Disk drive with airflow control

A disk drive comprising:

• a motor for rotating a recording disk;
• a base for housing said motor, and having a first bottom surface opposite to said recording disk and a second bottom surface, a distance between the second bottom surface and said recording disk being greater than a distance between said first bottom surface and the recording disk;
• a first step located between said first bottom surface and said second bottom surface, where rotation of the recording disk produces an airflow running from said first bottom surface toward said second bottom surface;
• and
• a second step located between said first bottom surface and said second bottom surface, where the rotation of the recording disk produces an airflow running from said second bottom surface toward said first bottom surface, the second step having an inclined angle larger than an inclined angle of said first step.