Papers by Author: Ying Xue Yao

Abstract: High speed machining is a promising technology for significantly increasing productivity and reducing production costs. Development of high-speed spindle technology is strategically critical to the implementation of high speed machining. Compared to conventional spindles, and motorized spindles are equipped with built-in motors for better power transmission and balance to achieve high-speed operation. However, the built-in motor introduces additional mass to the spindle shaft, besides, since its very high working speed, some high-speed rotational effects, including centrifugal forces and gyroscopic moments on the spindle shaft can not be neglected in the analysis as is done in conventional spindle, thus complicating its mechanical-dynamic behaviors. In this paper, the FEM model of motorized spindle is set up to research on its dynamic characteristics in theory with an eye to high-speed rotational effects, including centrifugal forces and gyroscopic moments on the motorized spindle shaft. The motorized spindle’s natural frequencies and corresponding vibration shapes are got through the modal analysis, and the effect of the axial preload on the natural frequency is programmed to be seen clearly.

Abstract: Cutting parameters play an essential role in the economics of machining. In this paper, particle swarm optimization (PSO), a novel optimization algorithm for cutting parameters optimization (CPO), was discussed comprehensively. First, the fundamental principle of PSO was introduced; then, the algorithm for PSO application in cutting parameters optimization was developed; thirdly, cutting experiments without and with optimized cutting parameters were conducted to demonstrate the effectiveness of optimization, respectively. The results show that the machining process was improved obviously.

Abstract: The NC machine tool is widely used in today's manufacturing industry. In this paper, a framework of the NC lathing dynamic simulation system is presented and the machining process simulation is developed based on the solid modeling method with ACIS geometric engine and 3D graphic display. The tool swept volume is designed and Boolean difference of the cutter swept volume with the raw stock in the system is calculated. The user or trainee can practice all operations, procedures and skills in complete safety, while maintaining a high degree of realism.

Abstract: Virtual manufacturing (VM) is an emerging technology that provides a digital tool for the optimization of the production efficiency through simulations prior to the start of actual production. A NC program translator is one of the crucial components for virtual machining which allows the simulation and verification of NC tool path before actual machining. In this paper, a framework of a NC program translator for diamond turning of precision optics is presented.

Abstract: The influence of parameters to load performances of a high-speed externally pressurized spherical gas bearing compensated by two-rows of orifices has been studied numerically based on finite element method (FEM). Reynolds equation governing the flow field in the clearance space in spherical coordinates system is transformed into a analogous style in Descartesian coordinates by parameter substitution, and Galerkin weighted residual method is applied to reduce the order of derivatives of the transformed equation. Pressure distribution on the gas-film is obtained by solving of the equation. On the basis of theories, influences of rotating speed, nominal gas-film thickness and supplying pressure to load carrying capacity and stiffness are analyzed. Comparison of performances between hydrostatic and hybrid state of the bearing has also presented.

Abstract: Due to the worldwide competition of manufacturing industry and the development of virtual reality (VR) technology, virtual assembly (VA) has attracted many researchers to reduce development cost and improve product quality. As a typical application of VR in engineering, VA has become increasingly important for modern industry. In this paper, a survey of research progress about VA is analyzed. The conception and architecture of VA are introduced at first, the classification is also presented, then the main research contents and key techniques are discussed, finally the limitations and future works are pointed out.

Abstract: A piezoelectric ceramic power supply with self-feedback adjustment was developed according to piezoelectric ceramic driver’s characteristic. It uses multi dc voltages connected in series as the high voltage supply circuit, and has many advantages, such as small ripple, high precision, high driving capability, quick response and so on.

Abstract: Nanoindentation has become the main method to obtain the micro- characteristic of materials by now. Nanoindentation device has the ability to make the load-displacement measurement with sub-nanometer indentation depth sensitivity, and the nanohardness of the material can be achieved by the load-displacement curve. The article discusses a new convenient nanohardness testing device, and approves its practicability and reliability by taking the indentation experiment on single-crystal aluminum.

Abstract: For spherical rotor of gyroscope and some other high speed rotor, static balance is important. The paper introduces a static balance method for spherical rotor: the position of the spherical rotor is fixed by the use of the special clamp apparatus, and then determines the unbalance mass using the electronic balance. This method has no strict requirement to the clamp’s symmetry and dimension and locating precision of the locating hole. The balance precision only depends on the precision of the electronic balance and shape error of the clamp’s locating surface, which makes the balance method has high precision and preferable operability.

Abstract: Nano-hardness test device has the ability to make the load-displacement measurement with sub-nanometer indentation depth sensitivity, and the nanohardness of the material can be got from the load-displacement curve by Oliver-Pharr method. In order to measure the small displacement accurately, we designed a capacitive displacement measuring system. This capacitance micrometer has a resolution of 0.1nm, and is suitable for our nano-hardness test device.