Study on the tooth profile design of twin-screw compressor derived from the line of action

• Main Authors: Kao Chih-Hong, 高志宏
• Other Authors: Fong Z.H
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/16494903960387343512

碩士 === 國立中正大學 === 機械系 === 93 === The leakage of rotors could be observed from the sealing line. The leakage is an important factor that influences the efficiency. Conventionally, the development of a twin screw rotor with high efficiency is started from designing a tooth profile. It is logical to observe the sealing line of the rotor to judge that the leakage is decreased or not. If the leakage is not decreased, modify the tooth profile till you obtain a good sealing line. Therefore, we try to develop a design process starts from the shape of the sealing line. Several segmented cubic splines are used to describe the sealing line. We develop a sealing line with little leakage and then use the sealing line to derive the equations of tooth profile. Control points on the sealing line are used as design variables. We can move the control points to change the shape of the sealing line and then derive the corresponding tooth profile of screw rotors. Using software to calculate the volumetric efficiency, isentropic indicated efficiency and average torque on male and female rotors. The tooth profiles are optimized by the isentropic indicated efficiency with the constraints of the transmitted torque, the minimum curvature of the tooth profile, etc. The design variables include the shape of the sealing line, tip radius, addendum, the ratio between rotor length and the outer diameter, and the wrap angle. A numerical example is presented to show the validation of the purposed design process.