Seagate Technology Incorporated

Western Digital Corporation

Andrew John Hudson

Michael John Raffetto

Kamran Oveyssi

Clifford T Jue

Walter Wayne Butler

Differing gram loads and actuator arm resonances are compensated for through the method and apparatus of positioning z-height of outer actuator arm at an optimal height. Specifically, an actuator arm driven by a closed loop servo motor system for a disc drive system is configured so that the outer upper and lower actuator arms are positioned at an optimum distance, called optimum z-height, from the disc surface. At the optimum z-height position, the gram load of the outer actuator arms are shifted as near as possible to the gram load of the inner actuator arms. At the optimum z-height, the resonances on the head gimbal assemblies of the inner and outer actuator arms are closest.

Disc drive actuator arm assembly with outer arm z-height less than inner arm z-height

A magnetic latch assembly for immobilizing a read/write head of a disk drive is provided which magnetically couples to an actuator assembly housing the read/write head with enhanced force. A disk drive which includes the magnetic latch assembly is also provided. The magnetic latch assembly includes a magnet and a magnet holder including ferromagnetic material which at least partially surrounds the magnet and provides a medium through which flux produced by one pole of the magnet travels to an opposing pole of the magnet. The latch assembly magnetically couples the actuator assembly by contacting the actuator assembly in an area adjacent one of the poles of the magnet. In one embodiment, the magnet holder includes ferromagnetic material which surrounds the magnet. In another embodiment, the magnet holder includes a plurality of ferromagnetic flanges which at least partially surround the magnet.

Magnetic latch assembly for a disk drive including a ferromagnetic

Method and apparatus for compensating for different gram loads and actuator arm resonances by positioning z-height of outer actuator arm at an optimum height. Specifically, an actuator arm driven by a closed loop servo motor system for a disc drive system is configured so that the outer upper and lower actuator arms are positioned at an optimum distance, called optimum z-height, from the disc surface. At the optimum z-height position, the resonances of the outer actuator arms are shifted as near as possible to the resonances of the inner actuator arms. At the optimum z-height, the gram loads on the head gimbal assemblies of the inner and outer actuator arms are closest for all z-heights measured. Accordingly, degradation of the performance of the servo motor system will be reduced.

Method of making a disc drive actuator arm with arm compliance

A limit stop for defining the extremes of the range of motion of a disc drive actuator, and a magnetic latch which may be incorporated into the limit stop for holding the actuator at one of the extremes of its range of motion. Both the limit stop and limit stop with incorporated magnetic latch allow compliance to be determined based on material selection and dimensions. The magnetic latch includes a flux concentrator mounted on a limit stop and a magnetically permeable striker mounted on the moving portion of the actuator, and derives magnetic force for latching from the permanent magnet in the voice coil motor of the actuator.

Growing community of inventors

Santa Cruz, CA, United States of America

Andrew John Hudson