Electric motor control

Claim 1

An electric motor having a bell-shaped rotor and a generally cylindrical stator, the rotor being positioned in an air gap between spaced inner and outer concentric portions of the stator, the stator comprising: a generally cylindrical permanent magnet, said magnet having a central axial aperture, said magnet defining the inner portion of the stator; an injection molded element, said injection molded element positioning said magnet in said motor, said molded element having a first portion positioned in, and conforming in shape to, said aperture of said magnet, and having a second portion forming a face plate which engages a first end of said magnet and which extends radially outwardly beyond the periphery of said magnet, said first portion of said molded element having a central bore positioned on the axis of said magnet, said central bore having end portions which carry bearings, said bearings supporting a shaft which passes through said central bore in said injection molded element, said shaft supporting the bell-shaped rotor for rotation in the air gap; a flux return element concentric with, and spaced radially outwardly from said magnet to define the air gap in which the bell-shaped rotor is positioned, said flux return element being cylindrical with a first end of said flux return element contacting said face plate radially outwardly of said magnet; a casing, said casing extending from said face plate radially outwardly of, and in intimate engagement with said flux return element, said casing extending beyond a second end of said magnet and terminating in a radially inwardly turned free end, said free end extending radially inwardly to an extent not exceeding an inner diameter of said flux return element; and, a brush cover, a wall portion of said cover contacting a second end of said flux return element, said radially inwardly turned free end of said casing engaging said wall portion of said brush cover to secure said cover to said casing.