LIFTINGSAFETY

Stainless Steel Anti-Backlash Machine Screwjack Actuator, 2t to 150t

Stainless anti backlash screwjack.

Model: 

SSAM-4052


Description

+

Stainless Steel Machine Screw Actuator

Stainless Steel Anti-backlash actuators reduce vertical backlash resulting in smooth, precise operation and minimal wear along with the same great corrosion resistance offered by our standard stainless steel actuators.

Backlash occurs when the motor driving an actuator reverses its load direction.

Since there is a gap between the lifting screw and the worm gear threads detrimental screw movement may occur.

When the actuator is under load, the lifting screws threads are supported by the worm gears threads.

The anti-backlash nut, being pinned by to the worm gear and being adjusted downwards by the shell cap, forces the bottom thread surfaces against the upper thread surfaces of the lifting screw, Thus backlash between the lifting screw and worm gear threads is reduced to a minimum.

  • The Duff Norton Anti-backlash design features a separate anti-backlash nut and reduces actuator backlash to less than 1 thousandths.
  • Available with either 316SS or 17-4PH worm.
  • Anti-backlash nuts reduce worm gear wear.
  • Anti-backlash nuts act as additional load safety devices when the worm gear has become worn.
Dimensions

+

Key Adaptor Dimensions for Anti-Backlash Actuators

Anti Backlash Ms Dimensions
Actuator Capacity (tons) Upright A Dia. (in) Upright B (in) Upright C (in) Inverted D Dia. (in) Inverted E (in) Inverted F (in)
1/4 & 1/2 1.66 Pipe Length 2.38 1.25 .81 2.88
1 1.66 .75 3.84 1.50 .38 3.38
2 2.25 1.25 3.88 2.25 .63 3.88
3 2.25 1.25 4.34 2.25 .63 4.34
5 2.75 1.75 5.44 2.75 .88 5.44
10 3.38 2.00 5.75 3.38 1.13 5.75
15 3.63 2.00 6.13 3.63 1.25 6.13
20 4.00 1.50 7.75 4.00 1.00 7.75
25 5.50 2.25 9.69 5.50 1.25 9.69
35 6.50 2.38 9.44 6.50 1.25 9.44
50 7.00 3.00 11.75 7.00 3.00 11.75
Specifications

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Stainless Steel Anti-Backlash Actuators Performance Specifications

Capacity (tons) - 17-4PH Worm 2 5 10 15 20 25 35 50 100
Capacity (tons) - 316 SS Worm 0.67 1.66 3.33 5.00 6.66 8.33 11.66 16.66 33.33
Lifting Screw Diameter (in) 1
 1 1/2
2
2 1/4
2 1/2
3
3 3/4
4 1/2
6
Pitch (in) 0.250
 0.375
0.500
0.500
0.500
0.666
0.666
0.666
0.750
Type  ACME ACME
ACME
ACME
ACME
ACME
ACME
Mod.Sq.
Mod.Sq.
Worm Gear Ratios Standard  6:1 6:1
 8:1
8:1
8:1
10 2/3:1
10 2/3:1 10 2/3:1  12:1
Optional Number 1 24:1
24:1
24:1
24:1
24:1
32:1
32:1
32:1
36:1
Optional Number 2  12:1 12:1
-
-
-
-
-
-
-
Turns of Worm for 1" Raise Standard  24 16
 16 16
 16 16
 16  16 16
Optional Number 1  96  64 48
48
48
48
48
48
48
Optional Number 2  48 32
-
 -
-
-
-
-
 -
Worm Torque at No Load (in-lb) Standard 5
10
20
20
30
40
50
100
200
Optional Number 1  5 10
 20
20
30
40
50
100
200
Optional Number 2  5 10
-
-
-
-
-
-
 -
Maximum Horsepower per Actuator Standard  2 4
5
5
5
8
8
15
25
Optional Number 1  1/2 3/4
1 1/2
1 1/2
1 1/2
2 1/2
 2 1/2
6
11
Optional Number 2  3/4 2
-
 -
 -
-
 -
 -
 -
Worm Torque at Full Load (in-lb) 17-4PH Worm Standard  120 450
750
1430
2050
2700
4000
7500
16000
Optional Number 1  50 185
400
820
1170
1700
2400
4200
8600
Optional Number 2  75 275
-
-
-
-
-
-
-
Worm Torque at Full Load (in-lb) 316SS Worm Standard  43  156  263  490  703 926
1366
2566
5466
Optional Number 1  20 68
147
287
410
593
833
1466
3000
Optional Number 2 28
98
-
-
-
-
-
-
 -
Efficiency Rating (%) Standard  20.4  21.2  25.2  20.3  18.9 17.9
17.0
12.9
12.1
Optional Number 1 11.1
12.1
15.1
11.6
10.8
 9.3 9.3
7.5
7.4
Optional Number 2 15.6 16.8 -
-
-
-
-
-
-
Weight with 6" Raise (lb) 17 35 52 66 93 160 240
 410
1200
Weight per Additional 1" Raise (lb) 0.3 0.9 1.4 1.5 2.6 2.5
 3.7
 5.5
 9.0
Key Torque (in-lb) 153
581
1565
2527
3538
4665
8828
15697
39396
Max Worm Speed at Full Load (rpm) Standard 1750 1615
1198
643
449
544
369
368
288
Optional Number 1  1576 694 645
330
231
266
189
258
231
Optional Number 2  1669 1286
-
 -
 -
-
-
-
-
Max Load at Full Horsepower and 1750 rpm (lb) Standard 1333 3047
4386
3406
2972
4664
4220
5949
8865
Optional Number 1 1156 972
1791
1276
843
1507
1192
2831
4671
Optional Number 2  1258  2339 -
  -  -  -  -  -  -
How Anti-Backlash Works

