A Power Flow Model for High Speed Motorized Spindles—Heat Generation Characterization

Lack of a more complete understanding of system characteristics, particularly thermal effects, severely limits the reliability of high speed spindles to support manufacturing. High speed spindles are notorious for their sudden catastrophic failures without alarming signs at high speeds due to thermal problems. In this paper, a qualitative power flow model is presented to characterize the power distribution of a high speed motorized spindle. Quantitative heat source models of the built-in motor and the bearings are then developed. These models are verified with a custom-built high performance motorized spindle of 32 KW and a maximum speed of 25,000 rpm (1.5 million DN). Several systematic test procedures are also developed to validate the models.