Siemens MOTOX BA 2010 Operating Instructions Manual page 17

NOTICE
Damaged or destroyed backstop
Do not run the motor against the backstop.
Note the directional arrow on the gearbox.
The gearbox can be fitted with a mechanical backstop. The backstop can be fitted either in
the coupling lantern or in the 2nd stage of the bevel helical gearbox. It permits only the
correct direction of rotation during operation. This is indicated by an arrow pointing in the
corresponding direction.
The backstop is fitted with centrifugally operated sprags. When the gearbox is running in the
specified direction, the inner ring and the cage with the sprags also rotate while the outer
ring remains stationary.
Where the backstop is used in the coupling lantern, lifting of the sprags is ensured when the
drive speed is above the speed listed in the table. The backstop is wear-free. It does not
require maintenance.
Table 2- 1
Motor size
80/90
100
112
132, 160
180/200, 225, 250
280
When used in the bevel helical gearbox (gearbox intermediate shaft), the backstop operates
at speeds below the lift-off speed of the sprags in a separate oil chamber. The oil must be
changed at the same intervals as the gearbox.
BA 2010
Operating Instructions, 02/2018, A5E38093846A/RS-AC
Drive speed when using backstops
Backstop
FXM-46 DX
FXM-51 DX
FXM-61 DX
FXM-76 DX
FXM-101 DX
FXM-100 SX
Technical description
2.4 Backstop
Minimum speed
[rpm]
> 820
> 750
> 750
> 670
> 610
> 400
15