Abstract: Variable compression ratio engines and methods for homogeneous charge, compression ignition operation. The engines effectively premix the fuel and air well before compression ignition. Various embodiments are disclosed including embodiments that include two stages of compression to obtain compression ratios well above the mechanical compression ratio of the engine cylinders for compression ignition of difficult to ignite fuels, and a controllable combustion chamber volume for limiting the maximum temperature during combustion. Energy storage with energy management are also disclosed.

Abstract: A piston engine is operated to close an exhaust valve, close an intake valve, and inject ammonia into a cylinder at a start of a compression motion of a piston before substantial compression occurs. The ammonia may be injected into the cylinder as a liquid. The ammonia may be pressurized sufficiently to prevent boiling of the ammonia at a temperature of the engine. A mixture of ammonia and air may be compressed sufficiently to obtain compression ignition of the ammonia. An amount of air in the cylinder during compression may be limited to limit combustion temperatures to below the temperatures for formation of NOx. Air may be injected into the cylinder after ignition of the ammonia and during combustion. The exhaust valve may be closed at a time to trap a predetermined amount of exhaust gas in the cylinder.

Abstract: Fuel injectors with intensified fuel storage and methods of operating an engine therewith. At least one storage cavity is provided in the intensifier type fuel injector, with a check valve between the intensifier and the needle chamber and storage cavity preventing loss of injection pressure while the intensifier plunger cylinder is refilling with fuel. This provides very efficient injector operation, particularly at low engine loads, by eliminating the wasted energy of compressing, venting and recompressing fuel for injection. Various injector designs and methods of operating the same in an engine are disclosed.

Abstract: Methods of operating fuel injectors with intensified fuel storage. At least one storage volume is provided in the intensifier type fuel injector, with a check valve between the intensifier and the needle chamber and storage volume preventing loss of injection pressure while the intensifier plunger cylinder is refilling with fuel. Using the check valve to isolate the storage volume from the intensifier to reduce and control pressure spikes that effect injector operation. This provides very efficient injector operation, particularly at low engine loads, by eliminating the wasted energy of compressing, venting and recompressing fuel for injection and reducing and controlling pressure spikes that effect injector operation.

Abstract: Fuel systems and methods for cold environments which includes a fuel pump having at least one solenoid coil in an unlaminated magnetic circuit, the fuel pump being disposed in a fuel tank, and a pump drive and pulsing system, the pump drive providing pump actuation current to the solenoid coil and the pulsing system providing short current pulses to the solenoid coil to cause Eddy current losses in the unlaminated magnetic circuit. The method includes, before cranking the engine for starting the engine, providing short, successive current pulses to the solenoid coil to cause eddy current heating in the unlaminated circuit and heating of the fuel in and around the fuel pump, turning on the fuel pump to commence fuel flow to the engine, and cranking the engine for starting after the fuel pump has been turned on. Various features are disclosed.

Abstract: Actuators with printed actuator coils facilitate efficient manufacturing and reliable operation. The printed actuator coils are in coil segments on multiple layers on a multilayer printed circuit board, which may contain a printed actuator coil for one or more additional actuators, and/or electronic circuitry, such, as may be used for control of the actuator(s).

Abstract: Hydraulic internal combustion engines having at least one combustion piston not mechanically connected to a crankshaft or any other combustion piston, but instead acting on hydraulic plungers through valving that is electronically controlled to control the piston position and velocity, typically through an intake stroke, a compression stroke, a combustion or power stroke and an exhaust stroke. Electronically controlled fuel injection and electronically controlled engine valves provided great flexibility in the operating cycles that may be used, with the engine pumping hydraulic fluid to a high pressure accumulator for use in hydraulic motors or other hydraulic equipment. Embodiments using high pressure air injection to sustain combustion are also disclosed.

