JPS5936737Y2 - shaft joint - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flexible shaft joint that rationally connects shafts for transmitting power in small-sized equipment and allows accurate transmission of power.

Traditionally, joints that connect drive shafts in small devices, precision equipment, etc. have a bulky structure such as shaft joints in general machines, which occupy a large volume and cause problems with other mechanisms. Conventional joints are not used, and in many cases a sleeve-shaped joint is fixed to the shaft using a pin.With this type of shape, if the shaft centers are not aligned correctly, the shaft may become distorted when rotating. This results in a lack of smoothness, which not only causes noise and reduced efficiency, but also causes shaft breakage.

Therefore, methods have been adopted in which a rubber joint is fitted directly onto the shaft to provide flexibility, but in this case, the joint itself twists when a large torque is applied, such as during startup. However, there are drawbacks such as repeated fatigue phenomena and poor durability.

Of course, some conventional universal joints are in practical use, but as they become smaller, they become more expensive and have other problems, such as poor durability.

In view of the current situation, the present invention has been developed to solve the conventional problems and to create a compact shaft joint that has an extremely simple structure, is flexible, and can transmit power accurately and smoothly without reducing efficiency. This is what we provide.

In the present invention, the joint piece that is fitted and fixed to the shaft end is made of metal or hard synthetic resin and has a hole in the center of the rear half for fitting and fixing the shaft, and inside the front half there is a hole from the shaft core to the shaft. Two or more appropriately narrow cut grooves are provided radially, and a ridge line with a downward slope is arranged in the center of each part divided by the cut grooves, and both sides of the ridge line have equal slopes toward the cut grooves. Two such joint pieces are made to face each other, and there are formed uneven parts that are symmetrically engaged with the cut groove of the joint piece and the chevron-shaped protrusion between them. It is constructed so that a connector made of a rubber material is fitted and connected, and the joint piece and the shaft are fixed together with a pin or key.

Below, the present invention will be described in detail with reference to drawings regarding one embodiment.
At the front of the boss 11, which has a shaft insertion hole 12 in the center,
Cut grooves 14 of an appropriate width are equally divided into the inside of the cut groove 14 in a cross shape passing through the axis and perpendicular to each other at a depth approximately equal to that of the boss length, and the portions divided by each cut groove 14 are divided into sections. At the center, that is, at positions displaced by 45 degrees from the center line of each cut groove, a ridge line 15' is formed with a downward slope at an appropriate angle from the periphery to the center, and both sides of this ridge line 15' are directed toward the cut groove 14, respectively. A connector receiving portion 13 is provided by forming a chevron-shaped protrusion 15 cut with an equal slope, and a joint piece 10 is constructed.

The end of the transmission shaft 1 is inserted into the shaft insertion hole 12 of the boss 11 of the joint piece 10, and is fixed with a pin 2 or a key. The two joint pieces 10.degree. 10 are opposed to each other, and are connected by interposing connectors 20 made of highly durable rubber or rubber material that fit into the respective receiving portions 13.

This connector 20 has a through hole 21 of an appropriate diameter drilled in the direction of the solid axis, and its outer shape has four fin-like protrusions 22 equally divided at both ends as shown in FIG. ,
Between each protruding piece 22, notches 23 with a slope matching the chevron-shaped protrusion 15 of the joint piece 10 are formed equally, and only the appropriate length of the intermediate part is cylindrical, and the front end surface of each protruding piece 22 and Each of the outer end surfaces is sloped so that it can be easily inserted into the receiving portion 13 of the joint piece.

The above-mentioned joint piece 10 can be easily mass-produced, dimensionally accurate, and inexpensive by using a hard synthetic resin, a metal that can be easily die-cast such as aluminum or zinc, or a sintered alloy.

