JP5131064B2 - Ball type constant velocity joint - Google Patents

Description

  The present invention relates to a ball type constant velocity joint used in an automobile.

  Conventionally, as ball-type constant velocity joints, for example, those described in Japanese Patent Application Laid-Open No. 2000-230568 (Patent Document 1) and Japanese Patent Application Laid-Open No. 2004-156699 (Patent Document 2) are known. This ball-type constant velocity joint is formed in a cylindrical shape having one end opened, and an outer ring 20 having a plurality of outer ring ball grooves 23 extending in the axial direction on an inner circumferential surface of a concave spherical surface, and an inner side of the outer ring 20. The inner ring 30 in which a plurality of inner ring ball grooves 32 extending in the axial direction is formed on the outer peripheral surface of the convex spherical surface, and the outer ring ball groove 23 and the inner ring ball groove 32 are rolled to each other. A plurality of balls 40 that transmit torque between them, and a cage 50 that is formed in an annular shape and disposed between the outer ring 20 and the inner ring 30 and has a plurality of window portions 53 that respectively accommodate the balls 40 in the circumferential direction. (Refer to FIG. 3).

  In the general ball type constant velocity joints described in these patent documents and the like, when the balls are assembled to the inner ring ball groove 32 and the outer ring ball groove 23, as shown in FIG. 3, the outer ring axis L1 and the inner ring axis L2 intersect. In a state where the angle (joint angle) θ is larger than the maximum angle (50 deg) in actual use (about 65 deg), between the inner ring ball groove 32 and the outer ring ball groove 23 from the opening side of the outer ring 20. The ball 40 is inserted and assembled. Therefore, as shown in FIG. 4, since it is necessary to secure a moving space for the ball 40 located on the opposite side of the opening of the outer ring 20, the track lengths of the inner ring ball groove 32 and the outer ring ball groove 23 are set to the actual track lengths. It is necessary to make it longer than the use area (practical area).

Normally, the inner ring ball groove 32 is formed in an arc shape drawn with a point on the inner ring axis L2 as the center of curvature, and the outer ring ball groove 23 is formed in an arc shape drawn with a point on the outer ring axis L1 as the center of curvature. Has been. In Patent Document 1, the inner ring ball groove has a first arc groove portion having a convex R shape at an axially intermediate portion, and a second arc groove portion having a straight line or a concave R at one or both ends in the axial direction. The outer ring ball groove is formed in a shape corresponding to the first arc groove part and the second arc groove part of the inner ring ball groove. Patent Document 2 describes that an arcuate groove portion is provided at an axial intermediate portion of an outer ring ball groove, and a linear groove portion is provided at both axial end portions or axial base end portions.
No. 2000-230568 2004-156699

  By the way, when the inner ring ball groove 32 is formed in an arc shape drawn with the point on the inner ring axis L2 as the center of curvature as described above, the bottom of the inner ring ball groove 32 at the axial end of the inner ring 30 and The thickness between the inner ring 30 and the inner peripheral surface becomes thinner toward the shaft end. In particular, when an inner peripheral spline for fitting (meshing) the outer peripheral spline of the power transmission shaft is formed on the inner peripheral surface of the inner ring 30, the large diameter surface of the inner peripheral spline and the bottom of the inner ring ball groove 32 are formed. The wall thickness between them becomes extremely thin. For this reason, a portion where the thickness t of the axial edge is thin becomes a starting point of occurrence of damage to the inner ring 30, so that the strength of the inner ring 30 is required to be improved. On the other hand, if the wall thickness t of the axial end edge of the inner ring ball groove 32 is increased, the insertion space of the ball 40 during ball assembly becomes narrow, and the assembly operation becomes difficult.

  As in Patent Document 1, it is possible to increase the thickness of the end of the inner ring by providing the second arc groove at one end or both ends in the axial direction of the inner ring ball groove. Nothing is stated about the movement of the ball.

  The present invention has been made in view of the above circumstances, and it is an object to be solved to provide a ball-type constant velocity joint that improves the strength of the inner ring without adversely affecting the ball assembly. Is.

