激光对中板在开掘巷道施工中的应用

针对在井下开掘巷道施工时,由激光指向仪指示开掘巷道方向时,由于激光对中偏差导致巷道施工方向的改变。通过激光对中板进行严格的激光对中,可很好的解决该问题。

论中小钢铁企业技术改造的经济评价

1996年以来,我国钢产量已连续三年超过一亿吨。1998年我国的铁、钢和钢材比1993年分别增长了37.30％、27.36％和32.44％,而利润却从294亿元下降到23亿元,降幅高达92％。说明我国钢铁工业的控制总量、优化结构已是迫在眉睫。

Theoretical analysis on water-inrush mechanism of concealed collapse pillars in floor

In order to study the water-inrush mechanism of concealed collapse pillars from the mechanical view, a mechanical model for water-inrush of collapse pillars has been established based on thick plate theory of elastic mechanics in this paper.By solving this model the deformation of water-resistant rock strata under the action of water pressure and the expression of critical water pressure for collapse pillar waterinrush have been obtained The research results indicate that：the boundary conditions and strength of water-resistant strata play important roles in influencing water-inrush of collapse pillars.The critical water-inrush pressure is determined by both relative thickness and absolute thickness of water-resistant strata.

抽油机刹车故障原因分析及对策

游梁式抽油机刹车装置在工作中失效的主要表现形式是刹车片磨损,刹车片除了正常工作磨损外,还有刹车片与刹车轮上下间隙不一致、左右间隙不一致,径向上内外间隙不一致等原因导致的非正常磨损,不但导致刹车片失效加快,也降低了刹车装置的工作性能。通过对刹车失效原因进行分析,采取设计安装蹄轴定位装置、可调节式对中板、对中板规格尺寸标准化等措施,有效延长了刹车片的使用寿命,提高了刹车装置的可靠性和安全性。