JP4587354B2

JP4587354B2 - Rotary joint for high pressure water

Info

Publication number: JP4587354B2
Application number: JP2001127007A
Authority: JP
Inventors: 幸明永田; 博義徳本; 征夫三辺
Original assignee: Sugino Machine Ltd
Current assignee: Sugino Machine Ltd
Priority date: 2001-04-25
Filing date: 2001-04-25
Publication date: 2010-11-24
Anticipated expiration: 2021-04-25
Also published as: JP2002323185A

Description

【０００１】
【発明の属する技術分野】
本発明は、主軸の両端部で管材同士を接続して一方の管材から他方の管材へ高圧水を導く高圧水用回転継手に関するものである。
【０００２】
【従来の技術】
図３は、従来の高圧水用回転継手の概略構成を示す断面図である。高圧水用回転継手は、筒状本体部（ボディ）３０４と、筒状本体部の中空部内に設けられて高圧水の流路となる貫通孔を有する主軸（ロータ）３０１と、筒状本体部３０４の中空部内周壁に設けられ回転する主軸３０１の先端部外周面と摺接する固定シール部（シールパッキン）３０２とを主に備えている。従来の高圧水用回転継手においては、主軸３０１の回転時に主軸先端が振れると、主軸先端と固定シール部３０２との間に隙間が生じてシール性の低下を招いたり、主軸先端の振れにより固定シール部３０２に過剰な力が作用することにより固定シール部３０２の早期摩耗を招いてしまうことから、固定シール部３０２と摺接する主軸の回転シール部３０１ａと、主軸の回転軸受部３０１ｂとを同芯削り出し加工して、主軸を一体形成していた。
【０００３】
また、主軸には耐食性が求められているため主軸の材質として耐食性に優れたＳＵＳ鋼を使用しているが、ＳＵＳ鋼は軟質で耐摩耗性に劣る。このため、従来の高圧水用回転継手では、主軸の中で固定シール部との接触部となる回転シール部３０１ａに特殊コーティングを施して、耐摩耗性を高くしている。
【０００４】
【発明が解決しようとする課題】
このように従来の高圧水用回転継手では、回転軸受部３０１ｂと回転シール部３０１ａとが一体形成されているので、回転シール部が摩耗した場合に主軸ごと交換する必要がある。しかし、主軸を交換する場合には筒状本体全体を分解しなければならず、実際の作業現場においてこのような分解作業を行うことは困難である。また、主軸は高価なため、回転シール部分の摩耗のためだけに主軸全体の交換を行うとすると、ランニングコストが高くなってしまう。
【０００５】
また、主軸には耐食性が要求されるため主軸として使用する材質はＳＵＳ鋼等に限定されてしまうが、限定された材質の中から固定シール部との摺接による損傷が生じないような固定シール部と相性のよい材質を必ずしも選択できるわけではない。このため、主軸の材質として固定シール部と相性の悪い素材を使用した場合には、主軸が損傷を受けやすく寿命が短くなってしまう。このため固定シール部を頻繁に交換する必要があり、これでは作業が煩雑になってしまう。一方、主軸の材質として固定シール部と相性の良い素材を使用した場合には、主軸の耐食性が悪化する場合もある。このように従来の高圧水用回転継手では、主軸の耐食性と固定シール部の接触部（回転シール部）との相性の良好性の両方を確保することができない場合があるという問題がある。
【０００６】
本発明はこのような問題点に鑑みてなされたものであり、シール部の交換作業等のメンテナンス作業を容易に行える高圧水用回転継手を提供することを主な目的とする。本発明の別の目的はランニングコストの低減を図ることができる高圧水用回転継手を提供することである。本発明の別の目的は、主軸の耐食性と回転シール部の固定シール部との相性の良好性を同時に確保できる高圧水用回転継手を提供することである。
【０００７】
【課題を解決するための手段】
上述の目的を達成するため、請求項１に係る発明は、筒状本体部と、高圧水の流路となる貫通孔を有し、筒状本体部の中空部で回転可能な主軸と、前記筒状本体部の中空部内周壁に設けられ、前記主軸に摺接する固定シール部とを備え、主軸の両端部で管材同士を接続して一方の管材から他方の管材へ高圧水を導く高圧水用回転継手において、前記主軸は、前記固定シール部に摺接する回転シール部と、回転シール部を高圧水出口側で受け入れて着脱可能に接合する回転軸受部とを別体で有するものであり、前記回転軸受部は、その軸心が前記回転シール部の軸心と一致するように前記回転シール部を受け入れるものであり、前記回転シール部の高圧水入口側端部の外径と高圧水出口側端部の外径が同一径であり、前記回転シール部は、熱伝導率が０．０２ｃａｌ／ｃｍ・ｓｅｃ・℃以上の熱伝導性材料で形成されており、前記回転シール部と前記回転軸受部との間隙に漏れた水を前記主軸外部へ導出する排出手段として、回転シール部の下部段差面と回転軸受部の上部段差面との間に生じている間隙からなる液溜め部と、回転シール部と固定シール部との間で形成される空間とを連通する水逃がし通路と、前記空間へ導出された水を外部へ排出する排出口と、を設けたことを特徴とする。
【０００８】
本発明では、主軸の回転軸受部と回転シール部とが別体で設けられているので、回転シール部に損傷等が生じた場合でも回転シール部のみを交換することが可能である。このため、主軸全体を交換する必要がある従来の高圧水用回転継手に比べて、交換作業等のメンテナンス作業を容易に行える。また、高価な主軸全体を交換する必要がないのでランニングコストの低減が図られる。
