A coaxial multilayer direct drive motor and its drive control system

Abstract

A coaxial multi-layer direct drive motor and its transmission control system, comprising a mounting base, several motor layers coaxially stacked on the mounting base, an upper gland fixed above the several motor layers, and a connection Servo drives for each motor layer, each motor layer includes an annular ball bearing support seat centered on the motor shaft, a rotor connected to the outer ring side wall of the ball bearing support seat, and a rotor located on the rotor Several segments on the outer ring side of the stator are distributed in an annular array, and the ball bearing support seats of adjacent motor layers have a relative degree of freedom of rotation around the motor axis, so that the rotors of adjacent motor layers can realize The relative displacement around the circumferential direction of the motor axis, the stators of adjacent motor layers are fixedly connected to each other and the stators are fixedly connected to the installation base. The invention can realize low-height, large-diameter coaxial direct drive motor transmission, and improve the mechanical transmission reliability and signal stability of the motor.

Description

technical field [0001] The invention belongs to the technical field of the direct drive motor industry, and in particular relates to a coaxial multilayer direct drive motor and a transmission control system thereof. Background technique [0002] Most of the existing multi-layer coaxial large-diameter transmissions use ordinary servo motors to drive large discs or large rings through mechanical transmission methods such as synchronous belts or gears. Among them, large-diameter direct-drive motors usually use a central rotating bearing to connect the stator and rotor, and use a circular grating or an angle encoder to feedback the position; or use a linear motor to realize circular motion using a circular guide rail. In order to ensure concentricity, there needs to be a rotating shaft and a bearing in the middle of the large disc or ring. On the other hand, the position and angle information of the multi-layer coaxial large-diameter transmission is indirectly obtained by multi...

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Problems solved by technology

[0004] 1. It needs mechanical transmission such as synchronous belt or gear, which has low precision, poor rigidity, high noise, and is prone to many problems such as wear, fatigue, cracking, and relaxation;

[0005] 2. The circular grating or encoder needs to be installed coaxially, which will occupy the internal space of the motor, and it is impossible to achieve both large hollowness and small height; there is a rotating shaft and bearing in the middle of the disc, which cannot realize a completely hollow structure, and the middle rotating shaft is prone to fatigue. result in a shorter working life;

[0006] 3. The power cable and encoder cable must be connected between each motor driver and the controller, which has poor anti-electromagnetic interference and poor reliability under vibration conditions; it is also necessary to install a mechanical origin switch or an electromagnetic origin switch to increase electrical Connecting wires, which are less reliable under vibration conditions;

[0007] 4. Its position and angle information is indirectly obtained by multiplying the encoder information of the servo motor by the transmission ratio of the mechanical transmission, and the precision is low. For example, the traditional general method is that the servo motor drives the large disc to rotate through the synchronous belt, and the outer ring of the large disc is processed into Synchronous wheel structure, the motor shaft end is equipped with a small synchronous wheel, assuming that the number of teeth of the large disc synchronous wheel is n 1 , the number of teeth of the small synchronous gear at the motor shaft end n 2 , the rotation angle of the large disc is θ 1 , the rotation angle of the motor is θ 2 , then there is θ 1 = θ 2 *n 2 / n 1 As we all know, the synchronous belt has a certain degree of elasticity, and it will deform as the use time increases and the temperature changes, and there is an meshing error between the synchronous wheel and the synchronous belt, so n 2 / n 1 The value of the value is unstable, if gear transmission is used, the wear of the gear and the transmission clearance also cause n 2 / n 1 Numerically unstable, resulting in θ 1 Unstable; after the indirectly obtained position information enters the feedback system, due to the existence of precision error and jitter, it is easy to cause servo system jitter, overshoot and other phenomena

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