scholarly journals Piston-Pin Rotation and Lubrication

Lubricants ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 30 ◽  
Author(s):  
Hannes Allmaier ◽  
David E. Sander
Keyword(s):  
Dynamic Behaviour ◽  
Gasoline Engine ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Operating Conditions ◽  
Second Step ◽  
Full Load ◽  
Thermal Boundary Conditions ◽  
Crucial Part ◽  
Rotational Direction

The rotational dynamics and lubrication of the piston pin of a Gasoline engine are investigated in this work. The clearance plays an essential role for the lubrication and dynamics of the piston pin. To obtain a realistic clearance, as a first step, a thermoelastic simulation is conducted for the aluminum piston for the full-load firing operation by considering the heat flow from combustion into the piston top and suitable thermal boundary conditions for the piston rings, piston skirt, and piston void. The result from this thermoelastic simulation is a noncircular and strongly enlarged clearance. In the second step, the calculated temperature field of the piston and the piston-pin clearance are used in the simulation of the piston-pin journal bearings. For this journal bearing simulation, a highly advanced and extensively validated method is used that also realistically describes mixed lubrication. By using this approach, the piston-pin rotation and lubrication are investigated for several different operating conditions from part load to full load for different engine speeds. It is found that the piston pin rotates mostly at very slow rotational speeds and even changes its rotational direction between different operating conditions. Several influencing effects on this dynamic behaviour (e.g., clearance and pin surface roughness) are investigated to see how the lubrication of this crucial part can be improved.

Influence of geometric parameters and operating conditions on the thermohydrodynamic behaviour of plain journal bearings

2000 ◽  
Vol 214 (5) ◽  
pp. 445-457 ◽  
Author(s):  
I Pierre ◽  
M Fillon
Keyword(s):  
High Speed ◽  
Journal Bearing ◽  
Three Dimensional ◽  
Journal Bearings ◽  
Operating Conditions ◽  
Thermal Dissipation ◽  
Radial Clearance ◽  
Geometric Factors ◽  
Essential Components ◽  
Mass Flowrate

Hydrodynamic journal bearings are essential components of high-speed machinery. In severe operating conditions, the thermal dissipation is not a negligible phenomenon. Therefore, a three-dimensional thermohydrodynamic (THD) analysis has been developed that includes lubricant rupture and re-formation phenomena by conserving the mass flowrate. Then, the predictions obtained with the proposed numerical model are validated by comparison with the measurements reported in the literature. The effects of various geometric factors (length, diameter and radial clearance) and operating conditions (rotational speed, applied load and lubricant) on the journal bearing behaviour are analysed and discussed in order to inform bearing designers. Thus, it can be predicted that the bearing performance obtained highly depends on operating conditions and geometric configuration.

Performance of Stern Tube Bearings under Different Lubrication and Operating Conditions

2009 ◽  
Author(s):  
Jan H. Andersen ◽  
Hiroyuki Sada ◽  
Seiji Yamajo
Keyword(s):  
Journal Bearing ◽  
Hydrodynamic Lubrication ◽  
Journal Bearings ◽  
Operating Conditions ◽  
Water Soluble ◽  
Analysis Tool ◽  
Test Rig ◽  
Experimental Performance ◽  
Shaft Alignment ◽  
Alignment Analysis

This paper presents the results of an investigation into the theoretical and experimental performance of oil lubricated journal bearings. DNV has developed a new calculation tool for the analysis of journal bearing performance as part of shaft alignment analysis. The results of the calculation tool have been compared to other research and analysis methods under static and dynamic conditions. In addition, white metal bearings were tested with decreasing Sommerfeld number until loss of hydrodynamic lubrication. The experiments were carried out in a bearing test rig and with three different lubricants, normal mineral oil, emulsifying oil, and water-soluble oil. The tests were done with increasing water content in the lubricant. Results from the test were compared with calculation using the DNV analysis tool.

Steady-State and Dynamic Behaviour of Multi-Recess Hybrid Oil Journal Bearings

1979 ◽  
Vol 21 (5) ◽  
pp. 345-351 ◽  
Author(s):  
M. K. Ghosh ◽  
B. C. Majumdar ◽  
J. S. Rao
Keyword(s):  
Perturbation Theory ◽  
Steady State ◽  
Theoretical Analysis ◽  
Dynamic Behaviour ◽  
Journal Bearing ◽  
Load Capacity ◽  
Journal Bearings ◽  
Time Dependent ◽  
Damping Coefficients ◽  
Stiffness And Damping

A theoretical analysis of the steady-state and dynamic characteristics of multi-recess hybrid oil journal bearings is presented. A perturbation theory for small vibrations is used to solve an incompressible, finite journal bearing with a time-dependent term. Load capacity, attitude angle, friction parameter, stiffness and damping coefficients are evaluated for a capillary-compensated bearing.

Stability Analysis of Two-Layered Finite Hydrodynamic Porous Journal Bearing Using Linear and Nonlinear Transient Method

2007 ◽  
Author(s):  
S. K. Kakoty ◽  
S. K. Laha ◽  
P. Mallik
Keyword(s):  
Journal Bearing ◽  
Journal Bearings ◽  
Operating Conditions ◽  
System Stability ◽  
Rigid Rotor ◽  
Transient Method ◽  
Porous Bearing ◽  
Nonlinear Transient ◽  
Linear And Nonlinear ◽  
The Stability

A theoretical analysis has been carried out to determine the stability of rigid rotor supported on two symmetrical finite two-layered porous oil journal bearings. The stability curves have been drawn for different eccentricity ratios and Sommerfeld numbers. The effect of bearing feeding parameter, L/D ratio on the stability is also investigated. This paper also deals with a theoretical investigation of stability using a non-linear transient method. This analysis gives the journal centre locus and from this the system stability can be determined. With the help of graphics, several trajectories of the journal centre have been obtained for different operating conditions. Finally a comparison between single-layered porous bearing and the two-layered porous bearing is presented here.

Incorporation of THD Boundary Conditions for the Efficient Evaluation of Journal Bearing Performance

2007 ◽  
Author(s):  
P. S. Keogh ◽  
M. M. Khonsari
Keyword(s):  
Boundary Conditions ◽  
High Speed ◽  
Current Practice ◽  
Journal Bearing ◽  
Coefficient Matrix ◽  
Journal Bearings ◽  
Heat Fluxes ◽  
Solid Component ◽  
Influence Coefficient ◽  
Thermal Boundary Conditions

The evaluation of the thermohydrodynamic (THD) performance of journal bearings continues to be an important issue. This is particularly so for high speed or heavily loaded bearing designs. This paper focuses attention on the thermal boundary conditions at the lubricant-bearing interface. The solid component conduction problem is solved in advance of the main THD analysis. Boundary conditions are then imposed on the lubricant THD analysis through use of an appropriate influence coefficient matrix that incorporates the solid component conduction problem. This avoids the current practice of solving the lubricant and solid component problems separately in an iterative loop to achieve continuous temperatures and heat fluxes at the interface. Instead, only the lubricant problem needs to be solved using the boundary conditions imposed by the influence coefficient matrix.

A Numerical Solution for the Hydrodynamic Lubrication of Finite Porous Journal Bearings

1973 ◽  
Vol 187 (1) ◽  
pp. 71-78 ◽  
Author(s):  
B. R. Reason ◽  
D. Dyer
Keyword(s):  
Numerical Solution ◽  
Numerical Method ◽  
Journal Bearing ◽  
Hydrodynamic Lubrication ◽  
Approximate Solutions ◽  
Journal Bearings ◽  
Operating Conditions ◽  
Variable Porosity ◽  
Present Solution

We present a numerical solution for the operating conditions of a hydrodynamic porous journal bearing. The numerical method allows for the possibility of variable porosity in the bearing matrix, but the solution has been achieved on the assumption of matrix homogeneity. The relation between the various bearing parameters have been shown for a variety of bearing geometries and permeabilities enabling the operating conditions for this type of bearing to be better appreciated. A comparison of the present solution with approximate solutions used by other authors has been made, which indicates the useful working range of the approximate solutions.

Development of an Active Control System for Rotating Machinery by Means of Tilting Pad Journal Bearings

2016 ◽  
Author(s):  
Steven Chatterton ◽  
Filippo Cangioli ◽  
Paolo Pennacchi ◽  
Andrea Vania ◽  
Phuoc Vinh Dang
Keyword(s):  
Control System ◽  
Journal Bearing ◽  
Sliding Mode ◽  
Resonance Condition ◽  
Journal Bearings ◽  
Operating Conditions ◽  
Rotating Machines ◽  
Tilting Pad ◽  
Tilting Pad Journal Bearing ◽  
Tilting Pad Journal Bearings

The current design trend of rotating machines like turbo-generators, compressors, turbines, and pumps is focused on obtaining both high dynamic performances and high versatility of machines in different operating conditions. The first target is nowadays achieved by equipping machines with tilting pad journal bearings. For the second target, State-of-the-Art researches are focused on the development of active systems able to adapt the dynamic behavior of the machine to the external environment and new operating conditions. Typical causes of large vibration in rotating machines are faults, residual unbalance, resonance condition and instabilities. Aiming at vibration reduction, in recent years many studies are carried out to investigate different solutions; one of them is based on active tilting pad journal bearing. In this paper, the authors investigate, by simulations, the reduction of shaft vibration by controlling the motion of the pads of a tilting pad journal bearing. The basic idea is to balance the exciting force on the shaft with a suitable resulting force of the oil-film pressure distribution. In particular, a sliding mode controller has been considered and both angular rotation of the pads about the pivot and the radial motion of the pivot have been analyzed. Sliding mode control guarantees high robustness of the control system in real applications that can be characterized by a strong non-linear behavior. In the paper a general consideration about the bearing, the actuating methods and the control system have been provided. A numerical analysis of large size rotor equipped with active pads has been carried out in order to verify the effectiveness of the system in several conditions, even during the most critical operating phase, i.e. the lateral critical speed.

