Abstract: A HEUI system uses a fixed displacement, radial piston pump to provide a generally constant pump flow of high pressure hydraulic fluid over the operating speed range of the radial piston pump to minimize parasitic power drains on the engine. The radial piston pump includes an orificing suction slot to vary the pump displacement over the operating speed of the pump. A throttling valve at the pump inlet may be provided to starve inlet fluid feed if reduced flow to the injectors is additionally required.

Abstract: A HEUI system uses a fixed displacement, piston pump to provide a generally constant pump flow of high pressure hydraulic fluid over the operating speed range of the pump to minimize parasitic power drains on the engine. The piston pump includes an orificing suction slot to vary the pump displacement over the operating speed of the pump. A throttling valve at the pump inlet may be provided to starve inlet fluid feed if reduced flow to the injectors is additionally required.

Abstract: A HEUI system uses a fixed displacement, piston pump to provide a generally constant pump flow of high pressure hydraulic fluid over the operating speed range of the pump to minimize parasitic power drains on the engine. The piston pump includes an orificing suction slot to vary the pump displacement over the operating speed of the pump. A throttling valve at the pump inlet may be provided to starve inlet fluid feed if reduced flow to the injectors is additionally required.

Abstract: A HEUI system uses a fixed displacement, piston pump to provide a generally constant pump flow of high pressure hydraulic fluid over the operating speed range of the pump to minimize parasitic power drains on the engine. The piston pump includes an orificing suction slot to vary the pump displacement over the operating speed of the pump. A throttling valve at the pump inlet may be provided to starve inlet fluid feed if reduced flow to the injectors is additionally required.

Abstract: A HEUI system uses a fixed displacement, radial piston pump to provide a generally constant pump flow of high pressure hydraulic fluid over the operating speed range of the radial piston pump to minimize parasitic power drains on the engine. The radial piston pump includes an orificing suction slot to vary the pump displacement over the operating speed of the pump. A throttling valve at the pump inlet may be provided to starve inlet fluid feed if reduced flow to the injectors is additionally required.

Abstract: A pilot operate, throttling valve is provided for a pump that has inlet valving sufficient to permit the pump to operate with charged fluid at a varying inlet pressure. The throttling valve includes a flow control slave valve operated by a pressure unbalanced mechanical actuator. The pressure differential in the actuator controlling the flow in the slave valve results from a constant pressure produced by a conventional pressure regulating valve generating an actuator force which is reduced by a controlled pressure generated from a solenoid actuated control valve. Because pressure, not flow, controls the pilot, the throttling valve is particularly suited for HEUI applications where the ECM must quickly and accurately control the pump irrespective of viscosity and flow considerations of the pumped oil.

Abstract: A pilot operate, throttling valve is provided for a pump that has inlet valving sufficient to permit the pump to operate with charged fluid at a varying inlet pressure. The throttling valve includes a flow control slave valve operated by a pressure unbalanced mechanical actuator. The pressure differential in the actuator controlling the flow in the slave valve results from a constant pressure produced by a conventional pressure regulating valve generating an actuator force which is reduced by a controlled pressure generated from a solenoid actuated control valve. Because pressure, not flow, controls the pilot, the throttling valve is particularly suited for HEUI applications where the ECM must quickly and accurately control the pump irrespective of viscosity and flow considerations of the pumped oil.

Abstract: A HEUI system uses a fixed displacement, axial displacement pump to provide a generally constant pump flow of high pressure hydraulic fluid over the operating speed range of the pump to minimize parasitic power drains on the engine. The axial piston pump includes a orificing suction slot to vary the pump displacement over the operating speed of the pump. A throttling valve at the pump inlet may be provided to starve inlet fluid feed if reduced flow to the injectors is additionally required.

Abstract: A priming system for a hydraulically actuated, electronically controlled unit injector fuel systems used on diesel engines and the like includes an accumulator charged at low pressure and in fluid communication with the manifold/rail passages leading to the individual fuel injectors, which passages are pressurized upon engine startup by the system's high pressure pump to actuate the injectors. The accumulator is plumbed into the hydraulic system by one way check valves which isolate the accumulator from the high pressure pump to permit the high pressure pump and the priming system to be located at any convenient position within the vehicle's engine compartment irrespective of their position relative to the manifold/rail passages.