Search results for "bearings"
showing 9 items of 9 documents
Oil whip-induced wear in journal bearings
2014
Published version of an article in the journal: International Journal of Advanced Manufacturing Technology. Also available from the publisher at: http://dx.doi.org/10.1007/s00170-014-5805-8 This paper investigates the effect of oil whirl and oil whip in fluid film radial bearings due to possible metallic contact. The degree of metallic contact and thereby wear and tear between rotating shafts and bearing bushes is assessed by measuring electric currents through the oil film. The current as well as the voltage varied in accordance with the contact ratio between the shaft and bush in the fluid film radial bearing. The gauge signal thus indicates the degree of metallic contact based on the thi…
Condition Assessment and Analysis of Bearing of Doubly Fed Wind Turbines Using Machine Learning Technique
2023
Condition monitoring of wind turbines is progressively increasing to maintain the continuity of clean energy supply to power grids. This issue is of great importance since it prevents wind turbines from failing and overheating, as most wind turbines with doubly fed induction generators (DFIG) are overheated due to faults in generator bearings. Bearing fault detection has become a main topic targeting the optimum operation, unscheduled downtime, and maintenance cost of turbine generators. Wind turbines are equipped with condition monitoring devices. However, effective and reliable fault detection still faces significant difficulties. As the majority of health monitoring techniques are primar…
DYNAMIC BEHAVIOUR COMPARISON OF ROTATING SHAFT SUSPENDED BY TWO RADIAL ACTIVE MAGNETIC BEARINGS.
2012
MULTIBODY NUMERICAL SIMULATION OF AN INTERNAL COMBUSTION ENGINE WITH APPRAISAL OF THE WEAR DAMAGE
2009
An internal combustion engine at four times (Otto cycle) and three cylinders is simulated by multibody software MSC Visual Nastran. The bearings are simulated by means of the library of constraint of the software, putting a particular attention to bench bearings and to the lubrication conditions. The loads on the bench bearings and in both the feet and head of the connecting rods, are evaluated by dynamical simulation, so that the inertia loads can be take in account, considering the condition of the maximum couple furnished by the engine. By making the necessary hypothesis, the evaluation of the wear damage is executed by Bayer theory on zero wear, obtaining that a good expectation of life…
A review of diagnostics and prognostics of low-speed machinery towards wind turbine farm-level health management
2016
Abstract Large wind farms are gaining prominence due to increasing dependence on renewable energy. In order to operate these wind farms reliably and efficiently, advanced maintenance strategies such as condition based maintenance are necessary. However, wind turbines pose unique challenges in terms of irregular load patterns, intermittent operation and harsh weather conditions, which have deterring effects on life of rotating machinery. This paper reviews the state-of-the-art in the area of diagnostics and prognostics pertaining to two critical failure prone components of wind turbines, namely, low-speed bearings and planetary gearboxes. The survey evaluates those methods that are applicabl…
REDESIGN OF AN AUTO-LEVELLING BASE FOR SUBMARINE SEISMIC SENSOR
2011
The OBS (acronym of Ocean Bottom Seismometer) is a system to monitor the submarine seismic activity. To properly work, an OBS system needs a suitable auto-levelling base to maintain a fixed (horizontal) position during the measurement phases. In this work a new auto-levelling base for submarine seismic sensors has been designed. During the redesign process a preliminary phase of analysis of the state of art has been made. Afterwards, the technological solutions chosen by different manufactures have been critically analysed, and a full description of their functionalities, working principles and system performances has been carried out. Later, some innovative concepts have been proposed. Amo…
Parallel distributed compensation for voltage controlled active magnetic bearing system using integral fuzzy model
2018
Parallel Distributed Compensation (PDC) for current-controlled Active Magnetic Bearing System (AMBS) has been quite effective in recent years. However, this method does not take into account the dynamics associated with the electromagnet. This limits the method to smaller scale applications where the electromagnet dynamics can be neglected. Voltage-controlled AMBS is used to overcome this limitation but this comes with serious challenges such as complex mathematical modelling and higher order system control. In this work, a PDC with integral part is proposed for position and input tracking control of voltage-controlled AMBS. PDC method is based on nonlinear Takagi-Sugeno (T-S) fuzzy model. …
UiA Accelerated Life Time Bearing Test Rig – Test 1, 250 rpm
2020
Vibration data from an accelerated lifetime test of a bearing. Contains raw vibration data and shaft position data. The mean shaft speed is 250 rpm. Can be used for fault diagnosis and remaining useful lifetime estimation. Please see "00_ReadMe.pdf" file for more details. Update - 3 January 2022: This dataset is now updated to use floating point values for shaft position data, which gives a much more accurate description of the shaft position.
UiA Accelerated Life Time Bearing Test Rig – Test 3, Variable speed around 50rpm
2021
Vibration data from an accelerated lifetime test of a bearing. Contains raw vibration data and shaft position data. The mean shaft speed is 50rpm with a variation +- 40 rpm. Can be used for fault diagnosis and remaining useful lifetime estimation. Please see "00_ReadMe.pdf" file for more details.