Corrosive environments can include anything from detergents and chemicals for washdown (the high-pressure cleaning of equipment), to acid baths and their related vapors, to chemicals in food processing. Because profiled linear rails, round shafts, and ball screws are made primarily from steel components, they’re highly susceptible to corrosive agents, which can quickly cause rust, pitting, […]
Ball Screw
How to calculate mean equivalent dynamic load
It’s rare in linear motion for a guide or ball screw to carry the same load throughout its move cycle. Even in simple pick-and-place applications, the load will be higher in one direction (the pick and carry phase) than in the other direction (the place and return phase). But even more common is for a […]
How does temperature affect ball screw assemblies?
As an integral part of industrial machines and processes, ball screw assemblies often operate in environments with elevated temperatures. Heat can be generated by other mechanical and electrical components in the machine, and in some cases, is a byproduct of the process itself. And, like other motion products with sliding or rolling friction, ball screws generate heat of […]
Common ball screw terms explained
When discussing ball screw assemblies, there is often confusion surrounding common nomenclature used to describe their structure and operation. Circuits, turns, lead, pitch, and starts are all widely used, and misused, terms to quantify various aspects of ball screw assemblies. Although these specifications are related to one another, each has a unique meaning and significance to […]
What’s the purpose of a double ball nut?
In its most basic form, a double ball nut is essentially two single ball nuts that have been tensioned against each other to induce preload. Three common methods for inducing preload in a double nut are: With a spacer ring between the ball nut halves With a spring between the ball nut halves By creating […]
How to calculate ball screw rigidity
The rigidity of a ball screw determines the amount of elastic deformation it will experience in the axial direction, under a given load. Elastic deformation, and therefore rigidity, is a fundamental characteristic in selecting and sizing a ball screw, as it affects the positioning accuracy of the system. δ = Elastic deformation (μm) Fa = Applied force in […]
Three ball nut recirculation methods
From a design standpoint, the most important criteria when selecting a ball screw assembly is the method used for recirculating the load-carrying balls of the ball nut. The ball nut recirculation method is a determining factor for the smoothness of motion and size of the ball screw assembly. It also has a significant influence of […]
Bearing lubricant: Choosing between grease and oil
Lack of bearing lubrication is generally regarded as the number one cause of linear-bearing failure. For recirculating linear bearings such as profiled rail guides and ball screws, lubrication separates the bearings (ball or roller) from the raceways, minimizes friction and wear, dissipates heat, and prevents corrosion. It also promotes smooth running of the seals and […]
Nook Industries offers complete line of worm gear screw jacks
Nook Industries, a leading innovator of linear motion components and systems, offers the ActionJac™ series worm gear screw jack product line. ActionJac models are ruggedly designed and produced in standard styles with load-handling capabilities from ¼ to 100 ton and can be used individually or in multiple arrangements. There are no specific travel lengths and each […]
A selection guide for linear systems
Gone are the days when machine designers and builders had to choose between constructing their own linear system from scratch or settling for a limited range of pre-assembled systems that, in most cases, were an imperfect fit for their application. Manufacturers today offer systems based on a range of drive mechanisms—ball screws, belts, rack and pinions, linear motors, […]
