中文摘要：

在分析柱塞组运动学的基础上，推出定子曲线的极坐标表达式，用有等速区段的等加速运动规律在Matlab中编程，绘制出了定子曲线，并提取曲线数据运用三维软件Pra／E绘制定子三维模型，为水压马达虚拟样机模型提供前提条件；详细推导曲线的扭矩脉动公式与速度脉动公式，并比较两种形式的曲线，最后选取合适的曲线作为马达内曲线，并运用Matlab）编程计算马达定子与滚球的接触应力的变化规律，设计的曲线接触应力变化基本为零，为马达定子材料的选择提供依据。

英文摘要：

Based on the analysis of the kinematics of the piston group, the polar coordinate expression of the stator curve was deduced. The stator curve was drawn by program which was with the rule of equal acceleration in the section of equal speed in Matlab. The extracted data were used to draw the 3 D model of the stator in Pro/E which provided premise for the virtual prototype of the water hydraulic motor. The torque pulsation formula and the velocity pulsation formula were deduced. The final suitable stator curve was cho- sen for the internal motor by comparing the two forms of stator curves. The rule of contact stress between stator and roller was calculated in term of the program in Matlab and the contact stress had little variation. The research work provides reference for the choice of stator material of motor.