Samsung M8 manual Disk Drive Operation, Head / Disk Assembly HDA, Base Casting Assembly

CHAPTER 5 DISK DRIVE OPERATION

This chapter describes the operation of the Spinpoint M8 hard disk drive functional subsystems. It is intended as a guide to the operation of the drive, rather than a detailed theory of operation.

5.1Head / Disk Assembly (HDA)

The Spinpoint M8 hard disk drive consists of a mechanical sub-assembly and a printed circuit board assembly (PCBA), as shown in Figure 5-1. This section describes the mechanism of the drive.

The head / disk assembly (HDA) contains the mechanical sub-assemblies of the drive, which are sealed between the aluminum-alloy base and cover. The HDA consists of the base casting assembly (which includes the DC spindle motor assembly), the disk stack assembly, the head stack assembly, and the rotary voice coil motor assembly (which includes the actuator latch assembly). The HDA is assembled in a clean room. These subassemblies cannot be adjusted or field repaired.

CAUTION: To avoid contamination in the HDA, never remove or adjust its cover and seals. Disassembling the HDA voids your warranty.

The Spinpoint M8 hard disk drive models and capacities are distinguished by the number of heads and disks. The ST250LM004 have one (1) disk and two (2) read/write heads. The ST320LM001 have one (1) disk and two (2) read/write heads. The ST500LM012 has one (1) disk and two (2) heads. The ST640LM001 have two (2) disks and four (4) read/write heads. The ST750LM022 have two (2) disks and four (4) read/write heads. The ST1000LM024 has two (2) disks and four (4) read/write heads.

5.1.1Base Casting Assembly

A one piece, aluminum-alloy base casting provides a mounting surface for the drive mechanism and PCBA. The base casting also serves as the flange for the DC spindle motor assembly. A gasket provides a seal between the base and cover castings that enclose the drive mechanism.

5.1.2DC Spindle Motor Assembly

The DC spindle motor assembly consists of the brush-less three-phase motor, spindle bearing (FDB) assembly, disk mounting hub, and a labyrinth seal. The entire spindle motor assembly is completely enclosed in the HDA and integrated to the base casting. The labyrinth seal prevents bearing lubricant from coming out into the HDA. The motor rotates the spindle shaft at 5400 rpm.

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