Abstract: A dynamic fluid sealing system for a fuel injection valve employs sealing-fluid to separate a gaseous fuel and a second fluid in the fuel injection valve, thereby preventing leakage of the gaseous fuel into the second fluid. A pressure-balancing system, which includes a pressure-balancing device, reduces the pressure differential between the sealing-fluid and the gaseous fuel used in the injection valve. At the same time, the pressure balancing system dynamically balances the sealing-fluid pressure such that the sealing-fluid pressure is equal to or slightly greater than the pressure of the gaseous fuel within the injection valve. The pressure differential between the gaseous fuel and the sealing-fluid may be maintained throughout the operating range of engine speeds, engine loads, and fuel cut-off conditions so as to prevent leakage of compressible gaseous fuel into the second fluid.

Abstract: Two different fuels are injected into the combustion chamber of an internal combustion engine. A main fuel is ignited by a pilot fuel that is more readily flammable than the main fuel. According to the method, load conditions on the engine are monitored and sets of conditions are defined to constitute low load conditions and high load conditions. Distinct operating modes are defined for each set of load conditions. Under low load conditions, a homogeneous mixture of main fuel and air is too lean to be flammable; consequently, the main fuel is injected at high pressure immediately following injection of the pilot fuel. Under high load conditions, fuel is injected in three stages. In the first stage, the main fuel is injected during the intake stroke or early in the compression stroke to form a substantially homogenous mixture of main fuel and air. However, the risk of knocking limits the quantity of main fuel that can be introduced in the first stage.

Abstract: This invention relates to a novel hydraulically actuated fuel injector for an internal combustion engine. More particularly, the application pertains to a hydraulically actuated gaseous injector for injecting main fuel and optional pilot fuel into an internal combustion engine at different times at controlled pressure. A hydraulically actuated fuel injector for a piston displacement engine comprising: (a) an injector which is actuated by an actuator means and injects fuel into the engine at predetermined times; (b) a means for introducing hydraulic oil into said injector; (c) means for pressurizing said hydraulic oil; (d) means for opening a fuel inlet means and injecting the fuel into the engine upon the pressure of the hydraulic oil reaching a predetermined level; and (e) a means for preventing the pressure of the hydraulic oil from rising above the predetermined level.

Abstract: The invention relates to an apparatus and method for supplying high pressure gaseous fuel from a storage vessel to a vehicle's internal combustion engine. More particularly, the invention is a fuel supply system with three main components: the storage vessel; an intensifier; and, an accumulator vessel. Fuel passages connect each one of the components directly with the other two components. The intensifier has a plurality of compression chambers and one of the compression chambers can be by-passed when the intensifier is operating in a low capacity mode, depending upon the pressure in the storage vessel. The intensifier operates continuously. When no fuel compression is required, the intensifier runs in an idle mode with the respective inlets and outlets of the compression chambers connected by fuel passages, thus preventing any fuel compression. The loading to the intensifier actuating mechanism is balanced in all modes of operation.