Title :
Study of electrical characteristics of the ball bearing motor
Author :
Moyssides, Paul G. ; Hatzikonstantinou, Paul
Author_Institution :
Dept. of Phys., Nat. Tech. Univ., Athens, Greece
fDate :
7/1/1990 12:00:00 AM
Abstract :
The electrical characteristics of the ball bearing electric motor are studied for applied steady currents ranging from 43.5 to 70.15 A. It is found that the ball bearing behaves like a motor when it starts self-rotating meaning that the shaft and inner race of the pair of the ball bearing system start rotating by themselves without the help of any external agent, but with a small efficiency at high currents. During self-rotation the motor´s counterelectromotive force depends on the angular velocity of the shaft and inner race. The ball bearing´s behavior at low currents is also explained when it is not self-rotating, (i.e. rotating with the help of a conventional motor). In the latter case, the motor does not behave like a generator. A theory, based on the electromagnetic interactions developed within each ball, is proposed to explain the action of the ball bearing as a motor. These interactions are caused by the ball´s primary currents and magnetic fields and the effects of the induced magnetic field from the current of the motor´s shaft
Keywords :
electric motors; electric potential; small electric machines; 43.5 to 70.15 A; angular velocity; applied steady currents; ball bearing motor; counterelectromotive force; electrical characteristics; electromagnetic interactions; inner race; magnetic fields; primary currents; self-rotation; Angular velocity; Ball bearings; Electric motors; Electric variables; Electromagnetic forces; Electrostatics; Equations; Magnetostatics; Shafts; Torque;
Journal_Title :
Magnetics, IEEE Transactions on