  Hereinafter, each means suitable for solving the above-described problems will be described while adding effects and the like as necessary.

1. Ball type constant velocity joint
An outer ring having a cylindrical shape with an opening on one side in the axial direction, and a plurality of outer ring ball grooves extending in the axial direction on the inner peripheral surface;
An inner ring disposed inside the outer ring and formed with a plurality of inner ring ball grooves extending in the axial direction 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 of an annular shape, disposed between the outer ring and the inner ring, and formed with a plurality of windows that respectively accommodate the balls in the circumferential direction;
In a ball-type constant velocity joint comprising
At the end of the inner ring ball groove on the opening side, when the torque is transmitted to and from the ball, the ball rolls on the inner ring ball groove at a portion other than the practical area, and on the opening side. A first taper portion that is inclined so as to approach the inner ring axis as it goes toward is provided,
At the end of the outer ring ball groove opposite to the opening, when the torque is transmitted to and from the ball, the first ring is located at a part other than the practical area where the ball rolls in the outer ring ball groove. A second taper portion that is inclined so as to move away from the first taper portion toward the opposite side of the opening when the ball contacts the taper portion is provided.

  In the first means, the end of the inner ring ball groove on the opening side is inclined to approach the inner ring axis toward the opening toward a portion other than the practical area where the ball rolls in the inner ring ball groove. One taper portion is provided. As a result, the thickness between the bottom of the inner ring ball groove and the inner peripheral surface of the inner ring at the end of the inner ring on the opening side increases, and the strength of the inner ring is improved, so the outer diameter of the constant velocity joint is increased. Therefore, the strength can be improved. Moreover, if it is the same intensity | strength, it can reduce in size.

  The “practical area” as used herein means that when the torque is transmitted to the ball-type constant velocity joint, the ball moves to the inner ring ball when operating with the maximum angle of intersection between the inner ring axis and the outer ring axis. The range that rolls in the groove. In the means 1, the first taper portion is provided in a portion other than the practical region in the end portion on the opening side of the inner ring ball groove.

  Further, in the means 1, the end of the outer ring ball groove opposite to the opening portion is provided with a first taper at a portion other than the practical area where the ball rolls in the outer ring ball groove toward the opposite side of the opening portion. A second tapered portion that is inclined so as to move away from the portion is provided. That is, the first taper portion and the second taper portion are provided so as to open toward the side opposite to the opening of the outer ring (back side). Thereby, when the ball is assembled, the ball located on the innermost side of the outer ring is pushed out to the inner side by the first taper portion and the second taper portion. Therefore, it becomes possible to easily insert a ball between the inner ring ball groove and the outer ring ball groove on the opening side of the outer ring.

  The “practical area” as used herein means that when the torque is transmitted to the ball-type constant velocity joint and the ball is operated with the maximum angle of intersection between the inner ring axis and the outer ring axis, The range that rolls in the groove. In the means 1, the second taper portion is provided at a portion other than the practical region in the end portion on the opposite side (back side) to the opening side of the outer ring ball groove.

  Therefore, according to the means 1, the strength of the inner ring can be improved without adversely affecting the ball assembly.

2. In the ball-type constant velocity joint described in means 1,
The first tapered portion is provided only in a portion other than the practical region of the inner ring ball groove, and the second tapered portion is provided only in a portion other than the practical region of the outer ring ball groove.

  According to the means 2, the ease of assembling the ball can be ensured more reliably, and the strength of the inner ring can be improved more reliably.

3. In the ball type constant velocity joint according to means 1 or 2,
The first taper portion and the second taper portion are used when the ball is assembled to the inner ring ball groove and the outer ring ball groove.

  According to the means 3, since the first taper portion and the second taper portion are provided, the assembly work when the ball is assembled is facilitated. It can be used effectively.

4). In the ball type constant velocity joint according to any one of means 1 to 3,
The practical area of the inner ring ball groove is formed in an arc shape drawn with a point on the inner ring axis as a center of curvature, and the practical area of the outer ring ball groove is drawn with a point on the outer ring axis as a center of curvature. It is formed in an arc shape.