In the shaft joint of the present invention, the shafts are connected by fitting together the parts configured as described above, and during the connection, the joint piece 10 is fixed to the end of the shaft to be connected, and the shaft joint is inserted into each connector receiving part 13. If the rubber connector 20 is inserted by fitting the protruding piece 22 of the connector 20 into the notch 14 on one side of the joint, the notch 23 of the connector 20 and the joint piece 1 are inserted.
0 and the chevron-shaped protrusions 15 come into surface contact with each other on the sloped surfaces, so that the axes of both automatically and positively align, and the joint piece 10 and the connector 20 contact and engage over a wide area, By engaging the protruding piece 22 and the cut groove 14, the chevron-shaped protrusion 15 traces the chevron-shaped protrusion 15, and exhibits a connection function that maintains the rotational state without causing contact and release with the corresponding notch 23, thereby reducing the rotational force of one shaft. can be reliably transmitted to the other shaft, and both joint pieces 10 and 10 can be easily connected and power can be transmitted without requiring fastening parts such as bolts.

In this way, the joint piece 10 and the connector 20 are connected to the chevron-shaped protrusion 1
5 and the corresponding notch 23 greatly assist the power transmission through centripetal action and surface contact, whereas the notch 1
4 and the protrusion 22 are used to maintain the transmission of rotational force, so the dimensional ratio between the two is such that the length in the axial direction is such that no excessive deformation force is applied to the protrusion, as illustrated in the figure. By having this, the purpose can be effectively achieved and the entire joint can be miniaturized without being elongated, which is advantageous.

Therefore, if there is a misalignment of the axes between the two shafts during rotation operation, it is natural that the connector 20 should be made of a rubber material with high durability (mechanically and chemically). Increasing torsion is absorbed by its elasticity, and by providing the through hole 21 in the center in particular, the strain is dispersed in this area, so that no strain occurs and smooth power transmission is achieved.

Furthermore, the initial torque at startup is quickly absorbed by the rubber connector interposed between the joint pieces due to the propagation of internal stress and the return of deformation (elasticity) caused by the shape, allowing smooth power transmission to the driven shaft. A shaft joint for small shafts that absorbs noise caused by vibrations generated during startup, etc., and that can faithfully transmit rotational force with the wide contact surface and locking mechanism provided by the mounting base structure as described above. It can be said that it has a great practical effect as it works effectively and solves the problems of the conventional method without being bulky.

In addition, in accordance with the spirit of the present invention, the number of cut grooves is not limited to the above embodiment, and the number of cut grooves may be divided into two or three linearly, or may be changed to four or more within a practical range. The outer shape of the joint piece can also be made into any desired shape.

[Brief explanation of drawings]

The drawings show one embodiment of the shaft joint of the present invention, in which Fig. 1 is a vertical cross-sectional view of the assembled state, Fig. 2 is a vertical cross-sectional view of one joint, and Fig. 3 is a view taken along line III-III of Fig. 2. FIG. 4 is a partially vertical side view of the connector, and FIG. 5 is a VV view of FIG. 4. 10... Joint piece, 11... Boss, 12
...... shaft insertion hole, 13... middle connector receiving part,
14... Cut groove, 15... Angular protrusion, 15'... Ridge line, 20... Connector, 21... Hole, 22...protrusion, 23.
・・・・・・Notch part.

Claims (1)

[Scope of utility model registration request] A shaft insertion fixing hole is provided at the center of the rear half boss part, and a plurality of suitably narrow cut grooves are equally divided radially from the shaft center leaving an outer peripheral wall inside the front half part, and each of the cuts is A connector receiving part is provided in the center of each part divided by the groove, with a ridge line with a downward slope in the center, and a chevron-shaped protrusion cut on both sides of the ridge line with an equal slope in the direction of the groove. two such joint pieces are arranged to face each other and are each fixed to a shaft end, and a projecting piece and a chevron-shaped protrusion that fit into the cut grooves of the joint piece symmetrically between the two joint pieces; 1. A shaft joint, characterized in that a connector made of a rubber material and having a notch that matches the shape of the connector is fitted into a connector receiving portion of each joint piece for connection.