JP2012251652A - Constant velocity universal joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a constant velocity universal joint, stably maintaining a lubricating state of a rolling face or a sliding face over a long time, and effectively cooling the rolling face or the sliding face by circulation of lubricant.SOLUTION: The constant velocity universal joint includes an outer joint member 83, an inner joint member 86, and a torque transmission member. An outer diameter face of the outer joint member 83 is fitted in a cylindrical housing 125. Between the outer diameter face of the outer joint member 83 and an inner diameter face of the housing 125, a pump structure 150 is disposed to circulate the lubricant to be filled in the joint, by rotating the joint.

Description

  The present invention relates to a constant velocity universal joint that is a power transmission device used in automobiles and various industrial machines, and more particularly to a constant velocity universal joint to which a boot that seals a joint opening is attached.

  FIG. 3 shows a general drive shaft. The drive shaft includes a shaft (intermediate shaft) 1, a fixed type constant velocity universal joint 2 connected to one end portion of the shaft 1, and a sliding type constant velocity universal joint 3 connected to the other end portion of the shaft 1. Is provided.

  As shown in FIG. 4, the fixed type constant velocity universal joint 2 includes an outer joint member 13 having a plurality of track grooves 12 formed on the inner diameter surface 11 and an inner joint member having a plurality of track grooves 15 formed on the outer diameter surface 14. 16, a plurality of balls 17 arranged on a ball track formed in cooperation with the track groove 12 of the outer joint member 13 and the track groove 15 of the inner joint member 16, and a pocket 18 for accommodating the ball 17. The main part is comprised with the cage 19 which has these.

  The outer joint member 13 includes a cup part (mouse part) 20 having a track groove 12 formed on the inner diameter surface 11 and a stem part 21 protruding from the bottom wall 20 a of the cup part 20. A female spline 22 is formed in the axial hole of the inner joint member 16, and the end 1 a of the shaft 1 is fitted into the axial hole of the inner joint member 16. A male spline 24 is formed at the end 1 a of the shaft 1, and the female spline 22 and the male spline 24 are fitted when the end of the shaft 1 is fitted into the axial hole of the inner joint member 16.

  A circumferential groove 25 is formed at the end of the female spline 22 of the shaft 1, and a retaining ring 26 is attached to the circumferential groove 25. In this manner, the retaining ring 26 is attached to prevent the shaft 1 from coming off.

  The opening of the outer joint member 13 is closed by the boot 30. The boot 30 includes a large-diameter portion 30a, a small-diameter portion 30b, and a bellows portion 30c that connects the large-diameter portion 30a and the small-diameter portion 30b. Then, the boot band 35 is fastened and fixed to the outer joint member 13 with the large-diameter portion 30 a of the boot 30 being fitted over the opening of the outer joint member 13. The small diameter portion 30 b of the boot 30 is fixed to the shaft 1 by tightening the boot band 35 in a state of being fitted on the boot mounting portion 36 of the shaft 1.

  As shown in FIGS. 5 and 6, the sliding type constant velocity universal joint 3 includes an outer joint member 41, a tripod member 42 as an inner joint member, and a torque transmission member (roller member) 43.

  The outer joint member 41 includes a cup-shaped cup portion 44 that is open at one end, and a shaft portion 45 that protrudes from the bottom wall 44 a of the cup portion 44. Three track grooves 46 extending in the axial direction are formed on the inner peripheral surface of the cup portion 44. Roller guide surfaces (roller sliding contact surfaces) 47a and 47a are formed on the side walls of each track groove 46 facing in the circumferential direction.

  The tripod member 42 includes a boss 48 and a leg shaft 49. The leg shaft 49 protrudes in the radial direction from the circumferentially divided position of the boss 48. The end portion 1 b of the shaft 1 is fitted into the axial hole of the boss 48. As shown in FIG. 3, a male spline 74 is formed at the end 1b of the shaft 1, and when the end of the shaft 1 is fitted into the axial hole of the boss 48 of the tripod member 42, the male spline 51 and the male spline 51 are connected. The spline 74 is fitted.

  By the way, the inner diameter surface of the cup portion 44 of the outer joint member 41 has a three-valve corollary shape in which small inner diameter portions 47b and large inner diameter portions 47c that appear alternately in the circumferential direction are connected by a roller guide surface 47a. That is, in the outer joint member 41, a track groove 46 composed of a roller guide surface 47a facing in the circumferential direction and a large inner diameter portion 47c provided between the roller guide surfaces 47a and 47a is formed at three locations on the inner periphery. Is.

