Turbomachinery Engineer Asked : We have speed factor in rolling bearings , what do we have for speed in journal bearings linked to oil lubrication ? Khash Replied: In rolling bearings, you’re used to the speed factor (n·dm) as a practical limit tied to heat generation and lubrication regime. For journal (hydrodynamic) bearings, the equivalent thinking is not … Continue reading The Role of Rotational Speed in Hydrodynamic Lubrication: Interpreting Journal Bearing Performance via Sommerfeld and Hersey Parameters