JP2010190265A - Ball-type constant velocity joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ball-type constant velocity joint raising the strength and rigidity of a retainer while suppressing the enlargement of the retainer. <P>SOLUTION: A cutout 34 is formed toward inside the radial direction at least at one end side in the axial direction of the outside circumferential side of an inner ring 30 and on at least one of a plurality of groove wall ridges 33 which constitute each wall surface of a plurality of inner ring ball grooves 32. The inner bottom part 34a in the radial direction of this cutout 34 is set so as to be positioned inside in the radial direction from the extended line of the path of contact of a ball 40 in the inner ring ball groove 32. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a ball type constant velocity joint.

  Conventionally, in assembling a ball-type constant velocity joint, as described in FIG. 5 of Japanese Patent Laid-Open No. 2000-154833 (Patent Document 1), first, an inner ring is assembled inside a cage. Specifically, with the axial direction of the inner ring and the axial direction of the cage being substantially orthogonal, one of the groove wall ridges constituting the wall surface of the inner ring ball groove is inserted into the window portion of the cage. In this state, the inner ring is rotated around the inner ring axis with respect to the cage, thereby allowing the entire inner ring to enter inside the cage. Thereafter, the axial direction of the inner ring is matched with the axial direction of the cage, and the assembly of the inner ring and the cage is completed.

  At the time of this assembly, in order to insert the groove wall protrusion of the inner ring into the window of the cage, a notch is formed radially inward at one end in the axial direction on the outer peripheral side of the inner ring (patent) (Refer FIG. 1 of literature 1). Thereby, the axial direction length of a groove wall protrusion part becomes narrow, and it can insert now in the window part of a holder | retainer.

JP 2000-154833 A

  By the way, the cage has a shape in which annular portions on both sides in the axial direction of the cage are connected by a plurality of pillars. That is, the window portion of the cage is a portion surrounded by adjacent column portions and annular portions on both sides. And it is not easy to ensure high strength and rigidity near the pillar. In particular, in order to ensure sufficient strength and rigidity in the vicinity of the pillar portion of the cage, the cage has been increased as a result. Naturally, the increase in the size of the cage leads to an increase in the size of the entire ball type constant velocity joint.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a ball-type constant velocity joint that can increase the strength and rigidity of the cage while suppressing an increase in size of the cage. And

  As a result of intensive studies to solve the above problems, the present inventors have come up with the following. In a ball type constant velocity joint applied to a front drive shaft of a vehicle, a joint operating angle capable of transmitting torque requires about 45 to 50 °, for example. On the other hand, a ball type constant velocity joint applied to a rear drive shaft of a vehicle has a small joint operating angle capable of transmitting torque. For example, the joint operating angle capable of transmitting torque is about 20 to 35 °. In the past, ball-type constant velocity joints for the front were often applied as they were for the rear, but in recent years, the constant velocity joint has been downsized to the extent that the required joint working angle can be secured. There has been a demand for weight reduction.

  Here, when examined in more detail, in the front case, the contact locus between the ball and the inner ring ball groove is formed over the entire axial length of the inner ring. Therefore, the notch formed at one end in the axial direction on the outer peripheral side of the inner ring is formed to such an extent that a contact locus between the ball and the inner ring ball groove can be secured. That is, the radially inner bottom portion of the notch is set radially outward from the contact locus with the ball in the inner ring ball groove.

  However, the rear ball type constant velocity joint has a smaller joint operating angle capable of transmitting torque compared to the front, so the contact locus between the inner ring ball groove and the ball for the rear is less than that for the front. Short and sufficient. Therefore, we considered the formation of deeper notches while securing the necessary contact locus for the rear.

