Lubrication performance of helical gear pair under dynamic load based on local involute profile

2021 ◽  
pp. 1-16
Author(s):  
Mingyong Liu ◽  
Yang Qu ◽  
Chenglong Hu ◽  
Enxi Deng
Keyword(s):  
Surface Roughness ◽  
Film Thickness ◽  
Tribological Properties ◽  
Dynamic Load ◽  
Helical Gear ◽  
Tooth Profile ◽  
Tooth Surface ◽  
Gear Pair ◽  
Lubrication Performance ◽  
Helical Gear Pair

Abstract The tribological properties of gear interface have been widely concerned in the past decades. In this study, based on the local involute profile and crown modification, a thermal elastohydrodynamic lubrication model is proposed for a helical gear pair. To discuss the influences of dynamic load on the tribological properties of helical gear pair, the dynamic mesh force of tooth surface is obtained by torsional vibration model. The influences of working conditions and surface roughness on the tribological properties of helical gear pair are investigated. The tribological properties are evaluated in terms of the average film thickness, friction coefficient, mechanical power loss etc. Results show that the dynamic effect of gears has a significant effect on the tribological properties, especially at a specific speed, such as resonance speed. In order to simulation gear lubrication accurately, it is recommended to adopt local involute tooth profile and consider tooth profile modification to calculate geometric clearance. The influence of input rotation speed on the dynamic characteristics and tribological properties of gear is more significant than that of input torque. The surface roughness significantly changes the distribution of interface pressure and film thickness. With the increase of roughness amplitude, the local fluctuation amplitude of pressure and film thickness increase and the dry contact occurs at the end of contact line. Meanwhile, the maximum subsurface stress moves toward the tooth surface, especial for the high frequency engineering roughness. This local stress concentration is harmful to the fatigue life of gear meshing process.

Analysis of mechanical power loss of a helical gear pair based on the starved thermal-elastohydrodynamic lubrication model

2019 ◽  
Vol 72 (3) ◽  
pp. 333-340
Author(s):  
Mingyong Liu ◽  
Peidong Xu ◽  
Jinxi Zhang ◽  
Huafeng Ding
Keyword(s):  
Surface Roughness ◽  
Tribological Properties ◽  
Power Loss ◽  
Elastohydrodynamic Lubrication ◽  
Helical Gear ◽  
Mechanical Power ◽  
Gear Pair ◽  
Content Type ◽  
Helical Gear Pair ◽  
Film Lubrication

Purpose Power loss is an important index to evaluate the transmission performance of a gear pair. In some cases, the starved lubrication exists on the gear contact interface. The purpose of this paper is to reveal the mechanical power loss of a helical gear pair under starved lubrication. Design/methodology/approach A starved thermal-elastohydrodynamic lubrication (EHL) model is proposed to evaluate the tribological properties of a helical gear pair. The numerical result has been validated against the published simulation data. Based on the proposed model, the influence of thermal effect, working conditions, inlet oil-supply layer and surface roughness on the mechanical power loss and lubrication performance has been discussed. Findings Results show that the thermal effect has a significant effect on the tribological properties of helical gear pair, especially on mechanical power loss. For a specified working condition, there is an optimal oil supply for gear lubrication to obtain the state of full film lubrication. Meanwhile, it reveals that the mechanical power loss increases with the increase of the surface roughness amplitude. Originality/value In this paper, a starved thermal-EHL model has been developed for the helical gear pair based on the finite line contact theory. This model can be used to analyze the tribological properties of gear pair from full film lubrication to mixed lubrication. The results can provide the tribological guidance for design of a helical gear pair.

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 distributed dynamic mesh model of a helical gear pair with tooth profile errors

2018 ◽  
Vol 25 (2) ◽  
pp. 287-303 ◽  
Author(s):  
Qi-bin Wang ◽  
Hong-bo Ma ◽  
Xian-guang Kong ◽  
Yi-min Zhang
Keyword(s):  
Helical Gear ◽  
Tooth Profile ◽  
Dynamic Mesh ◽  
Gear Pair ◽  
Mesh Model ◽  
Profile Errors ◽  
Tooth Profile Errors ◽  
Helical Gear Pair

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.

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