Rotary Unions

Many spindle applications require the smooth, non-influencing transfer of air, fluids, or vacuum into the rotating elements. Professional Instruments Company manufactures a line of air bearing rotary unions that provide non-contact operation. Air bearing journals at each end of the cylindrical housings support the stator. Single or multiple annular grooves allow fluid transfer to the rotating shaft. Low clearance capillary regions between the grooves provide sealing. The rotary unions are retained to the shaft with air bearing thrust collars completing the non-contact assembly.

Shown here are samples of the many different versions manufactured at Professional Instruments Company. The smallest is a single-channel version for the transfer of high pressure air to a chuck clamping mechanism. The longer union is designed to bring vacuum into a rotating shaft. The large diameter unit is a multiple-channel rotary union that allows water to flow into and out of the center shaft while providing separate seal regions for the high pressure air bearings. The last picture is an air bearing rotary union integrated into a vacuum chuck for holding very small optical elements. Professional Instruments Company’s considerable experience using our own air bearing products allows us to provide these carefully engineered, shop-proven solutions to our customers. The rotary unions are produced using materials proven to be robust enough to stand up to the rigors of machine shop use.