That is, the structural features of the invention according to claim 1 are:
An outer ring formed in a cylindrical shape having an opening at least in one axial direction, and a plurality of outer ring ball grooves formed on the inner peripheral surface;
An inner ring disposed inside the outer ring and having a plurality of inner ring ball grooves formed on the outer peripheral surface;
A plurality of balls that roll on each of the outer ring ball groove and the inner ring ball groove to transmit torque between the outer ring and the inner ring;
A cage formed in an annular shape, disposed between the outer ring and the inner ring, and formed with a plurality of windows for receiving the balls in the circumferential direction;
In a ball-type constant velocity joint comprising
At least one axial end of the outer ring side of the inner ring and radially inward of at least one of the plurality of groove wall ridges constituting each wall surface of the plurality of inner ring ball grooves. A notch is formed,
The radially inner bottom portion of the notch is set to be located radially inward from an extension line of a contact locus with the ball in the inner ring ball groove.

The structural feature of the invention according to claim 2 is that in claim 1,
The notch is formed over the entire circumference of the inner ring.
The structural feature of the invention according to claim 3 is that in claim 1 or 2,
The radially inner bottom portion of the notch is set to be positioned radially outward from the groove bottom of the inner ring ball groove.

The constitutional feature of the invention according to claim 4 is the structure according to any one of claims 1 to 3,
The joint operating angle capable of transmitting torque is set to 35 ° or less.
The structural features of the invention according to claim 5 are as follows:
The shortest distance between the center locus of the ball and the radially inner bottom of the notch when the ball rolls in the inner ring ball groove is h,
When the diameter of the ball is D,
The ratio h / D of the shortest distance to the diameter of the ball is set to 0.37 or more and 0.5 or less.

The structural feature of the invention according to claim 6 is that in claim 5,
The corner portion of the window portion is formed in an arc concave shape having a radius of curvature R,
The ratio h / D of the shortest distance to the diameter of the ball is further set to a predetermined value or more that changes based on the ratio R / D of the arc-shaped concave radius of curvature of the corner of the window to the diameter of the ball. It is that.

The structural feature of the invention according to claim 7 is that in claim 6,
The predetermined value is set so as to increase as the ratio R / D of the radius of curvature of the arc concave shape at the corner of the window portion to the diameter of the ball increases.
The structural feature of the invention according to claim 8 is the structure according to any one of claims 5 to 7,
The ratio R / D of the arcuate concave radius of curvature of the corner of the window with respect to the diameter of the ball is set to 0.26 or more.

  According to the first aspect of the present invention, the radially inner bottom portion of the notch is located radially inward from the extended line of the contact locus between the inner ring ball groove and the ball. Here, the radially inner bottom portion of the notch means a portion located radially inward of the surface forming the notch. The extension line of the contact locus between the inner ring ball groove and the ball means a line extended as it is while maintaining the curvature of the contact locus. For example, when the contact locus is a straight line, the extension line of the contact locus is a straight line obtained by extending the straight line as it is. In addition, when the contact locus is arcuate, the extension line of the contact locus is arcuately extended while maintaining the curvature of the arc.

  Therefore, the notch is formed so as to cut off the contact locus when the radially inner bottom portion of the notch is located radially inward from the extension line of the contact locus. That is, in the present invention, the depth of the notch (inward radial direction depth) is deeper than in the prior art. Therefore, in the part where the notch is formed, the member constituting the inner ring does not exist in the extension line of the contact locus. Here, when the notch is formed in the portion, the axial length of the groove wall ridge portion constituting the wall surface of the inner ring ball groove is shortened. And since the depth of the said notch is deeper than before in the present invention, the radial width of the portion where the axial length of the groove wall ridge is shortened becomes large.

  Here, in order to ensure the strength and rigidity of the cage, the corner portion of the window portion of the cage is not formed in a right-angled shape but is formed in an arcuate concave shape. As described above, when assembling the inner ring inside the cage, the axial direction of the inner ring and the axial direction of the cage are made substantially orthogonal to each other so that the groove wall ridge portion of the inner ring is the window portion of the cage. Insert into. At the time of this insertion, the vicinity of the notch in the groove wall ridge portion of the inner ring can interfere with the corner portion of the window portion of the cage. For this reason, it is not easy to increase the corners of the window of the cage.

