Apparatus and method for guiding bypass reentry flow through contraction and filter in a hard disk drive

A hard disk drive comprising:

• a housing;
• a disk pack mounted to the housing and having a plurality of disks that are rotatable relative to the housing, the disk pack defining an axis of rotation and a radial direction relative to the axis, and the disk pack having a downstream side wherein air flows away from the disks, and an upstream side wherein air flows toward the disk;
• an actuator mounted to the housing and being movable relative to the disk pack, the actuator having a plurality of heads for reading data from and writing data to the disks;
• a bypass channel formed in the housing for directing the air flows generated by rotation of the disks from the downstream side of the disk pack to the upstream side of the disk pack;
• and
• an airflow contractor and filter comprising:
• a contraction portion for accelerating a first portion of the air flows to the upstream side of the disk pack;
• and
• a filter portion integral with the contraction portion, said filter portion for filtering a second portion of the air flows to the upstream side of the disk pack.