ISO 20054:2016 pdf free

ISO 20054:2016 pdf free.Plain bearings – Bearings containing dispersed solid lubricants
The sliding performance and mechanical strength vary according to the volume of solid lubricants.Higher sliding performance requires more solid lubricants, while higher mechanical strength requires less solid lubricants.
Since solid lubricants are dispersed over the entire material, the bearings are particularly suitable for extra low speed or micro-motion applications, minimising static friction to achieve smooth sliding at the start of motion.
The solid lubricants are drawn out over both surfaces from the bearing material when it slides against the mating surface, forming a solid lubricant film. As the solid lubricant film is consumed, it is replenished from the bearing material to maintain a continuous film throughout the life of the product (see Figure 4).
The bearing can be used for rotational motion, reciprocating motion, oscillating motion and frequent start/stop cycles. The bearing is also used in such applications where no fluid lubrication can be expected because of high load and low speed operation. Bearings with appropriate materials are suited to applications with high or low temperature, liquids, gases and in vacuo.
The bearing has been developed to operate satisfactorily without oil or grease lubricants. However, if the application permits, oil or grease may be utilized to improve bearing durability, prevent dust from entering the bearing, flush out wear debris or prevent corrosion of the bearing components.
Many types of solid lubricants are available. They are selected to suit the operating conditions because their friction performances are influenced by the operating environment. The majority of bearings incorporate graphite and molybdenum disulphide as solid lubricants. Other solid lubricants with low friction, suited to demanding environments, include tungsten disulphide, boron nitride and polytetrafluoroethylene (PTFE). Table 3 shows an outline for the operating temperatures and the atmosphere for the solid lubricants.
The size and type of solid lubricants are selected based on the operating conditions.ISO 20054 pdf download.