Theoretical and experimental investigation on the effect of supply pressure on the nonlinear behaviors of the aerostatic bearing-rotor system

2021 ◽  
Vol 158 ◽  
pp. 107775
Author(s):  
Jianbo Zhang ◽  
Dongjiang Han ◽  
Mingbo Song ◽  
Zhongliang Xie ◽  
Zhushi Rao ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Rotor System ◽  
Aerostatic Bearing ◽  
Supply Pressure ◽  
Nonlinear Behaviors

Experimental Investigation on Cavitation Characteristics of a Three-Groove Journal Bearing

2013 ◽  
Vol 420 ◽  
pp. 47-50
Author(s):  
Ying Yang ◽  
Jing Hua Dai
Keyword(s):  
Experimental Investigation ◽  
High Speed ◽  
Journal Bearing ◽  
Rupture Zone ◽  
Work Characteristics ◽  
Oil Film ◽  
Rotating Speed ◽  
Clear Effect ◽  
Supply Pressure

Under high and super-high speed, oil film of the journal bearing is easy to crack and then becomes cavitation. The existence of cavitation has an important effect on the work characteristics of the shaft. On the journal bearing experiment rig the cavitation characteristics of the three-groove journal beaing were studied. The influences of the shaft rotating speed and supply pressure on cavitation shape were investigated. The results show that rotating speed and supply pressure have a clear effect on the cavitation shape, and the number of cavitation strip in the rupture zone decreases when the supply pressure increases.

Characteristics evaluation of gas film in the aerostatic thrust bearing within rarefied effect

2016 ◽  
Vol 231 (2) ◽  
pp. 149-157 ◽  
Author(s):  
Dongju Chen ◽  
Shuai Zhou ◽  
Jihong Han ◽  
Jinwei Fan ◽  
Qiang Cheng
Keyword(s):  
Machine Tool ◽  
Reynolds Equation ◽  
Thrust Bearing ◽  
Film Flow ◽  
Machining Accuracy ◽  
Aerostatic Bearing ◽  
Supply Pressure ◽  
Slip Regime ◽  
Key Factor ◽  
Gas Supply

The characteristic of gas film is a key factor in the performance of the aerostatic bearing. Because the gas film flow is in the slip regime, influence of the rarefied effect is significant. The modified Reynolds equation suitable for compressible gas in the rarefied effect is deduced through introducing the flow factor in the rarefied effect to the Reynolds equation. Pressure distribution, capacity, and stiffness of the gas film under the rarefied effect are analyzed. With the increase of gas pressure, the gas film capacity and stiffness of bearing would also increase. However, the greater the gas supply pressure, the more intense the gas film vibration, so it was important to select a reasonable gas supply pressure for achieving the optimal gas film characteristic. Finally, the gas rarefied effect is verified by the experiment indirectly, which agreed well with the analytical results and provided a theoretical guidance for the machining accuracy of the machine tool.

scholarly journals EFFECT OF FRICTION ON VIBRATIONAL CHARACTERISTICS OF ROTOR SYSTEM DURING ROTOR-STATOR INTERACTION

2020 ◽  
pp. 22-31
Author(s):  
Anton Kurakin ◽  
Keyword(s):  
Experimental Data ◽  
Experimental Investigation ◽  
Friction Coefficient ◽  
Rotor System ◽  
Aluminum Bronze ◽  
Rotor Systems ◽  
Vibrational Characteristics ◽  
Rotor Stator Interaction ◽  
Intermediate Value ◽  
Impact Motion

Systems operation which include rotating elements in certain cases is associated with occurrence of contact between the rotating parts (rotor) and the stationary parts (stator). There were cases then rotor-stator interaction led to damage or to complete unit destruction. For this reason, rotor-stator interaction is one of the main problem of rotor systems exploitation. The main aim of the work is to gather detail data about effect of friction on vibrational characteristics of rotor system during rotor-stator interaction. In this article the experimental investigation method and experimental investigation of dynamic behavior of rotor during rotor-stator interaction is presented. The analysis of experimental data obtained during interaction between steel rotor and stator made of aluminum, bronze and PTFE is presented. All results with rotor-stator contact and without were compared by using Campbell diagrams, orbits and frequency responses. Analysis of experimental data shows that friction has strong effect on vibrational characteristics of rotor system during rotor-stator interaction. According to friction ratio three kinds of vibrational characteristics of rotor system are distinguished: forward slipping if friction coefficient is small, backward rolling if friction coefficient is big, vibratory impact motion if friction coefficient has intermediate value. Created experimental method and gathered data about rotor dynamics during rotor-stator contact can be used for verification and tuning of mathematical models.

