Transmission Error as Gear Noise Excitation

2009 ◽  
Author(s):  
Mats Henriksson ◽  
Yuet-Yan Pang
Keyword(s):  
Transmission Error ◽  
Gear Pair ◽  
Bending Moments ◽  
Contact Pattern ◽  
Gear Noise ◽  
Correlate Noise ◽  
Edge Contact ◽  
Measurement Result ◽  
Static Transmission Error ◽  
The Difference

Traditionally, transmission error (TE) has been used in order to asses the noise properties of gears. Measurements of gear noise for a complete truck gearbox have been used to correlate noise from a gear pair with the concept of calculated static transmission error as noise excitation. Two gear pairs with very similar macro geometry but different micro geometry was used. Both transmission error as excitation and the excitation proposed by P. Velex and M. Ajmi which is the difference between the loaded and unloaded transmission error, are compared with measured noise. The result shows that the difference between the loaded and unloaded TE correlates well with measure noise for gear pair A but no excitation correlates with the measurement result gear pair B. A big difference between gear pair A and B can be seen in the contact pattern. The contact pattern of gear pair B shows that despite a large tip relief, edge contact occurs where the tip relief starts. This can be one explanation to the lack of correlation between TE and the measurement result for gear pair B. Another explanation can be other excitations such as friction and bending moments. The results show the limitations of only considering transmission error when designing quiet gears.

A Methodology to Experimentally Investigate the Impact of Wobble Errors on the Contact Pattern and Static Transmission Error of Helical Gear Pairs

2019 ◽  
Author(s):  
Michael Benatar ◽  
Michael Handschuh ◽  
Ahmet Kahraman ◽  
David Talbot
Keyword(s):  
Transmission Error ◽  
Helical Gear ◽  
Experimental Results ◽  
Gear Pair ◽  
Contact Pattern ◽  
Gear Mesh ◽  
Face Width ◽  
The Face ◽  
Static Transmission Error ◽  
The Impact

Abstract For a gear pair, both the contact pattern and the transmission error (TE) significantly impact durability and fatigue life. Design and manufacturing processes are often aimed at improving the contact pattern and reducing the overall TE. Other errors, such as runout and wobble, are often induced during the installation of power transmission systems, and they can alter the contact pattern and TE of an otherwise well-designed gear pair. This study provides a methodology to experimentally investigate the impact of wobble errors on the contact pattern and static transmission error (STE) of helical gears. It first provides a description of the modifications to an existing test machine. Next, it describes the gear specifications, preliminary testing matrix, data acquisition and processing procedure, as well as the experimental results obtained with regards to both the contact pattern and STE. The following are observed while describing the experimental results. For a test with no wobble and no runout, the contact pattern remains the same at every rotational position. However, by introducing even a small amount of wobble, the contact will shift from one side of the face width of the gear to the opposite side of the face width of the gear within one revolution. Introduction of wobble may increase the STE and sideband activity around gear mesh harmonics, especially as torque increases. Yet the modest increases in STE and sideband activity seen with the introduction of wobble are not enough to make definitive conclusions. The feasibility of the modified test setup has been demonstrated, and preliminary results have been presented. However, additional data collection should be completed in order to study the impact of runout and wobble on both spur and helical gear pairs with various microgeometry modifications and manufacturing errors.

Numerical and experimental investigation of a spur gear pair with unloaded static transmission error

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Duncai Lei ◽  
Xiannian Kong ◽  
Siyu Chen ◽  
Jinyuan Tang ◽  
Zehua Hu
Keyword(s):  
Transmission Error ◽  
Spur Gear ◽  
Gear Transmission ◽  
Dynamic Responses ◽  
Gear Pair ◽  
Mesh Stiffness ◽  
Content Type ◽  
High Order Harmonic ◽  
Static Transmission Error ◽  
Harmonic Components

Purpose The purpose of this paper is to investigate the dynamic responses of a spur gear pair with unloaded static transmission error (STE) excitation numerically and experimentally and the influences of the system factors including mesh stiffness, error excitation and torque on the dynamic transmission error (DTE). Design/methodology/approach A simple lumped parameters dynamic model of a gear pair considering time-varying mesh stiffness, backlash and unloaded STE excitation is developed. The STE is calculated from the measured tooth profile deviation under the unloaded condition. A four-square gear test rig is designed to measure and analyze the DTE and vibration responses of the gear pair. The dynamic responses of the gear transmission are studied numerically and experimentally. Findings The predicted numerical DTE matches well with the experimental results. When the real unloaded STE excitation without any approximation is used, the dynamic response is dominated by the mesh frequency and its high order harmonic components, which may not be result caused by the assembling error. The sub-harmonic and super-harmonic resonant behaviors are excited because of the high order harmonic components of STE. It will not certainly prevent the separations of mesh teeth when the gear pair is under the condition of high speed and heavy load. Originality/value This study helps to improve the modeling method of the dynamic analysis of spur gear transmission and provide some reference for the understanding of the influence of mesh stiffness, STE excitation and system torque on the vibration behaviors.

