JP2012189190A - Sliding-type constant-velocity universal joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the machining man-hour and the number of parts to reduce cost, to reduce the weight of an outer joint member, and to improve moldability and assemblability of a boot as well as retainability of an inner member.SOLUTION: The tripod type constant-velocity universal joint includes: an outer joint member 10 having facing roller guide surfaces 14 formed on inner walls of three track grooves 12; a tripod member 20 having three radially protruding foot shafts 22; and rollers 30 rotatably supported by the foot shafts 22, inserted in the track groove 12 of the outer joint member 10 so as to be rollable, and guided along the roller guide surface 14. The tripod type constant-velocity universal joint is formed by mounting a large-diameter end part 51 of the boot 50 for closing an opening 11 of the outer joint member 10 to an outer circumference of the opening 11. On the whole inner circumferential surface of the large-diameter end part 51 of the boot 50, a flange 54 is formed to protrude radially inward of the outer joint member 10 from the track groove 12.

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 sliding type constant velocity universal joint that allows axial displacement and angular displacement between them.

  There are two types of constant velocity universal joints incorporated in drive shafts, propeller shafts, and the like that transmit rotational force from an automobile engine to wheels at a constant speed: fixed constant velocity universal joints and sliding constant velocity universal joints. 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.

  A drive shaft that transmits power from an automobile engine to a driving wheel needs to cope with an angular displacement and an axial displacement caused by a change in a relative positional relationship between the engine and the wheel. Side) and a fixed type 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 roller type tripod type constant velocity universal joint (TJ) using a roller as a torque transmission member. Another sliding constant velocity universal joint includes a ball type double offset constant velocity universal joint (DOJ) using a ball as a torque transmission member.

  The tripod type constant velocity universal joint has 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 Formed on the outer joint member, a tripod member having three leg shafts projecting in the radial direction, and rotatably supported on the leg shaft of the tripod member and rollable in the track groove of the outer joint member The main part is composed of the roller inserted and guided along the roller guide surface.

  This type of constant velocity universal joint has a structure in which an internal part composed of a tripod member and a roller is accommodated in an outer joint member so as to be axially slidable. One end of a shaft is connected to the shaft hole of the tripod member by spline fitting, and the inner joint member of a fixed type constant velocity universal joint is connected to the other end of the shaft by spline fitting. Furthermore, in this constant velocity universal joint, a bellows-like shape is formed between the opening of the outer joint member and the shaft in order to prevent leakage of a lubricant such as grease enclosed in the joint and to prevent foreign matter from entering from the outside of the joint. The structure with the boots is generally installed.

  When assembling this 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 assembled on the drive wheel side (outboard side). It is common. When the tripod type constant velocity universal joint on the engine side is assembled, the fixed type constant velocity universal joint on the drive wheel side is not assembled to the suspension system on the vehicle body side and is completely suspended, and is further assembled only to the lower arm. A large load may be applied in the slide-out direction because the hub bearing and knuckle that are easily tilted or are not fixed anywhere are assembled.

  In such a state, there may be a slide over in which the internal parts of the tripod type constant velocity universal joint jump out of the opening of the outer joint member. At the time of such a slide-over, it becomes difficult to reinsert the internal part into the outer joint member because the roller of the internal part is inclined. Therefore, conventionally, in order to prevent this slide-over, the following retaining mechanism is employed.

  One of the retaining mechanisms includes a structure in which an annular groove is provided in the vicinity of the opening of the outer joint member on the inner peripheral surface of the boot, and a stopper member is fitted in the annular groove (for example, a patent) Reference 1). With this structure, when the internal component is displaced in the axial direction, the roller interferes with the stopper member, thereby restricting the amount of axial displacement of the roller, so that the internal component protrudes from the opening of the outer joint member. I try to prevent over.

  In addition, as a retaining mechanism for the ball type double offset constant velocity universal joint, a protrusion that fits inside the opening of the outer joint member is provided on the inner peripheral surface of the boot so as to be a wedge in the track groove axial direction. (For example, refer to Patent Document 2). With such a structure, when the internal component is displaced in the axial direction, the ball interferes with the protrusions to restrict the amount of axial displacement of the ball, so that the internal component protrudes from the opening of the outer joint member. Try to prevent. In addition, in this patent document 2, the case where it applies to a roller type tripod type constant velocity universal joint is also disclosed.

