JPH049458Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a flexible joint for power transmission called a low-rigidity coupling. This relates to flexible joints used for the purpose of

[Conventional technology]

In connection parts such as automobile propeller shafts, flexible parts with vibration absorption function are used to prevent torsional vibrations from being transmitted to driven devices (differential devices, etc.) during the power transmission process. Joints are often used.

This type of flexible joint has a structure in which driving side connecting elements and driven side connecting elements are arranged alternately on the circumference, and adjacent connecting elements are connected by an elastic joint element such as rubber. It is. The drive-side connection element and the driven-side connection element are connected to a metal inner cylinder into which a bolt for fixing to the drive shaft or a bolt for fixing to the driven shaft is inserted, and a joint element around which a reinforcing cord is wound. There is a known structure consisting of a metal outer cylinder fixed to the metal outer cylinder and a rubber bushing interposed between the two (for example, Japanese Patent Publication No. 56-37449).

By the way, in the conventional flexible joint described above, either the rubber bush fills the entire space between the inner cylinder and the outer cylinder, or the rubber bush intervenes with a part of space left in the axial direction, and these have the same thing in common. The point is that it is provided at a location that is constantly subjected to compressive deformation during the process of power transmission.

This structure is designed to provide a buffer by avoiding direct contact between the metal inner cylinder and the metal outer cylinder, but while it does not affect torque transmission under low or normal loads, it does not interfere with torque transmission under high loads. When transmitting a large torque of
There was a problem that large distortion occurred and the durability life was shortened.

Therefore, as a countermeasure for the above-mentioned problem, the driving side connecting elements 2 and the driven side connecting elements 3 are arranged alternately and equally on the circumference as shown in FIGS. 7 and 8.
an inner cylinder 4 into which a bolt (not shown) is inserted;
An outer cylinder 6 fixed to a joint element 5 such as rubber, a rubber bush 7 vulcanized and bonded to the axial center of the annular space between the inner cylinder 4 and the outer cylinder 6, and both ends of the inner cylinder 4 ( A pair of annular stoppers 8 having a rectangular cross section are fixed to the outer periphery of the rubber bushing 7 (both sides), and the durability of the rubber bushing 7 is improved by restricting compressive deformation of the rubber bushing 7 beyond a predetermined level by the stoppers 8. An improved flexible joint 1 has been proposed. (For example, Japanese Utility Model Application No. 59-122433).

Further, as shown in FIG. 9, a rubber bushing 7 is press-fitted into the center of the annular space between the inner cylinder 4 into which the bolt is inserted and the outer cylinder 6 which is fixed to the coupling element 5 in the axial direction. , a pair of annular stoppers 8 having a rectangular cross section are fixed to the outer periphery of both ends of the inner cylinder 4 (or the inner periphery of both ends of the outer cylinder 6), and reinforcing cords 9 are further wound around adjacent outer cylinders 6. Flexible joint 1 has been proposed (Utility Application No. 60-7586). In this structure as well, the stopper 8 similarly restricts compressive deformation of the rubber bush 7 beyond a predetermined value.

[Problem that the invention attempts to solve]

However, in the flexible joint configured as described above, low prying stiffness is maintained by the rubber bush 7 in the region until the annular stopper 8 comes into contact with the outer cylinder 6 or the inner cylinder 4.

However, the stopper 8 is not connected to the outer cylinder 6 or the inner cylinder 4.
There was a problem in that the prying stiffness became extremely high after contact with the bearing, that is, under a large torque load.

This high prying rigidity causes vibration and continuous noise in the vehicle (so-called muffled noise inside the vehicle) due to vibration of the drive shaft and the driven shaft.

In addition, since the contact portion between the stopper 8 and the outer cylinder 6 or the inner cylinder 4 is located at the front of the drive-side connection element 2 and the rear of the driven-side connection element 3, it not only has torsional rigidity but also prying rigidity when a large torque load is applied. It also becomes more expensive.

Therefore, an object of the present invention is to maintain low prying stiffness even under large torque loads.

