Direct current motor with crescent shaped brushes
AssigneeSiemens Electric Limited
InventorMarek Horski
Life of this patent
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Abstract
A single speed, two pole permanent magnet motor has compact brush card assembly mounted within the volume form by a plurality of ring shaped laminations forming the armature to allow the height of the motor to much less than a standard motor. In addition, there is shown a two speed, four pole permanent magnet motor having a height much less than a standard two speed motor. In each motor there are electrically connected to the supply lines a choke means and across each supply line is a capacitor for suppressing radio frequency interference.
Claims5
A direct current motor having a generally u-shaped housing open at one end-and having an aperture centrally located in a closed end, the aperture supporting a bearing member;
- a permanent magnet field;
- an end bell adapted to enclose the housing at its open end;
- bearing means centrally located in the end bell adapted to be aligned with the aperture in the housing;
- spring means for locating and maintaining the bearing means in the end bell;
- armature means including an armature shaft, a first commutator having hook members, and an armature, the armature shaft rotatably mounted in the bearing means at one end and the bearing member in the housing intermediate the ends of the shaft;
- brush card means having at least one pair of diametrically opposed brush means, each having a brush, the brush card means mounted in the end bell and positioned so that the brushes are in contact with the first commutator;
- characterized in that
- said armature comprises a plurality of ring shaped laminations mounted to a web member having a central hub for mounting on the armature shaft intermediate the bearing means and the bearing member;
- said first commutator is mounted adjacent to said hub and substantially within a cylinder formed by said ring shaped laminations of said armature,
- said brush card means comprises an electrically non-conductive base member having an outer periphery and a central aperture with a diameter larger than the diameter of the commutator, the base member supporting the at least one pair of brush means within the outer periphery of said base member and said brush means having an arcuate brush tube for retaining and guiding an crescent brush and a torsion spring mounted to said base member and biasing each of said brushes in an arcuate direction toward the commutator,
- said brush card means is mounted to said end bell and said at least one pair of diametrically opposed brush means is substantially contained within said ring shaped laminations.
Dependencies are inferred from the claim text.