On Dynamic Gear Tooth Loading Due to Coupled Torsional-Lateral Vibrations in a Geared Rotor-Hydrodynamic Bearing System

1989 ◽  
Vol 111 (3) ◽  
pp. 418-425 ◽  
Author(s):  
B. Kishor ◽  
S. K. Gupta
Keyword(s):  
Gear Tooth ◽  
Velocity Ratio ◽  
Operating Conditions ◽  
Hydrodynamic Bearing ◽  
Gear Teeth ◽  
Gear Mesh ◽  
Lateral Vibrations ◽  
Mass Unbalance ◽  
Stable Operating ◽  
Bearing System

This paper is an attempt to provide an estimation of dynamic gear tooth loading due to coupled torsional-lateral vibrations in a geared rotor-hydrodynamic bearing system. The effects of mass unbalance and geometrical eccentricity of the pinion and the combined effects of manufacturing errors and profile modifications of gear teeth have been considered. Gear mesh compliance and damping at gear teeth are also included in the analysis. Journal lateral motions in the oil film spaces of hydrodynamic bearings are shown to be associated with variations in the angular velocity ratio of meshing gears and with dynamic loading of gear teeth. The journal center is observed to trace trajectories of limited amplitudes under stable operating conditions.

scholarly journals Quantification of Gear Tooth Damage by Optimal Tracking of Vibration Signatures

1997 ◽  
Vol 3 (3) ◽  
pp. 143-151 ◽  
Author(s):  
F. K. Choy ◽  
R. J. Veillette ◽  
V. Polyshchuk ◽  
M. J. Braun ◽  
R. C. Hendricks
Keyword(s):  
Monitoring System ◽  
Health Monitoring ◽  
Gear Tooth ◽  
Operating Conditions ◽  
Diagnostic Process ◽  
Data Set ◽  
Health Monitoring System ◽  
Gear Teeth ◽  
Gear Mesh ◽  
Machine Health Monitoring

This paper presents a technique for quantifying the wear or damage of gear teeth in a transmission system. The procedure developed in this study can be applied as a part of either an onboard machine health-monitoring system or a health diagnostic system used during regular maintenance. As the developed methodology is based on analysis of gearbox vibration under normal operating conditions, no shutdown or special modification of operating parameters is required during the diagnostic process.The process of quantifying the wear or damage of gear teeth requires a set of measured vibration data and a model of the gear mesh dynamics. An optimization problem is formulated to determine the profile of a time-varying mesh stiffness parameter for which the model output approximates the measured data. The resulting stiffness profile is then related to the level of gear tooth wear or damage.The procedure was applied to a data set generated artificially and to another obtained experimentally from a spiral bevel gear test rig. The results demonstrate the utility of the procedure as part of an overall health-monitoring system.

scholarly journals Improvement on Meshing Stiffness Algorithms of Gear with Peeling

Symmetry ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 609
Author(s):  
Lingli Cui ◽  
Tongtong Liu ◽  
Jinfeng Huang ◽  
Huaqing Wang
Keyword(s):  
Simulation Analysis ◽  
Gear Tooth ◽  
Gear Wheel ◽  
Mesh Stiffness ◽  
Gear Teeth ◽  
Gear Mesh ◽  
Meshing Stiffness ◽  
Involute Gears ◽  
Gear Mesh Stiffness ◽  
Meshing Process

This paper investigates the effect of a gear tooth peeling on meshing stiffness of involute gears. The tooth of the gear wheel is symmetric about the axis, and its symmetry will change after the gear spalling, and its meshing stiffness will also change during the meshing process. On this basis, an analytical model was developed, and based on the energy method a meshing stiffness algorithm for the complete meshing process of single gear teeth with peeling gears was proposed. According to the influence of the change of meshing point relative to the peeling position on the meshing stiffness, this algorithm calculates its stiffness separately. The influence of the peeling sizes on mesh stiffness is studied by simulation analysis. As a very important parameter, the study of gear mesh stiffness is of great significance to the monitoring of working conditions and the prevention of sudden failure of the gear box system.

Dynamic Analysis of Gear Mesh for Gear Pump Based on ANSYS Workbench

2013 ◽  
Vol 706-708 ◽  
pp. 1290-1293 ◽  
Author(s):  
Lei Zhao ◽  
Qing Qing Lv ◽  
Li Quan Yang
Keyword(s):  
Contact Stress ◽  
Gear Tooth ◽  
Corrosion Damage ◽  
Structure Design ◽  
Gear Pump ◽  
Three Dimension ◽  
Tooth Contact ◽  
Gear Teeth ◽  
Gear Mesh ◽  
Ansys Workbench

Based on the FEA software ANSYS Workbench, the soft body dynamics performance of the gear pump gear mesh of a hydraulic pump company was analyzed. In the practical engineering applications, gear pump gear teeth are effected by alternating pressure in the two working cavity. It can cause pitting corrosion damage for gear tooth, and even cause tooth crack and fracture. At first, a three dimension finite element models of the gear pump gear teeth was established. In the start-up process, the gear pump tooth mesh deputy of tooth contact stress strain and dynamic characteristics of gear teeth was analyzed. Obtain the velocity curves, acceleration curve and tooth contact stress and strain dynamic curves of the tooth of gear pump. Providing a new analysis method for gear pump of gear Structure design and having a practical application value.

