JP2017110694A - Contact velocity universal joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce machining man-hours and machining time in recess groove machining, to easily contract a shaft.SOLUTION: A contact velocity universal joint includes an outside joint member 11, and an inside joint member 12 configured to transmit torque while allowing angle displacement through a ball 13 between itself and the outside joint member 11, wherein a shaft 19 is fitted into a shaft hole 20 of the inside joint member 12 in a torque transmittable manner, and the shaft 19 is prevented from falling out from the inside joint member 12. At a center hole 23 for machining formed on a shaft end surface 22 of the shaft 19, mounted is a stopper member 24 configured to prevent the shaft 19 from falling out from the inside joint member 12.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a constant velocity universal joint that is used in a power transmission system of an automobile or various industrial machines, and is particularly incorporated in a drive shaft or a propeller shaft for an automobile.

  There are two types of constant velocity universal joints incorporated in drive shafts and propeller shafts that transmit rotational force from the engine of an automobile 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.

  The drive shaft needs to cope with angular displacement and axial displacement due to a change in the relative positional relationship between the engine and the wheels. Therefore, the drive shaft is generally equipped with a sliding type constant velocity universal joint on the engine side (inboard side) and a fixed type constant velocity universal joint on the wheel side (outboard side). It has a structure in which universal joints are connected by a shaft.

  The constant velocity universal joint provided at both ends of the shaft constituting the drive shaft is an inner joint that transmits torque while allowing angular displacement between the outer joint member and the outer joint member via a torque transmission member. And the shaft is fitted into the shaft hole of the inner joint member so that torque can be transmitted, and the shaft is prevented from coming off from the inner joint member.

  As a shaft retaining structure for the inner joint member, there is one disclosed in Patent Document 1. The retaining structure disclosed in Patent Document 1 forms an annular groove at the shaft end of the shaft, and forms a recess at the back end of the shaft hole of the inner joint member. By locking the fitted retaining ring in the recess of the inner joint member, the shaft is prevented from coming off from the inner joint member.

JP 2006-207721 A

  By the way, the shaft retaining structure disclosed in Patent Document 1 forms an annular concave groove on the outer peripheral surface of the shaft end portion of the shaft, and forms a concave portion at the back end portion of the shaft hole of the inner joint member. The retaining ring fitted in the concave groove of the shaft is engaged with the concave portion of the inner joint member.

  In the case of such a shaft retaining structure, it is necessary to form a groove on the outer peripheral surface of the shaft end of the shaft, which increases the processing time and processing time for the groove processing at the shaft end of the shaft, thereby increasing the cost. May be incurred.

  Moreover, in order to form a ditch | groove in the outer peripheral surface of the axial end part of a shaft, the shaft requires the part which protrudes from the back | end side edge part of an inner side coupling member. The shaft length of the shaft is increased by the amount of the protruding portion, which also increases the cost.

  Furthermore, although there are those that retain the retaining ring by locking with the back end face of the inner joint member, as in Patent Document 1, it is formed at the back end of the shaft hole of the inner joint member. In the structure in which the retaining ring is locked to the recess, a process for forming the recess in the shaft hole of the inner joint member is required. In this respect as well, there is a possibility that the processing man-hours and processing time for the recess processing in the shaft hole of the inner joint member increase, resulting in an increase in cost.

  Therefore, the present invention has been proposed in view of the above-described problems, and the object of the present invention is to reduce the number of processing steps and processing time for the concave groove processing, and the constant speed at which the shaft can be easily shortened. It is to provide a universal joint.

  The constant velocity universal joint according to the present invention includes an outer joint member and an inner joint member that transmits torque while allowing angular displacement between the outer joint member and the outer joint member via the torque transmission member. The shaft hole is fitted to the shaft hole so that torque can be transmitted, and the shaft is prevented from coming off from the inner joint member.

  As a technical means for achieving the above-mentioned object, the present invention is characterized in that a stopper member for preventing the shaft from coming off from the inner joint member is attached to a processing center hole formed in the shaft end surface of the shaft. And

  In the present invention, a machining center hole formed on the shaft end surface of the shaft is used as a shaft retaining structure, so that it is not necessary to form a groove on the outer peripheral surface of the shaft end portion of the shaft as in the prior art. It becomes. As a result, the portion protruding from the back end of the inner joint member is not necessary, so that the shaft length of the shaft can be shortened. It is not necessary to form a recess in the shaft hole of the inner joint member.

