JPH04285319A - Slide type uniform velocity joint - Google Patents

Abstract

PURPOSE:To reduce friction resistance caused by slippage during sliding to make the rational design of a joint possible. CONSTITUTION:The first yoke member 22 has three yokes 34, and each of the yokes is provided with the first and the second ball groove 35, 36 on both its sides. The second yoke member 26 has three yokes 38, and each of the yokes is provided with the third and the fourth ball groove 39, 40 on both its sides. The first ball 28 is arranged between the ball grooves 35, 40, and the second ball 30 being smaller in diameter than the first ball is arranged between the ball grooves 36, 39. The two ball grooves positioned on both the sides of the ball incline in the form of point symmetry about the center of the ball.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a sliding constant velocity joint, and in particular to a sliding constant velocity joint that ensures constant velocity by the inclination of two ball grooves located between balls, and is particularly suitable for being incorporated into a drive shaft or propeller shaft of a vehicle. Concerning suitable constant velocity joints.

0002

BACKGROUND ART An outer ring having a plurality of ball grooves on its inner peripheral surface, an inner ring inserted into the outer ring and having the same number of ball grooves as the ball grooves on its outer peripheral surface, and each ball groove of the outer ring and the inner ring. and a cage that holds these balls, and the ball grooves of the outer ring and the ball groove of the inner ring are arranged so that the axes of the outer ring and the inner ring are aligned with the center of the ball. There is a constant velocity joint called the Rebro type, which is formed so as to intersect each other at equal angles with respect to the included virtual planes (for example, JP-A-62-317
Publication No. 24).

[0003] In the constant velocity joint, when focusing on one ball and the groove in which it is sandwiched, in a state where the joint angle is not taken, as shown in FIG. 6a, the ball groove 10 of the outer ring
and the ball groove 11 of the inner ring intersect so as to form a V-shape in plan view. Therefore, for example, drive shaft 1
When a driving force F is applied from the outer ring connected to the outer ring 2, the driving force is transmitted from the contact point between the ball 13 and the ball groove 10 toward the center of the ball 13, and its direction is tilted with respect to the plane formed by the centers of the plurality of balls. Therefore, from ball groove 10

[Outside 1] Pushed towards 15. In this case, an opposite force acts on the adjacent ball.

Therefore, when the driving shaft 12 and the driven shaft 16 make no angle, that is, when there is no joint angle, when the joint receiving the driving force slides in the axial direction, the ball 13 moves into the window of the cage. Since the ball 13 rotates while being pressed against the window 15, a large sliding resistance is generated between the ball 13 and the window 15, reducing sliding performance.

As shown in FIG. 6b, when the driving shaft 12 and the driven shaft 16 form a joint angle, the driving force acting on the ball from the contact point between the ball and the ball groove is
As the ball becomes more inclined with respect to the plane formed by the centers of the balls, the driving force vector

[Outside 2] The sliding resistance will be greater than in the normal state.

In view of the above, a sliding constant velocity joint capable of reducing the sliding resistance during sliding has been separately proposed (Japanese Patent Application No. 2-190773). This sliding constant velocity joint is a first yoke member connected to a first shaft, and has a plurality of yokes arranged at equal intervals in the circumferential direction, and each yoke has a plurality of yokes arranged at equal intervals in the circumferential direction. a first yoke member having first ball grooves on both sides; and a second yoke member connected to the second shaft, the number of yokes being arranged at equal intervals in the circumferential direction; a second yoke member having the same number of yokes, each yoke having a second ball groove on both sides in the circumferential direction, and disposed between two adjacent yokes of the first yoke member; a cage for holding these balls; and a cage for holding these balls; A ball groove is defined as a ball groove when the center of the ball disposed between the first ball groove and the second ball groove is located in a straight line with the first axis and the second axis. The inclination of each of the first ball grooves and the inclination of each of the second ball grooves are different between the first ball groove and the second ball groove. The direction between the ball groove and the ball groove is symmetrical with respect to the center of the ball.

[0007]

[Problems to be Solved by the Invention] In the slide type constant velocity joint according to the above proposal, torque transmission is limited due to its structure.
It is handled by half of the balls. In other words, half of the balls are used for torque transmission during normal rotation,
This is different from half the balls used for torque transmission during reversal, but all balls are the same size. Therefore, while half of the balls are responsible for transmitting torque during forward rotation, which is primarily required in a vehicle, the remaining half of the balls, responsible for transmitting torque during reverse rotation, have considerable leeway in terms of strength, lifespan, and capacity. . If you look at it from another perspective, this is an irrational design.

[0008] Accordingly, an object of the present invention is to provide a sliding constant velocity joint that can reduce the frictional resistance caused by sliding during sliding and that enables rational design.

