JP5868643B2 - Constant velocity universal joint - Google Patents

Description

  The present invention relates to a constant velocity universal joint including a boot used in a power transmission system such as an industrial machine.

  As is well known, constant velocity universal joints are widely used in power transmission systems of automobiles and various industrial machines in order to transmit torque while allowing angular displacement between two axes of a driving side and a driven side. As illustrated in FIG. 10, the constant velocity universal joint 31 includes an outer joint member 32, an inner joint member 33, a torque transmission member 34 that transmits torque between the outer joint member 32 and the inner joint member 33, The main component is a shaft 35 connected to the inner joint member 33 and a boot 36 disposed between the outer joint member 32 and the shaft 35.

  The boot 36 is used to prevent the lubricant encapsulated inside the outer joint member 32 from flowing out and foreign matter from entering the inside, and the large-diameter end portion attached to the outer peripheral surface of the opening of the outer joint member 32. 36a, a small diameter end portion 36b attached to the outer peripheral surface of the shaft 35, and a bellows-like bellows portion 36c connecting the large diameter end portion 36a and the small diameter end portion 36b.

  With the large-diameter end portion 36a and the small-diameter end portion 36b of the boot 36 fitted into the outer peripheral surface of the opening of the outer joint member 32 and the outer peripheral surface of the shaft 35, the boot bands 37a and 37b are compressed by means such as caulking. By making the diameter, the large diameter end portion 36a and the small diameter end portion 36b are tightened in the inner diameter direction, and the large diameter end portion 36a and the small diameter end portion 36b are fixed to the outer joint member 32 and the shaft 35, respectively. The boot 36 is made of rubber such as chloroprene rubber (see Patent Documents 1 and 2).

  By the way, the constant velocity universal joint 31 has various uses. In a severe condition, for example, a high temperature atmosphere in a paper machine dryer part, a high angle and high speed rotation condition, the boot 36 illustrated in FIG. It was a lifetime and could not be used.

  The main reasons for shortening the life of the boot 36 under such severe conditions are as follows. That is, when the outer joint member 32 of the constant velocity universal joint 31 and the shaft 35 rotate with an operating angle, the boot 36 rotates together with this rotation, and the respective parts in the circumferential direction of the bellows portion 36c are compressed and expanded. The state is repeated, and fatigue is caused in the boot 36 by this repetition.

  As a means for preventing such a repetition of the compressed state and the extended state of the boot 36, it is conceivable that the boot 36 is not rotated together with the outer joint member 32 and the shaft 35. As a technique for preventing the boot from rotating, for example, in Patent Document 3, the boot is attached to the outer joint member of the constant velocity universal joint and the shaft so as to be rotatable relative to each other via a bearing, and one portion in the circumferential direction of the boot is fixed. It is disclosed that it is fixed to a member or a weight is attached to one part in the circumferential direction of the boot.

Japanese Patent Laid-Open No. 11-159615 JP 2007-146959 A Japanese Utility Model Publication No. 53-64867

  However, in the method of Patent Document 3, since the fixing member is a separate member and is connected to the boot via a bracket, a link, and the like, the number of parts increases, so that the manufacturing cost is increased, and the radial direction with respect to the boot Space is required. Furthermore, a member is required to fix the fixing member to the floor. When the fixing member is the floor itself, it is necessary to lengthen the link or the like, so that the manufacturing cost and the required space are required. Will increase. Even when a weight is used, since the weight is connected to the boot via a bracket as a separate member, the manufacturing cost increases as the number of parts increases, and a radial space is required with respect to the boot. .

  In view of the above circumstances, an object of the present invention is to suppress co-rotation of the boot of a constant velocity universal joint while suppressing the number of parts and saving space.

The constant velocity universal joint according to the present invention for solving the above problems includes an outer joint member, an inner joint member, a torque transmission member for transmitting torque between the outer joint member and the inner joint member, and the inner joint. In a constant velocity universal joint comprising: a shaft coupled to a member; and a boot having a large-diameter end portion and a small-diameter end portion that are relatively rotatably attached to each of the outer joint member and the shaft via a bearing. , boot shape entirety of the boot, not fixed to the non-rotating member other than the constant velocity universal joint, wherein the outer joint member and the shaft to keep the boot in the form of a state took an operating angle A maintaining means is provided in the boot, and the shape of the boot in a state where the outer joint member and the shaft take the operating angle is maintained by the boot shape maintaining means. When the Kisotogawa joint member and the shaft is rotated taking the operating angle, characterized in that the boot is capable to suppress the co-rotation with the shaft and the outer joint member.

  In this configuration, the large-diameter end and the small-diameter end of the boot are attached to each of the outer joint member and the shaft so as to be relatively rotatable via bearings, and the outer joint member and the shaft are connected by the boot shape maintaining means. The shape of the boot with the operating angle taken is maintained. For this reason, when the outer joint member of the constant velocity universal joint and the shaft rotate at an operating angle, it is possible to suppress the boot from rotating together with them. And since the boot shape maintenance means is provided in the boot, the number of parts required for suppressing the co-rotation of the boot can be suppressed, and the space necessary for suppressing the co-rotation of the boot can be suppressed.

