The motorcycle consists of five parts: engine, transmission system, walking system, steering, braking system and electrical instrumentation. The overall structure of the motorcycle and the names of the various components.
1. the characteristics of motorcycle engines
(1) The engine is a two-stroke or four-stroke gasoline engine.
(2) It adopts air-cooled cooling, and there are two kinds of natural air cooling and forced air cooling. The general model adopts a natural air-cooling cooling method that relies on running air to blow through the cylinder head and the heat sink on the cylinder sleeve to remove heat. In order to ensure low speed and cooling of the engine before starting, the high-power motorcycle engine uses a forced air-cooling method that uses a fan and an air hood to blow the cooling fins with forced air.
(3) The engine speed is high, generally above 5000 rpm. The power (the effective power emitted per liter of engine displacement) is large, typically around 60 kW/liter. This shows that the motorcycle engine has a high degree of reinforcement and the engine has a small outer shape.
(4) The engine crankcase is integrated with the clutch and transmission, and has a compact structure.
The body consists of three parts: cylinder head, cylinder block and crankcase. The cylinder head is made of aluminum alloy and has fins. The new four-stroke motorcycle engine adopts overhead valve, chain drive and overhead camshaft structure. The cylinder block material is made of bimetal (abrasion-resistant cast iron cylinder liner cast aluminum heat sink) for better heat dissipation. Some motorcycles use wear-resistant cast iron cylinders. In some small mopeds, the engine uses a 0.15 mm hard chrome layer on the inner wall of the aluminum alloy cylinder. The crankcase is made of aluminum alloy die-casting from the combination of the left and right cabinets. Some motorcycles have a buffer block between the heat dissipation signs to suppress the noise generated by the vibration of the heat sink.