  Further, as a retaining mechanism in the roller type tripod type constant velocity universal joint, there is a structure in which a stopper portion for preventing shaft slipping protruding radially inward is integrally formed on the inner peripheral surface of the end portion of the boot (for example, (See Patent Document 3). This stopper for preventing shaft slippage is formed only in a portion corresponding to the track groove of the outer joint member in the circumferential direction. With such a structure, when the internal part is displaced in the axial direction, the roller interferes with the stopper for preventing the shaft from coming off, thereby restricting the amount of axial displacement of the roller. The slide-over which jumps out from the part is prevented.

JP 2000-283175 A JP-A-9-177816 Japanese Utility Model Publication No. 63-123829

  In the conventional constant velocity universal joint disclosed in Patent Document 1, a stopper member that regulates the axial displacement of the roller is assembled to the end of the boot, so that the inner peripheral surface of the boot is near the opening of the outer joint member. An annular groove must be formed in the part, the inner peripheral surface of the boot must be grooved, and a stopper member is also required, increasing the number of processing steps and the number of parts, increasing the cost of the product Will be invited.

  Further, in the conventional constant velocity universal joint disclosed in Patent Document 2, since the protrusion fitted into the opening inside the outer joint member is provided on the inner peripheral surface of the boot, the protrusion is a track groove of the outer joint member. The axial sliding range of the internal parts is narrowed by the amount of penetration. The axial sliding range of the internal part is determined by the axial length of the track groove of the outer joint member. As a result, in order to ensure the axial sliding range of the internal parts, it is necessary to lengthen the axial dimension of the outer joint member, and the weight of the outer joint member increases accordingly.

  Furthermore, in the conventional constant velocity universal joint disclosed in Patent Document 3, the stopper portion for preventing the shaft from protruding radially inward is integrated only in the portion corresponding to the track groove of the outer joint member in the circumferential direction of the boot. Therefore, it is very difficult to form the boot, resulting in an increase in cost. Further, when attaching the boot to the opening of the outer joint member, it is necessary to align the stopper portion for preventing the shaft from slipping off and the track groove, and the assembly work of the boot becomes complicated. In addition, when the internal parts are displaced in the axial direction, one roller interferes with one axial stopper to prevent the stopper from receiving an axial load. Therefore, the stopper is low in rigidity and has low locking performance. .

  The present invention has been proposed in view of the above-mentioned problems, and its object is to reduce costs by reducing the number of processing steps and the number of parts, and to reduce the weight without increasing the axial dimension of the outer joint member. Therefore, an object of the present invention is to provide a sliding type constant velocity universal joint that can improve the formability and assembly property of the boot and the ability to prevent the internal parts from coming off.

  As a technical means for achieving the above-mentioned object, the present invention is an outer joint in which a cup shape having an opening at one end is formed and track grooves extending in the axial direction are formed at a plurality of positions in the circumferential direction of the inner peripheral surface. A rolling element including a member and an inner coupling member that transmits torque while allowing angular displacement between the outer coupling member and a rolling element that is rotatably inserted in a track groove of the outer coupling member. The inner part including the inner joint member and the inner joint member are accommodated in the outer joint member so as to be axially slidable, and the end portion of the boot that closes the opening of the outer joint member is mounted on the outer peripheral surface of the opening. A universal joint is characterized in that a flange portion is provided over the entire inner peripheral surface of the end portion of the boot so as to project toward the radially inner side of the outer joint member and project from the track groove.

  In the sliding type constant velocity universal joint according to the present invention, by providing a flange portion that protrudes radially inward of the outer joint member and protrudes from the track groove over the entire circumference of the inner peripheral surface of the end portion of the boot, When the internal component is displaced in the axial direction, the internal component interferes with the flange portion to restrict the amount of axial displacement of the internal component, thereby preventing the internal component from sliding out from the opening of the outer joint member. This is especially effective when the fixed constant velocity universal joint, hub bearing, and knuckle load is applied in the slide-out direction of the sliding constant velocity universal joint when assembling this sliding constant velocity universal joint as a drive shaft in an automobile. Thus, the assembly performance of the constant velocity universal joint is improved.

