PUMP UNIT FOR FEEDING FUEL TO AN INTERNAL-COMBUSTION ENGINE

摘要

A pump unit (1) for feeding fuel to an internal-combustion engine is formed by a high-pressure pump (2) and a pre-feed pump (3) for feeding the fuel to the high-pressure pump (2); the high-pressure pump (2) is provided with a pump body (4) having a side wall (8) delimiting a first chamber (9) able to contain part of the fuel fed by the pre-feed pump (3) and with a drive shaft (5) housed partly inside the first chamber (9) and extending through the side wall (8) outside of the pump body (4), the pre-feed pump (3) being a gear pump which comprises a gear (20) keyed onto the drive shaft (5) and a shell (18) which defines a second chamber (24) for containing the gear (20) and the fuel and which is fixed to the side wall (8).