JP2008089013A - Cross groove type constant velocity joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cross groove type constant velocity joint capable of preventing balls from dropping into recesses for a grind stone without using another component or a special boot. <P>SOLUTION: An outer race member 11 has the recesses 11b for the grind stone for grinding outer race grooves. Each recess 11b is positioned at the inner side of the cup-like outer race member 11 rather than the outer race groove 11a and is formed continuously with the outer race groove 11a. The recess 11b for the grind stone is composed of a concave portion disposed at a position where the maximum distance between the recess 11b and an outer race rotary shaft is larger than the distance between a groove bottom surface of the outer race groove 11a and the outer race rotary shaft. The recess 11b has a projection 51 that makes contact with the ball 13 when the ball 13 is positioned at the innermost end of the outer race groove 11a. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a cross-groove type constant velocity joint, that is, a constant velocity joint formed so that a ball locus in an outer ring groove and a ball locus in an inner ring groove intersect in the circumferential direction.

  The outer ring groove formed in the outer ring member of the cross groove type constant velocity joint is formed in a direction twisted with respect to the outer ring rotating shaft. Therefore, the outer ring member was formed as follows. That is, after forming into a cup shape by forging, the outer ring groove is roughly formed by cutting, and finally the outer ring groove is finished by grinding. Here, in order to perform grinding of the outer ring groove, a grindstone relief portion is formed on the back side of the cup of the outer ring groove. The grindstone relief portion has, for example, a spherical shape having a diameter larger than the diameter of the outer ring groove.

  That is, the grindstone relief portion forms a recess from which the ball can drop off. Therefore, when the joint angle of the constant velocity joint becomes larger than a preset operation range, it is necessary to prevent the ball from dropping into the grindstone relief portion. For example, when the joint angle becomes larger than the preset operation range, for example, when the constant velocity joint is lifted by holding the shaft inserted through the inner ring member before the constant velocity joint is assembled to the vehicle body. The case where the outer ring member hangs down with respect to the shaft due to the weight of the outer ring member can be considered. If the ball falls off the grinding wheel relief, the constant velocity joint must be disassembled to return the ball to its original position and reassemble.

As countermeasures, for example, in FIGS. 1 and 2 of Japanese Utility Model Laid-Open No. 1-69916 (Patent Document 1), a metal fitting is arranged in the opening of the outer ring member, or a boot having rigidity equivalent to the metal fitting is used. By doing so, it is described that the joint angle is limited. In addition, Japanese Utility Model Publication No. 6-32755 (Patent Document 2) describes that the joint angle is limited by disposing a circlip on the back side of the cup on the inner peripheral surface of the outer ring member. .
Japanese Utility Model Publication No. 1-69916 Japanese Utility Model Publication No. 6-32755

  However, in any case, in order to prevent the balls from falling off at the grindstone escape portion, it is necessary to use another part such as a metal fitting or a circlip or use a special boot having rigidity equivalent to the metal fitting.

  The present invention has been made in view of such circumstances, and provides a cross-groove type constant velocity joint capable of preventing a ball from dropping off to a grindstone relief portion without using new parts or special boots. For the purpose.

  Therefore, the present inventor has intensively studied to solve this problem, and as a result of repeated trial and error, has come up with the idea of devising the shape of the grinding wheel escape portion itself, and has completed the present invention.

  That is, the cross groove type constant velocity joint of the present invention has a cup shape, an outer ring member in which a plurality of outer ring grooves are formed on the inner peripheral surface in a direction twisted with respect to the outer ring rotation shaft, and the outer ring shaft with respect to the outer ring member. The inner ring member is arranged inside the outer ring member so as to be slidable in the direction and has a plurality of inner ring grooves formed on the outer peripheral surface so as to be twisted with respect to the inner ring rotation shaft, and is engaged with the outer ring groove and the inner ring groove in the circumferential direction. And a plurality of balls arranged at the intersection of the outer ring groove and the inner ring groove intersecting the outer ring groove, and arranged between the outer ring member and the inner ring member, And a cage formed with a plurality of opening windows to be inserted.

