Duff-Norton Machine Screw Rotating 500lb - 1 Ton User Manual

Installation, Operating and
Maintenance Instructions

With Parts List
Publication Part No. SK-2389-R1

®

Rotating

Machine Screw

Actuators

1/4 Through 1-Ton Capacity

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, support, or otherwise transport people.

®

Contents

Section I General Information ................................................................................................. 3

1-1. General .................................................................................................................... 3

1-2. Applications.............................................................................................................. 3

1-3. Specifications........................................................................................................... 3

1-4. Dimensions .............................................................................................................. 4

Table 2. Upright Models......................................................................................................... 4

1-4. Dimensions (Cont.) .................................................................................................. 5

Table 3. Inverted Models ....................................................................................................... 5

1-5. Important Precautions.............................................................................................. 5

1-6. Warranty and Warranty Repair ................................................................................6

Section II Maintenance ............................................................................................................ 6

2-1 Lubrication ............................................................................................................... 6

2-2. Rebuild Procedure ................................................................................................... 6

2-3. Required Tools ......................................................................................................... 6

2-4. Disassembly............................................................................................................. 6

2-5. Cleaning................................................................................................................... 7

2-6. Inspection................................................................................................................. 7

2-7. Assembly ................................................................................................................. 7

Figure 2-1. Expansion Plug Replacement.................................................................................. 8

Section III lllustrated Parts List.................................................................................................. 9

3-1. General .................................................................................................................... 9

3-2. Parts List................................................................................................................ 10

Figure 3-1. Exploded Illustration

Rotating Machine Screw Actuators.........................................................................11

Section I

General Information

1-1. General

1-2. Applications

This manual contains maintenance instructions for Duff
Norton 1/4 through 1- ton rotating machine screw actua­tors. It describes and details procedures for installation,
disassembly, cleaning, inspection, and assembly of these
actuators.

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.

1.3. Specifications
Table 1. 1/4-ton through 1-ton Series Rotating Machine Screw Actuators

Actuator No. Upright UM2556 UM2626 UM2502
Standard Inverted DM2556 DM2626 DM2502
Actuator No. Upright UM3056 UM3626 UM3502
Special Inverted DM3056 DM3626 DM3502

Rated Load (lb) 500 1000 2000
Diameter of 1/2 5/8

Lifting Screw .250 Pitch .125 Pitch .200 Pitch
(inches) ACME ACME ACME
Base Size (in.) 2 1/4 x 4 2 1/4 x 4 2 3/4 x 5
Worm Gear Std. Ratio 5:1 5:1 5:1
Ratios Optional - - 20:1
Turns of Worm Std. Ratio 20 40 25
for 1" Raise Optional - - 100
Maximum H.P. Std. Ratio 1/3 1/3 1/2
Per Actuator Optional - - 1/4
Torque at Full Std. Ratio 13 21 55
Load* (in-lbs) Optional - - 2 5
Jack Efficiency Std. Ratio 33.0 20.0 24.5
Rating (%) Optional - - 14.0
Weight with Base
Raise of 6" (lb) 2.3 2.3 5.0

Weight for Each
Additional 1" Raise (lb) 0.1 0.1 0.3

3/4

* For loads from 25% to 100 % of Actuator load rating. Torque requirements are approximately proportional to the load.

3

1-4. Dimensions

(in)

Note: Housing Dimensions and Base Configurations vary.

Table 2. Upright Models

Model A B C F G H I J K

Number Rating (in)

U M - 25 5 6 1/4 Ton Raise + 1 1/2 5 / 8 2 3 /8 0.312 7 /8 3/8 2 1/4 4 Holes- 9/32 Dia. on 1 3/4 Dia. B.C. 1
UM-262 6 1/2 Ton Raise + 1 7/8 5 / 8 2 3/8 0.437 7/8 3 /8 2 1/4 4 Holes- 9/32 Dia. on 1 3/4 Dia. B.C. 1
UM-2502 1 Ton Raise + 1 3/4 5 / 8 3 1/4 0.500 1 1/2 1 / 2 3 1/4 4 Holes-13/32 Dia. on 2 3/8 Dia. B.C. 1 1/2

Note: Dimensions are subject to change without notice.

4

(in) (in) (in)(in)(in) (in) (in)

1-4 Dimensions (Cont.)

(in)

Note: Housing Dimensions and Base Configurations Vary.

Table 3. Inverted Models

Model A B C D F G H I J K

Number Rating ( i n )

DM-2556 1/4 TON Raise + 1 1/2 5 / 8 2 3/8 3 / 8 0.312 7 / 8 3 / 8 2 1/4 4 Holes- 9/32 Dia. on 1 3/4 Dia. B.C. 1
DM-2626 1/2 TON Raise + 1 7/8 5 / 8 2 3/8 3 / 8 0.437 7 / 8 3 / 8 2 1/4 4 Holes- 9/32 Dia. on 1 3/4 Dia. B.C. 1
DM-2502 1 TON Raise + 1 3/4 5 / 8 3 1/4 1 / 4 0.500 1 1/2 1/2 3 1/4 4 Holes- 13/32 Dia. on 2 3/8 Dia. B.C. 1 1/ 2

Note: Dimensions are subject to change wwithout notice.

