Experimental Study of Stabilisation of Small Size Journal Bearing With Oil Supply Groove by Using Starved Lubrication and Bearing Orientation Angle Change

2007 ◽  
Author(s):  
Masayuki Ochiai ◽  
Hiromu Hashimoto
Keyword(s):  
Experimental Study ◽  
High Speed ◽  
Journal Bearing ◽  
Orientation Angle ◽  
Journal Bearings ◽  
Rotating Machinery ◽  
Angle Change ◽  
Tilting Pad ◽  
Starved Lubrication ◽  
Rotating Machineries

Journal bearings are widely used for supporting high speed rotating machinery such as turbine, compressor and HDD spindle etc, because of their high load carrying capacity, stability and durability. Recently, the engineering trend is oriented to higher speed and smaller sizes of rotating machinery, and then it is important to enhance stabilities for the journal bearings. Tilting pad journal bearing is generally used for high-speed rotating machineries because of their advantages of stabilization. However, there are some problems using for compact size rotating machineries for their high manufacturing cost and complicated structure. Therefore, it is necessary to enhance the stability of more simple bearings compared with tilting pad bearing in order to use for small size rotating machinery. This paper describes the stabilization method of journal bearing based on the combination mechanism with starved lubrication and orientation angle change. From the results of stability experimental study of journal bearings, it is clarified that the stabilization of bearings is improved drastically by using above techniques.

Experimental Study on the Stabilization of Small-Bore Journal Bearings by Controlling Starved Lubrication and Bearing Orientation Angle

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
Hiromu Hashimoto ◽  
Masayuki Ochiai
Keyword(s):  
High Speed ◽  
Journal Bearing ◽  
Orientation Angle ◽  
Journal Bearings ◽  
Rotating Machinery ◽  
Manufacturing Cost ◽  
Compact Size ◽  
Tilting Pad ◽  
Starved Lubrication ◽  
Rotating Machineries

Journal bearings are widely used for supporting high-speed rotating machinery, such as turbine, compressor, and HDD spindle, because of their high load carrying capacity, stability, and durability. Recently, the engineering trend is oriented to higher speed and smaller sizes of rotating machinery, and then it is important to enhance stabilities for the small-bore journal bearings. Tilting pad journal bearing is generally used for high-speed rotating machineries because of their advantages of stabilization. However, there are some problems using compact size rotating machineries for their high manufacturing cost and complicated structure. Therefore, it is necessary to enhance the stability of more simple bearings compared with tilting pad bearing in order to use for small-size rotating machinery. This paper describes the stabilization method of the small-bore journal bearing based on the combination mechanism with starved lubrication and orientation angle change. It is found that the stabilization of small-bore journal bearings is improved drastically by hybrid lubrication combining these two kinds of mechanism.

Stabilization Method for Small-Bore Journal Bearings Utilizing Starved Lubrication

2009 ◽  
Vol 132 (1) ◽  
Author(s):  
Hiromu Hashimoto ◽  
Masayuki Ochiai
Keyword(s):  
High Speed ◽  
Journal Bearing ◽  
Control Mechanism ◽  
Journal Bearings ◽  
Test Rig ◽  
Stabilization Method ◽  
Speed Test ◽  
Nonlinear Motion ◽  
Starved Lubrication ◽  
Theoretical Results

This paper describes the stabilization method for small-bore circular journal bearings using starved lubrication. First, we describe the experimental examination to confirm the effect of supply oil conditions on stability of circular journal bearing by using a high-speed test rig. Then, the theoretical model considering the effect of amount of supply oil is discussed. Journal center trajectories are calculated by nonlinear motion analysis under various conditions. The theoretical results agree well with the experimental ones for three types of supply oil conditions and the mechanism of the stabilization by using the starved lubrication for small-bore journal bearings is clarified. Moreover, we suggest a supply oil control mechanism to stabilize the journal bearing using starved lubrication. Finally, the effectiveness of the proposed control mechanism on stability for high-speed small-bore journal bearings is verified experimentally.

