MULTIPLE FLOW PASSAGE TYPE ROTARY JOINT

PROBLEM TO BE SOLVED: To provide a multiple flow passage type rotary joint which seals relative rotating parts in multiple passages properly without variation.SOLUTION: The multiple flow passages 5, which are communicated with each other via connection spaces 4 formed sectionally by seal means 3, are formed between a case body 1 and a rotary shaft body 2. Each seal member 3 consists of a pair of seal rings 11 which are made of inelastic material fixed on the outer circumferential part of the rotary shaft body 2, and annular seal members 12 which are made of elastic material fitted and retained on the inner circumferential part of the case body 1. The annular seal member 12 have a pair of annular lips 17 which are pressed to contact both of seal rings 11. The connection spaces 4 sealed by a pair of seal rings 11 and the lips 17 are formed between the facing circumferential surfaces of the annular seal members 12 and the rotary shaft body 2. Each flow passage 5 is a series of structure made up of a fixed side passage 21 that penetrates the connection space 4, the case body 1, and the annular seal member 12, and a rotary side passage 22 that penetrates the rotary shaft body 2.