Fluid device having interchangeable displacement control means

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 and the direction of rotation. The fluid device, which is of the variable displacement type, has a rotatable cylinder barrel with one end of each of a plurality of pistons disposed for reciprocation within cylinder bores at one end of 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 the opposite end of the cylinder barrel. The other ends of the pistons engage a pivotably mounted thrust plate adapted to impart a reciprocal movement to the pistons within the cylinder bores as the cylinder barrel is rotated. In one example of the invention, the thrust plate is provided with a coupling mechanism adapted to be operated by any one of a plurality of interchangeable displacement control mechanisms which vary the inclination of the thrust plate with respect to the axis of rotation of the cylinder barrel and thus the amount of reciprocal movement of the pistons within the cylinder barrel. The device is adapted to be converted into a manifold system adapted to accommodate a plurality of valves with a minimum of external fluid conduits.

What is claimed is as follows: .[.1. A fluid pressure energy translating device of the axial piston type comprising: 
     
        .[.    A fluid pressure energy translating device of the axial piston type comprising: a housing;   a shaft rotatably mounted in said housing;   a cylinder barrel carried by said shaft and rotatable therewith, said cylinder barrel having a plurality of arcuately spaced cylinder bores and cylinder ports communicating 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 openings disposed for relative rotary movement with respect to said one end of said cylinder barrel, with said cylinder ports communicating successively with said arcuate openings as said shaft rotates said cylinder barrel;   a thrust plate pivotably mounted in said housing in a driving relationship with the outer end of said pistons for imparting said reciprocal stroking movement to said pistons within said cylinder barrel bores, the amount of reciprocal movement of said pistons being a function of the degree of inclination of said thrust plate with respect to the axis of rotation of said cylinder barrel;   an arm member carried by said thrust plate and pivotable therewith along an arcuate path; said thrust plate being movable along said arcuate path when said arm member is moved along said arcuate path;   a coupling means reciprocally mounted on said arm member, said coupling means being movable along a linear path in addition to the reciprocal movement on said arm member; said coupling means pivoting said arm member along said arcuate path when said coupling means is moved along said linear path and said coupling means reciprocates on said arm member, whereby the degree of inclination of said thrust plate with respect to the axis of said rotating cylinder barrel may be selectively varied;   a displacement varying mechanism carried by said housing and operatively coupled to said arm member by said coupling means and adapted to move said coupling means along said linear path to move said arm member along said arcuate path;   said displacement varying mechanism further comprising   a second housing carried by said first housing; said second housing having a bore with a pressure responsive member slidably mounted therein and biased to a predetermined position;   valve means responsive to a predetermined operating pressure of said fulid device to supply a second pressure of a predetermined value to said pressure responsive member to move same from said predetermined position, said coupling means being carried by said pressure responsive member; and   said coupling means being moved along said linear path as said pressure responsive means is moved from said predetermined position to pivot said thrust plate with respect to the axis of rotation of said cylinder   
     
     
        barrel..]. .[.6.  The fluid device defined in claim 5 wherein said coupling means comprises a U-shaped member reciprocably mounted on a portion of said arm member, said U-shaped member being movable along said linear path; a coupling pin carried by said U-shaped member and connecting said U-shaped member to said pressure responsive member of said mechanism, such that when said pressure responsive means is moved from said predetermined position said pin is moved along said linear path to reciprocate said U-shaped member along said arm member to impart said arcuate movement to said thrust plate..]. .[.7. A fluid pressure energy translating device of the axial piston type comprising: a housing;   a shaft rotatably mounted in said housing;   a cylinder barrel carried by said shaft and rotatable therewith, said cylinder barrel having a plurality of arcuately spaced cylinder bores and cylinder ports communicating 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 openings disposed for relative rotary movement with respect to said one end of said cylinder barrel, with said cylinder ports communicating successively with said arcuate openings as said shaft rotates said cylinder barrel;   a thrust plate pivotably mounted in said housing in a driving relationship with the outer end of said pistons for imparting said reciprocal stroking movement to said pistons within said cylinder barrel bores, the amount of reciprocal movement of said pistons being a function of the degree of inclination of said thrust plate with respect to the axis of rotation of said cylinder barrel;   an arm member carried by said thrust plate and pivotable therewith along an arcuate path; said thrust plate being movable along said arcuate path when said arm member is moved along said arcuate path;   a coupling means reciprocally mounted on said arm member, said coupling means being movable along a linear path in addition to the reciprocal movement on said arm member; said coupling means pivoting said arm member along said arcuate path when said coupling means is moved along said linear path and said coupling means reciprocates on said arm member, whereby the degree of inclination of said thrust plate with respect to the axis of said rotating cylinder barrel may be selectively varied;   said coupling means further comprising a U-shaped member reciprocably movable along a portion of said arm member;   a coupling pin carried by said U-shaped member and extending externally of said housing; and   means for moving said coupling pin along a linear path to impart said arcuate movement to said arm member as said U-shaped member reciprocably   
     
