JP2023183779A - Constant velocity universal joint and manufacturing method of the same - Google Patents

Abstract

To supply grease to an area between tooth surfaces of a spline fitting part of a slide type constant velocity universal joint to prevent a situation that spline parts are damaged early.SOLUTION: A slide type constant velocity universal joint 10 includes: an outer joint member 15; rolling elements 19; an inner joint member 18; and a sealing member 23. An internal space 15a of the outer joint member 15 is filled with grease G and the inner joint member 18 and a shaft 22 are connected with each other through a spline fitting part 26. A torsion angle θ is provided to one 27 of a male spline part 27 and a female spline part 28 forming the spline fitting part 26. Further, the grease G is adhered to one axial end part 26a of the spline fitting part 26 in an unused state of the slide type constant velocity universal joint 10.SELECTED DRAWING: Figure 1

Description

The present invention relates to a constant velocity universal joint and a method for manufacturing a constant velocity universal joint.

Constant velocity universal joints enable rotary power to be transmitted at a constant velocity between two shafts on the driving side and the driven side, and are used by being incorporated into power transmission systems such as automobiles and various industrial machines. This constant velocity universal joint is broadly classified into a fixed type constant velocity universal joint and a sliding type constant velocity universal joint, and the sliding type constant velocity universal joint is further divided into a ball type and a tripod type. In the case of a ball type, the inner part that can slide on the outer joint member mainly consists of an inner ring, a cage, and a ball, and in the case of a tripod type, the inner part mainly consists of a tripod member (trunnion) and a roller. Consists of.

In the case of the ball type, the female spline part provided on the inner periphery of the inner ring and the male spline part provided on the outer periphery of the shaft, which is the rotation axis, fit together (spline fitting), causing the inner ring and shaft to rotate and rotate. Connected to enable power transmission. In the case of the tripod type, the female spline part provided on the inner periphery of the tripod member and the male spline part provided on the outer periphery of the shaft, which is the rotation axis, fit together, allowing rotation and power transmission between the tripod member and the shaft. connected to.

In addition, in any type of sliding constant velocity universal joint, the inner space of the outer joint member is filled with a lubricant such as grease, and in the ball type, smooth sliding between the ball and the outer joint member, tripod In the type, smooth sliding between the roller and the outer joint member is achieved (see, for example, Patent Document 1 and Patent Document 2).

Unexamined Japanese Patent Publication No. 2018-155404 Japanese Patent Application Publication No. 2018-48695

By the way, in the spline fitting part of the above-mentioned sliding type constant velocity universal joint, the female spline part and the male spline part have interference or an extremely small gap from the viewpoint of suppressing backlash that causes vibration and noise. The dimensions of each spline part are set so that the spline parts can be fitted together. Therefore, even if the inner space of the outer joint member is filled with an amount of grease corresponding to the above-mentioned sliding part, the filled grease is transferred from one axial end of the spline fitting part to the tooth surface (fitting part) of each spline part. It is difficult to spread the word between the two. Even with spline fitting parts that are connected and fixed to each other, such as in this type of constant velocity universal joint, one spline part is pressed against the other spline part due to the repeated application of torque, causing considerable deformation. . Therefore, if the lubrication between the tooth surfaces is insufficient, each spline portion may be damaged early.

In view of the above circumstances, the technical problem to be solved by the present invention is to supply grease between the tooth surfaces of the spline fitting part of a sliding type constant velocity universal joint, thereby preventing the spline part from being damaged early. It's about doing.

The solution to the above problem is achieved by a sliding constant velocity universal joint according to the present invention. In other words, in this constant velocity universal joint, the outer joint member has a track groove formed on its inner circumferential surface, the rolling element is arranged to be able to roll in the track groove, and the outer joint member is connected via the rolling element. The inner joint member includes an inner joint member that transmits torque while allowing angular displacement and axial displacement, a shaft connected to the inner joint member, and a sealing member that seals the inner space of the outer joint member. In a sliding constant velocity universal joint in which the inner joint member and the shaft are interconnected through a spline fitting part, the male spline part and the female spline part forming the spline fitting part are filled with grease. , one of the spline parts is given a torsion angle, and when the sliding constant velocity universal joint is in an unused state, it is characterized by the fact that grease is attached to one axial end of the spline fitting part.

As a result of intensive study by the inventors on the influence of the manner of supplying grease to the spline fitting part on the durability of the spline fitting part, we found that a spline formed by imparting a torsion angle to one of the male spline part and the female spline part By transmitting torque through rotational motion with grease applied to one axial end of the fitting part, the grease will penetrate between the tooth surfaces of each spline part, improving the lubrication condition between the tooth surfaces. found. This is presumed to be due to the following mechanism, for example. That is, when the constant velocity universal joint rotates (transmits torque), one spline portion is pressed against the other spline portion, causing deformation. As a result, the circumferential gap between one spline portion and the other spline portion provided with a torsion angle widens at one end in the axial direction of the spline fitting portion (for example, on the stem portion side of the outer joint member). On the other hand, the other end of the spline fitting portion in the axial direction is in a closed state due to the fitting between one spline portion and the other spline portion provided with a twist angle. Therefore, as one spline part deforms due to torque transmission, a wedge-shaped negative pressure space is generated between the tooth surfaces of the spline part, and the grease adhering to one axial end of the spline fitting part is transferred to the spline part. drawn between the tooth surfaces.

