Permanent magnet DC motor is made up of many parts, then, what are the characteristics?

Take the principle of permanent magnet brushless DC motor for example to:

Brush motor stator installed on a fixed pole and brush, installed on the rotor the armature winding and commutator. DC power supply power through the brushes and commutator into the armature winding, armature current of armature current magnetic field interacts with the main magnetic field of electromagnetic torque, the motor spins the load. Given the existence of the brushes and commutator and brush motor complex structures, poor reliability, failure, maintenance workload and the short life of commutation spark is easy to produce electromagnetic interference.

PM DC motor pm body N-S alternating Exchange, makes location sensor produced phase 120 ° of u, and v, and w square, combined are/reverse signal produced effective of six State coding signal: 101, and 100, and 110, and 010, and 011, and 001, through logic component processing produced T1-T4 guide pass, and T1-T6 guide pass, and T3-T6 guide pass, and T3-T2 guide pass, and T5-T2 guide pass, and T5-T4 guide pass, that is will DC bus voltage followed by added in A+B-, and A+ C-, and B+C-, B+A-, C+A-, C+B-upper, so each turned a pair of rotor N-S, T1-T6 power tube in turn is fixed into the six-State conduction.

In this way, each part is essential for permanent magnet DC motor.