Calculation and Measurement of the Stiffness and Damping Coefficients for a Low Impedance Hydrodynamic Bearing

Goodwin, Michael; Ogrodnik, Peter; Roach, M. P.; Fang, Yong

doi:10.1115/1.2832480

Cited by 14 publications

(16 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In general, frequency-domain methods have proved superior in terms of data content. Goodwin et al (1997) used a test bearing, which was floating on a rigidly mounted rotating shaft due to hydrodynamic action. It was excited by a multi-frequency force signal (PRBS).…”

Section: Approaches For Increased Information Retrievalmentioning

confidence: 99%

Identification of Dynamic Bearing Parameters: A Review

Tiwari¹,

Lees²,

Friswell³

2004

shock vib digest

133

View full text Add to dashboard Cite

In this paper, we present a review of the experimental identification of dynamic parameters of bearings in a rotating machine. Major emphasis is given to vibration-based identification methods and the review encompasses descriptions of experimental measurement techniques, mathematical modeling, parameter extraction algorithms and uncertainty in the estimates applied to a variety of bearings. The parameter extraction algorithms include the descriptions of governing equations of the rotor-bearing system and identification methods in both time and frequency domains. The identification techniques have been classified based on methods used to excite the system. The review includes a variety of bearings and similar components, which play an active link between the rotating and stationary parts of a machine. Based on the state of the art in bearing identification, conclusions are made and future directions are suggested.

show abstract

Section: Approaches For Increased Information Retrievalmentioning

confidence: 99%

Identification of Dynamic Bearing Parameters: A Review

Tiwari¹,

Lees²,

Friswell³

2004

shock vib digest

133

View full text Add to dashboard Cite

show abstract

“…There are different methods to obtain the bearing coefficients,such as, experimental (Tiwari et al 2004, Mao et al 2016analytical (Chasalevris andSfyris, Wang andKhonsari 2006, Miraskari et al 2018a), finite difference method(FDM) (Gero and McC. Ettles 1986, Qiu and Tieu 1995, Goodwin et al 1997, finite element method (FEM) (Wada et al 1971, Mourelatos 1985, Arregui and Vázquez 2001, Nair and Nair 2004, Awasthi et al 2006, Hili et al 2010 , mesh less method with radial basis (MMRB) (Nicoletti 2013) and computational fluid dynamics (CFD) (Gao et al 2014, Zhang et al 2015.…”

Section: Introductionmentioning

confidence: 99%

Bifurcation Analysis of Rotor/Bearing System using Third Order Journal Bearings Stiffness and Damping Coefficients

El-Sayed

Sayed

2021

Preprint

View full text Add to dashboard Cite

Journal bearings have many applications in industry due to its high load carrying capacity. In addition proper design of journal bearings enables safe operation at very high speeds. However, they are susceptible to oil whirl instability which may cause bearing failure. The fluid film pressure distribution inside the journal bearing is described by Reynolds equation. Many studies had been done to approximate the bearing performance using first order bearing coefficients. Although this analysis is stable for evaluating the threshold speed but it is insensitive to limit cycles above the threshold speed. Mush literature show that above the threshold speed, subcritical or supercritical bifurcations may be observed. Therefore, the aim of the present paper is to evaluate the third order bearing coefficients for a finite length journal bearing using finite perturbation method. The values of these coefficients are evaluated using infinitesimal perturbation analysis. These values are used to investigate the bifurcation stability of flexible Jeffcott rotor supported by two symmetric journal bearings. The effect of rotor stiffness ratio on the bifurcation stability of the system is investigated. The results of this work show that the third order parameters can be used to evaluate the type of bifurcation above the threshold speed.

show abstract

“…Numerous articles have been written on the broad subject of bearing experimental and analytical properties calculations. [21][22][23] Recently, El-Shafei and Dimitri 24 presented a novel approach using a combination of an AMB and journal bearing to control the journal bearing instability. Farmakopoulos et al 25 presented the concept and the basic design of a new type of bearing, the active hydromagnetic journal bearing (AHJB); the authors also presented its dynamic characteristics.…”

Section: Introductionmentioning

confidence: 99%

“…Numerous articles have been written on the broad subject of bearing experimental and analytical properties calculations. 21–23…”

Section: Introductionmentioning

confidence: 99%

Design of an active hydromagnetic journal bearing

Farmakopoulos

Nikolakopoulos

Papadopoulos

2012

Proceedings of the Institution of Mechanical Engineers, Part J:

View full text Add to dashboard Cite

An active hydromagnetic journal bearing is designed and presented in this study, which is a new and innovative type of hybrid journal bearing. The proposed new mechatronic smart device has a common bearing shell that contains the two parts of the bearing, which is an attempt to combine the advantages of both types of bearings to overcome their drawbacks and give rise to new possibilities for instability control, increased load-carrying capacity, diagnostics of the rotor system, etc. The active hydromagnetic journal bearing should operate as either a hydrodynamic, active magnetic or hybrid journal bearing, depending on the needs of the rotating machinery. The hydrodynamic lubrication is developed in the inner bearing surface, and the electromagnets of the magnetic bearing are placed outside its outer surface. The active hydromagnetic journal bearing is designed with the appropriate clearance, so that both the hydrodynamic and magnetic bearings can operate. The suitable operational regions for the active hydromagnetic journal bearing are calculated and presented as a combination of the optimum ratio between the air gap and the clearance. Additionally, a simulation code using the two-dimensional finite element method (ANSYS) is developed to simulate the performance of the magnetic component of the active hydromagnetic journal bearing, and the ANSYS software is used to obtain a solution for the hydrodynamic pressure field. The dynamic characteristics of the hybrid journal bearing in terms of the stiffness and damping coefficients versus the Sommerfeld number are calculated and presented. In the hybrid bearing operation, the corresponding stiffness and damping coefficients are used to simulate the hydromagnetic bearing dynamic behaviour. Each hybrid coefficient consists of two parts; the hydrodynamic and the magnetic part. When the operation is purely hydrodynamic, the magnetic parts of the dynamic coefficients are zero and vice versa, whereas both parts are present in the hybrid operation mode.

show abstract

Calculation and Measurement of the Stiffness and Damping Coefficients for a Low Impedance Hydrodynamic Bearing

Cited by 14 publications

References 3 publications

Identification of Dynamic Bearing Parameters: A Review

Identification of Dynamic Bearing Parameters: A Review

Bifurcation Analysis of Rotor/Bearing System using Third Order Journal Bearings Stiffness and Damping Coefficients

Design of an active hydromagnetic journal bearing

Contact Info

Product

Resources

About