四冲程柴油机英文课件2.ppt

Physical principles related to operation Basic parts of the engine assembly Four stroke operating theory Physical Principles related to Engine Operation Energy conversion Atmospheric pressure Vacuum Pressure The relationship between temperature, pressure and volume. The three states of matter. Energy Conversion Engines take heat energy and convert it into mechanical energy. Motors take electrical energy and convert it into mechanical energy. Basic Parts of the Gasoline Engine Cylinder block Piston Piston rings Piston pin Connecting rod Crankshaft Cylinder head Intake valve Exhaust valve Camshaft Timing gears Spark plug Cylinder Block Basic frame of gasoline engine. Contains the cylinder. Piston A sliding plug that harnesses the force of the burning gases in the cylinder. Piston Rings The rings seal the compression gases above the piston keep the oil below the piston rings. Piston Pins Also known as the wrist pin, it connects the piston to the small end of the connecting rod. It transfers the force and allows the rod to swing back and forth. Connecting Rod Connects the piston and piston pin to the crankshaft. Crankshaft Along the the piston pin and connecting rod it converts the up and down motion (reciprocating) of the engine to spinning (rotary) motion. V Crank VS W Crank Flywheel Carries the inertia when there is no power stroke. Lower End Action Cylinder Head Forms the top of the combustion chamber. Contains the valves, the passageways for the fuel mixture to move in and out of the engine. W Head Intake and Exhaust Valves Doorway that lets the gases in and out of the engine. Camshaft Through the use of an eccentric the cam lobes push the valves open. The valve springs close them. Timing Gears These gears drive the camshaft from the crankshaft. Spark Plug Electric match used to begin the combustion process of burning air and gasoline to create heat. Engine Related Terms TDC (top dead center) BDC (bottom dead center) Stroke Bore Revolution Compression Ratio Displac