air spindles are one of the main elements of precise machine tools. vibration of these spindles is one of the vital issues necessary for investigation. among parameters which influence air spindle vibrations are rotational speed, compression air method, input nozzle diameter, air gap pressure. in this study using ansys, the effects of air gap thickness on air spindle vibrations have been invest...

background: creating a socket with proper fit is an important factor to ensure the comfort and control of prosthetic devices. several techniques are commonly used to cast transtibial stumps but their effect on stump shape deformation is not well understood. this study compares the dimensions, circumferences and volumes of the positive casts and also the socket comfort between two casting method...

background: creating a socket with proper fit is an important factor to ensure the comfort and control of prosthetic devices. several techniques are commonly used to cast transtibial stumps but their effect on stump shape deformation is not well understood. this study compares the dimensions, circumferences and volumes of the positive casts and also the socket comfort between two casting method...

air pads are applicable in ultra precision machines very much. two main components of these machines, spindle and table, use the advantages of such systems. the performance and efficiency of air pads have big influence on the whole machine quality. parameters affecting pressure distribution of air tables may be considered as, 1) air compressing method, 2) air nozzle diameter, shape, and size, 3...

Background: Creating a socket with proper fit is an important factor to ensure the comfort and control of prosthetic devices. Several techniques are commonly used to cast transtibial stumps but their effect on stump shape deformation is not well understood. This study compares the dimensions, circumferences and volumes of the positive casts and also the socket comfort between two casting method...

All moving objects possess six degrees of freedom – three linear and three rotary. The task of a linear motion guideway is to eliminate, as closely as possible, five of these degrees of freedom, leaving a single rotary or linear axis of motion. Air bearings are the purest and highest performance means of defining linear or rotary motion, and have substantial advantages over conventional mechani...

A high capacity aerodynamic air bearing (HCAB) has been developed for the laser scanning market. The need for increasing accuracies in the prepress and print plate-making market is causing a shift from ball bearing to air bearing scanners. Aerostatic air bearings are a good option to meet this demand for better performance however, these bearings tend to be expensive and require an additional a...

One of the advanced technologies incorporated into a micro gas turbine (MGT) is the dynamic air-lubricated (no oil lubrication) bearing. We investigated the performance characteristics of a self-acting air-lubricated bearing in a 50-kWe MGT. From the results of our experiments, we were able to clarify the following. (1) The thrust load of 300 N incurred by a 50kWe MGT cannot be supported by the...

We examined the effects of air pressure on the free-running speed of air-bearing and torque-type ball-bearing air-turbine handpieces. The air pressure for the former should be kept at a certain high level to maintain the stable super-thin air-bearing film and to provide the quasi-constant speed of around 420,000 to 480,000 rpm. On the other hand, the air pressure for the latter could be adjuste...

Byron R. Knapp, Brian P. O’Connor, Eric R. Marsh Machine Dynamics Research Lab The Pennsylvania State University, University Park, PA Introduction As the demand for higher precision machine tools and inspection equipment grows, there is a need for more precise bearing systems. The error motions of bearings with mechanical contact are dominated by the geometric and surface finish errors of their...