Integral transform solution for the analysis of hydrodynamic lubrication of thrust bearings

2017 ◽  
Vol 69 (6) ◽  
pp. 1074-1084 ◽  
Author(s):  
Nielson Veloso Medeiros ◽  
Emanuel Negrão Macêdo ◽  
Rui Nelson Otoni Magno ◽  
Claudio José Cavalcante Blanco ◽  
João Nazareno Nonato Quaresma
Keyword(s):  
Power Consumption ◽  
Integral Transform ◽  
Hydrodynamic Lubrication ◽  
Load Capacity ◽  
Point Of View ◽  
Content Type ◽  
Thrust Bearings ◽  
Engineering Parameters ◽  
Volume Method ◽  
Integral Transform Technique

Purpose The aim of this paper is related to an analysis of hydrodynamic lubrication of circular thrust bearings. Design/methodology/approach The modified Reynolds equation was treated to obtain a hybrid numerical-analytical solution through the generalized integral transform technique (GITT) for the problem. Findings Numerical results for the engineering parameters such as pressure field, load capacity and power consumption were thus produced as functions of the radial and circumferential directions. These parameters depend on the geometry of sector-shaped used: Rayleigh pad with 4, 8 and 16 steps. Comparing among them, on the numerical point of view, the Rayleigh pad geometry with N = 16 steps has a better satisfactory performance because it has a lower power consumption. Originality/value The present GITT results and those obtained by the finite volume method (FVM) from previous works in the literature were confronted to verify whether the results are consistent and to demonstrate the capacity of the GITT approach in handling thrust bearing problems.

Modeling and experimental research on engaging characteristics of wet clutch

2019 ◽  
Vol 71 (1) ◽  
pp. 94-101 ◽  
Author(s):  
Yanzhong Wang ◽  
Yuan Li ◽  
Yang Liu ◽  
Wei Zhang
Keyword(s):  
Contact Surface ◽  
Hydrodynamic Lubrication ◽  
Load Capacity ◽  
Lubricating Oil ◽  
Centrifugal Effect ◽  
Element Analysis ◽  
Content Type ◽  
Clutch Engagement ◽  
Wet Clutch ◽  
Engagement Process

PurposeTo gain in-depth understandings of engaging characteristics, the purpose of this paper is to improve the model of wet clutches to predict the transmitted torque during the engagement process.Design/methodology/approachThe model of wet clutch during the engagement process took main factors into account, such as the centrifugal effect of lubricant, permeability of friction material, slippage factor of lubricant on contact surface and roughness of contact surface. Reynolds’ equation was derived to describe the hydrodynamic lubrication characteristics of lubricant film between the friction plate and the separated plate, and an elastic-plastic model of the rough surfaces contact based on the finite element analysis was used to indicate the loading force and friction torque of the contact surface.FindingsThe dynamic characteristics of wet clutch engagement time, relative speed, hydrodynamic lubrication of lubricating oil, rough surface contact load capacity and transfer torque can be obtained by the wet clutch engagement model. And the influence of the groove shape and depth on the engaging characteristics is also analyzed.Originality/valueThe mathematical model of the wet clutch during the engagement process can be used to predict the engaging characteristics of the wet clutch which could be useful to the design of the wet clutch.

Experimental analysis of influence of double-layer bump foils on aerodynamic thrust foil bearings performance

2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Fangcheng Xu ◽  
Zeda Dong ◽  
Jianhua Chu ◽  
Haoming Wang ◽  
Yongliang Wang
Keyword(s):  
Power Consumption ◽  
Double Layer ◽  
External Force ◽  
Performance Optimization ◽  
Load Capacity ◽  
Foil Thickness ◽  
Selection Scheme ◽  
Content Type ◽  
Friction Power ◽  
Foil Bearings

