Coordinate transformation of screw rotor profile in different cross sections

Vacuum ◽  
2021 ◽  
pp. 110494
Author(s):  
Shuyi Gan ◽  
Qingzhou Yu ◽  
Qing Cao ◽  
Jun Zhang ◽  
Bin Li
Keyword(s):  
Cross Sections ◽  
Coordinate Transformation ◽  
Rotor Profile ◽  
Screw Rotor

Study of a screw rotor with different stocks and leads for a twin-screw multiphase pump

2009 ◽  
Vol 223 (11) ◽  
pp. 2637-2645 ◽  
Author(s):  
F Cao ◽  
T Gao ◽  
J Jiao ◽  
T Pan ◽  
Z Xing
Keyword(s):  
Dominant Role ◽  
Contour Plot ◽  
Leakage Flow ◽  
Normal Height ◽  
Plot Analysis ◽  
Rotor Profile ◽  
Twin Screw ◽  
Screw Rotor ◽  
Flow Through ◽  
Multi Phase

Rotor profile generation and geometry characteristics play a dominant role in developing twin-screw multi-phase pumps. The aim of this work is to present mathematical procedures to calculate screw rotor profile generation, design rotor cutter tools, and rotor geometry characteristics with given stocks for twin-screw multi-phase pumps. Analyses of the profile generation of a screw rotor for a multi-phase pump are carried out. The resulting rotor profile with different stocks is developed on the basis of the calculation of the forming cutter tool profile. An iso-height contour plot is presented for describing the shape and size of the overlapped cavity of the rotors. By inspecting the iso-height contour plot, analysis of all the possible leakage flow through the inter-lobe clearance is performed. According to the iso-height contour plot, the blowhole provides the major leakage path for the basic chambers through the overlapped cavity. The minimum normal height of the overlapped cavity has a linear relationship with the stock. The larger stocks lead to greater leakage and reduce pump performance. The leakage flow through the overlapped cavity will be aggravated and the performance of the twin-screw multi-phase pump will decline with the increasing lead of the screw rotor.

A mathematical model of the rotor profile of the single-screw compressor

2002 ◽  
Vol 216 (3) ◽  
pp. 343-351 ◽  
Author(s):  
S-C Yang
Keyword(s):  
Mathematical Model ◽  
Parameter Family ◽  
Cutting Edge ◽  
Screw Compressor ◽  
Single Screw ◽  
Rotor Profile ◽  
The Family ◽  
Screw Rotor ◽  
The One ◽  
Screw Rotors

This paper presents a method for determining the basic profile of a single-screw compressor including a gate rotor and a screw rotor. The inverse envelope concept for determining the cutting-edge curve of the gate rotor is presented. Based on this concept, the required cutter for machining the screw rotor can be obtained by an envelope of the one-parameter family of obtained screw rotors. The obtained screw rotor is an envelope of the family of gate rotor surfaces. Let the obtained envelope of the one-parameter family of gate rotor surfaces become the generating surface. The inverse envelope can be used to obtain the envelope of the family of generating surfaces. Then, the profile of the gate rotor with the cutting-edge curve can be easily obtained. The proposed method shows that the gate rotor and the screw rotor are engaged along the contact line at every instant. This is essential to reduce the effect of leakage on compressor performance. In this paper, a mathematical model of the meshing principle of the screw rotor with the gate rotor is established. As an example, the single-screw compressor for a compressor ratio of 11:6 is determined with the aid of the proposed mathematical model. Results from these mathematical models should have applications in the design of single-screw compressors.

Virtual Design and Structural Optimization of Dry Twin Screw Vacuum Pump with a New Rotor Profile

2009 ◽  
Vol 16-19 ◽  
pp. 1392-1396 ◽  
Author(s):  
Shi Wei Zhang ◽  
Zhi Jun Zhang ◽  
Cheng Hai Xu
Keyword(s):  
Structural Optimization ◽  
Three Dimensional ◽  
Vacuum Pump ◽  
Vacuum System ◽  
Virtual Design ◽  
Three Dimensional Modeling ◽  
Rotor Profile ◽  
Twin Screw ◽  
Screw Rotor ◽  
Involute Curve

Twin screw vacuum pump is an important kind of dry vacuum pump, which is widely used in the oil-free vacuum system. The design of the screw rotor profile directly influences the working performance and manufacture cost of the screw pumps. In this paper, a new rotor profile for twin screw vacuum pump is introduced which is comprised of the cycloid curve, the dedendum circle arc, the involute curve and the addendum circle arc. The processes of three-dimensional modeling, motion simulation, interference checking and structural optimization for twin screw vacuum pumps are studied by means of Solidworks software. The works provide theoretical basis for optimal designing and reference for test prototype manufacturing. The results showed the performance of the vacuum pump according with the designer’s intention.

