The selection calculation of servo motor generally includes the following steps:

Clarify application requirements

Motion mode: Determine whether linear motion or rotational motion is required, whether it is point control, continuous trajectory control, or other specific motion modes.

Accuracy requirements: including position accuracy, speed accuracy, etc. For example, in CNC machine tools, position accuracy may be required to reach ± 0.01mm, which has high requirements for the resolution and control accuracy of servo motors.

Working environment: Consider factors such as temperature, humidity, dust, vibration, etc. For servo motors working in high temperature environments, it is necessary to choose models with high temperature resistance.

Calculate load parameters

Load torque

Rotating load: Calculated based on the moment of inertia and angular acceleration, the formula is, where is the load torque, is the moment of inertia, and is the angular acceleration.

Linear load: calculated through friction, gravity, etc., such as when moving horizontally in a straight line, torque, where is friction, is friction coefficient, is load mass, is gravitational acceleration, and is transmission half diameter.

load inertia

Rotating components: For a cylinder, the moment of inertia, where is mass and is radius.

Linear motion components: If driven by a screw, the linear motion inertia can be converted into rotational motion inertia, where is the mass of the linear motion component and is the lead of the screw.

Determine motor parameters

Torque calculation

Acceleration torque: is the total inertia, including the inertia of the motor itself and the inertia of the load, is the change in angular velocity, and is the acceleration time.

Operating torque: It is determined based on the torque required by the load when running at a constant speed, taking into account factors such as transmission efficiency.

Safety factor: generally taken as 1.2-1.5, the safety factor required for the final motor torque operation.

Speed calculation

Rotating motion: based on the maximum speed required by the load (unit: rpm）， Motor speed transmission ratio.

Linear motion: calculated from the linear motion speed (unit: m/s) and transmission mechanism parameters, such as when transmitted through a screw,.

Inertia matching: Generally, the ratio of load inertia to motor inertia is required to be within a certain range.

Select motor model

Based on torque, speed, and inertia: search for the motor model that meets the calculated torque, speed, and inertia requirements in the servo motor product sample or selection software.

Other performance indicators include motor resolution, response time, overload capacity, etc. For example, in high-speed dynamic response applications, it is necessary to choose motors with shorter response times.

Communication interface and control mode: Select the appropriate communication interface (such as CANopen, EtherCAT, etc.) and control mode (such as position control, speed control, torque control) according to the requirements of the control system.