How to choose a suitable DC servo motor and reducer

A low-voltage DC servo motor refers to an engine that controls the operation of mechanical components in a servo system. It is a device that assists the motor in indirect speed change. Its main function: It is used in a closed loop to transmit signals to the system at any time, and at the same time use the signals given by the system to correct its own operation. The low-voltage DC servo motor includes a stator, a rotor core, a motor shaft, a motor winding commutator, a motor winding, a speed measuring motor winding, and a speed measuring motor commutator. The rotor core is composed of silicon steel punchings stacked and fixed on the motor shaft. The low-voltage DC servo motor has good speed control characteristics, can achieve smooth control in the entire speed range, has almost no oscillation, is small in size, energy-saving, low noise, no heat, and has a long life.

The servo motor reducer uses gears at all levels to reduce speed. It is composed of gears at all levels and is generally used for low-speed and high-torque transmission equipment. The power of the motor, internal combustion engine or other high-speed operation is reduced through the gear on the input shaft of the reducer meshing with the large gear on the output shaft to achieve the purpose of reduction. The reducer is a power transmission mechanism that uses a gear speed converter to reduce the number of revolutions of the motor to the desired number of revolutions and obtain a larger torque.

In practical applications, how to match the reducer with the servo motor?

1: Flange specifications

The cross-sectional dimensions of the reducer are generally similar to those of the motor. For other parameters, refer to the instructions of the selected brand. The technical sample generally indicates the selection steps and calculation examples. The specific models are expressed differently for each brand. Usually, they are roughly expressed by the output flange size or cross-sectional size. Generally, there are 40 flange, 60 flange, 80 flange, 120 flange, 160 flange, 18 flange and other specifications.

2: Speed ​​ratio

The reduction ratio of the reducer is roughly the result of dividing the rated speed of the motor by the output speed. For example, if the required output speed is 200RPM and the rated speed of the motor is 3000RPM, then the speed ratio of the reducer is preferably around 1:15. The output speed depends on the working conditions.

3: Torque

The rated torque of the reducer must be greater than or equal to the product of the motor's rated torque and the reduction ratio. Assuming the motor's rated torque is 10N.M and the reduction ratio is 15, the rated torque of the selected reducer model must be greater than 10*15=150N.M.

4: Accuracy

The return clearance (backlash, clearance or rotary clearance) of the reducer depends on the specific working requirements. Generally speaking, the clearance used with the servo motor should not be greater than 20 arcmin.

General principles:

Small servo motors can be equipped with large reducers, but large motors are generally not equipped with small reducers;

For the same specification, the higher the rigidity, the better the quality, so our process is hard tooth surface cutting process.

Servo motor selection:

Speed ​​(select as needed);

Torque (calculate the torque that the servo motor needs to output based on the load structure, weight and speed);

Moment of inertia (this parameter is related to the operating accuracy of the servo on the mechanical structure and is calculated by the weight of the load structure).

Generally, a certain margin should be left, and the model of servo motor should be selected based on these three parameters and the selection sample.

Reducer selection:

Reduction ratio (determined by the square root of the ratio of the motor speed to the required output speed, the ratio of the required output torque to the motor torque, and the ratio of the mechanical moment of inertia to the motor moment of inertia);

Rated load torque (the output torque should not be greater than the rated torque of the reducer, which is related to the life of the reducer);

Accuracy (select appropriate accuracy requirements according to user needs);

Installation matching dimensions (the matching installation between the load and the reducer, and the matching installation between the motor and the reducer, etc. are determined according to the product drawings).