Optimum Design of Fluid Film Bearing for HDD Spindle Considering the Tolerances

2010 ◽  
Author(s):  
Yuta Sunami ◽  
Masayuki Ochiai ◽  
Hiromu Hashimoto
Keyword(s):  
Optimum Design ◽  
High Speed ◽  
Low Noise ◽  
Production Costs ◽  
Fluid Film ◽  
Rotating Shaft ◽  
Fluid Film Bearings ◽  
Support Element ◽  
Characteristic Values ◽  
Bearing Characteristic

Fluid film bearings are widely used for high speed rotating machineries acting as rotating shaft support element. Especially, the bearings are widely applied to the OA equipments and IT devices. Optimization of bearing parameters is effective to improve the performance of the fluid film bearings since low noise and impact-proof characteristics are essential requirements for these equipments. On the other hand, bearings for miniaturized spindles are generally made by mass production process which will eventually requires reduction of production costs. In this paper, therefore small size HDD spindle using fluid film bearings is treated. Sensitivity analysis and optimum design that considered dimensional tolerances using the probabilistic techniques are conducted. As a result, the influence of bearing characteristic values on the occurrence of dimensional tolerances was clarified.

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.

Diesel Engine Turbocharger Stabilized With Novel Tilting Pad Bearing Design

2012 ◽  
Author(s):  
R. Gordon Kirk ◽  
Matthew Enniss ◽  
Daniel Freeman ◽  
Andrew Brethwaite
Keyword(s):  
High Speed ◽  
Fluid Film ◽  
Pressure Pulsations ◽  
The Past ◽  
Fluid Film Bearings ◽  
Film Instability ◽  
Tilting Pad ◽  
Full Speed ◽  
Bearing Design ◽  
Engine Testing

Many high speed turbochargers operate with limit cycle vibration as a result of fluid-film instability. This problem has been under investigation for the past seven years. Only now has a turbocharger with fluid film bearings been run to full speed and loaded, with essentially no bearing induced sub-synchronous vibration. The goal of this research was to have a stable synchronous response with a minimum of non-synchronous contribution excited only by the engine dynamics and exhaust pressure pulsations. Previous papers have documented experimental results of the fixed geometry bearing designs. This paper documents a new, modified tilting pad bearing concept that has replaced the fixed geometry bushings with minimal modifications to the stock bearing housing. The summary of the on-engine testing over the past year is documented in this paper.

Effects of Turbulence and Viscosity Variation on the Dynamic Coefficients of Fluid Film Journal Bearings

1985 ◽  
Vol 107 (2) ◽  
pp. 256-261 ◽  
Author(s):  
D. F. Wilcock ◽  
O. Pinkus
Keyword(s):  
High Speed ◽  
Dynamic Stiffness ◽  
Journal Bearings ◽  
Fluid Film ◽  
Turbulent Regime ◽  
Dynamic Coefficients ◽  
Damping Characteristics ◽  
Fluid Film Bearings ◽  
Viscosity Variation ◽  
Stiffness And Damping

Many high-speed or large fluid film bearings operate in the turbulent regime. However, relatively little consideration has been given to the effects of turbulence and of the variation in viscosity on the dynamic stiffness and damping characteristics of the bearings. Since the dynamic behavior of the rotor supported on such bearings is often closely tied to the bearing dynamic coefficients, knowledge of them may be critical to both the design and the in-place correction of rotor instabilities. These effects are here considered in some detail on the basis of computer calculated analytical results, both in general dimensionless terms and with regard to a specific numerical example.

Development of a High Speed Gas Bearing Test Rig to Measure Rotordynamic Force Coefficients

2011 ◽  
Vol 133 (10) ◽  
Author(s):  
J. Jeffrey Moore ◽  
Andrew Lerche ◽  
Timothy Allison ◽  
David L. Ransom ◽  
Daniel Lubell
Keyword(s):  
High Speed ◽  
High Amplitude ◽  
Fluid Film ◽  
Test Rig ◽  
Force Coefficient ◽  
Gas Bearings ◽  
Foil Bearings ◽  
Fluid Film Bearings ◽  
Wide Range ◽  
Gas Bearing

The use of gas bearings has increased over the past several decades to include microturbines, air cycle machines, and hermetically sealed compressors and turbines. Gas bearings have many advantages over traditional bearings, such as rolling element or oil lubricated fluid film bearings, including longer life, ability to use the process fluid, no contamination of the process with lubricants, accommodating high shaft speeds, and operation over a wide range of temperatures. Unlike fluid film bearings that utilize oil, gas lubricated bearings generate very little damping from the gas itself. Therefore, successful bearing designs such as foil bearings utilize damping features on the bearing to improve the damping generated. Similar to oil bearings, gas bearing designers strive to develop gas bearings with good rotordynamic stability. Gas bearings are challenging to design, requiring a fully coupled thermo-elastic, hydrodynamic analysis including complex nonlinear mechanisms such as Coulomb friction. There is a surprisingly low amount of rotordynamic force coefficient measurement in the literature despite the need to verify the model predictions and the stability of the bearing. This paper describes the development and testing of a 60,000 rpm gas bearing test rig and presents measured stiffness and damping coefficients for a 57 mm foil type bearing. The design of the rig overcomes many challenges in making this measurement by developing a patented, high-frequency, high-amplitude shaker system, resulting in excitation over most of the subsynchronous range.