+
How Backlash Works

How it Works

When the screw (1) is under a compression load, the bottom of its thread surfaces are supported by the top thread surfaces of the worm gear (2). The anti-backlash nut (3), being pinned to the worm gear and floating on these pins and being adjusted downwards by the shell cap, forcing its bottom thread surfaces against the upper thread surfaces of the lifting screw at point (B).

Thus backlash between the worm gear threadsand the lifting screw threads is reduced to a regulated minimum.

When wear occurs in the worm gear threads and the anti-backlash nut thread, the load carrting thickness of the worm gear thread will be reduced. This wear will create a gap at point (B) and provide backlash equal to the wear on the threads.

Under a compression load, the lifting screw will no longer be in contact with the lower thread surface of the anti-backlash nut. Under this condition, backlash will be present when a tension load is applied. The anti backlash feature can be maintained simply by adjusting the shell cap until the desired amount of backlash reduction is achieved.

This will reduce the separation (A) between the anti- backlash nut and the worm gear and will reduce the backlash between the worm gear threads and the lifting screw to the desired minimum value.

To avoid binding and excessive wear, do not adjust lifting screw backlash to less than .0005".

When separation (A) has been reduced to zero, the wear limit has been reached.

Replace the worn gear and backlash nut set at this point.

This feature acts as a built in safety device.

Downloads

+
Anti-BacklashActuatorsspecifications.pdf

Stainless Anti Backlash Actuator Specifications

(approx. 1.4Mb)
Pricing

+
Part N° Capacity (tons) - 17-4PH Worm Capacity (tons) - 316 SS Worm Lifting Screw Diameter (in) Lifting Screw Pitch (in) Lifting Screw Type Weight with 6" Raise (lb) Weight per Additional 1" Raise (lb) Key Torque (in-lb) Unit Price Quantity
4052-T22076 2 0.67 1 0.250 ACME 17 0.3 153 Quote Required
4052-T22077 5 1.66 1 1/2 0.375 ACME 35 0.9 581 Quote Required
4052-T22078 10 3.33 2 0.500 ACME 52 1.4 1565 Quote Required
4052-T22079 15 5.00 2 1/4 0.500 ACME 66 1.5 2527 Quote Required
4052-T22080 20 6.66 2 1/2 0.500 ACME 93 2.6 3538 Quote Required
4052-T22081 25 8.33 3 0.666 ACME 160 2.5 4665 Quote Required
4052-T22082 35 11.66 3 3/4 0.666 ACME 240 3.7 8828 Quote Required
4052-T22083 50 16.66 4 1/2 0.666 Mod.Sq. 410 5.5 15697 Quote Required
4052-T22084 100 33.33 6 0.750 Mod.Sq. 1200 9.0 39396 Quote Required
Add To Quote Request   ?  

