A Method for Predicting Motion Error of Internal Feedback Hydrostatic Turntable Under Eccentric Load

This paper proposes a method to analyze motion errors in a five-degree-of-freedom hydrostatic turntable with internal feedback under eccentric load. The motion error models of thrust and journal bearings are derived separately, revealing the mechanism of the influence of manufacturing errors of thrust plate and shaft on motion errors. The results demonstrate that the hydrostatic oil film exhibits an error averaging effect. When the amplitude of the mating surface error reaches 15 μm, the corresponding linear deviation of the turntable remains below 0.3 μm, indicating that the oil film can effectively suppress the transmission of manufacturing errors. However, the pressure oil film cannot completely balance the errors on the film binding surface, especially when the amplitude of the binding surface error is larger, resulting in a weaker ability of the oil film to balance.