Abstract: Multiple intensifier injectors with positive needle control and methods of injection that reduce injector energy consumption. The intensifiers are disposed about the axis of the injectors, leaving the center free for direct needle control down the center of the injector. Also disclosed is a boost system, increasing the needle closing velocity but without adding mass to the needle when finally closing. Direct needle control allows maintaining injection pressure on the fuel between injection events if the control system determines that enough fuel has been pressurized for the next injection, thus saving substantial energy when operating an engine at less than maximum power, by not venting and re-pressurizing on every injection event.

Abstract: Mixed cycle compression ignition engines and methods of operating a camless compression ignition engine by establishing a number of operating cycles for operating the engine, each for a particular engine load range and storing a respective algorithm and engine operating parameters for each operating cycle in a lookup table, receiving engine operating information, including piston position when compression ignition occurs, receiving a power setting for the engine, selecting from the lookup table, an algorithm and operating parameters for an operating cycle for the engine applicable to that power setting, operating the engine using the selected algorithm and operating parameters, and adjusting the engine operating parameters based on received engine operating information. Various operating cycles are disclosed.

Abstract: Fuel injectors with intensified fuel storage and methods of operating an engine therewith. At least one storage cavity is provided in the intensifier type fuel injector, with a check valve between the intensifier and the needle chamber and storage cavity preventing loss of injection pressure while the intensifier plunger cylinder is refilling with fuel. This provides very efficient injector operation, particularly at low engine loads, by eliminating the wasted energy of compressing, venting and recompressing fuel for injection. Various injector designs and methods of operating the same in an engine are disclosed.

Abstract: A method of operating a multi-cylinder compression ignition engine having at least one cylinder acting as a compression cylinder and at least one cylinder action as a combustion cylinder. The method comprise compressing air in the compression cylinder, and in the combustion cylinder, opening and then closing an exhaust valve during an exhaust stroke to trap some exhaust gas, during a compression stoke immediately following the exhaust stroke, injecting a controlled amount of fuel into the combustion chamber to obtain compression ignition at or near a top dead center piston position without reaching combustion temperatures at which NOX is formed, and injecting compressed air and fuel during a power stroke immediately following the compression stroke to sustain combustion to burn the fuel with an equivalence ratio within a predetermined range around unity. Various embodiments are disclosed.

Abstract: Digital hydraulic opposed free piston internal combustion engines having a pair of free pistons in a pair of cylinders defining a combustion chamber above each free piston. The pair of free pistons is arranged to move within the pair of cylinders with parallel axes of free piston motion, and preferably co-linear axes of free piston motion. At least one hydraulic plunger is under each free piston with each hydraulic plunger in a respective hydraulic cylinder. The hydraulic cylinders are coupled to electronically controlled hydraulic cylinder valving. A controller controls the electronically controlled hydraulic cylinder valving to control the pair of free pistons to have substantially equal and opposite motions.

Abstract: Digital fuel injector, injection and hydraulic valve actuation module and engine and high pressure pump methods and apparatus primarily for diesel engines. The digital fuel injectors have a plurality of intensifier actuation pistons allowing a selection of up to seven intensified fuel pressures. The disclosed engine operating methods include using at least one cylinder for a compression cylinder for providing compressed intake air to at least one combustion cylinder. A pressure sensor in each combustion cylinder may be used to indicate temperature in the combustion cylinder to limit combustion temperatures to below temperatures at which substantial NOX is generated. A re-burn cycle may be used to complete the burning of hydrocarbons, providing a very low emission engine. A compression cylinder may be provided with a pump actuated by the piston in the compression cylinder. Various aspects and embellishments of the invention are disclosed.

Abstract: Free piston engines having a free piston having a first piston diameter in a cylinder with a combustion chamber on a first side of the first piston and a piston rod having a second diameter fastened to a second side of the first piston and extending to a single second piston having a third diameter smaller than the first diameter, but larger that the second diameter, the single second piston extending into a hydraulic cylinder, the second piston having a first hydraulic area defined by the third diameter in a first hydraulic chamber, and a second hydraulic area defined by the area between the third diameter and the second diameter in a second hydraulic chamber, and valving to control the coupling of a high pressure, a low pressure and a reservoir to the first and second hydraulic chambers to control the free piston.

