Brush assemblies
View Patent ↗Detailed are brush assemblies for electric motors. The assemblies may include retention springs or other mechanisms designed to bias brushes away from surfaces of commutators during assembly of the motors. Such retention mechanisms additionally may be fitted into cavities in associated cover plates following motor assembly. The cover plates further may include tabs which, in use of the motor, assist in supporting side surfaces of the brushes and in orienting the plate relative to a corresponding brush card.
1. A brush assembly for an electric motor, the brush assembly comprising:
a brush card having an opening configured and dimensioned for receiving a commutator, the opening including a wall and a channel located along the wall, the channel including a channel side wall;
a brush coupled to and supported by the brush card, and positioned to contact, in the event one is received in the opening, a commutator; and
a resilient member including a restraining section and a flange, the flange being configured and dimensioned to be received in the channel;
wherein the resilient member is further adapted to assume a deflected position, and is mounted to the brush card at the opening in the deflected position such that the restraining section addresses the brush so as to restrain a movement thereof in at least one direction relative to the brush card, and such that the flange is received in the channel, and engages the channel side wall.
2. A brush assembly for an electric motor according to claim 1 , wherein the resilient member is adapted to be compressed so as to assume a closed deflected position, and is mounted to the brush card at the opening in the closed deflected position.
3. A brush assembly for an electric motor according to claim 1 , wherein the restraining section is included in a curved portion of a leg of the resilient member shaped to fit within the opening, the flange being located at an end of the leg.
4. A brush assembly for an electric motor according to claim 1 , wherein the channel extends along an axial direction of extension of the opening, and the flange is supported along the axial direction by an end surface of the channel.
5. A brush assembly for an electric motor according to claim 1 , wherein, when a commutator is received within the opening to a predetermined depth, such commutator moves the resilient element through the opening to an extent sufficient to prevent the restraining section from so addressing the brush, and to push the flange out of the channel, thereby permitting the resilient member to relax relative to the deflected position and thereby assume a rest position.
6. A brush assembly for an electric motor according to claim 5 , wherein, when the flange is pushed out of the channel, the resilient element is entirely dislodged from the opening.
7. A brush assembly for an electric motor according to claim 6 , further comprising a cover plate coupled to the brush card adjacent the opening, and defining a cavity in the cover plate adapted to receive and retain the resilient member in the rest position upon the resilient member being dislodged from the opening.
8. A brush assembly for an electric motor according to claim 7 , wherein the cover plate includes a first side facing the opening of the brush card, and a second side opposite the first side, and wherein the cavity is defined in the second side.
9. A brush assembly for an electric motor according to claim 1 , wherein the resilient element is a spring including two legs adapted to flex relative to each other, and the flange is associated with an end of one of the two legs.
10. A brush assembly for an electric motor according to claim 9 , wherein the spring includes a substantially linearly straight section disposed opposite the flange, and the restraining section is a section of the leg, with an end of which the flange is associated.
11. A brush assembly for an electric motor according to claim 1 , further comprising a biasing spring positioned at least partly within the brush card and in operative contact with the brush for biasing the brush inward relative to the opening.
12. A brush assembly for an electric motor according to claim 11 , wherein the restraining section is arranged in opposition to the bias of the biasing spring.
13. A brush assembly for an electric motor, comprising:
a brush card having an opening configured and dimensioned for receiving a commutator, the opening including a wall and a channel located along the wall, the channel including a channel side wall;
a brush coupled to and supported by the brush card, and positioned adjacent the opening such that the brush is positioned to contact, in the event one is received in the opening, a commutator; and
a resilient member including a restraining section and a flange configured and dimensioned to be received in the channel, the resilient member being further adapted to be assume a deflected position, and being received in the opening in the deflected position such that the restraining section is positioned adjacent the brush, thereby restraining the brush from moving inward relative to the opening, and the flange is received in the channel and engages the channel side wall.
14. A brush assembly according to claim 13 , wherein the resilient member is adapted to be compressed so as to assume a closed deflected position, and is mounted to the brush card at the opening in the closed deflected position.
15. A brush assembly according to claim 13 , wherein the resilient member is further adapted to receive an urging force applied along a first direction from a commutator inserted into the brush card opening along the first direction, and to react to the urging force by moving substantially in translation along the first direction at least until the restraining section is translated out of contact with the brush, and thereby no longer so restrains the brush.
16. A brush assembly for an electric motor according to claim 13 , further comprising a biasing spring positioned at least partly within the brush card and in operative contact with the brush for biasing the brush inward relative to the opening.
17. A brush assembly for an electric motor according to claim 16 , wherein the restraining section is in opposition to the bias of the biasing spring.
18. A brush assembly for an electric motor, comprising:
a brush card having a opening extending in a first direction and configured and dimensioned for receiving a commutator inserted into the brush card along the first direction, the opening including a wall and a channel extending in the first direction along the wall;
a brush coupled to and supported by the brush card, and positioned adjacent the opening such that the brush extends radially inward relative to the opening, and is positioned to contact, in the event one is received in the opening, a commutator; and
a resilient member including a first curved leg, a second curved leg, and a central span disposed between the first and second curved legs and configured and dimensioned to be received in and translate along the channel, and to key the resilient element rotationally relative to the opening;
wherein the resilient member is adapted to be assume a deflected position in which the first and second curved legs are flexed relative to each other about the central span, and the resilient member is received in the opening in the deflected position such that one of the first and second curved legs is positioned in operative contact with the brush, and is permitted to restrain the brush from moving radially inward relative to the opening; and
wherein the resilient member is further adapted to receive an urging force applied along the first direction from a commutator inserted into the brush card opening, and to react to the urging force by moving substantially in translation along the first direction at least until the one of the first and second legs is translated out of such operative contact with the brush.
19. A brush assembly for an electric motor in accordance with claim 18 , wherein the resilient member is adapted to be compressed so as to assume a closed deflected position in which the first and second curved legs are flexed toward each other about the central span, and the resilient member is received in the opening in the closed deflected position.
20. A brush assembly for an electric motor in accordance with claim 18 , wherein the central span has a substantially linearly straight shape.