A Scattering Similarity Based Calculation Model for Oil Film Identification

Optik ◽  
2021 ◽  
pp. 167340
Author(s):  
Kan Ren ◽  
Jing Zhou ◽  
Minjie Wan ◽  
Guohua Gu ◽  
Qian Chen
Keyword(s):  
Calculation Model ◽  
Oil Film

A Performance Prediction of Microgrooved Bearings Under Mixed Lubrication

2008 ◽  
Author(s):  
Katsuhiro Ashihara ◽  
Hiromu Hashimoto
Keyword(s):  
Film Thickness ◽  
Contact Pressure ◽  
Hydrodynamic Lubrication ◽  
Calculation Model ◽  
Mixed Lubrication ◽  
Severe Condition ◽  
Oil Film ◽  
Precise Prediction ◽  
Lubrication Condition ◽  
Bearing Alloy

In the designs and analysis of engine bearings for automobiles, the precise prediction of the lubrication condition in severe condition is important. In the mixed-elasto-hydrodynamic lubrication analysis, the contact between the projections of surface roughness distributed stochastically is usually considered. This paper describes a theoretical model under the mixed lubrication in the microgrooved bearing. In this modeling, it is assumed that the section shape of microgrooved bearing alloy takes the circular arc form. In the part where contact is caused, the contact pressure is calculated by the Hertzian equation. The elastic deformation of the bearing by the mixed pressure with which oil film pressure and contact pressure are mixed by each allotment ratio is considered. Moreover, the balance requirement between the sum total of mixed pressure on bearing surface and the journal load is met. Under such an assumption, the numerical calculation model is newly obtained to predict the bearing performance in the mixed lubrication of microgrooved bearing. The numeric solutions of EHL based on the mixed lubrication are compared with EHL based on the fluid lubrication. The predicted oil film thickness at the center of bearing by the mixed lubrication model is remarkably thin compared with that by the fluid lubrication model. This shows that the load ability of the oil film thickness decreases by generating contact.

Contact Damping and Stiffness Calculation Model for Rough Surface Considering Lubrication in Involute Spur Gear

2021 ◽  
Author(s):  
Gong Cheng ◽  
Ke Xiao ◽  
Jiaxu Wang
Keyword(s):  
Film Thickness ◽  
Contact Stiffness ◽  
Elastohydrodynamic Lubrication ◽  
Spur Gear ◽  
Calculation Model ◽  
Mixed Lubrication ◽  
Asperity Contact ◽  
Crucial Point ◽  
Normal Deformation ◽  
Oil Film

The contact properties of an interface are crucial to the performance of equipment, and it is necessary to study the contact damping and contact stiffness, especially in the case of mixed lubrication. A calculation model for contact damping and contact stiffness considering lubrication was proposed on the basis of the KE contact model and mixed elastohydrodynamic lubrication theory. Both the damping and the stiffness were composed of the oil film portion and the asperity contact portion. Since the damping and the stiffness of oil film mainly depended on the film thickness and the pressure, which can be obtained with the mixed lubrication model, another crucial point was to figure out the contribution of asperity contact. Ignoring the effect of the tangential deformation, the stiffness and the load determined with the normal deformation of the asperity were obtained. Then, the contact damping and the contact stiffness considering lubrication could be derived. Finally, the model was applied to the study of contact damping and stiffness of the involute spur gear.

Analysis of influencing factors on oil film shear torque of hydro-viscous drive

2018 ◽  
Vol 70 (7) ◽  
pp. 1169-1175 ◽  
Author(s):  
Hongwei Cui ◽  
Zisheng Lian ◽  
Long Li ◽  
Qiliang Wang
Keyword(s):  
Influencing Factors ◽  
Experimental Research ◽  
Flow Rate ◽  
Rotation Speed ◽  
Calculation Model ◽  
Film Rupture ◽  
Equivalent Radius ◽  
Content Type ◽  
Oil Film ◽  
Save Energy

Purpose The hydro-viscous drive (HVD) has been widely used in fan transmission in vehicles, fans, and scraper conveyors for step-less speed regulating and soft starting. It is an efficient method to save energy and reduce consumption. This study aims to analyze the influencing factors of oil film shear torque accurately. Design/methodology/approach The shear torque calculation model of double arc oil groove friction pairs was established. The influence of groove structure parameters on shear torque was analyzed. The interaction between viscosity temperature and shear torque was considered. Meanwhile, the equivalent radius was calculated when the rupture of oil film appeared. Finally, the test rig of torque characteristics was set up. The variance of shear torque with the input rotation speed under different oil film thickness, different oil temperature, and different flow rate was seen. Findings The results show that the shear torque increases with the growth of rotation speed. However, the increase of torque is quite gradual because of the effect of the change of viscosity, which is caused by the rise of temperature. The shear torque increases with the decrease of thickness, the increase of inlet flow rate, and the decrease of inlet oil temperature. Meanwhile, when the feeding flow rate is less than the theoretical, the oil film gets ruptured and the shear torque decreases sharply. Originality/value The influence on shear torque during full film shear stage in HVD can be achieved much more accurately through both experimental research and theoretical modeling in which groove parameters, influence of temperature, and oil film rupture are considered. Therefore, the shear torque of HVD can be predicted by theoretical model and experimental research in full film shear stage.