[Means for solving problems]

Therefore, the present invention employs the following configuration as a means for solving the above-mentioned problems.

That is, the present invention provides a flexible joint having the above-described structure, in which a rubber bush is press-fitted into both ends of the inner cylinder and the outer cylinder, and the rubber bush is compressed to a predetermined degree or more in the axial center between the two rubber bushes. The present invention is characterized in that an annular stopper is provided on either one of the inner cylinder and the outer cylinder, and the contact surface of the stopper is formed into a convex spherical shape.

Specifically, taking FIGS. 1 and 2 as examples, the flexible joint 10 has an inner cylinder 24 and an outer cylinder 2.
5 and a rubber bushing 26 interposed between them,
The drive-side connection elements 21 and the driven-side connection elements 22, which are connected by means 27, are arranged alternately and equally on the circumference.

A reinforcing cord 29 is wound around the adjacent connecting elements 21 and 22, and the adjacent connecting elements 23 are formed by covering the periphery with an elastic body 30 such as rubber or synthetic resin. element 21,
22 are connected to each other.

Furthermore, the rubber bushes 26 and 27 are press-fitted into both ends of the inner cylinder 24 and the outer cylinder 25, and the axial center between the two rubber bushes 26 and 27 is compressed to a predetermined level or higher. An annular stopper 28 for regulating deformation is provided on either the inner cylinder 24 or the outer cylinder 25.

Furthermore, the contact surface of the stopper 28 is formed into a convex spherical surface 31.

[Effect]

According to the above-mentioned means, when the drive shaft is rotated by being used as a connecting portion between the drive shaft and the driven shaft, the rubber bushes 26 and 27 are
is compressed to an appropriate value, and this compression force is used to transmit torque while exhibiting low torsional rigidity and low prying rigidity.

On the other hand, when a large torque load is applied, the stopper 28 comes into contact with the outer cylinder 25 before the rubber bushes 26, 27 are compressed so strongly that they lose their elasticity, so that torque is transmitted through the stopper 28.

At this time, since the stopper 28 and the outer cylinder 25 are in elliptical contact with each other at the center in the axial direction, low prying stiffness is maintained even under a large torque load.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

1 to 3 show a flexible joint according to a first embodiment of the present invention, and FIG. 4 shows a propeller shaft for an automobile using a flexible joint in a connecting portion.

First, to explain FIG. 4, flexibility 10
A sleeve yoke 11 and a propeller shaft 13 are spline-fitted to the output shaft of a transmission (not shown).
The yoke 12 is disposed between the yoke 12 and the yoke 12. Propeller shaft 13 is front propeller shaft 13A
and rear propeller shaft 13B,
They are connected to each other by a cross joint 14A so that they can be angularly displaced. Further, the rear propeller shaft 13B is connected to a differential device (not shown) via a cross joint 14B so as to be angularly displaceable. Note that 15 is a center bearing support device that elastically supports the propeller shaft 13 on the vehicle body. Then, one end of the flexible joint 10 is connected to the drive side sleeve yoke 11 with the bolt 16 and the nut 1.
7, and the other end is connected to the driven side yoke 12 by a bolt 18 and a nut 19.

As particularly shown in FIG. 2, the flexible joint 10 includes three drive-side connection elements (hereinafter referred to as first connection elements) into which bolts 16 for fixing to the drive-side sleeve yoke 11 are inserted. ) 21 and driven-side connection elements (hereinafter referred to as second connection elements) 22 into which bolts 18 for fixing to the yoke 12 of the driven-side propeller shaft are inserted are arranged alternately on the circumference. and are arranged equally. and,
Adjacent connecting elements 21 and 22 are connected to each other by six coupling elements 23, which form an annular shape when viewed from the axial direction, and have a tooth shape connected to concavities and convexities when viewed from the direction perpendicular to the axis, as shown in FIG. It has an integrated structure.

The first connecting element 21 and the second connecting element 22 each have an inner cylinder 24 and an outer cylinder 25 concentrically, and rubber bushes 26 and 27 are interposed between them to connect both cylinders 21 and 22. It is integrated and further has an annular stopper 28 fitted therein.

