Abstract: 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 eastic 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 are added up, and the final solution equations are 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.

Key words: Compatibility equations of deformation, Elastic body, Hydrostatic slide, Indeterminate problem, Superposition principle