Simulation studies on static thermal behaviour of true elliptical and orthogonally displaced non-circular journal bearing

Purpose The current trend of modern industry is to use machineries which rotate at high speed along with the capability of carrying heavy rotor loads. This paper aims at static thermal analysis of two different profiles of non-circular journal bearings – a true elliptical bearing and orthogonal bearing. Design/methodology/approach The Reynolds equation has been solved through finite difference method to compute the oil film pressure. Parabolic temperature profile approximation technique has been used to solve the energy equation and thus used for computation of various bearing performance characteristics such as thermo-hydrodynamic oil film pressure, temperature, load capacity, Sommerfeld number and power loss characteristics across the bearing. The effect of ellipticity ratio on the bearing performance characteristics has also been obtained for both the elliptical and vertical offset bearing using three different commercially available grades of oil (Hydrol 32, 68 and 100). Findings It has been observed that the thermo-hydrodynamic pressure and temperature rise of the oil film is less in orthogonal bearing as compared to the true elliptical bearing for same operating conditions. The effect of ellipticity ratio of non-circularity on bearing performance parameters have been observed to be less in case of elliptical bearing as compared to orthogonal bearing. It has been concluded that though the rise in oil film temperature is high for true elliptical bearing, but still it should be preferred over orthogonal profile under study, as it has comparably good load-carrying capacity. Originality/value The performance parametric analysis will help the designers to select such kind of non-circular journal bearing for various applications.

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Study on oil film pressure distribution and load capacity of textured rolling bearings

Industrial Lubrication and Tribology ◽

10.1108/ilt-02-2020-0055 ◽

2020 ◽

Vol 72 (7) ◽

pp. 961-967 ◽

Cited By ~ 2

Author(s):

Ka Han ◽

Junning Li ◽

Qian Wang ◽

Wuge Chen ◽

Jiafan Xue

Keyword(s):

Pressure Distribution ◽

Peer Review ◽

Hydrodynamic Lubrication ◽

Load Capacity ◽

Rolling Bearing ◽

Depth Range ◽

Film Pressure ◽

Content Type ◽

Oil Film ◽

Oil Film Pressure

Purpose The purpose of this study is to reveal the tribological performance of the textured rolling bearing. Design/methodology/approach In the present study, the oil film pressure distribution and load capacity analysis method are established, which integrate the micro-texture model and Hydrodynamic lubrication (HL) methods. The tribological performances of the textured rolling bearing under the various working condition, texture dimension and texture type are investigated systematically. Findings The results show that the oil film load capacity increases with the increase in the texture size. As the texture depth increases, the oil film load capacity increases first and then decreases, and then the load capacity is the largest at the texture depth range of 3 to 5 µm. In addition, the oil film load capacity of the matching pairs, such as Si4N3-Si4N3, GCr15- Si4N3 and GCr15-GCr15 are compared; the results show that the cases of using ceramic material can improve oil film load capacity of textured rolling bearing. Originality/value The current manuscript can be useful for supporting the reliability and life research of textured rolling bearing. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-02-2020-0055

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Experimental study for performance evaluation of steadily loaded true elliptical and orthogonally displaced non-circular journal bearing profiles

Industrial Lubrication and Tribology ◽

10.1108/ilt-10-2015-0155 ◽

2016 ◽

Vol 68 (6) ◽

pp. 702-711 ◽

Cited By ~ 3

Author(s):

Amit Singla ◽

Amit Chauhan

Keyword(s):

Experimental Study ◽

Thermal Performance ◽

Journal Bearing ◽

Journal Bearings ◽

Maximum Temperature ◽

Positive Pressure ◽

Film Pressure ◽

Content Type ◽

Oil Film ◽

Oil Film Pressure

Purpose The non-circular journal bearings may be used over circular journal bearings because of their superior thermal stability. The paper aims at experimental study of thermal performance of two different true elliptical and orthogonally displaced non-circular journal bearing profiles. Design/methodology/approach The experiments have been conducted on a specially designed test rig which simultaneously evaluates oil film pressure and temperature along the circumference of non-circular journal bearing. The tests are conducted for the designed true elliptical and orthogonally displaced journal bearing at three different rotational speeds of 2,000, 3,000 and 4,000 rpm under the influence of steadily applied load varied from 0.5 to 2.0 kN. The data collected during experimentation have been used to evaluate thermal performance parameters such as maximum pressure, flow rate and effective temperature of the bearings under study. Findings It has been observed experimentally that two lobes of pressure and temperature have been obtained for both the elliptical and orthogonally displaced journal bearing. The negative pressure zone (cavitation area) has been observed to be reduced along the circumference for both the journal bearings which results in less thermal degradation of an oil as compared to circular journal bearing. The oil film pressure and temperature increases with the increase in radial load of both the bearings. The maximum temperature rise of oil film is more in case of elliptical bearing as compared to the orthogonally displaced bearing. Originality/value The experimental data presented in this paper will help the designers to select such kind of non-circular journal bearing for various applications. The designed bearings have resulted in reduced cavitation zone and two positive pressure lobes have been observed which may result in application of such bearings as an alternate for circular journal bearing.

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Embedded Optical Sensor for Oil Film Pressure Measurements in Journal Bearings

Smart Materials, Adaptive Structures and Intelligent Systems, Volume 1 ◽

10.1115/smasis2008-363 ◽

2008 ◽

Cited By ~ 1

Author(s):

Helena Ronkainen ◽

Antti Valkonen ◽

Markku Kapulainen ◽

Varjus Simo ◽

Ari Hokkanen ◽

...

