JP2004066977A

JP2004066977A - Strut bearing of propeller shaft for marine vessel

Info

Publication number: JP2004066977A
Application number: JP2002229565A
Authority: JP
Inventors: Takero Makino; 牧野　武朗
Original assignee: Mitsubishi Heavy Industries Ltd
Current assignee: Mitsubishi Heavy Industries Ltd
Priority date: 2002-08-07
Filing date: 2002-08-07
Publication date: 2004-03-04
Anticipated expiration: 2022-08-07
Also published as: JP3962650B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a strut bearing of a propeller shaft for a marine vessel reducing abrasion of the bearing without lowering a bearing load ability of the bearing, preventing seizure of the bearing and the propeller shaft by enhancing a cooling efficiency of the bearing and reducing a maintenance work frequency and a work cost of the strut bearing in the strut bearing which is applied to a propeller bearing for the marine vessel and in which a plurality of water feed grooves are provided on an axial inner surface at equal intervals. <P>SOLUTION: The strut bearing supports the propeller shaft for the marine vessel and in the strut bearing, a plurality of water feed grooves are provided on the inner surface of a bearing body along an axial direction. The water feed grooves are provided on an upper inner surface and a lower inner surface at a central part of the bearing body. The end lower side inner surfaces positioned at both sides of the water feed grooves at the lower side inner surface at the central part are constituted to a smooth bearing surface. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、船舶のプロペラ軸受に用いられ、軸受本体内面に該軸受本体及び軸を冷却するための海水等の水を通す給水溝を備えた舶用プロペラ軸の張出軸受に関する。
【０００２】
【従来の技術】
船舶において張出軸受が使用される船尾構造を図７に示す。図においてプロペラ軸２は、船体１の船尾部と該船体１から張り出して取り付けられるブラケット３を貫通して設置され、その船尾側端部にプロペラ４が装着される。船体１には、プロペラ４より船尾側位置に舵５が設置される。かかる張出軸受は軸受本体が円筒形状をなして、ブラケット３内部に設けられ、プロペラ軸荷重を支えている。
