Roller chain and sprocket design requirements

Chain drives are often used in drivetrain design.In the chain drive, the design calculation of the roller chain is mainly used.Combined with the national standard GB/T 1243 and related industry standards, the following design requirements for roller chains are summarized.For non-standard designs, please refer to this design requirement.

1. If there is a chain drive, there will be a chain box. When designing the chain box, there must be enough clearance inside it.Since the elongation of the worn chain is concentrated on the loose side, the overhanging chain may hit the bottom of the chain case and damage the chain case and chain.Therefore, in addition to providing adequate chain overhang clearance, at least 76mm should be added around the perimeter of the chain, and there should be 19mm of clearance on each side of the chain. (Especially when the outer dimensions of the chain box are limited by space, more attention should be paid to the internal clearance of the chain box).

2. There are tension measures for the compensation of chain elongation, and the idle sag is less than 1% of the center distance.

3. When the inclination angle between the chain drive direction and the horizontal plane is greater than 60°, the chain must be tensioned with a tensioning device.

4. 链轮最小齿为17,。在中高速或最大允许载荷范围运行时,小链轮齿要淬火,齿数尽可能为21。链轮最大齿数为150齿。优先从17、19、21、23、25、38、57、76、95、114数中选择齿数。

5. The optimal center distance of chain drive is 30~50 times of chain pitch, and the minimum wrap angle of small sprocket is 120°.

6. When the roller chain runs at very low speed or dynamic load, the value of dynamic pulling force does not exceed 0.15 times of the minimum breaking force, regardless of centrifugal force.