JP2000009151A - Small diametral universal joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small diametral universal joint which is suitable to transmit high torque, small in size, easily assembled, and can transmit high loading in a limited small space. SOLUTION: This small diametral universal joint 10 is provided with paired cylindrical joints 12 and 12, paired U-shaped anchors 14 and 14, and with a spherical joint 16 over the surface of which through grooves 22 are engraved while being mutually intersected. The U-shaped anchors 14 and 14 are coupled with the intersected through grooves 22 of the spherical joint 16 so as to be faced to each other, and concurrently, the spherical joint 16 is held in between, the paired leg parts 19 and 19 of the U-shaped anchors are inserted into the recessed grooves 11 and 11 of the cylindrical joints 12, and it is so designed that each hole 13 of the cylindrical joint 12 is put together with each lateral hole 15 of the U-shaped anchor 14, and they are fastened with screws and pins inserted so as to be fixed thereto.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small-diameter universal joint for transmitting a large load in a narrow space, which is used for transmitting a high torque.

[0002]

2. Description of the Related Art Conventional universal joints (universal joints) are used everywhere to connect a power transmission shaft of a vehicle or the like. FIG. 8 is an external view of a conventional universal joint. An example of the configuration of a conventional universal joint will be described with reference to FIG.
The universal joint includes a cylindrical joint 2, an arm 4 formed at the end of the joint so as to be fitted with another joint 2,
A link 3 having a connecting pin 5 in a cross direction, and a concave portion 6 which engages with the connecting pin 5 is provided in each of the joints 2, 2. A link in which each of the joints 2 has a connecting pin in the cross direction. 3 are connected. In FIG. 8, reference numeral 7 denotes a screw hole for inserting, for example, a drive shaft into a joint and fixing the screw.

[0003] In such a conventional universal joint, it is difficult to obtain a primary balance because the joint is large in the outer diameter direction, and the space between the main driving shaft and the driven shaft must be close to each other. Was. Furthermore, since the torque of the joint on the drive shaft side is transmitted to the joint on the driven shaft side via the connecting pin 5, when a load W is applied to the connecting pin 5, bending and shear loads are concentrated on the connecting pin, and high torque is applied. In order to achieve strength, it was necessary to ensure strength, and it was large.

Here, the stress applied to the connecting pin 5 of the conventional universal joint can be considered as follows. FIG. 9A shows a schematic front view of a conventional universal joint,
(B) shows the right side view. In FIG. 9, d is the connecting pin 5.
L0 is the distance from the base of the arm 4 to the connecting pin, and L1 or L2 is the distance at a predetermined location in the figure. FIG.
0 indicates A when the load W is applied to the connecting pin 5 and B when the load W is applied to the base of the joint arm 4 without the connecting pin.
FIG. 3 is a conceptual diagram showing a model of FIG.

Referring to FIG. 9 and FIG.
Is F = W when a load W is applied to the arm, and when no connecting pin 5 is provided, the load W is applied to the base of the arm 4 and the shear force is F = W · L0. The maximum stress σmax at this time is σma, where Z is the second moment of area.
x = Fmax / Z. By specific numerical calculation, A
The result obtained is that the maximum stress in the case of (1) is about one to two orders of magnitude larger than the maximum stress in the case of (B). This means that stress is concentrated on the connecting pin in the universal joint having the connecting pin, and that the transmission strength is improved by a factor of 10 or more without the connecting pin. Therefore, a universal joint having no pin shape is excellent in strength and can be downsized accordingly.

A universal joint without a connecting pin of this type is proposed in Japanese Patent Application Laid-Open No. 8-184324. In the example shown in this publication, two sets of yokes each having a yoke portion having a rigid ball support surface formed on the inner surface are shifted by 90 degrees to sandwich the rigid spheres, and the yokes are rotatably connected. This is done by bringing the parts into contact with each other. As described above, since the torque is transmitted by bringing the yoke portions into contact with each other, there is no loss in torque transmission, and the rigid sphere itself does not transmit the torque, but simply connects the yoke portions to each other. Therefore, the yoke portion and the yoke base portion can be machined, so that the machining and assemblability can be improved.

[0007]

However, in the example disclosed in JP-A-8-184324, although the workability and assemblability of the yoke are improved, the configuration of the universal joint and the yoke portion and the like are not improved. There is room for improvement to make machining easier.

Accordingly, it is an object of the present invention to provide a small-diameter universal joint suitable for transmitting high torque and capable of transmitting a large load in a small space, and which is easy to assemble.

