Abstract: The present invention discloses a connecting rod type two-level locking device, a hopper car bottom door and a hopper car, and belongs to the technical field of rail wagons. The connecting rod type two-level locking device includes a transmission shaft, a door opening arm, a first roller, a second roller, a first locating pin, a standstill locking disk and a linkage mechanism. The hopper car bottom door includes the connecting rod type two-level locking device. The hopper car includes the bottom door. Even if the connecting rod type two-level locking device is accidentally stressed, the linkage mechanism cannot rotate, and at this time, the slave arm cannot rotate neither. The accidental opening of the hopper car bottom door can be avoided. The hopper car is more reliable to use.

Abstract: The present invention discloses a connecting rod type two-level locking device, a hopper car bottom door and a hopper car, and belongs to the technical field of rail wagons. The connecting rod type two-level locking device includes a transmission shaft, a door opening arm, a first roller, a second roller, a first locating pin, a standstill locking disk and a linkage mechanism. The hopper car bottom door includes the connecting rod type two-level locking device. The hopper car includes the bottom door. Even if the connecting rod type two-level locking device is accidentally stressed, the linkage mechanism cannot rotate, and at this time, the slave arm cannot rotate neither. The accidental opening of the hopper car bottom door can be avoided. The hopper car is more reliable to use.

Abstract: The present invention discloses a two-level locking device, a hopper car bottom door and a hopper car. The device includes a first transmission shaft, a second transmission shaft, a clutch, a pressure mechanism and a reset mechanism, wherein under the pressure action of the pressure mechanism, the clutch separates the first transmission shaft from the second transmission shaft, and under the action of the reset mechanism, the clutch joints the first transmission shaft with the second transmission shaft. The bottom door includes the device. The hopper car includes the bottom door. By adopting the device, when the clutch is accidently separated by the pressure action of the pressure mechanism, the reset mechanism can re-joint the clutch to prevent the accidental rotation of the first transmission shaft and the second transmission shaft. By adopting the bottom door, the hopper car bottom door opened and closed by a planar four-bar linkage passing a dead point is more reliable to use.

Abstract: The present invention discloses a connecting rod type two-level locking device, a hopper car bottom door and a hopper car, and belongs to the technical field of rail wagons. The connecting rod type two-level locking device includes a transmission shaft, a door opening arm, a first roller, a second roller, a first locating pin, a standstill locking disk and a linkage mechanism. The hopper car bottom door includes the connecting rod type two-level locking device. The hopper car includes the bottom door. Even if the connecting rod type two-level locking device is accidentally stressed, the linkage mechanism cannot rotate, and at this time, the slave arm cannot rotate neither. The accidental opening of the hopper car bottom door can be avoided. The hopper car is more reliable to use.

Abstract: The present invention discloses a two-level locking device, a hopper car bottom door and a hopper car. The device includes a first transmission shaft, a second transmission shaft, a clutch, a pressure mechanism and a reset mechanism, wherein under the pressure action of the pressure mechanism, the clutch separates the first transmission shaft from the second transmission shaft, and under the action of the reset mechanism, the clutch joints the first transmission shaft with the second transmission shaft. The bottom door includes the device. The hopper car includes the bottom door. By adopting the device, when the clutch is accidently separated by the pressure action of the pressure mechanism, the reset mechanism can re-joint the clutch to prevent the accidental rotation of the first transmission shaft and the second transmission shaft. By adopting the bottom door, the hopper car bottom door opened and closed by a planar four-bar linkage passing a dead point is more reliable to use.

Abstract: A wheel truck, including: a front wheel pair assembly and a rear wheel pair assembly, two side frame assemblies, two spring suspension devices, and a bolster assembly. The spring suspension devices include a bearing spring unit, a damping spring, and a wedge. The wedge includes a primary friction surface and a secondary friction surface. The primary friction surface is attached to a column surface of the side frame assembly. The secondary friction surface is attached to an inclined surface of the bolster assembly. The wedge has the following structure parameters: ?=16-30°, and ?<tg?<?+?1, in which a represents an included angle between the secondary friction surface and a vertical plane, ? represents a friction coefficient of the primary friction surface, and ?1 represents a friction coefficient of the secondary friction surface.

Abstract: A wheel truck for a railroad car, including: a front wheel pair assembly and a rear wheel pair assembly; two side frame assemblies, each side frame assembly including a square box and journal-box guides; two spring suspension devices; and a bolster assembly including two ends disposed on the two spring suspension devices, respectively. The bolster assembly includes a pilot hole in the center and two mounting holes on the two ends, the pilot hole is rotationally matched with a cylindrical upper center plate of a car body for transmitting vertical and horizontal forces from the car body, and the two mounting holes are disposed above the two spring suspension devices, respectively. Each mounting hole receives a lower side bearing, and the lower side bearing is matched with a corresponding upper side bearing disposed on each side of the car body for transmitting the vertical load from the car body.

Abstract: A lower side bearing for a wheel truck, including: a first friction board, a second friction board, an inner pedestal, a bearing sleeve sleeving the inner pedestal, a pressure block, a pressure plate, and an elastic component. The pressure block is disposed on an upper part of the inner pedestal, and the second friction board is disposed on a top of the pressure block. The pressure plate is disposed on an upper part of the bearing sleeve, and the first friction board is disposed on a top of the pressure plate. A friction coefficient ?k of the first friction board and a friction coefficient ?z of the second friction board meet the relation: ?k>?z. The elastic component is disposed between the inner pedestal and the bearing sleeve for controlling a relative position of the inner pedestal and the bearing sleeve.