the body 14 is provided with a multiplicity of open ended axial passageways 34 radially inwardly of the passages 16 and 18 and generally parallel with the ribs 22 these passageways 34 are so located to receive air from the fan 26 the cooling fluid is circulated by means of a dual action axial flow pump generally identified as 36 the pump 36 comprises a rotor 38 and a stator 40 the rotor 38 being connected to the shaft means 10 while the stator 40 is connected as by one or more machine bolts 42 to the body 14 the stator 40 defines with the body 14 a pair of cooling fluid chambers 44 46 each communicating with one of the mechanical seal means to be described the pump 36 has a central inlet 48 communicating with an inlet passage 50 in the body 14 which intersects the helical passages 18 and 20 adjacent one of their ends the opposite ends of the passages 18 and 20 intersect discharge passages 52 and 54 formed in the body 14 from the chambers 44 46 respectively one of the discharge passages is connected via suitable passages to a filter 56 so as to filter the cooling fluid and remove foreign material thereform the rotor 38 and the stator 40 of the pump 36 are so constructed with right and left.