What is ISO 7902‑1 standard about?
ISO 7902‑1 is the first part of a series of documents on cylindrical bearings. ISO 7902‑1 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.
ISO 7902‑1 deals with circular cylindrical bearings having angular spans, Ω, 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.
NOTE: Equivalent calculation procedures exist that enable operating conditions to be estimated and checked against acceptable conditions. The use of them is equally admissible.
Who is ISO 7902‑1 standard for?
ISO 7902‑1 on circular cylindrical bearings is relevant to:
- Manufacturer of hydrodynamic plain journal bearings
- Suppliers and customers of hydrodynamic plain journal bearings
- Mechanical engineer
- Mechanical drafters
Why should you use ISO 7902‑1 standard?
Hydrodynamic journal bearing is a bearing operating with hydrodynamic lubrication, in which the bearing surface is separated from the journal surface by a lubricant film generated by the journal rotation.
ISO 7902‑1 provides information on basis of calculation, assumptions, preconditions, calculation procedure, load-carrying capacity, frictional power loss, lubricant flow rate, heat balance, calculation examples of oil-lubricated hydrodynamic plain bearings.
As a buyer of ISO 7902‑1, you can be ensured of all the calculations required for designing oil-lubricated hydrodynamic plain bearings. ISO 7902‑1 helps you in manufacturing high quality hydrodynamic plain bearings. With the necessary guidance and compliance to ISO 7902‑1, the user can improve the quality and operation of oil-lubricated hydrodynamic plain bearings.
What’s changed since the last update?
BS ISO 7902‑1:2020 supersedes BS ISO 7902‑1:2013, which is withdrawn.
The main changes compared to the previous edition are as follows:
- Subclause titles have been added
- Symbols have been corrected and added in symbols and their designations tables
- Calculation values in annex a have been corrected
- Adjustments have been made to ISO/IEC directives, part 2:2018
- Typographical errors have been corrected
