Influence of squeezing and interface slippage on the performance of water-lubricated tilting-pad thrust bearing during start-up and shutdown

2018 ◽  
Vol 30 (4) ◽  
pp. 137-148 ◽  
Author(s):  
Zhanchao Wang ◽  
Ying Liu ◽  
Yuechang Wang ◽  
Xiangfeng Liu ◽  
Yuming Wang
Keyword(s):  
Thrust Bearing ◽  
Start Up ◽  
Tilting Pad

A Transient Thermoelastohydrodynamic Analysis of a Tilting-Pad Thrust Bearing During Start-up

2005 ◽  
Author(s):  
X. Wang ◽  
Z. Zhang ◽  
J. Pan
Keyword(s):  
Theoretical Analysis ◽  
Thrust Bearing ◽  
Three Dimensional ◽  
Running Time ◽  
Start Up ◽  
Tilting Pad

The aim of this work is to study the transient thermoelastohydrodynamic behavior of the tilting-pad thrust bearing during its start-up. The theoretical analysis of bearing performance is based on a three dimensional transient TEHD model. The effects of the running time and load on the bearing’s performance are studied. The results show that the above factors influence the performance of the bearing significantly.

Asymmetry characteristic of tilting-pad thrust bearing during the start-up and shut-down process

2018 ◽  
Vol 70 (9) ◽  
pp. 1806-1814
Author(s):  
Zhanchao Wang ◽  
Fei Guo ◽  
Ying Liu ◽  
Xiangfeng Liu ◽  
Yuming Wang
Keyword(s):  
Velocity Gradient ◽  
Thrust Bearing ◽  
Friction Torque ◽  
Content Type ◽  
Start Up ◽  
Tilting Pad ◽  
Torque Curve ◽  
The Difference ◽  
Thrust Pad ◽  
Squeeze Effect

Purpose This aim of this paper has been to investigate the squeeze effect of a water-lubricated tilting-pad thrust bearing during start-up and shut-down periods. Design/methodology/approach In this paper a numerical model with a squeeze and slippage effect was adopted to analyse the asymmetry characteristic of a tilting-pad thrust bearing during start-up and shut-down periods. A test rig was built to verify numerical results, which were a combined measurement method in which acceleration sensor and torque sensor were used simultaneously to determine the angle change of the thrust pad. Findings It was found that as the velocity gradient increased, the difference of the minimum dimensionless film Hmin could be ignored in the start-up process. But in the shut-down process, as the velocity gradient increased, the value of Hmin also increased, which showed that there was an asymmetry characteristic of the tilting bearing in two processes. This phenomenon was verified by measuring the friction torque curve in the test. Originality/value The results of the studies demonstrated that the velocity gradient could be designed to reduce the friction of the thrust bearing, which would be beneficial to the working life of the tilting-pad thrust bearing.

scholarly journals Influence of the Equalizing Beam Structure on the Water Lubrication Tilting-pad Thrust Bearing during Start-up and Shut-down

2020 ◽  
Vol 56 (1) ◽  
pp. 82
Author(s):  
WANG Zhanchao ◽  
GUO Fei ◽  
LIU Ying ◽  
GONG Changliang ◽  
LIU Xiangfeng ◽  
...  
Keyword(s):  
Thrust Bearing ◽  
Water Lubrication ◽  
Beam Structure ◽  
Start Up ◽  
Tilting Pad

On the Significance of the Inlet Pressure Build-Up in the Design of Tilting-Pad Bearings

1990 ◽  
Vol 112 (1) ◽  
pp. 17-22 ◽  
Author(s):  
Cz. M. Rodkiewicz ◽  
K. W. Kim ◽  
J. S. Kennedy
Keyword(s):  
Thrust Bearing ◽  
Ambient Pressure ◽  
Inlet Pressure ◽  
Load Carrying Capacity ◽  
Integral Theorem ◽  
Lubricating Film ◽  
Tilting Pad ◽  
Load Carrying ◽  
Momentum Integral ◽  
Entrance Pressure

An operating tilting-pad thrust bearing generates a fore-region which is responsible for maintaining, at the bearing entrance, a pressure which is higher than the ambient pressure. This entrance pressure, in the presented analysis, is obtained by applying to the fore-region the momentum integral theorem. The solution of the lubricating film region is then obtained by using this modified inlet pressure. This solution yields the pressure distribution, the load carrying capacity, the film ratio and the frictional force for several values of the modified Reynolds number and various pivot positions. The analysis shows that there is a significant influence of the fore-region pressure on the bearing performance and that to properly design efficient tilting-pad bearing this effect should be taken into consideration.

Some Effects of Start-Up and Shut-Down on Thrust Bearing Assemblies in Hydro-Generators

2003 ◽  
Vol 125 (4) ◽  
pp. 824-832 ◽  
Author(s):  
C. M. Ettles ◽  
J. Seyler ◽  
M. Bottenschein
Keyword(s):  
Thrust Bearing ◽  
Operating Conditions ◽  
Transient Effects ◽  
Design Studies ◽  
Thrust Bearings ◽  
Beneficial Effects ◽  
Start Up ◽  
Thermal Bending ◽  
Run Up ◽  
Basic Studies

The modernization of hydro-generators can involve the analysis of many different manufacturer’s designs of thrust bearings. Recent designs of bearing in common use are very reliable, but when failures do occur, it is often with older machines and within the first few minutes of start-up. This paper is a result of general design studies of various thrust bearing configurations subjected to transient operating conditions. It is shown that transient effects can induce an ‘overshoot’ of thermal deformation which can become unstable, leading to ‘thermal ratchetting.’ Examples are given of pads of various manufacturer’s bearings that have been subjected to this mechanism. Results from operating turbines, basic studies and measurements of the thermal bending of plates indicate that a peak deflection occurs well before thermal equilibrium is attained. The peaking phenomenon may be obscured in some designs or in cases where the run-up is gradual. The beneficial effects of using an oil-lift system during start-up are described. During shut-down it is important that the contact of hot, crowned pads against the runner be prevented. Minimum times for operation of the lift system are suggested, based on the thickness of the pads.

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