Stainless Steel Machine Screw Actuator

Stainless Steel Anti-backlash actuators reduce vertical backlash resulting in smooth, precise operation and minimal wear along with the same great corrosion resistance offered by our standard stainless steel actuators.

Backlash occurs when the motor driving an actuator reverses its load direction.

Since there is a gap between the lifting screw and the worm gear threads detrimental screw movement may occur.

When the actuator is under load, the lifting screws threads are supported by the worm gears threads.

The anti-backlash nut, being pinned by to the worm gear and being adjusted downwards by the shell cap, forces the bottom thread surfaces against the upper thread surfaces of the lifting screw, Thus backlash between the lifting screw and worm gear threads is reduced to a minimum.

  • The Duff Norton Anti-backlash design features a separate anti-backlash nut and reduces actuator backlash to less than 1 thousandths.
  • Available with either 316SS or 17-4PH worm.
  • Anti-backlash nuts reduce worm gear wear.
  • Anti-backlash nuts act as additional load safety devices when the worm gear has become worn.

Key Adaptor Dimensions for Anti-Backlash Actuators

Anti Backlash Ms Dimensions
Actuator Capacity (tons) Upright A Dia. (in) Upright B (in) Upright C (in) Inverted D Dia. (in) Inverted E (in) Inverted F (in)
1/4 & 1/2 1.66 Pipe Length 2.38 1.25 .81 2.88
1 1.66 .75 3.84 1.50 .38 3.38
2 2.25 1.25 3.88 2.25 .63 3.88
3 2.25 1.25 4.34 2.25 .63 4.34
5 2.75 1.75 5.44 2.75 .88 5.44
10 3.38 2.00 5.75 3.38 1.13 5.75
15 3.63 2.00 6.13 3.63 1.25 6.13
20 4.00 1.50 7.75 4.00 1.00 7.75
25 5.50 2.25 9.69 5.50 1.25 9.69
35 6.50 2.38 9.44 6.50 1.25 9.44
50 7.00 3.00 11.75 7.00 3.00 11.75

Stainless Steel Anti-Backlash Actuators Performance Specifications

Capacity (tons) - 17-4PH Worm 2 5 10 15 20 25 35 50 100
Capacity (tons) - 316 SS Worm 0.67 1.66 3.33 5.00 6.66 8.33 11.66 16.66 33.33
Lifting Screw Diameter (in) 1
 1 1/2
2
2 1/4
2 1/2
3
3 3/4
4 1/2
6
Pitch (in) 0.250
 0.375
0.500
0.500
0.500
0.666
0.666
0.666
0.750
Type  ACME ACME
ACME
ACME
ACME
ACME
ACME
Mod.Sq.
Mod.Sq.
Worm Gear Ratios Standard  6:1 6:1
 8:1
8:1
8:1
10 2/3:1
10 2/3:1 10 2/3:1  12:1
Optional Number 1 24:1
24:1
24:1
24:1
24:1
32:1
32:1
32:1
36:1
Optional Number 2  12:1 12:1
-
-
-
-
-
-
-
Turns of Worm for 1" Raise Standard  24 16
 16 16
 16 16
 16  16 16
Optional Number 1  96  64 48
48
48
48
48
48
48
Optional Number 2  48 32
-
 -
-
-
-
-
 -
Worm Torque at No Load (in-lb) Standard 5
10
20
20
30
40
50
100
200
Optional Number 1  5 10
 20
20
30
40
50
100
200
Optional Number 2  5 10
-
-
-
-
-
-
 -
Maximum Horsepower per Actuator Standard  2 4
5
5
5
8
8
15
25
Optional Number 1  1/2 3/4
1 1/2
1 1/2
1 1/2
2 1/2
 2 1/2
6
11
Optional Number 2  3/4 2
-
 -
 -
-
 -
 -
 -
Worm Torque at Full Load (in-lb) 17-4PH Worm Standard  120 450
750
1430
2050
2700
4000
7500
16000
Optional Number 1  50 185
400
820
1170
1700
2400
4200
8600
Optional Number 2  75 275
-
-
-
-
-
-
-
Worm Torque at Full Load (in-lb) 316SS Worm Standard  43  156  263  490  703 926
1366
2566
5466
Optional Number 1  20 68
147
287
410
593
833
1466
3000
Optional Number 2 28
98
-
-
-
-
-
-
 -
Efficiency Rating (%) Standard  20.4  21.2  25.2  20.3  18.9 17.9
17.0
12.9
12.1
Optional Number 1 11.1
12.1
15.1
11.6
10.8
 9.3 9.3
7.5
7.4
Optional Number 2 15.6 16.8 -
-
-
-
-
-
-
Weight with 6" Raise (lb) 17 35 52 66 93 160 240
 410
1200
Weight per Additional 1" Raise (lb) 0.3 0.9 1.4 1.5 2.6 2.5
 3.7
 5.5
 9.0
Key Torque (in-lb) 153
581
1565
2527
3538
4665
8828
15697
39396
Max Worm Speed at Full Load (rpm) Standard 1750 1615
1198
643
449
544
369
368
288
Optional Number 1  1576 694 645
330
231
266
189
258
231
Optional Number 2  1669 1286
-
 -
 -
-
-
-
-
Max Load at Full Horsepower and 1750 rpm (lb) Standard 1333 3047
4386
3406
2972
4664
4220
5949
8865
Optional Number 1 1156 972
1791
1276
843
1507
1192
2831
4671
Optional Number 2  1258  2339 -
  -  -  -  -  -  -
How Backlash Works