Experimental Study of Tilting-Pad Journal Bearings—Comparison With Theoretical Thermoelastohydrodynamic Results

1992 ◽  
Vol 114 (3) ◽  
pp. 579-587 ◽  
Author(s):  
Michel Fillon ◽  
Jean-Claude Bligoud ◽  
Jean Freˆne
Keyword(s):  
Experimental Study ◽  
Theoretical Model ◽  
Rotational Speed ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Operating Conditions ◽  
Operating Characteristics ◽  
Tilting Pad ◽  
Tilting Pad Journal Bearing ◽  
Tilting Pad Journal Bearings

Operating characteristics of four-shoe tilting-pad journal bearings of 100 mm diameter and 70 mm length are determined on an experimental device. The load, between pad configuration, varies from 0 to 10,000 N and the rotational speed is up to 4000 rpm. Forty thermocouples are used in order to measure bearing element temperatures (babbitt, shaft, housing and oil baths). The influence of operating conditions and preload ratio on bearing performances are studied. Comparison between theoretical and experimental results is presented. The theoretical model is also performed on a large tilting-pad journal bearing which was investigated experimentally by other authors.

Thermal Deformation of Pads in Tilting 5-Pad Journal Bearing

2005 ◽  
Author(s):  
S. Strzelecki ◽  
L. Kusmierz ◽  
G. Poniewaz
Keyword(s):  
High Speed ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Oil Film ◽  
Tilting Pad ◽  
Drive Trains ◽  
Shaft Misalignment ◽  
Tilting Pad Journal Bearings ◽  
Turbine Drive ◽  
Oil Film Pressure

In high speed compressors and turbine drive trains, the tilting 5-pad journal bearings are applied. Tilting-pad journal bearings are good option because they have very good hydrodynamic stability at high speed and are less sensitive to load direction and shaft misalignment. The paper introduces thermo-elastic deformations of tilting 3-pad journal bearing with asymmetric support of pads and operating at the conditions of adiabatic oil film. The deformations of pads were obtained based on the oil film pressure and temperature distributions. Reynolds, energy, geometry and viscosity equations have been solved numerically on the assumption of aligned orientation of bearing and journal axis and at static equilibrium position of journal.

scholarly journals Establishment of Approximate Analytical Model of Oil Film Force for Finite Length Tilting Pad Journal Bearings

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Yongliang Wang ◽  
Yu Gao ◽  
Ying Cui ◽  
Zhansheng Liu
Keyword(s):  
Finite Length ◽  
High Speed ◽  
Journal Bearing ◽  
Dynamic Stiffness ◽  
Nonlinear Effects ◽  
Journal Bearings ◽  
Force Model ◽  
Oil Film ◽  
Tilting Pad ◽  
Tilting Pad Journal Bearings

Tilting pad bearings offer unique dynamic stability enabling successful deployment of high-speed rotating machinery. The model of dynamic stiffness, damping, and added mass coefficients is often used for rotordynamic analyses, and this method does not suffice to describe the dynamic behaviour due to the nonlinear effects of oil film force under larger shaft vibration or vertical rotor conditions. The objective of this paper is to present a nonlinear oil force model for finite length tilting pad journal bearings. An approximate analytic oil film force model was established by analysing the dynamic characteristic of oil film of a single pad journal bearing using variable separation method under the dynamicπoil film boundary condition. And an oil film force model of a four-tilting-pad journal bearing was established by using the pad assembly technique and considering pad tilting angle. The validity of the model established was proved by analyzing the distribution of oil film pressure and the locus of journal centre for tilting pad journal bearings and by comparing the model established in this paper with the model established using finite difference method.

scholarly journals Improvement of Tilting-Pad Journal Bearing Operating Characteristics by Application of Eddy Grooves

Lubricants ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 18
Author(s):  
Eckhard Schüler ◽  
Olaf Berner
Keyword(s):  
High Speed ◽  
Journal Bearing ◽  
Load Capacity ◽  
Fluid Film ◽  
Operating Characteristics ◽  
Fluid Film Bearings ◽  
Tilting Pad ◽  
Bearing Load ◽  
Bearing Loads ◽  
Tilting Pad Journal Bearing

