JPH10122254A - Equal speed universal joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve a miniaturization and prevent the unstable behavior of an inner race by providing a pressurization giving means for push-pressing a button member to the inner race side in the outer diameter side of the button member. SOLUTION: The outside surface 5a of a wedge member 5 is taper fitted with the flat surface 1a of an outer race 1 and an inside surface 5b is face contacted with the outside surface 3a of a button member 3. A wedge is formed by the flat surface 1a of the outer race 1, the outside surface 3a of the button member 3 and a wedge member 5 in the outer diameter side of the button member 3 as the pressurization giving means of an axial direction. The wedge member 5 is push-pressed elastically in one side of the axial direction by the elastic force of a coil spring 6 stored in the recessed part 5c of the wedge member 5. Thereby, a miniaturization is carried out easily and a stable operation property can be ensured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a constant velocity universal joint used for power transmission in automobiles and various industrial machines, and more particularly, to a joint suitable for a steering device of an automobile or the like.

[0002]

2. Description of the Related Art In general, a constant velocity universal joint used for a steering device for controlling a traveling direction of an automobile has a large operating angle and a small rotational backlash (circular backlash). , Small size and light weight, and low cost are required.

[0003] The applicant of the present invention has the above-mentioned characteristics,
In particular, a constant velocity universal joint shown in FIGS. 7 (a) and 7 (b) has been developed as a constant velocity universal joint suitable for a steering device, and a patent application has been filed (see Japanese Patent Application No. 7-339378).

This joint has an outer ring (1) having a regular hexagonal hollow hole surrounded by six flat surfaces (1a) parallel to the axis XX, and is incorporated in the hollow hole of the outer ring (1). The inner ring (2) and the 6 interposed between the inner ring (2) and the outer ring (1)
The main elements are two block-shaped button members (3) and a shaft part (4) incorporated in the inner diameter part of the inner ring (2).

[0005] The inner ring (2) is divided at three places in the circumferential direction, and a pair of spherical outer wall surfaces (2a) are provided on the outer diameter surface of each divided body (each surface is provided with a pair). Are numbered 2a1, 2a2,..., 2a6 in the clockwise direction). A pair of spherical outer wall surfaces (2a1, 2a2) (2a3, 2a4) (2a5
2a6) each have a convex curved surface curved in opposite directions, and each of the two button members (3) is adjacent to each other.
It can contact with the inner wall surface (3b).

More specifically, the spherical outer wall surfaces (2a1) (2a
4) is drawn as a spherical surface having a radius r whose center is the intersection point (O ₁ ) of the PCD (the center at which the load is applied: depends on the load conditions using the joint) and the diagonal line (A1) of the hollow hole,
The spherical outer wall surfaces (2a3) and (2a6) are drawn as spheres having a radius r and centered on the intersection (O ₂ ) of the PCD and the diagonal line (A2) of the hollow hole, and the spherical outer wall surfaces (2a2) and (2a5) ) Is PCD
It is drawn as a sphere having a radius r with the center of the sphere at the intersection (O ₃ ) between the sphere and the diagonal line (A3) of the hollow hole. Three spherical centers (O ₁ )
(O ₂ ) and (O ₃ ) are located at equal circumferential positions on the PCD. As described above, since the spherical center of each spherical outer wall surface (2a) is offset by a predetermined amount in the predetermined direction from the joint center (O), the three spherical outer surfaces at the circumferentially equidistant positions are provided. The wall surfaces (2a1), (2a3), and (2a5) are deflected in the counterclockwise direction in FIG. 7A, and the remaining three spherical outer wall surfaces (2a2), (2a4), and (2a6) are arranged at equal circumferential positions. Each have a shape deflected rightward in FIG. The direction of the deflection is in a reciprocal relationship between a pair of spherical outer wall surfaces (2a1, 2a2), (2a3, 2a4), and (2a5, 2a6) adjacent in the circumferential direction.

An axial wedge is formed between the inner wall surface (2b) of the inner ring (2) and the outer wall surface (4b) of the shaft (4). Specifically, an axial wedge is formed by taper fitting the tapered inner wall surface (2b) of the inner ring (2) and the tapered outer wall surface (4b) of the shaft portion (4). One end is housed in the recess (4e) of the shaft (4), and the inner ring (2) and the shaft ( 4) are elastically pressed against each other in the direction of action of the wedge (opposite side of the axial direction). As a result, the inner ring (2) is pressed by the shaft portion (4) toward the outer diameter side, that is, toward the flat surface (1a) of the outer ring (1). As a result, the inner ring (2) is pressed against the spherical outer wall surface (2a) of the inner ring (2). The gap between the inner surface (3b) of the button member (3) and the outer surface (3a) of the button member (3) and the flat surface (1a) of the outer ring (1) are reduced, so that the entire joint is formed. Backlash can be reduced by reducing backlash in the circumferential direction.

