Duff-Norton SK-2389 Guide

®
CAUTION
This manual contains important information for the correct installation, operation and maintenance of the
equipment described herein. All persons involved in such installation, operation, and maintenance should be
thoroughly familiar with the contents. To safeguard against the possibility of personal injury or property
damage, follow the recommendations and instructions of this manual and keep it for further reference.
WARNING
The equipment shown in this manual is intended for industrial use only and should not be used to lift, sup-
port, or otherwise transport people.
Publication Part No. SK-2389

2
Section I
General Information
1-1. General
This manual contains maintenance instructions
for Duff Norton translating machine screw actuators
of two ton to 75 ton capacity. It describes and details
procedures for installation, disassembly, cleaning,
inspection, and assembly of these actuators.
1-2. Applications
Industrial Use Only The actuators described
and illustrated in this manual are intended for
industrial use only and should not be used to lift,
support or otherwise transport people unless you
have a written statement from Duff-Norton which
authorizes the specific actuator unit, as used in your
application, as suitable for moving people.
These actuators are intended for a clean, non-
corrosive environment with ambient temperatures
ranging from -20 to 200 °F. If your environment is
dirty and/or contains abrasive particles it is impor-
tant to protect the screw with a boot. If your atmo-
sphere is corrosive it is important to specify a non-
corrosive material or finish. Duff-Norton can provide
stainless steel, nickel plated or epoxy coated actua-
tors. If your duty is high or your use severe, more
frequent lubrication should be employed. Duff-
Norton publishes a Mechanical Actuator Design
Guide, Catalog No. 2003, which you may find helpful
in the selection and application of mechanical
actuators. If you need additional help, please con-
tact Duff-Norton at [phone].
*For loads from 25% to 100% of actuator load rating. Torque requirements are approximately proportional to the load.
** Closed heights are for standard upright top plate models and may vary with different screw end, inverted models, or when bellows boot is used.
Contents
Section I General Information................................................................................................................................................ 2
1-1. General .................................................................................................................................................................... 2
1-2. Applications ............................................................................................................................................................ 2
1-3. Specifications .......................................................................................................................................................... 2
1-4 Important Precautions ............................................................................................................................................. 3
1-5. Warranty and Warranty Repair ............................................................................................................................... 4
Section II Maintenance ............................................................................................................................................................ 4
2-1. Lubrication .............................................................................................................................................................. 4
2-2. Rebuild Procedure .................................................................................................................................................. 4
2-3 Required Tools ........................................................................................................................................................ 4
2-4. Disassembly ............................................................................................................................................................ 4
2-5. Cleaning .................................................................................................................................................................. 5
2-6. Inspection ................................................................................................................................................................ 5
2-7. Assembly ................................................................................................................................................................ 5
2-8. Anti-Backlash Nut Function ................................................................................................................................... 6
2-9. Anti-Backlash Nut Adjustment ............................................................................................................................... 6
