Tractor pump jet

摘要

A marine pump jet includes a rotor located upstream and in front of the rotor drive mechanism. The lower unit of the tractor pump jet has a rotor housing which substantially surrounds the rotor and a stator housing located downstream of the rotor and rotor housing. A drive shaft extending from an upper gear case enters the stator hub where a pinion gear engages a crown gear attached to the rotor shaft. This places the rotor drive mechanism downstream of the rotor so that the rotor is substantially the first mechanical element that water initially comes into contact with. The inlet opening of the pump jet is larger than the outlet opening at the outlet of the stator housing. Because the rotor operates on essentially undisturbed, non-turbulent water, it is more efficient than traditional pump jets where the rotor is located aft of the drive mechanism. The upper gear case includes a reverse shifting mechanism that permits the tractor pump jet to operate in either the forward or reverse direction.