  On the other hand, since it is possible to eliminate the processing for forming the annular concave groove as in the prior art and separate parts such as the stopper member, the cost can be reduced by reducing the number of processing steps and the number of parts. In addition, since there is no protrusion that fits inside the opening of the outer joint member as in the prior art, the axial sliding range of the internal part is ensured without increasing the axial dimension of the outer joint member. The weight of the outer joint member can be reduced.

  Furthermore, since the flange portion of the present invention is continuously formed over the entire inner peripheral surface of the end portion of the boot, it is easy to form the boot, and when attaching the boot to the opening of the outer joint member, There is no need to align the flange portion with the track groove, and the assembly of the boot is simplified. In addition, when the internal parts are displaced in the axial direction, the flange part formed continuously over the entire circumference of the boot receives the axial load, so the rigidity of the flange part is high and the internal parts can be prevented from coming off. it can.

  The flange part in this invention has the desirable structure provided so that the end surface of the opening part of an outer joint member may be contact | connected. In this way, when the joint takes an operating angle, it is possible to ensure good operability of the joint without the flange portion inhibiting the deformation of the boot.

  It is desirable that the flange portion in the present invention is integrally formed by boot injection molding. If it does in this way, the flange part which protrudes toward the radial inside of an outer joint member over the perimeter of the edge part inner peripheral surface of a boot, and protrudes from a track groove can be formed easily.

  The flange portion in the present invention is preferably set so that its axial thickness decreases from the radially outer side toward the radially inner side, and in particular, at least one of the boot side end surface or the outer joint member side end surface is tapered. It is preferable to make it into a shape. In this case, since it is easy to remove the mold at the time of molding the boot, the productivity can be improved and the cost is effective. Further, since the base portion of the flange portion can be thickened, the rigidity of the entire flange portion is improved, and the retaining performance of the internal parts is improved.

  The boot in the present invention is desirably made of an elastomer (elastic body), and in particular, either resin or rubber is suitable as the material. If the material is selected in this way, the expansion and contraction when the boot changes in angle can be absorbed without difficulty. The elastic modulus of the boot material is desirably 30 to 150 MPa. If this elastic modulus is smaller than 30 MPa, the rigidity of the flange portion is too small to prevent a slide-over in which the internal parts jump out, and if the elastic modulus is larger than 150 MPa, the rigidity of the entire boot is too large. When the joint takes an operating angle, the deformation resistance increases, which increases the torque of the joint or shortens the durability life.

  In the outer joint member of the present invention, three track grooves extending in the axial direction are formed on the inner peripheral surface, and roller guide surfaces facing each other are formed on the inner side wall of each track groove. A tripod member having three leg shafts inserted into the track groove, and the rolling element is rotatably supported by the leg shaft and is inserted into the track groove of the outer joint member to be guided along the roller guide surface. It is desirable to have a structure that is a roller to be used. That is, the present invention can be applied to a roller type tripod type constant velocity universal joint having such a structure.

  Further, in the inner joint member in the present invention, the linear track groove extending in the axial direction is formed at a plurality of locations on the outer peripheral surface in pairs with the track groove of the outer joint member, and the rolling element includes the track groove of the outer joint member. It is a ball that is disposed between the track grooves of the inner joint member and preferably has a cage that is interposed between the inner peripheral surface of the outer joint member and the outer peripheral surface of the inner joint member and holds the ball. That is, the present invention can be applied to a ball type double offset constant velocity universal joint having such a structure.

  According to the present invention, the axial displacement of the internal part is provided by providing the flange portion that protrudes radially inward of the outer joint member and protrudes from the track groove over the entire inner peripheral surface of the end portion of the boot. When the internal part interferes with the flange portion, the axial displacement amount of the internal part is regulated to prevent the internal part from sliding out from the opening of the outer joint member.

