Thermal Analysis of Elliptic Bore Journal Bearing Considering the Effect of Shaft-Misalignment

Abstract

Bore ovality or non-circularity is due to manufacturing irregularity or running in. Misalignment is the non-parallel positioning of the shaft due to the nature of non-central dynamic loading, elastic deformation and thermal distortion of shaft. Misalignment may be also due to manufacturing error of shaft or bush. Study of combined effect of bore-out-of-roundness and shaft misalignment is important in bearing design. In this paper, the steady state characteristics of elliptic bore journal bearing are analyzed considering the shaft misalignment. A case specific film profile is derived to address the bore ellipticity together with shaft misalignment in eccentric positioning. Combined solution of Reynolds equation and Energy equation is carried out considering non-Newtonian piezo-viscous behavior of lubricant. The performance parameters such as film thickness, load carrying capacity, friction force, flow rate and side leakages are analyzed taking into account the thermal effect. The combined effect of bore non-circularity and shaft misalignment on temperature rise is also presented in this paper.

Pengaruh Jarak Misalignment Drive Shaft Cooling Tower Terhadap Tegangan Normal Dan Tegangan Geser

“…Alignment adalah suatu pekerjaan atau proses mensimetriskan kedua objek atau sumbu poros sehingga sentris antara poros penggerak dengan sumbu poros yang digerakkan dengan dua tumpuan saling berkaitan. Misaligment itu sendiri bisa disebabkan oleh kesalahan manufaktur, yang mengakibatkan terjadinya deformasi elastis dan distorsi termal poros [9]. Ketika terjadi missaligment mesin bergetar dan muncul suara berisik yang harus segera diatasi [10], jika tidak diatasi dapat menyebabkan penurunan efisiensi dan dalam jangka panjang dapat menyebabkan kerusakan mesin [11,12].…”

“…Tetapi pada displacement 3, 4, 5 mm mulai nampak tegangan yang bervariatif pada permukaan poros hal ini disebabkan oleh kontak antara drive shaft dengan clutch yang semakin berkurang (tanda ellips). Ketika terjadi missaligment pada poros mengakibatkan kontak antara drive shaft dan clutch yang semakin berkurang sehingga memunculkan keparahan gesekan efek termal [9]. Poros menangung beban yang bervariasi sehingga menciptakan tegangan sepanjang poros sehingga cepat mengalami kelelahan.…”

Experimental evaluation of lubricating oil film pressure and temperarture of elliptical non-circular journal bearing profile

“…The results shown that from the various non-circular bearings under study, the offset-half and elliptical bearings have better overall performances. Mishra et al [13,14] have considered the non-978-1-4673-8253-3/15/$31.00 ©2015 IEEE circularity in bearing bore to be true elliptical and made a comparison with the circular case to analyze the effect of manufacturing irregularity in the bearing and have observed that with increasing non-circularity the pressure gets reduced and temperature rise is less in case of journal bearing with higher non-circularity value using finite difference method. Ostayen and Beek [15] have presented a thermo-hydrodynamic model for analyzing a lemon-bore journal bearing through finite element method and the presented model is used to check the design of the lemon bore bearings in a specific naval application.…”

Investigating Into the Effects of Bore Irregularities on the Hydrodynamic Performance Journal Bearing Using Response Surface Methodology

“…In earlier research initiatives, Crosby [1] and Mishra et al [2] investigated the influence of bore noncircularity upon the hydrodynamic characteristics of irregular journal bearing and predicted the presence of bore ellipticity up to (G=1.0) found to be favorable for journal bearing stability. Literatures also reported the effect of roughness pattern and its effect on the journal bearing for both circular [3,4] and non-circular [5] bore configurations. Rotating fluid film develops heat out of fluid shear of intermediate RESEARCH lubricating oil layers [6].…”

“…Hence, operational irregularities like misalignment also have profound effect on bearing performance. Mishra et al [7] studied a misaligned non-circular bore journal bearing with heat generating and non-Newtonian effects. From this study, it is realized that there are numerous parameters with their influence, makes the journal bearing analysis more complex, which requires the optimization techniques to understand most influential and least influential parameters.…”