Abstract: A propeller assembly includes an interchangeable drive sleeve, an inner hub, a biasing member forcing the drive sleeve into contact with the inner hub, and a propeller including an outer hub in which the drive sleeve and inner hub are inserted. In an exemplary embodiment, the drive sleeve includes a plurality of teeth that engage a plurality of teeth on the inner hub. The spring is configured to permit the drive sleeve to move axially away from the inner hub upon the occurrence of a sufficient torque and allow the drive sleeve to rotate relative to the inner hub. A bore extends through drive sleeve, and a plurality of grooves are in an inner diameter surface of the drive sleeve bore. These grooves are configured to mate with splines on a propeller shaft. The inner hub includes a plurality of keys and the outer hub includes a plurality of complimentary keyways to limit relative movement between the inner hub drive flange and the outer hub.

Abstract: The present invention provides a stern drive propulsion system that includes an internal combustion engine having a flywheel and a watertight housing that sealingly encloses the flywheel relative to the surrounding environment. The housing may support a starter coupled to the flywheel and extending toward the transom of a boat. A starter seal is provided to seal corresponding interface surfaces of the starter and the flywheel housing.

Abstract: A tilt-trim subsystem assembly affixed to an outdrive of a stern drive that may be supported by a gimbal unit and may be configured to rotate about a predetermined axis to impart a desired trim or tilt to the drive system is provided. The tilt-trim assembly has one respective end thereof configured to pivotally receive one anchor pin supported by the outdrive. The assembly includes one or more cylinders having one end thereof pivotally connected to another anchor pin so that when the cylinder is actuated the outdrive and the tilt-trim subsystem assembly are jointly rotated about the predetermined axis.

Abstract: A stern drive system having an outdrive generally disposed downstream relative to water flow aft a transom of the boat is configured to be rotated about a generally horizontal axis to impart a desired trim or tilt to the drive system. A tilt-trim subsystem assembly is affixed to the outdrive and has one respective end thereof configured to pivotally receive an anchor pin supported by the outdrive. The assembly includes at least one cylinder having one end thereof connected to another anchor pin so that when the cylinder is actuated by a circuit therein the outdrive and the tilt subsystem assembly are rotated about the generally horizontal axis during tilt maneuvers. A housing is provided to shield the tilt assembly and configured within the footprint of the outdrive to avoid resistance to water flow. Additionally, the housing may be configured to visually shield the tilt assembly from observers.

Abstract: An inboard/outboard powered watercraft (10) incorporating a transmission (30, 80) in its vertical drive unit (24) for providing two forward speeds plus reverse. The transmission is packaged to fit within the vertical drive unit (24) by incorporating a bevel gear apparatus (44, 120). In one embodiment, the transmission (30) also includes a planetary gear apparatus (46) together with two hydraulic clutches (70, 72) and a ring gear brake (56). In a second embodiment, three hydraulic clutches (98, 100, 114) are utilized with bevel gears (94,96,106,110,112) alone to provide the two forward and reverse speeds.

Abstract: A tilt-trim subsystem assembly affixed to an outdrive of a stern drive that may be supported by a gimbal unit and may be configured to rotate about a predetermined axis to impart a desired trim or tilt to the drive system is provided. The tilt-trim assembly has one respective end thereof configured to pivotally receive one anchor pin supported by the outdrive. The assembly includes one or more cylinders having one end thereof pivotally connected to another anchor pin so that when the cylinder is actuated the outdrive and the tilt-trim subsystem assembly are jointly rotated about the predetermined axis.

Abstract: A watercraft (10) having two sources of (22, 32) of cooling water (28, 34) for injection cooling of hot exhaust gas (30) being conveyed through an exhaust pipe (16) upstream of muffler (54). The first water source (22) may be an active apparatus such as the engine cooling apparatus (22). The second source of water (32) may be a passive apparatus such as a Pitot tube (38) formed in the stern drive (20) of the watercraft (10). By providing two independent sources of cooling water, the probability of exhaust component failures is significantly reduced.

Abstract: An inboard/outboard powered watercraft (10) incorporating a transmission (30, 80) in its vertical drive unit (24) for providing two forward speeds plus reverse. The transmission is packaged to fit within the vertical drive unit (24) by incorporating a bevel gear apparatus (44, 120). In one embodiment, the transmission (30) also includes a planetary gear apparatus (46) together with two hydraulic clutches (70, 72) and a ring gear brake (56). In a second embodiment, three hydraulic clutches (98, 100, 114) are utilized with bevel gears (94, 96, 106, 110, 112) alone to provide the two forward and reverse speeds.

Abstract: A propeller assembly that includes an interchangeable drive sleeve, a resilient inner hub having a bore in which the drive sleeve is inserted, and a propeller including an outer hub in which the drive sleeve and resilient inner hub are inserted, is described. In an exemplary embodiment, the drive sleeve includes a cylindrical shaped body and a plurality of splines extend from an outer diameter surface of drive sleeve body. A bore extends through drive sleeve, and a plurality of grooves are in an inner diameter surface of the drive sleeve bore. These grooves are configured to mate with splines on a propeller shaft. Resilient inner hub includes a cylindrical shaped body and a plurality of tapered grooves in an inner diameter surface of the inner hub body. Each groove is arranged to receive one drive sleeve spline. The inner hub also includes a drive flange at one end thereof.

