JP2007309421A - Pre-load loss preventive structure of conical roller bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pre-load loss preventive structure of a conical roller bearing which prevents pre-load loss of the conical roller bearing even in a high temperature region. <P>SOLUTION: A biasing member 6 presses an end on an end surface 51 side of a first part 40 in a lever member 5 radially outward. A second part 41 in the lever member 5 presses a large end surface of an outer ring 2 to a small end surface side of the outer ring 2. By so doing, a substantially constant axial load is imposed on the large end surface of the outer ring 2 in the second part 41 so as to prevent the pre-load loss of the conical roller bearing 1 even in high temperature. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a structure for preventing preload loss of a tapered roller bearing, and in particular, a cone that rotatably supports a pinion shaft of a vehicle pinion shaft support device having a pinion shaft such as a differential gear device, a transaxle device, or a transfer device. The present invention relates to a preload loss prevention structure for a tapered roller bearing that is suitable for preventing preload loss of a roller bearing.

  2. Description of the Related Art Conventionally, in a differential gear device, in order to reduce the weight of the differential gear device, a housing of the differential gear device is made of aluminum. Some bearings that support the pinion shaft of the differential gear device employ a tapered roller bearing.

However, in the above-described conventional differential gear device, the linear expansion coefficient of aluminum, which is the material of the housing, is larger than the linear expansion coefficient of steel materials (bearing steel, etc.), which are the material of the race rings and rolling elements of the tapered roller bearing. In the region where the temperature of the tapered roller bearing is high, the difference between the expansion of the housing and the expansion of the bearing components (inner ring, outer ring, tapered roller) increases, and the force with which the housing presses the outer ring radially inward is predetermined. There is a problem that preload loss occurs in the tapered roller bearing because it becomes smaller than the force. Accordingly, there is a problem in that the tapered roller bearing has a large backlash in a region where the temperature of the tapered roller bearing is high, and the tapered roller bearing does not fulfill a predetermined supporting performance.
JP 2000-192978 A

  Accordingly, an object of the present invention is to provide a preload loss prevention structure for a tapered roller bearing in which the preload loss of the tapered roller bearing hardly occurs even in a high temperature region.

In order to solve the above-described problem, the preload drop prevention structure for the tapered roller bearing of the present invention is
An outer ring having a conical raceway surface;
An inner ring having a conical raceway surface;
A tapered roller disposed between the conical raceway surface of the outer ring and the conical raceway surface of the inner ring, and having a large end surface and a small end surface;
A lever member that is supported by a fulcrum and has a force point and an action point that presses the large end face toward the small end face.
A biasing member that applies a force in the radial direction to the power point;
It is characterized by having.

  According to the present invention, when the housing of the differential gear device or the like in which the outer ring is fitted is made of a material having a large linear expansion coefficient as compared with the materials of the outer ring, the inner ring, and the tapered roller, When the temperature is high, the lever member presses the large end face toward the small end face even when the force with which the housing presses the outer ring radially inward is smaller than a predetermined force. A force can be applied in the direction from the conical raceway surface of the outer ring to the conical raceway surface of the inner ring via the, so that the preload loss of the tapered roller bearing can be suppressed. Therefore, since the preload of the tapered roller bearing can be maintained substantially constant regardless of the temperature of the tapered roller bearing, the tapered roller bearing can exhibit a predetermined support capability regardless of the temperature of the tapered roller bearing.

  Further, according to the present invention, since the urging member applies a force in the radial direction, the axial direction of the preload loss prevention structure for the tapered roller bearing is smaller than that in the type in which the urging member applies a force in the axial direction. The dimensions can be reduced. More specifically, since the urging member applies a force in the radial direction, the urging member needs to be disposed in the axially adjacent portion of the outer ring where components such as a differential gear device are densely packed. For example, in a differential gear device or the like, the urging member can be arranged to expand and contract in the radial direction in a space that is not used. Therefore, since the unused space can be used effectively, a device such as a differential gear device having a preload loss prevention structure for the tapered roller bearing is not greatly increased due to the provision of the preload loss prevention structure.

  Further, according to the present invention, the force applied by the lever member to the large end surface of the outer ring can be easily adjusted by adjusting the distance between the fulcrum and the force point, adjusting the distance between the fulcrum and the action point, or the like. Therefore, the preload of the tapered roller bearing can be easily adjusted to a predetermined preload simply and precisely.

  In one embodiment of the preload loss prevention structure for the tapered roller bearing, the lever member has an L-shaped bent shape, and the fulcrum supports the bent portion of the lever member.

