Has with brush and brushless motor. Structure, brushless motor and a brush is similar, also have the rotor and stator, and only has the structure of the brush motor instead; With brush motor rotor winding, and the power output shaft is linked together, the stator is permanent magnet steel; Brushless motor rotor is a permanent magnet steel, along with shell and output axis is linked together, the stator is winding coil, to remove a brush motor commutator brush to alternating electromagnetic field, so called brushless motor (Brushlessmotor)。 a brush motor
has brush motor is internal containing a motor commutation brush. What is the brush, and directly above. Brush through insulation fixed on the motor back cover, will be introduced to the power supply is negative on the commutation of the rotor, and the commutation device connected on the rotor coil, coil constant alternating polarity form with shell fixed magnet force and rolling. Below is will now see the brush after dismantling Crazepony used motor and phase switcher.
there are motor with brush and the physical contact between phase switcher, so there is big, fever, low efficiency of faults. But have same brush motor has simple manufacture, low cost advantages, so now there are motor still has the large share.
brushless motor
there are through the brush and brush motor phase switcher this kind of structure design for fixed direction magnetic field force and rolling. Brushless motor without brush and phase switcher, it is how to obtain a fixed direction of magnetic force? Rely on, in short, change the input to the brushless motor stator coil of alternating current wave frequency and waveform, the winding coil around a rotating magnetic field, electrical geometry axis on the magnetic field to drive the rotor permanent magnet magnetic rotation, the motor turns up. the performance of the motor and the number of magnetic steel, magnetic steel, magnetic flux intensity factors such as input voltage, the motor size, more with brushless motor control performance has much to do, this is the electric brushless motor with adjustable need to solve the problem. brushless motor with power, long life, high efficiency advantages. So four shaft are made of brushless motor, the appearance of the model of the brushless motor as follows, different from motor, the most obvious is the brushless motor has three wires, and cooperate with electricity use. brushless motor is one of the most important parameter is the KV value, this value is unique to the brushless motor of a performance parameter, is brushless motor performance characteristics of an important data. brushless motors KV value defined as RPM/v, means the input voltage increase 1 KV, brushless motor idling speed increase speed value (Revolutions per minute)。 Always this definition, we can know, brushless motor voltage input and motor idling speed is a strict linear proportional relationship.
for example, a brushless motors KV value of 1000 KV, which means the motor under 1 v voltage, the speed of 1000 rotations per minute (RPM). Under 10 v voltage, the motor speed as: 10 v * 1000 kv = 10000 r/min, of course, these are at the time of motor racing. the winding circle number, low KV value, maximum output current is small, but the torque is big. Winding circle number less, high KV value, maximum output current is big, but small torque.
here can be extended once, why all four axis aircraft is the use of exterior rotor brushless dc motor? External rotor motor will originally in the center position of magnetic steel into pieces and stick on the shell, when the motor running, is the whole shell in turn, and in the middle of the stator coil. Exterior rotor brushless dc motor is inside the rotor, the rotor moment of inertia of much larger (Because the rotor's main quality is focused on the shell), so the inner rotor motor speed slower, KV value between several hundred to several thousand, usually used in model aircraft propeller can be directly driven, and eliminate the mechanical retarding mechanism. （'In non-inductive electrical modulation design of brushless dc motor visitors') brushless motor manufacturers
