JP2018021570A - Constant-velocity universal joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a constant-velocity universal joint capable of improving lubricity of rolling elements (torque transmission members) and a rolling surface (a track groove).SOLUTION: A constant-velocity universal joint includes an outer joint member, an inner joint member, and torque transmission members disposed between the outer joint member and the inner joint member. The torque transmission members roll on a track groove. The torque transmission members and the track groove make angular contact. Flexible structures formed by a fiber material, a soft foam material, or a soft resin material are provided at a track groove bottom part which does not contact with the torque transmission members.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a constant velocity universal joint used in a power transmission device of an automobile or various industrial machines.

  The constant velocity universal joint includes a fixed type constant velocity universal joint that allows only angular displacement, and a sliding type constant velocity universal joint that allows not only angular displacement but also axial displacement (plunging). For fixed type constant velocity universal joints, the bar groove type constant velocity universal joint (BJ) in which the groove bottom of the track groove consists only of an arc portion and the undercut free type in which the groove bottom of the track groove consists of an arc portion and a straight portion There are constant velocity universal joints (UJ). The sliding type constant velocity universal joint includes a tripod type constant velocity universal joint, a double offset type constant velocity universal joint, a cross groove type constant velocity universal joint, and the like.

  By the way, when a ball is used as the torque transmitting member, the amount of sliding between the track groove and the ball can be reduced, and the contact surface pressure can be in a favorable range. There is an angular contact (see Patent Document 1). That is, in the fixed type constant velocity universal joint, as shown in FIG. 18, the track groove 2 of the outer joint member 1 and the track groove 4 of the inner joint member 3 are formed in a Gothic arch shape. By using a Gothic arch shape, the track grooves 2 and 4 and the ball 5 are in an angular contact. That is, the ball 5 is in contact with the track groove 2 of the outer joint member 1 at two points C11 and C12, and is in contact with the track groove 4 of the inner joint member 3 at two points C15 and C16. An angle formed by the contact point C11, C12, C15, C16 between the center O1 of the ball 5 and each of the track grooves 2, 4 is a contact angle α.

  In FIG. 18, 6 is a cage having a pocket (window) for holding a ball. That is, the cage 6 is interposed between the inner diameter surface 1 a of the outer joint member 1 and the outer diameter surface 3 a of the inner joint member 3.

  Even if a roller is used as the torque transmission member, there is a roller that makes an angular contact with the roller guide surface in order to stabilize the posture of the roller (see Patent Document 2). That is, in a tripod type constant velocity universal joint using a roller, as shown in FIG. 19, the roller guide surface 10 has a Gothic arch shape, and the roller 11 has an outer peripheral surface 11a and a roller guide surface having a circular cross section. There is a configuration in which 10 and 10 are in angular contact at two points.

JP 2011-106534 A Japanese Patent No. 4118537

  When the angular contact shape is employed, the lubricant may flow out of the gap between the ball and the track groove or the gap between the roller and the roller guide surface during high-speed rotation or the like. As described above, when it flows out, there is a possibility that sufficient lubrication cannot be performed on the contact portion between the ball and the track groove or the contact portion between the roller and the roller guide surface.

  Therefore, the present invention provides a constant velocity universal joint that can improve the lubricity of the rolling elements (torque transmission member) and the rolling surfaces (track grooves).

  The constant velocity universal joint of the present invention includes an outer joint member, an inner joint member, and a torque transmission member interposed between the outer joint member and the inner joint member, and the torque transmission member rolls in the track groove. A constant velocity universal joint in which a torque transmission member and a track groove form an angular contact, and a flexible structure made of a fiber material, a soft foam material, or a soft resin material is formed at the bottom of the track groove that does not contact the torque transmission member. It is provided.

  According to the constant velocity universal joint of the present invention, since the flexible structure is provided at the bottom of the track groove that does not contact the torque transmission member, the lubricant is held by the flexible structure. And since a torque transmission member does not contact a flexible structure, damage to a flexible structure can be prevented.

  A track groove is formed on the inner diameter surface of the outer joint member, and a track groove is formed on the outer diameter surface of the inner joint member. The ball of the torque transmission member is used, and the track groove of the ball and the outer joint member forms an angular contact. A constant velocity universal joint in which the ball and the track groove of the inner joint member form an angular contact, and at least one of the track groove of the outer joint member and the track groove of the inner joint member is provided with a flexible structure. Also good.

