Fluid device having means for aligning a cylinder barrel

Abstract

A fluid device of the axial piston type having high and low pressure operating passages, one of which may be an inlet and the other an outlet depending upon the pumping or motoring function of the device. The fluid device which may be of the fixed or variable displacement type has a rotatable cylinder barrel with each end of a plurality of pistons disposed for reciprocation within cylinder bores in the cylinder barrel, and cylinder ports successively communicating each of the cylinder bores with arcuate inlet and outlet passages formed in a valving face disposed at one end of the cylinder barrel. The other ends of the pistons are drivingly engaged by an inclined thrust plate assembly disposed to impart a reciprocal stroking movement to the pistons within the cylinder bores as the cylinder barrel is rotated. In one example of the invention, the thrust plate assembly, the cylinder barrel and other rotating components of the fluid device are constructed of a sintered material enclosed in a plastic housing which is preloaded by a predetermined amount that is a function of the expansion forces exerted on the housing by the fluid pressure acting against the pistons within the cylinder bores. In a second example of the invention, a variable displacement fluid device is disclosed as having several means for varying the inclination of the thrust plate assembly with respect to the longitudinal axis of the shaft on which the rotating cylinder barrel is carried.

What is claimed is as follows: 
     
       1. .[.A.]. .Iadd.In a .Iaddend.fluid pressure energy translating device of the axial piston type, comprising: a housing.[..]. .Iadd.having a longitudinal bore, a shaft mounted in said bore; .Iaddend.a cylinder barrel rotatably mounted within said housing, said cylinder barrel having a plurality of arcuately spaced cylinder bores and cylinder ports communicating each of said cylinder bores with one end of said cylinder barrel; a plurality of pistons with inner ends disposed for reciprocal stroking movement within said cylinder bores; a valve face having arcuate passages; said valve face and said one end of said cylinder barrel being disposed for relative rotary movement with said cylinder ports communicating successively with said arcuate passages in said valve face; thrust plate means comprising a yoke support fixedly mounted in said housing and a yoke movably supported by said yoke support, said yoke support, said yoke being in a driving relationship with the other ends of said pistons for imparting said reciprocal stroking movement to said pistons within said cylinder barrel bores as said cylinder barrel rotates: bearing means having an outer race carried within said housing, an inner race carried around a portion of the peripheral surfaces of said cylinder barrel, said bearing means providing radial support for said cylinder barrel, .[.said bearing means being in contact with said yoke support at a plurality of circumferentially spaced locations for properly locating said cylinder barrel with respect to said yoke;.]. said outer race being carried by said housing concentric with said .[.housing bore;.]. .Iadd.longitudinal bore; and means for varying the inclination of said yoke relative to the axes of said pistons; and wherein said outer race of said bearing means is in contact with said yoke support at a plurality of circumferentially spaced locations for properly locating said cylinder barrel with respect to said yoke; and .Iaddend.said means for varying the inclination of said yoke .[.comprising.]. .Iadd.comprises .Iaddend.a pair of sleeve members .Iadd.fixedly mounted in said housing, .Iaddend.each .Iadd.of said sleeve members being .Iaddend.disposed along an axis paralleling the axis of said shaft and radially outwardly spaced from the peripheral surface of said cylinder barrel, each of said sleeve members having one end of a piston member reciprocably mounted therein, the other ends of said piston members adapted to abut a portion of said yoke to pivot said voke, .Iadd.the improvement comprising .Iaddend.said sleeve members being radially spaced a distance from the centerline of said shaft axis .[.to abut.]. .Iadd.such that one end of each sleeve member axially abuts .Iaddend.the outer race of said bearing means at locations which are between said cylinder barrel and said sleeve members to maintain said .Iadd.outer .Iaddend.bearing .[.races.]. .Iadd.race .Iaddend.in abutment with said yoke support, said piston members carried within said sleeves being so spaced from said longitudinal axis of said shaft to freely reciprocate in a spaced relationship from the outer periphery of said outer race. 
     
     
       2. .[.The fluid pressure energy translating device.]. .Iadd.The invention .Iaddend.defined in claim 1 further comprising a plurality of roller bearings disposed between said inner and outer races, the yoke facing ends of said roller bearings and said inner race being substantially flush; a portion of said inner race extending beyond said other end of said cylinder barrel and having an annular inclined inner surface flared upwardly from said other cylinder barrel end and toward said yoke facing end of said inner race. 
     
