JPH07317791A - Constant velocity joint - Google Patents

Abstract

PURPOSE:To improve twisting strength of an opening end by forming an escape groove on an inner lace in the direction for increasing depth of a shallow groove part of the inner lace, thereby widening clearance between a ball and a groove when a joint shows a maximum angle, and reducing a load to be applied to the ball at the opening end of an outer lace. CONSTITUTION:An outer lace 11 is formed with recessed arcuate groove 12 with equal angular invervals. One end 11a of the outer lace 11 is opened, while the other end 11b is provided with a driven shaft 10. An inner lace 14 has a concaved surface on its outer peripheral surface on which a covexed arcuate groove 15 is axially extended on a position corresponding to the concanved arcuate groove 12 of the outer lace 11. An escape groove is formed in a direction for increasing depth of a shallow groove of the inner lace 14, so as to increase a clearance between balls 16 which are arranged on an opening side of the outer lace and the groove of the outer lace 11 compared to that in respect to other ball, when a joint shows a maximum angle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a constant velocity joint used for a driving force transmission shaft of an automobile.

[0002]

2. Description of the Related Art In a constant velocity joint of this kind, as shown in FIG. 7, concave arcuate grooves 12 extending in the axial direction are formed on a spherical inner peripheral surface at equal angular intervals, and one end 11a is Is opened,
Outer race 11 having driven shaft 10 at the other end 11b
And, a spline is fitted to one end of a drive shaft 13 having the same axis as the driven shaft 10, and a convex spherical surface is provided on the outer peripheral surface, at a position corresponding to the concave arc-shaped groove 12 of the outer race 11 on the convex spherical surface. An inner race 14 having a convex arcuate groove 15 extending in the axial direction, and a ball 16 rotatably interposed between the concave arcuate groove 12 and the convex arcuate groove 15.
The outer race 11 and the inner race 14 are rotatably interposed between the outer race 11 and the inner race 14, and the cage 17 holds the balls 16 in a holding window.

[0003]

In such a constant velocity joint, as shown in FIG. 3, when the maximum joint angle becomes large, the groove contact S of the ball 16 causes the outer race 11 to come into contact with the groove contact S.
Is removed from the concave arcuate groove 12 on the opening side of the one end 11a.

As shown in FIG. 8, in order to transmit the rotational torque T, the balls 16 are formed in a convex arcuate groove 15 of the inner race 14.
Is transmitted by the rotation torque transmission point T1 of the outer race 11 and the rotation torque transmission point T2 of the concave arc-shaped groove 12 of the outer race 11, but the contact point between the inner race 14 and the ball 16 is not at right angles to the rotation direction. 16
A force in the F direction acts on.

In this operation, the ball 16
When the groove contact S of the outer race 11 is disengaged from the concave arcuate groove 12 on the opening side of the one end 11a of the outer race 11, the ball 1 in the opening is formed.
In No. 6, since the contact portion of the outer race 11 is not elliptical, the stress concentrates in the F direction, which causes a problem that the outer race 11 has a chipped edge.

Further, the balls 16 are held by the interference of the cage window, but the convex arcuate groove 15 of the inner race 14 becomes shallower as the joint angle increases, so that the ball 16 is retained in the outer race 11. Since the ball 16 and the cage 17 are pushed out to the groove 12 side, the contact between the ball 16 and the cage 17 is disengaged from the cage window, so that when the ball 16 tries to return to the groove due to the rotation of the joint, the gap between the cage 17 and the outer race 11 is lost. There was a problem that the ball 16 clung to.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art. The characteristic feature of the present invention is that one end is opened and the spherical inner peripheral surface extends in the axial direction. The outer race has concave arc-shaped grooves that are present and whose groove depth increases toward the opening end side at equal angular intervals, and a convex spherical surface is provided on the outer peripheral surface, and the concave spherical groove of the outer race is formed on the convex spherical surface. An inner race having a convex arcuate groove extending axially at a position corresponding to and having a groove depth deeper toward the opening end side of the outer race, and the concave arcuate groove and the convex arcuate groove. In a constant velocity joint including a ball rotatably interposed between the groove and a cage that rotatably interposed between the outer race and the inner race and holding the ball, the joint has a maximum operating angle. When you take the The depth of the shallow groove portion of the inner race is deep so that the clearance between the ball and the groove of the outer race is larger than the clearances of the other balls with respect to the one or two balls coming to the open end side of the tarrace. The relief groove is formed in the inner race in the following direction.

