Thermal elastohydrodynamic lubrication analysis of helical gear pair under starved lubrication condition

2019 ◽  
Vol 31 (7) ◽  
pp. 321-334 ◽  
Author(s):  
Mingyong Liu ◽  
Jinxi Zhang ◽  
Peidong Xu ◽  
Hao Cai ◽  
Haofeng Ku ◽  
...  
Keyword(s):  
Elastohydrodynamic Lubrication ◽  
Helical Gear ◽  
Gear Pair ◽  
Lubrication Condition ◽  
Starved Lubrication ◽  
Helical Gear Pair

Effects of Working Conditions on TEHL Performance of a Helical Gear Pair With Non-Newtonian Fluids

2014 ◽  
Vol 136 (2) ◽  
Author(s):  
Mingyong Liu ◽  
Caichao Zhu ◽  
Huaiju Liu ◽  
Huafeng Ding ◽  
Zhangdong Sun
Keyword(s):  
Working Conditions ◽  
Power Law ◽  
Elastohydrodynamic Lubrication ◽  
Helical Gear ◽  
Gear Pair ◽  
Power Law Fluid ◽  
Finite Line Contact ◽  
Lubrication Performance ◽  
Finite Line ◽  
Helical Gear Pair

A thermal elastohydrodynamic lubrication (TEHL) finite line contact model is developed for a helical gear pair lubricated with an Eyring fluid or a power-law fluid in order to investigate the effects of the working conditions. A lubrication analysis within a meshing period shows that the differences between the Eyring and Newtonian solutions mainly lie in the film temperature and the shear stress. For the power-law fluid, the power index n has a significant effect on the film thickness. The effects of load and speed on lubrication performance along the line of action are discussed.

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.

A calculation method of sliding friction coefficient on tooth surface for helical gear pair based on loaded tooth contact analysis and elastohydrodynamic lubrication theory

2020 ◽  
pp. 135065012096689
Author(s):  
Cheng Wang ◽  
Mao Ken
Keyword(s):  
Friction Coefficient ◽  
Sliding Friction ◽  
Elastohydrodynamic Lubrication ◽  
Helical Gear ◽  
Tooth Surface ◽  
Gear Pair ◽  
Tooth Contact Analysis ◽  
Sliding Friction Coefficient ◽  
Loaded Tooth Contact Analysis ◽  
Helical Gear Pair

The sliding friction coefficient on tooth surface is related to power loss, carry capacity and transmission performance of gear. Reasonable transmission analysis of gear pair is the premise of accurate calculation of sliding friction coefficient on tooth surface. However, for helical gear pair, the line contact without considering machining error/installation error/modification of gear is usually adopted to replace the major axis of ellipse caused by contact load. Therefore, in this paper, contact path on tooth surface, length of contact line, load distribution on tooth surface and loaded transmission errors are accurately calculated by loaded tooth contact analysis (LTCA). Combing with elastohydrodynamic lubrication (EHL) theory, a calculation method of sliding friction coefficient on tooth surface for helical gear pair is proposed.

Parametric Studies of Mechanical Power Loss for Helical Gear Pair Using a Thermal Elastohydrodynamic Lubrication Model

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Mingyong Liu ◽  
Peidong Xu ◽  
Chunai Yan
Keyword(s):  
Friction Coefficient ◽  
Thermal Effect ◽  
Power Loss ◽  
Elastohydrodynamic Lubrication ◽  
Mechanical Efficiency ◽  
Helical Gear ◽  
Tribological Performance ◽  
Mechanical Power ◽  
Gear Pair ◽  
Helical Gear Pair

In this study, a comprehensive mechanical efficiency model based on the thermal elastohydrodynamic lubrication (TEHL) is developed for a helical gear pair. The tribological performance of the helical gear pair is evaluated in terms of the average film thickness, friction coefficient, mechanical power loss, mechanical efficiency, etc. The influence of basic design parameters, working conditions, thermal effect, and surface roughness are studied under various transmission ratios. Results show that the contribution of thermal effect on the tribological performance is remarkable. Meanwhile, the rolling power loss constitutes an important portion of the total mechanical power loss, especially around the meshing position where the pitch point is located in the middle of contact line and the full elastohydrodynamic lubrication (EHL) state with the friction coefficient less than 0.005. The proper increase of normal pressure angle and number of tooth can improve the tribological performance. The influence of helix angle on the mechanical efficiency is less significant. A positive addendum modification coefficient for pinion and a negative addendum modification coefficient for wheel are good for improving the mechanical efficiency. The results provide the tribological guidance for design of a helical gear pair in engineering.

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
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