Experimental Investigation of a Steam Lubricated Journal Bearing

摘要

An externally pressurized, orifice-compensated journal bearing was tested using both nitrogen and steam as lubricant gas. Non-rotating tests were performed to determine loaddeflection characteristics, stiffness and flow requirement. Performance with superheated steam, and shaft and bearing temperature equal to that of the inlet steam, was practically identical to the performance with nitrogen. Instability similar to pneumatic hammer was observed when shaft temperature was more than 10F below the inlet steam saturation temperature, using either saturated or wet steam. A minor instability of a different nature occurred when test conditions favored the condensation or accumulation of water droplets in the bearing supply manifold. The bearing was completely unstable when shaft temperatures were more than 25F below the inlet saturation temperature. The use of wet steam, saturated steam, or slightly superheated steam, while maintaining shaft temperature 10F below, at, or 10F above the inlet saturation temperature resulted in negligible differences in stiffness and loaddeflection curves. Some evidence was observed that increased rates of evaporation within the bearing clearance produced slight increases in bearing stiffness. (Author)