Patent ID: 11879549
Assignee: NIPPON PILLAR PACKING CO., LTD.
Field: Mechanical elements (Mechanical engineering)
Classification: CPC F | IPC F

Claim 0:
1. A rotary joint comprising:
a tubular case body in which a plurality of outer flow passages is formed by opening on an inner circumferential side, a sealed fluid flowing through the outer flow passages;
a shaft body relatively rotatably provided in the case body, a plurality of inner flow passages through which a sealed fluid flows being formed therein by opening on an outer circumferential side; and
a plurality of mechanical seal devices disposed side by side in an axial direction in an annular space formed between the case body and the shaft body,
wherein each of the mechanical seal devices includes
a first case side seal ring attached to the case body,
a first shaft side seal ring attached adjacent to one side of the first case side seal ring in the axial direction in the shaft body to slide relative to the first case side seal ring,
a second shaft side seal ring attached adjacent to one side of the first shaft side seal ring in the axial direction in the shaft body, and
a second case side seal ring attached adjacent to one side of the second shaft side seal ring in the axial direction in the case body to slide relative to the second shaft side seal ring,
the first shaft side seal ring and the second shaft side seal ring have contact surfaces facing in the axial direction and coming into direct contact with each other,
a groove for forming a communication flow passage connecting one of the outer flow passages and one of the inner flow passages is formed on at least one of the both contact surfaces of the first shaft side seal ring and the second shaft side seal ring, and
the groove is formed on each of the both contact surfaces.