【０００９】
また、主軸の回転軸受部と回転シール部とが別体で設けられているので、回転軸受部を耐食性に優れた材質で構成する一方、固定シール部と接触する回転シール部を固定シール部との摺接による損傷が生じにくい固定シール部と相性のよい材質で構成することも可能となる。これにより主軸の損傷を防止しつつも固定シール部の煩雑な交換は不要となる。
【００１０】
また、回転軸受部と回転シール部が別体であるため夫々の軸心がずれてしまうおそれがあるが、本発明の回転軸受部はその軸心が回転シール部の軸心と一致するように回転シール部を受け入れるので、軸心のずれにより主軸先端が振れてしまうことを防止することができる。
【００１１】
回転軸受部がその軸心が回転シール部の軸心と一致するように回転シール部を受け入れるように構成するためには、回転シール部の中空部に回転軸受部をいわゆる印籠式に差し込む構成としたり、回転シール部の中空部内壁を先細りテーパ状に形成し、このテーパ状の中空部に主軸先端部を挿入するように構成することができるが、かかる構成に限定されるものではない。
【００１２】
更に、本発明では回転シール部の高圧水入口側端部の外径は、高圧水出口側端部の外径とほぼ同一径となっているので、高圧水の入口側と出口側の端面の面積はほぼ同一となる。このため、高圧水からの水圧による荷重が回転シール部の両端面に対して均衡を維持し、前記接合部に過度に作用することはない。また、回転シール部と回転軸受部との接合部に例えばねじ等を使用する場合でも、このように接合部には前記荷重が過度に作用しないため、接合部にサイズの小さなねじを使用した場合でも十分に荷重に耐えることができる。更に、接合部に過剰な荷重が作用しないため、高圧水の圧力変動により回転シール部と回転軸受部とが外れたり、回転シール部や回転軸受部が損傷することを防止できる。
【００１３】
本発明における回転軸受部は、回転シール部を高圧水出口側で受け入れて着脱可能に接合するものであればよく、その固定方法は任意の構成をとることができる。例えば、主軸の回転軸受部の回転シール部側先端部にねじ山を設ける一方、回転シール部の中空部内周壁にこのねじ山と螺合するねじ山を設け、回転軸受部を回転シール部の中空部内に締着させて固定するように構成することができる。そして、このねじ山を、その締まり方向が回転シール部中空部の回転方向となるように形成すれば、使用中に主軸、回転軸受部が回転シール部から容易に外れることを防止できるという利点がある。
【００１５】
本発明では、回転シール部の材質として高熱伝導性材料を使用しているので、主軸の回転により生じた熱が固定シール部にこもらずに、外部へ排出される。このような高熱伝導性材料としては、熱伝導率が０．０２ｃａｌ／ｃｍ・ｓｅｃ・℃以上で、かつ硬度が高い材質のものを用いることが好ましい。
【００１７】
固定シール部、Ｏ−リング等の部品の損傷や摩耗等により高圧水が主軸の貫通孔から回転シール部と回転軸受部との間隙に漏れてしまうと、回転シール部の高圧水入口側端部に対する水圧により生じる力よりも高圧水出口側端部に対する水圧により生じる力の方が大きくなり、回転シール部の両端面に対する水圧による力の均衡が崩れてしまう。即ち、間隙内に徐々に水が漏れていくと、漏れた水は間隙内で行き場を失ってしまうため、間隙内部に圧力が発生し、回転シール部と回転軸受部とを互いに離反するように作用する。このため、回転シール部と回転軸受部とが外れたり、回転シール部又は回転軸受部が損傷を受けやすくなる。しかし、本発明では、前記間隙に漏れた水を排出手段によって主軸外部へ排出することにより、間隙内部で生じた圧力を開放している。これによって回転シール部の両端面に対する水圧による力の均衡を維持し、回転シール部と回転軸受部とが外れたり、回転シール部または回転軸受部が損傷することをより確実に防止することができる。
【００１８】
本発明における排出手段は、回転シール部と回転軸受部との間隙に漏れた水を主軸外部へ導出するものであればよく、導出された水を更に筒状本体部外部へ排出するように構成することも可能である。また、このような排出手段は、筒状本体部、主軸のいずれに設けても良い。
【００１９】
【発明の実施の形態】
（第１実施形態）
本発明の好ましい実施形態について、以下図示例とともに説明する。第１実施形態の高圧水用回転継手は、高圧水を噴射する噴射ガンに組み込まれたものである。図１は、第１実施形態の高圧水用継手の主要部分の構成を示す部分断面図である。他の構成については図３に示す従来の回転継手と同様なので、図示及び説明を省略する。
【００２０】
本実施形態の高圧水用回転継手は、図１に示すように、筒状ボディ１１０と、主軸１０１と、ボディ１１０の中空部内壁に設けられた略環状のシールパッキン１１１とを主に備えている。ここで、筒状ボディ１１０は本発明における筒状本体部を、シールパッキン１１１は本発明における固定シール部をそれぞれ構成する。
【００２１】
シールパッキン１１１は、下方から貫通孔を有するパッキン押さえ部材１１３により図１の上下方向の移動を規制されている。
【００２２】
本実施形態の回転継手では、主軸１０１はそれぞれ別体の回転軸受部１０１ｂと回転シール部１０１ａとに２分割されており、回転軸受部１０１ｂと回転シール部１０１ａは互いに連通する貫通孔１０３ａ，１０３ｂが設けられ、これらの貫通孔１０３ａ，１０３ｂが高圧水の通路となっている。即ち、回転シール部１０１ａの上端が高圧水ホース（図示せず）に接続され、回転軸受部１０１ｂの下端が噴射ガンの高圧水噴射路（図示せず）に接続され、高圧水ホースから供給される高圧水を噴射ガンの噴射路へ導くようになっている。
