液体静压导轨定压供油式油腔承载力的超静定力学模型

Indeterminate Mechanics Model of Bearing Capacity of Constant Pressure Oil Pockets in Hydrostatic Slide

在机床液体静压导轨的设计计算中,准确计算各油腔的承载力是正确设计液体静压导轨系统的前提。目前液体静压导轨的油腔承载力的计算一般采用'平移外负载'的方法。不同的油腔布置形式对应不同的力学模型,使'平移外负载'的通用性较差。根据叠加原理,利用逆向思维,将定压供油式油腔的承载力分为6部分,分别承受外载荷的6个分量。导轨上油腔的布置较复杂时,油腔承载力的计算变成超静定问题。借鉴'弹性体'的求解方法,列出油膜的变形协调方程,将超静定问题转化成静定问题,进而求解出各油腔的承载力。将油腔承载力的6部分进行矢量叠加,推导出油腔承载力的最终求解方程。以工程中的回转工作台为范例进行计算,与实际的已测结果进行比较,验证了该方法的正确可行性。所做研究提供了定压供油式液体静压导轨油腔承载力的通用计算方法,并能借助计算机编程求解,提高了设计效率和精度。

In the design and the calculation of the hydrostatic slide in the machine tools, calculating accurately the bearing capacity of the oil pocket is a prerequisite. At present, the method of translating external load is commonly used to calculate the bearing capacity of the oil pockets. The mechanics model of translating external load varies with the various arrangements of the oil pockets, and then it possesses the poor commonality. Based on the superposition principle of force, the bearing capacity of the constant pressure oil pocket is divided into 6 parts, which sustains the direction component of the external load. When the arrangement of the oil pockets is complicated, the calculation of the bearing capacity of the oil pockets is the indeterminate problem. Borrowing the solution method of castle body, the compatibility equations of deformations for oil films are presented, and then the bearing capacities of oil pockets are derived. The six components of the oil pocket arc added up, and the final solution equations am derived. Take the rotary worktable used in the practical engineering for example, in comparison with on-site field measurement, the feasibility and correctness of the method are verified. The proposed research offers the general method for calculating the bearing capacity, which can be done with the help of the computer programs and can improve the design efficiency and the accuracy.