高速精密电主轴静压滑动轴承设计及性能分析

Design and performance analysis of hydrostatic plain bearings for high-speed precision electrospindle

针对智能产线数控加工中心的需求,对电主轴支撑轴承进行了设计,设计的轴承为四油腔静压滑动轴承,核心设计参数包括内径、封油面宽度、回油槽宽度、节流比及半径间隙等。建立了静压轴承支撑刚度的计算模型,计算获得设计轴承在载荷为100~700 N时的刚度值为6.0×107~10.2×10^(7)N/m。分析了封油面宽度、回油槽宽度、节流比和半径间隙对刚度的影响,对轴承设计参数进行了优化,优化后轴承的刚度值为11.4~29.8×10^(7)N/m。进行了轴承的静刚度测试,载荷为100~700 N时水平刚度为3.1×107~25×10^(7)N/m、垂直刚度为2.5×10^(7)~23×10^(7)N/m。研究结果表明:封油面宽度和半径间隙对静压轴承刚度影响较大,是重要的设计参数;刚度试验测试值比理论计算值偏小,原因可能是制造和装配误差导致的轴承节流器、油腔等结构的性能对尺寸误差较为敏感导致。

In response to the needs of intelligent production line CNC machining center,a electrospindle support bearing was designed,the design bearing is a four-cavity hydrostatic plain bearing,and the core design parameters include inner diameter,oil sealing surface width,oil return groove width,throttle ratio and radius clearance.A calculation model of the support stiffness of hydrostatic bearings was established,and the stiffness value of the design bearing at a load of 100~700 N was calculated to be 6.0×10^(7)~10.2×10^(7)N/m.The effects of oil sealing surface width,oil return groove width,throttle ratio and radius clearance on stiffness were analyzed,and the bearing design parameters were optimized,and the stiffness value of the optimized bearing was 11.4~29.8×10^(7)N/m.The static stiffness test of the bearing was carried out,and the horizontal stiffness was 3.1×10^(7)~25×10^(7)N/m and the vertical stiffness was 2.5×10^(7)~23×10^(7)N/m when the load was 100~700 N.The results show that the width of the oil sealing surface and the clearance of the radius have a great influence on the stiffness of hydrostatic bearings and are important design parameters.The stiffness test test value is smaller than the theoretical calculation value,which may be caused by manufacturing and assembly errors caused by the performance of bearing throttle,oil cavity and other structures being more sensitive to dimensional errors.