Abstract: In one example, a centrifugal fan includes a bearing, a shaft rotatably supported by the bearing, fan blades operatively connected to and rotatable with the shaft to take in air axially and to exhaust air radially, and a groove in the shaft extending axially along an outer surface of the shaft through the bearing.

Abstract: An arrangement of a four cycle internal combustion engine 7 is provided. In the preferred embodiment the engine 7 has a plurality of combustion chambers 18 having reciprocating pistons 22 mounted therein. A fuel injector 80 is provided for each combustion chamber. The fuel injector injects a stratified 80 charge into the combustion chamber 18 upon a compression stroke of the piston 22. An intake manifold 32 is provided to provide air to each combustion chamber. A charging device 38 is provided to pressurize the air within the intake manifold 32. Preferably the charging device is a variable geometry turbocharger 38. The pressurizing of the air within the intake manifold 32 allows the engine 7 to extend the stratified charge operation of the engine 7 and facilitates in increased gas mileage by allowing the engine 7 to stay in a stratified mode of operation longer than prior stratified charged internal combustion engines.

Abstract: Swirl motion of gases in a combustion chamber of an engine is affected by changing the timing of opening and closing one of two intake and/or exhaust valves. By retarding the opening of one intake valve relative to a second intake valve, swirl motion can be enhanced for the intake gases in the engine cylinder. Similarly, by retarding the opening of one of two exhaust valves, swirl motion can be induced for the residual gases. The system may include electric or hydraulic actuators or mechanically controlled valves. A variable valve lift system can also be used to control swirl motion in a combustion chamber.

Abstract: A stratified-charge combustion system design for direct-injection spark-ignited engines with the piston bowl in the exhaust-valve side. The air flow from the inlet valve provides a normal tumble in cylinder air flow. The fuel injector is positioned on the intake-valve side of the combustion cylinder and forms a charge stratification in the combustion chamber. With the piston bowl on the exhaust-valve side, the distance for spray penetration of the fuel from the injector is extended. The rate of fuel spray penetration in the combustion chamber is reduced by counter air flow against the fuel spray. The air-fuel mixture is moved upwardly to the area of the spark plug by the tumble air flow for ignition. The invention provides less piston bowl wall wetting which results in less soot formation and less emissions of undesirable hydrocarbons.

Abstract: A three-valve cylinder head system for a direct-injected spark-ignited (DISI) internal combustion engine. Two inlet ports are positioned in opposite quadrants of the cylinder head, with the fuel injector directing fuel spray into a third quadrant and the exhaust port being positioned in the fourth quadrant. A helicoid intake port and an axially directed intake port generate a swirl-type air flow in the piston cylinder without the aid of flow activation devices. The spark plug is positioned centrally adjacent the longitudinal axis of the cylinder bore. The piston has a bowl in its upper surface with an enlarged downstream area and a harbor area adjacent and past the spark plug which allow the swirl-type air flow to mix with the fuel spray and provide an appropriate fuel air mixture at the spark plug.

Abstract: A method of controlling fuel supply during a deceleration fuel shutoff mode includes determining the amount of oxygen stored in the catalyst or the temperature thereof and intermittently supplying fuel to the engine such that the fuel reacts in the catalyst to reduce excess oxygen therein.

Abstract: A stratified charge is formed in a direct injection engine by injecting fuel at a predetermined velocity, a predetermined droplet size, and forming the injected fuel with a hollow cone having a predetermined initial cone angle. The injected fuel thereby shallowly penetrates the combustion chamber so as to float therein to reduce wall-wetting and subsequent soot formation. A substantially flat top piston forms the injected fuel into a ball-shaped kernel during a compression stroke of the engine. The ball-shaped kernel remains substantially unmixed with the inducted air, thereby producing the stratified charge. The continued motion of the piston causes the ball-shaped kernel to move toward the spark plug for ignition.

Abstract: A piston-type, multicylinder internal combustion engine includes a cylinder block and a cylinder head mounted thereto, with a combustion chamber defined by the cylinder head and the top of the piston, with the engine being fueled by an an in-cylinder gasoline injection system which is centrally located with a spark plug such that the spark plug is closer to exhaust valves than is the injector, and with the injector being closer to the intake valves than the spark plug.

Abstract: A spark ignited, reciprocating internal combustion engine, including a piston housed within a cylinder closed by a cylinder head has a fuel system for injecting fuel directly into the engine cylinder so as to achieve a homogeneous mixture with the fuel injection system injecting a first fraction of fuel during a first injection event and a second fraction of fuel during a second injection event.

Abstract: A cooling system for a reciprocating multicylinder internal combustion engine includes discharge passages for conducting coolant from the cylinder block to specific regions of the cylinder head so as to increase the localized heat transfer coefficient between coolant and the cylinder head. Flow through the cylinder head is separated into an intake side flow and a central and exhaust side flow so as to promote better heat transfer and to allow the engine to be operated with a higher compression ratio and greater spark advance.

Abstract: An internal combustion engine employs fuel injectors positioned to inject fuel directly into combustion chambers of the engine, and an electronic engine controller (EEC) to control operation of the engine. The EEC implements a cold start routine which controls the amount of fuel injected, the time at which the fuel is injected and spark timing to achieve a rapid increase in temperature of the engine and the exhaust system components, thereby decreasing tailpipe hydrocarbon emissions during cold start.