Patent ID: 6672285
Filing Date: 2004-01-06
Classification: F02M,F04B

Abstract:
A radial piston high pressure pump for an internal combustion engine, the engine having a hydraulically-actuated electronically-controlled fuel injection system including a fuel injector valving high pressure fluid in response to commands from an ECM to inject a quantity of fuel into an engine combustion chamber, the fuel injector in fluid communication with the outlet of the high pressure pump and the high pressure pump having an inlet in fluid communication with a low pressure pump and operable within a pump operating range, the high pressure pump comprising:a housing defining a centerline; a plurality of radially extending piston bores angularly spaced about the centerline, each piston bore having a discharge opening in fluid communication with the pump outlet, and each piston bore communicating with the pump inlet via an aperture having a set area; a check valve positioned in each discharge opening; a shaft rotatably received by the housing and substantially aligned with the central axis, the shaft defining a cam surface; and a plurality of pistons each having a first end engaging the cam surface and each reciprocatingly received within a respective piston bore, such that reciprocation of the pistons covers and uncovers the apertures, the pistons being reciprocable to pump fluid through the discharge openings to provide a substantially constant flow of fluid from the pump throughout the pump operating range.