JPH0711899Y2 - Rotation transmission device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a rotation transmission device, and more particularly to a transmission device suitable for use in an articulated robot or the like.

[Prior Art] Conventionally, in an articulated robot or the like, a first arm is attached to a base, and a second arm is attached to a tip end portion of the first arm. In this case, the second arm is attached to the first arm via a driving motor for driving the second arm, and the second arm is driven with the driving motor as a fulcrum. In such a drive system, generally, as shown in FIG. 7, the pulleys 3 and 4 are attached to the output shaft 1 of the drive motor and the attachment shaft 2 of the second arm, and between the pulleys 3 and 4. A loop-shaped tape made of a highly constant elastic material for power transmission, a belt or a transmission mechanism with a wire 5 is used.

However, in the transmission mechanism using the frictional force between the pulleys 3 and 4 and the belt 5 as described above, a deviation occurs between the pulleys 3 and 4 and the belt 5, which causes a large transmission torque, Moreover, it was not suitable as a transmission mechanism for a robot arm that rotates in both forward and reverse directions. On the other hand, in order to eliminate such defects, for example, as shown in FIG.
It is conceivable to use a method of welding the belt 5 to the pulley or fixing the belt 5 with screws 6, 6 or the like. However, such a transmission mechanism has a drawback that the rotatable range of the pulley, that is, the arm is limited (the rotation angle is 180 degrees at the maximum).

On the other hand, as a transmission mechanism that solves the above-mentioned drawbacks of the prior art and does not limit the rotatable range of the arm, for example, Japanese Patent Publication No. 61-57158, No. 9 (a), (b).
And (c), two belts 7 and 7 ', which are open belts and wound in parallel, are used, and these belts 7 and 7'are attached to the pulleys 3 and 4, respectively. It is known that both ends are fixed at the same angle.

[Problems to be Solved by the Invention] However, in the above-described conventional transmission mechanism, when the fixing portion of the one belt with respect to the pulley is disengaged, the rotational movement of the pulley is not regulated at all. For this reason, there is a problem in that the arm is free, which is dangerous.

Therefore, the present invention solves the above-mentioned problems in the prior art, provides a large rotatable range of the pulley or the arm, and allows the arm to rotate freely even when the fixing portion between the belt and the pulley is disengaged. It is an object of the present invention to provide a transmission device of a link mechanism that does not cause danger and is particularly suitable for use in an articulated robot or the like.

[Means for Solving the Problem] That is, the above-mentioned object of the present invention is to provide a rotation transmission device for transmitting torque applied to a drive pulley to a driven pulley,
Auxiliary pulleys are provided in the vicinity of the drive pulley and the driven pulley, respectively, and a loop-shaped belt composed of at least two first and second portions having the same length is formed, and these portions are vertically shifted to be integrally connected. , The auxiliary pulleys, and the auxiliary pulleys, and the drive pulley and the driven pulley. This is achieved by a rotation transmission device characterized in that each is fixed to the peripheral surface of the pulley.

[Operation] According to the transmission device of the link mechanism according to the present invention, the rotation of the pulley is effective even for high torque because the belt is fixed to the pulley and the method of transmitting the power by the friction force is used together. It is possible to transmit with high accuracy and stability. In addition, it is possible to make the rotatable range large. For example, when the auxiliary pulleys have almost the same diameter as the drive pulley and the driven pulley and they are close to each other, the rotation of 270 ° or more is required. Is possible. Further, even when the fixing portion between the belt and the pulley is disengaged, the rotation of the driven pulley is restricted by the friction of the belt and the driven pulley does not rotate freely.

[Embodiment] An embodiment of the present invention will be described below with reference to the accompanying drawings.

First, FIGS. 4A and 4B are front and top views of an articulated robot that employs a transmission device according to an embodiment of the present invention, which will be described in detail below. As is clear from this figure, the articulated robot has a base 10 and a first arm 11
And the second arm 12 is attached to the tip of the first arm 11. The drive motor 13 for driving the second arm is separated from the rotary mounting shaft 15 of the second arm 12 so as not to burden the drive motor 14 of the first arm 11, The first arm 11 is mounted at a position close to the rotary mounting shaft 16.

FIGS. 1 (a) and 1 (b) show a transmission device according to the present invention, which is adopted as a driving unit of the articulated robot. In these figures, for example, the first drive pulley 21
Is connected to the output shaft 17 of the drive motor 13 for driving the second arm 12 of the articulated robot, while the driven pulley 22 is connected to the second arm 12 of the articulated robot. A driven shaft 15 provided at the tip of the first arm 11 is connected for driving.

The auxiliary pulleys 23 and 24 are provided near the drive pulley 21 and the driven pulley 22. These auxiliary pulleys 23 and 24 are the drive pulley 21 and the driven pulley.
22 are provided close to and parallel to the axes thereof, and their diameters are slightly larger than the diameters of the drive pulley 21 and the driven pulley 22 and have substantially the same diameter dimension. Has become. Further, the auxiliary pulleys 23 and 24 are each divided into two parts, that is, an upper part and a lower part, which are rotatable in different directions. These drive pulley 21 and driven pulley
22 and these auxiliary pulleys 23, 24 have looped belts
25 is wound.