  And, the characteristic part of the cross groove type constant velocity joint of the present invention is that the outer ring member has a grinding wheel relief part for grinding the outer ring groove formed on the back side of the cup from the outer ring groove and continuously with the outer ring groove. The grinding wheel relief part has a concave shape in which the maximum distance from the outer ring rotating shaft is located on the side farther from the outer ring rotating shaft than the groove bottom surface of the outer ring groove, and when the ball is located in the innermost part of the cup in the outer ring groove It has the protrusion part contact | abutted to. Here, the case where the ball is located at the innermost part of the cup in the outer ring groove means a state where the center of the ball is located at the innermost cup end of the outer ring groove (the innermost cup end of the outer ring groove in the design value).

  As described above, since the grinding wheel relief portion has the protrusion, the ball comes into contact with the protrusion when the ball is located in the innermost part of the cup in the outer ring groove. In other words, even if the grindstone relief portion has a concave shape, it is possible to prevent the balls from dropping into the concave portion due to the protrusion. Thereby, it is possible to prevent the balls from falling off without using new parts or special boots.

  And it is good for the protrusion of a grindstone relief part to be a cup back side site | part among the outline parts of a grindstone relief part. Since the grindstone relief portion has a concave shape, the contour portion of the grindstone relief portion has a circumferential shape. The cup back side portion of the circumferential contour portion is a so-called portion located on the far side of the outer ring groove in the contour portion. That is, when the ball is located in the innermost part of the cup in the outer ring groove, it comes into contact with a portion located on the side farther from the outer ring groove in the contour part of the grindstone relief part. In other words, the ball comes into contact with the portion of the contour portion of the grinding wheel relief portion with a gap between the bottom of the grinding wheel relief portion and the recess bottom. Therefore, it is possible to reliably prevent the ball from dropping into the recessed portion of the grindstone relief portion. Furthermore, during the operation of the constant velocity joint, it is possible to prevent the ball from moving to the back side of the cup from the position where it comes into contact with the protrusion. That is, the movement range of the ball can be up to the innermost part of the cup. Therefore, it is possible to prevent the ball from detaching from the outer ring groove. Thereby, torque transmission can be performed reliably. Moreover, it becomes unnecessary to form a protrusion separately by making a protrusion into the outline part of a grindstone relief part. Thereby, design and manufacture can be facilitated.

  Further, the grindstone relief portion may be formed of an aspherical curved surface or a shape formed by a combination of flat surfaces. However, the grindstone relief portion is formed on the back side of the cup from each outer ring groove and continuously to the outer ring groove. Therefore, the grindstone relief portion is formed in the vicinity of the inner peripheral surface or the cup bottom surface of the outer ring member. Furthermore, the cross-sectional shape of the outer ring groove in the direction perpendicular to the groove is, for example, an arc shape. As described above, the grindstone relief portion is formed in a very complicated shape portion. Therefore, the grindstone relief portion can be formed more easily with a curved surface than with a combination of flat surfaces. For example, in the concave shape of the grindstone relief portion, the cup opening side portion is a curved surface having a relatively large curvature radius, and the cup back side portion is a curved surface having a relatively small curvature radius. By doing in this way, while being able to form reliably in the cup back | inner side of the whole groove surface of an outer ring groove, the protrusion mentioned above can be formed.

  Here, regarding the protrusion, the relationship with the shape of the grindstone for grinding the outer ring groove may be as follows. That is, the outer ring groove is formed by a grindstone having a tip portion that is shaped to be accommodated in a predetermined sphere having a diameter 1.0 to 1.1 times that of the ball, and the protrusion is formed on the outer ring groove of the cup. It may be formed outside the predetermined sphere when located in the back.

  That is, the protrusion does not interfere with the region where the predetermined sphere exists when the predetermined sphere is located in the innermost part of the cup in the outer ring groove. On the other hand, the tip of the grindstone has a shape stored in a predetermined sphere. Therefore, when the tip of the grindstone grinds the innermost part of the cup in the outer ring groove, the tip of the grindstone is a region where the predetermined sphere exists when the predetermined sphere is located at the innermost part of the cup in the outer ring groove. Located in. That is, when grinding the innermost part of the cup in the outer ring groove with the grindstone, the grindstone does not interfere with the protrusion. Thereby, the outer ring groove can be reliably ground.

