air bearing rotary table factory

With proper selection and integration of high-performance brushless DC servo motors ABTech’s air bearing rotary tables provide ultra-smooth and precise rotary motion. With high torque, high performance motor drives, our motion experts will gather your specific requirements and work closely with our motor suppliers to create/select a motor drive that suits your specific application. Whether you need sub-micron position accuracy with minimal settle time and stringent following error specifications, high-speed constant motion, or a combination of both there is an ABTech rotary table that will meet your needs.

ABTech’s modular design approach facilitates multiple system configurations to optimize the price-for-performance required in your application. This approach allows the user to define the level of control desired for the most cost-effective solution. Our complete engineering services allow us to respond quickly to provide a solution to your O.E.M. requirements for ultra-precision rotary motion.

Rotation tables with air bearings are used when rotary motion with the highest accuracy, smoothness, and geometric performance is required. 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.

PI is a leading manufacturer of precision motion control and automation systems, hexapod 6-axis parallel robotic stages, air bearing motion systems, Gantry Systems, 3D printing, laser machining, and piezoelectric nano-positioning solutions. Applications include photonics, semiconductor technology, medical engineering, assembly, inspection, materials handling, and bio-nanotechnology. PI has been developing and manufacturing standard & custom precision products with piezoceramic and electromagneti

Air Bearing Rotary Tables, Table Top and Work Load are Supported on Air Bearings whose Freedom from Friction Contributes to Extremely High Positional Accuracy

An Interlocking Switch is used when Motors are Incorporated to Prevent the Table Top from Moving when the Air Supply is Turned Off.  When the Air Supply is Turned Off, the Table Top Sits Firmly on our Cast Base with an Extremely High Accuracy of Parallelism Between the Base and Table Top

Rotary tables specifically developed for use in Metrology applications.  CMM tables, inspection tables, assembly tables.  Range of sizes 100mm thru 5,000mm.  Larger on request.

Air bearing rotary tables, when rotating, the table top and work load are supported on air bearings whose freedom from friction contributes to the extremely high positional accuracy.  High precision needle roller bearing maintains radial accuracy.

Supplied with each table.  On/off Switch controls the compressed air supply to the table.  Interlocking ensures that the motor drive can only operate if the air supply is on.  When air supply is off, table sits firmly on the base casting with extremely high accuracy of parallelism between the top surface and the underside of the base.

They come with worktable diameters from 4–24 in. (100–605 mm) with radial and axial accuracies from 0.000,001–0.000,010 in. (0.025–0.25 µm). Several models have load carrying capacities up to 1,000 lbs, and larger, heavy duty models can be supplied with air float centering assist or air/ball bearings. These heavy duty tables offer load capacities to 5,000 lbs and diameters to 60 in. (1,524 mm).

The modular design allows the rotary air bearing tables to be used in a variety of measurement and motion applications. They can be used with the company"s line of options and accessories.

X-ray inspection systems are inhigh demand. Known for their ability to identify anomalies, they have become crucial to ensuring quality and proper operation across a wide range of applications. These inspection systems function using specialized software to analyze the X-ray images. And, getting an accurate image relies on one deceptively simple tool: precisionrotary tables.

At their most basic, the precision rotary table consists of a motor or drive assembly and a spindle. For accurate data collection, the determining factor is the spindle. There are innumerable contact spindles on the market today, and while orifice bearing options are available as well, New Way® is here with the facts. Learn why Porous Media™ Air Spindles are the best choice for you.

Conventional roller bearings have many downsides in a rotary table. Uneven bearings can cause unpredictable movement and vibration, reducing precision. They also wear over time, compounding performance loss. Air bearings eliminate these inconsistencies. Using a stiff cushion of air, these bearingsremove frictionand provide a wide array of benefits, including:

Even among other air bearings, New Way is special. To understand why, the first step is understanding the two main groups that constitute broader category of air bearings:

Porous media, utilizing the natural permeability of porous carbon. Millions of sub-micron holes inherent to the material enable the even distribution of air across the bearing surface.

The key differentiator between orifice and porous media is how the air is distributed. OurTechnical Report 1covers this topic in detail, but the most important point concerns the pressure gradient created by the bearing. With orifice bearings, you have spikes and dips in pressure, while porous media produces a smooth, consistent air film. This allows for even pressure distribution, providing better support.

One of the major concerns when considering an orifice-based bearing design is the response to sudden pressure loss. For orifice bearings, this type of crash can be catastrophic, often resulting in hard, metal-to-metal contact which damages both the bearing surface and the stator surface. These scenarios become particularly problematic as precision rotary tables have become more widely adopted. Any failure in the rotary table means downtime for repair, costing you both time and money for new parts.

