Axial-piston machine

Claim 1

An axial piston machine comprising: a housing having a fluid-distribution surface; a cylinder drum received in said housing for rotation about an axis generally transverse to said surface and provided with a plurality of angularly spaced cylinders each communicating with said surface; a shaft keyed to said cylinder drum for rotatable entrainment therewith while permitting relative axial displacement of said drum and said shaft; an inclined guide body in said housing surrounding said shaft, said drum being provided with respective pistons each axially displaceable in a respective one of said cylinders and having a shoe slidably engaging said body; pressure means axially shiftable relative to said shaft for retaining said shoes against said body; first spring means bearing in opposite axial directions upon said drum and said shaft for urging said drum against said surface, said first spring means including a perforated disk acting upon said shaft; and second spring means surrounding said shaft and including a plurality of rods extending through perforations in said disk and acting upon said pressure means for urging same toward said body, said cylinder drum being provided with an annular shoulder surrounding said shaft at an intermediate location along the length of said cylinder drum, said first spring means including a first spring coaxially surrounding said shaft and bearing axially upon said disk and said shoulder, said second spring means including: a second spring coaxially surrounding said shaft and disposed between said first spring and said surface, a sleeve surrounding said shaft and coaxial with said first spring and with said shaft while being axially shiftable and seated against said second spring, and a ring axially entrained by said sleeve and bearing upon said rods.