Frame Assembly; Door Opening/Closing And Disk Clamp Mechanism; Spindle Mechanism; Read/Write Head And Carriage - Fujitsu M255XK Customer Engineering Manual

3.1.1 Frame Assembly
The frame assembly is the skeleton on which the mechanisms and circuit boards
are mounted. This aluminum die cast chassis ensures the drive has the strength,
accuracy and expansion ratio required for stable disk drive operations.
3.1.2 Door Opening/Closing and Disk Clamping Mechanism
The door opening/closing mechanism includes the clamp spring (flat spring), front
lever, and set arm. The disk clamp mechanism (Collet) is moved up and down by
the end of the set arm. When a diskette is inserted and the front lever is closed,
the collet enters the opening in the center of the disk, and presses against the
spindle to ensure the disk is accurately clamped into posi tion.
3.1.3 Spindle Mechanism
The disk rotating system is comprised of the spindle and spindle motor. The
spindle motor is a direct spindle coupled outer rotor type DC brushless motor with
a service life of 20,000 or more hours of continuous operation. The spindle motor
rotates at 300 or 360 RPM and maintains a constant speed, even with load and
temperature fluctuations, by using feedback signals from an AC tachometer built
into the motor.
The spindle and collet are precisely aligned to prevent injury to the center hole of
the disk and to allow accurate centering of the disk. This also ensures the heads
and disk come into contact at exactly the correct location.
3.1.4 Read/Write Head and Carriage
The flat shaped read/write heads are supported by a gimbal. The heads straddle
the disk and are mounted on the carriage. The read/write heads are designed to
obtain maximum playback from the disk, with minimum head to disk contact
pressure.
Refer to Figure 3-2. The tunnel erase read/write heads have a read/write gap to
record and playback data, and a tunnel erase gap to trim the edges of each track
immediately after it is written.
Rea.d/Write
core
_.Direc:tioa of
disk rotation
Erase
core
Figure 3-2 Tunnel Erase Type Read/Write Head
3-2 T5-021-013087 ••• 01