scholarly journals A Novel Optimization Design Method of Form Grinding Wheel for Screw Rotor

2019 ◽  
Vol 9 (23) ◽  
pp. 5079 ◽  
Author(s):  
Zongmin Liu ◽  
Qian Tang ◽  
Ning Liu ◽  
Pinghua Liang ◽  
Wei Liu
Keyword(s):  
Optimization Design ◽  
Design Method ◽  
Empirical Method ◽  
Grinding Wheel ◽  
Grinding Wheels ◽  
Grinding Performance ◽  
Form Grinding ◽  
Screw Rotor ◽  
Screw Rotors ◽  
Profile Accuracy

The profile accuracy of screw rotors plays a vital role in stabilizing the meshing operation between mated rotors. Such stability can minimize the vibration and noise, as well as improve the sealing performance and wear resistance. This is the main reason why form grinding is extensively applied as a finishing process to maintain high screw rotor profile accuracy. Since the installation parameters for form grinding wheels affect both the grinding wheel profile accuracy and grinding performance, it is essential to obtain reasonable installation parameters to guarantee the high precision and good grinding performance of form grinding wheels. In this paper, a novel optimization design method for form grinding wheels for screw rotors has been proposed. For the first time, the relationship between the grinding wheel installation parameters and profile accuracy is established to evaluate the grinding performance. A parameterized program has been designed based on space engagement theory. The characteristics of the contact line and profile features of form grinding wheels under different installation parameters have been investigated. Then, the proposed method was employed to select the correct range of installation parameters. To validate the proposed method, a set of experiments, including the manufacture and measurement of several screw rotors, was carried out. The results reveal that the precision of the screw profile is significantly improved compared with the empirical method, thus showing the effectiveness of the proposed method.

Development on Micro Precision Truing Method of ELID-Grinding Wheel (2nd Report: Application to Edge Sharpening of Large Wheel)

2005 ◽  
Vol 291-292 ◽  
pp. 213-220 ◽  
Author(s):  
Shao Hui Yin ◽  
Wei Min Lin ◽  
Yoshihiro Uehara ◽  
Shinya MORITA ◽  
Hitoshi Ohmori ◽  
...  
Keyword(s):  
Surface Quality ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Grinding Wheels ◽  
Elid Grinding ◽  
Diamond Grinding ◽  
Grinding Performance ◽  
Profile Accuracy ◽  
Large Wheel ◽  
Edge Sharpening

In V-groove ELID grinding process, to achieve optimal grinding performance and satisfactory surface quality and profile accuracy, metal bonded diamond grinding wheels need to be carefully sharpened. In this paper, we applied the proposed new micro-truing method consisting of electro-discharge truing and electrolysis-assisted mechanical truing to sharpen the edge of large grinding wheels. The minimum wheel tip radiuses of 6.3 and 8.5µm were achieved for the #4000 and #20000 grinding wheels. The truing mechanisms and sharpening performance are also discussed.

Mathematical Modeling for Screw Rotor Form Grinding on Vertical Multi-Axis Computerized Numerical Control Form Grinder

2013 ◽  
Vol 135 (5) ◽  
Author(s):  
Yu-Ren Wu ◽  
Chung-Wen Fan
Keyword(s):  
Numerical Control ◽  
Grinding Wheel ◽  
Noise Current ◽  
Form Grinding ◽  
Tooth Modification ◽  
Screw Rotor ◽  
Computerized Numerical Control ◽  
Rotor Tooth ◽  
Five Axis ◽  
Screw Rotors

The pair of screw rotors is a key element of a twin-screw compressor, and rotor tooth modification has gradually received attention because it can reduce operating compressor noise. Current rotor machining references are mainly related to forming tool design or abrasion of the “horizontal” grinder, but little attention has been paid to form grinding using a “vertical” grinder and simulating the machining flexibility of each grinder axis. Therefore, this paper established a general coordinate system for the screw rotor form grinding and connected it to a vertical five-axis computerized numerical control form grinder to simulate rotor grinding and tooth modification. Further, the influence of a form grinding wheel contour designed by different declination angles of a rotor tooth profile on a grinding rotor tooth and the influence of the motion parameter of each axis on the machining precision of the rotor and the tooth shape are proposed in this paper.

Development of Vitrified Bond CBN Wheel for Internal Precision Grinding of the Air-Conditioner Compressor Piston Hole

2006 ◽  
Vol 304-305 ◽  
pp. 29-32 ◽  
Author(s):  
Hang Gao ◽  
Y.G. Zheng ◽  
W.G. Liu ◽  
Jian Hui Li
Keyword(s):  
Cost Effective ◽  
Grinding Wheel ◽  
Manufacturing Cost ◽  
Air Conditioner ◽  
Grinding Wheels ◽  
Precision Grinding ◽  
Grinding Performance ◽  
Compressor Piston ◽  
Vitrified Bond ◽  
Cbn Grinding Wheel

Manufacturing of vitrified bond CBN wheels for internal precision grinding of the air-conditioner compressor piston hole is still big challenge to all of the domestic manufacturers. Recently, by choosing pre-melting mixed CBN abrasives and a proper sintering process, a cost-effective method was conceived to produce grinding wheels of comparative quality. The grinding performance of wheels was evaluated with a series of internal precision grinding of compressor piston hole. Experimental results show that the vitrified bond CBN grinding wheel produced by this method has better grinding performance, and can be substitute to the same type of grinding wheels imported. But the manufacturing cost is only 60% of the wheel imported according to estimation.

