JP2012149685A - Shaft for constant velocity universal joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shaft for a constant velocity universal joint without impairing rigid feeling while absorbing torsional vibration (vibration in a rotating direction).SOLUTION: In this shaft for the constant velocity universal joint, the constant velocity universal joints are connected to each of an output side end part 1a and an input side end part 1b. A damping mechanism 4 for suppressing torque fluctuation from the input side end part 1b by resistance in the rotating direction is provided at a shaft center part for the constant velocity universal joint between the output side end part 1a and the input side end part 1b. The damping mechanism 4 includes a shaft-shaped first member 31 and a cylindrical second member 32 externally fitted to the first member 31. The second member 32 is connected to the first member 31 on a torque input side or a torque output side. A third member 33 in sliding contact with either one of the first member 31 or the second member 32 is disposed on the torque output side or the torque input side, which is not connected to the first member 31.

Description

  The present invention relates to a constant velocity universal joint shaft that can suppress torsional vibration generated in a drive system.

  Power transmission means to drive wheels for automobiles is smoothly transmitted without torque fluctuation by a fixed type constant velocity universal joint and a sliding type constant velocity universal joint connected by a half shaft. As described above, in the drive system including the constant velocity universal joint, the vibration from the engine is mainly absorbed by the sliding type constant velocity universal joint so that the vibration is not transmitted to the vehicle body as an unpleasant vibration.

  However, the vibration absorption direction in the sliding type constant velocity universal joint is all in the sliding direction (axial direction) and cannot absorb the displacement in the twisting direction (rotating direction). That is, it is not possible to absorb torque fluctuations accompanying rotation fluctuations from the engine side, so-called torsional vibrations.

  For this reason, conventionally, the outer joint member (outer ring) has a two-layer structure of an outer cylinder part and an inner cylinder part, and relative movement in the axial direction and around the axis center between the outer cylinder part and the inner cylinder part. There is a constant velocity universal joint that interposes a guide device that allows relative rotation (Patent Document 1). The constant velocity universal joint includes a suppression device (made of a rubber material) that suppresses relative movement in the axial direction between the outer cylinder portion and the inner cylinder portion and relative rotation around the axis.

  As shown in FIGS. 18 and 19, the guide device 102 described in Patent Document 1 includes a sliding body 106 disposed between an outer cylinder portion 76 and an inner cylinder portion 82, An axial groove 108 is formed between the sliding body 106 and a circumferential groove 110 is formed between the inner cylinder portion 82 and the sliding body 106, and the rolling elements 112, 114 are fitted into the grooves 108, 110. It is to be combined.

  Further, as shown in FIG. 19, a relative restraining device having a first spring 96 and a second spring 98 interposed between the sliding plates 100, 100 is disposed in the vicinity of the sliding body 106 in the guide device 102. ing. This relative suppression device suppresses relative rotation of the outer cylinder portion 76 and the inner cylinder portion 82 around the axis.

  In the constant velocity universal joint described in Patent Document 1, the configuration as described above, “the torsional rigidity of the constant velocity universal joint for a vehicle that is a part of the drive system is reduced and the resonance frequency of the drive system is reduced. The torsional resonance of the drive shaft is suppressed, and the lockup rotation speed of the lockup clutch can be reduced while suppressing the generation of noise such as a lockup booming noise. Furthermore, “a damping element that generates a relative movement resistance according to the relative rotational speed of the outer cylinder portion and the inner cylinder portion around the axis center is provided, and the torsional vibration generated in the drive system is absorbed by the damping element. Therefore, the vibration generated in the drive system can be sufficiently suppressed. "

JP 2010-144663 A

  However, in Patent Document 1, the amount of relative displacement with respect to the rotation direction of the outer ring is regulated by the operating range of the rolling element 114, and the torsional rigidity during this period is determined by the spring force of the relative restraining device. You will tune it to get it.

  Further, since the rubber element (relative rotation suppressing device) is provided in the circumferential gap between the outer cylinder portion 76 and the inner cylinder portion 82, the torsional vibration generated in the drive system is always transmitted through the rubber element. It propagates between the outer cylinder part 76 and the inner cylinder part 82. For this reason, the torsional vibration generated in the drive system can be suppressed.

  However, since the torsional vibration absorbing structure described in Patent Document 1 is a structure that is largely twisted in the rotational direction in the low torque region, the displacement in the rotational direction becomes large in a situation where the torque input changes between positive and negative. For this reason, in a traveling state in which acceleration / deceleration is repeated (load torque is switched between positive and negative), the feeling of rigidity (= direct feeling) is impaired.

