A hub planetary belt transmission, comprising: a platform body supporting a motor drive having a motor drive shaft; a distributing pulley at least indirectly attached to the motor drive shaft; a collecting pulley attached to a first output shaft; said first output shaft being at least indirectly connected to a first propulsion element (40, 44); two or more distributing belts coupled to the distributing pulley from mutually opposite radial directions; two or more collecting belts coupled to the collecting pulley from mutually opposite radial directions; four or more transmitting pulleys (12, 14) arranged in two or more concentric pairs located around the distributing pulley and the collecting pulley and coupled to the distributing pulley and the collecting pulley via the distributing belts and the collecting belts, respectively; two or more peripheral shafts supporting said two or more pairs of transmitting pulleys (12, 14) by ball bearings (46, 48), and coupled to two or more tension arms; said concentric pairs of transmitting pulleys (12, 14) being driven by the distributing belts for rotating together with peripheral shafts, ball bearings and tension arms about a common axis of the distributing and the collecting pulleys so that when thus driven the transmitting pulleys (12, 14) create a centripetal force which stretches the distributing belts and the collecting belts, thus regulating the coupling force between said belts and said pulleys based on the rotation velocity, and characterized by a hub planetary belt transmission housing concentrically rotatable about a common axis of the distributing and the collecting pulleys, said housing being at least indirectly attached to the peripheral shafts and constituting a second output shaft at least indirectly connected to a second propulsion element (42, 45). a platform body supporting a motor drive having a motor drive shaft; a distributing pulley at least indirectly attached to the motor drive shaft; a collecting pulley attached to a first output shaft; said first output shaft being at least indirectly connected to a first propulsion element (40, 44); two or more distributing belts coupled to the distributing pulley from mutually opposite radial directions; two or more collecting belts coupled to the collecting pulley from mutually opposite radial directions; four or more transmitting pulleys (12, 14) arranged in two or more concentric pairs located around the distributing pulley and the collecting pulley and coupled to the distributing pulley and the collecting pulley via the distributing belts and the collecting belts, respectively; two or more peripheral shafts supporting said two or more pairs of transmitting pulleys (12, 14) by ball bearings (46, 48), and coupled to two or more tension arms; said concentric pairs of transmitting pulleys (12, 14) being driven by the distributing belts for rotating together with peripheral shafts, ball bearings and tension arms about a common axis of the distributing and the collecting pulleys so that when thus driven the transmitting pulleys (12, 14) create a centripetal force which stretches the distributing belts and the collecting belts, thus regulating the coupling force between said belts and said pulleys based on the rotation velocity, and characterized by a hub planetary belt transmission housing concentrically rotatable about a common axis of the distributing and the collecting pulleys, said housing being at least indirectly attached to the peripheral shafts and constituting a second output shaft at least indirectly connected to a second propulsion element (42, 45).