Conversely, porous media naturally acts as a restrictor for the air supply, creating a consistent, nanometer-thin air cushion with an unmatched combination ofdamping and stiffness. Even in a worse case scenario where a crash is unavoidable, the soft carbon face (at a compression strength of 91 MPa) means the carbon will absorb the blow, protecting your guide surface and other components which might be difficult or costly to replace.

Air bearings also offer massive improvements for precision. Manufacturing imperfections in ball bearings, coupled with the wear induced on multiple rotating surfaces, causesasynchronous and synchronous errors, impacting precision and creating hysteresis error. By suspending the rotor on a frictionless five micron-thick layer of air,synchronous error is standardized and asynchronous error is almost entirely eliminated. Additionally, because an air-bearing-based system doesn’t need to contend with unequal pressure loadings or theinternal momentumand inertia inherent to a ball-bearing-based system, porous-media-based rotary tables boast nano-scale accuracy.

New Way Air Bearings products have shown extensive increasedreliabilityover their contact and orifice bearing counterparts. Because rotary tables and spindles built on porous media have no dynamic parts in contact with one another, friction is eliminated, resulting in a product that is longer-lasting, while also providing superior performance.

Servo-Drive Rotary Stagesare New Way’s all-encompassing solution for your high-tolerance precision rotary needs. Combining air spindles with a slotless, brushless motor and a precision rotary encoder capable of 1.1-arcsecond precision, the Servo-Driven Rotary Stage offers 1,184,000 counts/rev.

T-Series Air Spindlesprovide our highest levels of resolution, ideal for precision rotary table operations. Available in several standard sizes in both round and square stator configurations, the T-series spindle provides frictionless rotary motion with the tightest tolerance, reducing radial and axial error motion down to 0.1 µM.

Thrust Bushingscan be utilized as a precision rotary table by floating the table on top of the thrust face. Thrust bushings are available in a range of standard sizes for different rotary applications.

For precision rotary tables requiring less precision, we offer a unique combination of ourFlat Round BearingsandAir Bushings. By placing the flat bearings in a ring configuration with the air bushing as the center “spindle,” a precision rotary table can be created.

Whether it’s for an X-ray system inspecting a life-saving medical device or a CNC setup for machining critical electronic parts, New Way has the solutions to create a precision rotary table to meet your requirements.

Discover the power of porous media’s increased precision and reliability in your operations. To learn more about how air bearings are changing industries,download our eBook! And, as always,contact us anytimeto discuss how our products can benefit your custom application!

The design of the ABRS series direct-drive rotary stage has been optimized to minimize stage height. The low profile of the stage reduces the effective working height of the system, minimizing "stack-up" related errors. In addition to the low overall height, the ABRS series provides a clear aperture that can be used for product feed-through, laser beam delivery, cable clearance or application-specific requirements.

The ABRS design features large air-bearing surfaces for high stiffness and load capacity, producing not only excellent axial and radial error motions but outstanding tilt error motion, as well. The resultant face error motion is significantly better than other rotary air-bearing tables and spindles, greatly benefiting applications requiring exceptional planar performance.

AB Series Air Bearing Spin Tables Rotary tables with high accuracy motion for assembly, test and inspection The AB Series tables utilise air lubricated hydrostatic bearings designed to provide very high radial and axial stiffness. This type of bearing offers significant advantages over conventional rolling element bearings permitting operation with minimal drag vibration and mechanical noise. The design principle of these bearings ensure axial laminar flow between shaft and housing compared with conventional orifice entry arrangements thereby ensuring exceptionally good motion geometry. From 200mm to 600mm diameter rotary spin tables with high geometric performance for assembly, test, inspection and metrology applications. High grade stabilised cast iron base and rotary platen, ensure rigidity and precision. Precision hydrostatic bearings designed to provide very high radial and axial stiffness. This type of bearing offers significant advantages over conventional rolling element bearings permitting operation with minimal drag vibration and mechanical noise. ROTARY PRECISION INSTRUMENTS UK LTD The Maltings Industrial Estate, Brassmill Lane, Bath, England, BA1 3JL sales@rpiuk.com www.rpiuk.com

Air bearings use a thin film of pressurized air to support a load, the same way the puck on an air hockey table "floats" on air. This type of bearing is called a "fluid film" bearing. Fluid film bearings have no solid-to-solid contact under typical running conditions; instead, a film of lubricating fluid (in our case pressurized air) forms a layer between the solid machine elements and serves to transfer forces from one to the other. To compare this with ball bearings, in ball bearings the balls are in constant contact with and form a solid bridge between the machine elements.

