Rotary joint

Patent metadata

Field	Value
Publication number	US-10655741-B2
Application number	US-201715656608-A
Country	US
Kind code	B2
Filing date	Jul 21, 2017
Priority date	Aug 24, 2016
Publication date	May 19, 2020
Grant date	May 19, 2020

Abstract

A rotary joint includes a tubular case body, an outer cylinder body provided to be relatively rotatable inside the case body, an inner shaft body provided to be relatively rotatable inside the outer cylinder body, a first mechanical seal for forming flow passages that connect a first flow passage of the case body and a second flow passage of the outer cylinder body to each other by dividing a first annular space formed between the case body and the outer cylinder body, and a second mechanical seal for forming flow passages that connect a third flow passage of the outer cylinder body and a fourth flow passage of the inner shaft body to each other by dividing a second annular space formed between the outer cylinder body and the inner shaft body.

First claim

The invention claimed is:

1. A rotary joint comprising:
a tubular case body in which a first flow passage, open on an inner circumferential side of the tubular case body, is formed;
an outer cylinder body provided to be relatively rotatable inside the tubular case body, wherein a second flow passage, open on an outer circumferential side of the outer cylinder body, and a third flow passage, open on an inner circumferential side of the outer cylinder body, are formed in the outer cylinder body;
an inner shaft body provided to be relatively rotatable inside the outer cylinder body, a fourth flow passage, open on an outer circumferential side of the inner shaft body, is formed in the inner shaft body;
a first mechanical seal provided in a first annular space formed between the tubular case body and the outer cylinder body to form a first connecting flow passage that connects the first flow passage and the second flow passage to each other by dividing the first annular space;
a second mechanical seal provided in a second annular space formed between the outer cylinder body and the inner shaft body to form a second connecting flow passage that connects the third flow passage and the fourth flow passage to each other by dividing the second annular space;
a first communication path formed using a part of the first mechanical seal to allow communication between a first sealing liquid region and a first opening of a through-hole disposed on one end side of the through-hole; and
a second communication path formed using a part of the second mechanical seal to allow communication between a second sealing liquid region and a second opening of the through-hole disposed on an other end side of the through-hole,
wherein the first sealing liquid region, in which a sealing liquid is supplied between the first mechanical seal and the tubular case body, is formed in the first annular space,
the second sealing liquid region, in which a sealing liquid is supplied between the second mechanical seal and the inner shaft body, is formed in the second annular space, and
the through-hole penetrates the outer cylinder body in a radial direction from an outer circumferential surface of the outer cylinder body to an inner circumferential surface of the outer cylinder body.

2. The rotary joint according to claim 1 ,
wherein a plurality of first mechanical seals is provided in an axial direction of the first annular space, and
a plurality of second mechanical seals is provided in an axial direction of the second annular space.

3. The rotary joint according to claim 1 , further comprising
a connection body connected to one axial end portion of the inner shaft body and the tubular case body.

Assignees

• Nippon Pillar Packing

Inventors

• Suzuki Osamu
• OKUMURA Junya

Classifications

• F16L39/06 Primary

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

• F16K11/085 Primary

  with cylindrical plug · CPC title

• F16L39/04

  allowing adjustment or movement · CPC title