  In this case, each leg shaft 49 includes a cylindrical outer peripheral surface 54 and an annular ring groove 56 formed near the shaft end. A roller 60 is externally fitted to the outer periphery of the leg shaft 49 via a plurality of needle rollers 62. The cylindrical outer peripheral surface 54 of the leg shaft 49 provides the inner raceway surface of the needle roller 62. The inner peripheral surface of the roller 60 is cylindrical and provides the outer raceway surface of the needle roller 62. In other words, this is a so-called single roller type consisting of a roller externally fitted to the cylindrical outer peripheral surface of the leg shaft 49 via a plurality of needle rollers.

  The needle roller 62 is in contact with the outer washer 64 at the outer end surface of the leg shaft 49 viewed in the radial direction, and is in contact with the inner washer 68 at the opposite end surface. Since the outer washer 64 is restricted from moving in the axial direction by the circlip 66 attached to the ring groove 56, the needle roller 62 is also restricted from moving in the axial direction. Some roller members are of a so-called double roller type having an inner roller and an outer roller.

  The opening of the outer joint member 41 is closed by the boot 70. The boot 70 includes a large-diameter portion 70a, a small-diameter portion 70b, and a bellows portion 70c that connects the large-diameter portion 70a and the small-diameter portion 70b. The boot band 75 is fastened and fixed to the outer joint member 41 with the large-diameter portion 70 a of the boot 70 being fitted over the opening of the outer joint member 41. The small diameter portion 70 b of the boot 70 is fixed to the shaft 1 by tightening the boot band 75 in a state of being fitted on the boot mounting portion 76 of the shaft 1.

  When a constant velocity universal joint (fixed constant velocity universal joint) transmits torque while rotating at an operating angle, the ball 17 receives the load while the track groove 12 of the outer joint member 13 and the track groove of the inner joint member 16 are received. 15 and roll. Further, the cage 19 is held between the inner diameter surface 11 of the outer joint member 13 and the outer diameter surface 14 of the inner joint member 16 and slides. Then, grease as a lubricant is sealed in the boot inner space that closes the opening of the outer joint member 13 and the inside of the joint so as to lubricate the rolling surface and sliding surface inside the joint. This ensures the durability of the constant velocity universal joint.

  That is, the grease used for the constant velocity universal joint intervenes and lubricates the rolling surface and the sliding surface due to its own viscosity and adhesion. For this reason, the grease used for the constant velocity universal joint has been devised with a composition of a thickener and an additive so as to exhibit performance in the use state as described above (Patent Document 1 and Patent Document). 2 etc.).

JP 2006-199761 A JP 2006-283830 A

  In conventional constant velocity universal joints, grease is lubricated by intervention of grease on the rolling surface of the ball and the sliding surface of the cage. For this reason, there is a concern that the lubrication performance may be degraded, such as the grease film running out, under conditions where the ball rolling speed or the cage sliding speed is high, such as high-speed rotation.

  Grease generally has a space volume of about 20% to 80% in the constant velocity universal joint and the boot so that the contact surface between the ball and the track groove and the sliding surface of the cage and the inner joint member and the outer joint member can be lubricated. The amount to be filled is enclosed. However, the grease contributing to the lubrication of the constant velocity universal joint during operation is mainly the grease existing inside the constant velocity universal joint, and the grease in the boot does not directly contribute to the lubrication.

  Further, in the conventional structure, when used under severe usage conditions such as surface pressure, sliding speed and temperature, the grease in the vicinity of the lubricating surface may partially deteriorate and the lubricating performance may be reduced. Furthermore, the constant velocity universal joint generates heat from the rolling surface and the sliding surface due to internal friction during operation. However, since grease has low thermal conductivity and does not circulate, the heat dissipation effect of grease cannot be expected so much. That is, local heat generation on the rolling surface and the sliding surface could not be radiated through the grease.

  Therefore, in view of such circumstances, the present invention can stably maintain the lubrication state of the rolling surface and the sliding surface over a long period of time, and effectively cool the rolling surface and the sliding surface by circulating the lubricant. It is an object of the present invention to provide a constant velocity universal joint that can be used.

