Gear

Gears are mechanical components with teeth on the rim that can continuously mesh to transmit motion and power. The tooth profile of the gear includes tooth profile curve, pressure angle, tooth height and displacement. Involute gears are relatively easy to manufacture, so among the gears used in modern times, involute gears account for the absolute majority, while cycloidal gears and arc gears are rarely used. In terms of pressure angle, gears with small pressure angles have smaller load-bearing capacity; while gears with large pressure angles have higher load-bearing capacity, but the load on the bearing increases when the transmission torque is the same, so they are only used in special circumstances. The tooth height of gears has been standardized, and standard tooth heights are generally used. Variable gears have many advantages and have been used in various types of mechanical equipment. Gears can also be divided into cylindrical gears, bevel gears, non-circular gears, racks, and worm gears according to their shape; they can be divided into spur gears, helical gears, herringbone gears, and curved gears according to the tooth line shape; they can be divided into gears according to the surface on which the gear teeth are located. They are external gears and internal gears; according to the manufacturing method, they can be divided into cast gears, cut gears, rolled gears, sintered gears, etc. Hard tooth surface gears have high load-bearing capacity. After the gears are precision cut, they are then quenched, surface quenched or carburized and quenched to increase the hardness. However, during heat treatment, the gear will inevitably deform, so it must be ground, ground or precision cut after heat treatment to eliminate errors caused by deformation and improve the accuracy of the gear.