This Bachelor of Science thesis consists of an efficiency evaluation and creation of atheoretical model for an Atlas Copcos epicyclic gearbox. The thesis starts with atheoretical chapter containing the fundamentals of epicyclic gearing and the build of thespecific gearbox investigated. The following chapter contains former testing and theoryof power losses in a gearbox. After the theory is explained the next chapter containstesting, compromises and assumptions during testing and also results from the testing.The next chapter explains the Matlab calculation program based on the theory andmeasurements. Finally the model is validated against reference a reference model andagainst real gearbox measurements followed by some closing conclusions. The finalmodel calculates the efficiency rather well and has a linear difference. The difference isstatic since some losses have been left out, it can be fixed with an empirical correctionfactor which corrects the values and predicts an acceptable efficiency. The correctionfactor for the surface roughness also decreases the difference.

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Thesis (Ph. D.)--Ohio State University, 2005. / Title from first page of PDF file. Includes bibliographical references (p. 227-233).

The conversion from low speed to high speed and vice versa in various forms, including rotary and linear motion, is a requirement for a wide range of applications. For example, wind power generation requires a conversion of low speed rotation of turbine blades to high speed generator rotation, and ocean wave power generation is achievable by conversion of low speed linear motion to either high speed rotation or high speed linear motion. Mechanical gearboxes, hydraulic and pneumatic actuators are commonly used to achieve these conversions. However, these systems suffer from reliability issues, high maintenance requirements, noise, and lack of overload protection. As an alternative, electromagnetic actuators overcome most of the issues related to the mechanical, hydraulic and pneumatic mechanisms. However, magnetic shear stress is constraint by current density and magnetic saturation. Recently, magnetic gearboxes have been proposed, which rely only on magnetic loading. They provide speed and force conversion like their mechanical counterparts, but without thermal constraints (current density limits). Unlike mechanical gears, magnetic gear contact-less operation enables it to operate without lubrication and with low noise, and higher efficiency. Its reliance on magnetic loading also provides overload protection. This dissertation focuses on investigating two new types of magnetic gears; first a magnetically-geared lead screw is proposed, which converts a low speed linear motion to a high speed rotary motion. The proposed actuator is a combination of two previously proposed actuators, the linear magnetic gear and the magnetic lead screw. Unlike these two topologies, the translator part of the proposed magnetically geared lead screw is made entirely of low-cost ferromagnetic steel. Therefore, the translator stroke length can be long without requiring more magnet material. In the second part of this dissertation, an axial flux magnetic gear is proposed that has an integrated outer stator. This axial flux magnetically-geared motor is unique in that the stator shares the high-speed rotor with the magnetic gear, so there is no need for a separate rotor. The high speed and low speed rotors use a flux-focusing typology. The stator is mounted outside the axial flux magnetic gear. This makes the design mechanically less complex. It also enables the stator to be cooled more easily. In the last part of this dissertation, analytical-based models are proposed for a linear permanent magnet coupling and magnetic lead screw. These models help to find the upper bound of the similar devices, which require a scaling analysis. Numerical methods like finite element analysis are accurate and effective enough for modeling various electromechanical and electromagnetic devices. However, these simulations are usually computationally expensive; they require a considerable amount of memory and time, especially when considering 3D finite element simulation. The proposed analytical models offer exact field solution while significantly reducing the computational time. Detailed analysis of two magnetic gears is given under their corresponding chapters. Preliminary experimental results are also provided. The analytical-based model is presented and verified by FEA results. A summary of research contributions and future works is outlined.

Thesis (Ph. D.)--Marquette University, 2009. / Access available to Marquette University only. Available for download on June 17, 2010. Robert J. Stango, Nicholas J. Nigro, Stephen Heinrich, Vikram Cariapa, Shuguang Huang, Advisors.

Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 309-316).

No description available.

The investigation of numerical methods for modelling the mechanism properties ofinvolute spur gears in mesh, over the mesh cycle, forms the major part of this thesis.Gearing is perhaps one of the most critical components in power transmission systemsand the transmission error of gears in mesh is considered to be one of the main causes ofgear noise and vibration. Numerous papers have been published on gear transmissionerror measurement and many investigations have been devoted to gear vibration analysis.There still, however, remains to be developed a general Finite Element Model capable ofpredicting the effect of variations in rigid body gear tooth position, in which the criticalstage is the prediction of gear behaviour with profile modifications (including tip-relief).In this thesis, FEA results have been obtained by using various techniques including: (a)adaptive re-mesh with contacts using quad (2D) and brick (3D) elements and (b) theelement birth and death option. Tooth profile modifications can affect the behaviour ofthe gear meshing including the T.E., ratio of local deformation and load-sharing ratioresults, etc, providing an alternative method for gear design. In the high order end, theelastic strains of the gear-shaft system have also been investigated. The results in thisthesis have shown the potential for using strain-vibration relationships to monitor orcontrol the transmission system.The investigations have also included some analysis with non-metallic gears, anapplication area that is rapidly growing. The results achieved here are at a fundamentalstage, and further research would necessitate applying a coupled field analysis (structuraland thermal).

Thesis (M.S.)--California Polytechnic State University, 2009. / Title from PDF title page; viewed on March 2, 2010. Major professor: Xi Wu, Ph.D. "Presented to the faculty of California Polytechnic State University, San Luis Obispo." "In partial fulfillment of the requirements for the degree [of] Master of Science in Mechanical Engineering." "June 2009." Includes bibliographical references (p. 90-91).

No description available.