  The constant velocity universal joint according to the present invention is a constant velocity universal joint that includes an outer joint member, an inner joint member, and a torque transmission member, and an outer diameter surface of the outer joint member is fitted into a cylindrical housing. A pump structure for circulating the lubricant filled in the joint by rotating the joint is arranged between the outer diameter surface of the outer joint member and the inner diameter surface of the housing.

  According to the constant velocity universal joint of the present invention, the lubricant circulates inside the joint in the pump structure in the joint rotation state. For this reason, the lubrication state of the rolling surface and the sliding surface can be improved, and partial deterioration of the lubricant in the vicinity of the lubricating surface can be prevented. Moreover, the rolling surface and the sliding surface can be cooled by circulating.

  A constant velocity universal joint in which a joint opening is closed by a boot, wherein the pump structure includes a gap between the inside of the boot, an outer diameter surface of the outer joint member, and an inner diameter surface of the housing. It is possible to form a circulation path through which the lubricant circulates through the back of the cup portion of the member. By the way, in the conventional constant velocity universal joint, the lubricant in the boot cannot be forcibly supplied to the inside of the joint, and it is difficult to directly contribute the lubricant in the boot to the lubrication in the joint. . On the other hand, by forming the circulation path as described above, the lubricant in the boot can be supplied to the inside of the joint, and the lubricant in the boot can contribute to the lubrication inside the joint. In particular, the outer joint member is provided with at least one lubricant circulation hole that opens from the outer diameter surface to the inside of the cup portion, so that the outer diameter side of the outer joint member and the cup portion back side of the outer joint member Can be cycled between.

  A shaft is fitted and fixed to the inner joint member, and the boot has a large diameter portion that is fitted and fixed to the housing, and a small diameter portion that is fitted and fixed to the shaft that is fitted and fixed to the inner joint member via a bearing. The large-diameter portion and the small-diameter portion are connected to each other, and a lubricant reservoir can be provided in the vicinity of the pump structure on the large-diameter portion inside the boot. By setting in this way, the lubricant can be stably supplied to the pump structure, and the circulation function is stabilized.

  It is preferable that the outer diameter surface of the outer joint member has an inner fitting shape in a housing made of a heat dissipating material having higher heat conductivity than iron. By setting in this way, the cooling performance to the lubricant that passes between the outer diameter surface of the outer joint member and the inner diameter surface of the housing can be enhanced.

  A pump structure can be comprised by the axial flow fan structure which has a cylinder part and the wing | blade part formed in the outer-diameter surface of this cylinder part. With this configuration, the pump structure can be simplified.

  The pump structure may be constituted by a member different from the outer joint member, and the pump structure and the outer joint member may be integrated by a fitting means or a fixing means. The pump structure can be made of resin.

  Even if a ball is used for the torque transmission member, a tripod member may be used for the inner joint member. The lubricant is preferably a lubricant having higher fluidity and intervention than grease.

  A constant velocity universal joint on the wheel side of the drive shaft, and even if a part of the knuckle constitutes the housing, it is a constant velocity universal joint on the wheel side of the drive shaft and a part of the hub bearing outer ring May constitute the housing.

  In the constant velocity universal joint of the present invention, the lubrication state of the rolling surface and sliding surface can be improved, sufficient lubricating oil film thickness is ensured, and fine wear generated on the rolling surface and sliding surface. Powder can be discharged and the joint life can be extended. In addition, it is possible to prevent partial deterioration of the lubricant in the vicinity of the lubrication surface, and it is possible to prevent a decrease in the lubrication function as the lubricant. Furthermore, effective cooling of the rolling surfaces and sliding surfaces can be achieved, and the life of the constant velocity universal joint and the lubricant can be improved.

  In the case of forming the circulation path described above, the lubricant in the boot can contribute to the lubrication inside the joint, and effective lubrication becomes possible.

  In the case where a plurality of lubricant circulation holes are provided, efficient circulation is possible, and the circulation function is stabilized by providing a lubricant reservoir in the vicinity of the pump structure on the large-diameter portion inside the boot. , Joint life can be greatly extended.

  Passes between the outer diameter surface of the outer joint member and the inner diameter surface of the housing when the outer diameter surface of the outer joint member is fitted into the housing made of a heat-dissipating material having higher heat conductivity than iron. The cooling performance to the lubricant to be improved can be improved, and the durability of the joint can be improved.

