JPH1089372A - Double cardan constant velocity joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a double cardan constant velocity joint which can secure practical strength of a pin and bent a socket yoke and a pin yoke with a wide angle. SOLUTION: A neck 71 and a spherical part 72 of a pin 7 of a pin yoke 2 are continuously formed through a first recessed curvature R1. Interference between a socket 6 and the pin 7 is prevented when a socket yoke 1 and the pin yoke 2 are bent. A first columnar part S1 whose mother line is extended straight is formed continuously from the first recessed curvature R1 of the neck 71 of the pin 7, and a small diameter side of the first recessed curvature R1 is projected outward in a diameter direction. Interference between the socket 6 and the pin 7 is prevented when the socket yoke 1 and the pin yoke 2 are further bent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a double cardan constant velocity joint.

[0002]

2. Description of the Related Art Conventionally, as one of constant velocity joints, as shown in FIG. 5, a socket yoke 11 having a cylindrical socket 11a at the tip and a pin yoke 12 having a pin 12a at the tip are provided. The spherical portion 12b provided at the tip of the pin 12a of the pin yoke 12 is rotatably connected to the coupling yoke 15 via the cross shafts 13 and 14.
There is provided a double cardan constant velocity joint which is slidably fitted into the inner surface of the socket 11a of the socket yoke 11.

[0003]

In this type of constant velocity joint, the maximum value of the refraction angle α between the socket yoke 11 and the pin yoke 12 is, as shown in FIG. 11b is defined by the point of time when it interferes with the boundary 12d between the spherical portion 12b of the pin 12a of the pin yoke 12 and the neck portion 12c continuous with the spherical portion 12b.

However, the above conventional constant velocity joint is
The neck 12c of the pin 12a is
Is formed in a columnar shape extending in parallel with the axis X, and the spherical portion 12b swells from the tip of the columnar portion, so that the refraction angle α between the socket yoke 11 and the pin yoke 12 is 30 to
At about 35 °, the inner peripheral edge 11b of the distal end of the socket 11a interferes with the boundary portion 12d between the spherical portion 12b and the neck portion 12c. For this reason, there is a problem that it cannot be used for applications requiring a larger refraction angle α.

Therefore, it is conceivable to reduce the axial diameter of the tip of the neck 12c to increase the refraction angle α. However, in this case, the more the refraction angle α is increased, the more the shaft diameter D at the forefront of the neck portion 12c becomes the calculated minimum limit shaft diameter d when the safety factor is 1 (see the broken line in FIG. 6) The bending force acting on the neck 12c when a torque is applied to the constant velocity joint.
c may be intolerable. The present invention has been made in view of the above problems, and an object of the present invention is to provide a double cardan constant velocity joint capable of refracting a socket yoke and a pin yoke at a wide angle while securing practical strength of a pin. And

[0006]

In order to achieve the above object, a double cardan constant velocity joint according to the present invention has a coupling yoke in which flange portions for mounting a cross shaft are protruded from both sides of a cylindrical base. A socket yoke having a cylindrical socket introduced inside the base portion, and rotatably connected to a flange portion on one side of the coupling yoke via the cross shaft; A coupling yoke is rotatably connected to a flange on the other side of the coupling yoke via a cross shaft, and a pin to be introduced into the socket is protruded at the tip of the main body. In a double cardan type constant velocity joint comprising a pin yoke having a spherical portion formed in sliding contact with an inner surface of a socket, a spherical portion of a pin of the pin yoke and a neck portion connected to the spherical portion are connected to a socket yoyo. In order to prevent the socket from interfering with the pin in a state in which the socket and the pin yoke are bent at a predetermined angle, the socket and the pin yoke are connected by a concave portion, and the socket yoke and the pin yoke are connected to a portion connected to the concave portion of the neck. Is characterized by forming a columnar portion having a generatrix extending linearly in order to prevent the socket from interfering with the pin in a state where the socket is bent further than the predetermined angle.

According to the double cardan type constant velocity joint having the above-described structure, the socket is bent with the pin yoke bent at a predetermined angle by the concave portion (hereinafter referred to as "first concave portion"). Can be prevented. Therefore, the angle of refraction between the socket yoke and the pin yoke can be increased. Further, the columnar portion (hereinafter, referred to as “first columnar portion”) continuous with the first concave portion prevents the socket from interfering with the pin in a state where the socket yoke and the pin yoke are further bent than the predetermined angle. Can be prevented. Therefore, the refraction angle between the socket yoke and the pin yoke can be further increased. In addition, since the refraction angle can be increased in a state where the minimum limit shaft diameter of the neck of the pin is secured, the practical strength of the neck can be secured.