The fluid is able to transfer forces because as the fluid is pushed through the bearing gap it generates a pressure profile across the bearing area. The force the bearing can support is then:

The actual pressure distribution in the bearing varies based on the bearing design and other parameters but a good rule of thumb is to expect 30% efficiency.

For flat pads and rectangular bearings this calculation is quite straightforward, but for journal and spherical bearings we use a few other approximations to estimate load capacity.

Fluid film bearings offer a number of advantages over mechanical bearings. First, because there is no contact, air bearings do not suffer from wear or heat generation due to friction. They also exhibit no starting or running friction, even under their highest design loading. In addition, the fluid film acts to center and average out small scale errors in the components resulting in motion which can be more accurate than the individual bearing components. Air bearings also offer much higher stiffness than rolling element bearings because the air film fully supports the components, as opposed to balls or rollers which have point or line contact and are therefore limited due to Hertzian contact stiffness.

While most engineers are familiar with oil fluid film bearings - for example the crankshaft journal bearings in car engines - knowledge of air bearings is less abundant. Remembering our high school physics class, there are two basic types of fluids - liquids and gasses. In terms of fluid film bearings, the difference between these two is essentially the viscosity - liquids have much higher viscosity than gasses. When applied to a fluid film bearing, this difference has a number of implications.

First, lower viscosity means that for the same working pressure gas bearings have lower load capacity (liquid fluid film bearings typically support five times the load of gas bearings for the same pad area). Second, because of the extremely low viscosity of gasses, gas film bearings operate with essentially zero static and running friction where liquid fluid film bearings have much higher friction and pumping losses within the bearings, which can cause heat generation. And third, gas bearings require very tight bearing gaps for proper operation (10 µm for gas compared to up to 100 µm for liquid bearing) which translates into extremely high accuracy requirements on the components.

What this means for air bearings is that although they have a lower load capacity, gas bearings have essentially zero friction at all speeds and because the tight bearing clearances demand high accuracy components this results in extremely high accuracy motion. Another benefit is the cleanliness of using air as a lubricating fluid as opposed to oil, water, or another fluid. Since compressed air is very common in industrial environments it is probably the most often used gas, however other gasses such as nitrogen can be used where they are available (such as in clean room environments).

The first question is how to generate the pressurized supply of fluid for the bearing. There are two ways to do this - one is using an external pressurized supply (hydrostatic) and the other is to use the relative motion of the machine components to generate the pressure internally (hydrodynamic or "self-generating"). While hydrodynamic bearings are common for oil fluid film bearings, which generate internal pressures quite easily due to the relatively high viscosity of oil, it is much rarer to see this technique used for air bearings because the pressure generated is quite low (although PI Nelson Air has built bearings of this type for low load, high speed rotary applications such as optical scanners).

Our typical air bearings are hydrostatic (or in our case aerostatic) and use a compressed air supply to create the fluid film. This supply should be clean and regulated to a constant pressure - simple off the shelf air handling components are more than adequate for most applications to clean, dehumidify, and regulate the supply. Typical operating pressures run as low as 20 psi up to 120 psi depending on the stiffness, load capacity, and air consumption requirements.

After entering the bearing and being routed though internal passages, the next step is to feed the pressurized air to where it is needed - namely directly into the bearing gap. There are two basic ways to accomplish this, orifices and porous media. For orifices, the air flows through a small hole (typically .004" to .015" dia.) into the bearing area. Porous media bearings use a porous material (typically carbon, bronze, or steel) which the air penetrates through into the bearing area.

The relative benefits of each approach are debatable. While orifices typically do not generate as uniform a pressure profile as can be achieved with porous media, there are ways to improve the pressure profile using a technique called "pocketed compensation". Porous media feeding provides more inherent damping than orifices, however proper sizing of the orifices can adjust damping. Orifices can become plugged if a very large particle gets into the air supply (this is extremely rare), where the porous media acts as a filter for the air. However, because of this filtering effect, over time the porous media itself can become clogged (oil vapor in the air is particularly bad) and a clogged porous bearing is much more difficult to clear than a clogged orifice.

Orifice fed bearings can be made from one piece of material (particularly when using drilled nozzles) where porous bearings are necessarily made using varying materials and adhesives.

At PI Nelson Air we have used both orifice and porous media feeding. Most of our standard products use pocket compensated orifices, however our LB series of linear bushings use porous bronze. Our typical orifice bearings are made using a special technique we have developed to drill the small orifices directly into the bearing, instead of using pressed in or glued in jewel nozzles. We believe that this technique reduces cost and complexity while increasing long term stability and reliability. However, jeweled nozzles are used when the design precludes drilled nozzles either because of geometry or because especially small orifice sizes (.004" for example) are required.

