Key Engineering Materials Vols. 392-394

Abstract: The traditional geometric modeling is generally described by means of Euclidean geometry, and objects for the geometric modeling are usually artificial work-pieces with smooth and regular contour. However in real world, there are so many irregular geometric objects(such as cavernous body, geological body, rough surface body and so on) with extremely complicated structure that the constructing method based on Euclidean geometry equation has been already helpless, while the process constructing method based on fractal geometry can. Taking rough surface body as examples, in order to explore a method for non-rule geometric modeling based on step-by-step subdivision. Research shows that such methods can preferably represent structure characteristics of non-rule geometric modeling, consequently opening up a new way for expanding the scope of geometric modeling and enhancing the capability of CAD.

Abstract: Modern industries use many types of robots. The biped or quadped robots are the most common robots in the robot category. However, in terms of efficiency, flexibility, and stability, the developing tripedal robots could be the best candidate. The research starts from establishing the platform of the tripedal robots. The mathematic model of the tripedal robot is generated by applying the forward kinematics and the inverse kinematics. The research then adopts the MSC Virtual Nastran simulation software to calculate the optimal values applied to the tripedal robots for verification. The major issue is about the balance of the static stability and dynamic stability. The research also tries to develop the most power-saving method and the largest moving steps. The platform of the tripedal robot will become a significant design reference for the commercialization of different industrial robots, and it will provide the design of industrial robots with more options and useful applications.

Abstract: The problems of slow convergence speed and being prone to converge to minimum were solved by combining the characteristics of chaos dynamics in the paper, whose characteristic of combining chaos optimal ergodicity and particle swarm optimal rapidness conquered deficiency of the traditional PSO algorithm. The proposed algorithm used for the decelerator of the electric submersible progressive cavity pump (ESPCP) design optimization compared with that of which was based on the standard PSO and genetic algorithm. By use of property mentioned, optimization searching could be carried out, firstly a series of chaos variables were produced as same number as optimization variable, then chaos was lead into optimization variable by the way of similar to carrier, that made the optimization variable into a chaos state, at the same time, the extent of chaos emotion was magnified to the value range of optimization variable, at last searched by chaos variable, searching technique based on chaos had more superiority than other searching technique. The results showed that the proposed algorithm was superior to the other two algorithms with a better astringency and stability. This article offered a new optimization method in machine.

Abstract: This paper presents that the high-speed steel tools with solid lubrication material coating can cut without fluid because it has the quality of self-lubrication. With the help of M-2 friction and wearing testing machine and KYKY2800 scan electron microscope, the coating preparation technology and mixture ratio of solid lubrication material in complex coating can be optimized. The results show: phosphate treatment can increase the power of the tools’ surface adsorbing solid lubricant, and the frictional behaviour of solid lubrication coating is excellent when surface roughness of phosphate coating is Ra 2μm~Ra 4μm; molybdenum bisulfide, graphite and trioxid aluminium are mixed together and form a kind of complex coating which has better antifriction effect. The cutting test shows that the solid lubricant coating on the high-speed steel tools can be helpful in increasing the service life of the tools, decreasing the cutting resistance, and reducing the chip deformation and surface roughness of finished work.

Abstract: Design reuse is the application of past designs knowledge and successful experience to current design process and it is a significant method for rapid design. A knowledge-reuse-based rapid product design model is proposed and a three-factor product design iterative process model is studied. Finally, it is applied successfully in the rapid product design of construction machinery combining with the requirement of the construct machinery product design.

Abstract: The transient characteristic of single-sided linear induction motor (LIM) was simulated and computed using the electromagnetic field finite element analysis software Ansoft. The change of the thrust, the primary current and the air-gap’s magnetic field of linear induction motor was analyzed under the different air-gap’s size condition. The analysis result shows that, with the growth of air gap, the motor thrust reduces but the primary current increases, and the distribution of motor air-gap magnetic field is uneven due to the existence of end effects. Finally a comparison is made between the simulation result and the experiment result, which indicates the correctness of simulated model, thus it can provide important basis for the manufacture, optimized design and control of LIM which is used in subways.

Abstract: The dimension of micro turbine engine is usually only few millimeters, so the centrifugal structure is usually adopt. It must be designed by transonic speed for the higher single pressure ratio. The speed of the ration axis can reach 105r/min, so the gas bearing is adopt because the general rolling bearing is impossible. This paper designs a new wedge structure for the micro gas journal bearing. First the feasibility of this structure is verified by using the FLUENT software simulation. Comparing the simulation results with various parameters, finally major optimization parameters are confirmed.

Abstract: Based on dynamic loads analysis for high speed milling, to investigate vibration and failure of high speed milling cutter with indexable inserts, and perform modeling for high speed milling stability based on safety. According to the theory of axiomatic design, to process decomposition of function of high speed milling cutter with indexable inserts, found the design matrix of cutter, and propose the design method of cutter based on high speed milling stability, high speed face milling cutter for machining aluminum alloy was developed. The results indicate that an uneven distribution of cutter teeth and higher precision of dynamic balance can depress vibration of cutter, the method of axiomatic design based on stability improves efficiently dynamic cutting stability, the safety and concurrent design cycle of high speed milling cutter.

Abstract: Based on premixed high pressure water jet cutting, five kinds of nozzle models were established, and the control equations and closed equtions of liquid-solid two-phase were given. The inside-outside liquid-solid two-phase flow characteristics of the nozzles were simulated by Hybrid Finite Analytic Method (HFAM). The results indicate that the taper-beeline nozzle has better convergence characteristic, good hydraulic characteristic and lower radical velocity, thus it is more suitable for premixed high pressure water jet cutting nozzle.

Abstract: This paper puts forward the concept of “disposable machine”, analyzes the characters of the disposable machine and introduces the design method of disposable machine taking spur gear for example. The validity of the design has been proved through emulation experiment. Compared with traditional and normal design, disposable machinery has advantages of lower price because of less capacity and weight.