JPH0478323A - Sliding type constant velocity joint - Google Patents

Abstract

PURPOSE:To reduce frictional resistance at the time of sliding by forming a joint so that the direction of the driving force working to balls with a joint angle at 0 is not inclined against a flat surface formed with centers of multiple balls, and eliminating component of a force for extruding the balls to the axial direction. CONSTITUTION:In the case that a first and a second axes 20, 24 are on one line, a first and a second ball channels 33, 37 are inclined and extended along a virtual surface S including centers C of balls 20 and axes thereof. In this case, the described ball channels 33, 37 are inclined reversely in point symmetry against the centers C of the balls 28, and since the described ball channels 33, 37 cross each other, the balls 28 are positioned at a cross part of both the ball channels 33, 37. Under this condition, the direction of the driving force working to the balls 28 is not inclined against the flat surface formed with centers of six balls 28. Generation of the force of extruding the balls 28 to the axial direction is therefore eliminated, and the force for pressing the balls 28 against a cage 30 is reduced by that quantity, and sliding resistance at the time of sliding is reduced to reduce the vibration and the noise.

Description

Detailed Description of the Invention (Field of Application of A Rakudo) The present invention relates to a sliding constant velocity joint, and in particular to a drive shaft for a vehicle that ensures constant velocity by the inclination of two ball grooves located with balls sandwiched between them. Concerning constant velocity joints suitable for incorporation into propeller shafts and propeller shafts.

(Prior Art) An outer ring having a plurality of ball grooves on an inner peripheral surface, an inner ring inserted into the outer ring and having the same number of ball grooves as the ball grooves on the outer peripheral surface, and each ball groove of the outer ring and the inner ring. and a cage that holds these balls, and includes the ball grooves of the outer ring and the ball groove of the inner ring, the axes of the outer ring and the inner ring, and the center of the balls. There is a constant velocity joint called a Lebro type which is formed so as to intersect each other at equal angles to a virtual plane (for example, Japanese Patent Laid-Open No. 31724/1983).

The constant velocity joint ensures constant velocity by intersecting the ball groove of the outer ring and the ball groove of the inner ring, and
It allows for axial movement, or sliding.

(Problem to be solved by the invention) In the above-mentioned constant velocity joint, when focusing on one ball and the groove in which it is held, 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, when a driving force F is applied from the outer ring connected to the drive shaft 12, the ball 13 and the ball groove 1
The driving force is transmitted from the point of contact with the ball 13 toward the center of the ball 13, and since the centers of the plurality of balls are tilted with respect to the formation plane, the drive shaft 12 is transmitted from the ball groove 10 to the ball 13. Vector component force F1 directed in the axial direction, or similarly vector component force F2 from two balls 11 to ball 13
As a result of this action, the ball 13 is pressed toward the window 15 of the cage 14 by a force f (-lF+Fy I), the absolute value of the difference between the two vector force components. In this case, an opposite force acts on the adjacent ball.

Therefore, when the driving shaft 12 and the driven shaft 16 do not form an angle, that is, when there is no joint angle, when the joint receiving the driving force moves forward in the axial direction, the ball 13 is pressed against the window 15 of the cage. Due to the rotation, a large sliding resistance is generated between the t'-rule 13 and the window 15, reducing the sliding property.

As shown in Figure 6, when the drive 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, or the center of the plurality of poles. , the hector component of the driving force F1. As a result of F2 becoming even larger, the absolute value of the difference between the two hector component forces becomes fl, and the above-mentioned tendency becomes even more remarkable. In this case, the vector components F, .

Therefore, an object of the present invention is to provide a sliding constant velocity joint that can reduce the frictional resistance caused by the heel during sliding.

(Means for Solving Problem B) The sliding constant velocity joint according to the present invention includes a first yoke member connected to a first shaft, and a plurality of first yoke members arranged at equal intervals in the circumferential direction. a first yoke member having a first ball groove on both sides in the circumferential direction of each yoke, and a second yoke member connected to a second shaft and having first ball grooves on both sides of each yoke in the circumferential direction. The number of yokes is the same as the number of yokes arranged at intervals, each yoke having a second ball groove on both sides in the circumferential direction, and between two adjacent yokes of the first yoke member. a second yoke member disposed in the tea confectionery 1, a ball disposed in a space defined by a ball groove of the tea confectionery 1 and a ball groove of the confectionery tea cake 2, and a cage for holding these balls; 1 and the ball groove of the tea confectionery 2 are the center of the ball disposed between the first ball groove and the second ball groove,
It extends obliquely along a virtual plane including the first axis and the axes of the second axis when these axes are located on a straight line, and the slope of the ball groove of the tea confection 1 and the confection 2 The inclinations of the ball grooves are opposite in direction and are point symmetrical with respect to the center of the ball between the first ball groove and the second ball groove.