Because of the very small gaps that are required for air bearings, the single most important factor in their manufacture is absolutely flawless geometry. Any variation in part size, straightness, squareness or out of roundness will result in a closing of the gap and will cause the bearing to lose its frictionless nature as well as degrade accuracy and load capacity. Typical tolerances on our rectangular bearings which run air gaps of ~0.0005" are part deviations less than ±0.0001" overall. This same tolerance applies over the entire length of the bearing, which for some models can be over 60".

In addition, the part geometry is what determines the accuracy of the final bearing motion - even though local deviations are averaged out by the air film, the overall accuracy is dictated by how well the parts are made. Because of this, PI Nelson Air has developed a variety of techniques and equipment which allow us to meet these stringent tolerances with repeatability and relatively low cost.

Air bearings offer the best of all worlds because they have excellent accuracy, precision and repeatability. They offer high accuracy because the components are manufactured with extremely tight tolerances and because of the air film"s averaging effects. Typical linear accuracies are 10 µin/in with maximum deviation of 100 µin/36 in. Rotary runout can be as low ±1 µin. Air bearings also offer extremely good tilt characteristics - 0.25 arcsec/in.

Because air bearings exhibit no stiction or running friction, the precision achievable is only limited by the abilities of the motor/controller/encoder. Positioning precision of ±1 encoder count can easily be achieved using linear motors.

The repeatability of air bearings far exceeds that of mechanical bearings for the simple reason that they have no contact or wear. Heat generation in mechanical bearings sometimes require "warm up" periods during which there is thermal movement. Also, the mechanical preload on roller bearings can vary with temperature and cause the bearings to operate differently (varying friction for example) and lack repeatability. When working at the highest accuracy levels, these effects can cause mechanical bearings to lose their accuracy from hour to hour, day to day, or month to month. Because the accuracy of our air bearings is built into its solid metal components (made from one type of material for uniform thermal expansion), they can operate for years without any degradation in accuracy. This way, a calibration done one day will "stick". They also can be run at top speed without any need for warm-up time (excluding motor heating effects) and maintain their best accuracy.

While some configurations of air bearings are self-preloading (e.g. journal bearings) others such as flat pads and linear rectangular bearings can benefit from preload. Air bearings can be used without any preload (such as a simple flat pad riding on a granite surface), however, in order to maximize the stiffness of the air bearing and help maintain constant air gap it is typical to preload it using one of four basic methods:

The simplest method is weight. Using a weight much heavier than the expected variation in the loading of the bearing preloads the air bearing so it rides at a smaller (and stiffer) air gap and makes it less prone to height variations. This method has the drawback of adding moving mass but can work very will with systems which already have a large amount of mass and low forces (such as parts inspection). Needless to say, this only works for bearings which operate horizontally.

The second method is using a vacuum preload. A vacuum is used to apply a preloading force to the air bearing (instead of using a weight). This is accomplished by providing an area of the bearing surface over which a vacuum is applied. Because vacuum is limited to around negative 14 psi (atmospheric pressure) and typical air bearing pressures are 40-80 psi the net effect is still a lifting of the bearing, even when the bearing and vacuum areas are equal. Vacuum preload enhances the stiffness and helps to maintain constant air gap, without adding unnecessary moving mass. The main drawbacks to this method are the need for a larger bearing area to accommodate both pressure and vacuum and the requirement of a vacuum source. This method has been used successfully in many applications, especially for flat pads and planar systems which do not lend themselves to other forms of preload.

The third method of preloading is magnetic preload. Magnetic attraction between a magnet on the moving part and a magnetic material on the stationary part of the bearing loads the bearing and adds stiffness. This configuration works well for linear bearings and can be very cost effective because it reduces the tolerances required for the air bearing components (as compared to air bearing preloaded systems). However, because many air bearings are made from nonmagnetic materials, it requires adding other materials to the bearing (such as iron). Another drawback is that at high speeds, the magnet generates eddy currents in the iron which oppose the motion and add a drag force (eliminating the "zero friction" of air bearings). However, in many applications magnetic preload provides an effective method of preloading air bearings.

The final method is opposing air bearing preload. This method uses opposing air bearings to preload each other. This method provides twice the stiffness of a single air bearing, although the load capacity is reduced by almost half (the other preload methods also reduce load capacity, based on the amount of force they apply) and is very effective in producing the most accurate and reliable air bearings. Because there are two air bearings working in parallel it also has the effect of averaging any errors on either bearing (centering) and can therefore deliver higher accuracy than any other method. In addition, air bearing preloaded bearings can be operated in any orientation. The majority of PI Nelson Air"s standard bearings use this method because we believe it provides the highest quality, accuracy and versatility. However, this method does require higher accuracy components with more precision surfaces.

