Patent ID: 8013482

Claim:
An axial disk electric motor for rotatably driving a connected load, comprising: a stator comprising a coil holder for holding a stator coil and a coil cover covering the stator coil; a rotor provided with magnets and provided so as to cover the stator from both sides; a stationary shaft-shaped central portion disposed so as to extend through respective central portions of the rotor, and the stator, the shaft-shaped central portion being fixed to the stator; and a cooling structure provided inside of the stator and the shaft-shaped central portion, wherein the cooling structure comprises: a coolant inlet tube fitting disposed in an end face of the shaft-shaped central portion for introducing a coolant into a coolant inlet port formed in the shaft-shaped central portion; a coolant outlet tube fitting disposed in the end face of the shaft-shaped central portion for discharging the coolant therefrom via a coolant outlet port formed in the shaft-shaped central portion; and a coolant manifold disposed between the coolant inlet and outlet ports formed in the shaft-shaped central portion and flow channels formed in at least one of the coil holder and the coil cover for allotting a supply path and a return path of the coolant to each individual cooling flow channel of the flow channels, wherein the coolant manifold has a distribution area in which the coolant supply path is formed, and a collection area in which the coolant return path is formed, wherein the distribution area and the collection area are formed as mutually different areas and the coolant manifold has a double layered structure in which the distribution area forms one layer and the collection area forms another layer, wherein the coil holder and the coil cover both have a planar disk shape, and each of the flow channels for cooling the stator coil is disposed on one side of the coil holder and on one side of the coil cover, wherein the flow channels for cooling the stator coil comprise a plurality of individual cooling flow channels divided in a circumferential direction of the coil holder and the coil cover, and each of the individual cooling flow channels comprises an outgoing path extending in a radial outward direction between center portions and outer peripheral portions of the coil holder and the coil cover, and a return path that extends in a radial inward direction between the central portions and the outer peripheral portions of the coil holder and the coil cover, and wherein the coil holder and the coil cover are connected together by a plurality of hollow bolts, and each of the individual cooling flow channels of the coil holder and a corresponding one of the individual cooling flow channels of the coil cover are connected together by a flow channel formed in each of the hollow bolts.