Research On Temperature Field And Deformation Field Of Large-Scale Constant-Current Hydrostatic Bearing

Heavy CNC machine tools are being used as the main equipment in heavy manufacturing industry of state in parts machining which with large diameter and rotating surface. Accompanied with high speed cutting technology, requirement for bearing performance keeps rising. Heavy hydrostatic thrust bearing suits well in high requirements for load, rigidity, stability and others, and it is being widely adopted in all kinds of heavy CNC machine tools. In hydrostatic bearing operation, thermal deformation which caused by temperature uneven distribution and mechanical deformation which caused by the weight of its own could impacts a serious effect on machining accuracy, and might produces a serious hazard. Aiming to improve accuracy and efficiency of machining, to solve the deformation problem of hydrostatic bearing, make deformation law clear is an inevitable step in hydrostatic bearing operation.Based on method and typical experiment of heat transfer theory, Convective heat transfer process of rotating workbench and base of hydrostatic bearing are analyzed and reasonably simplified separately. Convective heat transfer coefficient of rotating workbench and base were solved respectively through appropriative mathematical models. Further more, based on heat conduction theory, heat conduction equations and finite element model of hydrostatic bearing are established, of the heat transfer equations and the finite element model, temperature field of rotating workbench and base are numerical simulated respectively by using software ANSYS Workbench, selecting heat-structure coupling unit and defining reasonable boundary conditions. The results show that accompanied with the rising of rotating velocity, average temperature of rotating workbench gradually descended, but heat concentration on the workbench is more serious; In contrast, heat concentration emergences gradually on the lateral of base. In order to study the influence of deformation field on performance of heavy hydrostatic bearing, the research of deformation field is divided into three parts: deformation field research: thermal deformation field caused by rising of bearing temperature, mechanical deformation caused by bearing load and thermal-mechanical coupled deformation field. The deformation fields are numerically simulated after defining the boundary conditions, periodicity and fixed-side constraints. The results of coupled deformation field show that: the coupled deformation presented a wedge-shaped open outward as a whole by the effect of thermal joint with mechanical, whose deformation trend similar to the thermal deformation.Thermal effect and deformation law of hydrostatic bearing is obtained through numerical simulation of temperature field and coupled deformation of hydrostatic bearing. Not only prediction of large hydrostatic thrust bearing performance can be realized by the results, but also a theoretical basis for thermal structural designing and deformation problem resolving of hydrostatic bearing can it be provided by the results.