scholarly journals Study of Lubricant Jet Flow Phenomena in Spur Gears—Out of Mesh Condition

1978 ◽  
Vol 100 (1) ◽  
pp. 61-68 ◽  
Author(s):  
D. P. Townsend ◽  
L. S. Akin
Keyword(s):  
High Speed ◽  
Gear Tooth ◽  
Velocity Ratio ◽  
Jet Impingement ◽  
Gear Ratio ◽  
Experimental Program ◽  
High Speed Photography ◽  
Gear Mesh ◽  
Mesh Condition ◽  
Oil Jet

An analysis was conducted for oil jet lubrication on the disengaging side of a gear mesh. Results of the analysis were computerized and used to determine the oil jet impingement depth for several gear ratios and oil jet to pitch line velocity ratios. An experimental program was conducted on the NASA gear test rig using high-speed photography to experimentally determine the oil jet impingement depth on the disengaging side of mesh. Impingement depth reaches a maximum at gear ratio near 1.5 where chopping by the leading gear tooth limits the impingement depth. The pinion impingement depth is zero above a gear ratio of 1.172 for a jet velocity to pitch time velocity ratio of 1.0 and is similar for other velocity ratios. The impingement depth for gear and pinion are equal and approximately one-half the maximum at a gear ratio of 1.0. Impingement depth on either the gear or pinion may be improved by relocation of the jet from the pitch line or by changing the jet angle. Results of the analysis were verified by experimental results using a high-speed camera and a well lighted oil jet.

On the Dynamic Analysis of a Rigid Rotor-Gear Pair-Hydrodynamic Bearing System

1989 ◽  
Vol 111 (3) ◽  
pp. 234-240 ◽  
Author(s):  
B. Kishor ◽  
S. K. Gupta
Keyword(s):  
Mathematical Model ◽  
Dynamic Analysis ◽  
Static Load ◽  
Gear Tooth ◽  
Gear Pair ◽  
Rigid Rotor ◽  
Hydrodynamic Bearing ◽  
Bearing Loads ◽  
The Given ◽  
Bearing System

This paper is an attempt to provide a dynamic analysis of a rigid rotor-gear pair-hydrodynamic bearing system with journal motions in the oil film space of the bearings. A mathematical model has been developed considering the kinematics of the gear pair as affected by journal motions and using a concept of an instantaneous line of action. Effects of bearing parameters on dynamic tooth loads have been studied. The load-speed environment of hydrodynamic bearings supporting the geared rotors is shown to be affected by journal motions in bearings. Results indicate that, for the given gear pair and the given static load-speed conditions, dynamic increments in gear tooth loads and bearing loads vary with bearing parameters (viz. clearances and oil viscosities).

The bifurcation and chaos of a gear pair system based on a strongly non-linear rotor—bearing system

2010 ◽  
Vol 224 (9) ◽  
pp. 1891-1904 ◽  
Author(s):  
C-W Chang-Jian
Keyword(s):  
Operating Conditions ◽  
Speed Ratio ◽  
Gear Pair ◽  
Chaotic Motions ◽  
Systematic Analysis ◽  
Gear Mesh ◽  
Non Linear ◽  
Rotor Bearing ◽  
Linear Effects ◽  
Bearing System

A systematic analysis of the dynamic behaviours of a gear pair system based on a rotor—bearing system under strongly non-linear effects (i.e. non-linear suspension effect, non-linear oil-film force, non-linear rub-impact force, and non-linear gear mesh force) is presented in this study. The dynamic orbits of the system are observed using bifurcation diagrams plotted using the dimensionless unbalance coefficient, the dimensionless damping coefficient, and the dimensionless rotational speed ratio as control parameters. The onset of chaotic motion is specified from the phase diagrams, power spectra, Poincaré maps, Lyapunov exponents, and fractal dimension of the system. There exists various forms of periodic, quasi-periodic, and chaotic motions at different bifurcation parameters. The simulation results also found that highly non-periodic motions do exist in gear—rotor—bearing systems under those non-linear effects. The results presented in this study provide a better understanding of the operating conditions under which undesirable dynamic motion takes place in a gear—bearing system; they would therefore serve as a useful source of reference for engineers in designing and controlling such systems.

