...Hiroyuki Ohta; Shinya Hayashi; Soichiro Kato; Yutaka Igarashi This paper deals with effects of grease types on vibrations and acoustic emissions (AEs) of linear-guideway type recirculating ball bearings with a millimeter-sized artificial defect in the carriage. First, the vibration and AE of one...

... designs is investigated through experiments and analytical modeling. Nonlinear systems theory is used to highlight slider instabilities arising from an unfavorable coupling of system vibration modes through an internal resonance condition, as well as the favorable suppression of instabilities through...

...Frédéric Lévesque; Sylvain Goudreau; Louis Cloutier Aeolian vibrations represent a threat to the integrity of electrical transmission lines. The fretting fatigue of conductors is thus a major concern. The modelization of the contact conditions at critical points is an important tool in assessing...

... and outer race and balls were modeled through surface profile changes. Bearing load zones under various radial loads and clearances were simulated. The effects of type, size, and shape of faults on the vibration response in rolling element bearings and dynamics of contacts in the presence of localized...

... vibration. Numerical results show that the reduced damping coefficients and the threshold speed can be effectively enhanced by giving suitable pad pivot stiffness and damping simultaneously, and this analytical method can be applied to analyze dynamical behavior of the tilting-pad journal bearing rotor...

...M. S. Patil; Jose Mathew; P. K. Rajendrakumar; Sumit Karade The presence of defect in the bearing (outer race, inner race, or ball) results in increased vibrations. Time domain indices such as rms, crest factor, and kurtosis are some of the important parameters used to monitor the condition...

...Adolfo Delgado; Luis San Andrés Squeeze film dampers (SFDs) aid to reduce excessive vibration levels due to rotor imbalance and to raise stability thresholds in rotor-bearing systems. SFDs commonly include end seals to increase their damping capability with a lesser lubricant flow. Seals also aid...

...Du Chen; David B. Bogy Near or partial contact sliders are designed for the areal recording density of 1 Tbit / in. 2 or even higher in hard disk drives. The bouncing vibration of an air bearing-slider in near or partial contact with the disk is numerically analyzed using three different nonlinear...

...Hiroyuki Ohta; Kazuya Matsuura; Soichiro Kato; Yutaka Igarashi This paper deals with vibrations and acoustic emissions (AEs) of linear-guideway type recirculating ball bearings with a millimeter-sized artificial defect in the carriage. The vibration and AE of one normal bearing without a defect...

... characteristics of a squeeze-film gas bearing. This squeeze bearing for a noncontact moving table uses piezoelectric actuators as an ultrasonic vibrator to make the bearing surface vibrate at the ultrasonic resonant frequency of the bearing plate. The squeeze-film pressure is generated in the gap beneath...

... and the viscoelastic dampers added behind the FPTPGB pads delayed the onset of subsynchronous vibrations (from 43 krpm without damper to above 50 krpm with damper). Midrange subsynchronous vibrations of the destabilized system initiated at ∼ 20 krpm were suppressed by ∼ 25 krpm due to the stabilizing effect of rotor...

...Kyosuke Ono; Masami Yamane 16 06 2009 vibrations (1) In Table 2, the parameter values should be changed as follows: M = 1.918 mg (effective mass including suspension is 1.25 times the slider mass (1.59 mg)). J = 2.971 × 10 − 13 kg m 2 (effective...

...Kyosuke Ono; Masami Yamane 16 06 2009 mechanical stability vibrations (1) Equation 4 should be rewritten as 4 c f = 2 ζ f M k f , c r = 2 ζ r M k r (2) In Table 1, the parameter values should be rewritten as follows: M...

... such as high rotor-bearing stability and less severe thermal issues (due to multipad configurations) than foil gas bearings. However, extension of the application of the tilting pad gas bearings to flexible rotors and harsh environments with external vibrations/impacts poses significant design challenges...

...H. Arslan; N. Aktürk In this paper, a shaft-bearing model is developed in order to investigate the rolling element vibrations for an angular contact ball bearing with and without defects. The shaft-bearing assembly is considered as a mass-spring system. The system shows a nonlinear characteristic...

... squeeze film damper model is developed, and the results are compared with those obtained using a linear approach. The effect of unbalance eccentricity on the vibration response and the transmitted force of the HSFD are investigated using the linear and nonlinear models. The results show good agreement...

.... This paper is intended as a tutorial overview of bearing vibration signature analysis as a medium for fault detection. An explanation for the causes for the defects is discussed. Vibration measurement in both time domain and frequency domain is presented. Recent trends in research on the detection...

... disk are identified through regression analysis of tip damping vibration. PFPE lubricants with functional end groups were used to form a lubricant bridge between the DLC surface and a probe tip with a notably small curvature radius of 0.1 μ m . The tip was both retracted from and extended toward...

... and measured structural loss factor indicate that the damping of underlying structure can suppress the maximum peak at the critical speed very effectively but not the onset of hydrodynamic rotor-bearing instability. However, the damping plays an important role in suppressing the subsynchronous vibrations under...

... coefficients, damping, and added mass, are in good agreement with predictions based on the full film, short length damper model. 07 03 2006 08 02 2007 damping seals (stoppers) lubricants friction shock absorbers vibrations squeeze film damper force coefficients Squeeze...