提升机盘形制动器无石棉闸瓦的摩擦性能

Tribological behaviors of asbestos-free brake shoes for hoist winder disc brakes

为寻求导致矿井提升安全事故的深层次原因,探究了目前在提升机盘形制动器上广泛应用的无石棉闸瓦摩擦性能.采用XDZ-A型摩擦材料制样机、X-DM型调压变速摩擦实验机等制备闸瓦试样、开展模拟提升机盘形制动器实际使用工况与环境的摩擦实验,系统研究了名义接触压力、滑动速度和温度等对无石棉闸瓦与16Mn钢摩擦盘对摩时所表现出来的摩擦学行为的影响.实验结果表明:在接触表面间温度基本不变的情况下,摩擦因数随名义接触压力的升高而增大,随滑动速度的增加而减小,但滑动速度对摩擦因数的影响大于名义接触压力的影响;摩擦因数随温度的升高而降低,在300℃左右,下降比较明显;在降温实验过程中,摩擦因数随温度的降低而增加,但其在不同温度下的值比升温过程中对应温度下的值要小.因此,在研发、设计提升机制动装置时,不能把闸瓦摩擦因数看成定值,必须充分考虑制动工况对闸瓦摩擦性能的影响.

In order to seek for the deep reasons resulting in mine hoisting fatal accident, the tribological performance of asbestos-free brake shoes used widely in current hoist brakes was explored. A series of standard specimens were machined from the asbestos-free brake shoes for a commercial hoist winder with an XDZ - A friction material sampling machine, and friction experiments for simulating hoisting brake＇ s actual work conditions were conducted with an X-DM friction tester. The influences of nominal contact pressure, sliding speed and temperature on the tribological properties of asbestos-free brake shoe against 16Mn steel counter disc were systematically investigated. The results show that, under constant temperature within contacting surfaces, the friction coefficient rises with the increment of nominal contact pressure, and falls with the increment of sliding speed, but the effect of sliding speed on friction coefficient is greater than that of nominal contact pressure. With increasing temperature, the friction coefficient falls, and it obviously decreases at about 300 %. During the temperature dropping process, the friction coefficient increases in general, but its values at different temperatures are lower than those at the corresponding temperatures during temperature rising process. So it＇s incorrect to friction coefficient of brake shoes as a constant, and it＇ s essential to consider the influences of braking on the friction coefficient of brake shoes when developing and designing the braking equipment of hoist regard the conditions winders.