| 摘要 |
There is provided a fuel pump assembly for use in an internal combustion engine. The fuel pump assembly comprises a pumping plunger (16) for pressurising fuel within a pumping chamber (32) during a plunger pumping stroke; and a cam follower arrangement (18, 20) for imparting drive to the pumping plunger (16) including a cam follower member (18) which cooperates with the pumping plunger (16). The cam follower arrangement (18, 20) is biased into engagement with a cam drive (22, 26) whilst a degree of relative movement along the plunger axis is permitted between the cam follower member (18) and the pumping plunger (16). At least one of the pumping plunger (16) and the cam follower member (18) includes a surface provided with a feature which defines together with a facing surface of the other of the pumping plunger (16) and the cam follower member (18), a cushioning volume (44) there between for receiving fluid to provide a cushioning effect as the pumping plunger (16) and the cam follower member (18) move into contact with one another, in use. The feature includes a flat central portion (40) and an annular region (42) which is conical in form and which is angled relative to the facing surface. |