  According to the embodiment, the lever member has an L-shaped bent shape, and the fulcrum supports the bent portion of the lever member, so that one side of the bent portion is a boundary. By placing the lever member so that the biasing member is urged and the outer ring is pressed on the other side of the bent part, the space for the preload drop prevention structure of the tapered roller bearing is further increased. Can be small. Further, the outer ring can be efficiently pressed by the lever member.

  According to the preload loss prevention structure of the tapered roller bearing of the present invention, when the temperature of the tapered roller bearing is high, even if the force with which the housing presses the outer ring radially inward becomes smaller than a predetermined force, the lever member Presses the large end face of the tapered roller toward the small end face side, so that force can be applied from the conical raceway surface of the outer ring to the conical raceway surface of the inner ring via the tapered roller, and the preload of the tapered roller bearing is released. Can be suppressed.

  Further, according to the preload loss prevention structure for the tapered roller bearing of the present invention, the biasing member applies a force in the radial direction, so that the axial dimension of the preload loss prevention structure for the tapered roller bearing can be reduced. Further, since the urging member is structured to apply a force in the radial direction, the urging member does not need to be disposed in the axially adjacent portion of the outer ring where the components are densely packed. Can be efficiently arranged in a space that is not used in, for example, a differential gear device or the like. Therefore, since the unused space can be used effectively, a device such as a differential gear device having a preload loss prevention structure for the tapered roller bearing is not greatly increased due to the provision of the preload loss prevention structure.

  Further, according to the preload loss prevention structure of the tapered roller bearing of the present invention, the lever member is adjusted to the large end surface of the outer ring by adjusting the distance between the fulcrum and the force point, or adjusting the distance between the fulcrum and the action point. The applied force can be easily adjusted, and the preload of the tapered roller bearing can be easily and precisely adjusted to a predetermined preload.

  Hereinafter, the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a cross-sectional view in the axial direction of an embodiment of a preload loss prevention structure for a tapered roller bearing of the present invention. This structure for preventing the preload loss of the tapered roller bearing is a part of the differential gear device of the vehicle. In detail, FIG. 1 shows an axial section of the preload loss prevention structure of the tapered roller bearing in a state where the differential gear device is stopped (normal temperature state).

  The structure for preventing preload loss of the tapered roller bearing includes a tapered roller bearing 1, a lever member 5, a biasing member 6, a lever support member 20, and a housing member 22. The tapered roller bearing 1 includes an outer ring 2, an inner ring 3, and a tapered roller 4 as an example of a rolling element.

  The outer ring 2 is made of high carbon chromium bearing steel (SUJ2). The outer ring 2 has a conical track surface. The outer ring 2 is fitted into an inner peripheral surface 50 of an aluminum housing 8 of a differential gear device of a vehicle. A predetermined tightening allowance is set between the outer peripheral surface of the outer ring 1 and the inner peripheral surface 50 of the housing 8. With this tightening allowance, a predetermined radial load indicated by an arrow A in FIG. 1 is applied from the housing 8 to the outer ring 1 at a temperature in the vicinity of normal temperature (15 ° C. to 25 ° C.).

  The inner ring 3 is made of high carbon chromium bearing steel (SUJ2). The inner ring 3 has a conical track surface. The inner ring 3 is externally fitted on a pinion shaft (not shown) of the differential gear device. A plurality of the tapered rollers 4 are arranged between the conical raceway surface of the outer ring 2 and the conical raceway surface of the inner ring 3 while being held by a cage 9 and spaced apart at a constant interval in the circumferential direction. Yes.

  The lever support member 20 is fixed to the housing 8. Specifically, the housing 8 has an inner peripheral surface 50 extending in the axial direction and an end surface 51 bent from the inner peripheral surface 50 by 90 degrees and extending in the radial direction. Are fixed to the corners of the inner peripheral surface 50 and the end surface 51 of the housing 8.

  The lever support member 20 is an annular member and has a trapezoidal cross section. Specifically, the lever support member 20 has an outer peripheral surface, a small end surface, a large end surface substantially parallel to the small end surface, and a conical surface. The conical surface connects the radially inner edge of the small end surface and the radially inner edge of the large end surface. The center axis of the outer peripheral surface of the lever support member 20 substantially coincides with the center axis of the conical surface of the lever support member 20. The small end surface extends radially inward at one end of the outer peripheral surface of the lever support member 20 in the axial direction, while the large end surface of the lever support member 20 is the outer peripheral surface of the lever support member 20. The other end in the axial direction extends radially inward. The radial dimension of the small end surface of the lever support member 20 is smaller than the radial dimension of the large end surface of the lever support member 20.

