The BOSCH brand Timing Belt of a car is needed to transfer rotation from the engine crankshaft to the camshaft. In a modern car, the problem synchronization of the opening and closing of the engine valves is solved by combining the rotation of the crankshaft, on which the pistons are fixed, and the camshaft, which makes the valve move. Synchronization is achieved by installing a special pulley on both of these shafts and pulling a toothed belt or chain between them.

1. BX (XB-_)
2. BX Break (XB-_)
3. XM (Y3)
4. XM Break (Y3)
5. XM Estate (Y3)
6. ZX (N2)
7. XANTIA (X1_, X2_)
8. 205 II (20A/C)
9. 205 Mk II (20A/C)
10. 205 I Convertible (741B, 20D)
11. 205 � Convertible (741B, 20D)
12. 309 II (3C, 3A)
13. 309 Mk II (3C, 3A)
14. 405 I (15B)
15. 405 I Saloon (15B)
16. 405 � (15B)
17. 405 II (4B)
18. 405 II Saloon (4B)
19. 405 Mk II (4B)
20. 405 I Break (15E)
21. See more in applications

The principles of the timing belt work

In terms of a belt, it is an internally toothed belt made of high-strength, cord-based rubber. Correctly installed belt, due to its tension, transfers rotation from the crankshaft to the engine camshaft. The teeth of the belt prevent it from slipping and thereby ensure the rotation of the camshaft strictly depending on the angle by which the crankshaft turned. This achieves the opening and closing of the intake and exhaust valves of the engine at the right time, depending on the position of the engine pistons. To facilitate the installation and compensate for the stretching of the belt during operation, special tensioning rollers with a tensioning device are used.