【００２３】
また、主軸１０１の回転シール部１０１ａは回転軸受部１０１ｂと着脱可能となっている。回転シール部１０１ａの上部はパッキン押さえ部材１１３の貫通孔に回転可能な状態で挿入され、回転シール部１０１ａの上端部外周面がシールパッキン１１１と摺接し、シール性が確保されている。
【００２４】
また、回転シール部１０１ａは高硬度でかつ高熱伝導性の材料で形成されている。このため、主軸１０１の回転による回転シール部１０１ａのシールパッキン１１１に対する摺接により生じた熱は、シールパッキン１１１にこもらずに、外部へ排出され、また耐久性も確保される。
【００２５】
回転軸受部１０１ｂの上部には回転シール部１０１ａの突出部１０９により段差のある下部を印籠式にはめ込むための孔部が穿孔されている。この孔部は、その中心が回転シール部１０１ａの軸芯と一致する位置になるように設けられており、また挿入される回転シール部１０１ａの突出部１０９と段差に対応させた段差を形成し、各段差部分の内径は回転シール部１０１ａの突出の外径及び段差部分の外径とほぼ同一サイズとなっている。このため、回転軸受部１０１ｂの孔部に回転シール部１０１ａを差し込んだときに、回転シール部１０１ａの軸芯と回転軸受部１０１ｂの軸芯とが一致するような調芯構造となっている。このため、回転軸受部１０１ｂと回転シール部１０１ａとが別体であるにも拘わらず、主軸１０１先端の振れが確実に防止される。
【００２６】
回転シール部１０１ａの下部外周面には雄ねじ１０５が螺刻されており、回転軸受部１０１ｂの孔部内周面には回転シール部下部の雄ねじ１０５と螺合する雌ねじ（図示せず）が螺刻されている。このため、回転シール部１０１ａを回転軸受部１０１ｂに取り付ける場合には、回転シール部１０１ａの下部を回転軸受部１０１ｂの上部孔部に差し込んで更に締着することにより、回転シール部１０１ａと回転軸受部１０１ｂが確実に固定される。ここで、雄ねじ１０５と雌ねじとは、ねじの締まり方向が回転シール部１０１ａの回転方向と同一方向となるように形成されている。このため、主軸１０１の回転中に回転シール部１０１ａと回転軸受部１０１ｂに容易に緩みが生じない構造となっており、主軸１０１の振れが確実に防止される。
【００２７】
回転シール部１０１ａの高圧水入口側端部（上端部）の外径Ｄ_２は、回転シール部１０１ａの高圧水出口側端部（下端部）の外径Ｄ_１とほぼ同一径となっている。このため、回転シール部１０１ａの両端面の面積はほぼ等しくなり、高圧水の圧力による回転シール部上端部に対する力と下端部に対する水圧による力とが均衡を保った状態となり、かかる力による荷重が回転シール部１０１ａと回転軸受部１０１ｂの接合部である雄ねじ１０５と雌ねじとに過度に作用することはない。このため雄ねじ１０５と雌ねじのサイズを小さくした場合でも十分に荷重に耐えることができる。また、過剰な荷重が雄ねじ１０５と雌ねじに作用しないため、高圧水の圧力変動により、回転シール部１０１ａと回転軸受部１０１ｂとが外れたり、回転シール部１０１ａや回転軸受部１０１ｂに損傷を生じることが防止される。
【００２８】
また、本実施形態の高圧水用回転継手では、回転シール部１０１ａの下部段差面と回転軸受部１０１ｂの上部段差面との間に間隙（液溜め部１０８）が生じている。また、この間隙（液溜め部１０８）と、回転シール部１０１ａと固定シール部１１３との間で形成される空間Ａとを連通する２個の水逃がし通路１０７が回転シール部１０１ａの外縁付近に設けられている。ここで、水逃がし通路１０７は本発明の排出手段を構成する。
【００２９】
回転継手の使用中に、回転シール部１０１ａと回転軸受部１０１ｂとの接合部分をシーリングするパッキンに損傷や摩耗、あるいはＯ−リング等の部品に損傷が生じた場合、液溜め部１０８に噴射ガンの噴射路へ向かう高圧水が漏れてしまう場合がある。この場合、回転シール部１０１ａの高圧水入口側端部（上端部）に対する水圧による力よりも高圧水出口側端部（下端部）に対する水圧による力の方が大きくなり、回転シール部１０１ａの両端面に対する高圧水の水圧により生じる力の均衡が崩れてしまう。即ち、液溜め部１０８に徐々に水が漏れていくと、漏れた水は液溜め部１０８内で行き場を失ってしまうため、液溜め部１０８内部に圧力が発生し、この圧力は回転シール部１０１ａを押し上げ、かつ回転軸受部１０１ｂを押し下げるように（回転シール部１０１ａと回転軸受部１０１ｂとを互いに離反するように）作用する。このため、回転シール部１０１ａと回転軸受部１０１ｂとが外れたり、回転シール部１０１ａ又は回転軸受部１０１ｂが損傷を受けやすくなる。しかし、本実施形態の回転継手では、液溜め部１０８と空間Ａとを連通する水逃がし通路１０７を設けているので、液溜め部１０８に漏れた水を水逃がし通路１０７から前記空間Ａへ導出することにより、液溜め部１０８に生じた圧力を開放し、回転シール部１０１ａと回転軸受部１０１ｂとが外れたり、回転シール部１０１ａや回転軸受部１０１ｂに損傷が生じることを防止している。尚、空間Ａへ導出された水は、更に排出口１１６からボディ外部へ排出される。
【００３０】
このように本実施形態の回転継手では、主軸１０１の回転軸受部１０１ｂと回転シール部１０１ａとが別体で設けられているので、回転シール部１０１ａに損傷等が生じた場合でも回転シール部１０１ａのみを交換することができ、交換作業等のメンテナンス作業を容易に行える。また、高価な主軸全体を交換する必要がなく、ランニングコストの低減が図られる。
【００３１】
