Abstract: A railway freight car bogie includes a side frame, a bolster and a friction damper. The friction damper includes a wedge, a constant friction damping spring, a variable friction damping spring and an ejector rod. The variable friction damping spring in the middle and below the wedge is deviated at a distance in a direction away from a center of the bolster with respect to damping springs at two sides of the variable friction damping spring. An axis of each of the constant friction damping spring and the ejector rod is coincident with an axis of the variable friction damping spring in the middle and below the wedge. The bogie not only has an ideal relative friction coefficient in both an unloaded condition and a loaded condition, a large diamond resistant rigidity, a better vertical dynamics performance and a better transverse dynamics performance.

Abstract: A railway freight car bogie includes a side frame, a bolster and a friction damper. The friction damper includes a wedge, a constant friction damping spring, a variable friction damping spring and an ejector rod. The variable friction damping spring in the middle and below the wedge is deviated at a distance in a direction away from a center of the bolster with respect to damping springs at two sides of the variable friction damping spring. An axis of each of the constant friction damping spring and the ejector rod is coincident with an axis of the variable friction damping spring in the middle and below the wedge. The bogie not only has an ideal relative friction coefficient in both an unloaded condition and a loaded condition, a large diamond resistant rigidity, a better vertical dynamics performance and a better transverse dynamics performance.

Abstract: A central suspension device, a wagon bogie and an express railway wagon, wherein the central suspension device is arranged between a frame and a bolster of the wagon bogie and comprises a rubber-metal pad spring group composed of at least two rubber-metal pad springs, a bottom end of each rubber-metal pad spring is connected with the frame, a top end of at least one rubber-metal pad spring of the rubber-metal pad spring group is connected with the bolster, and a gap exists between the top end of at least one rubber-metal pad spring and the bolster. The central suspension device has multiple stages of rigidities in the transverse and vertical directions, so that the different rigidities can be mutually shifted conveniently on the empty vehicle condition and the heavy-load condition of the vehicle, therefore, the central suspension device is applicable to express railway vehicles for safe and stable running.

Abstract: A central suspension device, a wagon bogie and an express railway wagon, wherein the central suspension device is arranged between a frame and a bolster of the wagon bogie and comprises a rubber-metal pad spring group composed of at least two rubber-metal pad springs, a bottom end of each rubber-metal pad spring is connected with the frame, a top end of at least one rubber-metal pad spring of the rubber-metal pad spring group is connected with the bolster, and a gap exists between the top end of at least one rubber-metal pad spring and the bolster. The central suspension device has multiple stages of rigidities in the transverse and vertical directions, so that the different rigidities can be mutually shifted conveniently on the empty vehicle condition and the heavy-load condition of the vehicle, therefore, the central suspension device is applicable to express railway vehicles for safe and stable running.