The present invention has been made based on the above knowledge, and it provides a torsion angle to one of the male spline part and the female spline part constituting the spline fitting part, and also provides a twist angle to one of the male spline part and the female spline part constituting the spline fitting part. Grease was attached to one axial end of the fitting part. With this configuration, during rotational movement (torque transmission) of the constant velocity universal joint, the grease adhered to one axial end of the spline fitting portion is repeatedly supplied between the tooth surfaces of the spline portion. As a result, the grease spreads widely over each tooth surface, maintaining a good lubrication condition between the tooth surfaces. Therefore, it is possible to improve the durability of the spline fitting portion and prevent early damage.

Further, in the sliding type constant velocity universal joint according to the present invention, the torsion angle may be 10' or more and 20' or less.

By setting the torsion angle of one of the spline parts constituting the spline fitting part within the above-mentioned range, it is possible to ensure smooth fitting operation between the inner joint member and the shaft during assembly, while also preventing repeated torque action. This makes it possible to fully enjoy the effect of drawing in the grease.

Further, in the sliding constant velocity universal joint according to the present invention, the consistency of the grease may be 310 or more and 340 or less.

As the sliding constant velocity universal joint rotates, the grease filled in the inner space of the outer joint member is subjected to centrifugal force. Therefore, if the grease has high fluidity, it easily flows toward the inner circumferential surface of the outer joint member or the inner circumferential surface of a sealing member such as a boot as the sliding constant velocity universal joint rotates. By using a grease whose consistency has been adjusted within the above range, even if centrifugal force is generated due to the rotation of the sliding type constant velocity universal joint, at least one axial end of the spline fitting part It is possible to prevent as much as possible the situation in which the grease adhered to the grease is dispersed to the surroundings. Therefore, according to this configuration, it is possible to continuously and stably generate the action of drawing the grease between the tooth surfaces in an environment where torque is applied repeatedly.

Moreover, the solution to the above problem is also achieved by the method for manufacturing a sliding constant velocity universal joint according to the present invention. In other words, this manufacturing method produces angular displacement between an outer joint member in which a track groove is formed on the inner circumferential surface, a rolling element that is rollably arranged in the track groove, and the outer joint member via the rolling element. and an inner joint member that transmits torque while allowing axial displacement, a shaft connected to the inner joint member, and a sealing member that seals the inner space of the outer joint member. In a method for manufacturing a sliding constant velocity universal joint in which an inner joint member and a shaft are interconnected through a spline fitting portion, the rolling elements are held in the inner joint member and the shaft is connected. a preparation step for preparing the inner part in a state where the inner part is in a state where the grease is filled with grease, a filling step for filling the inner space of the outer joint member with grease, introducing the inner part into the inner space of the outer joint member, and assembling the inner part to the outer joint member. a first assembly step, and a second assembly step of assembling the sealing member to the outer joint member with the inner component assembled, and before performing the second assembly step, the axis of the spline fitting part is It is characterized by the fact that grease is attached to one end in the direction.

In this way, before assembling the sealing member to the outer joint member in which the inner parts (rolling elements, shaft, and inner joint member are integrated) are assembled, the spline fitting portion between the inner joint member and the shaft is By applying grease to one axial end of the spline fitting part, a sliding constant velocity universal joint can be obtained in which grease is applied to one axial end of the spline fitting part in an unused state. Therefore, similar to the sliding type constant velocity universal joint according to the present invention, when the constant velocity universal joint rotates (during torque transmission), one of the spline parts provided with the torsion angle deforms, thereby causing the gap between the tooth surfaces of the spline part to deform. A wedge-shaped negative pressure space is generated, and the grease attached to one axial end of the spline fitting portion is drawn between the tooth surfaces of the spline portion. As the above-mentioned phenomenon occurs repeatedly each time torque is transmitted, the grease is spread widely over each tooth surface, and the inter-tooth surfaces are kept in a good lubricated state. Therefore, the method of manufacturing a sliding type constant velocity universal joint according to the present invention also makes it possible to improve the durability of the spline fitting portion and prevent early damage.

Furthermore, in the method for manufacturing a sliding constant velocity universal joint according to the present invention, grease may be applied to one axial end of the spline fitting portion in the preparation step.

In this way, by applying grease to one axial end of the spline fitting part during the preparation process for assembling the inner parts, it is possible to easily apply grease to the necessary locations without changing any subsequent processes. Can be done. Furthermore, before the inner component is assembled to the outer joint member, the location where the grease is attached can be visually confirmed, so that the grease can be reliably attached to the one axial end of the spline fitting portion without leaking.