  However, according to the present invention, since the depth of the notch is deep, even if the corner portion of the cage window portion is greatly arranged, it is formed so that the radius of curvature R of the arc concave shape of the corner portion is increased. Even so, it is possible to avoid the vicinity of the notch in the groove wall protrusion from interfering with the corner of the window portion of the cage. That is, according to the present invention, it is possible to increase the strength and rigidity of the cage while ensuring easy assembly of the inner ring and the cage. As a result, the cage can be reduced in size, and as a result, the entire ball type constant velocity joint can be reduced in size.

  According to the invention which concerns on Claim 2, shaping | molding of a notch becomes easy. Furthermore, when assembling the inner ring inside the cage, the groove wall ridge portion of the inner ring inserted into the window portion of the cage may be any groove wall ridge portion, so that the assemblability is good.

  According to the invention of claim 3, the inner ring ball groove is slightly formed at the axial position where the notch is formed. Here, the balls of the ball type constant velocity joint are inserted one by one into the window portion, the outer ring ball groove and the inner ring ball groove of the corresponding cage in a state where the inner ring and the cage are arranged inside the outer ring. At this time, the inner ring ball groove and the outer ring ball groove need to have an axial length longer than a region necessary for a joint operating angle capable of transmitting torque. If the axial length of the ball groove is short, the ball is not easily positioned when the ball is inserted into the ball groove, so that the assembly is not easy.

  On the other hand, according to the present invention, since the inner ring ball groove is formed even at the axial position where the notch is formed, the assembly of the ball can be maintained well. That is, according to the present invention, it is possible to increase the strength and rigidity of the cage while maintaining good assembly of the balls.

  According to the invention of claim 4, by applying the joint operating angle capable of torque transmission to a ball type constant velocity joint of 35 ° or less, the portion where the notch is formed can be applied to the ball at the joint operating angle capable of torque transmission. It can be outside the operating area. That is, it is possible to improve the assemblability of the inner ring and the cage while reliably increasing the depth of the notch without affecting the operation as a ball type constant velocity joint.

According to the invention which concerns on Claim 5, the assembly property of an inner ring | wheel and a holder | retainer can be made favorable reliably.
According to the sixth aspect of the present invention, h / D can be in an appropriate range in consideration of the relationship between the diameter D of the ball and the radius of curvature R of the arcuate concave shape of the corner of the window. And the retainer can be reliably assembled.
According to the invention which concerns on Claim 7, h / D according to the relationship between the diameter D of a ball | bowl and the arc-shaped concave curvature radius R of the corner | angular part of a window part can be reliably made into an appropriate range.
According to the eighth aspect of the invention, the strength and rigidity of the cage can be increased.

It is sectional drawing which follows the axial direction of the ball type | mold constant velocity joint which concerns on this embodiment. It is a fragmentary sectional view which follows the axial direction which expands and shows the principal part of the inner ring which concerns on this embodiment. It is the whole front view which fractured the cage which shows the method of incorporating the inner ring of the ball type constant velocity joint concerning this embodiment in a cage. Lower: FIG. 3 is a right side view of FIG. Upper: FIG. 5 is a plan view of the lower cage in FIG. 4. The horizontal axis represents the ratio of the radius of curvature R of the arc concave shape at the corner of the window to the diameter D of the ball, and the vertical axis represents the shortest distance h between the center locus of the ball and the radially inner bottom of the notch with respect to the ball diameter D. It is a graph which shows a favorable range as a ratio.

  Hereinafter, an embodiment in which the ball type constant velocity joint of the present invention is embodied will be described with reference to the drawings.

