Tham khảo tài liệu 'sổ tay tiêu chuẩn thiết kế máy p33', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | CHAPTER 28 JOURNAL BEARINGS Theo G. Keith Jr. . Professor and Chairman of Mechanical Engineering University of Toledo Toledo Ohio INTRODUCTION BEARING AND JOURNAL CONFIGURATIONS BEARING MATERIALS AND SELECTION CRITERIA PRESSURE EQUATION FOR A LUBRICATING FILM JOURNAL BEARING PERFORMANCE LIQUID-LUBRICATED JOURNAL BEARINGS GAS-LUBRICATED JOURNAL BEARINGS HYDROSTATIC JOURNAL BEARING DESIGN REFERENCES LIST OF SYMBOLS a Axial-flow land width ar Pad load coefficient A Area b Circumferential-flow land width C Clearance C Specific heat D Diameter e Eccentricity f Coefficient of friction Fj Friction on journal h Film thickness h0 Minimum film thickness H Dimensionless film thickness J Mechanical equivalent of heat k Permeability L Bearing width M Rotor mass at bearing Mj Frictional torque on journal STANDARD HANDBOOK OF MACHINE DESIGN n Number of pads or recesses N Revolutions per unit time p Pressure pa Ambient pressure pQ Short-bearing pressure pr Recess pressure ps Supply pressure p Long-bearing pressure p Dimensionless pressure P Unit loading q Volume flow rate per unit length qf Flow factor Q Volume flow rate Qs Side leakage flow rate R Radius of journal Rb Radius of bearing R C 5 Stiffness S Sommerfeld number iN P RIC 2 t Time tp Thickness of porous liner T Temperature u v iv Velocity in x y z directions respectively U Velocity of journal W Load Load component directed along line of centers WT Load component normal to line of centers x y z Rectangular coordinates X Dimensionless minimum-film-thickness parameter 0 R P 27tNp 1 2 Y Dimensionless frictional torque parameter M W7 P 27tVp 1 2 a Porous material slip coefficient P Included angle of partial bearing porous bearing parameter Pi Angle from line of centers to leading edge of partial bearing y Circumferential-flow parameter e Eccentricity ratio e c Ç Dimensionless axial dimension z L 2 0 Angular position .
