What are the components of an engine?
2 Answers
An engine is composed of two major mechanisms and five major systems. The two major mechanisms are the valve train and the crankshaft connecting rod mechanism. The five major systems are the ignition system, cooling system, lubrication system, starting system, and fuel supply system. The following are detailed introductions: 1. Valve train: The engine valve train (internal combustion engine valve train) opens and closes the intake and exhaust valves of each cylinder in a timely manner according to the working cycle and ignition sequence requirements of each cylinder in the engine, allowing fresh combustible mixture (gasoline engine) or air (diesel engine) to enter the cylinder in time and exhaust gas to be discharged from the cylinder in time. During the compression and power strokes, the valves are closed to ensure the sealing of the combustion chamber. 2. Crankshaft connecting rod mechanism: The crankshaft connecting rod mechanism (crank-train) is the main moving mechanism of the engine. Its function is to convert the reciprocating motion of the piston into the rotational motion of the crankshaft, while converting the force acting on the piston into the torque output by the crankshaft to drive the car wheels. The crankshaft connecting rod mechanism is composed of piston group, connecting rod group, crankshaft, flywheel group and other components. 3. Ignition system: The ignition system is an important part of the gasoline engine. The performance of the ignition system has a great impact on the engine's power, fuel consumption and exhaust pollution. All the equipment that can generate an electric spark between the two electrodes of the spark plug is called the engine "ignition system". It is usually composed of a battery, generator, distributor, ignition coil and spark plug. 4. Cooling system: The cooling system keeps the engine within the appropriate temperature range under all operating conditions. The cooling system must prevent the engine from overheating and also prevent the engine from overcooling in winter. 5. Lubrication system: The so-called lubrication system refers to the general term for a series of oil supply, oil discharge and their auxiliary devices that supply lubricant to the lubrication parts. The lubrication system can be divided into five types, namely, circulating lubrication system, centralized lubrication system, spray lubrication system, immersion and splash lubrication system, and total loss lubrication system of oil and grease. 6. Starting system: To transition the engine from a stationary state to a working state, it is necessary to first use external force to rotate the engine's crankshaft, so that the piston makes reciprocating motion, the combustible mixture in the cylinder burns and expands to do work, pushing the piston downward to rotate the crankshaft. Only then can the engine run on its own, and the working cycle can proceed automatically. Therefore, the entire process from the rotation of the crankshaft under external force to the engine starting to idle automatically is called the starting of the engine. 7. Fuel supply system: The task of the gasoline engine fuel supply system is to prepare a certain amount and concentration of combustible mixture according to the requirements of various operating conditions of the engine, supply it to the cylinder, and make it ignite and burn near the end of compression to expand and do work. Finally, the supply system should also discharge the combustion product - exhaust gas into the atmosphere.
Every time someone asks me about engine components, I recall my days as an apprentice in an auto repair shop when I was young. An engine is like the human body: the crankshaft and connecting rods serve as the skeleton, driving the pistons and connecting rods into motion; the valve train acts as the respiratory system, controlling intake and exhaust via the camshaft and valves; the fuel system functions like the digestive system, with the fuel tank storing gasoline and the fuel pump plus injectors delivering it; the cooling system resembles blood circulation, where the water pump circulates coolant between the radiator and engine to prevent overheating. Then there’s the lubrication system—the caretaker—using the oil pump to distribute oil and reduce friction among moving parts. The starting system relies on the starter motor, powered by the battery to ignite the engine. Bottom line: every component has its role, and missing even one spells trouble. After 30 years of repairing cars, my biggest fear is novices recklessly modifying parts and ruining the entire engine.
