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.

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 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.

Research on Forms of Grinding Allowance Based on NC Form Grinding Cylinder Gear

2010 ◽  
Vol 42 ◽  
pp. 276-279
Author(s):  
Hong Xia He
Keyword(s):  
Numerical Control ◽  
Grinding Wheel ◽  
Axial Section ◽  
Gear Grinding ◽  
Form Grinding ◽  
Section Shape ◽  
Grinding Machine

The machining principle and characteristics of form grinding cylinder gear are introduced as well as the characteristics of form grinding machine in this paper. By analyzing and comparing three kinds of grinding allowance for cylinder gear grinding, a reasonable and effective axial section shape is determined in experience, which is a practical profile to shape the axial section of grinding wheel for numerical control grinding cylinder gears.

Secondary Development of Siemens CNC System for Large Grinding Machine

2013 ◽  
Vol 341-342 ◽  
pp. 1058-1061
Author(s):  
De Dong Han ◽  
Shi Jie Zhao ◽  
Hui Jiang ◽  
Hong Ya Fu
Keyword(s):  
System Development ◽  
Numerical Control ◽  
Secondary Development ◽  
Grinding Wheel ◽  
Cnc System ◽  
Control Software ◽  
Dynamic Link Library ◽  
Cylindrical Gear ◽  
Form Grinding ◽  
Grinding Machine

Form grinding is one of the most efficient processes for finish machining of gear wheels. This paper investigates the method of system development for wheel modification of involute cylindrical gear based on SINUMERIK 840D system and its OEM development package. The control software developed for form grinding is applied to dress form grinding wheel by using the numerical control dresser, and normal projection is adopted as the method to calculate the sectional shape of grinding wheel. The friendly interface of control software, edited by Visual Basic was developed to meet needs of users. Finally, personalized interface and processing methods are integrated and embedded in Siemens CNC system through Dynamic Link Library to implement parameterized automatic processing, which is more efficient in programming and machining.

scholarly journals Closed-Loop Feedback Flank Errors Correction of Topographic Modification of Helical Gears Based on Form Grinding

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Huiliang Wang ◽  
Jubo Li ◽  
Yang Gao ◽  
Jianjun Yang
Keyword(s):  
Closed Loop ◽  
Correction Method ◽  
Numerical Control ◽  
Grinding Wheel ◽  
Helical Gears ◽  
Form Grinding ◽  
Loop Feedback ◽  
Feedback Correction ◽  
Closed Loop Feedback ◽  
Tooth Flank

To increase quality, reduce heavy-duty gear noise, and avoid edge contact in manufacturing helical gears, a closed-loop feedback correction method in topographic modification tooth flank is proposed based on the gear form grinding. Equations of grinding wheel profile and grinding wheel additional radial motion are derived according to tooth segmented profile modification and longitudinal modification. Combined with gear form grinding kinematics principles, the equations of motion for each axis of five-axis computer numerical control forming grinding machine are established. Such topographical modification is achieved in gear form grinding with on-machine measurement. Based on a sensitivity analysis of polynomial coefficients of axis motion and the topographic flank errors by on-machine measuring, the corrections are determined through an optimization process that targets minimization of the tooth flank errors. A numerical example of gear grinding, including on-machine measurement and closed-loop feedback correction completing process, is presented. The validity of this flank correction method is demonstrated for tooth flank errors that are reduced. The approach is useful to precision manufacturing of spiral bevel and hypoid gears, too.

A Novel CNC Grinding Method for Relief Surface Based on a CAM System

2011 ◽  
Vol 295-297 ◽  
pp. 2521-2525 ◽  
Author(s):  
Xiao Feng Yue ◽  
Fei Tang ◽  
Shu Zhe Li ◽  
Zhan Hua You ◽  
Xiao Hao Wang
Keyword(s):  
Coordinate System ◽  
Numerical Control ◽  
Grinding Wheel ◽  
End Mill ◽  
Ball End Mill ◽  
Relief Surface ◽  
Cnc Grinding ◽  
Relief Angle ◽  
Five Axis ◽  
Mill Machining

A novel algorithm for the ball-end mill relief using a five-axis computer numerical control (CNC) grinding machine and the simulation of the ball-end mill based on a CAM system is presented in this paper. In this study, In order to obtain an accurate normal relief angle, which is one of the key factors affecting tool cutting performance, a tool coordinate system based on the required relief angle and the cutting edge was established. Then, by the proposed tool coordinate system, an algorithm to determine the position between the grinding wheel and the tool is proposed, and then the relevant formulations are deduced. The coordinates of grinding point when the step of relief surface is grinded are calculated.Using the input data of a ball-end mill geometry, wheels geometry, wheel setting and machine setting, the NC code for machining will be generated. Then the code will be used as input to simulate the ball-end mill machining in 3 Dimension before real machining. The algorithm of ball-end mill relief can be authenticated by the 3D simulation system.

A Calculating Method for the Movement Contrail in the Operation of Dressing the Profile Shape of Grinding Wheel Used for Numerical Control Form Grinding Spur Cylinder Gear

2010 ◽  
Vol 44-47 ◽  
pp. 2269-2273
Author(s):  
Hong Xia He ◽  
Hong Xia Liu
Keyword(s):  
Numerical Control ◽  
Transition Curve ◽  
Grinding Wheel ◽  
Axial Section ◽  
Profile Shape ◽  
Calculating Method ◽  
Form Grinding ◽  
Contour Machining ◽  
Involute Surface ◽  
Disc Grinding

This paper introduces the machining principles and characteristics of mold grinding cylinder gear as well as the composition of a form disc grinding wheel. By using contour machining principle，a mathematical model of form grinding the involute surface of a spur cylinder gear is established. And also a calculating formula used to dress the profile shape of the transition curve of grinding wheel is given by calculating. This provides a calculation method for dressing the profile shape of disc grinding wheel in the axial section used for the operation of numerical control form grinding spur cylinder gear. The example illustrates the method is effective in the use.

Rotor Profile Design for the Twin-Screw Compressor Based on the Normal-Rack Generation Method

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
Yu-Ren Wu ◽  
Zhang-Hua Fong
Keyword(s):  
Helix Angle ◽  
Tooth Profile ◽  
Normal System ◽  
Rotor Profile ◽  
Twin Screw ◽  
Screw Rotor ◽  
Profile Design ◽  
Rotor Tooth ◽  
Rotor Profiles ◽  
Screw Rotors

This paper proposes a method for designing the rotor profiles of twin-screw compressors using a rack defined in the normal plane. All tooth profile segments are explicitly defined as tangent continuous in the normal section to generate a pair of conjugated rotors. Numerical comparisons between the two types of screw rotor tooth profile design, one based on a normal system, the other on an axial system, show the advantages of using the normal-rack generation method (NRGM). Most particularly, this method allows the same hob used for screw rotors to be used to manufacture mating rotors even as the helix angle varies, because in a normal system the circular pitch remains the same. The numerical results also indicate that the rotor tooth thickness generated by the NRGM rack cutter can prevent serious deflection for a variety of helix angles and tooth combinations.

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