Purpose Gas thrust foil bearings (GTFBs) are used to balance the axial load of engines. However, in some working conditions of large axial force, such as the use of single impeller air compressor, the load capacity of GTFBs is still insufficient. To solve this problem, the load capacity can be improved by increasing the stiffness of bump foil. The purpose of this paper is to explore a scheme to effectively improve the performance of thrust foil bearings. In the paper, the stiffness of bump foil is improved by increasing the thickness of bump foil and using double-layer bump foil. Design/methodology/approach The foil deformation of GTFBs supported by three different types of bump foils, the relationship between friction power consumption and external force and the difference of limited load capacity were measured by experimental method. Findings The variation of the foil deformation, bearing stiffness, friction power consumption with the external force at different speeds and limited load capacity are obtained. Based on experimental results, the selection scheme of bump foil thickness is obtained. Originality/value This paper provides a feasible method for the performance optimization of GTFBs.

Thrust Bearings for Power Gas Turbines

1971 ◽  
Author(s):  
A. J. Leopard
Keyword(s):  
Gas Turbines ◽  
Load Capacity ◽  
Point Of View ◽  
Power Losses ◽  
Service Experience ◽  
Thrust Bearings ◽  
Tilting Pad ◽  
Bearing Assembly ◽  
Design Requirements ◽  
New System

The design requirements of thrust bearings for power gas turbines are discussed with reference to designs which have given satisfactory service. The shortcomings of these designs are analyzed both from the point of view of efficiency and that of service experience. The development of a new system of lubrication designed to overcome these shortcomings is outlined. It is shown that this system, when applied to tilting pad thrust bearings in power turbines, can result in a simpler bearing assembly with increased load capacity and substantially ower power losses.

Study of the influence of lubrication parameters on gear lubrication properties and efficiency

2016 ◽  
Vol 68 (6) ◽  
pp. 647-657 ◽  
Author(s):  
Kaiyue Li ◽  
Guoding Chen ◽  
Deng Liu
Keyword(s):  
Power Consumption ◽  
Film Thickness ◽  
High Speed ◽  
Hydrodynamic Lubrication ◽  
Quantitative Relationship ◽  
Gear Transmission ◽  
Content Type ◽  
Oil Film ◽  
Friction Power ◽  
Lubricating Properties

Purpose The analysis of lubricating properties and efficiency is important for aviation high-speed gear. So far, the project of lubricating properties and efficiency are processing under the condition of a given lubricating state, which is still depending on practical experience. This paper aims to mostly focus on the analysis of given lubricating state but lost sight of the relevance of lubrication parameters and lubricating state, which not only makes the analysis of aviation high-speed gear transmission and efficiency fail to trace to practical situation but also has an adverse effect on the reliance and validity of the project. Design/methodology/approach Based on this, the numerical model of spraying oil and oil film spreading is established, and the quantitative relationship between spray lubrication parameters and spreading characteristics of oil film is studied. According to the geometric and mechanical conditions of meshing points and taking the influence of rich-oil/starved-oil lubrication and roughness of teeth surface into consideration, corrected film thickness under condition of elasto-hydrodynamic lubrication and lubricating state of mesh points are analyzed. On this basis, power consumption and efficiency of gear transmission are also calculated by figuring out the solid friction and oil friction separately. Findings Through the research of this thesis, the effect of friction power consumption and efficiency with lubrication parameters is discussed. The effect of lubrication parameters on friction power consumption and efficiency of gear is complex. With the increase of spreading film thickness and film length, the frictional power consumption is less and the efficiency is higher. Originality/value This work provides a systematic technological approach to lubrication design and efficiency calculation of aviation high-speed gear transmission, which has remarkable engineering significance for the accurate lubrication design of the aviation mechanical parts.

