Influence of surface waviness in the heat generation and thermal expansion of the touchdown bearing

Neisi, Neda; Heikkinen, Janne; Sopanen, Jussi

doi:10.1016/j.euromechsol.2018.10.014

Cited by 18 publications

(5 citation statements)

References 36 publications

(63 reference statements)

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“…In this work, the thermal expansion of the touchdown bearing due to the friction heat is neglected. This simplification has been made as the dropdown will be studied for short period of time (0.2 s) and within this period no significant rise in the temperature of touchdown bearing is expected [23,38]. The recorded behavior of the rotor under investigation shows that the rotor speed in the dropdown follows the exponential profile.…”

Section: Model Of the Contact Between The Rotor And Touchdown Bearingmentioning

confidence: 99%

Performance evaluation of touchdown bearing using model-based approach

et al. 2020

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In the active magnetic bearings (AMBs) supported rotating machinery, touchdown bearings are considered as safety devices to support the rotor in the deficiency of electromagnetic field. Generally, the industrial AMB machines do not have force sensors for touchdown bearings and the system is only equipped with the position sensors to monitor the rotor displacement that disables the opportunity to measure the forces during dropdown events that might be destructive for the safe operation of the rotor system. This study explores the relative severity of dropdowns that are evaluated from a computational rotor model using the rotor displacement data recorded from the position sensors installed in the machine as an input. The model for double-row angular contact ball bearing type touchdown bearings is integrated with the rotor model. The simulation model is verified by comparing the simulated rotor orbits against measured orbits at four different dropdowns. The Fast Fourier transform (FFT) is used to observe the studied dropdown events in frequency domain revealing from the rotor response the following details: harmonics of the operation speed, rub-impact frequencies, pendulum motion of the rotor and the first two bending frequencies of the rotor settled on the touchdown bearings. The critical speed map also verifies the bending frequencies and identified support properties. The model-based approach can be used to evaluate and compare a single dropdown event with respect to previous events providing an insight for decision making whether touchdown bearing should be replaced.

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Section: Model Of the Contact Between The Rotor And Touchdown Bearingmentioning

confidence: 99%

Performance evaluation of touchdown bearing using model-based approach

et al. 2020

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“…Neisi et al presented a dynamic and thermal model of a touchdown bearing and calculated the heat generation with surface waviness. e result indicated that the amplitude of the waviness has a great effect on contact forces between balls, rotor, and inner race, thus affecting the temperature rise [24]. Nevertheless, the heat and temperature rise considered merely came from the friction between the bearing components while running.…”

Section: Introductionmentioning

confidence: 99%

Effect of Thermal-Related Fit Clearance between Outer Ring and Pedestal on the Vibration of Full Ceramic Ball Bearing

Shi

Bai

Zhang³

et al. 2019

Shock and Vibration

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Full ceramic bearing can work under a wide range of temperatures, but the thermal deformation difference between the ceramic outer ring and steel pedestal has a great increase with the rise of temperature and leads to obvious impact and friction. In this paper, the thermal deformation difference is considered and the fit clearance is taken as the boundary condition of the dynamic model. Investigations on the dynamic response of the outer ring are conducted, and the effect of thermal-related fit clearance is analyzed at different working temperatures and rotation speeds through parametric study and experiments. Results show that the vibration of the outer ring grows with the temperature and shows different changes with rotation speed as the temperature changes. The variation of working temperature brings difference in the interactions between the outer ring and the pedestal, and the trends of vibration with rotation speed also change at different temperatures. Impact and friction make great contributions to the interactions between the outer ring and the pedestal and show different changes with temperature. This study puts forward a method for the calculation of bearing vibration at variable temperatures and provides theoretical basis for the application of the full ceramic bearings.

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“…Tuhin et al 22 presented two novel methods including base excitation method and bearing kinematics augmented base excitation method for investigating the dynamic response of rotor-bearing system subjected to rolling element bearing waviness excitation. Neisi et al 23 focused on investigating the influences of surface waviness order on the generation and thermal expansion of touchdown bearing by establishing numerical and FE models. Wang et al 24 established a four degrees of freedom mathematical model of rotor system supported by roller bearing for investigating the nonlinear dynamic behaviors of rotor rolling bearing system by employing Newmark- β and Newton–Raphson iteration methods, the effects of nonlinear Hertzian contact force, radial clearances, and bearing waviness on the dynamic behaviors of rotor rolling bearing system.…”

Section: Introductionmentioning

confidence: 99%

Nonlinear dynamic behaviors of angular contact ball bearing with waviness based on a synthetical multi-degree-of-freedom mathematical modelling

Li,

Wang,

Wang

et al. 2023

Journal of Low Frequency Noise, Vibration and Active Control

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This paper proposes a synthetical multi-degree-of-freedom mathematical modelling for analyzing the dynamic characteristics of angular contact ball bearing with waviness subjected to the external load working conditions. The above multi-degree-of-freedom mathematical modelling is established based on nonlinear elastic Hertz contact theory and inner raceway control theory by employing improved Newton–Raphson iteration method; the validation of the established mathematical modelling is verified by comparing the presented results with the existing literature results. The above mathematical modelling has considered raceway waviness, ball waviness, bearing clearance, centrifugal force, gyroscopic moment, external loads, and rotating speed comprehensively. Firstly, the effects of waviness order and waviness amplitude on time-varying contact and stiffness characteristics of angular contact ball bearing are investigated systematically. Then, the influences of bearing clearance, rotating speed, axial force, radial force, and torque on the dynamic contact and stiffness characteristics of angular contact ball bearing with waviness are analyzed thoroughly. The main results show that the solution results of mathematical modelling have converged, respectively, when raceway waviness order increases to 25 and ball waviness order increases to 5; The variation tendencies of time-varying contact angle, contact force, and stiffness of angular contact ball bearing with waviness are aperiodic; The amplitudes of time-varying contact angle, contact force, and stiffness of angular contact ball bearing increase evidently with waviness amplitude increased; The bearing clearance has important influence on the contact angle and contact force of outer raceway and inner raceway, respectively; The effects of radial force and torque on contact and stiffness characteristics are consistent basically in the corresponding direction; The influences of axial force and rotating speed on the contact and stiffness characteristics are more remarkable compared with other factors. The investigations of contact and stiffness characteristics of angular contact ball bearing with waviness are helpful for the designation and manufacture of high precision angular contact ball bearing.

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Influence of surface waviness in the heat generation and thermal expansion of the touchdown bearing

Cited by 18 publications

References 36 publications

Performance evaluation of touchdown bearing using model-based approach

Performance evaluation of touchdown bearing using model-based approach

Effect of Thermal-Related Fit Clearance between Outer Ring and Pedestal on the Vibration of Full Ceramic Ball Bearing

Nonlinear dynamic behaviors of angular contact ball bearing with waviness based on a synthetical multi-degree-of-freedom mathematical modelling

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