  Even if it is a fixed type that allows only angular displacement between the outer joint member and the inner joint member, it is a sliding type that allows angular displacement and axial displacement between the outer joint member and the inner joint member. Also good.

    An outer joint member formed with three track grooves having roller guide surfaces arranged facing each other in the circumferential direction, a tripod member having three leg shafts projecting in the radial direction, and a leg shaft of the tripod member A sliding constant velocity universal joint provided with a torque transmission member to be mounted, wherein the torque transmission member includes a roller that forms an angular contact with a roller guide surface of the track groove, and does not contact the roller. May be provided with a flexible structure at the bottom of the roller guide surface.

  The flexible structure forming method of the present invention is a flexible structure forming method for forming a flexible structure of the constant velocity universal joint, wherein the flexible structure is a fiber grafted with short fibers of synthetic resin. Flexible structure by electrostatic spraying flocking, which is composed of a portion, and short fibers are sprayed onto the adhesive layer by air, and the short fibers are inclined with respect to the forming surface of the flexible structure and adhered to the adhesive layer Is formed.

  According to the flexible structure forming method of the present invention, the short fibers can be adhered to the adhesive layer while being inclined with respect to the surface on which the flexible structure is formed. For this reason, compared with electrostatic flocking, the flocking density decreases, and flocking can be performed with a small amount of short fibers. Here, electrostatic flocking is a technique in which an adhesive is applied to a processed material (planted member), an electrostatic field is created by a high voltage electrode, and short fibers are erected by the electrostatic attraction force.

  In the constant velocity universal joint of the present invention, by providing a flexible structure, the amount of lubricant retained at the track groove bottom increases, and the amount of lubricant supplied to the contact portion with the torque transmission member (rolling element) increases. It is possible to improve the lubricity. For this reason, the filling amount of the lubricant can be reduced, the weight and cost can be reduced, and the assemblability and high-speed rotation of the joint are improved. That is, even when a small amount of lubricant is enclosed, it is possible to suppress the outflow of lubricant near the torque transmission member during sliding and high-speed rotation, and to prevent a decrease in NVH (Noise, Vibration, Harshness) and a decrease in life. In particular, in the case where a flexible structure is provided in the track groove of the inner joint member, the lubricant is retained at the groove bottom of the track groove of the inner joint member even when the lubricant flows to the outer diameter side, Sufficient lubrication can be performed on the rolling element contact portion of the joint member.

It is a longitudinal cross-sectional view of the fixed type constant velocity universal joint of the undercut free type of this invention. It is a cross-sectional view of the constant velocity universal joint of the present invention. It is a principal part enlarged view of the constant velocity universal joint of this invention. It is a simplification figure showing the formation part of a fiber flocking part. The formation site | part of a fiber flocking part is shown, (a) is an enlarged view by the side of an outer joint member, (b) is an enlarged view by the side of an inner joint member. It is explanatory drawing of an electrostatic flocking process. A fiber flocking part is shown, (a) is an enlarged view at the time of forming by electrostatic flocking, (b) is an enlarged view at the time of forming by electrostatic spraying flocking. It is sectional drawing of a fixed type constant velocity universal joint of a bar field type. It is sectional drawing of a sliding type constant velocity universal joint of a double offset type. The formation site | part of the fiber flocking part of the constant velocity universal joint shown in FIG. 9 is shown, (a) is an enlarged view by the side of an outer joint member, (b) is an enlarged view by the side of an inner joint member. It is sectional drawing of the sliding type constant velocity universal joint of a cross groove type constant velocity universal joint. FIG. 12 is a development view of a ball groove of the cross groove type constant velocity universal joint shown in FIG. 11. The formation site | part of the fiber flocking part of the constant velocity universal joint shown in FIG. 11 is shown, (a) is an enlarged view by the side of an outer joint member, (b) is an enlarged view by the side of an inner joint member. It is a cross-sectional view of a tripod type constant velocity universal joint. It is a longitudinal cross-sectional view of the tripod type constant velocity universal joint shown in FIG. FIG. 15 is a simplified diagram showing a formation site of a fiber flocked portion of the tripod type constant velocity universal joint shown in FIG. 14. It is an enlarged view of the formation site | part of the fiber flocking part of the tripod type constant velocity universal joint shown in FIG. It is an expanded sectional view which shows the relationship between a ball | bowl and a track groove in case a torque transmission member is a ball | bowl. It is an expanded sectional view which shows the relationship between a roller and a track groove in case a torque transmission member is a roller.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. 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 as shown in FIGS. 1 and 2, an outer joint member 23, It consists of an inner joint member 26, a ball 27 and a cage 28. A plurality of track grooves 22 are formed in the inner diameter surface 21 of the outer joint member 23 at equal intervals in the circumferential direction and along the axial direction. On the outer diameter surface 24 of the inner joint member 26, track grooves 25 facing the track grooves 22 of the outer joint member 23 are formed at equal intervals in the circumferential direction and along the axial direction. A plurality of balls 27 for transmitting torque are interposed between the track grooves 22 of the outer joint member 23 and the track grooves 25 of the inner joint member 26. A cage 28 having a window portion 29 for holding a ball 27 is disposed between the inner diameter surface 21 of the outer joint member 23 and the outer diameter surface 24 of the inner joint member 26. The outer diameter surface 28 a of the cage 28 is fitted with the inner diameter surface 21 of the outer joint member 23, and the inner diameter surface 28 b of the cage 28 is fitted with the outer diameter surface 24 of the inner joint member 26.

