller 30.

  The open end portion 52 of the column portion 43 has a flat portion that continues from the end portion 51 of the oil guide passage 49 along the axial direction. For this reason, the momentum of the lubricating oil flowing out from the terminal end portion 51 of the oil guiding path 49 is weakened by hitting the open end portion 52 of the column portion 43, and from the open end portion 52 to the vicinity of the large end surface 32 of the tapered roller 30. It becomes easy to diffuse and as a result, it becomes easy to adhere to the large end face 32.

  The oil hole portion 50 includes a flow path that communicates from the region overlapping the column portion 43 in the axial direction to the oil guide passage 49 in the small diameter side annular portion 41. The oil hole portion 50 has an inlet formed in the width surface 45 of the small-diameter side annular portion 41 and an outlet formed so as to intersect the starting end portion of the oil guide path 49. The oil hole portion 50 forms a hole penetrating in the axial direction with a constant hole diameter. It is set to a dimension equivalent to the groove width w1 of the oil guide path 49.

  Lubricating oil can be held in the oil guide path 49 and the oil hole 50 by surface tension when the cage 40 is stationary. That is, during the operation of the bearing, the lubricating oil whose viscosity has been lowered by the temperature rise flows from the oil hole portion 50 to the oil guiding path 49. When the operation is stopped, the lubricant is prevented from flowing out of the oil guide path 49 and the oil hole 50 by gravity due to the surface tension of the lubricant existing in the oil guide path 49 and the oil hole 50. For this reason, lubricating oil remains in the oil guide path 49 and the oil hole 50. Thereafter, during the operation stop, the retainer 40 is in a stationary state. As time elapses from the stop of operation, the temperature of the lubricating oil remaining in the oil guide passage 49 and the oil hole portion 50 decreases, and the viscosity of the lubricating oil increases. For this reason, the lubricating oil is more likely to remain in the oil guide passage 49 and the oil hole portion 50. The geometric parameters such as the groove width w1, the groove depth, and the gradient that define the shape of the oil guide passage 49, and the geometric parameters such as the hole diameter and the penetration direction that define the shape of the oil hole portion 50 are determined depending on the operation. What is necessary is just to determine that lubricating oil is hold | maintained at the oil guide path 49 and the oil hole part 50 of the holder | retainer 40 in a stationary state with the surface tension of the lubricating oil at the upper limit oil temperature sometimes permitted. Ideally, the lubricating oil may remain in a state where the oil guiding path 49 and the oil hole 50 are filled.

  Specifically, the entire oil hole 50 has a shape along the axial direction. Since the oil hole part 50 consists only of the surface which does not have a gradient with respect to an axial direction, at the time of an operation stop, it becomes difficult for the lubricating oil remaining in the oil hole part 50 to flow down the oil hole part 50 by gravity.

  Further, when the width of the inner diameter surface 47 of the pillar portion 43 is W, the hole diameter of the oil hole portion 50 is preferably 25% or more and 60% or less of the width W of the inner diameter surface 47. With such a thin oil hole 50, when the bearing is stopped, the lubricating oil adheres entirely to the oil hole 50, and the lubricating oil is substantially not put into the oil hole 50 while the cage 40 is in a stationary state. Remains full. Here, the width W of the inner diameter surface 47 is, for example, 1.5 to 2.5 mm.

  In particular, if the hole diameter of the oil hole portion 50 is 40% or less of the width W of the inner diameter surface 47, when the cage 40 is in a stationary state, a capillary phenomenon occurs in the oil hole portion 50, and the width surface of the small diameter side annular portion 41 The lubricating oil adhering to 45 and the lubricating oil adhering to the oil guide path 49 are sucked into the oil hole portion 50, and the oil hole portion 50 is easily filled with the lubricating oil.

  Further, the groove width w1 of the oil guide path 49 is preferably 25% or more and 60% or less of the width W of the inner diameter surface 47. With such a thin oil guide path 49, when the bearing is stopped, the lubricating oil adheres to the oil guide path 49 against the gradient of the oil guide path 49, and the oil guide is provided while the retainer 40 is in a stationary state. Lubricating oil remains in the path 49 in a substantially full state.

