JP2012127450A - Tripod type constant velocity universal joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tripod type constant velocity universal joint, with which turning work or exclusive equipment are made unnecessary, reliable slip-stop is easily achieved by a simple tool, working processes are simplified and costs are reduced.SOLUTION: The tripod type constant velocity universal joint includes: an outer joint member 10 which is formed to have a cup shape having an opening 11 in one end, is formed with three track grooves 12 extending in an axial direction on an inner circumference face, and is formed with roller guide faces 14 opposing to each other on inner walls of each track groove 12; a tripod member 20 having radially protruding three leg shafts 22; and a roller unit 30 rotatably supported by the leg shaft 22 of the tripod member 20 and inserted, so as to freely roll, into the track groove 12 of the outer joint member 10 to be guided along the roller guide faces 14. Here, inner components including the roller unit 30 and the tripod member 20 are axially slidably housed in the outer joint member 10. The roller guide faces 14 in both sides of the track groove 12 are provided with recessed parts 15, in which the roller unit 30 as the inner components is to be fitted, on an inner circumference face of the opening 11 of the outer joint member 10.

Description

  The present invention is used in power transmission systems of automobiles, airplanes, ships, and various industrial machines, and is incorporated into a drive shaft, a propeller shaft, etc. used in, for example, a 4WD vehicle, an FR vehicle, etc. The present invention relates to a tripod type constant velocity universal joint which is a kind of a sliding type constant velocity universal joint that allows axial displacement and angular displacement between them.

  For example, there are two types of constant velocity universal joints, such as fixed constant velocity universal joints and sliding constant velocity universal joints, that are built into drive shafts and propeller shafts that transmit rotational force from automobile engines to wheels at constant speed. is there. Both of these constant velocity universal joints have a structure in which two shafts on the driving side and the driven side are connected so that rotational torque can be transmitted at a constant speed even if the two shafts have an operating angle.

  Since the drive shaft that transmits power from the engine of the automobile to the driving wheel needs to correspond to the angular displacement and axial displacement due to the change in the relative positional relationship between the engine and the wheel, the engine side (inboard side) ) And a fixed constant velocity universal joint on the drive wheel side (outboard side), and a structure in which both constant velocity universal joints are connected by a shaft.

  One of the sliding type constant velocity universal joints assembled to the drive shaft is a tripod type constant velocity universal joint. This tripod type constant velocity universal joint has a cup shape having an opening at one end, three track grooves extending in the axial direction are formed on the inner peripheral surface, and roller guides facing each other on the inner wall of each track groove An outer joint member formed with a surface, a tripod member having three leg shafts projecting in the radial direction, and rotatably supported by the leg shaft of the tripod member and rolling in a track groove of the outer joint member And a roller guided along the roller guide surface to form a main portion, and an internal component including the roller and the tripod member is accommodated in the outer joint member so as to be slidable in the axial direction.

  When assembling this type of tripod type constant velocity universal joint to an automobile, the tripod type constant velocity universal joint is assembled on the engine side (inboard side), and then the fixed type constant velocity universal joint is installed on the drive wheel side (outboard side). ) Is generally assembled. On the drive wheel side, the hub bearing is assembled to the fixed type constant velocity universal joint, and is assembled to the suspension system of the vehicle body by the knuckle, but when the hub bearing is assembled to the fixed type constant velocity universal joint, the hub bearing and the knuckle are attached to the vehicle body. Since the tripod type constant velocity universal joint is not assembled to the suspension device, a total load (for example, 0.3 kN or more) of the fixed type constant velocity universal joint, the hub bearing, and the knuckle may be applied. When such a load is applied to the tripod type constant velocity universal joint, a slide over may occur in which the internal part jumps out of the opening of the outer joint member. Therefore, conventionally, in order to prevent this slide-over, the following retaining mechanism is employed.

  As one of the retaining mechanisms, there is a structure in which an annular groove is provided on the inner peripheral surface of the opening of the outer joint member, and a circlip is fitted into the annular groove (see, for example, Patent Document 1). With such a structure, when the internal component is displaced in the axial direction, the roller interferes with the circlip so that the axial displacement amount of the roller is regulated.

  In addition, as another retaining mechanism, there is a structure in which a protruding portion is formed on the inner peripheral surface of the opening of the outer joint member by crushing the inner edge of the opening end face of the outer joint member by caulking (for example, a patent) Reference 2). With such a structure, when the internal component is displaced in the axial direction, the roller interferes with the raised portion so that the axial displacement amount of the roller is regulated.

