Selecting Holding Brakes; Sizing Of Holding Brakes (Application) - Bosch Rexroth IndraDyn A Series Project Planning Manual

Rexroth IndraDyn A

Selecting Holding Brakes

Electrically clamping holding
Electrically releasing holding

Sizing of Holding Brakes (Application)

DOK-MOTOR*-MAD/MAF****-PR03-EN-P
Brakes are either electrically clamping or electrically releasing.. Due to
functional differences, different brakes should be used for main spindle
and servo-axles. Observe the safety requirements during the system
design.
t 1
1
24
U n [V]
0
(1): Electrically clamping brake
t 1: Combination delay
t 2 : Release delay
Fig. 9-21: Holding brake diagram
Main Spindle Applications
An electrically clamping holding brake can be used to lock a main
brake spindle during standstill and when the control "controller enable" signal is
off, e.g. when a tool change is performed without a closed position loop.
⇒ Clamp the motor only at standstill, after the controller has signaled the
motor is at standstill.
The electrically releasing holding brake should not be used for main
spindles. Unintentional clamping of the holding brake at a high engine
speed can lead to extreme deterioration or even demolition of the brake
(e.g. in the case of power loss or wire breakage).
Servo Applications
The electrically releasing holding brake is used to hold the axes at a
brake standstill and when the "controller enable" signal is off. When the supply
voltage fails and the controller is enabled, the electrically releasing
brake will automatically close.
⇒ Do not use the holding brake as an operational brake for moving
axles.
If the brake is engaged repeatedly on a drive in motion or the rated brake
torque is exceeded, premature brake wear can occur.
The electrically clamping holding brake is inappropriate for servo
applications because clamping in a de-energized clamping state is not
possible.
The physical conditions of holding brakes require consideration of two
states. In addition to normal operation, failures must also be considered.
The effective braking torques are physically different.
t 2
2
24
U n [V]
0
t
(2): Electrically releasing brake
9-17
Application Notes
t 1
t 2
t
brake EPS