Patent ID: 7573174

Claim:
A universal motor ( 2 ) comprising: a commutator ( 14 ) having a motor axis (A); at least two carbon brushes ( 36 ) contacting the commutator ( 14 ) in respective commutation regions ( 34 ); a ventilation device ( 12 ) for producing a cooling flow (K) in a cooling flow path ( 24 ); dust protection means for preventing penetration of material particles (M) into the commutation regions ( 34 ) and including at least one guide member ( 26 ) that provides for delivering of the material particles (M) in the cooling flow (K), the at least one guide member ( 26 ) having a smooth concave guide surface ( 28 ) located between the two carbon brushes ( 36 ) and extending adjacent to an outer surface ( 30 ) of the commutator ( 14 ) and toward a suction opening ( 22 ) connected with the cooling flow path ( 24 ); and a baffle member ( 32 ) provided on a side of the suction opening ( 22 ) with the baffle member ( 32 ) being located remote, in the circumferential direction, from the guide member ( 26 ) and extending in a transverse direction relative to the motor axis (A).