  A configuration of the ball type constant velocity joint 10 (hereinafter, simply referred to as “constant velocity joint”) of the present embodiment will be described with reference to FIG. FIG. 1 is a cross-sectional view in the axial direction of the constant velocity joint 10 according to the present embodiment in a state where a predetermined joint angle θ is taken. In the following description, the opening side of the outer ring 20 means the left side of FIG. 1, and the back side of the outer ring 20 means the right side of FIG.

  As shown in FIG. 1, the constant velocity joint 10 of the present embodiment is a joint-fixed ball type constant velocity joint (also referred to as “Zepper type constant velocity joint”), which is an outer board of a rear drive shaft of a vehicle. It is preferably used as a joint. Therefore, the joint operating angle at which the constant velocity joint 10 can transmit torque is set to a range of 20 ° to 30 ° so as to be a small angle range of 35 ° or less.

  The constant velocity joint 10 includes an outer ring 20 having a plurality of outer ring ball grooves 23, an inner ring 30 having a plurality of inner ring ball grooves 32, a plurality of balls 40, a cage 50, and a shaft 60. . Hereinafter, each component will be described in detail.

  The outer ring 20 is formed in a cup shape (bottomed tubular shape) having an opening on the left side of FIG. 1 (corresponding to “one axial direction” of the present invention). A connecting shaft 21 is integrally formed on the outer side (right side in FIG. 1) of the cup of the outer ring 20 so as to extend in the direction of the outer ring axis. The connecting shaft 21 is connected to another power transmission shaft. The inner peripheral surface of the outer ring 20 is formed in a concave spherical shape. Specifically, the concave spherical inner peripheral surface 22 of the outer ring 20 is formed by a part of a spherical surface having an intersection O between the outer ring axis L1 and the inner ring axis L2 as a center of curvature, and is cut in the outer ring axis direction. When viewed in cross section, it is formed in an arc concave shape.

  Furthermore, a plurality of outer ring ball grooves 23 whose outer ring axis orthogonal cross section is substantially arc-shaped are formed on the inner peripheral surface of the outer ring 20 so as to extend substantially in the outer ring axis direction. These outer ring ball grooves 23 (six in this embodiment) are formed at equal intervals in the circumferential direction (60-degree intervals in this embodiment) when viewed in a cross section cut in the radial direction. Here, the outer ring axial direction means a direction passing through the central axis of the outer ring 20, that is, a rotation axis direction of the outer ring 20.

  The inner ring 30 is formed in an annular shape and is disposed inside the outer ring 20. The outer peripheral surface 31 of the inner ring 30 is formed in a convex spherical shape. Specifically, the convex spherical outer peripheral surface 31 of the inner ring 30 is formed by a part of a spherical surface drawn with the intersection O between the outer ring axis L1 and the inner ring axis L2 as the center of curvature, and is a cross section cut in the direction of the inner ring axis. Is formed in a uniform arc, that is, a convex partial spherical shape.

  In addition, a plurality of inner ring ball grooves 32 whose inner ring axis orthogonal cross section is substantially arc-shaped are formed on the outer peripheral surface of the inner ring 30 so as to extend substantially in the inner ring axis direction. The plurality of (six in this embodiment) inner ring ball grooves 32 are equally spaced in the circumferential direction (60 degrees in the present embodiment) and viewed from the outer ring 20 when viewed in a cross section cut in the radial direction. The same number of outer ring ball grooves 23 are formed. That is, each inner ring ball groove 32 is positioned so as to face each outer ring ball groove 23 of the outer ring 20.

  Between adjacent inner ring ball grooves 32, respective wall surfaces of these inner ring ball grooves 32 are formed, and groove wall ridges 33 projecting radially outward are formed. A notch 34 is provided radially inward on the convex spherical outer peripheral surface 31 side on one axial end side (left side in FIG. 1) of each groove wall protrusion 33. This notch 34 is formed over the entire circumference of the inner ring 30. Due to the notches 34, the axial length of the distal end portion in the radial direction of each groove wall protrusion 33 is shortened. Details of the notch 34 will be described later with reference to FIG.

