Two major mechanisms: 1. Crank-connecting rod mechanism: The crank-connecting rod is an important component of an automobile engine that realizes the working cycle and completes energy conversion. It consists of the cylinder block group, piston-connecting rod group, and crankshaft-flywheel group. 2. Valve train: The function of the valve train is to open and close the intake and exhaust valves according to the working sequence and process of the engine, allowing the combustible mixture or air to enter the cylinder and expelling the exhaust gas from the cylinder to achieve the gas exchange process. Five major systems: 1. Starting system: The process of turning the crankshaft under external force until the engine starts to idle automatically is called engine starting, and the device required to complete the starting process is called the engine starting system. 2. Fuel supply system: The function of the gasoline engine fuel supply system is to prepare a certain quantity and concentration of the mixture according to the requirements of the engine, supply it into the cylinder, and expel the exhaust gas after combustion from the cylinder. 3. Cooling system: The function of the cooling system is to dissipate part of the heat absorbed by the heated parts in time to ensure that the engine works at the most suitable temperature. The cooling system of a water-cooled engine usually consists of a water jacket, water pump, fan, radiator, thermostat, and other components. 4. Lubrication system: The function of the lubrication system is to deliver a certain amount of lubricating oil to the surfaces of relatively moving parts to achieve liquid friction, reduce frictional resistance, and minimize wear of the components. 5. Ignition system: The ignition system usually consists of a generator, battery, distributor, ignition coil, and spark plug.
