JPS6339784A - Wrist device for industrial robot - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a wrist device for an industrial robot.

Conventional technology FIG. 2 shows a conventional wrist device.

In Fig. 2, 21 is a main body arm, 22 and 27 are sprockets, 23 is a harmonic reducer for the rotation shaft, and 24
25 is a rotating shaft, 25 is a bevel gear, 26 is a bending shaft, 28 is a chain, 29 is a harmonic reduction gear for the bending shaft, 30 is a pulley, 31 is a belt, and 32 is a motor.

In the above configuration, the rotation of the bending shaft layer motor 32 is reduced by the bending shaft harmonic reducer 29, and the sprocket 22. ''' 27 and the chain 28 to the bending shaft 26.The rotation shaft 24 transmits the rotation of the bending shaft layer motor 32 to the harmonic reducer 23 for the rotation shaft via the belt 31 and the pulley 3Q, and the bevel gear 26. Rotating axis 2 through
Problems to be Solved by the Invention However, since the output shaft of the bending shaft harmonic reducer 29 and the bending shaft 26 are connected by the chain 28,
There are disadvantages such as a decrease in position repeatability at the tip of the wrist due to stretching, the need for periodic maintenance, and poor position repeatability due to poor hysteresis characteristics. In addition, a shaft drive, belt transmission, etc. can be considered as a transmission element for the chain on the output side, but shaft drives have the disadvantage of large hysteresis characteristics of couplings, and backlash between pulleys and belts and belt width This has the disadvantage of increasing the size of the wrist due to the increase in the amount of pressure, and furthermore, simply attaching two harmonic reducers for bending and rotating axes to the wrist increases the size of the wrist, which degrades the motion characteristics of the industrial robot. However, it has drawbacks such as reduced workability, making it difficult to put it into practical use.

Means for Solving the Problems In order to solve the above problems, the industrial robot wrist device of the present invention includes a harmonic reducer for the bending shaft between the main body arm and the bending shaft on the rotation center of the bending shaft. Install the harmonic reducer for the rotary shaft inside the harmonic reducer for the bending shaft between the bending shaft and the rotating shaft, attach pulleys to each of the input shafts of the bending shaft and the rotary shaft, and attach the belt. The pulley is connected to a motor installed on the arm of the main body through an intermediary.

Operation With the above configuration, the positional accuracy is increased by using belt transmission on the input side of the harmonic reducer, which has little effect on positional accuracy, and directly connecting the output side of the harmonic reducer, which is affected.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to FIG.

In FIG. 1, 1 is a main body arm portion, 6 is a bending shaft, and 9 is a rotation shaft. A bending shaft harmonic reducer 6 is mounted on the rotation center of the bending shaft 6 between the main body arm portion 1 and the bending shaft portion. Inside the bending shaft harmonic reduction gear 6, a harmonic reduction mode for the rotating shaft is incorporated between the bending shaft portion and the rotating shaft portion.

Pulleys 2 and 10 are attached to each input shaft of the shaft shaft 6 and rotation shaft 9, respectively.

The rotation of a motor (not shown) attached to the main body arm portion 1 is transmitted to the pulley 2 via the belt 4. This pulley 2 and the input part of the gnomonic reducer 5 are connected, and the output side thereof is fixed to the bending shaft 6. Rotation of another motor (not shown) different from the above motor is transmitted to the pulley 10 via the belt 3. This pulley 10 is connected to the input part of the harmonic reducer 7, and its output side is connected to the rotating shaft 9 via the gear 8.

Effects of the Invention As is clear from the above explanation, the present invention provides two harmonic reducers in the space of one harmonic reducer, thereby achieving reduction in size and weight, improving motion characteristics, and improving workability. Furthermore, by directly connecting the output section of the harmonic reducer to the bending and rotation axes, there is an effect of improving position repeatability and position reproducibility.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a wrist device for an industrial robot showing an embodiment of the present invention, and FIG. 2 is a sectional view of a conventional wrist device. 1... Body arm part, 2... Pulley,
3, 4...Belt, 6...Gnomonic reducer for bending shaft, e...Bending shaft, 7...
...Harmonic reducer for rotating shaft, 9...Rotating shaft, 10...Pulley.

Claims (1)

[Claims] In an industrial robot having a bending axis and a rotation axis at the wrist, a bending axis harmonic reducer is installed between the main body arm and the bending axis on the rotation center of the bending axis, and the bending axis harmonic reducer A harmonic reducer for the rotating shaft is installed between the bending shaft and the rotating shaft, pulleys are attached to each of the input shafts of the bending shaft and the rotating shaft, and a motor installed on the arm of the main body is connected to the pulley via a belt. A wrist device for an industrial robot, which is characterized by connecting two.