What lubricant is usually used in hydrostatic bearings?

Hydrostatic bearings rely on a thin film of liquid to maintain separation between the bearing surfaces, which minimizes friction and wear. The primary characteristic of the lubricant used in these bearings is its ability to create a stable film that can support the load and resist deformation under pressure. Oil is typically chosen for this application because it can maintain a consistent viscosity over a wide range of temperatures and under varying load conditions. It also provides better lubricating properties compared to other substances like grease or water, which can break down under pressure or may not provide the necessary film thickness.

In hydrostatic systems, the oil is often supplied under pressure, allowing it to flow into the bearing spaces and create a hydrodynamic lift. This helps to effectively support the loads while allowing for smoother operation. Grease, though used in many types of bearings, does not flow as easily or provide the necessary lubrication in the same way that oil does. Water, on the other hand, is generally not suitable due to its tendency to evaporate, freeze, or cause corrosion in metal components. Aerosol lubricants are typically used for other applications and don’t provide the sustained lubrication needed for hydrostatic bearings.

Thus, oil emerges as the most effective lubricant in hydrostatic bearing applications due to its