Rotary Air Bearings / Air Bearing Spindles
Rotary air bearings and rotation air bearing spindles for ultra-smooth, frictionless motion in metrology, optics, semiconductor processing, inspection, torque testing, and OEM automation systems.
Rotary air bearings provide smooth motion with extremely low wobble, eccentricity and run-out. PI Nelson Air has developed an extensive catalog of rotary air bearing spindles and air bearing tables for diverse applications such as optical grinding, roundness checking, disk drive inspection, semiconductor processing, torque testing, and many others.
In addition to standard air bearing tables, individually customized bearings for specific applications are available. When you call us with your rotary bearing application, we can quickly adapt one of our existing designs to fit the exact requirements.
Low Profile Series Rotary Air Bearings
Standard rotary air bearing tables for precision rotation, inspection, metrology, calibration, and clean noncontact motion applications.
Custom Motorized Rotary Air Bearings
Custom rotary air bearing systems can be designed for special payloads, apertures, motorization requirements, speed ranges, and geometric accuracy targets.
PI Rotary Tables with Air Bearings
Motorized rotary air bearing stages combine direct-drive motion control with noncontact air-bearing guidance for ultra-precision angular positioning.
| Feature | Typical Capability |
|---|---|
| Total Indicated Runout | ±1 millionths of an inch |
| Flatness of Rotation | ±5 millionths, with ±2 millionths available |
| Motion Principle | Inherently frictionless and stictionless air film support |
| Stiffness | From 50,000 lbs/in to 4,000,000 lbs/in |
| Load Capacity | From 1 lb to 1100 lbs |
| Operating Pressure | From 15 psi to 90 psi |
| Materials | Hardcoat aluminum, stainless steel, and other materials available |
| High-Speed Operation | Rotary bearings can be balanced for high-speed applications |
Ultra-Precision Positioning
- Roundness checking
- Optical grinding
- Disk-drive inspection
- Semiconductor processing
- Calibration and metrology
Frictionless Motion
- Torque testing
- Force measurement
- Inspection systems
- Cleanroom positioning
- Custom automation systems
Mechanical Options
- Clear apertures
- Mounting hardware
- Tip/tilt/centration tables
- Custom fixturing
- Granite bases
Air and System Options
- Air tubing and fittings
- Filter, dryer, and regulator assemblies
- Integrated motors and encoders
- Motion controllers
- Custom system integration
Need a special rotary bearing? PI Nelson Air can adapt existing rotary air bearing designs or develop custom assemblies for demanding OEM, scientific, semiconductor, metrology, and automation applications.
Rotary air bearings provide a fundamentally different approach to precision rotational motion compared to conventional mechanical bearing stages. Instead of relying on rolling elements such as ball bearings or crossed-roller bearings, the rotating shaft or table is supported on a thin film of pressurized air. This non-contact operating principle eliminates friction, wear, lubrication requirements, and many of the error sources that limit the performance of mechanical bearing systems.
For ultra-precision metrology, optics manufacturing, semiconductor inspection, calibration, and scientific instrumentation, rotary air bearings often provide superior accuracy, repeatability, velocity stability, and long-term performance.
| Feature | Rotary Air Bearings | Mechanical Bearing Stages |
|---|---|---|
| Motion Principle | Completely non-contact rotation on a pressurized air film | Rolling or sliding contact through balls, rollers, or races |
| Friction | Virtually zero friction and no stick-slip | Friction varies with load, speed, lubrication, and wear |
| Wear | No mechanical contact, therefore no rolling-element wear | Bearing races and rolling elements can wear over time |
| Lubrication | No grease or oil required | Lubrication is often required and can become a contamination source |
| Runout and Error Motion | Extremely low runout and excellent rotational accuracy | Generally higher error motion due to rolling-element imperfections |
| Velocity Smoothness | Very smooth rotation with minimal vibration or torque ripple | Can exhibit bearing noise, friction variation, and micro-vibration |
| Cleanroom Suitability | Excellent, with no wear particles and no oil or grease | Lubricants and wear particles may be present |
| Long-Term Stability | Maintains performance over very long service life | Performance can degrade as bearing components wear |
Superior Accuracy
The absence of rolling elements eliminates many sources of rotational error, enabling very low runout and excellent flatness of rotation for precision metrology, optical inspection, and calibration systems.
Frictionless Motion
Because the rotating element rides on a microscopic air film, there is virtually no friction, stiction, or hysteresis. This is especially valuable for torque measurement, precision indexing, and smooth scanning.
No Mechanical Wear
Rotary air bearings do not suffer from rolling-element fatigue or lubrication breakdown. They maintain their original performance characteristics over extremely long operating lifetimes.
Excellent Velocity Stability
The smooth, non-contact motion minimizes vibration, bearing noise, and velocity ripple, making rotary air bearings well suited for optics, semiconductor inspection, and high-precision scanning.
When to Choose a Rotary Air Bearing
Rotary air bearings are often the preferred solution when the application requires ultra-low runout, high rotational accuracy, frictionless motion, precision metrology, semiconductor inspection, optical manufacturing, torque measurement, long-term stability, cleanroom operation, or high-speed precision rotation.
For applications where maximum precision, smoothness, and repeatability are critical, rotary air bearings typically outperform even high-quality mechanical bearing rotary stages.
Air Bearing Spindles
Rotary air bearing spindle designs support high precision rotation with very low error motion.