BS ISO 7902-1:2020
$167.15
Hydrodynamic plain journal bearings under steady-state conditions. Circular cylindrical bearings – Calculation procedure
| Published By | Publication Date | Number of Pages |
| BSI | 2020 | 40 |
This document specifies a calculation procedure for oil-lubricated hydrodynamic plain bearings, with complete separation of the shaft and bearing sliding surfaces by a film of lubricant, used for designing plain bearings that are reliable in operation.
It deals with circular cylindrical bearings having angular spans, ?, of 360°, 180°, 150°, 120°, and 90°, the arc segment being loaded centrally. Their clearance geometry is constant except for negligible deformations resulting from lubricant film pressure and temperature.
The calculation procedure serves to provide dimensions and optimize plain bearings in turbines, generators, electric motors, gear units, rolling mills, pumps, and other machines. It is limited to steady-state operation, i.e. under continuously driven operating conditions, with the magnitude and direction of loading as well as the angular speeds of all rotating parts constant. It can also be applied if a full plain bearing is subjected to a constant force rotating at any speed. Dynamic loadings (i.e. those whose magnitude and direction vary with time), such as those that can result from vibration effects and instabilities of rapid-running rotors, are not taken into account.
Equivalent calculation procedures exist that enable operating conditions to be estimated and checked against acceptable conditions. The use of them is equally admissible.
PDF Catalog
| PDF Pages | PDF Title |
|---|---|
| 2 | National foreword |
| 6 | Foreword |
| 7 | 1 Scope 2 Normative references 3 Terms and definitions 4 Symbols and units |
| 11 | 5 Basis of calculation, assumptions, and preconditions 5.1 Reynolds equation 5.2 Assumptions and preconditions 5.3 Boundary conditions |
| 12 | 5.4 Basis of calculation 5.5 Permissible operational parameters 6 Calculation procedure 6.1 General 6.2 Freedom from wear |
| 13 | 6.3 The limits of mechanical loading 6.4 The limits of thermal loading 6.5 Influencing factors 6.6 Reynolds number 6.7 Calculation factors |
| 15 | 7 Definition of symbols 7.1 Load-carrying capacity 7.2 Frictional power loss 7.3 Lubricant flow rate 7.3.1 General |
| 16 | 7.3.2 Lubricant feed elements 7.3.3 Lubrication grooves 7.3.4 Lubrication pockets |
| 17 | 7.3.5 Lubricant flow rate 7.4 Heat balance 7.4.1 General |
| 18 | 7.4.2 Heat dissipation by convection 7.4.3 Heat dissipation via the lubricant |
| 19 | 7.5 Minimum lubricant film thickness and specific bearing load 7.6 Operational conditions |
| 20 | 7.7 Further influencing factors |
| 23 | Annex A (informative) Calculation examples |
| 38 | Bibliography |
