Overview
ISO 12130-1:2021 defines a calculation method for oil-lubricated hydrodynamic plain tilting pad thrust bearings operating under steady-state conditions. The standard covers bearings where the thrust collar and tilting pads are completely separated by a lubricant film and a wedge-shaped clearance gap forms automatically during operation. It applies to tilting-pad plain thrust bearings with a pad width-to-length ratio B/L = 0.5 to 2 and excludes heavily loaded designs. Equivalent calculation procedures are permitted where they provide comparable operating estimates.
Keywords: ISO 12130-1:2021, tilting pad thrust bearings, hydrodynamic plain bearings, calculation method, film lubrication, steady-state.
Key technical topics and requirements
- Calculation method based on Reynolds equation: Numerical solutions of Reynolds equation for finite-width sliding surfaces are the basis for load, pressure and flow predictions.
- Fundamental assumptions: Newtonian, incompressible lubricant; laminar flow; fully flooded clearance; negligible inertia, gravity and surface roughness effects; rigid components (no elastic deformation); isoviscous lubricant within the gap.
- Boundary conditions and similarity parameters: Prescribed pressure boundary conditions and use of dimensionless similarity parameters to reduce numerical solution effort.
- Primary calculation outputs and checks:
- Load-carrying capacity and centre-of-pressure coordinates
- Frictional power and heat generation
- Lubricant flow rates (inlet, outlet, lateral)
- Heat balance including convection and recirculation
- Minimum lubricant film thickness and specific bearing load limits
- Operating condition verification (steady-state speed and load)
- Design limits: Applicable pad geometries (B/L range) and exclusion of heavily loaded tilting-pad thrust bearings.
- Allowance for alternate methods: The standard recognizes that equivalent validated calculation procedures may be used.
Practical applications
ISO 12130-1 is used to design, size and validate tilting-pad thrust bearings for rotating machinery that relies on hydrodynamic film lubrication, including:
- Fans, pumps and compressors
- Turbines and electric machines
- Gearboxes and machine tools
- Industrial compressors and high-speed spindles
The standard supports bearing selection, thermal management, friction and oil-flow estimation, and verification of minimum film thickness for reliable separation of rubbing surfaces.
Who should use this standard
- Mechanical and rotating-equipment designers
- Bearing and tribology engineers
- OEMs and component manufacturers
- Maintenance and reliability engineers
- Technical consultants performing bearing calculations and root-cause analysis
Related standards
- ISO 12130-2 - Functions for calculation of tilting pad thrust bearings (numerical solution data)
- ISO 12130-3 - Guide values for the calculation of tilting pad thrust bearings
ISO 12130-1:2021 is the reference for engineers needing a standardized, repeatable method to calculate hydrodynamic performance of tilting-pad thrust bearings under steady-state conditions.
Open preview (PDF)Plain bearings — Hydrodynamic plain tilting pad thrust bearings under steady-state conditions — Part 1: Calculation of tilting pad thrust bearings
