Sprocket Indruction
[sprocket wheel]: a wheel with a cog-type sprocket for meshing with an accurate pitch on a chain link or cable [chain wheel]: a solid or spoked gear, and (roller ) The chain engages to transmit motion.
Sprockets are widely used in chemical transmission, textile machinery, food processing, instrumentation, petroleum machinery and other industries.
Introduction
Sprocket parameter calculation formula:
Indexing circle diameter: d = p / sin (180 ° / z) p = pitch
Tooth top circle (outer diameter): D = p × (0.54 + cot180 ° / z)
Common sprocket pitch:
3/8 = 9.525 1/2 = 12.7 5/8 = 15.875 3/4 = 19.05
3 points 4 points 5 points 6 points
Indexing circle diameter: d = p / sin (180 ° / z)
Tooth circle diameter: dmax = d + 1.25p-d1
dmin = d + (1-1.6 / z) p-d1
Tooth root diameter: df = d-d1
Note: p chain pitch
z Sprocket teeth
d1 chain roller diameter
The simplest algorithm is {? Minutes} = dividing circle diameter divided by {tooth number + 2}
Sprocket model: Including non-standard sprocket (customized according to customer drawings), standard sprocket (American standard and metric).
Sprocket Common Material: C45
Sprockets commonly used processing methods: quenching treatment, surface blackening treatment.
General principles for selection of sprocket teeth:
19 teeth or more
It is generally used for active sprockets running at medium and high speeds under normal operating conditions.
17 teeth
Only for small pitch active sprockets.
23 teeth or more
Recommended for impact situations. When the speed ratio is low, the use of high-tooth number sprocket can greatly reduce the rotation of the i-link, the tensile load of the chain and the load of the bearing.
Structural design
1. Tooth profile of the sprocket The profile of the sprocket must ensure that the chain enters and exits the mesh smoothly and energy-savingly, minimizes the impact and contact stress of the chain link during meshing, and is easy to process.
The commonly used tooth profile at the end of a sprocket consists of three segments of arcs aa, ab, cd and a segment of straight line bc. The tooth shape is processed by standard tools. It is not necessary to draw the end tooth shape on the sprocket work drawing. It is only necessary to indicate "the tooth shape is manufactured according to 3RGB1244-85" on the drawing. Refer to the relevant design manual for its dimensions. The parameter calculation has been mentioned previously, without repeating the description!
Sprocket structure
Figure 3 shows four commonly used sprocket structures. Small diameter sprocket is generally made as a whole (Figure 3a), medium diameter sprocket is mostly made as a spoke type. Made into a combined type (Figure 3d), at this time the ring gear and the wheel core can be made of different materials! For example, C45, stainless steel and other materials.
3. Sprocket material
The material of the sprocket should ensure that the teeth have sufficient strength and abrasion resistance, so the tooth surface of the sprocket is generally heat treated to achieve a certain hardness.
