Holding Brake - Bosch Rexroth MS2S Operating Manual

MS2S
CAUTION
Ingressing fluid may damage the motor!
Fluids (e.g., cooling lubricants, gear oil, etc.)
may not be present at the output shaft.
When attaching gearboxes, only use gearboxes
with a closed (oil-tight) lubrication system.
Gearbox oil should not be in permanent contact
with the shaft sealing ring of the motors.
Overdetermined bearing
When installing drive elements, avoid overdeter-
mined bearing, as impermissibly high bearing
reactions can be generated due to unfavorable
bearing ratios.
Remark: If an overdetermined arrangement of
bearings cannot be avoided, please contact
Bosch Rexroth.
Couplings
The machine construction and the drive elements
used must be carefully adapted to the motor type
so as to make sure that the load limits of the shaft
and the bearing are not exceeded.
Remark: When extremely stiff couplings are
attached, the revolving radial force may cause an
impermissibly high load on the shaft and bearing.
Bevel gear pinion or helical drive pinion
Due to thermal expansion, the DE side of the
drive shaft can be displaced by up to 0.25 mm in
relation to the motor housing. If helical drive pin-
ions or bevel gear pinions directly attached to the
output shaft are used, this change in the lengths
will lead to
R911410077, Edition 01
•
a shift in the position of the axis, if the driving
pinions are not axially fixed on the machine
side.
•
a thermally dependent component of the
axial force, if the driving pinions are axially
fixed on the machine side. This causes the
risk of exceeding the maximum permissible
axial force or of the gear backlash increasing
to an impermissible degree.
•
damage of the NDE bearing by exceeding the
maximum permissible axial force.
Remark: It is recommended to use drive ele-
ments with integrated bearings and mount them
on the motor shaft via axially compensating cou-
plings.
5.2.8

Holding brake

MS2S motors can optionally be provided with
spring force brakes. The holding brakes operate
according to the "electrically-released" principle
(closed-circuit principle) and open upon applying
the switching voltage.
•
The service life (switching cycles) of spring
force brakes depends on the number of start-
stop cycles. With spring force brakes, there is
always startup wear, since an air cushion
must first build up between the lining and the
friction surfaces when the speed increases.
This wear can be increased by accelerations
of the friction disk, e.g. in the case of a ver-
tical arrangement (acceleration due to
gravity) or by external centrifugal forces,
whereby in this case only one friction lining
side is affected in most cases.
•
The holding brakes with emergency stop
function are intended to secure motor shafts
at standstill. The holding brakes are no oper-
ation brakes to decelerate motors in opera-
tion from speed.
•
In case of an emergency stop or voltage drop,
the brake operation is only allowed to a lim-
ited extend. Up to 500 breaking cycles from
speed 3000 1/min can be performed,
whereas the maximum switched energy per
25 / 50
Features and functions
Bosch Rexroth AG