【０００３】
前記プロペラ軸荷重としては、主に次の２種類がある。
（１）プロペラ軸２とプロペラ４との自重
（２）船舶の旋回時の流体力
前記（１）のプロペラ軸２とプロペラ４との自重は、重力によって船体下方に向う荷重である。また前記（２）の船舶旋回時の流体力は、船舶進行方向と垂直方向に海水の抵抗によってプロペラ４が受ける横荷重である。従って、海水自体の運動によって受ける任意方向の荷重を除くと、張出軸受は、船舶直進時にはプロペラ軸２とプロペラ４の自重を受け、船舶旋回時には該自重と旋回時の流体力の合成力を受ける。
【０００４】
前記張出軸受は軸受全体が水没するので、油圧機構によってプロペラ軸荷重を支えるような可動部を有する軸受機構を一般的に利用しない。そこで、軸受構造自体でプロペラ軸２の軸荷重を支えるために、軸受内面の材料に弾性と潤滑性を具えたリグナムバイタやゴム材を用いる。リグナムバイタは、熱帯地方に成育する自然木で、樹脂に満ち、繊維が緻密で自己潤滑性に優れている材料である。
また、プロペラ軸２と軸受本体内面の摩擦による加熱を除去し、プロペラ軸２の焼付きを防止するために、プロペラ軸２と軸受本体内面とのすきまに海水または清水を通し冷却する。
【０００５】
次に、前記張出軸受の構造について説明する。図８（Ａ）は軸受本体６の軸心線に沿う断面図、（Ｂ）は（Ａ）の側面図である。軸受本体６はゴム、あるいは樹脂で構成されており、軸受本体６内面には軸方向に海水を通すための給水溝８が形成されている。該給水溝８は軸受中央部に設けた円周溝９によって周方向に連通されており、該円周溝９に軸受本体６の外部から給水できるように給水口７が設けられている。
船舶運航時には、取水した海水を給水口７に供給すると、海水は円周溝９を通じて、給水溝８に流れ込み、船尾側及び船首側の軸受端部から海中に排水される。また、給水口７への給水を止めたり、給水圧力を減らした場合、船首側の軸受端部から給水溝８に海水が流れ込み、船尾側端部から排水される。このように軸受本体６内面に海水を流すことによって軸受本体６とプロペラ軸２とが冷却されるとともに、給水溝８以外の軸受内面とプロペラ軸２の外面の隙間に海水の皮膜が形成され、この海水皮膜が潤滑の役目を果たす。
【０００６】
図８の軸受構造から円周溝９と給水溝８とを除いた軸受が特開２０００−２６６０４７に開示されている。この例では、薄板状の摺動材をその肉厚方向への突出形状に屈曲させることにより複数の潤滑溝を所定間隔で形成し、この摺動材を筒状に曲げて軸受内周に同心的に配置している。そして、軸受の船首側端部から潤滑溝に海水が入り、船尾側端部から抜けることによって、該海水がプロペラと薄板状摺動材の間の潤滑の役目を果たしている。
【０００７】
前記軸受本体６の軸方向に溝を切る代わりに、潤滑性を有する材質の細長い平板を軸受内面に円周方向に等間隔に並べて図８と同様の構造とする軸受が特開平１１−３５１２４１に開示されている。本例は所定寸法の直方体形状に形成した弾性体を円筒状の外筒の内周部に設けている。この場合、平板の厚さが溝の深さとなる。
【０００８】
図９（Ａ）は、図８の下側内面を軸受面１０とした軸受本体６の軸心線に沿う断面図、（Ｂ）は（Ａ）の側面図である。この構造の場合、軸受がプロペラ軸２を支える負荷能力は図８の場合に比べて向上し、且つ、プロペラ軸の回転による、軸受面１０とプロペラ軸２との間の水膜の形成は容易になる。
しかし、給水溝８が無いため軸受とプロペラ軸２を冷却する能力は低下するので、軸受が摩耗する速度は速くなる。
図８、図９に示される何れの張出軸受においても、軸受がプロペラ軸２を支える負荷能力は、軸受面の単位面積あたりの荷重となるので、図８のように給水溝８を設けた場合、軸方向に構造が均等とすると、軸受本体の内周長から複数の給水溝８の周方向幅を差し引いた面積で、プロペラ軸２を支えることになる。
プロペラ軸の軸受については、「１級舶用機関整備士指導書」（日本財団事業成果ライブラリー、日本舶用機関整備協会、平成８年度）に詳しく述べられている。
