Hand-held power tool with enhanced motor cooling - has radial and axial fans juxtaposed and keyed to motor armature shaft in space immediately ahead of downstream stator winding heads

摘要

The two fans (13, 14) are installed adjacent to each other on the shaft (10) of the motor (12) driving e.g. an angle-grinding tool. The axial fan (14) extends into the space (16) bounded by the stator winding heads (15) with an air-permeable screen (17) between these and the blades (13') of the radial fan (13). The air is inducted around the commutator (18) where an air-permeable ring (19) is in two parts, each combined with a brush holder. ADVANTAGE - Motor cooling is enhanced by axial fan increasing pressure and improving inflow rate at radial fan.