DE6302                    MECHANICS OF MACHINES

Level 6                                             Credits 15                                            Version July 2010

LEARNING TIME

RECOMMENDED PRE-REQUISITE

DE5302 Strengths of Material 1

RECOMMENDED CO-REQUISITE

Nil

AIM/PURPOSE

To develop understanding to solve complex problems involved with machinery dynamics such as power transmission, balancing, noise, and lubrication systems.

LEARNING OUTCOMES

On successful completion of this course, the student should be able to:

1.            Identify dynamic loads in rotational equipment and explain the need for balance and how it is achieved.

2.            Analyse mechanical systems to determine natural frequencies and the effects of resonance.

3.            Explain acoustic term and solve for noise level and noise attenuation in an engineering environment.

4.            Explain gear terminology. Solve velocity ratios and forces in gear systems.

5.            Analyse power transmission components for life, force and application.

INDICATIVE CONTENT

• Determine Static and dynamic balance and out of balance forces,
• Balancing machines, balancing reciprocating machines (descriptive)
• Vibration isolation.
• Free and forced vibration, self excitation, natural frequency, resonance, periodic motion, simple harmonic motion,
• Transverse vibration, whirling of shafts, Dynamic deflection and stress of shafts
• Torsional vibration (limit two inertia on shaft of two different section)
• Noise measurement, and terms,
• Noise control and transmission.
• Inverse square law, sound fields, noise addition
• Gear types, terms and definitions, pressure angle, gear tooth force, shaft loads, torque, power,
• Epicyclic gears, gear ratios.
• Clutches (types and calculations),
• Brakes, short block, self energizing band,
• Chain and belt drives, Tensions, shaft loads, selection for catalogs
• Bearings; Plane (dry), Rolling element (L10 calculations and selection from catalogs), and bearing lubrication.
• Flywheels, turning moment diagram, referred inertia through gear ratio
• Machines, MA, VR, efficiency, Limiting Efficiency, Machine law.