Application of sprocket: It is widely used in mechanical transmission in chemical, textile machinery, food processing, instrumentation, petroleum and other industries 

　　Sprocket parameter calculation formula: 

　　Diameter of the index circle: d=p/sin180°/zp=pitch can be found in the table z=number of teeth 

　　Addendum circle (outer diameter): D=p×(0.54+cot180°/z) 

　　Give you the commonly used sprocket pitch, you can calculate it yourself, ask me if you don’t understand 

　　3/8=9.525 1/2=12.7 5/8=15.875 3/4=19.05 

　　3 points 4 points 5 points 6 points 

　　Diameter of the index circle: d=p/sin (180°/z) 

　　Addendum circle diameter: dmax=d+1.25p-d1 

　　dmin=d+(1-1.6/z)p-d1 

　　Tooth root circle diameter: df=d-d1 

　　Note: p chain pitch 

　　z Number of sprocket teeth 

　　d1 Chain roller diameter 

　　Sprocket model: including non-standard sprocket (customized according to customer drawings), standard sprocket (American standard and metric). 

　　Commonly used materials for sprocket: C45 

　　Common processing methods for sprocket: quenching treatment, surface blackening treatment. 

　　General principles for selecting the number of sprocket teeth: 

　　19 teeth or more 

　　Generally used for active sprockets running at medium to high speeds and under normal working conditions. 

　　17 teeth 

　　Only used for small pitch drive sprocket. 

　　23 teeth or more 

　　It is recommended for impact situations.When the speed ratio is low, using a high-tooth sprocket can greatly reduce the amount of rotation of the i link, the tensile load of the chain and the load of the bearing. 

Structure design of roller chain sprocket

　　1. The tooth profile of the sprocket 

The tooth profile of the sprocket must ensure that the chain enters and exits the mesh smoothly and freely, minimizes the impact and contact stress of the chain link during meshing, and is easy to process. 

　　The tooth profile of the commonly used sprocket is shown in Figure 1.It is composed of three arcs aa, ab, cd and a straight line bc, referred to as three arc-straight tooth profile.The tooth profile is processed with a standard tool. It is not necessary to draw the end tooth profile on the sprocket work drawing. You only need to indicate "the tooth profile is manufactured in accordance with 3RGB1244-85" on the drawing, but the axial profile of the sprocket should be drawn. See Figure 2, and its dimensions refer to the relevant design manual.The parameter calculation has been mentioned before, so I won’t repeat it! 

　　2. Sprocket structure 

　　Figure 3 shows four commonly used sprocket structures.Small-diameter sprockets are generally made of integral type (Figure 4a), and medium-diameter sprockets are mostly made of spoke plate type. In order to facilitate handling, installation and weight reduction, holes are made on the spoke plate (Figure 3b). Large diameter sprockets can be Make it into a combined type (Figure 3d), at this time the ring gear and the wheel core can be made of different materials!For example, C3, stainless steel and other materials. 

　　3. Sprocket material 

　　The sprocket material should ensure that the gear teeth have sufficient strength and wear resistance, so the sprocket tooth surface is generally heat treated to make it reach a certain hardness.