Babbitt thrust bearings are sensitive to many parameters. Hydro thrust bearing failures are typically due to:

  • an excessive load capacity often because turbine efficiency is increased
  • a lack of oil due to oil pump failures
  • oil viscosity is too low to maintain an efficient oil wedge during slower rotational speeds
  • high temperature rises of oil because of lack of cooling water or low rotational braking speed
  • contaminants in the oil such as babbitt residues from the guide bearing
  • a misalignment of two halves thrust runner plate

PTFE Thrust bearings offer many advantages and solve these problems because:

  • have a higher admissible specific load capacity up to 6.5MPa(943psi)
  • can increase capacity up to 200%
  • have a greater flexibility; thus, eliminating cracking
  • have a lower coefficient of friction (0.05-0.08) which results in lower oil temperature in pot
  • are not sensitive to contaminants in oil
  • can hot start after stop
  • perform well at low speeds because the wedge profile is optimized to maintain the lubrication
  • withstand 3 times the temperature rises of that of babbitt
  • work best for pump storage because the pivot point is closer to the center
  • do not require a high-pressure lift system