How a linear guide is built
2024-03-20
A linear guide is a modern component used to move parts of a machine or device with high precision.
A good-quality linear guide gives you long service life, low friction, and very little maintenance. They’re also usually preloaded, meaning there’s no backlash—so you can make high-quality products for years without worrying about wear and tear.
Key components of a linear guide include:
- The rail and carriage, with their hardened raceways
- The rolling elements, like hardened steel balls that carry the load
The rolling elements are typically made from low-friction bearing steel, and they roll between the carriage and rail. This gives the system its super-low friction.
The end caps contain return channels, guiding the rolling elements from the loaded zone to the return path and back again. They also hold the seals in place.
Seals include:
- Profile seals, which seal against the shape of the rail
- Longitudinal seals, which prevent dirt from entering the carriage from underneath
Some brands also offer extra internal seals, placed above the ball tracks for added protection—because no one wants dirt and dust messing with their guide performance!
Contamination always shortens the life and function of a linear guide, and the quality of the seals really varies between manufacturers. It’s one of the reasons some brands last longer than others.
The carriage is lubricated via lubrication ports in the end caps, and generally, just one port is enough to keep things running smoothly.
Here’s a video on this topic with Carry Lindholm from Bosch Rexroth:
