Abstract: Ball screw is the key parts of NC machine, precise instrument and many kinds of mechanical devices. Whirlwind milling is a new and effective thread manufacture technology. This article studies the internal heat conduction equation of whirlwind milling ball screw based on Heat Transfer, calculates ANSYS simulation result. The simulation results show that the surface temperature distribution rule and internal temperature distribution rule of a ballscrew is consistent. The article analyzes the influence factors of the thermal elongation. It provides a basis for compensating the thermal deformation error of whirlwind milling ballscrew.
Abstract: The BP neural network model based on PSO particle swarm optimization algorithm is analyzed in this paper. The engine speed and torque is the input of the network and the fuel consumption rate is output. Appling PSO algorithm to optimize BP neural network weights and threshold value, which makes the BP network having high precision nonlinear mapping relation, and then realize it by MATLAB software. Practice proves that the method is effective and it provides a new method of rendering engine characteristic curve fitting.
Abstract: The paper mainly aimed at the complex manufacturing system of high-end special equipment which is multiple and nested.To search and establish a transmitting structure model .The model is about complex logistics operations distribution and it has a reconfigurable organization form. Research a new theory about all-around logistics operations which is cooperative multitasking planning scheduling based on super cubic path dynamic link algorithm. It solve the key theory problem caused by not real-time scheduling for logistics operations dynamic planning and not sensitive conduction for self-response required by the reconfigurable of production organization form in the operation of complex manufacturing system which has a great varietal model varieties and great varietal process sequences
Abstract: Direct metal sintering rapid prototyping mechanism is complex, including many kinds of transmission systems. Spreading powder device is important to direct metal sintering rapid prototyping mechanism. Based on grasping the working principle of the device, through the study of spreading powder device of direct metal rapid prototyping machine, grasp the process of spreading powder and the main structure of the device, and fabricate the simple model of the transmission system. In order to determine the necessary condition of how the spreading powder device functions, the dynamic parameters of the transmission system must be calculated, and the operation performance of the stepper motor must be checked. Then the precision and the processing quality of the finished part can be improved.
Abstract: The refueling process of a high-pressure vessel fixed on the rocket-propelled spacecraft was analyzed by the gas kinetics theories and the thermodynamics of variable mass system. A mathematical model was built up to simulate and analyze the refueling process so as to get rules of the pressure and temperature changes and lay the foundation for the design of the fast refueling control algorithm. During the simulation, the thermodynamic model based on natural convection was adopted to make the simulation close to the actual process. The studies shows that the best way to decrease the temperature of the gas within cylinder during refueling and keep the whole time prolong slightly is increase the heat transfer coefficient of cylinder and decrease the volume of stationary tank within measure.
Abstract: Mobile tail is an important part of the telescopic belt conveyor. It relies mainly on the hydraulic system to achieve its various functions, while the hydraulic height adjustment system is the basis of its different functions. So the operational principle of hydraulic height adjustment system of mobile tail was analyzed in this paper. Parameters which may affect the dynamic process were analyzed. Software AMESim was used to model and simulate the dynamic process. The velocity and displacement of piston and the pressure of the hydraulic cylinder were calculated by the software. Different pump flow and different heart diameter of one-way valve were used to analyze their influence on dynamic process, which provide a reference to the optimal design of hydraulic system of mobile tail.
Abstract: As an important part in sliding-limiting differential, the variable ratio noncircular bevel gears can increase the locking factor of the bevel gear differential and improve the vehicles’ off-road capability in transit. At present, this differential has become a study hotspot that many researchers are working over because of its compact structure, cheap cost, good assembly and perdurable capability. In order to get the bevel gear’s processing accuracy, this paper introduced the generating process of the bevel gear’s CMM measuring path, probed the similarity in motion between spherical cutter’s CNC machining and CMM measuring, and then simulated and analyzed the bevel gear’s CMM measuring path by power mill in use of NC authentication method, which provided a reference for the choice of complex surfaces’ measuring methods.
Abstract: The secondary system of Qinshan phase I nuclear power plant is simulated in this study. According to the characteristics of the JTopmeret model, the system is divided into six parts for modeling, which are the deaerator, the high pressure (HP) turbine, the low pressure (LP) turbine, the moisture separator reheater (MSR), the condensate system, and the feedwater system. All parts are built as the graphic automatic models in JTopmeret and debugged on the large-scale simulation platform GSE to complete the steady-state and dynamic simulation of the models. The results show that the steady-state and dynamic processes of the models are consistent with the characteristics of the actual system. It verifies the correctness of the simulation models. Thus, this research is able to provide guidance for the operation analysis and the equipment debugging of the secondary system of the nuclear power plant.
Abstract: Flow Shop Scheduling Problem is a class of scheduling problems with a work shop in which the flow control shall enable an appropriate sequencing for each job and for processing on a set of machines in compliance with given processing orders. In this paper, we propose a new heuristic algorithm based on the analysis and research of which problem, the new method introducing a evaluate mechanism of the relative position of any two jobs to the completion time, and the efficiency and performance has been improved .The result of simulation experiments shows that, our new heuristic algorithm has good performance, and the average quality and stability of scheduling sequences generated by new method is significantly better than other heuristic algorithm which has the same complexity.
Abstract: In order to predict defects of a complex casting that may arise during the die casting, The numerical analysis technique of Fluent' s VOF was used to establish the filling model. Based on the case of the wheel, it is expounded that the numerical simulation of VOF was utilized in application of casting. The five groups of simulation analysis were performed under the different pouring pressure. At last the pouring pressure has a great influence on the state of filling and the filling times are little difference. The research on pouring pressure and flow field during the casting process of wheels was conducted. The results of the study show that, when the pouring pressure is about 60000 KPa, the cavity is completely filled with the molten aluminum alloy.