SKF is introducing a high-performance range of ball and roller bearings designed with PEEK (polyetheretherketone) cages material. Rolling bearings fitted with PEEK cages are suitable for use in demanding applications such as screw compressors, traction motors, wind turbines and within the automotive and construction industries. As well as offering exceptionally high operating speeds, superior bearing qualities, reduced lubricant consumption and energy efficiency, the PEEK cage bearings also provide the added benefit of being lightweight, which makes them particularly attractive in the aerospace sector, for example.
Extensive testing carried out by SKF indicated that PEEK, a partially-crystalline thermoplastic, can withstand high continuous operating temperatures and poor lubrication conditions, thereby significantly extending bearing service life. Moreover, the use of PEEK as a cage material offers a range of other exceptional properties including a superior combination of high fatigue strength and flexibility, high chemical resistance (to all lubricants, additives and aggressive compressor media), and promoting the formation of a hydrodynamic film.
The proven thermal stability properties of PEEK make the new bearings suitable for use in applications where permanent operating temperatures exceed 120degC, yet they can also be used in areas where peak temperatures are at 250degC. In addition, PEEK offers considerably more resistance to ageing in contrast to other polymer cage materials. In tests comparing PEEK alongside polyamide 6.6, PEEK showed no significant signs of ageing under rigorous temperature and time variables and, as PEEK cages have a particularly low coefficient of friction, they are extremely wear-resistant.
Phil Burge, Marketing Manager at SKF, comments: "PEEK is an established material that is used in a variety of applications across a number of sectors. In many cases PEEK has replaced metals such as aluminium and brass, allowing users to realise considerable cost and weight savings, as well as eliminating the problems associated with 'metallic reactions'. It is also the one polymer that can accommodate the needs of demanding applications where very high or low temperatures or chemical resistance are key operational parameters."