  By pressing the outer peripheral surface of the lever support member 20 into the inner peripheral surface 50 of the housing member 8 until the small end surface of the lever support member 20 contacts the end surface 51 of the housing 8, the lever support member 20 is moved into the housing member. 8 is fixed.

  The lever member 5 has an L-shaped cross section. The lever member 5 has a first portion 40 and a second portion 41. The said 1st part 40 has a shape of a part of cylinder produced | generated when a pipe | tube is cut | disconnected by two different planes which pass the central axis of the cylinder. The second portion 41 has a plate shape and extends in the normal direction of the outer peripheral surface from one axial end portion of the outer peripheral surface of the first portion 40. A plurality of the lever members 5 are arranged at regular intervals in the circumferential direction.

  The intersecting line 14 between the bent portion of the lever member 5, that is, the outer peripheral surface of the first portion 40, and the end surface of the second portion 41 on the first portion 40 side is the conical surface of the lever support member 20 and a large diameter. It is supported by a fulcrum that is a line of intersection with the end face. The position of the intersection line 14 is fixed. In other words, the relative position of the intersection line 14 with respect to the housing 8 remains unchanged.

  Although not described in detail, for example, the lever member 5 can be rotated around the intersection line 14 and the relative position of the intersection line 14 with respect to the housing 8 is not changed in the following manner. That is, a protrusion extending in the circumferential direction is formed at a portion corresponding to the intersecting line 14 on the circumferential end face of the lever member 5, and this protrusion is rotated by a protrusion supporting portion protruding from the end face 51 of the housing 8. Support freely. In this manner, the relative position of the intersection line 14 with respect to the housing 8 is not changed, and the lever member 5 can be rotated around the intersection line 14.

  The housing member 22 is fixed to the end surface 51 of the housing 8. The housing member 22 has a linear groove 54 in which only one of the extending directions is closed. The side surface of the housing member 22 having the groove 54 is bonded to the end surface 51 of the housing 8. Further, the end of the groove 54 that is not closed faces outward in the radial direction. The groove 54 of the housing member 22 and the end surface 51 of the housing 8 define a housing space for housing the biasing member 6.

  The urging member 6 includes a rectangular parallelepiped pressing portion 30 and a coil spring 31 extending from a portion of the surface of the pressing portion 30 in the normal direction of the portion. The urging member 6 is accommodated in the accommodation space such that the pressing portion 30 is positioned radially outward from the coil spring 31.

  The pressing portion 30 is in contact with the end portion on the end surface 51 side of the first portion 40 of the lever member 5 in a state where the length of the coil spring 31 is shorter than the natural length of the coil spring 31. That is, the pressing portion 31 applies a force to the end of the first portion 40 on the end surface 51 side from the radially inner side of the outer ring 2 toward the radially outer side.

  Here, when the radial load acting on the outer ring 2 becomes a value smaller than a predetermined value, the end portion on the end surface 51 side of the first portion 40 receiving the radial outward force from the pressing portion 31 has a diameter. And the second portion 41 of the lever member 5 rotates around the intersection line 14 to move the large end surface of the outer ring 2 toward the small end surface side of the outer ring 2 in the axial direction. Yes. In this way, even if the radial load acting on the tapered roller bearing 1 at a high temperature is reduced, the axial load is applied to the outer ring 2 of the tapered roller bearing 1 from the large end surface to the small end surface side, thereby the tapered roller bearing. The preload applied to the is not lowered. The end portion on the end surface 51 side of the first portion 40 is a lever power point, and the second portion 41 of the lever member 5 is a lever action point.

  As shown in FIG. 1, when the differential gear device is in a stopped state (normal temperature state), that is, when the interference between the inner peripheral surface 50 of the housing 8 and the outer peripheral surface of the outer ring 2 is a predetermined value, A predetermined radial load indicated by an arrow A acts on the outer ring 2, and a predetermined axial load indicated by an arrow B acts on the outer ring 2.

  In this state, the second portion 41 of the lever member 5 is sandwiched between the large end surface of the lever support member 20 and the large end surface of the outer ring 2 without a gap. Further, in this state, the first portion 40 of the lever member 5 is in a state of extending in the axial direction, while the second portion 41 of the lever member 5 is in a state of extending in the radial direction. .

