Balancing for a Rigid Rotor with Measurement Errors in Initial Unbalanced Vibration. Comparison of Balancing Conditions between the Least Squares Method and the Influence Coefficient Method.

Abstract This article develops a more efficient technique for the balancing of the overhung rigid rotor, which is a variation of the exact influence coefficient method, that gives directly the correction weights for both balancing planes. During the calibration process, one trial weight is used for the second run and, to reduce the cross effect, only one trial weight to form a couple is used for the third run, improving the field balancing method for maintenance works.

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Further Experiments on Balancing of a High-Speed Flexible Rotor

Journal of Engineering for Industry ◽

10.1115/1.3438348 ◽

1974 ◽

Vol 96 (2) ◽

pp. 431-440 ◽

Cited By ~ 2

Author(s):

J. Tonnesen

Keyword(s):

Computer Program ◽

Least Squares ◽

High Speed ◽

Influence Coefficient ◽

Flexible Rotor ◽

Minimum Level ◽

Absolute Level ◽

Quality Class ◽

Influence Coefficient Method ◽

Coefficient Method

The accuracy of the influence coefficient method is experimentally investigated. The influence of the number of measurement transducers, their location, and type is demonstrated on a flexible rotor where simultaneous balancing is performed in up to five planes and passing through three critical speeds. The correction weights are calculated by means of a computer program, based on a least-squares minimizing procedure. The method itself is shown to be accurate and uses only a minimum of balancing runs to reduce the vibrations to a true minimum level. The overall accuracy in determining the unbalance weights is found to be 4.5 percent. The method’s effectiveness is demonstrated on a rotor with four balancing planes and with unbalance distributed at random in six and seven planes. The absolute level of residual vibrations is found to be in the ISO 0.4 quality class [5].

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The Optimization of Balancing Least Squares Influence Coefficient Method Based on Particle Swarm Optimization

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.105-107.56 ◽

2011 ◽

Vol 105-107 ◽

pp. 56-61 ◽

Cited By ~ 1

Author(s):

Xing Xing Wang ◽

Guo An Yang ◽

Ya Jun Fan

Keyword(s):

Particle Swarm Optimization ◽

Least Squares ◽

Particle Swarm ◽

Influence Coefficient ◽

Residual Vibration ◽

Swarm Optimization ◽

Measuring Point ◽

Influence Coefficient Method ◽

Rotor Balancing ◽

Coefficient Method

On the basis of the rotor dynamic balancing theory, the rotor balancing least squares influence coefficient method has been discussed in detail in this paper. In order to solve the problem that the residual vibration in some of the measuring point and the balancing weight are comparatively large in the balance process with least squares influence coefficient method, particle swarm optimization algorithm with cross-factor, which is an improved swarm intelligence algorithm, is introduced into rotor balancing least squares influence coefficient method. Theoretical analysis and numerical examples show that the algorithm has a good convergence, with reducing the balancing weight and residual vibration effectively compared with basic least squares influence coefficient method. The result can achieve better balance effect in the rotor balancing process.

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Rigid Rotor Dynamic Balancing by Two-Plane Correction with the Influence Coefficient Method

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.365-366.211 ◽

2013 ◽

Vol 365-366 ◽

pp. 211-215 ◽

Cited By ~ 1

Author(s):

Xiang Xu ◽

Ping Ping Fan

Keyword(s):

Dynamic Balance ◽

Balance Model ◽

Inertia Force ◽

Influence Coefficient ◽

Rigid Rotor ◽

Dynamic Balancing ◽

Balance Test ◽

Influence Coefficient Method ◽

Rotor Dynamic ◽

Coefficient Method

A rigid rotor dynamic balance model was established to analyze the vibration form of a rigid rotor under unbalance inertia force. The principle of two-plane correction with the influence coefficient method had been conducted, and the principle of the cross-correlation method calculating amplitude and phase of unbalance vibration signal was introduced. The method was found to be effective and practical. A dynamic balance test program was performed on a rigid rotor vibration simulation instrument and a dynamic balancing analyzer based on LabVIEW, which showed that rigid rotor dynamic balancing by two-plane correction with the influence coefficient method could satisfy the performance and required precision.

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Influence Coefficients Obtained by Hammer Beat Permit Significant Time Savings When Balancing Simple Flexible Rotors

Volume 7A: 17th Biennial Conference on Mechanical Vibration and Noise ◽

10.1115/detc99/vib-8260 ◽

1999 ◽

Author(s):

D. Wiese ◽

M. Breitwieser

Keyword(s):

Influence Coefficient ◽

Significant Time ◽

Flexible Rotors ◽

Influence Coefficients ◽

Flexible Roll ◽

Influence Coefficient Method ◽

Time Savings ◽

Positive Results ◽

Coefficient Method

Abstract The following paper presents a method for balancing simple flexible rotors with the help of influence coefficients obtained by hammer beat. The method permits time savings of approx. 50% compared to the conventional influence coefficient method. Initial positive results obtained on a flexible roll are also presented.

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Prototype design and size optimization of a hybrid lower extremity exoskeleton with a scissor mechanism for load-carrying augmentation

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/0954406214532078 ◽

2014 ◽

Vol 229 (1) ◽

pp. 155-167 ◽

Cited By ~ 4

Author(s):

Yunjie Miao ◽

Feng Gao ◽

Dalei Pan

Keyword(s):

Lower Extremity ◽

Influence Coefficient ◽

Input And Output ◽

Flexion Extension ◽

Load Carrying ◽

Influence Coefficient Method ◽

Prototype Design ◽

Coefficient Method ◽

Length Optimization ◽

Scissor Mechanism

A hybrid lower extremity exoskeleton SJTU-EX which adopts a scissor mechanism as the hip and knee flexion/extension joint is proposed in Shanghai Jiao Tong University to augment load carrying for walking. The load supporting capabilities of a traditional serially connected mechanism and the scissor mechanism are compared in detail. The kinematic influence coefficient method of the kinematic and dynamic analysis is applied in the length optimization of the scissor sides to minimize the transmitting errors between the input and output motions in walking and the load capacities of different scissor mechanisms are illustrated. The optimization results are then verified by the walking simulations. Finally, the prototype of SJTU-EX is implemented with several improvements to enhance the working performances.

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