Rotary joint

Patent metadata

Field	Value
Publication number	US-11953137-B2
Application number	US-201816978383-A
Country	US
Kind code	B2
Filing date	Dec 12, 2018
Priority date	Mar 6, 2018
Publication date	Apr 9, 2024
Grant date	Apr 9, 2024

Abstract

A rotary joint capable of lubricating a sealing surface of a mechanical seal forming a fluid passage through which a gas flows using a liquid even when the liquid flows through only one fluid passage is disclosed. A rotary joint includes a plurality of mechanical seals provided in an axial direction in an annular space between a case body and a shaft body to form a first intermediate flow passage that connects a first outer flow passage and a first inner flow passage of a first fluid passage through which a liquid flows to each other and form a second intermediate flow passage that connects a second outer flow passage and a second inner flow passage of a second fluid passage through which a gas flows to each other.

First claim

The invention claimed is:

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.

2. The rotary joint according to claim 1 ,
wherein the first intermediate flow passage includes
a first annular flow passage formed using some of the plurality of mechanical seals in the annular space to communicate with the opening of the first outer flow passage,
a second annular flow passage formed using some other mechanical seals among the plurality of mechanical seals in the annular space to communicate with the opening of the first inner flow passage, and
a connecting flow passage connecting the first annular flow passage and the second annular flow passage to each other.

3. The rotary joint according to claim 1 ,
wherein a plurality of second outer flow passages is formed in the axial direction in the case body,
the same number of second inner flow passages as the number of second outer flow passages are formed in the shaft body,
the plurality of mechanical seals includes a mechanical seal that forms the second intermediate flow passage connecting the second outer flow passages and the second inner flow passages one by one in the annular space to configure a plurality of second fluid passages,
the first outer flow passage and the first inner flow passage are open at mutually different positions in the axial direction with the plurality of second intermediate flow passages interposed therebetween, 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 seal forming the plurality of second intermediate flow passages.

4. The rotary joint according to claim 3 ,
wherein the first intermediate flow passage includes
a first annular flow passage formed using some of the plurality of mechanical seals in the annular space to communicate with the opening of the first outer flow passage,
a second annular flow passage formed using some other mechanical seals among the plurality of mechanical seals in the annular space to communicate with the opening of the first inner flow passage, and
a connecting flow passage connecting the first annular flow passage and the second annular flow passage to each other, and
the connecting flow passage includes
a third annular flow passage formed using the mechanical seal forming the plurality of second inner flow passages between the first annular flow passage and the second annular flow passage of the annular space, and
a plurality of flow passage holes formed in the case body to connect the first annular flow passage and the second annular flow passage through the third annular flow passage.

5. The rotary joint according to claim 3 ,
wherein the first outer flow passage is a supply flow passage that supplies a liquid into the case body from an outside,
the first inner flow passage is a discharge flow passage that discharges a liquid from an inside of the shaft body to an outside, and
the case body and the shaft body are disposed with the axial direction as a vertical direction such that the opening of the first outer flow passage is located below the opening of the first inner flow passage.

6. The rotary joint according to claim 5 ,
wherein a third inner flow passage serving as a supply flow passage that supplies a liquid into the shaft body from the outside is formed in the shaft body to open on an outer circumferential side,
a third outer flow passage serving as a discharge flow passage that discharges a liquid from the inside of the case body to the outside is formed in the case body to open on an inner circumferential side,
the plurality of mechanical seals includes a mechanical seal that forms a third intermediate flow passage connecting the third outer flow passage and the third inner flow passage to each other in the annular space to configure a third fluid passage, and
the third inner flow passage is open at a position on an upper side of the opening of the first inner flow passage in the axial direction in the shaft body.

7. The rotary joint according to claim 6 , wherein a branch flow passage branching from an intermediate portion of the third inner flow passage and communicating with an upper end portion of the third intermediate flow passage in the axial direction is formed in the shaft body.

8. The rotary joint according to claim 1 ,
wherein the opening of the first outer flow passage communicates with the first intermediate flow passage alone, and
the opening of the first inner flow passage communicates with the first intermediate flow passage alone.

Assignees

• Nippon Pillar Packing

Inventors

• Kikuyama Yoshinori
• Suzuki Osamu
• Nishi Takashi

Classifications

• F16L39/04 Primary

  allowing adjustment or movement · CPC title

• F16J15/324 Primary

  Arrangements for lubrication or cooling of the sealing itself · CPC title

• F16J15/3452

  the pressing force resulting from the action of a spring · CPC title

• B24B55/02

  Equipment for cooling the grinding surfaces, e.g. devices for feeding coolant (cooling or lubricating during dressing operation B24B53/095; incorporated in grinding wheels B24D) · CPC title

• F16L39/06 Primary

  of the multiline swivel type, e.g. comprising a plurality of axially mounted modules · CPC title