Patent ID: 11953137
Assignee: NIPPON PILLAR PACKING CO., LTD.
Field: Mechanical elements (Mechanical engineering)
Classification: CPC F  B | IPC B  F

Claim 0:
1. A rotary joint comprising a first fluid passage through which a liquid flows and a second fluid passage through which a gas flows, the rotary joint further comprising:
a tubular case body formed by each of a first outer flow passage through which a liquid flows and a second outer flow passage through which a gas flows opening on an inner circumferential side;
a shaft body provided to be relatively rotatable in the case body and formed by each of a first inner flow passage through which a liquid flows and a second inner flow passage through which a gas flows opening on an outer circumferential side; and
a plurality of mechanical seals provided in an axial direction in an annular space between the case body and the shaft body to form a first intermediate flow passage that connects the first outer flow passage and the first inner flow passage to each other and configure the second fluid passage by forming a second intermediate flow passage that connects the second outer flow passage and the second inner flow passage to each other,
wherein each of the mechanical seals includes a first seal ring which is attached to the case body and on which a first sealing surface is formed, and a second seal ring which is attached to the shaft body and on which a second sealing surface coming into sliding contact with the first sealing surface is formed,
the first fluid passage includes the first outer flow passage and the first inner flow passage opening at mutually different positions in the axial direction with the second intermediate flow passage interposed therebetween, and the first intermediate flow passage connecting an opening of the first outer flow passage and an opening of the first inner flow passage to each other, and
the first intermediate flow passage is formed such that a liquid flowing through the first intermediate flow passage lubricates first and second sealing surfaces of the mechanical seals forming the second intermediate flow passage.