  The stopper member in the present invention is preferably composed of a convex portion that is press-fitted into the machining center hole, and a flange portion that is provided at an axial end portion of the convex portion and abuts against the end face of the inner joint member. .

  In this retaining structure, the convex part is press-fitted into the machining center hole of the shaft, and the flange part is locked to the end face of the inner joint member, so that the shaft can be easily retained from the inner joint member by the stopper member. can do.

  The stopper member in the present invention is configured by a convex portion that is press-fitted into the machining center hole, and the convex portion is an outer portion that is set to a tightening allowance capable of expanding the shaft end of the shaft by press-fitting into the machining center hole. It is desirable to have a diameter.

  In this retaining structure, the shaft can be easily retained against the inner joint member by the stopper member by expanding the shaft end of the shaft by press-fitting the convex portion into the machining center hole. it can.

  According to the present invention, since the machining center hole formed on the shaft end surface of the shaft is used, it is not necessary to form a groove on the outer peripheral surface of the shaft end portion of the shaft. Moreover, since the part which protrudes from the back | inner side edge part of an inner side coupling member becomes unnecessary, the axial length of a shaft can be shortened.

  As a result, costs can be reduced by reducing the number of processing steps and processing time, and a lightweight and compact constant velocity universal joint can be provided by shortening the shaft.

It is sectional drawing which shows a fixed type constant velocity universal joint in embodiment of this invention. It is sectional drawing which follows the PP line | wire of FIG. It is sectional drawing which shows the sliding type constant velocity universal joint in other embodiment of this invention. It is sectional drawing which follows the QQ line of FIG. It is sectional drawing which shows other embodiment applied to the sliding-type constant velocity universal joint of FIG. It is sectional drawing which shows other embodiment applied to the sliding-type constant velocity universal joint of FIG.

  An embodiment of a constant velocity universal joint according to the present invention will be described below in detail with reference to the drawings.

  1 and 2 exemplify a case where the present invention is applied to a fixed type constant velocity universal joint. The illustrated fixed type constant velocity universal joint is an undercut-free type constant velocity universal joint (UJ), but can also be applied to a Rzeppa type constant velocity universal joint (BJ).

  3 and 4 exemplify the case where the present invention is applied to a sliding type constant velocity universal joint. The illustrated sliding type constant velocity universal joint is a tripod type constant velocity universal joint (TJ), but can also be applied to a double offset type constant velocity universal joint (DOJ) or a cross groove type constant velocity universal joint (LJ). is there.

  The fixed type constant velocity universal joint of the embodiment shown in FIG. 1 and FIG. 2 is composed mainly of an outer joint member 11, an inner joint member 12, six balls 13 as torque transmission members, and a cage 14. Has been.

  The outer joint member 11 has a cup shape with one end opened, and six curved track grooves 15 extending in the axial direction are formed at six equal intervals in the circumferential direction of the spherical inner peripheral surface 16. In the inner joint member 12, six curved track grooves 17 extending in the axial direction form pairs with the track grooves 15 of the outer joint member 11 and are formed at equal intervals in six circumferential directions on the spherical outer peripheral surface 18. .

  The ball 13 is disposed between the track groove 15 of the outer joint member 11 and the track groove 17 of the inner joint member 12 and transmits rotational torque between the outer joint member 11 and the inner joint member 12. The cage 14 is interposed between the inner peripheral surface 16 of the outer joint member 11 and the outer peripheral surface 18 of the inner joint member 12 to hold the ball 13. The number of balls 13 is six, but may be eight and the number is arbitrary.

  In the constant velocity universal joint configured as described above, the shaft 19 is coupled to the inner joint member 12 so as to transmit torque by spline fitting. In this spline fitting, a female spline is formed on the inner peripheral surface of the shaft hole 20 of the inner joint member 12 and a male spline is formed on the outer peripheral surface of the shaft end portion 21 of the shaft 19. The shaft end portion 21 of the shaft 19 is press-fitted into the shaft 20.

