Rapid calculation method for estimating static and dynamic performances of closed hydrostatic guideways

Abstract

Purpose The purpose of this paper is to establish a simplified model of the closed hydrostatic guideway for the rapid analysis of static and dynamic characteristics. Further, the influence of compressibility and dynamic frequency are taken into consideration in the new dynamic model. Design/methodology/approach The new model is based on the second kind of Lagrange equation. In this model, the closed hydrostatic guideway is supported by 12 pads, and each oil pad is equivalent to a nonlinear spring-damper system. The equivalent spring coefficient and damper coefficient of the oil pad are extracted by the three different equivalent methods. Finally, the validation experiments of step load response and dynamic stiffness are conducted on a hydrostatic guideway. Findings For solving the step response, the linear spring-damper model and the nonlinear spring-damper Model 1 are better than the nonlinear spring-damper Model 2. The accuracy of the three methods are very high for static stiffness calculation. For the calculation of dynamic stiffness, the nonlinear spring-damper Model 2 is better than the nonlinear spring-damper Model 1. The linear spring-damper model has low precision for dynamic stiffness calculation, especially at high frequency. The accuracy of the new model is validated by experiments. Originality/value The equivalent method of nonlinear spring-damper system has higher accuracy. Different equivalent methods should be adopted for different load types. The computational speeds of the new dynamic model with the three methods are much better than finite element method (about ten times).

Modeling and analysis on motion accuracy of hydrostatic guideways incorporating the manual lapping effect

“…While the explanations for the other symbols have been given in equation (15) similarly. Hence, as soon as the three motion errors at x A are acquired, then the vertical straightness error can be available through equation (17). The parameters involved in theoretical calculation and experiments have been illustrated in Table 1.…”

“…The LSE could even be extended to develop the analytical model for motion accuracy of aerostatic guideways, in which the air film was handled as an LSE. 15,16 Nonetheless, it is the fluid film stiffness that has been put into consideration only, according to Refs., 17–19 the fluid film damping should be concerned and incorporated together. (3) Flow Continuity Equation (FCE).…”

Influence of multisource errors of oil film contact surface on motion accuracy of hydrostatic guideway

“…To analyze the influence of oil film contact surface errors on the motion accuracy of the hydrostatic guideway, the hydrostatic guideway support to oil pad is typically treated as a linear spring-damper equivalent model (Wang et al , 2017). Khim et al (2014) simplified the opposed oil pad to a linear spring damping system and used the measured profile error of the guideway and the transfer function model to propose a 5-DOF (five degrees of freedom) motion error analysis model.…”

Simulation, Modeling and Experimental Research on the Thermal Effect of the Motion Error of Hydrostatic Guideways

“…Due to their high precision, high rigidity, and high load-bearing characteristics, the hydrostatic guideways are widely applied in the field of ultra-precision machine tools [7,8]. The friction pair interface of the hydrostatic guideway is separated by a layer of oil film, which avoids dry friction and abrasion.…”