  The entire cage 40 is integrally formed of synthetic resin. The synthetic resin may be, for example, a fiber reinforced resin containing reinforced fibers. Whether or not the surface properties of the oil guide path 49 and the oil hole 50 are oleophilic greatly affects the adhesion of the lubricating oil. For example, the oil guide path 49 and the oil hole portion 50 may be made oleophilic by selecting the lipophilicity of the synthetic resin forming the cage 40 and selecting the modifier added to the synthetic resin.

  The tapered roller bearing shown in FIG. 1 is as described above. During the operation of the bearing, external lubricating oil is sucked from the small diameter side of the inner ring 10 and the outer ring 20 toward the bearing inside. A part of the sucked lubricating oil easily enters the oil hole portion 50 opened in the width surface 45 of the small-diameter side annular portion 41 of the retainer 40 (the flow of lubricating oil is conceptually indicated by an arrow line in FIG. 1). Show.) In particular, in the tapered roller bearing of the present embodiment, by defining the dimensions of the gap δi and the gap δo as described above, the lubricating oil outside the bearing is placed between the small diameter side of the inner ring 10 and the cage 40, and between the outer ring 20 and the outer ring 20. It is difficult to flow between the small diameter side and the retainer 40 and easily flows into the oil hole 50. Then, the lubricating oil that has entered the oil hole portion 50 flows through the oil hole portion 50 to the oil guide path 49 in the inner diameter surface 47 of the column portion 43. The lubricating oil that has flowed out flows through the groove-shaped oil guide path 49 by the action of the pump and the centrifugal force. Since the lubricating oil flowing through the oil guide path 49 is guided along the groove shape to the large diameter side of the retainer 40, the sliding contact portion between the large collar portion 12 of the inner ring 10 and the large end surface 32 of the tapered roller 30 during the bearing operation. Lubricating oil is easily supplied to the sliding contact portion, and insufficient lubrication at the sliding contact portion is prevented.

  Further, since the lubricating oil flowing through the oil hole 50 penetrating the inside of the cage 40 and the oil guiding path 49 of the inner diameter surface 47 of the column part 43 is not subjected to shear from the tapered roller 30, it does not cause an increase in rotational torque. .

  After the operation is stopped, the lubricating oil is held in the oil hole portion 50 and the oil guide path 49 of the stationary retainer 40. For this reason, at the start of operation (initially when operation is resumed), first, the lubricating oil remaining in the oil guide passage 49 is supplied to the sliding contact portion at an early stage, and further, the lubricating oil remaining in the oil hole portion 50 passes through the oil guide passage 49. It is supplied to the aforementioned sliding contact portion. This prevents insufficient lubrication at the sliding contact portion at the start of operation.

  Therefore, the tapered roller bearing shown in FIG. 1 prevents insufficient lubrication at the sliding contact portion between the large collar portion 12 of the inner ring 10 and the large end surface 32 of the tapered roller 30 at the start of operation while avoiding an increase in rotational torque. The seizure resistance can be improved.

  Further, the tapered roller bearing shown in FIG. 1 has a terminal portion 51 having a shape in which the oil guide path 49 is enlarged in the groove width (w1, w2) toward the larger diameter side of the cage 40, and the column portion 43 Since it has an open end 52 that can supply the lubricating oil guided to the end portion 51 to the large end surface 32 of the tapered roller 30, the end portion 51 of the oil guide path 49 makes it easy for the lubricating oil to diffuse in the circumferential direction. Lubricating oil flowing out from the end portion 51 is easily supplied from the open end portion 52 of the column portion 43 to the large end surface 32 of the tapered roller 30, and the lubricating oil adhering to the large end surface 32 is increased by the rotation of the tapered roller 30. It becomes easy to be supplied to the sliding contact portion with the collar portion 12.

  Further, in the tapered roller bearing shown in FIG. 1, the gap δi between the small collar portion 13 of the inner ring 10 and the small-diameter side annular portion 41 of the cage 40 is 1.5% with respect to the outer diameter of the small collar portion 13. Since the following dimensions are set, the lubricating oil outside the bearing is prevented from flowing into the bearing from between the small collar portion 13 of the inner ring 10 and the small-diameter side annular portion 41 of the retainer 40, and the stirring resistance is reduced. Can be reduced.

