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Research on Rotational Accuracy of Cylindrical Roller Bearings

Procedia CIRP 2017年 62卷 380-385页

作者： Yu Yongjian Chen Guoding Li Jishun Xue Yujun School of Mechanical Engineering Northwestern Polytechnical University Xi’an 710072 China Henan Key Laboratory for Machinery Design and Transmission System Luoyang 471003 China School of Mechanical Engineering Henan University of Science and Technology Luoyang 471003 China

To investigate transferring mechanism of form error of bearing elements and rotational accuracy in cylindrical roller bearings, according to the bearing components motion and geometric relationships, a prediction model for rotational accuracy of cylindrical roller bearings based on roundness error of the inner raceway is presented. The effects of roundness error (i.e., amplitude, order) in the inner raceway, the number of rollers and radial clearance on the radial runout of inner ring are analyzed. Analytic solutions of the radial runout of inner ring are deduced when shapes of bearing elements are an ideal circle, which verifies the correctness of the presented model. The results show that the proposed model has better precision accuracy.

关键词： Cylindrical roller bearing Rotational accuracy Radial runout Roundness error Form error

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Pickup Manipulator design and Its Kinematics Simulation

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IOP Conference Series: Earth and Environmental science 2018年第4期170卷

作者： Zhongdang Zhang Zhaoqiang Zhang Shitai Ma Haibo Zhou Tianjin University of Technology Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control Tianjin 300384 China National Demonstration Center for Experimental Mechanical and electrical Engineering Education (Tianjin University of Technology) Tianjin 300384 China

In order to improve the flexibility of the pickup manipulator and solve the problem of picking up small sports balls in training ground such as golfing, tennis, and table tennis, a 5-DOF pickup manipulator structure is designed. According to the pickup task requirements of the manipulator, through theoretical calculations, the 86HS series stepping motor is selected as the driving motors of the front end joints. Based on this, the stepping motor control system is designed to realize the closed-loop control of the manipulator. Then the manipulator model is built using D-H method, the inverse kinematics solution is calculated, and the analysis of kinematic theory is conducted. Finally, the targeted pickup point is selected to carry out case simulation analysis of the manipulator, the motion law of the manipulator is verified to be reasonable and the task of picking up small sports balls is completed.

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Forecast for Radial Runout of Outer Ring in Cylindrical Roller Bearing

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Procedia CIRP 2017年 62卷 375-379页

作者： Li Jishun Yu Yongjian Xue Yujun Henan Key Laboratory for Machinery Design and Transmission System Luoyang 471003 China School of Mechanical Engineering Henan University of Science and Technology Luoyang 471003 China School of Mechanical Engineering Northwestern Polytechnical University Xi’an 710072 China

The radial runout of outer ringin cylindrical roller bearing is investigated by numerical computation. Considering form error of outer raceway, a forecasting model for the radial runout of outer ring in cylindrical roller bearing is developed to study the influences of roundness error (i.e., amplitude, order) of outer raceway, number of rollers and radial clearance on the radial runout of outer ring. To testify the presented forecasting method, an analysis algorithm for computing the radial runout of outer ring with outer raceway shape of ellipse is derived. The comparison of the prediction results with the analytical results shows that the presented forecasting method has the better forecast precision.

关键词： Cylindrical roller bearing Radial runout of outer ring Roundness error Forecast

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Acoustic multipole sources for the regularized lattice Boltzmann method: Comparison with multiple-relaxation-time models in the inviscid limit

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Physical Review E 2017年第6期95卷 063301-063301页

作者： Congshan Zhuo Pierre Sagaut Aix Marseille Univ CNRS Centrale Marseille M2P2 UMR 7340 13451 Marseille France National Key Laboratory of Science and Technology on Aerodynamic Design and Research Northwestern Polytechnical University Xi'an Shaanxi 710072 China

In this paper, a variant of the acoustic multipole source (AMS) method is proposed within the framework of the lattice Boltzmann method. A quadrupole term is directly included in the stress system (equilibrium momentum flux), and the dependency of the quadrupole source in the inviscid limit upon the fortuitous discretization error reported in the works of E. M. Viggen [Phys. Rev. E 87, 023306 (2013)] is removed. The regularized lattice Boltzmann (RLB) method with this variant AMS method is presented for the 2D and 3D acoustic problems in the inviscid limit, and without loss of generality, the D3Q19 model is considered in this work. To assess the accuracy and the advantage of the RLB scheme with this AMS for acoustic point sources, the numerical investigations and comparisons with the multiple-relaxation-time (MRT) models and the analytical solutions are performed on the 2D and 3D acoustic multipole point sources in the inviscid limit, including monopoles, x dipoles, and xx quadrupoles. From the present results, the good precision of this AMS method is validated, and the RLB scheme exhibits some superconvergence properties for the monopole sources compared with the MRT models, and both the RLB and MRT models have the same accuracy for the simulations of acoustic dipole and quadrupole sources. To further validate the capability of the RLB scheme with AMS, another basic acoustic problem, the acoustic scattering from a solid cylinder presented at the Second Computational Aeroacoustics Workshop on Benchmark Problems, is numerically considered. The directivity pattern of the acoustic field is computed at r=7.5; the present results agree well with the exact solutions. Also, the effects of slip and no-slip wall treatments within the regularized boundary condition on this pure acoustic scattering problem are tested, and compared with the exact solution, the slip wall treatment can present a better result. All simulations demonstrate that the RLB scheme with the AMS method is

关键词： Acoustics Lattice-Boltzmann methods

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A static analysis tool with optimizations for reachability determination 17

A static analysis tool with optimizations for reachability d...

