Two-tube rotary joint for cooling rolls

A double-tube type rotating joint for cooling roller is characterized in that: sealing parts(8) have a mechanical sealing device(8') which consists of a moving ring(8a'), a static ring(8b'), a static ring seat(8c') and a compression spring(8d'); the moving ring (8a') is inlayed at the end of a rotating shaft; the static ring(8b'), the static ring seat(8c') and the compression spring(8d') are successively arranged between the moving ring(8a') and the left end of a casing(2). Compared with the present technology, the plan has the following outstanding advantages: 1) compared the sealing method having mechanical sealing device with the simple static sealing structure of O type sealing ring, the sealing is more reliable, the leaking quantity is small and the service life is long. 2) that adopting rolling shaft to replace graphite sliding bearing can improve rotating speed and can be matched and used with rollers of different rotating speed requirements, which enlarges the using range.