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The 414 Centrifuge utilizes a spring loaded coupling to limit this torque. The torque
is exerted on this coupling which is mounted next to the gearbox sheave. Should the
torque exceed a preset limit, (50-60 ft/lb. (74.4-89.3 km)) the coupling will disengage
and trip a limit switch (See Item 224, Diagram 1). This will shut off both the feed
pump and main drive motor. The bowl should then be flushed with water to remove
any excess solids left in the bowl. The procedure for resetting the G.S. coupling is
discussed in the next paragraph. Continued coupling disengagements will require
removal of bowl and conveyor for cleaning.
Figure 12a illustrates the G.S. coupling in the engaged position. When excessive
torque is exerted on the gearbox, the G.S. coupling disengages from the driver (Figure
12b). The three balls of the coupling are forced out of the depressions in the driver an
slide down the slopes of the driver. This causes the coupling and the driver to rotate
60° in relation to each other. At the same time, the coupling moves 1/4" toward the
driver. This movement trips the limit switch which removes power from the feed
pump (when feed pump interlock is used) and the main drive motor. This movement
also allows the cams on the V-belt pulley to be released from the slots in the coupling
as shown in Figure 12b. The bowl and conveyor now rotate at the same speed.
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