  An object of the present invention is to propose a shaft for a constant velocity universal joint that absorbs torsional vibration (vibration in the rotational direction) and does not impair rigidity.

  In the constant velocity universal joint shaft of the present invention, the constant velocity universal joint is connected between the output side end and the input side end by connecting the constant velocity universal joint to the output side end and the input side end, respectively. The constant velocity universal joint shaft is provided with a damping mechanism that suppresses torque fluctuation from the input side end portion by a resistance in the rotation direction at the center, the damping mechanism comprising: a first shaft-shaped member; A cylindrical second member that is externally fitted to one member, and the second member is coupled to the first member on the torque input side or the torque output side, and the torque output side that is not coupled to the first member or On the torque input side, a third member that is in sliding contact with at least one of the first member and the second member is disposed.

  By providing the damping mechanism, the constant velocity universal joint shaft according to the present invention can suppress the rotational fluctuation accompanying the fluctuation of the input torque, that is, can absorb the vibration in the torsional direction. That is, the first member and the second member can be relatively displaced in the rotational direction via the third member. During this displacement, the contact surfaces of the members slide and generate frictional heat due to friction. Thereby, the vibration energy accompanying the torque fluctuation in the torsional direction that varies instantaneously is converted into frictional heat and absorbed, and the torsional vibration can be suppressed (= attenuated).

  The third member may be formed of a short cylindrical body having the same thickness along the axial direction as fitted to the insertion portion between the first member and the second member. It is a short cylindrical body whose thickness decreases toward the inside in the axial direction with respect to the fitting portion between the two members, and is preloaded inward in the axial direction.

  The third member may be formed by stacking a plurality of members, or may be formed by stacking a plurality of members of different materials.

  Preferably, a lubricant is interposed between the third member and the mating first member and / or the second member, and further, the third member and the mating first member and / or the second member. It is preferable to provide a lubricant reservoir for storing the lubricant between the members.

  Even if the chamfered portion is formed at the press-fitting start side end of the third member, the sliding contact surface of the third member with the counterpart first member or the second member is not the entire corresponding surface. There may be.

  The connection between the first member and the second member may be a serration connection or a connection by welding.

  A sliding type constant velocity universal joint can be attached to the input side end, a fixed type constant velocity universal joint can be attached to the output side end, and a sliding type constant velocity universal joint can be attached to the input side end and output side end. Can be attached.

In the constant velocity universal joint shaft according to the present invention, by providing a mechanism that attenuates torque fluctuation, torsional vibration due to torque fluctuation can be absorbed. If this constant velocity universal joint shaft is used as a means for transmitting power to the drive wheels of an automobile, excellent drivability is exhibited without impairing rigidity (= direct feeling) even when the vehicle is repeatedly accelerated and decelerated. Moreover, torsional vibration can be suppressed. In particular, it is possible to relatively displace by fitting the third member to the first member and the second member, so that a friction surface with a larger area can be used, which can absorb a large amount of vibration energy. it can.

  Since the first member is composed of a torque transmission shaft formed integrally with the output side end and the input side end, the configuration can be simplified. Since the second member is fitted on the first member that functions as a torque transmission shaft, the second member can be made compact.

  The third member can be formed of a short cylindrical body having the same thickness along the axial direction, and the sliding member may be of a simple shape, and the cost can be reduced. As the sliding member, it is possible to use a ball or a roller, but if a ball or a roller is used, a plurality of parts need to be arranged along the circumferential direction, and the number of parts increases. This will increase the number of assembly steps.

  In the case of applying a preload, an optimum resistance value can be secured by adjusting the preload amount. When the third member is formed by superimposing a plurality of members, the friction surface can be increased and the torsional vibration absorbability can be improved. In addition, it is possible to stabilize the optimum resistance value by superimposing materials having different materials.

  By interposing the lubricant, the relative displacement at the suppression site can be performed smoothly, and torsional vibration can be stably suppressed. As the lubricant in this case, grease or the like can be used.

  By providing the lubricant reservoir, it is possible to stabilize the intervention of the lubricant at the suppression site, reduce the frictional resistance at the suppression site, and smoothly perform the relative displacement.

  In the case where the chamfered portion is formed at the end of the third member on the press-fitting start side, the press-fitting workability can be improved. The slidable contact surface of each member may not be the entire corresponding surface, and the degree of freedom in designing the shaft is great, resulting in excellent productivity.