Further, in the method for manufacturing a sliding constant velocity universal joint according to the present invention, after the filling process is performed, one axial end of the spline fitting part is filled into the inner space of the outer joint member in the first assembly process. The inner part may be moved toward the bottom of the inner space of the outer joint member to a position where the inner part adheres to the grease that has been applied.

In this way, the grease can be applied to one end in the axial direction of the spline fitting part by utilizing the introduction operation of the inner part in the first assembling step, which has been conventionally performed. Therefore, it is possible to perform the grease application work at the same time as the internal parts assembly work, and it is possible to apply grease to one axial end of the spline fitting part while maintaining the same work efficiency as before. It becomes possible to manufacture quick adjustable joints.

Further, in the method for manufacturing a sliding constant velocity universal joint according to the present invention, a filling step is performed after the first assembly step, and in the filling step, grease is applied to one end in the axial direction of the spline fitting portion. The amount of grease filled may be adjusted to ensure good adhesion.

In this way, after the inner part is assembled and before the sealing member is assembled, grease can be filled, for example, from the gap between the outer joint member and the inner part toward the inner space of the outer joint member. In addition, with this method, it is possible to easily attach grease to the necessary locations by simply adjusting the amount of grease filled (for example, by simply filling a larger amount of grease than conventionally). Therefore, even with this method, it is possible to manufacture a sliding constant velocity universal joint in which grease is adhered to one axial end of the spline fitting part while maintaining the same working efficiency as the conventional method.

As described above, according to the present invention, since it is possible to supply grease between the tooth surfaces of the spline fitting part of a sliding type constant velocity universal joint, it is possible to prevent the spline part from being damaged at an early stage. Become.

1 is a sectional view of a sliding constant velocity universal joint according to a first embodiment of the present invention. FIG. 2 is a diagram conceptually showing a state in which the spline fitting portion shown in FIG. 1 is developed in a plane. FIG. 2 is a plan development view of the spline fitting portion shown in FIG. 1 during torque transmission. It is a flowchart which shows the procedure of the manufacturing method of the sliding type constant velocity universal joint concerning a first embodiment of the present invention. FIG. 5 is a cross-sectional view for explaining a grease application operation in the preparation process shown in FIG. 4. FIG. It is a flow chart which shows the procedure of the manufacturing method of the sliding type constant velocity universal joint concerning the second embodiment of the present invention. FIG. 7 is a cross-sectional view for explaining a grease application operation in the first assembly step shown in FIG. 6; It is a flowchart which shows the procedure of the manufacturing method of the sliding type constant velocity universal joint based on 3rd embodiment of this invention. FIG. 9 is a cross-sectional view for explaining a grease filling operation in the filling process shown in FIG. 8;

Hereinafter, a first embodiment of the present invention will be described based on the drawings.

In the following embodiments, a ball type sliding constant velocity universal joint that is incorporated into a drive shaft of an automobile is exemplified as a sliding constant velocity universal joint according to the present invention. Of course, the present invention is applicable not only to ball type but also to tripod type sliding constant velocity universal joints.

FIG. 1 shows a sectional view of a double offset type sliding constant velocity universal joint 10 according to a first embodiment of the present invention. This sliding constant velocity universal joint 10 is arranged, for example, on the inboard side of a drive shaft, and has track grooves 11 extending in the axial direction and having an arcuate cross section formed at multiple locations in the circumferential direction of an inner peripheral surface 12. An outer joint member 15 having a portion 13 and a stem portion 14, and track grooves 16 having an arcuate cross section and extending in the axial direction in pairs with the track grooves 11 of the outer joint member 15 are formed at a plurality of locations in the circumferential direction of the outer peripheral surface 17. a plurality of balls 19 that are interposed between the track grooves 11 of the outer joint member 15 and the track grooves 16 of the inner joint member 18 to transmit torque; and the inner circumference of the outer joint member 15. A cage 20 that is disposed between the surface 12 and the outer peripheral surface 17 of the inner joint member 18 and holds the ball 19 is provided. In this case, the inner joint member 18, the ball 19, and the cage 20 constitute an internal component 21 that can slide in the inner space of the outer joint member 15 along the joint axial direction.

The sliding constant velocity universal joint 10 further includes a boot 23 that covers the outer periphery of the outer joint member 15 and the shaft (here, intermediate shaft) 22, and boot bands 24 and 25 that are attached to predetermined locations of the boot 23. Be prepared. Note that the boot 23 here corresponds to the sealing member according to the present invention.

