Applied Mechanics and Materials Vols. 37-38

Abstract: The mean sliding friction factor was derived in the mixed elasto-hydrodynamic lubrication state, which contains the complete elasto-hydrodynamic and boundary lubrication synchronously. Based on the geometry and load contact characteristics of spiral bevel gears, the power loss from sliding friction of each point on the long axis of the instantaneous contact ellipse was calculated. Meanwhile, the function of sliding friction power loss in a mesh cycle was established. The meshing efficiency was obtained by integrating the above function. In addition, the meshing efficiency was increased through optimizing the contact parameters. The validity and superiority of the algorithm was demonstrated with analyzing an example.

Abstract: An adaptive tool system of polishing robots for large freeform surface which is installed discoid tool is proposed. To improve processing efficiency, the mechanical of adaptive tool system adjust to curvature changing of large freeform surface is designed. Adaptability of the processing is analyzed and simulated, and kinematic equation of tool system is established. The polishing process of large freeform surfaces with tool system is analyzed.

Abstract: The wiring of small mechanical and electrical equipment is one of the bottlenecks in rapid R&D and reliability. The path optimization is the essence of wiring. The paper proposed a new automatic wiring method based on improved A* algorithm, which adapts to three-dimensional path search. The cost for bending and processing was introduced into evaluating function, the rigidity factor was also introduced to improve search efficiency. The wiring module for virtual assembly is developed by UG API implementation. The results show that the method is effective.

Abstract: Only in the middle section of the tooth width, the profile of the gear with arcuate tooth traces is involute; the profiles are envelopes of hyperbolas in the other sections which arevparallel to the plane mentioned. Up to now, there is no publication dealing with the possibility of modification. By using mathematics in meshing theory, this paper shows that the gearing only with reference center distance could be used other than with modified center distance.

Abstract: Since almost all large die surfaces are free-form surfaces, currently, these are mostlty manually polished. In order to overcome this barrier, floating face polishing is a feasible polishing technology. The polishing force is a key problem of floating polishing technology. This paper tries to study face polishing force on base of analyzing 3D polishing physical model. The paper focuses on the establishment of the model of face polishing force with full friction condition. The research results will be used for the development of a portable, state-of-the-art polishing machine and the optimization of the associated polishing process parameters in the near future.

Abstract: A new computer-aided control system was developed for the first time, by adopting parallel testing design ideas in this paper. It solved, both of hardware and software, in the industrial field of many interferential factors and the complex process of measurement and control, the problems in dynamic test as high- precision and high-reliability, such as synchronous acquisition of multi-parameter and data processing and so on. This achievement filled the gaps in this field. The test results showed that the stability and reliability and high precision of the system fully meet the requirement of measurement and control for hydraulic impact machine.

Abstract: This paper introduces a methodology to evaluate and calculate the transmissible torque of the HSK-E tool system based on FEM. Calculation method of the transmissible torque and building of the FEM analysis model was first introduced. Using the model to analyze the effect of the interference, spindle speed, and drawbar force on the stress distributions of the contact surfaces of toolholder-spindle interface, then the transmissible torque is finally calculated. The results show that the HSK-E tool system satisfies high speed cutting requirements provided that reasonable parameters of the interference and the drawbar force are designed.

Abstract: ANSYS as finite element software is used to analyze oil film pressure of hydrodynamic oil film bearing, the stress of bearing bush alloy and the simulation movement of shaft and bearing, and then the reasons of oil film bearing failure and the wear mechanism of bearing bush are illustrated in detail.

Abstract: The working performance of Ni-P-Co alloy coating on the tooth surface of gears made from mechanical element of 45# steel was carried out. The experimental process on Ni-P-Co alloy coating was described. Several experimental results on the alloy coating such as surface shape, material element, metallographic structure, the adhesive strength between Ni-P-Co coating and 45# steel substrate, the shape characteristic of fatigue pitting and micro-hardness were analyzed. It is shown that the contact fatigue life and strength of steel gears with Ni-P-Co alloy coating is increased.

Abstract: In this study, 1mm thick Fe-Mn-Si shape memory alloy was welded by both sides using YAG laser welding. In a certain range of parameters, the optimal processing parameters for the maximum tensile strength are current 100 A, pulse frequency 3 Hz and pulse width 15 ms by orthogonal experiment. With the optimal processing parameters, the tensile strength of the welded joint can achieve 94% of base material,and the fracture appears in the center of welding seam and the surface morphology of welding seam is good. The influence of processing parameters on tensile strength of weld joint is directly embodied in cross-section of the welding seam morphology. In the laser welding, the tensile strength of nonpenetration in seam and hourglass shape welded joint is generally poor, and the perfect welded joint has conditions such as wide welding seam, deep penetration, weld pool filling and “non-hollow”. Most importantly, the central area in cross-section of the welding seam is the widest.