Simulation of Temperature Field of Oil Film in Super-High Speed Hybrid Journal Bearing Based on FLUENT

The hybrid journal bearing with the high rigidity and rotation accuracy has been used in super-high speed grinding machine in some cases. But the main shortcoming of hybrid journal bearing is the higher temperature rise in the oil film when bearing works, which can lower the bearing capacity and cause the bearing failure due to the drop of oil viscosity and the larger thermal deformation. Fluent is a special CFD soft to simulate and analyze the flow and the heat exchange of liquid in the complex geometrical field. In this paper, the simulations of the temperature field of the oil film in the super-high speed hybrid journal bearing were performed by Fluent based on the mathematical models. The simulation results can not only forecast the flow state and the thermal properties of the bearing oil, but also find the design limitation of the bearing for the more improvement of the bearing design.

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Lubrication of Mechatronical Metal Cutting Systems by Means of Technological Liquids

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.113.367 ◽

2006 ◽

Vol 113 ◽

pp. 367-370

Author(s):

Vladas Vekteris

Keyword(s):

Temperature Field ◽

Experimental Research ◽

High Speed ◽

Metal Cutting ◽

Reynolds Equation ◽

Grinding Process ◽

Mechatronic System ◽

High Speed Grinding ◽

Aeration Process ◽

Grinding Machine

Lubrication and cooling of a high speed grinding process in the grinding machine as in a mechatronic system using technological liquids are analyzed in this paper. It is shown that in the case of high grinding speed, technological liquids undergo an aeration process and due to this their physical properties change. Reynolds equation, which estimates the aeration liquid, is derived. It is shown, that the application of such an equation is proper only in the finishing of grinding. Experimental research is also presented in the paper, which shows the influence of technological liquids to the temperature field of the grinding machine and to its automatic control.

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Viscosity Effect on Stiffness of Non-conventional (Five Tilted Pads) Journal Bearing

Tikrit Journal of Engineering Sciences ◽

10.25130/tjes.25.3.09 ◽

2018 ◽

Vol 25 (3) ◽

pp. 53-57

Author(s):

Mohammed Oawed Atteaa Alhassany ◽

Ali Khalid Aldulaimy

Keyword(s):

High Speed ◽

Journal Bearing ◽

Cross Coupling ◽

High Viscosity ◽

Lubricating Oil ◽

Coupling Coefficients ◽

Oil Viscosity ◽

Viscosity Change ◽

Oil Film ◽

Stiffness Coefficients

In this tribological study, we highlight the effect of lubricating oil viscosity in the Multi-pads hydrodynamic journal bearings generate important improvement in characteristics of stiffness and stability in the high speed turbomachines. Depending on viscosity of oil film (three values) variation for five tilted pads bearing, each pad is pivoted and is facilitated to be tilted with small angles, by using Matlab program, we calculate the oil film thickness for convergence layer. We applied Reynold’s equation and solved it’s numerically by using finite difference method with 5 nodes technique to find the pressure distributed on each node in the mesh of tilted pad, then calculate stiffness coefficients. Results show that there is clear effect on stiffens with viscosity change. The increase in value of Krr (for n = 0.3) between viscosity (0.04 Pas. s) and viscosity (0.058 Pas. s) is14.33 MN/m, while the increase in Krr value between viscosity (0.058 Pas. s) and viscosity (0.087 Pas. s) is 11.37 MN/m. the increase in value the of Kss (for n = 0.3) between viscosity (0.04 Pas. s) and viscosity (0.058 Pas. s) is5.921 MN/m, while increase in Kss value between viscosity (0.058 Pas. s) and viscosity (0.087 Pas. s) is9.55 MN/m respectively. the increase in value of Ksr (for n = 0.3) between viscosity (0.04 Pas. s) and viscosity (0.058 Pas. s) is 8.95 MN/m, while the increase in Ksr value between viscosity (0.058 Pas. s) and viscosity (0.087 Pas. s) is 14.41 MN/m respectively. the increase in value of Krs (for n = 0.3) between viscosity (0.04 Pas. s) and viscosity (0.058 Pas. s) are 5.08 MN/m, while the increase in Krs value between viscosity (0.058 Pas. s) and viscosity (0.087 Pas. s) is8.19 MN/m respectively. The values of the dominate principal coefficients Krr is greater than that of Ksr, also The values of the principal coefficients Kss is greater than that of cross coupling Krs for all values of viscosity that studied. From this result, we can conclude the side effect of cross coupling coefficients (Ksr ,Krs) can be overcome by great values for principal coefficient (Krr, Kss) respectively, so we can get good improvement instability for this bearing by variation the viscosity. After that, we regarded to use high viscosity lubricant in multi-pad journal bearing to improve the performance and stability by controlling the stiffness coefficients.

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The Comparison of Four Pressure-Thermal Models of Oil Film Bearing With the Non-Newtonian and Temperature-Viscosity Effects

Volume 8: 28th Conference on Mechanical Vibration and Noise ◽

10.1115/detc2016-59127 ◽

2016 ◽

Cited By ~ 1

Author(s):

Feng Liang ◽

Quanyong Xu ◽

Xudong Lan ◽

Ming Zhou

Keyword(s):

