英语翻译The crankshaft,regarded as the"backbone" of the engine,a

英语翻译The crankshaft,regarded as the"backbone" of the engine,as shown in figure 2-6,serves to change the reciprocating motion of the piston into rotary motion and handles the entire power output.The periodic gas and inertia forces taken by the crankshaft may cause it ti suffer wear and bending and tensional strains.the crankshaft therefore must be adequately strong and wear-resistant.So the crankshaft is either forged from high quality steel or cast in a high-strong iron.The crankshaft shown in Figure 2-6 is actually made up of various pats such as main bearing journals,rod journal,crank arm,bearing,counter balanced weight and fiywheel end.the crankshaft revolves in bearings located in the engine crankcase ,but the number of bearings used usually depends on the number of cylinders in the engine,and the design of the engine.Mechanically,a crankshaft whiteout special balanced weight would have severe vibration when revolving.In order to reduce or eliminate such vibration,it must be provided with counter balanced weights that extend radically from the crankshaft are balanced and vibration is reduced.The rod journals are bored hollow in order to reduce the crankshaft inertia.Drilled diagonally through the crank arms are oil holes to supply oil to the rod journals.