Section III Illustrated Parts List ................................................................................................................................................ 6
3-1. General ................................................................................................................................................................... 6
3-2. Parts List ................................................................................................................................................................. 6
Figure 3-1. Exploded Illustration .............................................................................................................................................. 7
1-3. Specifications
Table 1. 1800 (2000) and 9000 (10000) Series
Standard Actuator Upright 1802 & 9002 9005 9010 9015 9020 9025 9035 1850 & 9050 9075
Model No. Inverted 1801 & 9001 9004 9009 9014 9019 9024 9034 1849 & 9049 9074
Special Actuator Upright 2002 & 1000
2
10005 10010 10015 10020 10025 10035 2050 & 1005
0
10075
Model No. Inverted 2001 & 10001 10004 10009 10014 10019 10024 10034 2049 & 1004
9
10074
Rated Load (tons) 251015 20 25 35 50 75
Diameter of 111/2221/4 2 1/2 3 3 3/4 4 1/2 5
Lifting Screw (inches) .250 Pitch .375 Pitch .500 Pitch .500 Pitch .500 Pitch .666 Pitch .666 Pitch .666 Pitch .666 Pitch
Acme Acme Acme Acme Acme Acme Acme Square Square
Closed Height** (inches) 5 1/4 7 7 1/4 8 9 1/4 11 12 13 16 1/2
Base Size (inches) 3 1/2 x 7
4 1/8 x 6 1/4 6 x 871/2 x 8 3/4 7 3/4 x 9 1/4 8 1/4 x 11 10 1/4 x 13 3/4
10 1/4 x
15 1/2
9 3/4 x 19 3/4
10 1/2 x 21 3/4
14 x 23
Worm Gear Ratios Std Ratio 6:1 6:1 8:1 8:1 8:1 10 2/3:1 10 2/3:1 10 2/3:1 10 2/3:1
Optional 24:1 24:1 24:1 24:1 24:1 32:1 32:1 32:1 32:1
Turns of Worm Std Ratio 24 16 16 16 16 16 16 16 16
For 1˝ Raise Optional 96 64 48 48 48 48 48 48 48
Maximum H.P. Std Ratio 24555881515
Per Actuator Optional 1/2 3/4 1 1/2 1 1/2 1 1/2 2 1/2 2 1/2 6 6
Torque at Std Ratio 120 450 750 1,430 2,050 2,700 4,000 7,500 12,000
Full Load* (in-lbs) Optional 50 185 400 820 1,170 1,200 2,400 4,200 6,600
Actuator Efficiency Std Ratio 23.2 22.1 23.7 20.2 18.8 18.7 15.8 13.8 12.4
Rating (%) Optional 13.3 12.1 15.1 12.9 12.0 10.5 8.9 8.3 7.5
Weight with Base
Raise of 6˝ (lbs) 17 35 52 66 93 160 240 410 650
Weight for Each
Additional 1˝ of
Raise (lbs)
.33 .85 1.4 1.5 2.6 2.5 3.7 5.5 6.5

3
Table 2. 4800 and 9400 Series
1-4 Important Precautions
In order to ensure that Duff-Norton actuators
provide good service over a period of years the
following precautions should be taken:
1. Select an actuator that has a load rating greater
than the maximum load that may be imposed on
it.
2. The structure on which the actuator is mounted
should have ample strength to carry the maxi-
mum load, and should be rigid enough to pre-
vent undue deflection or distortion of the actua-
tor supporting members.
3. It is essential that the actuator be carefully
aligned during installation so that the lifting
screws are perfectly plumb and the connecting
shafts are exactly in line with the worm shafts.
After the actuators, shafting, gear boxes, etc.,
are coupled together, it should be possible to
turn the main drive shaft by hand. If there are no
signs of binding or misalignment, that actuator
system is then ready for normal operation.
4. Actuators should have a greater raise than is
needed in the actual application. Should it be
necessary to operate the actuator at the ex-
treme limits of travel, it should be done cau-
tiously.
CAUTION
Do not allow actuator travel to go beyond
specified (catalog) closed height, or serious
damage to internal mechanism may result.
Refer to table of specifications (par. 1-3) for
closed heights of respective units.
5. The worm shaft speed for these actuators
should not exceed 500 RPM for heavy loads,
1200 RPM for light loads of one-fourth (or less)
of the actuators load rating.
6. The lifting screw should not be permitted to
accumulate dust and grit on the threads. If
possible, lifting screws should be returned to
closed position when not in use.
CAUTION
Where lifting screws are not protected from
airborne dirt, dust, etc., bellows boots should
be used. Inspect frequently at regular internals
to be certain that a lubricating film is present.
Lifting screws should never be run dry.
7. When using an 1800 (2000) or 9000 (10000)
Series Actuator, a periodic check of backlash of
the lifting screw thread is recommended to
check wear of the worm gear internal threads.
The normal backlash on a new unit of this type
is approximately .010 inch. Backlash of 50% or
more of the thread thickness indicates the need
to replace the worm gear.
The 4800 and 9400 Series Anti-backlash Actua-
Note: Additional specifications are same as for Series 1800 and 9000. See Table 1.
*For loads from 25% to 100% of actuator load rating. Torque requirements are approximately proportional to the load.
** Closed heights are for standard upright top plate models and may vary with different screw end, inverted models, or when bellows boot is used.
Table 3. Decimal Ratios
Note: All other data for these models same as shown in Table 1.