  Further, in the tapered roller bearing shown in FIG. 1, the gap δo between the small diameter side annular portion 41 of the cage 40 and the small diameter side of the outer ring 20 is 2.0% or less with respect to the small diameter inner diameter of the outer ring 20. Therefore, the lubricating oil outside the bearing can be prevented from flowing into the bearing from between the small diameter side of the outer ring 20 and the small diameter side annular portion 41 of the retainer 40, and the stirring resistance can be further reduced. it can.

  The tapered roller bearing shown in FIG. 1 has a shape in which all of the oil holes 50 of the cage 40 extend along the axial direction, so that it is difficult for the lubricating oil to flow down the oil holes 50 when the operation is stopped. Tends to remain in the oil hole portion 50.

  A second embodiment of the present invention will be described with reference to FIGS. In the following, only differences from the first embodiment will be described.

The cage 60 of the second embodiment shown in FIG. 3 is different from the first embodiment only in that the shape of the oil hole portion 63 communicating from the small diameter side annular portion 61 to the oil guide path 62 is changed. That is, the hole diameter d _{2 at} the outlet of the oil hole 63 intersecting the oil guide path 62 is larger than the hole diameter d _{1 at} the inlet of the oil hole 63. The oil hole portion 63 has a shape that gradually increases from the inlet having the hole diameter d _{1 to} the outlet having the hole diameter d ₂ toward the larger diameter side of the cage 60. The half of the oil hole 63 on the inner diameter side of the cage has a shape along the axial direction, and the half of the oil hole 63 on the outer diameter side of the cage gradually increases in the radial direction toward the larger diameter side of the cage 60. Thus, the hole diameter change of the oil hole portion 63 is realized.

  The retainer 60 shown in FIG. 3 has a shape in which the oil hole portion 63 becomes larger toward the larger diameter side of the retainer 60, and therefore the first embodiment in which all of the oil hole portions have a shape along the axial direction. In comparison, the capacity of the oil hole 63 can be increased, and more lubricating oil can be held in the oil hole 63.

  The cage 60 shown in FIG. 3 has a shape in which all of the oil guide path 62 and the oil hole portion 63 are opened in the axial direction toward the large diameter side of the cage 60, so as shown in FIG. It can be formed by two divided molds M10 and M20. In other words, in the mold M20 on the right side of the drawing, when the protruding surface M22 that is radially increased from the tapered surface M21 that transfers both circumferential ends of the inner diameter surface of the column portion is provided, the oil of FIG. The shape of the guide path 62 can be transferred. Further, a rod-like portion M23 protruding in the axial direction from the projecting surface M22 is provided in the mold M20, and when the tip of the rod-like portion M23 abuts on the side end surface M11 of the mold M10 on the left side in the drawing, the rod-like portion M23 It is possible to transfer the oil hole 63 of FIG.

  Since the retainer 60 of the second embodiment has a shape in which the hole diameter of the oil hole portion 63 is enlarged from the inlet to the outlet toward the larger diameter of the retainer, the rod-shaped portion M23 of FIG. 4 has a draft. For this reason, compared with 1st embodiment, 2nd embodiment has an advantage which is easy to pull out the rod-shaped part M23 when mold M10 and M20 of FIG. 4 are released.

  A third embodiment of the present invention will be described with reference to FIG. The cage 70 according to the third embodiment is different from the first embodiment only in that the shape of the oil guide path 71 is changed. That is, the entire oil guide path 71 has a shape in which the groove width is increased toward the larger diameter side of the cage 70. The groove width w3 in the vicinity of the oil hole 50 of the oil guide path 71 is not much different from that in the first embodiment, but the groove width w4 in the vicinity of the terminal end 72 of the oil guide path 71 is smaller than that in the first embodiment. It is about 1.5 times. A range of the oil guide path 71 closer to the oil hole 50 than the terminal end 72 has a shape in which the groove width is enlarged at a constant rate of change. The end portion 72 of the oil guide path 71 has a shape in which the groove width is enlarged at a rate of change larger than the above-described constant rate of change.

