环下润滑结构内部流动分析和收油叶片结构优化研究

Internal Flow Field Analysis and Optimization Structure of Oil Scoop Blade in Under-Race Lubrication Structure

关键词:  环下润滑  径向收油环  计算流体力学  油气两相流  收油效率

Key words:  Under-race lubrication  Radial oil scoop  Computational fluid dynamics  Oil-gas two-phase flow  Oil capture efficiency

摘要:

为了研究环下润滑结构内部流动并优化收油叶片结构，根据环下润滑结构内部高转速、强旋流的流动特点建立了数值计算模型，分析了原始结构内部的油气两相流动并总结了滑油的损失机理，在此基础上提出收油叶片的优化改进结构，详细讨论了不同收油叶片结构对环下润滑内部流动和收油效率的影响规律。研究结果表明，原始结构中滑油冲击主轴产生的碰撞飞溅和在离心作用下沿收油叶片被向外甩出均是引起收油效率下降的原因；优化收油叶片结构后的气流速度在叶尖附近的最大增加幅度不超过4m/s；收油叶片叶根拐角处采用圆弧过渡且叶根延伸后的收油效率仅在低转速范围内略高于原始结构的收油效率，收油效率最大提升了1.03%；在此基础上增加阶梯结构并进一步延伸叶根后可在全部转速范围内提升收油效率，相对原始结构的收油效率最大可提升接近5.0%。

Abstract:

In order to study the internal flow of the under-race lubrication structure and optimize the oil scoop blade structure， a numerical calculation model was established according to the flow characteristics of the high rotating speed and strong swirl flow inside the under-race lubrication structure. The oil-gas two-phase flow of the original structure was analyzed and the loss mechanism of the oil was summarized. On this basis， the optimized and improved structure of the oil scoop blade was proposed. The effects of the different oil scoop blade structures on the internal flow and the oil capture efficiency of under-race lubrication were discussed in detail. The results show that the collision splash generated by the oil impacting the main shaft and the oil being thrown out along the oil scoop blade under the centrifugal action in the original structure are the reasons for the drop in oil capture efficiency. The maximum increase of air velocity near the blade tip of the optimized oil scoop blade structure is not more than 4 m/s. After the circular arc transition is adopted at the corner of the oil scoop blade root and the blade root is extended， the oil capture efficiency is only slightly higher than that of the original structure in the low rotating speed range， and the maximum oil capture efficiency increased by 1.03%. In the structure of adding a stepped structure and further extending the blade root， the oil capture efficiency can be improved in the entire rotating speed range， and the maximum oil capture efficiency can increase by nearly 5.0% compared with the original structure.