A brushless motor comprises: a stator 21 having armature coils 21a, 21b, and 21c; a rotor 22 which is rotated by a revolving magnetic field; and a switching element 30a, wherein the brushless motor has a rotation number control unit 33 which switches between low-speed and high-speed mode, wherein in the low-speed mode, the rotation number control unit 33 supplies current to the armature coils 21a, 21b, and 21c at predetermined energization timing and controls a duty ratio to control the rotation number of the rotor 22, and in the high-speed mode, the rotation number control unit 33 supplies current to the armature coils 21a, 21b, and 21c at energization timing advanced from the energization timing for the low-speed mode, thereby performing field weakening control of weakening the revolving magnetic field from that of the low-speed mode to control the rotation number of the rotor 22.
Brushless motor and wiper apparatus
2018-03-20
Patent
Electronic Resource
English
IPC: | H02P CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS , Steuern oder Regeln von elektrischen Motoren, elektrischen Generatoren, dynamoelektrischen Umformern / B60S SERVICING, CLEANING, REPAIRING, SUPPORTING, LIFTING, OR MANOEUVRING OF VEHICLES, NOT OTHERWISE PROVIDED FOR , Warten, Reinigen, Instandsetzen, Unterstützen, Anheben oder Rangieren von Fahrzeugen, soweit nicht anderweitig vorgesehen / H02K Dynamoelektrische Maschinen , DYNAMO-ELECTRIC MACHINES |