scholarly journals Journal Bearing Fault Detection Based on Daubechies Wavelet

2017 ◽  
Vol 42 (3) ◽  
pp. 401-414 ◽  
Author(s):  
Babu T. Narendiranath ◽  
H.S. Himamshu ◽  
Kumar N. Prabin ◽  
Prabha D. Rama ◽  
C. Nishant
Keyword(s):  
Fault Detection ◽  
Time Domain ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Operating Conditions ◽  
Centrifugal Pumps ◽  
Bearing Fault ◽  
Bearing Fault Detection ◽  
Vibration Data ◽  
Target Values

AbstractJournal bearings are widely used to support the shafts in industrial machinery involving heavy loads, such as compressors, turbines and centrifugal pumps. The major problem that could arise in journal bearings is catastrophic failure due to corrosion or erosion and fatigue, which results in economic loss and creates major safety risks. Thus, it is necessary to provide suitable condition monitoring technique to detect and diagnose failures, and achieve cost savings to the industry. Therefore, this paper focuses on fault diagnosis on journal bearing using Debauchies Wavelet-02 (DB-02). Nowadays, wavelet transformation is one of the most popular technique of the time-frequency-transformations. An experimental setup was used to diagnose the faults in the journal bearing. The accelerometer is used to collect vibration data, from the journal bearing in the form of time domain. This was then used as input for a MATLAB code that could plot the time domain signal. This signal was then decomposed based on the wavelet transform. The fast Fourier transform is then used to obtain the frequency domain, which gives us the frequency having the highest amplitude. To diagnose the faults various operating conditions are used in the journal bearing such as Full oil, half loose, half oil, fault 1, fault 2, fault 3 and full loose. Then the Artificial Neural Networks (ANN) is used to classify faults. The network is trained based on data already collected and then it is tested based on random data points. ANN was able to classify the faults with the classification rate of 85.7%. Thus, the test process for unseen vibration data of the trained ANN combined with ideal output target values indicates high success rate for automated bearing fault detection.

A Mixed-TEHD Model for Journal-Bearing Conformal Contact—Part II: Contact, Film Thickness, and Performance Analyses

1998 ◽  
Vol 120 (2) ◽  
pp. 206-213 ◽  
Author(s):  
Qian (Jane) Wang ◽  
Fanghui Shi ◽  
Si C. Lee
Keyword(s):  
Journal Bearing ◽  
Thermal Conditions ◽  
Journal Bearings ◽  
Mixed Lubrication ◽  
Operating Conditions ◽  
Contact Theory ◽  
Asperity Contact ◽  
High Eccentricity ◽  
And Performance ◽  
Contact Part

Investigation of the mixed lubrication of journal-bearing conformal contacts is very important for failure prevention and design improvement. This paper studies the asperity contact in heavily loaded journal bearings with Lee and Ren’s asperity contact theory in a newly developed mixed-TEHD (Thermal Elasto-Hydro-Dynamic) model and analyzes the performance of simulated journal bearings under high eccentricity ratios. The effects of operating conditions, bearing structures, and thermal conditions on the contact severity were numerically investigated. The results indicate that the asperity contact pressure and the performance of journal bearings in the mixed lubrication are strongly affected by the geometric design and the thermal-elastic deformations. The heat transfer of the bearing-lubricant-journal system was also shown to play a role.

Experimental Study of Tilting-Pad Journal Bearings—Comparison With Theoretical Thermoelastohydrodynamic Results

1992 ◽  
Vol 114 (3) ◽  
pp. 579-587 ◽  
Author(s):  
Michel Fillon ◽  
Jean-Claude Bligoud ◽  
Jean Freˆne
Keyword(s):  
Experimental Study ◽  
Theoretical Model ◽  
Rotational Speed ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Operating Conditions ◽  
Operating Characteristics ◽  
Tilting Pad ◽  
Tilting Pad Journal Bearing ◽  
Tilting Pad Journal Bearings

Operating characteristics of four-shoe tilting-pad journal bearings of 100 mm diameter and 70 mm length are determined on an experimental device. The load, between pad configuration, varies from 0 to 10,000 N and the rotational speed is up to 4000 rpm. Forty thermocouples are used in order to measure bearing element temperatures (babbitt, shaft, housing and oil baths). The influence of operating conditions and preload ratio on bearing performances are studied. Comparison between theoretical and experimental results is presented. The theoretical model is also performed on a large tilting-pad journal bearing which was investigated experimentally by other authors.

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