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.

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.

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.

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.

scholarly journals An Analysis of Profile Error for Resharpened Screw Rotor Hob, Relieved with Pencil Type Grinding Wheel.

2002 ◽  
Vol 68 (11) ◽  
pp. 1455-1459
Author(s):  
Satoshi KISHI ◽  
Tomio HORIUCHI ◽  
Muneharu MOROZUMI ◽  
Yoshitaroh YOSHIDA ◽  
Masayuki SAITOH
Keyword(s):  
Grinding Wheel ◽  
Profile Error ◽  
Screw Rotor

Free-Form Flank Correction in Helical Gear Grinding Using a Five-Axis Computer Numerical Control Gear Profile Grinding Machine

2012 ◽  
Vol 134 (4) ◽  
Author(s):  
Yi-Pei Shih ◽  
Shi-Duang Chen
Keyword(s):  
Correction Method ◽  
Computer Numerical Control ◽  
Numerical Control ◽  
Free Form ◽  
Profile Grinding ◽  
Wheel Profile ◽  
Grinding Machine ◽  
Tooth Flank ◽  
Five Axis ◽  
Gear Profile

To reduce form grinding errors, this paper proposes a free-form flank topographic correction method based on a five-axis computer numerical control (CNC) gear profile grinding machine. This correction method is applied not only to the five-axis machine settings (during grinding) but also to the wheel profile (during wheel truing). To achieve free-form modification of the wheel profile, the wheel is formulated as B-spline curves using a curve fitting technique and then normal correction functions made up of four-degree polynomials are added into its working curves. Additionally, each axis of the grinding machine is formulated as a six-degree polynomial. Based on a sensitivity analysis of the polynomial coefficients (normal correction functions and CNC machine settings) on the ground tooth flank and the topographic flank errors, the corrections are solved using the least squares method. The ground tooth flank errors can then be efficiently reduced by slightly adjusting the wheel profile and five-axis movement according to the solved corrections. The validity of this flank correction method for helical gears is numerically demonstrated using the five-axis CNC gear profile grinding machine.

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.

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.

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.

Modified-Roll Profile Correction for a Gear Shaping Cutter Made by the Lengthwise-Reciprocating Grinding Process

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Chin-Lung Huang ◽  
Zhang-Hua Fong
Keyword(s):  
Tooth Profile ◽  
Roll Motion ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Profile Error ◽  
Sensitivity Matrix ◽  
Profile Correction ◽  
Wheel Profile ◽  
Profile Errors ◽  
Gear Shaping

The tooth profile error of a gear shaping cutter made by the lengthwise-reciprocating grinding process (LRGP) is usually corrected by modifying the grinding wheel profile. However, such grinding wheel modification cannot eliminate the twisting profile error along the face of the shaping cutter. A kinematic modified roll motion for generating a shaping cutter is proposed to minimize such twisted profile errors even after cutter resharpening. The tooth profile errors of the work gears generated by the shaping cutter with various resharpening depths are represented as a novel topographic error map. Based on the error map and its sensitivity matrix, the roll ratio between the shaping cutter and the grinding wheel stroke is modified to reduce the twisted profile error as illustrated by the numerical examples. Combining this modified roll motion modification and the grinding wheel profile correction, the high accuracy resharpening depth of the LRGP helical shaping cutter is increased.

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