Header
Stainless Steel Anti-Backlash Actuators (Specifications)

      

Stainless Steel Anti-Backlash Actuators
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

Stainless Steel Anti-Backlash Actuator Performance Specifications
Performance Table Instructions
When reviewing any Duff-Norton Actuator Performance Specifications Table, as part of the process of selecting the best-suited actuator for your application, there are several important worm-gear ratios to consider.

Standard Ratio - is frequently chosen when higher speeds and efficiency ratings are desired.
Optional Ratio(s) - is frequently chosen when the application requires higher lifting capacities, lower speeds, or to ease the use of a handwheel.

Capacity (Tons) - 17-4PH Worm

 

2

5

10

15

20

25

35

50

100

Capacity (Tons) - 316SS Worm

 

0.67

1.67

3.33

5.00

6.67

8.33

11.67

16.67

33.33

Lifting Screw

Daimeter (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

Std.

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 No. 1

24:1

24:1

24:1

24:1

24:1

32:1

32:1

32:1

36:1

Optional No. 2

12:1

12:1

¿

¿

¿

¿

¿

¿

¿

Turns of Worm for 1" Stroke

Std.

24

16

16

16

16

16

16

16

16

Optional No. 1

96

64

48

48

48

48

48

48

48

Optional No. 2

48

32

¿

¿

¿

¿

¿

¿

¿

Worm Torque at No Load (in-lb)

Std.

5

10

20

20

30

40

50

100

200

Optional No. 1

5

10

20

20

30

40

50

100

200

Optional No. 2

5

10

¿

¿

¿

¿

¿

¿

¿

Maximum Horsepower per Actuator

Std.

2

4

5

5

5

8

8

15

25

Optional No. 1

 1/2

 3/4

1 1/2

1 1/2

1 1/2

2 1/2

2 1/2

6

11

Optional No. 2

 3/4

2

¿

¿

¿

¿

¿

¿

¿

Worm Torque at Full Load (in-lb)

Std.

48

172

290

539

774

1019

1503

2823

6013

Optional No. 1

22

75

161

315

451

653

917

1613

3300

Optional No. 2

31

108

¿

¿

¿

¿

¿

¿

¿

Efficiency Rating (%)

Std.

55.7

57.7

68.7

55.4

51.4

48.8

46.3

35.2

33.1

Optional No. 1

30.1

33.1

41.1

31.5

29.4

25.4

25.3

20.6

20.1

Optional No. 2

42.6

46.0

¿

¿

¿

¿

¿

¿

¿

Weight with 6" Stroke (Raise) (lb)

17

35

52

66

93

160

240

410

1200

Weight per Additional 1'' Stroke (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

583

1567

2527

3542

4667

8833

15703

39400

Max Worm Speed at Full Load (rpm)

Std.

1750

1463

1088

585

407

495

335

335

262

Optional No. 1

1433

629

586

300

210

241

172

234

210

Optional No. 2

1517

1165

¿

¿

¿

¿

¿

¿

¿

Max Load at Max Horsepower and 1750 rpm (lb)

Std.

1333

2753

3958

3084

2691

4223

3823

5388

8031

Optional No. 1

1020

870

1605

1152

761

1361

1078

2557

4219

Optional No. 2

1122

2105

¿

¿

¿

¿

¿

¿

¿

*For loads from 25% to 100% of the actuator capacity, torque requirements are approximately proportional to the load.