  Further, the connection between the first member and the second member may be a serration connection or a connection by welding, and a known or public one can be used for this connection means, and the cost can be reduced. Can do.

  A sliding type constant velocity universal joint can be attached to the input side end, a fixed type constant velocity universal joint can be attached to the output side end, and it can slide to the input side end and output side end. Since a constant velocity universal joint can be attached, various types of power transmission means can be configured, and the versatility is excellent.

It is a longitudinal cross-sectional view of the shaft for constant velocity universal joints which shows the 1st Embodiment of this invention. FIG. 2 is an enlarged sectional view taken along line XX in FIG. 1. It is a principal part expanded sectional view of the fixed side of the said shaft for constant velocity universal joints. It is a principal part expanded sectional view which shows the modification of the 3rd member of a damping mechanism. It is a simplified sectional view of the constant velocity universal joint shaft. It is the YY line expanded sectional view of FIG. FIG. 6 is an enlarged sectional view taken along line ZZ in FIG. 5. It is a principal part expanded sectional view which shows 2nd Embodiment of the shaft for constant velocity universal joints of this invention. It is a principal part expanded sectional view which shows 3rd Embodiment of the shaft for constant velocity universal joints of this invention. It is a principal part expanded sectional view which shows 4th Embodiment of the shaft for constant velocity universal joints of this invention. It is a principal part expanded sectional view which shows 5th Embodiment of the shaft for constant velocity universal joints of this invention. It is a principal part expanded sectional view which shows 6th Embodiment of the shaft for constant velocity universal joints of this invention. It is a principal part expanded sectional view which shows 7th Embodiment of the shaft for constant velocity universal joints of this invention. It is a principal part expanded sectional view which shows 8th Embodiment of the shaft for constant velocity universal joints of this invention. It is a principal part expanded sectional view which shows 9th Embodiment of the shaft for constant velocity universal joints of this invention. It is a principal part expanded sectional view which shows 10th Embodiment of the shaft for constant velocity universal joints of this invention. It is sectional drawing which shows the modification of a 3rd member. It is principal part sectional drawing of the conventional constant velocity universal joint for vehicles. It is a principal part expanded sectional view of the constant velocity universal joint for vehicles shown in the said FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a longitudinal sectional view of a constant velocity universal joint shaft according to the present invention. The constant velocity universal joint shaft includes a shaft main body 1 and an outer member 2 fitted on the shaft main body 1. The shaft central portion 3 is provided with a damping mechanism 4.

  The shaft main body 1 includes an output side end 1a, an input side end 1b, a main body 1c, and a small diameter portion 1d and a large diameter portion 1e disposed between the output side end 1a and the main body 1c. The small-diameter portion 1f and the large-diameter portion 1g are disposed between the input-side end portion 1b and the main body portion 1c.

  In this case, a fixed type constant velocity universal joint (not shown) is connected to the output side end 1a, and a sliding type constant velocity universal joint (not shown) is connected to the input side end 1b. As the fixed type constant velocity universal joint, various types such as a bar field type in which the track groove bottom is only an arc portion and an undercut free type having a linear portion in a part of the track groove bottom can be used. . As the sliding constant velocity universal joint, various types such as a double offset type, a tripod type, and a cross groove type can be used.

  For this reason, the output side end portion 1a has a male spline 5 formed on the outer diameter surface thereof and a circumferential groove 6 into which a retaining ring (not shown) is fitted. Similarly, the input side end portion 1b is formed with a male spline 7 on its outer diameter surface and a circumferential groove 8 into which a retaining ring (not shown) is fitted.

  The large-diameter portion 1e on the output side end portion 1a constitutes a mounting portion for a boot (not shown) for closing the opening of a fixed type constant velocity universal joint (not shown). For this reason, the circumferential groove 9 is formed in the large diameter portion 1e. The large-diameter portion 1g on the input side end 1b side constitutes a mounting portion for a boot (not shown) for closing the opening of a sliding type constant velocity universal joint (not shown). For this reason, the circumferential groove 10 is formed in the large diameter portion 1g.

