Outboard Marine Corporation

Applied Combustion Technology, Inc.

Kimball P Hall

John D Martino

A Michael Varney

A marine outboard motor includes a power unit and a pump jet. The power unit includes a drive output and an exhaust outlet, and the pump jet includes a rotor hub and a rotor carried thereby. The rotor hub is connected to the drive output of the power unit for selective rotation for forward or reverse motion, and the rotor hub has an internal passageway connected in fluid communication with the exhaust outlet. The pump jet further includes an exhaust bypass movable between normal and bypassed positions. The exhaust bypass when in the normal position directing exhaust through the internal passageway of the rotor hub to discharge downstream of the rotor during forward motion. The exhaust bypass when in the bypassed position bypassing exhaust from the internal passageway to discharge downstream of the rotor during reverse motion.

Pump jet with an exhaust bypass and associated methods

An ETV-type pump jet having a stator housing with an attachment for minimizing the mismatches between the velocity and direction of the exhaust gas stream flowing out of a stator vane outlet and the velocity and direction of boat and pump jet motion. In one embodiment, a multiplicity of exhaust ducts are attached to the external surface of the stator housing, each exhaust duct being positioned to be in flow communication with the exhaust gas outlet of a respective hollow stator vane. Exhaust gases exiting the exhaust outlets are redirected by the inner surfaces of the ducts to flow in parallel with the rotor shaft axis. In another embodiment, a circumferential exhaust skirt made of sheet metal is substituted for the exhaust ducts. The exhaust skirt surrounds the stator housing and redirects the exhaust gas stream to be substantially parallel with the surrounding water flow.

Pump jet with redirected exhaust gas through stator vane for drag reduction

A pump jet apparatus having a double-walled stator housing containing an annular passage through which exhaust gas can flow. Gas enters the annulus through an exhaust gas inlet or port formed in the outer stator shell at the top of the stator housing, flows in two streams around the annular passage formed between the inner and outer stator shells, and exits the stator housing through exhaust outlets or ports formed in the outer stator shell near the bottom of the stator housing. The streams of exhaust gas and impelled water flowing through the stator housing of the pump jet are kept separate by the inner stator shell.

Pump jet with double-walled stator housing for exhaust noise reduction

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.

Tractor pump jet

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. The drive shaft extending from the power head 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. According to an alternative embodiment, a reverse shifting mechanism permits the tractor pump jet to operate in either the forward or reverse direction.

Growing community of inventors

Wading River, NY, United States of America

Kimball P Hall