[0008]

However, in the constant velocity universal joint shown in FIG. 7, the behavior of the inner ring (2) becomes unstable when the operating angle is large, regardless of whether the operating angle is small. It is expected that. That is, as shown in FIG. 8, when the shaft portion (4) is rotated at an operating angle (θ), a pressing force (joint load) P acts on the inner ring (2) from the button member (3). However, at this time, since the axial component (P _X ) of the pressing force (P) acts in the opposite direction between the upper inner ring (2) and the lower inner ring (2), the inner ring, Axial load (P _X ), especially in the direction of wedge loosening
The lower inner ring (2) that is subjected to this may move axially, which may have an undesired effect on the operability of the joint. To solve such a problem, the elastic force of the coil spring (6) may be increased. However, this may deteriorate the incorporation and operability.

Further, since the inner ring (2) is pressed against the outer ring (button member) side by a wedge to prevent the rattling, the inner ring must be divided in the circumferential direction. for that reason,
In consideration of the strength and the like of each inner ring divided body, it is more difficult to reduce the size of the inner ring as compared with an inner ring having an integral structure.

Also, the PCD of the inner ring and the center of the spherical surface may change due to differences in dimensional accuracy, wear progress speed, etc. of each of the divided inner rings.

Therefore, the present invention makes it possible to achieve downsizing without sacrificing the incorporation and operability, prevent the unstable behavior of the inner ring at a high operating angle, and improve the joint performance. It aims to further improve.

[0012]

Means for Solving the Problems In order to solve the above problems,
The constant velocity universal joint according to the present invention has an outer ring having a regular polygonal hollow hole surrounded by a plurality of flat surfaces, an inner ring incorporated into the hollow hole of the outer ring, and a flat surface between the outer ring and the inner ring. An interposed button member, wherein the inner ring is provided with a spherical outer wall surface in contact with the inner surface of the button member, and on the outer diameter side of the button member, a preload is applied to press the button member toward the inner ring side. Means are provided.

[0013] Further, an outer ring having a regular polygonal hollow hole surrounded by a plurality of flat surfaces, a pair of inner rings butt-fitted into the hollow holes of the outer ring, and a pair of inner rings between the flat surface of the outer ring and both inner rings. And a button member interposed on the inner member, and the inner ring is provided with a spherical outer wall surface in contact with the inner surface of the button member, and the button member is pressed toward the inner ring side on the outer diameter side of the button member. This is provided with a preload applying means.

The preload applying means is a wedge formed by a flat surface of the outer race, an outer surface of the button member, and a wedge member interposed therebetween. Then, the wedge member is pressed by the elastic means in the direction in which the wedge acts, and the button member is pressed toward the inner ring.

The wedge may be formed in the axial direction or in the circumferential direction.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In the following description, members and portions corresponding to the conventional configuration shown in FIGS. 7A and 7B are denoted by the same reference numerals.

FIGS. 1A and 1B show a first embodiment of the present invention. This constant velocity universal joint has six flat surfaces (1a)
For example, an outer ring (1) having a cylindrical shape with a bottom and a hollow hole having a regular hexagonal cross section surrounded by a circle, an inner ring (2) incorporated in the hollow hole of the outer ring (1), an inner ring (2), and an outer ring ( 1), a block-shaped button member (3) interposed therebetween, a shaft portion (4) connected to the inner ring (2) or integrally formed or joined to the inner ring (2), and an outer ring ( 1) Flat surface (1a)
And six wedge members (5) interposed between the outer ring (1) and the outer surface (3a) of the button member (3), and between the bottom surface (1b) of the outer ring (1) and the wedge member (5). The resilient means, for example, a coil spring (6) is a main component.

The inner ring (2) has an integral structure, and six spherical outer wall surfaces (2a1, 2a2,..., 2a6) are formed on the outer peripheral surface thereof. The shape of each spherical outer wall (2a) is shown in FIG.
(A) Since it is the same as that of a joint shown to (b), the explanation is omitted.

Each of the button members (3) is in the form of a vertically long block in the axial direction, and each of the flat surfaces (1a) of the outer ring (1).
In each case, only the same number as the flat surface (1a) (six in this embodiment) is provided. The outer surface (3a) of the button member (3) is formed in a flat shape parallel to the axial direction, and the inner surface (3b) has a recess capable of making surface contact with each spherical outer wall surface (2a) of the inner ring (2). It is formed in a spherical shape. In the present embodiment, the button member (3) has a block shape with a longer axial direction, but may have another shape, for example, a disk shape.

