Cicsa

For elevators and conveyors with round steel link chain equipment

Immediately after setting up the chains, and then regularly every 1-3 months, it is necessary to check(1) the matching of the links in the teeth of the driving wheels where applicable, (2) the horizontal position of all buckets, (3) the contact and centring of the chains on the lower wheels, (4) the locking nuts and bolts. After that it is also possible to check how much wear and tear are increasing (see the instructions below). The fi rst wear and tear measure (“PRELIMINARY CHECK”) should take place after the running in (at least 100 hours).
The “MACHINE CHECK FORM” enables to gather the measured data so that the average wear and tear of the area of contact of the links (interlink) can be determined.
By comparing these data, the increase of wear and tear can be controlled and it is possible to predict quite correctly when old chains should be replaced by new ones.

A/B-TYPE MEASURES

They are suggested for any kind of elevator, conveyor and scraper. With reference to the picture, the A-type measure is taken on groups of 3 links with a suitable sliding gauge, whereas the B-type is measured on groups of two consecutive links. A and B measures permit to calculate the average wear in the interlink.
In case of bucket elevators with chain shackles, the B measure can also be applied to the point of contact of the bracket and the chain link. In this case it is necessary to check if wear and tear in the contact areas are well distributed, since shackles and links are manufactured with two different technologies. At least 10 measures of this kind should be taken in different positions of the chain, both on the right and on the left side. Thus the average measures for each side can be determined.The measures taken during the “PRELIMINARY CHECK” make up a set of reference for the following machine checks which allow to defi ne exactly both the link pitch and the diameter value in the interlink of the worn chain.
After the second measurement the chain wear can be calculated by means of the relations below:

Wear can be expressed as percentage of the diameter:
W=WL × 100 / Dn (%)
or alternatively as a percentage of the chain pitch:
W2=WL ×2×100 / Pn (%)
Substitution of the chain is generally recommended when wear has exceeded the value of total hardening depth (for smooth wheel machines) or 3% of the pitch (for toothed wheel machines). In the second case, oversized teeth may be used to extend the chain life.For further details and special solutions contact CICSA technical staff.