There are few different kinds of linear bearings, sometimes called linear bushings. The two main categories are slide-type bearings and the rolling-type bearings, each with variations within category.
Such linear bearings or bushings are either rolling-element and fluid-film devices that serve the purpose of reducing friction in motion systems, especially in motion systems that move along a straight or curved line. For systems using a rotary motion, radial bearings are used instead.
Classic common examples of linear bearing applications include sliding doors, machine tools and many other applications where mechanical automation requires guided linear motion and with built-in friction reduction. They are also used in modern innovations such as 3D printers.
Here we will discuss the main types available though linear bearings suppliers such as YB Components.
Slide-Style Linear Bearings
This sliding-type of industrial linear bearings are usually made with sintered aluminium bronze along with other metal or polymer composites, though some models are made with powdered-metal bronze.
They usually feature carbon insert styles in polymer-lined sleeves, and the sintered type works by using a lubricating film installed between the shaft and the linear bearing while in operation. The powdered type makes use of the material’s porous construction and are imbued with lubricating oil via carbon plug inserts which heats up during operation and lubricates the shaft by producing a film of oil between the shaft’s surface and the bearing.
There are also polymer linear bearings in the slide-style, which are self-lubricating in that they have a natural slipperiness to reduce friction during motion. This polymer type is often used in the food industry as they can operate without the addition of often contaminating lubricants.
Some slide-type linear bearings suppliers offer models that feature special crowns that allow for some angular adjustment of the bearing according to its housing. This adjustment enables the bearing to adapt to angular variations caused by shaft deflection.
One of the great advantages of slide-type linear bearings is that they are tolerant of dirt and minor debris as they do not have moving parts like the rolling -style linear bearings do.
Rolling-Style Linear Bearings
The rolling-type linear bearing uses balls in open or closed cages that produce a very precise motion. There are variations in the models, such as some featuring re-circulating balls and others featuring balls that do not re-circulate. Both of these rolling-style types perform with a much lower starting friction than slide-type bearings.
The re-circulating ball and roller bearings can produce an endless loop of load-bearing elements and thus have fewer restrictions on application size. They use rounded or profiled rails with either open or closed cages, depending on what kind of support there is, such as a pillow block mounting or flanged supports.
The rolling-type bearing that do not use re-circulating balls have less range but also produce an extremely accurate linear motion. However the moving parts make these bearings vulnerable to dirt and debris and so must be kept clean with regular maintenance checks.
If you require any slide-type or rolling-type linear bearings, then contact YB Components who are the UK’s leading linear bearings suppliers.