Effect of Dynamic Balance Parameters on Vibration of Vertical and Horizontal Rotor System

The rotor system balance design is always one of the main concerns in scroll fluid machinery dynamics, as it affects the scroll mechanical reliability, safety and life. According to the scroll fluid machinery working principle and structure, combined with the dynamic balance theory, four kinds of balance weight design philosophy were proposed in this paper and verified by a specific example, in which the bearding loads were calculated using four design methods and compared. The results show that the balance design philosophy will have a significant effect on fluid dynamic characteristics. The result is helpful for optimizing the rotor balance design of scroll fluid machinery and improving the mechanical properties.

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Research on Dynamic Balance of Spindle Rotor System Based on Particle Swarm Optimization

Advances in Materials Science and Engineering ◽

10.1155/2021/9728248 ◽

2021 ◽

Vol 2021 ◽

pp. 1-12

Author(s):

Zhan Wang ◽

Dongzheng Li ◽

Zinan Wang ◽

Aoxiang Liu ◽

Ruiyao Tao

Keyword(s):

Particle Swarm Optimization ◽

Optimization Model ◽

Dynamic Balance ◽

Particle Swarm ◽

Optimization Method ◽

Rotor System ◽

Mode Shapes ◽

Swarm Optimization ◽

Nonlinear Dynamic Characteristics ◽

System Mode

The dynamic balance is a significant issue for the nonlinear dynamic characteristics of the spindle rotor system. However, there is a problem that the dynamic balance is lacking detailed study on optimization method. In the paper, a modal dynamic balance optimization model of spindle rotor system is proposed, which can intend to improve the accuracy of spindle rotor system modal dynamic balance. Because the multiorder unbalance components are the main spindle rotor system mode shapes, the particle swarm optimization (PSO) method is adopted. The sum of squares of residual vibration after balancing is taken as the optimization objective, and the correction is presented as the optimization variable in the optimization model. The optimal correction weight of every unbalance component is calculated through a modal matrix equation of PSO. The vibration amplitude that is greatly reduced after optimization balance is presented under different conditions. The balancing effect shows a better dynamic characteristic than that of traditional methods. And the fluctuation range of the axis track of the rotor system also shows reductive phenomenon. The proposed optimization spindle rotor system model is well verified through experiments. It can contribute a theoretical optimization foundation for available dynamic balance in spindle rotor system.

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Dynamic Characteristics of Air Cycle Machine Rotor System

Shock and Vibration ◽

10.1155/2018/1257274 ◽

2018 ◽

Vol 2018 ◽

pp. 1-16 ◽

Cited By ~ 1

Author(s):

Dongjiang Han ◽

Long Hao ◽

Jinfu Yang

Keyword(s):

Critical Speed ◽

Dynamic Balance ◽

Exciting Force ◽

Rotor System ◽

Parameters Optimization ◽

Response Analysis ◽

Response Characteristics ◽

Bearing Stiffness ◽

Harmonic Response Analysis ◽

Modal Method

Parameters optimization in the critical speed region has the important influence on operational stability of an air cycle machine. Effects of bearing stiffness and unbalanced exciting force on critical speed and response characteristics are investigated by the modal method and harmonic response analysis. Resonance separation phenomenon in the critical speed region is analyzed in detail. When difference exists in the phase of unbalanced exciting force, resonance separation appears in the conical whirling speed region. The characteristics after resonance separation are closely related to the phase difference value and amplitude of unbalanced exciting force. The paper provides theoretical and experimental foundations for resonance separation analysis and also provides data support for dynamic balance and dynamic design of the rotor system.