  According to the means 4, since the practical area of the inner ring ball groove and the practical area of the outer ring ball groove are formed in an arc shape, the direction in which each ball pushes the cage is on the opening side of the outer ring. The posture of the vessel can be stabilized. If the first tapered portion or the second tapered portion is provided in the practical area, the direction in which each ball pushes the cage is different, so that the cage becomes difficult to stabilize and the cage is likely to be loose. Become.

5. In the ball type constant velocity joint according to any one of means 1 to 4,
A stopper portion that prevents the ball from falling off from the second taper portion is provided at an end edge of the outer ring ball groove opposite to the opening.

  According to the means 5, the first taper portion and the second taper portion are provided so as to open toward the side opposite to the opening of the outer ring (back side). The ball pushed between the second taper portion and the second taper portion can be prevented from dropping from the second taper portion by the stopper portion. Further, by providing this stopper portion, the biting of the ball can be prevented. The stopper portion can be constituted by a tapered surface, a curved surface, or a protrusion.

6). In the ball-type constant velocity joint described in means 5,
The stopper portion includes a tapered surface that is inclined so as to approach the first taper portion toward the opposite side of the opening when the ball is in contact with the first taper portion and the second taper portion. Has been.

  According to the means 6, since the taper surface of the stopper portion and the first taper portion are provided so as to be closed toward the side opposite to the opening of the outer ring (back side), the ball falls off from the second taper portion. Can be more reliably prevented. Further, when the inner peripheral surface of the outer ring is processed by grinding or the like, the stopper portion can be easily formed in a series of processing steps.

  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 an axial cross-sectional view of the constant velocity joint 10 with the maximum joint angle 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 includes a fixed ball type constant velocity joint (also referred to as a “Zepper type constant velocity joint”). The constant velocity joint 10 includes an outer ring 20, an inner ring 30, a plurality of balls 40, and a cage 50. Hereinafter, each component will be described in detail.

  The outer ring 20 has a cup shape (bottomed cylindrical shape) having an opening on the left side in FIG. 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. Furthermore, 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 in an arc concave shape when viewed in a cross section cut in the outer ring axial direction.

  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. Details of the outer ring ball groove 23 will be described later. The plurality of (six in this embodiment) outer ring ball grooves 23 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 has 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 in a uniform arc, that is, a convex partial spherical shape when viewed in a cross section cut in the inner ring axial direction.

  Furthermore, 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. Details of the inner ring ball groove 32 will be described later. These multiple (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.

  Further, an inner peripheral spline 33 extending in the inner ring axial direction is formed on the inner peripheral surface of the inner ring 30. The inner peripheral spline 33 is fitted (engaged) with the outer peripheral spline of the power transmission shaft 35. 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 has 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 in a partial spherical shape substantially corresponding to the convex spherical outer peripheral surface 31 of the inner ring 30, that is, a spherical concave 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. Furthermore, the cage 50 has a plurality of window portions 53 that are substantially rectangular through holes formed at equal intervals in the circumferential direction (the circumferential direction of the cage axis). The same number of the window portions 53 as the balls 40 are formed. One ball 40 is accommodated in each window 53.

  Next, the first tapered portion 36 provided in the inner ring ball groove 32, the second tapered portion 24 provided in the outer ring ball groove 23, and the stopper portion 25 will be described in detail with reference to FIGS. FIG. 2 is an enlarged cross-sectional view showing an essential part of the constant velocity joint of FIG.

  As shown in FIG. 2, the first tapered portion that is inclined toward the inner ring axis L <b> 2 (see FIG. 1) toward the opening side of the outer ring 20 is located at the end of the inner ring ball groove 32 on the opening side. 36 is provided. The first taper portion 36 is provided only in a portion other than the practical region where the ball 40 rolls in the inner ring ball groove 32 when torque is transmitted between the inner ring ball groove 32 and the ball 40.

