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:
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:
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:
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:
A gas turbine engine fuel control system is provided that includes a fuel metering valve and a thrust control valve. The fuel metering valve includes a metering valve inlet and a metering valve outlet. The metering valve inlet is adapted to receive a flow of fuel, and is configured to control the flow of fuel through the metering valve outlet. The thrust control valve is adapted to receive thrust control valve override signals and is configured, in response thereto, to move from a first position, in which flow from the metering valve is not impacted, and a second position, in which flow from the metering valve is blocked while flow through a fixed-area orifice is allowed.
摘要:
A thrust reverser actuation system (TRAS) for a case assembly of an aircraft is provided. The TRAS includes a fuel-driven motor; one or more actuators coupled to the fuel-driven motor; and a transcowl coupled to the actuators such that the fuel-driven drives the transcowl during operation.
摘要:
In one embodiment, an ecology valve (EV) fuel return system includes a housing assembly, an ecology valve, and a fuel routing assembly. The ecology valve includes an EV piston slidably disposed within the housing assembly for movement between a fuel storage position and a fuel return position, a fuel storage chamber defined by the EV piston and the housing assembly, and an EV control chamber defined by the EV piston and the housing assembly. The fuel routing assembly, which is fluidly coupled to the EV control chamber and to the fuel storage chamber, is configured to route fuel: (i) from the fuel storage chamber to a fuel supply system when a gas turbine engine (GTE) is in a start-up mode, and (ii) from the first fuel manifold and from the EV control chamber to the fuel storage chamber when the GTE is in a shut-down mode.
摘要:
A turbofan gas turbine propulsion engine includes a system to transfer power from the low pressure turbine to the high pressure turbine and/or extract additional load from the low pressure turbine during certain turbofan engine operational conditions. The systems include a hydrostatic power transfer system that includes a hydraulic pump and a hydraulic motor coupled to the low pressure and high pressure turbine, respectively. The systems additionally include a mechanical and electrical load shifting/loading sharing systems that use clutches and gear assemblies to share and/or shift load between the turbines.
摘要:
A fuel return valve and system includes a flow-level select and shut-off valve and a servo control valve. The flow-level select and shut-off valve includes a first fuel inlet, a second fuel inlet, a return-to-tank fuel outlet, and a valve element movable between a shut-off position, a mid-flow position, and a max-flow position. The servo control valve is coupled to the flow-level select and shut-off valve and is configured to control relative fluid pressures therein to selectively move the valve element to the shut-off position, the mid-flow position, and the max-flow position.