The boot 23 integrally includes a large diameter end 23a, a small diameter end 23b, and a bellows 23c formed between the large diameter end 23a and the small diameter end 23b and having a bellows shape. In this case, by attaching the first boot band 24 to the large diameter side end 23a of the boot 23, the large diameter side end 23a is fixed to the opening side end of the outer joint member 15, and the second boot band 25 is fixed to the opening side end of the outer joint member 15. By attaching the small diameter end 23b of the boot 23, the small diameter end 23b is fixed to the outer circumferential surface 22a of the shaft 22. By fixing the boot 23 to the outer joint member 15 and the shaft 22 as described above, the inner space 15a of the outer joint member 15 is sealed, and leakage of the grease G to the outer space can be prevented.

The inner space 15a of the outer joint member 15 is filled with grease G as a lubricant. Thereby, when the shaft 22 rotates with respect to the outer joint member 15 while taking an operating angle within a predetermined range, it is possible to ensure the required lubricity in the sliding portion of the sliding constant velocity universal joint 10. Note that FIG. 1 shows the distribution state of the grease G after a predetermined rotation (the portion shown in a dotted pattern in FIG. 1). That is, as the sliding constant velocity universal joint 10 rotates, the grease G filled in the inner space 15a of the outer joint member 15 flows radially outward under the centrifugal force accompanying the rotation. As a result, as shown in FIG. 1, most of the grease G has flowed mainly onto the inner peripheral surface 12 (track groove 11) of the outer joint member 15 and the inner peripheral surface of the bellows 23c of the boot 23. .

The inner joint member 18 and one end of the shaft 22 are connected to each other via a spline fitting portion 26. The other end of the shaft 22 is connected to an inner joint member of a fixed constant velocity universal joint, for example, via a spline fitting (both not shown).

The spline fitting part 26 is composed of a plurality of male spline parts 27 and a plurality of female spline parts 28. The male spline portion 27 is provided on the outer periphery of one axial end of the shaft 22 , and the female spline portion 28 is provided on the inner periphery of the inner joint member 18 . By inserting one axial end of the shaft 22 into the inner periphery of the inner joint member 18, the male spline part 27 and the female spline part 28 are fitted, and the inner joint member 18 and the shaft 22 are interconnected. . In this embodiment, the male spline portion 27 is provided over the entire outer periphery of one axial end of the shaft 22, and the female spline portion 28 is provided over the entire inner periphery of the inner joint member 18. The portion 27 and the female spline portion 28 are fitted over the entire circumference. Further, in this embodiment, a circumferential groove 29 is formed in the outer circumferential surface 22a of the shaft 22 at a position slightly apart in the axial direction from one axial end 27a of the male spline portion 27; A retaining ring 30 is attached. Thereby, movement of the shaft 22 in the axial direction with respect to the inner joint member 18 can be restricted by the retaining ring 30.

FIG. 2 is a diagram conceptually showing a state in which the spline fitting portion 26 is developed in a plane. As shown in FIG. 2, one of the male spline portion 27 and the female spline portion 28 (here, the male spline portion 27) is provided with a predetermined twist angle θ. In this embodiment, when a torque is input from the outer joint member 15 side, the inner joint member 18 rotates (moves) upward in FIG. One end 27a (here, the inboard side end of the shaft 22) is pressed. In other words, the twisting direction of the male spline portion 27 is set so that the one axial end portion 27a of the male spline portion 27 is pressed and deformed when torque is transmitted. As will be described later, the actual torsion angle θ of the male spline portion 27 with respect to the female spline portion 28 is very small (a level that is difficult to visually recognize), so FIGS. 2 and 3 show the actual torsion angle θ. It is drawn more exaggerated than θ. Furthermore, for the same reason, the ratio of the circumferential dimension to the longitudinal dimension is also drawn large.

Here, the magnitude of the twist angle θ is arbitrary in principle; for example, when taking into consideration the negative pressure generation effect described later, the twist angle θ is set to 5' or more, more preferably 10' or more. On the other hand, when considering ease of fitting between the male spline part 27 and the female spline part 28, the twist angle θ is set to 30' or less, more preferably 20' or less.

Grease G is attached to one axial end 26a (in FIG. 1, the end near the bottom 13a of the mouth portion 13) of the spline fitting portion 26 configured as described above. This grease G adheres to one axial end portion 26a of the spline fitting portion 26 at least in an unused state. In this embodiment, as shown in the enlarged view in FIG. 1, an axial gap is formed between the retaining ring 30 attached to the circumferential groove 29 of the shaft 22 and the inner joint member 18. Therefore, it becomes possible to relatively easily supply and adhere the grease G to the one axial end portion 26a of the spline fitting portion 26, for example, in the grease adhesion step S5 described later.

Although not shown in the drawings, if there is no particular problem with the strength of the retaining ring 30, a plurality of notches may be provided in the retaining ring 30 to cut out the end of the shaft 22 (on the right side in FIG. 1). From this, one axial end portion 26a of the spline fitting portion 26 may be visible. By doing this, it becomes easier to attach the grease G to the one end 26a in the axial direction, and the number of selectable means for attaching the grease G increases.