[0009]

[Means for Solving the Problems] A sliding constant velocity joint according to the present invention includes a first yoke member connected to a first shaft, and a plurality of yoke members arranged at equal intervals in the circumferential direction. A first yoke member having a yoke, each yoke having a first ball groove and a second ball groove on both sides in the circumferential direction; and a second yoke member connected to the second shaft. The number of yokes is the same as the number of yokes arranged at equal intervals in the circumferential direction, and each yoke is arranged between two adjacent yokes of the first yoke member, and A second yoke member having a third ball groove facing the second ball groove and a fourth ball groove facing the first ball groove on both sides. A first ball is disposed in a space defined by each of the first ball grooves and each of the fourth ball grooves, and is defined by each of the second ball grooves and each of the third ball grooves. In the space where
A second ball having a smaller diameter than the first ball is arranged. The first ball and the second ball are held by a cage. Each of the first ball grooves and each of the fourth ball grooves is defined by a center of the first ball disposed between the first ball groove and the fourth ball groove, and a center of the first ball disposed between the first ball groove and the fourth ball groove. and the axes of these axes when the second axes are located in a straight line;
The inclinations of the ball grooves are opposite in direction and are point symmetrical with respect to the center of the first ball between the first ball groove and the fourth ball groove. The second ball groove and the third ball groove each have a center of the second ball disposed between the second ball groove and the third ball groove, and a center of the second ball disposed between the second ball groove and the third ball groove. The first axis and the second axis extend in an inclined manner along an imaginary plane including the axes of these axes when they are located in a straight line, and the inclination of each of the second ball grooves and the axis of each of the second axis and The inclinations of the ball grooves in No. 3 are opposite in direction and are point symmetrical with respect to the center of the second ball between the second ball groove and the third ball groove.

0010

[Operation and Effect] Assuming that the vehicle moves forward by rotation in the normal direction, the yokes of the first yoke member and the second yoke member are connected so that the first ball takes charge of torque transmission during normal rotation. Set. As a result, torque is transmitted by the first ball during normal rotation and by the second ball during reverse rotation.

When the joint angle is zero, that is, the first
When the axis of and the second axis are located in a straight line, the first ball groove and the fourth ball groove on both sides of the first ball in the circumferential direction intersect with each other, Further, since the second ball groove and the third ball groove on both sides of the second ball in the circumferential direction intersect with each other, the ball is located at the intersection of the opposing ball grooves. In this state, the driving force acting on the ball from the contact point between the ball and each ball groove is not inclined with respect to the plane formed by the centers of the plurality of balls, and therefore, since the plane coincides with the direction of the driving force, the ball No force is generated that tries to push out in the axial direction of the first shaft. Therefore, even if it slides, the resistance is small.

[0012] When the first axis and the second axis form a joint angle, the driving force acting on the ball center from the contact point between the ball and each ball groove is inclined with respect to the plane formed by the plurality of ball centers. Therefore, a vector component of the driving force is generated, and a force that tries to push the ball out of the ball groove acts on the ball. The reaction force of this force is received by the cage and the position of the ball is fixed. As a result, the torque transmission surface of the constant velocity joint is fixed on the bisecting plane of the axes of the two shafts, ensuring constant velocity.

[0013] When the first axis and the second axis form a joint angle, a force is generated that tries to push the ball from the ball groove, but this force is completely absent when the joint angle is zero. Since it does not occur, the overall value is small accordingly. In this way, the force that presses the ball against the cage is reduced, and as a result, the sliding resistance during sliding is reduced, and vibration and noise can be reduced.

[0014] Since the frictional force between the cage and the balls can be reduced, heat generation can be suppressed, so that it can be effectively used as a constant velocity joint for a high-speed rotating shaft.

[0015] The transmission of the driving force is substantially the same, such as the first ball groove, the first ball and the fourth ball groove, or the second ball groove, the second ball and the third ball groove. Since this is done on the pitch circle of , the area of the torque transmission surface can be increased within a limited space.

[0016] Since the diameter of the second ball is smaller than the diameter of the first ball, in other words, the diameter of the first ball is larger than the diameter of the second ball, the diameter of the second ball is If the size is set to the required size for strength, the diameter of the first ball, which is used to transmit torque during normal rotation, which is mainly required for the vehicle, will be large, and the strength and life capacity can be increased in the same space. . In this way, a rational design that increases the joint capacity only during forward rotation is possible in the same space as the one related to the previous proposal.

[0017]

[Embodiment] As shown in FIGS. 1 and 2, a sliding constant velocity joint includes a first yoke member 22 connected to a first shaft 20, and a second yoke member connected to a second shaft 24. It includes a yoke member 26, a first ball 28, a second ball 30, and a cage 32.