  The main body 1c has a central main body 12 and a large-diameter portion 13 connected to the large-diameter portion 1g on the input side end 1b side. The outer member 2 includes a main body cylindrical portion 2a and a supporting small-diameter portion 2b on the input side of the main body cylindrical portion 2a. The supporting small diameter portion 2b is coupled to the large diameter portion 13 of the main body portion 1c. The coupling in this case is a so-called serration coupling 15. That is, a male serration is formed on the outer peripheral surface of the large diameter portion 13 to constitute a male coupling portion, and a female serration is formed on the inner peripheral surface of the supporting small diameter portion 2b to constitute a female coupling portion. The shape coupling portion and the female coupling portion are coupled (engaged) to be coupled. In addition, the connection means of the large diameter part 13 and the support small diameter part 2b is not limited to the serration connection 15, and may be other means such as welding. In addition, the male serration in the male coupling portion in the serration coupling 15 includes a male spline, and the female serration in the female coupling portion in the serration coupling 15 includes a female spline. For this reason, the serration connection 15 includes a spline connection.

  In addition, a short cylindrical body 20 as a sliding member is disposed in the opening of the main body cylindrical portion 2a of the outer member 2 on the side opposite to the small diameter portion for support. That is, the shaft body 1 is provided with a large-diameter portion 1h, and the short cylindrical body 20 is fitted on the large-diameter portion 1h. A tapered portion 27 whose diameter increases toward the output side is formed at the opening end of the main body cylindrical portion 2a of the outer member 2 on the side opposite to the small diameter portion for support.

  The shaft main body 1 is made of, for example, the same material as the shaft for the drive shaft, and medium carbon steel, case-hardened steel, or the like is appropriate. Further, the outer member 2 is made of the same material as the shaft main body 1 or a material having a torsional rigidity equal to or higher than the material of the shaft main body 1. For example, a CFRP (carbon fiber reinforced plastic) material having high torsional rigidity is suitable. ing. Further, the short cylindrical body 20 can obtain a stable frictional force by applying the same material as the shaft main body 1 or a ceramic material or a carbon composite material having excellent wear resistance.

  By the way, the damping mechanism 4 includes a first member 31 that is the central body 12 of the shaft body 1, a second member 32 that is the outer member 2, a third member 33 that is the short cylindrical body 20, and the like. Is done.

  Next, a method for assembling the shaft will be described. In this case, the short cylindrical body 20 is fitted on the large diameter portion 1 h of the shaft body 1. Next, the outer member 2 as the second member 32 is inserted from the input side into the shaft body 1 to which the short cylindrical body 20 is assembled. At this time, the opening side of the outer member 2 is pressed into the sliding member that is the short cylindrical body 20, and the outer member 2 is inserted into the male coupling portion of the large-diameter portion 13 of the shaft body 1. The female coupling portion of the supporting small diameter portion 2b is press-fitted. Thus, the constant velocity universal joint shaft shown in FIG. 1 is completed. In addition, since the taper part 27 is formed in the opening edge of the outer member 2 as mentioned above, when the outer member 2 is inserted, this taper part 27 can be smoothly assembled as a guide.

  For this reason, the first member 31 and the second member 32 are tightly fitted to the third member 33 so that the first member 31 and the second member 32 can be relatively displaced. That is, the inner diameter surface of the third member 33 and the corresponding outer diameter surface of the first member 31 are in sliding contact, and the outer diameter surface of the third member 33 and the corresponding inner diameter surface of the second member 32 are Will come into sliding contact. For this reason, it is preferable to interpose a lubricant between the sliding contact surfaces as a measure for stick-slip. Stick-slip is a vibration phenomenon that occurs on a sliding surface.

  Further, as shown in FIG. 4, it is preferable to provide a lubricant reservoir 35 for storing the lubricant. In this case, it can be constituted by the concave groove 36 provided in the short cylindrical body 20 constituting the third member 33. The concave grooves 36 are arranged at a predetermined interval (60 ° pitch in the example) along the circumferential direction. Each concave groove 36 is an axial groove extending along the axial direction.

  Next, the function of the damping mechanism 4 will be described with reference to FIGS. An arbitrary predetermined dimension A is set between the serration coupling 15 on the input side and the relative displacement portion on the output side. On the input side, the first member 31 and the second member 32 are coupled by the serration coupling 15. Therefore, when a torque load is applied on the input side as shown in FIG. 5, as shown in FIG. In addition, the second member 32 is synchronized with the torsional displacement (θt) of the first member 31. In FIG. 6, P1 shows the phase of the 1st member 31 and the 2nd member 32 at the time of torque load. On the other hand, since they are not coupled on the output side, a phase difference (θt) is generated between the first member 31 and the second member 32 as shown in FIG. However, since the short cylindrical body 20 is fitted with a tightening margin between the first member 31 and the second member 32 on the output side, it fluctuates instantaneously due to the generated frictional force (resistance force). The fluctuation energy in the torsional direction is canceled (absorbed). For this reason, torsional vibration can be suppressed (damped). In FIG. 7, P2 indicates the phase of the first member 31 at the time of torque load, and P3 indicates the phase of the second member 32 at the time of torque load.

