A, choose to keep the torque: holding torque is also called static moment, refers to the brushless dc motor power but no turns, locked rotor torque of the stator. Because in the operation of brushless dc motor at low speed torque is close to the holding torque, the brushless dc motor torque and fast attenuation with the increase of speed, the output power also along with the increase of speed change, so keep measure of brushless dc motor torque is one of the most important parameters of load capacity. For example, generally do not add to about 1 n. M brushless dc motor, which can be understood as holding torque is 1 n. m。 2, select number: two phase brushless dc motor of low cost, step away from the Angle of at least 1. 8 degrees, when low speed vibration of large, high speed when the moment of falling fast, suitable for high speed and the precision and stability requirement is not high circumstance; Step three-phase brushless dc motor from the Angle of at least 1. 2 degrees, vibration is smaller than two phase brushless dc motor, low speed performance is better than two phase brushless dc motor, the highest speed by thirty percent higher than two phase brushless dc motor to 50, and is suitable for high speed and requiring higher precision and stability; Step 5 phase brushless dc motor from the Angle of smaller, low speed performance is good in three phase brushless dc motor, but the cost is high, suitable for low speed section and requiring higher precision and stability. 3, choose brushless dc motor, should follow the principle of first to choose after motor drive, explicitly load characteristic first, then by comparing the different type of static moment of brushless dc motor and the torque frequency curve, find and load characteristics of the brushless dc motor to match; Accuracy is high, should use mechanical reduction gear, to make the motor work in the state of the highest efficiency, lowest noise; Keep the motor working in vibration area, if must by changing the voltage, current, or to increase the damping of the methods to solve; Power supply voltage, it is recommended that the motor adopts dc 24 v - 5736 v dc 46, 86 motor USES a v, 110 motor use higher than dc 80 v; Big moment of inertia load elected into the seat number larger motor; Large inertia load, working at high speed, motor and frequency should be adopted gradually rise speed, in order to prevent the motor out of step, reduce noise and improve the positioning accuracy of a halt when; In view of the brushless dc motor torque generally under 40 nm, beyond the scope of this moment, and run faster than 1000 RPM, which should consider to choose servo motor, ac servo motor can be normal operation in commonly 3000 RPM, cocoa the dc servo motor running at 10000 RPM. 4, select the drive and fine fraction: step not to choose the best state, because the whole step state vibration; As far as possible choose low current, large inductance and low voltage drives; Is greater than the working current of the drive, when need low vibration or high precision subdivision drive, for large torque motor with high voltage type drive, to achieve good high speed performance; Actually used in motor speed is usually high and the requirements for precision and stability is not high, don't have to choose the high fine fraction drive, in order to save cost; Actually used in motor speed conditions are usually very low, should choose larger fine fraction, to ensure smooth operation, reduce the vibration and noise; In short, when choosing the fine fraction, the actual running speed of the motor be taken into account, the range of load torque, speed reducer Settings and the requirements on accuracy, vibration and noise.
