In this study the direct numerical method is applied to solve the perturbed Reynolds" equation. To solve it the perturbed dimensionless mass f low rate is used as the boundary condition under the inherently compensated restrictor. The dynamic characteristics of a rotor supported in the externally pressurized air bearings, such as stiffness and damping coefficients, are analyzed, and as a result...

The rotor power losses in magnetic bearings are due to eddy currents, hysteresis, and windage. The influence of air gap magnetic flux density and air gap thickness is not well understood at this time. This paper presents measured results in two magnetic bearing radial configurations with a laminated rotor. The rotor power losses were evaluated by measuring the rundown speed of the rotor, in air...

BACKGROUND This study investigated whether changing a tumor's oxygenation would alter tumor metabolism, and thus uptake of (18)F-FDG (fluorine-18 deoxyglucose), a marker for glucose metabolism using positron emission tomography (PET). RESULTS Tumor-bearing mice (squamous cell carcinoma) maintained at 37 degrees C were studied while breathing either normal air or carbogen (95% O(2), 5% CO2), k...

This study presents a blower for air management system of fuel cell modules. A blower is composed of BLDC motor and impeller. Magnetic equivalent circuit model and finite element analysis are used to design the motor, and an improved structure is considered to reduce a mechanical loss induced from bearing units. Finally, air blower system combined with the motor and an impeller is manufactured ...

The design and application of a patented active actuator design that combines the radial and axial actuator into one combination radial-axial actuator is presented. The theory of operation of the actuator is defined and magnetic finite element analysis modeling shown verifying operation. Its mechanical construction is then presented to show how this actuator configuration is successfully integr...

Foil gas bearings are in widespread commercial use in air cycle machines, turbocompressors and microturbine generators and are emerging in more challenging applications such as turbochargers, auxiliary power units and propulsion gas turbines. Though not well known, foil bearing technology is well over fifty years old. Recent technological developments indicate that their full potential has yet ...

Introduction With increasing technology, the requirements on the performance of rolling element bearings become more demanding. These types of bearings are used in such applications as computer hard disk drives, which require nanometer level error motion tolerances. In order to measure the error motions of rolling element bearings, the Bearing Analyzer was manufactured with a very precise air b...