초록 ▼

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 b

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.

대표청구항 ▼

A fluid-powered actuator, comprising: a body having first and second ends; a shaft disposed within said body and supported for rotation relative thereto, said shaft having a torque-transmitting first ball race; a first stop axially stationary with respect to said shaft for engaging and limiting trav

A fluid-powered actuator, comprising: a body having first and second ends; a shaft disposed within said body and supported for rotation relative thereto, said shaft having a torque-transmitting first ball race; a first stop axially stationary with respect to said shaft for engaging and limiting travel of balls along said first ball race toward said first end; a piston reciprocally mounted within said body and having a head for application a fluid pressure to one or the other opposing sides of said head to produce axial movement of said piston toward said first or second end, said piston further having an elongated sleeve with said shaft extending interior of said sleeve, said sleeve having a torque-transmitting second ball race corresponding to and confronting said first ball race to form a channel defined by the area of coincidence of said first and second ball races, said channel being helical, said second ball race extending over a sufficient axial length of said sleeve projecting beyond said first stop toward said first end, as measured with said piston positioned at its end limit of travel toward said first end, to permit substantially unimpeded rolling travel of balls within said channel toward said second end as said piston travels from an end limit of travel at said first end to an end limit of travel at said second end; one or more balls seated in said channel to a side of said first stop toward said second end for transmitting torque between said piston and said shaft upon axial movement of said piston by the application of fluid pressure to said head; and means for transmission of torque between said piston and said body.