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.

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 A Study on Error Compensation on High Precision Machine Tool System Using a 2D Laser Holographic Scale System

2012 ◽  
Vol 6 (6) ◽  
pp. 999-1014 ◽  
Author(s):  
Toru FUJIMORI ◽  
Kayoko TANIGUCHI ◽  
Chris ELLIS ◽  
Tojiro AOYAMA ◽  
Kazuo YAMAZAKI
Keyword(s):  
Machine Tool ◽  
High Precision ◽  
Error Compensation ◽  
Precision Machine

Development and Evaluation of a Non-Contact On-Machine Profile Measurement System Using a Compact Laser Probe

2008 ◽  
Vol 381-382 ◽  
pp. 187-190 ◽  
Author(s):  
Ryo Kobayashi ◽  
Shinya MORITA ◽  
Y. Watanabe ◽  
Y. Uehara ◽  
W. Lin ◽  
...  
Keyword(s):  
Machine Tool ◽  
High Precision ◽  
Measurement System ◽  
Error Compensation ◽  
Measurement Instrument ◽  
The Other ◽  
Profile Measurement ◽  
Form Error ◽  
Laser Probe ◽  
Comparison Of The Results

A non-contact on-machine measurement system has been developed since various precise machines are getting lighter and smaller; therefore, processing with nano-precision is demanded recently. This system makes possible to measure with high precision without any damages and it is unnecessary for workpieces to attach or detach from a machine tool. Moreover, this system achieves on-machine form error compensation with high precision. On the other hand, the details of the system performances are still unknown. This study focuses on evaluating the performances by the comparison of the results that measured by this system and an existing measurement instrument under various conditions. As a result, this system shows an equivalent capability of measurement with high precision as the existing measurement instrument.

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.

Error Compensation Method of Harmonic Analysis for Time Grating Sensor

2011 ◽  
Vol 121-126 ◽  
pp. 3850-3854
Author(s):  
Zi Ran Chen ◽  
Dong Lin Peng ◽  
Yong Zheng ◽  
Fang Yan Zheng ◽  
Tian Heng Zhang
Keyword(s):  
Harmonic Analysis ◽  
High Precision ◽  
Measurement System ◽  
Error Compensation ◽  
Production Cost ◽  
Measurement Accuracy ◽  
Compensation Method ◽  
Precision Time ◽  
Error Tracing ◽  
Mechanical Machining

Due to the complexity of measurement system, it is hard correct errors by using traditional error separation and error tracing technology. To reduce the production cost and improve the measurement accuracy, a novel error compensation method based on harmonic analysis is presented in this paper. In this way, high precision time grating sensors can be manufactured with low precision mechanical machining method. The experiment results prove that errors can be reduce within ±2″.

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 Engagement-Pixel Tracking Method for Meshing Clearance Layout of Twin-Screw Rotors

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Jie Lu ◽  
Zhiqin Cai ◽  
Sijie Cai ◽  
Bin Yao ◽  
Binqiang Chen
Keyword(s):  
Normal Vector ◽  
Discrete Point ◽  
Tracking Method ◽  
Rotor Profile ◽  
Twin Screw ◽  
Contact Models ◽  
Novel Method ◽  
Rotor Profiles ◽  
Screw Rotors

The performance of dry twin-screw compressors is primarily affected by the meshing clearance between a pair of meshing rotors. In this paper, a novel method for meshing clearance layout (MCL) is presented. The presented method is based on the engagement-pixel tracking (EPT) technique, which utilizes discrete-pixel curves generated by the two rotors. An algorithm for the proposed method is put forward. Firstly, when the profile of one rotor is known, the discrete point coordinates of the two rotor profiles and their thermal expansion profiles can be obtained. Secondly, the instantaneous contact models of the two rotors at special meshing positions are acquired under pixel coordinate system. Thirdly, through inspecting the pixels on the profile of a rotor and establishing the corresponding normal vector, the meshing clearance of the two rotors is extracted. Then, the meshing clearances can be generated by extracting the boundary pixels on the other rotor profile. Finally, the meshing clearance layout method is proposed. To verify the effectiveness of the presented method, a case study was conducted on a pair of meshing rotors to extract its meshing clearance. It was shown that the proposed method can be used as a tool for evaluating the clearance distribution of actual machined profiles.

