水下生产系统水下部分的核心设施单元是水下控制模块（SCM）。SCM的控制功能主要依靠液压回路为水下阀门提供驱动力来实现。SCM的下放、安装、回收是水下生产系统的一个重要课题，下放回收工具中常用的传动机构是丝杠螺母副。普通丝杠主要是利用滑动摩擦，效率通常为0.3~0.6，相比滚珠丝杠，传动效率和传动速度都较差，但因为其拥有自锁性，所以在起升机构中应用广泛。根据实际工程案例，通过力学分析计算，得到丝杠传动机构所需要的动力源——液压马达的功率及最小输出扭矩，可以用作动力源选型的参考数据。

 Subsea control module （SCM) is the core unit of subsea production system. The realization of the control function of the SCM mainly relies on the hydraulic power to provide the driving force for the subsea valves. The running， installation and recovery of SCM is an important issue in the subsea production systems. Ordinary screw mainly works with sliding friction， for which the efficiency is usually 0.3~0.6. Compared with the ball screw， the drive efficiency and the drive speed are far less. Because of its self locking， ordinary screw is still widely used in the lifting mechanism. In this paper， according to the actual project case， through the mechanical analysis and calculation， for the power source of the screw drive mechanism， i. e., hydraulic motor, the power and the minimum output torque are obtained. The results can be used as the reference data of the type selection of hydraulic motor.