基于离心作用的齿轮泵容积效率和困油现象分析

Theoretical analysis of volumetric efficiency and phenomenon of trapped oil under centrifugation in external spur-gear pump

为了解高速时工作油液的离心作用对泵容积效率和困油现象的影响,将离心作用对两者的影响归结于对泵进油侧原始含气比的修正。基于仅考虑工作油液中混入空气的可压缩性和含气、纯净工作油液分别累积在齿槽内、外侧的假设,建立了基于油液离心作用的下容积效率、困油区间内含气比和进油侧修正含气比的计算公式。两组数据的仿真结果表明离心应用对容积效率和困油现象的影响相反,转速越高,对容积效率越不利;出口压力越低,离心作用对困油现象的影响越有利;齿形参数的选择存在优化的问题;该研究为泵的高速化发展提供一定的依据。

For understanding the impact of high-speed centrifugation caused by rotating hydraulic oil on volumetric efficiency and phenomenon of trapped oil in external spur-gear pump,the amendment to original gas volume percentage mixed in inlet working oil was presented for analysis of this impact.From the assumption on only considering the compressibility of oil mixed with gas,and pure hydraulic oil and mixed oil respectively accumulated in outside and inside of non-tooth space,the formula of volumetric efficiency only under the impact of centrifugation,gas volume percentage mixed in trapped oil and amendment to original mixed gas volume percentage were derived.The simulation results of two sets of data showed that the impact on phenomenon of trapped oil under centrifugation was opposite to volume efficiency,the higher rotate speed,the smaller volume efficiency;the lower outlet pressure,the better effect of centrifugation on phenomenon of trapped oil.These indicate that the general parameters of gear pair in external spur-gear pump should be optimally designed,and the method can provide a reference for high-speed development of external spur-gear pump.