Utility Model Registration No. 2560806 Japanese Patent Application Laid-Open No. 11-336782

  By the way, in the conventional constant velocity universal joint disclosed in the above-mentioned Patent Document 1, a circular clip is formed on the inner peripheral surface of the opening of the outer joint member in order to assemble the circlip for restricting the axial displacement of the roller to the outer joint member. Since the inner peripheral surface of the opening of the outer joint member must be turned and a circlip is also required, the cost of the product is increased by turning and increasing the number of parts. . In addition, it takes time to assemble the circlip, resulting in a decrease in assembling workability.

  Further, in the conventional constant velocity universal joint disclosed in Patent Literature 2, the inner edge portion of the opening end face of the outer joint member is crushed by caulking, so that the outer joint member is accurately positioned with respect to the caulking jig. The positioning of the outer joint member is very difficult and requires special equipment for positioning the outer joint member. Moreover, since it forms by crushing a protruding part by caulking, the size dimension of the protruding part tends to vary.

  Therefore, the present invention has been proposed in view of the above-mentioned problems, and the object of the present invention is to eliminate the need for turning and dedicated equipment, and to easily realize reliable retaining by simple means and the machining process. An object of the present invention is to provide a tripod type constant velocity universal joint that can be simplified and cost can be reduced.

  As technical means for achieving the above-mentioned object, the present invention has a cup shape having an opening at one end, and three track grooves extending in the axial direction are formed on the inner peripheral surface. An outer joint member having roller guide surfaces facing each other on the inner wall, a tripod member having three leg shafts projecting in the radial direction, and an outer joint supported rotatably on the leg shaft of the tripod member A tripod in which an inner part including the roller and the tripod member is accommodated in the outer joint member so as to be axially slidable. A constant velocity universal joint, characterized in that a concave portion into which a roller of an internal part is fitted is provided on a roller guide surface on at least one side of a track groove on an inner peripheral surface of an opening of an outer joint member.

  The above-mentioned “at least one side” means that a recess is provided on one side of a pair of roller guide surfaces facing each other on the inner wall of the track groove, or a recess is provided on both sides of the pair of roller guide surfaces. It means to include both.

  In the tripod type constant velocity universal joint according to the present invention, a recess into which the roller of the internal part is fitted is provided on the roller guide surface on at least one side of the track groove on the inner peripheral surface of the opening of the outer joint member. By restricting the amount of axial displacement of the internal component by fitting the roller into the recess when the direction is displaced, it is possible to prevent the internal component from sliding out from the opening of the outer joint member. In particular, when this tripod type constant velocity universal joint is assembled to a car as a drive shaft, even if the total load of the fixed type constant velocity universal joint, hub bearing and knuckle is applied to the tripod type constant velocity universal joint, the internal parts are the outer joint members. This is effective in that it is possible to surely prevent a slide-over jumping out from the opening of the.

  The concave portion in the present invention is preferably formed in a portion closer to the inner diameter side that is fitted by a pressing force toward the inner diameter side due to interference of a boot attached to the opening of the outer joint member. When the internal component is displaced in the axial direction, the roller of the internal component that is about to jump out from the opening of the outer joint member interferes with the boot mounted in the opening of the outer joint member. Since the roller is pressed toward the inner diameter side of the outer joint member due to the interference with the boot, it is effective to provide a recess in the portion closer to the inner diameter side of the roller guide surface, and the internal part protrudes from the opening of the outer joint member. A slide-over can be reliably prevented.

  In this case, as the boot, either rubber or resin can be used. If you want to increase the force that the inner part roller trying to jump out of the opening of the outer joint member interferes with the boot when the inner part is displaced in the axial direction, It is effective to use harder resin boots.

  The recess in the present invention is preferably provided by simultaneous molding by forging of the outer joint member. In this way, there is no need for a conventional turning process for forming an annular groove, a separate part such as a circlip, or a dedicated facility for positioning the outer joint member with respect to the caulking jig. It is possible to form the recesses with high accuracy, and the recesses can be formed with high accuracy. In addition, by a simple means of simultaneous forming by forging of the outer joint member, the retaining function can be surely exhibited, and the machining process can be simplified and the cost can be reduced.

  The roller in the present invention preferably has a structure that is externally fitted to the leg shaft via needle rollers. That is, the present invention is applicable to a single roller type tripod type constant velocity universal joint.

