Head gimbal assembly and head stack assembly having accurate dimensions

A head stack assembly comprising:

• a cylindrical carriage support shaft having parallel flat surfaces;
• a carriage assembly having a mounting part mounted on the carriage support shaft, and a coil;
• and
• a head gimbal assembly including a head arm consisting of a hole having both rounded and only two straight edges and configured to receive the carriage support shaft therein, wherein extensions of the two straight edges meet at right angles;
• wherein when the carriage support shaft is received in a mounting hole, the head gimbal assembly is capable of rotating and locking into a position relative to the straight edges of the mounting hole and the flat surfaces of the carriage support shaft.

A head stack assembly comprising:

• a cylindrical carriage support shaft having parallel flat surfaces;
• a carriage assembly having a mounting part mounted on the carriage support shaft, and including a coil;
• and
• a head gimbal assembly consisting of a head arm including a hole having both rounded and only two straight edges and configured to receive the carriage support shaft therein, a flexure having one end attached to the head arm, and a load beam attached to the flexure, wherein extensions of the straight edges of the mounting hole, receiving the carriage support shaft, of the head arm meet at right angles;
• wherein when the carriage support shaft is received in the mounting hole, the head gimbal assembly is capable of rotating and locking into a position relative to the straight edges of the mounting hole and the flat surfaces of the carriage support shaft.

A magnetic disk drive comprising:

• a head gimbal assembly consisting of a head arm provided with a mounting hole having rounded and only two straight edges and configured to receive a carriage support shaft therein, a flexure having one end attached to the head arm, and a load beam attached to the flexure, wherein the carriage support shaft is cylindrical and has parallel flat surfaces;
• and
• a magnetic disk for writing information to and reading information from the magnetic disk;
• wherein when the carriage support shaft is received in the mounting hole, the head gimbal assembly is capable of rotating and locking into a position relative to the straight edges of the mounting hole and the flat surfaces of the carriage support shaft;
• wherein extensions of the two straight edges of the mounting hole of the head arm receiving the carriage support shaft therein meet at right angles.

A magnetic disk drive comprising:

• a head stack assembly consisting of a cylindrical carriage support shaft having parallel flat surfaces, a carriage assembly having a mounting part mounted on the carriage support shaft, and a coil, and a head gimbal assembly provided with a mounting hole having both rounded and only two straight edges and configured to receive the carriage support shaft, wherein extensions of the straight edges of the mounting hole of the head gimbal assembly receiving the carriage support shaft meet at right angles;
• and
• a magnetic disk to which the magnetic head write information and from which the magnetic head read information;
• wherein when the carriage support shaft is received in the mounting hole, the head gimbal assembly is capable of rotating and locking into a position relative to the straight edges of the mounting hole and the flat surfaces of the carriage support shaft.

A magnetic disk drive comprising:

• a cylindrical carriage support shaft having parallel flat surfaces;
• a carriage assembly having a mounting part mounted on the carriage support shaft, and a coil;
• a head arm consisting of a mounting hole having both rounded and only two straight edges and configured to receive the carriage support shaft therein, wherein extensions of the straight edges of the mounting hole of the head arm receiving the carriage shaft meet at right angles;
• a flexure having one end attached to the head arm and the other end including a gimbal;
• a load beam attached to the flexure and capable of loading the gimbal;
• a magnetic head attached to the gimbal;
• and
• a magnetic disk to which the magnetic head write information and from which the magnetic head read information
• wherein when the carriage support shaft is received in the mounting hole, and the head arm is capable of rotating and locking into a position relative to the straight edges of the mounting hole and the flat surfaces of the carriage support shaft.