Design and construction of an interferometric setup for dynamic measurement of clearances inside plain bearings

Jafari-Tabrizi, Atae
In this work with the help of fiber optic interferometry an experimental framework is designed and constructed to dynamically measure micron-level clearances inside main journal bearing of an engine crankshaft, and the trajectory of its shaft. For this purpose, the crankshaft is rotated at lower speeds than its operating speeds. An electric motor is used to rotate the crankshaft, and there are no pistons and connecting rods connected to the crankpins. Measured clearances from multiple points of the bearing are used to generate an estimate of the trajectory that the journal follows during a cycle. Experiments are performed both with and without lubricant inside bearing. Effect of lubricant, different rotating speeds, and repeatability of the measurement and estimation procedures are all investigated.


Design and construction of an experimental apparatus for the interferometric measurement of micrometer level clearances
Yıldırım, Murat; Dursunkaya, Zafer; Department of Mechanical Engineering (2009)
In this study a fiber optic interferometer (FOI) was designed and constructed to measure micron level clearances occurring in piston cylinder arrangements. A Cartesian model of the piston cylinder assembly is manufactured and lateral motion and vertical displacement are generated via a step motor, and micrometers, respectively. Clearance measurements are conducted in air and also in a lubricant. The range of vertical displacements is kept between 0-50 μm, and the lateral motion is 13.5 mm. The effect of the...
Design and Analysis of a Novel Mechanism for the Morphing of Trailing Edge of an Aircraft Wing
Şahin, Harun Levent; Yaman, Yavuz (2018-06-22)
In this paper, design of a novel deployable scissor-structural mechanism (SSM) for active camber and chord morphing airfoil has been presented. The mechanism is created via combination of one four-bar linkage and various scissor-like elements (SLEs). The theory behind scissor-like elements and hierarchical design procedure are adequately explained. Following that design procedure, a scissor-structural mechanism is created in order to satisfy the desired airfoil shapes, which have different camber lines with...
Yildirim, Alper; Kayran, Altan; Gulasik, Hasan; Çöker, Demirkan; Gürses, Ercan (2015-11-19)
In bolted flange connections, commonly utilized in aircraft engine designs, structural integrity and minimization of the weight are achieved by the optimum combination of the design parameters utilizing the outcome of Many structural analyses. Bolt size, the number of bolts, bolt locations, casing thickness, flange thickness, bolt preload, and axial external force are some of the critical design parameters in bolted flange connections. Theoretical analysis and finite element analysis (FEA) are two main appr...
Implementation of sensorless vector control drive with current position estimation
Filci, Tayfun; Ertan, Hulusi Bülent; Department of Electrical and Electronics Engineering (2016)
In this thesis, an algorithm will be developed and implemented online for the estimation of rotor position from the rotor slot harmonics in stator currents. Experiments will be done on an inverter driven induction motor hardware, and the performance of the position detection algorithm will be evaluated in comparison with commercial encoder outputs.
A novel approach to detection of some parameters of induction motors
Özlü Ertan, Hatice Gülçin; Colak, Baris (2007-05-05)
This paper describes a novel approach for offline stator leakage inductance and online stator resistance estimation that can be used for self-tuning of induction motor drives. The paper briefly describes the theory behind the approach. The proposed methods are experimentally tested on an industrial induction motor and also tested on a washing machine motor designed for variable speed operation. Test results are given and the robustness of the approach is illustrated.
Citation Formats
A. Jafari-Tabrizi, “Design and construction of an interferometric setup for dynamic measurement of clearances inside plain bearings,” M.S. - Master of Science, Middle East Technical University, 2017.