  Since the conventional processing for forming the annular concave groove and a separate part such as a stopper member can be made unnecessary, the cost can be reduced by reducing the number of processing steps and the number of parts. In addition, since there is no protrusion that fits inside the opening of the outer joint member as in the prior art, the axial sliding range of the internal part is ensured without increasing the axial dimension of the outer joint member. The weight of the outer joint member can be reduced.

  Furthermore, since the flange portion is continuously formed over the entire inner peripheral surface of the end portion of the boot, it is easy to form the boot, and it is not necessary to align the flange portion and the track groove when the boot is mounted. Assembling the boots is also simple. In addition, when the internal parts are displaced in the axial direction, the flange part formed continuously over the entire circumference of the boot receives the axial load, so the rigidity of the flange part is high and the internal parts can be prevented from coming off. it can.

  In this way, the flange part that protrudes radially inward of the outer joint member over the entire circumference of the inner peripheral surface of the end of the boot is provided to improve the retaining performance of internal parts. Thus, it is possible to provide a sliding type constant velocity universal joint that can be easily reduced in cost and weight.

1 is a longitudinal sectional view showing an overall configuration of a tripod type constant velocity universal joint in an embodiment of a sliding type constant velocity universal joint according to the present invention. It is A arrow directional view of FIG. 1 in the state before boot | wearing mounting. It is sectional drawing which follows the BB line of FIG. It is a principal part expanded sectional view which shows the boot band which enlarged the axial direction dimension. FIG. 6 is a longitudinal sectional view showing the overall configuration of a tripod type constant velocity universal joint in another embodiment of FIG. 1. FIG. 5 is a longitudinal sectional view showing the entire configuration of a double offset type constant velocity universal joint in another embodiment of the sliding type constant velocity universal joint according to the present invention. It is C arrow line view of FIG. 6 in the state before boot | wearing installation. It is sectional drawing which follows the DD line | wire of FIG. It is a principal part expanded sectional view which shows the boot band which enlarged the axial direction dimension. FIG. 7 is a longitudinal sectional view showing an overall configuration of a double offset type constant velocity universal joint in another embodiment of FIG. 6.

  Embodiments of the sliding type constant velocity universal joint according to the present invention will be described in detail below. In the following embodiment, a single roller type tripod type constant velocity universal joint is illustrated. In addition to the single roller type, the present invention can also be applied to a double roller type tripod type constant velocity universal joint capable of reducing vibration during operation. In addition to the tripod type constant velocity universal joint, the present invention can be applied to other sliding type constant velocity universal joints such as a ball type double offset type constant velocity universal joint.

  1 and 2 show the basic configuration of a single roller type tripod constant velocity universal joint, FIG. 1 is a longitudinal sectional view with respect to the axis of the joint, and FIG. 2 is a view of the joint in the direction of arrow A before the boot is mounted. Yes (however, only one roller 30 is shown in cross section). The tripod type constant velocity universal joint according to this embodiment includes an outer joint member 10, a tripod member 20 that is an inner joint member, and a roller 30 that is a rolling element.

  The outer joint member 10 has a cup shape having an opening 11 at one end, and a shaft 13 is integrally formed at the center of the bottom. 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, the portion corresponding to the space between the track grooves 12 is thinned to reduce the weight, and the concave portion 15 is formed in the axial direction. Inside the outer joint member 10, an internal component 60 composed of a tripod member 20 and a roller 30 is accommodated so as to be slidable in the axial direction.

  The tripod member 20 has three leg shafts 22 integrally formed radially at equal intervals in the circumferential direction (120 ° intervals) on the outer peripheral surface of a cylindrical boss 21. The front end of the leg shaft 22 extends in the radial direction to the vicinity of the bottom of the track groove 12, and the outer peripheral surface thereof is generally a cylindrical surface. 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 41.

  A roller 30 is rotatably disposed via a needle roller 31 between the roller guide surface 14 of the track groove 12 of the outer joint member 10 and the outer peripheral surface of the leg shaft 22. The outer peripheral surface of the roller 30 has an arc shape in vertical section, and may contact with the roller guide surface 14 at two locations by angular contact or contact at one location by circular contact. On the other hand, the inner peripheral surface of the roller 30 is formed in a cylindrical shape. A plurality of needle rollers 31 are arranged between the roller 30 and the leg shaft 22 in a so-called single row full roller state without a cage. The outer circumferential surface of the leg shaft 22 constitutes the inner rolling surface of the needle roller 31, and the inner circumferential surface of the roller 30 constitutes the outer rolling surface of the needle roller 31.