As the grease G, any known type of grease can be used without limitation as long as it is applicable to the sliding constant velocity universal joint 10. Here, when considering the difficulty of scattering of grease G attached to one axial end 26a of the spline fitting part 26 due to centrifugal force when the sliding constant velocity universal joint 10 rotates, the consistency is 310. Grease adjusted to the above and 340 or less is suitable.

Hereinafter, an example of a method for manufacturing the sliding constant velocity universal joint 10 having the above structure (first embodiment of the present invention) will be described mainly based on FIGS. 4 and 5.

FIG. 4 is a flowchart showing the flow of the method for manufacturing the sliding constant velocity universal joint 10 according to the first embodiment of the present invention. As shown in FIG. 4, the method for manufacturing the sliding constant velocity universal joint 10 according to the present embodiment includes a preparation process S1, a filling process S2, a first assembly process S3, and a second assembly process S4. , and a grease adhesion step S5. The details of each step S1 to S5 will be explained below in chronological order.

(S1) Preparation step (S5) Grease application step In this step S1, the inner part 21 in which the ball 19 is held in the inner joint member 18 and the shaft 22 is connected is prepared (preparation step S1). Specifically, as shown in FIG. 5, a cage 20 with a ball 19 accommodated in a pocket is attached to the outer periphery of the inner joint member 18. Further, one axial end of the shaft 22 is inserted into the inner periphery of the inner joint member 18, the male spline portion 27 is fitted into the female spline portion 28, and then the retaining ring 30 is attached. As a result, the inner component 21 is obtained in which the plurality of balls 19 are held rotatably relative to the inner joint member 18 and the shaft 22 is coupled to the inner joint member 18 so as to be capable of transmitting power.

Note that the above-described fitting operation is performed with a predetermined interference or a very small gap between the male spline portion 27 and the female spline portion 28. This ensures the fixing strength of the shaft 22 to the inner joint member 18.

After assembling the inner part 21, while holding the inner part 21 in a predetermined position and posture, grease G is applied to one axial end 26a of the spline fitting part 26 between the inner joint member 18 and the shaft 22. (grease adhesion step S5). In this embodiment, as shown in FIG. Grease G is discharged from the nozzle 40 while rotating around the central axis of the nozzle 40. As a result, the grease G is applied to one axial end portion 26a of all the spline fitting portions 26, and is in an adhered state.

In addition, in the above-mentioned grease application step S5, grease G is applied from the nozzle 40 to the spline fitting portion 26 of the inner part 21 (not shown) in a state before the retaining ring 30 is attached in the preparation step S1. You can.

(S2) Filling Step In this step S2, the inner space 15a of the outer joint member 15 before the inner component 21 is assembled is filled with grease G (not shown). At this time, the filling amount of the grease G is set to a conventionally appropriate value depending on the type, application, etc. of the sliding constant velocity universal joint 10.

(S3) First assembly process In this process S3, the inner part 21 with grease G adhered to a part of the spline fitting part 26 is introduced into the inner space 15a of the outer joint member 15 filled with grease G. Then, the inner part 21 is assembled to the outer joint member 15 (not shown).

(S4) Second assembly process In this process S4, a boot 23 as a sealing member is further attached to the integrated product of the inner part 21 and the outer joint member 15 obtained in the first assembly process S3. Specifically, as described above, the large-diameter end 23a of the boot 23 is fixed to the opening end of the outer joint member 15 by attaching the first boot band 24, and the boot is fixed by attaching the second boot band 25. By fixing the small diameter side end 23b of 23 to the outer circumferential surface 22a of the shaft 22, the internal space of the sliding constant velocity universal joint 10, including the internal space 15a of the outer joint member 15, is sealed. As a result, the sliding constant velocity universal joint 10 shown in FIG. 1 is completed.

Hereinafter, the effects of the sliding constant velocity universal joint 10 according to this embodiment will be explained.

First, when the sliding constant velocity universal joint 10 shown in FIG. 1 is not rotating (no torque is applied), as shown in FIG. Both end portions 27a and 27b are fitted into female spline portions 28 to form spline fitting portions 26. At this time, grease G is attached to one axial end 26a (the right end in FIG. 2) of the spline fitting portion 26.

When the sliding constant velocity universal joint 10 rotates (torque is transmitted), a torque T in a predetermined direction (direction shown by the arrow in FIG. 3) is applied from the outer joint member 15 to the inner joint member 18 via the ball 19. When transmitted, this torque T forces the male spline portion 27 of the shaft 22 from the female spline portion 28 of the inner joint member 18 in the same direction as the torque T. As a result, the one axial end 27a of the male spline portion 27 is deformed, and the tooth surface 27c of the male spline portion 27 comes into close contact with the tooth surface 28c of the female spline portion 28 on the side of the one axial end 27a. The circumferential interval W between the portion 27 and the female spline portion 28 increases from the axially one end portion 26a side of the spline fitting portion 26 to the axially intermediate region side. On the other hand, the other end 26b of the spline fitting portion 26 in the axial direction is in a closed state due to the fitting (close contact) between the male spline portion 27 and the female spline portion 28, which are provided with a twist angle θ. Therefore, as the male spline portion 27 deforms due to torque transmission, a wedge-shaped negative pressure space S is generated between the tooth surfaces 27c and 28c of the male spline portion 27 and the female spline portion 28. Here, grease G is attached to one axial end portion 26a of the spline fitting portion 26. Therefore, with the generation of the negative pressure space S, the grease G adhering to the one axial end 26a is drawn between the tooth surfaces 27c and 28c of the male and female spline portions 27 and 28.

