• Semester 4, position 3

Introducing students to solving practical tasks of a mechanical engineer related to mechanical power transmissions. Familiarization with the components of machine systems, their functions, applications, and design solutions for mechanical power transmissions. Mastery of methods for calculating the distribution and transformation of power and torque; for transmission elements, mastery of calculations of operational safety, service life, and load-carrying capacity, as well as of the basics of designing machine elements used in transmissions. Introducing students to the application of standards and other regulations in mechanical engineering for the calculation and design of machine elements in mechanical transmissions.

Upon successful completion of this course, students will be able to: • recognize and follow the flow (transformation) of mechanical energy in a transmission; • select design parameters of friction power transmissions; • determine dimensions, choose geometric parameters, and design gears in a transmission; • calculate load-carrying capacity and operational safety of gears (spur, bevel and worm gears); • calculate load-carrying capacity and service life of belt and chain transmission pairs; • select and design couplings (rigid, flexible, knuckle, toothed, friction).

Mechanical power transmission, fundamental equations of mechanical energy transformation, transmission ratio, and efficiency of power transmissions. Friction pairs: basic principles, operating characteristics, sliding and wear, materials. Cylindrical gear pairs: basic principles of meshing, gear geometry, and tooth meshing kinematics. Strength and load-carrying capacity of cylindrical gears. Bevel and worm gear pairs. Belt drives: loading, stresses, service life. Chain drives. Couplings, function, classification, design characteristics, calculation (rigid, flexible, knuckle, toothed, friction).

Determination of transmission ratios, torques, rotational speeds, and power flows in transmissions; distribution (transmission) of power. Determination of gear tooth parameters, calculation of tooth dimensions, gear dimensions (diameters and center distance), and degree of meshing. Strength (load-carrying capacity) calculation of gears (cylindrical, bevel, worm). Calculation of belt drives. Calculation of chain drives. Calculation of coupling load-carrying capacity. Demonstration of functions, design solutions, and testing of strength and load-carrying capacity of transmissions in the laboratory. Instructions for preparing project assignments.

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 the operation of mechanical power transmissions; video presentations of gear manufacturing and control; demonstration of design solutions) Laboratory (demonstration of elements, parts, and assemblies of mechanical power transmissions; simulation of the operation and manufacturing of involute gears)

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

Ristivojević, M., Stamenić, Z., Mitrović, R.: Machine Elements 2 (in Serbian), University of Belgrade, Faculty of Mechanical Engineering, 2021, ISBN 978-86-6060-112-6; Ognjanović, М: Machine Elements (in Serbian), University of Belgrade, Faculty of Mechanical Engineering, 2021, ISBN 978-86-6060-099-0; Lazović, T., Marinković, A.: Mechanical Power Transmissions - Problems with solutions (in Serbian), University of Belgrade, Faculty of Mechanical Engineering, 2022, ISBN 978-86-6060-116-4; Stamenić, Z., Mišković, Ž., Kolarević, N., Sedak, M., Dimić, A.: Machine elements 2 - Problems with solutions (in Serbian), University of Belgrade, Faculty of Mech. Eng, 2024, ISBN 978-86-6060-188-1