以流量控制靜壓軸承等膜厚之探討

Study in Flow Control for Constant Film of Hydrostatic Bearing

10.6840/cycu201700838

張協興

油靜壓軸承 ； 定量泵 ； 流量控制 ； 等膜厚 ； hydrostatic bearing ； quantitative pump ； flow control ； constant film

中原大學機械工程學系學位論文

2017年

碩士

康淵;張永鵬

繁體中文

液靜壓軸承被使用在旋轉刀具主軸、工作頭、直線導軌、導螺桿、迴轉台導軌，蝸桿蝸輪以及蝸桿齒條；以外部加壓的油膜支撐著旋轉的主軸或是工作台。作為靜壓軸承其提供了比滾動軸承及空氣軸承更大的承載力及更高的剛度和制振阻尼，比硬軌及滾動軸承有更低的摩擦係數及更高的精度與壽命，比動壓軸承有更好的迴轉精度以及零扭矩啟動能力。但是液靜壓軸承仍然有先天上的優點沒有發揮出來，而基本上與硬軌、滾動軸承、動壓軸承及空氣軸承有相同的缺點，其包括膜厚隨負荷增加而減少造成剛度不足以及非均勻負荷造成水平失準，潤滑油黏度係數隨溫度改變造成流量變化進一步造成膜厚的變化，抵抗動態負荷之反應時間太長影響精度表現；同時，靜壓軸承系統的設計由所需軸承特性以分析方法建立軸承幾何尺寸、節流器之型式及幾何尺寸以及液靜壓軸承系統的物理參數；但是製作組裝後的實際軸承特性參數與設計的特性參數有一定的差異，因此需要一套鑑別方法得到實際的特性參數；這些參數若不是理想值，則須建立一套方法校準幾何尺寸去滿足特性參數之理想值，以確保實際的液靜壓軸承系統特性參數。 本文以靜壓閉式軸承油膜厚度保持不變化及全體油膜均一為目標，探討控制定量泵轉速之流量控制解決膜厚不均勻及膜厚隨負荷而變的問題，以閉式軸承工作平台上四個點之位移及八個油腔之壓力、流量、馬達轉速作為回饋信號，並建立流量補償液靜壓軸承的控制方法，根據設計整體控制迴路使工作台保持水平且穩定不變。本文以LabView軟體建立感測與控制的人機介面，以感測器回饋訊號後，人機介面計算出流量差值進行補償，達到等膜厚控制。

Hydrostatic bearings are used in tool spindle, working head, linear guides, lead screw, rotary table slideway, worm-gear and worm-rack, where the spindle or worktable is supported by the external pressurized lubricant film. As a hydrostatic bearing which provides greater load capacity, higher stiffness and vibration damping than rolling bearings and air bearings, and has lower friction coefficient, greater accuracy and longer life than the hard guides, its rotation accuracy is better than hydrodynamic bearings and zero torque starting capacity. However, there are still innate advantages of hydrostatic bearings did not been developed. Basically, the hydrostatic bearings have the same drawbacks as the hard guides, rolling bearings, hydrodynamic bearings and air bearings, including decreases in the film thickness and stiffness with increased load, and non-uniform load causes the worktable or spindle tilt, and the lubricant viscosity varies with temperature change make the lubricant flow change and further more cause the film thickness changed, and the reaction for resisting to dynamic loads is too slow decreasing the accuracy. Therefore, this project proposes to establish the identification methods, calibration methods and control method to keep constant film thickness for hydrostatic bearing systems and level of worktable. The design of hydrostatic bearing system will be applying the analytical methods to establish bearing geometry, restrictor type and geometry and the physical parameters of the hydrostatic bearing system by according to the required bearing characteristics. But there are some differences between the actual bearing characteristic parameters after manufactured and assembled and the design features. In this paper, hydrostatic bearing oil film thickness does not change and the whole oil film uniform as the goal, to discuss the control of the displacement pump speed control to solve the film thickness uneven and the thickness of the load with the variable to the closed bearing work platform four Point of the displacement and eight oil sills pressure, flow, motor speed as a feedback signal, and the establishment of hydrostatic bearing control method, according to the design of the overall control loop to keep the work table stability. In this paper, the LabView software is used to establish the human-machine interface of sensing and control, to calculate the feedback and control the flow, to achieve equal thickness control.