  These needle rollers 31 are in contact with the inner washer 32 fitted to the base portion of the leg shaft 22 on the radially inner side, and are in contact with the outer washer 33 fitted on the tip portion of the leg shaft 22 on the radially outer side. Yes. The outer washer 33 is prevented from coming off by fitting a retaining ring 34 such as a round circlip into an annular groove 23 formed at the tip of the leg shaft 22.

  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 rotational direction via the roller 30 to rotate from the driving side to the driven side. Torque is transmitted at a constant speed. Further, the roller 30 rolls on the roller guide surface 14 while rotating with respect to the leg shaft 22, thereby allowing relative axial displacement and angular displacement between the outer joint member 10 and the tripod member 20. The

  This type of constant velocity universal joint is provided between the outer joint member 10 and the shaft 40 in order to prevent leakage of lubricant such as grease enclosed in the joint and to prevent foreign matter from entering from the outside of the joint. A structure in which a rubber or resin boot 50 that closes the opening 11 of the member 10 is mounted is provided. Thus, by sealing the lubricant in the inner space of the outer joint member 10 and the boot 50, the sliding part inside the joint during the operation in which the shaft 40 rotates with respect to the outer joint member 10 while taking an operating angle. In other words, the lubricity at the sliding portion constituted by the outer joint member 10, the tripod member 20 and the roller 30 is ensured.

  The boot 50 is fastened and fixed by the boot band 72 to the outer peripheral surface of the shaft 40 extending from the tripod member 20 and the large-diameter end portion 51 fastened and fixed to the outer peripheral surface of the opening 11 of the outer joint member 10. The small-diameter end portion 52 is connected to the large-diameter end portion 51 and the small-diameter end portion 52, and the telescopic bellows portion 53 has a diameter reduced from the large-diameter end portion 51 toward the small-diameter end portion 52.

  In the constant velocity universal joint of this embodiment, when the internal part 60 is displaced in the axial direction, the internal part 60 is prevented from sliding out from the opening 11 of the outer joint member 10, as shown in FIGS. 1 and 3. In addition, a retaining structure is provided in which a flange portion 54 is provided over the entire inner peripheral surface of the large-diameter end portion 51 of the boot 50 so as to protrude toward the radially inner side of the outer joint member 10 and project from the track groove 12. is doing. In this retaining structure of the internal component 60, the flange portion 54 can interfere with the internal component 60 when the internal component 60 is displaced in the axial direction by setting the inner diameter of the tip of the flange portion 54 to be smaller than the maximum outer diameter of the internal component 60. It becomes. In the illustrated embodiment, the flange portion 54 is protruded greatly inward in the radial direction so that the tip inner diameter of the flange portion 54 corresponds to the position of the roller 30 of the internal component 60.

  In this constant velocity universal joint, a flange portion 54 is provided that protrudes from the track groove 12 and protrudes radially inward of the outer joint member 10 over the entire inner peripheral surface of the large-diameter end portion 51 of the boot 50. As a result, when the internal component 60 is displaced in the axial direction, the internal component 60 interferes with the flange portion 54 to restrict the amount of axial displacement of the internal component 60, so that the internal component 60 is attached to the outer joint member 10. The slide over which jumps out from the opening part 11 is prevented. In particular, when this tripod type constant velocity universal joint is assembled to a car as a drive shaft, it is effective when the load of the fixed type constant velocity universal joint, hub bearing and knuckle is applied in the slide-out direction of the tripod type constant velocity universal joint, The assemblability of this constant velocity universal joint is improved.

  On the other hand, since it is possible to eliminate the processing for forming the annular concave groove as in the prior art and separate parts such as the stopper member, the cost can be reduced by reducing the number of processing steps and the number of parts. In addition, since there is no protrusion that fits inside the opening of the outer joint member as in the prior art, the axial sliding range of the internal component 60 is ensured without increasing the axial dimension of the outer joint member 10. This can reduce the weight of the outer joint member 10.