  In the coupling structure of the inner joint member 12 and the shaft 19, the shaft 19 is prevented from coming off from the inner joint member 12 with the following structure. This constant velocity universal joint includes a retaining structure in which a stopper member 24 that retains the shaft 19 with respect to the inner joint member 12 is attached to a machining center hole 23 formed in the shaft end surface 22 of the shaft 19.

  Generally, the shaft 19 is subjected to processing for forming a groove for mounting a boot or processing for forming a spline. In order to position the shaft 19 during the processing, a processing center hole 23 is provided in advance on the shaft end surface 22 of the shaft 19.

  In this embodiment, a machining center hole 23 formed in advance on the shaft end surface 22 of the shaft 19 is used. Thereby, the conventional process which forms a ditch | groove in the outer peripheral surface of the shaft end part 21 of the shaft 19 becomes unnecessary. As a result, it is possible to reduce the processing man-hours and processing time for the concave groove processing, and it is possible to reduce the cost.

  On the other hand, the stopper member 24 is provided integrally with the convex portion 25 that is press-fitted into the above-described machining center hole 23 and the axial end portion of the convex portion 25, and contacts the back end surface 26 of the inner joint member 12. It is comprised with the flange part 27 which touches. In the stopper member 24, the convex portion 25 is press-fitted into the machining center hole 23 of the shaft 19, and the flange portion 27 is locked to the end surface 26 of the inner joint member 12. The stopper member 24 may be made of metal such as SUS, SPC, and ZAM, or resin such as TE. As the material of the outer joint member 11 and the inner joint member 12, medium carbon steel for machine structures represented by S53C and the like is suitable.

  In this way, by using the processing center hole 23 of the shaft end surface 22 of the shaft 19 to prevent the shaft 19 from coming off from the inner joint member 12 by the stopper member 24, the inner joint member 12 as in the conventional shaft is used. The part which protrudes from the back | inner side edge part of is also unnecessary. As a result, since the shaft length of the shaft 19 can be shortened, the constant velocity universal joint can be reduced in weight and size.

  In the assembly of the fixed type constant velocity universal joint described above, the internal parts including the inner joint member 12, the ball 13, and the cage 14 are assembled in the outer joint member 11, and then the inner part of the outer joint member 11 is assembled. The shaft 19 is assembled into the inner joint member 12 by press-fitting the shaft 19 into the accommodated inner joint member 12.

  Therefore, the stopper member 24 is assembled by fixing the flange portion 27 in advance to the inner end surface 26 of the inner joint member 12 in a state before being assembled into the outer joint member 11 by welding or the like. The shaft 19 is press-fitted into the shaft hole 20 of the inner joint member 12 incorporated in the outer joint member 11, thereby coupling the shaft 19 to the inner joint member 12 by spline fitting so that torque can be transmitted, and a stopper. The convex portion 25 of the member 24 is press-fitted into the machining center hole 23 of the shaft 19. In this way, the shaft 19 is prevented from coming off from the inner joint member 12.

  Next, the sliding type constant velocity universal joint of the embodiment shown in FIGS. 3 and 4 includes an outer joint member 31, a tripod member 32 which is an inner joint member, and three rollers 33 which are torque transmission members. The main part is composed.

  The outer joint member 31 has a cup shape with one open end, and three linear track grooves 34 extending in the axial direction are formed at three equal intervals in the circumferential direction of the cylindrical inner peripheral surface 35. Each track groove 34 has a pair of roller guide surfaces 36 facing each other on both inner walls thereof. The roller guide surface 36 has an arc-shaped cross section and extends linearly in the axial direction of the outer joint member 31.

  In the tripod member 32, three leg shafts 38 are integrally formed radially on the outer peripheral surface of a cylindrical boss 37 at equal intervals in the circumferential direction (120 ° intervals). The leg shaft 38 has a distal end extending in the radial direction to the vicinity of the bottom of the track groove 34, and an outer peripheral surface thereof is generally a cylindrical surface.