Numerical and experimental study on the static performance of externally pressurized thrust bearings lubricated with refrigerant gases

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Chengjun Rong ◽  
Huaqi Lian ◽  
Yulong Li
Keyword(s):  
Heat Pump ◽  
Stokes Equations ◽  
Load Capacity ◽  
Heat Pumps ◽  
Static Stiffness ◽  
Space Applications ◽  
Content Type ◽  
Thrust Bearings ◽  
Bearing Clearance ◽  
Static Performance

Purpose Oil-free heat pumps that use the system refrigerant gases as lubricants are preferred for thermal management in future space applications. This study aims to numerically and experimentally investigate the static performance of externally pressurized thrust bearings lubricated with refrigerant gases. Design/methodology/approach The refrigerant gases R22, R410A and CO2 were chosen as the research objects, while N2 was used for comparison. Computational fluid dynamics was used to solve the full 3 D Navier–Stokes equations to determine the load capacity, static stiffness and static pressure distribution in the bearing film. The numerical results were experimentally verified. Findings The results showed that the refrigerant-gas-lubricated thrust bearings had a lower load capacity than the N2-lubricated bearings, but they presented a higher static stiffness when the bearing clearance was less than 9 µm. Compared with the N2-lubricated bearings, the optimal static stiffness of the R22- and CO2-lubricated bearings increased by more than 46% and more than 21%, respectively. The numerical and experimental results indicate that a small bearing clearance would be preferable when designing externally pressurized gas thrust bearings lubricated with the working medium of heat pump systems for space applications. Originality/value The findings of this study can serve as a basis for the further investigation of refrigerant gases as lubricants in heat pump systems, as well as for the future design of such gas bearings in heat pump systems for space applications.

Simulation and optimization of thrust circular bearings with planes sector-shaped

2014 ◽  
Vol 66 (1) ◽  
pp. 75-82 ◽  
Author(s):  
Claudio J.C. Blanco ◽  
Alvaro T. Prata ◽  
Francisco C.L. Pessoa
Keyword(s):  
Design Methodology ◽  
Reynolds Equation ◽  
Pressure Field ◽  
Content Type ◽  
Thrust Bearings ◽  
Simulation And Optimization ◽  
Method Of Lagrange Multipliers ◽  
Volume Method ◽  
Better Than ◽  
Optimized Geometries

Purpose – The purpose of this paper is to analyze journal thrust bearings geometries, used in household refrigerators, using a modified version of the Reynolds equation which includes the inertial terms. Design/methodology/approach – The Reynolds equation was solved through the finite volume method, thus providing the pressure field in the lubricant film and, consequently, the load and the power used by the bearing. Such parameters depend on bearing geometry, which was optimized through the method of Lagrange multipliers, to support a given load and use the lowest power possible. The optimized geometries included the Rayleigh pad with 4, 8 and 16 steps, and a milled geometry with 4 steps. Findings – For the Rayleigh pad, the number of steps was varied and a decrease in the power consumed with the increase in the number of steps was observed. The milled pad performance was better than that Rayleigh pad with 4 steps and comparable to the pad with 8 steps. Originality/value – The manufacture of pads, with a high number of steps, is complicated and, then, a milled pad with 4 steps was proposed in this paper. The use of milled pads is a technological innovation worthy of a more thorough investigation, considering its facility of manufacture when compared to the Rayleigh pad.

An exact GITT solution for static bending of clamped parallelogram plate resting on an elastic foundation

2019 ◽  
Vol 36 (6) ◽  
pp. 2034-2047 ◽  
Author(s):  
Guangming Fu ◽  
Yudan Peng ◽  
Baojiang Sun ◽  
Chen An ◽  
Jian Su
Keyword(s):  
Boundary Conditions ◽  
Elastic Foundation ◽  
Design Methodology ◽  
Significant Contribution ◽  
Integral Transform ◽  
Auxiliary Problem ◽  
Equation System ◽  
Differential Equation System ◽  
Content Type ◽  
Integral Transform Technique