  Further, the roller according to the present invention is an outer roller disposed on the outer peripheral side of the inner roller that is externally fitted to the leg shaft via needle rollers, the inner peripheral surface of the inner roller has a convex arc shape, and the leg shaft has a longitudinal section. It has a straight shape perpendicular to the joint axis on the surface, contacts the inner peripheral surface of the inner roller in the direction perpendicular to the joint axis in the cross section, and a gap between the inner peripheral surface of the inner roller in the joint axial direction. A structure in which is formed is desirable. That is, it is effective to apply the present invention to a double roller type tripod type constant velocity universal joint.

  According to the present invention, since the concave portion into which the roller of the internal part is fitted is provided in the roller guide surface on at least one side of the track groove on the inner peripheral surface of the opening of the outer joint member, Since the amount of axial displacement of the internal part is regulated by fitting in the recess, it is possible to prevent the internal part from sliding out from the opening of the outer joint member. As a result, there is no need for a turning process for forming an annular concave groove as in the prior art, a separate part such as a circlip, or a dedicated facility for positioning the outer joint member with respect to the crimping jig. With this simple means of forming, the retaining function can be surely exerted, the machining process can be simplified and the cost can be reduced, and an inexpensive and highly reliable tripod type constant velocity universal joint can be provided.

In embodiment of the tripod type constant velocity universal joint which concerns on this invention, it is a longitudinal cross-sectional view with respect to the axis line of a joint. It is sectional drawing which follows the AA line of FIG. It is sectional drawing which follows the BB line of FIG. It is sectional drawing which shows the leg axis | shaft and roller unit of FIG. It is a partial expanded sectional view which shows the state located in the axial direction displacement end which the roller unit of FIG. 1 protrudes from the opening part of an outer joint member. It is sectional drawing which follows the CC line of FIG. It is a principal part enlarged view which shows X part of FIG. FIG. 6 is a partially enlarged cross-sectional view showing a state in which the roller unit of FIG. 5 is fitted in a recess of the roller guide surface of the outer joint member. It is sectional drawing which follows the DD line | wire of FIG. It is a principal part enlarged view which shows the Y part of FIG. It is sectional drawing which follows the EE line | wire of FIG. It is a principal part enlarged view which shows Z part of FIG.

  The embodiment of the tripod type constant velocity universal joint according to the present invention will be described in detail below. In the following embodiments, a double roller type tripod type constant velocity universal joint capable of reducing vibration during operation will be exemplified.

  1 to 4 show the basic configuration of a double roller type tripod type constant velocity universal joint, FIG. 1 is a longitudinal sectional view with respect to the axis of the joint, and FIG. 2 is a sectional view taken along the line AA in FIG. 3 is a sectional view taken along line BB in FIG. 2, and FIG. 4 is a sectional view showing the leg shaft and the roller unit in FIG. The tripod type constant velocity universal joint of this embodiment includes an outer joint member 10, a tripod member 20 that is an inner joint member, and a roller unit 30 that is a torque transmission member.

  The outer joint member 10 has a cup shape having an opening 11 at one end, and a rotation shaft (for example, a drive shaft) (not shown) is integrally formed at the center of the bottom portion. Three linear track grooves 12 extending in the axial direction are formed on the inner peripheral surface of the outer joint member 10 at equal intervals in the circumferential direction. Each track groove 12 has a pair of roller guide surfaces 14 opposed to each other on both inner walls thereof. The roller guide surface 14 has an arc-shaped cross section and extends linearly in the axial direction of the outer joint member 10. On the outer peripheral surface of the outer joint member 10, a portion corresponding to the space between the track grooves 12 is thinned to reduce the weight, and a recess 13 is formed in the axial direction. Internal parts including the tripod member 20 and the roller unit 30 are accommodated in the outer joint member 10.

  The roller unit 30 includes an outer roller 32, an inner roller 34 disposed on the inner side of the outer roller 32 and fitted onto the leg shaft 22, and needle rollers 36 interposed between the outer roller 32 and the inner roller 34. And is accommodated in the track groove 12 of the outer joint member 10. The inner peripheral surface of the inner roller 34 has a convex arc shape. A plurality of needle rollers 36 are disposed between the inner roller 34 and the outer roller 32 in a so-called single row full roller state without a cage. The inner roller 34 and the needle roller 36 are fitted with retaining rings 31, 33 in annular grooves formed on the inner peripheral surface of the outer roller 32, and are prevented from coming off from the outer roller 32 by the retaining rings 31, 33. .

