Holding torque and positioning torque of stepping motor
Maintaining the torque refers to the maximum torque that the motor can output when the motor's phase windings pass the rated current and is in the static lock state. It is one of the most important parameters when selecting a motor.
The positioning torque refers to the torque generated by the permanent magnet material on the rotor of the hybrid motor when the motor windings of the motor are not energized and are in an open state. Generally, the positioning torque is much smaller than the holding torque. Whether or not there is a positioning torque is an important sign that a hybrid stepping motor is different from a reactive stepping motor.
As an actuator, stepper motor is one of the key products of mechatronics and is widely used in various automation control systems. With the development of microelectronics and computer technology, the demand for stepper motors is increasing day by day, and it has applications in various national economic fields.
A stepper motor is an actuator that converts electrical pulses into angular displacement. When the stepper driver receives a pulse signal, it drives the stepper motor to rotate a fixed angle (called the "step angle") in a set direction, and its rotation is step by step at a fixed angle. The angular displacement can be controlled by controlling the number of pulses to achieve the purpose of accurate positioning. At the same time, the speed and acceleration of the motor rotation can be controlled by controlling the pulse frequency, thereby achieving the purpose of speed regulation. The stepping motor can be used as a special motor for control, and it is widely used in various open-loop control because it has no accumulation error (100% accuracy).
More commonly used stepper motors include reactive stepper motors (VR), permanent magnet stepper motors (PM), hybrid stepper motors (HB), and single-phase stepper motors.
Permanent magnet stepping motor is generally two-phase, torque and volume are small, the step angle is generally 7.5 degrees or 15 degrees; reactive stepping motor is generally three-phase, can achieve large torque output, step angle is generally It is 1.5 degrees, but the noise and vibration are very large. The rotor of the reactive stepping motor is made of soft magnetic material, and the multi-phase excitation winding is arranged on the stator, and the torque is generated by the change of the magnetic permeability.
Hybrid stepper motors are a combination of permanent magnet and reactive. It is divided into two phases and five phases: the two-phase step angle is generally 1.8 degrees and the five-phase step angle is generally 0.72 degrees. This stepper motor is the most widely used and is the stepper motor selected for this subdivision drive scheme. Some basic parameters of the stepper motor;