Standard Actuator Upright 4802 & 9402 9405 9410 9415 9420 9425 9435 4850 & 9450 9475
Model No. Inverted 4801 & 9401 9404 9409 9414 9419 9424 9434 4849 & 9449 9474
Special Actuator Upright 5802 & 1040
2
10405 10410 10415 10420 10425 10435 5850 & 1045
0
10475
Model No. Inverted 5801 & 10401 10404 10409 10414 10419 10424 10434 5849 & 1044
9
10474
Rated Load (tons) 251015 20 25 35 50 75
Torque at Std Ratio 135 500 1045 1573 2255 1320 4400 4620 13200
Full Load* (in-lbs) Optional 55 205 905 1290 1320 1320 2640 4620 7260
Actuator Efficiency Std Ratio 19.6 19.9 19.8 18.0 17.6 13.4 13.7 12.4 11.3
Rating (%) Optional 11.9 10.9 12.6 11.0 10.8 8.3 7.7 7.3 6.8
Closed Height (in)** 5 1/4 7 7 1/4 8 9 1/2 12 13 14 18 1/2
Weight with Base
Raise of 6˝ (lbs) 18 37 55 70 101 197 250 440 700
Standard Actuator Upright 1802 & 9002 9005 9010 9015 9020 9025
Model No. Inverted 1801 & 9001 9004 9009 9014 9019 9024
Special Actuator Upright 2002 & 1000
2
10005 10010 10015 10020 10025
Model No. Inverted 2001 & 10001 10004 10009 10014 10019 10024
Rated Load (tons) 251015 20 25
1˝ Dia. 1 1/2˝ Dia. 2˝ Dia. 2 1/4˝ Dia. 2 1/2˝ Dia. 3˝ Dia.
Lifting Screw (inches) .250 Pitch .250 Pitch .250 Pitch .250 Pitch .250 Pitch .320 Pitch
Acme Acme Acme Acme Acme Square
Worm Gear Ratios 25:1 25:1 25:1 25:1 25:1 32:1
Turns of Worm For 1˝ Raise 100 100 100 100 100 100
Torque at Full Load (in-lbs) 48 175 370 640 925 1500
Actuator Efficiency Rating (%) 13.2 9.1 8.6 7.5 6.9 5.3
Maximum H.P. Per Actuator 1/2 3/4 1 1/2 1 1/2 1 1/2 2 1/2

4
tors are designed to be adjusted for minimum
backlash, approximately .002 inch. The worm
gear and anti-backlash nut are manufactured to
have a clearance between their surfaces of 1/2
the thread thickness. When adjustments have
been made to the point where all this clearance
is gone, 50% of the thread thickness is gone
and replacement is necessary. (See paragraph
2-8 for a detailed explanation of how the anti-
backlash nut functions.)
Note
For loads of from 25% to 100% of actuator
capacity, torque requirements are approximately
proportioned to the load.
8. The lubrication procedures for normal and
severe service conditions, as described in
Section II, paragraph 2-1, should be closely
followed.
1-5. Warranty and Warranty Repair
Subject to the conditions stated herein, Duff-
Norton will repair or replace, without charge, any
parts proven to Duff-Norton's satisfaction to have
been defective in material or workmanship. Claims
must be made within one year after date of ship-
ment. Duff-Norton will not repair or replace any
parts that become inoperative because of improper
maintenance, eccentric loading, overloading, chemi-
cal or abrasive action, excessive wear, or other
abuse.
Equipment and accessories not of Duff-Norton's
manufacture are warranted only to the extent that
they are warranted by the manufacturer, and only if
the claimed defect arose during normal use, appli-
cations and service. Equipment which has been
altered or modified by anyone without Duff-Norton's
authorization is not warranted by Duff-Norton.
EXCEPT AS STATED HEREIN, DUFF-NORTON
MAKES NO OTHER WARRANTIES, EXPRESS OR
IMPLIED, INCLUDING WARRANTIES OF MER-
CHANTABILITY AND FITNESS FOR A PARTICU-
LAR PURPOSE.
If you have any questions concerning warranty
repair, please contact Duff-Norton. Authorization for
return must be received from Duff-Norton before
returning any equipment for inspection or warranty
repair.
Section II
Maintenance
2-1. Lubrication
Unless otherwise specified, actuators are
shipped packed with grease which should be suffi-
cient for one month of normal operation. For normal
operation, the actuator should be lubricated once a
month using Extreme Pressure grease Shell Oil Co.
Albida LC EP #2 (Shell Product Code 70311).
This grease has been thoroughly evaluated in
Duff-Norton actuators and has demonstrated supe-
rior lubricating properties affecting both wear life
and maximum duty cycle. Duff-Norton is not aware
of an equivalent grease. If this grease is not
available in your area please contact your local
supplier for their recommendations. Greases con-
taining molybdenum disulfide should never be used.
