In this paper, the brushless dc motor with you to understand in the south of anhui known how to choose the brushless dc motor torque and rotational speed. The torque of the motor starting torque, maximum torque, and rated torque. Starting torque is produced when starting a 1 larger than the rated torque. 7 -2. 2 times of torque, the starting torque can overcome the static friction of the rotor and the brushless dc motor driven load resistance. Torque is the largest in the brushless dc motor under the condition of overload a parameter self-adjustment, but brushless dc motor in the case of overload, the rotor speed will drop, so under the condition of invariable in the frequency of the power supply, conducting bar cutting rotor speed, stator can produce more in the rotor induction electromotive force, and the rotor resistance of a conducting bar is certain, so the rotor current is produced by the conducting bar is bigger than normal runtime, according to the left hand rule can know, magnetic field and current proportional force, so the rotor on the output of the electromagnetic power will increase, and then on the rotor's output mechanical power is larger, thus make brushless dc motor has been running near the stable point. Rated torque is brushless dc motor torque can long-term stable operation. In simple terms, is the size of the spinning force. Torque is a kind of torque, torque is defined as: in physical moment = force & times; Lever arm here can be seen as the brushless dc motor drives the rotation radius of the object. If the brushless dc motor torque is too small, not move to bring the object, also is the feeling of brushless dc motor & other; Throughout the &; Is not big enough. Popular speak motor driven in mechanical drive is the torque of the motor, the torque of the motor = drag belt pulley force & times; And is proportional to the square of the power supply voltage so torque is determined by the factors of current and voltage of motor torque calculation of brushless dc motor & other; Torque & throughout; , the unit is N· m（Cattle meters)Calculation formula is T = 9549 * P/n. P is the rating of the brushless dc motor (Output)Power unit is the kw (千瓦)The denominator is rated speed n unit is turn per minute (r/min)。 P and n can be directly in the brushless dc motor nameplate.
