Applied Mechanics and Materials Vol. 709

Abstract: A type automobile belt tensioner brace parts need many times of the clamping in the process of machining, which will lead to the low accuracy ,low efficiency and high cost and so on. This paper based on the structural feature of the brace provided a special fixture for the brace and built a Petri nets model to describe the work process in detail by the analysis of the fixture‘s positioning ,the clamping process analysis and the clamping force analysis. Moreover , This fixture can clamp two belt tensioner brace at the same time during completing the three machining surface of workpiece without changing the fixture,which can clamp the workpiece more convenient with higher positioning accurate ,higher machinging accuracy and lower cost. This fixture has passed the practical proof , which provied a reference for designing a fixture to clamp a workpiece with more complex surface .

Abstract: Abstract：The dynamic design method was used to analyze the vibrating screens, which can reveal the distribution of the dynamic stress in the main structure exactly and ensure safety and rationality of the structure design. The screens of the type 5XF150/180 grain screening machine were analyzed by the dynamic method. And modal analysis, harmonic response analysis and transient dynamic analysis were studied by ANSYS Workbench software. According to the calculated results ,dynamic property and kinetic parameters were determined. Then the key technology in the dynamic design was discussed, which provided a reference to the dynamic design of such large vibrating screens.

Abstract: The regeneration process is simulated under the condition of different expansion tubes by the established model on CFD technology. It turns out that, increasing expansion angle of the expansion tube does good to lower the maximum wall temperature and the axial temperature gradient during the DPF regeneration, while it makes the uniformity of the wall regeneration temperature worse. At the same time, the regeneration rate becomes slower and the radial maximum temperature gradient increases. This study makes great significance to the design and optimization of DPF device structure and prolonging the service life of DPF.

Abstract: A dual-rotor calculation model which can expand freely in the axial direction is established in this paper, and the effects of one-dimensional axial temperature distribution on critical speeds of the dual-rotor system are analyzed with finite element method. The temperature distribution of the dual-rotor system is given referring to that of similar aero-engine rotor system. Assuming that the left end temperature remains at 0 °C, and the highest temperature on the section of the high-pressure turbine disk is 0 °C, 200 °C, 400 °C, 600 °C, and 800 °C respectively, the critical speeds of the dual-rotor system are calculated, analyzed and compared. Calculation results show that, with the increase of the highest temperature of the dual-rotor system, the reduction percentage of the critical speeds increases, and the impact on the first critical speed is most obvious. When the highest temperature is 800 °C, the first critical speed of the rotor system excited by the low-pressure rotor reduces 13.13%, and that excited by the high-pressure rotor reduces 13.49%.

Abstract: The important parts of passenger train—push plates, which force directly coupler and buffer device, and bear heavy load, easily have fatigue damage. The finite element analysis for them is to improve the design , for analyzing structure and checking intensity, so it has a guiding significance.

Abstract: Hydraulic engines can be widely used in many fields, such as agricultural machinery, construction machinery, duty vehicle, and many other fixing or mobile devices. The development analysis and study on their structural principle, technical and operational characteristics will be undoubtedly very useful for putting forward new type hydraulic engines. The structural principle of Hydraulic Free Piston Engine, Hydraulic Confined Piston Engine was introduced. The structural principle of Half Crank Hydraulic Engine (HCHE), which inherits the merits of traditional engine, HFPE and HCPE, was put forward.

Abstract: Traditional oil drilling equipment cannot meet the demand of oilfield drilling technology in the later period. Application of new technologies, energy saving and cost reduction are development directions of the oil pumping machine. This paper introduces a new energy-saving hydraulic pumping unit with hydraulic energy recovery system, which drives the hydraulic cylinder to finish pumping action that can reduce the equipment power by 40% under the same load. In this paper, the mechanical structure of a new type of oil pumping unit is built and analysis is done by Pro/E software. The analysis results show: The guiding vehicle mechanism itself contributes to counterweight, and hydraulic actuator is directly connected to the base. So it has the advantages of a simple structure, saves steel, light weight, smaller in size and the manufacturing process requirements are not high. This shows that the machine can directly replace the traditional conventional beam pumping unit and has higher application value.

Abstract: This paper introduces the basic function research idea and design scheme of the unity machine, combining with the actual production needs for stemming making blockage machine. This machine adopts pneumatic motor as power source to drive agitator and pump. It can achieve stemming production and the blockage of blasthole. It designs chassis which can walk and steer and workbench lifting mechanism used to implement each blasthole of tunnel face blocked automatically

Abstract: This paper does unidirectional fluid-solid coupling calculation on the runner strength under three designed head loading conditions of a certain Francis turbine in the north-eastern China. The water pressure on the blade in the flow fields of different operating conditions is calculated by means of CFD software CFX. With the help of ansys workbench, the water pressure is loaded to the blade as structural load to conclude the static stress distribution and deformation of the runner under different operating conditions. The results show that the maximum static stress increases with the rise of the flow and appears near the influent side of the blade connected to the runner crown; the maximum deformation increases with the rise of the flow and appears on the band. The results provides effective basis for the structural design and safe operation of the Francis turbine.