  An inner spline 35 extending in the inner ring axial direction is formed on the inner circumferential surface of the inner ring 30. The internal spline 35 is fitted (engaged) with the external spline of the shaft 60. Here, the inner ring axial direction means a direction passing through the central axis of the inner ring 30, that is, a rotation axis direction of the inner ring 30.

  Each of the plurality of balls 40 is disposed so as to be sandwiched between the outer ring ball groove 23 of the outer ring 20 and the inner ring ball groove 32 of the inner ring 30 facing the outer ring ball groove 23. Each ball 40 is rotatable with respect to each outer ring ball groove 23 and each inner ring ball groove 32 and is engaged in a circumferential direction (around the outer ring axis or around the inner ring axis). Therefore, the ball 40 transmits torque between the outer ring 20 and the inner ring 30.

  The cage 50 is formed in an annular shape. The outer peripheral surface 51 of the cage 50 is formed in a partial spherical shape substantially corresponding to the concave spherical inner peripheral surface 22 of the outer ring 20, that is, a convex spherical shape. On the other hand, the inner peripheral surface 52 of the cage 50 is formed into a partial spherical shape that substantially corresponds to the convex spherical outer peripheral surface 31 of the inner ring 30, that is, a concave spherical shape. The cage 50 is disposed between the concave spherical inner peripheral surface 22 of the outer ring 20 and the convex spherical outer peripheral surface 31 of the inner ring 30. The cage 50 includes a plurality of window portions 53 that are substantially rectangular through holes arranged at equal intervals in the circumferential direction (the circumferential direction of the cage axis). The number of window portions 53 of the cage 50 is the same as the number of balls 40. One ball 40 is accommodated in each window 53. Four corners of each window 53 are formed in a circular arc concave shape. Thereby, the improvement of the intensity | strength and rigidity of each pillar part located between the adjacent window parts 53 is achieved.

  Next, the details of the inner ring 30, particularly the notch 34, will be described with reference to FIG. 2. FIG. 2 is a partial cross-sectional view along the axial direction showing an enlarged main part of the inner ring according to the present embodiment.

  As shown in FIG. 2, the groove bottom of the inner ring ball groove 32 has an arcuate curve 32a drawn with a point b offset from the intersection O to the back side of the outer ring 20 (the right side in FIG. 2) as the center of curvature, and the curve thereof. It is formed by a straight line 32b extending in a tangential direction from one end of 32a.

  Here, as described above, the joint operating angle at which the constant velocity joint 10 of the present embodiment can transmit torque is set to 35 ° or less. The rolling range of the ball 40 in the inner ring ball groove 32 is a range between two contact points P5 and P6 where the ball 40 contacts the outer ring ball groove 23 when the joint operating angle becomes maximum.

  Here, in the description with reference to FIG. 1, the cross section in the direction perpendicular to the inner ring axis of the inner ring ball groove 32 is substantially arc-shaped. Specifically, the inner ring ball groove 32 has, for example, a so-called Gothic arch shape in which two arc concave shapes having different centers are connected. In this way, the contact point with the ball 40 in the inner ring ball groove 32 is set at two positions shifted radially outward from the groove bottom of the inner ring ball groove 32.

  When the ball 40 rolls in the inner ring ball groove 32 within the range of joint operating angles in which torque can be transmitted in the inner ring ball groove 32, the contact locus of the ball 40 in the inner ring ball groove 32 is as shown in FIG. The locus is indicated by a broken line (between P5 and P6). In other words, the contact locus is substantially arcuate when the inner ring ball groove 32 has an arcuate curved line 32a and the inner ring ball groove 32 has an almost straight line when the groove bottom of the inner ring ball groove 32 is a straight line 32b. .

