Metric Anti-backlash Screw Jacks

5-to-500-kN load capacity. Metric Anti-backlash actuators reduce vertical backlash resulting in smooth, precise operation and minimal wear. Backlash occurs when the motor driving an actuator reverses its load direction. 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.

Specifications

Performance Table Instructions 
When reviewing and Duff-Norton Actuator Performance Specification 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 - is frequently chosen when the application requires higher lifting capacities, lower speeds, or to ease the use of a handwheel.
Numeric Ratio - is frequently chosen for applications requiring fine adjustments, higher lifting capacities, lower speeds, the easy use of a handwheel, self locking applications, and also offers the benefit of an even number of worm input turns per inch of stroke.

Specifications - Metric Machine Screw Actuators - Capacities 5 to 500 (kN)

Capacity (Tons) 5 10 25 50 100 150 200 300 500
Lifting Screw Diameter (mm) 16 20 30 38 52 58 65 95 115
Lead (mm) 3 5 6 9 12 12 12 16 16
Type Metric Trapezoidal
Worm Gear Ratios Standard 5:1 5:1 6:1 6:1 8:1 8:1 8:1 10-2/3:1 10-2/3:1
Optional No. 1 20:1 24:1 24:1 24:1 24:1 24:1 32:1 32:1
Optional No. 2 12:1 12:1
Travel per Worm Turn (mm) Standard 0.60 1.00 1.00 1.50 1.50 1.50 1.50 1.50 1.50
Optional No. 1 0.25 0.25 0.38 0.50 0.50 0.50 0.50 0.50
Optional No. 2 0.50 0.75
Worm Torque at No Load (N-m) Standard 0.23 0.56 0.56 1.13 2.26 2.26 3.39 5.65 11.3
Optional No. 1 0.56 0.56 1.13 2.26 2.26 3.39 5.65 11.3
Optional No. 2 0.56 1.13
Maximum Input Power (kW) Standard 0.25 0.37 1.49 2.98 3.73 3.73 3.75 6.00 11.2
Optional No. 1 0.198 0.37 0.56 1.12 1.12 1.12 1.86 4.50
Optional No. 2 0.56 1.49
Worm Torque at Full Load (N-m) Standard 2.83 7.53 20.10 56.78 117.1 189.2 275.4 505.7 915.5
Optional No. 1 3.69 9.34 27.06 63.2 101.4 147.7 305.3 520.5
Optional No. 2 12.8 36.65
Efficiency Rating (%) Standard 16.9 21.1 19.8 21.0 20.4 18.9 17.3 14.2 13.0
Optional No. 1 10.8 10.7 11.0 12.6 11.8 10.8 7.8 7.6
Optional No. 2 15.5 16.3
Weight with 25mm Raise (kg) 1.04 2.27 7.71 15.88 23.59 29.94 42.18 100 173
Weight per Additional 25mm Raise (kg) 0.04 0.13 0.13 0.40 0.63 0.67 1.16 1.65 2.46
Key Torque (M-n) 8.48 22.80 76.61 213.37 579.94 943.98 1374.01 2954.25 5746.55
Maximum Worm Speed
at Full Load (RPM)
Standard 844 469 708 501 304 188 129 113 117
Optional No. 1 491 378 198 169 105 72 58 83
Optional No. 2 418 388
Maximum Load at Full
Horsepower and 1750
RPM (lb)
Standard 2.73 2.69 11.84 16.62 19.42 17.90 15.57 20.32 34.54
Optional No. 1

2.21 5.34 4.93 8.40 7.74 5.52 6.61 18.01
Optional No. 2 6.39 12.22
Note: For loads from 25% to 100% of actuator capacity, torque requirements are approximately proportional to the load. Raises, measured in increments
of 25mm, are available up to 6.1 meters, depending on lifting screw diameter and available bar stock length.
Note: Contact customer service for motorized performance.

Models

Key Adaptor Dimensions

Key-adaptor-dimensions-1.jpg

Key Adaptor Dimensions for Metric Anti-backlash Actuators
Actuator Capacity (kN) Upright Actuators Inverted Actuators
A
Diameter (mm)
B
(mm)
C
(mm)
D
(mm)
E
(mm)
F
(mm)
5 42.0 Pipe Length 64.0 31.8 20.6 73.0
10 42.0 Pipe Length 97.5 31.8 9.5 85.9
20 57.2 31.8 98.5 31.8 20.6 98.5
50 69.8 44.5 138.0 69.8 22.4 138.0
100 85.9 50.8

146.0

85.9 28.7 146.0
150 92.2 50.8 156.0 92.2 31.8 156.0
200 101.6 38.1 197.0 101.6 25.4 197.0
300 156.0 60.4 227.0 165.0 31.7 227.0
500 178.0 76.2 276.0 178.0 76.2 276.0