Fujitsu MAN3184MC - Enterprise 18.4 GB Hard Drive, Product/Maintenance Manual

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C141-E128-01EN 1 - 7
(2) Heads
The MR (Magnet - Resistive) of the CSS (contact start/stop) type heads are in contact with the
disks when the disks are not rotating, and automatically float when the rotation is started. Figure
1.3 shows the configuration of disks and heads
Figure 1.3 Disk/head configuration
(3) Spindle motor
The disks are rotated by a direct-drive hall-less DC motor. The motor speed is controlled by a
feedback circuit using the counter electromotive current to precisely maintain the speed at ±0.2%
of the specified speed.
(4) Actuator
The actuator, which uses a rotary voice coil motor (VCM), consumes little power and generates
little heat. The head assembly at the end of the actuator arm is controlled and positioned via
feedback of servo information in the data.
Heads are positioned on the CCS zone over the disk when the power is off or the spindle motor is
stopped.
(5) Air circulation (recirculation filter, breather filter)
The disk enclosure (DE) configures a sealed room to keep out dust and other pollutants. The DE
has a closed-loop air recirculation system. Using the movement of the rotating disks, air is
continuously cycled through a filter. This filter will trap any dust generated inside the enclosure
and keep the air inside the DE contaminant free. To prevent negative pressure in the vicinity of
the spindle when the disks begin rotating, a breather filter is attached. The breather filter also
equalizes the internal air pressure with the atmospheric pressure due to surrounding temperature
changes.
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