A brushless disc drive using powder iron stator

This paper investigates the use of insulated iron powder core material for the stator core of a computer disc drive eight pole six slot brushless DC motor. The use of this form of construction has advantages in high volume production. A comparison, by both finite element modelling and practical tests, between a conventional laminated machine and a powder iron version is made, and it is shown that after small adjustments to the tooth tip thickness a comparable torque performance can be obtained. The machine losses are measured and it is shown that whilst the iron loss of the powder iron machine is higher the total loss is comparable so that the powder iron machine is viable.