Analysis of Hydrodynamic Journal Bearings with Novel Elliptical Groove
Date Issued
2010
Date
2010
Author(s)
Abstract
A novel elliptical groove is proposed in this work to improve the performance of conventional journal bearings. Firstly, the present work utilizes the spectral element method to calculate the pressure distribution and dynamic coefficients of herringbone-grooved journal bearings (HGJBs), in which the thickness of the fluid film changes abruptly in the groove-ridge region. Conservation of mass is adopted to solve the problem. Additionally, the present method can be adopted for grooves with curvy geometry. It shows that for the case of HGJB, the numerical result by the present method is more accurate than the numerical results found in the literature. Furthermore, employing the present method with the Elrod’s algorithm can improve the accuracy of deriving loads of HGJBs when cavitation occurs.
In the secondary part of this work, the novel elliptical grooves are proposed. This work utilizes novel elliptical grooves on a journal bearing and analyzes the characteristics of the elliptical-grooved journal bearings (EGJB) numerically. Load capacity, stability parameter, and total side leakage of the EGJB are compared with those of the HGJB. The comparison shows that the introduced EGJB have higher radial force, higher load capacity, and lower side leakage than the conventional HGJB. The optimum geometrical parameters of groove of EGJB are investigated based on the maximum radial force. Finally, the load distributions of several grooved journal bearings are compared to elucidate how elliptical grooves enhance load characteristics. The load distribution along the axial direction in EGJB is more uniform than that in the HGJB. The low load near the bearing center for the EGJB may be offset by the load away the bearing center; thus, a higher total load capacity than that of HGJB is achieved.
In the end of this work, to improve the performance of the reversible rotation grooved journal bearing (Rev-HGJB), this work utilizes elliptical grooves on a reversible rotation journal bearing (Rev-EGJB) and analyzes its characteristics numerically. Load capacity, pressure distribution, power loss, and dimensionless radial stiffness of the Rev-EGJB are compared with those of the Rev-HGJB. The comparison shows that the introduced Rev-EGJB exhibits higher load capacity and lower power loss than the Rev-HGJB. A larger high pressure region in the Rev-EGJB than that in the Rev-HGJB is achieved not only in the pressure-generated region, but also in the pressure-restored region. Furthermore, the load distributions of the Rev-HGJB and Rev-EGJB are compared to elucidate how elliptical grooves enhance load characteristics. Ultimately, the radial stiffness of the Rev-EGJB compared with that of the Rev-HGJB with the optimum geometry is also shown to be greater; thus, the Rev-EGJB is more stable than the Rev-HGJB.
Subjects
Hydrodynamic journal bearing
Elliptical groove
Herringbone groove
Cavitation
Stability
Spectral element method
File(s)![Thumbnail Image]()
Loading...
Name
ntu-99-D93522036-1.pdf
Size
23.53 KB
Format
Adobe PDF
Checksum
(MD5):0933c0d6bbd112b8373b4802b6e3902a