Lad capacity of polymer gears with S-teeth flank shape

V tej doktorski disertaciji je predstavljena celovita eksperimentalna analiza odpovedi in akustičnega obnašanja S-polimernih zobnikov. Analizirani zobniki, izdelani iz dveh polimerov (POM in PA66), pogosto uporabljenih v proizvodnji zobnikov, so bili obdelani s standardiziranim rezalnim orodjem, nato pa preučeni in primerjani s standardiziranimi evolventnimi zobniki (E-zobniki) na namensko izdelani napravi za preskušanje zobnikov, ki omogoča stalno nastavljanje navora z uporabo pogonskega in zavornega asinhronskega elektromotorja. Eksperimentalno preskušanje je potekalo pod različnimi zunanjimi obremenitvami zobniškega para (navora) do končne okvare, ki se je pojavila v naslednjih treh različnih oblikah: zlom korena zoba, deformacija zoba ali taljenje zoba. Poleg tega so bile vključene osnovne karakteristike za ocenjevanje zajemanja hrupa med delovanjem, kar je še posebej pomembno, kadar se pričakuje zmanjšanje hrupa ob uporabi polimernih zobnikov. Izmerjeni signali so bili analizirani v časovnem in frekvenčnem prostoru, ravni akustične aktivnosti pa so bile medsebojno primerjane. Eksperimentalni rezultati so pokazali, da so ravni zvočnega tlaka zobnikov sorazmerne z velikostjo navora. Primerjava rezultatov je pokazala, da S-ozobje izkazuje boljšo nosilnost kot E-zobniki pri veliki obremenitvi in mehkejšem materialu zobnikov (POM), kjer lahko povišana temperatura znatno vpliva na taljenje zob zobnikov. Na področju ocenjevanja hrupa je analiza pokazala nekatere prednosti S- zobnikov v primerjavi z E- zobniki. V zvezi s tem je bilo ugotovljeno, da so S- zobniki primernejši za zmanjšanje hrupa zobniških pogonskih sistemov pri normalni obremenitvi in tipični pogonski hitrosti.A comprehensive experimental failure analysis and acoustic behaviour of S-polymer gears is presented in this doctorate thesis. The analysed gears, made of two frequently used polymers (POM and PA66) in gear manufacturing, were machined using the standardized cutting tool, and then investigated and compared to the standardized involute gears (E-gears) on a custom-made gear testing device, which allows a continuous torque setting by using a drive and braking asynchronous electric motors. The experimental testing has been done under different external loading of the gear pair (torque) until the occurrence of final failure, which has appeared in three different types: tooth root fracture, tooth deformation, or tooth melting. Additionally, basic evaluating characteristics were included to evaluate noise capture during operation, which is of particular significance when noise reduction is expected. The measured signals were analysed in time and frequency domains and the levels of acoustic activity were compared. The experimental results have shown that the sound pressure levels of both E- and S-polymer gears are proportional to the torque load. Result comparison has shown that S-gears demonstrate better load capacity than E-gears in the case of high loading and softer gear material (POM), where the increased temperature may have a significant impact upon melting of gear teeth. On noise evaluation front, the evaluation has shown some advantages of S-polymer gears if compared to E-polymer gears. In that respect, S-polymer gears were found more appropriate for noise reduction of gear drive systems in the case of normal loading and typical drive speed