Stepper Motor The working principle of
Stepper motor is a kind of induction motor, its working principle is the use of electronic circuit, direct current (dc) into multiphase sequential control of time-sharing power supply current, in this current for stepper motor power supply, step motor to work properly, is time-sharing power supply for step motor drive, multiphase timing controller. Although stepping motor has been widely used, stepper motor cannot be like ordinary dc motor. Ac motor is used in general, and it must be used by the control system such as double ring pulse signal and power drive circuit. Therefore, it is not easy to use a good stepper motor, which involves many professional knowledge, such as machinery, motor, electronics and computer. Stepping motor is one of the key products of electromechanical integration and is widely used in various automatic control systems. With the development of microelectronics and computer technology, the demand of stepper motor is increasing day by day, and it has been applied in various national economic fields.
Stepping motor is an actuator that converts electrical pulse into angular displacement. In plain English: when a step in a drive receives a pulse signal, it drives the step motor to move a fixed Angle (i.e., step Angle) in the set direction. The angular displacement can be controlled by controlling the number of pulses, so as to achieve accurate positioning. At the same time, the speed and acceleration of motor rotation can be controlled by controlling the pulse frequency. The reaction step is generally two phases, the torque and volume are smaller, and the step Angle is generally 7.5 degrees or 1.5 degrees. The permanent magnet step is generally three phases, which can realize the large torque output. The Angle of step Angle is generally 1.5 degrees, but the noise and vibration are very large. In the developed countries such as Europe and America, the 1980s were eliminated. Hybrid stepping refers to the advantages of a permanent magnet and an equation. It is divided into two phase, three-phase and five phase: two phase stepper Angle of 1.8 degrees commonly and five phase stepping Angle of 0.72 degrees commonly, hybrid stepping motor as the increase of the number of phase (several) winding the power supply, the stepping Angle decreases, and improve the precision and the application of the stepper motor is more extensive. There are three kinds of stepper motors used in the automation industry. As the products of hybrid stepping motors are becoming more and more complete, the first choice of mechanical engineers in the automation industry is the first choice of the mechanical engineers in the automation industry.
There are three main types of stepper motors in construction: permanent magnet (PM), reactive (VR) and hybrid (HB).
First of all, the equation is used to control the dynamic performance of the motor. Equation: the stator has winding and rotor composed of soft magnetic material. Simple structure, low cost, step Angle is small, can be up to 1.2 °, but poor dynamic performance, low efficiency, big fever, difficult to ensure reliability.
The second type is permanent magnet. The product with high demand and low precision can be used. Permanent magnet type: the rotor of the permanent magnet stepper motor is made of permanent magnet material. The pole number of the rotor is the same as the number of the stator. Is characterized by good dynamic performance, large output torque, but this kind of machine precision is poor, a step from the Angle of large (generally 7.5 ° or 15 °).
The third is the biggest hybrid stepper motor in market share at this stage, and the precision of the stable output torque colleague is improved. Combined with the advantages of equation and permanent magnet, the stator has a multiphase winding and permanent magnetic material on the rotor, with multiple small teeth on the rotor and stator to improve the moment precision. It is characterized by large output torque, good dynamic performance and small step Angle, but complex structure and relatively high cost.
The winding of the stator is divided into two phases, three phases and five equal series. One of the most popular is a two-phase hybrid stepping motor, accounted for more than 97% of market share, high performance/price ratio, and the reason is, deserve to go up after subdivision driver effect is good, can meet the requirements of the vast majority of automation products of precision.
For example; Stepper motor two-phase 57 stepper motor model SS2302A42A, step motor's basic pitch Angle is 1.8 ° / step, with subdivision driver MD2545, greatly improve the accuracy and high cost performance.