Flexure mounted gimbal support assembly

Claim 1

In a gimbal support system of the type including a stable platform for holding inertial components, a torque motor for providing driving torque between the gimbals, the rotor of the torque motor fixed relative to the stable platform and energized by brushes which are not fixed relative to said platform, and a slip ring assembly for enabling external electrical connection to said brushes and inertial components, the improvement being apparatus for rotatably coupling said stable platform to said gimbal, said apparatus minimizing the effects of friction on rotating parts, which comprises: (a) an antifriction ball bearing having an inner race and an outer race, the outer race of said bearing being rigidly coupled to the inner surface of said rotor and said stable platform; (b) an inner ring having its outer surface rigidly coupled to the inner race of said bearing and to said brushes, the aperture of said inner ring being adapted for rotatably supporting said slip ring assembly therein; (c) an outer ring concentric with said inner ring having its outer surface rigidly coupled to said gimbal; (d) a plurality of flexure elements coupled between the outer surface of said inner ring and the inner surface of said outer ring, said flexure elements allowing relative rotational movement between said inner ring and said outer ring; and (e) the resistance to rotational motion provided by said flexure elements being less than the resistance to said motion provided by said bearing for a preselected angle of rotation and less than the resistance to said motion provided by said slip ring assembly for said preselected angle of rotation, whereby there is no relative motion between the brushes and the rotor, between the slip ring assembly and the inner ring, and between the inner race and outer race of the bearing for rotational motion within the preselected angle, thereby minimizing effects of friction for rotational motion within said preselected angle.