As shown in FIG. 2, the loop-shaped belt 25 is such that the first and second portions 25 'and 25 "having the same strip shape are displaced in the axial direction of the pulleys 21 and 22, that is, vertically. As shown in Fig. 3, the loop-shaped belt 25 is wound around the auxiliary pulleys 23 and 24, and both connecting portions are connected to each other to form an integrated loop-shaped belt.
A part of the front and rear of 26, 26 'is drawn inward from the portion wound around the auxiliary pulleys 23, 24 so as to have a substantially "8" shape, and the auxiliary pulleys 23, 24 and the drive pulley 21 are connected to each other. It is wound around the driven pulley 22 in a plow (only the drive pulley 22 and the auxiliary pulley 24 are shown in FIG. 3). Further, as shown in FIG. 3 (b), the connecting portion 26 (shown by diagonal lines in the drawing) of the first and second portions is connected to the drive pulley 21 and the driven pulley 22 by welding, screwing or the like. It is fixed on the surface.

Next, the operation of the transmission device of the link mechanism will be described below.

In FIG. 1 (a), when the drive pulley 21 is rotated clockwise by the drive of the drive motor 13 via the output shaft 17, as shown by the solid arrow in FIG.
Also rotates counterclockwise as indicated by the solid arrow.
As a result, the upper and lower parts 2 of the loop belt 25 are
5'and 25 "run left and right respectively, and the auxiliary pulley 2
4 rotates counterclockwise and driven pulley 22 rotates clockwise. As a result, for example, the second arm 12 of the articulated robot shown in FIG. 4 is rotated via the drive shaft 15 connected to the driven pulley 22.

On the other hand, when the drive pulley 21 to which the driven shaft of the drive motor 13 is connected rotates in the counterclockwise direction as shown by the broken line arrow in the figure, the driven pulley 22 moves in the opposite direction to the above,
Like the drive pulley 21, it rotates counterclockwise.

5 (a), (b) and (c), and further in FIG.
Another embodiment of the transmission device of the link mechanism according to the present invention is shown. The looped belt 250 used in this embodiment is shown in FIG. This loop belt 2
In addition to two strip-shaped portions 250 'and 250 "having the same length as the loop-shaped belt 25 shown in FIG. 2 mentioned above, 50 further shifts another strip-shaped portion 250 in the pulley axial direction, They are joined at their ends to form an integral loop belt.

Then, a state in which such a three-stage loop belt 250 is wound around the drive pulley 21, the driven pulley 22, and these auxiliary pulleys 23 and 24 is a top view of FIG. 5 (a) and FIG. 5 (b). ), (C) in front and rear views. The transmission device of the link mechanism according to the other embodiment also operates essentially in the same manner as shown in FIGS. 1 (a) and 1 (b). In the transmission device of the link mechanism according to the other embodiment, the auxiliary pulleys 23 and 24 are divided into three stages in the axial direction.

In the link mechanism transmission device according to the above-described embodiment, the method of fixing the belt to the pulley and the method of transmitting the power by the friction force are used in combination to position the pulley or the arm accurately with respect to high torque. And it becomes possible to carry out stably. Further, the rotatable range thereof can be made relatively large as compared with the transmission device of the link mechanism according to the above-mentioned related art, and further, even when the fixing portion between the belt and the pulley is disengaged, the belt does not move on the pulley. Since the arm is always wound around, the arm does not rotate freely and there is no danger.

[Effects of the Invention] As is clear from the above description, according to the present invention, the pulley or the arm can be positioned accurately and stably with respect to high torque, and the rotatable range of the pulley or the arm is also increased. It can be taken big. Further, even if the fixing portion between the belt and the pulley is disengaged, the arm does not freely rotate to cause a danger, and a link mechanism transmission device most suitable for use in an articulated robot or the like is provided. Can be done.

[Brief description of drawings]

1A and 1B are a top view and a front view of a transmission device of a link mechanism according to an embodiment of the present invention, and FIG. 2 is a perspective view showing a belt used in the transmission device of the link mechanism. 3 (a) and 3 (b) are perspective views showing how the belt is wound around the transmission device of the link mechanism, and FIGS. 4 (a) and 4 (b) are transmission devices of the link mechanism according to the present invention. FIGS. 5A, 5B, and 5C are front and top views showing an articulated robot adopting the present invention. FIGS. 5A, 5B, and 5C are top and front views of a transmission device of a link mechanism according to another embodiment of the present invention. FIG. 6 is a perspective view showing the structure of a belt used in the transmission device of the link mechanism of the other embodiment described above, and FIG.
Figures and 8 and also Figures 9 (a), (b) and (c).
[Fig. 3] is an explanatory diagram for explaining a conventional technique. 10 ... base, 11 ... first arm, 12 ... second arm, 13,
14 ... Drive motor, 15, 16 ... Rotating mounting shaft, 21 ... Drive pulley, 22 ... Followed pulley, 23, 24 ... Auxiliary pulley, 25 ... Loop belt, 25 ', 25 ″ ... Belt belt, 26, 26 '...
Joining part, 250… Loop belt, 250 ′, 250 ″, 250
... Belt belt

Claims (1)

[Scope of utility model registration request] 1. A rotation transmission device for transmitting torque applied to a drive pulley to a driven pulley, wherein auxiliary pulleys are provided near the drive pulley and the driven pulley, respectively, and at least two first and second equal lengths are provided. A loop-shaped belt, which is made up of parts and is vertically connected to each other and integrally connected, is wound around the auxiliary pulleys, and further, it is provided between the auxiliary pulleys and the drive pulley and the driven pulley. A rotation transmission device, wherein one of the connecting portions is fixed to a peripheral surface of a drive pulley and the other of the connecting portions is fixed to a peripheral surface of a driven pulley.