新买的拖拉机、农用运输车、柴油机等动力机械,以及这些机械大修后投入使用前,都必须进行磨合试验。 因为新车有许多重要的相对运动件,如气缸套与活塞环、曲轴颈与轴瓦以及各种传动齿轮等,虽然在工厂 New tractors, agricultural vehicles, diesel engines and other power machinery, and these machines overhaul and put into use before, must be run-in test. Because the new car has many important parts of the relative movement, such as the cylinder liner and piston rings, crankshaft and bearing bush and a variety of transmission gears, although in the factory