In high speed, high load fluid-film bearings, the laminar-turbulent flow transition can lead to a considerable reduction of the maximum bearing temperatures, due to a homogenization of the fluid-film temperature in radial direction. Since this phenomenon only occurs significantly in large bearings or at very high sliding speeds, means to achieve the effect at lower speeds have been investigated in the past. This paper shows an experimental investigation of this effect and how it can be used for smaller bearings by optimized eddy grooves, machined into the bearing surface. The investigations were carried out on a Miba journal bearing test rig with Ø120 mm shaft diameter at speeds between 50 m/s–110 m/s and at specific bearing loads up to 4.0 MPa. To investigate the potential of this technology, additional temperature probes were installed at the crucial position directly in the sliding surface of an up-to-date tilting pad journal bearing. The results show that the achieved surface temperature reduction with the optimized eddy grooves is significant and represents a considerable enhancement of bearing load capacity. This increase in performance opens new options for the design of bearings and related turbomachinery applications.

An experimental investigation of a microturbine simulated rotor supported on multileaf gas foil bearings with backing bump foils

2017 ◽  
Vol 232 (9) ◽  
pp. 1169-1180 ◽  
Author(s):  
Bo Zhang ◽  
Shemiao Qi ◽  
Sheng Feng ◽  
Haipeng Geng ◽  
Yanhua Sun ◽  
...  
Keyword(s):  
High Speed ◽  
Preliminary Test ◽  
Journal Bearings ◽  
Rotating Machinery ◽  
System Stability ◽  
Test Rig ◽  
Thrust Bearings ◽  
Foil Bearings ◽  
Simulated System ◽  
First Time

Two multileaf gas foil journal bearings with backing bump foils and one set of gas foil thrust bearings were designed, fabricated, and used in a 100 kW class microturbine simulated rotor system to ensure stability of the system. Meanwhile, a preliminary test rig had been built to verify the simulated system stability. The rotor synchronous and subsynchronous responses were well controlled by using of the gas foil bearings. It is on the multileaf gas foil bearings with backing bump foils that the test was conducted and verified for the first time in open literatures. The success in the experiments shows that the design and fabrication of the rotor and the gas foil bearings can provide a useful guide to the development of the advanced high speed rotating machinery.

Influence of geometric parameters and operating conditions on the thermohydrodynamic behaviour of plain journal bearings

2000 ◽  
Vol 214 (5) ◽  
pp. 445-457 ◽  
Author(s):  
I Pierre ◽  
M Fillon
Keyword(s):  
High Speed ◽  
Journal Bearing ◽  
Three Dimensional ◽  
Journal Bearings ◽  
Operating Conditions ◽  
Thermal Dissipation ◽  
Radial Clearance ◽  
Geometric Factors ◽  
Essential Components ◽  
Mass Flowrate

Hydrodynamic journal bearings are essential components of high-speed machinery. In severe operating conditions, the thermal dissipation is not a negligible phenomenon. Therefore, a three-dimensional thermohydrodynamic (THD) analysis has been developed that includes lubricant rupture and re-formation phenomena by conserving the mass flowrate. Then, the predictions obtained with the proposed numerical model are validated by comparison with the measurements reported in the literature. The effects of various geometric factors (length, diameter and radial clearance) and operating conditions (rotational speed, applied load and lubricant) on the journal bearing behaviour are analysed and discussed in order to inform bearing designers. Thus, it can be predicted that the bearing performance obtained highly depends on operating conditions and geometric configuration.

Experimental Study on Cavitation Boundary of Journal Bearing

2013 ◽  
Vol 378 ◽  
pp. 362-366
Author(s):  
Ying Yang ◽  
Li Xu ◽  
Wen Qing Liu
Keyword(s):  
Experimental Study ◽  
High Speed ◽  
Journal Bearing ◽  
Theory Model ◽  
Work Characteristics ◽  
Oil Film ◽  
Rotating Speed ◽  
Supply Pressure ◽  
Rupture Area ◽  
Experimental Rig

Under high and super-high speed conditions, oil film of the journal bearing is easy to crack and then becomes cavitation. The existence of cavitation has a great effect on the work characteristics of the bearing. Cavitation boundary of a three-groove journal beaing was investigated on the journal bearing experimental rig. The influences of rotating speed and supply pressure on cavitation boundary were studied. And experimental equations of reformation location and the percent of rupture area are established. The results show that rupture location of oil film is not related with rotating speed and supply pressure, otherwise reformation location of oil film is effected greatly by them. The experimental equations lay foundations for next research on cavitation theory model and stability.

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