  The notch 34 is formed at the end of a range where the groove bottom of the inner ring ball groove 32 is an arcuate curve. The radially inner bottom portion 34a of the notch 34 is set so as to be located radially inward from the extended line of the contact locus with the ball 40 in the inner ring ball groove 32. The extension line of the contact locus is a line that is extended as it is while maintaining the state of the contact locus to be connected. That is, in the present embodiment, the contact locus to be connected is an arcuate curve, and thus is a line extended while maintaining the curvature radius of the curve.

  Further, the radially inner bottom 34 a of the notch 34 is set so as to be positioned radially outward from the groove bottom 32 a of the inner ring ball groove 32 in the axial range of the inner ring 30 where the notch 34 is formed. ing. That is, the inner ring ball groove 32 is slightly formed at the axial position of the inner ring 30 where the notch 34 is formed.

  Next, the case where the inner ring | wheel 30 comprised as mentioned above is assembled | attached to the holder | retainer 50 is demonstrated in detail with reference to FIG. 3 and FIG. FIG. 3 is an overall front view in which the cage 50 showing a method for incorporating the inner ring 30 of the constant velocity joint 10 according to the present embodiment into the cage 50 is broken. The lower part of FIG. 4 is a right side view of FIG. 3, and the upper part of FIG. 4 is a plan view of the cage 50 in the lower part of FIG.

  As shown in FIGS. 3 and 4, in order to assemble the inner ring 30 into the cage 50, first, the axial direction of the inner ring 30 and the axial direction of the cage 50 are in a substantially orthogonal state. In this state, one groove wall protruding portion 33 between the inner ring ball grooves 32 spans the inner ring ball groove 32 of the inner ring 30 on the introduction surface 54 formed on one end side of the inner peripheral surface of the cage 50. Is inserted into the window 53. At this time, since the notch 34 is formed deeply at one end side of the inner ring ball groove 32 (opening side of the outer ring 20), one groove wall ridge 33 of the inner ring 30 is placed inside the window 53 of the cage 50. Can be easily inserted without interference.

  Thereafter, the inner ring 30 is rotated in the direction of arrow X around the inserted groove wall ridge 33 and placed in the cage 50, and the center point of the convex spherical outer peripheral surface 31 of the inner ring 30 is set to the cage 50. The inner ring 30 is rotated by 90 ° after being aligned with the center point of the inner peripheral surface 52, and the axial direction of the inner ring 30 and the axial direction of the cage 50 are made to coincide. In this way, the convex spherical outer peripheral surface 31 of the inner ring 30 and the inner peripheral surface 52 of the retainer 50 are spherically engaged, whereby the assembly of the inner ring 30 and the retainer 50 is completed.

  The inner ring 30 and the cage 50 assembled in this way are arranged inside the outer ring 20. Thereafter, the balls 40 are inserted one by one into the outer ring ball groove 23, the inner ring ball groove 32, and the window 53 of the cage 50. At this time, the swing angle of the inner ring 30 with respect to the outer ring 20 is larger than the joint operating angle capable of transmitting torque. That is, when the constant velocity joint 10 is actually used, the ball 40 rolls in the outer ring ball groove 23 and the inner ring ball groove 32 within a range of joint operating angles where torque can be transmitted. An outer ring ball groove 23 and an inner ring ball groove 32 outside the range of possible joint operating angles are used.

  Thus, in order to assemble the ball 40, the inner ring ball groove 32 and the outer ring ball groove 23 must have a longer axial length than a region necessary for a joint operating angle capable of transmitting torque. If the axial lengths of the outer ring ball groove 23 and the inner ring ball groove 32 are short, the ball 40 is not easily positioned when the ball 40 is inserted into the ball grooves 23 and 32, so that the assembly is not easy. . However, in the present embodiment, since the inner ring ball groove 32 is formed even at the axial position where the notch 34 is formed, the assembly of the ball 40 can be maintained well.