It is preferable that the generatrix of the first columnar portion extends substantially in parallel with the axis of the pin from the minimum shaft diameter portion of the first concavely curved portion. In this case, the shaft diameter of the first columnar portion is reduced. And the first concave curved portion, the refraction angle between the socket yoke and the pin yoke can be further effectively increased.

The constant velocity joint comprises a concave portion, a columnar portion, and a concave portion (hereinafter referred to as a “second concave portion”, a “second concave portion”) sequentially from the first columnar portion of the pin toward the main body of the pin yoke. It is preferable that the “two columnar portions” and “third concave portions” are continuously formed in a state where the diameter gradually increases in this order.
In this case, the socket is prevented from interfering with the pin with the socket yoke and the pin yoke further bent by the second columnar portion between the second concave portion and the third concave portion. Can be. Therefore, the refraction angle between the socket yoke and the pin yoke can be further increased. In addition, since the first columnar portion and the second columnar portion are connected by the second concave portion, an edge is formed between the first columnar portion and the second columnar portion. As a result, it is possible to suppress occurrence of stress concentration in the portion. In addition, the shaft diameter of the pin between the first columnar portion and the main body of the pin yoke gradually increases, so that the strength of the portion can be increased.

The generatrix of the second columnar portion is preferably a tangent to the adjacent second concave portion and the third concave portion. In this case, the second concave portion, the second columnar portion, and the second The three concavely curved portions can be connected very smoothly. For this reason, it is possible to more effectively suppress the occurrence of stress concentration in the portion.

It is preferable that the boundary between the pin yoke main body and the pin is continuous by the concave curved portion.
In this case, the occurrence of stress concentration at the boundary between the pin yoke body and the pin can be suppressed.

[0012]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 2 is a partially cutaway front view showing one embodiment of the double cardan type constant velocity joint according to the present invention. In this constant velocity joint, a socket yoke 1 and a pin yoke 2 arranged along the axial direction are connected to a coupling yoke 5 via cross shafts 3 and 4, respectively. It is swingably connected via a socket 6 and a pin 7 formed at each end.

The coupling yoke 5 has a pair of flanges 5b for mounting the cross shafts 3 and 4 on both sides of a cylindrical base 5a. Needle bearings are interposed between and the cross shafts 3 and 4. The socket 6 at the distal end of the socket yoke 1 is a cylindrical shape with a bottom, and its inner periphery is formed in a perfect circle. The socket 6 is introduced inside the base portion 5a of the coupling yoke 5.

The pin 7 at the tip of the pin yoke 2 has a neck 71 connected to the body 21 of the pin yoke 2 and a spherical portion 72 connected to the tip of the neck 71. The spherical portion 72 is set so that its diameter is larger than the shaft diameter of the distal end portion of the neck portion 71, and a majority of the spherical portion 72 is slidably fitted into the inner periphery of the socket 6 of the socket yoke 1. I have. The spherical portion 72 is
The coil spring SP inserted into the socket 6 constantly urges the socket 6 so as to be located on the opening side of the inner periphery of the socket 6.

The neck 71 and the spherical surface 72 of the pin 7
As shown in detail in FIG. 3, the first yoke 1 and the pin yoke 2 are connected to each other by the first concave curved portion R1 so that the socket yoke 1 and the pin yoke 2 are bent around the axes Q1 and Q2 of the cross shafts 3 and 4, respectively. The refraction angle is α1 (for example, 36 °)
At this point, the inner peripheral edge 61 of the tip of the socket 6 is prevented from interfering with the tip of the neck 71 of the pin 7 (see the broken line in FIG. 4), and the refraction angle α between the socket yoke 1 and the pin yoke 2 is reduced. , Can be secured larger. Also,
The minimum shaft diameter D1 of the first concavely curved portion R1 has a safety factor of 1
Calculated minimum limit shaft diameter (see broken line in FIG. 1) d
It is set so as to be thicker than 1, so that even if a torque is applied to the constant velocity joint and a bending stress is applied to the pin 7, it can sufficiently withstand this. In the drawings, L1 indicates the axis of the socket yoke 1, and L2 indicates the axis of the pin yoke 2.

