Course detail
Tribology
FSI-ZTR Acad. year: 2019/2020 Winter semester
The overall aim of the course is to provide students with theoretical and practical knowledge of friction, wear and lubrication processes that take place in mechanical engineering systems and play important role at machine design, production and maintenance. The course is focused on the following topics: Surface interaction and friction theory; Tribological properties of materials; Lubricant and their properties; Hydrodynamic, hydrostatic, elastohydrodynamic, mixed and boundary lubrication; Nano- and microtribology; Tribology application in mechanical design. Laboratory exercises and seminars in computer labs allow to demonstrate tools for tribological engineering and practical application of theoretical knowledge in the design phase.
Language of instruction
Czech
Number of ECTS credits
5
Supervisor
Department
Learning outcomes of the course unit
Theoretical and practical knowledge of friction, wear and lubrication processes on the macro- and microscopic scale. Their application in mechanical engineering design. Materials and lubricant selection from the point of minimization and elimination of losses resulting from friction and wear.
Prerequisites
Knowledge in area of material science, strength of materials, machine design and hydromechanics
Planned learning activities and teaching methods
The course is taught through lectures explaining the basic principles and theory of the discipline. Exercises are focused on practical topics presented in lectures. Teaching is suplemented by practical laboratory work.
Assesment methods and criteria linked to learning outcomes
Course-unit credit is awarded on the following conditions: active participation in the seminars, good results of elaborated laboratory and computational exercises.
Examination: is composed of a test containing multiple choice questions and oral examination.
Aims
The course covers fundamental principles of tribology, multidisciplinary science which focuses on interacting surfaces in relative motion.The course provides theoretical and practical knowledge of friction, lubrication and wear, that are taking place in mechanical engineering systems and are essential in the design, production and maintenance.
Specification of controlled education, way of implementation and compensation for absences
Attendance at lectures is recommended, attendance at seminars is mandatory. The lessons are planned on the basis of a weekly schedule. The way of compensation for an absence is fully at the discretion of the teacher.
The study programmes with the given course
Programme M2I-P: Mechanical Engineering, Master's
branch M-KSI: Mechanical Engineering Design, compulsory
Type of course unit
Lecture
10 hours, optionally
Teacher / Lecturer
Syllabus
1. Introduction to tribology, its significance and historical development. Tribological system and processes.
2. Lubrication principles. Regimes of fluid film lubrication. Composition of lubricants and their manufacturing. Types of lubricating oil additives and their use.
3. Classifications of liquid lubricants. Oils for mobile machinery and industry.
4. Technological lubricants. Lubricants in the process of machining and forming.
5. Plastic and solid lubricants. Tribological surface layers.
6. Hydrodynamic lubrication.
7. Elastohydrodynamic and mixed lubrication.
8. Boundary lubrication. Mechanisms of boundary film formation. Lubricant additives.
Determination of lubricant film thickness in rolling bearings, gears and traction drives.
9. Wear.
10. Tribology of thin rigid layers, films and coatings. Tribology of filters and devices for cleaning of industrial fluids.
11. Characteristics and current tribological problems of microelectromechanical (MEMS) devices.
12. Tribological of biosystems.
Laboratory exercise
13 hours, compulsory
Teacher / Lecturer
Syllabus
Case study focused on one of the following topics:
1. Demonstration of pressure distribution across the film of oil in a Michell tilting pad slider bearing. Aerodynamic gas bearing demnostration.
2. Viscosity measurements with capillary, 'Falling Ball' and rotational viscometers.
3. Determining of the film thickness distribution in elastohydrodynamic lubricated contacts using the optical tribometer.
4. Application of high-speed camera to study the rheology and dynamic phenomena in elastohydrodynamic lubricated contacts.
5. Topography of engineering surfaces, its description and measurement using optical methods.
6. The traction curves assessment using 'Mini traction machine'. Dry friction measurement on inclined plane tribometer.
Computer-assisted exercise
13 hours, compulsory
Teacher / Lecturer
Syllabus
1. Hertzian contact theory. Parameters of the contact.
2. Elastohydrodynamic lubrication. Unit-less parameters and relations for the film thickness prediction.
3. Calculation of the lambda parameter, estimation the the lubrication regime and prediction of friction.