The invention relates to a heavy-load fast
railway freight car bogie with a mechanically suspended type secondary suspension device, and belongs to the technical field of design and manufacturing of railway vehicles. The heavy-load fast
railway freight car bogie aims to ensure that a vehicle has good running stability, curve passability and an anti-snake-shape ability during linear and curved running, and to effectively reduce wheel-
rail wear and operation and maintenance costs. The mechanically suspended type secondary suspension device is composed of a positive stiffness unit and a negativestiffness unit; the positive stiffness unit provides vertical, longitudinal and
transverse stiffness for traditional secondary suspension springs; and the
negative stiffness unit is composed of a horizontal spring, a vertical guide rod, rolling shaft rods, bearings, sliding block sliding rails, a linear bearing and the like, the unit mechanism can maintain free sliding in longitudinal and transverse directions, and only provides the vertical
negative stiffness characteristic, and the
negative stiffness unit mechanism is in spherical hinge connection with a vehicle body so as to ensure that thevehicle body has
six degrees of freedom of extending and retracting, transverse moving, ascending and descending, lateral rolling, diving and swinging. Better
vibration isolation performance is achieved, and the mechanically suspended type
bogie can improve vertical stationarity of vehicle linear running to a great extent and improve transverse stationarity of vehicle running.