[0009]

Means for Solving the Problems In order to achieve the above object, among the small diameter universal joints according to the present invention, the invention according to claim 1 comprises a step having a plurality of intersecting grooves formed on the surface thereof, An anchor fitted in a crossing groove and having a pair of legs, and a joint formed with a groove for fitting the pair of legs of the anchor, wherein a plurality of anchors are fitted facing the crossing grooves of the stepmother At the same time, the step was sandwiched, and the leg of the anchor was fitted and fixed in the groove of the joint. Claim 2
The invention described in (1) is characterized in that, in addition to the above configuration, the splicer is a spherical ball splicer, and the anchor is a U-shaped U-shaped anchor having the same radius of curvature as the radius of curvature of the pinched ball splicer. Things. Further, the invention described in claim 3 is characterized in that the load receiving area of the side surface of the groove of the joint and the side surface of the leg portion of the anchor abutting on the side surface of the groove is formed wide.

In the small-diameter universal joint of the present invention having such a configuration, since the pressing surface for transmitting the drive is the fitting surface of the joint, the stepper and the anchor, the transmission contact pressure area can be increased, and high torque can be transmitted. . Further, since the joint, the splicer and the anchor are independent from each other and fitted to each other, the assembling can be easily performed. In addition, since there is no connecting pin as in the prior art, the strength is excellent and the size can be reduced in the outer diameter direction. Therefore, the primary balance can be easily obtained.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a small diameter universal joint according to the present invention will be described below with reference to FIGS.
FIG. 1 is an external view of a small diameter universal joint according to an embodiment of the present invention. FIG. 2 is a side view of the small diameter universal joint according to the embodiment of the present invention. Referring to FIG. 1, a small diameter universal joint 10 of the present embodiment is carved with a pair of cylindrical joints 12 and 12, a pair of U-shaped U-shaped anchors 14, and grooves crossing through the surface. U-anchors 14, 14 are fitted in grooves crossing the ball joint 16 so as to be opposed to each other and clamp the ball joint 16. 11 shows a pair of legs 1 of a U-shaped anchor
The holes 9 and 19 are inserted, and the holes 13 of the cylindrical joint 12 are aligned with the lateral holes 15 of the U-shaped anchor 14 so that screws and pins are inserted and fixed.

The concave groove 11 of the cylindrical joint 12 is formed as a groove having a shape corresponding to the shape of the leg portion 19 of the U-shaped anchor 14. The joint 12 is formed so as to have the outer shape. Further, it is desirable that the concave groove 11 of the cylindrical joint 12 is formed as wide as possible on the side surface in contact with the leg 19 of the U-shaped anchor.

FIG. 3 is an external view of a ball splicer according to the present embodiment. 4A shows a front view of the ball splicer according to the present embodiment, FIG. 4B shows a top view, and FIG. 4C shows a right side view. As shown in FIG. 3, the ball step 16 according to the present embodiment has a groove 22 carved so as to intersect and cross at right angles on a spherical surface. As shown in FIG. 4, the groove 22 has a depth d, a width t, a center axis T1 passing through the center of the sphere and a center axis T2 having a phase shifted by 90 degrees from the center axis T1. Rotating slots are used as axes. FIG.
C in (a) indicates the side surface of the crossing groove 22,
R in (c) indicates a radius of curvature, and indicates that the portion indicated by R is a surface having this radius of curvature and formed in a circular shape.

Although the splicer of the present embodiment is a spherical splicer, it is not limited to such a shape, and an appropriate shape having, for example, a four-fold symmetry axis can be selected. For example, the shape may be square. In the case of such a square-shaped step, the U-shaped anchor is also formed so as to have a pressure receiving surface corresponding to the step.

FIG. 5 is an external view of a U-shaped anchor according to this embodiment. FIG. 6A is a top view of the U-shaped anchor, and FIG. 6B is a side view. Referring to FIGS. 5 and 6, the U-shaped anchor 14 has a U-shaped upper surface, and the U-shaped bent portion has a circular shape having the same radius of curvature as the ball splicer as shown in FIG. 6
As shown in (b), the peripheral side portion and the inner surface are also formed in a circular shape having the same radius of curvature as the ball joint, and correspond to the circular shape of the ball joint 16.

The width of the U-shaped anchor 14 coincides with the width t of the groove 22 formed on the ball splicer.
Is formed so as to coincide with the depth d of the passage groove 22, and can be fitted. The pair of legs 19, 19 of the U-shaped anchor 14 fits into the crossing groove 22 of the ball splicer 16, and the pressure receiving surface 18 of the U-shaped anchor has a groove in the front of the ball splicer 16 (see FIG. 4A). 6 (b), and the side face B shown in FIG.
Abuts against the side surface C.

In FIGS. 6 (a) and 6 (b), it is necessary to form the same circular shape as the ball splicer up to the position 17 which is in contact with the ball splicer. It can be flat. In this case, the location where the U-shaped anchor 14 abuts on the cylindrical joint 12 also needs to be formed correspondingly flat. It should be noted that B in FIG.
Indicates a side surface of the U-shaped anchor, which is a surface that partially abuts against the side surface C of the cross groove 22 where the ball joint intersects.

