Advanced Materials Research Vols. 199-200

Abstract: To research the change law of the load of the helical cutting mechanism cutting into the rock, the cutting experiment was done basing on the constructed rock. The constitutive model of the cutting load was build according to the experiment load, and the mechanical model of the rock was build too. Simultaneously, the mechanical model of the helical cutting mechanism cutting into the rock was build according to the actual working condition underground; and the cusp catastrophe model of the cutting process was build basing on the catastrophe analysis, the stiffness condition and the energy condition of the helical cutting mechanism cutting into the rock were acquired. Research results indicate that: the stiffness of the haulage system of the helical cutting mechanism must be smaller than the resistance stiffness of the rock, otherwise the strong vibration will be caused, and the helical cutting mechanism and the transmission system will be damaged too; the energy release rate of the helical cutting mechanism must be bigger than the required energy of the rock broken, or else the helical cutting mechanism will be lockout, even the cutting motor is damaged.

Abstract: A linkage with dynamic-state balance and small fluctuation load features on its crankshaft would both enhance a motor’s efficiency and load rate and reduce its input power by ensuring that the motor is driving as uniform load as possible. It could then be widely applicable to the saving of energy in oil pumping equipment. This paper presents a new model of oscillating block six-bar linkages in which the net crankshaft torque is reduced to a small fluctuation in load by adding the counterweights to the crank and rocking bar. The kinematics and kinetics models of this linkage under the counterbalance were therefore established. Factors influencing the net crankshaft torque fluctuations were analyzed. All parameters of design scheme were optimized using the MATLAB optimization toolbox. Analyses contrasting the effects of energy saving were performed under the actual load conditions.

Abstract: According to the actual production of large diameter pipe cutting presents a difficult problem planetary debris-free pipe cutting methods, design sketch of the entire system drive, cutter parameters are given, and deduced pipe cutting machine Motor and feed motor of the kinetic parameters for practical application provides a feasible solution.

Abstract: Construction method of transmission function was presented based on intermittent transmission characteristic of indexing cam mechanism. The transmission function with continuous acceleration has been deduced by an example, and verification method of transmission function was presented based on the virtual prototype technology. A model of parallel indexing cam mechanism was established using the constructed transmission function, and theoretical derivation was verified correctly through simulation.

Abstract: Isometric modification, as a new modification method of spur bevel gear was proposed. Based on the gear geometry theory and the normal meshing motion equation of gear pairs, changes of meshing points and angles are analyzed and the effect of axial modification on gear pair meshing movement is discussed, and then dynamics emulation analysis was operated with FEA software, the results show that the stress distribution of gear surface was controlled by isometric modification, the load concentration, agglutination and pitting of the gear can be avoided effectively.

Abstract: Evaluation method of reliability of industrial products needs to be improved effectively with the advance of science and technology. This paper introduces a new method, named E-Bayesian estimation method, to estimate failure probability in reliability engineering. The definition of E-Bayesian estimation of the failure probability is provided, moreover, the formulas of E-Bayesian estimation and hierarchical Bayesian estimation of the failure probability were provided, and properties of the E-Bayesian estimation, i.e. relations between E-Bayesian estimation and hierarchical Bayesian estimation, are also provided. Finally, calculation on practical problems shows that the provided method is feasible and easy to perform.

Abstract: Auto-control adjustable speed asynchronous magnetic coupling was designed according to principles of electromagnetic induction. Its development can effectively solved the vibration leading to the damage of mechanical coupling and the surrounding parts caused by rigid mechanical coupling link, as well as realized motor soft starting by controlling output speed in different torques. Based on the above working requirement, a novel magnetic coupling structure suit for auto-control by PLC in this paper was created. The motive simulation analysis of body structure and the simulation of magnetic torque at different air-gap length were obtained separately by ADAMS and ANSOFT. The results showed that the structure of auto-control adjustable speed asynchronous disk magnetic coupling was reasonable in practical condition.

Abstract: In order to solve some problems existing in the process of shift for automatic mechanical transmission vehicles such as great shift impact, engine noise and low shift success ratio between gears which have large speed ratio differences, a new method used to determine shift schedule was put forward in this paper. In this method, shift schedule and shift quality were synthetically considered, the downshift schedule was obtained based on the same optimization target with upshift schedule and proper downshift delay with shift impact and shift time controlled in a predetermined range. An optimal power shift schedule was developed with this method, and the performance of the automatic mechanical transmission vehicle controlled by this method was compared with that of controlled by skilled driver. The results indicate that the former obviously improved the performance of the vehicle with the shift quality controlled in a predetermined range.

Abstract: In order to calculate the cooperating characteristic of engine and hydrodynamic torque converter stably and accurately, obtain the best matching of hydrodynamic machine, based on the best matching principles of dynamic and economy, a kind of numerical computational method was put forward. Accuracy of intersection point calculation could be controlled by set step size of torque and rotational speed. The problem of multiple roots and instability of intersection point calculation could be avoided. Based on the graphical user interface (GUI) of MATLAB, the program was completed for matching and the graphs were plotted automatically. By this method, any hydrodynamic torque converter and engine with given performance, input and output cooperating characteristic could be derived accurately, rapidly and stably.

Abstract: In textbooks of mechanical engineering, rack has been mistakenly regarded as rack cutter so that minimum teeth without undercutting have been deduced, which has made people misunderstand undercut phenomenon more than 65 years. Theoretical research and computer simulation about undercut phenomenon are presented in this paper. Firstly, the theoretical analysis and calculation on minimum teeth without undercutting have been carried out, the rack cutter is used to infer minimum teeth without undercutting of standard involute gears, and correct minimum teeth without undercutting are get; And then computer simulation is applied to verify validity results of theoretical calculations, which not only corrects the long-standing mistakes about the traditional undercut phenomenon, but also provides the correct theoretical guidance for gears’ manufacturing.