Parr Instrument Magnetic Drive User Manual
Parr Magnetic Drives
Operating Instruction Manual
234M
Parr Magnetic Drives
Preface 3
Description 3
Related Instructions 3
Light Duty A1120HC/A2140HC/A2150HC Series 3
Heavy Duty Drives A1180HC/A1750HC/A2160HC/A2170HC
Series 3
Extra Heavy Duty Drives A1180HC2/A1750HC2/ A2160HC2/
A2170HC2 Series 3
Characteristics 3
Servicing the Magnetic Drive 4
The O-Ring Seal 5
Servicing the Outer Drive 5
Disassemble the Outer Drive 5
Reassemble the Outer Drive 5
Removing and Installing Mag netic Drives with Flat Gasket
Seals 6
Removing and Installing Mag netic Drives with Olive Seals 6
Servicing the Cooling Sleeve 6
Older Models 6
Installing the Stirrer Shaft on a Footless Magnetic Drive 6
Gasket Material Designations 7
Specifications 8
Magnetic Drives With Lower Foot Bearing 8
Magnetic Drives Without Lower Foot Bearing (Footless) 9
Drawings and Parts Lists 10
A1120HC6 Magnetic Drive 10
A1180HC Magnetic Drive 11
A1180HC5 Magnetic Drive 11
A1750HC Magnetic Drive 12
A1750HC2 Magnetic Drive 12
A2140HC/A2140HC2 Magnetic Drive 13
A2150HC Magnetic Drive 13
A2160HC Magnetic Drive 14
A2160HC4 Magnetic Drive 14
A2170HC Magnetic Drive 15
A2170HC2 Magnetic Drive 15
Customer Service
Questions concerning the installation or operation
of this instrument can be answered by the Parr
Customer Service Department:
Accessories 7
Drive Maintenance Tools 7
Spanner Wrenches 7
1-309-762-7716 • 1-800-872-7720
Fax: 1-309-762-9453
E-mail: parr@parrinst.com
http://www.parrinst.com
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Parr Instrument Company
Parr Magnetic Drives
Preface
Description
The principle operation of Parr magnetic drives provides for attaching the stirrer shaft to an inner set of
magnets. This inner assembly is then surrounded by
the drive housing that seals to the reac tor head allowing pressurization without leakage. A second set of
magnets is then mounted around the sealed hous ing.
The outer magnetic assembly is then coupled to a
motor drive system to provide rotation. The coupling
force be tween the two sets of magnets permits the
shaft to turn at the rpm selected for the motor.
Parr magnetic drives are available in three torque ratings: 16 in-lb, 60 in-lb, and 120 in-lb (1.8 Nm, 6.6 Nm, and
13.2 Nm). The drives are also available with two types
of shafts; one that requires a lower support bushing and
one that is “footless.” The Model number assigned to
each drive depends upon the above selection as well as
the type of connec tion used to mount the drive into the
re actor head and the type of upper cap used for connection to the overarm and motor drive system.
normally ade quate to carry the usual stirring loads developed in a Parr “Mini” reactor and the one and two
liter bench top and floor stand models with general
purpose stir rers. The outer magnetic drive housing
measures 2¼” O. D. x 3½” high.
Heavy Duty Drives A1180HC/A1750HC/ A2160HC/A2170HC Series
This is a 6-pole model with 60 inch pounds of coupling
torque to handle most of the stirring loads arising in
Parr one and two liter, and one, two, and 5 gallon floor
stand reactors with heavy duty stirrers. The drive housing meas ures 3½” O. D. x 4½ high.
Extra Heavy Duty Drives A1180HC2/ A1750HC2/ A2160HC2/A2170HC2 Series
This is the largest of the three Parr drives. It consists of
two, 6-pole mag nets assemblies mounted end-to end
to provide 120 inch-pounds of coupling torque for use
as an alternative drive for large Parr reactors when a
strong drive is required to handle very high viscosity
loads. The drive housing measures 3½” O.D. x 6½” high.
