新型动静压转台承载特性分析及结构改进

The Analysis of New-type Hybrid Rotary Table's Carrying-capacity Characteristics and Structure Improvement

提出了一种新型动静压转台的设计概念,油腔结构包括扇形静压油腔和螺旋油楔动压油腔,这种转台可用于重型车床、大齿轮加工机床等重型、大型精密机械。综合考虑雷诺方程和流量连续性方程,采用有限元法对螺旋油楔的油膜压力分布进行了计算,建立了转台承载特性计算模型。在分析过程中发现当转台负载较大油膜厚度较小时存在静压腔进入的流量小于动压油楔泄漏量的问题,针对该问题对静压腔结构进行了改进,并计算了一定工作条件下静压腔封油面与动压油楔封油面高度差的临界值,高度差大于该临界值时可以解决动压油楔供油不足的问题,研究了该临界值随转速变化的规律,为该种结构转台的设计提供了参考。

A new concept of hydrodynamic-static hybrid rotary table is proposed in this paper including fanshaped oil recess and spiral oil w edge. This type of rotary table can be applied on large-scale precision machine such as heavy-duty lathe and large gear processing machine tool. The oil's pressure on the spiral oil w edge is calculated using the finite element method Considering Renolds equation and flow continuity equation,the mathematical modeling of rotary table's carrying capacity is established. It is discovered that the flow rate of oil recess is smaller than that of spiral oil w edge w hen the load is huge. In order to solve the problem the structure of oil recess is improved. The critical value of height difference betw een the oil seal surface of oil recess and spiral oil w edge is calculated. When the height difference is greater than the critical value the problem can be solved. The influence of rotating speed on the critical value is also researched,w hich could provide a reference for the design of this kind of rotary table.