Development of On-Machine Measurement System Utilizing Line Laser Displacement Sensor

2011 ◽  
Vol 5 (5) ◽  
pp. 708-714 ◽  
Author(s):  
Go Abe ◽  
◽  
Masatoshi Aritoshi ◽  
Tomoki Tomita ◽  
Keiichi Shirase ◽  
...  
Keyword(s):  
Machine Tool ◽  
Precision Measurement ◽  
Error Compensation ◽  
Point Method ◽  
Displacement Sensor ◽  
Precision Machining ◽  
Laser Displacement Sensor ◽  
Cnc Machine ◽  
Machining Error ◽  
Measurement Device

Demand for precision machining of dies and molds with complex shapes has been increasing. Though high performance CNC machine tools are widely utilized for precision machining, machining error compensation is still necessary to meet accuracy requirements. For precision measurement, a workpiece must usually be unloaded from a CNC machine tool. Then, the workpiece is measured by a precision measurement device, such as 3D CMM. After the machining error is clarified according to the measurements taken, the workpiece must be re-clamped for the necessary error compensation machining. This error compensation machining is costly and time consuming, and it requires a highly skilled machinists. The re-clamping of the workpiece also causes positioning errors. Therefore, demands for on-machinemeasurement have been increasing. In this paper, an on-machine measurement device that consists of a line laser displacement sensor is developed. This measurement device, attached to the spindle head of a machine tool with magnetic clamps, has special features, such as noncontact, multi-point, high-speed measurement capabilities. Additionally, a sequential multi-point method, an extension of the two-point method, is applied for shape measurement accuracy.

scholarly journals High-Precision Machining Method of Weak-Stiffness Mirror Based on Fast Tool Servo Error Compensation Strategy

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 607
Author(s):  
Zelong Li ◽  
Yifan Dai ◽  
Chaoliang Guan ◽  
Jiahao Yong ◽  
Zizhou Sun ◽  
...  
Keyword(s):  
High Precision ◽  
Error Compensation ◽  
Machining Process ◽  
Precision Machining ◽  
Fast Tool Servo ◽  
Compensation Strategy ◽  
Machined Surface ◽  
Theoretical Simulation ◽  
Machining Errors ◽  
Cutting Error

Weak-stiffness mirrors are widely used in various fields such as aerospace and optoelectronic information. However, it is difficult to achieve micron-level precision machining because weak-stiffness mirrors are hard to clamp and are prone to deformation. The machining errors of these mirrors are randomly distributed and non-rotationally symmetric, which is difficult to overcome by common machining methods. Based on the fast tool servo system, this paper proposes a high-precision machining method for weak-stiffness mirrors. Firstly, the clamping error and cutting error compensation strategy is obtained by analyzing the changing process of the mirror surface morphology. Then, by combining real-time monitoring and theoretical simulation, the elastic deformation of the weak-stiffness mirror is accurately extracted to achieve the compensation of the clamping error, and the compensation of the cutting error is achieved by iterative machining. Finally, a weak-stiffness mirror with a thickness of 2.5 mm was machined twice, and the experimental process produced a clamping error with a peak to valley (PV) value of 5.2 µm and a cutting error with a PV value of 1.6 µm. The final machined surface after compensation had a PV value of 0.7 µm. The experimental results showed that the compensation strategy proposed in this paper overcomes the clamping error of the weak-stiffness mirror and significantly reduces cutting errors during the machining process, achieving the high precision machining of a weak-stiffness mirror.

Straightness Error Compensation for Ultra-Precision Machining Based on a Straightness Gauge

2008 ◽  
Vol 381-382 ◽  
pp. 105-108 ◽  
Author(s):  
Guo Hui Cao ◽  
Yoshiharu Namba
Keyword(s):  
Machine Tool ◽  
Error Compensation ◽  
Surface Profile ◽  
Displacement Sensor ◽  
Precision Machining ◽  
The Real ◽  
Nano Scale ◽  
Nc Program ◽  
Ultra Precision ◽  
Straightness Error

A method of straightness error compensation is presented, which is used in ultra-precision machining with nano-scale accuracy for a large mandrel manufacture. A set of measurement system in situ is developed, in which an ultra-smooth glass-ceramic flatness gauge and a non-contact micro displacement sensor with nano-scale resolution were used as a reference and sensor to get the straightness error of machine tool movement. The real straightness error can be obtained after subtracting the surface profile of the gauge from the original straightness error curve. Based on the real straightness error data, a new NC program was made for compensating the error from the axis movement of machine tool. As a result, after straightness error compensation, the straightness errors of two axes of ultra-precision machine tool are 68nm/400mm and 54nm/300mm respectively.

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