Brush motor
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 Z 1 . . . Z X . . . Z Y . . . Z M , 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 Z X and an end connected to another segment Z Y . 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. Z X and Z Y satisfy the following equation: |Y−X|=(M±1)/P.
1. A brush motor comprising a stator with 2P poles and a rotor comprising a rotor core, a commutator and windings wound about teeth of the rotor core,
wherein the rotor core comprises N teeth with a slot formed between adjacent teeth;
the commutator comprises M segments represented by Z 1 . . . Z X . . . Z Y . . . Z M , M being greater than N, N, P, Y and X being integers, M being an odd integer;
each winding comprises a start connected to a segment Z X and an end connected to another segment Z Y , Z X and Z Y satisfying the following equation: |Y−X|=(M±1)/P;
each winding comprises at least one coil wound on corresponding tooth/teeth, some of the windings comprise a plurality of coils wound on different teeth, the total number of turns of the coils of each winding being substantially the same; and
a winding unit formed by a plurality of windings is connected between every pair of adjacent segments.
2. The brush motor of claim 1 , wherein said some of the windings comprising a plurality of coils each have two coils wound about different teeth in opposite directions.
3. The brush motor of claim 2 , wherein the two coils of each of the windings having two coils are connected between two segments and cooperatively act as a virtual wave winding connected between said two segments.
4. The brush motor of claim 2 , wherein the two coils of the same winding have a different number of turns.
5. The brush motor of claim 2 , wherein each pair of adjacent windings have coils wound about a common tooth or group of teeth.
6. The brush motor of claim 5 , wherein in some of the winding units, the coils of adjacent pairs of windings are wound about the same teeth.
7. The brush motor of claim 1 , wherein each coil is wound about one tooth.
8. The brush motor of claim 7 , wherein the motor comprises 4 poles, 5 teeth, 25 segments and 25 windings.
9. The brush motor of claim 1 , wherein each coil is wound about multiple teeth.
10. The brush motor of claim 9 , wherein the motor comprises 4 poles, 15 teeth, 45 segments and 45 windings, with each coil being wound about 3 teeth.
11. The brush motor of claim 1 , wherein each winding unit comprises only two windings.