用于20MN基准测力机的新型静压润滑缸塞系统

A New Type of Loading Ram-Cylinder System by Using Hydrostatic Lubrication Technique in 20 MN Force Standard Machine

介绍了大力值标准测力机中使用的一种新型静压润滑原理的工作缸塞系统。由于油缸不转动，其有效长度得以减少，从而使工作油缸和活塞的超精加工成为现实。这种带有高压密封和零压槽的缸塞结构，还有助于消除工作油压控制的波动而造成的力值波动，从而可以改善液压式标准测力机的计量性能。实验表明，使用静压缸塞系统的２０ＭＮ基准测力机，其力值不确定度优于０．０１％，而灵敏阀优于０．００１％。

In this paper a new type of loading ram-cylinder system (LRCS) by using hydrostatic lubrication technique in large force standard machine is described. The unrotating loading cylinder has a shortened effective length to cause the superfine machining of the loading ram-cylinder being practicable. It has been found that this configuration of LRCS with seal groove and zero pressure groove is helpful to eliminate the fluctuation on the applied force (the working oil pressure control variation), therefore, it is also available to improve the metrological characteristics of the force standard machine with hydraulic multiplication. The experimental results of evaluation on a 20MN force standard machine by using the new LRCS have shown that the relative uncertainty of force measurement is <0.01% with a sensitivity threshold of <0.001%.