Temperature Analysis of Involute Gear Based on Mixed Elastohydrodynamic Lubrication Theory Considering Tribo-Dynamic Behaviors

2014 ◽  
Vol 136 (2) ◽  
Author(s):  
Hui L. Dong ◽  
Ji B. Hu ◽  
Xue Y. Li
Keyword(s):  
Contact Area ◽  
Temperature Rise ◽  
Gear Tooth ◽  
Elastohydrodynamic Lubrication ◽  
Gear Pair ◽  
Rolling Velocity ◽  
Involute Gear ◽  
Tooth Width ◽  
Asperity Contacts ◽  
Tooth Flank

An integrated model is proposed for involute gear pair combining the mixed elastodhydrodynamic lubrication (EHL) theory for finite line contact with surface temperature rise equations considering tribo-dynamic loading behaviors. The film stiffness and viscous damping as well as the friction force are taken into account. The surface topography of tooth flank measured by 3D surface profiler is also included to solve the local temperature and pressure distribution in the contact area. The results show that the temperature distributions in different meshing positions along the line of action exhibit dissimilar characteristics due to the varying of dynamic load and the changing slip-to-roll ratio, which denotes the relationship between sliding velocity and rolling velocity on the tooth flank. Besides, the maximum of temperature is likely to appear at different sides of the gear tooth width as the gear pair meshes along the line of action. Moreover, with the increasing surface roughness, the ratio of asperity contacts becomes larger, so more heat generates from the contact area and leads to higher temperature rise.

Effect of Design Parameters on Lubrication Behavior of Spur Gear Pairs

2017 ◽  
Author(s):  
Yanfang Liu ◽  
Qiang Liu ◽  
Peng Dong
Keyword(s):  
Power Loss ◽  
Elastohydrodynamic Lubrication ◽  
Spur Gear ◽  
Design Parameters ◽  
Curvature Radius ◽  
Gear Pair ◽  
Sliding Velocity ◽  
Rolling Velocity ◽  
Lubrication Performance ◽  
Meshing Process

An involute spur gear pair meshing model is firstly provided in this study to achieve relevant data such as rolling velocity, sliding velocity, curvature radius etc. These data are needed in a transient, Newtonian elastohydrodynamic lubrication (EHL) model which is provided later. Based on these two models, the behavior of an engaged spur gear pair during the meshing process is investigated under dynamic conditions, film thickness, pressure, friction coefficient etc. could be achieved through the models. Then, power loss under certain operating condition is calculated. Relationship between power loss and lubrication performance is also analyzed.

Analysis of Microelastohydrodynamic and Mixed Lubrication Effects in Gear Tooth Contacts

2003 ◽  
Author(s):  
M. J. A. Holmes ◽  
H. P. Evans ◽  
R. W. Snidle
Keyword(s):  
Contact Area ◽  
Transient Analysis ◽  
Gear Tooth ◽  
Point Contact ◽  
Elastohydrodynamic Lubrication ◽  
Contact Analysis ◽  
Line Contact ◽  
Hydrodynamic Equations ◽  
Analysis Technique ◽  
Film Thinning

The paper presents results obtained using a transient analysis technique for point contact elastohydrodynamic lubrication (EHL) problems based on a formulation that couples the elastic and hydrodynamic equations. Results are presented for transverse ground surfaces in elliptical point contact that show severe film thinning at the transverse limits of the contact area. This thinning is caused by transverse leakage of the lubricant from the contact in the remaining deep valley features. A comparison is also made between the point contact results on the entrainment centre line and the equivalent line contact analysis.

Recent Progress and Prospect on Tooth Modification of Involute Cylindrical Gear

2021 ◽  
Vol 14 ◽  
Author(s):  
Lin Han ◽  
Yang Qi
Keyword(s):  
Load Distribution ◽  
Power Transmission ◽  
Gear Tooth ◽  
Transmission Error ◽  
Gear Pair ◽  
Cylindrical Gear ◽  
Tooth Width ◽  
Modification Method ◽  
Power Transmission Systems ◽  
Tooth Modification

Background: Recent reviews on tooth modification of involute cylindrical gear are presented. Gear pairs are widely employed in motion and power transmission systems. Manufacturing and assembling errors of gear parts, time-varying mesh stiffness and transmission error of gear pair, usually induce vibration, noise, non-uniformly load distribution and stress concentration, resulting in earlier failure of gear. Tooth modification is regarded as one of the most popular ways to suppress vibration, reduce noise level, and improve load distribution of gear pairs. Objective: To provide an overview of recent research and patents on tooth modification method and technology. Methods: This article reviews related research and patents on tooth modification. The modification method, evaluation, optimization and machining technology are introduced. Results: Three types of modifications are compared and analyzed, and influences of each on both static and dynamic performances of gear pair are concluded. By summarizing a number of patents and research about tooth modification of cylindrical gears, the current and future development of research and patent are also discussed. Conclusion: Tooth modification is classified into tip or root relief along tooth profile, lead crown modification along tooth width and compound modification. Each could be applied in different ways. In view of design, optimization under given working condition to get optimal modification parameters is more practical. Machining technology and device for modified gear is a key to get high quality performance of geared transmission. More patents on tooth modification should be invented in future.