1. 1.Heller, Stanley, and Wibur Shaprio, “A Numerical Solution for the Incompressible Hybrid JournalBearing With Cavitation” Journal of Lubrication Technology, Transactions of the ASME, Vol. 91, No.3, pp.508-515 (1969).
   連結：
2. 2.O’Donoghue, J. P., Rowe, W. B., and Hooke, C. J., “Design of Hydrostatic Using An OperatingParameter,” Wear, Vol. 14, pp.355-362 (1969).
   連結：
3. 3.Rowe, W. B., O’Donoghue, J. P., and Cameron, A., “Optimization of Externally Pressurized Bearingsfor Minimum Power and Low Temperature Rise,” Tribology, Vol. 3, No. 3, pp.153-157 (1970).
   連結：
4. 4.Ghosh, B., “An Exact Analysis of a Hydrostatic Journal Bearing With a Large Circumferential Sill,”Wear, Vol. 21, pp.367-375 (1972).
   連結：
5. 5.Ghosh, B., “Load And Flow Characteristics of Capillary-Compensated Hydrostatic Journal Bearing,”Wear Vol. 23, pp.377-386 (1973).
   連結：
6. 6.Malanoski, S. B. and A. M. Loeb, “The effect of the method compensation on hydrostatic bearingstiffness,” Transaction of the ASME, Journal of Basic Engineering, vol. 83, no. 2, pp. 179-187, 1961.
   連結：
7. 7.Kang, Y., Lee, J. L., Huang, H. C., Lin, C. Y., Lee, H. H., Peng, D. X., Huang, C.-C., “Design for static stiffness of hydrostatic plain bearing: constant compensations,” Industrial Lubrication and Tribology.
   連結：
8. 10.Sharma, S. C., S. C. Jain, and D. K. Bharuka, “Influence of recess shape on the performance of acapillary compensated circular thrust pad hydrostatic bearing,” Tribology International, vol. 35, pp.347-365, 2002.
   連結：
9. 11.Wang, D., “Hydrostatic slideway and its design research,” Lubrication Engineering, no. 4, pp. 114-118,2004.
   連結：
10. 12.張永鵬，陳鎮憲，李建霖，周先慬，康淵，2010“封閉式圓形靜壓平支承使用定補償之工作台動態特性＂先進工程學刊5(4), pp. 391-397。
    連結：
11. 13.Moris, S. A., “Passively and actively controlled externally pressurized oil-film bearing,” Trans. ASME,Ser. F, vol. 94, 1972.
    連結：
12. 15.Cusano, C., “Characteristics of externally pressurized journal bearings with membrane type variableflow restrictor as compensating element,” IMechE, no. 188, pp. 36-527, 1974.
    連結：
13. 17.Lewis, G. K., “The stiffness and static of compensated hydrostatic cylindrical-pad bearing,” Proceedings of the Institution of Mechanical Engineers, vol. 198, no. 16, pp. 285-292, 1984.
    連結：
14. 18.Kang, Y., Chen, C. H., Lee, J. L., Chen, J. H., Chang, Y. P., 2010, ”Foresight in static stiffness of hydrostatic bearings with various compensations by film gradient versus recess pressure,” IndustrialLubrication and Tribology 62(5), pp. 304-319.
    連結：
15. 20.Kang, Y., Chou, H. C., Wang, Y. P., Chen, C. H., Weng, H. C., 2013, “Dynamic behaviors of a circularworktable mounted on closed-type hydrostatic trust bearing compensated by constant compensations,”Journal of Mechanics 29(1), pp. 1-12.
    連結：
16. 21.Kang, Y., Hu, S. Y., Chen, S. C., Chang, Y. P., 2013, “Dynamic Characteristics of the Spool-type Constant-Flow Valves,” Journal of Advanced Mechanical Design, Systems, and Manufacturing 7(2), pp.156-170.
    連結：
17. 22.Kang, Y., Peng, D. X., Lee, H. H., Hu, S. Y., Chang, Y. P., 2013, “Investigations of constant-flow valves
    連結：
18. 23.Kang, Y., Peng, D. X., Lee, H. H., Hu, S. Y., Chang, Y. P., 2013, “Investigations of constant-flow valves for hydrostatic bearings,” Industrial Lubrication and Tribology 65(6) pp. 379-389.
    連結：
19. 24.Kang, Y., Peng, D. X., Hung, Y. H., Hu, S. Y., Lin, C.-S., 2014, "Design for Static stiffness of hydrostatic bearings: double-action variable compensation of membrane-type restrictors and self compensation," 66(2), Industrial Lubrication and Tribology, pp. 322-334.
    連結：
20. 25.Kang, Y., Yang, D. W., Hu, S. Y., Hung, Y. H., Peng, D. X., Chen, S. K., 2014, “Design for static stiffness of hydrostatic bearing: double-action variable compensation of spool-type restrictors,” Industrial Lubrication and Tribology 66(1), pp. 83-99.
    連結：
21. 26.Hsiao, S.T., Kang, Y.*, Jong, S. M., Lee, H. H., Chang, Y. P., 2014, “Static analysis of hydrostatic conical bearings using flow resistance network method,” Industrial Lubrication and Tribology, 66(3), pp. 411-423.
    連結：
22. 27.Kang, Y., Hu, S. Y., Chang, Y. P., Wang, T. P., 2015, “Identification of characteristic parameters for hydrostatic bearings,” Journal of Mechanics 31(2), pp. 227-240.
    連結：
23. 8.Telingater, V. S., “Hydrostatic slideways using standard bearings,” Machines and Tooling, vol. 24, pp.15-20, 1972.
24. 9.Rohde, S. M. and H. A. Ezzat, “On the dynamic behavior of hybrid journal bearings,” Transaction of the ASME, Journal of Lubrication Technology, vol. 98, no. 1, pp. 90-94, 1976.
25. 14.Ingert, G. kh. and B. G. Lur’e, “Dynamic stiffness of hydrostatic slides,” Machines and Tooling, vol. 44,no. 8, pp. 28-32, 1973.
26. 16.孟心齋，「毛細管節流開式液體靜壓導軌油膜厚度─載荷特性的分析與改善特性的措施」，洛陽農機學院學報，第1期，第87-99頁，1981。
27. 19.Kang, Y., Hu, S. Y., Chou, H. C., Lee, H. H., 2012, “Dynamic Characteristics of the DSI-typeConstant-Flow Valves,” Journal of Advanced Mechanical Design, Systems, and Manufacturing 6(4),456-463.