一般认为,经维修的工程机械发动机只要与功率有关的缸套、活塞、活塞环、凸轮轴及其相配合的套、主轴承、连杆轴承、气门等主要部件符合技术要求,其功率值不会有明显的下降;然而,在维修过程中经常遇到一个难题,即上述各件虽未见异常,或大修时都已更换新件,但功率仍不足。追究其原因可归纳以下四个方面。 It is generally believed that as long as the engine of the repaired engineering machine has power-related cylinders, pistons, piston rings, camshafts and their associated sleeves, main bearings, connecting rod bearings, valves, and other major components meet the technical requirements, their power values ​​are not There will be a noticeable drop; however, one problem often encountered in the maintenance process is that although the above items are not abnormal or have been replaced with new ones during overhaul, the power is still insufficient. The reasons for the investigation can be summarized in the following four aspects.