Analysis of Gear Noise and Dynamic Transmission Error Measurements

2004 ◽  
Author(s):  
Mats Henriksson
Keyword(s):  
Dynamic Properties ◽  
Transmission Error ◽  
Gear System ◽  
Gear Pair ◽  
Gear Noise ◽  
Gear Teeth ◽  
Opposite Trend ◽  
Dynamic Transmission Error

Measurements of dynamic transmission error (DTE) and noise have been performed on a truck gearbox. The DTE is related to the dynamic properties of the complete gear system. To investigate the coupling between noise and DTE, the correlation between noise and DTE is calculated for fixed speeds, as the torque is increased. The highest correlation is found for the low split gear pair, which is located closest to the gearbox housing. When the correlation is low, one of the reasons can be a resonance of the shafts, although not all resonances effect the correlation between noise and DTE. The DTE is also compared to calculated static TE for the gear teeth. Both the DTE and noise for the fifth gear increases as the torque is increased. The calculated static TE shows the opposite trend and decreases as the torque is increased.

Meshing performance of spiral bevel gear with different loads and modules considering edge contact by finite element method

2019 ◽  
Vol 43 (3) ◽  
pp. 322-332
Author(s):  
Xiangying Hou ◽  
Zongde Fang ◽  
Xuezhong Fu ◽  
Xijin Zhang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Contact Stress ◽  
Load Sharing ◽  
Transmission Error ◽  
Contact Forces ◽  
Gear Pair ◽  
Edge Contact ◽  
Spiral Bevel ◽  
Element Method

To analyze the edge contact of spiral bevel gears, owing to its effect on meshing performance, batch processing is performed based on a static solver and the finite element method (FEM) because of its computational speed advantage. A series of programs automatically perform the functions of modeling, analysis, and extraction of performance indexes. Starting from the entrance meshing position to the exit meshing position, a series of models was built and analyzed to describe the whole meshing process of the gear pair. For a specific gear pair, contact and bending stresses, contact stress patterns, loaded transmission errors, contact forces, and load sharing coefficients are calculated under five different load conditions and the change rules are summarized. Edge contact phenomenon occurs as the load increases to a critical value, resulting in a sharp increase in contact stress. As the load increases, the load sharing coefficient decreases gradually and the absolute value of transmission error increases, but the fluctuation of transmission error first decreases and then increases. In addition, the effect of modules is discussed and the results show that large modulus will decrease stress, contact ratio, and edge contact, but there is a certain module to minimize the fluctuation of transmission error.

scholarly journals Influence of Optimal Tooth Modifications on Dynamic Characteristics of a Vehicle Gearbox

2019 ◽  
Vol 16 (1) ◽  
pp. 6319-6331
Author(s):  
Najeeb Ullah ◽  
T. Cong ◽  
B. Huan ◽  
H. Yucheng
Keyword(s):  
Contact Stress ◽  
Gear Tooth ◽  
Transmission Error ◽  
Optimum Level ◽  
Contact Pattern ◽  
Gear Noise ◽  
Tooth Modification ◽  
Proposed Modification ◽  
The Impact ◽  
Central Gear

Considering the practical problems of gear noise and vibration, this work focuses on the gearbox of the electric vehicle as the research object to analyse the impact of gear micro-tooth modification. First of all, the effort centres itself on minimising the contact stress and making the load distribution better by implementing the tooth modification on both upper and central speed phases. The procedural analysis of gear tooth modification is executed to make the contact pattern better, so edge contact has been avoided and the load is distributed over a wide area of the tooth for both upper and central gear sets. The contact pattern is positioned in the centre of teeth and contact stress is lowered by 20% to 837 MPA. Then, the peak to peak transmission error is decreased under three proposed modification approaches. Also, contact and bending safety factors are improved as a result of tooth modification. Meanwhile, it was noticed by performing dynamic analysis that right bearings of both upper and central phases have a higher radial response for first two orders which is further decreased to an optimum level as a result of micro-tooth modification strategies.

Effect of strain rate on bending and transmission characteristics of injection molded polyamide 66 spur gears

2017 ◽  
Vol 233 (6) ◽  
pp. 1145-1155 ◽  
Author(s):  
M Kodeeswaran ◽  
R Suresh ◽  
S Senthilvelan
Keyword(s):  
Strain Rate ◽  
Transmission Error ◽  
Nonlinear Material ◽  
Gear Pair ◽  
Bending Stress ◽  
Transmission Characteristics ◽  
Polyamide 66 ◽  
Material Models ◽  
Static Transmission Error ◽  
Injection Molded