  The tripod member 20 is formed by integrally forming three leg shafts 22 radially at equal intervals in the circumferential direction (120 ° intervals) on the outer peripheral surface of a cylindrical boss portion 21. The front end of the leg shaft 22 extends in the radial direction to the vicinity of the bottom surface of the track groove 12. The shaft end of the shaft 40 is connected to the shaft hole of the boss 21 by spline fitting, and is prevented from coming off from the tripod member 20 by an annular snap ring 42. The leg shaft 22 of the tripod member 20 has a straight shape perpendicular to the axis of the joint in a longitudinal section with respect to the axis, and an ellipse that contacts the inner roller 34 in a direction perpendicular to the axis of the joint in a cross section with respect to the axis of the leg shaft 22. A gap n is formed between the inner roller 34 and the inner roller 34 in the axial direction of the joint (see FIG. 4). The roller unit 30 is rotatably supported on the leg shaft 22 having such a shape.

  This type of constant velocity universal joint generally has a structure in which a rubber or resin boot 60 is mounted in order to prevent leakage of a lubricant such as grease enclosed in the joint and prevent foreign matter from entering from the outside of the joint. (See the broken line in FIG. 1). The boot 60 includes a large-diameter end portion fastened and fixed to the opening 11 of the outer joint member 10 by a boot band, a small-diameter end portion fastened and fixed to the shaft 40 extending from the tripod member 20 by a boot band, and a large-diameter end portion. And a bellows portion that is reduced in diameter from the large-diameter end portion toward the small-diameter end portion.

  In this constant velocity universal joint, the leg shaft 22 of the tripod member 20 and the roller guide surface 14 of the outer joint member 10 are engaged with each other in the biaxial rotation direction via the roller unit 30, so that the drive side is moved to the driven side. Rotational torque is transmitted at a constant speed. Further, when the roller unit 30 rolls on the roller guide surface 14 while rotating with respect to the leg shaft 22, relative axial displacement and angular displacement between the outer joint member 10 and the tripod member 20 are absorbed. Is done. Here, by encapsulating a lubricant in the inner space of the outer joint member 10 and the boot 60, the lubricity at the sliding portion inside the joint is ensured during the operation of rotating while taking the operating angle. .

  Further, a gap n is formed between the leg shaft 22 and the inner roller 34 in the axial direction of the joint, and the leg shaft 22 is tiltable with respect to the roller unit 30 that rolls on the roller guide surface 14. Even if the joint takes an operating angle, the roller unit 30 does not tilt with respect to the roller guide surface 14. In this way, the roller unit 30 and the roller guide surface 14 are prevented from being obliquely crossed with the inclination of the leg shaft 22, thereby reducing induced thrust and slide resistance.

  In the tripod type constant velocity universal joint according to this embodiment, the following retaining mechanism is employed in order to prevent a slide-over in which internal parts including the tripod member 20 and the roller unit 30 jump out of the opening 11 of the outer joint member 10. To do.

  As shown in FIGS. 1 to 3, the tripod type constant velocity universal joint includes a pair of rollers facing each other on both inner walls of the track groove 12 on the inner peripheral surface of the opening 11 of the outer joint member 10. The guide surface 14 has a structure in which a recess 15 into which an outer roller 32 as an internal part is fitted is provided. The recess 15 is formed at a portion closer to the inner diameter side that is fitted by a pressing force toward the inner diameter side due to interference of the boot 60 attached to the opening 11 of the outer joint member 10.

  In this embodiment, the case where the concave portions 15 are provided in the roller guide surfaces 14 of all three track grooves 12 is illustrated, but the concave portions 15 are provided in the roller guide surfaces 14 of at least one of the track grooves 12. Further, of the pair of roller guide surfaces 14 located on both sides of the track groove 12, the recess 15 may be provided only on the roller guide surface 14 located on one side.

  Here, the outer joint member 10 is manufactured, for example, by forming a material made of medium carbon steel into a general shape by forging, and then performing turning, high-frequency heat treatment, grinding, or the like. The recess 15 as a retaining mechanism for the internal parts is simultaneously formed by forging the outer joint member 10 described above. Moreover, the above-mentioned recessed part 15 does not need to perform the hardening process by heat processing.

  In this way, by forming the concave portion 15 simultaneously by forging the outer joint member 10, it is possible to perform turning processing for forming an annular concave groove as in the past, another part such as a circlip, and a caulking jig. Therefore, the dedicated equipment for positioning the outer joint member can be eliminated, the size of the recess 15 is not easily varied, and the recess 15 can be formed with high accuracy. Moreover, the simple means of simultaneous forming by forging of the outer joint member 10 can surely exert the retaining function, and can simplify the machining process and reduce the cost.