The first yoke member 22 has a plurality of yokes 34 arranged at equal intervals in the circumferential direction, as shown in detail in FIG. In the embodiment shown there are three yokes 3
4, and each yoke 34 is provided with a first ball groove 35 and a second ball groove 36 on both sides in the circumferential direction. Each ball groove is a cylindrical groove centered on a pitch circle P around the axis O of the shaft 20, and is formed so that its center axis L is inclined, as will be described later. three yokes 3
4 is supported in a cantilevered manner by a support portion 37, and the shaft 20 extends from the support portion 37 in a direction opposite to the yoke 34. The number of yokes 34 may also be four, five, etc.

The second yoke member 26 has the same number of yokes 38 as the yokes 34, which are arranged at equal intervals in the circumferential direction. In the illustrated embodiment, three yokes 38
is provided. Each yoke 38 is arranged between two adjacent yokes 34 of the first yoke member 22, and has a third ball groove 39 and a fourth ball groove 40 on both sides in the circumferential direction.
Equipped with. The third ball groove 39 is connected to the second ball groove 36 of the yoke 34, and the fourth ball groove 40 is connected to the second ball groove 36 of the yoke 34.
The first ball groove 35 faces the first ball groove 35 . Each ball groove is connected to shaft 2
It is a cylindrical groove whose center is on the pitch circle P around the axis O when the shafts 20 and 24 are located in a straight line, and as described later, the center axis is inclined. is formed. The three yokes 38 are the support parts 41
The shaft 24 extends from the support portion 41 in a direction opposite to the yoke 38 .

The configuration of the second yoke member 26 is substantially the same as that of the first yoke member 22. Therefore, by using the same yoke member, the constant velocity joint according to the present invention can be implemented. An end plate 42 is caulked to the support portion of each yoke member, and a boot 44 is passed from one end plate 42 to the other end plate 42.

The first ball 28 is connected to each first ball of the yoke 34.
and each fourth ball groove 40 of the yoke 38.
is placed in a space defined by In the illustrated embodiment, a total of three balls 28 are provided. The ball 28 has a radius centered on the pitch circle P, and is in contact with the two ball grooves 35 and 40.

The second ball 30 has a smaller diameter than the first ball 28 and is located within a space defined by each second ball groove 36 of the yoke 34 and each third ball groove 39 of the yoke 38. will be placed in In the illustrated embodiment, a total of three balls 30 are provided, these balls 30 being ball 28
located alternately. The ball 30 has a radius centered on the pitch circle P and touches two ball grooves 36 and 39.

A cage 32 holds these balls 28,30. In the illustrated embodiment, the cage 32 includes a cylindrical central holding portion 46 and a ball 2 extending from both ends of the central holding portion 42.
8, and a pair of end holders 48 extending radially from both ends of the center holder 46, corresponding to each ball 30. The distance between the pair of end holders 47 is such that the ball 28 can be accommodated in a motion fit, and the distance between the pair of end holders 48 is large enough to accommodate the ball 30 in a motion fit. The ball 30 is also rotatable relative to the pair of end holders 48. The three balls 28 and the three balls 30 are always positioned in the same plane by the cage 32.

Each first ball groove 35 of the yoke 34 and each fourth ball groove 40 of the yoke 38 are defined as the first ball groove 35 of the yoke 34 and the fourth ball groove 40 of the yoke 38. 1 and the axis O of the first shaft 20 and the second shaft 24 when they are located in a straight line. In this case, all the ball grooves 3 of the first yoke member 22
5 are in the same direction, and the inclinations of all ball grooves 40 of the second yoke member 26 are in the same direction. and,
The slope of each first ball groove 35 and each fourth ball groove 4
An inclination of 0 is an opposite direction that is point symmetrical with respect to the center C1 of the ball 28. As shown in Fig. 2, the slope of the ball groove of the yoke of each yoke member is not only downward from the bearing part to the free end of the yoke, but also upward from the bearing part to the free end of the yoke. Something like this is fine.

Each of the second ball grooves 36 of the yoke 34 and each of the third ball grooves 39 of the yoke 38 are defined as the second ball grooves 36 of the yoke 34 and the third ball grooves 39 of the yoke 38. 2 and the axis O of the first axis 20 and the second axis 24 when they are located in a straight line. In this case, the inclinations of all the second ball grooves 36 of the first yoke member 22 are in the same direction, and the inclinations of the first ball grooves 35 are also in the same direction. Moreover, the inclinations of all the third ball grooves 39 of the second yoke member 26 are in the same direction, and the inclinations of the fourth ball grooves 40 are also in the same direction. The inclinations of each of the second ball grooves 36 and the inclinations of each third ball groove 39 are point symmetrical and opposite to each other with respect to the center C2 of the ball 30.

