Analysing by Simulation to Evaluate the Method of Measuring Screw Rotors with CMM

2010 ◽  
Vol 36 ◽  
pp. 63-67
Author(s):  
Qian Cheng Zhao ◽  
Chang You Lu ◽  
Qiao Xu ◽  
Geng Huang
Keyword(s):  
Screw Compressor ◽  
Geometrical Parameters ◽  
Helical Surface ◽  
Key Technology ◽  
Sampling Density ◽  
Simulation Process ◽  
Probe Radius ◽  
Section Profile ◽  
Screw Rotor ◽  
Screw Rotors

The important parts of a screw compressor are the two rotors. At present, generally use a CMM to check the form and other parameters of the rotors to ensure its function. Among the all geometrical parameters of a rotor, the form of traverse section profile is the most important one. In the process of measurement, the key technology problem is the probe radius correction because of the complexity of 3D helical surface. When the nominal values of the rotors are unknown, the radius correction is more difficult than that is known. This paper presents a method to evaluate the precision of measuring screw rotors by simulation. Suppose a referenced helical surface, first select the probe ball radius and sampling density, calculate the coordinate values of the probe ball centers along a fixed plane, then calculate the values of measured contour by radius correction, finally compare the reconstructed contour with the referenced surface to evaluate the selected measuring parameters such as probe ball radius, sampling density, the algorithm of radius correction and so on. This simulation process is necessary for actually measuring a screw rotor.

Key Technology of Form Grinding Wheel’s Axis Section’s Derivation

2013 ◽  
Vol 753-755 ◽  
pp. 1557-1561
Author(s):  
Ling Zhang ◽  
Bin Yao ◽  
Zhi Huang Shen ◽  
Wen Chang Zhao ◽  
Bin Zhou
Keyword(s):  
Research Method ◽  
Screw Compressor ◽  
Grinding Wheels ◽  
Relevant Research ◽  
Key Technology ◽  
Form Grinding ◽  
Key Technologies ◽  
Twin Screw ◽  
Screw Rotors ◽  
The Mathematical Model

Upon researching on the form grinding principle of rotor of the twin-screw compressor, firstly, this article gives the mathematical model of acquiring form grinding wheels axis section from screw rotors end section which is given by a series of discrete points. Then some key technologies to solve problems during the derivation of grinding wheels axis section and relevant research method to optimize the best setting angle have been analyzed. And last, the results of simulation and actual processing prove that this method is reliable and can meet the requirements of machining precision.

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.

Solving the screw compressor rotor-forming grinding wheel using the edge detection method based on the graphic method

2019 ◽  
Vol 233 (5) ◽  
pp. 967-979 ◽  
Author(s):  
Jian Yang ◽  
Fang-Hong Sun ◽  
Zheng Lu
Keyword(s):  
Edge Detection ◽  
Detection Method ◽  
Grinding Wheel ◽  
Screw Compressor ◽  
Graphic Method ◽  
Grinding Wheels ◽  
Helical Surface ◽  
Compressor Rotor ◽  
Edge Detection Method ◽  
Screw Rotors

As a complex grinding wheel for special use, the screw compressor rotor-forming grinding wheel needs to be designed according to the specific profile of the workpiece. The design process is complicated and difficult to grasp, and various design issues are likely to occur. This study is based on the design theory of helical rotor-forming grinding wheels. Here, disc-shaped forming grinding wheels for machining a helical surface were studied, with discrete point workpiece cross-sections as examples. MATLAB was used as the development tool, and the Unigraphics motion simulation function was applied to establish a 3D model of screw rotors and design the forming grinding wheel for machining the helical surface. Additionally, the edge shape of the grinding wheel obtained with the analytical method and the edge shape obtained with the edge detection method based on the graphic method and the alpha-shape algorithm were compared. The results of this comparison show that the edge shape of the grinding wheel obtained by the edge detection method had high precision and was easy to solve. This method can also be used for the design of other similar conjugated products such as gears, worms, and grinding wheels. The research findings provide important reference value for the design and machining of screw rotors and grinding wheels.

