JPH0513796B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to an articulated robot having a first arm and a second arm, each of which has a rotation range of 360 degrees or more.

(Prior Art) Conventionally, a rotatable first arm has a second arm rotatable about an axis parallel to the rotary axis of the first arm, and an industrial tool is provided at the distal end of the second arm.
In order to position the above-mentioned work tool on a plane by appropriately rotating the first arm and the second arm, the first arm can be rotated more than 360 degrees to expand the working range. -No. 173487 and Utility Model Kai 59-
The one shown in No. 160182 has been proposed.

In these devices, the rotation drive sources of the two arms are placed on the fixed side, so that the first arm does not interfere with other objects, and the cables of the rotation drive sources do not get tangled or twisted. One of its features is that it can be rotated without any movement, making the working range more than 360°.

However, since both have a working tool installed at the tip of the second arm, an actuator or cable, etc. that connects the working tool and the control unit provided on the fixed part is used to supply compressed air and power to the working tool, and to send and receive signals. is essential. When considering the installation of tubes, cables, etc., if the first arm rotates 360 degrees or more, the tubes, cables, etc. may be twisted or bent, resulting in a risk of disconnection or damage. It was impossible to achieve a rotation range of 360° or more.

In particular, when an actuator is installed on a rotating part such as an arm in order to rotate an industrial tool around an axis parallel to the first arm rotation axis, the number of power lines and signal lines to the actuator increases. It was necessary to take some measure to prevent these wires from breaking.

(Purpose) The present invention has been made in view of the above circumstances, and it allows the first arm, the second arm, and the wrist (work tool) provided at the tip of the second arm to be rotated more than 360 degrees without disconnecting the cable or the like. The purpose of this study is to propose an articulated robot that can move.

(Structure) In order to achieve the above object, the present invention comprises two direct drive motors each having an annular rotor disposed between a pair of concentrically arranged stators, arranged vertically coaxially with a predetermined distance between them. A fixed shaft is fitted into the central cavity of both direct drive motors, and a first arm base and a second arm drive pulley fitted to the fixed shaft are rotatably pivoted, and two of each are provided. A driven pulley integrally coupled to the rotor of the direct drive motor and fixed to a second arm rotation shaft disposed at the tip of the first arm and the second arm driving pulley are connected using a rotation transmission means. A first slip ring is provided on the outer periphery of the direct drive motor for driving the first arm, and a third slip ring is provided on the outer periphery of the tool shaft at the tip of the second arm, and the wiring inside the base is routed through the first slip ring. Connect it to the third slip ring through the rotation shaft at the tip of the first arm, and then to the hand through the tool shaft, and fix the hand rotation motor to the robot with an axis parallel to the direct drive motor for driving the second arm. a pulley disposed in the section and connected to the output shaft of the motor, a pulley pivotally supported on the fixed shaft, a pulley pivotally supported on the pulley and the second arm rotation shaft, and a pulley and a tool connected to the pulley. This is characterized in that the pulleys connected to the shaft are connected to each other using rotation transmission means. Hereinafter, a detailed explanation will be given based on an example.

A servo motor 4 equipped with an encoder 2 and a brake 3 is installed on a fixed pedestal 1, and a shaft 5 of the servo motor 4 is connected to a bearing 8 connected to the upper part of the fixed pedestal 1 and provided in a support tube 7 via a coupling ring 6. It is connected to a pivotally supported ball screw 9. Reference numeral 10 denotes a linear bearing provided on a cylindrical base 11, which engages with a linear guide 12 provided on the support tube 7. The base 11 is fixed at its upper end to a flange 13a formed at the lower end of the fixed shaft 13. Further, a nut 15 screwed onto the ball screw 9 is fixed to the lower end of the support base 14 attached to the flange 13a.

A direct drive motor 16 is fixed to the upper end of the flange 13a. A fixed shaft 13 connected to a flange 13a is fitted into the central cavity 16a of the direct drive motor 16.

