Provided are first and second mutually rotatable elements and a bearing arrangement associated therewith including at least one single film-like chamber formed between the first and second elements, a number of fluid injectors for injecting fluid into the hydraulic chamber and a control device for separately controlling the pressure of the fluid injected by the injectors depending at least on loads on the first element or the second element. A driving device is also provided for driving at least one of the elements in rotation, including hydraulic chambers which volume is defined by the relative position of the first and second elements and a pump device for filling the chamber with fluid to rotate the elements.