A vibrating shaft assembly has a magnetic compensation system for its rotating shaft for reducing the dynamic loads on the shaft bearings. The magnetic support system includes a radially magnetized permanent arc magnet which has an outward facing magnetic pole face and which is circumferentially affixed to the heavy side of the shaft at least one axial location along the shaft; it also has a stationary magnet, such as a permanent ring magnet or an electromagnet, external to the shaft for providing a magnetic pole face that surrounds the shaft in opposition to and concentric with the pole face of the shaft's arc magnet. The opposing pole faces of the stationary magnet and the arc magnet are of the same magnetic polarity such that, as the shaft and thus the permanent magnet on the heavy side of the shaft rotates, a constant radial repelling force is exerted on the heavy side of the shaft which counteracts the centrifugal force produced by the shaft's unbalanced mass.