【０００９】
【発明が解決しようとする課題】
以上に示した従来技術に係わる張出軸受においては、次のような問題点がある。
重量の大きいプロペラ４を支える場合、プロペラ軸２が張出軸受の船尾側で片当たりする。また、船体内部にある船尾管軸受（不図示）からブラケット３までの距離が長いことから、プロペラ軸２がブラケット３内で湾曲し、張出軸受の船首側と船尾側の両方で大きな荷重が生じる。
この場合、図８に示す構造では、軸受下側内面に給水溝８を設けているので給水溝８がない場合に比べて、軸受負荷能力が低くなり、軸受の摩耗速度が速くなる。
図９に示す構造では、軸受負荷能力を維持するものの、大きな荷重を生じる船首側と船尾側端部は円周溝９から最も遠い位置にあること、及び負荷面側には給水溝８がないことから、プロペラ軸２と軸受本体６の冷却効率が悪く、軸受の摩耗速度が速くなる、或いは焼付きを起こす可能性がある。
【００１０】
本発明は、かかる従来技術の欠点に鑑み、船舶のプロペラ軸受に適用され、軸方向内面に複数の給水溝を均等間隔に設けた張出軸受において、軸受の軸受負荷能力を低下させることなく軸受摩耗を軽減するとともに、軸受の冷却効率を向上させることによって軸受とプロペラ軸との焼付きを防止し、これによって張出軸受のメンテナンス作業頻度及び作業コストの低減を図った張出軸受の提供を目的とする。
【００１１】
【課題を解決するための手段】
本発明は係る課題を解決するため、請求項１記載の発明として、船舶のプロペラ軸を支持し、軸受本体の内面に複数の給水溝を軸方向に沿って設けた張出軸受において、前記給水溝を前記軸受本体の上側内面及び中央部下側内面に設け、該中央部下側内面の給水溝の両側に位置する端部下側内面を平滑な軸受面に構成したことを特徴とする張出軸受を提案する。
請求項１記載の発明によれば、軸受両端部における軸受負荷能力を低下させず、軸受中央部下側内面に給水溝を設けることによって軸受下側内面の冷却能力を向上できる。その結果、軸受摩耗を軽減したり、プロペラ軸の焼付きを防止できるので、張出軸受のメンテナンス作業頻度や作業コストの低減を実現できる。
【００１２】
請求項２記載の発明は、請求項１記載の発明において、前記上側内面及び中央部下側内面の給水溝を円周方向に接続する円周溝を設けて、前記軸受本体外周面に連通される給水口を該円周溝に接続するとともに、前記中央部下側内面の給水溝の両側開口部を円周方向に接続する第２の円周溝を設けたことを特徴とする。請求項２記載の発明によれば、請求項１に加えて、軸受中央部下側内面の給水溝の両端開口部を円周方向に接続する第２の円周溝を設けたので、該円周溝と軸受端部との間の軸受面へ海水が浸透し、該海水の潤滑材としての機能と冷却媒質としての機能とが働き、軸受の負荷能力維持と冷却とができる。その結果、軸受摩耗を軽減したり、プロペラ軸の焼付きを防止できるので、張出軸受のメンテナンス作業頻度や作業コストの低減を実現できる。
【００１３】
請求項３記載の発明は、請求項１記載の発明において、前記上側内面及び中央部下側内面の給水溝を円周方向に接続する円周溝を設けて、前記軸受本体外周面に連通される給水口を該円周溝に接続するとともに、前記中央部下側内面の給水溝の深さを前記円周溝から前記軸受面に向うに従い浅くなるように形成したことを特徴とする。
請求項３記載の発明によれば、請求項１に加えて、前記軸受中央部下側内面の給水溝の深さを前記円周溝から前記軸受面に向うに従い浅くなるように形成したので、該給水溝に供給された冷却用水は円周溝を通じて排水されることがなく、該給水溝内の軸方向の水圧低下を維持することによって、プロペラ軸と前記軸受面の微小な隙間へその水圧を持って給水できる。従って、該円周溝と軸受端部との間の軸受面へ海水が浸透し、該海水の潤滑材としての機能と冷却媒質としての機能とが働き、軸受の負荷能力維持と冷却とができる。その結果、軸受摩耗を軽減したり、プロペラ軸の焼付きを防止できるので、張出軸受のメンテナンス作業頻度や作業コストの低減を実現できる。
【００１４】