  The retainer 70 of the third embodiment has a shape in which the groove width is enlarged toward the larger diameter side of the retainer 70, so that the oil guide path 71 of the retainer 70 of the third embodiment is larger than that of the first embodiment. The capacity can be increased and more lubricating oil can be held in the oil guide path 71. In addition, you may employ | adopt the oil guide path 71 of 3rd embodiment in 2nd embodiment.

  The tapered roller bearing according to each of the embodiments described above 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. An example of use of the above tapered roller bearing will be described with reference to FIG. FIG. 6 shows an example of an automobile differential.

  The differential shown in FIG. 6 includes 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. 7 shows an example of an automobile transmission.

  The transmission shown in FIG. 7 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.

  In the illustrated transmission, the gear trains 209 to 212 to be used are switched by selectively engaging a clutch, and the transmission gear ratio transmitted from the input shaft 201 to the output shaft 202 is changed. 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, and 203 to 208 illustrated in FIGS. 6 and 7 use the tapered roller bearings according to any of the first to third embodiments described above. 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 large collar portion and the cone of the inner ring at the start of operation are avoided. 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 in the amount of oil. 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 Inner ring 11 Raceway surface 12 Large brim part 13 Small brim part 20 Outer ring 30 Tapered roller 32 Large end surface 40, 60, 70 Retainer 41, 61 Annular part 43 Pillar part 45 Width face 47 Inner diameter face 49, 62, 71 Oil guide path 50 , 63 Oil hole portions 51, 72 Terminal portion 52 Open end portions 102, 103, 106, 203-208 Tapered roller bearing

Claims (8)

An inner ring, an outer ring, a plurality of tapered rollers interposed between the inner ring and the outer ring, and a resin cage that holds the tapered rollers,
The inner ring has a raceway surface on which the tapered roller rolls, and a large brim portion that is provided on the large diameter side of the raceway surface and is in sliding contact with the large end surface of the tapered roller,
The retainer includes an annular portion located between a small diameter side of the inner ring and a small diameter side of the outer ring, and a plurality of pillar portions extending from the annular portion to the large diameter side of the inner ring and the large diameter side of the outer ring. Have
The annular portion includes a width surface that is exposed in the axial direction from between the small diameter side of the inner ring and the small diameter side of the outer ring,
A groove-shaped oil guide path for guiding lubricating oil to the large diameter side of the cage is formed on the inner diameter surface of the pillar portion facing the raceway surface of the inner ring,
The retainer is formed with an oil hole portion through which the lubricating oil flows from the width surface of the annular portion to the oil guide path,
A tapered roller bearing in which the lubricating oil can be held in the oil guide path and the oil hole portion by surface tension when the cage is stationary.   The oil guide path has a terminal portion having a shape in which the groove width is increased toward the large diameter side of the cage, and the column portion receives the lubricating oil guided to the terminal portion of the oil guide path. The tapered roller bearing according to claim 1, wherein the tapered roller bearing has an open end that can be supplied to the large end face of the tapered roller.   The inner ring further includes a small collar portion provided on the small diameter side of the raceway surface of the inner ring and surrounded by the annular portion of the cage, and a gap between the small collar portion and the annular portion is provided. The tapered roller bearing according to claim 1, wherein a dimension of 1.5% or less is set with respect to the outer diameter of the small collar portion.   The clearance gap between the said annular part of the said holder | retainer and the small diameter side of the said outer ring | wheel is set to the dimension of 2.0% or less with respect to the internal diameter of the small diameter side of the said outer ring | wheel. The tapered roller bearing according to item 1.   The tapered roller bearing according to any one of claims 1 to 4, wherein all of the oil hole portions of the retainer have a shape along an axial direction.   The tapered roller bearing according to any one of claims 1 to 5, wherein the oil hole portion of the cage has a shape that increases toward a larger diameter side of the cage.   The tapered roller bearing according to any one of claims 1 to 6, wherein all of the oil guide path of the cage has a shape in which a groove width is enlarged toward a larger diameter side of the cage.   The tapered roller bearing according to any one of claims 1 to 7, wherein the tapered shaft supports an automobile transmission or a differential rotating shaft.

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