The most basic types of gear shaft rotation is used to change volume by meshing gears of different sizes. Parallel equipment can back them very effective and can transfer large amounts of power (Hamrock et al. 2005, p. 608). The simple gears in this category called spur gears because of its shape. Spur gears is advantageous because of its low cost and simple design. By changing the amount of rotation, more energy can be reflected from the process. This is an example of a windmill. There is one disadvantage of spur gears that can produce significant noise levels.
Theis useful in many applications, but may not be appropriate in situations that require very large torques because the tooth contact ratio is one-to-one. For higher torque applications, can use the helical equipment. Use the gear teeth angled to increase the ratio of contact between the teeth of two meshed gears. There are other advantages of to run more quietly than spur gears and a smaller gear can transmit helical same burden as more spur gear (Hamrock et al. 2005, p. 608). There is one disadvantage of helical gears they produce a final thrust further along the axis of the shaft to be compensated much for. They also tend to be slightly less effective than spur gears because efficiency is based on normal tooth load, which is higher in spur gears (Hamrock et al. 2005, p. 608).