Papers by Author: Chao Jun Yang

Abstract: Hitachi force motor valve has been widely used in the hydraulic automatic gauge control (AGC) system of rolling mill due to the characteristics of fast response, high control accuracy and strong anti-pollution ability. It is an important part to control the steel production cost by detecting the performance index of the FMV effectively and in real time. Traditional Servo valve test system detects its static characteristics through the flow and pressure changes between the traffic cavity, and this principle can solve the three position four way servo valve performance test. However, FMV is a special three-way valve and it is hard to test its static characteristic curve like three position four way servo valve. This paper proposes a FMV testing method and has realized it. The test platform is designed and built according to the hydraulic valve testing performance index for detecting the performance of a force motor valve. Not only were force motor valve (FMV) performance characteristics tested effectively but also the performance curves were drawn. The results show that the FMV performance testing method we have built can be effectively used to detect the static performance index of FMV.

Abstract: A field-modulated asynchronous magnetic coupling is a new type of composite magnetic transmission mechanism, which is based on the principles of magnetic field modulation and electromagnetic induction. The rotational velocity and direction of the inner conductor rotor could be changed, since the magnetic field generated by permanent magnet outer rotor is modulated by ferromagnetic pole-pieces. Therefore, the couplings can meet special conditions with special requirements for load and speed. The formula of the modulated magnetic flux density of inner air gap is analyzed through magnetic field analytic approaches, and then the formula of transmission ratio is also deduced by introducing slip ratio in the mean time. Finally, experimental research of the coupling is conducted. The results show that the transmission ratio of the coupling is not only related to the ratio of the number of pole pairs on outer permanent magnet rotor and the number of pole pairs of magnetic field flux density harmonic, but also related to the slip ratio. Besides, the transmission ratio of the coupling increases non-linearly with the slip ratio.

Abstract: This paper, by using technology of structural equation model (SEM) of the PLS model, discussed the relationship between FDI and promoting green innovation capability of MGIS. The research finds that it has a positive effect on FDI inflows to green innovation resources of MGIS inputs, but FDI information inflows have an inhibitory effect on the manufacturing green innovation human resources. At the same time, green innovation resources of MGIS inputs also have a positive effect on the green innovation capability, but the green innovation resources has an inhibitory effect on the green R&D capability. This paper also finds that based on the intermediary role of innovation resources, FDI inflows have a significant positive influence on green R&D capability and green manufacturing capability, but they have inhibitory effect on the market development capability for green products.

Abstract: The technique of hull block accuracy control is the main concern for modern shipbuilding. The method of no-excess block construction is introduced in Sevan Driller, the world’s first cylindrical ultra-deep offshore drilling platform. According to the structural characteristics of the drilling platform and production capacity, the partition and construction programs of the hull blocks are proposed. Modeling and drawing for platform in the design stage is analyzed. In the manufacturing stage, the factors affecting the block accuracy include plate-cutting, plate alignment, marking, assembling and welding. Additionally, the range of accuracy controlling aspect and compensation values are confirmed. The application of no-excess block construction in this drilling platform results in the improved quality of the drilling platform, reduced shipbuilding costs and the shortened shipbuilding cycle.

Abstract: Transmission performances of some squirrel cage magnetic couplings, which were different in magnet pole number, slot number, slot depth or slot area, were tested. Experimental results and analysis indicate that these parameters (magnet pole number, slot number, slot depth and slot area) all affect transmission performance of a squirrel cage magnetic coupling. In these factors, deep slot can not only increase slot area to improve a squirrel cage magnetic coupling’s transmission performance, but also can make skin effect on conducting bars more obvious to further improve the transmission performance. Therefore, slot depth affects transmission performance of a squirrel cage magnetic coupling greatly. The experimental results show that a deep slot squirrel cage magnetic coupling’s transmission performance is much better than a common one.

Abstract: Towing the large-scale drilling platform without self-propulsion is difficult. Towing resistance calculation is necessary for safe pilotage. The tug power decision and the fleet arrangement should be confirmed according to the features and performance of towed vessel, water flow, air flow and other meteorological factors in towing route. The resistance calculations of towed vessel and tugboats are carried out. Whether it is suitable to be towed by the fleet will be verified in accordance with the calculations of the hauling power of tugboats. In this paper, the towing resistance of the cylindrical ultra-deep drilling platform without self-propulsion capability is studied, which could provide reference for other cylindrical structures on the implementation of towing plans.

Abstract: Towing the ultra large ships without power is one of the difficult and high-risk navigation operations in the Yangtze River and coastal waters, where the ship flow is large and navigation environment is complex. For towing operations, the environmental, hydrological and meteorological factors should be taken into consideration. Firstly, making detailed towing programs is essential. The towing programs include the towing routes choice, the arrangement of tugboats and ropes. Then the towing experiment on the ultra-deep drilling platform Sevan Driller are carried out, and the security measures and urgent arrangements in the special environment are analyzed in detail. Through the towing work of the ultra large cylindrical offshore drilling platform with unpowered devices, experience and guidance could be provided for the same types of ships in the future.

Abstract: A new-type of solid rotor asynchronous magnetic coupling which works on the principle of electromagnetic induction is researched by ourselves. This kind of asynchronous magnetic coupling can solve the problem effectively that the permanent magnets on its inner rotor is demagnetized if its temperature is too high, because its inner rotor need not the permanent magnets. in order to study the transmission capability of the new-type magnetic coupling, its magnetic field should be analyzed. Because of its magnetic field variety, it is extremely complicated and a precision result is difficult to be got by the analytic method of the magnetic field calculation. Here the software ANSYS FEM is used to analyze its magnetic field. And some formulas were deduced and used to calculate its torque. The experimental and calculational results indicate that this design is practicable.

Abstract: The laser peen forming (LPF) uses high-power pulsed laser beam replacing the tiny medium balls to peen the surface of plate and generate compressive stress near the surface, the metals respond to this residual stresses by elongating at the peened surface and effectively bend the overall shape. In this paper, the deforming process of metal plate induced by repetitive pulsed laser was discussed from theory firstly, and the bending mechanism of LPF was investigated. Then a mathematical model of bending curvature concerning the depth of residual stress was presented, the influence of residual stresses on the deformation of plate was analyzed. Lastly, the line-track-peening experiment for SUS 304 plate was carried out to evaluate the reasonability of the theoretical analysis model.

Abstract: The laser honing technique is a new surface texturing technique. As the piston ring at the top or lower oil attachment point works under worse lubrication condition, its wear increases severely, laser texturing was used to the piston ring/liner, lineary extending grooves and regular arranged dimples with predetermined parameters was well-matched with the needs of lubrication. The effects of different dimple shapes, such as sphere coronal, combined sphere coronal ,columnar, hexahedral, and trapezoidal dimples was analyzed by the theory of hydrodynamic lubrication. It was deduced that trapezoidal dimples are fit for only single running orientation and sphere coronal and combined sphere coronal dimples are fit for double running orientations. The experimental researches show that laser texturing not only can reduce the oil consumption and the cost of engine but also can prolong its work life.