Spindle Motor
1. Spindle Motor Definition
A spindle motor is a small, high-precision, high-reliability electric motor that is used to
rotate the shaft, or spindle, on which the platters are mounted in a hard disk drive (HDD).
A platter is a thin, high-precision aluminum or glass disk that is coated on both sides with
a high precision magnetic material and which is used in a HDD to store data. Modern HDDs
typically contain multiple platters, all of which are mounted on a single shaft, in order to
maximize the data storage surface in a given volume of space
All HDD spindle motors are configured for direct driving of the platters. That is, the
rotating shaft of the motor and shaft on which the platters are mounted is a single, integral unit.
This is in contrast to most electric motors, which use gears or belts to transfer and modify their
output.