Magnetic bearings for a high-performance optical disk buffer, volume 1
Abstract
The innovation investigated in this project was the application of magnetic bearing technology to the translator head of an optical-disk data storage device. Both the capability for space-based applications and improved performance are expected to result. The phase 1 effort produced: (1) detailed specifications for both the translator-head and rotary-spindel bearings; (2) candidate hardware configurations for both bearings with detail definition for the translator head; (3) required characteristics for the magnetic bearing control loops; (4) position sensor selection; and (5) definition of the required electronic functions. The principal objective of Phase 2 was the design, fabrication, assembly, and test of the magnetic bearing system for the translator head. The scope of work included: (1) mechanical design of each of the required components; (2) electrical design of the required circuitry; (3) fabrication of the component parts and bread-board electronics; (4) generation of a test plan; and (5) integration of the prototype unit and performance testing. The project has confirmed the applicability of magnetic bearing technology to suspension of the translator head of the optical disk device, and demonstrated the achievement of all performance objectives. The magnetic bearing control loops perform well, achieving 100 Hz nominal bandwidth with phase margins between 37 and 63 degrees. The worst-case position resolution is 0.02 micron in the displacement loops and 1 micron rad in the rotation loops, The system is very robust to shock disturbances, recovering smoothly even when collisions occur between the translator and frame. The unique start-up/shut-down circuit has proven very effective.
- Publication:
-
Final Report
- Pub Date:
- May 1990
- Bibcode:
- 1990sctc.rept.....H
- Keywords:
-
- Buffer Storage;
- Data Storage;
- Magnetic Bearings;
- Optical Disks;
- Circuits;
- Design Analysis;
- Fabrication;
- Performance Tests;
- Prototypes;
- Mechanical Engineering