单缸摩托车发动机曲柄过量配重的计算与校核

B，θ，C是确定不平衡惯性力椭圆的3个要素，（θ、B／C）决定椭圆的形态，C决定椭圆的大小，而B／C≤cosθ是使M＋N=C的充分必要条件。设计过程中，通过选取合适的θ、B／C值，可以获得理想的椭圆形态，而尽量减小往复力C，如采用轻量化活塞组件，可获得较小的惯性力幅值但要注意（B，θ，C）的变化关系中，避免出现B／C〉cosθ的情况，以防惯性力无端增大。

The Calculation and Check of the Exceed Counter-weight of Cranks for the Single-cylinder Engines of Motorcycles

B, θ and C are three elements of defining the oval of the unbalanced inertia force, （ θ, B/C） defines the shape of the oval, C defines the size of the oval and B/C≤ cos θ is the necessary condition of making M＋N C. In the process of the design, proper selection of θ, B/C can help you with getting the ideal oval shape with the C reduced as far as possible. If lightweight piston cluster is applied, the amplitude of the inertia force will be less, but attention should be paid to the case that in the changing relationship of （B,θ ,C）, B/C〉cos θ should be avoided, for it will lead to the magnification of the inertia force for no reason.