  That is, the first taper portion 36 is provided at a position located on the opening side of the practical area of the inner ring ball groove 32. The portion of the inner ring ball groove 32 which is a practical area is formed in an arc shape drawn with a point O1 offset from the intersection O between the outer ring axis L1 and the inner ring axis L2 in the direction of the inner ring axis L2 as the center of curvature. The first taper portion 36 extends from the arc in a tangential direction with respect to the arc of the portion that becomes the practical area.

  When the ball 40 is in contact with the first taper portion 36 at the end opposite to the opening of the outer ring ball groove 23 (the back side of the outer ring 20), the first taper is directed toward the opposite side of the opening. A second taper portion 24 that is inclined so as to be away from the portion 36 is provided. The second taper portion 24 is provided only in a portion other than the practical region where the ball 40 rolls on the outer ring ball groove 23 when torque is transmitted between the outer ring ball groove 23 and the ball 40.

  That is, the second taper portion 24 is provided in a portion located on the opposite side of the opening portion from the practical area of the outer ring ball groove 23. The part of the outer ring ball groove 23 which is a practical area is formed in an arc shape drawn with the point O2 offset from the intersection O in the direction of the outer ring axis L1 as the center of curvature. The second taper portion 24 extends in a tangential direction from the arc of the portion that becomes the practical area.

  The first tapered portion 36 and the second tapered portion 24 are provided so as to open toward the side opposite to the opening of the outer ring 20 (the back side of the outer ring 20). Thereby, when the ball is assembled, the ball 40 (see FIG. 2) located on the innermost side of the outer ring 20 is pushed out to the inner side by the first taper portion 36 and the second taper portion 24. .

  Further, a stopper portion 25 for preventing the ball 40 from dropping off from the second taper portion 24 is provided at the end of the outer ring ball groove 23 opposite to the opening. The stopper portion 25 is configured by a tapered surface that is inclined so as to approach the first taper portion 36 toward the opposite side of the opening when the ball 40 contacts the first taper portion 36 and the second taper portion 24. Has been. That is, the tapered surface of the stopper portion 25 and the first tapered portion 36 are provided so as to close toward the side opposite to the opening of the outer ring 20 (the back side of the outer ring 20).

  In the constant velocity joint 10 of the present embodiment configured as described above, the first taper portion 36 is provided at a portion other than the practical region at the end of the inner ring ball groove 32 on the opening side. As a result, the wall thickness t1 between the bottom of the inner ring ball groove 32 and the inner peripheral surface of the inner ring 30 at the end of the inner ring 30 on the opening side is significantly increased as compared with the conventional wall thickness t2. Strength is greatly improved. Therefore, the strength can be improved without increasing the outer diameter of the constant velocity joint. Moreover, if it is the same intensity | strength, it can reduce in size.

  Further, a second taper portion 24 is provided at a portion other than the practical region at the end opposite to the opening of the outer ring ball groove 23. Thereby, when the ball 40 is assembled, the ball 40 located on the innermost side of the outer ring 20 is pushed out to the inner side by the first taper portion 36 and the second taper portion 24. Therefore, the ball 40 can be easily inserted between the inner ring ball groove 32 and the outer ring ball groove 23 on the opening side of the outer ring 20.

  Therefore, according to the constant velocity joint 10 of the present embodiment, the strength of the inner ring 30 can be improved without adversely affecting the ball assembly.

  Further, in the present embodiment, the first tapered portion 36 is provided only in a portion other than the practical region of the inner ring ball groove 32, and the second tapered portion 24 is provided only in a portion other than the practical region of the outer ring ball groove 23. . Therefore, the ease of assembling the ball 40 can be ensured more reliably, and the strength of the inner ring 30 can be improved more reliably.

  Since the first taper portion 36 and the second taper portion 24 are provided, the assembling work at the time of assembling the ball becomes easy. Therefore, the first taper portion 36 and the second taper portion 24 are effectively used. It becomes possible to use it.