  FIG. 2 shows a cross section in the axial direction of the preload loss prevention structure of the tapered roller bearing in a state where the differential gear device is operating (high temperature state). For easy understanding, the displacement of the position of the lever member 5 in FIG. 2 with respect to the position of the lever member 5 in FIG. 1 is exaggerated. In FIG. 2, 15 indicates a power point in the high temperature state (portion in contact with the pressing portion 30 in the first portion 40), and 16 indicates an action point in the high temperature state (the outer ring 2 in the second portion 41). The part in contact with

  As shown in FIG. 2, in this embodiment, the temperature of the tapered roller bearing 1 is increased due to the rotation of the inner ring 3 of the tapered roller bearing 1, and the linear expansion coefficient of aluminum that is the material of the housing 8 is Even if a predetermined radial preload does not act on the outer ring 2 due to weakness of the fitting between the housing 8 and the outer ring 2 due to the linear expansion coefficient with the bearing steel that is the material of the outer ring 2. The large end surface of the outer ring 2 can be pressed with a substantially constant force by the second portion 41 of the lever member 5 by the outward expansion of the urging member 6 in the radial direction. Therefore, the preload portion of the tapered roller bearing 1 which is reduced due to the weakening of the fitting between the housing 8 and the outer ring 2 due to this pressing can be compensated, and the preload loss in the tapered roller bearing 1 can be prevented. Therefore, in this embodiment, even when the temperature of the tapered roller bearing 1 becomes high, the preload loss of the tapered roller bearing 1 does not occur. It can suppress that the support performance of a tapered roller bearing falls.

  According to the preload loss prevention structure of the tapered roller bearing of the above embodiment, the lever member 5 can press the large end surface of the outer ring 2 to the small end surface side of the outer ring 2 with a substantially constant force. When the temperature of the tapered roller bearing 1 is high, the radial load applied to the outer ring 2 is reduced due to the fact that the housing 8 is made of aluminum having a larger linear expansion coefficient than the bearing steel. Even if preload loss occurs in the tapered roller bearing 1 due to this, the force applied to the large end surface of the outer ring 2 by the lever member 5 causes the inner ring 3 to move from the conical raceway surface of the outer ring 2 via the tapered roller 4. A force can be applied toward the conical raceway surface, and preload loss of the tapered roller bearing 1 does not occur. Accordingly, since the preload loss of the tapered roller bearing 1 can be prevented in a region where the temperature of the tapered roller bearing 1 is high, rattling of the tapered roller bearing 1 can be suppressed in a region where the temperature of the tapered roller bearing 1 is high, and at a high temperature. The tapered roller bearing 1 can exhibit a predetermined support capability.

  Further, according to the preload loss prevention structure of the tapered roller bearing of the above embodiment, the biasing member 6 applies a force in the radial direction, so that the tapered roller bearing is compared with a type in which the biasing member applies a force in the axial direction. The dimension in the axial direction of the preload loss prevention structure 1 can be reduced. More specifically, since the urging member 6 is structured to apply a force in the radial direction, the urging member 6 is disposed in the axially adjacent portion of the outer ring 2 where the components of the differential gear device are densely packed. There is no need, and the biasing member 6 can be efficiently arranged so as to expand and contract in the radial direction in an unused space in the differential gear device. Therefore, since the unused space can be used effectively, a device such as a differential gear device having a preload loss prevention structure for the tapered roller bearing is not greatly increased due to the provision of the preload loss prevention structure.

  Moreover, according to the preload loss prevention structure of the tapered roller bearing of the above embodiment, for example, by adjusting the distance between the fulcrum and the force point 15 at high temperature, adjusting the distance between the fulcrum and the action point 16 at high temperature, and the like. The force applied by the lever member 5 to the large end surface of the outer ring 2 can be easily adjusted. Therefore, the preload of the tapered roller bearing 1 can be easily adjusted to a predetermined preload simply and precisely.

  Further, according to the preload drop prevention structure for the tapered roller bearing of the above embodiment, the lever member 5 has an L-shaped bent shape, and the fulcrum supports the bent portion of the lever member 5, The first member 40 on one side with the bent portion as a boundary is urged by the urging member 6 and the outer ring 2 is pressed by the second portion 41 on the other side with the bent portion as a boundary. In addition, the lever member 6 can be arranged, and the arrangement space of the preload drop prevention structure for the tapered roller bearing can be further reduced. Further, the outer ring 2 can be efficiently pressed by the lever member 5.

