Hydraulically biased pumping element assembly and fuel injector using same
AssigneeCaterpillar Inc.
InventorYe Tian
Life of this patent
Estimating the term…
Abstract
A hydraulically actuated fuel injector includes an injector body that defines an unobstructed biasing passage substantially fluidly isolated from a fuel pressurization chamber. A pumping element is positioned in the injector body and moveable between a retracted position and an advanced position. The pumping element has a biasing surface exposed to fluid pressure in the unobstructed biasing passage, and a fuel surface exposed to fuel pressure in the fuel pressurization chamber. A source of biasing fluid at a working pressure is fluidly connected to the unobstructed biasing passage. A source of fuel fluid at a supply pressure is fluidly connected to the fuel pressurization chamber.
Claims17
A hydraulically biased pumping element assembly comprising:
- a body defining an unobstructed biasing passage substantially fluidly isolated from a pumping chamber;
- a pumping element positioned in said body and being movable between a retracted position and an advanced position, and said pumping element having a biasing surface exposed to fluid pressure in said unobstructed biasing passage, and a pressurization surface exposed to fluid pressure in said pumping chamber;
- a source of working fluid at a working pressure fluidly connected to said biasing passage;
- a source of other fluid at a supply pressure fluidly connected to said pumping chamber;
- and
- said working pressure is greater than said supply pressure.
A hydraulically actuated fuel injector comprising:
- an injector body defining an unobstructed biasing passage substantially fluidly isolated from a fuel pressurization chamber;
- a pumping element positioned in said injector body and being movable between a retracted position and an advanced position, and said pumping element having a biasing surface exposed to fluid pressure in said unobstructed biasing passage, and a fuel surface exposed to fluid pressure in said fuel pressurization chamber;
- a source of biasing fluid at a working pressure fluidly connected to said unobstructed biasing passage;
- a source of fuel fluid at a supply pressure fluidly connected to said fuel pressurization chamber;
- and
- said pumping element consists essentially of a plunger that is separate from an intensifier piston.
A hydraulically actuated fuel injector comprising:
- an injector body defining a biasing passage and a fuel pressurization chamber;
- a pumping element positioned in said injector body and being movable between a retracted position and an advanced position, and said pumping element having a biasing surface exposed to fluid pressure in said biasing passage, and a fuel surface exposed to fluid pressure in said fuel pressurization chamber;
- and
- said pumping element includes three segments, and each of said three segments have substantially uniform diameters that are different from one another.
Dependencies are inferred from the claim text.