Claims:We Claim

1. A high pressure fuel pump (10), said high pressure fuel pump (10) comprising:
a housing (12);
a driving shaft (14) inserted within said housing (12), said driving shaft (14) adapted to rotate within said housing (12); characterized in that
a universal coupler secured to said driving shaft (14) of said high pressure fuel pump (10), said universal coupler (16) adapted to rotate about two degrees of freedom; and
a first end of a tang (18) secured to an end of said universal coupler (16), an opposite second end of said tang (18) secured to a gear pump, wherein said tang (18) is adapted to remain stationary with a rotation of said universal coupler about two degrees of freedom to facilitate maintaining contact between said tang (18) and a gear pump when said driving shaft (14) is displaced about an axis of said driving shaft (14).

2. The high pressure fuel pump (10) in accordance with Claim 1 wherein said universal coupler (16) is secured to said driving shaft (14) of said high pressure fuel pump (10) by screwing said universal coupler (16) onto said driving shaft (14) of said high pressure fuel pump (10).

3. The high pressure fuel pump (10) in accordance with Claim 2 wherein a plurality of screw threads (20) are defined at an end portion of said universal coupler (16), said plurality of screw threads (20) that are defined at the end portion of said universal coupler (16) adapted to mate against a plurality of screw threads that are defined on said driving shaft (24) to fasten said universal coupler (16) to said driving shaft (14) of said high pressure fuel pump (10).

4. The high pressure fuel pump (10) in accordance with Claim 2 wherein said universal coupler (16) is secured to said driving shaft (14) by means of a fastener.

5. The high pressure fuel pump (10) in accordance with Claim 1 wherein said universal coupler (16) is secured to said tang (18) by means of a fastener.

6. The high pressure fuel pump (10) in accordance with Claim 1 wherein the displacement of said driving shaft (14) causes a rotation of said universal coupler (16) about two degrees of freedom, the rotation of said universal coupler (16) about two degrees of freedom causes said tang (18) to remain stationary to facilitate securing said tang (18) to said gear pump when said driving shaft (14) is displaced about an axis of said driving shaft (14).
, 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 a driving shaft of the high pressure fuel pump.

Background of the invention
[0002] CN 2353925 Y describes a speed variable high pressure pump which is used for plugging holes for coal, metallurgy, geology, etc. The utility model is characterized in that an input shaft of a gearbox is engaged with a reduction gear through a mechanical clutch, and the reduction gear is arranged on the output shaft of a motor. The output shaft of the gearbox is engaged with the speed reducer of a vehicle through a shaft coupling and a universal joint. The connection among a suction valve, a draining valve and a cylinder body is respectively formed into a single body, a single suction and a single draining structure. The draining quantity is large and one to four different serous fluids can be sucked simultaneously. The utility model has the advantages of novel design, small size, light weight and simple structure. The utility model is an optimal speed-variable high pressure pump for plugging holes.

Brief description of the accompanying drawing
[0003] Figure 1 illustrates a high pressure fuel pump depicting a driving shaft that is secured within a housing of the 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 in one embodiment of the invention. The high pressure fuel pump 10 comprises a housing 12, and a driving shaft 14 inserted within the housing 12, the driving shaft 14 adapted to rotate within the housing 12. A universal coupler 16 is secured to the driving shaft 14 of the high pressure fuel pump 10, the universal coupler 16 adapted to rotate about two degrees of freedom. A first end of a tang 18 is secured to an end of the universal coupler 16, an opposite second end of the tang 18 secured to a gear pump, wherein the tang 18 is adapted to remain stationary with a rotation of the universal coupler about two degrees of freedom to facilitate maintain contact between the tang 18 and a gear pump when the driving shaft 14 is displaced about an axis of the driving shaft 14.

[0005] Figure 1 illustrates a high pressure fuel pump 10 in one embodiment of the invention. The high pressure fuel pump 10 comprises a housing 12. A driving shaft 14 is inserted within the housing 12 to facilitate driving the high pressure fuel pump 10. More specifically, the driving shaft 14 is adapted to rotate within the housing 12 of the high pressure fuel pump 10 to impart a driving torque to the high pressure fuel pump 10. The driving torque that is imparted to the high pressure fuel pump 10 facilitates delivering pressurized fuel from the high pressure fuel pump 10. In the exemplary embodiment, a universal coupler 16 is secured to the driving shaft 14 of the high pressure fuel pump 10. The universal coupler 16 is secured about two hinges such that the universal coupler 16 is adapted to rotate about two degrees of freedom. The first degree of freedom that the universal coupler 16 is adapted to rotate is about the vertical axis while the second degree of freedom that the universal coupler 16 is adapted to rotate is about an axis that is orthogonal to the horizontal axis.

[0006] In the exemplary embodiment, a first end of a tang 18 is secured to an end of the universal coupler 16. An opposite second end of the tang 18 is secured to a gear pump. Therefore, as the universal coupler 16 is adapted to rotate about two degrees of freedom, the tang is adapted to remain stationary with a rotation of the universal coupler 16 about two degrees of freedom as well. Therefore, as the tang 16 is adapted to remain stationary, a degree of flexibility in maintaining contact with a gear pump is imparted to the tang 18 when the driving shaft 14 is displaced about an axis of the driving shaft 14. More specifically, when the driving shaft 14 is displaced about an axis of the driving shaft 14, the universal coupler is displaced about two degrees of freedom. As the universal coupler 16 is displaced, the tang that is secured to the universal coupler is maintained in the same position. Therefore, the contact between the tang 18 and the gear pump will continue to be maintained with minimal stress acting on the tang 18, although the driving shaft 14 is displaced from its original axial position.

[0007] In the exemplary embodiment, the universal coupler 16 is secured to the driving shaft 14 of the high pressure fuel pump 10 by screwing the universal coupler 16 onto the driving shaft 14 of the high pressure fuel pump 10. More specifically, a plurality of screw threads 20 are defined at an end portion of the universal coupler 16. Correspondingly, a plurality of screw threads are defined on the driving shaft 14 that are adapted to mate against the plurality of screw threads 20 that are defined at the end portion of the universal coupler 16. Once the plurality of screw threads that are defined on the driving shaft 14 mates against the plurality of screw threads 20 that are defined at the end portion of the universal coupler 16, the driving shaft 14 is fastened to the universal coupler 16 of the high pressure fuel pump 10.

[0008] In an alternate exemplary embodiment, the universal coupler 16 is secured to the driving shaft 14 by means of a fastener that is known in the art. Moreover, the universal coupler 16 is secured to the tang 18 by means of a fastener that is known in the art. Therefore, the displacement of the driving shaft 14 about the axis of the driving shaft 14 causes a rotation of the universal coupler 16 about two degrees of freedom. The rotation of the universal coupler 16 about two degrees of freedom causes the tang 18 to remain stationary even as a portion of the universal coupler 16 is displaced along with the displacement of the driving shaft 14 about the axis of the driving shaft 14. Therefore, the tang 18 is still secured to the gear pump when the driving shaft 14 is displaced about an axis of the driving shaft 14 with minimum stress acting on the tang 18 of the driving shaft 14.

[0009] 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.