Study of two‐lobe four recessed hybrid journal bearing

Abstract

Purpose -In recent years, researchers have focused a great deal of attention on multirecess hybrid journal bearing systems. The non-circular journal bearings are widely used in industry on account of their better stability, simplicity, efficiency and low cost. The purpose of this paper is to present a theoretical investigation into the performance of a two-lobe multirecess hybrid journal bearing system. Design/methodology/approach -The Reynold's equation governing the lubricant flow in the clearance space between the journal and bearing together with restrictor flow equations has been solved using finite element method. The bearing static and dynamic performance characteristics have been presented for the various values of the offset factors (0.75, 1, 1.25 and 1.50) for the hybrid mode of operation of the journal bearing system compensated by capillary and orifice restrictors for the commonly used bearing operating and geometric parameters. The offset of the journal has been accounted for by defining a non-dimensional factor called offset factor delta. Findings -The numerically simulated results indicate that a two-lobe four recessed hybrid journal bearing provides a better performance than the corresponding similar circular recessed journal bearing system. The study further reveals that in order to get an improved performance of a two-lobe four recessed journal bearing, a proper selection of bearing offset factors along with type of restrictor (capillary or orifice) is essential. Originality/value -The results presented in this paper are useful for bearing designers.

Combined influence of geometric irregularities of journal and turbulence on the performance of four-lobe hybrid journal bearing

“…The fluid film thickness for geometrically imperfect four-lobe hybrid journal bearing is expressed in the nondimensional form as 12,25,26 where, h¯ir is contribution of geometric irregularities of journal to the fluid film thickness (h¯) 19 where, a 1 , a 2 and a 3 are the amplitude of irregularities associated with cylindrical journal in the form of barrel, bellmouth and undulation type, respectively.…”

“…Ghosh and Satish 10,11 theoretically evaluated the stability and rotordynamic coefficients over a range of offset factor (0.5, 0.75, 1, 1.25 and 1.5) for four-lobe bearing. Jain et al 12 investigated the influence of offset factor through a comparative study on the two lobe and circular bearing configuration. Goenka and Booker 13 theoretically examined the influence of surface ellipticity on dynamically loaded cylindrical bearing and suggested an optimum shape of bearing on the basis of fluid film pressure and fluid film thickness.…”

Performance characteristics of two-lobe pressure dam bearings with micropolar lubrication

“…Research studies [6][7][8][9][10][11][12][13][14] in the area of non-circular bearings are discussed below. Non-circular bearings (two-lobe, three-lobe and four-lobe bearings) were examined by Rahmatabadi et al 6 They evaluated various static characteristics of these bearings and compared them.…”

“…They used Generalized Differential Quadrature technique to solve Reynold's equation and suggested that proper selection of tilt angle results in improved performance. The performance of a twolobe four recessed hybrid journal bearing was evaluated by Jain et al 13 Author observed that there was an enhancement in the performance of such bearing as compared with a circular recessed journal bearing system. They suggested that proper selection of bearing offset factors leads to improved performance.…”

Dynamic analysis of a 2-lobe geometrically imperfect journal bearing system

“…There are number of studies available in literature pertaining to multilobe and circular journal bearing, both analytical and experimental. [1][2][3][4][5][6][7][8] The journal surfaces obtained after machining are not really perfectly cylindrical or smooth. The actual machined surface of the journal may be associated with different types of periodic surface disturbance (waviness) which are also referred to as geometric irregularities.…”