Development of an Interferometric Technique to be Used in Measuring Micron Level Clearances Filled With a Lubricant

2009 ◽  
Author(s):  
Murat Yıldırım ◽  
Zafer Dursunkaya ◽  
Tuba Okutucu
Keyword(s):  
Step Motor ◽  
Surface Waviness ◽  
Piston Motion ◽  
Interferometric Technique ◽  
Piston Cylinder ◽  
Effect Of Surface

The aim of this study is to develop an interferometric technique to measure micron level clearances occurring in small piston-cylinder arrangements; such as hermetically sealed compressors. A Cartesian model of the piston cylinder arrangement is manufactured and lateral and vertical motions are generated via a step motor, and micrometers, respectively, to simulate the piston motion and the change of clearance during the motion. Experiments are conducted in air and a lubricant. Measurements show the important effect of surface waviness of the mirror and the effect of the motion of the carriage at micron level measurements.

An Interferometric Technique for Measuring Micron Level Clearances Filled With a Lubricant

2010 ◽  
Author(s):  
Murat Yıldırım ◽  
Zafer Dursunkaya ◽  
Tuba Okutucu
Keyword(s):  
Step Motor ◽  
Surface Waviness ◽  
Piston Motion ◽  
Interferometric Technique ◽  
Piston Cylinder ◽  
Effect Of Surface

The aim of this study is to develop an interferometric technique to measure micron level clearances occurring in small piston-cylinder arrangements; such as hermetically sealed compressors. A Cartesian model of the piston cylinder arrangement is manufactured and lateral and vertical motions are generated via a step motor, and micrometers, respectively, to simulate the piston motion and the change of clearance during the motion. Experiments are conducted in air and a lubricant. Measurements show the important effect of surface waviness of the mirror and the effect of the motion of the carriage at micron level measurements.

Effect of Transverse and Longitudinal Surface Waviness on the Operation of Journal Bearings

1972 ◽  
Vol 14 (3) ◽  
pp. 168-172 ◽  
Author(s):  
P. Shelly ◽  
C. Ettles
Keyword(s):  
High Speed ◽  
Load Capacity ◽  
Surface Waviness ◽  
Machining Processes ◽  
Finishing Process ◽  
Oil Flow ◽  
Method Of Solution ◽  
The Mean ◽  
Effect Of Surface ◽  
Bearing Friction

An analysis is made to evaluate the effect of surface finish produced by the two final machining processes of high speed aero boring and broaching. A finite difference method of solution is used in which the number of waves superimposed on the basic geometry is successively increased. A strong asymptotic trend was found for all bearing characteristics beyond a relatively small number of waves. It is found that the load capacity compared to a smooth bearing is reduced for both processes if the surface waviness is included as an addition to the film height. If the film thickness is assumed to extend to the mean wave height, the load capacity is increased. The effect of surface waviness becomes more pronounced at higher eccentricities or as the amplitude of the waviness is increased. The variation of bearing friction and oil flow is shown. It is concluded that neither finishing process would have a serious deleterious effect on journal bearing performance.

Effect of surface waviness on the static performance of aerostatic journal bearings

2016 ◽  
Vol 103 ◽  
pp. 394-405 ◽  
Author(s):  
Xinkuan Wang ◽  
Qiao Xu ◽  
Baorui Wang ◽  
Lianxin Zhang ◽  
Hong Yang ◽  
...  
Keyword(s):  
Journal Bearings ◽  
Surface Waviness ◽  
Static Performance ◽  
Effect Of Surface

The Effect of Surface Waviness and Number of Rolling Elements on the Dynamic Behavior of a Rotor-Bearing System

2007 ◽  
Author(s):  
S. P. Harsha ◽  
C. Nataraj
Keyword(s):  
Chaotic Behavior ◽  
Nonlinear Dynamic Analysis ◽  
Wave Number ◽  
Surface Waviness ◽  
Nonlinear Load ◽  
Nonlinear Springs ◽  
Rotor Bearing ◽  
Rolling Elements ◽  
Bearing System ◽  
Effect Of Surface

In the paper, the effects of the number of rolling elements and wave number of surface waviness on the nonlinear dynamic analysis of a rotor-bearing system has been studied. In the analytical formulation, the contacts between rolling elements and races are considered as nonlinear springs, whose stiffnesses are obtained by using Hertzian elastic contact deformation theory. The results are presented in the form of Fast Fourier Transformations (FFT) and Poincare´ maps, which show that the vibration characteristics of the rotor and its bearings change when the bearings operate in different regions of their nonlinear load deflection characteristics. The appearance of regions of periodic, sub-harmonic and chaotic behavior has been observed to be strongly dependent on number of rolling elements.

A comparison of methods of modelling the bearing surfaces in an internal combustion engine

2011 ◽  
Vol 226 (4) ◽  
pp. 913-920 ◽  
Author(s):  
P D McFadden ◽  
S R Turnbull
Keyword(s):  
Internal Combustion Engine ◽  
Dynamic Analysis ◽  
Journal Bearing ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Journal Bearings ◽  
Comparison Of Methods ◽  
Piston Motion ◽  
Piston Cylinder

An existing model for the dynamic analysis of the piston motion in an internal combustion engine has been modified to incorporate a simpler representation of the piston–cylinder interaction, and to represent the main and big-end bearings as lubricated rather than dry journal bearings. The results demonstrate that the differences in calculated bearing forces and output torques are negligible, indicating that the simple dry journal bearing model is sufficient, but show that the modelling of the interaction between piston and cylinder is considerably improved.

A Numerical Analysis for Piston Skirts in Mixed Lubrication—Part I: Basic Modeling

1992 ◽  
Vol 114 (3) ◽  
pp. 553-562 ◽  
Author(s):  
Dong Zhu ◽  
Herbert S. Cheng ◽  
Takayuki Arai ◽  
Kyugo Hamai
Keyword(s):  
Surface Profile ◽  
Mixed Lubrication ◽  
Contact Friction ◽  
Thermal Distortion ◽  
Surface Waviness ◽  
Piston Motion ◽  
Friction Forces ◽  
Crack Angle ◽  
Piston Skirts ◽  
Cylinder Bore

This paper presents a mathematical model for piston skirts in mixed lubrication. It takes into account the effects of surface waviness, roughness, piston skirt surface profile, bulk elastic deformation and thermal distortion of both piston skirts and cylinder bore on piston motion, lubrication and friction. The corresponding computer program developed can be used to calculate the entire piston trajectory and the hydrodynamic and contact friction forces as functions of crack angle under engine running conditions. This paper is the first part of a series of two papers. It gives basic information and some preliminary results. The second part will include the major results and discussions, focused on the influences of elastic and thermal deformations.

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