ISO 12130-1:2021

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.