Contents of Journal of Mechanical Engineering 63, 2 (2012) 




                                                                       
FADHIL, B. M.: Effect of pressure angle associated with rim thickness 
on gear tooth crack initiation and crack propagation path - numerical 
study                                                                         61                                                                                               

MADARÁS, J., FERENCEY, V., BUGÁR, M., GOGA, V.: The simulation of 
starting torque impact of an electric motor for the dynamic behaviour 
of the electric  vehicle transmission mechanism                               83

WANG, C., CUI, H. Y., WANG, R. X.: Loaded tooth contact analysis of 
modified double helical gears                                                 95  

BARTA, D., REPKA, J., TUČNÍK, P., SANIGA, J., MRUZEK, M., KUKUČA, P.:
A non-conventional Stirling engine with FIK mechanism                        109



Abstracts



The simulation of starting torque impact of an electric motor for the dynamic behaviour
of the electric vehicle transmission mechanism

B. M. FADHIL

A numerical model study was performed to investigate the influence of the gear pressure angle associated with rim thickness on gear tooth crack initiation and propagation besides the fatigue life. Three values of pressure angles (15°, 20°, and 22°) were taken into account associated with three values of rim thickness. Finite element programs FRANC2D and ABAQUS were used to simulate gear tooth initiation and propagation. The analysis used principles of linear elastic mechanics. FRANC program had a unique feature to automated crack propagation using automated re-meshing scheme. The computed stress intensity factors were used to determine the crack propagation direction. With the simple Paris equation, the fatigue life has been calculated. The results show that the gear pressure angle associated with rim thickness has a significant effect on the crack initiation position and crack propagation path in addition to the fatigue life.


The simulation of starting torque impact of an electric motor for the dynamic behaviour
of the electric vehicle transmission mechanism

J. MADARÁS, V. FERENCEY, M. BUGÁR, V. GOGA

The objective of the simulation is an analysis of impacts from starting torque of an electric motor, during the dynamic loads on the electric vehicle power train, which is represented by the driving resistances. In the first part of this paper the electric vehicles power trains are described. In the second part, the mathematical model of the chosen power train is analysed, and with the Lagrangian equations and stiffness matrix the motion equations is formed. The transmission mechanism with the tire model is simulated in MD ADAMS® computer environment. The result of simulations are time courses of the angular velocity and acceleration of the individual components, where it is possible to monitor the torsional oscillations of the transmission system caused by the highest starting value of the electric motor's torque.


Loaded tooth contact analysis of modified double helical gears

C. WANG, H. Y. CUI, R. X. WANG

This paper performs loaded tooth contact analysis of modified double helical gears by proposing a method that combines the mathematical programming method with finite element method. Firstly, based on reducing vibration and noise and raising working efficiency, the method of three segment modifications for pinion profile is presented. Cutter surface equation is deduced by changing the shape of cutter-edge, substituting three segment parabolas for the line. Secondly, according to the condition of compatibility of deformation, force equilibrium and the non-embedment, the model of loaded tooth contact of double helical gears is obtained. LTCA program is developed successfully in a personal computer. By using this program, tooth load distributions and loaded transmission error are obtained in a meshing period. Finally, the comparison experiment of loaded transmission error both before modification and after modification is carried out. The results indicate that the LTCA method of modified double helical gears is reliable.



A non-conventional Stirling engine with FIK mechanism

D. BARTA, J. REPKA, P. TUČNÍK, J. SANIGA, M. MRUZEK, P. KUKUČA

The paper deals with a design implementation of Stirling engine with a non-conventional FIK mechanism, contains a description of its operation and discusses the possibilities of compression ratio changes. It presents the results of research focused on individual parts of the engine, including the regenerator, heat transfer and FIK mechanism. These results have been obtained by calculation, simulation and experiments performed directly in selected engine parts. The software FLUENT was used for the simulation.