また、回転軸受部１０１ｂを耐食性に優れた材質（例えば、ＳＵＳ鋼等）で構成し、回転シール部１０１ａをシールパッキン１１１との摺接による損傷が生じにくい、シールパッキンと相性のよい高硬度で熱伝導率の高い材料で構成することができ、主軸の損傷を防止しつつもシールパッキン１１１の煩雑な交換は不要となる。
【００３２】
（第２実施形態）
次に第２実施形態の高圧水用回転継手について説明する。第２実施形態の回転継手も第１実施形態と同様に、高圧水を噴射する噴射ガンに組み込まれたるものである。図２は、第２実施形態の高圧水用継手の主要部分の構成を示す部分断面図である。本実施形態の回転継手は、回転シール部２０１ａと回転軸受部２０１ｂの接合部分と水逃がし通路２１７のみが第１実施形態と異なる。このため他の構成については図１と同一符号を付し説明を省略する。
【００３３】
第１実施形態の回転継手では、回転シール部２０１ａを回転軸受部２０１ｂにいわゆる印籠式に差し込んで、回転シール部２０１ａと回転軸受部２０１ｂの各軸芯を一致させるものであったが、第２実施形態では、回転シール部２０１ａと回転軸受部２０１ｂの接合面をテーパ状に形成して軸芯を一致させる方式を採用している。即ち、図２に示すように、回転シール部２０１ａの中央やや下方の部分を先細りテーパ状に形成している。そして、回転軸受部２０１ｂの上部には回転シール部２０１ａのテーパ状部２１３をはめ込むための孔部が穿孔されている。この孔部は、その中心が回転シール部２０１ａの軸芯と一致する位置になるように設けられており、孔部の内周面を回転シール部２０１ａのテーパ状部２１３が嵌るようにテーパ状部２１３と同一の傾斜角度のテーパ状に形成している。このため、回転軸受部２０１ｂの孔部に回転シール部２０１ａを嵌め込んだときに、回転シール部２０１ａの軸芯と回転軸受部２０１ｂの軸芯とが一致するような調芯構造となっている。尚、回転シール部２０１ａと回転軸受部２０１ｂの固定は、第１実施形態と同様に、回転シール部２０１ａの下部外周面の雄ねじ１０５を回転軸受部２０１ｂの孔部内周面の雌ねじに締着させることにより行われる。
【００３４】
また、第２実施形態の回転継手では、水逃がし通路２１７が回転軸受部２０１ｂの上端面の外縁付近から液溜め部１０８に通じるように設けられている。このため、回転継手の使用中に液溜め部１０８に漏れた水をパッキン押さえ部材１１３と回転シール部２０１ａの間の空間Ａ’に逃がして、液溜め部１０８に生じた圧力を開放し、回転シール部１０１ａと回転軸受部１０１ｂとが外れたり、回転シール部１０１ａや回転軸受部１０１ｂに損傷が生じることを防止している。尚、空間Ａ’へ導出された水は排出口１１６によりボディ外部へ排出される。
【００３５】
尚、第１実施形態及び第２実施形態では、本発明の高圧水用回転継手を噴射ガンに組み込んで使用しているが、適用範囲はこれに限られるものではない。例えば、回転する工具に流体を供給することが要求される工作機械におけるクーラント液供給用回転継手に本発明を適用することができる。
【００３６】
【発明の効果】
以上説明したとおり、請求項１に係る発明によれば、回転シール部のみを交換することができ、メンテナンス作業を容易に行えるという効果を奏する。また、ランニングコストの低減が図られるという効果を奏する。また、主軸の損傷を防止しつつも固定シール部の煩雑な交換は不要となり、装置寿命を長く維持することができるという効果を奏する。また、回転軸受部と回転シール部が別体であるにも関わらず、軸心のずれによる主軸先端の振れを防止できるという効果を奏する。更に、水圧による力が回転軸受部と回転シール部の接合部に過剰に作用せず、このため接合部に使用する部材のサイズを小さくすることができ、装置部品のコンパクト化を図ることができる。加えて、水圧による力が前記接合部に過剰に作用しないため、回転シール部と回転軸受部とが外れたり、回転シール部や回転軸受部が損傷することを防止できるという効果を奏する。
【００３７】
本発明によれば、主軸の回転により生じた熱が固定シール部にこもらせずに、外部へ効率よく逃がすことはできるという効果を奏する。
【００３８】
本発明によれば、回転シール部と回転軸受部との間隙に漏れた水により生じる圧力を開放して、回転シール部と回転軸受部とが外れたり、回転シール部や回転軸受部が損傷することをより確実に防止できるという効果を奏する。
【図面の簡単な説明】
【図１】第１実施形態に係る高圧水用回転継手の主要部分の概略構成を示す断面図である。
【図２】第２実施形態に係る高圧水用回転継手の主要部分の概略構成を示す断面図である。
【図３】従来の高圧水用回転継手の全体構成を示す断面図である。
【符号の説明】
１０１：主軸
１０１ａ：回転シール部
１０１ｂ：回転軸受部
１０３ａ，１０３ｂ：貫通孔（高圧水通路）
１０５：雄ねじ
１０７：水逃がし通路
１０８：液溜め部
１０９：突出部
１１０：ボディ
１１１：シールパッキン（固定シール部）
１１３：パッキン押さえ部材
１１５：ベアリング
１１６：排出口
２０１：主軸
２０１ａ：回転シール部
２０１ｂ：回転軸受部
２１３：テーパ状部
２１７：水逃がし通路
３０１：主軸
３０１ａ：回転シール部
３０１ｂ：回転軸受部
３０２：シールパッキン
３０３：パッキン押さえ部材
３０４：ボディ
３０５：ベアリング[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rotary joint for high-pressure water that connects pipe materials at both ends of a main shaft and guides high-pressure water from one pipe material to the other pipe material.