  By configuring the pump structure with an axial fan structure, the pump structure can be simplified, and the weight and cost can be reduced.

  In the case where the pump structure is constituted by a member different from the outer joint member, an existing one can be used for the outer joint member and the like, and it can be prevented from being disadvantageous in terms of productivity and cost. Moreover, the integration of the pump structure and the outer joint member may be a fitting means or a fixing means, and various fixing means can be used, and the assemblability is excellent. Moreover, weight reduction can be achieved by making the pump structure made of resin.

  The torque transmission member may be a ball, or the inner joint member may be a tripod member, and can be used for various types of constant velocity universal joints. In addition, by using a lubricant having good fluidity and intervention, higher lubricity can be secured.

It is a longitudinal cross-sectional view of the constant velocity universal joint which shows embodiment of this invention. The pump structure used for the constant velocity universal joint of the said FIG. 1 is shown, (a) is a perspective view of a 1st pump structure, (b) is a perspective view of a 2nd pump structure. It is sectional drawing of a drive shaft. It is a longitudinal section of the conventional fixed type constant velocity universal joint. It is a cross-sectional view of a conventional sliding constant velocity universal joint. It is a longitudinal cross-sectional view of the conventional sliding type constant velocity universal joint.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a constant velocity universal joint according to the present invention. This constant velocity universal joint is an undercut-free type fixed constant velocity universal joint, and an outer joint member having a track groove 82 formed on an inner diameter surface 81. 83, an inner joint member 86 having a track groove 85 formed on the outer diameter surface 84, and a torque transmission member interposed between the track groove 82 of the outer joint member 83 and the track groove 85 of the inner joint member 86. A torque transmission ball 87 and a cage 89 having a pocket 88 for accommodating the ball 87 and interposed between the outer joint member 83 and the inner joint member 86 are provided.

  The outer joint member 83 includes a cup portion 90 having a track groove 82 formed on the inner diameter surface 81 and a stem portion 91 projecting from the bottom wall 90 a of the cup portion 90. A female spline 92 is formed in the axial hole of the inner joint member 86, and the end of the shaft 93 is fitted into the axial hole of the inner joint member 86. A male spline 94 is formed at the end 93 a of the shaft 93, and the female spline 92 and the male spline 94 are fitted when the end of the shaft 93 is fitted into the axial hole of the inner joint member 86. A circumferential groove 96 is formed at the end of the male spline 94, and a retaining ring 97 of the circumferential groove 96 is fitted. Thereby, the shaft 93 is prevented from coming off.

  The cup portion 90 of the outer joint member 83 includes a large-diameter portion 90b on the opening side, a small-diameter portion 90c on the stem portion side, and a medium-diameter portion 90d disposed between the small-diameter portion 90c and the large-diameter portion 90b. Have. Further, the outer diameter surface of the large diameter portion 90b, the outer diameter surface of the medium diameter portion 90d, and the outer diameter surface of the small diameter portion 90c are respectively cylindrical surfaces. The middle diameter portion 90d and the small diameter portion 90c constitute the bottom wall 90a. The stem portion 91 of the outer joint member 83 has a male spline portion 91a and an end male screw portion 91b.

  In this case, the constant velocity universal joint is connected to the hub wheel 100. The hub wheel 100 includes a cylindrical portion 113 and a flange portion 114, and a mounting bolt 99 is attached to the flange portion 114. And the female spline 101a is formed in the internal diameter surface of the hole part 101 of the cylinder part 113, and the male spline part 91a of the stem part 91 meshes with this female spline 101a. Then, the nut member 102 is screwed to the end male thread portion 91 b protruding from the hole portion 101 of the hub wheel 100.

  The constant velocity universal joint and the hub wheel 100 are attached to a knuckle 105 constituting a suspension device via a bearing structure (hub wheel bearing) 103. The bearing structure 103 in this case includes a pair of inner rings 106 a and 106 b, one outer ring 107, and rolling elements 108 interposed between the inner rings 106 a and 106 b and the outer ring 107.

  Each inner ring 106a, 106b has rolling surfaces 111a, 111b on which the rolling element 108 rolls on the outer diameter surface, and the outer ring 107 has a rolling surface 112a on which the rolling element 108 rolls on the inner diameter surface. , 112b. In this case, a circumferential notch 113 a is provided on the outer peripheral surface of the cylindrical portion 113 of the hub wheel 100. The inner rings 106a and 106b are fitted into the circumferential cutout 113a.

