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5.1.7. Chain of the drive of camshafts

Fig. 4.20. Scheme of work of a chain of the drive with one camshaft: 1 – camshaft gear wheel; 2 – uspokoitel of a chain; 3 – TNVD drive gear wheel; 4 – uspokoitel of a chain; 5 – natyazhitel of a chain of the oil pump; 6 – gear wheel of the drive of the oil pump; 7 – gear wheel of a bent shaft; 8 – a boot of a natyazhitel of the operating chain; 9 – hydraulic natyazhitel

Camshafts are set in motion from a bent shaft by means of a two-row chain (so-called duplex chain). The gear wheel of the camshaft has twice bigger number of teeth, than a gear wheel of a bent shaft. Therefore the frequency of rotation of the camshaft is twice less than the frequency of rotation of a bent shaft (fig. 4.20). From the unregulated (tense) party the chain is limited by a special plate (an uspokoitel of a chain), on the other side of it presses a boot of a natyazhitel.
Check of wear of a chain

Fig. 4.21. Check of wear of a chain

At emergence of noise it is necessary to check a condition of a chain (fig. 4.21). At wear the chain is extended. This lengthening results in wear of a gear wheel of the camshaft. At worst teeth of a gear wheel can break, and the chain will slip that will lead to serious damages of the engine.
At timely check of a chain and detection of its wear it is enough to replace a chain and a gear wheel of the camshaft. At strong wear it is necessary to replace all parts of the drive of a chain. This work is performed on STOA by experts.
Natyazhitel of a chain
It is located on the right side of a head of cylinders. Through a boot the natyazhitel presses a chain. Its effort consists of force of the built-in spring and pressure of the oil passing through a natyazhitel. Oil in a natyazhitel also smoothes loadings at a sharp tension of a chain.
The faulty natyazhitel is subject to replacement. A new natyazhitel previously oil engine.