Internal-combustion engines – Charge forming device – Crankcase vapor used with combustible mixture
Reexamination Certificate
1999-08-26
2001-10-30
McMahon, Marguerite (Department: 3747)
Internal-combustion engines
Charge forming device
Crankcase vapor used with combustible mixture
Reexamination Certificate
active
06308695
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to outboard motors. More specifically, the present invention relates to layouts of cam covers for engines of outboard motors.
2. Description of Related Art
To improve the performance of a watercraft, the associated weight and drag of a watercraft may be reduced. In regard to the outboard motor, this means reducing the motors' weight and streamlining the structure of those portions extending above a transom of the watercraft and extending into the water in which the watercraft is operating.
Accordingly, U.S. Pat. No. 5,501,202 teaches an engine layout for reducing the weight and size of an outboard motor. The layout involves positioning a vapor separator of a crankcase ventilation system on a cam cover outside of a cam chamber. A fuel pump is also positioned at about the center of the cam cover, beneath the separator, to generally balance the length of fuel travel to each of a plurality of carburetors.
SUMMARY OF THE INVENTION
The present invention improves upon such a configuration. It has been discovered that positioning an oil fill below the lubricant outlet of the vapor separator results in possible flow of lubricant from the oil fill when the oil fill cap is removed. The flow of lubricant to the outside of the cam cover may result in fouling of electrical components positioned in close proximity. Accordingly, the positioning of the oil fill below the lubricant outlet of the vapor separator has been determined to be disadvantageous.
Moreover, it has been discovered that the lubricant escaping from the vapor separator through the lubricant outlet may be used to lubricant discrete contact points between moving elements. For instance, the lubricant may be used to lubricate the moving components of the fuel pump. In the fuel pump of the present invention, the lubricant is directed to the contact point between a rocker arm and a piston of the fuel pump. In this manner, the lubricant being drained from the vapor separator is directed to difficult to lubricant elements.
Accordingly, one aspect of the present invention involves an engine for an outboard motor. The engine has a cylinder block interposed between a cylinder head and crankcase. The engine further comprises a cam cover attached to the cylinder head to enclose a cam chamber within the cylinder head. The cam chamber contains a valve operating mechanism. A lubricant vapor separator is located on the cam cover outside of the cam chamber. The separator includes an upper opening communicating with a separator chamber. The chamber is in communication with the cam chamber through at least the upper opening. The separator also includes an intermediate opening through which ventilation gases are vented for recirculation through the engine and a lower opening through which lubricant, separated from the ventilation gases, flows from the vapor chamber into the cam chamber. The cam cover further comprises an oil fill port. The oil fill port includes an aperture extending through the cam cover. At least a portion of the aperture is positioned to lie at least generally vertically as high as or higher than the lower opening of the separator.
Another aspect of the present invention involves an outboard motor comprising a cowling. An engine compartment is defined within the cowling. An engine is mounted in the engine compartment. The engine comprises a cylinder block. A crank cover is mounted to a face of the cylinder block and a crankcase is defined between the crank cover and the cylinder block. A cylinder head is mounted to a face of the cylinder block opposite the crank cover. A cam cover is connected to the cylinder head and a cam chamber is defined by the cam cover and the cylinder head. At least one cam shaft is positioned within the cam chamber. A vapor separator is positioned on the cam cover and is arranged to protrude from the cam cover generally away from the cam shaft. The engine further comprises a fuel pump positioned along the cam cover at a location generally below the vapor separator.
REFERENCES:
patent: 5383440 (1995-01-01), Koishikawa et al.
patent: 5501202 (1996-03-01), Watanabe
patent: 5514015 (1996-05-01), Okazawa et al.
patent: 5794602 (1998-08-01), Kimura
patent: 5899197 (1999-05-01), Watanabe et al.
Hori Yuji
Watanabe Kazuhiko
McMahon Marguerite
Sanshin Kogyo Kabushiki Kaisha
LandOfFree
Outboard motor engine layout does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Outboard motor engine layout, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Outboard motor engine layout will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2569205