在一般迴轉工作台中，迴轉台的驅動系統多為非直驅式，因此有齒隙、齒輪匹配、需潤滑、反應速度慢等缺點，而且當工作平台遭受負載時，會產生油膜厚度變化，進而影響轉速。此外，液靜壓迴轉台會因加工精度、同步分流泵的分流不均及各油室節流器的壓力不同等問題，導致各油室油膜厚度不均。
本研究將針對傳統液靜壓迴轉台的缺失進行改善，針對油膜厚度不均勻的問題，將先使用同步分流泵進行初步分流，並在通往各個油室的管路上，使用比例壓力閥作初始油膜厚度的設定，進而使工作平台保持適當的油膜厚度及水平狀態，讓工作台能穩定的旋轉;另外，於迴轉驅動系統方面，本工作台將使用直驅式的可變量液壓馬達直接驅動工作台旋轉，以改善非直驅式馬達，有齒隙、齒輪匹配、需潤滑、反應速度慢等缺點，並且藉由改變排量來達到轉速控制與抵抗外部負載扭矩，同時藉由迴轉台的旋轉，補償因負載所造成的油膜厚度變化，藉由可變量液壓馬達速度控制的補償，能有效降低負載所帶來的油膜厚度變化。

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.

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