Further, in the constant velocity joint having the above structure, the relief groove portion is formed at an end portion of a first convex arc groove which is the convex arc groove of the inner race and is opposite to an opening end of the outer race. Formed by a second convex arc groove having a deeper groove depth, and a third convex arc groove in which the first convex arc groove and the second convex arc groove are joined by an arc smaller than these two groove arcs. It was done.

Further, in the constant velocity joint of the above construction, the convex arcuate groove of the inner race is formed from the inner race rotation center which is the intersection of the inner race rotation axis and the constant velocity bisector. The relief groove is formed by a first convex arc groove formed of an arc having a radius of curvature r ₁ with a center of curvature at a position offset from the opening end of the outer race on the rotation axis of the race. The first convex circular arc groove is formed at the end of the circular arc groove, and the curvature center is located between the rotation center of the inner race and the curvature center of the first convex circular arc groove on the rotation axis of the inner race. the radius of curvature r ₁ arc by opening end of the outer race of the larger radius of curvature r ₂ is obtained by forming the second projected circular grooves deeper groove depth toward the opposite side.

Also, an outer race having concave arc-shaped grooves which are open at one end and which extend in the axial direction on the spherical inner peripheral surface and whose groove depth becomes deeper toward the opening end side at equal angular intervals. , A convex circle provided on the outer peripheral surface and extending in the axial direction at a position corresponding to the concave arc-shaped groove of the outer race, and having a groove depth that increases toward the open end side of the outer race. An inner race having an arcuate groove formed therein, a ball rotatably interposed between the concave arcuate groove and the convex arcuate groove, and a ball rotatably interposed between the outer race and the inner race. In a constant velocity joint including a cage for holding the ball, the groove between the ball and the outer race is provided for one or two balls coming to the open end side of the outer race when the joint takes a maximum operating angle. Chestnut with Lance so is greater than the clearance for the other ball is a groove escape in the direction in which the groove depth of the opening end side deep grooves of the outer race is deeper that formed in the outer race.

[0011]

With the above configuration, the clearance groove between the inner race and the outer race is deeper toward the opening side of the outer race, and when the joint angle is taken, the clearance between the ball and the groove is expanded and the outer race The load applied to the ball at the opening end is reduced, the torsional strength at the opening end of the outer race is improved, and high strength and long life are secured.

Even if the contact point of the ball is out of the groove of the outer race by taking the maximum joint angle, edge breakage due to stress concentration acting on the opening end of the outer race is prevented and the ball smoothly moves in the arc groove. return,
Avoid sticking the ball between the cage and the outer race.

Further, in the escape groove formed in the inner race, the amount of pushing the ball toward the groove on the outer race side is reduced, and the ball is prevented from coming off from the cage window, thereby widening the joint angle. When the maximum joint angle is taken, the balls whose contact points are disengaged from the arc groove of the outer race do not transmit the rotational torque, so that the fatigue strength of the cage is improved.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 5 show that when the joint takes the maximum working angle, the clearance between the ball and the groove of the outer race is larger than that of the other balls with respect to one or two balls coming to the open end side of the outer race. FIG. 1 shows a specific embodiment of the structure in which the escape groove portion is formed in the inner race in the direction in which the groove depth of the shallow groove portion of the inner race becomes deeper. An outer race having concave arcuate grooves 12 extending in the axial direction formed on its surface at equal angular intervals, one end 11a of which is open, and the other end 11b is provided with a driven shaft 10. The concave arc-shaped groove 12 is generally formed by six grooves.

Reference numeral 14 denotes an inner race, which is spline-fitted to one end of a drive shaft 13 having the same shaft center as the driven shaft 10 and has a convex spherical surface on the outer peripheral surface, and the convex spherical surface is a concave arc shape of the outer race 11. The convex arcuate groove 15 extending in the axial direction is formed at a position corresponding to the groove 12.

The concave arcuate groove 12 and the convex arcuate groove 15
A ball 16 is rotatably interposed between the outer race 11 and the inner race 14, and the ball 1 is interposed between the outer race 11 and the inner race 14.
A cage 17 holding 6 by a holding window is rotatably interposed.