As described above, the grease G adhered to the one axial end 26a of the spline fitting part 26 is repeatedly supplied between the tooth surfaces 27c and 28c of each spline part 27 and 28 each time torque is transmitted. , the grease G is spread widely over each tooth surface 27c, 28c, and a good lubricating state is maintained between the tooth surfaces 27c, 28c. Therefore, according to the sliding constant velocity universal joint 10 according to the present embodiment, it is possible to improve the durability of the spline fitting portion 26 and prevent early damage.

In addition, in the method for manufacturing the sliding constant velocity universal joint 10 according to the present embodiment, in the preparation step S1 for preparing the inner part 21, grease G is applied to one axial end 26a of the spline fitting part 26. Therefore, the grease G can be easily applied to the required location (one axial end portion 26a) without changing the subsequent steps S2 to S4 from the conventional method. Furthermore, before assembling the inner part 21 to the outer joint member 15 (before the first assembly step S3), the attachment point can be visually confirmed (see FIG. 5), so the spline fitting part 26 Grease G can be reliably adhered to the one axial end portion 26a without leaking. Further, the nozzle 40 is disposed toward one axial end 26a of the spline fitting portion 26, and the sliding constant velocity universal joint 10 or the nozzle 40 is rotated around the central axis of the sliding constant velocity universal joint 10 (axis By discharging the grease G while rotating (rotating), the grease G can be easily applied to one axial end portion 26a of all the spline fitting portions 26 without leaking.

Furthermore, if the grease G is to be applied to the one axial end portion 26a of the spline fitting portion 26 in the preparation step S1, the grease G may be applied before the retaining ring 30 is attached as described above. It is valid. If the retaining ring 30 is not present, the grease G can be attached more easily, but since the inner part 21 is in the preparation stage, the retaining ring 30 can be easily attached after the grease G is attached. Become.

Although the first embodiment of the present invention has been described above, the sliding type constant velocity universal joint and the method for manufacturing the same according to the present invention are not limited to the above-mentioned exemplified forms, and may be any form within the scope of the present invention. can be taken.

FIG. 6 is a flowchart showing the flow of a method for manufacturing the sliding constant velocity universal joint 10 according to the second embodiment of the present invention. As shown in FIG. 6, the method for manufacturing the sliding constant velocity universal joint 10 in this embodiment, like the first embodiment, includes a preparation step S1, a filling step S2, a first assembly step S3, and a first assembly step S3. It includes two assembly steps S4 and a grease adhesion step S5. On the other hand, the implementation stage of the grease adhesion step S5 is different from the first embodiment. Hereinafter, details of each step S1 to S5 will be explained in chronological order, focusing on the differences from the first embodiment.

(S1) Preparation Step In this step S1, the inner component 21 in which the ball 19 is held by the inner joint member 18 and the shaft 22 is connected is prepared in the same manner as in the first embodiment. As a result, the inner component 21 is obtained in which the plurality of balls 19 are held rotatably relative to the inner joint member 18 and the shaft 22 is coupled to the inner joint member 18 so as to be capable of transmitting power.

(S2) Filling Step In this step S2, the inner space 15a of the outer joint member 15 before the inner component 21 is assembled is filled with grease G (not shown). In this embodiment as well, the filling amount of the grease G is set to an appropriate value as before, depending on the type, application, etc. of the sliding constant velocity universal joint 10.

(S3) First assembly step (S5) Grease application step In this step S3, the inner part 21 prepared in the preparation step S1 is introduced into the inner space 15a of the outer joint member 15 filled with grease G. The inner part 21 is assembled to the outer joint member 15.

At this time, the inner space 15a of the outer joint member 15 is filled with a predetermined amount of grease G. Therefore, when this outer joint member 15 is held in the attitude shown in FIG. reference). Therefore, at this time, by controlling the introduction depth position (in this case, the axial position) of the inner part 21, the one axial end 26a of the spline fitting part 26 can be positioned at the liquid level Ga of the grease G or from the liquid level Ga. is moved to a position close to the bottom 13a of the mouse portion 13 (the position indicated by the solid line in FIG. 7). This makes it possible to reliably apply the grease G to the one axial end portion 26a of the spline fitting portion 26 every time, even when it is not visible.