The wedge member (5) is formed in the shape of a vertically long block in the axial direction, and its outer surface (5a) is formed as an axial tapered surface and its inner surface (5b) is formed as a flat surface parallel to the axial direction. Is done. One end of the wedge member (5) (the end on the back side of the outer ring)
Is formed with a concave portion (5c) for accommodating one end of the coil spring (6).

The flat surface (1a) of the outer race (1) is formed as a tapered surface inclined in the axial direction. The wedge member (5)
It is arranged in a tapered wedge space formed between the flat surface (1a) of the outer ring (1) and the outer surface (3a) of the button member (3). The outer surface (5a) of the wedge member (5) is tapered into the flat surface (1a) of the outer ring (1), and the inner surface (5b) is in surface contact with the outer surface (3a) of the button member (3). I do. In this way, the flat surface (1a) of the outer ring (1), the outer surface (3a) of the button member (3), and the wedge member (5) interposed between the two make the button member (3) An axial wedge (preload applying means) is formed on the outer diameter side. Then, each wedge member (5) is moved to one side in the axial direction [reduced side of the wedge (opening side of the outer ring) by the elastic force of the coil spring (6) housed in the recess (5c) of the wedge member (5). ] Is elastically pressed. As a result, the wedge member (5) is pressed toward the inner ring side by the flat surface (1a) of the outer ring (1), so that the button member (3) is pressed toward the inner ring side. The gap between the inner ring (2) and the inner ring (2) is reduced so that there is no play in the circumferential direction. In the present embodiment, the wedge member (5) is pressed toward the opening of the outer ring (1), but in the opposite direction (toward the inner ring).
May be pressed. With this structure, it is possible to prevent rattling in the circumferential direction of the entire joint, and since the inner ring (2) is formed as an integral structure, the inner ring (2) has a high height like the inner ring split type joint shown in FIG. The problem of axial movement between the inner rings at the time of the operating angle cannot occur. Further, since the strength of the inner ring is improved as compared with the split type, it is easy to reduce the size of the inner ring (2) and, consequently, the joint. Further, there is no fluctuation of the PCD or the center of the spherical surface due to a processing error of the inner ring (2), and stable operability is secured.

At the time of assembly, the coil spring (6) is compressed so that the wedge member (5) is retracted to the rear side of the outer ring (1), so that the inner ring (2) and the button member (3) are retracted. ) Can be incorporated into the outer ring (1) with a gap, and can be easily assembled. Then, when the compression of the coil spring (6) is released after the incorporation, the gap between the constituent members is reduced as described above, and the circumferential joint is eliminated in the entire joint.

FIG. 2 is a diagram showing a second embodiment of the present invention. This constant velocity universal joint has a coil spring (6) in which the joint shown in FIG. 1 is arranged for each wedge member (5).
By using one coil spring (6) that can contact one end surface (the surface on the deep side of the outer ring) of all the wedge members (5), A uniform elastic force can be applied to the wedge member (5).

FIG. 3 shows the joint of FIGS. 1 and 2 using a wedge in the circumferential direction, while using the wedge in the axial direction. That is, by forming the outer surface (5a) of the wedge member (5) as a tapered surface in the circumferential direction, the flat surface (1) of the outer ring (1) parallel to the axial direction is formed.
a) a wedge formed in the circumferential direction by the outer surface () of the button member (3), which is also parallel to the axial direction, and the inner surface (5b) and the outer surface (5a) of the wedge member (5). is there. In this case, an elastic means for applying an elastic force to each wedge member (5), for example, a leaf spring (6 ') is arranged in a gap between circumferentially opposed surfaces of the pair of wedge members (5).

Incidentally, in the above-mentioned constant velocity universal joint, there is a certain limit in the allowable operating angle in consideration of the amount of movement of the button member (3), securing of spherical guide, and interference between the outer ring and the shaft. In order to obtain an operating angle equal to or larger than the limit value, it is necessary to further increase the diameter of the outer ring (1), which is not preferable in consideration of the incorporation into the steering device. In addition, if the shaft (4) is rotated with the outer ring shaft fixed, the shaft connected to the shaft (4) may swing around, which may reduce the durability of the bearing that supports the shaft. .

Therefore, in this case, as shown in FIGS. 4 to 6, a pair of inner rings (2) are butt-fitted into hollow holes of an outer ring (1: formed, for example, in a cylindrical shape with both ends open). Assembling, flat surface (1a) of outer ring (1) and both inner rings (2)
And a button member (3) may be interposed between them.
That is, the assembled body including the inner ring (2), the button member (3) and the shaft part (4) is paired, and these are assembled into the hollow hole of the outer ring (1) in abutting manner. 4 corresponds to FIG. 1, FIG. 5 corresponds to FIG. 2, and FIG. 6 corresponds to FIG.

