A Study of the Influence of Bearing Clearance on Lateral Coupled Shaft/Disk Rotordynamics

1992 ◽  
Author(s):  
George T. Flowers ◽  
Fang Sheng Wu
Keyword(s):  
Dynamical Behavior ◽  
High Amplitude ◽  
Bladed Disk ◽  
Bearing Clearance ◽  
Shaft System ◽  
Coupling Dynamics ◽  
Bearing Loads ◽  
Rotating Flexible Disk ◽  
Flexible Disk ◽  
Clearance Nonlinearity

This study examines the influence of bearing clearance on the dynamical behavior of a rotating, flexible disk/shaft system. Most previous work in nonlinear rotordynamics has tended to concentrate separately on shaft vibration or on bladed disk vibration, neglecting the coupling dynamics between them. The current work examines the important rotordynamical behavior of coupled disk/shaft dynamics. A simplified nonlinear model is developed for lateral vibration of a rotor system with a bearing clearance nonlinearity. The steady-state dynamical behavior of this system is explored using numerical simulation and limit cycle analysis. It is demonstrated that bearing clearance effects can produce superharmonic vibration that may serve to excite high amplitude disk vibration. Such vibration could lead to significantly increased bearing loads and catastrophic failure of blades and disks. In addition, multi-valued responses and aperiodic behavior was observed.

A Study of the Influence of Bearing Clearance on Lateral Coupled Shaft/Disk Rotordynamics

1993 ◽  
Vol 115 (2) ◽  
pp. 279-286 ◽  
Author(s):  
G. T. Flowers ◽  
Fang Sheng Wu
Keyword(s):  
Dynamic Behavior ◽  
High Amplitude ◽  
Bladed Disk ◽  
Bearing Clearance ◽  
Shaft System ◽  
Coupling Dynamics ◽  
Bearing Loads ◽  
Rotating Flexible Disk ◽  
Flexible Disk ◽  
Clearance Nonlinearity

This study examines the influence of bearing clearance on the dynamic behavior of a rotating, flexible disk/shaft system. Most previous work in nonlinear rotordynamics has tended to concentrate separately on shaft vibration or on bladed disk vibration, neglecting the coupling dynamics between them. The current work examines the important rotordynamic behavior of coupled disk/shaft dynamics. A simplified nonlinear model is developed for lateral vibration of a rotor system with a bearing clearance nonlinearity. The steady-state dynamic behavior of this system is explored using numerical simulation and limit cycle analysis. It is demonstrated that bearing clearance effects can produce superharmonic vibration that may serve to excite high-amplitude disk vibration. Such vibration could lead to significantly increased bearing loads and catastrophic failure of blades and disks. In addition, multivalued responses and aperiodic behavior were observed.

scholarly journals Whirl Analysis of an Overhung Disk Shaft System Mounted on Non-rigid Bearings

2021 ◽  
Author(s):  
Sanjib Chowdhury ◽  
Yashodhan V. Joshi
Keyword(s):  
Natural Frequencies ◽  
Coordinate Systems ◽  
Periodic Force ◽  
Campbell Diagram ◽  
Shaft System ◽  
Rotating Flexible Disk ◽  
Flexible Disk ◽  
Multi Body ◽  
Rotational Direction ◽  
Body Dynamic

Abstract Eigenvalues of a simple rotating flexible disk-shaft system are obtained using different methods. The shaft is supported radially by non-rigid bearings, while the disk is situated at one end of the shaft. Eigenvalues from a finite element and a multi-body dynamic tool are compared against an established analytical formulation. The Campbell diagram based on natural frequencies obtained from the tools differ from the analytical values because of oversimplification in the analytical model. Later, detailed whirl analysis is performed using AVL Excite multi-body tool that includes understanding forward and reverse whirls in absolute and relative coordinate systems and their relationships. Responses to periodic force and base excitations at a constant rotational speed of the shaft are obtained and a modified Campbell diagram based on this is developed. Whirl of the center of the disk is plotted as an orbital or phase plot and its rotational direction noted. Finally, based on the above plots, forward and reverse whirl zones for the two excitation types are established.

Influence of Bearing Clearance on Load Sharing in Planetary Gears

2011 ◽  
Author(s):  
Atsushi Suzuki ◽  
Takayuki Aoyama ◽  
Noboru Sugiura ◽  
Mizuho Inagaki ◽  
Takashi Shimizu
Keyword(s):  
Load Sharing ◽  
Tooth Surface ◽  
Surface Geometry ◽  
Planetary Gears ◽  
Gear Noise ◽  
Bearing Clearance ◽  
Modified Surface ◽  
Bearing Loads ◽  
Clearance Nonlinearity ◽  
Gear Meshes

