Abstract: A rotary head device with a fluid bearing including an upper cylinder and lower cylinder, a sleeve provided on the lower cylinder, a rotary shaft rotatably inserted in the sleeve, and pairs of cylindrical rotary transformers are mounted on the upper and lower cylinders, with two spaced apart herringbone patterns of grooves (26A and 26B) formed either on the rotary shaft or on the inside surface of the sleeve, the length of the herringbone pattern of grooves being larger on the upper cylinder end of the shaft or sleeve, and smaller on a motor end of the shaft or sleeve.

Abstract: A rotary head cylinder device with a fluid bearing having a lower cylinder, a fixed shaft supported at its bottom in a cantilever way, a sleeve rotatably fitted on the shaft and cylindrical rotary transformers arranged coaxially with the shaft, the shaft having herringbone groove patterns formed thereon with a larger surface area of the herringbone groove pattern on the free end side of the shaft than on the fixed end side thereof, thereby providing a compact structure.