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IEEE International Conference on Automated Software Engineering (ASE)

作者： Yuexing Wang Min Zhou Yu Jiang Xiaoyu Song Ming Gu Jiaguang Sun Ministry of Education Key Laboratory for Information System Security China School of Software Tsinghua University China Tsinghua National Laboratory for Information Science and Technology (TNList) China Electrical and Computer Engineering Portland State University USA

ISBN: (纸本)9781538626849

To reduce the false positives of static analysis, many tools collect path constraints and integrate SMT solvers to filter unreachable execution paths. However, the accumulated calling and computing of SMT solvers are time and resource consuming. This paper presents TsmartLW, an alternate static analysis tool in which we implement a path constraint solving engine to speed up reachability determination. Within the engine, typical types of constraint-patterns are firstly defined based on an empirical study of a large number of code repositories. For each pattern, a constraint solving algorithm is designed and implemented. For each program, the engine predicts the most suitable strategy and then applies the strategy to solve path constraints. The experimental results on some well-known benchmarks and real-world applications show that TsmartLW is faster than some state-of-the-art static analysis tools. For example, it is 1.32× faster than CPAchecker and our engine is 369× faster than SMT solvers in solving path constraints. The demo video is available at https://***/watch?v=5c3ARhFclHA&t=2s.

关键词： Tools Algorithm design and analysis Engines Benchmark testing Visualization Optimization

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Influence of Sn addition on mechanical properties of gas tungsten arc welded AM60 Mg alloy sheets

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Transactions of Nonferrous Metals Society of China 2016年第8期26卷 2051-2057页

作者： Jun GOU Ai-tao TANG Fu-sheng PAN Jia SHE Su-qin LUO Jun-hua YE Da-wei SHI College of Materials Science and Engineering Chongqing University Chongqing 400044 China National Engineering Research Center for Magnesium Alloys Chongqing University Chongqing 400044 China Chongqing Academy of Science and Technology Chongqing 401123 China Science and Technology on Reactor System Design Technology Laboratory College of Materials Science and Engineering Guilin University of Technology Guilin 541004 China

The effects of Sn addition on the microstructure and mechanical properties of gas tungsten arc butt-welded Mg?6Al?0.3Mn (AM60) (mass fraction, %) alloy sheets were investigated by optical microscopy, scanning electron microscopy, X-ray diffraction, transmission electron microscopy, and microhardness and tensile tests. The results indicate that both the average microhardness and joint efficiency of AM60 are improved by the addition of 1% Sn (mass fraction). The ultimate tensile strength of Mg?6Al?1Sn?0.3Mn (ATM610) reaches up to 96.8% of that of base material. Moreover, fracture occurs in the fusion zone ofATM610 instead of in the heat-affected zone of AM60 welded joint. The improvement in the properties is mainly attributed to the formation of Mg2Sn, which effectively obstructs the grain coarsening in the heat-affected zone, resulting in a relatively finemicrostructure. The addition of 1% Sn improves the mechanical properties of AM60 welded joint

关键词： AM60 Mg alloy ATM610 Mg alloy gas tungsten arc welding mechanical properties

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Dynamic Migration of Surface Fluorine Anions on Cobalt‐Based Materials to Achieve Enhanced Oxygen Evolution Catalysis

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Angewandte Chemie 2018年第47期130卷

作者： Pengzuo Chen Tianpei Zhou Sibo Wang Nan Zhang Yun Tong Huanxin Ju Wangsheng Chu Changzheng Wu Yi Xie Hefei National Laboratory for Physical Science at the Microscale iChEM (Collaborative Innovation Center of Chemistry for Energy Materials) CAS Key Laboratory of Mechanical Behavior and Design of Materials University of Science and Technology of China Hefei Anhui 230026 P. R. China National Synchrotron Radiation Laboratory University of Science and Technology of China Hefei Anhui 230029 P. R. China

Fluorine‐anion surface engineering has now been used to activate catalytic active species, representing a completely new way of reconstruction toward oxygen evolution reaction (OER) active species. The electronegativity of the fluorine anion is the strongest so that it will be much easier to form weak metal–fluorine bonds with stronger ionicity, contributing to the dynamic migration of fluorine anions and finally enriching on the surface of both cobalt‐based oxide/oxyhydroxide. Surface enrichment of fluorine anions endows more hydrophilic surface character for accelerating the key process of oxygen‐related intermediate adsorption. Combining with an obviously improved electron transfer capacity, the F‐CoOOH/NF catalyst exhibits a greatly enhanced OER activity (270 mV at 10 mA cm −2 ) and reaction kinetics (54 mV dec −1 ) in alkaline medium. Surface anion engineering introduces a new concept for rational design advanced OER catalysts for energy conversion system.

