Description of the motors
2.6 Mounting and options
1FK7 G2 synchronous motors
44
Operating Instructions, 05/2021, A5E50907562B AA
2.6.6
Holding brake
2.6.6.1
Type of holding brake
The holding brake is implemented as a permanent-magnet brake.
The magnetic field of the permanent magnets exerts a pulling force on the brake armature
disk. This means that in the no-current condition, the brake is closed and the motor shaft is
held.
When a 24 V DC rated voltage is applied to the brake, the current-carrying coil produces an
opposing field. This neutralizes the force of the permanent magnets and the brake opens
without any residual torque.
The permanent magnet brake has zero backlash.
NOTICE
Damage to the motor due to axial forces on the shaft extension
Axial forces on the shaft extension can damage motors with an integrated permanent-
magnet holding brake.
•
Avoid axial forces on the shaft extension.
2.6.6.2
Properties
•
The holding brake is used to clamp the motor shaft when the motor is at a standstill. The
holding brake is
not
a working brake for braking the rotating motor. When the motor is at
a standstill, the holding brake is designed for at least 5 million switching cycles.
•
A limited number of Emergency Stop operations is permissible.
WARNING
Unpredictable movements of the machine or system because of inadequate braking
performance
If you use the holding brake incorrectly, e.g. as an operating brake or you ignore the
permissible operating energy of the brake, then the brake will be subject to excessive
and impermissible wear. As a consequence, there may be no braking effect at all.
Unintentional movements of the machine or system can result in death or serious injury.
•
Observe the permissible operating energy and EMERGENCY STOP properties.
•
Operate the motor only in conjunction with an intact brake.
•
Avoid repeated brief acceleration of the motor against a holding brake that is still
closed.