JP2003294053A - Universal joint regulating movement in eccentric direction - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To precisely regulate movement in an eccentric direction between a pair of hubs by completely filling a gap between a pair of yokes and a block body by using an inexpensive bush and with simple and easy work. <P>SOLUTION: The universal joint comprises a pair of the hubs (1, 2) which have a pair of the yokes (11, 21) and are mounted to an end part of a drive shaft or a driven shaft, and the block body (3) to be inserted into the middle of a pair of the hubs (1, 2). The universal joint is so constituted that the bush (5) is inserted into the gap between a pin hole of the block body (3) and a pin (4) to be driven into the block body. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shaft joint attached to a drive shaft, and more particularly to a universal joint which allows bending of a drive shaft and a driven shaft to transmit a rotational force.

[0002]

2. Description of the Related Art As an example of a conventionally known universal joint, one disclosed in Japanese Patent Laid-Open No. 3-74632 is shown in FIGS. FIG. 5 is an assembled state, FIG.
Is a state in which they are separated in the axial direction, and one set of universal joints is a pair of hubs 1 and 2 attached to the ends of the drive shaft and the driven shaft, and is inserted between these hubs to connect the hubs to the pair of hubs. The block body 3 is engaged with the block body 3.

At the tips of the hubs 1 and 2, a pair of yokes 11 and 21 are provided at diametrically opposite positions. On the other hand, the block body 3 is, for example, a square plate-shaped body, has radial pin holes in four directions in a plane at right angles to each other, that is, in the center of four side surfaces of the plate-shaped body, and is driven into the pin holes. The yokes 11 and 21 of the pair of hubs 1 and 2 are engaged with each other via the pin 4.

The yokes 11 and 21 of the hubs 1 and 2 are arranged on both sides of the block body so as to be perpendicular to each other, and the pins 4 are driven into the pin holes of the block body 3 to form the yokes 11 and 21.
Is connected to the block body 3, the hubs 1 and 2 can freely rotate with respect to the orthogonal axes composed of the four pins 4, so that the hubs are allowed while allowing the bending of the driving shaft and the driven shaft. Rotational force is transmitted between 1 to the block body 3 to the hub 2.

Generally, there is a gap between the pair of yokes 11 and 21 and the block body 3 for moving the pair of hubs 1 and 2 in the radial direction (axial direction of the pin 4). This gap is
It is one of the problems of the universal joint because it causes eccentricity between the driving shaft and the driven shaft.

Japanese Unexamined Patent Publication (Kokai) No. 9-79281 discloses a small size in which a ball bearing is inserted into a gap between a pin driven into a block body and a pin hole of a yoke engaged with the block body by applying a preload in the axial direction of the pin. Universal joints are listed.

This universal joint employs a ball bearing as a rolling bearing which is suitable for a small-sized universal joint in terms of size. By inserting this ball bearing between a pin and a yoke, the eccentric angle between the pair of hubs 1 and 2 is increased. By smoothing the directional movement and preloading the ball bearing, the gap between the yoke and the block body can be eliminated, and movement in the eccentric direction between the pair of hubs 1 and 2 can be restricted.

However, since the ball bearing is expensive,
The universal joint described in Japanese Patent Laid-Open No. 9-79281 has a problem of increasing the cost of the product.

Further, in Japanese Laid-Open Patent Publication No. 10-26144, as shown in FIG. 7, a collar portion is provided in a gap between a pin 4 driven into a block body and pin holes of yokes 11 and 21 engaged with the pin 4. There is described a universal joint in which the bush 7 with a collar is inserted with the inside of the.

This universal joint is shown in FIGS.
In place of the cylindrical bush 6 of the universal joint shown in FIG. 3, a bush with a collar 7 provided with a collar on the head is used, and the bush with a collar 7 is connected to the yokes 11 and 21 from the inner peripheral surface side to the outer peripheral surface side of the yoke. By inserting into the pin holes, the bushing is prevented from coming off due to centrifugal force due to the rotation of the shaft, and a head with a collar is interposed in the gap between the hubs 1 and 2 and the block body 3 so that a pair of hubs can be provided. The movement in the eccentric direction between 1 and 2 can be restricted. Further, the bush has a simpler structure and is less expensive than the rolling bearing, and thus is suitable for a small-sized universal joint.

However, the universal joint disclosed in Japanese Unexamined Patent Publication No. 10-26144 discloses a yoke 1 in which the pin hole of the yoke and the bush are fitted in a clearance.
The dimensions of the inner peripheral surface of 1 and 21 and the dimensions of the block body 3 and the thickness of the rib portion of the bush are finished by ultra-precision machining, and the gap between the yoke and the block body must be completely filled with the rib portion of the bush. The eccentricity of the block body cannot be suppressed to zero or its vicinity. Moreover, since the bush inserted into the pin hole of the yoke is easy to move in the clearance fitting, it takes time and effort to align the bush with the block body.

