Siemens MOTOX BA 2010, Operating Instructions Manual

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Technical description
2.4 Backstop
BA 2010
Operating Instructions, 02/2018, A5E38093846A/RS-AC
15
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 Drive speed when using backstops
Motor size Backstop Minimum speed
[rpm]
80/90 FXM-46 DX > 820
100 FXM-51 DX > 750
112 FXM-61 DX > 750
132, 160 FXM-76 DX > 670
180/200, 225, 250 FXM-101 DX > 610
280 FXM-100 SX > 400
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.