爪式液態泵浦之間隙與洩漏分析

Clearance and Leakage Analysis of a Liquid Pump with Claw Rotors

龔玲玉(Ling-Yu Kung)

指導教授 ： 鍾添東

國立臺灣大學/工學院/機械工程學研究所/碩士(2011年)

https://doi.org/10.6342/NTU.2011.02376

摘要

爪式轉子可廣泛應用於工業，譬如液態泵浦、真空泵浦以及壓縮機。兩嚙合轉子之體積效率依據兩轉子外型有關，也會影響泵浦效率。另一降低泵浦效率的重要因素是由於泵浦兩鄰近腔室之壓差以及轉子間隙所產生的洩漏。因此本論文提出爪式轉子的數學模型來描述其嚙合條件以及利用數值方法來計算轉子間隙。而洩漏量以及設計參數對泵浦的總流量的影響也將被討論。此外，為了避免過切情形，也會提及設計參數之合理範圍。接下來會提出一個以總流量為目標函數，設計參數之尺寸為限制條件之爪式轉子最佳化過程。最後，本研究撰寫一電腦運算程式完成上述之流程。

關鍵字

爪式轉子 ； 間隙分析 ； 洩漏分析 ； 最佳化設計

並列摘要

The claw type rotors have been widely used in many industries, such as liquid pumps, vacuum pumps, and compressors. Volumetric efficiency of two matching rotors depends on the two rotor profiles, and hence influences the pump efficiency. Another important factor that reduces the pump efficiency is the leakage due to pressure difference between two adjacent cavities, and also clearances between two rotors and the chamber wall. The mathematical model of the claw rotor profile is presented to describe the meshing condition and calculate the clearance between rotors by numerical method. The leakage flow rate and the effect of design parameters on total flow rate are investigated. Moreover, to avoid undercutting, the appropriate ranges of design parameters for the driving rotor profile are also derived. Finally, an optimization procedure for finding the best claw rotor parameters is presented with the total flow rate as the object function and sizes of design parameters as constraints. A computer program for performing above-mentioned calculation is developed to fulfill the research requirement of claw rotor pumps.

並列關鍵字

Claw rotor ； clearance analysis ； leakage analysis ； optimum design

參考文獻

[1] Dearn, R., ‘‘The fine art of gear pump selection and operation,’’ World Pumps, pp. 38-40, 2001.

[2] Liu, H. C., Tong, S. H. and Yang, D. C. H., ‘‘Trapping-free rotors for high-sealing lobe pumps,’’ ASME Journal of Mechanical Design, vol. 122, no. 4, pp. 536–542, 2000.

[5] Hsieh, C. F., “A study of the geometric design and gas port of the claw-type rotor,” Proc. IMechE, Part C: J. Mechanical Engineering Science, vol. 223, no. 9, pp. 2063-2069, 2009.

[7] Fong, Z. H., Huang, F. C. and Fang, H. S., “Evaluating the inter-lobe clearance of twin-screw compressor by the iso-clearance contour diagram,’’ Mechanism and Machine Theory, vol. 36, pp. 725-742, 2001.

[10] U.S. patent 5,667,370, “Screw vacuum pump having a decreasing pitch for the screw members,” 1997.