Bevel gears are useful when the path of a shaft’s rotation must be changed. They are often installed on shafts that are 90 degrees aside, but could be designed to just work at other angles as well.
The teeth on bevel gears can be straight, spiral or hypoid. Straight bevel gear teeth actually have the same issue as straight spur equipment teeth — as each tooth engages, it Vacuum Pump impacts the corresponding tooth all at once.
Just like with spur gears, the answer to the problem is to curve the gear teeth. These spiral teeth engage just like helical teeth: the contact begins at one end of the apparatus and progressively spreads across the whole tooth.
On straight and spiral bevel gears, the shafts should be perpendicular to each other, but they must be in the same plane. If you were to expand the two shafts at night gears, they would intersect. The hypoid equipment, however, can build relationships the axes in various planes.
Hypoid bevel gears in a car differential
This feature can be used in many car differentials. The band equipment of the differential and the input pinion gear are both hypoid. This enables the input pinion to be mounted less than the axis 
of the ring gear. Figure 7 shows the input pinion engaging the ring equipment of the differential. Because the driveshaft of the car is connected to the insight 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 even more room for individuals and cargo.