Based on dynamic balance theory of normal rotate structure and crank - set , causation of inertia combined - force , a conclusion is drawn on the difference between the dynamic balance tests of single cylinder motor and normal rotate structure . that conclusion is the theory base of the whole test system 作为测试系统建立的基础,本文首先对一般回转体的动平衡理论、曲轴动平衡理论以及曲柄连杆机构惯性力产生的机理进行了较深入的研究,并在此基础上得出了单缸发动机曲柄连杆机构动平衡测试与一般回转体工件动平衡测试的不同之处,为测试系统的建立提供了理论依据。