Classification of oil-free bearings
Oil-free bearings can be divided into solid-inlaid bearings, composite bearings, oil-impregnated bearings, and new-type single-lubricating material bearings according to different product structures.
Solid inlaid bearings
It is common to embed solid lubricating materials such as graphite (black lead), polytetrafluoroethylene (PTFE), molybdenum disulfide, etc., into alloy materials such as high-strength brass, tin bronze, aluminum bronze, cast iron, or GCr15 using an inlay process. It breaks through the limitation of general sliding bearings relying on oil film lubrication. During use, the frictional heat causes the solid lubrication to rub against the shaft, forming the feature of coexisting oil and powder lubrication, which not only protects the shaft from wear, but also makes the solid lubrication properties eternal. The hardness of oil-free bearing high-strength brass is twice as high as that of ordinary copper sleeves, and its wear resistance is also twice as high as it has high bearing capacity.
Common composite bearings are composed of two layers of steel plate and copper powder layer (bimetal), or composed of three layers of steel plate, copper powder layer, self-lubricating materials (PTFE, PEEK, POM) and filler materials. This type of oil-free bearing uses a high-temperature sintering process to bond the self-lubricating material to the steel plate, which not only ensures the lubrication performance of the working surface of the product, but also ensures the structural stability and carrying capacity of the bearing.
Oil-impregnated bearings are made of metal materials. The bearings are lubricated during production and the lubricating oil is sealed in the bearings to achieve a "self-lubricating" effect during use. Because the bearing contains lubricating oil, it has good lubricity and avoids the work of oiling maintenance.
New type single lubricating material bearing
New types of single lubricating material bearings commonly include resin, ceramic, tungsten carbide bearings, etc., and new materials are constantly being developed, but such oil-free bearings may have the characteristics of high cost and narrow application range, so they cannot be used. Area promotion.