Can we get a rollaway ( bed ) for the two children?

我们能不能要一张供两个孩子睡的滚移式折叠床?

In this paper the mechanism of the ball- rollaway and the calculation of the contact stress is highlighted, the design of the hydraulic cylinder o.

重点介绍了箱梁横移台车的滚珠—滚道结构，滚珠—滚道结构接触应力的计算，及托梁液压缸的设计。