Related Instructions
The following Parr publications are available to
further your understanding of this equipment and its
component parts:
No. Description
201M Limited Warranty
Parr Magnetic Drive Service Instructional Video
Go to http://youtu.be/zjBw5l_yBHw to view a video
supplement to aid users with performing routine mainte-
nance on Parr Instrument Company’s Magnetic Drives.
Light Duty A1120HC/A2140HC/A2150HC Series
This is the smallest of the three drives. It is a 4-pole
model with 16 inch-pounds coupling torque. This is
Conversion from a smaller to a larger drive or to a
“footless” drive may require modification to the standard over/arm and motor configuration. It may require
a different head.
Note: Unless otherwise indicated, the instructions
given here apply to all of the above units.
Characteristics
Parr magnetic drives require minimal attention or
maintenance. The spe cially designed neodymiumironboron permanent magnets used in these drives have
excellent temperature sta bility and can be relied upon
to operate for long periods with little or no flux degradation. When properly installed, the outer rotor should
spin freely and the inner (driven) unit should follow
without slippage, providing a high torque stirring
action. The magnets in both inner and outer rotors are
epoxy bonded to their iron cores.
Care must be taken to prevent these components from
being heated above 100 °C, which would destroy the
bond ing of the magnet assemblies. To pre vent overheating, each magnetic drive has an attached cooling
sleeve through which a steady flow of cold water
should be fed during all vessel operations at temperatures above 100 ºC. Tubing connections for flowing
water connections are provided on each sleeve, and
a 10 foot length of tub ing is furnished to connect to a
water source.
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Parr Magnetic Drives
Servicing the Magnetic Drive
All non-wetted rotating parts in Parr magnetic drives
are permanently lubricated and do not require servicing during normal operation. During operation, inspect
the magnetic drive for unusual noise or leakage. If
problems are encountered with these items take corrective action. The magnetic drive has internal bearings
and thrust washers which require replacement over
time due to physical wear. Excessive lateral or axial
play in the stirrer shaft is an indication of worn bearings or thrust washers. Labored rotation or excessive
debris inside the reactor cylinder also indicates a need
for maintenance. It’s difficult to recommend a timebased preventative maintenance interval for the drive
due to the wide spectrum of operating conditions encountered. The experience of the laboratory should be
used to guide the need for preventative maintenance.
It is advisable to check the drive from time to time for
evidence of leakage into the confined space between
the inner and outer rotors. This can be done without
removing the drive from the vessel head and does
not require complete disassembly. While performing
maintenance or rebuilding the drive, the PTFE o-ring
that seals the top plug should always be renewed if the
plug is removed. To inspect the drive:
Outer Driving
Magnetic
Assembly
Inner Magnetic
Rotor
Non-Rotating
Inner Housing
Holes for
Pin Spanner
Wrench
Cooling
Sleeve
1. Remove the four socket head screws located near
the top of the outer housing and remove the top
cover from the housing. This will expose the plug
which aligns the inner rotor and carries the principle O-ring seal.
2. Unscrew the plug, using a 264AC5 face spanner inserted into the two holes at the top of the plug while
holding the rotor firmly with a 264AC3 or 264AC4
pin spanner inserted into one of the holes at the bottom of the assembly above the cooling sleeve. With
the plug removed, the sleeve bushing and thrust
washer at the top of the rotor will be exposed.
3. Check for any evidence of leakage past the O-ring
seal. If vapors from the reactor have produced
solid deposits in or around the rotor housing, the
deposits will have to be removed to keep them
from destroying the slide bushings or jamming the
rotor. If cleaning is not re quired, replace the plug
and close the drive.
4. If cleaning is required, the inner ro tor can be
removed without removing the entire drive from
the bomb head. To remove: Remove propeller from
shaft. For vessels with a one piece shaft, the shaft
can be used to push the rotor out of the stirrer
housing. For vessels with a lower coupled shaft assembly, the shaft will need to be disconnected from
Parr Magnetic Drive
the upper shaft. In the larger magnetic drives, the
rotor can be removed by attaching a threaded (5/16
– 24) rod to the top of the inner rotor and pulling up
from the top of the housing.
