Applied Mechanics and Materials Vol. 441

Abstract: Rack and pinion drilling rig is a more advanced rigs, which canceled winch, wire rope and hook in the traditional rig, Down movement of the top drive through the mutual engagement of the gear with the rack. Dynamic characteristic of similar model prototype was established based on the similarity theory and design methods were researched. Similar model prototype with complete control and detection system was developed while maintaining main structure and functions of the drilling rig the same premise. Through the simulation platform, the drilling operation was simulated, and provides a theoretical basis and experimental data for the future development of rack and pinion drilling rig.

Abstract: In order to study the effect of variable frequency drive system upon electromagnetic radiation environment in underground coal mines, the mechanism of electromagnetic radiation from the variable frequency speed regulation system has been analyzed deeply, and the radiated electromagnetic noise from the variable frequency winch system with rated voltage of 1140V in underground coal mines has been measured. The measuring results show that the radiated emission from variable frequency drive system has certain effects on electromagnetic radiation environment in underground coal mines. The maximum radiated E-field strength reaches 123dBμV/m within the range of 9kHz to 20MHz nearby the frequency converter, and radiated E-field strength is no more than 33dBuV/m above 20MHz. Nearby the winch motor, the radiated E-field strength is weak, but the frequency spectrum of radiated E-field noises is more wide, which mainly distributes from 20MHz to 1GHz, but the maximum radiated E-field strength is less than 37dBμV/m above 20MHz.

Abstract: Based on the second development platform of CAXA electronic board, using the object-oriented programming method and vc++6.0 as the second development language, combining with the user's actual production, the structure of dynamic and static grinding head has been analyzed and the parameters of dynamic and static grinding head have been determineed. A system with friendly interface, clear structure, convenient operation has been designed which can realize the structure parametric design of dynamic and static grinding head.

Abstract: A new kind of involute planetary gear drive with small teeth difference which meshes in point contact is put forward based on the kinematic method of gear geometry in this paper. The generation principle of tubular tooth surface is proposed according to a selected smooth curve attached to the planetary wheel tooth surface. The general equations of conjugate tooth surfaces are derived and its conjugated contact curve on the internal gear is also determined. Then the mathematical model is established. The parameter selection and meshing characteristics of point-contact involute planetary gear drive with small teeth difference are discussed respectively. The three dimensional model is finally established and its motion simulation is worked out. It lays the significant theoretical foundation and practical meaning for improving the gear transmission performance.

Abstract: In this paper, kinematics and singularity of a 2-RPU&SPR parallel mechanism are analyzed by algebraic method. Firstly, the inverse kinematics of the parallel mechanism is derived. Secondly, the Jacobian matrix of the parallel mechanism is obtained and the singularity of the mechanism is analyzed. Finally, the correctness of singularity analysis of the mechanism is verified by numerical simulations.

Abstract: In recent years, with many cities limiting motorcycle-related regulations in China, Electric bicycles due to the inexpensive, easy to maneuver, energy saving and environmental protection, are used by people of all ages. Now, electric bicycles have become one of the main means of transport, back of electric bicycles as "child seat" to carry child travel commonplace, traffic accidents are also frequent. Through the widespread use of electric bicycle child seat from the safety and comfort of both analysis concluded: these structures a variety of seat provides safety and security for their children is very limited. Next child safety seat structure, strength, and to do in-depth research, quality standards and quality control methods.

Abstract: Taking XK5034 vertical milling machine as the research object, its thermal characteristic's finite element analysis has been carried out through the ANSYS. The front-end of the spindle mainly affects the machining accuracy of machine tool, so on the basis of the temperature field analysis, its thermal deformation was analyzed under different environment temperature, and the change rules between environment temperature and thermal deformation of the front of the spindle was also acquired. The results show that the influence of machine tool thermal deformation under different temperature is obvious.

Abstract: In order to solve the vibration problem of diesel engine powertrain assembly at its idle state, a six degree-of-freedom dynamics model of the powertrain mounting system is established and a optimization based on Adams/View is applied to simulation and analysis on the powertrain mounting system with energy decoupling method. The results show that the optimized repositioning mounts installation position can effectively improve decoupling rate in main vibration directions of mounting system. Based on this, the vibration transmissibility and acceleration response before and after optimization are simulated. The results show that the optimized engine mounting system makes a great improvement of vibration isolation performance.

Abstract: The authors designed a set of adherent self-circulation evaporative cooling system for a general desktop computer, and also tested its performance.The results show that: this cooling system can effectively dissipate heat of the CPU, the temperature will be kept below 50°C while operating at full load; For this application,we remove the fan of the CPU and achieve zero-noise and zero-power of computer equipment basically.

Abstract: The condition of tank bottom corrosion is the determinant factor affecting the safe operation of the tank. Considering the difficulty to shut down and carry out testing on tank floors, This article determines the characteristic parameters of tank bottom corrosion based on tank bottom magnetic flux leakage testing results and the fuzzy support vector machine is established based on the characteristic parameters of tank bottom corrosion. Through the prediction and analysis on 25 tanks in a depot, comparing with the result of magnetic flux leakage test, coincidence rate reaches 100%.The results show that this prediction technique is able to resolve the problem of the prediction of tank bottom corrosion rank, and can be applied in engineering applications.