scholarly journals Noise Reduction in Spur Gear Systems

Entropy ◽  
2020 ◽  
Vol 22 (11) ◽  
pp. 1306
Author(s):  
Aurelio Liguori ◽  
Enrico Armentani ◽  
Alcide Bertocco ◽  
Andrea Formato ◽  
Arcangelo Pellegrino ◽  
...  
Keyword(s):  
Static Analysis ◽  
Rotational Speed ◽  
Acoustic Emissions ◽  
Spur Gear ◽  
Friction Material ◽  
State Equation ◽  
Gear Noise ◽  
Reducing Gear ◽  
Gear Case ◽  
Scientific Fields

This article lists some tips for reducing gear case noise. With this aim, a static analysis was carried out in order to describe how stresses resulting from meshing gears affect the acoustic emissions. Different parameters were taken into account, such as the friction, material, and lubrication, in order to validate ideas from the literature and to make several comparisons. Furthermore, a coupled Eulerian–Lagrangian (CEL) analysis was performed, which was an innovative way of evaluating the sound pressure level of the aforementioned gears. Different parameters were considered again, such as the friction, lubrication, material, and rotational speed, in order to make different research comparisons. The analytical results agreed with those in the literature, both for the static analysis and CEL analysis—for example, it was shown that changing the material from steel to ductile iron improved the gear noise, while increasing the rotational speed or the friction increased the acoustic emissions. Regarding the CEL analysis, air was considered a perfect gas, but its viscosity or another state equation could have also been taken into account. Therefore, the above allowed us to state that research into these scientific fields will bring about reliable results.

Dynamic Model of a Spur Gear System With Backlash and Friction Consideration

1994 ◽  
Author(s):  
T. K. Shing ◽  
Lung-Wen Tsai ◽  
P. S. Krishnaprasad
Keyword(s):  
Free Oscillation ◽  
Equations Of Motion ◽  
Spur Gear ◽  
Constant Load ◽  
Friction Torque ◽  
Gear System ◽  
Real Time Control ◽  
Dynamical Equations ◽  
Gear Noise ◽  
Time Control

Abstract A new model which accounts for both backlash and friction effects is proposed for the dynamics of a spur gear system. The model estimates average friction torque and uses it to replace the instantaneous friction torque to simplify the dynamical equations of motion. Two simulations, free oscillation and constant load operation, are performed to illustrate the effects of backlash and friction on gear dynamics. The results are compared with that of a previously established model which does not account for the friction. Finally, the effect of adding a damper on the driving shaft is also studied. This model is judged to be more realistic for real time control of electronmechanical systems to reduce gear noise and to achieve high precision.

scholarly journals 3D-Modeling and Motion Simulation of Composite Wheel Gears Transmission Based on UG

2018 ◽  
Vol 175 ◽  
pp. 03006
Author(s):  
Mingxia Zhao
Keyword(s):  
3D Modeling ◽  
Rotational Speed ◽  
Spur Gear ◽  
Transmission Mechanism ◽  
Gear Train ◽  
Gear Pair ◽  
Calculation Formula ◽  
Motion Simulation ◽  
Gear Trains ◽  
Simulation Parameters

Taking the compound gear trains as an example, the principle of the transmission mechanism was analyzed, and the rotational speed of the key gears in the compound gear trains was calculated by using the calculation formula of transmission ratio to obtain the simulation parameters of UG movement. The gear tool box in UG was applied to complete the modeling and meshing assembly of the bevel gear and spur gear, the rotation pair and gear pair was to motion simulation, the gear transmission state could have visually observed by motion simulation, and then the chart was analyzed to verify the design rationality of the gear train.

