The basic distinction between “standard” and “miniature” profiled rail guides is the width of the guide rail: profiled rails with a width of 15 mm or less — and the carriages that fit on them — are generally considered “miniature” by bearing manufacturers. (However, some manufacturers also produce 15 mm rail guides in standard versions, as we’ll […]
Linear bearings
How to size a spline shaft: Shaft strength in bending and torsion
Choosing a shaft for a traditional linear ball bushing is relatively easy — choose the appropriate diameter, material, and hardness, check the dimensional accuracies and tolerances, and if the shaft is unsupported, perform a beam deflection calculation. But because spline shafts can withstand both radial and torque loads, it’s important to ensure the shaft strength […]
How to calculate linear ball bushing life (and how it differs from other life calculations)
The standard life calculation for linear ball bearings is widely known as: L = bearing life (m) C = rated dynamic load (N) F = applied dynamic load (N) But linear ball bushings often experience operating conditions that aren’t accounted for in the general bearing life equation. To account for these adverse conditions, the life calculation […]
Round-rail linear guide or profile-rail linear guide?
In this article, we outline how to choose a linear guide for your application and environment. By Lindsey Brimage and Eric Schultz | Thomson Industries Ian Miller | Motion Industries Canada Designers of linear motion systems often find themselves weighing the pros and cons of round versus profile (also known as square) linear guides. Many […]
How does shaft hardness affect the life of a linear ball bushing?
A linear ball bushing riding on a round shaft is often compared to a radial ball bearing, with the bushing acting as the outer race of the bearing and the shaft acting as the inner race. But in linear bushing assemblies, the surfaces of both the ball and the shaft are spherical, so contact between […]
How to make sure you get the right linear bushing interchange
Linear ball bushings are one of the few interchangeable product types in linear motion, with industry-standard sizes and styles, so that a product from one manufacturer can often be substituted with a product from another manufacturer that has very similar dimensions and technical specifications. And most linear bushing manufacturers offer several product lines that are […]
Tips for mounting linear ball bearings: Pillow block housings
Linear ball bearings and round shafts are often used in applications that call for ease of use and simple mounting requirements. For example, where profiled rail guides require full support along their length, linear ball bearings, or bushings, can be used in many applications with shafts that are supported only at their ends. However, unlike […]
What to consider when specifying a linear slide
Here are some considerations when specifying a linear slide for a new or existing application. By Mike Quinn • LM76 When a design engineer has fully defined a linear-motion application’s requirements regarding travel length, speed, force, and accuracy as well as repeatability, the next question to answer is this: Does an off-the-shelf linear slide (or […]
What are fixed and floating bearings in the context of linear motion?
There are two instances when the terms “fixed bearing” and “floating bearing” are used in linear motion: to describe the support bearings used on ball and lead screws, and to describe linear guides mounted in parallel. And while the meanings of the terms are the same in both situations, their applications are different in each […]
FDA-compliant off-the-shelf linear motion components for urgently needed medical products
In dealing with the COVID-19 pandemic many companies have volunteered or been requested to produce urgently needed medical products such as masks, gowns, and ventilators. Tooling up quickly to produce medical grade products for some companies can bring challenges. In addition to needing FDA-compliant materials that will be used in the actual masks, gowns, and […]
