Damping device of window covering

A damping device of a window covering, wherein the window covering comprises a headrail, a covering material, and a driving device, wherein the driving device is located in the headrail to raise and extend the covering material;

• the damping device is provided in the headrail, and is connected to the driving device;
• the damping device comprising:
• a metal member comprising a metal roller;
• a magnetic member having a first magnetic pole and a second magnetic pole, wherein at least a part of the magnetic member is provided in the metal roller;
• at least a part of the first magnetic pole and at least a part of the second magnetic pole face an inner surface of the metal roller;
• and
• a gearbox provided between the metal member and the driving device;
• wherein the metal member is located within a magnetic field of the magnetic member;
• either one or both the metal member and the magnetic member is drivable by the driving device to make the metal member and the magnetic member move relative to each other;
• and
• wherein the gearbox comprises an input shaft and an output shaft;
• the input shaft is connected to the driving device, and the output shaft is connected to the metal member for synchronous rotation with the metal member and the gearbox.