危急保安器 meaning in English

emergency governor gear
emergency overspeed governor

So we ca n ' t do oil filler test when the units in operating to test the reliability of overspeed protection system . firstly , this thesis presented the theory of overspeed protection system . and pointed out the reason why the emergency stop system is often fails in stroke
本文首先分析了该型超速保护的动作原理，指出该型危急保安器注油试验拒动的原因；首次利用流体力学的相关理论引入射流的概念，提出了改造方案，同时对该型危急保安器注油试验装置改造后飞环提前动作作出了理论分析。