A servo motor is an engine that controls the operation of mechanical components in a servo system. The rotor speed of a servo motor is controlled by the input signal and can respond quickly. In automatic control systems, it is used as an actuator and has characteristics such as small electromechanical time constant, high linearity, and low starting voltage. It can convert the received electrical signal into angular displacement or angular velocity output on the motor shaft.
Servo motor
low inertia high inertia
low inertia
Low inertia motors are those with a relatively flat and long design and a small spindle inertia. When the motor performs high-frequency reciprocating motion, the low inertia results in less heat generation. Therefore, low inertia motors are suitable for high-frequency reciprocating motion. However, they generally have relatively lower torque.
high inertia
High-inertia servo motors are relatively bulky and have high torque, making them suitable for applications requiring high torque but not rapid reciprocating motion. Because stopping at high speed requires the driver to generate a large reverse drive voltage, this results in significant heat generation.
Moment of inertia is a measure of the inertia of a rigid body rotating about an axis. Rotational moment of inertia is a physical quantity that represents the magnitude of the rotational inertia of a rigid body. It is related to the mass of the rigid body and the distribution of its mass relative to the axis of rotation.
A rigid body is an object that will not change under ideal conditions.
Motor inertia is an important indicator for servo motor selection. It refers to the inertia of the servo motor rotor itself, which is crucial for the motor's acceleration and deceleration. If the inertia is not properly matched, the motor's operation will be very unstable.
Inertia and
Servo motor selection
Generally speaking, motors with low inertia have good braking performance, quick start-up, acceleration, and stopping response, and good high-speed reciprocating performance, making them suitable for light-load, high-speed positioning applications , such as linear high-speed positioning mechanisms. Motors with medium to large inertia are suitable for heavy-load applications with high stability requirements, such as circular motion mechanisms and machine tool applications.
If the load is large or the acceleration characteristics are large, choosing a motor with a small inertia may cause too much damage to the motor shaft. When selecting a motor, factors such as the load size and acceleration should be taken into account.
The optimal ratio of the load inertia to the motor rotor inertia for the servo driver to control the response of the servo motor is one, and the maximum ratio should not exceed five.
By designing the mechanical transmission device, the ratio of load inertia to motor rotor inertia can be made close to one or smaller.
When the load inertia is indeed very large, and the mechanical design makes it impossible to reduce the ratio of load inertia to motor rotor inertia to less than five times, a motor with a larger rotor inertia, also known as a high-inertia motor, can be used. To achieve a certain response when using a high-inertia motor, the driver capacity should be larger.