  Furthermore, since the flange portion 54 of this embodiment is continuously formed over the entire inner peripheral surface of the large-diameter end portion 51 of the boot 50, the boot 50 can be easily molded, and the boot 50 is connected to the outer joint. When attaching to the opening part 11 of the member 10, the alignment of the flange part 54 and the track groove 12 is unnecessary, and the assembly of the boot 50 is also simplified. Further, when the internal component 60 is displaced in the axial direction, the flange portion 54 continuously formed over the entire circumference of the boot 50 receives an axial load, so that the flange portion 54 has high rigidity and prevents the internal component 60 from coming off. Can be improved.

  When the internal component 60 is displaced in the axial direction, the tip of the flange portion 54 is deformed to the boot bellows side. Along with this deformation, there is a possibility that the boot outer diameter around the flange portion is deformed so as to bulge outward in the radial direction. Therefore, as shown in FIG. 4, the boot bellows side of the boot band 73 is extended in the axial direction, and the axial dimension of the boot band 73 is made larger than the boot band 71 in the embodiment of FIG. Good. Thus, by pressing the boot outer diameter around the flange portion radially inward with the boot band 73, when the internal component 60 is displaced in the axial direction, the outer diameter of the boot around the flange portion is deformed as the tip of the flange portion 54 is deformed. Prevents deformation to bulge outward in the radial direction.

  The flange portion 54 in this embodiment is provided such that the outer joint member side end surface 55 opposite to the boot side end surface is in contact with the end surface of the opening 11 of the outer joint member 10. By providing the flange portion 54 at such a position, when the joint takes an operating angle, the flange portion 54 does not hinder the deformation of the bellows portion 53 of the boot 50 and ensures good operability of the joint. Can do.

  In this embodiment, the flange portion 54 is integrally formed by injection molding of the boot 50. In this way, by forming the flange portion 54 simultaneously with the injection molding of the boot 50, the entire inner peripheral surface of the large-diameter end portion 51 of the boot 50 is directed radially inward of the outer joint member 10. The flange portion 54 that protrudes from the track groove 12 can be easily formed.

  The flange portion 54 is set so that its axial thickness decreases from the radially outer side toward the radially inner side. Since the outer joint member side end face 55 opposite to the boot side end face of the flange portion 54 is in contact with the end face of the opening 11 of the outer joint member 10, the boot side end face 56 of the flange portion 54 is tapered. Yes. By adopting such a structure, since it is easy to remove the mold when the boot 50 is molded, the productivity can be improved and the cost is effective. Moreover, since the base part of the flange part 54 can be thickened, the rigidity of the whole flange part improves and the fall prevention performance of the internal component 60 improves.

  This boot 50 is made of an elastomer (elastic body). As the material, either resin or rubber is suitable. By selecting the material in this way, the expansion and contraction when the boot 50 changes the angle can be absorbed without difficulty. Note that the elastic modulus of the material of the boot 50 is 30 to 150 MPa. If this elastic modulus is less than 30 MPa, the rigidity of the flange portion 54 is too small to make it difficult to prevent a slide-over in which the internal component 60 jumps out. If the elastic modulus is greater than 150 MPa, the rigidity of the entire boot is large. If this happens, the deformation resistance when the joint takes an operating angle increases, which increases the torque of the joint and shortens the durability life.

  In the embodiment of FIG. 1, the flange portion 54 is greatly extended radially inward so that the inner diameter of the tip of the flange portion 54 corresponds to the position of the roller 30 of the internal component 60. 12, and the flange portion 57 may protrude radially inward so that the tip inner diameter of the flange portion 57 corresponds to the position of the leg shaft 22 of the internal component 60 as shown in FIG. . The flange portion 57 is also provided so that the outer joint member side end surface 58 opposite to the boot side end surface is in contact with the end surface of the opening 11 of the outer joint member 10, and the boot side end surface 59 is tapered.