  Here, the outer ring groove may be formed in an arc shape by a grindstone having a tip portion having the same diameter as the ball diameter, but is made noncircular by a grindstone having a tip portion having a curvature slightly larger than the ball diameter. It may be formed. The non-arc shape includes, for example, a substantially elliptical shape. Thus, the curvature of the tip of the grindstone may be the same as the ball diameter or may be slightly larger than the ball diameter. And if the front-end | tip part of a grindstone is a shape accommodated in the predetermined spherical body of the diameter at least 1.0-1.1 times of a ball | bowl, an outer ring groove can be formed reliably.

  According to the cross groove type constant velocity joint of the present invention, it is possible to prevent the ball from dropping into the grindstone relief portion without using new parts or special boots.

  Next, the present invention will be described in more detail with reference to embodiments.

(1) First Embodiment A cross groove type constant velocity joint 10 (hereinafter simply referred to as “constant velocity joint”) according to a first embodiment will be described with reference to FIGS. FIG. 1 shows an axial sectional view of a constant velocity joint 10. FIG. 2 is an axial sectional view of the outer ring member 11 constituting the constant velocity joint 10. FIG. 3 is a cross-sectional view taken along the line AA in FIG.

  As shown in FIG. 1, the constant velocity joint 10 includes an outer ring member 11, an inner ring member 12, a ball 13, a cage 14, and a boot 15.

  As shown in FIGS. 1 and 2, the outer ring member 11 is integrally formed in a cup shape (bottomed cylindrical shape). A plurality of outer ring grooves 11 a are formed on the inner peripheral surface of the outer ring member 11. The outer ring groove 11a is formed so as to be twisted with respect to the outer ring rotation axis and so that the groove center is linear. And as shown in FIG. 2, the adjacent outer ring groove 11a is formed so that the twisting direction is opposite. That is, the adjacent outer ring grooves 11a and 11a are located close to one end side (for example, the right end side in FIG. 1) of the outer ring member 11 and away from the other end side (for example, the left end side in FIG. 1).

  Further, on the inner side surface of the outer ring member 11, the outer ring groove is formed on the inner side of the cup from the outer ring groove 11a (the left side in FIGS. 1 and 2) and continuously to each outer ring groove 11a. A grindstone relief 11b is provided. Details of the grindstone relief portion 11b will be described later.

  The inner ring member 12 has a cylindrical shape and is connected to the end of the shaft 20. The outermost peripheral surface 12a of the inner ring member 12 is formed in a shape that approximates a uniform arc shape when viewed in an axial cross section, that is, a shape that approximates a partial spherical shape. Further, a plurality of inner ring grooves 12 b are formed on the outer peripheral surface of the inner ring member 12. The inner ring groove 12b is formed in a direction twisting with respect to the inner ring rotating shaft of the inner ring member 12, and the groove center is formed in a straight line. The adjacent inner ring grooves 12b are formed so that the twisting direction is the opposite direction. That is, the adjacent inner ring grooves 12b and 12b are positioned so as to be close to one end side of the inner ring member 12 and away from the other end side. An inner peripheral spline 12 c is formed on the inner peripheral surface of the inner ring member 12. The inner peripheral spline 12c engages with an outer peripheral spline formed at the end of the shaft 20.

  The inner ring member 12 is disposed inside the outer ring member 11. Furthermore, the inner ring member 12 is disposed so as to be slidable in the direction of the outer ring rotation axis with respect to the outer ring member 11. At this time, the inner ring groove 12b of the inner ring member 12 is disposed so as to intersect the outer ring groove 11a of the outer ring member 11 when viewed from the radially outer side.

  The ball 13 is disposed so as to be circumferentially engaged with the outer ring groove 11a of the outer ring member 11 and the inner ring groove 12b of the inner ring member 12, and to be able to roll in the outer ring groove 11a and the inner ring groove 12b. The ball 13 is disposed at the intersection where the outer ring groove 11a and the inner ring groove 12b intersect. Specifically, the ball 13 is a position where the groove center of the outer ring groove 11a (corresponding to the ball locus in the outer ring groove 11a) and the groove center of the inner ring groove 12b (corresponding to the ball locus in the inner ring groove 12b) intersect in the circumferential direction. Is arranged. That is, torque is transmitted between the outer ring member 11 and the inner ring member 12 by the balls 13.