  The centers of curvature of the inner diameter surface 21 of the outer joint member 23 and the outer diameter surface 24 of the inner joint member 26 are respectively formed at the center O of the joint. The track groove 22 of the outer joint member 23 includes an opening-side straight portion 22a and a back-side arc portion 22b. On the other hand, the track groove 25 of the inner joint member 26 includes an arc portion 25b on the opening side and a straight portion 25a on the back side. The center of curvature O1 of the arc portion 22b of the track groove 22 of the outer joint member 23 and the center of curvature O2 of the arc portion 25b of the track groove 25 of the inner joint member 26 are equidistant F in the axial direction with respect to the center O of the joint. It is offset. As a result, when the joint takes an operating angle, the ball 27 is always guided on a plane that bisects the angle formed by both the outer joint member 23 and the inner joint member 26, and rotates at a constant speed between the two axes. Will be transmitted.

  A female spline 32 is formed in the axial hole of the inner joint member 26, and the end of the shaft 33 is fitted into the axial hole of the inner joint member 26. A male spline 34 is formed at the end of the shaft 33, and the female spline 32 and the male spline 34 are fitted when the end of the shaft 33 is fitted into the axial hole of the inner joint member 26. A circumferential groove 36 is formed at the end of the male spline 34, and a retaining ring 37 is fitted into the circumferential groove 36. Thus, the shaft 33 is prevented from coming off.

  The opening of the outer joint member 23 is closed by the boot 40. The boot 40 includes a large diameter portion 40a that constitutes one opening, a small diameter portion 40b that constitutes the other opening, and a bellows portion 40c that connects the large diameter portion 40a and the small diameter portion 40b. And the large diameter part 40a of the boot 40 is mounted | worn in the state externally fitted by the opening part of the outer joint member 23. FIG. Further, the small-diameter portion 40 b of the boot 40 is mounted in a state of being externally fitted to the boot mounting portion 33 a of the shaft 33.

  FIG. 3 is an essential part of FIG. 2, and more specifically, is a cross section of the track grooves 22 and 25 of the outer joint member 23 and the inner joint member 26 facing each other. As shown in FIG. 3, the ball 27 is in angular contact with the track groove 22 of the outer joint member 23 at two points C12 and C13, and is in angular contact with the track groove 25 of the inner joint member 26 at two points C15 and C16. . An angle α formed by a straight line passing through the ball center O5 and the contact points C12, C13, C15, C16 and a straight line passing through the ball center O5 and the joint center O is set to 30 ° to 38 °, for example.

  In this constant velocity universal joint, as shown in FIG. 4, a flexible structure 150 is provided on the track groove bottom portions 22 c and 25 c that do not contact the ball 27 that is a torque transmission member. The flexible structure 150 is made of a fiber material, a soft foam material, or a soft resin material. When comprised from a fiber material, it forms with the fiber flocking part formed by flocking a fiber material (short fiber: pile). Here, as shown in FIG. 3, the track groove bottom 22c is between the contacts C12 and C13, and the track groove bottom 25c is between the contacts C15 and C16.