Elastohydrodynamic Lubrication Analysis of Conjugate Meshing Face Gear Pairs

2012 ◽  
Vol 57 (3) ◽  
pp. 1-10 ◽  
Author(s):  
Zihni B. Saribay ◽  
Robert C. Bill ◽  
Edward C. Smith ◽  
Suren B. Rao
Keyword(s):  
Friction Coefficient ◽  
Film Thickness ◽  
Gear Tooth ◽  
Elastohydrodynamic Lubrication ◽  
Transmission Efficiency ◽  
Hertzian Contact ◽  
Maximum Efficiency ◽  
Gear Pair ◽  
Face Gear ◽  
Fixed Axis

This paper investigates the nominal elastohydrodynamic lubrication (EHL) characteristics of the conjugate meshing face gears and predicts the mesh efficiency of the pericyclic transmission system. The meshing face-gear tooth geometries and meshing kinematics are modeled. Hertzian contact and the isothermal non-Newtonian lubricant film characteristics of the meshing face-gear pair are investigated. The friction coefficient is calculated with the effects of lubricant behavior and mesh kinematics. Finally, the pericyclic transmission efficiency is calculated as a function of friction coefficient, mesh loads, and mesh kinematics. The Hertzian contact behavior, film thickness, and friction coefficient values are simulated for an example fixed axis face-gear pair rotating at 1000 rpm with 3.4 kN-m torque. The EHL film thickness ranges from 0.1 to 0.25 μm in this example. The average friction coefficient is predicted as 0.05. The efficiencies of three different 24:1 reduction ratio 760 HP pericyclic transmission designs are investigated. The minimum and maximum efficiency in the given design space are 97% and 98.7%, respectively.

Effect of Involute Tip Relief on Dynamic Response of Spur Gear Pairs

1999 ◽  
Vol 121 (2) ◽  
pp. 313-315 ◽  
Author(s):  
A. Kahraman ◽  
G. W. Blankenship
Keyword(s):  
Dynamic Response ◽  
Experimental Test ◽  
Torsional Vibration ◽  
Gear Tooth ◽  
Transmission Error ◽  
Spur Gear ◽  
Forced Response ◽  
Gear Pair ◽  
Response Curves ◽  
Tooth Flank

The influence of gear tooth flank modifications in the form of linear involute tip relief on the torsional vibration behavior of a spur gear pair is investigated by using an experimental test stand. Measured dynamic transmission error (DTE) values are compared and a family of forced response curves is presented. Guidelines for the design of quiet spur gear sets are also given.

Boundary slips induced temperature rise and film thickness reduction under sliding/rolling contact in thermal elastohydrodynamic lubrication

2021 ◽  
pp. 1-27
Author(s):  
Xianghua Meng ◽  
Jing Wang ◽  
Gyoko Nagayama
Keyword(s):  
Film Thickness ◽  
Contact Area ◽  
Temperature Rise ◽  
Elastohydrodynamic Lubrication ◽  
Volume Ratio ◽  
Velocity Slip ◽  
Rolling Contact ◽  
Thickness Reduction ◽  
Thermal Slip ◽  
Entrainment Velocity

Abstract Temperature rise and film thickness reduction are the most important factors in elastohydrodynamic lubrication (EHL). In the EHL contact area, interfacial resistances (velocity/thermal slips) induced by the molecular interaction between lubricant and solid become significant due to the large surface/volume ratio. Although the velocity slip has been investigated extensively, less attention has been paid on the thermal slip in the EHL regime. In this study, numerical simulations were conducted by applying three cases of boundary slips to surfaces under sliding/rolling contacts moving in the same direction for the Newtonian thermal EHL. We found that the coupled velocity/thermal slips lead the most significant temperature rise and film thickness reduction among the three cases. The velocity slip results in a lower temperature in the lubricant and solids, whereas the thermal slip causes a temperature rise in the entire contact area as the film thickness decreases simultaneously. Furthermore, the effect of thermal slip on lubrication is more dominant than that of velocity slip while increases the entrainment velocity or slide–roll ratio.

Surface fitting of an involute spur gear tooth flank roughness measurement to its nominal shape

Measurement ◽  
2016 ◽  
Vol 91 ◽  
pp. 479-487 ◽  
Author(s):  
José A. Brandão ◽  
Jorge H.O. Seabra ◽  
Manuel J.D. Castro
Keyword(s):  
Gear Tooth ◽  
Spur Gear ◽  
Surface Fitting ◽  
Roughness Measurement ◽  
Tooth Flank

Experimental and numerical study on cavitation under elastohydrodynamic lubrication point contact

2021 ◽  
pp. 135065012110527
Author(s):  
Mingfei Ma ◽  
Wen Wang ◽  
Wenxun Jiang
Keyword(s):  
Contact Area ◽  
Numerical Study ◽  
Ambient Pressure ◽  
Point Contact ◽  
Elastohydrodynamic Lubrication ◽  
Hertzian Contact ◽  
Pressure Area ◽  
Cavitation Pressure ◽  
Experimental Researches ◽  
State 1

As a common phenomenon in elastohydrodynamic lubrication, cavitation has an effect on the completeness of the oil film in the contact area. Many studies have therefore been conducted on cavitation. Experimental researches on cavitation usually rely on optical interference observation, which offers a limited resolution and observation range. In this paper, an infrared thermal camera is used to observe the cavity bubbles on a ball-on-disc setup under sliding/rolling conditions. The results show that the cavity length increases with an increases of the entrainment speed and the viscosity of the lubricants. These observations are explained by a numerical model based on Elrod's algorithm. Effects of entrainment speed and lubricant viscosity on the breakup of cavitation bubbles and the cavitation states are investigated. Both the simulation and experimental results show that a negative pressure area is present behind the Hertzian contact area. The ambient pressure plays a role in maintaining cavitation state 1. The cavitation pressure is close to the vacuum pressure when the entrainment speed is low and to the ambient pressure instead when the entrainment speed is high.

Sign in / Sign up

Export Citation Format

Share Document