For severe service conditions, the actuators
should be lubricated more frequently using the
above grease (daily to weekly depending upon the
conditions). If duty is heavy, an automatic lubrication
system is strongly recommended.
CAUTION
Where lifting screws are not protected from
airborne, dirt, dust, etc., bellows boots should
be used. Inspect frequently at regular intervals
to be certain that a lubricating film is present.
Lifting screws should never be run dry.
2-2. Rebuild Procedure
Duff-Norton recommends the following proce-
dures for assembly and disassembly of actuators.
1. Tag critical parts to facilitate reassembly.
2. Mark mating surfaces to ensure proper meshing.
3. Clean and lubricate all parts as required.
4. All seals must be replaced when rebuilding.
5. All screws, washers and other small common
parts must be replaced if damaged in any way.
6. Replace damaged or frozen lubrication fittings
with new ones.
2-3 Required Tools
A bearing puller or press, and common hand
tools are necessary for proper assembly and disas-
sembly.
2-4. Disassembly (Refer to Figure 3-1)
1. Remove lifting screw (5) from actuator.
2. Remove bottom pipe (4) from shell (3) (upright
models) or shell cap (2) (inverted models) or
base plate as applicable.
3. Loosen and remove set screws (1) in cap (2)
and remove cap from shell (3).
Note
It may be necessary to break shell cap or base
plate loose with a hammer.

5
4. Remove gear (6A) or worm gear and nut assem-
bly (6B) from shell (3).
Note
To facilitate removal of the gear from the shell
on models with 50- ton or higher load ratings,
partially reassembly the lifting screw into the
worm gear (or worm gear and nut assembly)
and use a hoist or pulley block to lift on the
screw.
5. Remove top load bearing (7) which may be
attached to either shell cap (2) or worm gear
(6A) or anti-backlash nut.
Note
Use only a soft face hammer to tap bearings
loose.
6. Remove bottom load bearing (8) which may be
attached to either the shell (3) base plate or
worm gear (6A).
7. Remove four cap screws (9) from each of the
two worm flanges (11) and remove flanges.
Note
Be careful not to lose flange shims (12).
8. Press oil seal (13) out of flange (11).
9. Remove worm (14) and worm bearings (15)
from shell (3) by striking one end of worm with a
soft face hammer.
10. Remove worm bearings (15) from worm (14)
with bearing puller or press. (Note: This step will
not be necessary if worm or worm bearings are
not damaged.
11. If actuator is keyed, remove screw in shell cap
and tap key out of keyway.
2-5. Cleaning
1. Use degreasing solvent to remove grease or oil
from all parts. Note
Remove grease from unit and do not reuse old
grease.
WARNING
Provide adequate ventilation during the use
of cleaning agents; avoid prolonged breath-
ing of fumes and contact with skin. Read &
follow manufacturer's instructions.
2. Use clean hot water or a soap solution for
general cleaning of painted surfaces.
3. Dry parts thoroughly after cleaning.
Note
Before installing new parts, remove any rust
preventive, protection grease, etc.
2-6. Inspection (Refer to Figure 3-1)
Inspect actuator parts as follows:
1. Make a visual inspection of shell (3) for broken,
cracked or distorted areas. Check threads of all
bores for burrs or broken threads.
2. Check shell cap (2), base plate, bottom pipe (4),
lifting screw (5), worm gear (6A) or worm gear
and nut assembly (6B) for burrs or scratches on
their working or mating surfaces.
3. Check fit between lifting screw thread and
internal thread in worm gear. If fit is excessively
loose, replace worm gear or lifting screw as
required. Replace worm gear and nut assembly
as a set [4800 (5800) and 9400 (10400) Se-
ries].
4. Check small common components (screws, etc.)
and replace as required.
5. Check bearings (7), (8) and (15) for seizure,
galling or play and replace as required.
2-7. Assembly (Refer to Figure 3-1)
1. Press worm bearings (15) onto worm shaft (14),
making sure that bearings are seated properly
against shoulder.
Note
When tapered roller bearings are used, the
small end of the cone should point to the worm
end.
2. Position worm shaft end (14) in shell (3).
Note
If tapered roller bearings are used, tap worm
bearing cups into place in the shell.
3. Press oil seals (13) into worm flange (11).
Note
The sealing element should point inward.
4. Position worm flanges (11) with shims (12) and
bolt in place.
