Journal Vibration: Influence of Compliant Bearing Design

2012 ◽  
Author(s):  
Matthew Cha ◽  
Sergei Glavatskih
Keyword(s):  
Dynamic Response ◽  
Nonlinear Dynamic ◽  
Dynamic Behaviour ◽  
Journal Bearings ◽  
Design Parameters ◽  
Radial Clearance ◽  
White Metal ◽  
Tilting Pad ◽  
Bearing Design ◽  
Tilting Pad Journal Bearings

In this paper, the nonlinear dynamic behaviour of vertical and horizontal rotors in compliant tilting pad journal bearings has been investigated. White metal and compliant bearings with line pivot pads are compared. The dynamic response of four pad bearings with different preload factors is studied. The effect of viscoelasticity is also considered in comparison with purely elastic compliant and white metal liners. The influence of radial clearance and pad offset is analysed. It is shown how pad design parameters such as preload factor, pivot offset, viscoelasticity of the liner, and radial clearance can be selected to control the size of the journal orbit in compliant bearings.

Experimental Study of Thermal Effects in Tilting-Pad Journal Bearings at High Operating Speeds

1996 ◽  
Vol 118 (3) ◽  
pp. 532-538 ◽  
Author(s):  
C. Bouchoule ◽  
M. Fillon ◽  
D. Nicolas ◽  
F. Barresi
Keyword(s):  
Thermal Effects ◽  
Applied Load ◽  
Journal Bearings ◽  
Test Machine ◽  
Power Losses ◽  
Test Bed ◽  
Tilting Pad ◽  
Oil Flow ◽  
Bearing Design ◽  
Tilting Pad Journal Bearings

In this work, a test machine, experimental results and the comparison between theoretical TEHD results and experimental data are presented. The tested bearings are located in two speed increasing and reduction gearboxes (back-to-back test bed). The shaft is driven by a 1 MW motor. The bearing diameter and the bearing length are equal to 160 mm. The rotational speed varies from 2700 rpm (22 m/s) to 11,880 rpm (100 m/s). The applied load is up to 88,000 N. Temperatures in the bearing (film/pad interface, oil, pad and housing), power losses and oil flow are measured. The influence of the bearing design and of the pivot position on the pad is analyzed.

scholarly journals Experimental Investigations on Tilting Pad Journal Bearings

1999 ◽  
Vol 5 (3) ◽  
pp. 181-191 ◽  
Author(s):  
Renato Brancati ◽  
Stefano Pagano ◽  
Ernesto Rocca ◽  
Michele Russo ◽  
Riccardo Russo
Keyword(s):  
Dynamic Behaviour ◽  
Experimental System ◽  
Journal Bearings ◽  
Operating Conditions ◽  
Experimental Investigations ◽  
Rigid Rotor ◽  
Tilting Pad ◽  
Set Up ◽  
The University ◽  
Tilting Pad Journal Bearings

The results of a survey conducted on an experimental system consisting of a rigid rotor supported on two radial bearings each with five tilting pads is presented. In particular, the system was set up in order to assess the dynamic behaviour of the bearing in unusual operating conditions. The response of the bearing to different unbalance values was determined after acquiring and analysing the orbits described by the journal axis for assigned unbalance values in different operating conditions. Analysis of the results shows some particular operating features that were not entirely predicted by the theoretical model and which may give rise to malfunctions in the rotor-tilting pad bearings system. The tests were carried out in the rotor dynamics laboratory of the Dipartimento di Ingegneria Meccanica per l'Energetica at the University of Naples.

Analysis of Eccentric Load Effect for Tiliting Pad Journal Bearing

2013 ◽  
Vol 364 ◽  
pp. 71-75
Author(s):  
Ming Hu Yin ◽  
Guo Ding Chen ◽  
Guo Yuan Zhang
Keyword(s):  
Dynamic Characteristics ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Eccentric Load ◽  
Load Effect ◽  
Static And Dynamic Characteristics ◽  
Tilting Pad ◽  
Bearing Design ◽  
Tilting Pad Journal Bearing ◽  
Tilting Pad Journal Bearings

Most of the studies about tilting pad journal bearings are for load-on-pad or load-between-pad tilting pad journal bearings, and for the other loading forms, the performance are often estimated by the performance of the two limited conditions, that may reduce the reliablity of bearing design or lead to waste materials in design. To obtained the influence of the load directions on the static and dynamic characteristics of the tilting pad journal bearing, which is called eccentric load effect in this papers, the performance calculation of the tilting pad journal bearing in different load directions is operated with a self-designed program. The results show that the load directions have considerable effects both on the static and dynamic characteristics of the tilting pad journal bearing, for the operating condition that load direction changed rapidly, it need performance analysis of the bearing in its special loading forms to enhance the precision and efficiency of bearing design, espacially where the dynamic performance of the tilting pad journal bearing is demanding.

