21-09-2008, 09:46 AM
A Brushless Servomotor has been developed by using interdisciplinary mechatronics engineering. A mechanical switching device (commutator) is replaced by electronic circuits and controllers resulting in maintenance free and high performance servo drive. The brushless servomotor is an ac motor, in all respects and is in fact called the ac servomotor. Combined with a dedicated control device, the performance of the brushless servomotor is found to be equal to the performance of the high performance dc servo motor. In dc motor when the current flows in the electrical conductor, after passing through the brushes and the commutator in the magnetic field generated by permanent magnets N and S, torque is generated. For getting a stable torque proportional to current, the line of magnetic force should intersect the direction of current at right angles in a dc motor. This is enabled by the use of rectifiers (a commutator and brushes).The brushless servomotor lacks the rectifiers that the de motor has, and has a device for making the current flow to fit the rotor position by controlling the power source. The increasing trend and need towards automated factories and sophisticated robotics would definitely make the use of servomotors more widespread..
