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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 22 for “"ball bearing"”.
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Numerical Modelling of Ball Bearing Stiffness to Predict Contact Stress Caused by Vibration Induced Gapping
The ball bearings that form part of mechanisms in space applications are subjected to vibrations. The result of these vibrations is gapping between the rings of the bearing. This gap allows collisions of the ball with the races, which produce high contact stresses. These high stresses can cause …
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Analysis of the Tribological Behaviour of Stainless and Ball Bearing Steels Sliding in the Presence of Sulphur Extreme-Pressure Additives
… material was used in turn for the upper (driven) ball and the lower (clamped) balls. The tribological behaviour of stainless and ball bearing steel were studied under extreme pressure and/or anti-wear lubrication conditions in the presence of sulphur and sulphur containing additives, in order to …
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A study on the response of a target plate to a foreign object placed at various depths in a cylindrical Charge
… that consist of readily available items, such as ball bearings, nails or glass. The versatile nature of IEDs makes it very difficult to conduct a generalised study on their impact. One major challenge in IED research is the wide range of potential IED geometries, sizes, explosion types and …
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Dynamic Performance of Turbocharger Rotor-Bearing Systems
… measure dynamics of differing turbocharger rotor bearing systems and to develop a coupled rotor-cartridge model for the ball bearing rotor system to corroborate the experimental and analytical results. The ball bearing rotor is supported by an angular contact ball bearing cartridge. In order to …
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The response of a structural target to oblique fragment and blast loading
… to nails, pieces of glass, nuts, bolts and ball bearings [2]. Fragments, released upon the detonation of the device, are propelled outwards at high velocities and different directions with devastating effects on structures or human lives. Investigating the fragment effect is vital to develop …
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The Response of a Structural Target to an Explosive Charge Incorporating Foreign Objects: A Numerical Study
… structure. The explosive, the container and the ball bearings were simplified representation of the key components of an improvised explosive device (IED). The numerical study was aimed at studying the ball bearing interaction with blast when incorporated into charge, and was based on previous …
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A vibration analysis of a bearing/cartridge interface for a fretting corrosion study
The relative motion between a ball bearing outer race and the bearing's cartridge was investigated. The investigation was part of a larger program, the objective of which is to examine the important parameters influencing fretting corrosion in rolling element bearings. The bearing examined was a …
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Reaction Wheel Ball Bearings Microvibration Source Characterisation
… misalignments and imperfections affecting the ball bearing components, are some of the main causes that generate microvibrations disturbances onboard, affecting the pointing stability of the satellite line-of-sight. The work presented in this thesis aims to characterize the RW disturbance …
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The influence of cylindrical charge geometry on the velocity of blast-driven projectiles in one dimension
… the velocity of a 5 mm diameter stainless steel ball bearing. The ball bearing was half-buried and centrally placed on the at face of a cylindrical charge which was detonated centrally on the opposite face. The geometric parameters of interest were the charge diameter and the charge aspect ratio …
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Predicting the dynamic behavior of rotor systems on ball bearings
… dynamic behavior of a rotor system supported by ball bearings are presented. Two computer programs were developed. The first uses a transfer matrix technique to compute rotor natural frequencies as a function of bearing stiffness. The second is a bearing analysis program which is used to …
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The vibration of instrument ball bearings in a controlled environment and the effect of the resulting fretting corrosion on bearing torque
… between two flat specimens or between a single ball and a flat plate held in contact by a normal force. There are a number of interrelated influencing factors involved in fretting corrosion including: the vibration frequency and amplitude, the environmental conditions, the characteristics of the …
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Biocompatibility of an implantable ophthalmic drug delivery device
… delivered by periodic injection into the eyeball. To avoid the risks and complications associated with this method, several implantable, timed release devices have been investigated to deliver these drugs directly to affected areas. Draper Laboratory and Massachusetts Eye and Ear Infirmary …
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A microcomputer-based data acquisition system for diagnostic monitoring and control of high-speed electric motors
… motors. The system was utilized in high-speed bearing life-testing, using an electric motor as a test vehicle. Bearing vibration and outer race temperature were continuously monitored for each ball bearing in the motor. In addition, the stator winding and motor casing temperature were …
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Design, and characterisation of impact based and non-contact piezoelectric harvesters for rotating objects
… beam mounted at each end of the tube. A ball bearing that has the freedom of movement between the two ends of the tube generates an impact force on the piezoelectric structures due to the effect of the centripetal force. The impact based piezoelectric harvester is modelled and its …
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Mammography machine compression paddle movement andobserver performance analysis
… is delayed from 5 to 10 s. In paper 3 all metal ball bearings shown increased in diameters and the range of magnification varied from 1.04 to 1.21. T-test results shown that there was a significant difference (p < 0.05) in the ball bearing diameters between the intensity thresholding and the edge …
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Fault detection in manufacturing equipment using unsupervised deep learning
… machines, two plasma etchers, and one spinning ball bearing. In our tests, the model is able to detect over 80% of faults in all cases without the use of labeled data and without hyperparameter changes between applications. We also find that the model is capable of classifying different failure …
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The measurement of the running torque of oil and grease lubricated instrument ball bearings under combined radial and axial loads
… on the operating characteristics of instrument bearings, most were conducted at two rpm or less and with thrust load only. A study by H.H. Mable tested the running torques of radially loaded bearings from 1,000 to 40,000 rpm. The purpose of this investigation was to study the running torques of …
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Assembly Optimization for Double Row Ball Bearings
… on optimal assembly methods for double row ball bearings. As with common single row bearings, double row ball bearings, consist of four general components, namely, an inner ring, an outer ring, a complement of balls and a cage or retainer to keep the balls separate. Unlike single row …
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Performance prediction model for positive displacement helical screw flowmeters
… constant friction, impulse energy losses and ball bearing friction, respectively.<br/><br/>This model was applied to a twin-screw type displacement flowmeter which uses two helical rotors which form separate pockets and allow the flow-rate of the fluid to be measured. Based on the general …
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Prediction and Measurement of the Frictional Torque Characteristics of Radially and Axially Loaded Radial Cylindrical Roller Bearings
… design and improvements in performance of roller bearings have resulted in an increased power transmission whilst size and spatial requirements have been reduced. Radial cylindrical roller bearings have followed this trend and due to their high performance characteristics (such as high loading …
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