采煤机牵引部液压系统试验研究

TEST OF HYDRAULIC HAULAGE SYSTEM OF SHEARER

对采煤机牵引部压力反馈、自动调速、补油泵补油的液压系统和无压力反馈、手动调速、单向阀自吸补油、溢流阀压力峰值及过载保护的液压系统进行阶跃负载试验研究．结果表明，在相同的阶跃负载下，无压力反馈、溢流阀压力峰值及过载保护系统的压力响应曲线稳定性要好于压力反馈自动调速系统；两种系统的压力峰值一致，反映了压力反馈系统不能减小压力响应的第一次峰值．压力反馈自动调速系统在压力反馈环节作用后，马达转速曲线呈下滑趋势，无振荡，近似恒功率工作，调速性能好．

Step tests of the hydraulic system of a shearer with pressure feedback, automatic speed control and oil supplied by a pump; test of a system without pressure feedback, manual speed control,self-suction of oil by non-return valve; and test of a system with direct-acting relief valve to restrict pressure peak value and overload protection are described. The test result of the latter is better than the former two system in pressure response curve stability under the same conditions of step load. The pressure peak values of the two systems are the same. It reflects that the first pressure peak value of pressure response can not be reduced by pressure feed back system. In the pressure feedback automatic speed control system, after the pressure is fed back, the rotational speed curve of motor tends to drop down without oscillation, which is similar to working in constant power, and speed regulation is better.