Foreword and general information
Explanation of terms for maintenance standard
PC800, 850-8E0
4.
Repair limit and allowable value or allowable
dimension
q
The dimension of a part changes because of
wear and deformation while it is used. The
limit of changed dimension is called the "re-
pair limit".
q
If a part is worn to the repair limit, it must be
replaced or repaired.
q
The performance and function of a product
lowers while it is used. A value with which the
product can be used without causing a prob-
lem is called the "allowable value" or "allow-
able dimension".
q
If a product deviates from the allowable val-
ue, it must be checked or repaired. However,
since most of the allowable values are esti-
mated from various tests or experiences in
most cases, it must be judged after consider-
ing the operating condition and customer's
requirement.
5.
Allowable clearance
q
Parts can be used until the clearance be-
tween them is increased to a certain limit.
The limit at which those parts cannot be used
is called the "allowable clearance".
q
If the clearance between the parts exceeds
the allowable clearance, they must be re-
placed or repaired.
6.
Allowable interference
q
The allowable maximum interference be-
tween the hole of a part and the shaft of an-
other part to be assembled is called the
"allowable interference".
q
The allowable interference shows the repair
limit of the part of smaller tolerance.
q
If the interference between the parts exceeds
the allowable interference, they must be re-
placed or repaired.
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