JP2004176763A - Tripod type constant velocity universal joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tripod type constant velocity universal joint capable of holding rigidity and providing excellent workability and assemblage without increasing the height of a flange even if a needle roller diameter is increased. <P>SOLUTION: This tripod type constant velocity universal joint comprises a track groove 2 formed in the inner periphery of an outer ring 1 in the direction of the axis of the outer ring, a leg shaft 5 installed on a tripod member 4 inserted into the outer ring projectedly from the radial direction of the tripod member 4, and rollers 7 installed on the leg shaft rotatably through needle rollers 6, and allows the rollers to be rotatable and slidable along a roller guide face 3 formed in the track groove. The end faces 6a of the needle rollers are formed flat and installed in the rollers by a keystone system, and comprise flanges 7a formed at the end parts of the rollers and preventing the rollers from coming off the rollers in the axial direction of the leg shaft. Even when the radial drop amount δ is maximum, the height of the flanges is set so that a contact width A between the inner side faces 7c of the flanges of the rollers and the end faces to 5 to 10% of the needle rollers is 5 to 10% of the needle roller diameter ψ Da. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a tripod type constant velocity universal joint used for automobiles, industrial machines, and the like.
[0002]
[Prior art]
FIGS. 4 and 5 show a tripod type universal joint that transmits rotation at a constant speed even when there is an angle between two axes on the driving side and the driven side. The three track grooves 2 formed on the inner circumference 1a of the outer race 1 in the axial direction of the outer race, the three leg shafts 5 protruding in the radial direction of the tripod member 4 inserted into the outer race are rounded. The rotation force between the tripod member 4 and the outer ring 1 is provided by a structure in which the roller 17 rotatable via the needle roller 16 on the end surface is rotatable along the roller guide surface 3 of the track groove 2 and is slidable. Communicate. FIG. 6 is a partial cross-sectional view of the leg shaft 5 of FIG. 4 or 5. As shown in FIG. 6, this is a leg shaft of the needle roller 16 assembled to the inner surface 17b of the roller 17 by a keystone method. Rollers 17 are provided with flanges 17a, 17a at both ends in order to prevent the rollers from slipping in the direction (for example, see Patent Document 1).
[0003]
[Patent Document 1]
JP-A-10-184717 (paragraphs 0007, 0010, 0017)
[0004]
[Problems to be solved by the invention]
However, generally, both end surfaces 16a of the needle roller 16 have a round surface shape. For this reason, the setting of the flange height h1 for preventing the roller from falling out needs to be set at least larger than the center position 16c of the needle roller diameter φDa. In this case, as the roller diameter φDa of the needle roller 16 increases, the height h1 of the flange 17a inevitably increases, and the rigidity of the flange decreases. Further, if the height h1 of the flange 17a is large, there is a problem that the tool life during machining is shortened and the assemblability is difficult. In addition, although the figure of the above-mentioned patent document 1 is a figure in the case of a plane end face, there is no suggestion and disclosure about such end size and shape. ,
[0005]
In view of the above, it is an object of the present invention to provide a tripod type in which the rigidity of the flange is maintained without increasing the height of the flange even when the diameter of the needle roller is increased, and the workability and assemblability are improved. It is to provide a constant velocity universal joint.
[0006]
[Means for Solving the Problems]
In the present invention, three track grooves formed in the inner circumference of the outer race in the axial direction of the outer race, three leg shafts protruding in the radial direction of the tripod member inserted in the outer race, and A roller rotatable through a needle roller, wherein the roller is rotatable and slidable along a roller guide surface provided in the track groove. Has a flat end face, and is fitted to the roller by a keystone method, and has a flange formed at an end of the roller for preventing the needle from rolling off the roller in the leg axis direction from the roller. Even when the height of the flange is the largest in the radial direction of the needle roller, the contact width between the inner surface of the flange of the roller and the end surface of the needle roller is the same as that of the needle roller. To filter diameter, it has solved the above problems by providing a tripod type constant velocity universal joint and from 5% to 10%.
[0007]
According to the configuration of the present invention, when trying to move in the axial direction of the needle roller, the needle end face of the flat end face is in contact with the inner side face of the collar, so that the needle can be prevented from coming off, and the round end face can be prevented. Unlike the needle roller on the end face, even if the flange height is smaller than the center position of the needle roller diameter, it is possible to sufficiently prevent the needle roller from slipping off, so that it is not necessary to increase the flange height even if the needle roller diameter increases. Can maintain its rigidity. Further, since the flange height can be set smaller than before, workability and assemblability are also improved. If the contact width is less than 5%, the contact pressure between the needle roller end and the flange is increased, which tends to cause abrasion, etc., and if it exceeds 10%, the frictional resistance due to contact increases. In addition, a recess may be provided at the center of the end face of the needle roller in order to further determine the contact portion. The end face of the needle and the end face of the flange are chamfered. Needless to say, the contact width is a value excluding the chamfer.