  In the above configuration, the entire boot may be made of metal, and the boot shape maintaining means may be the rigidity of the boot metal.

  Metal has rigidity compared to rubber or the like, and it is easy to maintain the boot shape by this rigidity. Moreover, since it is easy to maintain a boot shape, even if it makes it compact, there is almost no possibility of interfering with an outer joint member or a shaft. Accordingly, the boot can be made compact, and the amount of lubricant filled in the joint can be reduced. If the boot has a reduced diameter portion that is connected to the large diameter end portion and the small diameter end portion and gradually decreases in diameter from the large diameter end portion toward the small diameter end portion, the boot can be further downsized. In addition, since metal is more rigid than rubber or the like, even if it is used in an atmosphere where scattered matter such as scale exists, the occurrence of damage or the like is suppressed.

  In any one of the above configurations, an annular body made of an elastic member is interposed between at least one of the large-diameter end portion and the inner peripheral side bearing and between the small-diameter end portion and the inner peripheral side bearing. Also good.

  The annular body made of the elastic member can absorb the error of the shape of the boot and the operating angle α between the outer joint member and the shaft. Therefore, it is not necessary to improve the shape accuracy of the boot, and an increase in manufacturing cost can be suppressed.

  In the configuration at the beginning, the boot is composed of a metal large diameter portion including a large diameter end portion and a rubber or resin small diameter portion including a small diameter end portion. It may be the rigidity of the metal and the elastic restoring force of the rubber or resin of the small diameter portion.

  Rubber or resin is more flexible than metal or the like. Therefore, if a part of the boot is rubber or resin, the constant velocity universal joint can be used even when the operation angle is slightly different from the assumed operation angle. In this configuration, if the large-diameter portion is connected to the large-diameter end portion and is gradually reduced in diameter from the large-diameter end portion toward the small-diameter end portion, the same as described in the case where the entire boot is made of metal. For this reason, the boots can be made compact. Further, if the small diameter portion is formed of an angled boot, the large diameter portion can be made a simple shape, which makes it easy to form the large diameter portion, thereby reducing the manufacturing cost of the large diameter portion. be able to.

  Here, the boot with an angle is made of rubber or resin, and is a boot having a shape in which the open ends form an angle with each other in a natural state, and is molded in an angled state, for example. The natural state is a state in which the boot is not attached to a member such as an outer joint member or a shaft, and no external force is applied to the boot. In addition, molding in the state of imparting an angle indicates that the boot is molded in a shape that maintains the operating angle.

  In the opening configuration, the entire boot may be formed of an angled boot, and the boot shape maintaining means may be an elastic restoring force of the angled boot.

  With this configuration, the constant velocity universal joint can be used even when the operation angle is considerably different from the assumed operation angle due to the flexibility of rubber or resin.

  Further, in the structure at the beginning, the boots are all made of rubber or resin, and the boot shape maintaining means is a tension of a connecting member that directly or indirectly connects portions having different positions in the axial direction of the boots. Also good.

  If it is this structure, the shape of a boot can be made to respond | correspond to a wide operating angle by adjustment of a connection member.

  In any one of the configurations described above, a dust cover that covers the end surface of the bearing may be provided on one or both of the outer joint member and the outer peripheral surface of the shaft.

  If it is this composition, it can control that the lubricant with which the inside of a joint was filled through a bearing flows out of the joint outside, and foreign material from the outside of a joint entering a joint inside via a bearing.

  According to the present invention as described above, it is possible to suppress the joint rotation of the boot of the constant velocity universal joint while suppressing the number of parts and without taking a space.

It is an axial sectional view showing the constant velocity universal joint according to the first embodiment of the present invention. It is a figure which shows the boot concerning 1st Embodiment of this invention, (A) is a front view, (B) is a side view. It is an axial sectional view showing a constant velocity universal joint according to a second embodiment of the present invention. It is an axial sectional view showing a constant velocity universal joint according to a third embodiment of the present invention. It is an axial sectional view showing a constant velocity universal joint according to a fourth embodiment of the present invention. It is an axial sectional view showing a constant velocity universal joint according to a fifth embodiment of the present invention. It is an axial sectional view showing a constant velocity universal joint according to a sixth embodiment of the present invention. It is an axial sectional view showing a constant velocity universal joint according to a reference example of the present invention. It is a figure which shows the ring which concerns on the reference example of this invention, (A) is a front view, (B) is a longitudinal cross-sectional view. It is an axial sectional view showing a conventional constant velocity universal joint.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is an axial sectional view showing a constant velocity universal joint according to a first embodiment of the present invention. In this embodiment, the constant velocity universal joint 1 is a Rzeppa type fixed constant velocity universal joint. The constant velocity universal joint 1 includes an outer joint member 2, an inner joint member 3, a ball 4 as a torque transmission member, a cage 5, a shaft 6, bearings 7 and 8, and a boot 9 as main components. .

