scholarly journals Study on Heat Sources of Horizontal Lathe Machine by Using Inverse Method

2021 ◽  
Author(s):  
Thi-Thao Ngo ◽  
◽  
Chi-Chang Wang ◽  
Ming-Lun Chang ◽  
Van-The Than ◽  
...  
Keyword(s):  
Machine Tools ◽  
Measurement Errors ◽  
High Speed ◽  
Inverse Method ◽  
Heat Sources ◽  
Growing Up ◽  
Load Rate ◽  
Lathe Machine ◽  
Measured Distance ◽  
Processing Errors

Thermal has significantly effect on high speed machine tools. When temperature growing up, it often causes processing errors and further reduces product quality. This paper aims to investigate magnitude of heat sources and temperature distribution in a horizontal lathe based on inverse method. In present thermal model, there is not only consideration of spindle but also analyzing relative structures. Simulated and experimental temperatures are used as input data to predict heat sources and temperature field. Effects of speed, number measured points, measurement errors and measured distance on predicted results are analyzed. Results indicate that this inverse method can accurately estimate the heat sources based on two measured temperatures at front and rear outer rings. The trend of estimated heat sources is then compared to measured load rate. Results herein are useful information for designing horizontal lathe spindle and reducing thermal errors.

Study on Thermal Errors of High Speed Motorized Spindle on 5-Axis CNC Machine Tools

2009 ◽  
Vol 626-627 ◽  
pp. 411-416 ◽  
Author(s):  
Z.C. Wang ◽  
X.L. Hu ◽  
C.H. Zhang
Keyword(s):  
Machine Tools ◽  
High Speed ◽  
Axial Direction ◽  
Cnc Machine Tools ◽  
Heat Sources ◽  
Cnc Machine ◽  
Motorized Spindle ◽  
One Dimensional ◽  
Thermal Errors ◽  
The Relationship

A simplified one-dimensional model, accounting for thermal errors related to high speed spindle of 5-axis CNC machine tools, is developed, and the relationship between heat sources of rotating spindle and thermal deformation in axial direction is found with the help of Fourier’s law for heat transfer under two different boundary conditions. Based on the theory of homogeneous coordinate transformation in robotic, the transformation matrixes between the coordinate system of kinematic pairs and the relationship between errors and compensations are obtained, through which the compensation of thermal errors in high speed motorized spindle is obtainable.

scholarly journals USING INVERSE METHOD FOR EVALUATING THERMAL CHARACTERISTICS OF A MICRO HIGH SPEED MOTORIZED SPINDLE

2018 ◽  
Vol 54 (5A) ◽  
pp. 238
Author(s):  
Ngo Thi Thao
Keyword(s):  
Direct Problem ◽  
High Speed ◽  
Thermal Deformation ◽  
Inverse Method ◽  
Gradient Methods ◽  
Thermal Characteristics ◽  
Conjugate Gradient Methods ◽  
Heat Sources ◽  
Motorized Spindle ◽  
Inverse Solutions

A combination of finite element and conjugate gradient methods to establish an inverse method for estimating heat sources as well as temperatures of a micro high speed motorized spindle is presented in this article. The proposed method is simple in constructing the direct problem by using COMSOL software. Experiment setup and measurement process are introduced. Results show that inverse solutions agree with experimental data based on temperatures at only one measurement point. Influence of speed on heat sources and temperatures is indicated. Temperature distribution in the spindle is also given and discussed. From these findings, it can be said that the proposed method is appropriated for inversely determining the heat source in micro high speed motorized spindle. The obtained results provide useful information to estimate thermal deformation.

An inverse method for estimating heat sources in a high speed spindle

2016 ◽  
Vol 105 ◽  
pp. 65-76 ◽  
Author(s):  
Jin-Huang Huang ◽  
Van-The Than ◽  
Thi-Thao Ngo ◽  
Chi-Chang Wang
Keyword(s):  
High Speed ◽  
Inverse Method ◽  
Heat Sources

Discussion—Session III: High speed machine tools for aircraft production

1955 ◽  
Vol 34 (4) ◽  
pp. 224
Author(s):  
F.C. Cooke ◽  
S. Radcliffe ◽  
H.A. Chambers ◽  
C. Bromage ◽  
Menelaus ◽  
...  
Keyword(s):  
Machine Tools ◽  
High Speed ◽  
Discussion Session ◽  
Aircraft Production ◽  
High Speed Machine

scholarly journals Phase Stability under Thermal Drifts in Photodiode-Conditioning Transimpedance Amplifiers for Distance Metrology

Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3455
Author(s):  
Francisco Javier Meca Meca ◽  
Ernesto Martín-Gorostiza ◽  
Miguel Ángel García-Garrido ◽  
David Salido-Monzú
Keyword(s):  
Delay Time ◽  
Measurement Errors ◽  
Continuous Wave ◽  
Signal To Noise Ratio ◽  
Circuit Board ◽  
Transimpedance Amplifiers ◽  
Optical Distance ◽  
High Measurement ◽  
Analytic Expressions ◽  
Measured Distance

Transimpedance amplifiers (TIA) are widely used for front-end signal conditioning in many optical distance measuring applications in which high accuracy is often required. Small effects due to the real characteristics of the components and the parasitic elements in the circuit board may cause the error to rise to unacceptable levels. In this work we study these effects on the TIA delay time error and deduce analytic expressions, taking into account the trade-off between the uncertainties caused by the delay time instability and by the signal-to-noise ratio. A specific continuous-wave phase-shift case study is shown to illustrate the analysis, and further compared with real measurements. General strategies and conclusions, useful for designers of this kind of system, are extracted too. The study and results show that the delay time thermal stability is a key determinant factor in the measured distance accuracy and, without an adequate design, moderate temperature variations of the TIA can cause extremely high measurement errors.