[0002]
[Prior art]
FIG. 3 is a cross-sectional view showing a schematic configuration of a conventional rotary joint for high-pressure water. The rotary joint for high pressure water includes a cylindrical main body (body) 304, a main shaft (rotor) 301 provided in a hollow portion of the cylindrical main body and having a through hole serving as a flow path for high pressure water, and a cylindrical main body. A fixed seal portion (seal packing) 302 that is provided on the inner peripheral wall of the hollow portion 304 and that is in sliding contact with the outer peripheral surface of the distal end portion of the main shaft 301 is mainly provided. In the conventional high-pressure water rotary joint, if the main shaft tip swings during rotation of the main shaft 301, a gap is generated between the main shaft tip and the fixed seal portion 302, resulting in a decrease in sealing performance, or fixed due to the vibration of the main shaft tip. Since excessive force acts on the seal portion 302, premature wear of the fixed seal portion 302 is caused. Therefore, the rotation seal portion 301a of the main shaft slidably contacting the fixed seal portion 302 and the rotation bearing portion 301b of the main shaft are the same. The main shaft was integrally formed by machining the core.
[0003]
Further, since the main shaft is required to have corrosion resistance, SUS steel having excellent corrosion resistance is used as the material of the main shaft, but SUS steel is soft and inferior in wear resistance. For this reason, in the conventional rotary joint for high-pressure water, a special coating is applied to the rotary seal portion 301a which is a contact portion with the fixed seal portion in the main shaft to increase the wear resistance.
[0004]
[Problems to be solved by the invention]
As described above, in the conventional rotary joint for high-pressure water, since the rotary bearing portion 301b and the rotary seal portion 301a are integrally formed, it is necessary to replace the main shaft when the rotary seal portion is worn. However, when exchanging the main shaft, the entire cylindrical main body must be disassembled, and it is difficult to perform such disassembly work at an actual work site. Further, since the main shaft is expensive, if the entire main shaft is replaced only for wear of the rotary seal portion, the running cost becomes high.
[0005]
In addition, since the main shaft is required to have corrosion resistance, the material used as the main shaft is limited to SUS steel or the like, but a fixed seal that does not cause damage due to sliding contact with the fixed seal portion among the limited materials. It is not always possible to select a material that is compatible with the part. For this reason, when a material having a poor compatibility with the fixed seal portion is used as the material of the main shaft, the main shaft is easily damaged and its life is shortened. For this reason, it is necessary to frequently replace the fixed seal portion, which complicates the work. On the other hand, when a material having good compatibility with the fixed seal portion is used as the material of the main shaft, the corrosion resistance of the main shaft may deteriorate. As described above, the conventional rotary joint for high-pressure water has a problem that it is sometimes impossible to ensure both the corrosion resistance of the main shaft and the compatibility with the contact portion (rotary seal portion) of the fixed seal portion.
[0006]
The present invention has been made in view of such problems, and a main object thereof is to provide a rotary joint for high-pressure water that can easily perform maintenance work such as replacement work of a seal portion. Another object of the present invention is to provide a rotary joint for high-pressure water that can reduce running costs. Another object of the present invention is to provide a rotary joint for high pressure water that can simultaneously ensure good corrosion resistance of the main shaft and good compatibility with the fixed seal portion of the rotary seal portion.
[0007]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the invention according to claim 1 includes a cylindrical main body part, a main shaft that has a through-hole serving as a flow path for high-pressure water and is rotatable in a hollow part of the cylindrical main body part, For high-pressure water, which is provided on the inner peripheral wall of the hollow portion of the cylindrical main body and includes a fixed seal portion that is in sliding contact with the main shaft, and connects the pipes at both ends of the main shaft to guide high-pressure water from one pipe to the other. In the rotary joint, the main shaft includes a rotary seal portion that is in sliding contact with the fixed seal portion, and a rotary bearing portion that receives the rotary seal portion on the high-pressure water outlet side and is detachably joined thereto, and The rotary bearing portion receives the rotary seal portion so that the axis of the rotary seal portion coincides with the axis of the rotary seal portion, and the outer diameter of the end portion on the high pressure water inlet side of the rotary seal portion and the high pressure water outlet side The outer diameter of the end portion is the same diameter, and the rotary seal portion Rate is formed by 0.02cal / cm · sec · ℃ or more thermally conductive material, the gap leakage water between the rotating seal portion and the rotational bearing as a discharge means for deriving the said main axis outside, Water that communicates a liquid reservoir formed by a gap formed between the lower step surface of the rotary seal portion and the upper step surface of the rotary bearing portion, and a space formed between the rotary seal portion and the fixed seal portion. An escape passage and a discharge port for discharging water led out to the space to the outside are provided .
[0008]
In the present invention, since the rotary bearing portion and the rotary seal portion of the main shaft are provided separately, only the rotary seal portion can be replaced even if the rotary seal portion is damaged or the like. For this reason, maintenance work such as replacement work can be easily performed as compared with the conventional rotary joint for high-pressure water that requires replacement of the entire main shaft. In addition, since it is not necessary to replace the entire expensive main spindle, the running cost can be reduced.
[0009]
Further, since the rotary bearing portion and rotary seal portion of the main shaft are provided separately, the rotary bearing portion is made of a material having excellent corrosion resistance, while the rotary seal portion that contacts the fixed seal portion is defined as a fixed seal portion. It is also possible to configure the fixed seal portion that is unlikely to be damaged by sliding contact with a material that is compatible with the fixed seal portion. This eliminates the need for complicated replacement of the fixed seal portion while preventing damage to the main shaft.
[0010]
In addition, since the rotary bearing portion and the rotary seal portion are separate bodies, there is a possibility that the respective shaft centers may be shifted. However, in the rotary bearing portion of the present invention, the axis center thereof coincides with the shaft center of the rotary seal portion. Since the rotary seal portion is received, it is possible to prevent the main shaft tip from being shaken due to the shift of the shaft center.
[0011]
In order to configure the rotary bearing portion to receive the rotary seal portion so that the axis of the rotary seal portion coincides with the axis of the rotary seal portion, the rotary bearing portion is inserted into the hollow portion of the rotary seal portion in a so-called stamp type. Alternatively, the inner wall of the hollow portion of the rotary seal portion can be tapered and the tip end of the main shaft can be inserted into the tapered hollow portion. However, the present invention is not limited to this configuration.
