磨：即磨合。无论是新的还是大修后的柴油机，都必须按规范磨合后方可投放正常作业。　　净：即油净、水净、气净、机体净。若柴油不净，会使轴颈和轴瓦间隙变大，油压降低，甚至造成抱轴烧瓦等严重事故。若空气中含有大量尘土，将会加速缸套、活塞和活塞环的磨损。若冷却水不 Mill: That run-in. Whether it is a new or overhauled diesel engine, it must be run in accordance with the specifications before it can be put into normal operation. Net: that the net oil, water net, air net, the body net. If the diesel is not clean, the gap between the journal and the bearing bush will be enlarged, the hydraulic pressure will be reduced, and even serious accidents such as the axle shingling may occur. If the air contains a lot of dust, will accelerate the cylinder liner, piston and piston ring wear. If the cooling water is not