  Next, the position of the radially inner bottom 34a of the notch 34 was examined in more detail. Specifically, the position of the radially inner bottom portion 34a of the notch 34 and the arcuate concave radius of curvature R of the corner portion of the window portion 53 of the retainer 50 are respectively changed so that the retainer 50 and the inner ring 30 are The viewpoint of assembling property and the viewpoint of strength and rigidity of the cage 50 were examined. Here, as shown in the upper part of FIG. 4, the arcuate concave radius of curvature R at the corner of the window 53 means that the one window 53 is viewed from the front so that the one window 53 is substantially rectangular. When viewed, it means arc-shaped concave radii of curvature at the four corners of the window 53.

  The shortest distance between the center locus of the ball 40 when the ball 40 rolls in the inner ring ball groove 32 and the radially inner bottom 34a of the notch 34 is defined as h. The diameter of the ball 40 is D. The ratio h / D of the shortest distance h to the diameter D of the ball 40 is used as an index related to the position of the radially inner bottom 34a of the notch 34. That is, when h / D is 0.5, the inner ring ball groove 32 does not exist at the axial position where the notch 34 is formed. As h / D becomes smaller, the position of the radially inner bottom 34a of the notch 34 moves outward in the radial direction of the inner ring 30.

  Further, a ratio R / D of the curvature radius R to the diameter D of the ball 40 is used as an index regarding the arc-shaped concave curvature radius R of the corner portion of the window portion 53 of the cage 50. The smaller the R / D, the smaller the radius of curvature R of the arc concave shape at the corner of the window 53, and the larger the R / D, the larger the radius of curvature R of the arc concave at the corner of the window 53. Means. That is, the larger the R / D, the higher the strength and rigidity in the vicinity of the column portion of the window portion 53.

  The examination results are shown in FIG. In FIG. 5, the horizontal axis is R / D and the vertical axis is h / D. In FIG. 5, the hatching range is a favorable range for the above two viewpoints.

  Specifically, this good range has h / D of 0.5 or less. Thus, by setting the upper limit value of h / D with respect to R / D, the radially inner bottom portion 34a of the notch 34 has a groove bottom of the inner ring ball groove 32 in the axial range where the notch 34 is formed. It is set to be positioned radially outward from 32a. That is, the inner ring ball groove 32 is slightly formed at the axial position where the notch 34 is formed. Therefore, the assembling property of the ball 40 can be improved.

Further, in the favorable range, h / D is 0.37 or more. In particular, the lower limit value of h / D in a favorable range has a relationship that increases linearly as R / D increases. More specifically, the lower limit value of h / D can be expressed as Equation 1. For example, the lower limit value of h / D is 0.37 when R / D is 0.26, and the lower limit value of h / D is 0.44 when R / D is 0.37.
[Equation 1]
Y = 0.64X + 0.2 (1)
Y: Lower limit of h / D
X: R / D

As described above, by setting the lower limit value of h / D with respect to R / D, it is possible to improve the assembling property between inner ring 30 and cage 50.
Furthermore, R / D in the said favorable range is 0.26 or more. Thereby, the intensity | strength and rigidity of the holder | retainer 50 can be made high.

  As described above, the joint operating angle capable of transmitting torque is set to 35 ° or less, so that the depth of the notch 34 is formed deeper than the conventional one. That is, the notch 34 is formed so as to cut off the contact locus between the ball 40 and the inner ring ball groove 32. Therefore, in the part where the notch 34 is formed, the member constituting the inner ring 30 does not exist in the extension line of the contact locus. Here, the notch 34 is formed in the part, so that the axial length of the groove wall ridge 33 constituting the wall surface of the inner ring ball groove 32 is shortened. And since the depth of the notch 34 is deep, the radial direction width | variety of the part where the axial direction length of the groove wall protrusion part 33 is short becomes large.

  Here, in order to ensure the strength and rigidity of the cage 50, the corners of the window portion 53 of the cage 50 are formed in an arc concave shape, and the larger the radius of curvature R of the arc concave shape of the corner portion, the larger the cage. 50 strength and rigidity are increased.

