NORD Drivesystems B1000 - Manual (Page 33)

www.nord.com A31 G1000 – Subject to Change Without Notice
INTRODUCTION
Counter Rotating Drives
Often mixing tanks use a dual agitation system. For
example, a scraper blade rotates in one direction along
the sides and bottom, while a turbine blade rotates in
the opposite direction in the middle of the tank.
Nord can provide an economical, compact drive system
to perform this function. A standard hollow bore re-
ducer is used as the top drive that rotates the turbine.
This drive may have a standard B5 output fl ange
slightly modifi ed to fi t the mating B14 fl ange on the
bottom reducer. Or, in some cases, it may be necessary
to use an adapter plate between the two units in or-
der to match the fl anges. The top drive can be any
hollow bore reducer, such as a helical shaft mount, a
helical-bevel, or a helical-worm reducer.
For stacked-mixer applications, a bore differential be-
tween the two units is essential. Thus, it is necessary
to have a larger diameter on the lower unit and a
smaller diameter on the upper unit. Nord can provide
the upper unit with a smaller bore by using an “AXF”
style bevel. Likewise, Nord can supply a larger alter-
nate bore on several of the “AZ” or “AF” style bevels
for the lower unit.
If the bore differential is still not suffi cient when us-
ing an “AXF” on top with a larger bore on bottom,
Nord can provide a special hollow shaft for the lower
gearbox. This shaft has no inner keyway. The shaft
extends below the gearbox and has an outer keyway
onto which the customer can mount a coupling. This
shaft is similar to a solid shaft except that it has a hol-
low bore running through it.
Since the mixer components usually require fi nal po-
sitioning adjustment, Nord units can be supplied with
a keyless shrink disc attachment on the upper unit.
This method allows for easy installation and adjust-
ment. It also greatly facilitates disassembly and elimi-
nates fretting corrosion.
SK9052.1AXF-160M/4 (top)
+ SK9072.1AF-132M/4 (bottom)
• Flange used on bottom of lower gearbox (optional).
• No adapter plate needed between gearboxes.
• Taper bearings standard on both units.
• Special extended hollow shaft with externally
mounted coupling. SK5282AFSH-132S/4
+ SK9082.1AF-160M/4
• Flange used on bottom of lower gearbox (optional).
• Adapter plate needed between gearboxes.
• Shrink disc on top gearbox
• Taper bearings on top gearbox
Gear Unit
Options