The Recent Patents on Design and Investigation of Hydrostatic Spindle

Background: With the continuous improvement of spindle speed, and the occurrence of problems, such as chattering, the hot bite of bearings or premature bearing failures during high-speed rotation are gradually exposed. Objective: The purpose of this paper is to explore the problem of premature failure of hydraulic dynamic- static bearing caused by temperature rise and vibration at high speed. Methods: The hydraulic dynamic-static spindles are taken as the research objects, and the spindles, static pressure bearings, and oil system are carried out based on theoretical analysis design. MATLAB is used to establish the mathematical model of hydraulic dynamic-static bearing, and thus the bearing gap and the diameter of small holes are determined. ANSYS is used to carry out static and thermodynamic simulation analysis of the main shaft and dynamic and static pressure bearings. In addition, the temperature rise, rotation accuracy, and overall vibration, amplitude fluctuation and vibration power of the spindle system are mainly tested, studied, and analyzed. Results: The highest temperature area of hydraulic dynamic-static bearings is mainly distributed around the oil cavity inside the bearing and the bearing end surface; the speed of the spindle system continues to increase, the rate of temperature rise accelerates, and the temperature stability range also rises. At the same time, the vibration frequency is also increasing, and the operation is unstable during the acceleration process. The rotation frequency of the spindle fluctuates greatly, but the vibration amplitude is within the accuracy range. Conclusion: The obtained parameters will provide references for hydraulic dynamic-static spindle design and reducing the design cycle.