  As described with reference to FIGS. 3 and 4, when the inner ring 30 is assembled inside the retainer 50, the axial direction of the inner ring 30 and the axial direction of the retainer 50 are substantially orthogonal to each other. The 30 groove wall ridges 33 are inserted into the window 53 of the cage 50. At the time of this insertion, the vicinity of the notch 34 of the groove wall projection 33 of the inner ring 30 can interfere with the corner of the window 53 of the cage 50. However, according to the present embodiment, since the depth of the notch 34 is deep, even if the arc-shaped concave curvature radius R of the corner portion of the window portion 53 of the cage 50 is formed large, the groove wall ridge portion 33. It is possible to avoid the vicinity of the notch 34 from interfering with the corner of the window 53 of the cage 50.

  Therefore, according to the present embodiment, it is possible to increase the strength and rigidity of the cage 50 while ensuring easy assembly of the inner ring 30 and the cage 50. As a result, the cage 50 can be reduced in size, and as a result, the entire ball type constant velocity joint 10 can be reduced in size.

10: Ball type constant velocity joint 20: Outer ring, 21: Connecting shaft, 22: Concave spherical inner peripheral surface, 23: Outer ring ball groove 30: Inner ring, 31: Convex spherical outer peripheral surface, 32: Inner ring ball groove, 33: Groove wall ridge 34: notch, 34a: radially inner bottom, 35: internal spline 40: ball 50: cage, 53: window 60: shaft

Claims (8)

An outer ring formed in a cylindrical shape having an opening at least in one axial direction, and a plurality of outer ring ball grooves formed on the inner peripheral surface;
An inner ring disposed inside the outer ring and having a plurality of inner ring ball grooves formed on the outer peripheral surface;
A plurality of balls that roll on each of the outer ring ball groove and the inner ring ball groove to transmit torque between the outer ring and the inner ring;
A cage formed in an annular shape, disposed between the outer ring and the inner ring, and formed with a plurality of windows for receiving the balls in the circumferential direction;
In a ball-type constant velocity joint comprising
At least one axial end of the outer ring side of the inner ring and radially inward of at least one of the plurality of groove wall ridges constituting each wall surface of the plurality of inner ring ball grooves. A notch is formed,
A ball type constant velocity joint, wherein the radially inner bottom portion of the notch is set to be radially inward from an extension line of a contact locus with the ball in the inner ring ball groove. In claim 1,
The ball type constant velocity joint, wherein the notch is formed over the entire circumference of the inner ring. In claim 1 or 2,
A ball-type constant velocity joint characterized in that a radially inner bottom portion of the notch is set to be positioned radially outward from a groove bottom of the inner ring ball groove. In any one of Claims 1-3,
A ball-type constant velocity joint characterized in that the joint operating angle capable of transmitting torque is set to 35 ° or less. In claim 4,
The shortest distance between the center locus of the ball and the radially inner bottom of the notch when the ball rolls in the inner ring ball groove is h,
When the diameter of the ball is D,
The ball type constant velocity joint, wherein a ratio h / D of the shortest distance to the diameter of the ball is set to 0.37 or more and 0.5 or less. In claim 5,
The corner portion of the window portion is formed in an arc concave shape having a radius of curvature R,
The ratio h / D of the shortest distance to the diameter of the ball is further set to a predetermined value or more that changes based on the ratio R / D of the arc-shaped concave radius of curvature of the corner of the window to the diameter of the ball. A ball-type constant velocity joint. In claim 6,
The ball-type constant velocity joint is characterized in that the predetermined value is set to increase as the ratio R / D of the radius of curvature of the arc concave shape at the corner of the window portion to the diameter of the ball increases. . In any one of Claims 5-7,
A ball-type constant velocity joint characterized in that a ratio R / D of a radius of curvature of a concave arc at a corner of the window with respect to a diameter of the ball is set to 0.26 or more.

Images