  The outer joint member 2 includes a spherical inner surface 2b formed with a plurality of track grooves 2a. The inner joint member 3 is disposed radially inward of the outer joint member 2 and includes a spherical outer surface 3b and a shaft hole 3c formed with a plurality of track grooves 3a. The ball 4 is disposed on a ball track formed by the cooperation of the track groove 2 a of the outer joint member 2 and the track groove 3 a of the inner joint member 3, and torque is applied between the outer joint member 2 and the inner joint member 3. introduce. The cage 5 is disposed between the spherical inner surface 2b of the outer joint member 2 and the spherical outer surface 3b of the inner joint member 3, and has pockets 5a for accommodating the balls 4 in the circumferential direction.

  The shaft 6 is connected to the shaft hole 3 c of the inner joint member 3 so as to be able to transmit torque, for example, by spline fitting, and extends from the opening of the outer joint member 2. In the illustrated example, the shaft 6 is in a state of forming a predetermined operating angle α (for example, 20 °) with respect to the outer joint member 2.

  In this embodiment, the bearing 7 is a deep groove ball bearing, and is press-fitted into the outer peripheral surface of the spacer 10 that is press-fitted into the outer peripheral surface on the opening end side of the outer joint member 2. Further, an annular body 11 made of an elastic member such as rubber is press-fitted into the outer peripheral surface of the bearing 7. The annular body 11 has projecting portions projecting toward the inner diameter side at both ends in the axial direction, and the projecting portions engage with the outer ring of the bearing 7 in the axial direction, thereby positioning in the axial direction. In this embodiment, the bearing 8 is composed of two identical deep groove ball bearings, and is press-fitted into the outer peripheral surface of the shaft 6 adjacent to each other.

  The boot 9 has a large-diameter end portion 9a attached to the outer peripheral surface of the annular body 11, a small-diameter end portion 9b attached to the outer peripheral surface of the bearing 8, and a gradually increasing diameter from the large-diameter end portion 9a toward the small-diameter end portion 9b. The reduced diameter portion 9c is provided. The shape of the boot 9 corresponds to a state in which the outer joint member 2 and the shaft 6 take the operating angle α. In this embodiment, the boot 9 is made of a metal plate, and the material of the metal plate is preferably a light metal such as aluminum. The boot 9 prevents leakage of the lubricant encapsulated in the constant velocity universal joint 1 to the outside and entry of foreign matter into the constant velocity universal joint 1.

  In addition, the outer joint member 2 of the constant velocity universal joint 1 of the present embodiment also has an opening on the side opposite to the opening from which the shaft 6 extends. A flange 2c is provided around the opening by welding or the like. The opening of the outer joint member 2 is closed by a shaft on the industrial machine side to which the constant velocity universal joint 1 is assembled and a flange provided on the shaft. The constant velocity universal joint 1 is assembled to the shaft on the industrial machine side by fastening the flange 2c of the outer joint member 2 to the flange of the shaft on the industrial machine side with a fastening member such as a bolt and a nut. Is done.

  As shown in FIG. 2, the boot 9 has a symmetrical shape with an axial plane including the central axis of the outer joint member 2 and the shaft 6 as a symmetry plane. The boot 9 is divided into two along the central axis of the shaft 6. In this embodiment, the boot 9 is divided into two on the axial plane including the outer joint member 2 and the central axis of the shaft 6. . The two divided parts of the boot 9 are respectively described as a boot piece 9d. Both ends in the circumferential direction of the large-diameter end portion 9a of each boot piece 9d are provided with a large-diameter side mounting portion 9e protruding outward, and both ends in the circumferential direction of the small-diameter end portion 9b of each boot piece 9d. The portion is provided with a small-diameter side attachment portion 9f protruding to the outer diameter side. For the two boot pieces 9d, one large-diameter side attachment portion 9e and small-diameter side attachment portion 9f are fastened to the other large-diameter side attachment portion 9e and small-diameter side attachment portion 9f with, for example, bolts 9g and nuts 9h. Thus, the boot 9 is appropriately clamped and fixed to the outer peripheral surface of the annular body 11 and the outer peripheral surface of the bearing 8. After the boot 9 is attached, the angle and the distance between the outer joint member 2 and the shaft 6 cannot be changed. Therefore, the boot 9 is attached after the outer joint member 2 and the shaft 6 are assembled to an industrial machine or the like.

  For example, liquid packing may be applied to the circumferential end surface of the boot piece 9d (divided portion of the boot 9) in advance or after attachment. If this liquid packing is solidified, the sealing performance of the boot is improved.