     
        moves along said arm member..]. 8. .[.A a fluid device of the type.]. .Iadd.In an axial piston pump .Iaddend.having .Iadd.a main housing including a valve face, a cylinder barrel mounted in said main housing for rotation about a main axis normal to said valve face and carrying an annular array of pump pistons axially reciprocable within said barrel, drive shaft means extending coaxially through said barrel for driving said barrel in rotation about said main axis, said drive shaft means being rotatably supported in said main housing by axially spaced bearing means located adjacent opposite ends of said main housing, .Iaddend.an inclinable thrust plate with a .Iadd.pump .Iaddend.piston engaging face at one end thereof, .[.said thrust plate adapted to be pivoted about a predetermined axis,.]. .Iadd.coaxially aligned support pin means projecting outwardly from opposite sides of said thrust plate rotatably seated in said main housing for mounting said thrust plate for pivotal movement in said main housing about a second axis normal to and intersecting said main axis, said thrust plate having a central passage therethrough through which said drive shaft means freely passes at all pivotal positions of said thrust plate, .Iaddend.said thrust plate having an arm member .[.disposed.]. .Iadd.fixedly mounted thereon and extending longitudinally .Iaddend.along an axis .Iadd.radial to said second axis and along .Iaddend.which .Iadd.said arm member .Iaddend.extends .Iadd.away from said barrel and .Iaddend.toward the other end of said thrust plate; .Iadd.the improvement wherein said arm member is mounted at the axial outer end of one of said support pin means and said pump further comprises a displacement control mechanism having a control housing adapted to be fixedly and detachably mounted on the exterior of said main housing adjacent said arm member, said main and said control housings each having an opening therethrough which openings are in registry with each other and said arm member when said control housing is fixedly mounted on said main housing, a control mechanism mounted in said control housing for reciprocable movement relative to said control housing along a linear path aligned with the aforementioned opening in said control housing and perpendicular to both said main and said second axes and located externally of said main housing, a coupling pin having one end attachable to said control mechanism and movable when so attached along said linear path with said control mechanism with the other end of said pin projecting from said control mechanism through said openings into the interior of said main housing; .Iaddend.a U-shaped member, the legs of which encompass a portion of said arm member, said U-shaped member being reciprocable along a portion of said arm member; .[.as.]. .Iadd.said other end of said pin being carried by and coupled to said U-shaped member to move .Iaddend.said arm member .[.moves.]. through an arcuate path to pivot said thrust plate about said .[.predetermined.]. .Iadd.second .Iaddend.axis.[.; and a coupling pin movable along a linear path having one end carried by said U-shaped member,.]. .Iadd.upon movement of said pin along said linear path imparted thereto by reciprocating movement of said control mechanism, .Iaddend.said coupling pin being disposed along an axis which is perpendicular to the path of reciprocal movement of said U-shaped member .[.the other end of said coupling pin being attachable to a displacement control mechanism adapted to impart a linear motion to said coupling pin such that.]. .Iadd.along said arm, whereby .Iaddend.said U-shaped member is simultaneously moved along said reciprocal and linear paths .[.for.]. .Iadd.while .Iaddend.pivoting said thrust plate about said predetermined   
     
     
        axis. .[.9.  An article of manufacture for use within a variable displacement fluid pressure energy translating device, comprising: a pivotable yoke having a bearing surface adapted to cooperate with the fluid displacement means of said device, said movable yoke having a pair of axially aligned mounting pins defining an axis about which said yoke is pivoted;   an arm member carried by and radially extending from one of said support pins and pivotal therewith about the axis of said support pins;   motion transfer means reciprocally mounted on a portion of said arm and adapted to pivot said arm about said axis when said motion transfer means is moved along a linear path;   a coupling pin carried by said motion transfer means and extending externally of said housing, said pin adapted to be coupled to a displacement varying mechanism carried externally of said housing and so connected to said coupling pin as to impart a linear motion to said pin when said displacement varying mechanism is actuated, whereby said arm is pivoted about said axis;   said motion transfer means comprising a U-shaped member encompassing a portion of said arm member and reciprocably mounted along said portion of said arm member, said coupling pin being fixedly attached to said U-shaped member and movable therewith along said linear path as said U-shaped member reciprocates relative to said arm member, said coupling pin extending externally of said housing and rotatably attached to said displacement varying mechanism..].