Internal-combustion engines – Lubricators – Crankcase – pressure control
Reexamination Certificate
2000-02-01
2001-08-21
Kamen, Noah P. (Department: 3747)
Internal-combustion engines
Lubricators
Crankcase, pressure control
C123S1950HC
Reexamination Certificate
active
06276327
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an arrangement of components for an engine, and particularly to an arrangement of a lubrication system, an intake system, an exhaust system and a cooling system for an outboard motor.
2. Description of Related Art
The air intake and exhaust systems of an engine can be arranged in a variety of ways. One of the most common arrangements is a cross-flow type in which the air intake system and the exhaust system are disposed on opposite sides of the engine. Another arrangement, which is not so common, is a counter-flow type in which, unlike the cross-flow type, the air intake system and the exhaust system are disposed on the same side of the engine.
There are several advantages to the counter-flow type engine. For example, because the air intake passage is positioned close to the exhaust passage, the intake air charge is warmed by the heat of the exhaust gasses. This expedites engine warm up, particularly during a cold conditions.
Another advantage of the counter-flow type of engine is that there is room on the side opposite the intake and exhaust systems for other engine components. Alternatively, this side of the engine can be placed closer to an inner wall of an engine compartment or a protective cowling.
A counter-flow type of engine includes a cylinder body that defines a cylinder bore or cylinder bores in which a piston or pistons reciprocate and a cylinder head affixed on an end of the cylinder body. The cylinder head, the pistons(s), and the cylinder bore(s) define a combustion chamber or combustion chambers. In general, part of the air intake system and the exhaust system are formed in the cylinder head. Because both of these systems are positioned on the same side of the engine, they occupy a relatively large space. This increases the size of the engine. A need therefor exists for an improved arrangement of the other engine components, and in particular, the lubrication system to make the counter-flow engine as compact as possible.
Outboard motors (counter or cross-flow types) typically include a vertically disposed crank chamber, which houses a vertically disposed crankshaft. Lubricant is supplied to the crank chamber by the lubrication system. Typically, lubricant is sprayed into the crank chamber and is deposited on the inner wall of the crank chamber because of the airflow generated by the circular motion of the crankshaft. The lubricant then flows down the sides of the crank chamber and collects at the bottom of the crank chamber. A return passage is usually provided at the bottom of the crank chamber. Lubricant flows through the return passage and is returned to an lubricant reservoir, which is usually located beneath the engine. A problem with this arrangement is that it typically takes a long time for the lubricant to travel down the sides of the crank chamber. Accordingly, a larger amount of lubricant is required in the lubrication system. A need therefore exists for a lubrication system that reduces the amount of time it takes for the lubricant to travel through the crank chamber.
Most outboard motors (counter or cross-flow types) are stored on their side with one side of the engine facing upward. While in this position, lubricant can accumulate in the crank chamber of the engine. The lubricant may then leak into the combustion chamber through the space between the cylinders and the piston. When the engine is started, this lubricant may cause poor emissions and retard ignition. It is, therefore, another object of the present invention to provide an improved lubrication system that prevents lubricant from accumulating in the crank chamber during storage.
It is well known that the lubricant in the lubricant reservoir must be periodically removed and changed. Accordingly, an lubricant drain for the lubricant reservoir is provided and is typically located near the center or rear side of the bottom surface of the lubricant reservoir. To add lubricant, an insertion port is also provided. Usually, the lubricant is drained from the reservoir by removing a plug of the lubricant drain. Alternatively, lubricant can be sucked out of the lubricant reservoir through a suction pipe that has been inserted into the insertion port. Typically, a problem with both of these methods is that old lubricant still remains in the bottom of the lubricant reservoir. A need therefore exists for an improved means for removing most or all of the lubricant from the lubricant reservoir.
SUMMARY OF THE INVENTION
In accordance with one aspect of the present invention includes an outboard motor that comprises an internal combustion engine, an exhaust guide, and a lubrication system. The lubrication system includes a lubricant reservoir that is located below the exhaust guide. The engine comprises a cylinder body, which defines a plurality of cylinder bores in which pistons reciprocate. The pistons are coupled to a crankshaft, which is covered by a crank case forming a crank chamber. A cylinder head is affixed to an end of said cylinder body. A combustion chamber is defined between the pistons and the cylinder bores. A plurality of air intake passages supply air charges to the combustion chambers. A plurality of exhaust passages discharge burnt charges from the combustion chambers. The intake and exhaust passages are located on the same side of the cylinder body. At least one crank chamber lubricant return passage communicates with the crank chamber and the lubricant reservoir. The return passage is located on the same side of the cylinder body as the intake and exhaust passages. An opening of the crank case return passage is located at least in part on a substantially vertical side wall of the crank case.
Another aspect of the present invention involves an outboard motor comprising an internal combustion engine, an exhaust guide, and a lubrication system including. The lubrication system includes a lubricant reservoir that is located below the exhaust guide. The engine comprises a cylinder body that defines a plurality of cylinder bores in which pistons reciprocate. The pistons are coupled to a crankshaft that is covered by a crank case that forms a crank chamber. A cylinder head is affixed to an end of said cylinder body and defines a combustion chamber along with the pistons and the cylinder bores. A plurality of air intake passages supply air charges to the combustion chambers. A plurality of exhaust passages discharge burnt charges from the combustion chambers. The intake and exhaust passages are located on the same side of the cylinder body. At least one crank chamber lubricant return passage communicates with the crank chamber and the lubricant reservoir. The return passage is located on the same side of the cylinder body as the intake and exhaust passages.
Yet another aspect of the present invention involves an outboard motor comprises an internal combustion engine and a lubrication system for lubricating the engine. The lubrication system includes a lubricant reservoir that is located below the engine. The engine includes a cylinder body that defines a plurality of cylinder bores in which pistons reciprocate. The pistons are coupled to a crank shaft. A crank case covers the crank shaft. The reservoir includes an insertion port located on an upper side of the reservoir and a drain located under the insertion port. The insertion port is pointed towards the drain.
Another aspect of the present invention involves an outboard motor comprises an internal combustion engine and a lubrication system for lubricating the engine. The lubrication system includes a lubricant reservoir that is located below the engine. The engine includes a cylinder body that defines a plurality of cylinder bores in which pistons reciprocate. The pistons are coupled to a crank shaft. A crank case covers the crank shaft. The insertion port and said drain being located in a same vertical plane.
Another aspect of the invention involving an outboard motor that includes an internal combustion engine and a lubrication system for lubricating the eng
Fukuoka Yoshihito
Kumita Atsushi
Oishi Hiroshi
Huynh Hai
Kamen Noah P.
Knobbe Martens Olson & Bear LLP
Sanshin Kogyo Kabushiki Kaisha
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