  Thus, in this embodiment, the boot 9 is attached to the outer joint member 2 and the shaft 6 through the bearings 7 and 8 so as to be relatively rotatable. The outer joint member 2 and the shaft 6 have an operating angle α. The boot 9 is entirely made of metal and has rigidity. Due to the rigidity of the boot 9, the shape of the boot 9 in the state of being attached to the outer joint member 2 having the operating angle α and the shaft 6 is maintained. That is, the rigidity of the boot 9 is a boot shape maintaining means for maintaining the shape of the boot 9. Since the shape of the boot 9 is maintained by the boot shape maintaining means, when the outer joint member 2 and the shaft 6 are rotated, the rotation of the boot 9 is suppressed even if the boot 9 attempts to rotate together therewith. And since the boot shape maintenance means is provided in the boot 9, the number of parts required for suppression of the joint rotation of the boot 9 can be suppressed, and the space required for suppression of the joint rotation of the boot 9 can be suppressed.

  Moreover, since the boot 9 has rigidity and it is easy to maintain a shape by rigidity, even if it makes compact, there is almost no possibility of interfering with the outer joint member 2 or the shaft 6. Therefore, the boot 9 can be made compact, whereby the amount of lubricant filled in the joint can be reduced. Further, since the boot 9 is rigid, even if it is used in an atmosphere where scattered objects such as scales are present, the occurrence of damage or the like is suppressed.

  Further, since the annular body 11 made of an elastic member is disposed between the bearing 7 and the boot 9, an error between the shape of the boot 9 and the operating angle α between the outer joint member 2 and the shaft 6 is It can be absorbed by the annular body 11. Therefore, it is not necessary to improve the shape accuracy of the boot 9, and an increase in manufacturing cost can be suppressed.

  FIG. 3 is an axial sectional view showing a constant velocity universal joint according to a second embodiment of the present invention. Hereinafter, the constant velocity universal joint according to the second embodiment will be described focusing on differences from the first embodiment. In this embodiment, both the bearing 7 and the bearing 8 are needle roller bearings with a seal that do not have an inner ring. An annular body 12 made of an elastic member such as rubber is pressed into the outer peripheral surface of the bearing 8 as well as the annular body 11, and the small-diameter end portion 9 b of the boot 9 is fixed to the outer peripheral surface.

  The outer joint member 2 is provided with a dust cover 13 that covers the bearing 7, and the shaft 6 is provided with a dust cover 14 that covers the bearing 8. The dust covers 13 and 14 suppress entry of foreign matter into the joint through the bearings 7 and 8 and suppress leakage of the lubricant from the inside of the joint through the bearings 7 and 8.

  The dust covers 13 and 14 have an annular shape with an L-shaped cross section, and have cylindrical portions 13a and 14a and flange portions 13b and 14b. The cylindrical portion 13 a of the dust cover 13 is press-fitted into the outer peripheral surface of the outer joint member 2, and the cylindrical portion 14 a of the dust cover 14 is press-fitted into the outer peripheral surface of the shaft 6. In order to prevent interference with the annular body 11, the collar portion 13 b is disposed with a gap in the axial direction with respect to the axial end portion of the annular body 11, and the collar portion 14 b prevents interference with the annular body 12. In order to prevent this, a gap is provided in the axial direction with respect to the axial end of the annular body 12. These axial gaps are preferably 0.5 to 2.0 mm, for example. If it is less than 0.5 mm, the dust covers 13 and 14 and the annular bodies 11 and 12 may interfere with each other during rotation of the outer joint member 2 and the shaft 6, and the rotation may be hindered. This is because the effect of suppressing the leakage and the leakage of the lubricant cannot be sufficiently obtained.

  In the illustrated example, the dust covers 13 and 14 are disposed on the outer side of the constant velocity universal joint 1 with respect to the bearings 7 and 8, but may be disposed on the inner side of the constant velocity universal joint 1. . Since other configurations and effects are the same as those of the first embodiment, the same components are denoted by the same reference numerals and description thereof is omitted.

  FIG. 4 is an axial sectional view showing a constant velocity universal joint according to a third embodiment of the present invention. Hereinafter, the constant velocity universal joint according to the third embodiment will be described focusing on differences from the first embodiment. The boot 15 includes a large-diameter portion 16 made of a metal plate such as light metal, and a small-diameter portion 17 made of rubber such as chloroprene rubber. Further, the spacer 10 does not exist, and the bearing 7 is directly press-fitted into the outer peripheral surface of the outer joint member 2.

  The large-diameter portion 16 includes a large-diameter end portion 16a attached to the outer peripheral surface of the bearing 7, a cylindrical portion 16b disposed in parallel to the outer peripheral surface of the shaft 6, and the large-diameter end portion 16a toward the cylindrical portion 16b. And a reduced diameter portion 16c that gradually decreases in diameter. The large diameter portion 16 is not a divided member but an integral member. The small-diameter portion 17 includes a small-diameter end portion 17a attached to the outer peripheral surface of the bearing 8 press-fitted into the shaft 6, a cylindrical portion 17b attached to the outer peripheral surface of the cylindrical portion 16b of the large-diameter portion 16, and a cylinder from the small-diameter end portion 17a. And an enlarged diameter portion 17c that gradually increases in diameter toward the portion 17b. The small diameter portion 17 is not an angled boot.