  The cage 14 has a substantially cylindrical shape. Specifically, the inner peripheral surface of the cage 14 is formed in a partial spherical shape substantially corresponding to the outermost peripheral surface 12a of the inner ring member 12, and the outer peripheral surface of the cage 14 is also formed in a partial spherical shape. The cage 14 is disposed between the outer ring member 11 and the inner ring member 12. Specifically, the cage 14 is disposed between the inner peripheral surface of the outer ring member 11 and the outermost peripheral surface 12 a of the inner ring member 12. Further, the cage 14 has a plurality of substantially rectangular hole opening windows 14a formed at equal intervals in the circumferential direction. The same number of the opening windows 14 a as the balls 13 are formed. The balls 13 are inserted through the opening windows 14a. That is, the cage 14 holds the ball 13.

  The boot 15 is formed in a bellows cylinder shape. One end of the boot 15 is directly fixed to the outer peripheral surface of the open end of the outer ring member 11 by a clamp member. Further, the other end side of the boot 15 is directly fixed to the outer peripheral surface of the shaft 20 by a clamp member. That is, the boot 15 seals the opening side of the outer ring member 11.

  Next, the detailed shape of the grindstone relief portion 11b will be described with reference to FIG. FIG. 3 is an enlarged view of the AA cross section of FIG. 2 as described above. That is, FIG. 3 is a cross-sectional view along the groove direction of the outer ring groove 11a (hereinafter referred to as “groove direction cross section”).

  That is, as shown in FIG. 3, the outer ring groove 11 a is a portion formed in a range from the open end (right end in FIG. 3) to the point B of the outer ring member 11. And the grindstone relief part 11b is a part formed in the cup back | inner side (left side of FIG. 3) from this outer ring groove 11a, and following the outer ring groove 11a. That is, the grindstone relief portion 11b is formed in the range from the cup back end B point to the C point of the outer ring groove 11a. The grindstone relief portion 11b is not formed on the entire inner peripheral surface of the outer ring member 11, but is formed by cutting only on the back side of the cup of the outer ring groove 11a.

  The grindstone relief portion 11b is formed in an aspheric curved concave shape. Specifically, the grindstone relief portion 11b is formed in a concave shape in which the maximum distance from the outer ring rotating shaft is located on the side farther from the outer ring rotating shaft than the groove bottom surface of the outer ring groove 11a. That is, in the grindstone relief portion 11b, the distance from the outer ring rotation axis to the intermediate point between the points B and C is longer than the distance from the outer ring rotation axis to the point B.

  Furthermore, the grindstone relief portion 11b contacts the ball 13 when the ball 13 is located at the innermost part of the cup in the outer ring groove 11a (when the ball 13 is located at a position indicated by a two-dot chain line in FIG. 3). It has the protrusion 51 which touches. This protrusion 51 is a cup back side site | part among the outline parts of the grindstone relief part 11b. Here, since the grindstone relief portion 11b has a concave shape, the contour portion has a circumferential shape. Therefore, the cup back side portion of the contour portion of the grindstone relief portion 11b is a portion located on the far side from the outer ring groove 11a in the so-called contour portion.

  That is, when the ball 13 is positioned at the innermost part of the cup, the ball 13 comes into contact with the protrusion 51. Therefore, it is possible to prevent the ball 13 from dropping into the concave grindstone relief portion 11b. In other words, the grindstone relief portion 11b is not a concave shape from which the ball 13 can drop off.

  Furthermore, even if the ball 13 tries to move to the back side of the cup from the innermost part of the cup of the outer ring groove 11a, the movement of the ball 13 is restricted because the ball 13 comes into contact with the protrusion 51. That is, when the ball 13 comes into contact with the protrusion 51, the ball 13 can be prevented from being detached from the outer ring groove 11a, and as a result, torque transmission can be reliably performed.

