Fluid device having plastic housing and means for mounting a cylinder barrel

Claim 1

A fluid pressure energy translating device of the axial piston type comprising: a housing having a longitudinal bore with a stationary valve plate at one end thereof; a drive shaft rotatably carried within said housing bore, said drive shaft having a male spline; a rotatable cylinder barrel mounted on said drive shaft and having one end in abutment with said valve plate, said cylinder barrel having a plurality of arcuately spaced cylinder bores, said cylinder barrel having a female spline mating with said drive shaft male spline to form a driving connection thereinbetween; a bearing means having an inner race carried by the outer peripheral surface of said cylinder barrel, said bearing means having an outer race carried by the wall of said housing longitudinal bore such that said bearing means providing radial support for said cylinder barrel; said male and female splines having complementary configurations for permitting self-centering alignment between said cylinder barrel and said drive shaft such that said cylinder barrel will float on said valve plate and said cylinder barrel will be centered with respect to said bearing means, said female spline having a pitch diameter which is greater than the pitch diameter of said male spline such that there is an enlarged radial clearance space between said splines; a plurality of pistons with inner ends disposed for reciprocal stroking movement within said cylinder bores; and an inclined thrust plate mounted in said housing in a driving relation with the other ends of said pistons for imparting a reciprocal stroking movement to said pistons within said cylinder barrel bores as said cylinder barrel rotates whereby the radially directed forces exerted on said cylinder barrel are not transferred to said drive shaft.