Abstract: A single phase brushless motor and a power tool are provided. The single phase brushless motor includes a stator and a rotor. The stator includes a stator core and windings wound around the stator core. The stator core includes a yoke and at least two teeth. The tooth includes a tooth body and a tooth tip. The tooth tip includes first and second pole shoes. The two pole shoes of each tooth are symmetrical about a center line of the tooth body. Each tooth defines a positioning groove facing the rotor between the two pole shoes. Pole shoes of adjacent two of the at least two teeth are spaced apart by a slot opening. A width of the positioning groove is greater than a width of the slot opening. The peak value of the cogging torque of the motor is increased, and the motor has a large startup torque.

Abstract: A commutator (10, 40, 54, 60, 64, 70, 76, 78) for a brush motor includes a cylindrical insulating base (12), a plurality of segments (14) disposed on an outer surface (68) of the insulating base (12), circumferentially spaced from each other, and defining a plurality slots (42) between adjacent segments (14), and a plurality of insulating outgas elements (24) capable of releasing a gas having a lower conductivity than air and disposed on the outer surface (68) of the cylindrical insulating base (12). Each outgas element (24) is located between a corresponding pair of the plurality of segments (14), having a gas releasing surface (26) between the corresponding pair of segments (14) and lower than outer surfaces (28) of the corresponding pair of segments (14). A method for making a commutator is also provided.

Abstract: A fan unit for a heat exchanger, particularly for a motor vehicle, has a support structure or cowling having a main aperture forming a passage for a flow of air, and an electric fan having an impeller and an electric motor. A flexible electrical cable connects the motor to a source of supply voltage and/or to an associated control circuit. The cable has a terminal electrical connector having a body with one end connected to the cable, and another end provided with at least one connection aperture. A seat is provided in the support structure or cowling for receiving and retaining the terminal electrical connector, and for covering the at least one connection aperture of the connector.

Abstract: A starter motor includes an electric motor, a drive shaft driven by the motor and an inertia drive pinion which includes a driver in threaded engagement with the drive shaft, a pinion shaft rotatably sleeved on the drive shaft, an output pinion being able to rotate with the pinion shaft, and a one way clutch. At least one elastic member is arranged between the output pinion and the pinion shaft in the axial direction to resiliently support the output pinion to move along the pinion shaft. A one way clutch especially suitable for the starter motor was also disclosed.

Abstract: A commutator (10, 40, 54, 60, 64, 70, 76, 78) for a brush motor includes a cylindrical insulating base (12), a plurality of segments (14) disposed on an outer surface (68) of the insulating base (12), circumferentially spaced from each other, and defining a plurality slots (42) between adjacent segments (14), and a plurality of insulating outgas elements (24) capable of releasing a gas having a lower conductivity than air and disposed on the outer surface (68) of the cylindrical insulating base (12). Each outgas element (24) is located between a corresponding pair of the plurality of segments (14), having a gas releasing surface (26) between the corresponding pair of segments (14) and lower than outer surfaces (28) of the corresponding pair of segments (14). A method for making a commutator is also provided.

Abstract: A speed sensor for an electric motor detects the variation in the electric field of the armature due to commutation to produce an output signal indicative of the speed of rotation of the motor.