Category Archives: Ball Screw Jacks

Worm Gear Essentials – Horsepower

The following is taken from an excellent white paper from Ron Givannone, Director of Application Engineering and Business Operations at Nook Industries (hyperlink). Titled “How to Size a Worm Gear Jack,” it looks at the key factors in figuring out what size and configuration of jack will work based on the needs of your application. Over the next few weeks, we’ll look at the different factors, and offer a bit more background.

This week, how Horsepower limitations can affect jack sizing.

When determining the lifting power of a jack, it’s a common mistake to assume the lifting capabilities of a jack are determined solely by its tonnage size. The load’s capacity is more often determined by its horsepower limitations. For example, a 10-ton jack may only be able to lift a one-ton load, because it is temperature-limited by the working horsepower it requires to lift the load.

The horsepower limit of the jack is a result of its ability to dissipate the heat generated from the inefficiencies of its components. The maximum horsepower value represents the point at which the heat that is generated by the working horsepower to move a given load meets the maximum temperature of the internal components. The working horsepower to move a given load is calculated by using the following formula:

How well a jack can dissipate heat is influenced by many application-specific variables, including mounting, environment, duty cycle and lubrication. The best way to determine whether performance is within horsepower limits is to measure the jack temperature. The temperature of the housing near the worm gear must not exceed 200 degrees Fahrenheit.

Looking for help in figuring out the right horsepower? Here are some tools:

Calculate Horsepower with this calculator

Calculate Kilowatts

Worm gear jacks definitions and technical data

Linear Motion 101 – Learn From the Pros

Just a click away are over 20 linear motion videos.  Want to learn the basics of a ball screw jack?  Perhaps, you need to load a standard ball nut?

Check us out :  Nook Industries!!

 

Making Motion Happen

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3 Key Reasons To Use Ball Screws in Linear Motion

  1. High Efficiency – Ball screws typically operate at a minimum of 90 percent efficiency, which makes them an optimal choice in converting rotary motion into precision linear motion.
  2. Load Capabilities – A part of what makes ball screws versatile in so many industries is their ability to carry remarkably heavy loads at fast, efficient speeds.
  3. Cost-Efficient – In the long run, ball screw systems can prove to be a cost-effective alternative to pneumatic or hydraulic systems, which require constant electrical and air power.

Ball screws provide unique benefits when compared to other standards, such as roller screws or acme screws. Want more info for your ball screw application?  Click here.

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Ball Screw Jack vs. Acme Screw Jack

Standard Nook Logo

Tips for how to select the right one for your application
Worm Gear Screws Jacks can provide long duty life, high load capacity and flexible design. They come in two major categories, Ball Screw and Machine Screw. In this post, we hope to help you identify the best type for your application.

Ball Screw Jacks use a ball screw and nut made from hardened alloy steel with bearing balls carrying the load between nut & screw. This rolling action reduces the friction between nut and screw, permitting smooth and efficient load movement that requires approximately 1/3 less torque than a machine screw jack with the same load.

inch ball

Machine Screw Jacks incorporate an alloy or sometimes stainless steel worm which drives a high strength bronze worm gear, or drive sleeve. The worm shaft is supported on anti-friction tapered roller bearings with external seals that prevent lubrication loss. The drive sleeve can also be supported on tapered roller bearings, or ball thrust bearings. Rotation of the drive sleeve causes the acme thread lifting screw to translate or rotate, depending on the jack configuration.

inch inverted machine

Because of their efficiency and lower power requirements, Ball Screw Jacks are often preferred. However, several factors can make Machine Screw Jacks preferable. For quick reference …

Machine Screw Jacks are best used for:
• Resistance to backdriving
• Environments with vibration
• Manual operation
• High static loads
• Corrosion resistance (with stainless steel versions)

Ball Screw Jacks are preferred for:
• Long travel lengths
• Long, predictable life
• High duty cycles
• Oscillating motion

Both types can be metric or inch, come in several types (Upright, Inverted, Upright Rotating and Inverted Rotating) and multiple jacks can be laid out in H, U, T and In-Line arrangement.

You can also employ multiple jacks in tandem, depending on the physical design and size of the equipment, its stiffness and the guide system. This will, however, introduce challenges with drive, alignment and synchronization.

Any jack system is limited by multiple constraints: load capacity, duty cycle, horsepower, column strength, critical speed, type of guidance, brake motor size and ball screw life. To properly size your jack for these constraints, application information must be collected.

All Your Equations In One Place

calculators

When a linear motion solution is in place & running, it’s easy for the casual observer to think it looks easy. That’s what our industry is all about; making the difficult or even impossible look easy.

But what few people outside the industry realize is just how much work needs to go into the design of a successful linear motion system. The old adage “Measure twice, cut once” doesn’t even begin to cover all the variables, that have to be dealt with.

Now, a new app looks to make that successful design at least a little easier. The Design Guide Pro not only offers selectors for Bevel Gears, Worm Gear Jacks, Bearings and Electric Cylinders, but it also has a calculator section. Here, you’ll find tools to help you establish Energy, Critical Speed, Column Load, Torque and Nut Life as well as helping with Unit Conversions.

All in the palm of your hand. Check it out today by clicking here.

#MakingMotionWork