JP3087091B2 - Power transmission device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power transmission device suitable as a nut runner adapter suitable for tightening and loosening bolts and nuts located in narrow gaps.

[0002]

2. Description of the Related Art When using a nut runner to tighten or loosen a bolt or nut provided in a narrow gap, the nut or runner body with a built-in electric motor or air motor is in the way, and the bolt and nut are directly connected to the rotation shaft of the nut runner. May not be installed. In this case, an adapter generally called a clearance wrench is used to transmit the rotational force of the nut runner from a position away from the bolt and nut.

This adapter usually has an input shaft connected to a rotating shaft of a nut runner, and an output shaft for mounting a socket on a bolt / nut side. A belt, a chain, a gear, or the like is provided between the input shaft and the output shaft. Are connected by power transmission means.

[0004]

When the above-mentioned adapter is used, it is desirable to reduce the outer dimensions of the output shaft on which the socket is to be mounted, as small as possible so that the adapter can be used with as small a gap as possible. However, in general, the tightening torque of bolts and nuts used in a building or a building is considerably large, and in a power transmission device used for such a nut runner, the tension applied to a chain or a belt becomes extremely large. Here, if the outer dimensions of the output shaft are reduced, the diameter of the sprocket or pulley provided on the output shaft must be reduced, and there is a problem that the tension is further increased and the durability of the chain or belt is reduced.

In this type of prior art, when the output shaft is rotated by a chain or a belt, a large force acts between the input shaft and the output shaft in the direction of approaching each other due to the tension of the chain or the belt. As a result, uneven wear of the bearings of these shafts is promoted, and there is also a problem that their durability is reduced.

In order to improve such a point, for example,
As in the invention described in Japanese Patent Application Laid-Open No. Sho 60-212265, there has been proposed a method of transmitting torque by combining an endless power transmission member such as a chain or a belt with a gear train. Indeed, according to such a proposal, a force that pushes the input shaft and the output shaft away from each other at the time of rotation transmission by the gear train is applied, and this separating force and the approaching force by the chain or the belt cancel each other, and The force applied to the shaft is reduced, and uneven wear of the bearing is also improved.

However, in such a conventional technique, since the output shaft and the input shaft are connected by a gear train, if the shaft is used for an adapter for a nut runner in which both shafts are separated from each other, the number of gears and their bearings is inevitably reduced. However, there is a disadvantage that the apparatus becomes complicated and heavy. Further, the separating force by the gear train is obtained by multiplying the rotation transmitting force by a sine count based on the pressure angle of the gear, and not all of the rotating transmitting force can be used as the separating force between the two shafts. Therefore, it has been impossible to obtain a separating force sufficient for the approaching force of the chain or the belt.

The present invention has been proposed to solve the above-mentioned problems of the prior art. It is an object of the present invention to provide a simple structure that does not use a gear train, and to provide an approaching force for a chain or a belt. An object of the present invention is to provide a power transmission device capable of obtaining a sufficient separation force with respect to the above, and being applicable to a nutrunner adapter or other device in which the input shaft and the output shaft are separated.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention has a sprocket or pulley fixed to an output shaft and an input shaft, respectively, and a chain or belt is interposed between the sprocket or pulley of each shaft. In the power transmission device for transmitting the rotation of the output shaft to the input shaft by multiplying the output shaft and the input shaft, a sprocket or pulley for separating force is fixed to the sprocket or the pulley in parallel with the sprocket or the pulley. A compression type belt formed by connecting a number of blocks in an endless manner is hung between sprockets or pulleys for separating force to transmit rotation of an input shaft to an output shaft.

[0010]

The operation of the power transmission device of the present invention having the above-described configuration is as follows. That is, an approaching force acts between the two shafts by a chain or a belt hung between the input shaft and the output shaft. On the other hand, in a compression type belt, since the rotational force of the input shaft is transmitted to the output shaft with the compression side of the belt being rigid, a separating force acts between the two shafts. As a result, the approaching force of the chain or belt and the separating force of the compression belt are offset, and even without using a gear train,
A biased force applied between both shafts can be eliminated.

[0011]

【Example】

(1) First Embodiment--FIG. 1 Hereinafter, a first embodiment of the present invention will be specifically described with reference to FIG.

In FIG. 1, reference numeral 1 denotes a hollow case, and an input shaft 2 extending in the same direction is provided at both ends of the case 1.
And the output shaft 3 are rotatable via bearings 4 and 4, respectively. Both ends of the input shaft 2 are exposed from openings 5, 5 provided on the front and back surfaces of the case 1, respectively, and concave portions 7, 7 for fitting the output shaft on the nut runner 6 side are provided on the exposed portions. . Output shaft 3 is case 1
Exposed from the openings 8, 8 formed on the front and back surfaces of
One of the exposed ends is provided with a recess 9 for fitting the output shaft of the nut runner 6 like the input shaft 2.
Further, the other end of the output shaft 3 is a convex portion 10, and a socket 11 to be fitted to a bolt / nut is detachably attached to a tip of the convex portion 10.