Abstract: A vent plug includes a main body configured to be secured within an opening in a wall of a gear case in flow communication with an exhaust passageway through the gear case. The vent plug main body includes a flow passage therethrough and a planar flow restriction member extends across the flow passage that includes an opening. The main body also includes a variable flow restriction member chamber having an annular groove extending around the chamber. A variable flow restriction member is located in the chamber, and includes an opening having the same diameter as the diameter of the opening in the flow restriction member. The variable flow restriction chamber is movable within the chamber groove to adjust an amount of exhaust passing through the openings of the flow restriction member and the variable flow restriction member.

Abstract: A marine propulsion system having an integral-piece gimbal ring and steering means is provided. The system is made up of a gimbal housing affixed through the rear of a boat transom and a gimbal ring pivotally connected to the gimbal housing. The system is further made up of a steering assembly configured to provide pivotal movement of the gimbal ring relative to the gimbal housing about a steering axis. The gimbal ring and the steering assembly comprise an integral-piece assembly.

Abstract: A marine propulsion device (12) including a sleeve (32) formed around an exhaust conduit (26) to form an air cooling passage (34) there between. Cooling air (38) is moved through the cooling passage (34) by an active fan (42) and/or a passive venturi (56). Cooling air (38) is drawn from within an engine compartment (24) for a predetermined time before and after the engine (16) is operated. A water-cooled discharge support (70) is located above the waterline (28), thereby preventing the intermixing of exhaust gasses (36) with the environmental water (27).

Abstract: A propeller assembly that includes, in an exemplary embodiment, a spring for securing a propeller to a propeller shaft is described. In the exemplary embodiment, the propeller assembly includes a thrust bearing which tightly fits to an inclined surface of the propeller shaft. The thrust bearing includes a hub mating surface which forms a tight fit with one end of a hub of the propeller. The propeller hub has a cylindrical shape, and a plurality of blades extend from an outer surface of the hub. A bore extends through the propeller hub, and the spring fits securely within the hub bore. The spring is located within the propeller hub bore and is secured, e.g., welded, at one end to an interior surface of the hub. The assembly further includes a washer and a nut which engages to a threaded end of the propeller shaft.

Abstract: An inboard/outboard powered watercraft (10) incorporating a transmission (30, 80) in its vertical drive unit (24) for providing two forward speeds plus reverse. The transmission is packaged to fit within the vertical drive unit (24) by incorporating a bevel gear apparatus (44, 120). In one embodiment, the transmission (30) also includes a planetary gear apparatus (46) together with two hydraulic clutches (70, 72) and a ring gear brake (56). In a second embodiment, three hydraulic clutches (98, 100, 114) are utilized with bevel gears (94,96,106,110,112) alone to provide the two forward and reverse speeds.

Abstract: A transom seal assembly for sealing an opening in a boat transom is provided. A propulsion system has a part thereof extending through the transom opening. The seal assembly comprises an inflatable seal between respective peripheries of the part and the transom opening to provide water-tight sealing relative to the interior of the boat even in the presence of a seal puncture condition.

Abstract: A tilt-trim subsystem assembly affixed to an outdrive of a stern drive that may be supported by a gimbal unit and may be configured to rotate about a predetermined axis to impart a desired trim or tilt to the drive system is provided. The tilt-trim assembly has one respective end thereof configured to pivotally receive one anchor pin supported by the outdrive. The assembly includes one or more cylinders having one end thereof pivotally connected to another anchor pin so that when the cylinder is actuated the outdrive and the tilt-trim subsystem assembly are a jointly rotated about the predetermined axis.

Abstract: A propulsion system made up of an engine located in the interior of a marine vessel is provided. The engine has an exhaust discharge member in communication with a propulsion unit. A gimbal ring has a pivotable exhaust passage connected to pass exhaust from the discharge member to the propulsion unit.

Abstract: A propeller including, in one embodiment, a flare having a sinusoidal, or tulip, shape is described. The flare is located at a trailing edge of the propeller, and the sinusoidal flare shape of the propeller trailing edge has reduced stresses as compared to stresses associated with known flare rings. Specifically, stress is reduced in the sinusoidal flare shape due to smooth trailing surfaces and the uneven edge of the flare. As a result, and during fabrication, potential for cracking the trailing edge of the flair is reduced. In addition, the flare has greater strength as compared to at least some known flare rings in that stresses are more evenly distributed along the tulip shaped trailing edge.

Abstract: A propeller assembly that includes, in an exemplary embodiment, a cantilever spring for securing a propeller to a propeller shaft is described. In the exemplary embodiment, the propeller assembly includes a thrust bearing which tightly fits to an inclined surface of the propeller shaft. The thrust bearing includes an annular slot which forms a tight fit with one end of a hub of the propeller and one end of the spring. The propeller hub has a cylindrical shape, and a plurality of blades extend from an outer surface of the hub. A bore extends through the propeller hub, and the spring extends into the hub bore. The assembly further includes a washer and a nut which engages to a threaded end of the propeller shaft.