  Thus, in the present invention, by providing the damping mechanism 4 for suppressing torque fluctuation, torsional vibration due to torque fluctuation can be absorbed. For this reason, if this constant velocity universal joint shaft is used as a power transmission means to drive wheels in an automobile, excellent drivability without impairing rigidity (= direct feeling) in a running state where acceleration and deceleration are repeated And torsional vibration can be suppressed.

  Since the damping mechanism 4 includes the first member 31 and the second member 32, and the first member 31 includes a torque transmission shaft formed integrally with the output side end 1a and the input side end 1b, the configuration is simplified. Can be achieved. Since the second member 32 is externally fitted to the first member 31 that functions as a torque transmission shaft, the second member 32 can be made compact.

  Since the second member 32 can be set so that one end side is coupled to the first member 31 and the other end side is displaced relative to the first member 31, the function of absorbing vibration in the torsional direction can be effectively exhibited. Further, since the short cylindrical body 20 is fitted with a tightening margin, a frictional force can be generated at the tightening margin, and the reliability of the function of absorbing vibration in the torsional direction can be improved. For this reason, as this interference, what is necessary is just to generate | occur | produce the frictional resistance which a phase difference produces in this relative displacement part between the 1st member 31 and the 2nd member 32. FIG.

  As described above, the first member 31, the second member 32, the short cylindrical body 20, and the like can effectively exhibit the function of absorbing vibration in the torsional direction and can exhibit a highly reliable function.

  The third member 33 can be formed of a short cylindrical body having the same thickness along the axial direction, and the sliding member may be of a simple shape, and the cost can be reduced. As the sliding member, it is possible to use a ball or a roller, but if a ball or a roller is used, a plurality of parts need to be arranged along the circumferential direction, and the number of parts increases. This will increase the number of assembly steps.

  By interposing the lubricant, the relative displacement at the suppression site can be performed smoothly, and torsional vibration can be stably suppressed. As the lubricant in this case, grease or the like can be used.

  By providing the lubricant reservoir 35, the intervention of the lubricant at the suppression site is stabilized, the frictional resistance at the suppression site can be reduced, and the relative displacement can be performed smoothly. Moreover, when providing such a ditch | groove 36, it is preferable to make the circumferential direction edge part of the ditch | groove 36 into a round part. By providing the rounded portion in this manner, the circumferential edge of the concave groove 36 can be prevented from being caught and the relative displacement can be performed more smoothly.

  In the embodiment, the constant velocity universal joint shaft has a sliding type constant velocity universal joint attached to the input side end 1b and a fixed type constant velocity universal joint attached to the output side end 1a. However, as another embodiment, a sliding type constant velocity universal joint can be attached to the output side end 1a and the input side end 1b. Also, as the sliding type constant velocity universal joint in this case, various types such as a double offset type, a tripod type, and a cross groove type can be used. As described above, the constant velocity universal joint shaft of the present invention can constitute various types of power transmission means and is excellent in versatility.

  In the embodiment, the second member 32 is coupled to the input side of the first member 31. However, as another embodiment, the second member 32 is coupled to the output side of the first member 31, and the second member 32 is coupled. The short cylindrical body 20 may be arranged on the input side. Even in such a case, rotational fluctuation due to torque load from the input side end can be suppressed, and vibration in the torsional direction can be absorbed.

  By the way, in the said embodiment, although the short cylindrical body 20 was comprised by one member, as shown in FIG. 8, you may comprise by several members. In FIG. 8, the first short cylindrical body 20A on the inner diameter side and the second short cylindrical body 20B on the outer diameter side are configured. Thus, when the third member is formed by superimposing a plurality of members, the friction surface can be increased, and the absorbability of torsional vibration can be improved. Further, when the short cylindrical body 20 is composed of a plurality of short cylindrical bodies 20A and 20B, the cylindrical bodies 20A and 20B may be made of the same material or different materials. By using different materials, it is possible to stabilize the optimum resistance value.

