SwRI researchers design and build gas bearing test rig

May 5, 2010
The SwRI-designed 60,000 rpm gas bearing test rig was developed for evaluating the rotordynamic stability of gas bearings.

(PhysOrg.com) -- Researchers at Southwest Research Institute have designed and built a 60,000 rpm gas bearing test rig to test the rotordynamic stability of gas bearings.

The use of gas bearings has increased over the past several decades to include microturbines, air cycle machines and hermetically sealed compressors and turbines. Gas bearings have many advantages over traditional oil-lubricated or rolling-element bearings. Gas bearings typically have a longer life span, can accommodate high shaft speeds and can operate over a wide range of temperatures. And because there are no lubricants, there is no process contamination.

Good rotordynamic stability is important for bearings to function properly. Gas bearings are challenging to design and require a fully coupled, thermo-elastic, hydrodynamic analysis to test their stability. However, few methods exist to verify bearing stability.

"To assist industry in the design of gas bearing systems, we have designed a test rig that overcomes the many challenges of measuring rotordynamic coefficients," said Dr. J. Jeffrey Moore, a program manager in SwRI's Mechanical Engineering Division.

The test rig consists of two coaxial shafts capable of rotating at different speeds. The outer shaft, driven by an electric motor, rotates inside the foil air bearing and is responsible for generating the hydrodynamic pressure that supports the rotating shaft.

The inner shaft excites the vibration in the shaft system by using end discs where unbalance can be added and adjusted easily. Its speed is controlled by an eddy current brake system.

The bearing undergoing evaluation is supported by a cantilever bearing housing that prevents pitching of the bearing and allows the bearing to transmit forces to load cells mounted in the horizontal and vertical planes. Two accelerometers mounted on the bearing housing measure the inertial forces of the bearing in the horizontal and vertical planes, and proximity probes measure the relative displacement. A patent is being pursued on the concept.

"Development of this test rig is helping SwRI's clients achieve the design objectives of their turbomachinery," Moore said.

Explore further: RESEARCHERS IN ENGLAND DEVELOP A NEW TYPE OF ARTIFICIAL HIP

Related Stories

RESEARCHERS IN ENGLAND DEVELOP A NEW TYPE OF ARTIFICIAL HIP

December 15, 2004

Researchers at the University of Leeds have developed a new type of hip prosthesis that they claim offers improved durability and longer life than current models in use today. In the effort to minimize material wear, the ...

Automatic tire pressure maintenance system

May 19, 2005

The National Nuclear Security Administration's Sandia National Laboratories recently provided three engineering concepts to small business owner Dale Petty for a gadget that keeps car tires inflated to the right pressure. ...

Muscle loss tested in artificial gravity

September 15, 2005

University of California-Irvine researchers say a bike-like centrifuge that creates artificial gravity may help astronauts combat muscle atrophy in space.

Spin cycle: a new kind of washer (Video)

February 19, 2009

(PhysOrg.com) -- In many developing countries, electricity is unreliable or unavailable and water must be carried by hand, so conventional modern washing machines are not an option. Washing clothes can take up a significant ...

New deep water ocean simulator available at SwRI

March 19, 2010

A new hyperbaric test chamber for items that require high-pressure, high-temperature (HPHT) testing is now available for use at Southwest Research Institute (SwRI). The deepwater ocean simulator is capable of attaining pressures ...

Recommended for you

Team develops targeted drug delivery to lung

September 2, 2015

Researchers from Columbia Engineering and Columbia University Medical Center (CUMC) have developed a new method that can target delivery of very small volumes of drugs into the lung. Their approach, in which micro-liters ...

Team creates functional ultrathin solar cells

August 27, 2015

(Phys.org)—A team of researchers with Johannes Kepler University Linz in Austria has developed an ultrathin solar cell for use in lightweight and flexible applications. In their paper published in the journal Nature Materials, ...

Magnetic fields provide a new way to communicate wirelessly

September 1, 2015

Electrical engineers at the University of California, San Diego demonstrated a new wireless communication technique that works by sending magnetic signals through the human body. The new technology could offer a lower power ...

Smart home heating and cooling

August 28, 2015

Smart temperature-control devices—such as thermostats that learn and adjust to pre-programmed temperatures—are poised to increase comfort and save energy in homes.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.