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(1) Background: To better understand the dynamic characteristics of a ball bearing with an elastic ring squeeze film damper (ERSFD) under sudden unbalance, a novel dynamic model was established by fully considering the coupling between the ERSFD, bearing outer ring (the journal), rotor, and disc (loading bearing); (2) Methods: An improved secant method was developed to determine the initial eccentricity values of the bearing's outer ring and the disc. The dynamic response of the outer ring under different speed ratios, damping ratios, and mass ratios was solved using the variable-step Runge–Kutta method; (3) Results: In comparison, a low-speed ratio, high damping ratio, and low mass ratio were more conducive to suppressing the bearing vibration. When the imbalance was suddenly introduced, the displacement amplitude of the eccentricity, transmissibility, amplitude–frequency response, and the radius of the outer ring center locus increased; (4) Conclusions: This work provides a reference for further studying the nonlinear vibration of rolling bearings coupled with an ERSFD. [ABSTRACT FROM AUTHOR]

Under high temperature and water lubrication environment, the properties of high temperature non magnetic alloy GH05 material for bearings will change,which will affect the wear coefficient of material so as to affect the bearing wear performance,resulting in increased vibration and noise of bearings. The friction and wear tests of high temperature non-magnetic alloy GH05 under high temperature and water lubrication were carried out by using a high temperature friction and wear tester,and the effects of temperature,load and lubrication on the friction and wear properties of the material were analyzed.The wear coefficient of the material was obtained,which provided test data for bearing life evaluation under special working conditions and lubrication conditions.The results show that the friction coefficient of the bearing material GH05 is about 0. 53 at 300 T and about 0. 35 with water lubricating medium.Compared with the friction coefficient at 25 T,the friction coefficient at 300 T has a smaller fluctuation range and a stronger stability. Compared with the friction coefficient under dry friction state,the friction coefficient under water lubrication condition is smaller,and the stability of friction coefficient is better. With the increase of temperature,the wear resistance of the GH05 material decreases. At the same test load, the wear volume of GH05 material under dry friction at high temperature of 300 T is the largest,and the smallest under water lubrication at room temperature.The wear coefficient of GH05 is from 1. 93x10 7 mm2/N to 3. 02x10 7mm2/N under dry friction at high temperature of 300 T . [ABSTRACT FROM AUTHOR]

• High-speed ball bearing coupled ERSFD model is built excited by ball-raceway interaction rather than rotor unbalance force. • Ball centrifugal force, contact angle change and heavy thrust-applied load are outlined when deriving bearing force. • Thin-walled ring model is employed to evaluate elastic ring deformation. • Low squirrel cage stiffness matched with high rotor speed favors journal whirl but high stiffness worsens vibration damping. This paper explores an elastic ring squeeze film damper (ERSFD) model incorporating high-speed ball bearings to study the journal dynamics at different rotor operating speeds and squirrel cage stiffness. Firstly, dynamic model of the ERSFD is established. The journal works under ball-outer raceway excitation rather than rotor unbalance force. Bearing high-speed characteristics including ball centrifugal force, contact angle change and heavy thrust-applied load are outlined in quasi-static model when deriving bearing force. Oil film pressure is governed by the Reynolds equation and solved iteratively using the central finite difference scheme. Flow performance through the orifice and its effect on the oil film pressure are analyzed using computational fluid dynamics (CFD) technique. Elastic ring deformation is addressed using a thin-walled ring model. Secondly, squirrel cage stiffness and rotor operating speeds were chosen as influence parameters to numerically examine the journal steady-state and transient dynamics, and finally the center orbit and vibration of the journal were experimentally measured. The results demonstrate that an increase in squirrel cage stiffness enables the journal to orbit at small size but leads to higher transmissibility. Small squirrel cage stiffness and rotor operating speed result in high amplitude and velocity oscillations and destabilize the journal; alternatively, higher squirrel cage stiffness is ineffective in transmissibility attenuation regardless of rotor operating speed. It was concluded that a small squirrel cage stiffness cooperating with high rotor operating speed contributes to stabilize journal and attenuate vibration effectively. [Display omitted] [ABSTRACT FROM AUTHOR]