Claims:CLAIMS

We Claim

1. A high-pressure fuel pump (10), said high pressure fuel pump (10) comprising:
a housing (12);
a barrel (14) positioned within said housing (12) and secured to said housing (12);
a plunger (15) positioned within said barrel (14), said plunger (15) adapted to reciprocate within an element chamber (17) defined within said barrel (14) to facilitate delivering pressurized fuel from the element chamber (17) to a fuel injector; a control sleeve (19) positioned within the said housing (12) of the high pressure fuel pump; characterized in that
a shaft sealing ring (16) positioned within said control sleeve (19), a first end of said shaft sealing ring (16) positioned proximate to said plunger (15), an opposite second end of said shaft sealing ring (16) positioned against said control sleeve (19), and wherein a top portion of said shaft sealing ring (16) abuts against a bottom of said barrel (14), and wherein a bottom portion of said shaft sealing ring (16) abuts against said control sleeve (19) to facilitate securing said shaft sealing ring (16) within said control sleeve (19) assembled on to the said housing (12) of said high-pressure fuel pump (10).

2. The high-pressure fuel pump (10) in accordance with Claim 1, wherein said shaft sealing ring (16) extends circumferentially around an outer circumference of said plunger (15), such that said shaft sealing ring (16) circumscribes said plunger (15) of said high-pressure fuel pump.

3. The high-pressure fuel pump (10) in accordance with Claim 1, wherein said shaft sealing ring (16) comprises a top portion and a bottom portion, wherein the top portion of said shaft sealing ring (16) comprises a conically shaped groove defined therein, wherein the conically shaped groove defined on the top portion of said shaft sealing ring (16) comprises a conically shaped metallic portion (25) that is inserted within the conically shaped groove (27) and secured thereto, wherein the conically shaped metallic portion (25) is adapted to receive fuel that flows through a clearance of said barrel (14) and said plunger (15).

4. The high-pressure fuel pump (10) in accordance with Claim 3, wherein a stem of an F-shaped groove (18) comprising a longitudinal groove (20) that is defined along a longitudinal axis of said plunger (15) extends partially beyond a circumferential groove (22) that circumscribes said plunger (15), wherein the longitudinal groove (20) that extends partially beyond the circumferential groove (22) is in flow communication with the conically shaped metallic portion (25) that is inserted within the conically shaped groove (27) defined at the top portion of said shaft sealing ring (16) to facilitate channeling fuel from said conically shaped metallic portion (25) of said shaft sealing ring (16) towards the F-shaped groove (18) via the longitudinal groove (20).

5. The high-pressure fuel pump (10) in accordance with Claim 1, wherein said shaft sealing ring (16) comprises a top portion and a bottom portion, wherein the bottom portion of said shaft sealing ring (16) comprises an inverted conically shaped groove (29) defined therein, wherein the inverted conically shaped groove (29) defined on the bottom portion of said shaft sealing ring (16) comprises an inverted conically shaped metallic portion (31) that is inserted within the inverted conically shaped groove (29) and secured thereto, wherein the inverted conically shaped metallic portion (31) is adapted to receive lubrication oil that splashes from an oil sump towards said shaft sealing ring (16).

6. The high-pressure fuel pump (10) in accordance with Claim 1, wherein said shaft sealing ring (16) is positioned proximate to said plunger (15), such that a clearance exists between said shaft sealing ring (16) and said plunger (15) to facilitate reciprocating said plunger (15) within said shaft sealing ring (16) and preventing said plunger (15) from contacting said shaft sealing ring (16).

7. The high-pressure fuel pump (10) in accordance with Claim 1, wherein said shaft sealing ring (16) is manufactured from a synthetic resin material such as but not limited to polytetrafluoroethylene.

8. The high-pressure fuel pump (10) in accordance with Claim 1, wherein said shaft sealing ring (16) is positioned between said plunger (15) and said control sleeve (19) of said high-pressure fuel pump (10) such that fuel from an element chamber (17) defined within said barrel (14) is prevented from flowing due to gravity into an oil sump via a clearance that is defined between said plunger (15) and said shaft sealing ring (16), and wherein lubrication oil from the oil sump is prevented from flowing due to a translation of said plunger (15) into the element chamber (17) via the clearance that is defined between said plunger (15) and said shaft sealing ring (16).
, Description:Complete Specification:

The following specification describes and ascertains the nature of this invention and the manner in which it is to be performed.
Field of the invention
[0001] This invention relates to a high-pressure fuel pump, and more specifically to an element seal ring that is positioned between a housing and a plunger of a high-pressure fuel pump.