  In the above embodiment, the case where it is applied to a roller type tripod type constant velocity universal joint has been described. However, the present invention can also be applied to a ball type double offset type constant velocity universal joint shown in FIGS. FIG. 6 is a longitudinal sectional view with respect to the axis of the joint, and FIG. As shown in FIGS. 6 and 7, the double offset type constant velocity universal joint includes an outer joint member 110, an inner joint member 120, a ball 130 that is a rolling element, and a cage 170, and the main part.

  This constant velocity universal joint has a cup shape having an opening 111 at one end, an outer joint member 110 in which linear track grooves 112 extending in the axial direction are formed at a plurality of locations on the inner peripheral surface, and a straight line extending in the axial direction. The inner joint member 120 is formed at a plurality of locations on the outer peripheral surface in pairs with the track grooves 112 of the outer joint member 110, and the track grooves 112 of the outer joint member 110 and the track grooves 122 of the inner joint member 120 are formed. And a cage 180 that is interposed between the inner peripheral surface of the outer joint member 110 and the outer peripheral surface of the inner joint member 120 to hold the ball 130.

  In this embodiment, a six-ball constant velocity universal joint is illustrated, but the present invention can also be applied to an eight-ball constant velocity universal joint, and the number of balls 130 is arbitrary. Inside the outer joint member 110, an inner part 160 composed of the inner joint member 120, the ball 130 and the cage 180 is housed so as to be slidable in the axial direction. Further, the shaft end of the shaft 140 is connected to the shaft hole of the inner joint member 120 by spline fitting, and is prevented from coming off from the inner joint member 120 by an annular snap ring 141.

  This type of constant velocity universal joint is provided between the outer joint member 110 and the shaft 140 in order to prevent leakage of a lubricant such as grease enclosed in the joint and to prevent foreign matter from entering from the outside of the joint. A structure in which a rubber or resin boot 150 for closing the opening 111 of the member 110 is mounted is provided. The boot 150 is fastened and fixed to the outer peripheral surface of the opening 111 of the outer joint member 110 by a boot band 171 and the outer peripheral surface of the shaft 140 extending from the inner joint member 120 by the boot band 172. The small-diameter end portion 152, the large-diameter end portion 151, and the small-diameter end portion 152 are connected to each other, and the telescopic bellows portion 153 is contracted from the large-diameter end portion 151 toward the small-diameter end portion 152. .

  In the constant velocity universal joint of this embodiment, when the internal part 160 is displaced in the axial direction, the internal part 160 is prevented from jumping out from the opening 111 of the outer joint member 110, as shown in FIGS. In addition, a retaining structure is provided in which a flange portion 154 is provided over the entire inner peripheral surface of the large-diameter end portion 151 of the boot 150 so as to protrude toward the radially inner side of the outer joint member 110 and project from the track groove 112. is doing. In this retaining structure of the internal part 160, the flange part 154 can interfere with the internal part 160 when the internal part 160 is displaced in the axial direction by setting the inner diameter of the tip of the flange part 154 to be smaller than the maximum outer diameter of the internal part 160. It becomes. In the illustrated embodiment, the flange portion 154 protrudes greatly inward in the radial direction so that the tip inner diameter of the flange portion 154 corresponds to the position of the inner joint member 120 of the internal part 160. Since the action and effect of the flange part 154 preventing the internal part 160 from coming off are the same as those in the embodiment of the tripod type constant velocity universal joint described above, redundant description is omitted.

  Also in this embodiment, as shown in FIG. 9, the boot bellows side of the boot band 173 is extended in the axial direction, and the axial dimension of the boot band 173 is larger than the boot band 171 in the embodiment of FIG. You may do it. As a result, by pressing the boot outer diameter around the flange portion radially inward with the boot band 173, when the internal component 160 is displaced in the axial direction, the boot outer diameter around the flange portion is deformed along with the deformation of the tip of the flange portion 154. It is possible to prevent deformation so as to bulge outward in the radial direction.

