The Effects of Oil Supply Pressure at different Groove Position on Temperature and Pressure Profile in Journal Bearing

2013 ◽  
Vol 66 (3) ◽  
Author(s):  
Mohamad Ali Ahmad ◽  
Salmiah Kasolang ◽  
R. S. Dwyer-Joyce ◽  
Aidah Jumahat

The effects of oil supply pressure on the temperature and pressure at different groove locations on a hydrodynamic journal bearing were investigated. A journal with a diameter of 100 mm and a ½ length-to-diameter ratio was used. The supply pressure was set to 0.2, 0.5, and 0.7 MPa at seven different groove locations, namely, -45°, -30°, -15°, 0°, +15°, +30°, and +45°. Temperature and pressure profiles were measured at speed values of 300, 500, and 800 rpm with 10 kN radial load. The results show that the change in oil supply pressure simultaneously reduced the temperature and increased the pressure profile.

2013 ◽  
Vol 315 ◽  
pp. 809-814 ◽  
Author(s):  
Mohamad Ali Ahmad ◽  
Salmiah Kasolang ◽  
Rob Dwyer-Joyce ◽  
Nik Rosli Abdullah

In hydrodynamic lubrication, the pressure condition of the fluid is critical to ensure good performance of the lubricated machine elements such as journal bearings. In the present study, an experimental work was conducted to determine the effect of oil supply pressure on pressure profile around the circumference of a journal bearing. A journal diameter of 100mm with a ½ length-to-diameter ratio was used. The oil supply pressure was set at three different values (0.3, 0.5, 0.7 Mpa) and the circumferential pressure results for 400, 600 and 800 RPM at different radial loads were obtained. It was observed that the maximum pressure values were affected by changes in oil supply pressure.


2013 ◽  
Vol 393 ◽  
pp. 907-912 ◽  
Author(s):  
Mohamad Ali Ahmad ◽  
Salmiah Kasolang ◽  
Rob Dwyer-Joyce ◽  
Mimi Azlina Abu Bakar

Axial groove is a common supply method of distributing lubricant within a journal bearing. Lubricant is generally fed at a specific supply pressure to ensure that the journal and the bearing surface are separated. Shearing action between lubricant and bearing parts creates frictions which contribute to power loss in journal bearing. In the present study, an experimental work was conducted to determine the effect of oil groove location on torque and frictional force in hydrodynamic journal bearing. A journal diameter of 100mm with a 12 length-to-diameter ratio was used. The oil supply pressure was set at 0.20 to 0.25 MPa. The groove was positioned at 3 different locations namely 00, +150and +300. Measurements of torque and frictional force were obtained for speed values of 300, 500 and 800 RPM at different radial loads. It was observed that the change in oil groove location has affected the fluid frictional force and friction coefficient to some extent.


1990 ◽  
Vol 112 (1) ◽  
pp. 60-67 ◽  
Author(s):  
D. Vijayaraghavan ◽  
T. G. Keith

The effect of journal misalignment on the predicted performance of a finite grooved journal bearing is analyzed in this paper. The numerical procedure used incorporates a cavitation algorithm, which automatically predicts film rupture and reformation in the bearings. The misalignment considered varies in magnitude and direction with reference to the boundaries of the bearing. In addition to the misalignment, the effect of lubricant starvation at the groove is also considered and compared with flooded inlet conditions. The effects of various degrees of starvation, or higher lubricant supply pressure, bearing length to diameter ratio and groove size are also investigated.


2013 ◽  
Vol 315 ◽  
pp. 977-981 ◽  
Author(s):  
Mohamad Ali Ahmad ◽  
Salmiah Kasolang ◽  
Rob Dwyer-Joyce

Journal bearing is widely applied in most of rotating machineries for transmission of large loads at mean speed of rotation. Friction caused by the shearing condition between journal, bearing and lubricant contribute to power loses in journal bearing system. In the present study, an experimental work was conducted to determine the effect of oil supply pressure on frictional force, friction coefficient and torque of a journal bearing. A journal diameter of 100 mm with a ½ length-to-diameter ratio was used. The oil supply pressure was set at three different values (0.3, 0.5, 0.7 MPa). Frictional force and friction coefficient results for 400, 600 and 800 RPM at different radial loads were obtained. It was observed that the change in oil supply pressure has affected the fluid frictional force and friction coefficient to some extent.


1982 ◽  
Vol 104 (3) ◽  
pp. 311-320
Author(s):  
L. J. Nypan

Measurements of roller skewing of a 1.15 length to diameter ratio roller in 118 mm bore roller bearings of 0.18 and 0.21 mm (0.0073 and 0.0083 in.) clearance operating with a 4450 N (1000 lb) radial load at shaft speeds of 4000, 8000, and 12,000 rpm with outer race misalignment of 0, 0.5, and −0.5 deg are reported.


Author(s):  
Ritu P. Marpu ◽  
Chad H. Custer ◽  
Venkataramanan Subramanian ◽  
Jonathan M. Weiss ◽  
Kenneth C. Hall

An unsteady simulation of a two-stage, cooled, high pressure turbine cascade is achieved by applying the harmonic balance method, a mixed time domain and frequency domain computational fluid dynamic technique for efficiently solving periodic unsteady flows. A comparison of computed temperature and pressure profile predictions generated using the harmonic balance method and a conventional steady mixing plane analysis is presented. The predicted temperature and pressure profiles are also compared to experimental data at the stage exit plane. The harmonic balance solver is able to efficiently model unsteady flows caused by wake interaction and secondary flow effects due to cooling flows. It is demonstrated that modeling the unsteady effects is critical to the accurate prediction of time-averaged flow field quantities, particularly for cooled machines.


2012 ◽  
Vol 497 ◽  
pp. 99-104 ◽  
Author(s):  
Zhi Quan Hou ◽  
Wan Li Xiong ◽  
Xue Bing Yang ◽  
Ju Long Yuan

The dynamic characteristics of a hydrostatic and hydrodynamic journal bearing with two arrays of eight holes have been investigated theoretically by the three-dimensional Computational Fluid Dynamics (CFD) models with respect to equilibrium position. The various dynamic coefficients for design parameters, such as orifice diameter, length to diameter ratio, eccentricity ratio, supply pressure, and rotational speed, are analyzed systematically under the action of displacement disturbance and velocity disturbance which are considered by the User Definition Function (UDF) programs. Results show that the dynamic coefficients greatly affected by design parameters. The cross stiffness coefficients increase rapidly more than direct stiffness with an increase of length to diameter ratio and rotational speed. Conversely, the direct stiffness coefficients are larger than cross stiffness with an increase of supply pressure and eccentricity ratio. It indicates that the journal bearing with two arrays of eight holes is suitable for their applications to small diameter grinding spindle by the means of optimizing the operating parameters and the structural parameters in order to obtain a better dynamic characteristic.


1973 ◽  
Vol 95 (4) ◽  
pp. 546-552 ◽  
Author(s):  
G. R. Kulkarni

Oil feed rate is an important parameter governing the operating characteristics of a journal bearing. In the present paper investigation is carried out to explore the effect of oil groove location and supply pressure on the oil feed rate to the bearing. These results are further used to get variation in Sommerfeld number and attitude angle for different oil groove locations and supply pressures. The results indicate that oil groove location has a great influence on oil feed rate to the bearing. It is also observed that oil supply arrangement does not have a significant influence on Sommerfeld number and attitude angle.


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