[0012]
Furthermore, in the present invention, the outer diameter of the end portion on the high pressure water inlet side of the rotary seal portion is substantially the same as the outer diameter of the end portion on the high pressure water outlet side. The areas are almost the same. For this reason, the load by the water pressure from high pressure water maintains balance with respect to the both end surfaces of a rotation seal part, and does not act on the said junction part excessively. In addition, even when using, for example, a screw or the like at the joint between the rotary seal and the rotary bearing, the load does not act excessively on the joint as described above, and therefore when a small screw is used at the joint. But it can withstand the load sufficiently. Further, since an excessive load does not act on the joint portion, it is possible to prevent the rotation seal portion and the rotation bearing portion from being detached due to the pressure fluctuation of the high pressure water, and the rotation seal portion and the rotation bearing portion from being damaged.
[0013]
The rotary bearing part in the present invention may be any one as long as it receives the rotary seal part on the high-pressure water outlet side and is detachably joined, and the fixing method thereof can take any configuration. For example, a screw thread is provided at the front end of the rotary bearing portion of the main shaft on the rotary seal portion side, while a screw thread that engages with this screw thread is provided on the inner peripheral wall of the hollow portion of the rotary seal portion so that the rotary bearing portion is hollow in the rotary seal portion. It can be configured to be fastened and fixed in the part. And if this thread is formed so that the tightening direction is the rotational direction of the hollow part of the rotary seal part, there is an advantage that it is possible to prevent the main shaft and rotary bearing part from being easily detached from the rotary seal part during use. is there.
[0015]
In the present invention, since a high thermal conductivity material is used as the material of the rotary seal portion, the heat generated by the rotation of the main shaft is discharged outside without being trapped in the fixed seal portion. As such a high thermal conductivity material, it is preferable to use a material having a thermal conductivity of 0.02 cal / cm · sec · ° C. or higher and a high hardness.
[0017]
If high-pressure water leaks from the through hole of the main shaft to the gap between the rotary seal part and the rotary bearing part due to damage or wear of parts such as the fixed seal part and O-ring, the end part on the high pressure water inlet side of the rotary seal part The force generated by the water pressure on the end portion on the high pressure water outlet side is larger than the force generated by the water pressure with respect to the pressure, and the balance of the force due to the water pressure on both end surfaces of the rotary seal portion is lost. That is, when water gradually leaks into the gap, the leaked water loses its place in the gap, so that pressure is generated inside the gap and the rotary seal portion and the rotary bearing portion are separated from each other. Works. For this reason, the rotary seal portion and the rotary bearing portion are detached, and the rotary seal portion or the rotary bearing portion is easily damaged. However, in the present invention, the pressure generated inside the gap is released by discharging the water leaking into the gap to the outside of the main shaft by the discharging means. As a result, the balance of force due to water pressure on both end faces of the rotary seal portion can be maintained, and the rotary seal portion and the rotary bearing portion can be more reliably prevented from being detached or the rotary seal portion or the rotary bearing portion being damaged. .
[0018]
The discharge means in the present invention may be any means as long as it discharges the water leaked into the gap between the rotary seal portion and the rotary bearing portion to the outside of the main shaft, and is configured to further discharge the derived water to the outside of the cylindrical main body portion. It is also possible to do. Such discharge means may be provided on either the cylindrical main body or the main shaft.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
A preferred embodiment of the present invention will be described below together with illustrated examples. The rotary joint for high pressure water according to the first embodiment is incorporated in an injection gun that injects high pressure water. FIG. 1 is a partial cross-sectional view showing the configuration of the main part of the high-pressure water joint of the first embodiment. Other configurations are the same as those of the conventional rotary joint shown in FIG.
[0020]
As shown in FIG. 1, the high-pressure water rotary joint of the present embodiment mainly includes a cylindrical body 110, a main shaft 101, and a substantially annular seal packing 111 provided on the inner wall of the hollow portion of the body 110. Yes. Here, the cylindrical body 110 constitutes a cylindrical main body portion in the present invention, and the seal packing 111 constitutes a fixed seal portion in the present invention.
[0021]
The seal packing 111 is restricted from moving up and down in FIG. 1 by a packing pressing member 113 having a through hole from below.
[0022]
In the rotary joint of the present embodiment, the main shaft 101 is divided into two parts, that is, a separate rotary bearing portion 101b and a rotary seal portion 101a, and the rotary bearing portion 101b and the rotary seal portion 101a are through holes 103a and 103b communicating with each other. These through holes 103a and 103b serve as high-pressure water passages. That is, the upper end of the rotary seal portion 101a is connected to a high pressure water hose (not shown), and the lower end of the rotary bearing portion 101b is connected to a high pressure water injection path (not shown) of the injection gun, and is supplied from the high pressure water hose. High pressure water is guided to the injection path of the injection gun.
[0023]
Further, the rotary seal portion 101a of the main shaft 101 is detachable from the rotary bearing portion 101b. The upper portion of the rotary seal portion 101a is inserted into the through hole of the packing presser member 113 in a rotatable state, and the outer peripheral surface of the upper end portion of the rotary seal portion 101a is in sliding contact with the seal packing 111 to ensure sealing performance.
[0024]
The rotary seal portion 101a is formed of a material having high hardness and high thermal conductivity. For this reason, the heat generated by the sliding contact of the rotary seal portion 101a with the seal packing 111 due to the rotation of the main shaft 101 is not trapped in the seal packing 111 but is discharged to the outside, and the durability is also ensured.
