Technical data

MHD Sychronous motors Startup, Operation, and Maintenance 19-3
DOK-MOTOR*-MHD********-PR05-EN-P version 0.1
Holding Brake
In order to ensure proper functioning of the holding brake, it must be
checked before the motors are installed.
Measure the holding torque of the brake; grind in the holding brake, if
necessary.
Proceed as follows:
1. De-energize the motor and secure it against re-energization.
2. Measure the transmittable holding torque of the holding brake using a
torque spanner. The holding torque of the brakes is specified in the
data sheets.
3. If the holding torque specified in the data sheets is attained, the
holding brake is ready for operation.
If the holding torque specified in the data sheets is not attained, the
holding brake must be ground in as described in step 4.
4. Grinding in: With the holding brake closed, manually turn the output
shaft by approx. five revolutions and measure the transmittable
holding torque of the brake using a torque spanner.
5. If the holding torque specified in the data sheets is attained, the
holding brake is ready for operation.
If the holding torque specified in the data sheets fails to be reached,
repeat steps 4 and 5 of the grinding-in process.
If the specified holding torque is not attained after the second grinding-in
process, the holding brake is not operable. Notify Rexroth Service.
If holding brakes are required only sporadically (braking cycle >48 h)
during operation, film rust may develop on the brake friction surface.
To prevent the holding torque from dropping below the specified holding
torque, we recommend the grinding procedure described below:
Recommendation for grinding in
Interval Once in 48 h
Grinding-in speed 100 rpm
Number of grinding-in revolutions 1
Ambient temperature –20 °C to +50 °C
Fig. 19-1: Recommended procedure for grinding in motor holding brakes
Note: The option of automatically implementing the grinding-in
routine in the program run is described in the documentation
of the particular drive controllers.
During normal operation, it is not necessary to grind in the brake.
It is sufficient if the brake is activated twice a day by removing the
controller enable signal.
Before initial startup
During operation