Wittur servogearless WSG-S3.4 Instructions De Service page 56

Technical specifications
3.1.3 Brake release
When the brakes are applied, an air gap "s
To release the brake, the coil of the stator (1.1) is energised with the DC voltage provided. The resulting mag-
netic flux works against the spring force to draw the armature plate (2) to the stator (1.1). This releases the
rotor (3) from the spring force and allows it to rotate freely
3.1.4 Release monitoring
The spring-activated brake has a micro-switch for each braking circuit to monitor the switching state. When
the brake is released, the micro-switches toggle. This means that it is possible to prevent the drive from being
operated when the brake is closed. The micro-switches can be connected as both normally open and also
normally closed.
To check that the micro-switches function correctly, we recommend testing the switching status (refer to ta-
ble 6) in both the released and applied braking states.
3.1.5 Encapsulated design (optional)
This design not only avoids the penetration of spray water and dust, but also the spreading of abrasion par-
ticles outside the brake. This is achieved by:
❚ a cover seal over the armature plate and rotor.
3.1.6 Project planning notes
❚ The brakes are dimensioned in such a way that the given rated torques are reached safely after a short
run-in process.
❚ However, since the organic friction linings used do not all have identical properties and because envi-
ronmental conditions can vary, deviations from the specified braking torques are possible. These must
be taken into account in the form of appropriate dimensioning tolerances. Increased breakaway torque
is common in particular after long downtimes in humid environments where temperatures vary.
❚
If the brake is used as a pure holding brake without dynamic load, the friction lining must be reactivated
regularly.
INTORQ | BA 14.0196 | 04/2016
" is present between the stator (1.1) and the armature plate (2).
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