Nonlinear Dynamic Behaviour of a Motorcycle’s Forecarriage During Braking

2005 ◽  
Author(s):  
M. Pezzola ◽  
F. Braghin ◽  
M. Brembilla ◽  
G. Brambilla
Keyword(s):  
Numerical Model ◽  
Dynamic Response ◽  
Nonlinear Dynamic ◽  
Dynamic Behaviour ◽  
Experimental Tests ◽  
Design Parameters ◽  
Numerical Experience ◽  
Flexural Mode ◽  
Nonlinear Dynamic Response ◽  
Braking System

An experimental and numerical experience was carried out to investigate the nonlinear dynamic response of the forecarriage of a motorcycle, paying attention to a particular type of vibration that occurs during the braking. In fact, it was found that, in particular conditions of load on the handlebar, braking pressure, speed and temperature, the first flexural mode of the front fork is strongly excited. Thanks to the numerical model, solutions to these undesired vibrations were identified. Experimental tests were carried out modifying the design parameters of the motorcycles and of the braking system as suggested by the numerical model thus verifying that the purposed solutions were effective.

Optimization of Tilting-Pad Journal Bearings for Integrally Geared Compressors

2015 ◽  
Author(s):  
Nico Havlik ◽  
Michael Lutz
Keyword(s):  
High Speed ◽  
Journal Bearings ◽  
Gravity Force ◽  
Power Losses ◽  
Tilting Pad ◽  
Compressor Design ◽  
Overall Efficiency ◽  
Bearing Design ◽  
Tilting Pad Journal Bearings ◽  
Highly Loaded

Tilting-pad journal bearings (TPJBs) support highly loaded high speed rotors with high requirements on rotordynamic behavior. Typical applications therefore are integrally geared compressors, where the gear force of the high speed pinions (HSPs) is at least one magnitude higher than the gravity force. A continuously rising demand for increasing the overall efficiency of integrally geared compressors leads to a necessity to expand TPJBs operation limits. Allowable limits of actual bearings often result in limitations for thermodynamical compressor design. In addition, bearings generate 20% to 40% of the mechanical power losses in integrally geared compressors. Improvements in the bearing design have to be performed in order to meet the challenges of rising loads and speeds. This paper presents an optimization of TPJBs for integrally geared compressors to meet the further demand of higher operation limits.

Prediction of nonlinear dynamic coefficients of tilting-pad journal bearings with pad perturbation

2021 ◽  
pp. 135065012110548
Author(s):  
Mohammad Hojjati ◽  
Seyed Younes Farzanmehr ◽  
H. M. Navaz ◽  
Hassan Haddadpour
Keyword(s):  
Partial Derivative ◽  
Nonlinear Dynamic ◽  
Perturbation Technique ◽  
Journal Bearings ◽  
Eccentricity Ratio ◽  
Linear Dynamic ◽  
Dynamic Coefficients ◽  
Tilting Pad ◽  
Derivative Method ◽  
Tilting Pad Journal Bearings

In this paper, a modified partial derivative method is developed to predict the linear and nonlinear dynamic coefficients of tilting-pad journal bearings with journal and pad perturbation. To this end, Reynolds equation and its boundary conditions along with equilibrium equations of the pad are used. Finite difference, partial derivative method, and perturbation technique have been employed simultaneously for solving these equations. The accuracy of the results is investigated by comparing the linear dynamic coefficients of three types of tilting-pad journal bearings with those published the literature. It is shown that the nonlinear dynamic coefficients depend on Sommerfeld number, eccentricity ratio, and length to diameter ratio. Similar to the case of linear dynamic coefficients of TPJB, it is observed that the eccentricity ratio effects on nonlinear dynamic coefficients are more notable when the eccentricity ratio is higher than 0.8 or less than 0.2.

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