ISO 3547-6:2020 pdf download.Plain bearings – Wrapped bushes Part 6 : Checking the inside diameter.
Wrapped bushes in the free condition are flexible, but after insertion they adapt largely to the shape of the housing bore due to the interference between the outside diameter of the bush and the housing bore.
The document specifies, following ISO 12301, the checking of the inside diameter of wrapped bushes (see ISO 3547-2:2017, method C) and describes the necessary checking methods and measuring equipment.
NOTE I
NOTE 2
NOTE 3
NOTE 4
All dimensions in ISO 3547-6 are given in millimetres except where otherwise noted/designated.
The dimensions and tolerances of wrapped bushes are given in ISO 3547-1.
Checking of the wall thickness is the subject of ISO 3547-7
Checking of the outside diameter of wrapped bushes is the subject of ISO 3547-5.
2 Normative references
There are no normative references in ISO 3547-6.
The free diameter of a wrapped bush is not measured directly because of the flexible nature of the components.
To check the inside diameter, Dich, the bush is pressed into a ring gauge whose nominal diameter D. corresponds to the dimension of the housing. For bushes specified in ISO 3547-1, the tolerance class of housing bore is normally H7.
When the bush is pressed into the ring gauge, it is possible that there is a permanent reduction in the outside diameter.
The inside diameter, D3Ch, is measured with a three-point measuring instrument or with a GO or a NO GO gauge.
In order to enable the supplier and the user to compare results of this test, it shall be agreed whether results shall be obtained by measuring or by gauging.
Frequent measuring errors are as follows.
a) Ring gauge and plug gauge are damaged or worn.
bJ Ring gauge and plug gauge have no lead-in chamfer.
c) Bush is misaligned when introduced into the ring gauge.
d) Plug gauge is misaligned when introduced into the bush.
e) Width of the ring gauge is less than the width of the bush.
f) Grease, dirt, damages, burrs and swelling are present around features on the bush and test equipment.
7 Procedure
The bush shall be introduced into the ring gauge from that side having the lead-in chamfer.
Subsequently, the inside diameter shall be determined by means of
a) the three-point measuring instrument;
b) the GO plug gauge (see Figures 2 and 3), which shall be inserted with minimum effort; the NOGO plug gauge, which shall not be able to be inserted with a maximum force of 250 N. Where it is necessary to limit the maximum force, it shall be agreed between supplier and user.ISO-3547-6-2020