Worm 1 is keyed to shaft a of electric motor 4 and rotates about axis A-A. Worm 1 meshes with worm wheel 2 which rotates about axis B of housing b. The housing is rigidly attached to the frame of motor 4. Crank 3 is rigidly attached to wheel 2 and is connected by turning pair C to link 5 which turns about fixed axis D. Electric motor 4 and housing b turn about fixed axis A. When worm 1 is driven through shaft a by motor 4, the motor, vanes d and housing b oscillate about axis A.
$2820$WG,ML$