Air-powered splined rotary actuator

Abstract

An air-powered actuator having a body with first and second ends, an axially transverse annular bulkhead positioned therebetween, and an output shaft with a splined exterior portion. The body includes first and second end walls with each end wall having a sleeve mounted coaxially within the body about the shaft and projecting axially inward within the body. A piston sleeve is disposed for axial reciprocating movement within the body. The piston sleeve has a pair of piston heads, an outer sleeve, and an inner sleeve. The outer sleeve is mounted coaxially within the body inward of the bulkhead and about the first and second sleeves to define therewith a fluid-tight outer chamber containing the piston heads, each positioned to an opposite side of the bulkhead to define four fluid-tight chambers and to which pressurized air is applied. Also defined is a fluid-tight inner chamber containing lubricating oil. The outer sleeve is attached to the piston heads for reciprocating travel therewith. The inner sleeve is mounted coaxially within the inner chamber, inward of the second sleeve and about the shaft. The inner sleeve is attached to the outer sleeve for reciprocating travel therewith. The inner sleeve has a splined exterior portion meshing with the second sleeve splined interior portion and a splined interior portion meshing with the shaft splined exterior portion to translate axial movement of the piston sleeve into relative rotational movement between the shaft and the body.