A typical hard disk drive has two electric motors, disk motor that spins the disks & an actuator (motor) that positions the read/write head assembly across the spinning disks.
The disk motor has an external (rotor) attached to the disks; the stator windings are fixed in place.
Opposite the actuator at the end of the head, support arm is the read-write head near center in photo, a thin (printed-circuit) cables connect the read-write heads to amplifier electronics mounted at the pivot of the actuator. A flexible somewhat U-shaped, ribbon cable, seen edge-on below and to the left of the actuator arm continues the connection to the controller board on the opposite side.
Head support arm is very light, but also stiff; in modern drives, acceleration at the head reaches 550g
The silver-colored structure at the upper left of the first image is the top plate of the actuator, a permanent-magnet and moving coil motor that swings the heads to the desired position (it is shown removed in the second image). The plate supports a squat neodymium-iron-boron (NIB) high-flux magnet.
Beneath this plate is the moving coil, often referred to as the voice coil by analogy to the coil in loudspeakers, which is attached to the actuator hub, and beneath that is a second NIB magnet, mounted on the bottom plate of the motor some drives only have one magnet.
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