文档介绍：Available online at hanism
and
Machine Theory
Mechanism and Machine Theory 43 (2008) 695–711
ate/mechmt
Improved rotor profiling based on the arbitrary sealing line
for twin-pressors
Yu-Ren Wu, Zhang-Hua Fong *
Department of Mechanical Engineering, National Chung-Cheng University, No. 168, University Rd., Min-Hsiung,
Chia-Yi 621, Taiwan, ROC
Received 9 May 2007; received in revised form 21 May 2007; accepted 25 May 2007
Available online 16 July 2007
Abstract
A design method for the rotor profile of twin-pressor from an arbitrary sealing line is presented. The sealing
line is divided into several functional segments that control the high-pressure side and the low-pressure side performances
independently. Each functional segment is fitted by cubic spline and the shape of the segment can be adjusted by moving
the control points of the cubic spline. Based on the shape of the sealing line, the performance of pressor can be
directly calculated and the corresponding rotor profiles are derived considering the non-undercutting condition. A numer-
ical example which considers the geometric constraints of rotor profiles is presented to demonstrate the flexibility and sta-
bility in parametric study of the rotor design.
Ó 2007 Elsevier Ltd. All rights reserved.
Keywords: Twin-pressor; Sealing line; Rotor profile
1. Introduction
Twin-pressors are rotary positive displacement machines capable of high speed operation over a
wide range of operating pressures and flow rates with high efficiencies. The explode view and sectional graph
of a typical twin-pressor as shown in Fig. 1. Male rotor and female rotor are meshing with each
other in opposite rotation direction, wherein the sealing line on the transverse plane is a projecting curve
of the instant contact line between two rotor surfaces.
In the conventional rotor tooth profile design process [1–4], the designer first generates the rotor profiles
and then calculates the instant contact line and project