(in)(in)(in) (in)(in)(in) (in) (in)

1-5. Important Precautions

To ensure that Duff-Norton actuators provide reliable
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 upon it.

2. The structure on which the actuators are mounted

should have ample strength to carry the maximum

load, and should be rigid enough to prevent undue

deflection or distortion of the actuator supporting

members.

3. It is essential that the actuators 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 misalign-

ment, the actuator system is then ready for normal

operation.

4. Actuators should have a greater raise than is needed

in the actual installation. Should it be necessary to
operate these actuators at the extreme limits of
travel, it should be done cautiously .

Caution

Do not allow actuator travel to go beyond catalog

closed height (A), or serious damage to lifting nut
or the internal actuator mechanism may result.
Refer to tables of specifications (par. 1-4) for
closed height (A) of respective units.

5. The worm shaft speed should not exceed 900 RPM
for heavy loads or 1800 RPM for light loads of one­fourth (or less) of the actuator load rating for 500 and
1000 pound rated units. For units with a one-ton load
rating, worm shaft speed should not exceed 1800
RPM.

6. The lifting screw should not be permitted to accumu­late dust and grit on the threads. If possible, screws

5

should be protected by some means such as a boot.

Note

Rotating screws should never be run dry. Inspect

frequently at regular intervals to be certain that a
lubrication film is present.

Note

For loads of 25% to 100% of actuator capacity, torque

requirements are approximately proportioned to the
load.

7. These actuators are self-lowering and these units
require a brake or other hold back device.

8. The lubrication procedures for normal and severe
service conditions, as described in Section II para­graph 2-1, should be closely followed.

one year after date of shipment. Duff-Norton will not
repair or replace any parts that become inoperative
because of improper maintenance, eccentric loading,
overloading, chemical 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, applications 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 MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE.

1-6. 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

Section II

2-1. Lubrication

Unless otherwise specified, actuators are shipped
packed with grease which should be sufficient for one
month of normal operation. For normal operation, the
actuator should be lubricated once a month using Shell
Albida® LC EP2 grease, (Shell Product Code 70311).

This grease has been thoroughly evaluated in Duff­Norton actuators and has demonstrated superior 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 containing 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.

Note

Lifting screws should never be run dry. Inspect
frequently at regular intervals to be certain that a lubrica­tion film is present.

2-2. Rebuild Procedure

Duff-Norton recommends the following procedures
for assembly and disassembly of machine screw
actuators.

Maintenance

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.

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.

Please Note: Only Duff-Norton factory supplied parts
should be used.

2-3. Required Tools

A bearing puller and press, soft jaw table clamp and
common hand tools are necessary for proper assembly
and disassembly.

2-4. Disassembly (Refer to Figure 3-1)

1. Remove lifting nut (23) from screw (5)

2. Remove set screws (1) from shell cap (2) and remove

shell cap from shell (3).

Note

It may be necessary to tap on shell cap (2) or shell (3)

with a hammer to loosen shell cap for removal.

These units are sealed with an expansion plug. If

necessary, these can be removed later.

3. Remove lifting screw (5) and gear (6) from shell (3).

4. Remove top bearing (7) which may be attached to

either shell cap (2) or worm gear (6).

6

Note

If necessary, tap bearing loose with a soft face

hammer.

5. Remove bottom load bearing (8), which may be
attached to either shell (3) or gear (6).

6. 1/4 and 1/2-ton - remove four set screws (9) from the
shell (3) to loosen worm retainer bushings (10). If
threaded bushings are used, remove these, using a
spanner wrench. 1-ton - remove two retainer rings
(17) from worm housing.

7. Remove worm (11), needle bearing (13) and race
washers (12)(bearing Index No. 18 on 1-ton unit)
from the shell by striking one end of the worm with a
wooden or lead mallet.

8. Slide off worm retainer bushings (10) and needle
bearings (12 and 13) or bearing (18).

9. Restraining lifting screw (5) from turning (use soft
jaws), remove locknut (20) and lockwasher (21)(if
used) from screw(5).

10.Remove worm gear (6) from screw (5).

Note

It may be necessary to tap on worm gear. Use only a

soft-face hammer. Do not tap on gear teeth.

11. Remove key (22) from screw (5).

12.Inverted models — remove guide bushing (14) from
shell (3).

13.For units with damaged expansion plug (4a) in shell
(3) or shell cap (2), drive or press plug out of shell (3)
or shell cap (2) with a large die punch (1" diameter).
Disassembly is now complete.

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 agent; avoid prolonged breathing of
fumes and contact with skin. Read and 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 preven-

tive, protection grease, etc.

2-6. Inspection (Refer to Figure 3-1)

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), lifting screw (5), lifting nut (23)

and worm gear (6) for burrs or scratches on their
working or mating surfaces.

