Lots of transmissions – specifically for transportation purposes – have a number of gears that are accustomed to alter the ratio of enter velocity (e. Spur and helical gears are used in the sliding mesh gearbox to act. Spur equipment’s tooth make a parallel reference to the gear axis. https://gearbox41963.theideasblog.com/34282808/not-known-factual-statements-about-gearbox