Stepping motor concept and working principle of stepping motor is a kind of the pulse signal transformation into corresponding

angular displacement (or line displacement) electromagnetic device, is a special kind of motor. General motor are continuous rotation, and stepping motor have positioning and running two basic state, when a pulse input cubits stepping motor step by step and rotation, each to rotating joints give it a pulse signal, it turned the certain Angle. Stepping motor angular displacement quantity and input pulse is proportional to the number of strictly, in time and input pulse synchronization, so as long as the control input pulse number, frequency and motor winding energized phase sequence, can obtain the needed Angle, speed and rotation direction. In no pulse input, in winding power under the excitation of air gap magnetic field can make the rotor keep original position in positioning state.
Stepping motor according to the output torque on the size of the points, can be divided into rapid stepping motor and power stepping motor. Rapid stepping motor continuous high working frequency and output torque is small, usually in N · cm level, can be used as a control small precision machine tool table (cases of linear cutting machine) can also and hydraulic torque amplifier composition electrohydraulic pulse motor to drive nc machine tool's table, and power stepping motor output torque is big is N · m level can be directly to drive the machine moving parts. Stepping motor according to rotary union the excitation phase, can be divided into three phase, four phase, five phase, six phase even eight phase. Generally speaking with phase increases, in the same frequency, each phase guide electricity flow time increased, each phase average current will be higher, so that the motor speed - torque characteristic will be better, step Angle is also small.
But as the phase increases, the size of the motor will increase, the structure is complex, the multi-purpose 3 ~ 6 phase stepping motor. Due to the stepping motor speed along with the input pulse frequency change and change, speed range is very wide, high sensitivity, output Angle can control, and output high precision, and can realize synchronous control, so widely used in open loop system, also can be used in general universal machine tool, improve feeding mechanism of automation level. Stepping motor according to its working principle to points, basically have magnetoelectric and equation two categories, here only introduce common reaction stepping motor work principle, we use the following step motor simplified diagram to illustrate. In the motor stator has A and B, C three pairs of pole, pole round A coil, respectively called A phase, B and C phase, and rotor is A toothed core, this kind of stepping motor called three-phase stepper motor. If the coil zhongtong with direct current, it will produce A magnetic field, when A and B, C three pole coil in turn in electricity, then A, B, C three pairs of pole is in turn take turns to produce A magnetic field to attract rotor rotation. First there is A phase coil (set to A phase) electricity, the rotor 1, 3 two tooth be pole A absorb, rotor will stay in figure 5-5 A position. Then, A phase without electricity, 6 communicate electrical, the pole A magnetic field disappear pole B produced magnetic field, magnetic pole called magnetic fields to the nearest 2, 4 two tooth attract the past, stop in figure B position, then rotor counterclockwise turned 30 °.
Then the next phase power B, C communicate electrical. According to the same truth, rotor and counterclockwise turned 30 °, stop in the diagram c position. If A mutually electricity, C phase off, then the rotor to reverse 30 °, make the pole A magnetic field to 2, 4 two tooth absorb. Stator each phase take turns to power on a rotor turned a tooth. According to such A - B - C - A - B - C - A -... Order take turns to electricity, stepping motor is step by step according to the anti clockwise. Electricity coil each conversion once, stepping motor rotate 30 °, we put the stepping motor each step turned Angle called step pitch Angle. If the stepping motor power on coil conversion order upside down into A - C - B - A - C - B -... Order, the stepping motor will be made according to fiber optic rotary joint clockwise, so to change stepping motor rotation direction can be in any of the same electric.