  A roller 33 is rotatably disposed between the roller guide surface 36 of the outer joint member 31 and the outer peripheral surface of the leg shaft 38 via a needle roller 39. The outer peripheral surface of the roller 33 has an arc shape in the longitudinal section, and the inner peripheral surface of the roller 33 is formed in a cylindrical shape. A plurality of needle rollers 39 are disposed between the roller 33 and the leg shaft 38 in a so-called single row full roller state without a cage. The outer peripheral surface of the leg shaft 38 constitutes the inner rolling surface of the needle roller 39, and the inner peripheral surface of the roller 33 constitutes the outer rolling surface of the needle roller 39.

  The needle rollers 39 are in contact with the inner washer 40 fitted to the base of the leg shaft 38 on the radially inner side, and are in contact with the outer washer 41 fitted on the tip of the leg shaft 38 on the outer side in the radial direction. . The outer washer 41 is prevented from coming off by fitting a retaining ring 43 into an annular groove 42 (see FIG. 3) formed at the tip of the leg shaft 38.

  In the constant velocity universal joint configured as described above, the shaft 19 is coupled to the boss 37 of the tripod member 32 so as to transmit torque by spline fitting. In this spline fitting, a female spline is formed on the inner peripheral surface of the shaft hole 44 of the boss 37, a male spline is formed on the outer peripheral surface of the shaft end portion 45 of the shaft 19, and the shaft 19 is inserted into the shaft hole 44 of the boss 37. The shaft end portion 45 is press-fitted.

  In the coupling structure of the tripod member 32 and the shaft 19, the shaft 19 is prevented from coming off from the tripod member 32 with the following structure. The constant velocity universal joint of this embodiment has a retaining structure in which a stopper member 24 for retaining the shaft 19 with respect to the tripod member 32 is mounted in a processing center hole 47 formed in the shaft end surface 46 of the shaft 19. To do.

  In this embodiment as well, as in the case of the fixed type constant velocity universal joint described above, the processing center hole 47 formed in advance on the shaft end surface 46 of the shaft 19 is used, and the convex that is press-fitted into the processing center hole 47. A stopper member 24 is used, which is composed of a portion 25 and a flange portion 27 that is provided integrally with the end portion in the axial direction of the convex portion 25 and abuts against the back end surface 48 of the tripod member 32. In the stopper member 24, the convex portion 25 is press-fitted into the machining center hole 47 of the shaft 19, and the flange portion 27 is locked to the end surface 48 of the tripod member 32.

  In this way, by using the processing center hole 47 of the shaft end surface 46 of the shaft 19 to prevent the shaft 19 from coming off from the tripod member 32 by the stopper member 24, Conventional processing for forming the groove is not required. As a result, it is possible to reduce the processing man-hours and processing time for the concave groove processing, and it is possible to reduce the cost. Moreover, the part which protrudes from the back side edge part of the tripod member 32 like the conventional shaft becomes unnecessary. As a result, since the shaft length of the shaft 19 can be shortened, the constant velocity universal joint can be reduced in weight and size.

  In the assembly of the sliding type constant velocity universal joint described above, the shaft 19 can be assembled to the tripod member 32 before incorporating the internal parts including the tripod member 32 and the roller 33 into the outer joint member 31. Is possible.

  Therefore, after the shaft end portion 45 of the shaft 19 is press-fitted into the shaft hole 44 of the tripod member 32, the convex portion 25 of the stopper member 24 is press-fitted into the machining center hole 47 of the shaft end surface 46 of the shaft 19, and the flange portion 27. Is locked to the end surface 48 of the tripod member 32. In this way, the shaft 19 is prevented from coming off from the tripod member 32.

  In the above two embodiments, the case where the convex portion 25 of the stopper member 24 has a cylindrical shape and the convex portion 25 is press-fitted into the processing center holes 23 and 47 of the shaft 19 has been described. However, the present invention is limited to this. Instead, a retaining structure as shown in FIG. 5 may be used.

