Momentum compensated rotary actuator with harmonic drive

Abstract

The momemtum compensated actuator in this invention directly torques the compensating inertia relative to the pointed structure with the harmonic drive used to insure the rotational rate ratio between the compensating inertia and pointed structure is constant at all times. Improvements to the actuator are: 1. a harmonic drive wave generator shaft coupling that is torsionally very stiff with no backlash about the wave generator rotational axis, but is compliant to small wave generator motions orthogonal to the rotational axis due to harmonic drive ring gear-flexspline tooth mesh errors; 2. a shaft link between the pointed structure and the base vehicle with a threaded means to compressional preload all the rotational structure support ball bearings; 3. a means to provide a rotational bias rate to the actuator rotational reference structure assuring that during pointing each rotating structure support ball bearing race has a different rotational rate eliminating non linear stiction friction effects.

Dependencies are inferred from the claim text.