FIG. 4 shows a constant velocity universal joint of this type.
As shown by a two-dot chain line, when the pair of inner rings (2) is displaced by an angle (θ) with respect to the outer ring (1),
Since the two inner rings (2) are each angularly displaced with respect to the outer ring (1), an operating angle (2θ) that is twice that of the conventional product can be obtained. In some cases, the constant velocity universal joint used in the steering device needs to be able to take an operating angle of 50 ° or more, but this type of constant velocity universal joint sufficiently satisfies this requirement. be able to. Moreover,
The structure is relatively simple and small and lightweight. Also, 2
If the two inner rings (2) are assembled in phase, whirling occurs only at the outer ring (1), and the two shafts (4) can rotate without whirling.

[0028]

According to the present invention, on the outer diameter side of the button member, a preload applying means for pressing the button member to the inner ring side, that is, a flat surface of the outer ring, an outer side surface of the button member, and an intermediate portion between the both. Since the wedge formed by the mounted wedge member is provided, rattling in the circumferential direction of the entire joint can be prevented. In addition, since the inner race is of an integral structure, there is no problem of axial movement between the inner races at a high operating angle unlike the conventional inner ring split type constant velocity universal joint. Further, since the strength of the inner ring is improved as compared with the split type, it is easy to reduce the size of the inner ring, and thus the joint. Furthermore, stable operability is ensured without fluctuation of the PCD or the center of the spherical surface due to an inner ring machining error or the like.

[Brief description of the drawings]

FIG. 1 is an axial sectional view (a) and a radial sectional view (b) showing a first embodiment of the present invention.

FIG. 2 is a sectional view (a) in the axial direction and a sectional view (b) in the radial direction showing a second embodiment of the present invention.

FIG. 3 is a sectional view in the axial direction (FIG. 3A) and a sectional view in the radial direction (FIG. 3B) showing the third embodiment of the present invention.

4A and 4B are cross-sectional views of a joint in which a pair of inner rings are arranged in abutment within an outer ring. FIG. 4A is a cross-sectional view in the axial direction, and FIG.
The figure is a sectional view in the radial direction.

5A and 5B are cross-sectional views of a joint in which a pair of inner races are arranged in abutment within an outer race. FIG. 5A is a cross-sectional view in the axial direction, and FIG.
The figure is a sectional view in the radial direction.

6A and 6B are cross-sectional views of a joint in which a pair of inner races are arranged in abutment within an outer race. FIG. 6A is an axial cross-sectional view, and FIG.
The figure is a sectional view in the radial direction.

FIG. 7 is a sectional view in the radial direction showing another example of the conventional joint (a).
FIG. 3) and an axial sectional view (b).

FIG. 8 is an axial sectional view of a constant velocity universal joint (see FIG. 7) at an operating angle.

[Explanation of symbols]

 Reference Signs List 1 outer ring 1a flat surface 2 inner ring 2a spherical outer wall surface 3 button member 3a outer surface 3b inner surface 4 shaft portion 5 wedge member 5a outer surface 5b inner surface 6 coil spring (elastic means)

Claims (5)

[Claims] 1. An outer ring having a regular polygonal hollow hole surrounded by a plurality of flat surfaces, an inner ring incorporated in the hollow hole of the outer ring, and a button interposed between the flat surface of the outer ring and the inner ring. The inner ring is provided with a spherical outer wall surface in contact with the inner surface of the button member, and the outer diameter side of the button member is provided with a preload applying means for pressing the button member toward the inner ring side. A constant velocity universal joint characterized by: 2. An outer ring having a regular polygonal hollow hole surrounded by a plurality of flat surfaces, a pair of inner rings butt-fitted into the hollow holes of the outer ring, and between the flat surface of the outer ring and both inner rings. And a button member interposed on the inner ring, and a spherical outer wall surface in contact with the inner surface of the button member is provided on the inner ring, and the button member is pressed toward the inner ring side on the outer diameter side of the button member. A constant velocity universal joint comprising a preload applying means. 3. The wedge member is formed by a flat surface of an outer race, an outer surface of a button member, and a wedge member interposed therebetween, wherein the wedge member is formed by an elastic means. The constant velocity universal joint according to claim 1 or 2, wherein the button member is pressed in a direction in which the button member is pressed to the inner ring side. 4. The constant velocity universal joint according to claim 3, wherein said wedge is formed in an axial direction. 5. The constant velocity universal joint according to claim 3, wherein the wedge is formed in a circumferential direction.