  In this embodiment, the practical area of the inner ring ball groove 32 is formed in an arc shape drawn with the point O1 as the center of curvature, and the practical area of the outer ring ball groove 23 is formed in an arc shape drawn with the point O2 as the center of curvature. Is formed. As a result, the direction in which each ball 40 pushes the cage is on the opening side of the outer ring 20, so that the posture of the cage 50 can be stabilized, and the occurrence of rattling of the cage 50 can be avoided. it can.

  In the present embodiment, a stopper portion 25 is provided on the edge of the outer ring ball groove 23 opposite to the opening. Thereby, at the time of ball assembly, it is possible to prevent the ball 40 pushed out between the first taper portion 36 and the second taper portion 24 from falling off from the second taper portion 24 and biting of the ball 40. .

  The stopper portion 25 is configured by a tapered surface that is inclined so as to approach the first taper portion 36 toward the opposite side of the opening when the ball 40 contacts the first taper portion 36 and the second taper portion 24. Therefore, it is possible to more reliably prevent the ball 40 from dropping from the second taper portion 24.

It is an axial sectional view in the state where the maximum joint angle of the constant velocity joint according to the embodiment is taken. It is an expanded sectional view which expands and shows the principal part of the constant velocity joint of FIG. It is an axial direction sectional view showing the state at the time of ball assembly of a constant velocity joint. It is explanatory drawing which shows the track | orbit length of the ball | bowl in an inner ring | wheel ball groove.

Explanation of symbols

  10: Ball type constant velocity joint, 20: Outer ring, 21: Connection shaft, 22: Concave spherical inner peripheral surface, 23: Outer ring ball groove, 24: Second taper part, 25: Stopper part, 30: Inner ring, 31: Convex outer peripheral surface, 32: inner ring ball groove, 33: inner spline, 36: first taper part, 40: ball, 50: cage, 53: window part, L1: outer ring axis, L2: inner ring axis.

Claims (6)

An outer ring having a cylindrical shape with an opening on one side in the axial direction, and a plurality of outer ring ball grooves extending in the axial direction on the inner peripheral surface;
An inner ring disposed inside the outer ring and formed with a plurality of inner ring ball grooves extending in the axial direction 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 of an annular shape, disposed between the outer ring and the inner ring, and formed with a plurality of windows that respectively accommodate the balls in the circumferential direction;
In a ball-type constant velocity joint comprising
At the end of the inner ring ball groove on the opening side, when the torque is transmitted to and from the ball, the ball rolls on the inner ring ball groove at a portion other than the practical area, and on the opening side. A first taper portion that is inclined so as to approach the inner ring axis as it goes toward is provided,
At the end of the outer ring ball groove opposite to the opening, when the torque is transmitted to and from the ball, the first ring is located at a part other than the practical area where the ball rolls in the outer ring ball groove. A ball-type constant velocity joint, characterized in that a second taper portion that is inclined so as to move away from the first taper portion toward the opposite side of the opening when the ball contacts the taper portion.   2. The first tapered portion is provided only in a portion other than the practical region of the inner ring ball groove, and the second tapered portion is provided only in a portion other than the practical region of the outer ring ball groove. Ball type constant velocity joint as described in 1.   The ball type constant velocity joint according to claim 1 or 2, wherein the first taper portion and the second taper portion are used when the ball is assembled to the inner ring ball groove and the outer ring ball groove.   The practical area of the inner ring ball groove is formed in an arc shape drawn with a point on the inner ring axis as a center of curvature, and the practical area of the outer ring ball groove is drawn with a point on the outer ring axis as a center of curvature. The ball-type constant velocity joint as described in any one of Claims 1-3 currently formed in circular arc shape.   The edge part on the opposite side to the said opening part of the said outer ring | wheel ball groove is provided with the stopper part which prevents dropping of the said ball | bowl from the said 2nd taper part. Ball type constant velocity joint.   The stopper portion includes a tapered surface that is inclined so as to approach the first taper portion toward the opposite side of the opening when the ball is in contact with the first taper portion and the second taper portion. The ball-type constant velocity joint according to claim 5.

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