Komatsu PC200-8M0, Shop Manual, Page: 28 / 1254

SEN06112-00
00-200
12
PC200, 200LC, 220, 220LC-8M0
200 Foreword and general information
Explanation of terms for maintenance standard
Repair limit and allowable value or allowable
dimension
q
The dimensions of parts change because of
the wear or deformation while they are used.
When the dimension changes exceeding cer-
tain value, the parts can not be used any lon-
ger. This value is called “repair limit”.
q
If a part is worn to the repair limit, it must be
replaced or repaired.
q
The performance and function of the products
lower while they are used. When the value of
the performance and function lowers exceed-
ing a certain limit and it influences the opera-
tion etc., this value is called the allowable
value or allowable dimension.
q
A product whose dimension is out of the allow-
able value, must be repaired. However, since
the allowable values are generally estimated
through various tests or experiences in most
cases, the judgement must be made in consid-
eration of the operating condition and cus-
tomer’s requirement.
Allowable clearance
q Parts can be used until the clearance between
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 replaced or
repaired.
Allowable interference
q
The allowable maximum interference between
the hole of a part and the shaft of another part
to be assembled is called the “allowable inter-
ference”.
q
The allowable interference shows the repair
limit of the part of smaller tolerance.
q
The parts whose interferences are out of the
allowable interference must be replaced or
repaired.