为保证航空遥感器的成像质量，对遥感器偏移的焦平面进行校正，设计了等径共轭凸轮调焦机构。研究了影响凸轮机构精度的因素，分析了滚子径向跳动误差、凸轮加工误差、基圆半径对机构位移正确度的影响，并提出了一种基于最小二乘法，保证凸轮共轭等径、消除机构空回误差及防止机构卡死的优化方法。优化设计了某等径共轭调焦凸轮机构并对其进行了精度分析。结果表明，等径共轭凸轮机构的最大位移误差为±4.7 μm，最大空回误差为4.8 μm，机构运行稳定可靠。

In order to ensure the imaging quality and modulate the focusing plane, a focusing mechanism based on a constant-diameter conjugate cam is designed. To improve focusing accuracy, factors affecting the accuracy of cam are studied. The influences of the roller radial runout, cam machining error and the base circle radius on focusing accuracy are analyzed. Then, a method to guarantee the cam diameter constant and remove return stroke error is studied by using least-squares method. The analysis results indicate that the focusing accuracy can reach ± 4.7 μm, and the return stroke error can reach 4.8 μm. The functioning of institutions is stable and reliable.