On the other hand, the joint element 23 is constructed by forming reinforcing cords 29 such as polyester yarn in multiple layers and in multiple rows to connect the adjacent outer tubes 29 to 23.
5 and 25 to form an endless band having appropriate elasticity, and the reinforcing cord 29 is integrally covered with an elastic body 30 such as rubber or synthetic resin to form a predetermined solid layer. formed into a shape.

Of course, in the illustrated flexible joint 10, after the reinforcing cord 29 is sequentially wound between the outer cylinders 25, 25 of the first and second connecting elements 21 and 22 arranged at predetermined locations, the rubber 30 is wound. It is also possible to construct a flexible joint in which joint elements 23 of a predetermined shape are connected by batch vulcanization molding of the raw materials.

Now, in this embodiment, as shown in FIG. 1, the rubber bushes 26 and 27 interposed in the annular space between the inner cylinder 24 and the outer cylinder 25 are not interposed over the entire axial length, but are located at the axial center of the rubber bushes 26 and 27. It is inserted in a compressed state at both ends with . That is, a pair of annular rubber bushes 26 and 27 are vulcanized and bonded to the outer periphery of both ends of the inner cylinder 24, and then the inner cylinder 24 is press-fitted into the outer cylinder 25, thereby connecting the inner cylinder 24 and the outer cylinder 2.
It is integrated with 5.

On the other hand, the annular stopper 28 is used to restrict compressive deformation of the rubber bushes 26, 27 beyond a predetermined level, and is made thinner than the rubber bushes 26, 27. The stopper 28 is fitted and fixed on the outer periphery of the inner cylinder 24 at a central position in the axial direction between the pair of rubber bushes 26 and 27. Furthermore, the outer peripheral surface of the stopper 28 forms a contact surface with the outer cylinder 25, and the contact surface is formed into a convex spherical surface 31.

In the flexible joint configured in this way, the bolt 16 inserted into the inner cylinder 24 of the first connecting element 21
It is used by being connected to the sleeve yoke 11 on the drive side by a bolt 18 inserted into the inner cylinder 24 of the second connecting element 22 and to the yoke 12 of the propeller shaft on the driven side.

In the first connecting element 21, the torque during driving is from the inner cylinder 24 to the rubber bushes 26 and 27 to the outer cylinder 25.
It is transmitted to the joint element 23 via the outer cylinder 25 → rubber bushes 26 and 27 → the inner cylinder 24 in the second connecting element 22 to the driven side. At that time,
The first connecting element 21 is connected to the inner cylinder 2 with respect to the rotation direction.
4 is brought close to the inner surface of the outer tube 25, and the rear surface of the second connecting element 22 is brought closer to the inner surface of the outer tube 25, so that the rubber bushes 26, 27 interposed between them are compressed and deformed. It begins to transmit torque.

If the shape, dimensions, and elastic hardness are set at the design stage so that the rubber bushes 26 and 27, which are compressively deformed, have sufficient resistance to this deformation in the load state until the steady load is reached, the elastic The necessary elasticity can be maintained for a long period of time without causing fatigue, and vibrations during torque transmission can be effectively reduced.

On the other hand, when a large torque load is applied, the rubber bushes 26 and 27 are further compressed and deformed, and the inner cylinder 24 further approaches the outer cylinder 25, and the annular stopper 28 finally comes into contact with the inner surface of the outer cylinder 25. Thus, torque is directly transmitted between the rigid inner cylinder 24, stopper 28, and outer cylinder 25.

At this time, the stopper 28 and the outer cylinder 25 are in elliptical contact at the center in the axial direction, so that low prying stiffness is maintained even under this large torque load. In this state, the rubber bushes 26 and 27 are in a state of maximum compression deformation with a margin determined at the design stage, and are stable without being highly compressed.
Therefore, it is possible to avoid a situation where the elastic limit is exceeded. In other words, when a large torque load is applied, low prying stiffness and the rubber bush 26,
It is possible to achieve both durability and durability of 27.