Development and Optimization of Screw Machines With a Simulation Model—Part II: Thermodynamic Performance Simulation and Design Optimization

1997 ◽  
Vol 119 (3) ◽  
pp. 664-670 ◽  
Author(s):  
K. Hanjalic´ ◽  
N. Stosˇic´
Keyword(s):  
Fluid Flow ◽  
Control Volume ◽  
Performance Simulation ◽  
Design Procedures ◽  
Rotor Profile ◽  
Screw Machine ◽  
Twin Screw ◽  
Fluid Properties ◽  
Screw Rotor ◽  
Tip Radius

This paper presents a method for the design of twin screw compressors and expanders, which is based on a differential algorithm for defining the rotor profile and an analytical model of the fluid flow and thermodynamic processes within the machine. Part I of the paper presents a method for screw rotor profile generation which simplifies and improves design procedures. An example is given of its use in the development of a new “N” rotor profile, which is shown to be superior to other well-known types. Part II describes a numerical model of the thermodynamic and fluid flow processes within screw machines, which is valid for both the compressor and expander modes of operation. It includes the use of the equations of conservation of mass and energy applied to an instantaneous control volume of trapped fluid within the machine with allowance for fluid leakage, oil or other fluid injection, heat transfer, and the assumption of real fluid properties. By simultaneous solution of these equations, pressure-volume diagrams may be derived of the entire compression or expansions, process within the machine. The procedure has been developed over a period of fifteen years and validated with experimental results obtained from both reciprocating and screw compressors and screw expanders, some of which are included. The rotor profile generation processor, thermofluid solver and optimizer, together with preprocessing facilities for the input data and graphical post-processing and CAD interface, have been incorporated into a design package which provided a suitable tool for analysis and optimization of twin screw machine design. An example of its use is given in the optimization of the gate tip radius of a selected compressor design.

Novel laser triangulation measurement method for screw rotor profile under multi-factor constraints

Measurement ◽  
2020 ◽  
Vol 152 ◽  
pp. 107317 ◽  
Author(s):  
Bin Yao ◽  
Zhiqin Cai ◽  
Jie Lu ◽  
Xiaofan Ma ◽  
Binqiang Chen
Keyword(s):  
Measurement Method ◽  
Laser Triangulation ◽  
Rotor Profile ◽  
Screw Rotor

scholarly journals Profile Design Method of Twin-Screw Compressor Rotors Based on the Pixel Solution

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Zhihuang Shen
Keyword(s):  
High Precision ◽  
Design Method ◽  
Base Point ◽  
Surface Boundary ◽  
The Best Approximation ◽  
Rotor Profile ◽  
Twin Screw ◽  
Screw Rotor ◽  
Point Set ◽  
Data Point

A new design method based on pixel solution is proposed to achieve an efficient and high-precision design of a twin-screw rotor profile. This method avoids the complex analytic calculations in the traditional envelope principle. The best approximation of the pixels of the rotor conjugate motion sweeping surface in the lattice screen pixels is illuminated using a specific color. The sweeping surface of the screw rotor single-tooth profile is roughly scanned to capture the base point set of the sweeping surface boundary pixels. The chord length and tilt angle of each interval are calculated using the value of the base point set to adjust the position, phase, and magnification of each interval sweeping surface. Each interval sweeping surface is finely scanned to capture the data point set of the subinterval, and then the data point set is converted to the same coordinate system to generate the conjugated rotor profile. Finally, an example is used to verify the feasibility and adaptability of this method. The approach provided can be used to design screw rotor profiles with high precision.

scholarly journals A correction method of screw rotor profile error based on parameter adjustment for grinding wheel dresser