Therefore, FIGS. 1 and 2 show a first embodiment of the present invention, in which the convex arcuate groove 15 of the inner race 14 is formed with three arcs having different radii of curvature. That is, as shown in FIG. 2, the opening end 11a of the outer race 11 is defined on the rotation axis center line X of the inner race 14 from the intersection 01 of the rotation axis center of the inner race 14 and the constant velocity bisecting line Y. Center of curvature 0 at the position offset D to the opposite side
With the arc having the curvature radius r ₁ of 2, the groove depth is increased toward the opening side 11a of the outer race 11 in the range A.
The convex arc groove 15a is centered on the intersection point 01 of the rotation axis of the inner race 14 and the constant-velocity bisecting line Y so that the groove depth becomes deeper than the ridge line of the first convex arc groove 15a. The outer race 14 in the range B is formed by an arc having a radius of curvature r _2.
Second convex arcuate groove 15b having a deeper groove depth toward the side opposite to the open end 11a of the first convex arcuate groove 15a and the second convex arcuate groove 15a.
The convex arcuate groove 15b, is obtained by forming in a third convex arcuate groove 15c who succeeded in C range by the two circular arcs of small radius of curvature r ₃ from the groove circular arc subtended by the center of curvature 03.

In the above construction, when the joint angle is taken, the clearance between the ball 16 and the convex arcuate groove 15 becomes wider, the load applied to the ball at the opening end of the outer race 11 is reduced, and the opening end of the outer race 11 is reduced. The torsional strength of the part is improved, ensuring high strength and long life.

When the driven shaft 10 and the drive shaft 13 are on the same axis, the six balls 16 on the circumference have a constant velocity including the constant velocity bisecting line Y at the center thereof. The first convex arc groove 15a in the range A of the convex arc groove 15 of the inner race 14 and the outer race 11 on the bisector surface.
Located between the groove 12 and the concave arc-shaped groove 12, and transmits the rotational torque by all six balls 16 on the circumference.

As the driven shaft 10 and the drive shaft 13 form a joint angle, the contact point between the ball 16 and the inner race 14 coming to the opening end side of the outer race 11 is from the first convex arc groove 15a to the third convex arc groove 15a. Move to 15c. That is,
The ball 16 moves from the range A to the range C in the convex arcuate groove 15 of the inner race 14. (See the chain double-dashed line in Figure 2)

The third convex arcuate groove 15c of the inner race 14 in the C range has a groove depth which gradually becomes deeper toward the side opposite to the opening end 11a of the outer race 11,
Since the facing distance between the arcuate groove 12 of the outer race 11 and the third convex arcuate groove 15c of the inner race 14 is slightly widened, it is positioned at the third convex arcuate groove 15c which is the C range in the convex arcuate groove 15. The load applied to the ball 16 is reduced. Therefore, the rotational torque is transmitted by the six balls 16 while the load applied to the one or two balls 16 on the circumference is small.

When the joint angle between the driven shaft 10 and the drive shaft 13 becomes close to the maximum joint angle, the contact point between the ball 16 and the inner race 14 coming to the opening end side of the outer race 11 is from the third convex arc groove 15c. Second convex arc groove 15b
Move to. That is, the ball 16 moves from the C range in the convex arc-shaped groove 15 of the inner race 14 to the B range.

The second convex arcuate groove 15b of the inner race 14 in the range B has a groove depth that gradually increases toward the side opposite to the opening end 11a of the outer race 11, and the concave arcuate groove 12 of the outer race 11 is formed. Since the opening end 11ad of the outer race 11 is greatly widened by the facing distance between the inner race 14 and the second convex arc groove 15b, one or two balls 16 are provided more than the concave arc groove 12 of the outer race 11.
The contact of is released and escapes from the edge of the outer race 11.
The rotation torque is not transmitted by the ball 16 whose contact point is disengaged from the concave arcuate groove 12 of the outer race 11. However, since the other five to four balls 16 do not come out of contact with the concave arcuate groove 12 of the outer race 11,
The five to four balls 16 transmit the rotational torque at the maximum joint angle.

A concave arcuate groove 12 of the outer race 11
Since the contact point of the ball 16 is disengaged from the outer race 11 and escapes from the edge of the outer race 11 and the rotational torque is not transmitted by the ball 16, the outer race 11 is free from the edge chipping and when the ball 16 tries to return to the groove, The ball 16 does not cling to the outer race 11.

Further, since the groove depth of the shallow groove portion of the inner race 14 becomes deep and the holding window of the cage 17 also has an interference, the balls 16 will not come off from the holding window of the cage 17.

3 to 5 are examples of design changes in the first embodiment. That is, in the above embodiment, the first convex circular arc groove 15a, the second convex circular arc groove 15b, and the third convex circular arc groove 15c.
3 is a convex arcuate groove 15 of the inner race 14 formed of three different arcs of curvature, the convex arcuate groove 1 of the inner race 14 in the modified design of FIGS.
5 is formed by two arcs having different radii of curvature.