On the Dynamic Gear Tooth Loading as Affected by Bearing Clearances in High Speed Machinery

1982 ◽  
Vol 104 (4) ◽  
pp. 724-730 ◽  
Author(s):  
B. M. Bahgat ◽  
M. O. M. Osman ◽  
T. S. Sankar
Keyword(s):  
High Speed ◽  
Design Method ◽  
Gear Tooth ◽  
Contact Point ◽  
Velocity Ratio ◽  
Spur Gears ◽  
Governing Equations ◽  
Contact Mode ◽  
Gear Teeth ◽  
Geometrical Constraints

The paper studies the effect of bearing clearances in the dynamic analysis of gear mechanisms in high speed machinery. For this purpose, an analytical model is developed based on the interdependence between kinematics and kinetic relationships that must be satisfied when contact is maintained between the journal and its bearing. The contact modes are formulated such that the bearing eccentricity vector must align itself with bearing normal force at the point of contact. The analysis mainly relies on determining the direction of the bearing eccentricity vector defined as the clearance angles βi at the bearing revolutes for each contact mode of the gear teeth. The governing equations of the clearance angles are developed using the geometrical constraints of the contact point location and the velocity ratio. The clearance angles and their derivatives are subsequently used to systematically evaluate kinematic and dynamic quantities of each gear as well as the dynamic tooth load. A pair of rigid tooth spur gears with two revolute clearances is analyzed to illustrate the procedure. The model presented in the paper provides a design method for investigating the effect of bearing tolerances and wear on the evaluation of dynamic tooth load in high speed gearing systems.

The Stress Intensity Factor and Stiffness for a Cracked Spur Gear Tooth

1994 ◽  
Vol 116 (3) ◽  
pp. 697-700 ◽  
Author(s):  
S. R. Daniewicz ◽  
J. A. Collins ◽  
D. R. Houser
Keyword(s):  
Stress Intensity ◽  
Gear Tooth ◽  
Fatigue Cracks ◽  
Spur Gear ◽  
Potential Method ◽  
Mapping Technique ◽  
Gear Teeth ◽  
Gear Mesh ◽  
Face Width ◽  
Tooth Pair

The stiffness of a spur gear tooth mesh controls load sharing in an operating gearset as well as vibratory properties which further dictate fatigue resistance and gear noise. A spur gear mesh consisting of a pinion with a single cracked tooth and an uncracked gear is considered. Expressions are presented which allow the determination of stress intensity factors for small through face width fatigue cracks in spur gear teeth. Predictions of tooth pair stiffness for a cracked pinion tooth and uncracked gear tooth pair are made using an analytical model. The model is based on elastic energy methods and fracture mechanics principles. The model employs a conformal mapping technique from elasticity theory, often denoted in spur gear applications as the complex potential method, in which a gear tooth is mapped onto on elastic half-plane.

scholarly journals Local Regularity Analysis with Wavelet Transform in Gear Tooth Failure Detection

2017 ◽  
Vol 25 (3) ◽  
pp. 176-182 ◽  
Author(s):  
Juhani Nissilä
Keyword(s):  
Wavelet Transform ◽  
Gear Tooth ◽  
Theoretical Perspective ◽  
Turbine Blades ◽  
Failure Detection ◽  
Local Regularity ◽  
Measured Signal ◽  
Gear Teeth ◽  
Gear Mesh ◽  
Modulus Maxima

Abstract Diagnosing gear tooth and bearing failures in industrial power transition situations has been studied a lot but challenges still remain. This study aims to look at the problem from a more theoretical perspective. Our goal is to find out if the local regularity i.e. smoothness of the measured signal can be estimated from the vibrations of epicyclic gearboxes and if the regularity can be linked to the meshing events of the gear teeth. Previously it has been shown that the decreasing local regularity of the measured acceleration signals can reveal the inner race faults in slowly rotating bearings. The local regularity is estimated from the modulus maxima ridges of the signal’s wavelet transform. In this study, the measurements come from the epicyclic gearboxes of the Kelukoski water power station (WPS). The very stable rotational speed of the WPS makes it possible to deduce that the gear mesh frequencies of the WPS and a frequency related to the rotation of the turbine blades are the most significant components in the spectra of the estimated local regularity signals.

The Stress Intensity Factor and Stiffness for a Cracked Spur Gear Tooth

1992 ◽  
Author(s):  
S. R. Daniewicz ◽  
J. A. Collins ◽  
Donald R. Houser
Keyword(s):  
Stress Intensity ◽  
Gear Tooth ◽  
Fatigue Cracks ◽  
Spur Gear ◽  
Potential Method ◽  
Mapping Technique ◽  
Gear Teeth ◽  
Gear Mesh ◽  
Face Width ◽  
Tooth Pair

Abstract The stiffness of a spur gear tooth mesh controls load sharing in an operating gearset as well as vibratory properties which further dictate fatigue resistance and gear noise. A spur gear mesh consisting of a pinion with a single cracked tooth and an uncracked gear is considered. Expressions are presented which allow the determination of stress intensity factors for small through face width fatigue cracks in spur gear teeth. Predictions of tooth pair stiffness for a cracked pinion tooth and uncracked gear tooth pair are made using an analytical model. The model is based on elastic energy methods and fracture mechanics principles. The model employs a conformal mapping technique from elasticity theory, often denoted in spur gear applications as the complex potential method, in which a gear tooth is mapped onto an elastic half-plane.

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