The sprocket is an important part of the chain transmission. Whether the sprocket tooth profile, pitch and other dimensions related to the chain are processed correctly will directly affect the service life of the chain. Therefore, sufficient attention must be given.　　 1. The shape and structure of common sprocket 　　 Usually, the sprocket is composed of three parts: the ring gear, the wheel and the spokes. Common sprocket shapes are: 　　 1. Single-piece single- and double-row sprocket. 2. Single flange type single and double row sprockets. 3. Double flange type single and double row sprockets.　　 Changzhou sprocket manufacturer The structure of the sprocket is roughly as follows: 1. The overall structure. It is generally used in the processing of single and double row, single and double flange sprockets with standard chain P=38.1 or less.　　 2. Welding structure. Mainly used in the processing of medium and large size single and double flange sprockets. When processing, the flange part adopts bar car to make convex shape. The ring gear part can be cut with a plate to process the outer diameter and the shaft hole, and one end of the hole is turned out and the welding groove is sleeved into the flange part for welding. When welding, both ends should be welded, using low-hydrogen electrode such as T506 electrode.　　 3. Cast sprockets. It is mainly used in the processing of large sprocket wheels. During processing, only the gear ring, flange end faces, outer and inner diameters and keyways are processed, and then the tooth profile is processed. The ring sprockets are all cast. There are generally two kinds of materials for casting sprocket, cast iron and cast steel such as HTl5O, HT2O0 and ZG310-570 (ZG45).　　 Changzhou sprocket manufacturer 4. Forged sprocket. It is mainly used in the production of medium and large sprocket with large force. When forging, whether it is a single-flange type or a double-flange type, it is generally forged into a convex shape, leaving enough machining allowance for the shaft hole, low material utilization, and high cost.　　 Second, the choice of sprocket material　　 For chip sprockets that do not require heat treatment, they can be made of Q235, Q345 (16Mn), or 10, 20 steel. Generally, the hardness is below HBl40, which is suitable for the processing of medium-speed, medium-power, and large sprockets. Sprockets requiring heat treatment are generally made of 45 steel, 45 steel forging, 45 cast steel or 4OCr steel, which is suitable for the processing of driving and driven sprockets that are matched with high-strength chains on important occasions with greater stress. Cast iron sprockets are mainly used in sprockets with low accuracy requirements or complex shapes, such as ring sprockets.　　 Three, the basic parameters of the sprocket　　 l, Z-tooth number, 2. P-chain pitch, 3. d-roller diameter, 4. d is the diameter of a dividing circle, 5. The diameter of the top circle of d top, 6. The diameter of d root and one root circle, Changzhou sprocket manufacturer 7. Pitch angle 8. Q is the pressure angle and R is the arc radius of the tooth groove. The first three parameters are important data provided by users, and the latter parameters are sprocket design parameters, which can be calculated with reference to relevant standards.