Reading volume:5 发表时间:2020/5/28 14:13:10
According to the hardness, the tooth surface can be divided into two types: soft tooth surface and hard tooth surface.Gears with soft tooth surfaces have relatively low load-bearing capacity, but they are relatively easy to manufacture. They have good running-in properties and are mostly used for transmission size and weight without strict restrictions, as well as small-volume production of ordinary machinery.Because the small wheel bears a heavier burden in the matched gears, so in order to make the working life of the large and small teeth roughly equal, the hardness of the small wheel tooth surface is usually higher than that of the large wheel.
The load-carrying capacity of hardened gears is relatively high. After the gear is cut, it is quenched, surface quenched or carburized and quenched to increase the hardness.However, in the heat treatment, the gear will inevitably be deformed, so after the heat treatment, grinding, grinding or fine cutting is carried out to facilitate the dissipation of errors caused by the deformation and improve the accuracy of the gear.
The strength of cast steel is relatively lower than that of forged steel, and is often used for larger gears; gray cast iron has poor mechanical properties and can be used in light-load open gear transmissions; ductile iron can partially replace steel gears; Plastic gears are mostly used in places where light loads and low noise are required, and the gears matched with them are usually steel gears with good thermal conductivity.
The structure of the sprocket
1. Tooth shape of the sprocket: The shape of the tooth must ensure that the chain link can enter and retreat steadily, to minimize the collision and contact stress of the chain link during meshing, and it is also convenient for processing.
2. Sprocket structure: if it is a small diameter, it is usually made as an integral form, if it is a medium majority. It is made in the form of a spoke, which is convenient for transportation, installation and weight reduction. Open the hole on the upper part, then the large diameter can be used as a combined style. At this time, the ring, wheel and core can be made of different materials.
3. Sprocket material: The material needs to ensure that it has sufficient strength and wear resistance, so its tooth surface is usually solved by heat to make it reach a certain hardness.