Polymer material exhibits time-dependent mechanical behavior due to its viscoelastic characteristics. Thus, unlike steel gears, polymer gears exhibit complex behavior when transmitting loads at various rotational speeds. In general, gear tooth surfaces exhibit complex stress due to their nonconformal geometry. Hence, the nonlinear material and nonlinear geometric aspects of polymer gear mesh prompted an investigation of the bending and transmission characteristics of injection molded polyamide 66 gears at various strain rate conditions. The injection molded tensile specimens made from the gear material were subjected to various rates of loading. The stress–strain performance at various rates of loading was evaluated and used to model linear and nonlinear gear materials for the numerical analysis. The numerical investigation was carried out on the steel–polyamide gear pair with the commercial finite element analysis tool ABAQUS® to predict the bending stress and static transmission error. The predicted static transmission error of the gear pair was compared with the experimental results obtained using an in-house developed gear test rig. The bending stress with the linear material models was higher than that of the nonlinear material models. An increase in bending stress with the strain rate was observed in the case of the nonlinear material models. The static transmission error predicted with the nonlinear material model at a higher strain rate was lower for both the single tooth contact and the double teeth contacts.

Effect of Axial Vibrations on the Dynamics of a Helical Gear Pair

1993 ◽  
Vol 115 (1) ◽  
pp. 33-39 ◽  
Author(s):  
A. Kahraman
Keyword(s):  
Natural Frequencies ◽  
Helix Angle ◽  
Transmission Error ◽  
Helical Gear ◽  
Forced Response ◽  
Dynamic Mesh ◽  
Gear Pair ◽  
Gear Mesh ◽  
Static Transmission Error ◽  
Helical Gear Pair

In this paper, a linear dynamic model of a helical gear pair has been developed. The model accounts for the shaft and bearing flexibilities, and the dynamic coupling among the transverse, torsional, axial and rotational (rocking) motions due to the gear mesh. The natural frequencies and the mode shapes have been predicted, and the modes which are excited by the static transmission error have been identified. The forced response due to the static transmission error has also been predicted, including the dynamic mesh and bearing forces. A parametric study has been performed to investigate the effect of the helix angle on the free and forced vibrational characteristics of the gear pair. It has been shown that the helix angle can be neglected in predicting the natural frequencies and the dynamic mesh forces. An accurate prediction of dynamic bearing forces and moments requires inclusion of the helix angle in the analysis.

Effects of directional rotation radius and transmission error on the dynamic characteristics of face gear transmission system

2013 ◽  
Vol 228 (7) ◽  
pp. 1108-1118 ◽  
Author(s):  
Jinyuan Tang ◽  
Zehua Hu ◽  
Siyu Chen ◽  
Duncai Lei
Keyword(s):  
Dynamic Characteristics ◽  
Transmission Error ◽  
Transmission System ◽  
Gear Transmission ◽  
Dynamic Factor ◽  
Gear Pair ◽  
Face Gear ◽  
Amplitude Variation ◽  
Gear Transmission System ◽  
Static Transmission Error

The effects of directional rotation radius and transmission error excitation on the nonlinear dynamic characteristics of face gear transmission system are analyzed. First, the accurate time-varying mesh stiffness is calculated using finite element method, and the nonlinear motion equation of the system under static transmission error excitation is proposed. The frequency response curve, time history curve, dynamic mesh force curve and dynamic factor curve are given, and the phenomena of jump, multiple solutions and tooth impact are observed. The numerical results show that the effect of amplitude variation of directional rotation radius on the dynamic characteristics of face gear pair is less conspicuous than that of transmission error but actually existing. The amplitude of the dynamic response of face gear pair reduces to some extent with the uniform distribution of the loading area through enlarging the amplitude variation of directional rotation radius. The static transmission error excitation should be reduced to perfect the transmission property. The system is in periodic motion most of the time, and tooth impact occurs only near [Formula: see text] . Since its dynamic property at low velocity and high velocity is good, the system should get through the resonant area quickly in work.

Dynamic Analysis of Contacting Spur Gear Pair for Fast System Simulation

2006 ◽  
Vol 110 ◽  
pp. 151-162 ◽  
Author(s):  
Daisuke Suzuki ◽  
Shigeru Horiuchi ◽  
Jin Hwan Choi ◽  
Han Sik Ryu
Keyword(s):  
System Simulation ◽  
Transmission Error ◽  
Spur Gear ◽  
Contact Analysis ◽  
Gear System ◽  
Force Model ◽  
Gear Pair ◽  
Time Step ◽  
Efficient System ◽  
Static Transmission Error

The prime source of vibration and noise in a gear system is originated from transmission error between the meshing gears. In this paper, the dynamic modeling method and response of a spur gear pair for the efficient system simulation are investigated by using a detailed contact analysis at each time step. Input values such as time-varying mesh stiffness and static transmission error excitation are not required in this investigation because mesh forces are obtained by contact analysis directly. The efficient contact search kinematics and algorithms in the context of the compliant contact model are developed to detect the interactions between teeth surfaces. In this investigation the compliant force model based on the Herzian law is employed using Coulomb friction force model, and dynamic transmission error (DTE) and mesh frequency values of contacting gear system are also illustrated.

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