Analiza menjalnika BCS kosilnice

Gams, Žiga (author), Nagode, Marko (mentor), Oman, Simon (comentor)

V zaključni nalogi smo razstavili in analizirali menjalnik stare BCS-kosilnice s ciljem poglobiti znanje o njegovem delovanju in dobiti vpogled v razmišljanje inženirjev, ki so ga zasnovali. Menjalniku smo najprej analizirali mehanizem za spreminjanje prestav in delovanje diferenciala, nato pa smo se poglobili v zobniški prenos, pri katerem smo z ročnimi meritvami in preračuni določili parametre zobnikov. Te rezultate smo preverili s pomočjo lastnega programa za risanje zobniških profilov, ki smo ga napisali v jeziku \emph{Python}. Na koncu smo naredili še CAD-model menjalnika in simulirali njegovo delovanje. Ugotovili smo, da je menjalnik zasnovan na enostaven način, da deluje na principu pomičnega trna in da zobniški prenos uporablja samo valjaste evolventne zobnike z ravnim ozobjem. Ugotovili smo, da večina zobnikov nima profilnega premika ali pa imata zobnika v dvojici enak, a nasprotno predznačen profilni premik. Zagotove vrednosti premika nismo mogli določiti le pri enem zobniku. Uporabljene medosne razdalje zobniških dvojic niso bile standardne, so pa bile v večini enostavne vrednosti.

• Language: Slovenian
• Keywords: menjalniki, BCS kosilnice, zobniki, profilni premiki zobnikov, analiza ozobja, Python, simulacije
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: FS - Faculty of Mechanical Engineering
• Year: 2025
• Number of pages: XX, 57 str.
• PID: 20.500.12556/RUL-171464
• UDC: 621.83:631.352:004.94(043.2)
• COBISS.SI-ID: 247191299
• Publication date in RUL: 27.08.2025

Secondary language

• Language: English
• Title: Analysis of BCS mower transmission

Abstract

In this thesis we disassembled and analyzed the gearbox of an old BCS mower with the aim of deepening our understanding of its operation and gaining insight into the thought process of the engineers who designed it. We first examined the gear-shifting mechanism and the working of the differential, and then delved into the gear transmission. Using manual measurements and calculations, we determined the parameters of the gears, which we verified with our own gear profile drawing program written in Python. Finally, we created a CAD model of the gearbox and simulated its operation. We found that the gearbox is designed in a simple manner, operating on the principle of a sliding pin, and that the gear transmission uses only involute spur gears. Additionally, we discovered that most gears have no profile shift, or that the paired gears have identical but opposite profile shifts. We were unable to determine the exact shift value only for one of the gears. The center distances of the gear pairs were not standard values but were still mostly simple.

• Keywords: transmission, BCS mowers, spur gears, gear profile shift, gear tooth analysis, Python, simulations