A component in the landing gear for absorbing landing shock by transferring oil from one chamber to another through a metering valve.
起落架上通过计量活门将油液从一室转到另一室以减少着陆时产生的冲击震动的部件。
2
The landing is thread connected with stop ring and tightened on and put into downhole with drill string. The landing sub is used as a sub above drill string before check valve is run in downhole.
就位接头与止动环用螺纹联结并上紧扣和钻柱连接下入井内，在未投入止回阀时作为钻柱上的一个接头。
3
The main problems of the camshaftless valve actuation are long response time, hard valvelanding, high power consumption and complex…