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