ID: 1614
Course type: scientific and vocational
Course coordinator: Lazović-Kapor M. Tatjana
Lecturers: Dimić R. Aleksandar, Kolarević M. Nenad, Lazović-Kapor M. Tatjana, Marinković B. Aleksandar, Mišković Z. Žarko, Sedak I. Miloš, Stamenić V. Zoran
Contact: Lazović-Kapor M. Tatjana
Level of studies: B.Sc. (undergraduate) Academic Studies – Mechanical Engineering
ECTS: 6
Final exam type: written
Department: Department of General Machine Design
Introducing students to solving practical tasks of a mechanical engineer. Familiarization with the components of machine systems, their functions, applications, and design solutions. Mastery of methods for calculating safety in operation, service life, load-carrying capacity, as well as the basics of designing machine elements. Mastery of the application of standards and other regulations in mechanical engineering.
Upon successful completion of this course, students will be able to: • recognize machine elements; • apply tolerances of linear dimensions, form, position, and surface roughness; • perform basic strength calculations of machine parts; • calculate and design shafts and axles; • select, calculate, and design rolling and sliding bearings; • select, calculate, and design bolted joints and screw drives.
The definition and classification of machine elements. Tolerances of linear dimensions, tolerances of form and position of axes and surfaces, and surface roughness tolerances of machine parts. Stress concentration, critical (ultimate) stresses in machine parts. Failures of machine parts, fatigue and dynamic strength (endurance limit). Safety factor, permissible stresses, and load-carrying capacity of a machine part. Surface failures, working and critical stresses of the surface layer of machine parts. Shafts, axles, and pins: function, structural forms, applications. Loads on shafts and axles, stresses, dynamic strength (endurance limits), and safety factor. Shaft stiffness. Shaft–hub connections: by friction, keys, splines, and shape. Rolling bearings: function and application, types and characteristics of standard rolling bearings. Bearing loads. Failures and service life of rolling bearings. Selection and installation of rolling bearings. Sliding bearings: function, characteristics, classification. Load-carrying capacity of sliding bearings with friction of partially wetted surfaces. Load-carrying capacity of hydrodynamic sliding bearings. Heating, cooling, and lubrication of sliding bearings. Design, parts and materials of sliding bearings. Bearing sealing. Thread, threaded pairs, threaded joints: function, characteristics, classification. Bolted joints, axially and transversely loaded: characteristics, classification, loading, tightening, deformations, safety factors. Movable threaded joints – screw drives.
Selection of tolerances of linear dimensions. Analysis of fits: clearance, interference, and transition fits. Determination of stress concentration factors. Dynamic strength of machine parts. Determination of the safety factor. Shaft loading diagram. Loads and stresses in shafts. Determination of shaft dimensions and safety factor. Calculation of shaft–hub connections. Determination of load-carrying capacity and service life of rolling bearings. Selection and installation of bearings. Calculation of bolted joints, selection of bolts, calculation of movable threaded joints. Project assignment, instructions for task preparation, reviews, and corrections.
Defined by study curricula.
Books (textbooks and books of problems with solutions) Handouts (lectures, questions and problems for tests, instructions for project assignments) Video presentations (simulations of machine element operation; video presentations of manufacturing and control; demonstration of design solutions) Laboratory (demonstration of machine elements, parts, and assemblies; demonstration of testing of machine elements; simulation of operation and manufacturing of machine parts)
Total assigned hours: 75
New material: 20
Elaboration and examples (recapitulation): 10
Auditory exercises: 6
Laboratory exercises: 4
Calculation tasks: 10
Seminar paper: 0
Project: 6
Consultations: 0
Discussion/workshop: 4
Research study work: 0
Review and grading of calculation tasks: 4
Review and grading of lab reports: 0
Review and grading of seminar papers: 0
Review and grading of the project: 2
Test: 4
Test: 0
Final exam: 5
Activity during lectures: 5
Test/test: 25
Laboratory practice: 5
Calculation tasks: 0
Seminar paper: 0
Project: 15
Final exam: 50
Requirement for taking the exam (required number of points): 26
Mitrović, R., Ristivojević, M., Rosić, B.: Machine Elements 1 (in Serbian), University of Belgrade, Faculty of Mechanical Engineering, 2021, ISBN 978-86-6060-101-0; Ognjanović, М: Machine Elements (in Serbian), University of Belgrade, Faculty of Mechanical Engineering, 2021, ISBN 978-86-6060-099-0; Lazović, T.: Machine elements 1 - Problems with solutions (in Serbian), University of Belgrade, Faculty of Mechanical Engineering, 2022, ISBN 978-86-6060-133-1