Motor for rotating brush

Claim 1

A vacuum cleaner and sweeper unit comprising a housing, said housing having an interior, means defining a lower face of the housing, and means for coupling a vacuum hose to the housing interior, a cylindrical rug cleaning brush rotatably supported within said housing and having a longitudinal side exposed from the interior of the housing through said face, electric motor means within said brush, said electric motor means including rotor means directly connected to said cleaning brush and rotatably supported by common bearing means for coaxial rotation together, said rotor comprising a hollow armature including a cylindrical tube of soft magnetic material and a winding unit disposed within said magnetic tube, magnetic field producing means disposed within said armature, electric brushes within said armature, and commutating means on said armature cooperating with said electrical brushes to supply electrical current to said armature, said magnetic tube providing a return path for magnetic flux produced by said magnetic field producing means, said winding unit being fixed to said magnetic tube, whereby said magnetic tube radially supports said winding unit substantially along its full axial length such that said magnetic tube is adapted to operate as a heat sink for said winding unit, said magnetic tube being arranged to transmit substantially all of the heat developed by said winding unit to the outer surface of said cleaning brush, whereby air flow over said cleaning brush induced by rotation of said cleaning brush and a vacuum in said housing functions to cool said armature.