Air Bearing Spindles, Rotary Tables, Motorized Rotation Stages

High Precision Rotation Stages for High Performance Motion Requirements

A-625 air bearing spindles ready for performance testing.

Rotation tables with air bearings are used when rotary motion with the highest accuracy, smoothness, and geometric performance is required, for example in optical metrology and semiconductor manufacturing. Due to the lack of friction, these high precision rotation bearings and direct-drive motorized rotary tables can achieve angular resolution in the sub-microradian range. PI’s air bearing design and manufacturing group provides hundreds of man years of design experience along with the manufacturing and test equipment to produce high quality rotary tables with the tightest tolerances.

Rotary air bearings (air bearing spindles) are friction free, and all of PI’s motorized air bearing rotation stages employ closed-loop, non-contact 3-phase direct-drive torque motors, and optical high-resolution rotary encoders for ultra-reliable maintenance-free operation with basically unlimited service life.

Absolute angle-measuring feedback sensors are available to provide closed-loop control with single digit microradian bi-directional repeatability. Direct-drive rotary air bearing tables also provide better eccentricity, flatness, and minimized wobble compared to rotary stages based on mechanical bearings. The friction-free design allows for high angular velocity without vibrations and noise.

Applications of rotary air bearing spindles / motorized direct-drive rotary tables include indexing, metrology, optical lens testing, bio-medical engineering, runout measurements of machined parts, and fiber optics.

PI’s high-performance closed loop servo motor controllers are available to precisely control position, acceleration and velocity, with advanced algorithms. Fully integrated multi-axis motion systems with linear air bearing stages and combinations with gantry systems are also available from PI’s air bearing division.

Single Axis Rotary Air Bearings and 3-Axis Spherical Bearings (non-motorized)

Closed-loop Motion Controllers for Motorized Air Bearing Stages

The preloaded motorized air bearing rotary tables of the A-621 - A-627 family are designed to be operated in any orientation with significant side loads up to 1200N for the largest types. The low-profile rotary table family A-635/A-637 is for horizontal use only. All PI motorized air bearing rotary stages feature high performance, low-cogging frameless and slotless torque motors, with closed-loop optical encoders. Various options can be combined to create a solution ideal for point-to-point indexing or constant velocity scanning. Applications include optical alignment, metrology, inspection, calibration, and scanning. These precision rotation stages offer superior runout, flatness, and wobble performance. Since they are completely frictionless, they exhibit no breakaway “stiction” or drag friction during operation. They are ideal for use in cleanrooms, require no maintenance or lubrication, and have unlimited life.

The PIglide RM series of motorized rotary air bearing stages are a complete positioning solution designed for accuracy, precision, high stiffness, and ease of use. They can be used in any orientation. These stages feature high performance, low-cogging frameless slotless torque motors, and optical encoders. Various options can be combined to create a solution ideal for point-to-point indexing or constant velocity scanning. Applications include optical alignment, metrology, inspection, calibration, and scanning. The RM stages offer superior runout, flatness, and wobble performance. Since they are completely frictionless, they exhibit no breakaway “stiction” or drag friction during operation. They are ideal for use in cleanrooms, require no maintenance or lubrication, and have unlimited life.

Direct Drive, High Load

2/4/6/8/12” table diameter
13 to 420kg load
0.008µrad max. resolution
40 to 100nm flatness
500 to 2500 RPM max.

Details Article

Low Profile, Large Diameter

6/8/14” table diameter
20/32/60/120kg load capacity
0.03µrad max. resolution
<100nm eccentricity & flatness
500 RPM max.
Self-locking option at rest

Details

Large Clear Aperture

⌀260mm clear aperture
77kg load capacity
0.0015µrad max. resolution
500 RPM max.
Flatness/Eccentricity <175/300nm
Wobble: < 1µrad
Direct drive

Details

Low Profile

⌀250mm table
8 kg load capacity
5mm Z-stroke, to 2° tip/tilt
10nm/0.06µrad incremental motion
1nm sensor resolution

Details YouTube

Voice Coil Driven, Low Profile

5mm x 5mm x 2° Travel
40mm height, ø200mm
Air Bearings & Voice Coils
Parallel Kinematics
Lock-down Capable
6-DOF Option

Details

Article t3://file?uid=30442

These single-axis rotary air bearings and 3-axis spherical rotary air bearings come without motor but can be customized and encoder options are available for the single axis bearings. A manual X-Z-Tip-Tilt platform is available to help with the alignment of measured parts.

he PIglide RT series of non-motorized passive rotary air bearings are designed for accuracy, precision, high stiffness, and ease of use. They can be used in any orientation and are easy to integrate with motors and encoders for complete positioning solutions. Applications include optical alignment, metrology, inspection, calibration, and scanning. The RT series bearings offer superior runout, flatness, and wobble performance. Since they are completely frictionless, they exhibit no breakaway “stiction” o r drag friction during operation. They are ideal for use in cleanrooms, require no maintenance or lubrication, and have unlimited life. An optional high resolution optical encoder can be added to allow precision table angle recording during manual operation. Applications include parts inspection, optical alignment and drag torque measurement.

Non Motorized, Encoder Options

Ideal for optics testing
2/3/4/6/8/12” table diameter
13 to 420kg axial load
5 to 270kg radial load
75 to 300nm eccentricity
Optional high resolution encoder

Details

The PIglide HB series spherical air bearing enables unique positioning and simulation applications in both research and industrial fields. These bearings provide excellent load capacity and stiffness while allowing three axes of inherently frictionless rotational motion. Commonly used for zero-g satellite research, spherical bearings are also used in systems for precision chip bonding and optical alignment. Extremely rigid spindles can be made using a spherical bearing at each end of the spindle shaft. This arrangement also allows precision alignment of the spindle shaft on the fly by moving one spherical bearing relative to the other.

3 Degrees of Freedom

Ideal for zero gravity simulation
2/3/4/6/8/10/12” sphere diameter
15 to 635kg load
±45 degrees rotation range

Details Article Video

The PIglide MTT series of manual alignment tabletops can manually adjust a payload mounted to a rotary air bearing in four degrees of freedom, allowing alignment of the payload to the bearing’s axis of rotation. Adjustments can be made in two linear orthogonal directions (X and Y) and in two angular directions (tip and tilt). The tabletop surface is made from durable, wear- resistant stainless-steel. This accessory is ideal for metrology, roundness measurement, and part gauging applications.

Add-On For Rotary Stage

Ideal for optics testing
4 degrees of freedom: X, Y, θX, θY
Manual operation
Travel to ±3mm, ±1.25°
3/4/6/8/10” table diameter
Direct mount on A-60x / A-62x

Details

PI also provides state-of-the-art motion controllers to operate its precision rotational and linear motion systems. Based on ACS SPiiPlusEC motion control modules and an EtherCAT® master, they come with ServoBoost™ for improved servo performance, insensitive to noise or (load) changes, as shown in the video.