Apr 17, 2024
2020-2021 Course Catalog
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# ELT 143 - Mechanisms

Credits: 3
Lecture Hours: 2
Lab Hours: 2
Practicum Hours: 0
Work Experience: 0
Course Type: Voc/Tech
This introductory course covers linear and angular displacement, velocities, and accelerations of linkages, gear trains, and belt and friction drives. Topics include vectors, simple and complex machines, and toggle and intermittent motion mechanisms.
Competencies
1. Rank kinematics in relation to physics, kinetics and statics
2. Analyze four bar as well as other mechanisms
1. Describe and differentiate between a crank, lever arm, rocker arm, bell crank, constrained and locked kinematic chains
2. Determine the limits of travel of a four link mechanism
3. Demonstrate proficiency in vectorial and graphical vectorial math
1. Resolve vectors into components that might not be perpendicular
2. Perform vectorial subtraction using the concurrent method of subtraction.
3. Solve graphic vectorial equations
4. Analyze angular and lineal displacements, velocities and accelerations
5. Analyze gear train, belt and pulley, and cam problems
6. Discuss epicyclic gears, reverted gears, coupling methods, and intermittent-motion drives
7. Discuss assorted clutches, brakes, couplers, constant velocity drives, harmonic drives, ratchets and geneva mechanisms
8. Analyze gear train, spring, pulley, hoist and joint mechanisms
1. Calculate and measure torque and angular velocity ratios for simple, internal, reverted, planetary, helical, bevel and differential gearing arrangements
2. Calculate and measure rack and pinion, worm and wheel, block and screw arrangement parameters
9. Assemble mechanisms
1. Gear trains
2. Spring mechanisms
3. Pulley and hoist mechanisms
4. Joint mechanisms
5. Practice proper techniques for handling and assembling gears, bearing plate 1 assemblies, shafts, collars
10. Relate gear terms: diametral pitch, pitch diameter and pitch
1. Use mechanical terms; pitch circle, center distance, pinion, pitch radii, involute gear, root radius and lands
2. Use mechanical terms; addendum, dedendum, whole depth, working depth, chordal thickness, circular thickness, pressure angle, module, fellows stub tooth and compound gear trains
11. Analyze mechanical devices
1. Construct and take measurements on spring mechanisms, toothed belts, disk drives, rotary cams, universal joints, and crossed helical gears
2. Construct and take measurements on inertial configurations, pulley blocks, chain drives and differential or chain hoists

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