Temperature Field ◽

Numerical Model ◽

High Speed ◽

Reynolds Equation ◽

Pressure Field ◽

Journal Bearing ◽

Three Dimensional ◽

Two Dimensional ◽

Oil Film ◽

Viscosity Effects

The thermohydrodynamic analysis of oil film bearing is essential for high speed oil film bearing. The temperature field is coupled with the pressure field. The numerical model can be built or chosen according to the complexity of the objects and requirement of the accuracy. In this paper, four pressure-thermal (P-T) models are proposed, which are zero-dimensional temperature field coupled with Reynolds equation (0D P-T model), two-dimensional temperature field coupled with Reynolds equation (2D P-T model), two-dimensional temperature with third dimensional correction coupled with Dawson equation (2sD P-T model), three-dimensional temperature field coupled with Dawson equation (3D P-T model). The non-Newtonian and temperature-viscosity effects of the lubrication oil are considered in all the four models. Two types of cylindrical journal bearing, the bearing with/without axial grooves, are applied for the simulation. All the simulated cases are compared with the solutions of the CFX. The results show that the 0D P-T model fails to predict the behavior of high speed bearing; The 2D and 2sD P-T model have an acceptable accuracy to predict the performance of the bearing without grooves, but are not able to simulate the P-T field of the bearing with grooves because of the under-developed thermal boundary layer; The 2sD P-T model shows a great improvement when calculating the pressure field compared with the 2D P-T model; the 3D P-T model coincides well with the CFX at any condition. The comparison of these four models provides a reference to help designer choose a proper numerical model for a certain project.

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Study on Thermal Properties of Hybrid Journal Bearing for Super High Speed Grinding Machine

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.126-128.808 ◽

2010 ◽

Vol 126-128 ◽

pp. 808-813 ◽

Cited By ~ 1

Author(s):

Shi Chao Xiu ◽

Shi Qiang Gao ◽

Zhi Li Sun

Keyword(s):

Thermal Properties ◽

Temperature Rise ◽

High Speed ◽

Journal Bearing ◽

Spindle System ◽

Key Factor ◽

High Speed Grinding ◽

Machine Spindle ◽

Grinding Machine ◽

Heat Mechanism

As the high speed bearings, hybrid journal bearings are usually used in high and super high speed grinding machine spindle system. Since the bearing operates under high speed conditions, the excessive temperature rise of bearing is a key factor to lower the accuracy of the spindle system and limit the bearings working speed, so restrict the bearing applications. In this paper, the model of hybrid journal bearing is established to analyze the heat mechanism. In addition, the temperature field distribution for the certain hybrid journal bearing at high speed is studied by ANSYS considering the heat transfer characters between fluid and solid. The experiment of temperature for hybrid journal bearing system in super high speed grinding machine is also performed. The thermal properties and the measure for controlling temperature rise of such bearings are analyzed.

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

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.420.47 ◽

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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Experimental Research on Cavitation Characteristics of a Novel Hybrid Journal Bearing

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.420.74 ◽

2013 ◽

Vol 420 ◽

pp. 74-77

Author(s):

Ying Yang ◽

Jing Hua Dai ◽

Xu Li

Keyword(s):

Experimental Research ◽

High Speed ◽

Work Performance ◽

Journal Bearing ◽

Rupture Zone ◽

Oil Film ◽

Rotating Speed ◽

Supply Pressure ◽

Experimental Rig

Under high and super high speed, the oil film of a journal bearing is easy to crack and then becomes cavitation. The existence of cavitation has a great effect on the work performance of the bearing. The cavitation mechanism of a spiral oil wedge journal bearing was investigated on the experimental rig. The effects of rotating speed and supply pressure on the cavitation shape of oil film and the number of cavitation strip in the rupture zone were analyzed. The results show that the cavitation shape of oil film is a long strip. The number of cavitation strip increases when supply pressure has been improved, and the location of oil outlet must be designed optimally.

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Development of Wheel Spindle for Ultra-High Speed Surface Grinding Machine. Studies on Ultra-High Speed Grinding. (1st Report).

Journal of the Japan Society for Precision Engineering ◽

10.2493/jjspe.62.569 ◽

1996 ◽

Vol 62 (4) ◽

pp. 569-573 ◽

Cited By ~ 6

Author(s):

Yutaka INADA ◽

Katsuo SYOJI ◽

Tsunemoto KURIYAGAWA ◽

Kunihiko UNTIO

Keyword(s):

High Speed ◽

Surface Grinding ◽

Ultra High Speed ◽

High Speed Grinding ◽

Grinding Machine

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Experimental Study on Cavitation Boundary of Journal Bearing

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.378.362 ◽

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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Design, Analysis and Testing of an Inside-Out Tilting-Pad Journal Bearing With Real-Time Controllable Preload and Stiffness

World Tribology Congress III, Volume 2 ◽

10.1115/wtc2005-63067 ◽

2005 ◽

Author(s):

Maurice L. Adams ◽

Michael A. Laurich

Keyword(s):

Real Time ◽

High Speed ◽

Journal Bearing ◽

High Stiffness ◽

Tilting Pad ◽

High Speed Grinding ◽

Bearing Stiffness ◽

Centerless Grinding ◽

Tilting Pad Journal Bearing ◽

Inside Out

It has recently been shown that high-speed grinding can be applied to the finishing of ceramics with considerable improvements in throughput and quality. This will require new high-speed high-power centerless grinding spindles (7,000 RPM, 50 HP), with high-stiffness of three hundred and fifty million Newtons/meter (2 million lb/in). To meet these requirements a novel inside-out, three-pad, pivoting-pad oil-fed hydrodynamic journal bearing has been devised, built and tested. One of the three pad’s pivot point is supported by a hydraulically-actuated radial-motion loading piston. This provides real-time controllable preload to all three bearing pads, thereby controlling bearing stiffness, providing less-stiff spindle bearings for initial rough grinding and very high stiffness spindle bearings for precision finish grinding. Extensive bearing test data compare favorably with theoretically predicted bearing performance.

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