The Development of Nanocrystalline CBN for Enhanced Superalloy Grinding Performance

1997 ◽  
Vol 119 (1) ◽  
pp. 110-117 ◽  
Author(s):  
Y. Ichida ◽  
K. Kishi
Keyword(s):  
Wear Rate ◽  
Grinding Wheel ◽  
Grinding Wheels ◽  
Wear Rates ◽  
Grinding Performance ◽  
Wide Range ◽  
Edge Distribution ◽  
Order Of Magnitude ◽  
Life Analysis ◽  
Magnitude Increase

CBN grinding wheels are increasingly used on a wide range of engineering materials. This paper compares the grinding performance of monocrystalline (M-CBN) and polycrystalline (P-CBN) abrasives with a newly developed nanocrystalline (N-CBN) abrasive, when grinding nickel-based superalloys. The N-CBN grits possess average crystal grain diameters less than 1 μm compared to average primary grain diameters of 2.3 μm for P-CBN. It was found that the nanocrystalline CBN grits possess higher fracture strength which give reduced wear rates and yield an order of magnitude increase in grinding wheel life. Analysis of the cutting edge distribution shows that the reduced wear rate of N-CBN is due to the predominance of a micro-fracturing mode of abrasive wear. The size of this micro-fracturing is considerably smaller in N-CBN than in P-CBN.

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.

Effect of Novel Grinding Wheels on Grinding Performance

2013 ◽  
Vol 405-408 ◽  
pp. 3302-3306
Author(s):  
Ming Yi Tsai ◽  
Shi Xing Jian ◽  
J. H. Chiang
Keyword(s):  
Surface Roughness ◽  
Pure Water ◽  
Minimum Quantity Lubrication ◽  
Grinding Wheel ◽  
Grinding Temperature ◽  
Grinding Wheels ◽  
Wheel Wear ◽  
Grinding Performance ◽  
Conventional Grinding ◽  
Removal Processes

Grinding, a technique for removing abrasive materials, is a chip-removal process that uses an individual abrasive grain as the cutting tool. Abrasive material removal processes can be very challenging owing to the high power requirements and the resulting high temperatures, especially at the workpiece-wheel interface. This paper presents a novel system that uses graphite particles impregnated in an aluminum oxide matrix to form a grinding wheel. This study specifically investigated grinding wheels with a graphite content of 0.5 wt%. The new grinding wheel was compared with conventional grinding wheels by comparing the factors of grinding performance, such as surface roughness, morphology, wheel wear ratio, grinding temperature, and grinding forces, when the wheels were used under two different coolant strategiesdry and with minimum quantity lubrication (MQL) using pure water. This study found that there is a considerable improvement in the grinding performance using graphite-impregnated grinding wheels over the performance obtained using conventional grinding wheels. The use of 0.5 wt% graphite provided better surface roughness and topography, lower grinding temperature, and decreased force; in addition, wheel consumption was lower, resulting in extended wheel life.

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.

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.

Slot and Vertical Face Grinding of Aerospace Components

1996 ◽  
Vol 118 (3) ◽  
pp. 620-625
Author(s):  
R. B. Mindek ◽  
T. D. Howes
Keyword(s):  
Heat Input ◽  
Thermal Damage ◽  
Cubic Boron Nitride ◽  
Grinding Wheel ◽  
Grinding Wheels ◽  
Grinding Forces ◽  
Wheel Wear ◽  
Inconel 713C ◽  
Profile Accuracy ◽  
Face Grinding

Workpiece profile accuracy, wheel wear, and thermal damage were investigated for the grinding of slots and vertical faces on MAR-M-247, Inconel 713C, and M-2 tool steel using both alumina and cubic boron nitride (CBN) grinding wheels. It was found when grinding with alumina wheels that the wheel corner and first 2.5 mm of the grinding wheel sidewall account for all the grinding forces in the vertical, horizontal, and transverse directions, and therefore is responsible for all the significant grinding done on the sideface of the workpiece. Since previous work links wheel wear and workpiece thermal damage during grinding to grinding forces, this finding suggests that the area around the wheel corner is the critical region of importance in grinding these types of profiles in terms of wheel wear and the heat input to the workpiece. These, in turn, are linked to workpiece profile accuracy and metallurgical damage. Results also show that striation marks inherent in sidewall grinding can be minimized by controlling the maximum normal infeed rate of the wheel. A method for minimizing the heat input into the workpiece by minimizing grinding force during vertical face grinding is also reported.

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