FUJITSU MHK2090AT - Manual (Page 54)

4.2 Subassemblies
C141-E088-03EN 4-3
MHJ2181AT
3
4
5
Head
1
2
0
MHK2120AT
3
1
2
0
Head
Head
MHK2060AT
1
0
MHK2090AT
1
2
0
Figure 4.1 Head structure
4.2.3 Spindle
The spindle consists of a disk stack assembly and spindle motor. The disk stack
assembly is activated by the direct drive sensor-less DC spindle motor, which has
a speed of 4,200 rpm
±
1%. The spindle is controlled with detecting a PHASE
signal generated by counter electromotive voltage of the spindle motor at starting.
4.2.4 Actuator
The actuator consists of a voice coil motor (VCM) and a head carriage. The VCM
moves the head carriage along the inner or outer edge of the disk. The head
carriage position is controlled by feeding back the difference of the target position
that is detected and reproduced from the servo information read by the read/write
head.
4.2.5 Air filter
There are two types of air filters: a breather filter and a circulation filter.
The breather filter makes an air in and out of the DE to prevent unnecessary
pressure around the spindle when the disk starts or stops rotating. When disk
drives are transported under conditions where the air pressure changes a lot,
filtered air is circulated in the DE.
The circulation filter cleans out dust and dirt from inside the DE. The disk drive
cycles air continuously through the circulation filter through an enclosed loop air
cycle system operated by a blower on the rotating disk.