In a portion of the neck 71 of the pin 7 adjacent to the first concavely curved portion R1, a first columnar portion S1 whose generatrix extends linearly substantially in parallel with the axis of the pin 7, that is, the axis L2 of the pin yoke 2. The first columnar portion S1 causes the small diameter side of the first concavely curved portion R1 to project radially outward, so that the socket yoke 1 and the pin yoke 2 are larger than the refraction angle α1. Refraction angle α2 (for example, 40 °)
The inner peripheral edge 61 at the tip of the socket 6
Prevents interference with the portion of the neck 71 adjacent to the first concavely curved portion R1 (see the dashed line in FIG. 4). The generatrix of the first columnar portion S1 is aligned with a tangent line passing through the minimum shaft diameter portion of the first concave curved portion R1, so that the shaft diameter of the first columnar portion S1 is larger than the limit minimum shaft diameter d1. It is as thin as possible in the thick range. Therefore, the socket yoke 1 and the pin yoke 2 can be bent at a wider angle.

Further, from the first columnar portion S1 of the neck portion 71 of the pin 7 toward the main body portion 21 of the pin yoke 2, the second
The concave curved portion R2, the second columnar portion S2, and the third concave curved portion R3 are continuously formed while gradually increasing in diameter in this order, whereby the first columnar portion S1 and the main body of the pin yoke 2 are formed. The shaft diameter between the shaft shaft 21 and the shaft shaft 21 is set to be considerably larger than the calculated minimum limit shaft diameter when the safety factor indicated by the broken line in FIG.

The generatrix of the first columnar portion S1 is made coincident with a tangent passing through the minimum shaft diameter portion of the second concave portion R2, and the generatrix of the second columnar portion S2 is the maximum of the second concave portion R2. The tangent passes through the shaft diameter. For this reason, the 1st columnar part S1 and the 2nd columnar part S2 can be continued very smoothly, without generating an edge. Therefore, concentrated stress is generated between the first columnar portion S1 and the second columnar portion S2,
The neck 71 can be prevented from being repeatedly broken due to fatigue.

The second columnar portion S2 refracts the socket yoke 1 and the pin yoke 2 more than the refraction angle α2 because the large diameter side of the second concavely curved portion R2 protrudes largely outward in the radial direction. To prevent the inner peripheral edge 61 at the tip of the socket 6 from interfering with a portion adjacent to the second concavely curved portion R2 at this time, whereby the socket yoke 1 and the pin yoke 2 can be wider in angle. Can be refracted.

The third concave portion R3 smoothly connects the second columnar portion S2 and the end face of the main body 21 of the pin yoke 2 to each other. The end surface of the main body 21 is formed by the third concave portion R3. The tangent passes through the maximum shaft diameter. Therefore, the second
By forming an edge between the columnar portion S2 and the main body portion 21, it is possible to suppress the occurrence of stress concentration in the portion.

According to the constant velocity joint having the above-described structure, the angle of refraction α between the socket yoke 1 and the pin yoke 2 can be finally widened to about 50 °.
Can be greatly increased from the maximum value of 35 °.

The double cardan type constant velocity joint according to the present invention is constituted by a spherical body having a spherical surface formed separately from the neck 71 of the pin 7, and this spherical body is rotatably and slidably fitted on the pin 7. Of course, the present invention can also be applied to a combined type double cardan type constant velocity joint (for example, see Japanese Utility Model Laid-Open No. 5-89966).

[0023]

As described above, according to the double cardan type constant velocity joint according to the first aspect, the concave curved portion (the first curved portion) between the spherical portion of the pin of the pin yoke and the neck portion connected to the spherical portion. The concave portion) and the columnar portion (first columnar portion) continuous with the concave portion can prevent the socket from interfering with the pin when the socket yoke and the pin yoke are bent at a predetermined angle. Thus, the angle of refraction between the socket yoke and the pin yoke can be increased. For this reason,
Its application range can be expanded. Moreover, the first
Since the minimum limit shaft diameter of the columnar portion can be secured, it is possible to practically sufficiently endure the bending stress acting on the pin.

