Internal-combustion engines – Charge forming device – Crankcase vapor used with combustible mixture
Reexamination Certificate
2001-01-02
2002-07-02
McMahon, Marguerite (Department: 3747)
Internal-combustion engines
Charge forming device
Crankcase vapor used with combustible mixture
C123S572000, C123S041860
Reexamination Certificate
active
06412478
ABSTRACT:
FIELD OF THE INVENTION
This invention relates generally to an internal combustion engine, and in particular, to a breather which is mountable on a cylinder head of a crankcase of the internal combustion engine in order to separate oil from the crankcase blow-by.
BACKGROUND AND SUMMARY OF THE INVENTION
As is known, in internal combustion engines, pistons are housed within corresponding cylinders for reciprocal movement therein. Fuel and air enter a combustion chamber in a corresponding cylinder on a first side of a piston. The fuel in each combustion chamber is ignited so as to cause linear motion of the pistons within their corresponding cylinders. The linear motion of the pistons is converted into rotary motion by the crankshaft.
Ideally, all of the gases in the combustion chambers after ignition of the fuel are exhausted from the combustion chambers via an exhaust pipe for the engine. However, a portion of the combustion gases may pass between the piston rings and the cylinder walls of the cylinders housing the pistons. These combustion gases contain various by-products of combustion which may be harmful if vented to the environment. As such, in order to prevent discharge of the combustion gases directly into the environment, the combustion gases are routed through the crankcase and into the air intake system of the internal combustion engine.
During routing of the combustion gases to the air intake system of the engine, the combustion gases often become contaminated with oil mist as the high pressure combustion gases are blown past the piston rings into the crankcase. This mixture of combustion gases and oil mist is known as crankcase blow-by. It has been observed that if crankcase blow-by is inputted directly into the engine air intake system, excess carbon builds-up in the engine, thereby causing increased exhaust emissions. As is known, excessive exhaust emissions maybe harmful to the environment. Further, any oil mist in the crankcase blow-by which is fed back into the combustion chambers will be burned during operation of the internal combustion engine. As such, the consumption of oil by the internal combustion engine will increase, thereby increasing the overall costs associated with operating the same.
Therefore, it is a primary object and feature of the present invention to provide a breather for an internal combustion engine which separates oil from the crankcase blow-by.
It is a further object and feature of the present invention to provide a breather for an internal combustion engine which does not utilize any filtration material.
It is a still further object and feature of the present invention to provide a breather for an internal combustion engine which reduces the oil consumption and the hydrocarbon emissions of the same.
It is a still further object and feature of the present invention to provide a breather for an internal combustion engine which is simple and inexpensive to manufacture.
In accordance with the present invention, a breather is provided which is mountable on a cylinder head of a crankcase of an engine. The breather separates oil from the crankcase blow-by and includes a rocker cover mountable to the cylinder head of the crankcase. The rocker cover defines a cavity therein. A plate is positioned within the cavity of the rocker cover for separating the cavity into first and second portions. The plate has a first opening for allowing the crankcase blow-by to flow between the first and second portions of the cavity and a drain hole for allowing oil to drain from the second to the first cavity. An oil separator is positioned within the second portion of the cavity and has first and second sides. The oil separator divides the second portion of the cavity into a first upper chamber and a second lower chamber. A first set of baffles project from the first side of the oil separator into the upper chamber and a second set of baffles projects from the second side of the oil separator into the lower chamber. It is contemplated that the oil and the crankcase blow-by cling to the oil separator and the first and second sets of baffles as the crankcase blow-by flows therepast.
The oil separator includes an outer periphery spaced from the rocker cover so as to allow the crankcase blow-by to flow between the lower and upper chambers. The rocker cover includes a vent communicating with the second portion of the cavity for allowing the crankcase blow-by to exit the rocker cover. The oil separator and the first and second set of baffles are integrally molded and the second set of baffles engages the plate.
A check valve is positioned over the first opening in the plate. The check valve is movable between a first closed position wherein the crankcase blow-by is prevented from flowing from the first portion of the cavity into the second portion of the cavity and a second open position wherein the crankcase blow-by is allowed to flow from the first portion of the cavity into the second portion of the cavity. A plurality of ribs extend from the second side of the oil separator towards the plate. The check valve includes a flap interconnected to the plate. The flap engages the plurality of the ribs with the check valve in the opened position.
In accordance with a further aspect of the present invention, a breather is provided which is mountable on a cylinder head of a crankcase of an engine. The breather separates oil from the crankcase blow-by generated by the engine and includes a rocker cover mountable to the cylinder head of the crankcase. The rocker cover defines a cavity therein for receiving the crankcase blow-by. The plate is positioned within the cavity of the rocker cover for separating the cavity into first and second portions. The plate has a first opening for allowing the crankcase blow-by to flow between the first and second portions of the cavity. An oil separator is positioned within the second portion of the cavity for dividing the second portion of the cavity into a first upper chamber and a second lower chamber. The oil separator has first and second sides and an outer periphery spaced from the rocker cover so as to allow the crankcase blow-by to flow between the lower and the upper chambers. A first set of baffles project from the first side of the oil separator into the upper chamber and a second set of baffles project from the second side of the oil separator into the lower chamber.
The rocker cover includes a vent communicating with the second portion of the cavity for allowing the crankcase blow-by to exit the rocker cover. The oil separator and the first and second sets of baffles are integrally molded and the second set of baffles engages the plate.
A check valve is positioned over the first opening in the plate. The check valve is movable between a first closed position wherein the crankcase blow-by is prevented from flowing from the first portion of the cavity into the second portion of the cavity and a second open position wherein the crankcase blow-by is allowed to flow from the first portion of the cavity into the second portion of the cavity. A plurality of ribs extend from the second side of the oil separator towards the plate. The check valve includes a flap interconnected to the plate. When the check valve is in the opened position, the flap engages the ribs.
In accordance with a still further aspect of the present invention, a breather is provided for mounting on a cylinder head of a crankcase of an engine. The breather separates oil from the crankcase blow-by and includes a rocker cover mountable to the cylinder head of the crankcase. The rocker cover defines a cavity therein for receiving the crankcase blow-by therein. A plate is positioned within the cavity of the rocker cover for separating the cavity into first and second portions. The plate has an opening for allowing the crankcase blow-by to flow between the first and second portions of the cavity. A flap is interconnected to the plate and overlaps the opening. The flap is movable between a first closed position wherein the crankcase blow-by is prevented from flowing from the
Chen Dawei
Haworth Edward M.
Ruehlow Gerald C.
Boyle Fredrickson Newholm Stein & Gratz S.C.
Generac Power Systems, Inc.
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