How it Works

When the screw (1) is under a compression load, the bottom of its thread surfaces are supported by the top thread surfaces of the worm gear (2). The anti-backlash nut (3), being pinned to the worm gear and floating on these pins and being adjusted downwards by the shell cap, forcing its bottom thread surfaces against the upper thread surfaces of the lifting screw at point (B).

Thus backlash between the worm gear threadsand the lifting screw threads is reduced to a regulated minimum.

When wear occurs in the worm gear threads and the anti-backlash nut thread, the load carrting thickness of the worm gear thread will be reduced. This wear will create a gap at point (B) and provide backlash equal to the wear on the threads.

Under a compression load, the lifting screw will no longer be in contact with the lower thread surface of the anti-backlash nut. Under this condition, backlash will be present when a tension load is applied. The anti backlash feature can be maintained simply by adjusting the shell cap until the desired amount of backlash reduction is achieved.

This will reduce the separation (A) between the anti- backlash nut and the worm gear and will reduce the backlash between the worm gear threads and the lifting screw to the desired minimum value.

To avoid binding and excessive wear, do not adjust lifting screw backlash to less than .0005".

When separation (A) has been reduced to zero, the wear limit has been reached.

Replace the worn gear and backlash nut set at this point.

This feature acts as a built in safety device.

Anti-BacklashActuatorsspecifications.pdf

Stainless Anti Backlash Actuator Specifications

(approx. 1.4Mb)
Part N° Capacity (tons) - 17-4PH Worm Capacity (tons) - 316 SS Worm Lifting Screw Diameter (in) Lifting Screw Pitch (in) Lifting Screw Type Weight with 6" Raise (lb) Weight per Additional 1" Raise (lb) Key Torque (in-lb) Unit Price Quantity
4052-T22076 2 0.67 1 0.250 ACME 17 0.3 153 Quote Required
4052-T22077 5 1.66 1 1/2 0.375 ACME 35 0.9 581 Quote Required
4052-T22078 10 3.33 2 0.500 ACME 52 1.4 1565 Quote Required
4052-T22079 15 5.00 2 1/4 0.500 ACME 66 1.5 2527 Quote Required
4052-T22080 20 6.66 2 1/2 0.500 ACME 93 2.6 3538 Quote Required
4052-T22081 25 8.33 3 0.666 ACME 160 2.5 4665 Quote Required
4052-T22082 35 11.66 3 3/4 0.666 ACME 240 3.7 8828 Quote Required
4052-T22083 50 16.66 4 1/2 0.666 Mod.Sq. 410 5.5 15697 Quote Required
4052-T22084 100 33.33 6 0.750 Mod.Sq. 1200 9.0 39396 Quote Required
Add To Quote Request   ?  
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