FIG. 3 shows a first design modification example, which is described above on the rotational axis X of the inner race 14 from the intersection 01 of the center of rotation of the inner race 14 and the constant-velocity bisecting line Y. A radius of curvature r having a center of curvature 02 at a position offset to the side opposite to the opening end 11a of the outer race 11
_With the circular arc of ₁ , the opening side 11 of the outer race 11 in the A range
a first convex arcuate groove 15a having a groove depth deeper toward a,
The second convex arc groove 1 in the range B1 is formed by an arc having a radius of curvature r ₂ whose center of curvature 04 is between the intersection point 01 and the center of curvature 02.
This is a configuration in which a relief groove of 5d is provided.

FIG. 4 shows a second modification of the design, which is described above on the rotational axis X of the inner race 14 from the intersection 01 of the center of rotation of the inner race 14 and the constant-velocity bisecting line Y. A radius of curvature r having a center of curvature 02 at a position offset to the side opposite to the opening end 11a of the outer race 11
_With the circular arc of ₁ , the opening side 11 of the outer race 11 in the A range
a first convex arcuate groove 15a having a groove depth deeper toward a,
The curvature center 05 is located at a position where the center of curvature 05 is offset D2 from the intersection point 01 toward the opening end 11a side of the outer race 11.
The relief groove of the second convex arc groove 15e is provided in the range B2 by the arc having the radius of curvature r ₂ .

FIG. 5 shows a third design modification example, which is described above on the axis of rotation X of the inner race 14 from the intersection 01 of the center of rotation of the inner race 14 and the constant-velocity bisecting line Y. A radius of curvature r having a center of curvature 02 at a position offset to the side opposite to the opening end 11a of the outer race 11
_With the circular arc of ₁ , the opening side 11 of the outer race 11 in the A range
a first convex arcuate groove 15a having a groove depth deeper toward a,
The relief groove of the second convex arc groove 15f is provided in the range B3 where the sectional inclination angle α is formed with respect to the rotation axis X of the inner race 14.

The relief groove in the convex arc-shaped groove 15 of the inner race 14 having two different arcs of curvature according to the first to third design modifications can also obtain the same operation as that of the first embodiment. . That is, the shape of the escape groove provided in the inner race 14 can be variously applied regardless of the type of curve (including straight line), the number of curves, and the position of the center of curvature.

FIG. 6 shows a second embodiment of the present invention. While the first embodiment and its design modification are technical ideas in which the escape groove is formed on the inner race 14 side, the second embodiment is formed on the outer race 11 side. That is, FIG.
As shown by, on the rotational axis X of the outer race 11 from the intersection 01 of the rotation center of the outer race 11 and the constant velocity bisecting line Y, a position offset by D3 from the intersection 01 to the opening end 11a side of the outer race 11. Is the center of curvature 06
Curvature radius concave arcuate groove 1 that deeper groove depth toward the opening side 11a of the outer race 11 by the arc of R ₁ to
2a and the angle between the tangent line at the opening end 11a of the conventional outer race and the rotation axis X of the outer race 11 are β
Then, the cross-sectional shape is provided with the escape groove 12a which is a straight line forming an angle with the rotation axis center line X of the outer race 11 at an angle γ smaller than this angle β.

As described above, even when the escape groove 12a is provided on the opening end side of the outer race 11, the same operation as that of the first embodiment and its design modification can be obtained.

The shape of the escape groove 12a provided on the opening end side of the outer race 11 can be variously applied regardless of the type of curve (including straight line and reverse arc), the number of curves, and the position of the center of curvature. Also, the escape groove may be provided not only in one of the inner race and the outer race but also in both.

[0034]

As described above, according to the present invention, the groove depth of the inner race or the outer race becomes deeper toward the opening side of the outer race. The clearance with the groove is widened, the load applied to the ball at the opening end of the outer race is reduced, the torsional strength at the opening end of the outer race is improved, and high strength and long life as a whole can be secured.

Even if the contact point of the ball comes out of the groove of the outer race by taking the maximum joint angle, edge breakage due to stress concentration acting on the opening end of the outer race is prevented and the ball smoothly moves in the arc groove. return,
Avoid sticking the ball between the cage and the outer race.

