| CODE | TET2010 | ||||||||||||
| TITLE | Mechanisims for Technology | ||||||||||||
| UM LEVEL | 02 - Years 2, 3 in Modular Undergraduate Course | ||||||||||||
| MQF LEVEL | 5 | ||||||||||||
| ECTS CREDITS | 4 | ||||||||||||
| DEPARTMENT | Technology and Entrepreneurship Education | ||||||||||||
| DESCRIPTION | Mechanisms is the study of mechanical structures in motion where emphasis is placed on the dynamics of the system. This study unit presents mechanisms such as levers, linkages, cams, gears, pulleys, belt drives and clutches that can be used to design different types of motion for example linear motion, rotary motion, oscillating and reciprocating motion, or the transmission of motion. This unit also covers the physics underlying simple machines and analyzes some abstract parameters of these machines such as mechanical advantage, velocity ratio and efficiency that would enable a designer to compare and evaluate different designs. It also presents typical applications within commonly found mechanical systems and discusses some procedures necessary for the correct operation and maintenance of machines for example lubrication. Study-Unit Aims: 1. Develop the student's knowledge of rotational motion and mechanics of machines; 2. Develop an understanding of mechanical problems and apply mathematical techniques to their analysis; 3. Introduce the basic devices and components of power transmission systems including gears, pulleys, cams, belts and clutches. Learning Outcomes: 1. Knowledge & Understanding: By the end of the study-unit the student will be able to: 1. Knowledge and understanding of mechanical system: • Demonstrate that mechanical systems may contain input, process and output; • Analyse and describe mechanisms in terms of input, process and output. 2. Transmission of motion (a) levers and linkages: • Demonstrate that levers can be used to change force and movement; • Describe, and explain the three classes of lever and their applications; • List design factors for levers; • Explain and use in calculations the terms load, effort and fulcrum; • Calculate the mechanical advantage (MA), velocity ratio (VR) in a simple lever system; • Describe the term moments, equilibrium and use in calculations; • Demonstrate that levers and linkages are assembled in a specific way to produce a particular output, i.e. reverse motion links, push-pull links, rotary, linear links, bell cranks and parallel links. 3. Transmission of motion (b) pulleys and gear systems: • Explain simple pulley system and calculate speed and velocity ratios; • Describe design factors of belt and pulley transmission systems; • Explain chain and sprocket systems and calculate speed and velocity ratios; • Describe design factors of chain and sprocket systems; • Explain spur gears and calculate simple gear ratios and transmission speed; • Calculate driver/driven speeds and rotational directions in simple and compound gear systems; • Describe the design factors of gear transmission systems; • Describe the types of factors involving the choice of the following gears for practical applications: spur, bevel, helical, worm, crown wheel, rack and pinion; • Demonstrate domestic and commercial uses for flat, vee and toothed belts; • Describe standard systems to maintain the tension in drive belts; • Calculate the Mechanical Advantage (MA), Velocity ratio (VR) and Efficiency of simple machines. 4. Transmission of motion (c) cams, cranks and sliders: • Demonstrate practical examples of the use of linear, rotary, oscillating and reciprocating motion; • Describe and explain the use of cam shapes such as pear, circular, heart, snail and eccentric and cam followers such as point, roller, flat and plain; • Describe the Geneva mechanism; • Explain and describe the terms cycle, dwell, rise, fall and stroke; • Describe, compare and select appropriately, crankshafts, crank/slider mechanisms, rack and pinion, ratchet and pawl as simple methods of converting linear motion to rotary motion and vice versa. 5. Transmission of motion (d) inclined plane and screw threads: • Demonstrate that a screw thread is an inclined plane wrapped around a cylinder and recognise associated terms, i.e. pitch, thread form, lead, root, and crest; • Describe and demonstrate applications for ‘v’, square and buttress screw threads. 6. Fixings and couplings: • Explain methods of fixing wheels and pulleys to shafts, i.e. keyways, cotter pins, splined shafts, and grub screws; • Explain and demonstrate the use standard fittings, i.e. nuts and bolts, washers, screws, pop rivets, and use of adhesives. 7. Bearings and lubrication: • Explain the use of basic types of bearings: plain, roller, ball and thrust; • Explain the use of common bearing materials, i.e. bronze, cast iron, and nylon; • Demonstrate that friction in mechanical systems can be affected by choice of materials, i.e. low frictional properties of nylon and brass; • Demonstrate that lubrication between two surfaces will reduce friction and wear; • Explain that the property of viscosity in oil and how this can be affected by temperature change. Grading of lubricants using a numbering system (SAE). 8. Control of motion: • Explain the function of brakes, comparing the method of operation and effectiveness of hydraulic, disc, drum and cable operated brakes; • Describe appropriate applications for each type of brake; • Explain the function of clutches, describing and giving practical applications of single plate clutches, dog clutches and centrifugal clutches. 2. Skills: By the end of the study-unit the student will be able to: 1. Apply knowledge of mathematics, science, technology and engineering (STEM), to analyse and solve mechanical systems involving gears, pulleys, cams, etc.; 2. Design a system or process to meet desired needs within realistic constraints; 3. Work in multidisciplinary teams; 4. Design and manufacture mechanical artifacts or models for educational purpose. Main Text/s and any supplementary readings: - W.Bolton, 2006, Mechanical Science, 2nd Ed.,Wiley-Blackwell. - Hannah J. and Hillier M.J., 1999, Mechanical Engineering Science, 3rd Ed., Prentice Hall. - William F. Riley, Leroy D. Sturges 1966, Engineering Mechanics, 2nd Ed., John Wiley. - Neil Sclater, 2001, Mechanisms and Mechanical Devices Sourcebook, 5th Ed., McGraw-Hill. |
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| ADDITIONAL NOTES | Pre-requisite Study-units: TET1008; TET1013. Co-requisite Study-unit: TET2008. |
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| STUDY-UNIT TYPE | Lecture and Tutorial | ||||||||||||
| METHOD OF ASSESSMENT |
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| LECTURER/S | Carmel Navarro |
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The University makes every effort to ensure that the published Courses Plans, Programmes of Study and Study-Unit information are complete and up-to-date at the time of publication. The University reserves the right to make changes in case errors are detected after publication.
The availability of optional units may be subject to timetabling constraints. Units not attracting a sufficient number of registrations may be withdrawn without notice. It should be noted that all the information in the description above applies to study-units available during the academic year 2023/4. It may be subject to change in subsequent years. |
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