Rotary actuator with annular fluid coupling rotatably mounted to shaft

Abstract

A fluid-powered rotary actuator attachable to a boom and usable with a work implement having two hydraulic actuators. The rotary actuator has a body with a drive shaft extending longitudinally therewithin. The shaft has one end located outward of the body and fixed to an attachment flange which can be connected to a vehicle boom. An annular fluid coupling is rotatably mounted on the shaft between the flange and the body. Fluid passageways in the shaft conduct fluid to the coupling, which has three circumferential fluid distribution channels. The coupler provides the fluid to flexible hoses which extend to the hydraulic actuators. The coupling is freely rotatable relative to the shaft but has a connection finger attached thereto which is received in a hole in a connection flange which is attached to the body. The connection flange transmits a rotational force on the coupling through the finger as the body rotates to produce rotation of the coupling with the body, but the receiving hole is sufficiently larger than the finger positioned therein that axial and bending forces are not transmitted between the body and the coupling. A set of annular body and shaft inserts is positioned at each end of the body to rotatably support the body on the shaft.