MGM BAH 132 Series, Use And Maintenance Manual

Page: 36 / 63

Page 36 of 63
Doc. Ref.: A79H0319
Air gap useful range
Motor Frame Size 132 160-180-200 225-250-280
Airgap (mm) 0.35 ÷ 0.8 0.45 ÷ 1.0 0.7 ÷ 1.1
Table 1
It's strongly advisable not to exceed these values. Out of range airgap can cause vibrations of the brake moving
element, prominent noise, the burning of the brake coil or the damaging of the brake assembly. The airgap tends to
increase with the wear of the brake disc, therefore it's advisable to periodically check the air gap. It’s important to
remark that the brake linings wear more during the run-in period (a few thousands stops).
To check the airgap:
-
Remove the BAH brake cover following the instructions in the relative paragraph;
-
Remove vacuuming the eventually accumulated lining material dust;
-
To measure the airgap use the feeler (thickness) gauge as indicated in table 1. Check the airgap again around the magnet
cores in three different points at 120°. The airgap must be uniform.
Remark: photos shown in this manual are just an indicative reference for the operation to be performed. The photos shown do
not necessarily represent all types of brake.
NOTE: to check the airgap properly do not
insert the feeler gauges between two polar
faces.
If the measured airgap does not fall within the range indicated in table 1 then it’s necessary to reset the airgap according to
the below instructions.
-
Loosen but don’t remove the nuts (21) and the locknuts (22) on all the
brake adjusters so that the brake coil can slightly slide up and down. Make
sure that the nuts (21) do not hold the brake coil and that the brake coil
leans against the moving element.
It is not possible to modify the position of the brake coil by operating only
on one nut (21) without having loosened all the locknuts (22) on all brake
adjusters.
-
Insert a feeler gauge with the thickness corresponding to the lower value
of the airgap allowed range indicated in table 1, between one of brake coil
(25) cores and the moving element (24) just next to the brake adjusters
(19). Operate the nuts (21) and the locknuts (22) until the feeler gauge
tightly fits, but is not stuck between the two cores. Use an upper size
feelers gauge (0.1-0.15 thicker compared to the one previously used) to
check that the airgap is not set to a higher value than required. If the
airgap is properly set, the upper size feeler gauge will not enter the airgap.
NO
YES