On the Bifurcation of Periodic Motion of Rotor Ball Bearing System Considering Five Degrees of Freedom

2014 ◽  
Vol 945-949 ◽  
pp. 707-710
Author(s):  
Li Cui ◽  
Qing Sheng Wang
Keyword(s):  
Periodic Motion ◽  
Degrees Of Freedom ◽  
Ball Bearing ◽  
Dynamic Equations ◽  
Radial Clearance ◽  
Rotating Speed ◽  
Under Five ◽  
Bifurcation And Stability ◽  
Shooting Algorithm ◽  
Bearing System

Nonlinear bearing forces of ball bearing under five-dimensional loads are given, and five-DOF dynamic equations of rotor ball bearing system are constructed. Bifurcation of periodic motion of rotor ball bearing system in unbalance-rotating speed and radial clearance-rotating speed parametric domains are studied by use of continuation-shooting algorithm. Results show that the way of bifurcation and stability of period-1 motion vary with radial clearance and unbalance.

Study on Bifurcation of Rigid Rotor Roller Bearings System Considering Nonlinear Dynamic Behavior

2010 ◽  
Vol 34-35 ◽  
pp. 467-471
Author(s):  
Li Cui ◽  
Jian Rong Zheng
Keyword(s):  
Dynamic Behavior ◽  
Nonlinear Dynamic ◽  
Roller Bearing ◽  
Radial Clearance ◽  
Rigid Rotor ◽  
Rotating Speed ◽  
Rotor Bearing ◽  
Nonlinear Dynamic Behavior ◽  
Bifurcation And Stability ◽  
Bearing System

Rigid rotor roller bearing system displays complicated nonlinear dynamic behavior due to nonlinear Hertzian force of bearing. Nonlinear bearing forces of roller bearing and dynamic equations of rotor bearing system are established. The bifurcation and stability of the periodic motion of the system in radial clearance-rotating speed and ellipticity-rotating speed parametric domains are studied by use of continuation-shooting algorithm for periodic solutions of nonlinear non-autonomous dynamics system. Results show that the parameters of rotor bearing system should be designed carefully in order to obtain period-1 motion.

Parameters research on time-varying stiffness of the ball bearing system without race control hypothesis

2021 ◽  
pp. 095440622110179
Author(s):  
Yongzhen Liu ◽  
Yimin Zhang
Keyword(s):  
Ball Bearing ◽  
Combined Loading ◽  
Time Varying ◽  
Noticeable Effect ◽  
Rotating Speed ◽  
Bearing Stiffness ◽  
Vibration Mechanism ◽  
Control Hypothesis ◽  
Full Consideration ◽  
Bearing System

When the ball bearing serving under the combined loading conditions, the ball will roll in and out of the loaded zone periodically. Therefore the bearing stiffness will vary with the position of the ball, which will cause vibration. In order to reveal the vibration mechanism, the quasi static model without raceway control hypothesis is modeled. A two-layer nested iterative algorithm based on Newton–Raphson (N-R) method with dynamic declined factors is presented. The effect of the dispersion of bearing parameters and the installation errors on the time-varying carrying characteristics of the ball-raceway contact and the bearing stiffness are investigated. Numerical simulation illustrates that besides the load and the rotating speed, the dispersion of bearing parameters and the installation errors have noticeable effect on the ball-raceway contact load, ball-inner raceway contact state and bearing stiffness, which should be given full consideration during the process of design and fault diagnosis for the rotor-bearing system.

Dynamic Analysis of a Motorized Spindle With Externally Pressurized Air Bearings

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
Chundong Xu ◽  
Shuyun Jiang
Keyword(s):  
Dynamic Characteristics ◽  
Degrees Of Freedom ◽  
Equations Of Motion ◽  
Forced Response ◽  
Air Bearings ◽  
Motorized Spindle ◽  
Static And Dynamic Characteristics ◽  
Rotating Speed ◽  
Rotor Bearing ◽  
Bearing System

The purpose of this paper is to investigate the dynamic characteristics of a motorized spindle with externally pressurized air bearings. The externally pressurized air bearings consist of a journal bearing and a double pad thrust bearing with orifice restrictors. The equations of motion for the rotor-bearing system are established considering five degrees-of-freedom (DOF). The perturbation method and the finite difference method are introduced to calculate the static and dynamic characteristics of the air bearings; and the effects of the rotating speed and tilt angle of the rotor on the dynamic characteristics of the air bearings are analyzed. With the dynamic coefficients of the air bearings and the 5DOF rotor-dynamic model obtained, the stability, the unbalance response, and the forced response of the rotor-bearing system are investigated. Finally, the static and dynamic characteristics of the spindle are verified by an experimental study.

