| 摘要 |
<p>A fluid-powered differential ball screw actuator with torque-transmitting helical ball-carrying races. The actuator includes a body with an interior first ball race and first and second ends; a first stop stationary with respect to the body for engaging and limiting travel of balls along the first ball race toward the first end; and output shaft rotatably supported within the body and having an exterior second ball race; a second stop stationary with respect to the shaft for engaging and limiting travel of balls along the second ball race toward the first end; and a piston reciprocally mounted within the body for application of fluid pressure to produce movement of the piston toward the first or second end. The piston has a sleeve coaxially receiving the shaft, with a third ball race cvonfronting and corresponding to the first ball race to form an outer set of races and a fourth ball race confronting and corresponding to the second ball race to form an inner set of races. The third and fourth ball races extend over a sufficient axial length of the sleeve projecting beyond the first and second stops, respectively, toward the first end, as measured with the piston positioned at its end limit of travel toward the first end, to permit substantially unimpeded rolling travel of balls within the outer and inner sets of races as the piston reciprocates within the body between its end limits of travel. The actuator further has a third and a fourth stop stationary with respect to the sleeve for engaging and collecting balls in the outer and inner sets of races for regrouping balls toward the first stop as the piston travels toward the first end.</p> |