  That is, the end surface 115a on the thick portion side of the inner ring 106a abuts on the cut end surface 116 of the circumferential cut portion 113a, and the end surface 115b on the thick portion side of the inner ring 106b is the outer joint member 83 of the constant velocity universal joint. It contacts the back face 117 of the bottom wall 90 a of the cup 90. At this time, the end surface 118a on the thin portion side of the inner ring 106a abuts on the end surface 118b on the thin portion side of the inner ring 106b.

  Further, the inner diameter surface of the knuckle 105 includes a small-diameter portion 120 into which the outer ring 107 of the bearing structure 103 is fitted, and a large-diameter portion 121 into which the cup portion of the outer joint member 83 is fitted loosely. By forming the large-diameter portion 121, a cylindrical housing 125 in which the outer diameter surface of the outer joint member 83, that is, the outer diameter surface of the cup portion 90 is fitted, is formed.

  In addition, an inner flange 126 is provided on the side of the small diameter portion 120 of the knuckle 105 opposite to the large diameter portion 126, and a stopper 127 is mounted on the large diameter portion 121 side of the small diameter portion 120. For this reason, the outer ring 107 of the bearing structure 103 is sandwiched between the inner flange 126 and the stopper 127. In the bearing structure 103, seal members 130a and 130b are attached to both ends in the axial direction. A sealing device (oil seal) 135 is attached to the small diameter side of the large diameter part 121.

  The opening of this constant velocity universal joint is closed by a boot 140. The boot 140 includes a large-diameter portion 140a, a small-diameter portion 140b, and a bellows portion 140c that connects the large-diameter portion 140a and the small-diameter portion 140b. In this case, the large diameter portion 140a is externally fitted to the boot mounting portion 125a formed on the outer diameter surface of the opening portion of the housing 125, and the boot is inserted into the circumferential fitting groove formed on the outer diameter surface of the large diameter portion 140a. A band 141 is attached. Then, by tightening the boot band 141, the large-diameter portion 140 a of the boot 140 is fixed to the housing 125.

  The small-diameter portion 140b is attached to a bearing 142 that is externally fixed to the attachment portion 93b of the shaft 93. In other words, the bearing 142 is fitted to the inner ring 142a having a rolling surface on the outer peripheral surface, the outer ring 142b having a rolling surface on the inner peripheral surface, and the rolling surfaces of the inner ring 142a and the outer ring 142b. A moving body (ball) 142c and a cage (cage) 142d for holding the ball 142c are provided. Further, both axial openings are sealed with seal members 143 and 143.

  In this case, the mounting portion 93b of the shaft 93 is provided with a circumferential fitting groove, and the inner ring 142a of the bearing 142 is fitted into the circumferential fitting groove. A retaining ring 144 is fitted on the universal joint side to restrict the removal of the bearing 142 on the constant velocity universal joint side.

  A small-diameter portion 140b of the boot 140 is externally fitted to the bearing 142, and a boot band 141 is attached to a circumferential fitting groove formed on the outer-diameter surface of the small-diameter portion 140b. Then, by tightening the boot band 141, the small-diameter portion 140b of the boot 140 is fixed to the bearing 125, and consequently the mounting portion 93b of the shaft 93.

  In the present invention, the lubricant filled in the joint between the inner diameter surface of the housing 125 and the outer diameter surface of the large diameter portion 90b of the cup portion 90 of the outer joint member 83 is rotated inside the joint by rotating the joint. A pump structure 150 for circulating the gas is disposed.

  In this case, the housing 125 is constituted by a member separate from the knuckle 105, and the housing 125 is constituted by a metal having good heat dissipation such as aluminum, and is fixed to the knuckle 105 through fixing means such as welding. You may make it do.

  As shown in FIGS. 2A and 2B, the pump structure 150 is constituted by an axial fan structure having a cylindrical portion 151 and a wing portion 152 formed on the outer diameter surface of the cylindrical portion 151. be able to. In FIG. 2A, the wing portion 152 is composed of a plurality of protruding plates 152a disposed on the outer diameter surface of the cylindrical portion 151 at a predetermined pitch along the circumferential direction. The protruding plate 152a is an arc-shaped body, and is inclined at a predetermined angle with respect to the axial center of the cylindrical portion 151. In FIG. 2B, the wing portion 152 includes a plurality of protrusions 152 b that are spirally disposed on the outer diameter surface of the cylindrical portion 151. That is, in FIG. 2A, it is a propeller type axial flow pump, and in FIG. 2B, it is a helical type axial flow pump.

