Active noise control unit for motor or engine includes oscillating baffle mounted within airflow conduit to exert dynamic effect on air flow

摘要

An electro-dynamic or an electromagnetic motor (5) generates a reciprocating motion on an output shaft (4). A shaped element (3) is attached to the end of the output shaft in order to undergo reciprocating movement within the air flow (V). The shaped element (3) exerts a dynamic effect on the air flow. The electro-acoustic source comprises an electro-dynamic or an electromagnetic motor (5) generating a reciprocating motion on an output shaft (4). A shaped element (3) is attached to the end of the output shaft in order to undergo reciprocating movement within the air flow (V). The shaped element (3) exerts a dynamic effect on the air flow. The motor may be either a rotary or a linear device configured to produce a reciprocating movement. It may comprise an oscillating coil mounted within a magnetic induction field. The oscillating action may be provided by the action of a spiral spring which returns the shaft and hence the shaped element (3) to its rest position.