Types Bevel Gear and Their Applications

Bevel gears are very different with simple or spur gears. The lines drawn along the teeth of a bevel gear is assembled whereas, in the simple gear the it is parallel to the shaft. The bevel gear enables to change the direction of the shaft's rotation. The shafts are mounted over one another at 90 degree. Types of bevel gear can be classified on basis of the design of the teeth – straight tooth, spiral tooth and hypoid bevel gears. The feature and application of each bevel gear is given below.

 

Straight Tooth Bevel Gears
These are normal bevel gears used to change the direction of the rotation. Their application could mostly be seen in watches, hand drills, vending machines, dentists drill and electric typewriters. Generally in such gears, the intersection of the two shafts are in 90 degrees. However, the degree may differ due to varying angle of the teeth. They are ideal for using for slow rotating shafts.

 

Spiral Bevel Gears
Unlike straight tooth, bevel gear with spiral cut teeth is ideal for high speed use like bicycle and motorcycle gears. The spiral cut teeth slowly draws each other starting from edge and gradually the whole teeth. Which is why they are best for automotive use. Same like the straight tooth type, the shaft of the spiral bevel gear is placed perpendicular to one another.

 

Hypoid Bevel Gears
The shafts of straight and spiral teeth bevel gears intersect if the shafts were continued. However, the shafts of hypoid bevel gear does not intersect. They are used in automobiles for differential gears. The drive shaft intersects the differential gears below the level of the real wheel axis--leaving more room in the passenger compartment.