  The large-diameter end 16a of the large-diameter portion 16 is press-fitted into the outer peripheral surface of the bearing 7, and is fastened and fixed by the boot band 18a. A small-diameter end 17a of the small-diameter portion 17 is press-fitted into the outer peripheral surface of the bearing 8, and is fastened and fixed by a boot band 18b. The cylindrical portion 17b of the small diameter portion 17 is fitted to the outer peripheral surface of the cylindrical portion 16b of the large diameter portion 16, and is fastened and fixed by the boot band 18c. In the present embodiment, the annular body 11 does not exist on the outer peripheral surface of the bearing 7.

  Thus, in this embodiment, since the small diameter portion 17 of the boot 15 is made of rubber, it has flexibility. For this reason, even if the annular body 11 is not provided, the error of the shape of the boot 15 and the operating angle α between the outer joint member 2 and the shaft 6 can be absorbed by the small diameter portion 17. Since the constant velocity universal joint 1 can change the operating angle α to some extent even when the boot 15 is attached, the constant velocity universal joint 1 can be applied to an industrial machine or the like with the boot 15 attached. It is possible to assemble. Therefore, the constant velocity universal joint 1 can be circulated with the boot 15 attached.

  The shape of the small-diameter portion 17 of the boot 15 when attached to the outer joint member 2 and the shaft 6 having the operating angle α (the state shown in FIG. 4) conforms to the shape of the small-diameter portion 17 in the natural state. . Thereby, when the small diameter part 17 deform | transforms even a little, the elastic restoring force which tries to maintain the shape in the state of FIG. 4 acts on the small diameter part 17. FIG. Due to this and the rigidity of the large diameter portion 16, the shape of the boot 15 in the state of being attached to the outer joint member 2 and the shaft 6 having the operating angle α is maintained. That is, the rigidity of the large-diameter portion 16 and the elastic restoring force of the small-diameter portion 17 are boot shape maintaining means for maintaining the shape of the boot 15. Since the shape of the boot 15 is maintained by the boot shape maintaining means, when the outer joint member 2 and the shaft 6 rotate, the rotation of the boot 15 is suppressed even if the boot 15 tries to rotate with them. And since the boot shape maintenance means is provided in the boot 15, the number of parts required for the suppression of the joint rotation of the boot 15 can be suppressed, and the space required for the suppression of the rotation of the boot 15 can be suppressed.

  Since other configurations and effects are the same as those of the first embodiment, the same components are denoted by the same reference numerals and description thereof is omitted.

  FIG. 5 is an axial sectional view showing a constant velocity universal joint according to a fourth embodiment of the present invention. Hereinafter, the constant velocity universal joint according to the fourth embodiment will be described focusing on differences from the third embodiment. The large-diameter portion 16 of the boot 15 includes a cylindrical portion 16d as a large-diameter end portion attached to the outer peripheral surface of the bearing 7 press-fitted into the spacer 10 press-fitted into the outer joint member 2, and one axial end of the cylindrical portion 16d. It is a bottomed cylindrical shape having a bottom portion 16e for closing. A through hole 16 f is formed in the bottom portion 16 e of the large diameter portion 16. In order to avoid interference with the shaft 6, the through-hole 16 f is a side where the shaft 6 is inclined with respect to the central axis of the cylindrical portion 16 d or the outer joint member 2 (the lower side in FIG. 5). It is formed at a position offset. In the present embodiment, the through hole 16f has a circular shape, and the distance d between the center of the through hole 16f and the central axis of the cylindrical portion 16d or the outer joint member 2 is appropriately set in consideration of the diameter of the shaft 6, the operating angle α, and the like. The

  The small-diameter portion 17 of the boot 15 has a small-diameter end portion 17d attached to the outer peripheral surface of the bearing 8 press-fitted into the shaft 6, and a bellows-like shape disposed between the small-diameter end portion 17d and the bottom portion 16e of the large-diameter portion 16. And a bellows portion 17e. The end of the bellows portion 17e of the small diameter portion 17 on the large diameter portion 16 side is connected to the side surface of the through hole 16f in the bottom portion 16e of the large diameter portion 16 by, for example, baking. In the present embodiment, the through hole 16f of the large diameter portion 16 and the end portion on the large diameter portion 16 side of the bellows portion 17e of the small diameter portion 17 are circular, but the present invention is not limited to this. It may be a shape. In addition, the end of the bellows portion 17e of the small diameter portion 17 on the large diameter portion 16 side has a slightly larger diameter than the small diameter end portion 17d.

