What kind of reducer can be equipped with a stepper motor?

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2023-12-28 09:22:09

1. Reasons why stepper motors are equipped with reducers

The stepper motor switches the frequency of the stator phase current, such as changing the input pulse of the stepper motor drive circuit to make it move at a low speed. When the low-speed stepper motor is waiting for the step command, the rotor is in a stopped state. When stepping at low speed, the speed fluctuation will be large. If it is changed to high-speed operation at this time, the speed fluctuation problem can be solved, but the torque will be insufficient. That is, torque will fluctuate at low speeds, and torque will be insufficient at high speeds, so a reducer is needed .

2. What are the reducers commonly used with stepper motors?

The reducer is an independent component consisting of gear transmission, worm transmission, and gear-worm transmission enclosed in a rigid shell. It is often used as a reduction transmission device between the prime mover and the working machine. It is used between the prime mover and the working machine or the execution unit. The mechanisms play the role of matching speed and transmitting torque; There are many types of reducers. According to the transmission type, they can be divided into gear reducers , worm reducers and planetary gear reducers ; according to the number of transmission stages, they can be divided into single-stage and multi-stage reducers ; According to the shape of the gear, it can be divided into cylindrical gear reducer , bevel gear reducer and cone-cylindrical gear reducer ; According to the transmission layout, it can be divided into expansion reducer , split reducer and coaxial reducer . The reducers assembled with stepper motors include planetary reducers , worm gear reducers , parallel gear reducers , and screw gear reducers .

What is the accuracy of the stepper motor planetary reducer?

The accuracy of the reducer is also called the return clearance. When the output end is fixed and the input end rotates clockwise and counterclockwise, so that the output end generates rated torque +-2% torque, there is a slight angular displacement at the input end of the reducer. This angle The displacement is the return clearance. The unit is an "arc minute", which is one sixtieth of one degree. The usual return clearance value refers to the output end of the reducer . The stepper motor planetary reducer has the characteristics of high rigidity, high precision (single stage can achieve within 1 minute), high transmission efficiency (single stage is 97%-98%), high torque/volume ratio, and maintenance-free. The transmission accuracy of the stepper motor cannot be adjusted. The running angle of the stepper motor is completely determined by the step length and the number of pulses. The number of pulses can be counted completely. There is no concept of precision in digital quantities. One step is one step. Two steps is two steps. The accuracy that can currently be optimized is the gear return clearance accuracy of the planetary reducer gearbox :

1. Spindle accuracy adjustment method:

Adjustment of the rotation accuracy of the main shaft of the planetary reducer. If the machining error of the main shaft itself meets the requirements, then the rotation accuracy of the main shaft of the reducer is generally determined by the bearing. The key to adjusting the spindle rotation accuracy is to adjust the bearing clearance. Maintaining a proper bearing clearance is critical to spindle component performance and bearing life. For rolling bearings, when there is a large gap, not only will the load be concentrated on the rolling elements in the direction of stress, but also serious stress concentration will occur at the contact between the inner and outer raceways of the bearing, shortening the bearing life, and also causing The centerline of the spindle drifts, which can easily cause the spindle components to vibrate. Therefore, the adjustment of rolling bearings must be pre-loaded to produce a certain amount of interference inside the bearing, thereby producing a certain elastic deformation at the contact point between the rolling element and the inner and outer ring raceways, thus improving the stiffness of the bearing.

2. Adjust the gap method:

The planetary reducer will generate friction during the movement, causing changes in the size, shape and surface quality of the parts, and causing wear and tear, which will increase the clearance fit between the parts. At this time, we need to carry out reasonable adjustments on it. Adjust to ensure the accuracy of relative movement between parts.

3. Error compensation method:

By properly assembling the parts themselves, the errors will cancel each other out during the running-in period to ensure the accuracy of the equipment's motion trajectory.

Comprehensive compensation method:

Use the tools installed on the reducer itself to process the worktable that has been adjusted correctly to eliminate the comprehensive results of various precision errors.

What kind of reducer can be equipped with a stepper motor?