(Operation and Effect) When the joint angle is zero, that is, when the first axis and the second axis are located on a straight line, the first ball grooves on both sides of the ball in the circumferential direction with the ball in between Since the ball groove and the second ball groove intersect with each other, the ball is located at the intersection of both ball grooves. In this state, the driving force acting on the ball from the point of contact 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 the plane coincides with the direction of the driving force. Since no force is generated to push it in the axial direction of the first shaft, even if it slides, the resistance is small. The driving force is transmitted, for example, from the first ball groove of the yoke of the first yoke member, through the ball, to the second ball groove of the yoke of the second yoke member, in substantially the same pitch circle direction. Ru.

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 tilted with respect to the plane formed by the multiple ball centers, so the driving force A vector component of the 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 respective axes of the two shafts, and uniform velocity is ensured.

When the first and second shafts have a joint angle, a force is generated that tries to push the ball out of the ball groove, but this force does not occur at all when the joint angle is zero. Therefore, the overall size is small. In this way, the force pressing the ball against the cage is reduced, which reduces the sliding resistance and reduces vibration and noise.

By reducing the frictional force between the cage and the balls, heat generation can be suppressed, so it can be effectively used as a constant velocity joint for high-speed rotating shafts.

Since the transmission of driving force is carried out on essentially the same pitch circle, such as the first ball groove, the ball, and the second ball groove, the area of the torque transmission surface can be increased within a limited space. I can do something.

(Example) As shown in FIGS. 1 and 2, the sliding constant velocity joint includes a first yoke member 22 connected to a first shaft 20, and a second yoke member 22 connected to a first shaft 20. It includes a second yoke member 26 connected to b24, a ball 28, and a cage 30.

The first yoke member 22, as shown in detail in FIG.
A plurality of yokes 32 arranged at equal intervals in the circumferential direction
has. In the illustrated embodiment, three yokes 32 are provided, and each yoke 32 is provided with a first ball groove 33 on both sides in the circumferential direction.

The ball groove 33 is a cylindrical groove whose center is on a pitch circle P of a constant diameter around the axis O of the shaft 20, and is formed so that its center axis is inclined, as will be described later. The three yokes 32 are supported by an end plate 34 in a cantilevered manner, and the shaft 20 extends from the end plate 34 in a direction opposite to the yokes 32.

The second yoke member 26 has the same number of yokes 36 as the yokes 32 arranged at equal intervals in the circumferential direction. In the illustrated embodiment, three yokes 36 are provided. Each yoke 36 is provided with second ball grooves 37 on both sides in the circumferential direction, and is disposed between two adjacent yokes 32 of the first yoke member 22. The ball 7137 is connected to the shaft 24
There is a cylindrical groove whose center is on the pitch circle P of a constant diameter around the axis 0 when the axis 30 and the axis 24 are located on a straight line, and as described later, the central axis is inclined. It is formed like this. The three yokes 36 are cantilevered by the end plate 28, and the shaft 24 extends from the end plate 38 in a direction opposite to the yokes 36.

The configuration of the second yoke member 26 is substantially the same as the configuration of the first yoke member 22. Therefore, by using the same yoke member, it is possible to implement the constant velocity joint according to the present invention. However, in the illustrated embodiment,
A cylindrical casing 40 extends from the end plate 38 and substantially covers the yoke 32 of the first yoke member 22. This is based on the convenience of encapsulating the grease. That is, the casing 40 is provided integrally with the end plate 38, and a boot (not shown) is passed between the casing 40 and the shaft 20, thereby enclosing the grease.

The ball 28 is arranged in a space defined by each Ml ball groove 33 of the yoke 32 and the eight second ball grooves 37 of the yoke 36. In the illustrated embodiment, a total of six balls 28 are provided. The ball 28 has a radius centered on the pitch circle P and touches two ball grooves 33, 37.

