A study of cooling system in a grease-lubricated precision spindle

In this article, an integrated thermal model is numerically analyzed to calculate the heat generation of spindle bearings and temperature distribution of the spindle system, with consideration of the operating conditions and lubrication conditions, such as rotation speed, preload, and oil film thickness. Surface roughness is an important parameter of elastohy-drodynamic lubrication, which is measured by an optical topographer and characterized by statistical parameters. The experimental measurement system of the precision spindle is composed of a set of laser triangulation sensors and thermal infrared imagers. After the thermal characteristics, mathematical models are experimentally verified, and the effects of cooling oil temperature, cooling oil flow rate, and characteristic dimensions of the cooling channel on keeping the spindle gradient are analyzed in detail. The results indicated that temperature gradient across the spindle system can be significantly controlled by optimizing the technical parameters of the oil-cooling system.