Claims:1. A high pressure fuel pump (10), said high pressure fuel pump (10) comprising:
10 a housing (12), and a plunger (14) adapted to reciprocate within a pumping
chamber defined within said housing (12);
a helix groove (16) defined on an outer circumference of said plunger (14), the
helix groove (16) adapted to channel pressurized fuel from within the pumping
chamber defined within said housing (12) to a fuel gallery (20) during an end
15 of a pumping stroke of said plunger (14);
a stop groove (18) defined at an end of the helix groove (16), the stop groove
(18) adapted to channel pressurized fuel from within the pumping chamber
defined within said housing (12) to said fuel gallery (20) during stop condition
of said high pressure fuel pump (10), and wherein said plunger (14) is adapted
20 to be rotated to facilitate varying an orientation of the helix groove (16) and
the stop groove (18) for different loading conditions of said high pressure fuel
pump (10);
a barrel (22) positioned between said plunger (14) and said housing (12);
characterized in that
25 a circular groove (24) defined from an end of said plunger (14) that is
proximate to the pumping chamber defined within said housing (12) and
extending along a longitudinal axis of said plunger (14), the circular groove
(24) adapted to vary a delivery timing of pressurized fuel from the pumping
chamber defined within said housing (12) of said high pressure fuel pump (10)
30 to a fuel injector.
2. The high pressure fuel pump (10) in accordance with 5 Claim 1 wherein a
diameter of the circular groove (24) is smaller than a diameter of said plunger
(14), and wherein the circular groove (24) is sized such that a film of fuel is
formed between the circular groove (24) and the barrel (22) at higher pumping
speeds of said plunger (14) of said high pressure fuel pump (10).
10
3. The high pressure fuel pump (10) in accordance with Claim 1 wherein the
circular groove (24) extends from the stop groove (18) defined at an end of the
helix groove (16) at its first end to an opposite end of the helix groove (16) at
its opposite second end and along an outer circumference of said plunger (14).
15
4. The high pressure fuel pump (10) in accordance with Claim 1 wherein the
circular groove (24) extends from the stop groove (18) defined at an end of the
helix groove (16) at its first end to an opposite end of the stop groove (18) at
its opposite second end and along an outer circumference of said plunger (14).
5. The high pressure fuel pump (10) in accordance with Claim 1 wherein the
circular groove (24) is of a uniform diameter along a circumference of said
plunger (14).
25 6. The high pressure fuel pump (10) in accordance with Claim 1 wherein a
diameter of the circular groove (24) is defined by a user.
7. The high pressure fuel pump (10) in accordance with Claim 1 wherein a length
of the circular groove (24) is defined by a user. , Description:A high pressure fuel pump 10 is described. The high pressure fuel pump 10 comprises
a housing 12, and a plunger 14 adapted to reciprocate within a pumping chamber
defined within the housing 12. A helix groove 16 is defined on an outer circumference
10 of the plunger 14. A stop groove 18 is defined at an end of the helix groove 16. The
plunger 14 is adapted to be rotated to facilitate varying an orientation of the helix
groove 16 and the stop groove 18. A circular groove 24 is defined from an end of the
plunger 14 that is proximate to the pumping chamber defined within the housing 12
and extending along a longitudinal axis of the plunger 14. The circular groove 24 is
15 adapted to vary a delivery timing of pressurized fuel from the pumping chamber of the
high pressure fuel pump 10 to a fuel injector.