DRIVE MECHANICS

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Versione italiana
Academic year
2015/2016
Teacher
GIORGIO DALPIAZ
Credits
6
Didactic period
Secondo Semestre
SSD
ING-IND/13

Training objectives

The main aim of the course is to provide the methodologies and procedures for the dynamic analysis of machines and for the functional design of mechanical drives.

The acquired knowledge includes:
- Dynamic analysis and balancing of reciprocating machines;
- Equation of motion of one-degree-of-freedom machines;
- Torque-speed characteristics;
- Steady state conditions of mechanical systems;
- Flywheels;
- Run-ups and run-downs;
- Typologies and design of clutches and brakes;
- Pulley systems.

The main skill (the ability to apply acquired knowledge) will be the ability to choose by catalogue the most common components of mechanical drives, applying the correct criteria, methodologies and procedures, according to the functional requirements of the machine: electric motors and geared motors, clutches, brakes, flywheels, pulley systems.

Prerequisites

Courses of Mathematics, Physics, Theoretical Mechanics and Mechanics of Machines.

Course programme

The course lasts 48 hours, including lessons and exercises.

The course topics are the following.
DYNAMICS OF RECIPROCATING MACHINES: Dynamics of reciprocating machines. Balancing of reciprocating machines with one or four pistons.
TORQUE-SPEED CHARACTERISTICS: Dynamics of mechanical drives. Steady condition. Torque-speed characteristics for the motor and the user. Torque-speed characteristics of electrical motors.
FLYWHEELS: Types of steady conditions. Coefficient of speed fluctuation. Case of engines. Flywheel design.
TRANSIENT CONDITIONS: Transient duration of run-ups and run-downs. Choose of clutches and brakes.
CLUTCHES AND BRAKES: Typologies and design.
MOTOR REDUCERS: Criteria and choose of electrical motors and gear trains.
PULLEY SYSTEMS: Stiffness in flexible links. Pulley systems: fixed, movable and compound. Efficiency.

Didactic methods

Theoretical and practical lessons; the practical lessons concern numerical exercises on component design and catalogue selection.

Learning assessment procedures

Written/oral examination. It consists in three questions: two questions are theoretical and methodological, mainly aimed at assessing the knowledge; one question is a numerical exercise, mainly aimed at checking skills in the procedures for dimensioning and selection of components. The questions are carried out in writing and are immediately corrected and discussed orally. The rating assigned to each question refers to both written and oral performances. The final grade is the average of the votes on the three questions. To pass the exam you must achieve a minimum final grade of 18/30.

Reference texts

- Funaioli, A. Maggiore, U. Meneghetti, Lezioni di Meccanica applicata alle macchine. Prima parte: Fondamenti di meccanica delle macchine, Patron, Bologna, ISBN 88-555-2829-7, 2005 [Vol. I].
- Funaioli, A. Maggiore, U. Meneghetti, Lezioni di Meccanica Applicata alle Macchine. Seconda parte: Elementi di Meccanica degli Azionamenti, Patron, Bologna, ISBN 978-88-555-2948-8, 2007 [Vol. II].
- N. Bachschmid, S. Bruni, A. Collina, B. Pizzigoni, F. Resta, Fondamenti di meccanica teorica e applicata, ISBN: 88 386 6083-2, maggio 2003, McGraw-Hill Companies, S.r.l., Milano.