The composition, structure characteristics and suspension pattern of a
driving-braking unit system used in high speed power bogie with double hollow axles is
analyzed in this paper. During the process of motion, the relative movement between
the unit and its adjacent components is analyzed and calculated in detail. It is proved
that this new type of driving-braking system can satisfy the kinematical requirements of
the high-speed power bogies, with the body suspension of the driving motor being
achieved.