Papers by Author: Bang Chun Wen

Abstract: Established the unsteady oil-film force with rub-impact fault of rotor-stator-bearing system mechanical models by using Lagrange equation, Application of numerical analysis to study it, concluded that the rotor system in frequency as the only incentive system control parameters of orbit and bifurcation diagrams; analysis of the nonlinear behavior of the response of the system and the failure mechanism, provide a theoretical basis for the safe operation of the rotor system and fault diagnosis. The results show that, when the excitation frequency as the only control parameters, the system exist periodic motion, quasi periodic motion and chaotic motion etc abundant nonlinear phenomena.

Abstract: Established the unsteady oil-film force with rub-impact fault of rotor-stator-bearing system mechanical models by using Lagrange equation, Application of numerical analysis to study it, concluded that the rotor system in frequency as the only incentive system control parameters of orbit and bifurcation diagrams; analysis of the nonlinear behavior of the response of the system and the failure mechanism, provide a theoretical basis for the safe operation of the rotor system and fault diagnosis. The results show that, when the excitation frequency as the only control parameters, the system exist periodic motion, quasi periodic motion and chaotic motion etc abundant nonlinear phenomena.

Abstract: According to the LaGrange energy equation, the establishment of the unsteady oil film force of the rotor - stator - bearing system dynamics model, the application of numerical method, the system with the speed change time domain waveforms, amplitude spectra and Axis Orbit, the results show that: the unsteady oil film force and speed of change is closely related to changes in the process of oil film force oil whirl Oil Whip. Provide a theoretical basis for effective diagnosis of rotor - stator - bearing oil film instability fault research.

Abstract: It expounded the design quality connotation, product generalized quality was “the integrated embodiment of product function and performance”, the generalized product quality and the whole function and performance are equivalent. Clearly it made the design quality concretized into the product function and three performances. Expounded the concept of product design quality control, analyzed the influencing factors of product design quality, formed the design idea of quality control; aiming at the existing problems of traditional product design, established design quality control preliminary model by applying systematic design theory.

Abstract: Based on Newton method, the nonlinear differential equation of FSI vibration of hydraulic pipe on aero-engine has been established. The equation include visco-elastic coefficient, and the dimensionless equation was got. The influence of mass ratio, velocity of fluid and axial force on natural frequency of the pipe was researched by analyzing the FSI vibration equation of the pipe. The influence of fluid pressure on natural frequency was verified by experiment. And vibration response of the pipe was obtained by experiment at different driving frequency. The conclusion of the experiment was consistent with the result of the theory.

Abstract: The dynamic model of a rotor system of assembled compressor is established. Based on the single axis analysis, and considering the tilting-pad bearing stiffness characteristics with speed variations, the paper analyses whole system’s nature characteristic with gearing mesh factors. It mainly expands with the form of amplitude-frequency drawing and spectrum charts, and examines the dynamic response with each key position of coupled systems under the two working conditions. The results show that, because of the existence of gear meshing effect, Low speed axis and high-speed axis in the corresponding speed shaft appeared a few larger vibration amplitudes, at high speed axis add unbalance force, can arouse resonance of this axis in the first two order critical speed, but in the other axis don’t have obvious display.

Abstract: The rub-impact fault of Jeffcott rotor system which is generally made of an elastic shaft with supported by two bearings at ends and a lumped mass at the mid-span of shaft is the main research subject of this paper. The mechanical model and finite element model of a lump mass at the mid-span of shaft is set up. The dynamics of it are studied by nonlinear finite element method under the rub-impact conditions, and by investigating the effects of stiffness of stator and the clearance between rotor-stator. From the study results, use finite element method to study the rotor system failure problem is intuitive and convenient, high accuracy, high reliability, can be widely applied.

Abstract: The A new design method of the products named “Systematize Design” has been advanced in this paper. From the view of the point of the system engineering, the planning of product design makes the product design qualities improve to a great extent. Besides the understanding of the client requirements, the design planning of products, the so-called 7D’s: Design ideas, Design environments, Design objective, Design process, Design contents, Design methods and the Design quality evaluation, should be considered completely and planned systematically. Based on the previous work, the product design should be conducted according to the systematic design method. The paper makes a detailed expatiation of the systematic design method, viz. 1+3+X design method, in which 1 represents the optimal design for product functions, 3 means the design method synthesizing the dynamic optimization, intelligent optimization and visualized optimization combined organically, and X is the design method for the special requirements of the products.

Abstract: The product design theory and methods based on “the Scientific Outlook on Development” have been set up by our group in recent 10 years, The new progress concerning Research of product design theory and methods include: 1) QCTES was instead of IQCTES including six requirements of product design; 2) traditional design stages were replaced with four new stages including investigation, planning, implement and inspection; 3) green design was replaced with harmonious design; 4) traditional design method was replaced with deep-layer design method; 5) concept and connotation of product top-layer design were proposed; 6) more detailed contents of product synthesis design method were advanced. We got good effects to apply above product design methodology on many product designs recent years.

Abstract: Linear rolling guide is one of the most essential parts of the NC modern machine tools, and they play a significant supporting and guiding role in machine tools components. Especially, the joint surface between guides has great influence on machine's dynamic characteristics. According to this, in this work, taken the Japanese THK Corporation's SNS35LR rolling guide as specific study object, the finite element model of guide pair has been established with the joint surface influence considered. And by the method of the theoretical analysis with the experimental confirmation combined; the dynamic characteristics of the linear rolling guide pair's were studied relatively. Thus, the theoretical model and the finite element model established in this paper can be confirmed by the experiment. It has been found that the theoretical models established are consistent with the results of experiment. This study results can provide useful guidance for the dynamic analysis and the structure optimization of CNC machine tools, and numerical simulation in engineering and design in the development of such machines with rolling guide used.