5. Position bottom load bearing (8) or bearing cup
in shell (3).
5a. On 5-ton, 35-ton and 75-ton models, press load
bearing cones onto worm gear (6A) or worm
gear and nut assembly (6B).
6. Install worm gear (6A) or worm gear and nut
assembly (6B) in shell (3).
Note
Strike each end of worm shaft sharply with a
soft face hammer to seat bearing properly.
Recheck flange bolts for tightness. Worm should
turn freely with minimum drag and end play. If
too much end play is present, remove shims as
required. If worm does not turn freely, add shims

6
as required.
7. Install top load bearing (7) or bearing cup on
worm gear (6A) or worm gear and nut assembly
(6B).
8. Fill housing fully with grease.
9. Install shell cap (2) and screw down until tight.
Note
Shell cap flange does not necessarily have to
bear against top of shell, there will usually be a
gap. This will put a slight drag on the worm. If
worm is hard to turn, back off slightly on the
shell cap.
10. Lock base plate in place with set screws.
Note
If new parts have been installed, it may be
necessary to respot holes for these screws.
11. Screw bottom pipe (4) into shell (3) (upright
models) or into shell cap (2) (inverted models).
12. Brush lifting screw (5) with a light film of grease
and install in actuator. On inverted models,
install guide bushing (16) and then install lifting
screw (5).
13. If actuator is keyed, install key in shell cap (2)
and bolt in place.
14. Operate unit to ensure proper functioning of all
components prior to reinstallation.
2-8. Anti-Backlash Nut Function
As shown in Figure 2-1, the worm gear (2) and
anti-backlash nut (3) are pinned together with guide
pins. The threads in the anti-backlash nut work in
opposition to the threads in the worm gear as they
engage the threads of the lifting screw (1). Adjust-
ment of backlash is made by running down on the
shell cap of the actuator. This forces the anti-back-
lash nut threads into closer contact, reducing clear-
ance and thus reducing backlash.
2-9. Anti-Backlash Nut Adjustment
1. To minimize backlash remove the two set
screws (4) and tighten down on shell cap until
the desired backlash is obtained. Spot drill top of
shell through set screw holes, then replace set
screws and tighten to prevent shell cap backing
off.
2. To avoid binding and excessive wear, do not
adjust lifting screw backlash to less than 0.002
inch.
3. The clearance (A) designed into the worm gear
and anti-backlash nut set is one-half the thread
thickness. When adjustments have been made
to use all this clearance replace the worm gear
and anti-backlash nut as a set.
Figure 2-1. Anti-Backlash Nut Adjustment
Section III
Illustrated Parts List
3-1. General
This section contains an exploded illustration of the
1800, 9000, 4800 and 9400 Series translating machine
screw actuators. The number adjacent to each part on
the illustration is the index number. Keyed to this index
number on the parts list is the part name.
When ordering parts be sure to include:
1. The nameplate model of your unit.
2. Index number and name of part.
3-2. Parts List For 1800 (2000), 9000 (10000), 4800 (5800) and 9400 (10400) Series Translating
Machine Screw Actuators.
I
ndex Qt
y
.Index Qt
y
.
No. Part Name
R
e
q
.No. Part Name
R
e
q.
1Screw, Set 1 9 Screw, Cap 12
2Cap, Shell 1 10 Washer, Lock 12
3Shell, Actuator 1 11 Flange, Worm 2
4Pipe, Bottom 1 12 Shim, Flange 2
5Screw Assembly, Lifting 1 13 Seal, Oil 2
6A Worm Gear 1 1 4 Worm 1
6B
Worm Gear and Anti-backlash Nut
Assembly (Mfg’d and sold in sets
onl
y)
1
15 Bearin
g
, Worm 2
7Bearing, Top Load 1 16 Bushin
g
, Guide
(
inverted model o 1
8Bearin
g
, Bottom Load 118Name
p
late 1

7
AB
Figure 3-1. Exploded Illustration 1800 (2000), 9000 (10000), 4800 (5800) and 9400 (10400)
Series Translating Machine Screw Actuators

P.O. Box 7010
Charlotte, NC 28241-7010
General Office [phone]
Customer Service [phone]
Customer Service [phone]
FAX [phone]
Email: duf[email protected]
www.duffnorton.com
SK-2389
2M/1002
®
© 2000 Yale Industrial Products, Inc.