Background of the invention
[0002] IN 201941021454 describes a shaft sealing ring for a high pressure fuel pump. The shaft sealing ring comprises a first portion and a second portion that are secured together to form an integral assembly. A first lip is defined at a base of the first portion, and a second lip is defined at a base of the second portion. The first lip and the second lip are each adapted to abut against a pump shaft to prevent lubrication oil flowing on the pump shaft from entering into the high pressure fuel pump via a space defined between the first lip and the second lip.

Brief description of the accompanying drawing
[0003] Figure 1 illustrates a seal ring that is positioned between a plunger and a housing of a high-pressure fuel pump in one embodiment of the invention.

Detailed description of the embodiments
[0004] Figure 1 illustrates a high-pressure fuel pump 10. The high pressure fuel pump 10 comprises a housing 12, and a barrel 14 positioned within the housing 12 and secured to the housing 12. A plunger 15 is positioned within the barrel 14, the plunger 15 adapted to reciprocate within an element chamber 17 defined within the barrel 14 to facilitate delivering pressurized fuel from the element chamber 17 to a fuel injector. A control sleeve 19 positioned within the housing 12 and secured to the housing 12. A shaft sealing ring 16 is positioned within the control sleeve 19, a first end of the shaft sealing ring 16 positioned proximate to a plunger 15. An opposite second end of the shaft sealing ring 16 is positioned against the control sleeve 19, and wherein a top portion of the shaft sealing ring 16 abuts against a bottom of the barrel 14. A bottom portion of the shaft sealing ring 16 abuts against the control sleeve 19 to facilitate securing the shaft sealing ring 16 within the control sleeve 19 of the high-pressure fuel pump 10.

[0005] Figure 1 illustrates a seal ring 16 that is positioned between a plunger 15 and a control sleeve 19 of a high-pressure fuel pump 10 in one embodiment of the invention. In an exemplary embodiment, the high-pressure fuel pump 10 comprises a housing 12. A barrel 14 is positioned within the housing 12, and secured to the housing 12. In an exemplary embodiment, a plunger 15 is positioned within the barrel 14. The plunger 15 is adapted to reciprocate within an element chamber 17 defined within the barrel 14 to facilitate delivering pressurized fuel from the element chamber 17 to a fuel injector as is known in the art. A control sleeve 19 positioned within the housing 12 and secured to the housing 12. A shaft sealing ring 16 is positioned within the control sleeve 19. More specifically, the shaft sealing ring 16 that is positioned within the control sleeve 19 is positioned proximate to a plunger 15 at its first end. An opposite second end of the shaft sealing ring 16 is positioned against the control sleeve 19 such that the shaft sealing ring 16 is secured firmly between the plunger 15 and the control sleeve 19 respectively. A top portion of the shaft sealing ring 16 abuts against a bottom of the barrel 14 and constitutes a sealing interface between the shaft sealing ring 16 and the bottom of the barrel 14. A bottom portion of the shaft sealing ring 16 abuts against the control sleeve 19 to facilitate securing the shaft sealing ring 16 within the control sleeve 19 of the high-pressure fuel pump 10. The shaft sealing ring 16 that is positioned between the barrel 14 and the control sleeve 19 facilitates securing the shaft sealing ring 16 firmly between the barrel 14 and the control sleeve 19 respectively.

