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The Top 3 Benefits of Porous Media™ Bearings for Precision Rotary Tables

The Top 3 Benefits of Porous Media™ Bearings for Precision Rotary Tables

Superior Performance for All Types of Rotary Table

X-ray inspection systems are in high 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: precision rotary tables.

Close-up of woman patient doing panoramic teeth X-ray in dental clinic.Precision rotary tables aren’t just for inspection, however. They are also used for the milling and machining of precision tools. In fact, indexable rotary tables are necessary tools for testing and manufacturing in a wide range of industries including:

  • Medical
  • Manufacturing
  • Food Packaging
  • Electronics
  • Defense
  • Plastics

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.

Why Porous Media is the Best Choice

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 bearings remove friction and provide a wide array of benefits, including:

  • Improved precision
  • Higher speeds
  • No wear
  • Less heat generation
  • Decreased maintenance downtime

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:

  1. Orifice compensation, utilizing a series of holes or grooves to supply air to the bearing surface.
  2. 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. Our Technical Report 1 covers 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.

3 Benefits of Porous Media in a Precision Rotary Table

Submerged Porous Media Air Bearings making bubbles in waterCrash Resistance

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 of damping 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.

Higher Precision

Air bearings also offer massive improvements for precision. Manufacturing imperfections in ball bearings, coupled with the wear induced on multiple rotating surfaces, causes asynchronous 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 the internal momentum and inertia inherent to a ball-bearing-based system, porous-media-based rotary tables boast nano-scale accuracy.

Improved reliability

New Way Air Bearings products have shown extensive increased reliability over 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.

A New Way for Precision Rotary Tables

Servo-Drive Rotary Stages are 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 Spindles provide 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 Bushings can 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 our Flat Round Bearings and Air 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.

Make the Difference for Your Process Today!

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 anytime to discuss how our products can benefit your custom application!

Learn More About the Porous Media Difference