It represents the angle at which the motor rotates each time the control system sends a step pulse signal. The motor is given a step angle value when it leaves the factory. For example, the value given by the 86BYG250A motor is 0.9°/1.8° (0.9° for half-step operation and 1.8° for full-step operation). This step angle It can be called 'the inherent step angle of the motor', it is not necessarily the true step angle of the actual working of the motor, and the true step angle is related to the drive. The number of phases of the stepper motor:
It refers to the number of coil groups inside the motor. Currently, two-phase, three-phase, four-phase, five-phase stepping motors are commonly used. The number of phases of the motor is different, and the step angle is also different. Generally, the step angle of the two-phase motor is 0.9°/1.8°, the three-phase is 0.75°/1.5°, and the five-phase is 0.36°/0.72°. When there is no subdivision driver, the user mainly chooses the stepping motor with different phase numbers to meet the requirements of the step angle. If you use a subdivision drive, the 'phase number' will become meaningless, and the user can change the step angle by simply changing the number of subdivisions on the drive.
Hold torque (HOLDINGTORQUE):
It refers to the moment that the stator locks the rotor when the stepper motor is energized but does not rotate. It is one of the most important parameters of a stepper motor. Usually, the torque of the stepper motor at low speed is close to the holding torque. Since the output torque of the stepping motor is continuously attenuated as the speed increases, the output power also changes with the increase of the speed, so the holding torque becomes one of the most important parameters for measuring the stepping motor. For example, when people say that a 2N.m stepper motor, unless otherwise specified, is a stepper motor that maintains a torque of 2N.m.
Positioning torque (DETENTTORQUE):
It refers to the moment that the stator locks the rotor when the stepper motor is not energized. DETENTTORQUE does not have a unified translation method in China, which is easy to misunderstand. Since the rotor of the reactive stepping motor is not a permanent magnet material, it does not have DETENTTORQUE. Some features of the stepper motor:
1. The accuracy of a general stepper motor is 3-5% of the step angle and does not accumulate. 2. The maximum temperature allowed by the stepper motor appearance.
If the temperature of the stepping motor is too high, the magnetic material of the motor will be demagnetized firstly, resulting in a torque drop and even out of step. Therefore, the maximum allowable temperature of the motor surface should depend on the demagnetization point of the magnetic material of different motors; in general, the demagnetization of the magnetic material The points are all above 130 degrees Celsius, and some even up to 200 degrees Celsius, so the external temperature of the stepper motor is completely normal at 80-90 degrees Celsius.
3. The torque of the stepper motor will decrease as the speed increases.
When the stepper motor rotates, the inductance of each phase winding of the motor will form a back electromotive force; the higher the frequency, the larger the back electromotive force. Under its action, the motor decreases with increasing frequency (or speed), resulting in a drop in torque.
4. The stepper motor can run normally at low speed, but if it is higher than a certain speed, it cannot be started, accompanied by howling. The stepping motor has a technical parameter: the no-load starting frequency, that is, the pulse frequency that the stepping motor can start normally under no-load conditions. If the pulse frequency is higher than this value, the motor cannot start normally, and lost or blocked may occur. In the case of load, the starting frequency should be lower. If the motor is to be rotated at a high speed, the pulse frequency should have an acceleration process, that is, the starting frequency is low, and then rise to a desired high frequency (the motor speed is increased from a low speed to a high speed) at a certain acceleration. With its remarkable features, stepper motors play a major role in the digital manufacturing era. With the development of different digital technologies and the improvement of the technology of stepping motors, stepping motors will be applied in more fields.