Note that if the reference position at the time of completion of assembly is determined, first move the inner part 21 to the position where grease G is applied, then move it in the opposite direction from when grease G was applied and move it inside to the reference position. All you have to do is return the part 21.

Depending on the consistency of the grease G, it is also possible to hold the outer joint member 15 with the axial direction of the outer joint member 15 aligned with the vertical direction, and insert the inner component 21 from above to below on the outer joint member 15 in this position. Grease G is deposited on one axial end portion 26a of the spline fitting portion 26 by introducing the grease G toward the surface and moving the inner part 21 to the liquid level Ga position of the grease G or to a position below the liquid surface Ga. Good too.

(S4) Second assembly process In this process S4, similarly to the first embodiment, a boot as a sealing member is added to the integrated product of the inner part 21 and the outer joint member 15 obtained in the first assembly process S3. Install 23. Thereby, the internal space of the sliding constant velocity universal joint 10 including the internal space 15a of the outer joint member 15 is in a sealed state. As a result, the sliding constant velocity universal joint 10 shown in FIG. 1 is completed.

As described above, in the method for manufacturing the sliding constant velocity universal joint 10 according to the present embodiment, after the filling step S2 is performed, in the first assembly step S3, one axial end portion 26a of the spline fitting portion 26 is Since the inner part 21 is moved toward the bottom 13a of the mouth portion 13 of the outer joint member 15 to the position where it adheres to the grease G filled in the inner space 15a of the outer joint member 15, the conventional method is avoided. Grease G can be applied to one axial end portion 26a of the spline fitting portion 26 by utilizing the introduction operation of the inner part 21 in the first assembly step S3. Therefore, the work of applying the grease G can be performed at the same time as the work of assembling the inner part 21, and the grease G can be applied to the one axial end 26a of the spline fitting part 26 while maintaining the same work efficiency as before. It becomes possible to manufacture the sliding type constant velocity universal joint 10.

FIG. 8 is a flowchart showing the flow of a method for manufacturing the sliding constant velocity universal joint 10 according to the third embodiment of the present invention. As shown in FIG. 8, the method for manufacturing the sliding constant velocity universal joint 10 in this embodiment includes a preparation step S1, a filling step S2, and a first assembly step S3, as in the first and second embodiments. , a second assembly step S4, and a grease adhesion step S5. On the other hand, the implementation stage of the grease adhesion step S5 is different from both the first embodiment and the second embodiment. Hereinafter, details of each step S1 to S5 will be explained in chronological order, focusing on the differences from the first and second embodiments.

(S1) Preparation Step In this step S1, similarly to the first and second embodiments of the present invention, the inner component 21 in which the ball 19 is held by the inner joint member 18 and the shaft 22 is connected is prepared. As a result, the inner component 21 is obtained in which the plurality of balls 19 are held rotatably relative to the inner joint member 18 and the shaft 22 is coupled to the inner joint member 18 so as to be capable of transmitting power.

(S3) First assembly step In this step S3, similarly to the first and second embodiments of the present invention, the inner part 21 prepared in the preparation step S1 is assembled into the outer joint member 15 filled with grease G. The inner part 21 is introduced into the inner space 15a and assembled to the outer joint member 15. Thereby, an integral product of the inner part 21 and the outer joint member 15 is obtained. At this point, the grease G has not yet adhered to the one axial end portion 26a of the spline fitting portion 26.

(S2) Filling step (S5) Grease application step In this step S2, the inner space 15a of the outer joint member 15 with the inner component 21 assembled is filled with grease G. Here, when the inner part 21 is arranged at a predetermined axial position of the outer joint member 15, the grease G is applied to one axial end 26a of the spline fitting part 26 of the inner part 21 at the predetermined axial position. The filling amount of grease G is set so that it can adhere. In the present embodiment, as shown in FIG. 9, when the inner part 21 is arranged at an axial reference position that is set depending on where the sliding constant velocity universal joint 10 is attached (for example, a drive shaft of an automobile), The grease G is filled so that the grease G reaches at least one axial end portion 26a of the spline fitting portion 26 of the inner part 21. The example shown in FIG. 9 shows a state in which the inner component 21 is placed at the axial reference position and the grease G is filled up to the axial position of the center of the ball 19. This makes it possible to reliably apply the grease G to the one axial end portion 26a of the spline fitting portion 26 every time, even when it is not visible.

Also in this embodiment, depending on the consistency of the grease G, the outer joint member 15 and the inner part 21 are held as one body with the axial direction of the outer joint member 15 aligned with the vertical direction, and this position The grease G may be attached to the one axial end portion 26a of the spline fitting portion 26 by filling the inner space 15a of the outer joint member 15 with the above amount of grease G.

(S4) Second assembly process In this process S4, similarly to the first and second embodiments, a sealing member is added to the integrated product of the inner part 21 and the outer joint member 15 obtained in the first assembly process S3. Attach the boots 23. Thereby, the internal space of the sliding constant velocity universal joint 10 including the internal space 15a of the outer joint member 15 is in a sealed state. As a result, the sliding constant velocity universal joint 10 shown in FIG. 1 is completed.

