|
|
Determination of transmission error at helical gear
Czakó, Alexander ; Prokop, Aleš (referee) ; Řehák, Kamil (advisor)
This diploma thesis primarily deals with the transmission error issue which is one of the dominant sources of vibration in gear pairs and transmission systems. The vibrations subsequently generate noise which is often subjected to increasingly stricter demands across the industry, including the automotive one. It turns out that reducing the peak-to-peak value of the transmission error has a beneficial effect on the vibro-acoustic properties of gears and gear pairs. This thesis aims to determine the transmission error under static conditions, since a gear pair with a low static transmission error is a good assumption for a low transmission error even under dynamic effects. The resulting values of the transmission error can be influenced already during the design of the gear macro-geometry. It is also suitable to apply micro-geometric adjustments – modifications to the gear teeth. For this reason, the search part of the thesis is dedicated to theoretical knowledge, especially concerning the geometry of gears, modifications of teeth and the overall transmission error and its determination. The transmission error can be determined in several ways, including a technical experiment. However, due to time and financial reasons, this is not always possible, and therefore, the possibility of using numerical simulations is offered. In this thesis, the approach using stress-strain quasi-static contact analysis using the finite element method in Ansys Workbench software is used. The advantage is, among other things, a good comparability of results. The input to the FEM analysis is 3D CAD geometry – in this case, it is specifically a helical gear pair with parallel axes. The model/assembly of this gear pair is created in PTC Creo software fully parametrically, so it is possible to generate arbitrary gear pair configurations by changing the input parameters, which significantly saves time. At the end of this diploma thesis, the stress-strain analysis of various gear configurations is evaluated, with respect to the equivalent stress and contact pressure. Furthermore, the static transmission error – its graphs and peak-to-peak values – is determined from FEM analyses for different gear geometry, including tooth modifications, and for various loading torques. Last but not least, the effects of contact/overlap ratio and centre distance are evaluated.
|
|
|
Determination of transmission error at helical gear
Czakó, Alexander ; Prokop, Aleš (referee) ; Řehák, Kamil (advisor)
This diploma thesis primarily deals with the transmission error issue which is one of the dominant sources of vibration in gear pairs and transmission systems. The vibrations subsequently generate noise which is often subjected to increasingly stricter demands across the industry, including the automotive one. It turns out that reducing the peak-to-peak value of the transmission error has a beneficial effect on the vibro-acoustic properties of gears and gear pairs. This thesis aims to determine the transmission error under static conditions, since a gear pair with a low static transmission error is a good assumption for a low transmission error even under dynamic effects. The resulting values of the transmission error can be influenced already during the design of the gear macro-geometry. It is also suitable to apply micro-geometric adjustments – modifications to the gear teeth. For this reason, the search part of the thesis is dedicated to theoretical knowledge, especially concerning the geometry of gears, modifications of teeth and the overall transmission error and its determination. The transmission error can be determined in several ways, including a technical experiment. However, due to time and financial reasons, this is not always possible, and therefore, the possibility of using numerical simulations is offered. In this thesis, the approach using stress-strain quasi-static contact analysis using the finite element method in Ansys Workbench software is used. The advantage is, among other things, a good comparability of results. The input to the FEM analysis is 3D CAD geometry – in this case, it is specifically a helical gear pair with parallel axes. The model/assembly of this gear pair is created in PTC Creo software fully parametrically, so it is possible to generate arbitrary gear pair configurations by changing the input parameters, which significantly saves time. At the end of this diploma thesis, the stress-strain analysis of various gear configurations is evaluated, with respect to the equivalent stress and contact pressure. Furthermore, the static transmission error – its graphs and peak-to-peak values – is determined from FEM analyses for different gear geometry, including tooth modifications, and for various loading torques. Last but not least, the effects of contact/overlap ratio and centre distance are evaluated.
|
|
|
To some dynamic properties of parametric - heteronomous systems with internal kinematic couplings and split power flow
Hortel, Milan ; Škuderová, Alena
The contribution deals partly with the problems of influence of material damping of gearing by normal and inverse mesh and the effect of viscous damping of lubricant surrounding, i.e. the influence of oil during cog contact bounce in the gap - technological backlash and partly with the analysis of issue causation of sharp discontinuity locality in the resonance characteristics, which is associated with the cog contact bounce with the impact effects in dependence with given resonance tuning, the gear mesh duration term on stiffness level of the parametric stiffness function or the modify stiffness function, inclusive the time phase shifts of relative motion towards these stiffness function.
|
|
| |
|
|
Influence of linear and nonlinear damping on the stability of motion of kinematic pairs of gears
Hortel, Milan ; Škuderová, Alena
The damping of dynamic phenomena in the structural complicated mechanical systems with different i.e. rigid or liquid substances of elements is the matter till this time generally recondite. The contribution deals therefore both qualitative and quantitative with the model of different combinations of linear and nonlinear - quadratic and cubic - damping both in the phase of normal gear mesh and in the phase of dynamic tuning when happens to contact bounces of tooth faces in gear mesh and to following contacts with impacts.
|
|
|
To the analysis of linear and nonlinear damping in gearing systems with impacts
Hortel, Milan ; Škuderová, Alena
The point of contribution consists in the analysis of linear and nonlinear – cubic - damping influence on the dynamic properties of the specific case of pseudoplanetary system with split power flow. The damping in the area of tooth backlash in the course of tooth face contact loss and consecutive contact with impact is assumed zero. The results of solution are illustrated in 3D space in the form of the phase planes of relative motion in gear mesh in relation to the given damping.
|
guest ::
