JPH0684023U - Pin type torque transmission structure between shaft and rotating body - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] To provide a torque transmission structure for a shaft and a rotating body, which is composed of a small number of parts and can surely transmit torque. [Structure] After the shaft 10 and the sprocket (rotating body) 20 are fitted to each other, a circular hole H is drilled along each cylindrical surface with a drill. As a result, the shaft 10 is formed with the outward axial groove 14 and the sprocket 20 is formed with the inward axial groove 24. A slit 32 is formed in the pin 30 so as to open in the radial direction from the center line of the pin 30, but does not reach the center of the pin 30. The pin 30 has a screw hole 34 on the end surface. The diameter of the pin 30 is slightly larger than the diameter of the hole H. When the pin 30 is pressed into the circular hole H, the slit 32 narrows slightly. And after press fitting,
The pin 30 is pressed into the hole H by the so-called springback effect. The shaft 10 and the sprocket (rotating body) 12 cannot rotate relative to each other, and torque is transmitted reliably.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a structure for transmitting torque between a shaft and a rotating body.

[0002]

[Prior art]

 As a typical means for transmitting torque between the shaft and the rotating body, a means using a key and a key groove, or a tapering type fastening device as described in Japanese Utility Model Publication No. 3-15858. is there.

[0003]

[Problems to be solved by the device]

 The means of using the key and the key groove is to process the key groove on each cylindrical surface of the shaft having the outer peripheral cylindrical surface and the rotating body having the inner peripheral cylindrical surface and insert the JIS standard key into the key groove. It is a thing. However, this means has the following drawbacks. (1) A special machine tool is required to machine the keyway. (2) Precision is required for processing the keyway. And its processing relies exclusively on skilled workers. (3) The strength of the shaft and rotating body that have been machined with the keyway decreases.

On the other hand, in the taper ring type fastening device, the inner ring having the outer peripheral side taper surface and the outer ring having the inner peripheral side taper surface are wedge-engaged with each other by the tapered surfaces, and the surface pressure generated in the radial direction causes the shaft and the rotating body to rotate. And torque transmission is performed by frictional force. However, this device has the following drawbacks. (1) The tapering type fastening device is composed of many components, and has a complicated structure and a large size. Also, the cost increases. (2) Since torque is transmitted by frictional force, when an impact occurs on the shaft or rotating body, slippage occurs between them. The size increases when safety is taken into consideration.

An object of the present invention is to provide a torque transmission structure for reliably transmitting torque between a shaft and a rotating body with a small number of parts.

[0006]

[Means for Solving the Problems]

 The present invention provides a torque transmission structure for transmitting torque between a shaft having a cylindrical surface and a rotating body having an inner cylindrical surface with the cylindrical surfaces fitted together. The torque transmission structure has an outward axial groove formed on the outer peripheral cylindrical surface of the shaft and an inward axial groove formed on the inner peripheral cylindrical surface of the rotating body. The directional groove and the inward axial groove together form a substantially circular hole, and further has a pin with a diameter slightly larger than the diameter of the hole, the pin being radially The above problem has been solved by the torque transmission structure between the rotating body and the shaft that has a slit that is open and penetrates in the axial direction.

[0007]

[Action]

 After fitting the shaft and the rotor on their respective cylindrical surfaces, a substantially circular hole is formed. The pre-insertion pin has a diameter slightly larger than the circular hole and has a slit that opens radially in the pin and penetrates axially. Therefore, when the pin is press-fitted into the circular hole, the slit is narrowed, and after the press-fitting, the pin is securely pressed into the circular hole by the so-called springback effect. Relative rotation between the shaft and the rotating body is blocked, and torque is transmitted through the pin.

Further, in the above torque transmission structure, when the slit is arranged so as to face the direction normal to the cylindrical surface and the pin is fitted in the hole, no shearing force acts on the slit.

[0009]

【Example】

 In the following embodiments, the case where the sprocket is a rotating body and the sprocket is attached to the shaft will be described.

As shown in FIGS. 1 to 3, the shaft 10 and the sprocket 20 are fitted to each other at the outer peripheral cylindrical surface 12 and the inner peripheral cylindrical surface 22. In that state, a circular hole H is drilled along the fitted cylindrical surfaces 12 and 22. In this manner, the shaft 10 is formed with the outward axial groove 14 and the sprocket 20 is formed with the inward axial groove 24.

As shown in FIGS. 3 and 4, the pin 30 has a slit 32 that penetrates in the axial direction. The slit 32 is open in the radial direction, but does not reach the center of the pin 30. Further, the pin 30 has a screw hole 34 on the end surface.

The diameter of the pin 30 before insertion is slightly larger than the diameter of the hole H. When the pin 30 is pressed into the circular hole H, the slit 32 narrows slightly. After the press-fitting, the pin 30 is pressed into the hole H by the so-called springback effect. After that, the plate P is attached to the end faces of the shaft 10 and the sprocket 20 to prevent the pin 30 from coming off.

The number of circular holes and pins can be two or more depending on the magnitude of the torque to be transmitted. When removing the pin 30, a jig may be inserted into the screw hole 34 and then removed. Since such a technique is well known, its explanation is omitted.

As shown in FIG. 4, when the pin 30 is press-fitted so that the slit 32 faces in the direction normal to the cylindrical surface, the slit 32 does not follow the cylindrical surface, so that the shearing force does not act on the slit 32. , The pin 30 can be protected.

[0015]

[Effect of device]

 Since the present invention has the above configuration, it has the following effects. (1) The torque transmission structure of the present invention has a small number of parts and is simple in structure like the torque transmission structure by the key and the key groove. What's more, ordinary tools are sufficient for the tools used. In this respect, it is advantageous as compared with the tapering type fastening device. (2) Moreover, since the pin has a narrow slit and is press-fitted into a circular hole, precise machining such as a key and a key groove performed by a skilled person is unnecessary. Since the press-fitted pin is pressed into the circular hole by the so-called springback effect, it is possible to reliably prevent the shaft and the rotating body from being displaced.

According to the configuration of claim 2, since the shearing force does not act on the slit, the pin can be protected.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a torque transmission structure according to the present invention.

FIG. 2 is a left side view of FIG.

FIG. 3 is an exploded perspective view of the torque transmission structure of FIG.

FIG. 4 is an enlarged view of the torque transmission structure with the plate removed from FIG. 1.

[Explanation of symbols]

 H circular hole 10 shaft 12 outer peripheral cylindrical surface 14 outward axial groove 20 sprocket (rotating body) 22 inner peripheral cylindrical surface 24 inward axial groove 30 pin 32 slit

Claims (2)

[Scope of utility model registration request] 1. A torque transmission structure in which a shaft having an outer peripheral cylindrical surface and a rotating body having an inner peripheral cylindrical surface are fitted to each other at their cylindrical surfaces to transmit torque between the shaft and the rotating body. The torque transmission structure has an outward axial groove formed on the outer peripheral cylindrical surface of the shaft and an inward axial groove formed on the inner peripheral cylindrical surface of the rotating body. The axial groove and the inward axial groove together form a substantially circular hole, and further has a pin with a diameter slightly larger than the diameter of the hole, the pin being radially A torque transmission structure between the shaft and the rotating body, which has a slit that opens and penetrates in the axial direction. 2. The torque transmission structure between the shaft and the rotating body according to claim 1, wherein the slit is arranged so as to face in a direction normal to the cylindrical surface.