Why the Choice Comes Down to Operating Conditions
In the core support of spindles and rotary tables, fluid hydrostatic bearings and rolling bearings (angular-contact ball or cylindrical roller) represent two distinct routes. The selection is not about which is "more advanced" but about matching the duty cycle.
Side-by-Side Comparison
| Dimension | Fluid Hydrostatic Bearing | Rolling Bearing |
|---|---|---|
| Rotational accuracy | Extremely high (no contact deformation) | High (limited by rolling-element error) |
| Stiffness | High and adjustable via oil pressure | Medium-high (fixed) |
| Damping / anti-vibration | Excellent (oil film absorbs vibration) | Moderate |
| Service life | Near-infinite (no wear) | Fatigue-limited |
| Speed | Medium-high (thermal-limited) | High |
| Thermal stability | Excellent (circulating oil removes heat) | Moderate |
| Cost | Higher (requires oil supply system) | Lower |
When Hydrostatic Wins
For ultra-precision grinding, long continuous running, applications sensitive to roundness and surface finish, or spindles and rotary tables that demand maintenance-free long life, the hydrostatic route is the better fit. For general roughing and cost-sensitive jobs, rolling bearings remain more economical.
Typical Hydrostatic Specifications
| Metric | Typical range |
|---|---|
| Oil film thickness | Several μm to tens of μm |
| Load capacity | Designed by area and oil pressure |
| Filtration requirement | ≤ 10 μm (dual-filter) |
Need Help Choosing?
Not sure which route fits? Send us your duty cycle — speed, load, accuracy and running hours — and we will provide a selection recommendation with a cost comparison.
Related: hydrostatic motorized spindles, hydrostatic rotary tables, the full hydrostatic product line.