  Here, the process of grinding the outer ring groove 11a with the grindstone G will be described with reference to FIG. FIG. 4 is a partial cross-sectional enlarged view of the same outer ring member 11 as in FIG. 3, and is a view for explaining the grinding of the outer ring groove 11a.

  The outer ring groove 11a is ground by a grindstone G shown in FIG. The grindstone G includes a base portion G1 of a cylindrical portion and a front end portion G2 formed on the front end side of the base shaft portion G1. The distal end portion G2 includes an arc-shaped portion G21 whose diameter is reduced in an arc shape from an end portion of the base shaft portion G1, and an end surface portion G22 that is a plane that is positioned on the distal end side of the arc-shaped portion G21 and orthogonal to the grindstone axis Gs. The arcuate portion G21 has a curvature that follows the outer peripheral surface of the ball 13. Furthermore, the tip G2 of the grindstone G has a shape that is housed in a sphere 100 having a diameter 1.0 to 1.1 times that of the ball 13.

  Then, the grindstone axis Gs of the grindstone G is positioned in a state where it is inclined at a predetermined angle θ1 with respect to the groove center of the outer ring groove 11a. In this state, the grindstone G is translated from the cup opening end toward the back of the cup while rotating the grindstone G about the grindstone axis Gs. Then, the outer ring groove 11a is formed from the cup opening side to the cup back side. And the state which grinds the innermost part of the cup of this outer ring groove 11a with the grindstone G is the state where the grindstone G is at the position shown in FIG.

  By the way, as described above, the tip G2 of the grindstone G has a shape accommodated in the sphere 100 having a diameter 1.0 to 1.1 times that of the ball 13. Furthermore, the protrusion 51 is formed outside the sphere 100 when the sphere 100 is located at the innermost part of the cup. That is, the grindstone G does not interfere with the protrusion 51. Thereby, the outer ring groove 11a can be reliably ground by the grindstone G.

An axial sectional view of the constant velocity joint 10 is shown. An axial direction sectional view of outer ring member 11 which constitutes constant velocity joint 10 is shown. The enlarged view of the AA cross section of FIG. 2 is shown. It is a figure explaining the grinding process of the outer ring groove 11a.

Explanation of symbols

10: Cross groove type constant velocity joint,
11: Outer ring member, 11a: Outer ring groove, 11b: Wheel relief part for grinding outer ring groove,
12: inner ring member, 12a: outermost peripheral surface, 12b: inner ring groove, 12c: inner peripheral spline,
13: Ball, 14: Cage, 14a: Opening window, 15: Boot
20: Shaft 51: Projection 100: Sphere
G: Grinding wheel, G1: Base shaft part, G2: Tip part

Claims (3)

An outer ring member having a cup shape and having a plurality of outer ring grooves formed in a direction twisted with respect to the outer ring rotation shaft on the inner peripheral surface;
An inner ring member that is arranged inside the outer ring member so as to be slidable in the outer ring axis direction with respect to the outer ring member, and in which a plurality of inner ring grooves are formed in a direction twisted with respect to the inner ring rotation shaft on the outer peripheral surface;
Plurally disposed at the intersection of the outer ring groove and the inner ring groove that intersects the outer ring groove and is arranged so as to be able to roll by engaging with the outer ring groove and the inner ring groove in the circumferential direction. And the ball
A cage disposed between the outer ring member and the inner ring member and formed with a plurality of open window portions through which the balls are respectively inserted;
A cross groove type constant velocity joint comprising:
The outer ring member has a grindstone relief portion for grinding the outer ring groove formed on the back side of the cup from the outer ring groove and continuously with the outer ring groove,
The grindstone relief portion has a concave shape in which the maximum distance from the outer ring rotating shaft is located on the side farther from the outer ring rotating shaft than the groove bottom surface of the outer ring groove, and the ball is located at the innermost part of the cup in the outer ring groove. A cross-groove type constant velocity joint having a protrusion that abuts against the ball when positioned.   The cross groove type constant velocity joint according to claim 1, wherein the protrusion is a cup back side portion of the contour portion of the grindstone relief portion.   The cross groove type constant velocity joint according to claim 1, wherein the grinding wheel relief portion is formed of an aspherical curved surface.

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