Further, in this universal joint, when the pin hole of the yoke and the bush are tightly fitted, the amount of eccentricity cannot be suppressed to zero or the vicinity thereof unless the push amount of the bush is precisely controlled during assembly. However, with the method of press-fitting the bush into the pin hole of the yoke from the inner peripheral surface side toward the outer peripheral surface side (radial direction), it is extremely difficult to precisely control the pushing amount in the assembly, and the work is troublesome. Hang up. In particular, when such a labor-intensive work is performed on a small-sized universal joint, there is a problem that productivity is significantly impaired.

[0013]

SUMMARY OF THE INVENTION The present invention is to completely fill a gap existing between a pair of yokes and a block body by an inexpensive member and a labor-free operation.
The purpose is to precisely regulate the movement in the eccentric direction between the pair of hubs.

[0014]

According to the present invention, a pair of hubs (11, 21) having a pair of yokes (11, 21) at diametrically opposed positions at their tips are attached to the ends of a drive shaft and a driven shaft ( 1, 2) and the pair of hubs (1, 2) are inserted in the middle, and have pin holes in four directions perpendicular to each other in one plane, and through the pins (4) driven into the pin holes. Each yoke (11, 2) of the pair of hubs (1, 2)
In a universal joint consisting of a block body (3) engaged with 1), a bush (5) is inserted into a gap between a pin hole of the block body (3) and a pin (4) driven into the block body. It is a universal joint, which is characterized by

As the bush (5), a bush with a collar can be used. Further, it is preferable that at least an end surface of the bush that faces the inner surface of the pin receiving hole or the inner peripheral surface of the yoke is formed of a self-lubricating material.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. 1 to 4 show the same embodiment, FIG. 1 is a front view showing a partial cross section of a universal joint, FIG. 2 is a side view of the same, and FIG. 3 is a state in which a bush is inserted into a block body during assembly of the universal joint. Fig. 4 is a side view showing a partial cross section of Fig. 4, and Fig. 4 is a perspective view showing the universal joint in an exploded state. The reference numerals 1 and 2 are hubs attached to the drive shaft and the driven shaft, 11 and 21 are jaw-like yokes at the tips of the hubs 1 and 2, 3 is a block body, and 4 is a pin. It is the same as that described with reference to FIGS. A bush 5 is inserted into the block hole of the block body 3. This differs from the previously described prior art bushing inserted in the yoke. Bush 5
In addition to a simple winding bush or a cylindrical bush, a bush with a collar provided with a collar on its head as in the embodiment may be used.

As an example of dimensions, in a small-sized universal joint with a shaft diameter of the hub portion of 9 mm and an outer diameter of the yoke portion of 19 mm, the inner diameter of the bush 5 used is 2.5 m.
m, outer diameter 5 mm, total length 3.8 mm, brim thickness 0.8 m
m, the outer diameter of the collar is 7 mm.

In the present invention, in the gap between the pin hole of the block body 3 and the pin 4 driven into the block body,
The bush 5 is inserted from the outer peripheral side of the block body. The bush 5 is fixed in a position in which the gaps between the yokes 11 and 21 and the block body 3 are completely filled, and the rotation axes of the driving side and the driven side are completely aligned without any “misalignment”. As a method of inserting and fixing, it is preferable to press-fit to make an interference fit in terms of workability, but it is also possible to use a relatively loose bush for the pin hole of the block body and fix it by adhesion, welding, etc. It is possible.

As described above, when the gap between the yokes 11 and 21 and the block body 3 is completely filled by the bush 5 inserted and fixed in the pin hole of the block body 3, the eccentric direction between the pair of hubs is increased. Movement can be regulated precisely,
Misalignment between the drive shaft and the driven shaft is prevented.

In order to assemble the universal joint of the present invention, first, as shown in FIG.
Insert the bush into the pin holes provided in the center of the two sides,
Fix it. The shape of the block body is not particularly limited,
A disk-shaped or cylindrical block body as shown in FIG. 3 may be used. When the bush 5 is press-fitted in this step, the bush can be driven toward the center from the outside of the block body. This method requires less labor than the method shown in FIG. 7, that is, the method in which the bush with collar 7 is driven into the pin hole of the yoke toward the outer side in the radial direction. Moreover, according to this method, the distance x between the opposing bushes can be accurately adjusted to the inner width dimension of each of the yokes 11 and 21, so that the movement in the eccentric direction between the pair of hubs can be precisely regulated. it can.

