Tension of timing chain has obvious effect on improving working reliability and supply long service life. But excessive tension will increase the specific pressure of the hinge and reduce the chain transmission capacity.

Therefore, it require to tension for timing chain in the following situations:
1. The timing chain length is stretched after being worn, in order to ensure a reasonable sag and a stable loose load.
2. When the center distance between the two wheels is not adjustable or difficult to adjust;
3. When the center distance of the sprocket is over-worked (A>50P);
4. When vertically arranged;
5. Pulsating load, vibration, impact;
6. Large speed ratio, small sprocket wrap angle is less than 120°. The tension of the timing chain is controlled by the amount of sag: min is (0.01-0.015)A for vertical arrangement and 0.02A for horizontal arrangement; max is 3min for general transmission and 2min for precision transmission.

5 method to Tension timing chain:
1. Adjust the center distance of the sprocket;
2. Adopt sprocket tension;
3. Adopt tension roller to tension;
4. Adopt elastic pressure plate or elastic sprocket to tension;
5. Hydraulic tension. When tightening the tension tight side, it should be tension inside the tight side to reduce vibration; when the tension is on the loose side, if the sprocket wrap angle relationship is considered, it should be tension at the small sprocket 4p; if the sag is considered to be eliminated , it should be tension against the large sprocket 4p or where the loose edge sags the most.