Gears can be divided into: spur gears, helical gears, bevel gears, curved teeth, arc gears, worm gear, noncircular gears.
The gear profile includes tooth profile curve, pressure angle, tooth height and displacement. Involute gears are relatively easy to manufacture, so in modern gear, involute gears occupy an absolute majority, while cycloidal and circular gears are less used.
In terms of pressure angle, the bearing capacity of small pressure angle gears is small, while the large pressure angular gears, although the bearing capacity is higher, but the bearing load increases with the same transmission torque, so it is only used in special cases. And the gear tooth height has been standardized, generally using standard tooth height. The advantages of the modified gears are many, and they are all kinds of mechanical equipments.
In addition, the gears can also be divided into cylindrical gears, bevel gears, noncircular gears, rack, worm worm gear, according to the shape of the tooth line is divided into straight gears, helical gears, herringbone gears, curved gears, according to the surface of the tooth is divided into external gear, internal gear, according to the manufacturing method can be divided into casting gears, cutting gears, rolling gears, sintered gears.
The manufacturing material and heat treatment process of gears have great influence on the bearing capacity and the dimension weight of gears. The 1950s ago, the gear was more carbon steel, the 60 to alloy steel, and 70 for more surface hardened steel. According to the hardness, the tooth surface can be distinguished as soft tooth surface and hard tooth surface two kinds.
Soft tooth surface of the gear bearing capacity is relatively low, but easy to manufacture, good running, and more for transmission size and weight without strict restrictions, as well as a small number of general machinery production. Because the pair of gears, small wheel burden is heavier, so in order to make the size of the gear working life is roughly equal, small tooth surface hardness is generally higher than the big wheel.
subscribe by our newsletter and get update daily