The gear can be classified according to the shape of the tooth shape, the shape of the gear, the shape of the tooth line, the surface of the wheel tooth and the manufacturing method.
The tooth shape of the gear includes the tooth curve, pressure angle, high tooth, and variable position. Gradually open gears are easier to make, so in modern gears, the ranging gears are absolutely large, and the application of the wire and the arc gear is less.
In terms of pressure angle, the carrying capacity of small pressure angle gears is small; and the large pressure corner gear, although the loading capacity is high, the load of the bearing increases under the same conversion torque, so it is only used for special circumstances. The high tooth height of the gear has been standardized and generally uses standard tooth height. The advantages of variable gears have more advantages, and they have spread to various machinery and equipment.
In addition, gears can also be divided into cylindrical gears, cone gears, non -round gears, bars, and worm worms; The surface is divided into external gears and inner gears; according to the manufacturing method, it can be divided into cast gears, cut gears, rolled gears, sintering gears, etc.
The manufacturing material and thermal treatment process of gear have a great impact on the carrying capacity and size of the gear. Before the 1950s, the gear was multi -carbon steel. In the 1960s, alloy steel was changed, and the surface hardening steel was used in the 1970s. According to the hardness, the tooth surface can be divided into two types: soft tooth surface and hard tooth surface.
The gear loading capacity of the soft tooth surface is low, but the manufacturing is relatively easy, the running is good, and it is mostly used in general machinery that has no strict restrictions on the size and weight of the transmission size and weight. Because of the pairing gear, the small wheels have a heavy burden, so in order to make the working life of the large and small gears roughly equal, the hardness of the small wheels is generally higher than the large wheel.
The bearing capacity of the hard tooth surface gears is high. It is quenching, surface quenching or carburizing quenching treatment after the gear is squeezed to improve the hardness. However, in thermal treatment, the gear will inevitably cause deformation. Therefore, after the heat treatment, grinding, grinding, or sperm must be performed to eliminate errors caused by deformation and improve the accuracy of the gear.