Keyword(s):

Optical Sensor ◽

Journal Bearing ◽

Theoretical Calculations ◽

Journal Bearings ◽

Operating Conditions ◽

Dynamic Loads ◽

Sensor Design ◽

Film Pressure ◽

Oil Film ◽

Oil Film Pressure

The oil film pressure is one of the essential functional parameters in journal bearings. Until now, the oil film pressure has been estimated by theoretical calculations, since the measurement of oil film pressure has been a demanding or even unfeasible task in journal bearings, especially in bearings carrying dynamic loads. In this study a new approach has been developed for experimental determination of the oil film pressure. The sensor design utilizes the optical fibre technique and the sensor is integrated in the sliding surface of the bearing thus providing the possibility to measure the actual oil film pressure under load. The finite element method (FEM) calculations have been used for optimizing the design of the sensor and for ensuring the appropriate mechanical performance of the sensor design. The optical sensor was integrated in a hydrodynamic journal bearing made of bronze. A versatile bearing test rig was used for testing the journal bearing with integrated optical sensor. The tests were carried out with both static and dynamic loading. The oil film pressure was measured with different loads and speeds and the data was compared with simulated one. The results showed that the optical sensor was capable to measure the oil film pressure in journal bearing at real operating conditions and the sensitivity of the sensor was good enough to verify the speed and load effects on pressure. According to this work, it is possible to increase the knowledge of true operating conditions of journal bearings by using the optical sensor for oil film pressure measurement. The knowledge can be utilized in the development work of safer and more efficient machines and engines with journal bearings carrying high and dynamic loads. The optical sensor can be used also in other applications for smart control of pressure.

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Fuzzy Logic based Model to Predict Maximum Oil-Film Pressure in Journal Bearing

Research Journal of Applied Sciences Engineering and Technology ◽

10.19026/rjaset.6.3604 ◽

2013 ◽

Vol 6 (20) ◽

pp. 3871-3878 ◽

Cited By ~ 1

Author(s):

Diyar I. Ahmed ◽

S. Kasolang ◽

Basim A. Khidhir ◽

B.F. Yousif

Keyword(s):

Fuzzy Logic ◽

Journal Bearing ◽

Film Pressure ◽

Oil Film ◽

Oil Film Pressure

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Experimentally study of dynamic pressure distribution and oil film forces in journal bearing using ElectroMechanical Film sensor array

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/0954406219884971 ◽

2019 ◽

Vol 234 (4) ◽

pp. 903-913

Author(s):

Changmin Chen ◽

Jianping Jing ◽

Jiqing Cong ◽

Chao Ji

Keyword(s):

Pressure Distribution ◽

Sensor Array ◽

Journal Bearing ◽

Dynamic Pressure ◽

Vertical Direction ◽

Journal Bearings ◽

Film Sensor ◽

Film Pressure ◽

Oil Film ◽

Oil Film Pressure

The acquisition of the oil film pressure and forces on the bearing pads through experimentation is crucial to understanding the characteristics of journal bearing. Lots of efforts had been taken in film pressure measurement, and the pressure was obtained at specified position on the bearing pads. However, due to the space and structure constraint, merely very limited number of the point pressure can be obtained with traditional sensors and acquiring the detail pressure field on whole bearing pad surface is still an open challenge. In this paper, a method based on thin-film sensors technique is proposed and employed to measure the pressure distribution and oil film forces of journal bearings. The measurement is conducted on a cylindrical journal bearing with two axial grooves, and ElectroMechanical Film sensor arrays are designed and laid on the surface of the bearing pads. The oil film pressure is acquired at up to 32 measurement points in total along the bearing pads in both circumference and axial directions. The pressure distribution in a wide rotation speed range is obtained successfully by using fitting algorithm. Furthermore, the oil film forces on horizon and vertical direction are obtained through the integration of the measured pressure filed. The test results prove that it is feasible to measure the oil pressure filed of journal bearings using ElectroMechanical Film piezo-film sensor array.

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An Experimental Study of Static and Dynamic Characteristics of a 580mm(22.8in.) Diameter Direct Lubrication Tilting Pad Journal Bearing

Journal of Tribology ◽

10.1115/1.2114929 ◽

2005 ◽

Vol 128 (1) ◽

pp. 146-154 ◽

Cited By ~ 18

Author(s):

Kazunori Ikeda ◽

Toshio Hirano ◽

Tatsuo Yamashita ◽

Makoto Mikami ◽

Hitoshi Sakakida

Keyword(s):

Dynamic Characteristics ◽

Large Scale ◽

Load Capacity ◽

Metal Temperature ◽

Film Pressure ◽

Static And Dynamic Characteristics ◽

Oil Film ◽

Analysis And Design ◽

Tilting Pad ◽

Oil Film Pressure

Direct lubrication tilting pad journal bearings (DLTPJ bearings) have rarely been applied to large-scale rotating machinery, such as turbines or generators, whose journal diameters are more than 500mm. In this paper, static and dynamic characteristics of a 580mm(22.8in.) diameter DLTPJ bearing were studied experimentally using a full-scale bearing test rig. In the static test, distribution of metal temperature, oil film pressure, and bearing loss were measured in changing oil flow rate, with mean bearing pressure ranging up to 2.9MPa. The maximum metal temperature of the DLTPJ bearing was compared to that of a conventional flood lubrication bearing, and it was confirmed that the direct lubrication could increase load capacity. In the dynamic test, spring and damping coefficients of oil film were obtained by exciting the bearing casing that was floated by air bellows. These data will be used for analysis and design of steam turbine rotors and their bearing systems. Also, vibration of pads was investigated because metal failure on upper pads due to vibration has been found in some actual machines. In order to generate oil film pressure on the surface of upper pads, a Rayleigh-step was machined there, and it was confirmed that vibration was reduced by the Rayleigh-step.

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