液压作动器工作点自动回中特性分析

针对液压作动器自动回中问题,本文建立了作动器回中数学模型并搭建了仿真计算平台。通过仿真与试验结合的方式验证了模型的正确性。提出了作动器自动回中功能实现的判断条件,分析了结构参数以及对中孔布置方式对作动器回中特性的影响。研究发现:对应不同的冷却孔尺寸,存在对应临界负载力。当活塞位于对中孔右侧,压负载下,冷却孔及对中孔越大,活塞的回中速度越快,回中位置越小。无杆腔节流孔半径越小,回中速度越慢,回中位置越小,有杆腔节流孔对回中特性的影响与无杆腔节流孔相同。周向布置的对中孔其回中位移较小,且在一定负载下回中位置发生突变。

Research on U-steel yieldable support with backfill technology in rock roadway

The loading on U-steel yieldable support cannot be organically combined withthe law of strata behaviors from the surrounding rocks of roadway. In order to effectivelysolve the problem, U-steel yieldable support with backfill material and the performancerequirements of backfill material were analyzed on the basis of structural mechanics. Themechanical properties of backfill material selected were tested in the laboratory, and thetest results show that the ratio of the backfill material complies with the requirements ofbackfill technology; it can effectively optimize the relationship between the support and thesurrounding rock, and the filling layer can avoid the partial stress concentration and fullyimprove the support performance. Compared with U-steel yieldable support with ganguefilling, the filed application shows that the supporting result of U-steel yieldable supportwith backfill technology is satisfactory, the stress on U-steel yieldable support with backfilltechnology decreases greatly and distributes uniformly, convergence of the surroundingrock of roadway is decreased by more than 50%, and the surrounding rocks of roadwayare controlled effectively.

硬式空中加油系统对接机构设计及其动力学特征

针对硬式空中加油系统的对接问题,设计锁紧结构和回中结构,用于提高空中加油的可靠性。基于拉格朗日方程,推导机构的动力学方程。利用加油过程的技术要求,推算对接机构的结构参数,构建数字化模型,探究结构设计的合理性。结果表明本设计使输油机、伸缩管和受油机在对接过程中能顺利完成回中和锁紧,保证加油的顺利进行;在加油完成之后,输油机和受油机相应的部分能够实现油路自封,为后续飞行提供了可靠保障。