In the direct drive motor 16, an annular rotor 16d between a pair of concentrically arranged stators 16b and 16c is supported by bearings 16e and 16f, and the rotor 16d is connected to the stator 16.
It is configured to protrude from the upper ends of b and 16c as an output shaft. This protrusion 16g is connected to a base 17a into which the first arm 17 is fitted onto the fixed shaft 13.

The fixed shaft 13 protrudes further from the direct motor 16, passes through the hole 17b formed in the base 17a of the first arm 17, and protrudes until a gap is created above the direct drive motor 16, and the flange 18 is fixed to the upper part. ing. A hole 19 passing through the center between the lower surfaces of the flange 18
A direct drive motor 19 is attached so that the fixed shaft 13 passes through the a.
In the direct drive motor 19, an annular rotor 19d is supported by bearings 19e and 19f between a pair of concentrically arranged stators 19b and 19c, and the rotor 19d is connected to the stators 19b and 19.
It is configured to protrude from the lower end of c as an output shaft. The output shaft 19g has a bearing 2 on the fixed shaft 13.
It is connected to a sleeve 21 which is pivotally supported by 0. A pulley 22 is pivotally supported in the middle of the sleeve 21, and is connected to the output shaft of a servo motor 23, which is connected to the upper part of the pulley and the flange 18 so that its output shaft is parallel to the direct drive motor 19. A timing belt 25 is stretched between the pulley 24 and the pulley 24, and is rotatably connected to the timing belt 25.

A pulley 26 is fixed to the lower end of the sleeve 21. On the other hand, at the distal end of the first arm 17, a second arm rotation shaft 27 is supported in parallel to the fixed shaft 13 by bearings 28 and 29 fixed to the distal end 17. A hollow pulley 30 is fixed to the upper end of the second arm rotation shaft 27, and a timing belt 31 is stretched between the pulley 26 and the pulley 26, and the pulley 30 is rotatably connected thereto. This hollow second arm rotation shaft 27
Inside the second arm rotation shaft 27, an inner shaft 32, which is also hollow, is supported by bearings 33 and 34 provided on the inner diameter of the second arm rotation shaft 27. One end of the inner shaft 32 protrudes beyond the pulley 30, and a pulley 35 is fixed to this protrusion. The pulley 35
is rotatably connected to the lower part of the pulley 22 by a timing belt 36 stretched between the pulley 22 and the lower part of the pulley 22.

The second arm rotation shaft 27 is connected to the base 37a of the second arm 37 at its lower part. The other end of the inner shaft 32 protrudes from the base 37a of the second arm 37, and is connected to a pulley 38 at the protrusion. The pulley 38 includes a pulley 42 fixed to a tool shaft 41 which is supported at the tip of the second arm 37 by bearings 39 and 40 in parallel with the second arm rotation shaft 27, and a timing belt 43 stretched between them. Rotationally connected by. 44 is a hand fixed to the lower end of the tool shaft 41. The wiring connected to the power source is connected from the connector 50 of the fixed pedestal 1 through the inside of the base 11, through the inside of the hollow fixed shaft 13, and to the first slip ring 49 on the outer periphery of the fixed shaft 13, the drive motor 19, and the servo motor 23. A second slip ring 48 attached to the second arm and a first slip ring 49 are connected by a wiring 46. The wiring 46 connected to the second slip ring 48 passes through the guide pipe 47 in the rotation shaft 27 and passes through the tool shaft 4.
1, and is connected to the hand 44 through the inside of the tool shaft 41.

Further, the second arm 37 has a length such that it does not engage with the base 11 when rotated, as shown in FIG.

In the above embodiment, a timing belt is used to drive the second arm, but this can be replaced with a parallel link mechanism. However, in this case, the rotation angle of the second arm is approximately 135°, so the second slip ring 48 is not necessarily required. Also, if a rotary joint is used instead of a slip ring, compressed air, etc. can be supplied.

Next, the effect will be explained. Servo motor 4
When the arm is rotated, the base 11 moves up and down together with the arm. Since the servo motor 4 is equipped with a brake 3, it can be prevented from falling during a power outage. Further, when the direct drive motor 16 is rotated, the first arm 17
By rotating the servo motor 23, the timing belt 31 can rotate the second arm 37, and by rotating the servo motor 23, the timing belts 25, 36, 43 can rotate the tool shaft 41. The positioning of the hand 44 in the air and the rotational attitude of the hand around the axis can be controlled.