  In FIG. 9, a protrusion 40 is provided at the end of the shaft body 1 on the main body side of the large diameter portion 1 h, and the short cylindrical body 20 is engaged with the protrusion 40. For this reason, it is possible to regulate the displacement of the short cylindrical body 20 toward the inner side of the outer member 2. The protrusion 40 is constituted by a circumferential ridge having a rectangular cross section.

  In FIG. 10, the taper part 41 which diameter-expands toward the main body part side is provided in the main body part side of the large diameter part 1h of the shaft main body 1. Further, a taper portion 42 whose diameter is increased toward the side opposite to the opening side is provided on the side opposite to the opening side of the inner diameter surface of the short cylindrical body 20. For this reason, when the short cylindrical body 20 is press-fitted, the tapered portion 42 of the short cylindrical body 20 is in pressure contact with the tapered portion 41 on the shaft body 1 side, and the inside of the outer member 2 of the short cylindrical body 20 It is possible to regulate the displacement to the side.

  As described above, by providing the protrusion 40 or the tapered portions 41 and 42, the axial displacement of the third member 33 can be restricted, and vibration in the torsional direction can be stably absorbed. it can. Further, the tapered portion 42 of the short cylindrical body 20 constitutes a chamfered portion provided at the press-fitting start end portion of the short cylindrical body 20. By providing the chamfered portion in this way, it is possible to improve the press-fit workability.

  11 and 12, the third member 33 is preloaded. That is, in FIG. 11, the short cylindrical body 20 has a tapered surface 45 whose outer diameter surface is reduced in diameter toward the inner side of the outer member 2, and its inner diameter surface is the inner side in the axial direction of the outer member 2. The diameter of the taper surface 46 is increased toward the surface, and the cross-sectional shape thereof is a wedge shape. Also, the inner diameter surface opening of the main body portion 2a of the outer member 2 is a tapered portion 47 whose diameter increases toward the opening side, and the large diameter portion 1h of the shaft main body 1 faces the inner side of the outer member 2. Thus, the diameter of the tapered portion 48 is increased. As a result, a ring-shaped gap 50 whose gap dimension decreases from the opening side toward the inner side in the axial direction is formed.

  The short cylindrical body 20 having a wedge-shaped cross section is press-fitted into the gap 50. Further, a male screw part 51 is provided in the vicinity of the tapered part 48 of the shaft body 1, and a pressing member 52 is screwed to the male screw part 51. The pressing member 52 has a short cylindrical main body portion 54 having a female screw portion 53 and an outer flange portion 55 formed on the outer diameter surface of the main body portion 54. That is, the inner diameter surface of the main body portion 54 has a large diameter portion 54a and a small diameter portion 54b, and the female screw portion 53 is formed in the small diameter portion 54b.

  Therefore, by screwing the female thread portion 53 of the pressing member 52 to the male thread portion 51 of the shaft body 1, the outer end surface 57 of the short cylindrical body 20 is pressed by the distal end surface 54c of the pressing member 52, and the arrow direction Of preload. In this case, the outer flange portion 55 is screwed until it comes into contact (contact) with the end edge 60 of the outer member 2.

  In FIG. 12, the outer diameter surface of the short cylindrical body 20 is not a tapered surface but a cylindrical surface, and the tapered surface is not formed in the opening of the outer member 2. Also in this case, by screwing the female thread portion 53 of the pressing member 52 to the male thread portion 51 of the shaft 1, the outer end surface 57 of the short cylindrical body 20 is pressed by the distal end surface 54c of the pressing member 52, and the arrow The direction preload can be loaded.

  Thus, in the case of applying a preload, an optimum resistance value can be secured by adjusting the preload amount.

  Next, in FIG. 13, the third member 33 is constituted by a disc body 70 having a central hole. In this case, the outer surface of the large-diameter portion 1h to which the disc body 70 is fitted is not a tapered surface, but is a cylindrical surface similar to the shaft body 1 shown in FIG. An inner flange 71 that bulges toward the inner diameter side is provided at the opening of 2. The inner flange 71 includes a thick part 71a and a continuous part 71b having a thickness that decreases from the thick part 71a toward the inside in the axial direction.

