Development of an Eddy Current Door Closer

North Carolina State University, 2003 - $15,000

Conventional door closing devices use springs and hydraulic dampeners to create restoring and damping forces that maintain the desired closed-door profile. But these devices have several problems: potential hydraulic fluid leakage, reduced performance due to dust and temperature, and limited life cycles due to friction between the piston and frame case. To solve these problems, this E-Team developed an eddy current door closer to replace conventional hydraulic door closers.

The eddy current door closer is constructed from passive electromechanical components and uses permanent magnets in conjunction with a rotating copper disk to generate braking torques similar to standard door closing devices. This results in decreased maintenance requirements and environmental concerns due to absence of hydraulic fluid, low cost , and easily adjustable damping force.

The E-Team included two PhD students with backgrounds in mechatronics, electromechanical systems, robust control, and structural vibrations. A faculty advisor with expertise in mechanical engineering supported the students, along with an industry expert.