As described above, in the method for manufacturing the sliding constant velocity universal joint 10 according to the present embodiment, the filling step S2 is performed after the first assembly step S1, and the spline fitting is performed in the filling step S2. The filling amount of the grease G was adjusted so that the grease G adhered to one axial end portion 26a of the portion 26. In this way, after the inner part 21 is assembled and before the boot 23 is assembled, the outer joint member 15, or more precisely, the grease G can be filled in a region of the inner space 15a closer to the bottom 13a than the inner part 21. Further, with this method, the grease G can be easily attached to the one axial end portion 26a of the spline fitting portion 26 by simply filling the grease G in a larger amount than conventionally. Therefore, even with this method, it is possible to manufacture the sliding type constant velocity universal joint 10 in which the grease G is attached to the one axial end portion 26a of the spline fitting portion 26 while maintaining the same work efficiency as before. becomes.

Note that the method for manufacturing the sliding constant velocity universal joint 10 according to the present invention is not limited to the method described above. In short, as long as the grease G can be attached to the one axial end 26a of the spline fitting part 26 before the boot 23 is attached to the outer joint member 15 and the shaft 22 in the second assembly step S4, any grease can be attached. It is possible to adopt means.

10 Sliding type constant velocity universal joint 11 Track groove 12 Inner peripheral surface 13 Mouth part 13a Bottom part 14 Stem part 15 Outer joint member 15a Inner space 16 Track groove 17 Outer peripheral surface 18 Inner joint member 19 Ball 20 Cage 21 Inner part 22 Shaft 22a Outer peripheral surface 23 Boot 23a Large diameter end 23b Small diameter end 23c Bellows 24, 25 Boot band 26 Spline fitting part 26a One axial end 26b Other axial end 27 Male spline part 27a One axial end 27b Axial direction Other end portions 27c, 28c Tooth surface 28 Female spline portion 29 Circumferential groove 30 Retaining ring 40 Nozzle G Grease Ga Liquid level S Negative pressure space S1 Preparation process S2 Filling process S3 First assembly process S4 Second assembly process S5 Grease Adhesion process T Torque W Circumferential spacing θ Torsion angle

Claims (7)

Angular displacement and axial displacement between an outer joint member having a track groove formed on its inner circumferential surface, a rolling element rollably disposed in the track groove, and the outer joint member via the rolling element. the inner joint member that transmits torque while allowing the inner joint member to transmit torque; a shaft connected to the inner joint member; and a sealing member that seals the inner space of the outer joint member; In a sliding constant velocity universal joint in which the inner joint member and the shaft are interconnected via a spline fitting portion,
Of the male spline part and the female spline part constituting the spline fitting part, one of the spline parts is provided with a torsion angle, and when the sliding constant velocity universal joint is in an unused state, the spline fitting part is A sliding constant velocity universal joint characterized in that the grease is attached to one end in the axial direction. The sliding constant velocity universal joint according to claim 1, wherein the torsion angle is 10' or more and 20' or less. The sliding constant velocity universal joint according to claim 1, wherein the grease has a consistency of 310 or more and 340 or less. Angular displacement and axial displacement between an outer joint member having a track groove formed on its inner circumferential surface, a rolling element rollably disposed in the track groove, and the outer joint member via the rolling element. the inner joint member that transmits torque while allowing the inner joint member to transmit torque; a shaft connected to the inner joint member; and a sealing member that seals the inner space of the outer joint member; In a method for manufacturing a sliding constant velocity universal joint, the inner joint member and the shaft are interconnected via a spline fitting part,
a preparation step of preparing an inner part in which the rolling element is held by the inner joint member and the shaft is connected;
a filling step of filling the inner space of the outer joint member with the grease;
a first assembly step of introducing the inner part into the inner space of the outer joint member and assembling the inner part to the outer joint member;
a second assembling step of assembling the sealing member to the outer joint member with the inner component assembled;
A method for manufacturing a sliding constant velocity universal joint, characterized in that, before performing the second assembly step, the grease is applied to one axial end of the spline fitting portion. 5. The method for manufacturing a sliding constant velocity universal joint according to claim 4, wherein in the preparation step, the grease is applied to one axial end of the spline fitting portion. After carrying out the filling process, in the first assembly process, the inner side is moved to a position where one axial end of the spline fitting part adheres to the grease filling the inner space of the outer joint member. The method for manufacturing a sliding constant velocity universal joint according to claim 4, wherein the component is moved toward the bottom of the inner space of the outer joint member. After performing the first assembly step, the filling step is performed, and in the filling step, the filling amount of the grease is adjusted so that the grease adheres to one end in the axial direction of the spline fitting portion. A method for manufacturing a sliding constant velocity universal joint according to claim 4.

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