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a partial cross-sectional view of a roller portion showing an embodiment of the present invention, FIG. 2 is a partially enlarged view showing the amount of radial drop of a needle roller assembled by a keystone method, viewed from the axial direction, and FIG. It is the elements on larger scale seen from the direction. As shown in FIG. 1, a needle roller 6 is mounted on an inner diameter surface 7b of a roller 7 by a keystone method. The end surface of the needle roller 6 is flat, and the rollers 7 are provided with flanges 7a at both ends in order to prevent the flat end surface of the needle roller 6 from rolling off in the axial direction.
[0009]
As shown in FIG. 2, the keystone method is a method in which rolling elements are arranged in series on the inner peripheral surface of a roller. In addition, the last one needle roller 6 is press-fitted into a gap g formed between two ends of the series of needle rollers 6 to assemble. Since the diameter φDa of the (last one) needle is set to be several μm to several tens μm larger than the distance d between the adjacent needle rollers of the gap g, all the needle rollers are successively inserted into the inner diameter surface by press-fitting. Are arranged, and the needle rollers interfere with each other and are temporarily held. Except for one needle roller, all the needle rollers are in contact with the inner diameter surface, and if only one is set to fall inward in the radial direction, it moves δ in the radial direction by the circumferential gap e as shown in FIG. become. However, it does not fall as described above.
[0010]
In the present invention, when the movement amount δ is the maximum, as shown in FIG. 3, the contact width A between the inner side surface 7c of the flange 7a of the roller 7 and the flat end surface 6a of the needle roller 6 is larger than the needle roller diameter φDa. The height h of the flange is set so that 5% or more and 10% or less remain. The drop amount is ultimately the maximum movement width of the needle roller 6 in the radial direction. Thus, while securing the contact width A and the maximum movement distance of the needle roller, an appropriate dimension of the height h of the flange 7a is secured. it can. Reference numeral 8 denotes a chamfer between the cylindrical surface 6b and the end surface 6a of the needle roller 6, and reference numeral 9 denotes a chamfer between the inner peripheral portion 7d of the flange 7a and the inner flange surface 7d.
[0011]
【The invention's effect】
According to the product of the present invention, the end face of the needle roller is set to be a flat end, and the height of the flange is determined so that the contact load does not become excessive according to the amount of drop of the needle roller and that the contact resistance does not increase. Therefore, even if the needle roller diameter becomes large, the flange height can be set small, so that the flange can be held without reducing the rigidity, and further, a tripod type constant velocity universal joint excellent in workability and assemblability is provided. It can be done.
[Brief description of the drawings]
FIG. 1 is a partially enlarged cross-sectional view of a roller unit according to an embodiment of the present invention.
FIG. 2 is a partial sectional view showing the amount of drop in the radial direction of a needle roller assembled by a keystone method according to an embodiment of the present invention, viewed from the axial direction.
FIG. 3 is a partial enlarged view showing a radial drop amount of a needle roller assembled by a keystone method according to an embodiment of the present invention, as viewed from a circumferential direction.
FIG. 4 is a partial longitudinal sectional view of a tripod type constant velocity universal joint.
FIG. 5 is a partial cross-sectional view of a tripod type constant velocity universal joint.
FIG. 6 is a partially enlarged sectional view of a leg shaft 5 of FIG. 4 or 5;
[Explanation of symbols]
Reference Signs List 1 outer ring 1a inner circumference of outer ring 2 track groove 3 roller guide surface 4 tripod member 5 leg shaft 6 needle roller 6a needle roller end face 7 roller 7a flange 7c inner surface of flange 10 tripod type constant velocity universal joint A contact width h flange height δ Needle roller drop in diameter direction φDa Roller diameter

Claims (1)

Three track grooves formed on the inner periphery of the outer race in the axial direction of the outer race, three leg shafts projecting in the radial direction of the tripod member inserted into the outer race, and a needle roller on the leg shaft. A tripod-type constant velocity universal joint having a rotatable roller and a rotatable and slidable roller along a roller guide surface provided in the track groove, wherein the needle roller has a flat end face. And is assembled to the roller by a keystone method, and has a flange formed at an end of the roller for preventing the needle from rolling off in the leg axis direction from the roller, Even when the height of the flange is the largest drop in the radial direction of the needle roller, the contact width between the inner surface of the flange of the roller and the end surface of the needle roller is relative to the roller diameter of the needle roller. 5% Tripod type constant velocity universal joint is characterized in that it is the upper 10% or less.

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