润滑油黏度对液体静压导轨性能的影响

摘要

为了提高液体静压导轨的性能,采用5种牌号润滑油,定量分析了润滑油黏度对导轨性能的影响。首先,根据现场工况确定了导轨系统的初始设计参数,计算了不同温度、不同牌号润滑油的动力黏度；接着,基于导轨的力平衡方程及流量方程,建立了导轨系统总功率损失、静态性能、动态性能的线性化数学模型,以总功率损失、承载能力、静刚度、固有频率、调整时间和动刚度作为导轨系统的性能指标；最后,利用 MATLAB 软件分析了润滑油黏度对导轨性能的影响。研究表明：增大润滑油牌号(VG22→VG100),降低工作温度(60℃→10℃),润滑油黏度增大,导轨系统总功率损失由507.58W (VG22,60℃)降低至33.93W (VG100,10℃),承载能力、静刚度、固有频率恒定不变,调整时间由29.84μs (VG22,60℃)缩短至0.46μs (VG100,10℃),动刚度由173kN/μm (VG22,60℃)增大至10369kN/μm (VG100,10℃)。因此,增大润滑油的动力黏度,能降低导轨系统的功率损失,静态性能不受其影响,动态性能大大提高。%In order to improve the characteristics of a liquid hydrostatic slide,the influences of the viscosity of five different grades of hydraulic oil on the characteristics of the slide system were ana-lyzed quantitatively.First,based on the practical working conditions,the initial design parameters of the hydrostatic slide system and the dynamic viscosities of different brands of hydraulic oil at different temperatures were calculated.Then based on force balance equation and flow equation of the hydro-static slide,the linearized mathematical models of power loss,static performance and dynamic per-formance of the hydrostatic slide were established.Total power loss,bearing capacity,static stiff-ness,natural frequency,adj usting time,dynamic stiffness were regarded as the key performance inde-xes of the hydrostatic slide system.Finally,the influences of the hydraulic oil viscosity on the charac-teristics of ultra-precision hydrostatic slide system were simulated with MATLAB software.The re-sults indicate that as the grade of hydraulic oil increases (VG22→VG100)and the working tempera-ture decreases (60℃→10℃),the viscosity increases accordingly,and then the total power loss de-creases from 507.58W (VG22,60℃)to 33.93W (VG100,10℃),the bearing capacity,the static stiffness and the natural frequency remain constant,the adjusting time decreases from 29.84μs (VG22,60℃)to 0.46μs (VG100,10℃),and the dynamic stiffness increases from 173kN/μm (VG22,60℃)to 10 369kN/μm (VG100,10℃).So it is best to increase the viscosity of hydraulic oil in order to decrease the power loss and to improve the dynamic characteristics of hydrostatic slide sys-tem,but the static characteristics are not affected.