A bevel gear is shaped like a right circular cone with most of its tip cut off. When two bevel gears mesh, their imaginary vertices must occupy the same point. Their shaft axes also intersect at this point, forming an arbitrary non-straight angle between the shafts. The angle between the shafts can be anything except zero or 180 degrees. Bevel gears with equal numbers of teeth and shaft axes at 90 degrees are called mitre gears.
Spur gears are the most popular form and the most efficient type of gearing for the cost when transmitting power and uniform rotary motion from one parallel shaft to another. Within the limitations of center distance, spur gears provide a positive, constant speed drive, the speed of which may be increased or decreased by increasing or decreasing the number of teeth in the driving gear.
It’s used to limit the direction and trend of motion,also easier for positioning shafts’parts。Main material include carton steel and alloy steel。 Carbon steel is cheaper than alloy steel, and because stress concentration and smaller sensitivity, it’s used more than alloy steel. Normal carbon steel include C30, C40, C45 and C50, among them, C45 is the most popular.In order to improve the mechanical property，it shall be normalized and tempered or quenched and tempered