A Visual Basic Program for Designing of Gear Pair for Front Power Take-Off Unit Of Higher HP Tractors

Abstract

With a view to fully utilize the available power, reduce soil compaction and for timeliness of tillage operations, now-a-days, front three point linkages are used in higher power tractors. So, front power take-off (PTO) also desirable with front three point linkages to operate passive implements like rotavator, mower etc. With this requirement in view, a program was developed in visual basic for design of a front PTO gear pair of higher hp tractors. In this design, the drive was taken from engine crankshaft running at rated speed of 2200 rpm and was reduced to 1000 rpm using helical gear pair. For validation of developed Visual Basic program, contact stresses and bending stresses analysis of gear and pinion was done in KISS software. The maximum bending root stress on pinion and gear was 330 N/mm2 and 300 N/mm2 against limiting stress value of 430 N/mm2 where contact stresses are 1000 N/mm2 against limiting value of 1500 N/mm2 and therefore, designed gear pair was safe against bending and pitting. The output results of KISS software was used for validation of developed visual basic program. Developed program shows approximately the same results as in KISS software. Developed VB program is cheap, simple and can be used to design and for analysis of single gear pair.

Kod traktora veće snage se danas koriste prednji hidraulični uređaji radi potpunog iskorišćenja raspoložive snage, smanjenja sabijanja zemljišta i rokova za obradu zemljišta. Tako je i prednje priključno vratilo potrebno sa podiznim uređajem, za pogon gonjenih priključaka kao što su freza, kosačica i sl. Imajući u vidu ovaj zahtev, razvijen je program u visual basic za konstrukciju zupčastog prenosnika prednjeg priključnog vratila kod traktora veće snage. U ovoj konstrukciji korišćen je pogon sa kolenastog vratila motora brzine 2200 min-1, redukovane na 1000 min-1 spiralnim zupčastim parom. Za ocenu razvijenog programa i analizu kontaktknog opterećenja i opterećenja na savijanje zupčanika i vratila korišćen je KISS softver. Maksimalno opterećenje na savijanje vratila i zupčanika bilo je 330 N/mm2 i 300 N/mm2 u odnosu na graničnu vrednost od 430 N/mm2, a kontaktno opterećenje 1000 N/mm2 u odnosu na hgraničnu vrednost od 1500 N/mm2, tako da je konstruisani zupčasti par bio bezbedan pri udaru i savijanju. Izlazni rezultati programa KISS su korišćeni za ocenu razvijenog visual basic programa. Razvijeni program je pokazao približno iste rezultate kao i program KISS. Razvijeni program je je jevtin, jednostavan i može da se upotrebi pri konstruisanju i analizi pojedinačnih zupčastih parova.