杆环

Thirdly, Friction, wear and lubrication for toroidal drive are discussed systematically and completely.

第三，对超环面行星蜗杆传动的摩擦学问题进行了深入系统的研究。

Firstly, the engaging theories for toroidal drive are discussed systematically and completely.

第一，对超环面行星蜗杆传动的啮合理论进行了深入系统的研究。

Meanwhile the meshing theory analyzing of toroidal drive for different rollers are also studied.

对不同滚动体情况下超环面行星蜗杆传动的啮合理论进行了探讨。

The constructions of toroidal drive are analyzed and compared, and the parameters for designing this kind of drive and the construction of all parts are determined. On this basis, the designing of toroidal drive are furnished.

对超环面行星蜗杆传动的结构进行了分析、对比，确定了这种新型传动的设计参数和各个零件的结构，在此基础上对这种传动进行了设计。

The difference on efficiency, lubrication and wear for toroidal drive with different planet gear tooth shape are discussed.

比较了三种不同齿形超环面行星蜗杆传动在效率、润滑和耐磨寿命三个方面的差异。

Sulphurized-nitrided compound layer is prepared on the surface of drilling pipe joint material 35CrMo steel by the application of ion nitriding and ion sulfurizing technology.

应用离子渗氮与离子渗硫技术，在钻杆接头材料35CrMo钢表面制备了硫氮复合处理层。采用M-200环块磨损试验机，对比研究了原始渗氮表面与硫氮复合表面在干摩擦条件下的抗磨损性能。

During oil production, pumping rod is eccentric in the long oil tube, in which flow of the swabbed fluid can be regarded as an unsteady flow of second-order fl.

在采油过程中，由于油井较深的缘故，抽油杆在油管中是处于偏心位置的，可以把聚驱井抽汲液在井筒中的流动视为二阶流体在内管做轴向往复运动的偏心环空中的非定常流动。

Hold the lower valve rod, place hydrant seat into lower barrel until the bottom contacts drain ring.

用双手握住下阀杆，把阀座放入地下埋管，直到底部与放水环接触为止。

Stem up and down the middle with two glass fiber reinforced epoxy phenolic cloth laminated board to achieve insulation, aluminum flange gasket sealing surface, use PTFE packing, use two special sealed cylinder to reduce friction, the overall use of the valve polyurethane foam insulation.

上下两段阀杆中间用环氧酚醛层压玻璃钢布板实现绝热，法兰密封面采用铝垫片，填料使用聚四氟乙烯，汽缸使用双特密封，以减小摩擦力，阀门整体采用聚氨酯发泡保温。

Methods The circular spring buffer is adopted with throttling bar as damping device.

采用环型弹簧与节制杆式阻尼器相结合的缓冲器原理。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。