How To Inspect The Chain - Hitachi L Series Service Manual

6-8. How to inspect the chain

1. Confirmation and application of the chain lubricant
( 1 ) Since it is difficult for the lubricant oil to reach the contact
points of the chains in the load-hoisting state, please apply
lubricating oil to the chain contact points A in a state when
the chain is slackened.
( 2 ) After the application, wind up and down the chain along
the whole head for 2.3 times, and apply the lubricant
such that it can also reach the contact points between the
chains.
( 3 ) When usage frequency is high, we recommend applying the lubricant periodically about once a week.
( 4 ) Please use Shell Tona S3 M220 (Hitachi genuine parts: part code 836492) as the lubricating oil.
2. Elongation, wear limit
( 1 ) That the inner length dimension L of the chain is greater than the value in the table below due to wear and
elongation. (The wear and elongation of the inner length is 5% or more from the original dimension)
( 2 ) The diameter d of the link falls below the value in the table below due to wear (wear of not less than 10%
of nominal diameter)
* When there is a sever chain, also verify the wear condition of the sprocket and sprocket guide at the
same time.
Chain
Diameter
6.3
3. Measurement of wear and elongation by the limit gauge
( 1 ) Using the attached limit gauge, measure the wear and elongation using the two measuring methods of
pitch and wire diameter, as shown in the figure below.
( 2 ) Perform measurements on all the chains, and if one is judged not usable, please exchange it.
* If a worn or elongated chain is continued to be used, there is a danger of it breaking.
( 3 ) When incorporating in an automatic machine etc. and using it to wind up/down a constant head length,
please conduct focused and more frequent checks on the chains' meshing with the sprocket and
surrounding when the machine is stopped.
A gap must remain
4. Others
( 1 ) No scratches or other harmful defects allowed.
( 2 ) No attached foreign matter is allowed.
Usage limit dimension
d
5.7
Pitch measurement
Usable Not usable
unit : mm
L
20
Measurement of the line gauze
The wire must not
enter the notch
of the gauge
Usable
- 24 -
A
Contact points
d
L
Not usable