SKF composite dry sliding thrust washers are designed for applications where axial space is limited, maintenance is not possible and where lubricant starvation can occur.
As well as for composite bushings and strips, SKF manufactures composite thrust washers as standard from PTFE and POM composite materials.
Designs and variants
SKF composite dry sliding thrust washers (table 1) provide a cost-effective and space-saving solution for axial location. Both, PTFE and POM composite thrust washers are suitable where oscillating and rotational movement can occur. These washers are punched from the composite material and have as standard a hole to take a pin or screw to prevent the washers from rotating on their seat.
PTFE composite thrust washers
SKF PTFE composite thrust washers (fig. 1) are self-lubricating as well as maintenance-free and provide a long service life due to low friction. Despite of their compact design, these washers can accommodate heavy axial loads and are suitable for relatively slow rotational or oscillating movements. They also have good dimensional stability and thermal conductivity.
PTFE composite washers consist of a sheet steel backing on which a 0,2 to 0,4 mm thick porous layer of tin/bronze is sintered (fig. 2). Furthermore, by a rolling process the pores of the sintered layer are filled with a mixture of PTFE (polytetrafluoroethylene) and molybdenum disulphide additives. This additional 5 to 30 μm thick running-in layer provides an optimum combination of the mechanical properties of the sintered tin/bronze and the good sliding and lubricating properties of the PTFE mixture.