The position of the bush inserted into and fixed to the block body 3 by a method such as press fitting can be arbitrarily set, and the bush can be easily fixed at the set position (depth). In order to match the centers of the drive shaft and the driven shaft connected to the pair of hubs 1 and 2 with the center of the block body, the distance x between the opposing bushes is set to the inner width dimension of each yoke 11, 21. And the distance from the center of the block to the tip of the head of each bush is x / 2,
It is desirable to fix each bush in a uniform position.
Further, the method of using each bush and the bush with a rib and pushing the bush to a position where the entrance of the bush is stopped by the collar is easy to align.

In this way, the bush 5 is attached to the block body 3.
After inserting and fixing at a predetermined position, four pin holes in which the bush 5 of the block body 3 is fitted into the pin holes provided in the yokes 11, 11, 21, and 21 of the hubs 1 and 2, respectively. Align. Next, the pins 4 are driven in from the outer peripheral side of the yoke to make the yokes 11, 11, 21, 21
Through the pin hole of the block body 3 and further through the pin receiving hole of the bush 5 to connect the hubs 1 and 2 to the block body 3. Since the bush 5 is fixed to the pin hole of the block body 3, the bush 5 does not fall out at the time of the above alignment, and the assembly can be easily performed.

Further, even if centrifugal force is applied after the assembly, the bush 5 inserted in the block body 3 still has the yoke 1
It stops at the entrance on the inner peripheral surface side of the pin holes 1 and 21, so it will not fall out.

According to the above method, the bush 5 which is cheaper than the ball bearing and has a simple structure is used, and the bush 5 is inserted from the outside of the block body 3, particularly preferably press-fitting, which is a labor-free operation. Since the movement in the eccentric direction between the pair of hubs can be precisely regulated, it is particularly suitable as a method for regulating the eccentricity of a small-sized universal joint.

Further, since the bush is interposed between the pin hole of the block body 3 and the pin 4 to smoothen the rotation between the two, the movement in the declination direction between the pair of hubs 1 and 2 is smoothed. be able to. In order to make the rotation between the pin hole of the block body 3 and the pin 4 smoother, it is preferable that at least the end surface of the bush 5 facing the inner surface of the pin receiving hole or the inner peripheral surface of the yoke is made of a self-lubricating material. Especially bush 5
It is preferable to integrally form the whole body with a self-lubricating material, because the self-lubricating property and the insulating property of the bush are not lost even after long-term use. As the self-lubricating material, for example, a polyacetal resin such as Delrin, or a fluororesin such as Somalite POM (trade name) or Teflon (registered trademark), etc. is used.

[0026]

According to the present invention, the gap between the pair of yokes and the block body is completely filled by a labor-saving operation using an inexpensive bush, so that the eccentricity between the pair of hubs is increased. It is possible to precisely regulate the movement in the direction.

[Brief description of drawings]

FIG. 1 is a front view showing a partial cross section of a universal joint according to an embodiment of the present invention.

FIG. 2 is a side view showing a partial cross section of the universal joint according to the embodiment of the present invention.

FIG. 3 is a side view showing, in a partial cross section, a state in which a bush is inserted in the block body in the embodiment of the present invention.

FIG. 4 is a perspective view showing the universal joint of the embodiment of the present invention in an exploded state.

FIG. 5 is a front view showing a conventional universal joint in a partial cross section.

FIG. 6 is a perspective view showing a conventional universal joint in an exploded state.

FIG. 7 is a front view showing another universal joint showing a conventional technique in a partial cross section.

[Explanation of symbols]

1, 2 ... hub 3 ... Block body 4 ... pin 5 ... Bush 6 ... Cylindrical bush inserted in the yoke 7 ... Bush with brim inserted in yoke 11, 21 ... York

Claims (3)

[Claims] 1. A pair of hubs (1, 2) having a pair of yokes (11, 21) at diametrically opposite positions at their tips and attached to the ends of a drive shaft and a driven shaft, and a pair of these hubs (1, 2). Of the pair of hubs (1, 2) through pin (4) which is inserted in the middle of the hubs (1, 2) in four directions perpendicular to each other in one plane and is driven into the pin holes. ) In the universal joint consisting of the block body (3) engaging with the respective yokes (11, 21), the gap between the pin hole of the block body (3) and the pin (4) driven into the block body. A universal joint with restricted movement in the eccentric direction, characterized in that a bush (5) is inserted in the. 2. The universal joint according to claim 1, wherein the bush (5) is a bush with a collar. 3. The universal joint according to claim 1, wherein at least an end surface of the bush facing the inner surface of the pin receiving hole or the inner peripheral surface of the yoke is made of a self-lubricating material.