摘要:
A rotor body (22) having a plurality of cylindrical bores (24) each adapted to receive a piston (30) for reciprocating movement therein, each of the bores (30) being lined with a ceramic liner (42) having a first split (44), and a method of forming a rotor (16) having a ceramic bore liner (42) that includes the steps of providing a rotor body having at least one bore (140), providing a ceramic bore liner having a first end, a second end and a split having a width (142), and compressing the bore liner to decrease the width and securing the bore liner in the at least one bore (144).
摘要:
Methods and apparatus are provided for lubricating a piston-to-shoe interface in a hydraulic motor or pump. Piston assemblies are installed in a housing that are each adapted to receive a reciprocating drive force and are each configured, in response thereto, to cyclically move between an intake direction and a discharge direction. Each piston assembly includes a piston and a piston shoe, and the piston, the piston shoe, or both have a plurality of pockets formed in a surface that defines a piston-to-shoe interface. When the pistons cyclically move, liquid is supplied to each piston-to-shoe interface to form a hydrostatic bearing at each piston-to-shoe interface. A portion of the liquid that is supplied to each piston-to-shoe interface is selectively supplied to and from one or more of the plurality of pockets.
摘要:
Methods and apparatus are provided for lubricating a piston-to-shoe interface in a hydraulic motor or pump. Piston assemblies are installed in a housing that are each adapted to receive a reciprocating drive force and are each configured, in response thereto, to cyclically move between an intake direction and a discharge direction. Each piston assembly includes a piston and a piston shoe, and the piston, the piston shoe, or both have a plurality of pockets formed in a surface that defines a piston-to-shoe interface. When the pistons cyclically move, liquid is supplied to each piston-to-shoe interface to form a hydrostatic bearing at each piston-to-shoe interface. A portion of the liquid that is supplied to each piston-to-shoe interface is selectively supplied to and from one or more of the plurality of pockets.
摘要:
A method of manufacturing a wear resistant shoe (26) includes upsetting (46) one end portion (38) of cylindrical member to work harden that portion to a substantial depth, machining (48) the cylindrical member portion to finished dimensions and surface hardening (56) a face (28 or 34) of the machined cylindrical member portion. The cylindrical member may comprise rod stock of a diameter less than the greatest diameter of the finished shoe and be upset or swaged to axially reduce and radially increase the dimensions of the one end portion. A hollow region (30) is formed in an opposite rod stock end portion and the periphery (50) of the hollow region is crimped about a rounded end (18) of the piston (20). The cold work done during the swaging or forming process provides a foundation for hardened faces comprising balance (28) and auxiliary balance (34) lands, forms a crude shape of the shoe, and imparts work hardening and wear property improvements. The harder metal surface provides a foundation for subsequent surface hardening such as coating with TiN. The crimping process used to join the shoe to the piston imparts cold work to the skirt region of the shoe and enhances the wear resistance of the shoe. The cold heading step (46) may be omitted if a hardened rod stock is used, but the skirt should be annealed (66) prior to crimping to the piston.
摘要:
An auxiliary cam assembly for an axial piston pump includes an auxiliary cam plate and an auxiliary cam retainer. The auxiliary cam plate is configured to be coupled a rotatable shaft. A central shaft opening extends through the auxiliary cam plate. A plurality of piston openings surround the central opening and extend through the auxiliary cam plate. A circumferential cut is formed in and extends around the outer peripheral surface of the auxiliary cam plate. The auxiliary cam retainer has a plurality of ramps formed therein, and each ramp slopes upwardly from a first end to a second end. A plurality of substantially flat pads are disposed between each of the ramps, and each pad extends between the first end of one ramp and the second end of another ramp.
摘要:
In a fluid transfer device (10) that includes a housing (12), a rotor (16) rotatably mounted in the housing (12) and having a bore (24) and at least one piston (30) slidingly mounted in the bore (24), a port plate (42) that includes a body portion (44) mountable in the housing (12) and formed from a first material and a wear layer (56) formed of a second material, different from the first material, attached to the body portion (44) and adapted to contact the rotor (16). Also a fluid transfer device (10) including such a port plate (42).
摘要:
A method of producing a piston that involves providing a piston body formed of a first material, the piston body having a cylindrical portion having a diameter, a rounded end, and a neck connecting the rounded end to the cylindrical portion and having a diameter less than the diameter of the piston body, cladding a portion of the cylindrical portion with a first tool steel layer, cladding a portion of the rounded end with a second tool steel layer spaced from the first tool steel layer, heat treating the piston body and nitriding the first and second tool steel layers. Also a piston (10) having first (18) and second (22) nitrided, tool steel clad portions.