FUEL PUMP FOR A DIRECT INJECTION SYSTEM WITH A REDUCED STRESS ON THE BUSHING OF THE PISTON

摘要

Fuel pump (4) having: a pumping chamber (14); a piston (15) slidingly mounted within the pumping chamber (14); a cylindrical containing seat (26) which is defined below the pumping chamber (14), has a diameter larger than the one of the pumping chamber (14) and is delimited on top by an annular abutment (28) which externally has the diameter of the containing seat (26) and internally has the diameter of the pumping chamber (14); and a guide bushing (27), which is housed in the containing seat (26) and has an upper surface (30) which abuts against the annular abutment (28); the upper surface (30) of the guide bushing (27) has a convex shape having an increasing height from outside to inside; and the annular abutment (28) has a step (31) against which the upper surface (30) of the guide bushing (27) rests.