FIG. 7 is an assembly view of the small diameter universal joint according to the present embodiment. Referring to FIGS. 1, 2 and 7, small diameter universal joint 10 sandwiches ball joint 16 such that a pair of legs 19 of U-shaped anchor 14 intersect, and U-shaped anchor 14 intersects ball joint 16. It is inserted into and incorporated into each of the passage grooves 22. The legs 19 of the U-shaped anchor are inserted into the grooves 11 formed on the side of the cylindrical joint 12 in parallel to the axial direction, respectively, so that the center of the hole 13 of the cylindrical joint 12 and the side hole 15 of the U-shaped anchor 14 are aligned. At the same time, the ball joint 16 is inserted and fixed with a screw or a pin, so that the ball joint 16 can be held in a properly fitted state by the U-shaped anchor 14 and the cylindrical joint 12.

In the small diameter universal joint having such a configuration, when driven from the main drive shaft, as shown in FIG. 7, the surface A of the cylindrical joint 12 to be driven comes into contact with the legs 19, 19 of the U-shaped anchor.
To the surface B of the U-anchor driven from this surface, to the surface C of the ball joint driven from this surface B, to the surface C of the ball joint transmitted from this surface C, to the surface B of the U-shaped anchor transmitted from this surface C The surface B of the joint is pressed from the surface B to the surface A of the joint to transmit the driving force to the transmission shaft. In the small-diameter universal joint of the present embodiment, the surface A of the concave groove 11 of the cylindrical joint 12 and the surface B of the U-shaped anchor are loaded surfaces, but the loaded area can be widened.

Further, since the U-shaped anchor and the ball splicer are not inserted by the pin, the shear strength of the U-shaped anchor can be increased, so that even if the entire universal joint is small with respect to the driving shaft, it can withstand high torque transmission. Can be. In particular, since the outer diameter of the universal joint can be reduced, the increase in weight due to an increase in the number of members is suppressed, which is advantageous for obtaining a primary balance, the shape is relatively simple, and the number of parts is small, and the number of parts is small. The number is reduced to three points, and the manufacture is easy and the assembly is extremely easy.

[0021]

As will be understood from the above description, in the small diameter universal joint according to the present invention, since the pressing surface for transmitting the drive is the fitting surface of the joint, the splicer and the anchor, the transmission contact pressure area can be increased. The effect is that high torque can be transmitted. Further, the joint, the splicer, and the anchor are independent components, and can be fitted to each other, so that there is an effect that the assembly can be easily performed. In addition, since there is no connecting pin as in the prior art, the strength is excellent and the size can be reduced in the outer diameter direction. Therefore, there is an effect that the primary balance can be easily obtained.

[Brief description of the drawings]

FIG. 1 is an external view of a small diameter universal joint according to an embodiment of the present invention.

FIG. 2 is a side view of the small diameter universal joint according to the embodiment of the present invention.

FIG. 3 is an external view of a ball splicer according to the present embodiment.

4A and 4B show a ball splicer according to the embodiment, FIG. 4A is a front view of the ball splicer according to the embodiment, FIG.
(C) is a right side view.

FIG. 5 is an external view of a U-shaped anchor according to the embodiment.

6A and 6B show a U-shaped anchor according to the present embodiment, and FIG.
Is a top view of the U-shaped anchor, and (b) is a side view.

FIG. 7 is an assembly diagram of the small diameter universal joint according to the present embodiment.

FIG. 8 is an external view of a conventional universal joint.

FIG. 9 is a conceptual diagram of a conventional universal joint, in which (a) is a schematic front view of the universal joint, and (b) is a right side view thereof.

FIG. 10 is a conceptual diagram showing a model of a conventional universal joint when a load is applied to a connection pin and a model where a connection pin is not provided and a load is applied to the base of an arm of the joint.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Small diameter universal joint 11 Concave groove 12 Cylindrical joint 13 Cylindrical joint hole 14 U-anchor 16 Ball joint 19 Leg 22 Through groove

Claims (3)

[Claims] 1. A step having a plurality of intersecting grooves formed on a surface thereof, an anchor having a pair of legs fitted into the intersecting grooves of the surface of the splicer, and a groove engaging the pair of legs of the anchor. And a plurality of the anchors are fitted in opposition to the intersecting grooves of the splicer, while clamping the splicers, and fitting the legs of the anchors into the grooves of the joints. A small diameter universal joint that is fixed. 2. The method according to claim 1, wherein the splicer is a spherical ball splicer, and the anchor is a U-shaped U-shaped anchor having the same radius of curvature as the radius of curvature of the ball splicer to be clamped. 2. The small diameter universal joint according to 1. 3. The load receiving area according to claim 1, wherein a side surface of the groove of the joint and a side surface of a leg portion of the anchor contacting the side surface of the groove are formed to have a large load area. Small diameter universal joint.