Further, since the stopper 28 contacts the outer cylinder 25 at the center of the driving side connecting element 21 and the driven side connecting element 22, a larger joint angle can be obtained than in the conventional case.

FIG. 5 shows the main parts of a flexible joint according to a second embodiment of the present invention.

In FIG. 5, the parts corresponding to those in FIG. 1 are designated by the same reference numerals as in FIG. 1, and detailed explanation thereof will be omitted.

In this embodiment, an annular stopper 32 having a convex spherical surface 33 on the inner circumferential surface is fitted onto the inner circumferential surface of the outer cylinder 25.

According to this embodiment, the convex spherical surface 33 of the stopper 32 comes into contact with the outer circumferential surface of the inner cylinder 24 when a large torque is loaded, and the operation regarding torque transmission is the same as in the previous embodiment.

FIG. 6 shows a flexible joint according to a third embodiment of the present invention, and similarly in FIG.
Portions corresponding to those in the figure are designated by the same reference numerals as in FIG. 2, and detailed explanation thereof will be omitted.

In this embodiment, unlike the previous embodiment, a plurality of coupling elements are not connected in a concave and convex shape, but a single coupling element 34 in the shape of a disk is used.

Although the present invention has been described above with reference to specific embodiments, the present invention is not limited to the above-mentioned embodiments, but includes various embodiments within the scope of the claims for utility model registration. For example, it is possible to change the shape of the joint element by changing the number of turns of the reinforcing cord on the acceleration side and the deceleration side depending on the rotation direction, changing the plate thickness, or changing the wall thickness of the rubber bush in the rotation direction.

[Effect of idea]

As described above, according to the present invention, low prying stiffness can be maintained even under large torque loads.

As a result, vibration between the drive shaft and the driven shaft can be reduced, and vibration and continuous noise in the vehicle (so-called muffled noise inside the vehicle) can be prevented.

Furthermore, the durability of the rubber bushing can be greatly improved.

Furthermore, it is also possible to increase the joint angle compared to the conventional one.

[Brief explanation of the drawing]

Fig. 1 shows the main parts of the flexible joint according to the first embodiment of the present invention, and is an enlarged sectional view taken along the - line in Fig. 2; Figure 3 is a plan view of the flexible joint, Figure 3 is a side view of the main parts seen from the direction of the arrow in Figure 2, Figure 4 is an external view of an automobile propeller shaft using a flexible joint in the connection part, Figure 5 is A diagram corresponding to FIG. 1 showing the main parts of a flexible joint according to a second embodiment of the present invention, FIG. 6 is a plan view of a flexible joint according to a third embodiment of the present invention, and FIG. 7 is a conventional FIG. 8 is an enlarged sectional view taken along the line - in FIG. 7, and FIG. 9 corresponds to FIG. 8, which is an enlarged view showing the main parts of another conventional flexible joint. This is a diagram. Explanation of symbols, 10... Flexible joint, 21... Drive side connection element, 22... Driven side connection element, 23,
34...Joint element, 24...Inner cylinder, 25...Outer cylinder, 26, 27...Rubber bushing, 28, 32...
...Circular stopper, 29...Reinforcement cord, 30...
...Elastic body, 31, 33...Convex spherical surface of stopper.

Claims (1)

[Claims for Utility Model Registration] Drive-side connection elements and driven-side connection elements formed by connecting an inner cylinder and an outer cylinder with a rubber bushing interposed between them are arranged alternately and equally on the circumference. A flexible structure in which the adjacent connecting elements are connected by a joint element formed by winding a reinforcing cord around the adjacent connecting elements and covering the periphery with an elastic material such as rubber or synthetic resin. In the joint, the rubber bushing is press-fitted into both ends of the inner cylinder and the outer cylinder, and an annular stopper is provided in the axial center between the two rubber bushings to restrict compressive deformation of the rubber bushing beyond a predetermined level. and a flexible joint, which is disposed on either one of the outer cylinders, and further has a stopper whose abutting surface has a convex spherical shape.