|
Predictive assessments of the performance characteristics of metal-polymer (MP) plain
bearings at the design stage are necessary and important for engineering practice. They include
assessments of bearing capacity, linear wear of the bushing, and bearing life. However, no method
for their calculation has been developed. The authors created a generalized analytical method for
the mathematical modeling of MP sliding bearings as a classical science-based method to study the
contact mechanics of conformal cylindrical bodies with consideration of polymer bushing wear. The
contact problem of the theory of elasticity takes into account the significant difference in the elasticity
characteristics of polymeric materials from those of steel: their Young’s modulus is 60–250 times
smaller, and Poisson’s ratio is 1.27–1.37 times larger. The method was used to study MP bearings
with bushings made from several common groups of tribopolymers: polyamides (PAs), polytetrafluo-
roethylenes (PTFEs), polyethylene terephthalates (PETs), and polyetheretherketones (PEEKs). The
maximum contact pressures and durability of the dry friction bearings were calculated while taking
into account the load; radial clearance; bushing thickness; the tribopolymers’ elasticity characteristics
and wear resistance; the sliding friction coefficient; and the type of tribopolymer material. The
Young’s modulus of a polymer material had a significant impact on the level of maximum contact
pressures. Polymer fillers, depending on their type and the type of polymer, had very different
effects on pressure changes (increase, no change, or decrease). An increase in pressure caused an
increase in contact pressures. The durability of a mechanical bearing depended not only on the
contact pressure but also on the polymer’s wear resistance, Young’s modulus, and friction coefficient.
This study determined the quantitative and qualitative effects of these factors on the maximum
contact pressures and bearing durability. The presented analytical method provides an effective and
reasonable assessment of the specified service characteristics of sliding bearings with consideration
of the multifactorial influence of the above factors.
|
