... for publication in the J ournal of T ribology . 24 11 2019 31 07 2020 01 08 2020 01 09 2020 hybrid bearing floating ring mixed flow THD model stability hydrodynamic lubrication The hybrid floating ring bearing (FRB) has been widely used in many high-speed and super...

...Fangxu Sun; Xianbiao Zhang; Xing Wang; Zhenzhong Su; Dong Wang Effects of shaft shape errors are studied on dynamic characteristics of a rotor-bearing system. Stability characteristics of the cylindrical journal bearing are studied. It is shown that the rotating speed at which the oil whip occurs...

... can be calculated as M ¯ c = K eq / ω cr 2 . The stability charts can be easily presented and comparisons between Newtonian, MR, and NMR lubrication can be achieved. We calculate the critical rotational velocity as follows [ 22 ]: (14) M ¯ c...

... , McGraw-Hill , New York , pp. 80 – 83 . 22 09 2010 13 01 2011 22 03 2011 22 03 2011 convection electric power generation fuel cells machine bearings rotors solar cells stability turbomachinery For fuel cell applications, air/hydrogen delivery systems should...

... to follow the structural motion, which is due to unsteady aerodynamic forces applied onto the structure by the fluid. Such an integrated time-domain approach allows the direct computation of aeroelastic time histories from which the aerodynamic damping, and hence, the flutter stability, can be determined...

...Hiromu Hashimoto; Masayuki Ochiai This paper describes the stabilization method for small-bore circular journal bearings using starved lubrication. First, we describe the experimental examination to confirm the effect of supply oil conditions on stability of circular journal bearing by using a high...

... their characteristics under different operating conditions. Numerical results are compared with the experimental results. The stability parameters of hybrid conical, hydrodynamic, and hydrostatic bearings are compared. The results show that the hybrid conical bearing has the advantages of high load carrying capability...

...Hiromu Hashimoto; Masayuki Ochiai Journal bearings are widely used for supporting high-speed rotating machinery, such as turbine, compressor, and HDD spindle, because of their high load carrying capacity, stability, and durability. Recently, the engineering trend is oriented to higher speed...

... time steps are used for one revolution. Adopting the total bearing structural loss factor measured by the unidirectional excitations to the individual elastic foundation may not be fully justified. However, as presented in ( 22 ), the major difference of the rotor-bearing stability comes from...

...Daejong Kim Experimental and analytical studies on air foil bearings have been performed extensively over the past decades, and significant improvement in load capacity and rotor dynamics stability have been reported. Often, advanced air foil bearings are believed to have complicated bump foil...

... bearings is optimized in a sense of enhancing the stability of the full circular bearing at high rotational speeds. A performance index is chosen as the sum of the squared whirl-frequency ratios over a wide range of eccentricity ratios, and a Fourier series is used to represent an arbitrary clearance...

... design parameter to determine the stability of a bearing-rotor system. Generally, smaller clearance increases system stiffness, thus the critical speed and onset speed of instability. However, small clearance limits the maximum operating speed. Larger clearance has more allowance for rotor growth...

... a numerical procedure for stability analysis of a liquid lubricated rough journal bearing. The Elrod generalized theory of Reynolds roughness provides a governing equation based on the surface configuration. The Elrod cavitation algorithm conserves mass throughout the bearing and automatically predicts...

...T. V. V. L. N. Rao, Assistant Professor; Jerzy T. Sawicki, Fellow ASME Stability characteristics of the herringbone grooved journal bearings (HGJBs) are analyzed taking into account cavitation of the fluid flow. The perturbed values of pressure and film thickness from a given equilibrium position...

... of the mechanical face seal. Closed-form solutions are presented for the transient natural response to initial velocity conditions, the steady-state response to rotor runout and initial stator misalignment, the transmissibility ratios, and the stability threshold. Results from the closed-form solutions are all...

... coefficients. shear deformation rotors damping seals (stoppers) friction stators gas turbines stability Turbomachinery annular seals are provided to limit leakage between regions at different pressures. Seals increase the efficiency of turbomachines; however, they can also significantly...

... techniques was relatively scarce. Indeed, most existing theoretical studies either deal with the structural behavior, or use simplified flow modeling. The aeroelasticity stability of a simplified air-riding seal geometry, devised for this particular feasibility study, was analyzed in three dimensions...

...S. Yoshimoto, Professor; S. Oshima, Graduate Student; S. Danbara, Research Associate; T. Shitara In this paper, the stability of water-lubricated, hydrostatic, conical bearings with spiral grooves for high-speed spindles is investigated theoretically and experimentally. In these bearing types...

...K. Raghunandana; B. C. Majumdar, and; R. Maiti The purpose of this paper is to study the effect of non-Newtonian lubricant on the stability of oil film journal bearings mounted on flexible support using linear perturbation technique. The model of non-Newtonian lubricant developed by Dien and Elrod...

...Kwangjin Lee Thermoelastic instability in automotive drum brake systems is investigated using a finite layer model with one-sided frictional heating. With realistic material properties of automotive brakes, the stability behavior of the one-sided heating mode is similar to that of the antisymmetric...