  Such a pump structure 150 is press-fitted into the large-diameter portion 90 b of the cup portion 90 of the outer joint member 83 and integrated with the outer joint member 83. In this case, for example, a thermoplastic resin such as nylon or polyethylene is used. Further, the pump structure 150 is maintained in a non-contact state with the inner diameter surface of the housing 125. That is, a gap is formed between the outer diameter portion of the pump structure 150 and the inner diameter surface of the housing 125. The gap affects the ability to feed the lubricant, and the gap may be reduced for efficient feeding, but is determined by the deflection accuracy of the outer joint member 93 of the constant velocity universal joint with respect to the housing 125.

  The pump structure 150 may be bonded to the large diameter portion 90b of the cup portion 90 of the outer joint member 83 via an adhesive. Further, the pump structure 150 may be made of metal without being made of such a resin. For this reason, the pump structure 150 and the large-diameter portion 90b of the cup portion 90 depend on the material of the pump structure 150 or the like, but it is possible to use only press-fitting or use joining means such as welding or adhesion in addition to press-fitting. Alternatively, only the joining means such as welding or adhesion may be used without press-fitting.

  As shown in FIG. 1, the cup portion 90 of the outer joint member 83 is provided with a lubricant circulation hole 155 that opens from the outer diameter surface to the inside of the cup portion. That is, the lubricant flow hole 155 is between the pump structure 150 and the sealing device 135, that is, on the taper portion 90e (between the large-diameter portion 90b and the medium-diameter portion 90d) side of the medium-diameter portion 90d of the cup portion 90. Is provided. In this case, at least one lubricant circulation hole 155 may be provided, but a plurality of lubricant circulation holes 155 may be provided along the circumferential direction.

  Further, in this constant velocity universal joint, a lubricant is sealed inside the joint and the boot. Examples of the lubricant include lubricating oil and grease. Examples of the lubricating oil include paraffinic and naphthenic mineral oils, ester synthetic oils, ether synthetic oils, hydrocarbon synthetic oils, GTL base oils, fluorine oils, and silicone oils. These can be used alone or as a mixed oil.

  The grease is obtained by adding a thickener to a base oil, and examples of the base oil include the above-described lubricating oil. Thickeners include, but are not limited to, soaps such as lithium soap, lithium complex soap, calcium soap, calcium complex soap, aluminum soap, aluminum complex soap, and urea-based compounds such as diurea compounds and polyurea compounds. It is not a thing.

  As the lubricant, it is preferable to select a lubricant that has better fluidity and intervention than grease.

  As described above, in the constant velocity universal joint configured as described above, the bearing structure portion is fixed to the knuckle 105 of the suspension part. The outer joint member 83 is integrated with the hub wheel 100 and rotates with respect to the knuckle 105 together with the inner rings 106 a and 106 b of the bearing structure 103 and the hub wheel 100. On the other hand, since the boot 140 is fixed to the housing 125 on the fixed side and the bearing 142 attached to the shaft 93, it does not rotate with respect to the rotation.

  In the constant velocity universal joint configured as described above, the lubricant encapsulated in the joint or the boot due to the rotation of the constant velocity universal joint or the bending due to the turning of the constant velocity universal joint causes the lubricant reservoir A (circumference) on the large diameter portion 140a side. Gathered in a pool formed over the entire direction). The lubricant is caught in the rotating pump structure 150 and sent from the lubricant reservoir A to the hub bearing side lubricant reservoir B.

  When the hub bearing side lubricant reservoir B becomes full, the pressure in the lubricant reservoir B rises, and the lubricant accumulates in the lubricant reservoir C inside the joint through the lubricant flow hole 155. When the lubricant reservoir C becomes full, the pressure in the lubricant reservoir C increases. As a result, the ball 87 and the track grooves 82 and 85 are forcibly supplied to the vicinity of the contact point and the sliding surface of the cage 89, the inner joint member 86 and the outer joint member to lubricate them. Thereafter, the lubricant is discharged from the joint opening into the boot. Thus, the lubricant circulates inside the boot and inside the joint.

