US 11,939,035 B2
Outboard motor
Shuhei Okamoto, Shizuoka (JP); and Naoki Sugita, Shizuoka (JP)
Assigned to YAMAHA HATSUDOKI KABUSHIKI KAISHA, Shizuoka (JP)
Filed by YAMAHA HATSUDOKI KABUSHIKI KAISHA, Iwata (JP)
Filed on Aug. 17, 2021, as Appl. No. 17/403,917.
Claims priority of application No. 2020-153169 (JP), filed on Sep. 11, 2020.
Prior Publication US 2022/0081087 A1, Mar. 17, 2022
Int. Cl. B63H 20/32 (2006.01); B63H 20/14 (2006.01); B63H 20/24 (2006.01); B63H 20/28 (2006.01)
CPC B63H 20/32 (2013.01) [B63H 20/14 (2013.01); B63H 20/245 (2013.01); B63H 20/28 (2013.01)] 10 Claims
OG exemplary drawing
 
1. An outboard motor comprising:
an engine;
a drive shaft extending downward from the engine;
a propeller shaft extending in a direction intersecting with the drive shaft;
a housing to accommodate the engine, the drive shaft, and the propeller shaft and that defines a discharge chamber to discharge exhaust gas from the engine;
a first passage to guide the exhaust gas from the engine to the discharge chamber inside the housing;
a second passage to guide water to the discharge chamber that enters the housing when a forward propulsive force is generated; and
a valve to regulate or permit passage of the exhaust gas at a first connection due to exhaust pressure and water pressure, the first connection connecting the first passage and the discharge chamber, the exhaust pressure acting from the first passage toward the discharge chamber, and the water pressure acting from the second passage toward the discharge chamber; wherein
the valve regulates the passage of the exhaust gas at the first connection due to the water pressure when the forward propulsive force is generated;
the valve permits the passage of the exhaust gas at the first connection due to the exhaust pressure when a backward propulsive force is generated;
the housing includes a water intake to take the water into the second passage when the forward propulsive force is generated; and
the water intake includes an opening, and at least a portion of the opening opens forward.