Gear Case Shape and Rib Distribution for Reducing Automobile Transmission Gear Noise

1992 ◽  
Author(s):  
N. Maruyama ◽  
K. Morikawa ◽  
N. Hitomi
Keyword(s):  
Cross Section ◽  
Natural Frequencies ◽  
Gear Noise ◽  
Transmission Case ◽  
Section Shape ◽  
Gear Case ◽  
The Relationship ◽  
Transmission Gear ◽  
Mode A ◽  
Simplified Formula

Abstract This paper deals with an analysis of gear case shape and rib distribution with the aim of reducing automobile transmission gear noise. Modal analysis results and FEM calculations are presented to show that the vibration characteristics of the transmission case are basically determined by its cross section shape. A case with a cocoon section shape, composed of two curved planes, is shown to have greater plane stiffness, resulting in higher natural frequencies and a smaller number of modes in the 0–5 KHz bandwidth. It is concluded that, in order to raise the natural frequency of vibration of a plate mode, a reinforcement rib should be placed orthogonally to the bending direction at the antinode. A simplified formula for estimating natural frequencies with respect to the relationship between flat and ribbed plates is proposed.

scholarly journals Dynamic Characteristics of Spur Gear Pair with Dynamic Center Distance and Backlash

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Jie Liu ◽  
She Liu ◽  
Weiqiang Zhao ◽  
Lei Zhang
Keyword(s):  
Rotational Speed ◽  
Chaotic Behavior ◽  
Nonlinear Differential Equations ◽  
Spur Gear ◽  
Reference Source ◽  
Vibration Displacement ◽  
Frequency Components ◽  
Chaos Motion ◽  
Six Degree Of Freedom ◽  
Center Distance

Effect of dynamic backlash and rotational speed is investigated on the six-degree-of-freedom model of the gear-bearing system with the time-varying meshing stiffness. The relationship between dynamic backlash and center distance can be defined clearly. The nonlinear differential equations of the model are solved by the Newmark-β method. The results show that system amplitude increases in the wake of increasing rotational speed. After reaching a certain rotational speed, the system jumps from periodic motion to chaos motion, and the effective amplitude is changed violently. Comparing the dynamic backlash with fixed backlash, the amplitude of the dynamic backlash is augmented and the frequency components are diversified. The vibration displacement is enlarged by the dynamic backlash and the chaotic behavior of the system becomes complex with increasing rotational speed. The numerical results provide a useful reference source for engineers to select rotational speed section for steady running.

Evaluation of Tooth Surface Micro-Finishing on Gear Noise

2015 ◽  
Vol 651-653 ◽  
pp. 498-503 ◽  
Author(s):  
Simon Jolivet ◽  
Sabeur Mezghani ◽  
Jérôme Isselin ◽  
Alain Giraudeau ◽  
Mohamed El Mansori ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Tooth Surface ◽  
Gear Noise ◽  
Macro Scale ◽  
Load Carrying ◽  
Reducing Gear ◽  
Scale Characteristics ◽  
Gear Contact ◽  
Finishing Processes ◽  
Geometrical Defects

For automotive gear manufacturers, reducing gear noise while maintaining the gear load-carrying capacity as well as the wear resistance has become more and more important. Macro- and micro-geometrical defects have long been studied in order to explain the vibratory behavior of gears. However, the contribution of the micro-scale roughness of the flanks, essential in the gear contact mechanics, has not yet been fully understood.This paper addresses this issue where gears were manufactured with two industrial finishing processes (grinding and power-honing) while having the same macro-scale characteristics. Tridimensional topographical features of teeth surface were hence measured using a three-dimensional white light interferometer. As manufactured surface topographies are highly complex, irregular, and multiscale, all the teeth surfaces were characterized in the entire wavelength band using a multiscale method based on wavelets transform. Vibration performances of the gears were then tested on a single-stage low powertrain. Results demonstrate the influence of micro-roughness scales on vibrations amplitude.

scholarly journals Gear Case Shape and Rib Distribution for Reducing Automobile Transmission Gear Noise.

1998 ◽  
Vol 64 (627) ◽  
pp. 4361-4366
Author(s):  
Kunihiko MORIKAWA ◽  
Noboru MARUYAMA ◽  
Nobuteru HITOMI ◽  
Yasuharu ENOMOTO
Keyword(s):  
Gear Noise ◽  
Gear Case ◽  
Transmission Gear
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