Title :
Adjustable balancer with electromagnetic release of balancing members
Author :
Hredzak, Branislav ; Guo, Guoxiao
Author_Institution :
A* Star, Data Storage Inst., Singapore, Singapore
fDate :
5/1/2006 12:00:00 AM
Abstract :
Adjustable balancers are useful in applications where rotational imbalance is frequently varied. For example, in media level servo track writers used in the hard disk drive industry, a set of blank disks is loaded on a spindle motor for the purpose of servo writing. Since servo writing is performed at high speeds, imbalance introduced by disks and spacers results in significant vibrations that can affect the quality of the servo writing process. This paper proposes a new configuration of adjustable balancer that enables to compensate for rotational imbalance each time a new set of blank disks is loaded into the servo track writing machine. The adjustable balancer is ring shaped with a number of grooves displaced around axis of rotation. Steel balls are placed inside the grooves and held by permanent magnets. Imbalance compensation is achieved by electromagnetically activated release of the steel balls. The main advantage of the proposed configuration is its large compensation range. Presented three-dimensional finite-element analysis results and experimental results demonstrate and prove the effectiveness of this novel configuration.
Keywords :
compensation; electromagnetic devices; finite element analysis; hard discs; servomotors; adjustable balancer; balancing members; electromagnetic forces; electromagnetic release; finite-element analysis; hard disks; imbalance compensation; permanent magnets; rotational imbalance; servo track writing machine; Finite element methods; Gravity; Hard disks; Memory; Permanent magnets; Servomechanisms; Servomotors; Shafts; Steel; Writing; Electromagnetic forces; hard disks; vibrations;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2005.863619