Bevel gears are useful when the direction of a shaft’s rotation must be changed. They are usually mounted on shafts that are 90 degrees apart, but can be designed to just work at various other angles as well.
One’s teeth on bevel gears could be straight, spiral or hypoid. Straight bevel gear teeth already have the same issue as straight spur gear tooth — as each tooth engages, it impacts the corresponding tooth all at one time.
Exactly like with spur gears, the answer to the problem is to curve the apparatus teeth. These spiral teeth engage exactly like helical teeth: the contact starts at one end of the apparatus and gear box for greenhouse progressively spreads over the whole tooth.
On straight and spiral bevel gears, the shafts should be perpendicular 
to one another, but they must also be in the same plane. If you were to extend the two shafts at night gears, they might intersect. The hypoid gear, on the other hand, can engage with the axes in various planes.
Hypoid bevel gears in a car differential
This feature can be used in many car differentials. The band gear of the differential and the insight pinion equipment are both hypoid. This enables the input pinion to be installed lower than the axis of the ring gear. Figure 7 shows the input pinion engaging the ring gear of the differential. Because the driveshaft of the car is connected to the input pinion, this also lowers the driveshaft. This means that the driveshaft doesn’t intrude in to the passenger compartment of the automobile as much, making more room for people and cargo.