Disk drive with controlled reduced internal pressure

A magnetic recording disk drive having a rigid magnetic recording disk, an electrical spindle motor connected to the disk for rotating the disk, a spindle motor driver for controlling the spindle motor, a head for reading data from or writing data to the disk, a carrier for supporting the head near the surface of the disk, an actuator connected to the carrier for moving the carrier and supported head across the disk, a power supply for providing electrical power to the spindle motor, a controller coupled to the spindle motor driver and the head for controlling the spindle motor driver and the reading and writing of data by the head, and a housing providing a substantially sealed gaseous environment for the disk and carrier, and wherein the spindle motor driver provides a spindle motor speed status signal and a spindle motor current signal to the controller, the disk drive comprising:

• an electrically-powered vacuum pump electrically coupled to the power supply and attached to the housing, the pump having an inlet connected to the interior of the housing;
• a switch coupled between the pump and the power supply and controlled by the controller;
• and
• wherein, when the head is not reading or writing data, the controller turns on the switch when the spindle motor status signal indicates the spindle motor is operating at substantially its operating speed and the spindle motor current signal indicates the spindle motor current is above a first value representative of a high gas pressure level within the housing, and turns off the switch when the spindle motor current signal indicates the spindle motor current is below a second value representative of a low gas pressure level within the housing;
• whereby the gas pressure within the housing is maintained within a predetermined reduced pressure range.

A magnetic recording disk drive comprising:

• a rigid magnetic recording disk;
• an electrical motor connected to the disk for rotating the disk;
• a head for reading data from or writing data to the disk;
• a carrier for supporting the head near the surface of the disk;
• an actuator connected to the carrier for moving the carrier and supported head across the disk;
• a disk drive housing providing a substantially sealed gaseous environment for the disk and carrier;
• an electrically-powered pump attached to the housing for removing gas from within the housing;
• and
• electrical control circuitry responsive to the disk motor current and coupled to the pump for turning the pump on when the disk motor current exceeds a first value corresponding to a first level of gas pressure within the housing.

A magnetic recording disk drive comprising:

• a rigid magnetic recording disk;
• an electrical spindle motor connected to the disk for rotating the disk;
• a head for reading data from or writing data to the disk;
• a carrier for supporting the head near the surface of the disk;
• an actuator connected to the carrier for moving the carrier and supported head across the disk;
• a disk drive housing providing a substantially sealed gaseous environment for the disk and carrier;
• a pump attached to the housing and having an inlet connected to the interior cif the housing;
• an electrical motor coupled to the pump for driving the pump;
• pump control circuitry responsive to a signal representative of spindle motor current and connected to the pump motor for turning the pump motor on and off to maintain the pressure within the housing within a range of pressures less than the pressure external to the housing;
• and
• means connected to the pump control circuitry for providing said spindle motor current signal to the pump control circuitry.