Paper 9: A Theoretical Analysis of the Floating-Pad Journal Bearing

1969 ◽  
Vol 184 (12) ◽  
pp. 60-69
Author(s):  
R. B. Howarth
Keyword(s):  
Energy Dissipation ◽  
Theoretical Analysis ◽  
High Speed ◽  
Journal Bearing ◽  
Low Energy ◽  
Rigorous Analysis ◽  
Simplified Approach ◽  
Lubricant Flow ◽  
Excited Vibration ◽  
Low Load

Limited applications and investigations have shown that the floating-pad journal bearing is a practical form of bearing which can be used to advantage. The operational complexities make a rigorous analysis exceedingly difficult if not impossible, and a simplified approach is adopted. The results of the analysis suggest that the floating-pad journal bearing is most suitable for high-speed, low-load applications where advantage can be taken of its desirable properties, in particular low energy dissipation and the high lubricant flow that can be accommodated for cooling purposes. The analysis also predicts the occurrence of a self-excited vibration becoming more pronounced as the eccentricity increases.

Paper 8: An Experimental Investigation of the Floating-Pad Journal Bearing

1969 ◽  
Vol 184 (12) ◽  
pp. 54-59
Author(s):  
R. B. Howarth
Keyword(s):  
Experimental Investigation ◽  
High Speed ◽  
Journal Bearing ◽  
Load Capacity ◽  
Excited Vibration ◽  
Low Load ◽  
Static Performance

This paper describes an experimental investigation into the static performance of a floating-pad journal bearing with four pads. Up to moderate eccentricities the test bearing was found to have a somewhat greater load capacity than an equivalent plain journal bearing, and there was no evidence of instability. The geometry of the bearing also allows high lubricant flows to be used for cooling purposes without requiring excessive supply pressures. Some difficulties were experienced with starting under load and with a self-excited vibration which occurred at moderate to high eccentricities. The results of the investigation suggest that this form of bearing is most suitable for low-load, high-speed applications.

Separation Cavitation; Solutions for the Infinite Width Cylinder-Plane and Journal-Bearing Configurations

1973 ◽  
Vol 15 (3) ◽  
pp. 237-239 ◽  
Author(s):  
C. M. Taylor
Keyword(s):  
Boundary Condition ◽  
Theoretical Analysis ◽  
Experimental Work ◽  
Journal Bearing ◽  
Low Load

Theoretical analysis of the infinite width cylinder-plane and journal-bearing configurations is undertaken using the separation cavitation boundary condition. The results could form the basis of experimental work designed to check the appropriateness of the boundary condition for low-load situations.

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.

Top-down Fabricated Gold Nanostrip on Silicon-on-insulator Wafer: A Promising Building Block towards Ultra-compact Optical Device

Nanoscale ◽  
2020 ◽  
Author(s):  
Fuping Zhang ◽  
Weikang Liu ◽  
Li Chen ◽  
Zhiqiang Guan ◽  
Hongxing Xu
Keyword(s):  
Optical Communication ◽  
Data Transmission ◽  
Building Block ◽  
High Speed ◽  
Large Data ◽  
Low Energy ◽  
Silicon On Insulator ◽  
Fundamental Building Block ◽  
Low Energy Consumption ◽  
Controllable Fabrication

he plasmonic waveguide is the fundamental building block for high speed, large data transmission capacity, low energy consumption optical communication and sensing. Controllable fabrication and simultaneously optimization of the propagation...

scholarly journals Cavitation between cylinder-liner and piston-ring in a new designed optical IC engine

2021 ◽  
pp. 146808742110080
Author(s):  
Jamshid Malekmohammadi Nouri ◽  
Ioannis Vasilakos ◽  
Youyou Yan
Keyword(s):  
High Speed ◽  
Contact Point ◽  
Cylinder Liner ◽  
Optical Methods ◽  
Engine Management System ◽  
Great Success ◽  
Ic Engine ◽  
Contact Points ◽  
Lubricant Flow ◽  
Cavitation Intensity

A new engine block with optical access has been designed and manufactured capable of running up to 3000 r/min with the same specification as the unmodified engine. The optical window allowed access to the full length of the liner over a width of 25 mm to investigate the lubricant flow and cavitation at contact point between the rings and cylinder-liner. In addition, it allowed good access into the combustion chamber to allow charged flow, spray and combustion visualisation and measurements using different optical methods. New custom engine management system with build in LabView allowed for the precise full control of the engine. The design of the new optical engine was a great success in producing high quality images of lubricant flow, cavitation formation and development at contact point at different engine speeds ranging from 208 to 3000 r/min and lubricant temperatures (30°C–70°C) using a high-speed camera. The results under motorised operation confirmed that there was no cavitation at contact points during the intake/exhaust strokes due to low in-cylinder presure, while during compression/expansion strokes, with high in-cylinder pressure, considerable cavities were observed, in particular, during the compression stroke. Lubricant temperatures had the effect of promoting cavities both in their intensity and covered ring area up to 50°C as expected. Beyond that, although the cavitation intensity increases further with temperature, its area reduces due to possible collapse of the cavitating bubbles at higher temperature. The change of engine speed from 208 to 800 r/min increased cavitating area considerably by 52% of the ring area and was further increased by 19% at 1000 r/min. After that, the results showed very small increase in cavitation area (1.3% at 2000 r/min) with similar intensity and distribution across the ring.

scholarly journals Low energy dissipation readout of single-molecule ferroelectronic states by a spin-Seebeck signal

2020 ◽  
Vol 2 (4) ◽  
Author(s):  
Hua-Hua Fu ◽  
Dan-Dan Wu ◽  
Gui-Fang Du ◽  
Qing-Bo Liu ◽  
Menghao Wu
Keyword(s):  
Energy Dissipation ◽  
Single Molecule ◽  
Low Energy

Experimental Investigation on Cavitation Characteristics of a Three-Groove Journal Bearing

2013 ◽  
Vol 420 ◽  
pp. 47-50
Author(s):  
Ying Yang ◽  
Jing Hua Dai
Keyword(s):  
Experimental Investigation ◽  
High Speed ◽  
Journal Bearing ◽  
Rupture Zone ◽  
Work Characteristics ◽  
Oil Film ◽  
Rotating Speed ◽  
Clear Effect ◽  
Supply Pressure

Under high and super-high speed, oil film of the journal bearing is easy to crack and then becomes cavitation. The existence of cavitation has an important effect on the work characteristics of the shaft. On the journal bearing experiment rig the cavitation characteristics of the three-groove journal beaing were studied. The influences of the shaft rotating speed and supply pressure on cavitation shape were investigated. The results show that rotating speed and supply pressure have a clear effect on the cavitation shape, and the number of cavitation strip in the rupture zone decreases when the supply pressure increases.

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