When meshed in the gearbox, Helical gears present additional teeth Make contact with in between each other, developing a constant link. That is as opposed to spur gears, that have a lot less steady contact. A mix of helical and bevel gears characterizes the bevel helical or proper-angle gearbox. https://gearbox33084.blue-blogs.com/41075800/what-does-gearbox-mean