Dynamic Characteristic of Hydrostatic Air Journal Bearing with Supply Pressure Control

2017 ◽  
Vol 2017.66 (0) ◽  
pp. 122
Author(s):  
Tomohiko ISE ◽  
Takemichi UEKI ◽  
Masami MATSUBARA ◽  
Shozo KAWAMURA
Keyword(s):  
Dynamic Characteristic ◽  
Journal Bearing ◽  
Pressure Control ◽  
Supply Pressure

Vibration Reduction of Large Unbalanced Rotor Supported by Externally Pressurized Gas Journal Bearings With Asymmetrically Arranged Gas Supply Holes (Verification of the Effectiveness of a Supply Gas Pressure Control System)

2018 ◽  
Vol 141 (3) ◽  
Author(s):  
Tomohiko Ise ◽  
Mitsuyoshi Osaki ◽  
Masami Matsubara ◽  
Shozo Kawamura
Keyword(s):  
Control System ◽  
Vibration Amplitude ◽  
Journal Bearing ◽  
Load Capacity ◽  
Vibration Reduction ◽  
Pressure Control ◽  
Test Rig ◽  
Supply Pressure ◽  
Unbalanced Rotor ◽  
Gas Supply

A rotor supported by gas bearings vibrates within the clearance. If the static imbalance of the rotor is large, even if the rotation speed is low, large amplitude vibration is generated by the centrifugal force. This is a serious problem because the risk of bearing damage increases. In order to solve this problem, an externally pressurized gas journal bearing with asymmetrically arranged gas supply holes has been developed. This type of bearing has a large load capacity as compared with the conventional symmetric gas supply bearing because pressurized gases are supplied to the loaded and counter-loaded side bearing surfaces via asymmetrically arranged gas supply holes. The bearing has a new gas supply mechanism in which gas is supplied from the rotor through inherent orifices. The characteristics of the developed bearing are beneficial from the viewpoint of using the bearing in rotational-type vibration exciters. In other words, this rotor has a large static imbalance. Numerical calculations of the characteristics of this bearing were performed, and the resulting characteristics were compared with those of a conventional symmetric gas supply journal bearing. The bearing load capacity of the developed bearing is considerably larger than that of conventional symmetric type bearings. The load capacity increases owing to the asymmetry of the gas supply holes. In the controlled gas supply pressure condition, rotor radial vibration during rotation can theoretically be zero. A test rig and gas control system to realize vibration reduction was constructed. A rotational test under the gas pressure control condition was conducted using a large unbalanced rotor taking advantage of this property. The control program was constructed using matlab and simulink. The devices were driven by a digital signal processor. The magnitude of the unbalance of the rotor is 13.5 × 10−3 kg m. The bearing diameter and length were 60 and 120 mm, respectively. The rotational vibration amplitude decreased at a high rotational frequency under the proposed bearing configuration, although the amplitude increases monotonically with the frequency in the conventional bearing. When the gas supply pressure was controlled synchronously with the rotation frequency modulation of the large unbalanced rotor, the amplitude of the vibration amplitude was greatly reduced. The rotor of the test rig was safely supported by this bearing, and effective data for practical operation were obtained.

Machine learning-based performance analysis of two-axial-groove hydrodynamic journal bearings

2021 ◽  
pp. 135065012199289
Author(s):  
Biswajit Roy ◽  
Sudip Dey
Keyword(s):  
Journal Bearing ◽  
Journal Bearings ◽  
Hydrodynamic Performance ◽  
Support Vector ◽  
Oil Viscosity ◽  
Hydrodynamic Analysis ◽  
Supply Pressure ◽  
Input Parameters ◽  
Precise Prediction ◽  
Output Behavior

The precise prediction of a rotor against instability is needed for avoiding the degradation or failure of the system’s performance due to the parametric variabilities of a bearing system. In general, the design of the journal bearing is framed based on the deterministic theoretical analysis. To map the precise prediction of hydrodynamic performance, it is needed to include the uncertain effect of input parameters on the output behavior of the journal bearing. This paper presents the uncertain hydrodynamic analysis of a two-axial-groove journal bearing including randomness in bearing oil viscosity and supply pressure. To simulate the uncertainty in the input parameters, the Monte Carlo simulation is carried out. A support vector machine is employed as a metamodel to increase the computational efficiency. Both individual and compound effects of uncertainties in the input parameters are studied to quantify their effect on the steady-state and dynamic characteristics of the bearing.

