REVOLVING HEAD ASSEMBLY FOR MAGNETIC RECORDING AND REPRODUCING DEVICE

PURPOSE:To simplify the shaft direction displacing mechanism of a magnetic head and to decrease the number of parts by constituting a central shaft of a piezoelectric element between a first shaft member, which is fixed to a fixed cylinder, and a second shaft member in a thrust fluid bearing side, impressing a voltage to the piezoelectric element and executing the expansion and contraction of this element in the shaft direction of the central shaft. CONSTITUTION:A central shaft 3 is composed of a first shaft member 302, which is fixed to a fixed cylinder 1, a second shaft member 303 in the thrust fluid bearing side and a piezoelectric element 304 to be held and fixed between these shaft members 302 and 303. When information to be recorded at a standard speed are especially reproduced, the voltage to correspond to this special reproducing is generated from a power source 10 and impressed to the piezoelectric element 304. The piezoelectric element 304 is enpanded and contracted in the shaft direction of the central shaft 3 in correspondence to this voltage and this expansion and contraction is transmitted to a revolving cylinder 5. Then, a magnetic head 6, which is fixed to this cylinder, is displaced in the shaft direction. Thus, the shaft direction displacing mechanism of the magnetic head 6 is simplified and the number of the parts is decreased.