7. the cylinder body adopts 3 + 3 + 3 + 3 + 3 + 3 six section and whole pipe bearing structure. The support frame at the entrance of pay off is supported by double row roller self-aligning bearing, and a set of thrust bearing is added at the same time to ensure the bearing capacity of the axial movement of the cylinder body. The middle and outlet ends are supported by two groups of large bearings, which are flange butted and equipped with bearing core connecting pipe body, which is convenient for maintenance and disassembly. The large bearings are new Oil and gas lubrication: oil is supplied by single oil pump motor, thin oil lubrication, labyrinth seal, with dual functions of lubrication and temperature reduction. Oil is stored in the inner cavity of bearing pedestal, without single oil tank, covering a small area, and working condition is clean.