A Study on Oil Film Thickness Control in Hydrostatic Rotary Machine Driven by a Variable Hydraulic Motor

• Main Authors: Wei-TaiChu, 褚偉泰
• Other Authors: Ming-Chang Shih
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/11366000694685034924

碩士 === 國立成功大學 === 機械工程學系 === 103 === In a general hydrostatic guideway rotary working table system, the rotary driving system is usually not a direct type, so there are some disadvantages like backlash, the gear matching, lubrication, slow response and other shortcomings. When external load applied on the table, the oil film thickness will be decreased, so the rotary speed will be affected. Moreover, the initial oil film thickness of each chamber are not the same due to manufacture precision of hydrostatic guideway, unequal oil from spilt-flow dividers and uneven pressure of each restrictor. This study will improve the lacks of traditional hydrostatic guideway rotary system. One will use relief valves to regulate the initial oil film thickness and let it be the same. For the rotary driving system, one will use a variable displacement hydraulic motor as a direct type driving system to improve the lacks of a general non-direct one. By regulating the displacement of a hydraulic motor with a self-tuning fuzzy controller, one can control the rotary speed of working table and resist external load. Moreover, when external load applying to the table, it will decrease oil film thickness. With speed control compensation, it will improve the change of oil film thickness. The experimental results show that the variable hydraulic motor can resist external load and let the working table rotate at constant speed. When an eccentric load applies on the table, the variable motor will compensate the load torque and decrease the change oil film thickness.