A research report submitted in fulfilment of the requirements for the degree of Master’s in Engineering to the Faculty of Engineering and the Built Environment, School of Mechanical, Industrial and Aeronautical Engineering, University of the Witwatersrand, Johannesburg, 2018 / The automotive industry is experiencing a major transition with regards to powertrain where the traditional internal combustion engine is being replaced by hybrid or all-electric solutions. As a result of this transition, many powertrain engineering firms, such as Integral Powertrain, are required to adapt or develop tools to improve the quality and time to respond to the rapid increase in new electric motor enquiries. This paper details the development of the foundations of a software tool (AIEED) used to improve the time and quality of response to new motor enquiries. The foundations of the AIEED tool are built into a Microsoft Excel document which contains the necessary logic required to convert customer requirements data into geometrical design data. A series of macros are included in the tool which allow for the automated generation of a first-level computer-aided design (CAD) model of the motor, including the following components; stator, windings, rotor, magnets, housing and cover. The CAD models, which serve to improve the quality of response to new motor enquiries and provide a basis for further detailed development, are generated on the CATIA V5 design platform. In addition, the tool makes use of the CAD model to determine the estimate cost of the unit based on average material costs per unit mass defined in the materials database stored in the tool. It is estimated that the AIEED tool reduces the response time to new motor enquires by 75%. Certain assumptions and limitations have been applied such that the foundations of the tool only include support for the following motor specifications: Surface Permanent Magnet Alternating Current cylindrical radial flux motors (external stator and internal rotor). • The units are designed for 3-phase supply. • The winding configuration is limited to concentrated double layer option. • Parallel tooth, arc-bottom, semi-closed stator slot profiles. • Arc-shaped radially magnetised surface magnet rotor configuration option. A simple data verification filter is applied to minimise the potential for invalid inputs. However, a full validation and verification process is recommended for future work. In addition, it is recommended that the tool be expanded to support additional motor types and specifications as well as package the foundations into a single, easy-to-use utility. / XL2019

No description available.

Thesis (Ph. D.)--University of Hong Kong, 2006. / Title proper from title frame. Also available in printed format.

Thesis (Ph.D.)--University of Hong Kong, 1998. / Includes bibliographical references. Also available in print.

Manufactured products, such as furniture, laminate flooring, and large signs, are very labour intensive, time-consuming, and costly to produce as they require multiple coating and cutting operations on a series of independent machines, which can each introduce manufacturing errors between the tools and the work piece. By combining the processes of printing and milling, printing integrated manufacturing has the potential to eliminate some of these steps, significantly reduce errors, and preserve resources. Inkjet printing is an ideal method for both image transfer and coating operations due to its non-contact method of directly depositing various types of fluid onto a substrate. With improved positioning accuracy and droplet miniaturisation, inkjet printing could even be used for future applications like the mass-production of MEMS devices, which are traditionally fabricated with a highly complex process involving photolithography. This thesis presents the integration of a Xaar 126 inkjet printing system with an existing industrial flatbed CNC router to develop a combined printing and cutting system. This integration required modification to the overall system through mechanical, electrical, and software means to the existing 3-axis CNC milling system. A secondary z-axis was installed onto the router gantry for positioning of the printheads relative to the substrate, which required development of a separate homing routine to consistently position the printheads to a specified location. Based on the identified frequency response of the machine, a loop-shaping controller was designed for improved y-axis positioning, which is one of the main contributions to droplet placement accuracy. This resulted in a continuous motion tracking accuracy within ±20.2 µm at 250 mm/sec along a print pass (measured by 1.22 nm resolution linear encoder), which is significantly better than the industrial benchmark of ±100 µm. Extensive image processing and calibration methods were utilised on various substrate preparations of paper, wood, and coatings, to demonstrate the capability of the printing system and quantify the quality of print resolution. Calibration results tested on high-gloss Hewlett-Packard paper showed that the swath angle could be aligned within ±1°. Also, bidirectional printing could be used to reduce print time by at least 15% in multi-colour printing with comparable droplet placement accuracy to unidirectional printing. The inkjet system was successfully used to print custom designs on paper and, to a certain extent, on medium density fibreboard at a feed rate of 250 mm/sec. It was difficult to achieve satisfactory image results on wood, as the wood or paint grain was visible through the ink. Thus, without a white pre-coat, the printed image would appear significantly darker than the original image, even after adjusting the image in a graphics editor. For better quality results, it is recommended that greyscale printheads be implemented for greater resolution and a UV system should be investigated for more versatility in printing on different substrates such as glass, metals, plastics, and ceramics.

Manufactured products, such as furniture, laminate flooring, and large signs, are very labour intensive, time-consuming, and costly to produce as they require multiple coating and cutting operations on a series of independent machines, which can each introduce manufacturing errors between the tools and the work piece. By combining the processes of printing and milling, printing integrated manufacturing has the potential to eliminate some of these steps, significantly reduce errors, and preserve resources. Inkjet printing is an ideal method for both image transfer and coating operations due to its non-contact method of directly depositing various types of fluid onto a substrate. With improved positioning accuracy and droplet miniaturisation, inkjet printing could even be used for future applications like the mass-production of MEMS devices, which are traditionally fabricated with a highly complex process involving photolithography. This thesis presents the integration of a Xaar 126 inkjet printing system with an existing industrial flatbed CNC router to develop a combined printing and cutting system. This integration required modification to the overall system through mechanical, electrical, and software means to the existing 3-axis CNC milling system. A secondary z-axis was installed onto the router gantry for positioning of the printheads relative to the substrate, which required development of a separate homing routine to consistently position the printheads to a specified location. Based on the identified frequency response of the machine, a loop-shaping controller was designed for improved y-axis positioning, which is one of the main contributions to droplet placement accuracy. This resulted in a continuous motion tracking accuracy within ±20.2 µm at 250 mm/sec along a print pass (measured by 1.22 nm resolution linear encoder), which is significantly better than the industrial benchmark of ±100 µm. Extensive image processing and calibration methods were utilised on various substrate preparations of paper, wood, and coatings, to demonstrate the capability of the printing system and quantify the quality of print resolution. Calibration results tested on high-gloss Hewlett-Packard paper showed that the swath angle could be aligned within ±1°. Also, bidirectional printing could be used to reduce print time by at least 15% in multi-colour printing with comparable droplet placement accuracy to unidirectional printing. The inkjet system was successfully used to print custom designs on paper and, to a certain extent, on medium density fibreboard at a feed rate of 250 mm/sec. It was difficult to achieve satisfactory image results on wood, as the wood or paint grain was visible through the ink. Thus, without a white pre-coat, the printed image would appear significantly darker than the original image, even after adjusting the image in a graphics editor. For better quality results, it is recommended that greyscale printheads be implemented for greater resolution and a UV system should be investigated for more versatility in printing on different substrates such as glass, metals, plastics, and ceramics.

Thesis (M. Phil.)--University of Hong Kong, 2002. / Includes bibliographical references.

published_or_final_version / Industrial and Manufacturing Systems Engineering / Master / Master of Philosophy

No description available.

No description available.