According to the double cardan type constant velocity joint according to the second aspect, the generatrix of the first columnar portion extends from the minimum shaft diameter portion of the first concavely curved portion substantially parallel to the axis of the pin. Since the shaft diameter of the columnar portion is made equal to the minimum shaft diameter of the first concave portion, the refraction angle between the socket yoke and the pin yoke can be further widened.

According to the double cardan type constant velocity joint according to the third aspect, when the socket yoke and the pin yoke are further bent, the interference of the socket with the pin is prevented by the concave curved portion continuous with the first columnar portion. This can be prevented by a columnar portion (second columnar portion) between the (second concavely curved portion) and a concavely curved portion (third concavely curved portion) continuous with the main body of the pin yoke. Therefore, the refraction angle between the socket yoke and the pin yoke can be further increased. In addition, since the first columnar portion and the second columnar portion are made continuous by the second concave portion, the occurrence of stress concentration between the first columnar portion and the second columnar portion is suppressed. can do. Therefore, it is possible to prevent the portion from being repeatedly broken due to fatigue. Moreover, the shaft diameter of the pin between the first columnar portion and the main body of the pin yoke gradually increases, so that the practical strength of the portion can be sufficiently increased.

According to the double cardan constant velocity joint according to the fourth aspect, since the generatrix of the second columnar portion is a tangent to the second concave portion and the third concave portion adjacent thereto,
The concave curved portion, the second columnar portion, and the third concave curved portion can be connected very smoothly. For this reason, it is possible to more effectively suppress the occurrence of stress concentration in the portion.

According to the double cardan constant velocity joint according to the fifth aspect, since the boundary between the pin yoke main body and the pin is made continuous by the third concave curved portion, the boundary between the pin yoke main body and the pin is provided. The occurrence of stress concentration in the portion can be suppressed.

[Brief description of the drawings]

FIG. 1 is an enlarged view of a main part of a double cardan type constant velocity joint according to the present invention.

FIG. 2 is a partially cutaway front view of the double cardan constant velocity joint.

FIG. 3 is an enlarged view of a pin portion.

FIG. 4 is an essential part enlarged view showing a state where a socket yoke and a pin yoke are gradually bent.

FIG. 5 is a partially cutaway front view showing a conventional example.

FIG. 6 is an enlarged view of a main part of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Socket yoke 2 Pin yoke 3 Cross axis 4 Cross axis 5 Coupling yoke 5a Base part 5b Flange part 6 Socket 7 Pin 71 Neck 72 Spherical part R1 First concave part R2 Second concave part R3 Third concave part S1 First part 1 columnar portion S2 2nd columnar portion LI Axis of pin yoke

Claims (5)

[Claims] 1. A coupling yoke having flange portions for mounting a cross shaft on both sides of a cylindrical base portion, and a cylindrical socket introduced into the base portion,
A socket yoke rotatably connected to a flange on one side of the coupling yoke via the cross shaft; and a rotatable via a cross shaft to a flange on the other side of the coupling yoke. A double cardan constant velocity comprising a pin yoke formed by projecting a pin to be inserted into the socket at the tip of the main body, and forming a spherical portion at the tip of the pin to be in sliding contact with the inner surface of the socket. In the joint, a spherical portion of the pin of the pin yoke and a neck continuous with the spherical portion are connected by a concave portion to prevent the socket from interfering with the pin when the socket yoke and the pin yoke are bent at a predetermined angle. The socket yoke and the pin yoke are further bent at a predetermined angle from the socket at a portion continuous with the concave curved portion of the neck. There order to prevent from interfering with the pin, the double Cardan constant velocity joint busbar is characterized in that the formation of the columnar portion extending linearly. 2. The double-cardan constant velocity joint according to claim 1, wherein the generating line of the columnar portion extends from the minimum shaft diameter portion of the concave portion substantially parallel to the axis of the pin. 3. The concave portion, the column portion, and the concave portion are continuously formed in such a state that the diameter gradually increases in this order from the column portion of the pin toward the main body portion of the pin yoke. Double Cardan constant velocity joint. 4. The double cardan constant velocity joint according to claim 3, wherein the generatrix of the columnar portion is a tangent to each of the adjacent concavely curved portions. 5. The double cardan constant velocity joint according to claim 3, wherein a boundary between the pin yoke main body and the pin is continued by the concave curved portion.