Patent ID: 8022590
Filing Date: 2011-09-20
Classification: H01R,H02K

Abstract:
1. An electric machine comprising: a casing a stator and a rotor supported by the casing, the rotor having at least one rotor winding; a commutator connected permanently to the rotor and electrically connected to the rotor winding; at least one pair of brushes, each brush having a first end slidably engaged with the commutator and being electrically connected to respective terminals which may be connected to an electricity mains supply; at least one pair of brush holder elements supported by the casing, each brush holder element being associated with a respective brush to keep it pressed on the commutator; each brush holder element having at least one lateral surface to face a butting portion of the casing and which may be joined to the butting portion to transmit thermal power to the butting portion, the lateral surface being electrically isolated from the butting portion; the casing comprising a wall lying in a plane substantially perpendicular to an axis of rotation of the rotor, the butting portion being positioned on the wall and facing a space inside the electric machine; an elastic element active between the casing and the brush holder elements to provide a force against the brush holder elements toward the wall in an axial direction of the casing parallel to the axis of rotation of the rotor to maintain the lateral surfaces of the brush holder elements axially pressed against the butting portion; a support element slideable along the axis of rotation of the rotor and on which the brush holder elements are permanently fitted, the elastic element being operationally active between the casing and the slideable support element; and the elastic element having an annular shape, the slideable support element having a discoidal shape, the elastic element being active on a periphery of the slideable support element.