A cage 30 holds these balls 28.

In the illustrated embodiment, the cage 30 includes a cylindrical central holding part 42, an end holding part 43 extending radially from one end of the central holding part 42, and an end extending radially from the other end of the central holding part 42. A holding part 44 is provided. Ball 28 is rotatable relative to each holding portion. The six balls 28 are always positioned in the same plane by the cage 30.

The ball groove 33 of the famous confectionery 1 of the yoke 32 and the ball groove 37 of the famous confectionery 2 of the yoke 36 are connected to the center C of the ball 28 disposed between the first ball groove 33 and the second ball groove 37. , extends obliquely along a virtual plane S that includes the axis 0 of the first axis 20 and the second axis 24 when they are located on a straight line. In this case, the slopes of all the ball grooves 33 of the first yoke member 22 are in the same direction,
The slopes of all the ball grooves 37 of the second yoke member 26 are in the same direction. The inclination of the ball groove 33 of the famous confectionery 1 and the inclination of the ball groove 37 of the famous confectionery 2 are point symmetrical and opposite directions with respect to the center C of the ball 28. As shown in Figure 2, the slope of the ball groove in the yoke of each yoke member is not only tapered from the end plate to the free end of the yoke, but also widened from the end plate to the free end of the yoke. It may be something like that.

As shown in FIG. 4, when the joint angle is zero, the first ball groove 33 and the second ball groove 37 on both sides of the ball 28 in the circumferential direction intersect with each other. Therefore, the ball 28 is located at the intersection of the two balls.

In this state, the direction of the driving force acting on the ball center from the contact point between the ball 28 and each ball groove 33, 37 is not inclined with respect to the plane formed by the six ball centers, so the fifth
As shown in Figure a, 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 33 of the yoke 32 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 have a joint angle (Fig. 5b), there are six directions of driving force acting on the center of the ball from the contact point between the ball and each ball groove during sliding. Since the ball is tilted with respect to the plane formed by the center of the ball, a vector component of the driving force is generated, and a force f2 is applied to push the ball from the ball groove to the ball 28.

The reaction force of this force is received by the cage 30 and the position of the ball 28 is fixed. Thereby, the torque transmission surface of the constant velocity joint is fixed on the bisecting plane of the respective axes of the two shafts 20, 24, and uniform velocity is ensured.

In the Revlo type constant velocity joint, as shown in FIG.
Since the outer ring 17 is located with a gap in the radial direction from the outer ring 17, the driving force is transferred from the outer ring 17 to the ball 13 at the point of contact as indicated by F'. This driving force F' and moment arm r'
Because it is necessary to transmit the driving torque T by
F' = (r/r')F, and the force applied to the contact point between the outer ring and the ball increased, resulting in 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 the sliding constant velocity joint according to the present invention, Fig. 2 is a sectional view taken along line 2-2 in Fig. 1, and Fig. 3. is a perspective view of the yoke member, FIG. 4 is a partial sectional view similar to FIG. 2 showing the action, and FIGS. 5 a and b are schematic plan views showing the action of the constant velocity joint according to the present invention. Figures 6a and 6b are schematic diagrams in plan view showing the action of the Revlot type constant velocity joint, and Fig. 7 is a schematic diagram in front view showing the action of the Revlot type constant velocity joint. 20. 24・Shaft, 22, Yoke member, Ball: Cage, 32, Yoke, 33, Ball full.

Claims (1)

[Claims] A first yoke member connected to a first shaft, having a plurality of yokes arranged at equal intervals in the circumferential direction, each yoke having a first ball groove on both sides in the circumferential direction. Prepare first
and a second yoke member connected to the second shaft, the number of yokes being equal to the number of yokes arranged at equal intervals in the circumferential direction, each yoke having a circular shape. a second yoke member having second ball grooves on both sides in the circumferential direction and disposed between two adjacent yokes of the first yoke member; a ball disposed in a space defined by a ball groove, and a cage that holds these balls; each of the first ball groove and each of the second ball groove is defined by the first ball groove; along a virtual plane that includes the center of the ball disposed between the ball groove and the second 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 second ball grooves are such that the center of the ball between the first ball groove and the second ball groove extends. A sliding constant velocity joint that is symmetrical with respect to the opposite direction.