Dynamic Characteristics of Ball Bearing-Coupling-Rotor System with Angular Misalignment Fault

2021 ◽  
Author(s):  
Pengfei Wang ◽  
Hongyang Xu ◽  
Yang Yang ◽  
Hui Ma ◽  
Duo He ◽  
...  
Keyword(s):  
Dynamic Characteristics ◽  
Degrees Of Freedom ◽  
Ball Bearing ◽  
Element Model ◽  
Rolling Bearing ◽  
Rotor System ◽  
Radial Clearance ◽  
Axial Vibration ◽  
Restoring Force ◽  
Misalignment Fault

Abstract The rotor misalignment fault, which occurs only second to unbalance, easily occurs in the practical rotating machinery system. Rotor misalignment can be further divided into coupling misalignment and bearing misalignment. However, most of the existing references only analyze the effect of coupling misalignment on the dynamic characteristics of the rotor system, and ignore the change of bearing excitation caused by misalignment. Based on the above limitations, a five degrees of freedom nonlinear restoring force mathematical model is proposed, considering misalignment of bearing rings and clearance of cage pockets. The finite element model of the rotor is established based on the Timoshenko beam element theory. The coupling misalignment excitation force and rotor unbalance force are introduced. Finally, the dynamic model of the ball bearing-coupling-rotor system is established. The radial and axial vibration responses of the system under misalignment fault are analyzed by simulation. The results show that the bearing misalignment significantly influences the dynamic characteristics of the system in the low-speed range, so bearing misalignment should not be ignored in modeling. With the increase of rotating speed, rotor unbalance and coupling misalignment have a greater impact. Misalignment causes periodic changes in bearing contact angle, radial clearance, and ball rotational speed. It also leads to reciprocating impact and collision between the ball and cage. In addition, misalignment increases the critical speed and the axial vibration of the system. The results can provide a basis for health monitoring and misalignment fault diagnosis of the rolling bearing-rotor system.

The Radial Stiffness and Application of Double-Decker Ball Bearing

2010 ◽  
Vol 450 ◽  
pp. 353-356 ◽  
Author(s):  
Yi Li Zhu ◽  
Long Xiang Xu
Keyword(s):  
Ball Bearing ◽  
Contact Angles ◽  
Initial Contact ◽  
Rotating Speed ◽  
Unbalance Response ◽  
Double Decker ◽  
Rotor Bearing ◽  
Nature Frequency ◽  
Bearing Stiffness ◽  
Bearing System

Single Decker Ball Bearing (SDBB) is widely used in Rotor-Bearing system. A new method using DDBB composed of two ball bearings as support bearings is proposed. The mechanical model of the DDBB based on the quasi-dynamic method is established and the corresponding calculating program compiled in Matlab is developed after considering the radial load, axial load, centrifugal force as well as gyroscopic moment acted on the bearing simultaneously. And then a simple Rotor-DDBB model is adopted to analyze the rotor unbalance response with different parameters. The simulation results show that shaft rotating speed, ball materials, axial preload and the initial contact angles to some extent impact the bearing stiffness while have little affects on system nature frequency and the rotor unbalance response which greatly affected by the system base stiffness. The results provide a theoretical basis for the design of DDBB and application in a Rotor-Bearing system.

scholarly journals Nonlinear Dynamics Analysis of a Gear-Shaft-Bearing System with Breathing Crack and Tooth Wear Faults

2015 ◽  
Vol 9 (1) ◽  
pp. 483-491 ◽  
Author(s):  
Li Cui ◽  
Chilan Cai
Keyword(s):  
Periodic Motion ◽  
Nonlinear Dynamic ◽  
Tooth Wear ◽  
Radial Clearance ◽  
Breathing Crack ◽  
Nonlinear Dynamic Model ◽  
Shaft System ◽  
Nonlinear Dynamic Equations ◽  
Chaos Motion ◽  
Bearing System

Considering backlash, time-varying mesh stiffness and radial clearance of bearing, nonlinear dynamic model of gear bearing flexible shaft system is established taking into account breathing crack in shaft and tooth wear. Nonlinear dynamic equations are solved by Runge-Kutta method. Effect of backlash, crack in shaft and tooth wear faults on the nonlinear dynamic behavior of gear-shaft-bearing system is studied. The results show that gear-shaft-bearing system may change from periodic motion to non-periodic motion as backlash increases, and gear pair change from normal mesh to tooth separation, double-sided impact fault. If crack fault appears, quasi-periodic and chaos motion region increases, and gentle crack fault can result in instantaneous tooth separation and double-sided impact faults. Serious tooth wear fault will also induce tooth separation and double-sided impact faults. If both shaft crack and tooth wear faults exist, tooth wear fault will be intensified by double-sided impact fault from shaft crack, which will result in early failure of the gear system.