  In this retaining structure, a male spline 49 is formed on the outer peripheral surface of the convex portion 25 of the stopper member 24, and the convex portion 25 is press-fitted into the cylindrical processing center hole 47 of the shaft 19. By this press-fitting, the shape of the male spline 49 of the convex portion 25 is transferred to the machining center hole 47 to form a concave portion on the peripheral surface of the machining center hole 47, and the convex portion 25 of the stopper member 24 and the machining center of the shaft 19 are formed. The hole 47 is connected by forming a concave-convex fitting structure in which the entire fitting contact portion between the convex portion and the concave portion is in close contact. As the material of the outer joint member 11 and the inner joint member 12, medium carbon steel for machine structure containing 0.40 to 0.60% by weight of carbon represented by S53C and the like is suitable. The material of the shaft 19 is made of medium carbon steel containing 0.30 to 0.55% by weight of carbon such as S40C, and the processing center hole 47 is unhardened. The stopper member 24 is obtained by quenching and hardening SUS and medium carbon steel.

  By adopting such a structure, the stopper member 24 can be firmly attached to the shaft 19, and a strong retaining structure can be realized. This structure is applicable not only to the illustrated sliding type constant velocity universal joint, but also to the above-described fixed type constant velocity universal joint.

  Further, in the embodiment described above, the convex portion 25 press-fitted into the machining center hole 47 of the shaft 19 and the end surface on the back side of the tripod member 32 provided integrally with the axial end portion of the convex portion 25. Although the stopper member 24 configured with the flange portion 27 that abuts on the 48 has been described, the present invention is not limited to this, and a retaining structure as shown in FIG. 6 may be used.

  In this retaining structure, a stopper member 51 composed of only the convex portion 50 press-fitted into the machining center hole 47 of the shaft 19 is used. The convex portion 50 of the stopper member 51 has an outer diameter set to a tightening allowance capable of expanding the shaft end portion 45 of the shaft 19 by press-fitting into the processing center hole 47.

  By adopting such a structure, the shaft end 45 of the shaft 19 is expanded in diameter by press-fitting the convex portion 50 of the stopper member 51 into the machining center hole 47 of the shaft 19 (see the arrow in the figure). . By increasing the diameter of the shaft end portion 45 of the shaft 19, the coupling force with the tripod member 32 at the shaft end portion 45 increases, so that the shaft 19 can be prevented from coming off from the tripod member 32. The material of the shaft 19 is made of medium carbon steel containing 0.30 to 0.55% by weight of carbon such as S40C, and the processing center hole 47 is unhardened. The stopper member 24 is obtained by quenching and hardening SUS and medium carbon steel.

  This structure is effective for a sliding type constant velocity universal joint in which the shaft 19 can be assembled to the tripod member 32 before incorporating the internal parts including the tripod member 32 and the roller 33 into the outer joint member 31. .

  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.

11, 31 Outer joint member 12, 32 Inner joint member 13, 33 Torque transmission member (ball, roller)
19 Shaft 22, 46 Shaft end face 23, 47 Processing center hole 24 Stopper member 25 Convex part 27 Flange part

Claims (4)

An outer joint member and an inner joint member that transmits torque while allowing angular displacement between the outer joint member and the outer joint member via the torque transmission member, and capable of transmitting torque to the shaft hole of the inner joint member A constant velocity universal joint that is fitted and the shaft is prevented from coming off from the inner joint member,
A constant velocity universal joint, wherein a stopper member for preventing the shaft from coming off from the inner joint member is mounted in a machining center hole formed in the shaft end surface of the shaft.   The said stopper member is comprised by the convex part press-fitted in the said center hole for a process, and the flange part which is provided in the axial direction edge part of the said convex part, and contact | abuts the end surface of an inner joint member. The constant velocity universal joint described.   The stopper member includes a convex portion that is press-fitted into the machining center hole, and the convex portion is an outer portion that is set to a tightening allowance that allows the shaft end portion of the shaft to be expanded by press-fitting into the machining center hole. The constant velocity universal joint according to claim 1, wherein the constant velocity universal joint has a diameter.   The stopper member forms a male spline on the outer peripheral surface of the convex portion press-fitted into the machining center hole, and presses the convex portion into the cylindrical machining center hole of the shaft, thereby forming the male spline of the convex portion. The constant velocity universal joint according to claim 2, wherein the shape is transferred to the machining center hole to constitute a concave-convex fitting structure in which the entire fitting contact portion between the convex portion and the concave portion is in close contact.

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