Basic Study on the Seismic Response of the High-Speed Rotational Body Supported by Fluid Film Bearings

2011 ◽  
Author(s):  
Masayoshi Hatta ◽  
Atsuhiko Shintani ◽  
Tomohiro Ito
Keyword(s):  
High Speed ◽  
Seismic Waves ◽  
Equations Of Motion ◽  
Rotating Disk ◽  
Fluid Film ◽  
Basic Study ◽  
Fluid Forces ◽  
Shaft System ◽  
Fluid Film Bearings ◽  
Response Behaviors

In this study, the seismic responses of a disk and a shaft are evaluated analytically. In an analytical model, the disk-shaft system is treated as an elastic shaft with a rigid disk, and the shaft is supported by fluid film bearings. Furthermore, the gyroscopic effect of a disk and the fluid forces due to fluid film bearings are considered. The equations of motion are derived for the translational and rotational motions when the floor is subjected to horizontal and vertical excitations. The displacements of the centers of the disk and the shaft are evaluated by numerical simulations. At first, the response behaviors of a rotating disk without base excitation are evaluated, and at second, the effects of sinusoidal base excitations are investigated. Finally, the response behaviors of this system are subjected to seismic waves of varying frequencies. The results of the different seismic wave input are studied.

G1101-3-2 Optimum Design of Fluid Film Bearings Used in Small Size Spindle Motor

2009 ◽  
Vol 2009.4 (0) ◽  
pp. 21-22
Author(s):  
Kei ITO ◽  
Yuta SUNAMI ◽  
M. Danial IBRAHIM ◽  
Tadashi NAMBA ◽  
Masayuki OCHIAI ◽  
...  
Keyword(s):  
Optimum Design ◽  
Spindle Motor ◽  
Fluid Film ◽  
Fluid Film Bearings

Development of a High Speed Gas Bearing Test Rig to Measure Rotordynamic Force Coefficients

2010 ◽  
Author(s):  
J. Jeffrey Moore ◽  
Andrew Lerche ◽  
Timothy Allison ◽  
David L. Ransom ◽  
Daniel Lubell
Keyword(s):  
High Speed ◽  
High Amplitude ◽  
Fluid Film ◽  
Test Rig ◽  
Force Coefficient ◽  
Gas Bearings ◽  
Foil Bearings ◽  
Fluid Film Bearings ◽  
Wide Range ◽  
Gas Bearing

The use of gas bearings has increased over the last several decades to include microturbines, air cycle machines, and hermetically sealed compressors and turbines. Gas bearings have many advantages over traditional bearings, such as rolling element or oil lubricated fluid film bearings, including longer life, ability to use the process fluid, no contamination of the process with lubricants, accommodating high shaft speeds, and operation over a wide range of temperatures. Unlike fluid film bearings that utilize oil, gas lubricated bearings generate very little damping from the gas itself. Therefore, successful bearing designs such as foil bearings utilize damping features on the bearing to improve the damping generated. Similar to oil bearings, gas bearing designers strive to develop gas bearings with good rotordynamic stability. Gas bearings are challenging to design requiring a fully coupled thermo-elastic, hydrodynamic analysis including complex non-linear mechanisms such as Coulomb friction. There is a surprisingly low amount of rotordynamic force coefficient measurement in the literature despite the need to verify the model predictions and the stability of the bearing. This paper describes the development and testing of a 60,000 rpm gas bearing test rig and presents measured stiffness and damping coefficients for a 57 mm foil type bearing. The design of the rig overcomes many challenges in making this measurement by developing a patented, high-frequency, high-amplitude shaker system resulting in excitation over most of the subsynchronous range.

Analysis and Selection of Fluid-Film Bearings for Spool-Shaft Gas Turbines

1970 ◽  
Vol 92 (4) ◽  
pp. 597-606
Author(s):  
W. Shapiro ◽  
R. Colsher ◽  
O. Decker
Keyword(s):  
Gas Turbines ◽  
High Speed ◽  
Degrees Of Freedom ◽  
Ambient Pressure ◽  
Time History ◽  
Fluid Film ◽  
Fluid Film Bearings ◽  
High Speed Rotation ◽  
History Of ◽  
Speed Rotation

The mechanical simplicity and damping qualities of fluid-film bearings makes them attractive possibilities for spool-shaft bearings of gas turbines. The simultaneous high-speed rotation of journal and bearing, however, causes whirl stability to be a major problem. Computerized analysis was utilized to screen a spectrum of practical candidate configurations. Stability threshold plots were expeditiously generated using accurately determined cross-coupled spring and damping coefficients to represent the bearings. Performance of each bearing type was determined as a function of configuration, ambient pressure, and machined clearance. The selected three-lobe design was further tested with a “time-transient” analysis that accurately traced a complete time history of the motions of the system in its various degrees of freedom.

Vibration Problems With High-Speed Turbomachinery

1968 ◽  
Vol 90 (1) ◽  
pp. 174-185 ◽  
Author(s):  
B. Sternlicht ◽  
Paul Lewis
Keyword(s):  
High Speed ◽  
Theory And Practice ◽  
Fluid Film ◽  
Support Structure ◽  
Critical Speeds ◽  
Fluid Film Bearings ◽  
Vibration Problems ◽  
Rotor Stiffness

The paper presents several examples of vibrational problems recently experienced by several turbine manufacturers. These problems include stability, system critical speeds, rotor response to unbalance, and balancing of high-speed compressors and turbines. The effects of fluid-film bearings and seals, bearing pedestals, and other parts of support structure on rotor response and critical speeds are discussed. The effects of rotor stiffness, mass, and inertia distribution are presented. The paper gives a comparison between theory and practice and provides guidelines to machinery designers.

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