When the sliding constant velocity joint rotates forward in the direction of arrow A in FIGS. 1 and 2, the three balls 28 transmit torque in the forward direction, and when the sliding constant velocity joint rotates in the opposite direction to the arrow, three It is assumed that two balls 30 transmit torque in the backward direction. The action during forward rotation in this case will be described below. The action at the time of reversal is to change the ball 28 to the ball 30.
In addition, the two ball grooves 35 and 40 are connected to the two ball grooves 3.
This is the same as replacing numbers 6 and 39.

As shown in FIG. 4, when the joint angle is zero, the first ball groove 35 and the fourth ball groove 40 on both sides of the ball 28 in the circumferential direction intersect with each other. Therefore, the ball 28 is in both ball grooves 35.
, 40. In this state, ball 28
Since the direction of the driving force acting on the center of the ball from the point of contact with each of the ball grooves 35 and 40 is not inclined with respect to the plane formed by the centers of the three balls 28, as shown in FIG. 5a,
No force is generated to push the ball 28 in the axial direction of the shaft. In this case, the driving force F is transmitted, for example, from the first ball groove 35 of the yoke 34 of the first yoke member 22 in the tangential direction of the pitch circle P.

When the first shaft 20 and the second shaft 24 form a joint angle (FIG. 5b), the ball 28 during sliding
Since the direction of the driving force acting on the ball center from the contact point with each ball groove 35, 40 is inclined with respect to the plane formed by the three ball centers, a vector component of the driving force is generated, and the ball groove A force f2 that tries to push the ball acts on the ball 28 from 35 and 40. The reaction force of this force is received by the cage 32 and the position of the ball 28 is fixed. As a result, the torque transmission surfaces of the constant velocity joint are divided into two axes 20,
24 are fixed on the bisecting plane of each axis to ensure constant velocity.

In the Revlo type constant velocity joint, as shown in FIG. 7, if the driving force F acts on the pitch circle of the ball 13, the driving torque T is Fr, but in reality,
is located with a gap in the radial direction from the inner ring 18, so the driving force acts as F' from the outer ring 17 to the ball 13 at its contact point. Since it is necessary to transmit the driving torque T by this driving force F' and moment arm r',
In the end, F'=(r/r')F, and the force applied to the contact point between the outer ring and the ball increased, resulting in a severe surface pressure. In contrast, in the present invention, since the driving force acts substantially on the pitch circle of the ball, the surface pressure can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a sectional view taken along a plane perpendicular to the axis of a sliding constant velocity joint according to the present invention.

FIG. 2 is a cross-sectional view taken along line 2-2 in FIG. 1;

FIG. 3 is a perspective view of a yoke member.

FIG. 4 shows a part in a sectional view similar to FIG. 2 showing the operation.

FIG. 5 is a schematic plan view showing the operation of the sliding constant velocity joint according to the present invention, where a shows a state where the joint angle is not set, and b shows a state where the joint angle is set.

FIG. 6 is a schematic plan view showing the action of the Rebro type constant velocity joint, where a shows a state where the joint angle is not set, and b shows a state where the joint angle is set.

FIG. 7 is a schematic front view showing the action of the Rebro type constant velocity joint.

[Explanation of symbols]

20, 24 axis 22, 26 Yoke member 28, 30 ball 32 Cage 34, 38 York 35, 36, 39, 40 Ball groove

Claims (1)

[Claims] Claims: 1. A first yoke member connected to a first shaft, comprising a plurality of yokes arranged at equal intervals in the circumferential direction, each yoke having a plurality of yokes on both sides in the circumferential direction. a first yoke member having a first ball groove and a second ball groove; and a second yoke member connected to the second shaft, the yoke being arranged at equal intervals in the circumferential direction. a third ball having the same number of yokes as the number of balls, each yoke being arranged between two adjacent yokes of the first yoke member, and facing the second ball groove on both sides in the circumferential direction; a second yoke member having a groove and a fourth ball groove facing the first ball groove; and a second yoke member disposed within a space defined by each of the first ball grooves and each of the fourth ball grooves. a first ball, each second ball groove, and each third ball groove;
disposed within a space defined by a ball groove;
The first ball groove includes a second ball having a smaller diameter than the first ball, and a cage that holds the balls, and each of the first ball groove and the fourth ball groove are connected to the first ball groove and the second ball groove. A virtual plane including the center of the first ball disposed between the fourth ball groove and the axes of the first axis and the second axis when these axes are located in a straight line. The slope of each of the first ball grooves and the slope of each of the fourth ball grooves extend along the first ball groove between the first ball groove and the fourth ball groove. are oppositely oriented in point symmetry with respect to the center of the ball, and each of the second ball groove and each of the third ball groove is between the second ball groove and the third ball groove. and extends obliquely along an imaginary plane that includes the center of the second ball arranged in , the slope of each second ball groove and the slope of each third ball groove are at a point with respect to the center of the second ball between the second ball groove and the third ball groove. A sliding constant velocity joint with symmetrical and opposite directions.