Installation and Operational Instructions for
ROBA-stop
®
-Z Type 892.101.0
Size 125
(E073 01 046 000 4 EN)
18/05/2022 TK/HW/SU
Chr. Mayr GmbH + Co. KG
Eichenstraße 1, D-87665 Mauerstetten, Germany
Phone: +49 8341 804-0, Fax: +49 8341 804-421
Page 13 of 16
www.mayr.com
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Braking Torque
The (nominal) braking torque is the torque effective in the shaft
train on slipping brakes, with a sliding speed of 1 m/s referring to
the mean friction radius.
The brake is loaded statically when used as a service brake and
loaded dynamically in EMERGENCY STOP operation.
Respectively, there are different speed values for the friction
material, which in practice also leads to different friction values
and therefore braking torques. Amongst other things, the braking
torque is dependent on the respective quality / condition of the
friction surfaces (conditioning). Therefore, bedding in of the brake
linings on newly installed brakes or on rotor replacement when
mounted is required, taking into account the permitted loads: The
following applies as a reference value for the bedding in of new
brake linings. The load in new condition may not be more than 50
% of the max. friction work, acc. Technical Data. This process is
to be carried out at reduced speed, approx. 30 % of the operating
speed.
If the bedding in should take place under works-specific
conditions, we ask you to contact us, so that we can provide the
appropriate parameters.
Friction materials develop their optimum effect only under speed
at the appropriate contact pressure, as continuous regeneration
of the friction surface then takes place (torque consistency).
Permanent grinding of the rotors can lead to overheating /
damage to the brake linings, and therefore to a drop in braking
torque.
Furthermore, friction materials are subject to aging, which is also
influenced, among other things, by higher temperatures and other
ambient influences. We recommend regular inspection of the
braking torque (1 x per year) including the respective dynamic
braking actions as a refresher.
Brake Inspection
(before brake initial operation)
Air gaps inspection (Fig. 4)
Measure the air gap “a” (brake de-energized) several times
on the circumference.
The nominal air gap acc. Table 1 must be given.
Measure the min. individual air gap "b" (brake energized) of
brake circuit 1 (inside) and brake circuit 2 (outside) several
times on the circumference.
The respective minimal air gap acc. Table 1 must be given.
Braking torque inspection:
Please compare the requested braking torque with the
torque stated
on the Type tag (24).
Release function inspection
by energizing the brake.
Switch function inspection of the release monitoring
with microswitch (NO contact)
Brake de-energized
Signal “OFF”
Brake energized
Signal “ON”
Hand release functional inspection
By deflecting the hand release (18) manually, the friction
linings are relieved. The brake is free but for a residual
torque of max. 8 %.
When actuating the hand release (18), a
switching signal of the release monitoring
device (11) cannot be guaranteed.
Dual Circuit Brake Functional Inspection
The ROBA-stop
®
–Z brake is equipped with a double safety
(redundant) braking system. If one brake circuit fails, min. 50 % of
the braking torque remain. The single brake circuit inspection is
carried out using the reference gauges (10) included in delivery.
DANGER
Should the load begin to move after tilting the
feeler gauges (10) or should it fail to react to
the braking procedure, the reference gauges
must be pivoted back and removed
immediately.
The dual circuit braking function is not
guaranteed.
Shut down the system, lower and secure the
load, remove and inspect the brake.
Please observe the accident prevention
regulations.
Remove the
reference gauges
(ideally attached to the motor or
the gearbox).
Inspection brake circuit 1
(mounting-side, see Fig. 1):
1. Push both reference gauges, 180° offset to each other, with
the flattened section between the brake body (2) and the
machine wall.
Set up the reference gauges at 90° (tilt) and hold in this
position (no spring force on rotor 1 (Item 5)).
2. Energize the brake and put the drive into operation.
3. De-energize the brake (= EMERGENCY STOP) and inspect
the stopping distance.
4. Turn the flat sections of the reference gauges once more
and remove them from the brake.
Inspection brake circuit 2
(brake plate-side, see Fig. 1):
1. Push both reference gauges, 180° offset to each other, with
the flattened section between the armature disk (14) and the
brake plate (15). Set up the reference gauges at 90°
(tilt) and hold in this position (no spring force on rotor 2 (Item
6)).
2. Energize the brake and put the drive into operation.
3. De-energize the brake (= EMERGENCY STOP) and inspect
the stopping distance.
4. Turn the flat sections of the reference gauges once more
and remove them from the brake.
Attach the reference gauges to the motor or gearbox again.