  Also in this embodiment, the flange portion 154 is provided such that the outer joint member side end surface 155 opposite to the boot side end surface is in contact with the end surface of the opening 111 of the outer joint member 110. The point formed integrally by molding and the point where the axial thickness is set so as to decrease from the radially outer side toward the radially inner side (particularly, the boot-side end surface 156 of the flange portion 154 is tapered). Is the same as the above-described embodiment of the tripod type constant velocity universal joint, and the operation and effect thereof are also the same, and thus the duplicated explanation is omitted.

  Further, the boot 150 is also made of an elastomer (elastic body) as a material, as the material, either resin or rubber is suitable, and the elastic modulus of the material of the boot 150 is 30 to 150 MPa. Since it is the same as that of the above-mentioned embodiment of the tripod type constant velocity universal joint and its operation and effect are also the same, the duplicate description is omitted.

  In the embodiment of FIG. 6, the flange portion 154 protrudes greatly inward in the radial direction so that the inner diameter of the tip of the flange portion 154 corresponds to the position of the inner joint member 120 of the internal part 160, but the flange portion 154 is the minimum necessary. As shown in FIG. 10, the flange portion 157 may protrude slightly inward in the radial direction so that the inner diameter of the tip of the flange portion 157 corresponds to the position of the ball 130 of the internal part 160 as shown in FIG. Good. The flange portion 157 is also provided so that the outer joint member side end surface 158 opposite to the boot side end surface is in contact with the end surface of the opening 111 of the outer joint member 110, and the boot side end surface 159 is tapered.

  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 20 Inner joint member (tripod member)
22 Leg shaft 30 Rolling element (roller)
50 Boot 51 End (Large diameter end)
54 Flange 60 Internal parts

Claims (10)

An outer joint member having a cup shape having an opening at one end and extending in the axial direction at a plurality of locations in the circumferential direction of the inner peripheral surface, and a roll groove inserted into the track groove of the outer joint member. An inner joint member that transmits torque while allowing angular displacement with the outer joint member via a rolling element, and an inner part including the rolling element and the inner joint member is pivoted on the outer joint member. A slidable constant velocity universal joint that is slidably accommodated in a direction and has an end of a boot that closes an opening of the outer joint member mounted on an outer peripheral surface of the opening;
A sliding type constant velocity universal joint provided with a flange portion that protrudes radially inward of the outer joint member and protrudes from the track groove over the entire inner peripheral surface of the end portion of the boot. .   The sliding type constant velocity universal joint according to claim 1, wherein the flange portion is provided so as to be in contact with an end face of the opening portion of the outer joint member.   The sliding type constant velocity universal joint according to claim 1 or 2, wherein the flange portion is integrally formed by injection molding of a boot.   The sliding constant velocity universal joint according to any one of claims 1 to 3, wherein the flange portion is set so that an axial thickness thereof decreases from a radially outer side toward a radially inner side.   The sliding type constant velocity universal joint according to any one of claims 1 to 4, wherein the flange portion has at least one of a boot side end surface or an outer joint member side end surface tapered.   The sliding constant velocity universal joint according to any one of claims 1 to 5, wherein a material of the boot is an elastomer.   The sliding type constant velocity universal joint according to any one of claims 1 to 6, wherein a material of the boot is selected from resin or rubber.   The sliding constant velocity universal joint according to any one of claims 1 to 7, wherein an elastic modulus of a material of the boot is 30 to 150 MPa.   In the outer joint member, three track grooves extending in the axial direction are formed on the inner peripheral surface, and roller guide surfaces facing each other are formed on the inner side wall of each track groove. A tripod member having three leg shafts inserted into the track groove, wherein the rolling element is rotatably supported by the leg shaft and is inserted into the track groove of the outer joint member to form the roller guide surface. The sliding type constant velocity universal joint according to any one of claims 1 to 8, wherein the roller is a roller guided along the axis.   In the inner joint member, linear track grooves extending in the axial direction are formed at a plurality of locations on the outer peripheral surface in pairs with the track grooves of the outer joint member, and the rolling elements include the track grooves of the outer joint member and the inner joint A ball disposed between a track groove of the member and a cage for holding the ball interposed between an inner peripheral surface of the outer joint member and an outer peripheral surface of the inner joint member. The sliding constant velocity universal joint according to any one of claims 8 to 9.

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