  The fiber flocking portion that is the flexible structure 150 can be formed by electrostatic flocking. Examples of the electrostatic flocking process include an adhesive application process, an electrostatic flocking process, a drying process, and a finishing process. The electrostatic flocking process is shown in FIG. In electrostatic flocking, an adhesive is applied to an object (base material) 151 to form an adhesive layer S, an electrostatic field is created by a high voltage electrode, and short fibers are raised on the adhesive layer S by electrostatic attraction force. After that, a drying process for drying the adhesive of the adhesive layer S is performed, and then a finishing process for performing hair removal or the like is performed.

  In the electrostatic flocking process, short fibers 152 (which are coated with an electrolyte or a surfactant coating on the surface thereof, that is, an electrodeposition treatment agent coated) are cut into a predetermined size. It throws in the vicinity of. With this input, the short fiber 152 is attracted to the electrode by the Coulomb force. For this reason, the short fiber 152 is charged to the same potential as the electrode at the moment when it touches the electrode 153 and is repelled by Coulomb force. Since the repelled short fibers 152 are given a high potential, they fly toward the ground side. At this time, since the adhesive layer S is formed on the surface 151 a of the ground-side object 151, the short fibers 152 are pierced (throwed) into the adhesive layer S.

  The short fibers 152 are not particularly limited as long as they can be used as short fibers for flocking. For example, (1) polyolefin resins such as polyethylene and polypropylene, polyamide resins such as nylon, aromatic polyamide resins, polyethylene terephthalate, polyethylene naphthalate Polyester resin such as phthalate, polyethylene succinate and polybutylene terephthalate, synthetic resin fiber such as acrylic resin, vinyl chloride and vinylon, (2) inorganic fiber such as carbon fiber and glass fiber, (3) regeneration of rayon and acetate Examples include fibers and natural fibers such as cotton, silk, hemp, and wool. These may be used independently and 2 or more types may be used together. It is preferable to use synthetic resin fiber among the above because it is difficult to cause swelling and dissolution with oil, is chemically stable, can produce a large amount of homogeneous fibers, and can be obtained at low cost.

  The shape of the short fiber is not particularly limited as long as it does not interfere with other members that adversely affect the constant velocity universal joint function at the place where the flocked portion is formed. As a specific shape, for example, those having a length of 0.5 to 2.0 mm and a thickness of 0.5 to 50 dtex are preferable, and the density of short fibers in the flocked portion is occupied by fibers per planted area. A ratio of 10 to 30% is preferable. There are straight and bend (shape where the tip is bent) as the shape of the short fiber, and the cross-sectional shape is circular or polygonal. The bend shape can hold the grease more strongly than the straight shape. By using the short fibers having a polygonal cross section, the surface area can be made larger than that of the short fibers having a circular cross section, and the surface tension of the lubricant can be increased. It is preferable to select the shape of the short fiber according to each characteristic.

  Examples of the adhesive used for the adhesive layer S include adhesives mainly composed of urethane resin, epoxy resin, acrylic resin, vinyl acetate resin, polyimide resin, silicone resin, and the like. For example, urethane resin solvent adhesive, epoxy resin solvent adhesive, vinyl acetate resin solvent adhesive, acrylic resin emulsion adhesive, acrylate-vinyl acetate copolymer emulsion adhesive, vinyl acetate emulsion adhesive , Urethane resin emulsion adhesive, epoxy resin emulsion adhesive, polyester emulsion adhesive, ethylene-vinyl acetate copolymer adhesive and the like. These may be used independently and 2 or more types may be used together.

  When electrostatic flocking is performed as described above, as shown in FIG. 7A, the short fibers 152 are stuck into the adhesive layer S applied to the surface 151 a of the object (base material) 151. In this case, it is usually thrown perpendicular to the surface 151a of the object (base material) 151.

  On the other hand, if electrostatic spraying is performed, the short fibers 152 can be fixed to the object (base material) 151 at a constant angle as shown in FIG. The electrostatic spraying flocking is based on substantially the same principle as the electrostatic flocking, and air is blown against the short fibers 152. That is, the short fibers are pierced into the adhesive layer S from one end by an electrostatic suction force, and are fixed to the object (base material) 151 at a certain angle by the action of air.

