Advanced Materials Research Vols. 311-313

Abstract: Abstract．High-speed motorized spindle is a promising technology widely used in high speed machining．The lathe motorized spindle is the key component of the high speed NC lathe and the thermal characteristics of the lathe motorized spindle is one of the major factors influencing the performance of the machine tools．In order to improve the accuracy and reliability of the high speed NC lathe，the thermal characteristic of the high speed NC motorized spindle has been studied in this paper．Firstly，the structure feature of the spindle has been introduced and two major internal heat sources of motorized spindle have been investigated．Secondly，the heat transfer coefficients of the major components of the lathe spindle have been conducted．Then，the 2D temperature field model has been developed with finite element method．Based on it, the temperature field and temperature rises of the spindle have been simulated and the reasonability of temperature distribution of the spindle unit has also been discussed．The research results provide the reference to evaluate of the thermal behavior of the high speed NC motorized spindle．

Abstract: he paper introduces the analysis of finite element for gearbox’s intensity, then optimal design for gearbox has achieved good optimal result leading to the weight reduced 3746kg, 23.18%less than original weight with the thickness of the main board as deign variables and the stress and displacement as constraint conditions. The optimization results have practical significance on the structural optimization and the weight of the gearbox, offering reference data for weight reduction of gear box design.

Abstract: Silicone-modified butyl acrylate-methyl methacrylate copolymer latex was prepared via semi-continuous emulsion polymerization with different coupling agents. Effect of coupling agent content on polymerization of acrylate and properties of latex film were discussed in details. It is found that the monomer conversion and degree of crosslinking increased gradually for both Z-6300 and Z-6040 as coupling agent with increasing coupling agent feed concentration. Shear strength and tensile strength decreased with increasing Z-6300 content. While for Z-6040 as the coupling agent, the tensile strength increased with Z-6040 content and the shear strength was in the range of 0～0.6wt%. Dynamic mechanical analysis showed that the freeze resistance of copolymer was effectively improved.

Abstract: Abstract. Pressure balance workover is an advanced downhole operation technique. It can hoist the strings of the tube or put it down under certain pressure. The research on pressure balance workover rig has become a hotspot in both domestic and overseas. Pressure balance workover operation technique has been widely used oversea. At the present time, relevant studies have been developed in China. In this paper, domestic and international technology status is fully analyzed, working principle of hydraulic lifting system is studied, then equivalent calculation model and calculation method of hoist force are put forward, calculation program of hoist force was compiled for the different oil pipe depth, curve and charts changing with the oil pipe depth are given, It provides a theory reference to field operation.

Abstract: The stiffness of cable flight control systems is one of the most important design parameter for aviation aircraft, because it can change the characteristic of control stick and influence the maneuverability and stability of the flight control system. Flexible cable control system is the main type of mechanical flight control system, in which movement can only be transmitted by cable in tension, the stiffness of cable control system is affected mainly by predetermined preload(PP), however the excessive PP would increase friction between cable and pulley which leads pilot an unfavorable maneuver. In this paper, the theoretical stiffness calculation of cable control system with the complex cable braided construction has been calculated and discussed, in addition the effects of cable deflection and linkage pulley are taken into account to obtain a precise stiffness calculation, and also the predetermined preload related to friction is studied through numerical example, as well as the numerical results have been compared with the experimental results.

Abstract: Modern products become more and more complex, the modeling and simulation of them are carried out with different software on heterogeneous platforms, which always caused the heterogeneous data, separated disciplines and cannot obtain the result of unified model correctly. Therefore, a Modelica-based modeling and simulation method for aircraft landing gear is proposed. The landing gear library based on Modelica was established. The unified physical model of landing gear which is composed of structural, thermodynamics and hydromechanics disciplines is constructed. The aircraft landing process, the track of retraction mechanism and the impact work amount of the shock absorber are obtained through multi-domain unified simulation, which provides references for deisgners.