Sprockets 12 and 13 are fixed to the input shaft 2 and the output shaft 3, respectively.
A chain 14 is stretched between 2 and 13.
The input shaft 2 and the output shaft 3 have the sprocket 1
Pulleys 15 and 16 having V-shaped grooves in parallel with 2, 13
Is fixed, and a compression type belt 17 is stretched between the pulleys 15 and 16.

FIGS. 2 to 4 show an example of the compression type belt 17, which is an endless steel strip 1. FIG.
A large number of wedge-shaped metal blocks 17b are attached to 7a. A convex portion is formed on the surface of each metal block 17b,
The protruding portion is configured so as to enter into the concavity on the back surface of another adjacent metal block.

The operation of this embodiment having the above configuration is as follows. That is, when the rotational force of the nut runner 6 is transmitted to the input shaft 2, the input shaft 2 rotates, and the rotational force is transmitted to the output shaft 3 by the sprockets 12, 13 and the chain 14 interposed therebetween, and the output shaft 3 3 rotates. At this time, as in the prior art, the chain 14
, A proximity force acts between the two axes.

At the same time, the pulley 15 fixed to the input shaft 2
Rotates, and the outer periphery of the pulley 15 presses the inner periphery of the compression belt 17 in the direction of the arrow in FIG. 4 via the contact pressure. Then, since the compression type belt 17 cannot be further contracted after each metal block 17b is brought into close contact, the rotational force of the pulley 15 is applied to the compression type belt 17 that has become tightly attached and becomes rigid.
Press to the side. When the compression belt 17 is pressed in this way, the force is transmitted to the pulley 16 on the output shaft 3 side, and the contact pressure between the inner periphery of the compression belt 17 and the outer periphery of the pulley 16 causes the pulley 16 to move as indicated by an arrow in the drawing. Rotate in the direction. At this time, the two shafts 2 and 3 are pressed by the compression type belt 17 which has become a rigid body, and a separating force acts between the two shafts.

As described above, according to the present embodiment, the approach force due to the tension of the chain 14 and the separating force due to the pressing force of the compression belt 17 act on the input shaft 2 and the output shaft 3.
The approaching force and the separating force cancel each other out, so that no offset force is applied to both axes. In particular, unlike conventional gear trains, since both are caused by the tension and compression force between the chain and the belt, the magnitudes of the approaching force and the separating force are almost equal, and the two have an excellent canceling effect. Further, since a large number of members are not required between the two shafts unlike the gear train, even if the distance between the two shafts is large, the torque can be transmitted with a simple structure. Further, since the transmission of the rotational force is performed by both the chain and the compression type belt, the transmitted force is divided, the individual pulleys and sprockets are reduced in size, and are suitable as adapters used in narrow gaps.

(2) Second Embodiment--FIG. 5 In the first embodiment, a chain and a compression type belt are used one by one, but as in the second embodiment shown in FIG. It is also possible to use a combination of a plurality of belts 21 and 21 and a compression belt. Of course, the present invention is not particularly limited to the types of chains and belts, and the number thereof, as long as a combination of a pull-type driving means and a compression-type driving means cancels the approaching force and the separating force between both shafts. good.

[0019]

As described above, according to the power transmission device of the present invention, there is no bias in the force applied between the input shaft and the output shaft, and the uneven wear of the bearings of both shafts can be eliminated. The durability of the bearing can be improved. In addition, transmission loss due to uneven wear of the bearing is eliminated, and transmission efficiency of rotational force is also improved. Furthermore, the overall size of the apparatus is reduced by downsizing each shaft portion and simplifying the structure by eliminating the need for a gear train. For example, it is possible to realize an adapter for a nut runner that can cope with a narrow gap.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment in which a power transmission device of the present invention is applied to an adapter of a nut runner.

FIG. 2 is a cross-sectional view of the compression-type belt in the embodiment of FIG. 1 cut at a right angle to its length direction.

FIG. 3 is a sectional view taken along lines AA and BB in FIG. 2;

FIG. 4 is a side view showing the principle of a compression type belt.

FIG. 5 is a sectional view showing a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Case 2 ... Input shaft 3 ... Output shaft 14 ... Chain 17 ... Compression type belt

Claims (1)

(57) [Claims] 1. A power transmission device in which a sprocket or a pulley is fixed to an output shaft and an input shaft, respectively, and a chain or a belt is hung between the sprockets or pulleys of these shafts to transmit rotation of the output shaft to the input shaft. A sprocket or pulley for separating force is fixed to the output shaft and the input shaft in parallel with the sprocket or pulley, and a number of blocks are endlessly arranged between the separating sprocket or pulley for each shaft. A power transmission device for transmitting a rotational force of an input shaft to an output shaft by hanging a compression type belt connected in a shape.