  The open end of the cylindrical portion 16d of the large-diameter portion 16 is press-fitted into the outer peripheral surface of the bearing 7, and is fastened and fixed by the boot band 18a. A small-diameter end 17d of the small-diameter portion 17 is fitted to the outer peripheral surface of the bearing 8, and is fastened and fixed by a boot band 18b.

  The small-diameter portion 17 of the boot 15 is an angled boot, and the shape of the small-diameter portion 17 of the boot 15 when attached to the outer joint member 2 and the shaft 6 having the operating angle α (the state shown in FIG. 5) is natural. It conforms to the shape of the small-diameter portion 17 in the state. Accordingly, when the small diameter portion 17 is deformed even a little, an elastic restoring force is applied to the small diameter portion 17 so as to maintain the shape in the state of FIG. Due to this and the rigidity of the large diameter portion 16, the shape of the boot 15 in the state of being attached to the outer joint member 2 and the shaft 6 having the operating angle α is maintained. That is, similarly to the third embodiment, the rigidity of the large diameter portion 16 and the elastic restoring force of the small diameter portion 17 are boot shape maintaining means for maintaining the shape of the boot 15. Since the shape of the boot 15 is maintained by the boot shape maintaining means, when the outer joint member 2 and the shaft 6 rotate, the rotation of the boot 15 is suppressed even if the boot 15 tries to rotate with them. And since the boot shape maintenance means is provided in the boot 15, the number of parts required for the suppression of the joint rotation of the boot 15 can be suppressed, and the space required for the suppression of the rotation of the boot 15 can be suppressed. In this embodiment, the proportion of the small diameter portion 17 in the entire boot 15 is larger than that in the third embodiment, and the shape of the boot 15 is maintained by the elastic restoring force that maintains the shape of the small diameter portion 17 in FIG. large.

  Thus, in this embodiment, since the large diameter part 16 is a bottomed cylindrical shape, since it is easier to form than the large diameter part 16 of 3rd Embodiment, manufacturing cost can be reduced. Further, since the small diameter portion 17 is made of rubber and has a bellows portion 17e, and this bellows portion 17e is longer than the enlarged diameter portion 17c (see FIG. 4), the entire small diameter portion 17 is smaller than the small diameter portion 17 of the third embodiment. High flexibility. Therefore, the effect resulting from the softness | flexibility of the small diameter part 17 mentioned above in 3rd Embodiment can further be acquired. Since other configurations and effects are the same as those of the third embodiment, the same components are denoted by the same reference numerals and description thereof is omitted.

  FIG. 6 is an axial sectional view showing a constant velocity universal joint according to a fifth embodiment of the present invention. Hereinafter, the constant velocity universal joint according to the fifth embodiment will be described focusing on differences from the third embodiment. The bearing 7 press-fitted into the outer joint member 2 is a needle roller bearing with a seal that does not have an inner ring. The bearing 8 press-fitted into the shaft 6 is one deep groove ball bearing.

  The boot 19 is entirely made of rubber such as chloroprene rubber. The boot 19 has a large-diameter end portion 19a attached to the outer peripheral surface of the bearing 7, a small-diameter end portion 19b attached to the outer peripheral surface of the bearing 8, and a bellows-like shape connecting the large-diameter end portion 19a and the small-diameter end portion 19b. The bellows portion 19c is provided. The large-diameter end 19a of the boot 19 is fitted to the outer peripheral surface of the bearing 7, and is fastened and fixed by the boot band 18a. The small-diameter end 19b of the boot 19 is fitted to the outer peripheral surface of the bearing 8, and is fastened and fixed by the boot band 18b.

  The boot 19 is an angled boot, and the shape of the boot 19 when attached to the outer joint member 2 having the operating angle α and the shaft 6 (the state shown in FIG. 6) conforms to the shape of the boot 19 in the natural state. doing. Accordingly, when the boot 19 is deformed even a little, an elastic restoring force is applied to the boot 19 to maintain the shape in the state shown in FIG. Due to this elastic restoring force, the shape of the boot 19 in the state of being attached to the outer joint member 2 having the operating angle α and the shaft 6 (the state of FIG. 6) is maintained. That is, the elastic restoring force of the boot 19 is a boot shape maintaining means for maintaining the shape of the boot 19. Since the shape of the boot 19 is maintained by the boot shape maintaining means, when the outer joint member 2 and the shaft 6 are rotated, the rotation of the boot 19 is suppressed even if the boot 19 tries to rotate with them. And since the boot shape maintenance means is provided in the boot 19, the number of parts required for suppression of the joint rotation of the boot 19 can be suppressed, and the space required for suppression of the joint rotation of the boot 19 can be suppressed.

  In the present embodiment, since the entire boot 19 is made of rubber and has a bellows portion, the flexibility of the entire boot 19 is high. For this reason, an error or the like between the shape of the boot 19 and the operating angle α between the outer joint member 2 and the shaft 6 can be absorbed by the boot 19 itself. In addition, since the constant velocity universal joint 1 can greatly change the operating angle α even when the boot 19 is attached, the constant velocity universal joint 1 can be applied to an industrial machine or the like with the boot 19 attached. It is possible to assemble. Therefore, the constant velocity universal joint 1 can be circulated with the boot 19 attached. Since other configurations and effects are the same as those of the third embodiment, the same components are denoted by the same reference numerals and description thereof is omitted.

