Coupling device for a heating, cooling and/or ventilation system

The device has two units (5, 6), each with an engaging segment. The segments in a plane are presented angularly with constant spacing relative to axles (10, 11) of one unit, and the segments in parallel, curved and discontinuous planes are presented angularly in direction opposite relative to the axles of the other unit to modify direction of rotation and/or angular velocity of one unit at constant angular velocity of other unit. An independent claim is also included for a use of a coupling device on a heating, ventilation and/or air-conditioning system.