中文摘要：

以东方红某型号拖拉机液压机械无级变速器中的机械变速机构为研究对象，探究其传动误差随时间的变化规律，目的是减少变速器的功率损耗。利用当量啮合误差原理，建立变速器中行星齿轮组、定轴齿轮副和两者共同作用时的传动误差与时间的关系式。比较各挡位的总传动误差和行星齿轮组传动误差，得到瞬时总传动误差最大、最小的挡位以及总传动误差的主导因素。在角频率相同时，行星齿轮组传动误差和定轴齿轮副传动误差存在耦合关系。利用蒙特卡罗法，验证了研究所得规律的正确性。建立总传动误差与功率损耗的关系式，结果表明两者存在正比关系。以减小传动误差为目的，提出了减少变速器功率损耗的措施。

英文摘要：

Based on the mechanical shift gear in HMCVT of Dongfanghong,the rules of the trans-mission error changing with time were researched to reduce the power loss of the transmission.The formula among transmission errors of planetary gear set,fixed-axle gear pair,the two factor function simultaneously and time were established by using the theory of equivalent mesh error.The gear which had the transient maximum and the minimum transmission errors and the dominant factor of transmission errors were found by comparing the whole transmission error and the transmission errors of planetary gear set.There existed coupling relationship among the transmission errors of planetary gear set and fixed-axle gear pair when the angular frequency was the same.The correctness of the rules was verified by using the Monte-Carlo method.The formula among transmission errors and pow-er loss was established.It turns out that there is positive relationship among them.The measures which reduce the power loss of transmission were put forward by using the method which was used to reduce the transmission errors.