Caterpillar Inc.

Other

Active Power, Inc.

David J Beatty

Joseph F Pinkerton

David E Perkins

Ralph A Smith, Iii

Alan Ray Stockner

Travis E Barnes

William H Lane

Steven Y Tian

Robert S Hudson

Mark Eldo Groskreutz

Chetan J Desai

George M Matta

Jon E Kasen

Donald M Hudson

Donald L Stamets

Steven J Bockelman

Backup energy systems utilizing compressed air storage (CAS) systems and bridging energy systems to supply backup power to a load are provided. During a power failure, the bridging energy system provides backup power to the load at least until the CAS system begins supplying adequate power. In various embodiments, backup power capability is enhanced through the use of one or more exhaustless heaters, which are used to heat compressed air. The compressed air, in turn, drives a turbine which is used to power an electrical generator. In various embodiments, ambient air heat exchangers or other types of heat exchangers are used to heat compressed air prior to the compressed air being routed to the turbine, thereby increasing system efficiency. Backup power and backup HVAC are also provided by utilizing turbine exhaust, heat exchangers and various resistive heating elements.

Systems and methods for providing backup energy to a load

A thermal storage unit having at least one conduit around which a cast is made is provided. The thermal storage unit uses conventional piping or tubing to create conduits that economically maximize the surface area of flow in contact with the thermal mass by proving multiple passes for the fluid through the cast. This enables the thermal storage unit to economically provide heat storage as well as effective heat delivery and pressure containment for a fluid flowing through the conduit.

Thermal storage unit and methods for using the same to heat a fluid

A turbocharger with variable geometry turbine inlet nozzle employs a rotating unison ring for actuation of multiple vanes. A crank arm engages a slot in the unison ring to convert linear actuator motion into rotation of the unison ring. A crank pin having a rectangular tongue adapted to be received in the slot and a circular body received in an aperture in the crank arm reduces contact stresses between the crank tongue and unison ring slot. The crank pin is retained in the crank arm by the unison ring and center housing flange of the turbocharger.

Actuator crank arm design for variable nozzle turbocharger

Existing poppet valves have a tendency to rebound or bounce during operation. This rebound or bounce adversely affects engine governability, high pressure injector fuel flow, noise and idle stability. The present invention reduces or nearly eliminates poppet valve (52) rebound or bounce. The apparatus (161) for compensating for the rebound of bounce overcomes the problem of variable injection. For example, as the poppet valve (52) rebounds the weight (174) strikes the bottom or contacting surface (168) preventing the poppet valve (52) from moving toward the first position (156). Thus, the variation in the injection of fuel is prevented or eliminated. Additionally, with the variation in the injection of fuel eliminated, the adverse affects of the bounce or rebound enables better engine governability, high pressure injector fuel flow and idle stability with reduced noise.

Apparatus for reducing the bounce of a poppet valve

Past methods for starting an engine have included increasing the amount of fuel to support combustion creating an excess of unburned fuel in the exhaust causing white smoke. Such past methods for starting an engine additionally required additional components, such as heater, and required an excessive draw on the battery to provide extensive glow plug operation and extensive cranking. The present method of starting an engine reduces and essentially eliminates white smoke, reduces the need for extensive glow plug operation and reduces the need for extensive cranking. The method of starting an engine includes the steps of: positioning an intake valve in a closed position; positioning an exhaust valve in a closed position; rotating a piston to a top dead center position; rotating the piston from the top dead center position toward a bottom dead center position; and injecting a fuel into the cylinder.

Method of starting an engine

A hydraulically-actuated fuel injector includes an injector body having a nozzle chamber that opens to a nozzle outlet and a plunger bore, and further has a prime spill port and an idle stability port that open to the plunger bore. A hydraulic means for pressurizing fuel in the nozzle chamber includes a plunger mounted to reciprocate in the plunger bore between a retracted position and an advanced position. A portion of the plunger bore and plunger define a fuel pressurization chamber. A needle valve member is mounted to reciprocate in the nozzle chamber between an open position in which the nozzle outlet is open and a closed position in which the nozzle outlet is closed. A portion of the plunger blocks the prime spill port when the plunger is in its retracted position. A different portion of the plunger blocks the idle stability port when the plunger is in its retracted position. The prime spill port opens to the fuel pressurization chamber over part of the plunger stroke between its retracted position and its advanced position. The idle stability port opens to the fuel pressurization chamber over a different part of the plunger stroke between its retracted position and its advanced position. The prime spill port has a relatively unrestricted flow area, whereas the idle stability port has a relatively restricted flow area about equal to that of the nozzle outlet.

Hydraulically-actuated fuel injector with idle stability port

A plunger and barrel assembly includes a barrel that defines a plunger bore. A plunger having a pressure face end and a side surface is positioned in the plunger bore and moveable between an advanced position and a retracted position. An O-ring is in contact with the side surface of the plunger and the plunger bore. At least one of the plunger and the barrel define a receiver volume that opens into the plunger bore. A compressible member is positioned in the receiver volume.

Fluid seal for cyclic high pressures within a fuel injector

A fuel injector includes an injector body that defines a low pressure space, a trapped volume and a fuel pressurization chamber in fluid communication with a nozzle outlet. A needle valve member is positioned in the injector body and moveable between an inject position in which the fuel pressurization chamber is opened to the nozzle outlet, and a closed position in which the nozzle outlet is blocked to the fuel pressurization chamber. The needle valve member includes a lifting hydraulic surface exposed to fluid pressure in the fuel pressurization chamber, and a closing hydraulic surface exposed to fluid pressure in the trapped volume. At least one of the injector body and the needle valve member define a pressure decay passage extending between the trapped volume and the low pressure space.

Pressure decay passage for a fuel injector having a trapped volume

A method of fuel injection comprises the initial step of providing a fuel injector with a solenoid actuated control valve mounted in an actuation fluid cavity. The valve is biased to a first position but movable to a second position against the bias when the solenoid is energized. When in its first position, the actuation fluid cavity is opened to a high pressure actuation fluid inlet, but opened to a low pressure fluid actuation fluid drain when in its second position. In the next step, the desired amount of fuel to be injected is determined. An actuation duration for the solenoid corresponding to the desired amount of fuel is calculated. Then, it is determined whether the actuation duration corresponds to a cavitation zone of operation for the control valve. Next an injection event is initiated by moving the valve to open the actuation fluid cavity to the high pressure actuation fluid inlet. After the actuation duration, the control valve is moved toward the position that opens the low pressure actuation fluid drain. If it is determined that the injector was operating within the cavitation zone of operation, then the movement rate of the control valve while closing is slowed while it is moving to close the high pressure actuation fluid inlet. This slowing of the valve's closure sufficiently alters conditions within the injector that pressure does not drop to cavitation levels.

Method of preventing cavitation in a fuel injector having a solenoid

A variable displacement pump has a fluid passageway formed through a swash plate fluidly communicating a piston chamber with a drive shaft chamber not later than when the piston chamber comes into open fluid communication with a valve blcok resident inlet port to prevent erosion of the swash plate and the valve block about the inlet port. Secondary port portions of reduced flow area per unit rotation communicate with and circumferentially lead primary port portions of greater flow area per unit rotation.

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Bloomington, IL, United States of America

David J Beatty