Through-the-hub-propulsion unit exhaust

A marine drive for a watercraft comprising a propulsion device supported by a lower unit, said propulsion device including a propeller comprising an inner hub and at least one blade attached to an outer hub between front and rear ends of said outer hub, and an exhaust system including a main propeller outer hub and terminates at a first discharge end located behind the propeller blade, and an auxiliary exhaust passage which extends through at least a portion of the propeller outer hub and terminates at a second discharge end located in front of the propeller blade, said auxiliary exhaust passage and said second discharge end being formed between the outer hub and an intermediate collar of the propeller which is arranged within the outer hub and forms a dividing wall between the main exhaust passage and the auxiliary exhaust passage, said collar including a plurality of apertures through which the auxiliary exhaust passage communicates with an exhaust discharge passage formed between the collar and the inner hub.

A marine drive for a watercraft comprising a propulsion device supported by a lower unit, said propulsion device including a propeller shaft carrying at least one-propeller, the propeller comprising at least one propeller blade attached to an outer hub, and an exhaust system including a main exhaust passage which extends at least partially through the propeller and terminates at a first discharge end, the first discharge end having a diameter at least equal to a maximum inner diameter of the outer hub, an auxiliary exhaust passage which extends at least partially through the propeller and terminates at a second discharge end, said first and second discharge ends arranged on the propeller to discharge exhaust gases on opposite sides of the propeller blade, a dividing wall that lies between the auxiliary exhaust passage and the main exhaust passage, said dividing wall being coupled to the propeller shaft to rotate generally with the propeller shaft and the propeller, and at least one juncture between the main and auxiliary exhaust passages being located forward of the propeller blade.

A marine drive for a watercraft comprising a propulsion device supported by a lower unit, such propulsion device including a propeller shaft carrying at least one propeller, the propeller comprising at least one propeller blade attached to an outer hub, an exhaust system including a main exhaust passage that extends at least partially through the propeller and terminates at a first discharge end, an auxiliary exhaust passage which extends at least partially through the propeller and terminates at a second discharge end, said first and second discharge ends arranged on the propeller to discharge exhaust gases in opposite sides of the propeller blades, and a divider carried by a propulsion shaft to which the propeller is attached independent of the propeller, and providing a dividing wall that lies between the auxiliary exhaust passage and the main exhaust passage.

A propeller comprising at least one propeller blade attached to an outer hub between front and rear ends of the outer hub, a main exhaust passage that extends through at least a portion of the propeller outer hub and terminates at a first discharge end located behind the propeller blade, an auxiliary exhaust passage which extends through at least a portion of the propeller hub and terminates at a second discharge end located in front of the propeller blade, said auxiliary exhaust passage being defined between the outer hub and an intermediate collar of the propeller, the intermediate collar being arranged within the outer hub to form a dividing wall between the main exhaust passage and the auxiliary exhaust passage, and at least one juncture between said main and auxiliary exhaust passages being located in front of the propeller blade.