Journal Bearing Simulator
Free online simulation of plain and spiral-groove journal bearings: mixed and elastohydrodynamic lubrication, elastic deformation by FEA, friction and power loss.
What the app does
The Journal Bearing app runs an elastohydrodynamic (EHL) simulation of a three-dimensional journal bearing, including the mixed-lubrication regime where asperities start to carry load. The bearing can be plain or have spiral grooves. Unlike textbook design charts, which assume rigid surfaces, the app couples the lubricant film with a finite element (FEA) model of the shaft and bushing, so the elastic deformation of the parts under load is part of the solution.
A distinctive feature is the surface micro-structure: you can pick a surface from a library of production-specific types, or upload your own measured surface using the sample templates provided. Shaft, bushing and lubricant are chosen from a materials library or defined by you.
Workflow, inputs and outputs
- Bearing geometry — shaft diameter, bore (inner) and outer diameter of the bushing, bearing length, plain or spiral-groove design, surface micro-structure.
- Material properties — Young’s modulus, yield strength and Poisson ratio of shaft and bushing; density and viscosity of the lubricant.
- Operating conditions — rotational speed and radial load.
- Results — the calculation runs on our cloud server; no installation or licence is needed, and each simulation is stored in your personal list so you can return to it or compare variants.
The report gives the minimum and maximum lubrication gap, maximum pressure, friction force, coefficient of friction, power loss and eccentricity ratio, together with interactive 3D views of the von Mises stress in the solids, the lubricant pressure and the lubricant gap.
Worked example
A small plain bearing: carbon-steel shaft (AISI 1060) of 29.94 mm in a cast bronze bushing (CuPb10Sn10) with a 30.0 mm bore, 40 mm outer diameter and 30 mm length, lubricated with a 20W-50 engine oil at 40 °C (174.5 mm²/s), running at 500 rpm under 1000 N.
The app returns:
| Quantity | Value |
|---|---|
| Minimum lubrication gap | 18.85 µm |
| Maximum lubrication gap | 41.17 µm |
| Maximum pressure | 2.29 MPa |
| Friction force | 12.66 N |
| Coefficient of friction | 0.013 |
| Power loss | 9.92 W |
| Eccentricity ratio ε | 0.37 |
Change the load, speed, lubricant or surface and re-run to see how close the bearing gets to mixed lubrication, and how much friction and power loss you can save.
Typical uses
- Sizing and checking plain bearings and bushings before prototyping.
- Comparing plain and spiral-groove designs.
- Studying the effect of surface finish and micro-texturing on friction and film thickness.
- Comparing lubricants and greases for the same bearing.
- Teaching hydrodynamic and EHL lubrication.
How to access the app
The Journal Bearing Simulator runs in your web browser on Tribology Universe, the app platform of i-TRIBOMAT: The European Tribology Centre. Use is free; you only need a Tribology Universe account, which takes a minute to create.
Need more than the free app?
Our Modelling & Simulation team builds custom models for your geometry, materials and lubricants, and can validate them against tests on more than 130 tribometers across our partner laboratories. Contact us or write to office@i-tribomat.eu.
References
- A. A. Raimondi, J. Boyd, A solution for the finite journal bearing and its application to analysis and design: I, ASLE Transactions 1 (1958) 159–174
- N. Patir, H. S. Cheng, An average flow model for determining effects of three-dimensional roughness on partial hydrodynamic lubrication, Journal of Lubrication Technology 100 (1978) 12–17
- J. A. Greenwood, J. B. P. Williamson, Contact of nominally flat surfaces, Proceedings of the Royal Society A 295 (1966) 300–319
- O. Reynolds, On the theory of lubrication and its application to Mr. Beauchamp Tower’s experiments, Philosophical Transactions of the Royal Society of London 177 (1886) 157–234
- Explore a Powerful Web App for Journal Bearing Simulations, X. Borràs, TriboNet, 2024