Patent Application
20140057508
The present disclosure relates to marine propulsion systems and particularly to exhaust systems for marine propulsion systems.
U.S. Patent Application Publication No. 2012/0028517 discloses a marine vessel including an outboard motor mounting portion provided at a stern of a hull, an outboard motor locating hole provided rearward of the outboard motor mounting portion and near the outboard motor mounting portion and penetrating vertically through the stern, a platform provided rearward of the outboard motor locating hole, and an outboard motor located in the outboard motor locating hole and mounted to the outboard motor mounting portion. This structure enables an occupant of the marine vessel to freely move in a space around the outboard motor on the platform and use the space.
This summary is provided to introduce a selection of concepts that are further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.
Through research and experimentation, the present inventors have discovered that marine propulsion systems, such as described in the above referenced patent publication wherein the outboard motor is enclosed, have certain drawbacks. For example, the present inventors have found that exhaust gas emitted by idle relief components on the outboard motors are entrapped in the enclosed space of the outboard motor. This has been found to cause problems such as ingestion of carbon monoxide gas by the outboard motor, negatively affecting combustion performance. Further, carbon monoxide buildup within the enclosure can present dangerous situations for the operators of the vessel. Therefore, through research and experimentation the present inventors arrived at the present inventive concepts for overcoming these problems.
In one example, a marine propulsion system for propelling a marine vessel in water comprises at least one outboard motor coupled to a marine vessel. The outboard motor comprises an exhaust gas relief outlet that is located above the water when the marine vessel is stationary, the outlet relieving exhaust gas, for example when the marine vessel is idling. A conduit conveys exhaust gas from the exhaust gas relief outlet to a discharge outlet located on the marine vessel. The outboard motor also comprises a primary exhaust gas outlet that is located vertically lower than the exhaust gas relief outlet on the outboard motor and that discharges exhaust gas to the water. The noted conduit can be sloped along its length so that water does not stagnate therein.
Examples marine propulsion devices and exhaust systems for marine propulsion devices are described with reference to the following figures. The same numbers are used throughout the figures to reference like features and components.
In the present description, certain terms have been used for brevity, clearness and understanding. No unnecessary limitations are to be inferred therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes only and are intended to be broadly construed. The different methods and systems described herein may be used alone or in combination with other methods and systems. Various equivalents, alternatives, and modifications are possible within the scope of the appended claims.
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A muffler 46 is located on the engine well 38, internally of the hull 42 and is for decreasing idle relief noise. The muffler 46 can instead, optionally be attached to the outboard motor 14.
Although only a few example embodiments have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the example embodiments without materially departing from this invention. Accordingly, all such modifications are intended to be included within the scope of this disclosure as defined in the following claims. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents, but also equivalent structures. Thus, although a nail and a screw may not be structural equivalents in that a nail employs a cylindrical surface to secure wooden parts together, whereas a screw employs a helical surface, in the environment of fastening wooden parts, a nail and a screw may be equivalent structures. It is the express intention of the applicant not to invoke 35 U.S.C. §112, paragraph 6 for any limitations of any of the claims herein, except for those in which the claim expressly uses the words “means for” together with an associated function.
