The invention provides a rotationally lubricating type sealing
brake cylinder for railway vehicles, which comprises a cylinder body and a
front cover assembly, wherein a
piston and a
piston rod are arranged inside the cylinder body, a sealing ring and a lubricating sleeve are arranged on the outer wall of the
piston, a release spring is arranged between the bottom of the piston and the
front cover assembly, the
piston rod sticks out of the
front cover assembly, a guiding ring is fixed on the inner wall of the ring slot in the top of the piston, a guiding sleeve is arranged on the inner side of the guiding ring, a reset spring is arranged between the guiding sleeve and the ring slot of the top of the piston, and a guiding base is fixed at the bottom of the cylinder body; and the guiding ring and the guiding sleeve form a screw rotation mechanism, the guiding sleeve and the guiding base form a
clutch mechanism, the reset spring and the release spring form a
clutch control mechanism, so as to enable the piston to rotate in only one direction under the action of the three mechanisms, the lubricating
grease deposited at the bottom of the cylinder body is brought to mid-upper part of the cylinder body, the
grease is pasted on the inner wall of the cylinder body uniformly, uniform lubricating of the piston sealing ring is guaranteed, and harmful or leaking faults are avoided. The rotationally lubricating type sealing
brake cylinder provided by the invention has a simple structure, is small in revamping
workload, and does not affect the basic performance of the conventional braking device of the vehicle.