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 […]
FAQs + basics
What are stroke ball splines and how do they differ from standard ball splines?
Standard ball splines use balls that recirculate within a nut, or housing, similar to that of a recirculating ball linear bushing. But the mechanisms and geometry required for ball recirculation result in a spline nut that is relatively large in diameter compared to the diameter of the spline shaft. For a more compact assembly, several […]
What’s the difference between a ball screw spline and a traditional ball screw?
A ball screw spline is a combination of two components — a ball screw and a rotary ball spline. By combining a driving element (the ball screw) and a guiding element (the rotary ball spline), a ball screw spline can provide both linear and rotary motion, as well as spiral motion, in a highly rigid, […]
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 […]
How to protect ball screws in harsh environments
Harsh environments can wreak havoc on motion system components — especially rolling element systems such as linear guides and ball screws. And while protective devices such as rail covers, wipers, and scrapers are widely available for linear guides, protecting ball screws in harsh environments is a bit more tricky. But despite being more difficult to […]
What is a linear variable differential transformer (LVDT)?
In previous articles, we’ve covered a variety of technologies for measuring linear position: magnetic and optical encoders, magnetostrictive sensors, and even measuring systems integrated into linear guide systems. Another technology for measuring absolute linear position is the linear variable differential transformer (LVDT). A linear variable differential transformer is an induction-based measuring system that consists of […]
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 […]
What are planar motors and where are they used?
Linear motors are often described as rotary motors cut open and rolled out flat, so they produce motion in a straight line along one axis. Their construction is relatively simple, with a primary part (also referred to as a forcer) that contains windings, and a secondary part that contains magnets. The primary part is typically […]
What are boxway slides and where are they used?
Recirculating linear guides get significant media attention, thanks to their versatility and wide range of uses. But linear guides based on sliding contact — namely boxway and dovetail slides — are often the bearings of choice for applications that call for high load capacity, extreme stiffness, and excellent vibration damping characteristics. Boxway slides are a type […]
