Claims:We Claim

1. A guide bush (10) for a high pressure fuel pump (12), said guide bush (10) comprising:
a cylindrical portion (14) that is inserted within a barrel (16) of said high pressure fuel pump (12);
a flanged portion (18) formed at an end of said cylindrical portion (14); characterized in that
a notched portion (20) defined at an outer circumference of said flanged portion (18), said notched portion (20) adapted to secure said guide bush (10) to the barrel (16) of said high pressure fuel pump (12).

2. A high pressure fuel pump (12), said high pressure fuel pump (12) comprising:
a barrel (16);
a piston (22) inserted within a first bore (24) of said barrel (16), said piston (22) adapted to reciprocate within the first bore (24) of said barrel (16);
a guide bush (10) inserted through a second bore (26) of said barrel (16), wherein the second bore (26) is coaxial with the first bore (24), wherein said guide bush (10) comprises:
a cylindrical portion (14) that is inserted within said barrel (16) of said high pressure fuel pump (12);
a flanged portion (18) formed at an end of said cylindrical portion (14); characterized in that
a notched portion (20) defined at an outer circumference of said flanged portion (18), said notched portion (20) adapted to secure said guide bush (10) to the barrel (16) of said high pressure fuel pump (12).
3. The high pressure fuel pump (12) in accordance with Claim 2 wherein said barrel (16) comprises an opening (28) and a slot (30) extending from the opening (28) along an outer circumference of the barrel (16).

4. The high pressure fuel pump (12) in accordance with Claim 3 wherein said notched portion (20) that is defined at an outer circumference of said flanged portion (18) of said guide bush (10) is inserted through said opening (28) and rotated to facilitate securing said guide bush (10) within the slot (30) that extends from the opening (28) along the outer circumference of the barrel (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 guide bush, and more specifically to a guide bush that is secured to a high pressure fuel pump in an absence of a sealing ring element.

Background of the invention
[0002] DE 102008043846 A1 describes a high pressure pump that has a pump assembly and a piston with a guide bush and a pressure piece which is indirectly connected with the guide bush. The piston is guided in a bore of a housing part on the guide bush, where a front face of the pressure piece limits a pump working chamber. A sealing ring is provided between the guide bush and the pressure piece which is arranged on an inner wall of the bore.

Brief description of the accompanying drawing
[0003] Figure 1 illustrates a schematic diagram of a guide bush that is positioned within a barrel of a high pressure fuel pump.

Detailed description of the embodiments
[0004] Figure 1 illustrates a guide bush 10 for a high pressure fuel pump 12. The guide bush 10 comprises a cylindrical portion 14 that is inserted within a barrel 16 of the high pressure fuel pump 12. A flanged portion 18 is formed at an end of the cylindrical portion 14. A notched portion 20 is defined at an outer circumference of the flanged portion 18, the notched portion 20 adapted to secure the guide bush 10 to the barrel 16 of the high pressure fuel pump 12.

[0005] The high pressure fuel pump 12 comprises a barrel 16 and a piston 22 that is adapted to reciprocate within the barrel 16. More specifically, the piston 22 is inserted within a first bore 24 of the barrel 16, wherein the piston 22 is adapted to reciprocate within the first bore 24 of the barrel 16. A guide bush 10 is inserted through a second bore 26 of the barrel 16. In the exemplary embodiment, the second bore 26 is coaxial with the first bore 24 and is adapted to receive the guide bush 10 therein. The guide bush 10 is inserted within the second bore 26 of the barrel 16 and is secured within a groove that is defined within the barrel 16. The guide bush 10 comprises a cylindrical portion 14 that is inserted within the barrel 16 of the high pressure fuel pump 12. The guide bush 10 further comprises a flanged portion 18 that is formed at an end of the cylindrical portion 14. A notched portion 20 is defined at an outer circumference of the flanged portion 18 of the guide bush 10. The notched portion 20 comprises a projection that extends outwardly from an outer circumference of the flanged portion 18. The notched portion 20 is adapted to secure the guide bush 10 to the barrel 16 of the high pressure fuel pump 12.

[0006] In the exemplary embodiment, the barrel 16 comprises an opening 28 that is adapted to receive the notched portion 20. A slot 30 extends from the opening 28 along the outer circumference of the barrel 16 and is adapted to secure the notched portion 20 therein that extends from the flanged portion 18 of the guide bush 10. More specifically, the slot 30 is milled along the outer circumference of the barrel 16 and is in communication with the opening 28. When the notched portion 20 that is defined at an outer circumference of the flanged portion 18 of the guide bush 10 is inserted through the opening 28 and rotated, the notched portion 20 secures the guide bush 10 within the slot 30 that extends from the opening 28 along the outer circumference of the barrel 16.

[0007] An assembly of the guide bush 10 for the high pressure fuel pump is described as an example. The opening 28 that is defined in the barrel 16 is adapted to receive the notched portion 20 of the guide bush 10. A slot 30 that is milled around the outer circumference of the barrel 16 is in communication with the opening 28. The guide bush 10 comprises the cylindrical portion 14 and a flanged portion 18 that is secured to the cylindrical portion 14. The notched portion 20 is formed at an end of the flanged portion 18 and extends from the flanged portion 18. The notched portion 20 that is inserted within the opening 28 is rotated by rotating the guide bush 10 by a user. Due to the rotation of the guide bush 10 by the user, the notched portion 20 is inserted within the groove 30 that is in communication with the opening 28. Due to the notched portion 20 that is secured within the groove 30, the guide bush 10 is locked in place, and cannot be removed from the barrel 16 of the high pressure fuel pump. Therefore, a sealing ring element that is normally used in combination with the guide bush 10 can be eliminated. The guide bush 10 with the notched portion 20 that is extending from the flanged portion 18 is a better alternative than the sealing ring element that is used in combination with the guide bush 10 to secure the flanged portion 18 of the guide bush 10 to the barrel 16 of the high pressure fuel pump 12.

[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 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.