Scroll Compressor, Lubrication, Thrust Slide Bearing, Tribology, Fluid Lubrication
The present study focuses on the effect of the thickness and inner form of the thrust plate in a scroll compressor upon the lubrication features. A simplified model of a annular thrust slide-bearing with thinner thrust plate submerged in a refrigerant oil VG-56 was operated under pressure using R-22 as the pressurizing gas, where the pressure difference was adjusted from 0 to 1.0 MPa. The friction force and coefficient of friction were measured over a wide range of orbiting speeds. The wedge angle due to elastic deformation is naturally increased with decreasing thrust plate thickness, resulting in a clear improvement in lubrication characteristics of the thrust slide-bearing. Subsequently, similar lubrication tests were conducted for the thrust plate model with a realistic inner form, one as complicated as that in actual scroll compressors, while maintaining the thickness of the thrust plate as in the previous test. No significant change in lubrication features relative to those from the simplified annular model were identified, confirming the validity of using simplified annular model tests to assess the basic lubrication characteristics of the thrust slide-bearing in scroll compressors.