Helical Groove Fluid Static Pressure Sliding Bearing Shunt Characteristics

Spiral oil wedge hydrodynamic bearing is a novel sliding bearing, and has many outstanding features. Arc oil recesses are tilted, the working clearance of the bearing is the function of circumferential coordinates and axial coordinates, it has oil feed holes and oil return holes. The study for the oil flow separation performance of spiral oil wedges, will reduce temperature and find a new method for solving the problem of overheating and holding spindle in the journal bearing of superspeed and precision machine. The static and dynamic characteristics that the twist effect of three spiral oil wedges produces, will establish the foundation that spiral oil wedge hydrodynamic bearing is applied to superspeed machine tool spindles.In this paper, the oil flow separation performance of spiral oil wedge hydrodynamic bearing is simulated and analyzed.(1) According to the features of three tilted spiral oil wedges in spiral oil wedge hydrodynamic bearing, an equation is formulated between the rectangular axis and the oblique coordinate system, and an oblique coordinate system is used to formulate the Reynolds equation of bearing.(2) An oblique coordinate system is used to formulate the film thickness equation, the velocity equation, Reynolds equation of perturbance pressure for spiral oil wedge hydrodynamic bearing.(3) Using MATLAB, author analyzes static and dynamic characteristics and flow trail of lubricant oil in spiral oil wedge hydrodynamic bearing, and analyzes effects of spiral angle, eccentricity ratio and rotational speed etc. on the characteristics of bearing. Many valuable conclusions are obtained.(4) A visible analysis software of spiral oil wedge hydrodynamic bearing is developed under the circumstance of Win2000 and VC++6.0, which can realize the analysis, calculation and design of bearing. The software is convenient and applied, and it has the graphical and literal interfaces.The results show that the spiral oil wedges can realize the flow separation between the hot oil and the cold oil, avoid heating oil repeatedly, but conduce to the decrease of carrying capacity. Eccentricity and spiral angle have different effects onpressure, frictional resistance, the side leakage flow and temperature rise.