Comparison of the reluctance laminated and solid rotor synchronous machine operating at high temperatures

2019 ◽  
Vol 38 (4) ◽  
pp. 1111-1119 ◽  
Author(s):  
Marcin Lefik ◽  
Krzysztof Komeza ◽  
Ewa Napieralska-Juszczak ◽  
Daniel Roger ◽  
Piotr Andrzej Napieralski
Keyword(s):  
High Speed ◽  
Design Methodology ◽  
Three Dimensional ◽  
Synchronous Machine ◽  
Point Of View ◽  
Heat Sources ◽  
Model Calculations ◽  
Content Type ◽  
Thermal Phenomenon ◽  
Practical Implications

Purpose The purpose of this paper is to present a comparison between reluctance synchronous machine-enabling work at high internal temperature (HT° machine) with laminated and solid rotor. Design/methodology/approach To obtain heat sources for the thermal model, calculations of the electromagnetic field were made using the Opera 3D program including effect of rotation and the resulting eddy current losses. To analyse the thermal phenomenon, the 3D coupled thermal-fluid (CFD) model is used. Findings The presented results show clearly that laminated construction is much better from a point of view of efficiency and temperature. However, solid construction can be interesting for high speed machines due to their mechanical robustness. Research limitations/implications The main problem, despite the use of parallel calculations, is the long calculation time. Practical implications The obtained simulation and experimental results show the possibility of building a machine operating at a much higher ambient temperature than it was previously produced for example in the vicinity of the aircraft turbines. Originality/value The paper presents the application of fully three-dimensional coupled electromagnetic and thermal analysis of new machine constructions designed for elevated temperature.

scholarly journals An Improved Lagrangian-Inverse Method for Evaluating the Dynamic Constitutive Parameters of Concrete

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1871
Author(s):  
Xinlu Yu ◽  
Yingqian Fu ◽  
Xinlong Dong ◽  
Fenghua Zhou ◽  
Jianguo Ning
Keyword(s):  
High Speed ◽  
Inverse Method ◽  
Image Correlation ◽  
Analysis Method ◽  
Stress Strain ◽  
Optical Techniques ◽  
Element Simulation ◽  
Non Linear ◽  
Constitutive Parameters ◽  
Inverse Analysis Method

The dynamic constitutive behaviors of concrete-like materials are of vital importance for structure designing under impact loading conditions. This study proposes a new method to evaluate the constitutive behaviors of ordinary concrete at high strain rates. The proposed method combines the Lagrangian-inverse analysis method with optical techniques (ultra-high-speed camera and digital image correlation techniques). The proposed method is validated against finite-element simulation. Spalling tests were conducted on concretes where optical techniques were employed to obtain the high-frequency spatial and temporal displacement data. We then obtained stress–strain curves of concrete by applying the proposed method on the results of spalling tests. The results show non-linear constitutive behaviors in these stress–strain curves. These non-linear constitutive behaviors can be possibly explained by local heterogeneity of concrete. The proposed method provides an alternative mean to access the dynamic constitutive behaviors which can help future structure designing of concrete-like materials.

Stability of Milling Operations With Asymmetric Cutter Dynamics in Rotating Coordinates

2016 ◽  
Vol 138 (8) ◽  
Author(s):  
Alptunc Comak ◽  
Orkun Ozsahin ◽  
Yusuf Altintas
Keyword(s):  
Time Domain ◽  
Machine Tools ◽  
High Speed ◽  
End Mill ◽  
Spindle Shaft ◽  
Milling Operations ◽  
Stability Model ◽  
Principal Directions ◽  
The Stability ◽  
Rotating Coordinates

High-speed machine tools have parts with both stationary and rotating dynamics. While spindle housing, column, and table have stationary dynamics, rotating parts may have both symmetric (i.e., spindle shaft and tool holder) and asymmetric dynamics (i.e., two-fluted end mill) due to uneven geometry in two principal directions. This paper presents a stability model of dynamic milling operations with combined stationary and rotating dynamics. The stationary modes are superposed to two orthogonal directions in rotating frame by considering the time- and speed-dependent, periodic dynamic milling system. The stability of the system is solved in both frequency and semidiscrete time domain. It is shown that the stability pockets differ significantly when the rotating dynamics of the asymmetric tools are considered. The proposed stability model has been experimentally validated in high-speed milling of an aluminum alloy with a two-fluted, asymmetric helical end mill.

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