Valley Center Pivot 7000 Series, Owner'S Manual, Page: 21 / 106

Center Pivot 7000, 8000, 8120 Series 21
OVERVIEW
Pivot
The center pivot is the structure which the entire ma-
chine rotates around. The water entry point for the
machine is at the riser pipe. See Figure 21-1.
The legs of a conventional center pivot are bolted
to a concrete foundation. Some pivots are towable
with a pivot point that is equipped with wheels so it
can easily be moved from one field to the other. See
Figure 21-1.
Collector Ring and J-Pipe
The collector ring allows the electric cable to rotate
with the pivot and is used with all public power op-
tions. See Figure 21-1.
The collector ring consists of brass rings in a stack
that remain stationary and are separated by insula-
tors.
Contact brushes revolve around the brass rings pro-
viding continuous flow of current without twisting the
cable as the machine makes revolutions around the
field.
One electrical cable from the collector ring goes
down through the J-pipe, exiting near the bottom of
the riser and then is connected into the public power
panel.
The other electrical cable from the collector ring goes
out of the conduit and then connects into the control
panel.
Pivot Flex
A pivot flex allows for flexibility between the pivot
point and the first span. A Pivot Flex is required
where the first drive unit is 4% above or below the
level of the pivot pad. See Figure 21-1.
Grounding Jumper must be installed from the pivot
swivel flange to the span flange.
Copyright © 2005 Valmont Industries, Inc.
8P4W0128
09-03
Assembly / Part Functional Area
1
4 Wheel EZ Tow Overall Assembled View
Quality checked for better irrigation
ENG13/ORIG/02-97
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Figure 21-1 1. Conventional Center Pivot
2. 4 Wheel E-Z Tow Pivot
3. 2 Wheel E-Z Tow Pivot
4. Collector Ring
5. Pivot Flex Coupling
6. Control Panel
7. Riser Pipe