Experimental Investigation into the Vibration Response of an Aero-Engine Rotor-Damper Assembly

1994 ◽  
Vol 208 (1) ◽  
pp. 52-66 ◽  
Author(s):  
M C Levesley ◽  
R Holmes
Keyword(s):  
Experimental Investigation ◽  
Harmonic Balance ◽  
Vibration Response ◽  
Linear Vibration ◽  
Film Rupture ◽  
Supply Pressure ◽  
Balance Principle ◽  
Aero Engine ◽  
Rupture Pressure ◽  
Engine Rotor

This paper presents experimental results on the non-linear vibration response of a rotating assembly comprising a rotor, flexible bearing housing and oil film damper. For the latter, due consideration is given to the effects of oil-supply pressure, film-rupture pressure and end sealing. The results are compared with predictions based on the Harmonic Balance principle described in a complementary paper (1).

An Experimental Investigation on the Response of a Flexible Rotor Mounted in Pressure Dam Bearings

1980 ◽  
Vol 102 (4) ◽  
pp. 842-850 ◽  
Author(s):  
R. D. Flack ◽  
M. E. Leader ◽  
E. J. Gunter
Keyword(s):  
Experimental Investigation ◽  
Rotor System ◽  
Flexible Rotor ◽  
The Stability

The response of a flexible rotor mounted in six bearing sets has been experimentally determined. One set of axial groove bearings and five sets of pressure dam bearings were tested. Conventional synchronous tracking was used in the analysis and other techniques utilizing an FFT analyzer were developed. The stability of the system was seen to strongly depend on the design of the step bearings. The dam bearings were also noted to lock into subsynchronous whip during deceleration after the system went unstable. The response of the system with varying degrees of unbalance is also analyzed and several structural resonances of the rotor system are discussed.

Synthesis of Experimental and Theoretical Analysis of Pneumatic Hammer Instability in an Aerostatic Bearing

2015 ◽  
Vol 138 (2) ◽  
Author(s):  
Mihai Arghir ◽  
Mohamed-Amine Hassini ◽  
Franck Balducchi ◽  
Romain Gauthier
Keyword(s):  
Theoretical Analysis ◽  
Operating Conditions ◽  
Orifice Diameter ◽  
Aerostatic Bearing ◽  
Pneumatic Hammer ◽  
Usual Practice ◽  
Rotordynamic Coefficients ◽  
Supply Pressure ◽  
Direct Stiffness ◽  
Different Diameters

The present work is focused on the pneumatic hammer instability in an aerostatic bearing with shallow recesses and orifices of four different diameters. Operating conditions were zero rotation speed, zero load, and different supply pressures. The diameters of the tested orifices were large compared to the usual practice and correspond to a combined inherent and orifice restriction. The theoretical analysis was based on the computational fluid dynamics (CFD) evaluation of the ratio between the recess and the feeding pressure and on the “bulk flow” calculation of the rotordynamic coefficients of the aerostatic bearing. Calculations showed an increase of the direct stiffness with decreasing the orifice diameter and increasing the supply pressure and, on the other hand, a decrease toward negative values of the direct damping with decreasing the orifice diameter. These negative values of the direct damping coefficient indicate pneumatic hammer instabilities. In parallel, experiments were performed on a floating bearing test rig. Direct stiffness and damping coefficients were identified from multiple frequency excitations applied by a single shaker. Experiments were performed only for the three largest orifices and confirmed the decrease of the direct damping with the orifice diameter and the supply pressure. The identification of the rotordynamic coefficients was not possible for the smallest available orifice because the aerostatic bearing showed self-sustained vibrations for all feeding pressures. These self-sustained vibrations are considered the signature of the pneumatic hammer instability. The paper demonstrates that aerostatic bearings with shallow recesses and free of pneumatic hammer instabilities can be designed by adopting orifice restrictors of large size diameter.

Nonlinear Behaviors and Bifurcation of Flexible Rotor System with Axial-Grooved Self-Acting Gas Bearing Support

2011 ◽  
Vol 4 (4) ◽  
pp. 1796-1802 ◽  
Author(s):  
Weimin Wang ◽  
Yanjun Lu ◽  
Zhijun Cao ◽  
Yongfang Zhang ◽  
Lei Feng ◽  
...  
Keyword(s):  
Rotor System ◽  
Flexible Rotor ◽  
Nonlinear Behaviors ◽  
Gas Bearing
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