REXROTH MKD025A-144, Manual

Page: 126 / 184

13-8
Application Instructions Synchronous Motors MKD
19.05.2004 Version7.0 DOK-MOTOR*-MKD*******-PR07-EN-P
13.5 Holding Brakes
Optional. Required for holding the servo axis when the machine is in the
de-energized state.
DANGER
Hazardous movements! Persons endangered by
falling or descending axes!!
⇒
The serially delivered motor holding brake does not
suffice to ensure overall personal protection!
⇒
Ensure personal protection by superordinate failsafe
measures:
⇒
Block off the hazardous range by means of a safety
fence or a safety screen.
⇒
Additionally secure vertical axes to prevent them from
falling or descending after having switched off the
motor, for instance as follows:
– lock the vertical axis mechanically,
– provide an external braking / collecting / clamping
device, or
– ensure proper weight compensation of the axis.
The holding brake is operated according to the “electrically releasing”
principle. In the de-energized state, a magnetic force acts upon the
brake armature disk. This causes the brake to close and to hold the axis.
By applying 24 V
DC
, the permanent magnetic field is compensated by
the electrically generated magnetic field: the brake opens.
t
Un [V]
0
24
t
1
t
2
brake_diagr.fh7
t
1:
Connection time
t
2:
Disconnection time
Fig. 13-14: Holding brake diagram