[0025]
In the upper part of the rotary bearing part 101b, a hole for fitting a lower part having a step into a stamping style is perforated by the protruding part 109 of the rotary seal part 101a. The hole portion is provided so that the center thereof is aligned with the axis of the rotary seal portion 101a, and forms a step corresponding to the step with the protruding portion 109 of the rotary seal portion 101a to be inserted. The inner diameter of each step portion is substantially the same as the outer diameter of the protrusion of the rotary seal portion 101a and the outer diameter of the step portion. For this reason, when the rotation seal portion 101a is inserted into the hole of the rotation bearing portion 101b, the alignment structure is such that the axis of the rotation seal portion 101a coincides with the axis of the rotation bearing portion 101b. For this reason, although the rotary bearing portion 101b and the rotary seal portion 101a are separate bodies, the tip of the main shaft 101 is reliably prevented from shaking.
[0026]
A male screw 105 is threaded on the lower outer peripheral surface of the rotary seal portion 101a, and a female screw (not shown) that engages with the male screw 105 on the lower portion of the rotary seal portion is threaded on the inner peripheral surface of the hole of the rotary bearing portion 101b. Has been. For this reason, when attaching the rotation seal | sticker part 101a to the rotation bearing part 101b, the lower part of the rotation seal | sticker part 101a is inserted in the upper hole part of the rotation bearing part 101b, and is further fastened, and the rotation seal | sticker part 101a and a rotation bearing are carried out. The part 101b is securely fixed. Here, the male screw 105 and the female screw are formed so that the tightening direction of the screw is the same as the rotating direction of the rotary seal portion 101a. Therefore, the rotation seal portion 101a and the rotary bearing portion 101b are not easily loosened during rotation of the main shaft 101, and the main shaft 101 is reliably prevented from shaking.
[0027]
Outer diameter D ₂ of the high-pressure water inlet end of the rotating seal portion 101a (upper end portion) are substantially the same diameter as the outer diameter D ₁ of the high pressure water outlet end of the rotating seal portion 101a (a lower end) . For this reason, the areas of both end faces of the rotary seal portion 101a are substantially equal, and the force applied to the upper end portion of the rotary seal portion due to the pressure of the high-pressure water and the force caused by the water pressure applied to the lower end portion are kept in balance. It does not act excessively on the male screw 105 and the female screw that are the joint between the rotary seal portion 101a and the rotary bearing portion 101b. For this reason, even when the size of the male screw 105 and the female screw is reduced, the load can be sufficiently resisted. Moreover, since an excessive load does not act on the male screw 105 and the female screw, the rotary seal portion 101a and the rotary bearing portion 101b are detached due to pressure fluctuation of the high-pressure water, or the rotary seal portion 101a and the rotary bearing portion 101b are damaged. Is prevented.
[0028]
In the high-pressure water rotary joint of the present embodiment, a gap (a liquid reservoir 108) is generated between the lower step surface of the rotary seal portion 101a and the upper step surface of the rotary bearing portion 101b. In addition, two water escape passages 107 communicating between the gap (the liquid reservoir 108) and the space A formed between the rotary seal portion 101a and the fixed seal portion 113 are located near the outer edge of the rotary seal portion 101a. Is provided. Here, the water escape passage 107 constitutes the discharge means of the present invention.
[0029]
If the packing that seals the joint between the rotary seal portion 101a and the rotary bearing portion 101b is damaged or worn during use of the rotary joint, or parts such as an O-ring are damaged, the spray gun is applied to the liquid reservoir portion 108. There is a case where high-pressure water directed to the injection path of the water leaks. In this case, the force due to the water pressure at the high pressure water outlet side end (lower end) is larger than the force due to the water pressure at the high pressure water inlet side end (upper end) of the rotation seal portion 101a. The balance of force generated by the water pressure of the high-pressure water on the surface will be lost. That is, when water gradually leaks into the liquid reservoir portion 108, the leaked water loses its place in the liquid reservoir portion 108, so that pressure is generated inside the liquid reservoir portion 108, and this pressure is applied to the rotary seal portion. It acts to push up 101a and push down the rotary bearing portion 101b (so that the rotary seal portion 101a and the rotary bearing portion 101b are separated from each other). For this reason, the rotary seal portion 101a and the rotary bearing portion 101b are detached, and the rotary seal portion 101a or the rotary bearing portion 101b is easily damaged. However, in the rotary joint of the present embodiment, the water escape passage 107 that communicates the liquid reservoir portion 108 and the space A is provided, so that water leaked into the liquid reservoir portion 108 is led out from the water escape passage 107 to the space A. By doing so, the pressure generated in the liquid reservoir portion 108 is released, and the rotation seal portion 101a and the rotation bearing portion 101b are prevented from being detached and the rotation seal portion 101a and the rotation bearing portion 101b are prevented from being damaged. In addition, the water led out to the space A is further discharged from the discharge port 116 to the outside of the body.
[0030]
As described above, in the rotary joint according to the present embodiment, the rotary bearing portion 101b and the rotary seal portion 101a of the main shaft 101 are provided separately, so that even when the rotary seal portion 101a is damaged, the rotary seal portion 101a. The maintenance work such as the replacement work can be easily performed. Further, it is not necessary to replace the entire expensive main spindle, and the running cost can be reduced.
[0031]
In addition, the rotary bearing portion 101b is made of a material having excellent corrosion resistance (for example, SUS steel), and the rotary seal portion 101a is hardly damaged by sliding contact with the seal packing 111, and has high hardness compatible with the seal packing. The seal packing 111 can be made of a material having a high thermal conductivity, and the complicated replacement of the seal packing 111 is not necessary while preventing the main shaft from being damaged.
[0032]
(Second Embodiment)
Next, the rotary joint for high pressure water of 2nd Embodiment is demonstrated. Similarly to the first embodiment, the rotary joint of the second embodiment is also incorporated in an injection gun that injects high-pressure water. FIG. 2 is a partial cross-sectional view showing the configuration of the main part of the high-pressure water joint of the second embodiment. The rotary joint of this embodiment is different from the first embodiment only in the joint portion of the rotary seal portion 201a and the rotary bearing portion 201b and the water escape passage 217. For this reason, the other components are denoted by the same reference numerals as those in FIG.
