Claims:We Claim:
1. A governor (10) for a high pressure fuel pump, said governor (10) comprising:
a governor spring (12);
a pair of flyweights (14) connected to said governor spring (12) via linkages, said pair of flyweights (14) adapted to be in dynamic equilibrium with said governor spring (12);
a rocker arm (16), an end of said rocker arm (16) secured to said governor spring (12);
a swiveling lever (18), said swiveling lever (18) secured to said rocker arm (16) by means of a pivot;
a notch setting screw (20) secured to said rocker arm (16), said notch setting screw (20) adapted to increase a pre-tension acting on said governor spring (12); characterized in that
a spacer (22) positioned between said rocker arm (16) and a stem (24) of said notch setting screw (20), said spacer (22) facilitates movement of said notch setting screw (20) to a predetermined displacement.

2. The governor (10) for a high pressure fuel pump in accordance with Claim 1 wherein an increase in thickness of said spacer (22) decreases a pre-tension acting on said governor spring (12).

3. The governor (10) for a high pressure fuel pump in accordance with Claim 1 wherein a decrease in thickness of said spacer (22) increases a pre-tension acting on said governor spring (12).

4. The governor (10) for a high pressure fuel pump in accordance with Claim 1 wherein said spacer (22) is formed of a wear resistant material.

5. A high pressure fuel pump, said high pressure fuel pump comprising:
a governor (10), said governor (10) comprising
a governor spring (12);
a pair of flyweights (14) connected to said governor spring (12) via linkages, said pair of flyweights (14) adapted to be in dynamic equilibrium with said governor spring (12);
a rocker arm (16), an end of said rocker arm (16) secured to said governor spring (12);
a swiveling lever (18), said swiveling lever (18) secured to said rocker arm (16) by means of a pivot;
a notch setting screw (20) secured to said rocker arm (16), said notch setting screw (20) adapted to increase a pre-tension acting on said governor spring (12); characterized in that
a spacer (22) positioned between said rocker arm (16) and a stem (24) of said notch setting screw (20), said spacer (22) facilitates movement of said notch setting screw (20) to a predetermined displacement.
, Description:Field of the invention
[0001] This invention relates to a high pressure fuel pump and more particularly to a governor for the high pressure fuel pump.

Background of the invention
[0002] U.S. Patent Number 5,086,742 describes a fuel injection pump for internal combustion engines. A centrifugal governor is driven in a known manner by a cam shaft of a pump piston. The rotations per minute of the drive shaft is transmitted to flyweights via a camshaft. With increasing rotations per minute, centrifugal force comes into play, and the flyweights are moved outward. In this motion, each flyweight rotates about a respective hinge point, and via their inner shanks they displace the governor sleeve seated axially displaceable on the holder. The governor sleeve transmits its displacement motion in a known manner to an intermediate lever, which in turn varies the position of the control rack. The linkages and springs in the centrifugal governor work in tandem to achieve the desired governing characteristics.

Brief description of the accompanying drawing
[0003] Figure 1 illustrates a governor for a high pressure fuel pump in accordance with one embodiment of the invention.

Detailed description of the invention
[0004] Figure 1 illustrates a governor 10 for a high pressure fuel pump. The governor 10 comprises a governor spring 12 and a pair of flyweights 14 coupled to the governor spring 12 via linkages, the pair of flyweights adapted to be in dynamic equilibrium with the governor spring 12. A rocker arm 16, an end of the rocker arm 16 secured to the governor spring 12 and a swiveling lever 18, the swiveling lever 18 secured to the rocker arm 16 by means of a pivot. A notch setting screw 20 is secured to the rocker arm 16, the notch setting screw 20 adapted to increase the pre-tension acting on the governor spring 12. A spacer 22 is positioned between the rocker arm 16 and a stem 24 of the notch setting screw 20, the spacer 22 facilitates tightening the notch setting screw 20 to a predetermined displacement.
[0005] The governor 10 for the high pressure fuel pump comprises a governor housing 11. A governor spring 12 is secured to the tensioning lever 11. More specifically, a first end of the governor spring 12 is secured to the tensioning lever 11. A second end of the governor spring 12 is secured to a rocker arm 16. Therefore, an upward movement of the rocker arm 16 causes the governor spring 12 to distend, thereby causing a pre-tension of the governor spring 12. The rocker arm 16 is inserted into a stem 24 of the notch setting screw 20 and secured thereto by means of the notch setting screw 20. A swiveling lever 18 is secured to the rocker arm 16 by means of a pivot at a first end. The opposite second end of the swiveling lever 18 is secured to a governor cover 13 by means of a pivot.
[0006] A spacer 22 is positioned between the rocker arm 16 and a stem 24 of the notch setting screw 20. The notch setting screw 20 is positioned on the rocker arm 16 to facilitate sealing the rocker arm 16 between the spacer 22 and the notch setting screw 20. The spacer 22 facilitates movement of the notch setting screw 20 to a predetermined displacement. A thickness of the spacer 22 may be increased to decrease a pre-tension acting on the governor spring 12. More specifically, when a thickness of the spacer 22 is increased, the notch setting screw 20 may be rotated and displaced to a lesser extent because the rocker arm 16 comes in contact with the spacer 22 sooner than it were possible if the thickness of the spacer 22 is lesser, thereby preventing any further displacement of the rocker arm 16. The reduced displacement of the rocker arm 16 causes a lesser pre-tension in the governor spring 12. The thickness of the spacer 22 may be decreased to increase a pre-tension on the governor spring 12. More specifically, when a thickness of the spacer 22 is decreased, the notch setting screw 20 may be rotated and displaced to a greater extent because the rocker arm 16 comes in contact with the spacer 22 later than it were possible if the thickness of the spacer 22 is greater, thereby causing the rocker arm 16 to be displaced further than when a thicker spacer were employed. The increased displacement of the rocker arm 16 causes a greater pre-tension in the governor spring 12.
[0007] A working of the governor 10 for the high pressure fuel pump is described as an example. The spacer 22 is inserted within the notch setting screw 20 such that it abuts against a flange defined in the stem 24 of the notch setting screw 20. Therein, the rocker arm 16 is inserted within the notch setting screw 20. When the notch setting screw 20 is rotated, the notch setting screw 20 is displaced, thereby compressing the rocker arm against the spacer 22. By clearly selecting a spacer of a known thickness, the displacement of the notch setting screw 20 against the rocker arm 16 may be controlled. Therefore, the pre-tension acting on the governor spring 12 may be precisely controlled, thereby changing the dynamic equilibrium between the governor spring 12 and the pair of flyweights 14.
[0008] 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 leverage and dimensions of various levers are envisaged and form a part of this invention. The scope of the invention is only limited by the claims.