B4935 - Fluid Power Actuation M

Learning outcomes

At the end of the course, the student acquires an engineering knowledge of hydraulic drive systems, widely known as Fluid Power Systems. In particular, the student acquires: theoretical and practical expertise in mechanical actuation systems with fluid as an internal energy vector, to identify shapes and characteristics of the machines; knowledge of fluid machinery components and their operation, with a focus on displacement pumps, actuators, and valves, and also on the systems arrangement; knowledge of basic and advanced architectures for industrial and mobile applications, operating principles, standards, and key design parameters of fluid power systems.

Course contents

The course provides the fundamentals of fluid power systems, with particular attention to hydraulic components, control architectures, hydrostatic transmissions and vehicular applications. The programme is organized by topic and includes practical and seminar-based activities.

• Introduction to Fluid Power — 10 h
  Fundamentals, advantages and performance indicators of fluid power systems. Transmission efficiency, examples of applications, basic fluid-mechanics equations, properties and classification of hydraulic fluids. ISO 1219 symbols, elementary circuits and introduction to positive-displacement pumps.
• Pumps for Fluid Power Applications — 15 h
  Architecture, operating principles and performance of gear pumps, vane pumps, piston pumps and other fixed-displacement pump designs. Displacement generation, flow-rate calculation, flow ripple, balancing issues, characteristic curves and variable-displacement pump architectures. Practical exercise on gear pump disassembly.
• Regulation of Variable-Displacement Pumps — 5 h
  Displacement adjustment mechanisms and main regulation strategies: pressure control, load sensing, constant-power regulation and power summation. Energy comparison between fixed- and variable-displacement pump systems.
• Actuators — 5 h
  Linear hydraulic and pneumatic actuators, single- and double-acting cylinders, braking systems, pressure multipliers and piston rod design. Rotary hydraulic motors, torque and power characteristics, and main motor architectures.
• Hydrostatic Transmissions — 5 h
  Functional layout, transmission ratios and open- and closed-circuit configurations. Mechanical characteristics of hydrostatic transmissions with fixed- and variable-displacement pumps and motors. Applications to vehicle propulsion.
• Directional Control Valves — 7.5 h
  Functions, symbols, architectures and operating limits of directional control valves. Spool valve design, lap conditions and proportional directional control valves. Dynamic behaviour of valve-motor systems and hydraulic power steering.
• Other Control Valves and Basic Hydraulic/Pneumatic Circuits — 7.5 h
  Pressure control valves, relief valves, reducing valves, sequence valves, back-pressure valves, braking valves and overcenter valves. Flow control valves, compensated and non-compensated configurations, regenerative circuits, actuator connections, synchronization circuits and flow dividers.
• Seminars on Vehicular Applications of Fluid Power — 5 h
  Seminar activities focused on selected applications of fluid power systems in vehicles.

Readings/Bibliography

SLIDES and LECTURE NOTES (available after each lesson).

The topics of the lectures are based on the following texts:

UNIVERSITY BOOKS

Nervegna N., Rundo M. Passi nell'oleodinamica, Vol.1-2, Ed. Epics Torino, 2021

Vacca A., Franzoni G. Hydraulic Fluid Power: Fundamentals, Applications, and Circuit Design. John Wiley And Sons Ltd, 2021

Belladonna U. Elementi di Oleodinamica. Principi – componenti - impianti, Hoepli, 2001

G. Bacchielli, F. Danielli, S. Sandrolini. Dinamica e controllo delle macchine a fluido. Pitagora, Bologna

Belladonna U., Mombelli A. Pneumatica, Principi – componenti – impianti… Hoepli, 2001

TECH. HANDBOOKS

Assofluid. Hydraulics in industrial and mobile applications. Milano 2007

Mannesmann, Rexroth, Manuale di oleodinamica (il) volume 1: fondamenti e componenti oleodinamici, Mannesmann-Rexroth GmbH 0-8023-0619-8, 1990

Mannesmann, Rexroth, Manuale di pneumatica (il) volume 1: Fondamenti di pneumatica, Mannesmann-Rexroth GmbH, 1991

Teaching methods

Class Lectures on the Course contents. Use of electronic device to project the main schematics and formulas.

Lectures attendance is recommended, but it is not mandatory to pass the exam.

Assessment methods

Assessment Methods

Assessment consists of an individual final examination, conducted orally and covering the entire course programme, with reference to the topics developed during the lectures.

The examination normally includes 2 or 3 questions on topics addressed in the course. During the examination, the student may be required to reproduce formulas, graphs, circuit diagrams and freehand drawings to support the oral discussion.

The examination may include an integrated written component aimed at representing:

• circuit diagrams according to ISO standards;
• analytical formulas related to the quantitative aspects covered in the course;
• derivations, graphs and functional relationships presented during the lectures.

The oral description of drawings, components and complex system diagrams discussed in class may form an integral part of the examination.

The examination is intended to assess the achievement of the course learning objectives, with particular reference to:

• understanding of the functions of the systems addressed in the course;
• ability to describe and represent component, circuit and system diagrams;
• mastery of derivations and analytical relationships;
• understanding of the main quantitative and performance parameters;
• appropriate use of the technical language of the discipline.

Assessment Criteria

Assessment is expressed on a 30-point scale.

To pass the examination, students must demonstrate adequate knowledge of the fundamental concepts of the course, the ability to apply them to the description of the systems studied, and command of the essential technical language.

Higher marks are awarded to students who demonstrate a full understanding of the topics, the ability to connect the course contents, accuracy in representing diagrams, formulas and graphs, and autonomy in analysing systems and components.

Failure to pass the examination may result from insufficient knowledge of the key concepts, significant errors in the representation of diagrams or analytical relationships, or limited command of technical terminology.

Honours may be awarded in the case of complete and in-depth preparation, particular accuracy in graphical and analytical representation, full command of technical language, and the ability to discuss the course contents autonomously and critically.

In accordance with the University’s Code of Ethics, students are reminded to maintain the highest standards of integrity. Any activity aimed at improperly altering the outcome of assessments is strictly prohibited (e.g., cheating, plagiarism, accessing online course materials, or using unauthorized AI tools).

Please note in particular that mere possession of unauthorized devices or materials during an exam will result in the immediate invalidation of the test and reporting to the relevant authorities.

Conduct that violates these rules may lead to disciplinary proceedings or, where applicable, reports to the competent authorities; in the latter case, students involved may face criminal proceedings.

Teaching tools

The use of overhead projector and pc is considered in order to draw schemes, to represent formulas and to show complex layouts, plant components and systems related with the course contents. All the projected content is available for students after the lectures.

Office hours

See the website of Andrea De Pascale