Expansion of idle relief exhaust gases in outboard motors
AssigneeBrunswick Corporation
InventorsRyan G. Bonde, Michael J. Biel
Life of this patent
Estimating the term…
Abstract
An outboard motor has an adapter plate that supports an internal combustion engine, a driveshaft housing disposed below the adapter plate, and a lower cowl. A lower cowl volume is defined between the adapter plate, cowl and driveshaft housing. A lower cowl volume inlet is configured to supply idle relief exhaust gases to the lower cowl volume and a lower cowl volume outlet is configured to discharge idle relief exhaust gases from the lower cowl volume to atmosphere. The lower cowl volume is configured to cause expansion of the relief exhaust gases prior to discharge of the idle relief exhaust gases to atmosphere.
Claims17
An outboard motor comprising:
- an internal combustion engine;
- an adapter plate that supports the engine;
- a driveshaft housing that is suspended below the adapter plate;
- a lower cowl that surrounds the driveshaft housing;
- a lower cowl volume that is defined between the adapter plate, the lower cowl and the driveshaft housing;
- a lower cowl volume inlet that is configured to supply relief exhaust gases to the lower cowl volume;
- and
- a lower cowl volume outlet that is configured to discharge the relief exhaust gases from the lower cowl volume to atmosphere surrounding the outboard motor;
- wherein the lower cowl volume is configured to cause expansion of the relief exhaust gases prior to discharge of the relief exhaust gases to the atmosphere without passing through an intervening labyrinth structure;
- wherein the exhaust tube is configured to discharge the exhaust gas to an exhaust gas volume that is located below the lower cowl volume;
- and
- wherein the exhaust gas volume is at least partially separated from the lower cowl volume by the driveshaft housing.
A method of expanding relief exhaust gases in an outboard motor having an adapter plate that supports an internal combustion engine, a driveshaft housing that is suspended below the adapter plate, and a lower cowl that surrounds the driveshaft housing, the method comprising:
- supplying relief exhaust gases to an exhaust gas volume that is at least partially separated from the lower cowl volume by the driveshaft housing and then to a lower cowl volume that is defined between the adapter plate, the lower cowl and the driveshaft housing, wherein the lower cowl volume is configured to cause expansion of the relief exhaust gases;
- and
- discharging the relief exhaust gases to atmosphere without passing through an intervening labyrinth structure.
An outboard motor comprising:
- an internal combustion engine
- an adapter plate that supports the engine;
- a driveshaft housing that is suspended below the adapter plate;
- a lower cowl that surrounds the driveshaft housing;
- a gear case housing that is disposed below the driveshaft housing and that contains a transmission for the outboard motor;
- a lower cowl volume that is defined between the adapter plate, the lower cowl and the driveshaft housing;
- an exhaust tube that is configured to convey exhaust gas from the engine past the lower cowl volume for discharge from the outboard motor via the gear case housing, wherein the exhaust tube is configured to discharge the exhaust gas to an exhaust gas volume that is located below the lower cowl volume;
- and
- a relief exhaust passage having a first end receiving the relief exhaust gases from the exhaust gas in exhaust gas volume and a second end discharging the relief exhaust gases to the lower cowl volume;
- wherein the relief exhaust passage extends through the driveshaft housing;
- wherein the lower cowl volume is configured to cause expansion of the relief exhaust gases prior to discharge of the relief exhaust gases to the atmosphere without passing through an intervening labyrinth structure;
- wherein the exhaust gas volume is at least partially separated from the lower cowl volume by the driveshaft housing.
Dependencies are inferred from the claim text.