2018 ◽  
Vol 10 (9) ◽  
pp. 168781401879897 ◽  
Author(s):  
Lijia Tao ◽  
Yu Xing ◽  
Mingxin Yuan ◽  
Sijie Chen
Keyword(s):  
Correction Method ◽  
Numerical Control ◽  
Grinding Wheel ◽  
Profile Error ◽  
Dressing Method ◽  
Parameter Adjustment ◽  
Rotor Profile ◽  
Wheel Profile ◽  
Screw Rotor ◽  
Screw Rotors

Accuracy of grinding wheel profile that is generated by form grinding theory and formed by grinding wheel dresser is a crucial factor affecting profile accuracy of screw rotors. A correction method for screw rotor profile error based on parameter adjustment for grinding wheel dresser such as diameter and distance of diamond rollers is proposed. Influence of diameter and distance of diamond rollers on grinding wheel profile and screw rotor profile based on theory of segmented dressing method is analyzed, and the adjustment method for parameters of grinding wheel dresser is presented. The results of the analysis provide a theoretical basis for error correction in screw rotor grinding. Grinding experiments for female rotor were performed due to the character that the female rotor has smooth bottom profile where the change of profile error is easy to observe. The experimental results show that the height difference between the long and short sides of rotor profile at the bottom of the rotor is significantly reduced from 0.22 mm to 0.034 mm by adjusting diameter of diamond rollers, and the distance between the long and short sides of the actual rotor profile is almost consistent with the theoretical one by measuring the distance again and adjusting its value in the computer numerical control system. These results verify the correctness of the correction method.

scholarly journals A Novel Rotor Profile Error Tracing and Compensation Strategy for High Precision Machining of Screw Rotor Based on Trial Cutting of Limited Samples

2015 ◽  
Vol 2015 ◽  
pp. 1-9
Author(s):  
ZhiHuang Shen ◽  
Bin Yao ◽  
BinQiang Chen ◽  
Wei Feng ◽  
XiangLei Zhang
Keyword(s):  
Machine Tool ◽  
High Precision ◽  
Error Compensation ◽  
Precision Machining ◽  
Limited Sample ◽  
Rotor Profile ◽  
Screw Rotor ◽  
Novel Method ◽  
Error Tracing ◽  
Screw Rotors

The machining precision plays an important role in the operation reliability and service life of screw rotors. However, the actual machined rotor profile of screw rotors is different from its theoretical profile due to the errors of the machine tool. This paper proposes a novel method of error tracing and compensation to reduce the machined errors of rotor profile on the basis of the limited sample trials, and the method is based on a matrix of error compensation. The errors of rotor profile are obtained based on limited sample trials machining of screw rotors,and fitted into piecewise smooth data. A matrix of error compensation is established to compute the errors of rotor profile to generate a compensated rotor profile. The compensated rotor profile is then used to regenerate forming tool and a new rotor product is processed on the same machine tool. And the errors of new rotor profile are smaller and can be reduced within (−0.01 mm, 0.01 mm) after compensations. Finally, the actual machining examples illustrate that the method of error compensation can not only satisfy the machining requirement of high-precision rotors, but also has the characteristics of good stability and applicability.

Synthesis and Optimization for Rotor Profiles in Twin Rotor Screw Compressors

1998 ◽  
Vol 122 (4) ◽  
pp. 543-552 ◽  
Author(s):  
Shyh-Haur Su ◽  
Ching-Huan Tseng
Keyword(s):  
Contact Line ◽  
Optimization Problems ◽  
Synthesis Method ◽  
Line Length ◽  
Contact Lines ◽  
Rotor Profile ◽  
Twin Screw ◽  
Screw Rotor ◽  
Rotor Profiles ◽  
Parameter Values

This paper proposes a systematic synthesis method for twin-screw rotor profiles for compressors. Both “original generating curves” and “generated curves” are distributed on each rotor profile, and all the geometric parameters of these curves can be determined with satisfying the conditions of continuity in tangency by given only several specific parameter values. The contact lines on rotor surfaces and the blowhole area calculation are also presented. Three cases of optimization problems are shown in this paper and both contact-line length and blowhole area are reduced when letting the contact-line length be the object function with a constraint of blowhole area. [S1050-0472(00)01103-X]

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