JPH0325309B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a joint device for an industrial robot used for assembly work and the like.

Conventional configuration and its problems A conventional articulation device for an industrial robot is shown in Fig. 1. The rotational force of the motor 1 is transmitted to the rotation of the shaft 3 by the bevel gear 2, the speed is reduced by the harmonic reducer 4, and the driven member 6 rotates about the shaft 3 with respect to the fixed member 5. The motor position detector 7 is attached to the side opposite to the output shaft of the motor. In the above configuration, the joints are modular, allowing various combinations of joints, and the motor is placed perpendicular to the rotation axis, so the width of the joint can be made compact, and the motor etc. can be connected to the joint. Since it can be stored in the arm between the two, it has the advantage of making the industrial robot compact as a whole. However, with the above configuration, the rotating shaft of the bevel gear 2 on the motor side that transmits the driving force can only be supported on one side of the bevel gear 2, which poses problems in terms of accuracy and reliability. Furthermore, since the position detector is attached to the rear side of the motor, it is difficult to shorten the combined length of the motor and position detector, which poses a problem when connecting joints at short distances.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned drawbacks of the conventional art, and provides a compact, precise, and reliable joint device for industrial robots.

Composition of the Invention The present invention includes a driven shaft positioned parallel to a joint rotation axis, a drive shaft arranged in a cross shape without intersecting the driven shaft, and a mechanism for transmitting the rotational force of the drive shaft to the driven shaft. Consisting of a transmission gear and bearings that support both sides of each shaft, it is compact and
It has the unique effect of being able to construct a joint device with high accuracy and reliability. Further, by connecting an actuator to one end of the drive shaft and a position detector to the other end, there is a unique effect that a compact joint with a shorter overall length can be constructed.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 2 is a sectional view of the first embodiment of the present invention, and FIG. 3 is a conceptual side view. In FIG. 2, 8 is a motor, 9 is an input gear of a hypoid gear, 10 is an output gear of a hypoid gear, and a shaft 11 is an input shaft of a harmonic reducer 12. The motor 8 is fixed to a fixed member 13 , and the output shaft of the motor drives the input gear of the high-hoid gear and is connected to the input shaft of the position detector 15 via the shaft 14 . Reducer 1
The output of No. 2 is fixed to the driven member 16. FIG. 3 is a side view showing the positional relationship between the hypoid gears 9 and 10, and the shafts 11 and 14 are arranged not to intersect at right angles.

The operation of the industrial robot joint device configured as described above will be explained below.

First, the rotational drive of the motor 8 is transmitted to the gear 9 and then to the gear 10, which rotates the shaft 11. At the same time, the rotation of the motor 8 is transmitted to the input shaft of the position detector 15 by the shaft 10, and the motor Detects the amount of rotation. At this time, since there is a highly rigid connection with the motor output shaft and there is no breakage in the middle,
High resolution position detectors can be used.

Also, the position detector 15 is connected to the motor 8 with respect to the gear 9.
By placing the position detector on the opposite side of the motor and utilizing the empty space above the joint, the overall length can be made shorter than when the position detector is installed at the rear of the motor.

Further, the rotation of the shaft 11 becomes an input to the speed reducer 12, and after deceleration, the driven member 16 is rotated about the shaft 11 with respect to the fixed member 13. At this time gear 9
A force is applied in the radial direction to transmit the driving force, but the displacement and deformation caused by this are reduced because the shaft 14 is supported on both sides of the gear 9, improving accuracy and reliability. be able to.

As described above, according to this embodiment, the motor drive shaft and the reducer input shaft are arranged so that they do not intersect at right angles, a hypoid gear is used for transmission, and a bearing and a shaft are installed on the drive shaft on the opposite side of the motor. By providing a position detector connected to the fixed side member and fixed to the fixed side member,
It is possible to construct joints for industrial robots that are compact, precise, and reliable.

In the embodiment, a hypoid gear is used as the transmission gear, but any gear capable of transmitting two axes that do not intersect at right angles may be used, such as a spiral gear or a worm gear. In addition, in the embodiment, after transmitting the driving force to the driven shaft by the transmission gear,
Although the speed was reduced using a harmonic speed reducer, any type of speed reducer may be used, as long as the joint rotation axis and the driven shaft are parallel.

Further, deceleration may be performed on the drive side before the transmission gear, or a worm gear or the like may be used as the transmission gear, and deceleration may be performed at the transmission gear portion.

Effects of the Invention As described above, the present invention has a driven shaft positioned parallel to the joint rotation axis, a drive shaft arranged in a cross shape without intersecting the driven shaft, and a drive shaft that transfers the rotational force of the drive shaft to the driven shaft. By providing a transmission gear that transmits data to the drive shaft and bearings that support both sides of each shaft, and by connecting an actuator to one end of the drive shaft and a position detector to the other end, the drive shaft is highly accurate, reliable, and compact. It can be used as a joint device for industrial robots, and the effects are significant.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a conventional joint device for an industrial robot, FIG. 2 is a sectional view of a joint device for an industrial robot according to an embodiment of the present invention, and FIG. 3 is a side view of FIG. 2. . 8...Motor, 9...Input side hypoid gear,
10...Output side hypoid gear, 12...Reducer, 15...Position detector.

Claims (1)

[Claims] 1. A fixed member and a driven member constituting a rotatable joint, a driven shaft positioned parallel to the joint rotation axis, a drive shaft arranged so as not to intersect with the driven shaft at right angles but to form a cross; In order to transmit the rotational force of the drive shaft to the driven shaft, a transmission gear fixed to each shaft, and two fixed members provided to rotatably support each shaft on both sides of the transmission gear. An articulation device for an industrial robot, comprising a pair of bearings, an actuator connected to one end of the drive shaft, and a position detector connected to the other end.