It has cylinder body, cylinder body ends has cylinder head, two cylinder head Center has sleeve axis, sleeve axis end has round board type bushings, and axis head, sleeve axis another end has round board type bushings, and sliding ring, and sliding block, cylinder body of subject is ends opened hole of casting metal cylindrical shaped tube body, casting metal cylindrical shaped tube body wall Middle axis to uniform has electric components fixed cavity, in electric components fixed cavity within has electric components, casting metal cylindrical shaped tube body wall outside side and inside respectively has outside tube and lining tube, Both ends of the sleeve with sleeve with openings at both ends of the circular plate cast metal cylindrical shell ring-shaped end cap by more than one unit is connected at both ends fixed