The spindle motor, also sometimes called the spindle shaft, is responsible for turning
the hard disk platters, allowing the hard drive to operate. The spindle motor is sort of a
"work horse" of the hard disk. It's not flashy, but it must provide stable,
reliable and consistent turning power for thousands of hours of often continuous use, to
allow the hard disk to function properly. In fact, many drive failures are actually
failures with the spindle motor, not the data storage systems.

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A hard disk spindle motor, stripped of its platters and
other components, and detached
from the drive's base casting. You can see that it attaches with three screws around its
perimeter. The shiny metal is the shaft, which rotates; the dull metal is the base of the
motor.
The six small screw holes on the top of the shaft are for securing the platters. You can
also see
a large screw hole in the center top of the shaft, which is used to attach the top cover
to the
spindle shaft for added stability. the four wire connector attaches to the hard disk logic
board. |
For many years hard disks all spun at the same speed. In the interests of performance,
manufacturers have been steadily ratcheting up their products' spin speeds over the
last few years. These higher-speed spindles often have issues related to the amount of
heat and vibration they generate. The increased performance and also the new potential
issues related to the spindle motor have given it renewed attention in the last few years.
Next: Spindle Motor Operation