In addition, the first arm 17, second arm 37, and hand 44 are arranged so that they do not interfere with each other so that each can rotate more than 360 degrees, and the wiring of the motor that drives the second arm and the hand is fixed to a fixed axis. 13 to the fixed side, and the wiring to the hand is also connected to the fixed side via three slip rings.
Wiring does not twist or break even when rotated more than 360°.

Note that the above-mentioned timing belt can be replaced by various rotation transmission means such as links, wires, chains, etc.

(Effects) The present invention comprises two direct drive motors each having an annular rotor arranged between a pair of concentrically arranged stators, which are arranged vertically and coaxially with a predetermined gap between the two direct drive motors. A fixed shaft is fitted into the central hollow part of the shaft, and a first arm base and a second arm drive pulley, which are fitted to the fixed shaft, are rotatably connected to the rotors of the two direct drive motors. The first
A driven pulley fixed to a second arm rotating shaft disposed at the tip of the arm and the second arm driving pulley are connected using a rotation transmission means, and a second arm is connected to the outer periphery of the direct drive motor for driving the first arm. In addition, a third slip ring is provided on the outer periphery of the tool shaft at the tip of the second arm, and the wiring inside the base is connected to the first slip ring through the first slip ring.
It is connected to the third slip ring through the rotation shaft at the end of the arm, and then to the hand through the tool shaft, and the hand rotation motor is arranged on the fixed part of the robot with an axis parallel to the direct drive motor for driving the second arm. a pulley coupled to the output shaft of the motor; a pulley pivotally supported on the fixed shaft; a pulley coupled to the pulley and pivotally supported on the second arm rotation shaft; a pulley coupled to the pulley coupled to the tool shaft; Since the pulleys are connected using rotation transmission means, the first arm, the second arm, and the wrist can rotate more than 360 degrees without interfering with each other, and at the same time, the danger of twisting or breaking the wiring can be prevented. Furthermore, since the wiring is not exposed, it is possible to prevent the wiring from interfering with other equipment.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view of an embodiment of the present invention, and FIG. 2 is a front view of the same. 1...Fixed pedestal, 13...Fixed shaft, 16, 19
...Direct drive motor, 16a, 19
a...Central cavity, 16b, 16c, 19b, 1
9c... Stator, 16d, 19d... Rotor, 17... First arm, 27... Second arm rotation axis, 37... Second arm, 44... Tool axis,
45...Third slip ring, 46...Wiring, 4
8...Second slip ring, 49...First slip ring.

Claims (1)

[Claims] 1. Two direct drive motors each having an annular rotor arranged between a pair of concentrically arranged stators are arranged vertically and coaxially with a predetermined distance between them, and the direct drive motors are placed in the central cavity of both direct drive motors. A fixed shaft is fitted, a first arm base and a second arm driving pulley fitted to the fixed shaft are rotatably pivoted, and each is integrally connected to the rotor of two direct drive motors. , a driven pulley fixed to a second arm rotating shaft disposed at the tip of the first arm and the second arm driving pulley are connected using a rotation transmission means, and a direct drive motor for driving the first arm is connected. A first slip ring is provided on the outer periphery, and a third slip ring is provided on the outer periphery of the tool shaft at the tip of the second arm, and the wiring inside the base is passed through the first slip ring and into the rotating shaft at the tip of the first arm. To the third slip ring,
Further, a pulley is connected to the hand through the tool shaft, and a hand rotation motor is disposed on a fixed part of the robot with an axis parallel to the second arm drive direct drive motor, and coupled to the output shaft of the motor; a pulley pivotally supported on the fixed shaft;
An articulated robot using a direct drive motor in which the pulley, a pulley pivotally supported by a second arm rotation shaft, a pulley connected to the pulley, and a pulley connected to a tool shaft are connected using rotation transmission means, respectively. rotation device.