| 摘要 |
Disclosed is a brushless DC motor capable of generating a substantially constant torque regardless of an angular velocity of its rotor. The brushless DC motor comprises a circular rotor and a plurality of circumferentially spaced solenoids (32). The circular rotor comprises a plurality of circumferentially separated permanent magnets (31) and a plurality of spacers made of high magnetic permeability material. Each of the spacers is interposed between two of the permanent magnets (31) to reduce variations in axial magnetic flux. The plurality of circumferentially spaced solenoids (32) is provided each around a static solenoid housing. The solenoid housing is structured with a void portion through which the plurality of magnets (31) can pass when the rotor rotates around its axis. The motion of the magnets (31) with respect to the solenoids (32) is quasi-linear in the direction of a solenoid axis. Each of the plurality of solenoids (32) is energised with a timing sequence to ensure that it will interact with only one of the permanent magnets (31) at any given time, thereby minimizing back EMF. |