关键词： Cobaltoxide Dynamische Migration Fluorid Oberflächenrekonstruktion Sauerstoffentwicklung

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On the lift force modeling for single bubble in water 3

On the lift force modeling for single bubble in water

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3rd International Topical Meeting on Advances in Thermal Hydraulics 2016, ATH 2016

作者： Li, Zhongchun Song, Xiaoming Jiang, Shengyao Ishii, Mamoru Science and Technology on Reactor System Design Technology Laboratory Chengdu610041 China Nuclear Power Institute of China Chengdu610041 China Tsinghua University Beijing100084 China Department of Nuclear Engineering Purdue University 47906 United States

ISBN: (纸本)9780894487330

Lift force is one of the interfacial momentum transfer terms in the framework of two-fluid modeling. It is vital for accurate understanding of two phase flow system. The present study concluded the lift force modeling and correlations proposed using analytical, experimental and numerical approaches. The correlations were assessed with the existing experimental and numerical simulation results. The regions where insufficient data and contradictions between modeling and experimental data were presented were identified. A strategy for the lift force modeling was proposed based on the similarity between drag force and lift force. In addition, the effects of bubble size, fluid properties, contamination and shear flow rate were discussed. © 2016, American Nuclear Society. All rights reserved.

关键词： Shear flow

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A flexible nonlinear diffusion acceleration method for the first order eigenvalue SN equations discretized with discontinuous FEM

A flexible nonlinear diffusion acceleration method for the f...

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Physics of reactors 2016: Unifying Theory and Experiments in the 21st Century, PHYSOR 2016

作者： Schunert, Sebastian Wang, Yaqi Ortensi, Javier Gleicher, Frederick Baker, Benjamin DeHart, Mark Martineau, Richard Thermal Science and Safety Idaho National Laboratory Idaho FallsID United States Reactor Physics Analysis and Design Idaho National Laboratory Idaho FallsID United States Nuclear Science and Technology Modeling and Simulation Idaho National Laboratory Idaho FallsID United States

ISBN: (纸本)9781510825734

This work describes a nonlinear diffusion acceleration (NDA) method for the first order SN equations that discretizes both the transport equation and the associated diffusion system using discontinuous finite elements;the diffusion system is solved on a potentially coarser mesh and with a coarser energy group structure than the SN equations. The developed method differs from current methods by allowing the SN and diffusion system to be discretized with arbitrary FEM bases and by using an additive update of the SN system. The benefit of this capability is extension of the stability region to optically thicker mesh cells without underrelaxing the iterative algorithm. The presented method introduces the notion of consistency of the SN and diffusion solutions and derives suitable definitions of the cross sections, drift vectors, and element face closures. The NDA equations are solved using a Picard iteration scheme. Numerical results are presented for the C5G7 benchmark problem highlighting the effectiveness of the methods when deployed with the diffusion system discretized on the same mesh as the SN system. Additional results are presented for cases where the diffusion system features a coarser mesh, coarser energy group structure, or both, demonstrating its stability and effectiveness in these cases. It is observed that the effectiveness of the NDA method reduces when reducing the resolution of the associated diffusion system.

关键词： Finite element method

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Application of Arduino Control Mainboard with Color Light Sensor TCS3200 in Color Recognition of Edge Banding In Laser Edge Banding Machine

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IOP Conference Series: Earth and Environmental science 2019年第2期252卷

作者： Trong Tuan Nguyen Tat Thang Nguyen Van Tuu Nguyen Chi Cong Cao Jun Hua Department of Mechanical Design and Theory College of Mechanical Engineering Northeast Forestry University Harbin 150040 China Vietnam Academy of Forest Sciences Ha Noi Vietnam Key Laboratory of Bio-based Material Science and Technology of Ministry of Education Northeast Forestry University Harbin 150040 P.R. China. Vietnam National University of Forestry Ha Noi Viet Nam Traffic College Northeast Forestry University Harbin 150040 P.R. China.

In the laser edge banding system, automatic color reading and adjustment of input color matching that of edge banding is an important factor in achieving high automation level. This paper describes a working prototype designed for color-based automatic sorting of objects. TCS3200 sensor was used to detect the color of the product; and Arduino board was used to control the overall process in which matching sealing edge was introduced. Color input was based on analysis of reading of TCS3200 sensor. Results illustrated matching of color in a series of products coded E1, E2, E3, E4, E5, E6, E7, and E8. According to the results, we concluded that laser edge sealing reduces unstable factors, reduces labor and stalibizes product quality.

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