[0006] In an exemplary embodiment, the shaft sealing ring 16 extends circumferentially around an outer circumference of the plunger 15 such that the shaft sealing ring 16 circumscribes the plunger 15 of the high-pressure fuel pump 10. The shaft sealing ring 16 comprises a top portion and a bottom portion. The top portion of the shaft sealing ring 16 comprises a conically shaped groove 27 defined therein. The conically shaped groove 27 that is defined on the top portion of the shaft sealing ring 16 comprises a conically shaped metallic portion 25 that is inserted within the conically shaped groove 27 and secured thereto. More specifically, the conically shaped metallic portion 25 that is inserted within the conically shaped groove 27 is secured within the conically shaped groove 27 by means of a press fit arrangement. In the exemplary embodiment, the conically shaped metallic portion 25 that is inserted within the conically shaped groove 27 is adapted to receive fuel that flows through the clearance of the barrel 14 and the plunger 15.

[0007] In an exemplary embodiment, an F-shaped groove 18 is defined on an axis of the plunger 15. The F-shaped groove 18 comprising an F-shaped portion and a longitudinal groove 20 that extends from the F-shaped portion and is defined along a longitudinal axis of the plunger 15. More specifically, the longitudinal groove 20 extends partially beyond a circumferential groove 22 that is defined circumferentially around the plunger 15 and extends along the longitudinal length of the plunger 15. The longitudinal groove 20 that extends partially beyond the circumferential groove 22 is in flow communication with the conical shaped metallic portion 25 that is inserted within the conically shaped groove 27. More specifically, when the fuel flows through the clearance between the plunger 15 and the barrel 14, the fuel is channeled into the conically shaped metallic portion 25 that is inserted within the conically shaped groove 27. From within the conically shaped metallic portion 25 that is inserted within the conically shaped groove 27, the fuel is channeled along the longitudinal groove 20. Therein, the fuel flows along the longitudinal groove 20 towards the F-shaped portion of the F-shaped groove 18 and therein delivered to the F-shaped portion of the F-shaped groove 18. From the F-shaped groove 18, the fuel is channeled into the fuel gallery via the spill port.

[0008] In an exemplary embodiment, the shaft sealing ring 16 comprises a top portion and a bottom portion. The bottom portion of the shaft sealing ring 16 comprises an inverted conically shaped groove 29 defined therein. The inverted conically shaped groove 29 defined on the bottom portion of the shaft sealing ring 16 comprises an inverted conically shaped metallic portion 31 that is inserted within the inverted conically shaped groove 29 and secured thereto. The inverted conically shaped metallic portion 31 that is inserted within the inverted conically shaped groove 29 is adapted to receive lubrication oil that splashes from an oil sump towards the shaft sealing ring 16. The lubrication oil that splashes from the oil sump on the inverted conically shaped metallic portion 31 drips down from the inverted conically shaped metallic portion 31 back into the oil sump.

[0009] In an exemplary embodiment, the shaft sealing ring 16 is positioned proximate to the plunger 15. More specifically, the shaft sealing ring 16 is positioned proximate to the plunger 15 such that a clearance exists between the shaft sealing ring 16 and the plunger 15. The clearance that exists between the plunger 15 and the shaft sealing ring 16 facilitates the plunger 15 reciprocating within the shaft sealing ring 16, and thereby preventing the plunger 15 from contacting the shaft sealing ring 16. In the exemplary embodiment, the shaft sealing ring 16 is manufactured from a synthetic resin material. The synthetic resin material may be, but is not limited to polytetrafluoroethylene.

[0010] In an exemplary embodiment, the shaft sealing ring 16 is positioned between the plunger 15 and the control sleeve 19 of the high-pressure fuel pump 10. More specifically, the shaft sealing ring 16 is positioned between the plunger 15 and the control sleeve 19 of the high-pressure fuel pump 10 such that fuel from an element chamber 17 that is defined within the barrel 14 is prevented from flowing due to gravity into an oil sump via a clearance that is defined between the plunger 15 and the shaft sealing ring 16. More specifically, the shaft sealing ring 16 acts like an obstacle and prevents the fuel from the element chamber 17 from flowing into the oil sump. Moreover, the shaft sealing ring 16 prevents the lubrication oil from the oil sump from flowing into the element chamber 17 via the clearance that is defined between the plunger 15 and the shaft sealing ring 16.

[0011] It must be understood that the embodiments explained above are only illustrative and do not limit the scope of the disclosure. Many modifications in the embodiments with regard to dimensions of various components are envisaged and form a part of this invention. The scope of the invention is only limited by the scope of the claims.