If you need to lift heavy loads with minimal force, you need a machine screw mechanical actuator. And if you need a machine screw actuator, look no further than C.H. Bull. We offer reliable, high performance machine screw actuators from Duff Norton. A Duff Norton upright rotating machine screw mechanical actuator is the ideal solution for a wide range of load-lifting challenges.
Request a quote on an upright translating machine screw actuator, or contact us to learn more.
Duff Norton Upright Translating Machine Screw Actuators
Duff Norton manufactures upright translating machine screw mechanical actuators with lifting capacities from 500 lbs. up to 250 tons. A variety of customizable options are available, making it easy to find the right device for any application (see below).
Operated manually or via electric, pneumatic, or hydraulic gear motors, these machine screw actuators can be used singly, in pairs, or in multiple arrangements, depending on your load lifting needs. Because most models operate at a uniform speed, actuators of varying capacities can be used on the same load simultaneously.
Most of these upright translating machine screw actuators are self-locking, and will hold heavy loads in place indefinitely. They can be used to push, pull, or apply pressure, and can also function as linear actuators. Furnished with standard raises in increments of 1”; models with total raises up to 20’ are available.
A variety of screw end options are available, including threaded ends, clevis ends, plain ends, and top plates. Limit switches are available to regulate the actuator’s vertical travel (up or down).
Features
• Positive, mechanical positioning
• Uniform lifting speed
• Optional anti-backlash
• Precision positioning within thousandths of an inch
• Customizable (see below)
We also offer inverted translating, upright rotating, and inverted rotating machine screw actuators, as well as Duff Norton ball screw actuators.
Customizable to Meet Your Application Requirements
To meet your unique requirements, C.H. Bull can provide a customized upright translating machine screw mechanical actuator. Numerous features are customizable, making it easy to develop a custom actuator that delivers the exact performance you need. Customizable options include:
• Lifting capacity
• Stroke length
• Motor type
• Screw end type
• Limit switch
• and more
Request a quote on the upright translating machine screw mechanical actuator you need. Contact C.H. Bull for more information on these or any of our quality products.
Selecting the Right Mechanical Actuator for Your Needs
Step 1: Define operating parameters such as total load, load per actuator (if multiple are required), desired lifting speed, total travel required, load type, and ambient working temperature.
Step 2: Determine which type of actuator is best for your application. There are numerous factors to consider when choosing between a machine screw actuator or a ball screw actuator. Machine screw actuators are inherently load-holding, and are better suited to applications which experience constant vibration. Ball screw actuators, meanwhile, are more efficient, faster, and require less motor horsepower to move an equivalent load.
Step 3: Calculate the necessary actuator performance. Start with an actuator with capacity greater than the load it must lift. Then, use the formulae below to calculate your needs.
For loads greater than 25% of the actuator’s capacity, consider the torque to be proportional to the load.
A) Actuator torque (in.-lbs.) = Actuator load (lbs.) x worm torque at full load
Actuator capacity (lbs.)
(For loads under 25% of the actuator’s capacity, add “Worm torque at no load” to the above torque calculation to account for frictional losses.)
Calculate input RPM. (WARNING: Shaft input should never exceed 1,800 RPM.)
B) Input RPM = Desired lifting speed (in./min.) x turns of worm for 1” lift
Calculate actuator input HP.
C) Actuator input HP = Actuator torque (in.-lbs.) x RPM
63,000
Compare the necessary input HP to the maximum HP of the actuator. If the necessary HP exceeds the maximum, an actuator with a higher HP rating is required.
If a gear reducer is used, motor HP must be multiplied by the reducer’s efficiency to obtain reducer output (actuator input) HP.
For multiple-actuator arrangements, where two or more actuators are shaft driven from a single motor or gear reducer, sum the input HP requirements of all actuators. If mitre gear boxes are used, allow for 2% power loss for every 90° turn in the power path.
Step 4: Determine actuator configuration. Consider your capacity, speed, and duty cycle requirements to select the actuator type that best matches your application.
Step 5: Are you lifting unattached or unguided loads? If your load is unattached or free to rotate, the actuator must be configured so that the lifting screw will extend when the actuator is in motion. To prevent rotation of the translating screw, Duff Norton mechanical actuators include a keyed shell and screw (for machine screw actuators) or square nut inside a square cover pipe for the end of the lifting screw (for ball screw actuators).
Step 6: Verify your actuator selection and double-check the travel and load requirements of the application, as well as the ratio, capacity, and speed of the actuator. Determine which end fitting (threaded end, clevis end, plain end, or top plate) is right for your application.
Safety Warnings
Actuator input speeds should never exceed 1,800 RPM.
Never exceed the static or dynamic capacities of the actuator.
Never exceed the specified horsepower limits. If maximum HP must be exceeded, reduce the lifting speed, use an actuator with higher capacity, choose a different actuator ratio, or consider a more efficient actuator.
