NORD Drivesystems B1904 - Manual (Page 10)

Operating and Installation Instructions FDB (Getriebebau NORD)
Version 08.2011
Page 10 of 23
3.2 Technical Information
3.2.1 Operation of the Brake (Illustration 3.1)
The electromagnetically released spring-applied brakes of the FDB series are fail-safe brakes,
this means that the braking torque is generated by means of spring force, and released by
magnetic force.
During braking, the pressure springs (item 4, illustration 3.1) apply pressure to the armature
plate (item 2) trapping the rotor (item 3.1 / 3.2) which is keyed to the machine shaft, against the
counter-friction surface (flange (item 7), friction plate (item 8) or motor flange). The two friction
sides of the rotor and the armature disk and/or the counter-friction surface produces the braking
torque.
During releasing, a magnetic force is produced through applying a direct voltage to the magnet
body (item 1.1 / 1.2) via the field winding. Said magnetic force draws the armature disk (item 2)
to the magnet body and the brake rotor is released.
During manual releasing (only if brakes are designed with manual release), the armature disk
is mechanically pulled against the magnet body by pulling the manual release handle (item 5,
with screwed-in manual releasing lever (item 5.1)) and thus the rotor is released. This enables
you to release the brake, for example, even if there is a power failure.
ÎAttention!
For safety reasons, the adjustment of the manual release must not be changed!
Illustration 3.1:
Operation of the
brake (sectional
view)