Gearbox; Couplings - Bosch Rexroth MAD Project Planning Manual

MAD / MAF Asynchronous Housing Motors
9.14.2

Gearbox

9.14.3

Couplings

Recommended couplings
NOTICE
Fluids (e.g., cooling lubricants, gear oil, etc.) may not be present at the output
shaft. When gears are attached, only gears with a closed (oil-tight) lubrication
system may be used.
Couplings are attached to transmit torques of two separate shaft ends. Usual‐
ly, shaft offset, phase-angle errors or axial distances have to be compensa‐
ted. If the couplings attached are too stiff, a circumferential radial load (= con‐
stantly changing the angular position) can therefore be generated on the out‐
put side. This circumferential radial load may result in an inadmissible high
load of the bearing seat and therefore to a significantly reduced service life of
the bearing.
Rexroth offers bearing variant "A" for attaching couplings to
MAD/MAF motors.
By selecting bearing "A", increased circumferential radial forces can be ab‐
sorbed without limiting the speed of the motor. In addition, there is no signifi‐
cant thermally induced change in length in the vicinity of the connection of the
motor output shaft.
Motor frame size
Bearing A
MAD/MAF...
100B
100C
100D
130B
130C
130D
160B
160C
180C
180D
225C Not available
Tab. 9-21: Allowed circumferential radial forces
In connection with bearing A, Rexroth recommends axially compensating
couplings, such as
● Spring disk couplings with two sets of springs (double gimbal),
● Metal bellows couplings.
These coupling variants are free from play and have a high torsional strength
with low radial spring stiffness.
If the recommended coupling types cannot be used, it is absolute‐
ly necessary that consult Bosch Rexroth be consulted.
For example, recommended manufacturers of the aforementioned couplings
are:
Ingressing fluid may damage the motor!
Allowed circumferential radial forces F
Bearing N / H / V
1000
1000
1000
1200
1200
1200
1500
1500
1800
1800
R911295781_Edition 11 Bosch Rexroth AG
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Application notes
in N
radial_max
25
25
30
40
50
55
65
65
95
100
120