Advanced Materials Research Vols. 989-994

Abstract: There is also a monomer leak valve body on the single spool, Leakage between the guide groove affected the layout of the form guide groove. Two end faces of the single spool work in the different fluid pressure in the chamber. When the working pressure of the hydraulic system is high, the pressure differential will cause the spool bearings subject to large axial force. It will increase the resistance torque of bearing rotation. Effects of axial force also limits the increase spool diameter. Double spool valve with two spool rotation series manner. Each spool in the same pressure in the working medium. Eliminating the axial force of the valve body due to fluid pressure differential generated, also reduces the resistance to rotation of the spool moment and the impact of guide groove arrangement by oil leak, and also the commutation frequency of the rotary valve can be improved by increasing the diameter of the spool.

Abstract: Auto-rotated precision of gun barrel is a key operation of firing, and the research of its testing method should depend on its index computing. According to discrete value in the firing table and the exterior ballistic computation based on least square polynomial fit method, the mapping function between battle sight and range dispersion was confirmed. And by analyzing the effect of offset induced by auto-rotated precision of gun barrel, the index function which could offer a data origination for the verification of testing method of auto-rotated precision of gun barrel was provided.

Abstract: Based on design requirements of plug-in hybrid vehicle, using the method of theoretical analysis, the parameters matching design of drive motor, engine-generator set, battery, transmission and other subsystems is executed, and modeling and simulation are carried out using AVL-CRUISE software, simulation results show that the design is reasonable, laying a good foundation for the smooth development of the plug-in hybrid vehicle.

Abstract: Compression deformation will cause a micro-spring to buckle, and structural parameters, constraint conditions and structural forms of a micro-spring will affect its critical load and buckling mode. In order to study the influence on the micro-spring’s stability caused by structural forms and find a structure to improve its critical load in the end, this paper designs a new kind of parallel micro-springs, which consists of two same-structured S-shaped planar micro-springs. We have carried on eigenvalue buckling analysis on the parallel micro-spring by software ANSYS, and have gotten its six orders’ buckling mode. Because the critical load of the parallel micro-spring may change with the length of the beam connecting the two sub-springs, this paper studies the effect of the beam’s length on the parallel micro-spring’s critical loads and buckling mode. From comparing the analysis results between parallel micro-spring and single micro-spring with same stiffness, this paper concludes the stability’s degree of improvement.

Abstract: To achieve high-precision tracking control of motor speed for magnetically suspended reaction wheel, mathematical model combining BUCK converter with permanent magnet brushless DC motor system is established, and a MSRFW speed mode Passivity-based control method is presented. A passivity-based controller of speed tracking is designed in order to enhance the speed of tracking performance. Experiments on MSRW platform show that passivity-based control method can improve the speed of the dynamic response and tracking accuracy, from which the validity is verified.

Abstract: In this paper, the shell’s strength and stiffness is calculated according to the theory of elastic mechanics and elastic-plastic mechanics theory.And the analysis of the ANSYS software verify the reliability of the theoretical calculation . Using ANSYS parameter design language (APDL) and the optimized design module of ANSYS,the author studies Material nonlinear static analysis ,and establish the parametric analysis program.

Abstract: Rotary valve is a device to achieve fast commutation hydraulic transmission . Rotary valve is driven by a hydraulic motor drive and can achieve rapid conversion of the hydraulic circuit . Rotary valve spool by a rotating shaft , housing , shafts and bearings and other components. Guide grooves machined on the spool shaft is evenly distributed for hydraulic cylinder into the oil and return oil conversion. The coordinate gap between the spool shaft and valve chamber bore Because will affect the leakage in the leak. How to improve the guide groove structure We can put the guide groove by high and low partition instead of overlapping arrangement. Reducing leakage within the valve chamber and Meet with the requirements of the spool shaft and valve chamber bore.

Abstract: Radar-scattering characteristic which is an important aspect in stealth technology plays a key role in radar detection. Based on shape technique, this work studied the influence of geometric parameter on radar-scattering characteristic for a tank turret by establishing a scaled model as well as calculating the radar cross section (RCS) of this model. The results show that the tank turret can obtain better radar-scattering characteristic with much lower RCS by optimizing its shape and the dihedral angles between the tank turret and the tank body.

Abstract: Based on multi-layer film interference theory and optimization calculation, a film structure that can satisfy both visible and 1064nm laser camouflage requirements were put forward. The light transmission property of the structure was analyzed systematically and the thickness and refractivity of different layers were obtained.

Abstract: Due to the active inverter in industrial application, if use hard switching mode, not only may have the switch losses, but also may produce electromagnetic interference and harmonic, these power quality is affected. This paper presents the design of a soft-switching active inverter, that active clamped resonant DC-link inverter topology was used on the main circuit, the voltage space vector pulse width modulation (SVPWM) control mode was used on control circuit, using TMS320LF2407DSP programming, while the AT89C51 was responsible for liquid crystal display task, data exchanged and coordinated between double CPU. The experimental results show that, the device switching-losses can effectively reduce, the switching frequency can improve, input power quality can improve.