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Nonlinear dynamic properties of disk-bolt rotor with interfacial cutting faults on assembly surfaces

Journal of Vibration and Control ◽

10.1177/1077546317724602 ◽

2017 ◽

Vol 24 (19) ◽

pp. 4369-4382

Author(s):

Yi Liu ◽

Heng Liu ◽

BoWen Fan

Keyword(s):

Nonlinear Dynamic ◽

Dynamic Properties ◽

Dynamic Balance ◽

Three Dimensional ◽

Rotor System ◽

Contact Algorithm ◽

Mass Eccentricity ◽

Specific Shape ◽

Nonlinear Dynamic Properties ◽

Coupling Characteristics

Interfacial cutting faults on assembly surfaces are considered in a three-dimensional (3D) disk-bolt rotor system. The traditional finite element method is used to establish the 3D model of faulted disk-bolt rotor. A contact algorithm is applied to calculate the static features of this combined rotor. It is revealed that interfacial cutting faults produce rotor bending which is gradually strengthened as rotational speed increases besides disk’s mass eccentricity. The 3D dynamic equations of a faulted disk-bolt rotor system include these cutting faults’ static influences. The nonlinear dynamic properties are investigated by Poincaré mapping, Newton iteration and a prediction-correction algorithm. As a result, the rotor bending due to cutting faults reduces the global stability of the complicated rotor and enlarges the vibration amplitude obviously. This speed-variant bending also decides the feature that rotor vibration increases again after critical speed no matter whether dynamic balance is carried out. The maximum allowable fault depth is obtained and it gives an explanation as to why the machining precision of assembly surfaces should be strictly controlled in the disk-bolt rotor. Generally, this paper originally tries to provide a feasible approach to consider a 3D interfacial cutting fault with specific shape and to analyze the static–dynamic coupling characteristics for a disk-bolt rotor.

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Study on Dynamic Balance Weighting for Single-Disk Rotor System Based on Phase Difference Mapping

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.430-432.1437 ◽

2012 ◽

Vol 430-432 ◽

pp. 1437-1441 ◽

Cited By ~ 1

Author(s):

Qing Liang Zhao ◽

Hua Qing Wang ◽

Jin Ji Gao

Keyword(s):

Phase Difference ◽

Dynamic Balance ◽

Mechanical Vibration ◽

Rotor System ◽

Influence Coefficient ◽

Weighting Method ◽

Single Disk ◽

Influence Coefficient Method ◽

Rotor Mass ◽

Coefficient Method

The rotor mass imbalance is main reason of rotating mechanical vibration. A new dynamic balance weighting method for single-disk rotor system based on phase difference mapping is presented. Firstly, the influence coefficient method and its characteristics are analyzed in detail. Secondly, the equivalent phase difference mapping relationship between incentive and vibration response for single-disk rotor system is proved by differential equations and Laplace transform theory. Finally, a specific application instance is showed. The new method is simple and easy to peel the phase coupling relationship between incentive and response, which can be used to guide dynamic balance weighting for single-disk rotor system on site.

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Study on modal dynamic balance method of bearing rotor system

Journal of Physics Conference Series ◽

10.1088/1742-6596/1820/1/012070 ◽

2021 ◽

Vol 1820 (1) ◽

pp. 012070

Author(s):

Huimin Zhou ◽

Zhan Wang

Keyword(s):

Dynamic Balance ◽

Rotor System ◽

Balance Method

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Use of Vestibular Rehabilitation in the Pediatric Population

Perspectives of the ASHA Special Interest Groups ◽

10.1044/2019_pers-sig7-2019-0002 ◽

2019 ◽

Vol 4 (6) ◽

pp. 1399-1405 ◽

Cited By ~ 1

Author(s):

Jennifer Christy

Keyword(s):

Pediatric Population ◽

Dynamic Balance ◽

Vestibular Rehabilitation ◽

Rehabilitation Program ◽

Gross Motor ◽

Gaze Stabilization ◽

Motor Delay ◽

Rehabilitation Programs ◽

Motor Practice ◽

Balance Exercises

Purpose The purpose of this article was to provide a perspective on vestibular rehabilitation for children. Conclusion The developing child with vestibular dysfunction may present with a progressive gross motor delay, sensory disorganization for postural control, gaze instability, and poor perception of motion and verticality. It is important that vestibular-related impairments be identified early in infancy or childhood so that evidence-based interventions can be initiated. A focused and custom vestibular rehabilitation program can improve vestibular-related impairments, enabling participation. Depending on the child's age, diagnosis, severity, and quality of impairments, vestibular rehabilitation programs may consist of gaze stabilization exercises, static and dynamic balance exercises, gross motor practice, and/or habituation exercises. Exercises must be modified for children, done daily at home, and incorporated into the daily life situation.

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