88153 - Mechanical Actuators P

Course Unit Page

SDGs

This teaching activity contributes to the achievement of the Sustainable Development Goals of the UN 2030 Agenda.

Quality education Industry, innovation and infrastructure

Academic Year 2021/2022

Learning outcomes

The course provides the fundamentals for the kinematic and dynamic analysis of mechanical systems and machines.

 

Course contents

1. Dissipative actions in machine components.

Kinetic friction and Static friction. Wear: Reye hypothesis; distribution of contact pressure.

Rolling friction: applications of rolling contact. Rolling bearings: choice and applications.

Lubrication: introduction to lubricated kinematic pairs; hydrodynamic lubrication; hydrostatic lubrication.

2. Functional analysis of power transmissions.

Gears: involute profiles; geometrical parameters; cylindrical spur gears and helical gears; force transmission; bevel gears; worm gears. Gear trains: ordinary gears; epicyclic trains; differential trains. Change gears. Transmission of motion between two shafts: belt drives; transmissions with chains.

3. Functional analysis of devices connecting two shafts.

Brakes: classification; block brakes; brake torque.

Clutches: classification; disk friction clutches; conical friction clutches.

Couplers: classification; solid couplings; Oldham’s joint; Hooke's joint; constant velocity joints; flexible joints.

4. Dynamic analysis of machines.

Fundamental equation of dynamics: kinetic energy; energy equation. Metodi energetici per lo studio della dinamica di sistemi di corpi rigidi. Dynamics of the slider crank mechanism: calculation; methods for the compensation of inertia actions. Dynamics of the four-bar linkage. Rotor dynamics: static and dynamic imbalance.

5. Mechanical vibrations.

Mass-spring-damper model. Free and forced vibration response of one degree-of-freedom system. Free and forced vibration response of two dof systems. Applications: reduction of the force to the ground; reduction of vibrations generated by a vibrating ground; mass damper; torsional vibrations of shafts.

Readings/Bibliography

1. FUNAIOLI E., MAGGIORE A., MENEGHETTI U.,

Lezioni di Meccanica Applicata alle Macchine. Prima parte: Fondamenti di Meccanica delle Macchine, ed. Pàtron, Bologna.

2. Callegari M., Fanghella P., Pellicano F., Meccanica Applicata alle Macchine, CittàStudi, 2013.

3. Copy of the slides.

Teaching methods

The course is based on lectures dealing with the theoretical aspects of the course topics and application examples.

Class attendance, although not mandatory, plays a fundamental role in the learning and evaluation process.

Assessment methods

The final examination consists of questions that aim to ensure the acquisition of knowledge expected by the course program and to assess the achievement of learning objectives.

Both oral and written questions might be proposed during the examination.

The ability of the student to articulate and correctly explain the answers to the questions, has a fundamental weight in the attribution of the final marks.

In accordance with the Art. 16 of the University Didactic Regulations, if a positive grade does not meet the expectations of a student, the latter may ask its cancellation and the repetition of the examination. The instructors of the course comply with the following rules:

  • a student may request the cancellation of a positive grade only within the date of the examination;
  • a cancelled positive grade can in no way be recovered;
  • a student may request the cancellation of a positive grade at most once.

Teaching tools

Blackboard, PC.

On the E-learning Platform (https://virtuale.unibo.it/ ), students may find: slides of the course lectures; exercises and application examples.

Office hours

See the website of Alessandro Rivola

See the website of Vincenzo Parenti Castelli

See the website of Andrea Gamberoni