Steady-State and Dynamic Properties of the Floating-Ring Journal Bearing

1968 ◽  
Vol 90 (1) ◽  
pp. 243-253 ◽  
Author(s):  
F. K. Orcutt ◽  
C. W. Ng
Keyword(s):  
Steady State ◽  
Journal Bearing ◽  
Dynamic Properties ◽  
Calculated Data ◽  
Experimental Results ◽  
Supply Pressure ◽  
Pressure Parameter

Calculated data on steady-state and dynamic properties of the plain cylindrical floating-ring bearing with pressurized lubricant supply are given. The data are for a bearing with L/D of 1, and values of the ratio of inner to outer film clearances of 0.7 and 1.3. One value of dimensionless supply pressure parameter is covered. Experimental results are presented which verify the calculated results and which supplement them, particularly with respect to stability characteristics of the bearing.

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.

Experimental Research on Cavitation Characteristics of a Novel Hybrid Journal Bearing

2013 ◽  
Vol 420 ◽  
pp. 74-77
Author(s):  
Ying Yang ◽  
Jing Hua Dai ◽  
Xu Li
Keyword(s):  
Experimental Research ◽  
High Speed ◽  
Work Performance ◽  
Journal Bearing ◽  
Rupture Zone ◽  
Oil Film ◽  
Rotating Speed ◽  
Supply Pressure ◽  
Experimental Rig

Under high and super high speed, the oil film of a journal bearing is easy to crack and then becomes cavitation. The existence of cavitation has a great effect on the work performance of the bearing. The cavitation mechanism of a spiral oil wedge journal bearing was investigated on the experimental rig. The effects of rotating speed and supply pressure on the cavitation shape of oil film and the number of cavitation strip in the rupture zone were analyzed. The results show that the cavitation shape of oil film is a long strip. The number of cavitation strip increases when supply pressure has been improved, and the location of oil outlet must be designed optimally.

Characteristics of Gas Mixture Supply/Pressure Control Using Non-Evaporable Getters in a Discharge-Type Fusion Neutron Source

2017 ◽  
Vol 72 (4) ◽  
pp. 773-779
Author(s):  
Yasushi Yamamoto ◽  
Hiroki Konda ◽  
Yuki Matsuyama ◽  
Hodaka Osawa ◽  
Masami Ohnishi
Keyword(s):  
Neutron Source ◽  
Pressure Control ◽  
Gas Mixture ◽  
Fusion Neutron ◽  
Supply Pressure ◽  
Fusion Neutron Source

Experimental Study on Cavitation Boundary of Journal Bearing

2013 ◽  
Vol 378 ◽  
pp. 362-366
Author(s):  
Ying Yang ◽  
Li Xu ◽  
Wen Qing Liu
Keyword(s):  
Experimental Study ◽  
High Speed ◽  
Journal Bearing ◽  
Theory Model ◽  
Work Characteristics ◽  
Oil Film ◽  
Rotating Speed ◽  
Supply Pressure ◽  
Rupture Area ◽  
Experimental Rig

Under high and super-high speed conditions, oil film of the journal bearing is easy to crack and then becomes cavitation. The existence of cavitation has a great effect on the work characteristics of the bearing. Cavitation boundary of a three-groove journal beaing was investigated on the journal bearing experimental rig. The influences of rotating speed and supply pressure on cavitation boundary were studied. And experimental equations of reformation location and the percent of rupture area are established. The results show that rupture location of oil film is not related with rotating speed and supply pressure, otherwise reformation location of oil film is effected greatly by them. The experimental equations lay foundations for next research on cavitation theory model and stability.

The Effects of Oil Supply Pressure at different Groove Position on Temperature and Pressure Profile in Journal Bearing

2013 ◽  
Vol 66 (3) ◽  
Author(s):  
Mohamad Ali Ahmad ◽  
Salmiah Kasolang ◽  
R. S. Dwyer-Joyce ◽  
Aidah Jumahat
Keyword(s):  
Journal Bearing ◽  
Pressure Profile ◽  
Diameter Ratio ◽  
Radial Load ◽  
Oil Supply ◽  
Supply Pressure ◽  
Pressure Profiles ◽  
Hydrodynamic Journal Bearing ◽  
Temperature And Pressure ◽  
Length To Diameter Ratio

The effects of oil supply pressure on the temperature and pressure at different groove locations on a hydrodynamic journal bearing were investigated. A journal with a diameter of 100 mm and a ½ length-to-diameter ratio was used. The supply pressure was set to 0.2, 0.5, and 0.7 MPa at seven different groove locations, namely, -45°, -30°, -15°, 0°, +15°, +30°, and +45°. Temperature and pressure profiles were measured at speed values of 300, 500, and 800 rpm with 10 kN radial load. The results show that the change in oil supply pressure simultaneously reduced the temperature and increased the pressure profile.

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