  FIG. 7 is an axial sectional view showing a constant velocity universal joint according to a sixth embodiment of the present invention. Hereinafter, the constant velocity universal joint according to the sixth embodiment will be described focusing on differences from the fifth embodiment.

  The entire boot 19 of this embodiment is made of rubber such as chloroprene rubber, but unlike the fifth embodiment, the boot 19 is not an angled boot. That is, the boot 19 is the same as the conventional boot 36 (see FIG. 10). The large-diameter end 19 a of the boot 19 is fitted to the outer peripheral surface of the bearing 7 and is fastened and fixed by the boot band 20. The small-diameter end 19 b of the boot 19 is fitted to the outer peripheral surface of the bearing 8 and is fastened and fixed by the boot band 21.

  The boot bands 20, 21 are projecting portions 20 a projecting to the outer diameter side at positions where the outer joint member 2 taking the operating angle α and the shaft 6 approach each other in the circumferential direction (lower side in FIG. 7). , 21a are formed. Each of the protrusions 20a and 21a is provided with a slit (not shown), and the protrusions 20a and 21a are connected to each other by, for example, connecting a string 22 or the like as a connecting member. The shape of the boot 19 in the state of being attached to the outer joint member 2 having the operating angle α and the shaft 6 (the state shown in FIG. 7) is maintained by the tension of the string 22 and the like. That is, the tension of the string 22 as the connecting member is a boot shape maintaining means for maintaining the shape of the boot 19. Since the shape of the boot 19 is maintained by the boot shape maintaining means, when the outer joint member 2 and the shaft 6 are rotated, the rotation of the boot 19 is suppressed even if the boot 19 tries to rotate with them. And since the boot shape maintenance means is provided in the boot 19, the number of parts required for suppression of the joint rotation of the boot 19 can be suppressed, and the space required for suppression of the joint rotation of the boot 19 can be suppressed.

  In the present embodiment, as in the fifth embodiment, since the entire boot 19 is made of rubber and has the bellows portion 19c, the flexibility of the entire boot 19 is high. Therefore, the same effects as those described in the fifth embodiment can be enjoyed.

  Moreover, in this embodiment, since the boot 19 can use the conventional boot 36, it is not necessary to update the installation for boot manufacture, and can suppress manufacturing cost.

  In the present embodiment, the large-diameter end 19a and the small-diameter end 19b of the boot 19 are connected by the string 22 as a connecting member via the boot bands 20 and 21 attached thereto, but the present invention is limited to this. Instead, the portions of the boot 19 main body whose positions are different in the axial direction of the boot 19 may be directly connected by a connecting member.

  Since other configurations and effects are the same as those of the fifth embodiment, the same components are denoted by the same reference numerals and description thereof is omitted.

FIG. 8 is an axial sectional view showing a constant velocity universal joint according to a reference example of the present invention. Hereinafter, the constant velocity universal joint according to the reference example will be described focusing on differences from the fifth embodiment.

The boot 19 of this reference example is the same as the conventional boot 36 in the same manner as the sixth embodiment. The large-diameter end 19a of the boot 19 is fitted to the outer peripheral surface of the bearing 7, and is fastened and fixed by the boot band 18a. The small-diameter end 19b of the boot 19 is fitted to the outer peripheral surface of the bearing 8, and is fastened and fixed by the boot band 18b.

  A ring 23 is fitted to the outer periphery of the minimum diameter portion in the valley portion of the bellows portion 19 c in the boot 19. The ring 23 is fixed to the boot 19 with, for example, an adhesive. As shown in an enlarged view in FIG. 9, the ring 23 is composed of a metal having a high density, for example, iron, and the other half 23b having a low density, such as rubber. Are connected by, for example, baking. With this configuration, the center of gravity of the ring 23 is biased toward the side of the half 23a having a high density. The plurality of rings 23 fitted to the boot 19 have the same direction in the circumferential direction of the boot 19 on the side where the center of gravity of the ring 23 is biased. Thereby, when the boot 19 rotates in the circumferential direction even a little, gravity acts on the boot 19 through the ring 23 so that the side where the center of gravity of the ring 23 is biased is always on the lower side.

In the illustrated example, for easy understanding, the outer joint member 2 and the shaft 6 do not take the operating angle α. However, even if the operating angle α is taken, the ring 19 Gravity acts on the boot 19 via the ring 23 so that the side of the center of gravity at 23 is always on the lower side. Therefore, if the outer-side joint member 2 and the shaft 6 is rotated, the boot 19 is also an attempt to rotate together with these, the rotation of the boot 19 is suppressed. And since the boot shape maintenance means is provided in the boot 19, the number of parts required for suppression of the joint rotation of the boot 19 can be suppressed, and the space required for suppression of the joint rotation of the boot 19 can be suppressed.

