US 7,621,792 B2Granted

Outboard motor

AssigneeYamaha Hatsudoki Kabushiki Kaisha

InventorsYoshihito Fukuoka, Daisuke Nakamura

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Abstract

An outboard motor has a construction in which the area of an exhaust passage can be secured easily and exhaust noise is less likely to escape into the air, allowing the exhaust noise to be lowered. The outboard motor includes a lower case, a propeller shaft rotatably supported in the lower case, a propeller fixed to the propeller shaft, an engine, and a power transmission mechanism through which a driving force from the engine is transmitted to the propeller shaft to rotate the propeller. An exhaust case is provided in the lower case. The exhaust case includes an upper exhaust passage above the propeller shaft, the upper exhaust passage directing therethrough an exhaust gas from the engine, an exhaust outlet which is open in a rearward direction of the propeller shaft, and a communication exhaust passage arranged to communicate the upper exhaust passage with the exhaust outlet.

Claims11

Dependent claims

An outboard motor comprising:

a lower case;
a propeller shaft rotatably supported in the lower case;
a propeller fixed to the propeller shaft, the propeller positioned in a rear of the lower case;
an engine;
a power transmission mechanism through which a driving force from the engine is transmitted to the propeller shaft to rotate the propeller;
and
an exhaust case through which an exhaust gas from the engine is emitted into water, the exhaust case including:
an upper exhaust passage above the propeller shaft, the upper exhaust passage directing therethrough an exhaust gas from the engine;
an exhaust outlet which is open in a rearward direction of the propeller shaft;
and
a communication exhaust passage arranged to communicate the upper exhaust passage with the exhaust outlet, and the communication exhaust passage is positioned rearward of the propeller;
wherein
the lower case supports a forward end of the propeller shaft, and a section defining the exhaust outlet of the exhaust case rotatably supports a rear end of the propeller shaft, the rear end of the propeller shaft being located on an opposite side of the propeller from the forward end of the propeller shaft.

10 more elements

Dependencies are inferred from the claim text.

Facts

Application: 11/954,093Filed 11 Dec 2007
Priority: JP 2006-34132719 Dec 2006
Published: US 2008/0146095 A119 Jun 2008
Granted: 24 Nov 2009
Term ends: Not estimatedThe source records don’t support an estimate.

Classification4 codes

B63H 20/245
Arrangements, apparatus and methods for handling exhaust gas in outboard drives, e.g. exhaust gas outlets: exhaust gas outlets
B63H 1/20
Propellers: hubs; Blade connections
B63H 5/10
Of more than one propeller: of coaxial type, e.g. of counter-rotative type
B63H
Marine propulsion or steering