Abstract: Dual fuel compression ignition engines and methods that allow compression ignition on gaseous fuels like compressed natural gas, hydrogen and ammonia, yet will run on liquid fuels, including diesel fuels for such purposes as starting or when the gaseous fuel is not available or has been consumed and greater range or operating time is needed. Ignition of fuels having a high self ignition temperature is assured by recirculating high temperature exhaust gas back into the intake charge before compression. Existing engines may be converted to run as a dual fuel engine by replacement of the engine head or heads. Various embodiments are disclosed.

Abstract: A control valve has an inlet, a first outlet and a second outlet. The control valve includes a poppet valve to selectably close one of the first outlet and the second outlet. A pair of diaphragms move from a first position to a second position when fluid is supplied to the control valve to permit the poppet valve to close the first passage when fluid is removed from the control valve. A magnet operably couples a wireless transmitter to a power source when fluid is supplied to the control valve. The wireless transmitter may send a signal to terminate irrigation by the control valve when the control valve is one of a plurality of control valves connected serially to a master valve only by a fluid supply line.

Abstract: Two stage spool valves having, in a single assembly, a first stage spool and a second stage spool. The first stage spool may have a solenoid actuator with a return spring, with the second stage spool having either a hydraulic return or a spring return, or both. The solenoid actuator may be comprised of a stationary structure defining a magnetic flux path, including a stationary structure pole face, that together with a moveable structure, including a moveable structure pole face, define a substantially zero air gap magnetic circuit when the solenoid actuator is actuated, the pole faces of the stationary structure and the moveable structure each being defined in part by soft magnetic iron and in part by hardened steel, the hardened steel of the moveable structure contacting the hardened steel of the stationary structure and the soft magnetic iron of the moveable structure being face to face with the soft magnetic iron of the stationary structure when the solenoid actuator is actuated.

Abstract: Compression ignition engines and methods of the type wherein the engines operate with one cylinder used as a compression cylinder and a second cylinder used as a combustion cylinder. The engines have all cylinders configured so as to be able to operate as a compression cylinder or a combustion cylinder. In the method of operation, a cylinder may switch its operation between being a compression cylinder and then operate a combustion cylinder. Switching the operation between compression and combustion operation results in an even temperature distribution within the engine, and eliminates the need for special cooling requirements, facilitating retrofit of existing engines. Also use of an air storage tank allows all cylinders to operate as combustion cylinders for short bursts of power. Various other features are disclosed.

Abstract: High performance, low emission engines, multiple cylinder engines and operating methods based on compression ignition of a combustion chamber charge. In accordance with the methods, fuel is injected into the combustion chamber after the exhaust valve closes, and air is injected into the combustion cylinder before the end of the compression stroke in an amount to limit the temperature after ignition to less than the temperature at which NOX forms. After ignition and during the power stroke, more air is injected into the combustion chamber to sustain combustion until all fuel is consumed, the air being injected so as to again limit the combustion temperatures to less than the temperature at which NOX forms. The air injected during the compression stroke is injected at substantially the same combustion chamber pressure as the air injected during the power stroke, so that air may efficiently be injected from the same pressurized source.

Abstract: Hydraulic internal combustion engines having at least one combustion piston not mechanically connected to a crankshaft or any other combustion piston, but instead acting on hydraulic plungers through valving that is electronically controlled to control the piston position and velocity, typically through an intake stroke, a compression stroke, a combustion or power stroke and an exhaust stroke. Electronically controlled fuel injection and electronically controlled engine valves provided great flexibility in the operating cycles that may be used, with the engine pumping hydraulic fluid to a high pressure accumulator for use in hydraulic motors or other hydraulic equipment. Embodiments using high pressure air injection to sustain combustion are also disclosed.