Research on Modeling Method for Oil-Film Stiffness Calculation of Point Contact Based on EHL

2014 ◽  
Vol 945-949 ◽  
pp. 802-810
Author(s):  
Song Sheng Li ◽  
Juan Shao ◽  
Feng Yu ◽  
Jie Ling ◽  
Bin Chen
Keyword(s):  
Contact Region ◽  
Point Contact ◽  
Elastohydrodynamic Lubrication ◽  
Calculation Model ◽  
Oil Film ◽  
Rolling Ball ◽  
Film Distribution ◽  
Lubrication Condition ◽  
Set Up ◽  
Film Stiffness

Internal lubrication condition affects dynamic characteristics of rolling ball bearing in operation.According to the calculating problem of the elastic fluid lubricant film stiffness in point contact zone, the oil-film stiffness calculation model was set up based on the elastohydrodynamic lubrication theory (EHL) ,which considers the oil-film distribution and the pressure characteristic of the whole contact region. The stiffness of the oil-film was obtained from this model and compared with the experiment. The results indicate that the data calculated by the model fit the experiment very well, improving the calculation accuracy of the oil-film stiffness.

Evaluation standard and improvement method for multi-column envelope profile in single screw compressors

2020 ◽  
Vol 234 (6) ◽  
pp. 900-916
Author(s):  
Rui Huang ◽  
Guoqing Chen ◽  
Ting Li ◽  
Quanke Feng
Keyword(s):  
Hydrodynamic Lubrication ◽  
Optimization Method ◽  
Calculation Model ◽  
Test Results ◽  
Evaluation Standard ◽  
Oil Film ◽  
Single Screw ◽  
Improvement Method ◽  
Hydrodynamic Lubrication Theory ◽  
Total Oil

Multi-column envelope profile is the newly proposed engagement pair’s profile for single screw compressors. Based on hydrodynamic lubrication theory, a calculation model of the oil film moments for star wheel teeth with multi-column envelope profile was established. In order to balance the total oil film moments of the teeth, a profile evaluation standard and improvement method for the multi-column envelope profile were proposed. Then, the profile for a single screw compressor was optimized. The meshing pair with optimized profile is loaded into a prototype to carry out the running test. Results show that the optimization method improves the wear resistance of the star wheel teeth, especially the teeth’s front side, and enhances the running stability of the compressor.

scholarly journals Dynamic characteristics of high-speed gasoline engine turbocharger based on thermo-elasto-hydrodynamic lubrication bearing model and flexible multibody dynamics method

2020 ◽  
Vol 103 (1) ◽  
pp. 003685041989771
Author(s):  
Can song Gu ◽  
Zhao cheng Yuan ◽  
Zheng rui Yang ◽  
Jia xin Liu ◽  
Hong liang Li
Keyword(s):  
Film Thickness ◽  
Dynamic Characteristics ◽  
Gasoline Engine ◽  
Hydrodynamic Lubrication ◽  
Synthesis Method ◽  
Calculation Model ◽  
Oil Film ◽  
Surface Vibration ◽  
Flexible Multibody ◽  
Dynamics Method

A flexible multibody dynamic calculation model based on thermo-elasto-hydrodynamic lubrication bearing model was established. This numerical simulation method provided a more realistic turbocharger calculation model and a more reliable theoretical support for studying the dynamic vibration characteristics of the floating ring bearing turbocharger system. In order to fully consider the dynamic characteristics of each component, the behavior of the floating ring bearing was described by generalized incompressible Reynolds equation in thermo-elasto-hydrodynamic lubrication model. The flexible body substructure models were established by the modal synthesis method. Based on this model, the direct mathematical model of the relationship between the eccentricity of the rotor and the oil film clearance on the turbocharger’s surface vibration was established. The influence of eccentricity and oil film thickness on the surface vibration of the turbocharger body was calculated by transient dynamics method. The results showed that the eccentricity of the rotor and the vibration of turbocharger housing were monotonic functions, but the interaction between the whirl of internal and external oil films made the mechanism of the influence of the oil film thickness on the turbocharger body’s vibration complicated. The research provided a new idea for the structural vibration and synchronous noise control of the supercharger.

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