Sprocket structure design and the selection of teeth quantity

A sprocket is a wheel with toothed fastener teeth used to engage a properly pitched block on a link ring or cable, a solid or spoked gear that engages the chain to transfer motion. Next, let GEEPRO explain the structure design of the sprocket and the relevant knowledge of the number of teeth.

The tooth shape of a sprocket

The sprocket tooth shape must ensure that the chain can enter and exit meshing smoothly and energy saving, minimize the impact and contact stress of the chain joint during meshing, and be easy to process.

It is composed of three arc aa, ab, cd and a straight line bc, referred to as the three arc - straight tooth shape. Tooth shape with standard cutter processing, in the sprocket work drawing do not have to draw the end face tooth shape, just on the drawing marked "tooth shape according to 3RGB1244-85 provisions" can be, but should draw Sprocket shaft surface tooth shape, its size refer to the relevant design manual. Parameter calculation has been mentioned before, do not repeat the statement!

Chain structure

4 kinds of commonly used sprocket structure, small diameter sprocket generally made whole, medium diameter sprocket made more spoke plate, for easy handling, loading card and weight reduction, in the spoke plate opening, large diameter sprocket can be made into a combination, at this time ring gear and wheel core can be made of different materials! Such as C45, stainless steel and other materials.

Sprocket material

Sprocket material should ensure that the teeth have enough strength and wear resistance, so sprocket teeth surface generally through heat treatment, so that it reaches a certain hardness.

General principle of sprocket tooth number selection

1）17 teeth

Only for small drive sprockets.

2）19 teeth or above

Generally used in high and medium speed, normal working conditions of the active sprocket.

3）23 teeth or more

Recommended for impact situations. When the speed ratio is low, with a high number of teeth sprocket can greatly reduce the i chain segment spin momentum, chain stretch negative sprocket sprocket load and bearing load.