Abstract: The engines include compression cylinders, combustion cylinders, an air rail, and a heat exchanger. The methods of operating a compression ignition engine include taking air into a compression cylinder of the engine, compressing the air in the compression cylinder to raise the pressure and temperature of the air, passing the compressed air through a heat exchanger, and from the heat exchanger into a combustion cylinder, further compressing the compressed air during a compression stroke of the combustion cylinder, igniting fuel in the combustion cylinder at or near the end of the compression stroke by compression ignition, followed by a power stroke, and opening an exhaust valve at the end of the power stroke and passing at least some of the exhaust in the combustion cylinder through the heat exchanger to heat air that has been compressed in the compression cylinder and is then passing through the heat exchanger.

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: Methods and systems of operating hydraulically powered electric generators are disclosed. The hydraulically powered electric generators comprise opposing stators spaced apart by an armature. The armature is positioned against a first stator. A conduction path is established through a coil of the first stator. The armature is magnetically held against the first stator for a specific time period. The armature is hydraulically moved away from the first stator to capture electrical energy resulting from a collapse in magnetic field in the first stator and the armature.

Abstract: Methods of operation of liquid and gaseous multi-fuel compression ignition engines that may be operated on a gaseous fuel or a liquid fuel, or a combination of both a gaseous fuel and a liquid fuel at the same time and in some embodiments, in the same combustion event. Various embodiments are disclosed.

Abstract: Power plants using multiple identical engine block assemblies to form multiple engines, each contributing to a common output or outputs, and each using an intake manifold, an exhaust manifold and an air rail. Air is first compressed by some engine cylinders and delivered to the air rail, and then coupled to combustion cylinders from the air rail. Compressions and combustion may be in the same cylinders, the same engine block assembly but different cylinders or in different engine block assemblies. Multiple engines in the power plants are less costly than single large engines because of the quantity of manufacture and ease of maintenance. Various embodiments are disclosed.

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: Power plants using multiple identical engine block assemblies to form multiple engines, each contributing to a common output or outputs, and each using an intake manifold, an exhaust manifold and an air rail. Air is first compressed by some engine cylinders and delivered to the air rail, and then coupled to combustion cylinders from the air rail. Compressions and combustion may be in the same cylinders, the same engine block assembly but different cylinders or in different engine block assemblies. Multiple engines in the power plants are less costly than single large engines because of the quantity of manufacture and ease of maintenance. Various embodiments are disclosed.

Abstract: Methods of operation of liquid and gaseous multi-fuel compression ignition engines that may be operated on a gaseous fuel or a liquid fuel, or a combination of both a gaseous fuel and a liquid fuel at the same time and in some embodiments, in the same combustion event. Various embodiments are disclosed.

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: 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: 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: 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: A compression ignition engine includes a high pressure injector for injecting a liquid fuel into a first combustion cylinder and a low pressure injector for injecting a gaseous fuel into a second combustion cylinder. A controller is coupled to the high pressure injector and the low pressure injector. The controller selects one of a liquid fuel mode and a gaseous fuel mode. If the liquid fuel mode is selected, air is compressed in a first cylinder, the compressed air is transferred to a second cylinder, and the liquid fuel is injected into the second cylinder. If the gaseous fuel mode is selected, air is compressed in the second cylinder, the compressed air is transferred to the first cylinder, and the gaseous fuel is injected into the first cylinder.

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: 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.