  In this electrostatic spraying flocking, the short fibers 152 can cover the base material surface 151a having a larger area than when the short fibers 152 are upright. For this reason, the number of short fibers fixed per base material surface 151a can be reduced and the density can be reduced. That is, the flocking density is reduced as compared with electrostatic flocking, and flocking can be performed with a small amount of short fibers 152. In the case of mass production, the cost can be reduced by reducing the number of short fibers 152 and shortening the time.

  In addition, when the flexible structure 150 is formed of a soft foam material or a soft resin material, a material that has been formed and processed in advance in a predetermined shape is bonded to the formation site of the flexible structure 150 with an adhesive or the like. do it.

  Soft foam materials are obtained by foaming synthetic resins such as polyurethane, polystyrene, polyolefin, phenol, and polyvinyl chloride, and rubbers such as natural rubber, chloroprene rubber, ethylene propylene rubber, nitrile rubber, silicon rubber, and styrene butadiene rubber. Foamed material. Examples of the soft resin material include cork materials, rubber plate materials, and soft sheets such as polyethylene and vinyl chloride. Moreover, as an adhesive agent when using a soft foam material or a soft resin material, the adhesive agent used when flocking the short fibers can be used. That is, it can be said that it is preferable to use a fiber material, a soft foam material, and a soft resin material that are excellent in lubricant retention, and use a fiber material. Among fiber materials, use of synthetic resin short fibers because they are chemically stable, resistant to swelling and dissolution by oil, can be produced in large quantities and can be obtained at low cost. Is preferred.

  FIG. 8 shows a bar field type fixed type constant velocity universal joint, and the constant velocity universal joint is an outer joint in which a track groove 22 is formed on the inner diameter surface 21 like the undercut free type fixed type constant velocity universal joint. As a torque transmission member interposed between the member 23, the inner joint member 26 in which the track groove 25 is formed on the outer diameter surface 24, and the track groove 22 of the outer joint member 23 and the track groove 25 of the inner joint member 26. , And a cage 28 interposed between the outer joint member 23 and the inner joint member 26.

  In this case, each of the track groove 22 of the outer joint member 23 and the track groove 25 of the inner joint member 26 is composed of one arc portion. For this reason, the other structure of the constant velocity universal joint of FIG. 8 is the same as that of the constant velocity universal joint shown in FIG.

Therefore, also in this fixed type constant velocity universal joint, as shown in FIGS. 4 and 5 (a) (b),
A flexible structure 150 made of a fiber material, a soft foam material, or a soft resin material is provided on the track groove bottom portions 22c and 25c that do not come into contact with the ball 27 that is a torque transmission member.

  Next, FIG. 9 shows a double offset type sliding type constant velocity universal joint. The constant velocity universal joint includes an outer joint member 43 having a track groove 42 formed on the inner diameter surface 41 and a track on the outer diameter surface 44. An inner joint member 46 in which a groove 45 is formed; a ball 47 as a torque transmission member that is interposed between the track groove 42 of the outer joint member 43 and the track groove 45 of the inner joint member 46; A pocket 49c for accommodating the ball 47 is provided, and a cage 49 interposed between the outer joint member 43 and the inner joint member 46 is provided. The center of curvature of the outer peripheral surface 49a of the cage 49 and the center of curvature of the inner peripheral surface 49b are offset in the axial direction opposite to the angular center of the joint.

  A female spline 46 a is formed in the axial hole of the inner joint member 46, and the end of the shaft 48 is fitted into the axial hole of the inner joint member 46. A male spline 48a is formed at the end of the shaft 48. When the end of the shaft 48 is fitted into the axial hole of the inner joint member 46, the female spline 46a and the male spline 48a are fitted. A circumferential groove 48b is formed at the end of the male spline 48a, and a retaining ring 50 is fitted in the circumferential groove. Thereby, the shaft 48 is prevented from coming off.

