Lubrication Characteristics of Tilting Oil Pad Hydrostatic Thrust Bearing Applied to a Heavy CNC Machine Under Eccentric Load Conditions

ABSTRACT When the hydrostatic thrust bearing is machining parts, the machined parts are easily disturbed by external factors and deviate from the centre of the workbench so that the hydrostatic thrust bearing is in the state of eccentric load. In order to explore the lubrication characteristics of hydrostatic thrust bearings under eccentric load conditions, the hydrostatic thrust bearing with 12 tilting oil pads is taken as the research object in this paper. Based on the tribology principle and lubrication theory, the flow equation, load capacity equation and oil film thickness equation of double rectangular oil cavity are derived from the working and structural parameters of hydrostatic thrust bearing. The matching relationship between load and oil film thickness is obtained. The effects of rotational speed, load, and offset distance on the oil film pressure field and temperature field are studied. The experimental platform of hydrostatic thrust bearing is built to verify the correctness of the simulation method of the oil film temperature field and pressure field.