中文摘要：

为研究活齿无级变速器（movable-teeth continuously variable transmission，MCVT)的传动效率，分析了MCVT的功率损失机理，建立了其传动效率理论计算模型，搭建了其传动效率试验台，开展了定传动比条件下MCVT传动效率与其转速、转矩关系的试验研究.结果表明：由齿侧间隙产生的滑动摩擦功率损失、冲击功率损失、搅油功率损失以及油封功率损失是MCVT的主要功率损失.在定传动比为1.2时，MCVT的传动效率可达95%左右.转矩对MCVT传动效率的影响显著，而转速对MCVT的传动效率影响不显著，但MCVT髙转速时的传动效率要大于低转速时的传动效率.当转速、转矩同时从低到髙变化时，传动效率逐渐增大.

英文摘要：

In order to investigate the transmission efficiency of movable-teeth CVT ( MCVT) , the power losses of MCVT was analyzed and the theoretical model of its transmission efficiency was set up. T h en,transmission efficiency test platform was set up for the MCVT. Lastly, experimental study of the relations among transmission efficien cy, speed and torque was conducted when the transmission ratio was fixed.The results show that the power losses of the sliding friction and impact caused by the backlash of the tooth, the power loss of the oil stirring and the power loss of oil seal are the main power losses of iMCVT.The transmission efficiency of iMCVT can reach 95% when the constant transmission ratio is 1 . 2 . Torque is the most significant impact to the transmission efficiency. The effect of speed on the transmission efficiency of iMCVT is not significant, but the efficiency of high speed is greater than that of low speed.The transmission efficiency is gradually increasing when speed and torque both range from the low to high.