  The opening of the outer joint member 43 is closed by the boot 40 similarly to the boot 40 shown in FIG. Therefore, the boot 40 includes a large-diameter portion 40a that constitutes one opening, a small-diameter portion 40b that constitutes the other opening, and a bellows portion 40c that connects the large-diameter portion 40a and the small-diameter portion 40b. . And the large diameter part 40a of the boot 40 is mounted | worn in the state externally fitted by the opening part of the outer joint member 43. FIG. Further, the small diameter portion 40 b of the boot 40 is mounted in a state of being externally fitted to the boot mounting portion 48 c of the shaft 48.

  Also in this sliding type constant velocity universal joint, as shown in FIGS. 10A and 10B, a fiber material, a soft foam material, or A flexible structure 150 made of a soft resin material is provided.

  FIG. 11 shows a cross-groove type sliding constant velocity universal joint. This constant velocity universal joint has ball grooves 52 (52a, 22b) twisted in directions opposite to each other on the outer peripheral surface 51 with respect to the axis (see FIG. 12). ) Are alternately formed in the circumferential direction, and ball grooves 55 (55a, 55b) (see FIGS. 2 and 3) twisted in the inner circumferential surface 54 in opposite directions with respect to the axis are circumferential. A plurality of torques incorporated at the intersections of the outer joint members 56 formed alternately in the direction and the ball grooves 52 of the inner joint member 53 and the ball grooves 55 of the outer joint member 56 twisted in opposite directions with respect to the axis. The transmission ball 57 includes a window 58c that is interposed between the outer peripheral surface 51 of the inner joint member 53 and the inner peripheral surface 54 of the outer joint member 56 and holds the torque transmission ball 57 at a predetermined interval in the circumferential direction. With cage 58

  In FIG. 12, β indicates the crossing angle of each ball groove 52a, 52b, 55a, 55b with respect to the axis. The torque transmission ball 57 is incorporated at the intersection of each ball groove 52a, 52b, 55a, 55b.

  As shown in FIG. 11, a shaft 60 is inserted into a center hole (inner diameter hole) 59 of the inner joint member 53 and is spline-fitted, and torque can be transmitted between the two by the spline fitting. That is, a female spline 59 a is formed in the center hole 59 of the inner joint member 53, a male spline 60 a is formed at the shaft end portion of the shaft 60, and the shaft end portion of the shaft 60 is fitted into the center hole 59 of the inner joint member 53. Thus, the female spline 59a of the inner joint member 53 and the male spline 60a of the shaft 60 are fitted. A circumferential groove 60b is formed at the end of the male spline 60a, and a retaining ring 61 is fitted into the circumferential groove. Thereby, the shaft 60 is prevented from coming off.

  An end cap 62 is fitted on one end side in the axial direction of the outer joint member 56 (an opening on the opposite shaft protruding side), and an outer ring opening on the shaft protruding side is closed by a sealing device 63. The sealing device 63 includes a boot 65 made of rubber or resin and a metal adapter 64 made of metal.

  The boot 65 includes a small end portion 65b, a large end portion 65a, and a V-shaped or U-shaped folded portion 65c that connects the small end portion 65b and the large end portion 65a. The metal adapter 64 includes a cylindrical main body portion 64c and a large-diameter cylindrical portion 64a that is connected to the main body portion 64c via a ring-shaped flat plate 64b and is fitted onto the outer joint member 56. . The small end portion 65 b of the boot 65 is attached to the shaft 60 and fastened with a boot band 66. The large end portion 65 a of the boot 65 is held by crimping the end portion of the main body portion 64 c of the metal adapter 64.

  The end cap 62 includes a cylindrical portion 62a fitted on the outer joint member 56, a deep dish-like member 62c that bulges to the opposite joint side, and a ring that continuously connects the cylindrical portion 62a and the deep-plate-like member 62c. And a flat plate 62b. A bolt member (not shown) is attached to the outer joint member 56, and the metal adapter 64 and the end cap 62 of the sealing device 63 are supported by the outer joint member 56 by the attachment of the bolt member. That is, the ring-shaped flat plate 62b of the end cap 62 and the ring-shaped flat plate 64b of the adapter 64 are provided with through holes 67 and 68, respectively, and the outer joint member 56 is provided with a through hole 69. And a bolt member is inserted in the through hole 69.

Also in this sliding type constant velocity universal joint, as shown in FIGS. 13 (a) and 13 (b), a fiber material, a soft foam material, or A flexible structure 150 made of a soft resin material is provided.
Is provided.

