Elastohydrodynamic lubrication and lubricant rheology in refrigeration compressors

Sammanfattning: The introductory chapter gives a general description of the lubrication of rolling element bearings in refrigeration compressors and rheological properties of oil-refrigerant mixtures. The influence of refrigerants on the viscosity, pressure-viscosity coefficient and film forming ability in a EHD-contact is described. A method is described for measuring the viscosity of oil-refrigerant mixtures measured using optical interferometry film thickness. The effect of pressured natural gas on the viscosity of polyalkyleneglycols was measured ar pressures up to 10 MPa. Viscosity and pressure-viscosity coefficient was measured on different polyolesters mixed with refrigerant R- 134a. Optical film thickness measurements was used to compare film forming ability of polyolesters with different structure. Lubrication limits and wear of rolling element bearings operating in a refrigerant atmosphere was studied. A new method of supplying lubricants to refrigeration compressor using controlled superheat of the lubricant mixture is suggested.

  Denna avhandling är EVENTUELLT nedladdningsbar som PDF. Kolla denna länk för att se om den går att ladda ner.