Limited angle torque motor

Abstract

A two pole stationary coil rotary magnet motor which provides for increased work and reduced rotary inertia. The motor consists of two main assemblies, a rotor assembly contained within a rotor casing and a stator and housing assembly surrounding the rotor casing. One end of the casing is closed, whereas the other end is open to eliminate the need for a dynamic shaft seal. Fluid enters the casing at the open end thereof to provide a lubricating fluid for the rotor bearings and a heat conductive path. The rotor casing isolates the critical movement of the rotor from the contaminated atmosphere of the stator environment and allows replacement of the stator assembly without disturbing the rotor assembly. A permanent magnet rotor may be formed using one or more rare earth magnets which may be suitably bonded to the rotor shaft. A protective cover surrounds the rotor magnets to eliminate potential rotor magnet breakage contamination. The relationship between the rotor magnet angle and stator winding may be such as to produce a relatively large output work potential. Also, the lamination slot configuration and stator winding may be graded to optimize the torque versus rotation profile to more closely match the cosine function of various rotary to linear output gearing to provide a substantially constant force output.