  14 and 15 show a tripod type sliding constant velocity universal joint. This sliding type constant velocity universal joint is a tripod type, and an inner side provided with an outer joint member 72 provided with three track grooves 71 extending in the axial direction on the inner periphery and three leg shafts 73 projecting in the radial direction. A tripod member 74 as a joint member, and a roller 75 as a torque transmission means that is rotatably supported by the leg shaft 73 and is rotatably inserted into the track groove 71 of the outer joint member.

  In this case, the roller 75 is fitted on the outer diameter surface of the leg shaft 73 via a plurality of needle rollers 76 disposed along the circumferential direction. The outer circumferential surface of the leg shaft 73 constitutes the inner rolling surface of the needle roller 76, and the inner circumferential surface of the roller 75 constitutes the outer rolling surface of the needle roller 76. The plurality of needle rollers 76 are disposed between the outer peripheral surface of the leg shaft 73 and the inner peripheral surface of the roller 75 in a full roller state.

  These needle rollers 76 are in contact with the inner washer 80 fitted to the base of the leg shaft 73 on the inner side in the radial direction, and are in contact with the outer washer 81 fitted on the tip of the leg shaft 73 on the outer side in the radial direction. Yes. The outer washer 81 is prevented from coming off by fitting a retaining ring 83 such as a circular circlip into an annular groove 82 formed at the tip of the leg shaft 73.

  The tripod member 74 includes a boss portion 77 and the leg shaft 73 extending in the radial direction from the boss portion 77. A female spline 86 is provided in the shaft hole 85 of the boss portion 77 of the tripod member (trunnion) 74. A shaft 88 having a male spline 87 formed at the end is fitted into the shaft hole 85, and the male spline 87 and the female spline 86 are fitted. A circumferential groove 89 is provided at the end of the male spline 87, and a retaining ring 90 is attached to the circumferential groove 89.

  By the way, the outer joint member 72 has a cup-shaped mouth portion 91 opened at one end and a shaft portion 92 projecting from the bottom wall of the mouth portion. A track groove 71 extending in the axial direction is formed at an equal position. As shown in FIG. 15, the mouse portion 91 has a non-cylindrical shape in which a large diameter portion 91a and a small diameter portion 91b appear alternately when viewed in a cross section. That is, the mouse portion 91 is formed with the large-diameter portion 91a and the small-diameter portion 91b, whereby the three track grooves 71 extending in the axial direction are formed on the inner peripheral surface thereof. Roller guide surfaces (roller sliding contact surfaces) 71a and 71b are formed on the side walls of each track groove 71 facing in the circumferential direction.

  In this case, the torque transmission member includes a roller 75 that forms an angular contact with the roller guide surfaces 71a and 71b of the track groove 71. Therefore, the roller guide surface 71a (71b) that forms the track groove bottom 71c that does not contact the roller 75. The flexible structure 150 is provided in the bottom part of this. The track groove bottom 71c that does not contact the roller 75 is between the contacts C21 and C22 between the roller 75 and the roller guide surfaces 71a and 71b.

  In the constant velocity universal joint of the present invention, by providing the flexible structure 150, the amount of lubricant retained in the track groove bottom portions 22c, 25c, 42c, 45c, 52c, 55c, 71c increases, and the torque transmission member (the rolling member) The amount of lubricant supplied to the contact portion with the moving bodies 27, 47, 57, and 75) can be increased, and the lubricity can be improved. For this reason, the filling amount of the lubricant can be reduced, the weight and cost can be reduced, and the assemblability and high-speed rotation of the joint are improved. That is, even when a small amount of lubricant is enclosed, it is possible to suppress the outflow of lubricant near the torque transmission member during sliding and high-speed rotation, and to prevent a decrease in NVH (Noise, Vibration, Harshness) and a decrease in life. In particular, in the case where the flexible structure 150 is provided in the track grooves 25, 45, 52 of the inner joint members 26, 46, 53, the lubricant remains in the inner joint member even when the lubricant flows to the outer diameter side. 26, 46, 53 are held at the groove bottoms of the track grooves 25, 45, 52, and sufficient lubrication can be performed on the rolling element contact portions of the inner joint members 26, 46, 53.

