Screw stepper motors, or linear stepper motors, are rotated by the magnetic rotor core interacting with the pulsed electromagnetic field generated by the stator, and the lead screw stepper motors convert rotational motion into linear motion inside the motor.
The lead screw stepper motor uses a screw and nut to engage, and some method is used to prevent the screw and nut from rotating relative to each other, so that the screw moves axially. Generally speaking, there are two ways to achieve this conversion. The first is to build a rotor with internal threads in the motor, and the internal threads of the rotor are meshed with the screw to achieve linear motion. The second is to use the screw as the motor. Out of the shaft, an external drive nut engages with the screw outside the motor to achieve linear motion. The result of this is that the design of the screw stepper motor is greatly simplified, making it possible to directly use the screw stepper motor for precise linear motion in many application fields without installing an external mechanical linkage.
1. When the screw stepper motor is working, each phase winding is not constantly energized, but is energized in turn according to a certain rule.
2. The angle at which the rotor rotates every time a pulse electric signal is input to the screw stepper motor is called the step angle.
3. The screw stepping motor can control the angle according to specific instructions, and can also control the speed. In angle control, every time a pulse is input, the stator winding is switched once, and the output shaft rotates through an angle. The number of steps is consistent with the number of pulses, and the angular displacement of the output shaft is proportional to the input pulse. During speed control, continuous pulses are fed into the windings of the stepping motor, and the windings of each phase are continuously energized in turn, and the screw stepping motor rotates continuously, and its speed is proportional to the pulse frequency. Changing the power-on sequence, that is, changing the rotation direction of the stator magnetic field, can control the forward or reverse rotation of the motor.
4. The screw stepper motor has self-locking ability. When the input of the control pulse is stopped, and the winding controlled by the last pulse continues to be energized with direct current, the screw stepper motor can be kept at a fixed position, that is, it stops at the end position of the angular displacement controlled by the last pulse. In this way, The screw stepper motor can realize the positioning of the rotor during parking.