Investigation on the transient response of a speed-varying rotor with sudden unbalance and its application in the unbalance identification

Xia, Yebao; Ren, Xiaobin; Qin, Weiyang; Yang, Yue; Lu, Kuan; Fu, Chao

doi:10.1177/1461348419861837

Cited by 14 publications

(3 citation statements)

References 38 publications

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“…The results showed the interaction between different faults on the vibration behavior of system. The transient response of the speed-varying rotor in the presence of occurring sudden unbalance fault was studied by Xia et al and the results indicated a novel method for unbalance identification using the transient response [11]. A study on the transient analysis of a complex rotor with nonlinear bearings and dampers was studied by Cao [12].…”

Section: Introductionmentioning

confidence: 99%

Effect of straightness tolerance on unbalanced response of flexible shaft passing through critical speed

Mousavi,

Firouz-Abadi,

Mehralian

et al. 2023

J Braz. Soc. Mech. Sci. Eng.

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Since the more destruction in rotating machinery occurs during start up or run down, the main purpose of this study is to investigate the influences of shaft bow coupling with unbalance fault on the rotor response for passing through critical speeds. The Finite element model is developed for a more realistic analysis. The Newmark-β method to solve the nonlinear lateral vibration of rotor-bearing systems is approached and the effects of various parameters including shaft bow, unbalanced mass and support parameters are shown. The results illustrate the crucial role of shaft bow when it is coupled with unbalance fault in phase of each other for passing through critical speed. As a result, in order to bring a rotor up to speed over the critical one, the source of energy can only grow the amplitude of vibration instead of angular velocity.

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Section: Introductionmentioning

confidence: 99%

Effect of straightness tolerance on unbalanced response of flexible shaft passing through critical speed

Mousavi,

Firouz-Abadi,

Mehralian

et al. 2023

J Braz. Soc. Mech. Sci. Eng.

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“…Identifying rotor unbalance without test runs is the current trend [15]. This approach can be divided into two types: a method with external excitation and a method without external excitation.…”

Section: Introduction 1background and Formulation Of The Problemmentioning

confidence: 99%

Continuous Rotor Dynamics of Multi-Disc and Multi-Span Rotors: A Theoretical and Numerical Investigation of the Identification of Rotor Unbalance from Unbalance Responses

Wang

Feng

et al. 2022

Applied Sciences

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Rotor unbalance identification plays a critical role in balancing rotors. In this paper, concerned with multi-disc and multi-span rotor-bearing systems, two novel algorithms called the Single Direction Algorithm (SDA) and the Two Orthogonal Direction Algorithm (TODA) are proposed for identifying rotor unbalance from unbalance responses. A matrix method is proposed to solve the problem of the equations being non-linear transcendental, there being too many unknown variables in the equations, and rotor unbalances and bearing coefficients being coupled together. The unbalance responses at all the eccentric discs are necessary for identifying their unbalances. Numerical simulations are conducted to validate the proposed methods. Moreover, an adjustment point is found, and a proper sensor resolution is suggested to achieve high identification accuracy by means of numerical studies. In addition, the identification accuracy of SDA is better than TODA, and SDA is more practical and suitable for medium-speed and high-speed rotors. The proposed algorithms have the flexibility to incorporate any number of bearings and discs and provide a technique for monitoring rotor unbalance without test runs or external exciters.

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“…By using run-up and shutdown process, Sinha et al [13] proposed a method for speed-variant machines to calculate unbalance and misalignment of a flexible rotary machine. There have also been various kinds of modalbased balancing methods developed during the last few years [14][15][16][17]. The application of these methods have been studied for industrial-sized equipment [18][19][20][21][22][23][24].…”

Section: Introductionmentioning

confidence: 99%

A Speed-Variant Balancing Method for Flexible Rotary Machines Based on Acoustic Responses

et al. 2021

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As rotary machines have become more complicated, balancing processes have been classified as a vital step in condition monitoring to ensure that machines operate reliably, smoothly and safely. All rotating objects will deflect during rotation and all objects possess certain natural frequencies in the absence of rotation. However, an unbalanced object can cause significant unwanted deflection created by resonant vibration at a frequency (cycles/second) close to certain rotational speeds (rotations/second), known as critical speeds. This is especially important for flexible machines which normally work at rotations above their critical speeds. Imbalance is a common problem in flexible rotating machinery that can lead to extreme vibration and noise levels. This is one of the major reasons for studying various balancing methods applied to the vibration response of rotating machines. Recently, the relation between acoustic and vibration response during a rotary machine balancing process based on the original Four-Run method has been presented for constant speed machines. This method cannot be applied to machines in start-up or shut-off. Hence, by considering the acoustic and vibration responses of a machine between its critical speeds, this research presents a new innovative speed-variant balancing method based on the original Four-Run method, named as (PPCS) Peak to Peak for Critical Speeds. The proposed method consists of two major types of application: the first is in the run-up of the machine and the second is in shut down. Experimental laboratory results show that this method can be implemented for speed-variant and flexible rotary machines during run-up or shut-down transient processes based on acoustic and vibration measurements. Further, the results show the same trend in acoustic and vibration responses during balancing process which was shown for constant speed rotary machines. With a 40% improvement in response compared to around 55% obtained by traditional vibration measurements, the results found show an appreciable benefit in an alternative acoustic methodology that may have not been considered previously for run-up and shut-down issues. In addition, since only the magnitude of response is required and this is a non-contact technique an acoustic-only methodology, it can be employed with some confidence as an innovative and readily available method for condition monitoring.

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Investigation on the transient response of a speed-varying rotor with sudden unbalance and its application in the unbalance identification

Cited by 14 publications

References 38 publications

Effect of straightness tolerance on unbalanced response of flexible shaft passing through critical speed

Effect of straightness tolerance on unbalanced response of flexible shaft passing through critical speed

Continuous Rotor Dynamics of Multi-Disc and Multi-Span Rotors: A Theoretical and Numerical Investigation of the Identification of Rotor Unbalance from Unbalance Responses

A Speed-Variant Balancing Method for Flexible Rotary Machines Based on Acoustic Responses

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