Patent ID: 8113545

Claim:
A rotary joint circulating supply fluid without leaking said supply fluid outside a fluid passage upon relative rotation of a fluid passage in a housing as a fixed part and a fluid passage in a sleeve joined to a rotary shaft to rotate together with said rotary shaft, in which said supply fluid does not intrude into a joining portion between said sleeve and said rotary shaft, said fluid passage being formed inside said sleeve, the rotary joint comprising: said housing having said fluid passage through which said supply fluid flows; a partition ring fitted in an inner circumferential surface of said housing, said partition ring being provided with a communicatively connecting fluid passage forming a part of said fluid passage; the sleeve being made from a rustless material, the sleeve having a second connecting fluid passage therein through which said supply fluid from said fluid passage in said housing flows, and having an inner circumferential surface that is fitted onto an outer circumferential surface of said rotary shaft; a rotary seal ring having: an inner circumferential surface fitted onto an outer circumferential surface of said sleeve; a first connecting fluid passage passing through said inner circumferential surface to communicatively connect said second connecting fluid passage and said communicatively connecting fluid passage; a first sealing surface on one side surface, and a second sealing surface on other side surface; a first stationary seal ring having a first counterpart sealing surface contacting said first sealing surface, and hermetically held by said fixed part; and a second stationary seal ring having a second counterpart sealing surface contacting said second sealing surface; hermetically held by said fixed part.