Thus, also in the present reference example , as in the fifth embodiment, the entire boot 19 is made of rubber and has the bellows portion 19c. Therefore, the same effects as those described in the fifth embodiment can be enjoyed.

Also in this reference example , since the boot 19 can use the conventional boot 36, it is not necessary to update equipment for manufacturing the boot, and the manufacturing cost can be suppressed.

Further, in this reference example , if the half 23b of the ring 23 is an elastic member such as rubber, the crest 19c of the bellows portion is used to fit the ring 23 to the outer periphery of the minimum diameter portion in the valley portion of the bellows portion 19c. It is easy to pass the part, and the production efficiency can be improved.

In the present reference example , the bias of the center of gravity of the ring 23 fitted on the boot 19 is used to suppress the rotation of the boot 19. The center of gravity of the boot 19 itself may be used.

  Since other configurations and effects are the same as those of the fifth embodiment, the same components are denoted by the same reference numerals and description thereof is omitted.

  The rubber parts of the boots 15 and 19 in the above embodiment may be made of a resin such as a thermoplastic elastomer, and particularly when made of a thermoplastic polyester elastomer, fatigue resistance, wear resistance, and heat aging. Improve.

  The bearings 7 and 8 press-fitted into the outer joint member 2 and the shaft 6 are not limited to the above-described embodiment, and may be other rolling bearings such as cylindrical roller bearings, or other types of bearings such as sliding bearings. Good.

  Further, in the above embodiment, the fixed constant velocity universal joint of the Zepper type is used as the constant velocity universal joint 1, but the present invention is not limited to this, and another fixed constant velocity universal joint such as an undercut free type or the like. Further, a sliding type constant velocity universal joint such as a double offset type, a tripod type, or a cross groove type may be used.

1 constant velocity universal joint 2 outer joint member 3 inner joint member 4 ball (torque transmission member)
6 Shaft 7, 8 Bearing 9, 15, 19 Boots 9a, 16a, 16d, 19a Large diameter end portions 9b, 17a, 17d, 19b Small diameter end portions 9c, 16c Reduced diameter portions 11, 12 Annulus 13, 14 Dust cover 16 Large diameter part 17 Small diameter part 22 String (connecting member)
α Working angle

Claims (10)

An outer joint member, an inner joint member, a torque transmission member for transmitting torque between the outer joint member and the inner joint member, a shaft connected to the inner joint member, and each of the outer joint member and the shaft In a constant velocity universal joint provided with a large diameter end portion and a boot having a small diameter end portion that are attached to each other in a relatively rotatable manner via a bearing,
The entire boot is not fixed to a non-rotating member other than the constant velocity universal joint,
Boot shape maintaining means for maintaining the shape of the boot in a state where the outer joint member and the shaft take an operating angle is provided in the boot,
The boot shape maintaining means maintains the shape of the boot in a state in which the outer joint member and the shaft take the operating angle, so that the outer joint member and the shaft rotate by taking the operating angle. In this case, it is possible to suppress the boot from rotating together with the outer joint member and the shaft. All of the boots are made of metal;
The constant velocity universal joint according to claim 1, wherein the boot shape maintaining means is a metal rigidity of the boot.   3. The constant velocity universal joint according to claim 2, wherein the boot has a reduced diameter portion that is connected to the large diameter end portion and the small diameter end portion and gradually decreases in diameter from the large diameter end portion toward the small diameter end portion. .   An annular body made of an elastic member is interposed between at least one of the large-diameter end and the inner peripheral bearing and at least one of the small-diameter end and the inner peripheral bearing. The constant velocity universal joint described. The boot is composed of a metal large diameter portion including the large diameter end portion, and a rubber or resin small diameter portion including the small diameter end portion,
2. The constant velocity universal joint according to claim 1, wherein the boot shape maintaining means is rigidity of the metal of the large diameter portion and elastic restoring force of rubber or resin of the small diameter portion.   The constant velocity universal joint according to claim 5, wherein the large-diameter portion includes a reduced-diameter portion that is connected to the large-diameter end portion and gradually decreases in diameter from the large-diameter end portion toward the small-diameter end portion.   The constant velocity universal joint according to claim 5, wherein the small diameter portion is formed of an angled boot. All of the boots are composed of angled boots,
The constant velocity universal joint according to claim 1, wherein the boot shape maintaining means is an elastic restoring force of the angled boot. All of the boots are made of rubber or resin,
2. The constant velocity universal joint according to claim 1, wherein the boot shape maintaining means is a tension of a connecting member that directly or indirectly connects portions having different positions in the axial direction of the boot.   The constant velocity universal joint according to any one of claims 1 to 9, wherein a dust cover that covers an end face of the bearing is provided on one or both of the outer joint surface of the outer joint member and the shaft.

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