Bifurcation and Stability of the Periodic Motion of a Rotor Bearing System With Pedestal Looseness and Rub-Impact

2009 ◽  
Author(s):  
Changli Liu ◽  
Xiuli Zhang ◽  
Li Cui ◽  
Pengru Xie ◽  
Jianrong Zheng
Keyword(s):  
Periodic Solution ◽  
Hopf Bifurcation ◽  
Vibration Control ◽  
Periodic Motion ◽  
Autonomous System ◽  
Shooting Method ◽  
The Past ◽  
Rotor Bearing ◽  
Bifurcation And Stability ◽  
Bearing System

A rotor bearing system usually has various faults that could simultaneously exist (e.g., rub-impact, pedestal looseness etc), but, in the past, individual fault has been mostly modeled and analyzed separately. In this paper, the dynamic model of rotor bearing system with rub-impact and pedestal looseness is formulated. Continuation-shooting method for the periodic solution of nonlinear non-autonomous system is used to obtain the bifurcation and stability of the periodic motion of the rotor-bearing system. The effect of the unbalance and rotor/stator clearance on the bifurcation and stability of the periodic motion of the rotor bearing system are analyzed respectively. It has been observed that the periodic motion of the system lose stability by Hopf and doubling bifurcation respectively under the small and large unbalance; the system with coupling faults has the same way of losing stability as the system with rub-impact only. The Hopf bifurcation set is broadened with the rotor/stator clearance decreases. The results of the paper may provide theory references to fault diagnoses, vibration control and security operating of the rotor system.

On the Bifurcation and Stability of Periodic Motion of the Rotor-Bearing System with Rub-Impact and Oil Whirl

2009 ◽  
Vol 626-627 ◽  
pp. 517-522
Author(s):  
Chang Li Liu ◽  
X.L. Zhang ◽  
L. Cui ◽  
J. Jiang ◽  
J.R. Zheng
Keyword(s):  
Periodic Solution ◽  
Dynamic Model ◽  
Periodic Motion ◽  
Autonomous System ◽  
Shooting Method ◽  
Oil Whirl ◽  
Rotor Bearing ◽  
Bifurcation And Stability ◽  
Bearing System

In this paper, the dynamic model of rotor bearing system with rub-impact and oil whirl is formulated. Continuation-shooting method for the periodic solution of nonlinear non-autonomous system is used to obtain the bifurcation and stability of the periodic motion of the rotor-bearing system. The effect of the unbalance and rotor/stator clearance on the bifurcation and stability of the periodic motion of the rotor bearing system are analyzed respectively. The results obtained are compared with those of rotor-bearing system with oil whirl fault.

A Dynamic Modeling Approach for Spindle Bearing System Supported by Both Angular Contact Ball Bearing and Floating Displacement Bearing

2017 ◽  
Vol 140 (2) ◽  
Author(s):  
Songtao Xi ◽  
Hongrui Cao ◽  
Xuefeng Chen ◽  
Linkai Niu
Keyword(s):  
Dynamic Model ◽  
Dynamic Modeling ◽  
Ball Bearing ◽  
Radial Clearance ◽  
Fe Method ◽  
Angular Contact Ball Bearing ◽  
Modeling Approach ◽  
Spindle Shaft ◽  
Spindle Bearing ◽  
Bearing System

This paper presents a new dynamic modeling approach for spindle bearing system supported by both angular contact ball bearing (ACBB) and floating displacement bearing (FDB). First, a dynamic model of FDB is developed based on the discrete element method with each bearing component having six degrees-of-freedom (DOFs). Based on the developed FDB dynamic model and Gupta ACBB dynamic model, a fully coupled dynamic model of the spindle bearing system combined both ACBBs, and FDB is developed. In the proposed spindle bearing system model, the spindle shaft is modeled using finite element (FE) method based on the Timoshenko beam theory with the consideration of centrifugal force and gyroscopic moment. The coupling restriction between the dynamic bearing models and the FE spindle shaft model are the restoring forces and moments that are transmitted to the shaft by the bearings and the dynamic vibration response shared by both the bearing inner races and the corresponding nodes of the shaft where bearings are installed. A Fortran language-based program has been developed for the spindle bearing system with the dynamic bearing models solved using the Runge–Kutta–Fehlberg integration method and FE shaft model solved by Newmark-β method. Based on the developed model, the effect of the FDB radial clearance, system preload, and spindle rotating speed on the system dynamics, and the effect of the FDB radial clearance on the system unbalanced response have been investigated.

Sign in / Sign up

Export Citation Format

Share Document