The pumping characteristics of screw rotors. I. The theory of calculation of the pumping capacity of screw rotors

1987 ◽  
Vol 52 (2) ◽  
pp. 357-371 ◽  
Author(s):  
František Rieger
Keyword(s):  
Present State ◽  
Flow Rate ◽  
Volumetric Flow Rate ◽  
Screw Rotor ◽  
Screw Rotors

This paper summarizes the present state of the theory of calculation of the pumping capacity of screw rotors. The calculation starts from the equation for the volumetric flow rate of the flow between two unconfined plates modified by correction coefficients obtained from the relationships for the flow rate in simpler geometrical configurations to which the screw rotor may be, under certain circumstances, reduced.

A mathematical model of a cc-type single-screw compressor

2004 ◽  
Vol 218 (4) ◽  
pp. 437-448 ◽  
Author(s):  
S-C Yang
Keyword(s):  
Mathematical Model ◽  
Cutting Edge ◽  
Screw Compressor ◽  
Contact Lines ◽  
Full Size ◽  
Single Screw ◽  
The Family ◽  
Screw Rotor ◽  
Design And Manufacture ◽  
Further Development

In this paper, a method is proposed for determining a basic profile of a cc-type single-screw compressor including the gate rotor and the screw rotor. The cc-type has a cylindrical screw and two cylindrical gate rotors. Based on this method, a mathematical model of the meshing principles of a cc-type screw rotor meshed with a gate rotor, that has either straight edge teeth or conical teeth, is presented. The inverse envelope concept is used to determine the cutting-edge curve of a gate rotor. Based on this concept, the required cutter for machining a cc-type screw rotor can be obtained by the envelope of a one-parameter family. The obtained screw rotor is an envelope to the family of the gate rotor's surfaces. The obtained envelope becomes the generating surface. The inverse envelope can be used to obtain the envelope to the family of generating surfaces. Then the profile of a gate rotor cutting-edge curve can be easily obtained. The surface analysis including contact lines is shown for the design and manufacture of a screw compressor. As an example, the cc-type single-screw compressor with a compressor ratio of 11:6 was determined with the aid of the proposed mathematical model. Using rapid prototyping (RP) and manufacturing technology, a cc-type single-screw rotor with a gate rotor was designed. The RP primitives provide an actual full-size physical model that can be analysed and used for further development. Results from these mathematical models should have applications in the design of cc-type single-screw compressors.

Research on Processing Technology and Cutting Parameter of the Spiral Surface of Screw Rotor

2011 ◽  
Vol 314-316 ◽  
pp. 543-546
Author(s):  
Xing Wei Sun ◽  
Guang Lv ◽  
Ke Wang
Keyword(s):  
Cutting Parameters ◽  
Element Model ◽  
Milling Process ◽  
Screw Compressor ◽  
Processing Quality ◽  
Excellent Performance ◽  
Single Screw ◽  
Screw Rotor ◽  
Spiral Surface ◽  
The Finite Element Model

The key components of the single screw compressor are rotor screw and two star-wheels which are symmetrical arrangement. The rotor screw and two star-wheels have composed a special spatial meshing pair. The high meshed precision is the guarantee of its excellent performance. In this paper, we will study the milling technology of screw milling cutter to the rotor screw, and establish the finite element model of the cutter, and analyze the cutter’s stress situation during the milling process, make the cutting parameters of the screw optimization, In this paper, we will also study the influence of the Milling depth and cutting width to tool in displacement and stress, in order to provide a theoretical reference of selecting of appropriate cutting parameters ,improving of processing quality and reducing wear of the tool.

Stochastic Methods in Microsystems Engineering

2018 ◽  
pp. 161-176
Author(s):  
Irina Stanciu
Keyword(s):  
Simulation Method ◽  
Stochastic Methods ◽  
Geometrical Parameters ◽  
Mems Devices ◽  
Functional Parameters ◽  
Simulation Process ◽  
Deterministic Methods ◽  
Passive Micromixer ◽  
Fabrication Tolerances ◽  
Variation Of Functional

The main objective of this chapter is to present a stochastic modeling and simulation methodology for estimating the variation of functional parameters of MEMS devices as a result of fabrication tolerances. The approach used for achieving this objective is to implement in the simulation process the variations of the geometrical parameters caused by the fabrication dispersion as random variables and to model the influence of these variations on the performance of the simulated device. The proposed method is demonstrated using two test structures: a micro-com resonator and a passive micromixer. In each example there are underlined important characteristics of the proposed simulation method: the ability to predict variation ranges of functional parameters, the ability to improve the design in function of the fabrication process, and the possibility of obtaining more precise results than the traditional deterministic methods.

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