If you work with linear ball or roller bearings, you’re familiar with the L10 bearing life equation, which states that bearing life is equal to the bearing’s rated dynamic load capacity, divided by the applied load, raised to a power of 3 (for ball elements) or 10/3 (for roller elements). Introduced in 1947 by Gustaf […]
FAQs + basics
What are differential roller screws and how do they differ from planetary designs?
Traditional roller screws — sometimes referred to as planetary roller screws — can produce axial forces comparable to hydraulic cylinders, with the speed and precision capabilities of ball screws, at a price point that falls between the two. A variation of the planetary roller screw — referred to as a differential roller screw — reduces some […]
Synchronous belt materials: What’s the difference between urethane and neoprene?
Synchronous belts for linear motion applications — such as general transport conveyors or high-speed gantry positioning — are available in a wide range of materials suitable for virtually any application. The most common synchronous belt materials are neoprene and polyurethane, but specialty materials and backing surfaces are also available to address requirements such as temperature extremes, […]
What makes a linear guide suitable for high temperature use?
For most recirculating ball and roller linear guides, the allowable operating temperature range is -10° to 80° C, with some configurations rated up to 100° C for brief periods. But not all applications fall within this temperature range, and each component in the linear bearing assembly (housing, rail, balls, seals, etc.) has a different maximum […]
What options are there for integrated motor and screw designs?
Ball and lead screw assemblies are often driven by a motor connected in-line with the screw shaft via a coupling. While this mounting arrangement is simple and easy to service, the addition of a non-rigid mechanical component (the coupling) can introduce windup, backlash, and hysteresis — all of which affect positioning accuracy and repeatability. The […]
Acme or trapezoidal? What’s the difference between lead screw designs?
In power transmission applications, there are two primary types of screw drives: those that use recirculating balls or rollers, for applications that require high rigidity, excellent positioning accuracy, and high duty cycles, and those that rely on sliding contact, for applications that require corrosion-resistance, self-locking operation, and customizable nut designs. The second category — screw […]
Electromagnetism basics for mechanical engineers
Electromagnetism — the relationship between electricity and magnetism — is the underlying principle for the operation of electric motors, as well as generators and transformers. And even though most of us aren’t designing motors (or generators or transformers) from scratch, it’s helpful to have a basic understanding of the concepts and laws that drive their operation. […]
What’s the best timing belt tooth profile for high-speed applications?
Synchronous belts (also referred to as timing belts) are used in a wide range of power transmission and transport applications that require good positioning accuracy. Tensile cords molded into the belt material help eliminate or minimize belt stretch, and positive engagement between the teeth of the belt and the pulley make synchronous belts less likely […]
What you need to know about corrosion-resistant linear guides
Recirculating ball and roller guides are the backbone of many automation processes and machines, thanks to their high running accuracy, good rigidity, and excellent load capacities — characteristics made possible by the use of high-strength AISI/ASTM 52100 chrome steel (commonly referred to as bearing steel) for the load-bearing parts. But because bearing steel isn’t corrosion-resistant, […]
Linear Motion Tips – Top 10 articles of 2019
Linear motion publications are typically dominated by topics related to linear guides, ball screws, and lead screws. But looking back at this site’s most-viewed articles in 2019, it’s obvious that while these are important technologies in the world of linear motion, they’re not the only things our readers are interested in. Case in point: In […]