  In addition, the disk member 70 can be pressed against the open end surface 74 of the outer member 2 constituting the second member 32 by the pressing member 75 screwed into the male screw portion 51 provided on the shaft body 1. In this case, the pressing member 75 has a shape obtained by omitting (cutting) the protruding portion on the side opposite to the female thread portion from the outer flange portion 55 in the pressing member 52 shown in FIGS. 11 and 12. For this reason, the end surface 75 a of the pressing member 75 can press the outer end surface 70 a of the disc body 70 by screwing the female thread portion 53 of the pressing member 75 to the male screw portion 51 of the shaft body 1. That is, the preload in the direction of the arrow can be applied to the third member 33 configured by the disc body 70.

  In FIG. 13, the outer end surface 70 a of the disk body 70 and the end surface 75 a of the pressing member 75 are in sliding contact with each other, and the inner end surface 70 b of the disk body 70 and the opening end surface 74 of the outer member 2 are relatively in contact with each other. It will be in sliding contact with. In addition, the inner diameter surface 70 c of the disk body 70 and the outer diameter surface of the large diameter portion 1 h of the shaft body 1 are in sliding contact with each other.

  Therefore, even when the third member 33 formed of such a disk body 70 is used, the damping mechanism 4 for suppressing torque fluctuation is provided, and torsional vibration due to torque fluctuation can be absorbed. That is, the same effect as the shaft shown in FIG.

  By the way, in FIG. 13, the disc body 70 is composed of a single member, but as shown in FIG. 14, it may be composed of a plurality of members (two in the illustrated example). In other words, the second disk body 70B on the second member side and the first disk body 70A on the pressing member 75 side are provided. Thereby, the outer end surface 70Aa of the first disc body 70A and the end surface 75a of the pressing member 75 are in sliding contact with each other, and the inner end surface 70Ab of the first disc body 70A and the outer end surface 70Ba of the second disc body 70B are mutually connected. The inner end surface 70Bb of the second disc body 70B and the opening end surface 74 of the outer member 2 are in sliding contact with each other, and the inner diameter surfaces 70Ac, 70Bc of the first disc body 70A and the second disc body 70B, The outer diameter surface of the large diameter portion 1h of the shaft body 1 is in sliding contact with each other.

  In this case as well, torsional vibration due to torque fluctuation can be absorbed, and a preload in the direction of the arrow can be applied, and an optimal resistance value can be ensured by adjusting the amount of preload.

  In FIG. 15, a dust cover 80 is disposed on the outer diameter side of the disk body 70. That is, the dust cover 80 is formed of a thin short cylindrical body, and covers from the outer diameter surface of the pressing member 75 to the outer diameter surface on the opening side of the second member 32 through the outer diameter surface of the disc body 70. is there. In this case, the dust cover 80 is fixed to the second member 32 side or the third member side.

  In FIG. 15, the dust cover 80 is configured by a member different from the first, second, and third members. However, in FIG. 16, the dust cover 81 is disposed at the opening end of the outer member 2 that is the second member 32. Provided. That is, a short cylindrical portion 85 extending in the axial direction is provided at the opening end of the outer member 2, and the dust cover 81 is configured by the peripheral wall 85 a of the short cylindrical portion 85. In this case, the disc body 70 is fitted into the short cylindrical portion 85, and the pressing end portion of the pressing member 75 is fitted into the short cylindrical portion 85. That is, the outer diameter surface of the pressing member 75 and the outer diameter surface of the disc body 70 are covered with the dust cover 81.

  As shown in FIGS. 15 and 16, by providing the dust covers 80 and 81, it is possible to prevent foreign matter from entering between the sliding contact surfaces of the third member 33 and the mating member that is in sliding contact with the third member 33, and torque fluctuations. The torsional vibration absorbing function can be stably exhibited. In particular, as shown in FIG. 16, when the dust cover 81 is formed integrally with the second member 32, the productivity and cost efficiency are excellent.

  Incidentally, in the case where the third member 33 is configured by a disk body as shown in FIGS. 14 to 16 and the like, a lubricant reservoir 87 for storing the lubricant may be provided as shown in FIG. In this case, the lubricant reservoir 87 can be constituted by a radial hole 86. As shown in FIGS. 13 and 15, when the disk body 70 is configured by one member, the radial groove is formed on the sliding contact surface with the other side, that is, the outer end surface 70 a and / or the inner end surface 70 b. The lubricant reservoir 87 may be formed by providing it. As shown in FIG. 14, when the disk body 70 is constituted by two members, radial grooves are provided on the outer end faces 70Aa and 70Ba and / or the inner end faces 70Ab and 70Bb of the respective disk bodies 70A and 70B. Alternatively, the lubricant reservoir 87 may be formed.

