A servo device for radio control fine-adjusts a linkage rod, which links the servo device and an operation unit, in an accurate positional relationship. The servo device includes a servo motor having a servo output shaft on which a serration is formed, and a servo horn having a shaft bore opened at the lower side thereof, the shaft bore having an inner wall on which an inner serration to be engaged to the servo output shaft is formed. The servo horn has a servo horn base from which the horn output shaft protrudes, the horn output shaft being above and coaxially to the shaft bore, an operation unit having a shaft bore engaging the horn output shaft, and an angular adjustment mechanism for linking the shaft bore of the operation unit to the horn output shaft so as to movably fix circumferentially and at an arbitrary angle.

A disk drive having a novel actuator assembly. The actuator assembly comprises a voice coil motor assembly, a pivotable actuator arm, and a head gimbal assembly including a read/write head. The voice coil motor assembly is attached at a back end of the actuator arm, and the head gimbal assembly is mounted on the actuator arm on a front end opposite of the back end. The voice coil motor assembly includes a voice coil interposed between two magnets and a top plate and a bottom plate. The voice coil motor assembly is secured to the base of the disk drive by posts. The actuator arm includes the back end, a pivot point and impeding apertures. The impeding apertures include two holes located near the back end of the actuator arm between the pivot point and the voice coil motor assembly and extend entirely through the actuator arm. The actuator arm may also include plugging members. The plugging members are inserted into the impeding apertures and extend entirely through the impeding apertures. The plugging members are of the same circumferential size and configuration as the impeding apertures. In operation, the voice coil motor assembly produces a force which pivots the actuator arm in order to position the read/write heads over individual tracks on the disk. The force produced by the voice coil motor assembly creates a vibration which emanates throughout the actuator arm and propagates toward the read/write heads. The vibration reaches the impeding apertures and is reflected back towards the voice coil motor. The vibration may also be dampened if plugging members are inserted in the impeding apertures.

A stacked suspension assembly for a data storage drive having, for example, at least two suspension members with each suspension member has a bearing hole therethrough. At least one spacer is positioned between the at least two suspension members to separate adjacent suspension members Each spacer has a bearing hole therethrough. A bearing member can be inserted within the bearing holes of the at least two suspension members and the at least one spacer. The bearing member has an actuator hole into which an actuator pivot member is insertable.

The arrangement is such that the ratio of the diameter of balls 3 in the ultrathin-walled ball bearing to the pitch circle diameter PCD is not more than 0.03, and that the balls 3 are arranged in a single row and in two-point contact with the raceway surfaces 1a and 2a of the outer and inner members 1 and 2. The inner member 2 is composed of first and second raceway rim members 21 and 22 opposed to each other with an axial clearance S defined therebetween, and the internal clearances of the bearing are made negative by adjusting the width of the axial clearance S.