Further, in the escape groove formed in the inner race, the amount of pushing the ball toward the groove on the outer race side is reduced, so that the ball does not come off from the cage window. As a result, the joint angle is widened, and when this maximum joint angle is taken, the balls whose contact points are disengaged from the arc groove of the outer race do not transmit rotational torque, improving fatigue strength of the cage. Further, it is possible to provide a constant velocity joint having high strength and long life as a whole.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment of a constant velocity joint according to the present invention.

FIG. 2 is an enlarged sectional view of an inner race according to the first embodiment.

FIG. 3 is an enlarged cross section of an inner race according to a first design modification example of the first embodiment.

FIG. 4 is an enlarged cross section of an inner race according to a second design modification example of the first embodiment.

FIG. 5 is an enlarged cross section of an inner race according to a third design modification example of the first embodiment.

FIG. 6 is a sectional view of an essential part showing a second embodiment of the constant velocity joint according to the present invention.

FIG. 7 is a sectional view of a conventional constant velocity joint.

FIG. 8 is an explanatory diagram of a defect in a conventional constant velocity joint.

[Explanation of symbols]

 10 Driven shaft 11 Outer race 12 Concave arc groove 12a Escape groove 13 Drive shaft 14 Inner race 15 Convex arc groove 15a First convex arc groove 15b Second convex arc groove 15c Third convex arc groove 15d Second convex arc Groove 15e Second convex arc groove 15f Second convex arc groove 16 Ball 17 Cage

Claims (4)

[Claims] 1. An outer race in which concave arc-shaped grooves, which are open at one end and extend in the axial direction on a spherical inner peripheral surface and whose groove depth becomes deeper toward the opening end side, are formed at equal angular intervals. , A convex circle provided on the outer peripheral surface and extending in the axial direction at a position corresponding to the concave arc-shaped groove of the outer race, and having a groove depth that increases toward the open end side of the outer race. An inner race having an arcuate groove formed therein, a ball rotatably interposed between the concave arcuate groove and the convex arcuate groove, and a ball rotatably interposed between the outer race and the inner race. In a constant velocity joint that is equipped with a cage that holds the ball, the groove of the ball and the outer race with respect to the one or two balls that are on the open end side of the outer race when the joint has the maximum working angle. Cleara with Scan so is greater than the clearance for other balls, the constant velocity joint, wherein a groove portion escape to the groove depth increases direction of the shallow groove of the inner race is formed on the inner race. 2. The constant velocity joint according to claim 1, wherein the relief groove portion is formed at an end portion of a first convex arcuate groove that is the convex arcuate groove of the inner race, and an open end of the outer race. Is a third convex arc groove in which the second convex arc groove whose groove depth is increased toward the opposite side, and the first convex arc groove and the second convex arc groove are joined by an arc smaller than these two groove arcs. A constant velocity joint characterized by being formed with. 3. The constant velocity joint according to claim 1, wherein the convex arcuate groove of the inner race is a rotation of the inner race which is an intersection of a rotation axis of the inner race and a constant velocity bisector. On the rotational axis of the inner race from the center, it is formed by a first convex arc groove formed of an arc having a radius of curvature r ₁ whose center of curvature is offset to the side opposite to the opening end of the outer race, and the escape groove portion is formed. The curvature center is formed on the rotation axis of the inner race formed at the end of the first arc groove, and the curvature center is located between the rotation center of the inner race and the curvature center of the first convex arc groove. A constant velocity joint characterized by being formed by a second convex arc groove whose groove depth is deepened toward the side opposite to the opening end of the outer race by an arc having a radius of curvature r ₂ larger than the radius of curvature r _{1 of the} convex arc groove. . 4. An outer race in which concave arc-shaped grooves, each having an opening at one end and extending in the axial direction on a spherical inner peripheral surface and having a groove depth increasing toward the opening end side, are formed at equal angular intervals. , A convex circle provided on the outer peripheral surface and extending in the axial direction at a position corresponding to the concave arc-shaped groove of the outer race, and having a groove depth that increases toward the open end side of the outer race. An inner race having an arcuate groove formed therein, a ball rotatably interposed between the concave arcuate groove and the convex arcuate groove, and a ball rotatably interposed between the outer race and the inner race. In a constant velocity joint that is equipped with a cage that holds the ball, the groove of the ball and the outer race with respect to the one or two balls that are on the open end side of the outer race when the joint has the maximum working angle. Cleara with Scan so is greater than the clearance for other balls, the constant velocity joint, characterized in that a groove escape in the direction of the groove depth of the opening end side deep grooves of the outer race is more deeply formed in the outer race.