  By the way, the pump structure 150 can make the direction to attract | suck differ by the direction of the wing | blade part, etc. For this reason, when this constant velocity universal joint is applied to an automobile, it is preferable to set the lubricant to circulate from the inside of the boot to the inside of the joint through the pump structure 150 by the forward rotation used mainly.

  In the constant velocity universal joint of the present invention, the lubricant circulates inside the joint by the pump structure 150 in the joint rotation state. For this reason, it is possible to improve the lubrication state of the rolling surface and sliding surface, ensuring a sufficient lubricating oil film thickness, and discharging fine wear powder generated on the rolling surface and sliding surface. Thus, the joint life can be extended. In addition, it is possible to prevent partial deterioration of the lubricant in the vicinity of the lubrication surface, and it is possible to prevent a decrease in the lubrication function as the lubricant. Furthermore, effective cooling of the rolling surfaces and sliding surfaces can be achieved, and the life of the constant velocity universal joint and the lubricant can be improved.

  In the pump structure 150, the lubricant circulates through the inside of the boot, the gap between the outer diameter surface of the outer joint member 83 and the inner diameter surface of the housing 125, and the inner portion of the cup portion of the outer joint member 83 by rotating the joint. A circulation path will be formed. For this reason, the lubricant in the boot can contribute to the lubrication inside the joint, and effective lubrication becomes possible.

  In the case where a plurality of lubricant circulation holes 155 are provided, efficient circulation is possible, and by providing the lubricant reservoir A in the vicinity of the pump structure on the large-diameter portion inside the boot, the circulation function is improved. It is stable and the joint life can be greatly extended.

  In this embodiment, the outer diameter surface of the outer joint member 83 is fitted into a housing 125 made of a heat dissipating material having higher heat conductivity than iron. For this reason, the cooling performance to the lubricant passing between the outer diameter surface of the outer joint member 83 and the inner diameter surface of the housing 125 can be enhanced, and the durability of the joint can be improved. In consideration of cooling performance, the housing 125 may be provided with heat-radiating fins.

  By configuring the pump structure 150 with an axial fan structure, the pump structure 150 can be simplified, and weight reduction and cost reduction can be achieved.

  Since the pump structure 150 is constituted by a member different from the outer joint member 83, the existing one can be used in the outer joint member 83 and the like, and it can be prevented from being disadvantageous in terms of productivity and cost. . Moreover, the integration of the pump structure 150 and the outer joint member 83 may be a fitting means or a fixing means, and various fixing means can be used, and the assemblability is excellent. Moreover, weight reduction can be achieved by making the pump structure made of resin. Higher lubricity can be ensured by using a lubricant that has better fluidity and intervention than grease.

  In the above-described embodiment, the pump structure 150 is disposed in the fixed type constant velocity universal joint, and the lubricant is circulated between the inside of the boot and the inside of the joint. However, as shown in FIGS. In such a sliding constant velocity universal joint, the pump structure may be arranged. In this way, if the pump structure is arranged in the sliding type constant velocity universal joint, this sliding type constant velocity universal joint can also improve the lubrication state of the rolling surface and sliding surface. It is possible to secure a sufficient lubricating oil film thickness and discharge fine wear powder generated on the rolling surface and sliding surface, thereby extending the life of the joint.

  In the above-described embodiment, the housing 125 is provided on the knuckle 105. However, the housing 125 is provided on a part of the outer ring (hub bearing outer ring) 107 of the bearing structure 103 without providing the knuckle 105. It may be.

  As described above, the embodiment of the present invention has been described. However, the present invention is not limited to the above-described embodiment, and various modifications are possible. For example, in the above-described embodiment, as a fixed type constant velocity universal joint, a track groove The bottom of the groove was an undercut free fixed constant velocity universal joint having an arc portion and a straight portion, but the track groove groove bottom was a barfield type fixed constant velocity universal joint consisting of an arc portion. Also good. The sliding type constant velocity universal joint may be a sliding type constant velocity universal joint such as a tripod type, a double offset type, or a cross groove type.

