JPH0632912B2 - Rotating device for articulated robot using direct drive motor - Google Patents

Description

TECHNICAL FIELD The present invention relates to a rotating device for an articulated robot using a direct drive motor.

(Prior Art) A so-called direct drive type robot in which a robot arm is directly connected to a shaft of a motor without using a conventional mechanical speed reducer is disclosed in Japanese Patent Laid-Open No. 58-34779. This is a joint structure of a robot, in which a motor stator or rotor is provided on each of two links that are in a rotating pair, and one side is supported by bearings so that the stator and rotor are sandwiched. The motor is built in.

With such a structure, since high torque is generated at a low speed, there is an advantage that the joint portion becomes compact even when a large motor is used. However, since the motor is housed inside, the shaft diameter of the joint must be larger than that of the motor, which is a large diameter, and the rotation angle of the robot cannot be increased due to arm interference, etc. Since the parts are integrated, there is a drawback that it is not easy to change the bearing so as to strengthen it and increase the rigidity of the joint.

(Object) The object of the present invention is to make the diameter of the joint portion the same as the diameter of the direct drive motor to make the whole compact, increase the rigidity of the joint portion, and increase the rotation angle of the robot.

(Structure) In order to achieve the above object, the present invention is configured such that a central hollow portion of a direct drive motor in which an annular rotor is arranged between a pair of concentric annularly arranged stators is fitted into a fixed shaft fixed to a base, The first arm base is pivotally attached to the upper end of the fixed shaft and is integrally fixed to the rotor, and the fixed central shaft of the direct drive motor is fitted to the fixed shaft fixed to the tip of the first arm. The arm base is pivotally attached to the fixed shaft and is integrally fixed to the rotor, and the output shaft is arranged at the tip of the second arm. A specific description will be given below based on Examples.

A servo motor 4 including an encoder 2 and a brake 3 is provided on the fixed base 1, and a shaft of the servo motor 4 is supported by a bearing 7 provided on a support cylinder 6 continuously provided on the upper side of the fixed base 1 via a coupling 5. It is connected to a ball screw 8 which is axially supported. Reference numeral 9 is a linear bearing provided on the cylindrical base 10 and is engaged with the linear guide 11 provided on the support cylinder 6. The base 10 is fixed at its upper end to a flange 12a formed at the lower end of the first fixed shaft 12. In addition, the support base 13 attached to this flange 12a
At the lower end of the nut 14 is a nut 14 screwed into the ball screw 8.
Is fixed.

Reference numeral 15 is a direct drive motor, and an annular rotor 15 is provided between a pair of stators 15a and 15b arranged concentrically in an annular shape.
c, and is supported by bearings 15d and 15e, and the rotor 15c is configured to project from one end of the motor as an output shaft. The first fixed shaft 12 which fits the central hollow portion of the direct drive motor 15 to the fixed shaft and is fixed to the flange 12a projects further upward from the upper end of the direct drive motor 15. The first arm 18 is pivotally supported by the bearing 17 at this protrusion.

Also, the first arm 18 has a base portion 18 formed in a flange shape.
It is connected to the rotor 15c described above at a. The first fixed shaft 12 and the ball screw 8 are parallel to each other. A second fixed shaft 19 is attached to the front end of the first arm by a flange 19a formed in the shape of a flange so that the shaft is parallel to the first fixed shaft 12 on the first arm 18. .
A direct drive motor 20 is attached to the second fixed shaft 19.
The central cavity portion of is fitted and fixed to the flange 19a.

In the direct drive motor 20, a rotor 20c between a pair of stators 20a and 20b arranged in a concentric annular shape is rotatably supported by bearings 20d and 20e, and the rotor 20c is fixed to the stators 20a and 20b. It is configured to project as an output shaft from the lower end. The second arm 24 is pivotally attached to the protruding second fixed shaft 19 by a bearing 23, and is connected to the rotor 20c by a flange-shaped base portion 24a. A motor 26 having a hand 25 attached to its output shaft is provided at the tip of the second arm.

The first fixed shaft 12 and the second fixed shaft 19 have a hollow structure, and the cables 27 and 28 are wired so as to pass through the hollow holes.

Next, the operation will be described. When the motor 4 is rotated, the entire base 10 moves up and down together with the arm. Motor 4
Since it has a brake 3, it can be prevented from falling at the time of power failure.

Further, the hand 25 provided at the tip of the second arm 24 can be positioned within a plane by appropriately rotating the direct drive motors 15 and 20, respectively.
Since the hand 25 is attached to the motor 26, the posture of the gripped work can be controlled.

(Effect) In the present invention, the central cavity of a direct drive motor having an annular rotor disposed between a pair of concentric annular stators is fitted into a fixed shaft fixed to a base to fix the first arm base. A central hollow portion of the same direct drive motor as that described above is fitted to a fixed shaft fixed to the rotor at the upper end of the shaft and integrally fixed to the rotor, and the second arm base is fixed to the fixed shaft. Since it is pivotally attached to the rotor and is integrally fixed to the rotor, and the output shaft is arranged at the tip of the second arm, the diameter of the joint is made the same as the diameter of the direct drive motor to make the whole compact, This has the effect of increasing the rigidity of the section and increasing the rotation angle of the robot.

[Brief description of drawings]

The drawing is a front sectional view of an embodiment of the present invention. 12,19 …… Fixed shaft, 12a, 19a …… Flange, 15,20 ……
Direct drive motor, 15a, 15b, 20a, 20b …… stator, 15c, 20c …… rotor, 15d, 15e, 20d, 20e …… bearing, 18 …… first arm,
24 …… Second arm.

Claims (1)

[Claims] 1. A center shaft of a direct drive motor having an annular rotor disposed between a pair of concentric annular stators is fitted into a fixed shaft fixed to a base, and the first arm base is fixed to the fixed shaft. The central hollow portion of the direct drive motor similar to the above is fitted to the fixed shaft fixed to the rotor and integrally fixed to the rotor, and fixed to the tip of the first arm, and the second arm base is fixed to the fixed shaft. A joint type robot rotation device using a direct drive motor that is pivotally mounted and integrally fixed to a rotor, and has an output shaft provided at the tip of a second arm.