Search

Reliable operating conditions of hydrostatic turntables are prerequisite to ensuring machine tool performance. The hydrostatic turntable is affected by multiple working conditions, therefore, methods for evaluating turntable load-carrying capacity has become research hotspot. In this paper, by analyzing bearing capacity, parameters closely related to the support performance of turntables are selected as recognition features and an artificial neural network (ANN) training method is proposed. The ANN method is based on numerical solutions of over-determined nonlinear equations (ODNE) to intelligently evaluate turntable performance. In this study, ANN and ODNE training are applied to evaluate the performance of hydrostatic turntables. Finally, to verify the feasibility of the method, an intelligent monitoring system is established to collect data on machine tools.

Purpose This paper aims to study the nonlinear supporting performance of hydrostatic ram under the impact of cutting force and search for an optimal solution to improve its stiffness. Design/methodology/approach The Reynolds equation was applied to resolve the carrying capability of a single oil pad numerically, and an iteration method was used to analyze the nonlinear supporting force and stiffness of a pair of oil pads placed face-to-face. The total offset of ram could be obtained after the displacement of aspectant oil pads was solved by the bisection method. From the comparison of the offset values of ram evaluated under different support conditions, the optimal solution was determined. Findings In this study, an optimized oil supply allocation, concluded as 1.16:0.84, is proposed to improve the performance of hydrostatic ram supporting structure. Originality/value The supporting performance of hydrostatic ram could be improved by appropriate allocation of oil supply without extra energy consumption.

Analyzing of nonlinear carrying performance of hydrostatic ram is among key research questions to improve heavy machine tools because the machining precision will be directly influenced by it. A dynamic model of nonlinear supporting characters for hydrostatic ram is developed in this work. Modified Reynolds equation is resolved by finite difference method numerically to determine the carrying capability. Dynamic equilibrium equation of hydrostatic ram under cutting force impact is solved by Runge–Kutta method to obtain the variation of tool tip position and evaluate the machining accuracy. An optimal oil supply rate allocation and oil pad size is proposed to improve the static and dynamic performance simultaneously based on method of bisection.

Hydrostatic systems are considered as essential supporting structures in heavy machine tools. The calculations and analyses for hydrostatic bearings are always laborious because of the involvement of several disciplines such as elastic mechanics, hydromechanics, thermodynamics, and other factors in the design. It is well known that large data and cloud technology are capable of processing and transmission of hydrostatic system studies. In this work, a cloud manufacture model is presented to provide big data storage, transmission, and processing platform for designers, manufacturers, and users of hydrostatic bearings. All participants involved in the manufacturing were linked together by timely information communication in order to ensure that the customized products met with the actual conditions in the cloud server. Based on the actual requirements of the user, the carrying capacity of hydrostatic system was analyzed by a designer using finite difference method and the results were sent to the manufacturer for machining of components. The monitored data from the consumer could be fed back to the designer for performance evaluation through the cloud server. It was found that customized manufacturing tasks could be finished more reliably and efficiently if all participants exchanged the data through cloud platform in real time.

Hydrostatic bearing is a key part that provides precision and long life to machine tools. It is one of the embodiments of tribology, mechanics, optimization method, and structural design in engineering practice. Articles about hydrostatic bearings since 1990 are collected in this review. Researching status is evaluated in two aspects: basic theory and typical application. This article presents a review of research articles related to introducing developments in hydrostatic bearings. Basic theory contains equations and analysis methods which include analytic, numerical, and experimental methods. Typical applications are based on rectangular oil pad, circular oil pad, and journal bearings. Moreover, this article focuses on the analysis of the relevant model, solution, and optimization and summarizes the hotspots and development directions.