Short-circuit member for a commutator and an armature

1. A short-circuit member comprising a first conductor member group and a second conductor member group, each conductor member group including a plurality of conductor members that are arranged to form a circle, the number of the conductor members belonging to the first conductor member group and the number of the conductor members belonging to the second conductor member group being equal to each other and represented by n;

wherein each conductor member has an outer terminal located at an outer portion with respect to a radial direction of the corresponding conductor member group, an inner terminal located at an inner portion with respect to the radial direction of the corresponding conductor member group, and a coupling portion coupling the outer terminal and the inner terminal to each other, wherein the inner terminal of each conductor member is displaced from the outer terminal of the same conductor member with respect to a circumferential direction of the corresponding conductor member group;

wherein the first conductor member group and the second conductor member group are stacked on each other such that the direction in which the inner terminal is displaced from the outer terminal in each conductor member of the first conductor member group is opposite to the direction in which the inner terminal is displaced from the outer terminal in each conductor member of the second conductor member, and

wherein each inner terminal of the first conductor member group is aligned with a corresponding one of the inner terminals of the second conductor member group, and wherein each outer terminal of the first conductor member group is displaced from any one of the outer terminals of the second conductor member with respect to the circumferential direction of the first conductor member group.

2. The short-circuit member according to claim 1 , wherein, regarding each pair of a conductor member of the first conductor member group and a conductor member of the second conductor member group, of which the inner terminals are aligned with each other, the linear distance between the inner terminal and the outer terminal of one of the conductor members of the first conductor member group is different from the linear distance between the inner terminal and the outer terminal of the other conductor member of the second conductor member group.

3. The short-circuit member according to claim 1 , wherein, regarding at least some of the pairs of a conductor member of the first conductor member group and a conductor member of the second conductor member group, of which the inner terminals are aligned with each other, a first angle, which is a displacement angle between the inner terminal and the outer terminal in one of the conductor members of the first conductor member group, is different from a second angle, which is a displacement angle between the inner terminal and the outer terminal of the other conductor member of the second conductor member group.

4. The short-circuit member according to claim 3 , wherein the number of the conductor member belonging to the first conductor member group and the number of the conductor member belonging to the second conductor member group are even numbers, and wherein, regarding all the pairs of a conductor member of the first conductor member group and a conductor member of the second conductor member group, of which the inner terminals are aligned with each other, the first angle is different from the second angle.

5. The short-circuit member according to claim 4 , wherein the first angle is represented by (90+(360/(4n))°, and the second angle is represented by (90−(360/4n))°, the conductor members belonging to each conductor member group include first conductor members and second conductor members, wherein the first conductor members are consecutively arranged along the circumferential direction of the conductor member group and make up half of the conductor member group, the number of the first conductor members being represented by n/2, wherein the second conductor members are consecutively arranged along the circumferential direction of the conductor member group and make up the other half of the conductor member group, the number of the second conductor members being represented by n/2, and wherein the inner terminals of the conductor members belonging to each conductor member group are arranged at equal angular intervals along the circumferential direction of the conductor member group.

6. The short-circuit member according to claim 5 , wherein the first conductor member group and the second conductor member group have a same shape, wherein each inner terminals of each conductor member group is arranged to be axisymmetric with a corresponding one of the inner terminals with respect to a first straight line that passes through the center of the conductor member group, wherein each outer terminals of each conductor member group is arranged to be axisymmetric with a corresponding one of the outer terminals with respect to a second straight line that passes through the center of the conductor member group and is perpendicular to the first straight line, and wherein the first conductor member group and the second conductor member group are stacked on each other in a state where one of the first conductor member group and the second conductor member group are inverted about the first straight line.

7. The short-circuit member according to claim 1 , wherein either the coupling portion of each of the conductor members belonging to the first conductor member group and the coupling portion of each of the conductor members belonging to the second conductor member group is bent such that its center portion bulges in an axial direction of the corresponding conductor member group, and wherein the direction in which the center portions bulge from the corresponding conductor member group is a direction away from the other conductor member group.

8. The short-circuit member according to claim 7 , wherein each pair of the coupling portions with bulging center portions that are adjacent to each other in the circumferential direction of the corresponding conductor member group contact each other before the coupling portions are bent, and separate from each other only after the coupling portions are bent.

9. A commutator comprising:

segments the number of which is represented by 2n, n being a positive integer; and

short-circuit member having a first conductor member group and a second conductor member group, each conductor member group including a plurality of conductor members that are arranged to form a circle, the number of the conductor members belonging to the first conductor member group and the number of the conductor members belonging to the second conductor member group being equal to each other and represented by n;

wherein each conductor member has an outer terminal located at an outer portion with respect to a radial direction of the corresponding conductor member group, an inner terminal located at an inner portion with respect to the radial direction of the corresponding conductor member group, and a coupling portion coupling the outer terminal and the inner terminal to each other, wherein the inner terminal of each conductor member is displaced from the outer terminal of the same conductor member with respect to a circumferential direction of the corresponding conductor member group, wherein the outer terminal of each conductor member is connected to the corresponding one of the segments;

wherein the first conductor member group and the second conductor member group are stacked on each other such that the direction in which the inner terminal is displaced from the outer terminal in each conductor member of the first conductor member group is opposite to the direction in which the inner terminal is displaced from the outer terminal in each conductor member of the second conductor member;

wherein each inner terminal of the first conductor member group is aligned with a corresponding one of the inner terminals of the second conductor member group, and wherein each outer terminal of the first conductor member group is displaced from any of the outer terminals of the second conductor member with respect to the circumferential direction of the first conductor member group.

