Abstract: A housing assembly for magnetic head supporting arms of a magnetic disk device includes a housing which has a cylindrically shaped through-hole having two bearings each provided at each end of the through-hole and is formed integrally with supporting arms for supporting magnetic heads. The housing has a cylindrically shaped collar which is constituted by a member having the same linear expansion coefficient as that of the bearings and is fitted between the bearings in an exact fitting dimensional relationship with the bearings. The housing has a slit which extends through an entire axial length and is disposed in a wall defining the through-hole of the housing. The thermal strain in the head supporting arms integral with the housing can be suppressed so as not to be influenced by a temperature rise of the device or a temperature change of environments.

Abstract: A magnetic head for use in a magnetic disk drive. An arm included in the head is partly constituted by a member which is different in the coefficient of thermal expansion from the other portion of the arm. This is successful in readily correcting a tracking error ascribable to the thermal expansion of the arm despite the varying ambient temperature.

Abstract: A magnetic disk device has a spindle hub fixed to a spindle shaft. The spindle hub includes a flange member formed at its lower end portion and an annular groove formed in the flange member. A plurality of magnetic disks and spacer rings are stacked alternately on the flange member of the spindle hub in an axial direction. A cylindrical support member disposed in the annular groove of the spindle hub to form a predetermined gap between its inner peripheral surface and an outer peripheral surface of the spindle hub, while an outer peripheral surface of the cylindrical support member contacts the inner peripheral surfaces of the plurality of magnetic disks and spacer rings. Another magnetic disk device has a spindle hub fixed to a spindle shaft. The spindle hub includes a flange member formed at its lower end portion and has at least two grooves formed on its outer periphery at a predetermined distance apart.