Abstract: A universal motor has a rotor and a stator. The stator comprises a pair of symmetrical C-shaped stator cores and two windings respectively wound on the stator cores. Each stator core comprises a yoke and a pair of poles extending from opposite ends of the yoke. The windings are wound on the yokes. Each pole has a curved surface and the surfaces of the poles cooperatively form an opening. The rotor is rotatably received in the opening.

Abstract: A motor comprises a stator and a rotor. The stator comprises 2P poles wherein P is an integer greater than one. The rotor comprises a shaft, a rotor core and a commutator fixed to the shaft. The commutator comprises m segments where m is an even integer greater than P. Every two adjacent segments are electrically connected by a winding unit so that the rotor winding comprises m winding units with at least one of the winding units comprising P coils connected in series; and each coil of each winding unit is directly connected to a corresponding two segments.

Abstract: A brush motor includes a stator with 2P magnetic poles and a rotor which includes a rotor core, a commutator and windings wound on the rotor core. The rotor core includes N teeth with a slot formed between adjacent teeth. The commutator includes M segments represented by Z1 . . . ZX . . . ZY . . . ZM, wherein M, N, P, Y and X are integers and M is odd and greater than N. Each winding includes a start connected to a segment ZX and an end connected to another segment ZY. Each winding includes at least one coil wound about a corresponding tooth or set of teeth. Some of the windings include a plurality of coils wound on different teeth. The total number of turns of the coils for each winding is substantially the same. A winding unit consisting of a plurality of windings is connected between each pair of adjacent segments. ZX and ZY satisfy the following equation: |Y?X|=(M±1)/P.