  Further, if electrostatic spraying is carried out, the flocking density is reduced as compared with electrostatic flocking, and the flocking can be carried out with a small amount of fibers (short fibers) 152. Therefore, in the case of mass production, it is possible to reduce the cost by reducing the short fibers 152 and shortening the time.

  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 can be made, and the torque transmission member as shown in FIGS. In the above embodiment, the flexible structure is provided in the track groove of the outer joint member and the track groove of the inner joint member. However, the track groove of the outer joint member and the track groove of the inner joint member are used. Only one of them may be used.

  Further, the number of balls as the torque transmitting member is not limited to eight, and the increase / decrease is arbitrary. As a cross-glove type constant velocity universal joint, even if it is a float type (the maximum outer diameter of the inner joint member is set larger than the minimum inner diameter of the cage and the axial displacement is regulated by interference between the inner joint member and the cage) , Non-float type (in which the maximum outer diameter of the inner joint member is set smaller than the minimum inner diameter of the cage and the axial displacement is regulated by the interference between the ball and the cage), torque transmission in the case of the tripod type The member may be a single roller type or a double roller type.

  For electrostatic flocking, different processing methods depending on the flying direction of the short fibers (pile), that is, the up type (method of flying the pile from below), the down type (method of flying the pile from above), There are a side type (a method in which a pile is caused to fly in a horizontal direction) and an up-down type (a method in which an up type and a down type are combined at the same time).

21 inner surface 22, 25 track groove 22c, 25c track groove bottom 23 outer joint member 24 outer surface 26 inner joint member 27 ball 41 inner surface 42, 45 track groove 42c, 45c track groove bottom 43 outer joint member 44 outer surface 46 Inner joint member 47 Ball 51 Outer peripheral surface 52, 52a, 52b Ball groove 52c Track groove bottom 53 Inner joint member 54 Inner peripheral surface 55, 55a, 55b Ball groove 56 Outer joint member 57 Torque transmission ball 71 Track groove 71a, 71b Roller Guide surface 71c Track groove bottom 72 Outer joint member 73 Leg shaft 74 Tripod member 75 Roller 150 Flexible structure 152 Short fiber S Adhesive layer

Claims (6)

A constant velocity universal joint comprising an outer joint member, an inner joint member, and a torque transmission member interposed between the outer joint member and the inner joint member, wherein the torque transmission member rolls on the track groove,
The torque transmission member and the track groove form an angular contact, and a flexible structure made of a fiber material, a soft foam material, or a soft resin material is provided at the bottom of the track groove that does not contact the torque transmission member. Fast universal joint. A track groove is formed on the inner diameter surface of the outer joint member, and a track groove is formed on the outer diameter surface of the inner joint member. The ball of the torque transmission member is used, and the track groove of the ball and the outer joint member forms an angular contact. A constant velocity universal joint in which the track groove of the ball and the inner joint member forms an angular contact,
The constant velocity universal joint according to claim 1, wherein a flexible structure is provided in at least one of the track groove of the outer joint member and the track groove of the inner joint member.   3. The constant velocity universal joint according to claim 1, wherein the constant velocity universal joint is a fixed type that allows only an angular displacement between the outer joint member and the inner joint member. 4.   3. The constant velocity universal joint according to claim 1, wherein the constant velocity universal joint according to claim 1 is a sliding type that allows angular displacement and axial displacement between the outer joint member and the inner joint member. 4. An outer joint member formed with three track grooves having roller guide surfaces arranged facing each other in the circumferential direction, a tripod member having three leg shafts projecting in the radial direction, and a leg shaft of the tripod member A sliding constant velocity universal joint provided with a torque transmission member to be mounted;
The torque transmission member includes a roller that forms an angular contact with a roller guide surface of a track groove, and a flexible structure is provided at a bottom portion of the roller guide surface that forms a track groove bottom portion that does not contact the roller. Item 2. The constant velocity universal joint according to Item 1. A flexible structure forming method for forming a flexible structure of a constant velocity universal joint according to any one of claims 1 to 5,
The flexible structure is composed of a fiber-planted portion in which short fibers of synthetic resin are planted, and the short fibers are sprayed onto the adhesive layer by air to incline the short fibers with respect to the surface on which the flexible structure is formed. And forming the flexible structure by electrostatic spraying flocking to adhere to the adhesive layer.

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