10. The commutator according to claim 9 , wherein, regarding each pair of a conductor member of the first conductor member group and a conductor member of the second conductor member group, of which the inner terminals are aligned with each other, the linear distance between the inner terminal and the outer terminal of one of the conductor members of the first conductor member group is different from the linear distance between the inner terminal and the outer terminal of the other conductor member of the second conductor member group.

11. The commutator according to claim 9 , wherein, regarding at least some of the pairs of a conductor member of the first conductor member group and a conductor member of the second conductor member group, of which the inner terminals are aligned with each other, a first angle, which is a displacement angle between the inner terminal and the outer terminal in one of the conductor members of the first conductor member group, is different from a second angle, which is a displacement angle between the inner terminal and the outer terminal of the other conductor member of the second conductor member group.

12. The commutator according to claim 11 , wherein the number of the conductor member belonging to the first conductor member group and the number of the conductor member belonging to the second conductor member group are even numbers, and wherein, regarding all the pairs of a conductor member of the first conductor member group and a conductor member of the second conductor member group, of which the inner terminals are aligned with each other, the first angle is different from the second angle.

13. The commutator according to claim 12 , wherein the first angle is represented by (90+(360/(4n))°, and the second angle is represented by (90−(360/4n))°, the conductor members belonging to each conductor member group include first conductor members and second conductor members, wherein the first conductor members are consecutively arranged along the circumferential direction of the conductor member group and make up half of the conductor member group, the number of the first conductor members being represented by n/2, wherein the second conductor members are consecutively arranged along the circumferential direction of the conductor member group and make up the other half of the conductor member group, the number of the second conductor members being represented by n/2, and wherein the inner terminals of the conductor members belonging to each conductor member group are arranged at equal angular intervals along the circumferential direction of the conductor member group.

14. The commutator according to claim 13 , wherein the first conductor member group and the second conductor member group have a same shape, wherein each inner terminals of each conductor member group is arranged to be axisymmetric with a corresponding one of the inner terminals with respect to a first straight line that passes through the center of the conductor member group, wherein each outer terminals of each conductor member group is arranged to be axisymmetric with a corresponding one of the outer terminals with respect to a second straight line that passes through the center of the conductor member group and is perpendicular to the first straight line, and wherein the first conductor member group and the second conductor member group are stacked on each other in a state where one of the first conductor member group and the second conductor member group are inverted about the first straight line.

15. The commutator according to claim 9 , wherein either the coupling portion of each of the conductor members belonging to the first conductor member group and the coupling portion of each of the conductor members belonging to the second conductor member group is bent such that its center portion bulges in an axial direction of the corresponding conductor member group, and wherein the direction in which the center portions bulge from the corresponding conductor member group is a direction away from the other conductor member group.

16. The commutator according to claim 15 , wherein each pair of the coupling portions with bulging center portions that are adjacent to each other in the circumferential direction of the corresponding conductor member group contact each other before the coupling portions are bent, and separate from each other only after the coupling portions are bent.

17. An armature comprising:

a rotary shaft;

an armature core fixed about the rotary shaft, a coil being wound about the armature core; and

a commutator that is fixed about the rotary shaft, segments of the commutator are electrically connected to the coil,

wherein the commutator includes:

said segments the number of which is represented by 2n, n being a positive integer, and

short-circuit member having a first conductor member group and a second conductor member group, each conductor member group including a plurality of conductor members that are arranged to form a circle, the number of the conductor members belonging to the first conductor member group and the number of the conductor members belonging to the second conductor member group being equal to each other and represented by n,

wherein each conductor member has an outer terminal located at an outer portion with respect to a radial direction of the corresponding conductor member group, an inner terminal located at an inner portion with respect to the radial direction of the corresponding conductor member group, and a coupling portion coupling the outer terminal and the inner terminal to each other, wherein the inner terminal of each conductor member is displaced from the outer terminal of the same conductor member with respect to a circumferential direction of the corresponding conductor member group, wherein the outer terminal of each conductor member is connected to the corresponding one of the segments,

wherein the first conductor member group and the second conductor member group are stacked on each other such that the direction in which the inner terminal is displaced from the outer terminal in each conductor member of the first conductor member group is opposite to the direction in which the inner terminal is displaced from the outer terminal in each conductor member of the second conductor member, and

wherein each inner terminal of the first conductor member group is aligned with a corresponding one of the inner terminals of the second conductor member group, and wherein each outer terminal of the first conductor member group is displaced from any of the outer terminals of the second conductor member with respect to the circumferential direction of the first conductor member group.