  In this manner, by providing the lubricant reservoir 87, as in the case shown in FIG. 3, it is possible to stabilize the intervention of the lubricant in the suppression part, reduce the frictional resistance in the suppression part, and perform the relative displacement smoothly. Can do.

  As described above, the embodiments of the present invention have been described. However, the present invention is not limited to the above-described embodiments, and various modifications are possible. For example, as shown in FIGS. When a plurality of disk bodies are overlapped, the number is not limited to two. Moreover, as shown in FIG.3 and FIG.17, when providing a lubricant reservoir, the number can be set arbitrarily. In the case of configuring the lubricant reservoir, in the embodiment, it is formed by the groove provided on the third member side, but it is provided on the first member 31 and the second member 32 which are the other side of the third member 33. You may comprise a groove | channel and the groove | channel provided in the 3rd member 33 and the 1st member 31, and the 2nd member 32, etc.

  In the embodiment, the third member 33 and the first member 31 are in sliding contact, and the third member 33 and the second member 32 are in sliding contact. On the other hand, the third member 33 may not be displaced relative to the first member 31 or the second member 32. That is, in the present invention, it is sufficient that at least one of the first member 31 and the second member 32 or both of them can be relatively displaced with respect to the third member 33. The means for preventing relative displacement may be a joining means such as welding or a coupling means such as spline fitting.

DESCRIPTION OF SYMBOLS 1a Output side edge part 1b Input side edge part 3 Constant velocity universal joint shaft center part 4 Damping mechanism 15 Serration coupling 20, 20A, 20B Cylindrical body 31 1st member 32 2nd member 33 3rd member 35 Lubricant reservoir part 70, 70A, 70B Disc body

Claims (15)

A constant velocity universal joint is connected to each of the output side end and the input side end, and the torque from the input side end is applied to the center of the constant velocity universal joint shaft between the output side end and the input side end. A constant velocity universal joint shaft provided with a damping mechanism that suppresses fluctuations by resistance in the rotation direction,
The damping mechanism includes a shaft-shaped first member and a cylindrical second member that is externally fitted to the first member, and the second member is a first member on a torque input side or a torque output side. A constant velocity characterized in that a third member that is in sliding contact with at least one of the first member and the second member is disposed on the torque output side or the torque input side that is coupled and not coupled to the first member. Universal joint shaft.   The said 3rd member was comprised by the short cylindrical shape body with the same thickness along the axial direction fitted to the insertion part between the 1st member and the 2nd member. The shaft for constant velocity universal joints according to 1.   The third member is a short cylindrical body whose thickness decreases toward the inside in the axial direction with respect to the fitting portion between the first member and the second member, and is preloaded inward in the axial direction. The constant velocity universal joint shaft according to claim 1, wherein   2. The constant velocity universal joint shaft according to claim 1, wherein the third member is formed of a disc body that abuts against an end surface of the second member, and is loaded with a preload inward in the axial direction.   The shaft for a constant velocity universal joint according to any one of claims 1 to 4, wherein the third member is formed by overlapping a plurality of members.   The shaft for a constant velocity universal joint according to any one of claims 1 to 4, wherein the third member includes a plurality of members made of different materials.   The constant velocity according to any one of claims 1 to 6, wherein a lubricant is interposed between the third member and the first member and / or the second member on the other side. Universal joint shaft.   The constant velocity universal joint according to claim 7, wherein a lubricant reservoir for storing a lubricant is provided between the third member and the counterpart first member and / or second member. shaft.   9. The constant velocity universal joint shaft according to claim 1, wherein a chamfered portion is formed at an end of the third member on a press-fitting start side.   The constant velocity universal joint according to any one of claims 1 to 9, wherein a sliding contact surface of the third member with the counterpart first member or the second member is not the entire corresponding surface. Shaft.   The said 1st member is integrally molded by the output side edge part and the input side edge part, The constant velocity freedom of any one of Claims 1-10 characterized by the above-mentioned. Joint shaft.   12. The constant velocity universal joint shaft according to claim 2, wherein the first member and the second member are connected by serration.   The shaft for a constant velocity universal joint according to claim 2, wherein the first member and the second member are joined by welding.   The sliding constant velocity universal joint is attached to the input side end portion, and the fixed type constant velocity universal joint is attached to the output side end portion. Quick universal joint shaft.   The shaft for a constant velocity universal joint according to any one of claims 1 to 13, wherein a sliding type constant velocity universal joint is attached to the input side end portion and the output side end portion.

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