3. Check fit between rotating screw thread and internal
thread of lifting nut. If fit is excessively loose, replace
lifting nut or rotating screw as required.

4. Check small common components (screws, etc.) and
replace as required.

5. Check bearings (7,8, 13 and 18) for seizure, galling or
play and replace as required.

2-7. Assembly (Refer to Figure 3-1)

1. To replace expansion plug (4a) refer to Figure 2-1.
For upright models, plug is installed in shell (3) (see
Figure 3-1) and in shell cap (2) for inverted units (see
Figure 3-1, Detail A).

a. As is appropriate, set shell cap (2) or shell (3) over

a steel bar which is approximately 1/8" or 3/16"
shorter than the shell or shell cap. The diameter of
the bar should be close to the I.D. of the shell or
shell cap.

b. Place expansion plug (4a) on the bar (concave

surface down) and flatten the plug against the bar.
Use a large diameter punch or press making sure
that the plug is flattened throughout its entire
diameter.

2. For 1-ton models, press bearing cones on worm gear
(6) with small end of cone facing away from gear
surface. Be sure that cone is seated properly against
shoulder.

3. Insert key (22) in screw (5).

4. Assemble worm gear (6) on screw (5).

5. Assemble lock washer (21) if used and lock nut (20)
to screw (5). Torque lock nut to appropriate torque as
follows: 1/4 ton-100 in-lb.; 1/2 ton-180 in-lb.; 1 ton-40
ft-lb.

6. Inverted units only. Install guide bushing (14) in shell
(3). Guide bushing must be flush with base. Lock
guide bushing in place by peening on the thread O.D.
of the bushing and shell with a center punch.

7. Place bottom load bearing (8) into shell (3) -on 1-ton
units, press bearing cup into shell first.

8. Install worm (11) into housing (3). For 1/4-ton and 1/2­ton models- proceed as follows:

a. Slide thrust race (12), needle bearing (13) and

another thrust race on each end of worm (11).
b. Position worm (11) in shell (3).
c. Slide bronze worm retainer bushings (10) on both

sides of the worm shaft and place them in shell

until bushings are positioned to control lateral

movement of the worm to about .002 inches. If

bushings are the threaded type, the same proce-

dure should be followed except bushing should be

threaded into position in the shell. Install four set

screws (9) in shell (3). Tighten them down until

they seat against bronze retainer bushing (10).

For one ton model-press in one worm bearing (18),

position retainer ring (17) behind this bearing, place

7

Figure 2-1. Expansion Plug Replacement

other worm bearing on end of worm shaft, insert
other worm shaft end through worm housing, tap
lightly to position worm and both bearings and snap
in second retainer ring.

9.Install screw (5) and gear (6) assembly into shell (3).

10.For 1-ton models-install bearing (7) cup into shell
cap (2). For 1/4-ton and 1/2-ton models - place top
load bearing (7) on hub of gear (6).

11. Fill housing (3) with grease.

12.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 shell cap.

13.Install set screws (1) in shell cap(2). Tap shell cap
sharply with hammer and re-tighten set screws

Note

If new parts have been installed it may be necessary

to spot holes for set screws.

14.Brush screw (5) with light film of grease and thread
lifting nut (23) on screw (5). The face of lifting nut
flange should be toward shell (3).

15.Operate unit to insure proper functioning of all compo­nents prior to installation and use.

Assembly is now complete.

8

3-1. General

Section III

Illustrated Parts List

This section contains an exploded illustration of the1/4,
1/2 and 1-Ton rotating 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 spare parts be sure to include:

1. The nameplate model number of your actuator.

2. Index number and name of part.

9

3-2. Parts List for 1/4, 1/2 and 1-Ton
Rotating Machine Screw Actuators

INDEX QTY.

NO. PART NAME REQ.

1 Screw, Set 2
2 Cap, Shell 1
3 Shell, Unit 1

4a Expansion Plug 1

5 Screw, Lifting 1
6 Worm Gear 1
7 Bearing, Top Load 1

8 Bearing, Bottom Load 1
9* Screw, Set 4
1 0 * Bushing, Worm Retainer 2

11 Worm 1
1 2 * Thrust Race 4
1 3 * Bearing, Needle 2

1 4 Bushing, Guide 1

1 5 Fitting, Grease 1

1 6 Nameplate 1

17** Retainer Ring 2
18** Bearing, Worm 2

19 Screw, Drive 2

2 0 Lock Nut 1
2 1* Washer, Lock 1

2 2 Key 1

23 Lifting Nut 1

* Used on 1/4 and 1/2 ton only.
**Used on 1 ton only.

10

For Inverted Model See Detail A

Figure 3-1. Exploded Illustration 1/4, 1/2 and 1-Ton Rotating Machine Screw Actuators

11

© 2001 Yale Industrial Products, Inc.

®

P.O. Box 7010
Charlotte, NC 28241-7010

General Office [phone]
Customer Service [phone]
Customer Service [phone]
FAX [phone]

SK-2389-R1

1M/401