Global ETD Search
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 68 for “"Gearbox"”.
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Acoustic Emission Signal Classification for Gearbox Failure Detection
… test stand of a rotating H-60 helicopter tail gearbox by using mathematical algorithms and visual inspection. Signs of fatigue crack growth were observed from the AE signals acquired from the result of the optimal number of clusters in a data set. Previous researches have determined the number …
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Computational intelligence for fault diagnosis in gearbox systems
… machine faults at the earlier stage. Damage in gearbox system is one of the most catastrophic failures in machineries. Any defects related to a gearbox will in influence the performance of an entire mechanical system. A reliable and efficient fault diagnosis system is required to reduce the …
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Design of a Proprioceptive Actuator Utilizing a Cycloidal Gearbox
… a high torque density motor paired with a gearbox with a high gear ratio for torque multiplication. Previously work has been done to design a proprioceptive actuator design that utilizes a planetary gearbox to create a modular low-cost actuator for legged robotics. The purpose of this …
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An Experimental Investigation of Churning Power Losses of a Gearbox
… study, load-independent (spin) power losses of a gearbox operating under dip-lubrication conditions are investigated experimentally. A family of final drive helical gear pairs from an automotive transmission is considered as the example for this investigation. A dedicated gearbox is designed and …
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Vibration Analysis of a Wind Turbine Multi-Stage Planetary Gearbox Incorporating a Flexible Body Component
… to represent the behavior of a wind turbine gearbox. This model is developed based on the overall parameters of a NORDEX N90 2.5MW wind turbine developed by a German company Nordex SE. This research focuses on the combination of a flexible body and a multibody dynamics analysis software. This …
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Experiment and Simulation of the Acoustic Signature of Fatigued-Cracked Gears in a Two-Stage Gearbox
… development of a health monitoring system for gearbox transmissions. This was accomplished by developing and understanding a two-stage gearbox computer model that emulates an actual gearbox test rig. The computer model contains actual gearbox geometry, flexible shafts, bearings, gear contact …
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Analysis of a Split-Path Gear Train with Fluid-Film Bearings
… for use in helicopter transmissions and marine gearboxes. The goal in these systems is to equalize the torque in each path as much as possible. There are other gear trains where the operator intends to hold the torque split unevenly. This allows for control over the gearbox bearing loading which …
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Wind tunnel testing of a nacelle bypass concept for a quiet supersonic aircraft
… sonic boom signature of the vehicle, the engine gearbox and protuberances create a highly complex 3-D flow in the annular bypass region. To better understand the 3-D flow features, an approximately 1/6th engine model was tested in a newly constructed 11.1 inch diameter axisymmetric test section …
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Control of Vibration Systems with Mechanical Motion Rectifier and their Applications to Vehicle Suspension and Ocean Energy Harvester
… of a novel mechanical motion rectifier (MMR) gearbox that uses mechanical one-way clutches in both systems. The flow is from the control for common system to the control design for a specifically designed system. In the thesis, active (model predictive control: MPC), semi-active (Skyhook, …
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High efficiency pulse motor drive for robotic propulsion
… low power hardware demonstration without the gearbox transmission shows that the pulse drive achieves an energy efficiency of 80% compared to an efficiency of 50% achieved in the conventional direct drive where an electromechanical actuator is driving a viscous load equal to its own motor …
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Design and manufacturing analysis of a window shading system
… a manufacturing cost analysis and redesign of a gearbox assembly for the window shading system. This is a logical next step in the product's development. An estimate for the assembly time for the current version of the gearbox assembly is found. The parts are then redesigned for improved assembly …
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Modeling and control of a wind turbine as a distributed resource in an electric power system
… wind turbine system consisting of a rotor, a gearbox and a three-phase ac generator was developed, and it was used as a basis for the design of a controller for the wind turbine. The wind turbine (rotor and gearbox) transfer function was derived and its performance was studied using the MATLAB …
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Intelligent fault diagnosis of gearboxes and its applications on wind turbines
… and fault diagnosis systems for wind turbines. Gearbox, as one of the highest risk elements in wind turbines, is responsible for smooth operation of wind turbines. Moreover, the availability of the whole system depends on the serviceability of the gearbox. This work presents signal processing …
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Unobtrusive integration of magnetic generator systems into common footwear
… small electrical generators through a stepped-up gearbox. A one-way clutch mechanism was used to transmit torque to the gearbox. This allowed for additional spin following the initial impact of a step, also preventing lockup due to rotary inertia in the gears. The entire generator system was …
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In situ blocked force measurement in gearboxes with potential application for condition monitoring
The use of gearboxes for power transfer is widespread throughout industry. However, machines today are operating at higher speeds than ever before and gear failures such as wear or tooth breakage is serious and legitimate concerns. Incipient fault detection in gears has thus become the subject of …
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The electric vehicle experiment : developing the theoretical model for 2.672
… increased as the torque increased. The gearbox and controller efficiencies were modeled as constants in the simplified model since the manufacturer's literature only quoted one value for the gearbox and since there was a lack of detailed information about the controller. The overall …
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Electrical instrumentation of a contra-rotating propeller drive system
… a single motor to spin both propellers without a gearbox. The rotor is attached to one propeller and the stator to the other. It relies on the propellers to balance rotational speeds of the two shafts. Non-intrusive Load Monitoring (NILM) techniques were used to diagnose performance of the …
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Design, Test, and Evaluation of a High Powered 4 DOF Prosthetic Leg for Transfemoral Amputees
… roll. In addition, a yaw motor with a planetary gearbox combination is used for yaw actuation providing up to 21~Nm of torque. The prosthesis was designed to accommodate a variety of activities including, but not limited to, walking, running, and stair climbing.
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Design of a high torque, lightweight clutch for use in an exoskeleton to augment human running
… of radial, ratcheting clutch plates, a planetary gearbox, and a novel mechanical decoupling concept to meet the design requirements.
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Early Damage State Criterion from a Fault-Seeded Helicopter Gear Using Acoustic Emission and Neural Networks
… response to five failures since 2008 of the tail gearbox of multiple models of Sikorsky's H-60 helicopter, acoustic emission (AE) data collected from a rotating gearbox test stand at the Naval Air Station in Patuxtent River, MD, was used to monitor the initiation and propagation of a flaw from an …
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