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 […]
Ball + roller guides
How to calculate bearing life for a ball spline
A ball spline is much like a linear ball bushing and shaft, but with axial grooves along the outer diameter of the shaft and the inner diameter of the nut. These grooves prevent rotation of the bearing (referred to as a spline nut) and allow the ball spline to transmit torque. Because a ball […]
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 […]
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 […]
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 […]
THK develops smoothest moving miniature LM Guide, the Type RSX
New from THK, the Type RSX Miniature LM Guide offers the smoothest movement in its class. Featuring, an optimized circulation structure, it achieves smoother movement than existing miniature LM Guides. The compact outer dimensions of the Type RSX enable the realization of space-saving designs. It is available in a standard Type RSX-M and a Type […]
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 […]
