3-1-2. Mechanical Section
Since the disk is a flexible recording media made of mylar film base
and data interchangeability between disks and FDDs is required, the
mechanical section of the FDD uses precision parts and it is also
assembled with high precision. For this reason, only trained technicians
can handle the internal mechanism. Never apply excessive impact nor
drop the FDD down on the desk.
The mechanical section is constructed’ with frame, door mechanism, disk
clamp mechanism# disk rotation mechanism, magnetic head and carriage,
head load' mechanism (or CSS mechanism) , head seek mechanism, various
detection mechanisms, etc.
(1) Frame «
The main structure for mounting the various mechanisms and printed
circuit boards. The frame is made of aluminum die cast to maintain
the stability of the FDD in strength, precision, durability, and
expansion coefficient.
(2) Door mechanism and disk clamp mechanism
The door mechanism .is constructed with the main parts of set arm which
forms the structure for installing the disk on the spindle other parts
of front*lever, clamp arm, etc. The set arm is sttacKed to the rear
of the frame with leaf springs and on the tip of the set arm a collet,
which forms the disk clamp mechanism, is attached.
When a disk is inserted and the door is closed, the tip of the collet
is inserted in the central window of the disk and the window area is
depressed to the spindle so that the center of the disk is clamped in
the correct position along the outer circumference of the collet.
(3) Disk rotation mechanism
302
