Patent ID: 7349183

Claim:
An actuator assembly for a hard disk drive, comprising: a slider with a read/write head mounted thereon; a suspension supporting the slider; an actuator arm rotatably coupled to a pivot shaft, in which the suspension is fixed to a front end of the actuator arm; and a voice coil motor rotates the actuator arm, wherein: the actuator arm includes a structure of a 4-bar linkage defined by an opening formed between the front end of the actuator arm and the pivot shaft; the opening has an approximately trapezoidal shape, in which a first rounded extension portion and a second rounded extension portion are formed at two corners adjacent to the pivot shaft of the opening, respectively, and a third rounded extension portion is formed at two corners adjacent to a front end of the opening, and hinges H 1 , H 2 , H 3 and H 4 are formed at the actuator arm by the first, second and third extension portions; a position vector corresponding to linkage H 1 -H 2 connecting two hinges H 1 and H 2 formed at one side of the opening is W, a position vector of the read/write head at the hinge H 2 is Z, an angle of the vector Z is α, an angle of the vector W is β, and displacement of the head/write head of the actuator assembly in a main resonance mode is δ, design factors determining a shape of the opening are optimized to meet the following relations for the structure of 4-bar linkage: W (cos β−1)+ Z (cos α−1)=δ x =0 W sin β+ Z sin α=δ y =0.