     
       3. .[.A.]. .Iadd.In a .Iaddend.fluid pressure energy translating device of the axial piston type, comprising: a housing having a longitudinal bore; first bearing means mounted in said bore; a shaft rotatably supported by said bearing means; a cylinder barrel drivingly connected to and rotatable with said shaft, said cylinder barrel having a plurality of arcuately spaced cylinder bores and cylinder ports communicating each of said cylinder bores with one end of said cylinder barrel; a plurality of pistons with inner ends disposed for reciprocal stroking movement within said cylinder bores; a valve face .Iadd.fixed to said housing and .Iaddend.having arcuate passages; said valve face and said one end of said cylinder barrel being disposed for relative rotary movement with said cylinder ports communicating successively with said arcuate passages in said valve face, said first bearing means being spaced from said cylinder barrel a fixed distance; thrust plate means comprising a U-shaped yoke support journalled on said first bearing means and in .Iadd.axially separable .Iaddend.abutment with said housing, said yoke support having .Iadd.four .Iaddend.longitudinally extending and laterally spaced legs defining concave bearings .[.therein between and corners at the extended ends of said yoke support legs,.]. .Iadd.therebetween .Iaddend.a movable yoke having correspondingly shaped bearing surfaces mating with said yoke support bearing surfaces, such that said yoke is movably supported by said yoke support; said yoke being in a driving relationship with the other ends of said pistons for imparting said reciprocal stroking movement to said pistons within said cylinder barrel bores as said cylinder barrel rotates; second bearing means having an outer race carried around a portion of the peripheral surfaces of said cylinder barrel, said second bearing means providing radial support for said cylinder barrel.[.,.]. .Iadd.while accommodating slight axial shifting movement of said barrel in either direction relative to said outer race, and spring means biasing said barrel axially against said valve face; and means defining corner surfaces at the extended ends of each of said yoke support legs, said corner surfaces lying in a common general plane, the improvement wherein .Iaddend.the four .[.corners.]. .Iadd.corner surfaces .Iaddend.of the yoke support defined .[.by.]. .Iadd.at .Iaddend.said extended ends providing abutments to .[.support.]. .Iadd.axially engage .Iaddend.said second bearing means at circumferentially spaced locations on said .Iadd.outer race of .Iaddend.second bearing means .[.for properly locating.]. .Iadd.to radially locate .Iaddend.said cylinder barrel with respect to said yoke.[...]..Iadd.while axially locating said outer race with respect to said yoke and to maintain said yoke support in axial abutment with said housing, and means engageable with the outer race of said second bearing means and detachably mounted on said housing for axially locating said outer race of second bearing means relative to said housing. .Iaddend. 
     
     
       4. The .[.fluid pressure energy translating device.]. .Iadd.invention .Iaddend.defined in claim 3 further comprising a plurality of roller bearings disposed between said inner and outer races, the yoke facing end of said roller bearings and said inner race being substantially flush, a portion of said inner race extending beyond the other end of said cylinder barrel and having an annularly inclined inner surface flared upwardly from said other cylinder barrel end and toward said yoke facing end of .Iadd.said other cylinder barrel end and toward said yoke facing end of .Iaddend.said inner race. 
     
     
       5. The .[.fluid pressure energy translating device.]. .Iadd.invention .Iaddend.defined in claim 3, further comprising: means for varying the inclination of said yoke with respect to the longitudinal axis of said shaft for selectively varying the amount of reciprocal stroking movement imparted to said pistons within said cylinder barrel bores. 
     
     
       6. .[.A.]. .Iadd.In a .Iaddend.fluid pressure energy translating device of the axial piston type comprising: a housing .Iadd.having a longitudinal bore.Iaddend.;   a cylinder barrel rotatably mounted within said housing, said cylinder barrel having a plurality of arcuately spaced cylinder bores and cylinder ports communicating each of said cylinder bores with one end of said cylinder barrel;   a plurality of pistons with inner ends disposed for reciprocal stroking movement within said cylinder bores;   a valve face having arcuate passages, said valve face and said one end of said cylinder barrel being disposed for relative rotary movement, with said cylinder ports communicating successively with said arcuate passages in said valve face;   an inclined thrust plate comprising a yoke support fixedly mounted in said housing and a yoke movably supported by said yoke support, said yoke being in a driving relationship with the other end of said piston for imparting a reciprocal stroking movement to said pistons within said cylinder barrel as said cylinder barrel rotates;   means for varying the inclination of said yoke with respect to the longitudinal axis of rotation of said cylinder barrel for selectively varying the amount of reciprocal stroking movement imparted to said pistons as said cylinder barrel rotates;   bearing means having an outer race carried by said housing concentric with said housing bore;   an inner race carried around a portion of the peripheral surface of said cylinder barrel;   a plurality of roller bearings disposed between said inner and outer races;   .Iadd.the improvement wherein .Iaddend.said means for varying the inclination of said yoke .[.comprising.]. .Iadd.comprises .Iaddend.a pair of spaced sleeve members, each .Iadd.of said sleeve members being fixedly mounted on said housing and .Iaddend.disposed along an axis parallel to the axis of rotation of said cylinder barrel and radially outwardly spaced from the peripheral surface of said cylinder barrel, each of said sleeve members having one end of a piston reciprocably mounted therein, the other end of said pistons adapted to abut a portion of said yoke to pivot said yoke about an axis transversely disposed with respect to the axis of rotation of said cylinder barrel .Iadd.the improvement comprising.Iaddend., said sleeves being radially spaced a distance from the axis of rotation of said cylinder barrel .[.to abut.]. .Iadd.such that one end of each sleeve member axially abuts .Iaddend.the outer race of said bearing means at locations which are between said cylinder barrel and said sleeve members to maintain said outer race in contact with said yoke support at a plurality of circumferentially spaced locations for properly locating said cylinder barrel with respect to said yoke, said piston members being carried within said sleeves and so spaced from said axis of rotation of said cylinder barrel as to freely reciprocate in a spaced relationship with respect to the outer periphery of said outer race.