scholarly journals Time-varying dynamic analysis for a helical gear pair system with three-dimensional motion due to bearing deformation

2020 ◽  
Vol 12 (5) ◽  
pp. 168781402091812
Author(s):  
Ying-Chung Chen
Keyword(s):  
Three Dimensional ◽  
Helix Angle ◽  
Helical Gear ◽  
Dynamic Responses ◽  
Time Varying ◽  
Gear Pair ◽  
Contact Ratio ◽  
Transverse Pressure ◽  
Helical Gear Pair ◽  
Center Distance

The dynamic response of a helical gear pair system is investigated. A new dynamic model for a helical gear pair system, considering three-dimensional motion due to bearing deformation, is proposed. The proposed model considers the helix angle, gear pair center distance, transverse pressure angle, and the contact ratio as time-dependent variables, which are considered as constants in other models. In fact, three-dimensional motion due to bearing deformation will lead to the changes in a series of dynamic responses. The system equations of motion were obtained by applying Lagrange’s equation and the dynamic responses are computed by the fourth-order Runge–Kutta method. The time-varying dynamic displacements, helix angle, gear pair center distance, transverse pressure angle, and the contact ratio are investigated with bearing deformation, different radial bear stiffness, different axial bear stiffness, and gear eccentricity. The results show that, due to the time-varying effect, this new helical gear pair model provides more accurate dynamic responses than those previous models which are considered as constant. In the future, this study can provide some useful information for the time-varying dynamic design of a helical gear pair system.

scholarly journals Time-Varying Dynamic Analysis of a Helical-Geared Rotor-Bearing System with Three-Dimensional Motion Due to Shaft Deformation

2020 ◽  
Vol 10 (4) ◽  
pp. 1542
Author(s):  
Ying-Chung Chen
Keyword(s):  
Equations Of Motion ◽  
Three Dimensional ◽  
Helix Angle ◽  
Dynamic Responses ◽  
Time Varying ◽  
Contact Ratio ◽  
Rotating Shaft ◽  
Rotor Bearing ◽  
Shaft Deformation ◽  
Bearing System

The rotordynamics of a helical-geared rotor-bearing system were investigated. A new dynamic model for a helical-geared rotor-bearing system, which takes into account three-dimensional (3-D) motion due to rotating shaft deformation, was proposed. The proposed model considers the time-varying effect, which in other models, is considered constant. The system equations of motion were obtained by applying Lagrange’s equation, and the dynamic responses were computed by the fourth-order Runge–Kutta method. The time-varying dynamic responses of the helix angle, transverse pressure angle, gear pair center distance, and total contact ratio were investigated. The numerical results show that the time-varying effect is an important factor in gear vibration analysis and cannot be neglected when the helical geared rotor-bearing system has a lower stiffness.

Vibration-based fault diagnosis of helical gear pair with tooth surface wear considering time-varying friction coefficient under mixed EHL condition

2021 ◽  
pp. 1-16
Author(s):  
Siyu Wang ◽  
Rupeng Zhu
Keyword(s):  
Dynamic Response ◽  
Hydrodynamic Lubrication ◽  
Helical Gear ◽  
Calculation Model ◽  
Tooth Surface ◽  
Time Varying ◽  
Gear Pair ◽  
Surface Wear ◽  
Mesh Stiffness ◽  
Helical Gear Pair

Abstract Based on “slice method”, the improved time-varying mesh stiffness (TVMS) calculation model of helical gear pair with tooth surface wear is proposed, in which the effect of friction force that obtained under mixed elasto-hydrodynamic lubrication (EHL) is considered in the model. Based on the improved TVMS calculation model, the dynamic model of helical gear system is established, then the influence of tooth wear parameters on the dynamic response is studied. The results illustrate that the varying reduction extents of mesh stiffness along tooth profile under tooth surface wear, in addition, the dynamic response in time-domain and frequency-domain present significant decline in amplitude under deteriorating wear condition.

A Helical Gear Pair Pocketing Power Loss Model

2013 ◽  
Author(s):  
David Talbot ◽  
Ahmet Kahraman ◽  
Satya Seetharaman
Keyword(s):  
Fluid Dynamics ◽  
Power Loss ◽  
Control Volume ◽  
Fluid Pressure ◽  
Helix Angle ◽  
Helical Gear ◽  
Gear Pair ◽  
Dynamics Model ◽  
Gear Mesh ◽  
Helical Gear Pair

A new fluid dynamics model is proposed to predict the power losses due to pocketing of air, oil, or an air-oil mixture in the helical gear meshes. The proposed computational procedure treats a helical gear pair as combination of a number of narrow face width spur gear segments staggered according to the helix angle and forms a discrete, fluid dynamics model of the medium being pocketed in the gear mesh. Continuity and conservation of momentum equations are applied to each coupled control volume filled with a compressible fluid mixture to predict fluid pressure and velocity distributions from, which the instantaneous pocketing power loss is calculated. The proposed model is exercised in order to investigate fluid pressure and velocity distributions in time, as well as pocketing power loss as a function of speed, helix angle and oil-to-air ratio.

