Wahlberg Winch 25, Руководство пользователя

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220.805.011 36 Date: 2021-12-09
Life of the wire
It is Wahlberg Motion Design policy to apply the strictest possible calibration
procedures and use the best quality materials available to ensure optimum
performance and the longest possible component lifetimes. However, wires are subject
to wear and tear over the life of the product, resulting in special attention to the state
of the wire. The extent of wear and tear depends heavily on operating conditions and
environment, so it is impossible to specify precisely whether and to what extent the
wire performance will be affected.
The expected lifetime of the wire depends on the load and travel length as well as
duty cycle.
Wire discard criteria
When the wire is exposed, the following guidelines can be used to control whether the
wire must be discarded. The following serves as guidelines and if any of the discard
criteria are reached, the winch must immediately be taken out of service, and the
wire replaced, before using the winch again.
The wire should be discarded when:
−
When the overall diameter of the wire is reduced by 8 %, or the outer wires
have lost its diameter by 33 % through wear. This reduction in diameter of the
wire is measured on a portion of the wire which has been subjected to abrasion
and stresses with respect to the portion of the wire which is subjected to
stresses but not abrasion e.g. portions near drum or anchorage.
−
When there is evidence of considerable plastic wear or surface embrittlement.
−
When the diameter of the wire has suddenly reduced or the lay length has
suddenly increased or decreased.
−
When there is evidence of severe corrosion like chain pitting.
−
When there is any evidence of internal corrosion in the rope. This can be
recognized by slackness of outer wires due to the internal wires corroding
away.
−
When the wire has been subjected to mechanical damage, crushing, kink,
bends, bird cage, etc.
Figure 1: When using a calliper to measure wire diameter, measure
from crown to crown, not from valley to valley.