Slide bearings are a type of linear slide, which are linear motion devices used to provide free motion in one direction. Slide bearings often replace other systems like roller bearing systems or ball bearing systems. Slide bearing systems, roller bearing systems and ball bearing systems all share in common compositions involving a stationary base and a moving carriage. However, they differ in that, while roller bearing and ball bearing systems rely on the rotation of cylinders or balls to move a load, slide bearings move a load using the low friction movement created when the bearings slide or glide against one another. Slide bearings are popular for use in a large number of industrial applications. These include: component manufacturing and testing, food processing, oil and water transportation, pipelines, steel fabrication and more.
Slide bearings are available in a wide variety of iterations and in a number of different materials. However, they are usually made from the combination of a soft material and a hard material. Typically, these materials are self lubricating materials like graphite or high performance polymers. Their goal is to provide low resistance to motion. Other materials with which slide bearings are commonly made include: babbitt, PTFE coated bronze and polymers like nylon, urethane, rulon, PEEK and vespel. If a material is not self lubricating, it may require the supplement of a lubricant to keep the friction levels low. To help distinguish between bearings and their levels of lubrication, bearings used are divided into three classes. Bearings in Class I require the application of lubricant from an external force, while bearings in Class II, such as carbon, graphite, or bronze, contain a lubricant within their walls. To reach maximum performance levels, Class II bearings can receive the application of a lubricant from an external source. Finally, Class III slide bearings are considered self-lubricating. Of all slide bearing designs available, the most common is the sandwich style. The sandwich style of slide bearing consists of two plates of low friction material sandwiched in between metal backing plates. Said plates are typically attached to a high strength metal bar, such as a steel bar, which helps it bear the weight of the load being moved. In addition to these, other possible components of sandwich slide bearings include intermittent rail supports, shaft end blocks and shaft end supports.
When designing a precision linear bearing system such as a slide bearing system, manufacturers must consider a number of different factors. Factors such as these include: the desired speed of the motion system, the projected size of the motion system, the dimensions of the area in which the motion system will be installed, the intended load of the bearing system, the temperature(s) to which the system will most likely be exposed and the physical elements (such as dirt and dust) it may encounter. This helps them decide many different things, such as in what way a slide bearing system may need to be attached to a structure. Possible solutions to that include: by welding, with bolts and with industrial adhesives. Likewise, knowing the details of the environment in which slide bearings will be placed helps manufacturers decide if perhaps a system would benefit from the addition of bellows or covers. Additions such as these can be easily attached to a slide system in order to shield in from dirt particles, which would undoubtedly interfere with the low friction properties borne by slide bearings.
Slide bearings are an advantageous addition to any linear motion system for a number of reasons. First, they typically last far longer than roller bearings or ball bearings. This is even more true if the slide bearings are constructed from high performance materials. In addition, slide bearings are much quieter than other linear motion systems that provide similar services. This is because, as they do not have any metal components rotating and rattling around within the railings, the only sound they make is the barely audible noise of slides gliding against one another. Also, because slide bearings are constructed using fewer fewer materials, last much longer and are highly adaptable and versatile, they are far more cost effective than ball bearings or roller bearings. Note that, as with any system exposed to outdoor elements and regular wear and tear, all slide bearings will eventually have to be repaired or replaced. However, the time that it takes for this to come to pass is much longer than their contemporaries. For more in-depth information on how slide bearings may be incorporated into your application, what materials and/or configurations may be best for your application and how much they may cost, reach out to one or more of the many linear bearing system manufacturers we have listed on this page. To fit your unique needs, they can offer both standard and custom configurations.