Influence of Tooth Profile Modification on Helical Gear Durability

2002 ◽  
Vol 124 (3) ◽  
pp. 501-510 ◽  
Author(s):  
Parag Wagaj ◽  
Ahmet Kahraman
Keyword(s):  
Three Dimensional ◽  
Helical Gear ◽  
Tooth Profile ◽  
Gear Pair ◽  
Profile Modification ◽  
Mechanics Model ◽  
Tooth Profile Modification ◽  
Bending Stresses ◽  
Helical Gear Pair ◽  
Maximum Stresses

A nonlinear finite element contact mechanics model of a helical gear pair was used to study the effect of intentional tooth profile modifications on durability of helical gear pairs. Both two-dimensional (2D) and three-dimensional (3D) modifications were considered. A detailed parametric study was performed to quantify the changes in the contact and bending stresses as a function of tooth profile modification parameters as compared to an unmodified gear pair baseline. The combined influence of modification parameters and torque transmitted on the maximum stresses is described. Results indicate that both bending and contact stresses of a helical gear pair are increased significantly when 2D modifications are applied, potentially causing an underestimation of the actual stress values when the modifications are not included in stress calculations. When properly selected, 3D modifications cause significantly less stress increases.

scholarly journals Analisis Variasi Jarak Sumbu Poros Terhadap Tegangan Kontak Dan Tegangan Bending Pada Helical Gear Pair Berdasarkan Metode Elemen Hingga

2012 ◽  
Vol 2 (2) ◽  
Author(s):  
Sopyan Ali Rohman ◽  
IDK Okariawan ◽  
Achmad Zainuri
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Contact Stress ◽  
Helical Gear ◽  
Gear Pair ◽  
Security Design ◽  
Bending Stress ◽  
Helical Gear Pair ◽  
Center Distance ◽  
Element Method

This researchs object is determining  the effect of modifying center distance to bending stress and contact stress on the helical gear pair based on the finite element method. And to know the safety factor on each center distance variation within helical gear pair.Gear being analyzed is one of the gears on Honda motor cycles branded Beat. To know the specification of gear, the helical gear geometry measurements were taken. Based on the results of measurements was carried out models of helical gear pair by AUTO CAD software. Then,  bending stress and contact stress analysis with finite element method on  ANSYS 12.1. Optimal center distance of gear pairs is determined by safety factors on the quasi statatis condition.From the research results can be concluded that the change of center distance can affect the bending stress and contact stress on gears and affect of security design. A safe center distance variation is 52.65 mm, 52,75 mm, 52,85mm and 52.95 mm.

Dynamic Behavior of Helical Gears with Effects of Shaft and Bearing Flexibilities

2011 ◽  
Vol 86 ◽  
pp. 26-29
Author(s):  
Kai Feng ◽  
Shigeki Matsumura ◽  
Haruo Houjoh
Keyword(s):  
Experimental Tests ◽  
Time Varying ◽  
Gear Pair ◽  
Contact Ratio ◽  
Mesh Stiffness ◽  
Helical Gears ◽  
Shaft System ◽  
Proposed Model ◽  
Center Distance ◽  
Good Agreement

This study presents a numerical model of helical gears to consider the effects of shaft and bearing flexibility. A primary feature of this study is that the time-varying mesh stiffness is not just determined by the geometry of gear pair but also updated for each iteration according to the change of center distance. The effects of shaft and bearing flexibilities are discussed by comparing the dynamic response of gear pairs supported with a rigid and a flexible bearing-shaft system. The results show that the pressure angle and contact ratio are significantly changed due to the center-distance variation of gears and the gear pair with a flexible bearing-shaft system has much larger vibration. Finally, experimental tests are conducted to validate the proposed model. The predicted results show good agreement with the experimental data.

External High-Order Multistage Modified Elliptical Helical Gears and Design Procedure of Its Gear Pair

2014 ◽  
Author(s):  
Jiang Han ◽  
Youyu Liu ◽  
Dazhu Li ◽  
Lian Xia
Keyword(s):  
Design Procedure ◽  
Mathematical Expression ◽  
Gear Ratio ◽  
Helical Gear ◽  
High Order ◽  
Curvature Radius ◽  
Gear Pair ◽  
Contact Ratio ◽  
Helical Gears ◽  
Helical Gear Pair

In view of the limited number of the modified segments for high-order and two-stage modified elliptical helical gears, and poor adjustment capacity for gear ratio, the formation mechanism of a high-order multistage modified ellipse was studied, and a unified mathematical expression of the family of ellipses was obtained. Thus, a design procedure for the helical gear pair of the high-order multistage modified ellipse was suggested, and its transmission characteristics were discussed exhaustively. Moreover, some checking methods such as the curvature radius of the pitch curve, convexity, pressure angle, root cutting, and contact ratio were offered. Finally, two design cases, including two-order and three-stage modified elliptical helical gear pair and two-order and four-stage one, were implemented. The cases indicate that a high-order multistage modified elliptical helical gear can be utilized in practice.

Utilization of Tooth Contact Pattern in a Gear Meshing Model for Estimation of Sliding Loss in a Parallel-Axis Gear Pair

2014 ◽  
Vol 619 ◽  
pp. 68-72
Author(s):  
Jetsada Phraeknanthoe ◽  
Natcha Ponchai ◽  
Chanat Ratanasumawong
Keyword(s):  
Helix Angle ◽  
Helical Gear ◽  
Experimental Results ◽  
Gear Pair ◽  
Contact Pattern ◽  
Tooth Contact ◽  
Parallel Axis ◽  
Helical Gear Pair

The utilization of tooth contact pattern in a gear meshing model for estimation of sliding loss in a spur and helical gear pair is presented in this paper. The photo of tooth contact pattern taken after the gear operation is used as the database to generate the simplified tooth contact pattern. Then the simplified contact pattern is used along with the gear meshing model to estimate the sliding loss of a gear pair. Experiments are done to verify the results. The estimated results from the presented method agree well with the experimental results. The presented method is able to estimate the effect of the helix angle on the sliding loss correctly whereas the estimation without using the data of tooth contact pattern cannot.

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