If you have a high speed load-lifting application, a ball screw mechanical actuator is an ideal solution. C.H. Bull is a leading supplier of mechanical actuators, offering reliable, high performance Duff Norton ball screw actuators. Duff Norton’s upright translating ball screw mechanical actuators deliver highly efficient, highly reliable performance in any application.
Request a quote on an upright translating ball screw actuator, or contact us to learn more.
Duff Norton Upright Translating Ball Screw Actuators
Duff Norton manufactures upright translating ball screw mechanical actuators with lifting capacities from 500 lbs. up to 50 tons. With a variety of customizable features, it’s easy to create a device that is perfectly tailored to your performance needs (see below).
These ball screw actuators move loads and apply force more efficiently than other mechanical actuator types. This permits faster operation (up to six times faster than machine screw actuators) and longer working life under load. Their ball screw design also reduces friction for lower power consumption.
Duff Norton ball screw mechanical actuators are capable of handling full load in tension or compression. They can be operated via electric, pneumatic, or hydraulic gear motors, and are furnished with standard raises in increments of 1”. Multiple units can be synchronized for simultaneous use on the same load.
A range of screw end options are available for varying application needs—plain ends, clevis ends, threaded ends, and top plates. Optional limit switches can be installed to regulate vertical travel (up or down).
C.H. Bull also offers inverted translating, upright rotating, and inverted rotating ball screw mechanical actuators, as well as Duff Norton machine screw actuators.
Customizable to Meet Your Application Requirements
Based on the performance requirements of your application, C.H. Bull can customize a ball screw actuator to deliver the exact performance you need. Numerous features can be customized, including:
• Lifting capacity
• Stroke length
• Motor type
• Screw end type
• Limit switch
• and more
Request a quote on an upright translating ball screw mechanical actuator. 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 the operating parameters: Total load, load per actuator (if multiple actuators will be used), desired lifting speed, total travel required, load type, and ambient working temperature.
Step 2: Determine which actuator style is best-suited to your application. Various factors must be considered when choosing between a ball screw actuator or machine screw actuator. Ball screw actuators are faster and more efficient, and require less horsepower to lift an equivalent load. Machine screw actuators are inherently load-holding and are preferred for applications which experience constant vibration.
Step 3: Calculate the required actuator performance. Start with an actuator with a capacity greater than the load you’ll be lifting. Then, use the formulae below to calculate performance requirements.
For loads greater than 25% of the actuator’s capacity, consider the torque proportional to the load.
A) Actuator torque (in.-lbs.) = Actuator load (lbs.) x worm torque at full load
Actuator capacity (lbs.)
(For loads less than 25% of the actuator’s capacity, add “Worm torque at no load” to the above formula to account for frictional losses.)
Calculate the 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 the input HP of the actuator.
C) Actuator input HP = Actuator torque (in.-lbs.) x RPM
63,000
Compare the necessary input HP to the actuator’s maximum HP rating. If the required HP exceeds the specified maximum, an actuator with higher HP rating must be used.
If using a gear reducer, the motor HP must be multiplied by the efficiency of the reducer to determine the reducer output HP (actuator input HP).
For multi-actuator arrangements where two or more mechanical actuators will be shaft driven by a single motor or gear reducer, sum the input HP requirements of all actuators. If a mitre gear box is used, allow for 2% power loss for every 90° turn in the power path.
Step 4: Determine the ideal actuator configuration. Consider your capacity, speed, and duty cycle requirements when selecting the actuator type that best meets your application requirements.
Step 5: Is your load unattached or free to rotate? If so, the actuator must be configured so that the lifting screw will extend when the actuator is in motion. Duff Norton mechanical actuators include a square nut inside a square cover pipe for the end of the lifting screw (for ball screw actuators) or a keyed shell and screw (for machine screw actuators) to prevent rotation of the translating screw.
Step 6: Verify actuator selection. Double-check your application’s travel and load requirements, as well as the ratio, capacity, and speed of the actuator. Determine which end fitting—plain end, clevis end, threaded end, or top plate—is best for your needs.
Safety Warnings
Actuator input speeds should never exceed 1,800 RPM.
Never exceed the actuator’s static or dynamic capacities.
Never exceed the actuator’s horsepower limits. If the specified max HP must be exceeded, reduce the lifting speed, use a higher-capacity actuator, select a different actuator ratio, or consider a more efficient actuator.