Load sharing among plural pinions in planetary gears should be equal to reduce gear noise and to secure the strength of the gears and bearings. This study investigates the influence of bearing clearance on load sharing using multibody dynamics analysis. One of the characteristics of this analysis is its capability to calculate dynamic gear meshes and bearing clearance nonlinearity. Contact analysis of the gears defines the tooth surface expressed by numerical formula involving modified surface geometry. Moreover, nonlinear stiffness is used to express the bearing clearance. The numerical method is verified by experiments that measure bearing loads on pinions using strain gauges. Subsequently, the influence of bearing clearance is examined numerically. The results confirm that the clearance of the carrier is dominant. In addition, unequal loads arise from reductions in the bearing loads and inclination of the carrier. Finally, this paper suggests an appropriate clearance for well-balanced load sharing.

scholarly journals Effect of Lateral Disk Flexibility on the Dynamics of Squeeze Film Damper Supported Rotors

1993 ◽  
Author(s):  
Huajun Xie ◽  
George Flowers ◽  
Fangsheng Wu
Keyword(s):  
Critical Speed ◽  
Dynamical Behavior ◽  
Rotor System ◽  
Operating Conditions ◽  
Squeeze Film ◽  
Operating Speed ◽  
Wide Range ◽  
Balance Analysis ◽  
Coupling Dynamics ◽  
Flexible Disk

This paper investigates the influence of disk flexibility on the dynamical behavior of a flexible disk/shaft rotor system supported with squeeze film dampers. A simplified nonlinear rotor model incorporating disk/shaft coupling dynamics is developed for lateral vibration of a rotor system. The steady state performance of the system is explored over a wide range of operating conditions using numerical integration and harmonic balance analysis. It is shown that disk flexibility may significantly affect the dynamical behavior of the system at high operating speed by creating an additional critical speed. It is observed that both the SFD journal motion and the disk motion associated with the additional critical speed are aperiodic and of large amplitudes. It is demonstrated that the influence of disk flexibility can be shifted out of the operating speed range by increasing the retainer spring stiffness.

Transient Vibration of High-Speed, Lightweight Rotors Due to Sudden Imbalance

1983 ◽  
Vol 105 (3) ◽  
pp. 480-486 ◽  
Author(s):  
M. Sakata ◽  
T. Aiba ◽  
H. Ohnabe
Keyword(s):  
Transient Response ◽  
High Speed ◽  
Rotor System ◽  
Response Analysis ◽  
Transient Vibration ◽  
Flexible Shaft ◽  
Shaft System ◽  
Transient Response Analysis ◽  
Flexible Disk ◽  
Blade Loss

In the field of rotor dynamics, increased attention is being given to the transient response analysis of the rotor, since the effects of impact loading and vibrations of the rotor arising from blade loss can be studied by a time transient solution of the rotor system. As recent trends in rotating machinery have been directed towards lightweight, high-speed flexible rotors, the effect of flexibility on transient response analysis is becoming of increasing importance. In the present paper, a transient vibration analysis is carried out on a flexible-disk/flexible-shaft system or rigid-disk flexible-shaft system subjected to a sudden imbalance that is assumed to represent the effect of blade loss. To solve the basic equation governing a rotating flexible disk the Galerkin’s method is used, and the equation of motion of the rotor system is numerically solved by employing the Runge-Kutta-Gill’s method. Experiments were conducted on a model rotor having a blade loss simulator; the shaft vibrations were also measured. The validity of the anaytical results was demonstrated by comparison with the experimental results.

Vibrational response of a moving suspension-slider loading system exciting a rotating flexible disk

2012 ◽  
Vol 331 (16) ◽  
pp. 3762-3773 ◽  
Author(s):  
Yong-Chen Pei ◽  
Qing-Chang Tan ◽  
Xin Yang ◽  
Chris Chatwin
Keyword(s):  
Vibrational Response ◽  
Loading System ◽  
Rotating Flexible Disk ◽  
Flexible Disk

Axisymmetric Solution of a Flexible Disk Rotating Near a Rigid Surface

1988 ◽  
Vol 110 (4) ◽  
pp. 674-677 ◽  
Author(s):  
M. Carpino ◽  
G. A. Domoto
Keyword(s):  
Plane Stress ◽  
Asymptotic Expansions ◽  
Reynolds Equation ◽  
Flat Surface ◽  
Inertial Effects ◽  
Rigid Surface ◽  
Axisymmetric Solution ◽  
Spinning Disk ◽  
Rotating Flexible Disk ◽  
Flexible Disk

A rotating flexible disk separated from a rigid flat surface by a gas film is addressed. The gas film between the disk and the plate is represented by an incompressible Reynolds equation. Inertial effects are included. The disk is treated as a membrane where the tension is found from the plane stress solution for a spinning disk. Two different methods for the axisymmetric solution of this system are developed. The first uses the method of matched asymptotic expansions. The second method is a mixed numerical/perturbation procedure.

Dynamic stability of rotating flexible disk perturbed by the reciprocating angular movement of suspension–slider system

2010 ◽  
Vol 329 (26) ◽  
pp. 5520-5531 ◽  
Author(s):  
Yong-Chen Pei ◽  
Qing-Chang Tan ◽  
Fu-Sheng Zheng ◽  
Yong-Qi Zhang
Keyword(s):  
Dynamic Stability ◽  
Angular Movement ◽  
Rotating Flexible Disk ◽  
Flexible Disk
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