[0033]
In the rotary joint according to the first embodiment, the rotary seal portion 201a is inserted into the rotary bearing portion 201b in a so-called indicia type so that the axes of the rotary seal portion 201a and the rotary bearing portion 201b are aligned with each other. In the embodiment, a method is adopted in which the joint surfaces of the rotary seal portion 201a and the rotary bearing portion 201b are formed in a tapered shape so that the axes are aligned. That is, as shown in FIG. 2, the central portion of the rotary seal portion 201 a slightly below is formed in a tapered shape. A hole for fitting the tapered portion 213 of the rotary seal portion 201a is formed in the upper portion of the rotary bearing portion 201b. The hole portion is provided so that the center thereof is aligned with the axis of the rotary seal portion 201a, and the inner peripheral surface of the hole portion is tapered so that the tapered portion 213 of the rotary seal portion 201a is fitted. It is formed in a tapered shape having the same inclination angle as the portion 213. For this reason, when the rotation seal part 201a is fitted in the hole of the rotation bearing part 201b, the alignment structure is such that the axis of the rotation seal part 201a coincides with the axis of the rotation bearing part 201b. . The rotation seal portion 201a and the rotation bearing portion 201b are fixed by fastening the male screw 105 on the lower outer peripheral surface of the rotation seal portion 201a to the female screw on the inner peripheral surface of the hole of the rotary bearing portion 201b, as in the first embodiment. Is done.
[0034]
Further, in the rotary joint of the second embodiment, the water escape passage 217 is provided so as to communicate with the liquid reservoir portion 108 from the vicinity of the outer edge of the upper end surface of the rotary bearing portion 201b. For this reason, the water leaked to the liquid reservoir 108 during use of the rotary joint is released to the space A ′ between the packing pressing member 113 and the rotary seal portion 201a, and the pressure generated in the liquid reservoir 108 is released to rotate. This prevents the seal portion 101a and the rotary bearing portion 101b from coming off and damage to the rotary seal portion 101a and the rotary bearing portion 101b. In addition, the water led out to the space A ′ is discharged to the outside of the body through the discharge port 116.
[0035]
In the first embodiment and the second embodiment, the high-pressure water rotary joint of the present invention is incorporated in a spray gun, but the application range is not limited to this. For example, the present invention can be applied to a coolant liquid supply rotary joint in a machine tool that is required to supply fluid to a rotating tool.
[0036]
【The invention's effect】
As described above, according to the first aspect of the present invention, only the rotary seal portion can be replaced, and the maintenance work can be easily performed. In addition, the running cost can be reduced. In addition, it is possible to prevent the main shaft from being damaged and to eliminate the need for complicated replacement of the fixed seal portion and to maintain the apparatus life longer. Further, although the rotary bearing portion and the rotary seal portion are separate bodies, there is an effect that it is possible to prevent the main shaft tip from being shaken due to the shift of the shaft center. Further, the force due to the water pressure does not act excessively on the joint portion between the rotary bearing portion and the rotary seal portion, so that the size of the member used for the joint portion can be reduced, and the device parts can be made compact. . In addition, since the force due to the water pressure does not act excessively on the joint portion, it is possible to prevent the rotation seal portion and the rotation bearing portion from coming off and the rotation seal portion and the rotation bearing portion from being damaged.
[0037]
According to the present invention, there is an effect that heat generated by the rotation of the main shaft can be efficiently released to the outside without being trapped in the fixed seal portion.
[0038]
According to the present invention, the pressure generated by the water leaked into the gap between the rotary seal portion and the rotary bearing portion is released, and the rotary seal portion and the rotary bearing portion are detached, or the rotary seal portion and the rotary bearing portion are damaged. This has the effect of preventing this more reliably.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a schematic configuration of a main part of a rotary joint for high pressure water according to a first embodiment.
FIG. 2 is a cross-sectional view showing a schematic configuration of main parts of a rotary joint for high pressure water according to a second embodiment.
FIG. 3 is a cross-sectional view showing the overall structure of a conventional rotary joint for high-pressure water.
[Explanation of symbols]
101: Main shaft 101a: Rotary seal portion 101b: Rotary bearing portion 103a, 103b: Through hole (high-pressure water passage)
105: Male screw 107: Water escape passage 108: Liquid reservoir 109: Protruding portion 110: Body 111: Seal packing (fixed seal portion)
113: Packing pressing member 115: Bearing 116: Discharge port 201: Main shaft 201a: Rotating seal portion 201b: Rotating bearing portion 213: Tapered portion 217: Water escape passage 301: Main shaft 301a: Rotating seal portion 301b: Rotating bearing portion 302: Seal packing 303: Packing pressing member 304: Body 305: Bearing

Claims

A cylindrical main body, a through-hole that serves as a flow path for high-pressure water, a main shaft that is rotatable in the hollow portion of the cylindrical main body, and an inner peripheral wall of the hollow main body that are slid on the main shaft. A high-pressure water rotary joint that connects the pipes at both ends of the main shaft and guides high-pressure water from one pipe to the other pipe,
The main shaft has a rotary seal portion that is in sliding contact with the fixed seal portion and a rotary bearing portion that receives the rotary seal portion on the high-pressure water outlet side and is detachably joined thereto,
The rotary bearing portion receives the rotary seal portion so that its axis coincides with the axis of the rotary seal portion,
The outer diameter of the high pressure water inlet side end of the rotating seal portion and the outer diameter of the high pressure water outlet side end are the same diameter,
The rotary seal portion is formed of a heat conductive material having a thermal conductivity of 0.02 cal / cm · sec · ° C. or more ,
A gap formed between a lower step surface of the rotary seal portion and an upper step surface of the rotary bearing portion as a discharging means for leading water leaking into the gap between the rotary seal portion and the rotary bearing portion to the outside of the main shaft. And a water relief passage communicating with the space formed between the rotary seal portion and the fixed seal portion, and a discharge port for discharging the water led to the space to the outside. A rotary joint for high-pressure water characterized by that.