For more than 35 years, plastic bearings by igus® have been a technically and economically advantageous alternative to metallic plain bearings. Improved by precise additions of reinforcing materials and solid lubricants, they are suitable for applications and requirements of all kinds, reduce maintenance work and allow for technical improvements.
The reasons are obvious – bearings made of high-performance plastics are:
Long service life and low coefficients of friction regardless of motion type
High media resistance
High temperature resistance
High resistance to dirt
High vibration dampening
Very good price-performance ratio
A classic metal composite bearing essentially consists of a metal cover and a very thin layer of polytetrafluoroethylene (PTFE). Typically, these types of bearing have a maximum wear zone of approx. 0.05 mm or approx. 0.002 inches. During operation, the PTFE layer is worn out. In extreme cases, it is completely worn away until metal runs on metal, resulting in shaft damages or "seizing up" of the bearing.
iglidur® plastic bearings are made of modern polymer compounds, which consist of base polymer, solid particles and so-called solid lubricants. These help reduce the iglidur® plain bearing's coefficient of friction. A transfer to the shaft is not absolutely necessary, but improves functionality. With this homogeneous structure, theoretically the entire wall thickness is available as wear zone.
The oil is absorbed by the body of the porous sintered bearing and provides lubrication, especially at higher rotation speeds. The oil film necessary to ensure that sintered bearings function effectively does not work in the case of slow and/or linear or pivoting movements. In addition, the amount of oil available for the duration of the operation decreases.
The homogeneous and consistent structure with solid lubricating and reinforcing materials but without oil saturation ensures that the solid lubricants incorporated in the material are always available irrespective of the kind of movement. Very low coefficients of friction and wear over the entire life cycle of the product.
Due to the line contact between needle rollers and raceways, needle bearings have – compared to the point contact of the ball bearings – indeed a better load distribution at the contact point during rolling, yet the line contact requires a high Hertzian pressure. Therefore, like all rolling bearings, they are sensitive to vibrations and shocks. In addition, wear of the shafts can occur, which is why usually hardened shafts have to be used. Needle bearings can only absorb radial forces.
Due to the large load-bearing surface and the comparatively elastic properties of the plastic, iglidur® plain bearings are also suitable for heavy shocks and edge loads. Reinforcing fibres provide an additional improvement of the mechanical properties. In combination with iglidur® plain bearings, "soft" shafts can be used in many applications. Even with edge loads, the risk of shaft wear is significantly lower than with needle bearings.
The temperature resistance of high-performance polymer plain bearings is usually underestimated. igus® plastic bearings prove their suitability at up to 250°C.
The iglidur® plain bearing materials for high loads combine high wear resistance with the ability to withstand high (static) loads, shocks and edge loads. They have proven themselves in different heavy-load applications for many years.
iglidur® plastic plain bearings are characterised by their robustness and high service life, especially in dirty applications. An important reason: as no lubrication is necessary, dirt and lubricant cannot stick to the bearing locations.
Extreme environmental conditions, such as chemicals combined with high temperatures, require special properties of the plain bearings in use. All iglidur® plain bearings can be used in diluted acids and diluted alkalis. Differences occur in particular with higher concentrations or higher temperatures. For this, special iglidur® materials are available.
igus® has also developed plain bearing materials for continuous use in water and other liquid media. In addition to corrosion resistance, minimised moisture absorbency and high wear resistance in liquid media are necessary.