Multisegmented Magnet Array on Voice Coil Motor in Rotating Data Storage Devices

Abstract

The swing-arm-type voice coil motor (VCM) is widely used as an actuator in rotating data storage devices. Recently, it has been found that to achieve a faster data transfer rate and a higher data storage areal density, a high performance actuator is required. Moreover, a small form factor has become desirable for portable devices. In this paper, a novel magnetic circuit of VCM with multisegmented magnet array (MSMA) is proposed. Both the magnetic circuits of the conventional VCM and the MSMA VCM are optimized using the 3D finite element method. Sample magnetic circuits are fabricated with optimally designed parameters and a comparative analysis is carried out. The performances of magnetic circuits are evaluated and the experimental results prove the effectiveness of the proposed magnet array.

Thickness Minimized Magnetic Circuit for Rotary-Type Voice Coil Motor

“…Previously, a multisegmented magnet arrary (MSMA) VCM which could provide higher flux density in the air gap than a conventional VCM was proposed. 4) In this paper, we show that the total thickness of the magnetic circuit for a rotary-type VCM can be reduced without changing the coil and air gap parameters if the MSMA is applied to a VCM. The effect of the horizontally magnetized magnet size on the total thickness and flux density constant range are also discussed.…”

Halbach Magnetic Circuit for Voice Coil Motor in Hard Disk Drives

“…In our previous work, we proved the effectiveness of the Halbach magnet array as a magnetic circuit for a rotary-type VCM in terms of generated force and compactness [9]. Also we proposed a Halbach magnetic circuit and analyzed its performance in a labmade VCM [10].…”

Optimization of Seesaw Swing Arm Actuator Design for Small Form Factor Optical Disk Drive

“…A conventional VCM uses only a vertically magnetized magnet, however, the new MSMA VCM contains both vertically (Y-direction) and horizontally (X-direction) magnetized magnets. 17,18) The principle is that the magnetic field is concentrated on one side while it is diminished on the other side if X-directional magnets are combined with the Y-directional magnet array. If the MSMA is used in an electric motor instead of a conventional magnet array, the coil is exposed to more magnetic flux.…”