| 摘要 |
<p>A pump assembly for use in delivering fuel to a common rail of an internal combustion engine, including a pumping plunger ( 28; 128 ) which is co-operable with an intermediate drive member in the form of a tappet ( 34 ). The tappet ( 34 ) is co-operable with an engine-drive cam ( 11 ), in use, so as to impart drive to the plunger ( 28; 128 ). A cam rider member ( 38 ) of generally tubular form has an inner surface which co-operates with the cam ( 11 ) and an outer surface which cooperates with the bucket tappet ( 34 ). A main pump housing ( 10 ) is provided with a radially extending opening ( 18 a) within which is received, at a first end thereof, a separate pump head ( 20 a) and, at a second end thereof, the tappet ( 34 ) so that the opening ( 18 a) serves to guide axial movement of the tappet ( 34 ), in use. The separate pump head ( 20 a) is provided with a plunger bore ( 26 ) which serves to guide movement of the plunger ( 28; 128 ) and within which is defined a pump chamber ( 30 ) in which fuel is pressurised as the plunger ( 28 ) is driven.</p> |
