Cryo-rotary joint

A cryo-rotary joint comprising:

• a rotating-machine housing;
• a refrigerant tube configured to be non-rotating, installed within the rotating-machine housing, connected at one end to an external refrigerant source, communicated at the other end with a target part of a rotating machine, and adapted to allow a refrigerant to pass inside;
• a rotating member installed within the rotating-machine housing, loosely fitted inside with the refrigerant tube, and configured to be rotatable together with a rotary part of the rotating machine by being fixed at one end to the rotary part;
• and
• a relatively rotating member configured to be cylindrical in shape and coaxial with the refrigerant tube and the rotating member and equipped with a fixed-side member fixed to the rotating-machine housing and a rotating-side member rotatably disposed inside the fixed-side member,
• the fixed-side member of the relatively rotating member being connected to the refrigerant tube via a refrigerant tube extension section,
• the rotating-side member of the relatively rotating member being connected to the rotating member via a rotating member extension section,
• a space between the refrigerant tube and the rotating member as well as a space between the refrigerant tube extension section and the rotating member extension section being communicated with a gap between the fixed-side member and rotating-side member of the relatively rotating member to form a refrigerant zone,
• a sealing member being positioned to seal between adjacent surfaces of the fixed-side member and the rotating-side member of the relatively rotating member, and
• a vacuum chamber and a pressure chamber being defined within the housing by a peripheral wall of the refrigerant tube, the refrigerant tube extension section, and the fixed-side member of the relatively rotating member with the refrigerant zone between the refrigerant tube extension section and the rotating member extension section being thermally insulated by the vacuum chamber.

A cryo-rotary joint comprising:

• a housing;
• a refrigerant tube configured to be non-rotating, installed within the housing, connected at one end to an external refrigerant source, communicated at the other end with a target part in a rotating machine, and adapted to allow a refrigerant to pass inside;
• a rotating member installed within the housing, loosely fitted inside with the refrigerant tube, and configured to be rotatable together with a rotary part of the rotating machine by being fixed at one end to the rotary part;
• and
• a relatively rotating member configured to be cylindrical in shape and coaxial with the refrigerant tube and the rotating member and equipped with a fixed-side member fixed to an inner surface of the housing and a rotating-side member rotatably disposed inside the fixed-side member,
• the fixed-side member of the relatively rotating member being connected to the refrigerant tube via a refrigerant tube extension section,
• the rotating-side member of the relatively rotating member being connected to the rotating member via a rotating member extension section,
• a space between the refrigerant tube and the rotating member as well as a space between the refrigerant tube extension section and the rotating member extension section being communicated with a gap between the fixed-side member and rotating-side member of the relatively rotating member to form a refrigerant zone,
• a sealing member being installed between the fixed-side member and rotating-side member of the relatively rotating member, and the sealing member comprising a magnetic fluid sealing member, and
• a vacuum chamber and a pressure chamber being defined within the housing by a peripheral wall of the refrigerant tube, the refrigerant tube extension section, and the fixed-side member of the relatively rotating member with the refrigerant zone between the refrigerant tube extension section and the rotating member extension section being thermally insulated by the vacuum chamber.