Now that you understand the basics of how air bearings work, here are some of the most common configurations for using them to create motion with a variety of degrees of freedom. If you have any additional questions, please contact us and we would enjoy assisting you.

The ABRT series precision rotary tables from Kuroda Jena Tec utilise robust high precision roller axial bearings with an air bearing in the horizontal axis for smooth, precise rotary motion. The air bearing principle offers a compact overall height of only 100mm with a cost effective bearing solution and high geometric accuracy. A hollow shaft design means that centralised services for pnuematic or hydraulic clamping can be provided easily. Units can be supplied in either manual or CNC format with a standard range of torque motors offered.

PI’s A-630 series of low-profile rotary tables was recently extended by the new A-634 rotary stage with 150mm table diameter and the A-638 model with 350mm diameter. These high precision, high speed direct drive rotary tables are only 60mm tall and provide high speed to 3000 degrees/second. For transmitted light applications, the A-688 model with a large aperture is available.

As all of PI’s direct drive air bearing rotary tables, the A-688 high precision stage is also equipped with absolute measuring feedback encoders for closed loop position control. They provide resolution to 0.0015µrad (0.00003 arcsec), and flatness and eccentricity as low as 175nm and 300nm, respectively.

The rotary tables use low-cogging frameless and slotless torque motors to enable this excellent geometric performance. Different designs allow use in horizontal, vertical or any orientation. Air bearings guarantee a virtually unlimited service life with no wear, and zero required maintenance. As with all other PI linear air bearings and stages, the rotary tables are clean room compatible and requires no lubrication. For transmissive light applications, the A-688 direct drive rotary table with large aperture is available.

The highest motion performance is achieved with PI’s A-800 series of EtherCat-based, high precision motion controllers, ideally suited for closed-loop control of the rotation tables. Advanced algorithms are available to deal with changing load conditions and to suppress external disturbances.

Air-bearings have no mechanical elements such as rollers or slides, and deliver frictionless, non-contact motion, resulting in negligible reversal error, better flatness, and minimal wobble and eccentricity. All these are ideal prerequisites for applications such as inspection and metrology, calibration, and scanning of high-end parts (i.e., infrared and precision optics, turbine blades, shafts and bearings) in industries like aerospace, aircraft, automotive, semiconductors, and photonics.

PI is a privately held company that designs and manufactures world-class precision motion and automation systems including air bearings, hexapods and piezo drives at locations in North America, Europe, and Asia. The company was founded 5 decades ago and today employs more than 1300 people worldwide. PI’s customers are leaders in high-tech industries and research institutes in fields such as photonics, life-sciences, semiconductors, and aerospace.

Air bearing stages are used where vibration-free motion is required, velocity needs to be highly constant, and optimum angular repeatability is requested.

Air bearings avoid friction, wear, and backlash effects. PIglide linear, rotary and spherical bearings are precision components that can be integrated and motorized for applications in OEM, industrial, and research markets.

Rotary tables are a versatile tool found in many workshops and factories. There are various types of rotary tables, each with its own unique set of applications.

Air bearing rotary tables work by using air pressure to create air film between the table and the product. This film of air allows the table to rotate freely without friction. As a result, these tables are ideal for holding and turning products during manufacturing processes.

In addition, air-bearing rotary tables can be used in tandem with other machines, such as lathes and milling machines. This combination allows for even more precise and intricate work to be performed. Some of the products made with air-bearing rotary tables include medical implants, electronic components, and jewelry.

Rotary tables are used in hydrostatic piercing, which is a method of making oil wells. In this process, a table goes around while fluid finds its way into the well at high pressure. The fluid pierces the rock, and the table helps to stabilize the well.

Hydrostatic rotary tables also make other products, such as pipes and tubing. In this process, the table rotates while a metal rod goes into the center of the table. The rod is then cooled, and as it cools, it shrinks and forms a tight seal around the metal pipe.

A mechanical bearing rotary table essentially consists of a platform that can rotate around a central axis. The platform gains support from bearings, which allow it to rotate smoothly and without friction. Typically, you can control the platform"s rotational speed. You can stop the platform at specific intervals to work on it.

Common uses for a mechanical bearing rotary table include the production of circular saw blades. The blade blanks go on the rotating platform, and then they are cut to the desired size and shape using a saw.

Another common use for these devices is in the machining of metal parts. The parts are mounted on the table and then machined using various tools. Rotary tables can also be used for welding, assembling, and testing products.