  Incidentally, the embodiment shown in FIG. 1 shows a wheel bearing device that supports a wheel of an automobile, and is arranged between a knuckle constituting a suspension device and a hub to which the wheel is attached. Such a wheel bearing device has a structure called “first generation” in which a wheel bearing composed of bearings having double-row raceway surfaces is fitted, or a vehicle body mounting flange or "2nd generation" structure with wheel mounting flanges, "3rd generation" structure with a hub ring with one inner raceway surface directly formed on the outer periphery of the hub, or freely adjustable with the hub ring It is roughly classified into a “fourth generation” structure in which the inner raceway surface is directly formed on the outer periphery of the outer joint member of the joint. For this reason, in this invention, as a wheel bearing apparatus, a 1st generation, a 2nd generation, a 3rd generation, or a 4th generation may be sufficient.

  The pump structure 150 is not limited to that shown in FIGS. 2 (a) and 2 (b). The number of the protrusion plates (wings) 152a in FIG. The number of the protrusions 152b, the spiral angle, etc. in b) can be arbitrarily set. Since the rotation direction of the constant velocity universal joint is not necessarily constant, as described above, the constant velocity universal joint circulates along the aforementioned direction (that is, a direction such as A → B → C) in the rotation direction mainly used. Although it is preferable to design in such a manner, it is of course not limited to this.

83 Outer joint member 86 Inner joint member 87 Torque transmission ball 103 Bearing structure part 105 Knuckle 125 Housing 140 Boot 140a (boot) Large diameter part 140b (boot) Small diameter part 140c (boot) bellows part 150 Pump structure 151 Tube part 152 Wings Part 155 Lubricant flow hole A Lubricant reservoir

Claims (13)

A constant velocity universal joint comprising an outer joint member, an inner joint member, and a torque transmission member, wherein an outer diameter surface of the outer joint member is fitted into a cylindrical housing;
A constant velocity universal joint characterized in that a pump structure for circulating a lubricant filled in the joint by rotation of the joint is disposed between the outer diameter surface of the outer joint member and the inner diameter surface of the housing.   The joint opening is a constant velocity universal joint in which a boot is closed by a boot, and the pump structure includes an inside of the boot, a gap between an outer diameter surface of the outer joint member and an inner diameter surface of the housing, an outer side The constant velocity universal joint according to claim 1, wherein a circulation path through which the lubricant circulates through the cup portion inner portion of the joint member is formed.   3. The constant velocity universal joint according to claim 2, wherein the outer joint member is provided with at least one lubricant circulation hole which opens from the outer diameter surface to the inside of the cup portion.   A shaft is fitted and fixed to the inner joint member, and the boot has a large diameter portion that is fitted and fixed to the housing, and a small diameter portion that is fitted and fixed to the shaft that is fitted and fixed to the inner joint member via a bearing. The lubricant reservoir is provided in the vicinity of the pump structure on the large-diameter portion inside the boot, comprising a bellows portion connecting the large-diameter portion and the small-diameter portion. The constant velocity universal joint according to any one of claims.   The outer diameter surface of an outer joint member becomes an internal fitting shape in the housing comprised with the heat dissipation material whose heat conduction is higher than iron, The any one of Claims 1-4 characterized by the above-mentioned. Constant velocity universal joint.   6. The pump structure according to claim 1, wherein the pump structure is constituted by an axial fan structure having a cylindrical portion and a wing portion formed on an outer diameter surface of the cylindrical portion. The constant velocity universal joint described in 1.   7. The pump structure according to claim 1, wherein the pump structure is constituted by a member different from the outer joint member, and the pump structure and the outer joint member are integrated by a fitting means or a fixing means. The constant velocity universal joint according to any one of claims.   The constant velocity universal joint according to any one of claims 1 to 6, wherein the pump structure is made of resin.   The constant velocity universal joint according to any one of claims 1 to 8, wherein a ball is used for the torque transmission member.   The constant velocity universal joint according to any one of claims 1 to 8, wherein a tripod member is used as the inner joint member.   The constant velocity universal joint according to any one of claims 1 to 10, wherein the lubricant is a lubricant having better fluidity and intervention than grease.   The constant velocity universal joint according to any one of claims 1 to 11, wherein the constant velocity universal joint on the wheel side of the drive shaft, a part of the knuckle forms the housing.   The constant velocity universal joint according to any one of claims 1 to 11, wherein the constant velocity universal joint on the wheel side of the drive shaft, wherein a part of the outer ring of the hub bearing constitutes the housing. .

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