Purpose The purpose of this study is to propose generalised integral transform technique (GITT) to obtain the exact solutions for bending of clamped parallelogram plate resting on elastic foundation. Design/methodology/approach The GITT is used to solve the bending problem of the full clamped parallelogram plate under an elastic foundation. The auxiliary problem was developed and the corresponding eigenfunction and eigenvalue were calculated simultaneously. The original partial differential governed equation has been represented by the transformed ordinary differential equation system and solved by the subroutine DBVPFD from International Mathematics and Statistics Library. Findings The GITT has been proven to be an efficient approach to solve the bending problem of the plate with different loads, boundary conditions and elastic foundations. The parametric study indicates that the elastic foundation modulus has significant contribution in reducing the vertical deflections and moments for both rectangular and parallelogram plates. With the increasing of aspect ratio (a/b) and the elastic foundation modulus, the trends of the deflection and moment reduction decreased significantly. Originality/value The present hybrid analytical-numerical methodology was first used to solve the mechanics problem of the clamped parallelogram plate resting on elastic foundation. Excellent convergence and high accuracy was observed by comparing with the published results. It exhibits potential application to investigate the mechanics problem of the composite plate with different boundary conditions in the shipbuilding and civil engineering.

Study on oil film pressure distribution and load capacity of textured rolling bearings

2020 ◽  
Vol 72 (7) ◽  
pp. 961-967 ◽  
Author(s):  
Ka Han ◽  
Junning Li ◽  
Qian Wang ◽  
Wuge Chen ◽  
Jiafan Xue
Keyword(s):  
Pressure Distribution ◽  
Peer Review ◽  
Hydrodynamic Lubrication ◽  
Load Capacity ◽  
Rolling Bearing ◽  
Depth Range ◽  
Film Pressure ◽  
Content Type ◽  
Oil Film ◽  
Oil Film Pressure

Purpose The purpose of this study is to reveal the tribological performance of the textured rolling bearing. Design/methodology/approach In the present study, the oil film pressure distribution and load capacity analysis method are established, which integrate the micro-texture model and Hydrodynamic lubrication (HL) methods. The tribological performances of the textured rolling bearing under the various working condition, texture dimension and texture type are investigated systematically. Findings The results show that the oil film load capacity increases with the increase in the texture size. As the texture depth increases, the oil film load capacity increases first and then decreases, and then the load capacity is the largest at the texture depth range of 3 to 5 µm. In addition, the oil film load capacity of the matching pairs, such as Si4N3-Si4N3, GCr15- Si4N3 and GCr15-GCr15 are compared; the results show that the cases of using ceramic material can improve oil film load capacity of textured rolling bearing. Originality/value The current manuscript can be useful for supporting the reliability and life research of textured rolling bearing. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-02-2020-0055

A hydrodynamic lubrication model and comparative analysis for coupled microgroove journal-thrust bearings lubricated with water

2019 ◽  
Vol 234 (11) ◽  
pp. 1755-1770
Author(s):  
Guo Xiang ◽  
Yanfeng Han ◽  
Renxiang Chen ◽  
Jiaxu Wang ◽  
Xiaokang Ni ◽  
...  
Keyword(s):  
Thrust Bearing ◽  
Hydrodynamic Lubrication ◽  
Load Capacity ◽  
Mutual Effect ◽  
Hydrodynamic Pressure ◽  
Isosceles Triangle ◽  
Maximum Load ◽  
Hydrodynamic Effect ◽  
Thrust Bearings ◽  
Lubrication Performance

The novelty of this study is to develop a hydrodynamic lubrication numerical model for coupled microgroove journal-thrust bearings (or coupled bearings) under water-lubricated condition. In the present model, the continuity of the hydrodynamic pressure and the fluid field (or coupled hydrodynamic effect) at common boundary is considered to reveal the mutual effect between the hydrodynamic behavior of the journal bearing and the thrust bearing. The lubrication performances of the coupled microgroove bearing with three bottom shapes, i.e., isosceles triangle, right triangle, and left triangle, are studied comparatively. Additionally, the effects of the microgroove depth on the lubrication performances of the coupled bearing are discussed. The present study reveals that the coupled hydrodynamic effect generated by the coupled bearing can improve the lubrication performance for both the journal and the thrust bearing. The microgroove with left triangle bottom shape yields the optimal lubrication performance as compared to the other two. There is an optimal groove depth that generates the maximum load capacity and the minimum friction coefficient for both the journal and the thrust bearing.

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