  In the preload loss prevention structure for the tapered roller bearing of the above embodiment, the lever member 5 has a bent shape with a substantially L-shaped cross section in a cross section including the central axis of the outer ring 2 and passing through the lever member 5. The cross section had a shape bent at a right angle. However, in the present invention, the lever member may be bent at an acute angle or an obtuse angle instead of a right angle in a cross section including the central axis of the outer ring and passing through the lever member. Further, in the cross section including the central axis of the outer ring and passing through the lever member, the lever member may have a linear cross section.

  Further, in the structure for preventing preload loss of the tapered roller bearing of the above embodiment, the lever support member 20 is an annular member. However, in the present invention, the lever support member may not be an annular member, and may be fixed to the housing instead of being press-fitted into the housing. In this case, the same number of lever support members as the lever members may be arranged at a constant interval in the circumferential direction.

  In the preload loss prevention structure of the tapered roller bearing of the above embodiment, the lever support member 20 supports the intersecting line 14 of the lever member 5, but in the present invention, the lever support member 20 may be omitted. . For example, the housing may be provided with a projecting portion projecting radially inward from the inner surface of the housing, and the lever member may be supported by the tip of the projecting portion. That is, it is good also considering the front-end | tip of the protrusion part which protrudes inward in the radial direction from the inner surface of a housing as a fulcrum.

  In the preload loss prevention structure for the tapered roller bearing according to the above-described embodiment, the housing member 22 is provided separately from the housing 8, and the urging member 6 is provided in the housing space defined by the housing member 22 and the end surface 51 of the housing 8. However, the housing and the housing member may be integrated. In the preload loss prevention structure for the tapered roller bearing of the above embodiment, the biasing member 6 has the coil spring 31, but the biasing member has a component having a restoring force other than the coil spring, such as a leaf spring. May be.

  Further, in the preload loss prevention structure for the tapered roller bearing of the above embodiment, the second portion 41 of the lever member extends in the radial direction at room temperature (15 ° C. to 25 ° C.). The second portion of the lever member does not have to extend in the radial direction.

  In the preload loss prevention structure for the tapered roller bearing of the above embodiment, the urging member 6 presses the first portion 40 of the lever member 5 outward in the axial direction, and the second portion 41 of the lever member 5 is the outer ring. The large end surface of No. 2 was pressed toward the small end surface. However, in the present invention, for example, a lever member having a substantially straight section rather than an L-shaped section is adopted, and the biasing member pulls the first end portion in the extending direction of the lever member inward in the radial direction. The second end portion in the extending direction of the lever member applies a force to the large end surface of the outer ring 2 on the small end surface side in the axial direction and the outward side in the radial direction to prevent preload loss of the tapered roller bearing. May be.

  Moreover, in the said embodiment, although the material of the housing 8 of the differential gear apparatus in which the outer ring | wheel 2 is fitted was made into aluminum and the weight reduction of the differential gear apparatus was implement | achieved, in this invention, an outer ring is fitted. The material of the housing of the vehicle pinion shaft support device (differential gear device, transaxle device or transfer device, etc.) may be a light metal material other than aluminum, such as magnesium. In this case as well, the weight of the differential gear device is reduced. Can be realized.

It is a figure which shows the cross section of the axial direction of the preload loss prevention structure of a tapered roller bearing in the state (normal temperature state) in which the differential gear apparatus has stopped. It is a figure which shows the cross section of the axial direction of the preload loss prevention structure of a tapered roller bearing in the state (high temperature state) in which the said differential gear apparatus is drive | operating.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tapered roller 2 Outer ring 3 Inner ring 4 Tapered roller 5 Lever member 6 Energizing member 8 Housing 15 Power point 16 Action point 30 Press part 31 Coil spring 40 1st part 41 2nd part

Claims (2)

An outer ring having a conical raceway surface;
An inner ring having a conical raceway surface;
A tapered roller disposed between the conical raceway surface of the outer ring and the conical raceway surface of the inner ring, and having a large end surface and a small end surface;
A lever member that is supported by a fulcrum and has a force point and an action point that presses the large end face toward the small end face.
A preload loss prevention structure for a tapered roller bearing, comprising: an urging member that applies a force in a radial direction to the force point. In the preload loss prevention structure of the tapered roller bearing according to claim 1,
A structure for preventing preload loss of a tapered roller bearing, wherein the lever member has an L-shaped bent shape, and the fulcrum supports a bent portion of the lever member.

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