The inner rotor is a laser-welded, sealed unit which
should require no mainte nance, but it can be damaged
by over heating as mentioned earlier. With the rotor
removed, it may be advisable to re place the three sleeve
bushings which guide the inner rotor. Two of these, plus
a spacer, are located deep in the mag netic drive housing.
The third sleeve bushing is held in the top plug. Although
these bushings can be pulled out with a wire hook or
scribe, removal is much easier using a specially designed bush ing removal tool (See Page 8). Simply screw
the threaded end of the removal tool into the bushing
until it is firmly en gaged, then pull out the bushing. The
spacer between the two bushings should slide out freely.
Remove the bottom bushing in the same manner.
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Parr Instrument Company
Parr Magnetic Drives
When replacing the bushings in the magnetic drive
housing, slide the parts into place carefully and be sure
to separate the two lower bushings with a spacer. A
specially designed bushing insertion tool is available
for this operation (See Page 8). Using the insertion tool,
slide a bushing onto the end of the tool with the longest
shank, then insert the tool with the bushing into the
opening in the rotor chamber and push it down until the
shoulder on the tool strikes the bottom of the chamber.
This will position the bushing properly. Then drop the
spacer into the opening and use the short end of the
installation tool to insert the upper sleeve bushing,
again pushing the tool downward until it strikes the
bottom of the plug. When properly installed, the top of
the upper bushing should be flush with the bottom of
the rotor chamber.
After cleaning the rotor and the chamber, install the
inner rotor as follows:
1. Set the lower thrust washer into posi tion so that it
will be available to cushion the rotor if it should accidentally slam into the bottom of the chamber.
2. Lower the rotor into the chamber slowly, but be
prepared to resist the strong pull of the outer
magnets during this operation. Use the same rod
employed when removing the rotor to resist the
strong pull during assembly.
3. Replace the upper sleeve bushing and the O-ring
in the top plug; insert the upper thrust washer; lubricate the threads with 424HC2 anti-seize lubricant
(careful not to get any on the O-ring) and screw the
top plug into place. Then replace the top cover and
secure it with the four socket head screws.
The O-Ring Seal
The O-ring, which seals the top plug in Parr magnetic
drives, is made of PTFE. If solvent attack becomes a
problem, the O-ring may have to be replaced with an
O-ring made of another material.
Servicing the Outer Drive
The outer drive is supported by two high quality sealed
ball bearings which do not require lubrication. Any oil
leak or noise from the bearing will indicate that the
seal or the bearing has failed and the bearing must be
replaced.
Disassemble the Outer Drive
1. Remove the four socket head screws located near
the top of the outer housing; then lift the cover
from the housing to expose the upper snap ring.
Peel the snap ring out of its groove with a small
screwdriver; slide it upward and remove it.
2. Take a firm grip on the outer drive housing and
pull it upward to separate the outer assembly from
the magnetic drive housing. The lower bearing may
not come out with the housing. If not, remove at
this time.
Reassemble the Outer Drive
1. Slide the lower spiral snap ring back into its
groove; then slide the lower ball bearing onto the
inner hous ing. The inner magnets should hold the
bearing at the middle of the housing.
2. Slide the outer drive assembly over the rotor,
thereby pushing the lower bearing down against
the lower spiral snap ring. Hold both parts firmly
during this step so that the magnets do not slam
the outer drive into place.
3. Insert the upper wave spring into its groove in
the outer drive housing and slide the ball bearing
into place against the wave spring, then anchor
the bearing by pushing the retaining snap ring
downward until it snaps into its groove above the
bearing. During this step sufficient pressure must
be applied against the snap ring and force the
wave spring downward and allow the snap ring to
drop bearing to force the wave spring down ward
and allow the snap ring to drop into its groove. This
can be done with a pair of screw drivers, using
alternating pressure on the snap ring. This must be
done carefully to be sure that the screw drivers do
not slip and damage the seals in the bearings. To
simplify the opera tion, Parr offers a magnetic drive
assem bly tool (Part No. 2086HC) consisting of a
properly sized cup which can be pushed downward
against the snap ring to force it into its groove.
There are cups on the 2086HC assembly tool to fit
both the small and larger Parr magnetic drives.
4. Replace the top cover and secure it with the four
socket head screws.
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