Tractor pump jet

摘要

A marine pump jet includes a rotor 132 located upstream and in front of the rotor drive mechanism within a stator hub 134. The lower unit 102 of the tractor pump jet has a rotor housing 106 which substantially surrounds the rotor 132 and a stator housing 108 located downstream of the rotor 132 and rotor housing 106. The drive shaft 34 extending from the powerhead of an outboard motor enters the stator hub 134 where a pinion gear 138 engages a crown gear 140 attached to the rotor shaft 142. This places the rotor drive mechanism downstream of the rotor 132 so that the rotor 132 is substantially the first mechanical element that water initially comes into contact with. The inlet opening 114 ofthe pump jet is larger than the outlet opening 116 at the outlet of the stator housing 108. Because the rotor 132 operates on essentially undisturbed, non-turbulent water, it is more efficient than traditional pump jets where the rotor is located aft ofthe drive mechanism. According to an alternative embodiment, a reverse shifting mechanism permits the tractor pump jet to operate in either the forward or reverse direction. <IMAGE>