  In this tripod type constant velocity universal joint, when the internal components are displaced in the axial direction, as shown in FIGS. 5 to 7 (in the figure, the leg shaft 22 is omitted), the tripod type constant velocity universal joint tends to jump out from the opening 11 of the outer joint member 10. The outer roller 32 as an internal part interferes with the boot 60 attached to the opening 11 of the outer joint member 10. Since the outer roller 32 is pressed toward the inner diameter side of the outer joint member 10 due to the interference with the boot 60, as shown in FIGS. The outer roller 32 is fitted.

  In this way, the outer roller 32 fits into the recess 15 to restrict the amount of axial displacement of the internal component, thereby preventing the internal component from sliding out from the opening 11 of the outer joint member 10 in advance. it can. For example, when this tripod type constant velocity universal joint is assembled to a car as a drive shaft, the inner part is an outer joint member even if the total load of the fixed type constant velocity universal joint, hub bearing and knuckle is applied to the tripod type constant velocity universal joint. The slide over which jumps out from the 10 opening parts 11 can be prevented reliably.

  In this way, the outer roller 32 fitted in the recess 15 on the roller guide surface 14 of the outer joint member 10 can prevent a slide-over from jumping out of the opening 11 of the outer joint member 10 due to interference with the boot 60, while the inner parts The return movement of the outer joint member 10 to the inner side of the outer joint member 10 can be realized by the outer roller 32 being easily detached from the concave portion 15 of the roller guide surface 14 because there is no interference with the boot 60.

  In addition, when the inner component is displaced in the axial direction, the outer roller 32 of the inner component that is about to jump out from the opening 11 of the outer joint member 10 interferes with the boot 60, so that the force pressed toward the inner diameter side of the outer joint member 10 is increased. In order to achieve this, it is effective to use a boot 60 made of resin harder than rubber.

  In the above embodiment, the double roller type tripod type constant velocity universal joint having the two rollers 32 and 34 (the outer roller 32 and the inner roller 34) has been described. However, the present invention is not limited to this, and the double roller type. Besides, it is also applicable to a single roller type tripod type constant velocity universal joint. This single roller type tripod type constant velocity universal joint has a structure in which a single roller is externally fitted to a leg shaft 22 of a tripod member 20 via needle rollers.

  The present invention is not limited to the above-described embodiments, and can of course be implemented in various forms without departing from the gist of the present invention. It includes the equivalent meanings recited in the claims and the equivalents recited in the claims, and all modifications within the scope.

DESCRIPTION OF SYMBOLS 10 Outer joint member 11 Opening part 12 Track groove 14 Roller guide surface 15 Recessed part 20 Tripod member 22 Leg shaft 32 Roller (outer roller)
34 Innerola

Claims (7)

An outer joint member having a cup shape having an opening at one end, three track grooves extending in the axial direction on the inner peripheral surface, and roller guide surfaces facing each other on the inner wall of each track groove; A tripod member having three leg shafts projecting in the radial direction; and a roller guide surface rotatably supported on the leg shaft of the tripod member and rotatably inserted into a track groove of the outer joint member. A tripod type constant velocity universal joint in which an inner part including the roller and the tripod member is accommodated in the outer joint member so as to be axially slidable,
A tripod type constant velocity universal joint characterized in that a concave portion into which a roller of the internal part fits is provided on at least one side of the track groove on the inner peripheral surface of the opening of the outer joint member.   2. The tripod type constant velocity adjustable according to claim 1, wherein the recess is formed at a portion closer to the inner diameter side to be fitted by a pressing force toward the inner diameter side due to interference of a boot attached to the opening of the outer joint member. Fittings.   The tripod type constant velocity universal joint according to claim 2, wherein the boot is made of rubber.   The tripod type constant velocity universal joint according to claim 2, wherein the boot is made of resin.   The tripod type constant velocity universal joint according to any one of claims 1 to 4, wherein the concave portion is provided by simultaneous molding by forging of the outer joint member.   The tripod type constant velocity universal joint according to any one of claims 1 to 5, wherein the roller is externally fitted to the leg shaft via a needle roller.   The roller is an outer roller disposed on the outer peripheral side of an inner roller that is externally fitted to the leg shaft via needle rollers, the inner peripheral surface of the inner roller has a convex arc shape, and the leg shaft has a longitudinal section. In a straight shape perpendicular to the axis of the joint, in a cross-section in a direction perpendicular to the axis of the joint, and in contact with the inner peripheral surface of the inner roller, and between the inner peripheral surface of the inner roller in the axial direction of the joint The tripod type constant velocity universal joint according to any one of claims 1 to 5, wherein a gap is formed.

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