請求項４記載の発明は、前記中央部下側内面の給水溝の両端開口部及び前記上側内面の給水溝を円周方向に接続する２個の円周溝を設け、前記軸受本体の外周面に連通される給水口を各円周溝に接続したことを特徴とする。
請求項４記載の発明によれば、請求項１に加えて、軸受両端部の下側内面に構成した軸受面へのプロペラ軸の荷重状態をモニターしながら２つの給水口７への給水圧力を調整することによって、軸受全体を均等に冷却できるようになる。その結果、軸方向に不均一な軸受摩耗を抑制したり、プロペラ軸の局所的な焼付きを防止できるので、張出軸受のメンテナンス作業頻度や作業コストの低減を実現できる。
【００１５】
請求項５記載の発明は、請求項４記載の発明において、前記２個の円周溝に挟まれた中央部上側内面を平滑な軸受面としたことを特徴とする。
請求項５記載の発明によれば、請求項１及び請求項４に加えて、プロペラ軸が軸受本体内部で撓む場合に対応して軸受中央部の上側内面の軸受負荷能力を向上させることができる。その結果、軸受摩耗を軽減したり、プロペラ軸の焼付きを防止できるので、張出軸受のメンテナンス作業頻度や作業コストの低減を実現できる。
【００１６】
請求項６記載の発明は、船舶のプロペラ軸を支持し、軸受本体の内面に複数の給水溝を軸方向に沿って設けた張出軸受において、前記軸受本体の片側端部の下側内面を平滑な軸受面に構成し、該軸受本体の内面の他の部位に前記給水溝を設けたことを特徴とする。
請求項６記載の発明によれば、張出軸受と船体内に設置された船尾管軸受との間隔が短い場合、プロペラ軸の荷重が最も大きくなる、張出軸受の軸受本体の船尾側端部における軸受負荷能力を維持できるとともに、軸受全体の冷却ができる。その結果、軸受摩耗を軽減したり、プロペラ軸の焼付きを防止できるので、張出軸受のメンテナンス作業頻度や作業コストの低減を実現できる。
【００１７】
請求項７記載の発明は、請求項６記載の発明において、前記各給水溝を円周方向に接続し、一側部が前記軸受面に開口する円周溝を設けたことを特徴とする。
請求項７記載の発明によれば、請求項６に加えて、前記円周溝から前記軸受面へ海水が浸透し、該海水の潤滑材としての機能と冷却媒質としての機能とが働き、軸受の負荷能力維持と冷却とができる。その結果、軸受摩耗を軽減したり、プロペラ軸の焼付きを防止できるので、張出軸受のメンテナンス作業頻度や作業コストの低減を実現できる。
【００１８】
請求項８記載の発明は、請求項６記載の発明において、前記給水溝の一部を前記軸受面に直接開口したことを特徴とする。
請求項８記載の発明によれば、請求項６に加えて、軸受本体の船首側端部から給水溝に流入する海水によって軸受の冷却ができる。その結果、軸受の構造が簡単になり、また給水に必要なポンプ等の機器が不要となるので、軸受の不具合発生要因が減り、張出軸受のメンテナンス作業頻度や作業コストの低減を実現できる。
【００１９】
請求項９記載の発明は、請求項１または８の何れかの項に記載の発明において、プロペラ運転中にプロペラ軸の荷重がかかる方向に面した部位を平滑な軸受面としたことを特徴とする。
請求項９記載の発明によれば、請求項１または８の何れかの項に加えて、プロペラ軸とプロペラの自重による軸受下側内面への荷重、およびプロペラ軸の撓みによる軸受上側内面への荷重だけでなく、船舶の旋回や海水の運動によってプロペラが受ける任意の方向の流体力に対しても軸受負荷能力を維持できる。その結果、軸受摩耗を軽減したり、プロペラ軸の焼付きを防止できるので、張出軸受のメンテナンス作業頻度や作業コストの低減を実現できる。
【００２０】
請求項１０記載の発明は、請求項１または９の何れかの項に記載の発明において、前記円周溝と該円周溝に連通する前記給水口との軸受軸方向位置を、軸受全長に対して船尾側から２０％ないし５０％の範囲、及び船首側から１０％ないし５０％の範囲の何れか一方または双方の範囲としたことを特徴とする。
請求項１０記載の発明によれば、請求項１または９の何れかの項に加えて、軸受本体の両端部へのプロペラ軸荷重が不均等な場合に、前記円周溝と該円周溝に連通する前記給水口との位置を変更することによって、軸受全体を均等に冷却できる。その結果、軸受摩耗を軽減したり、プロペラ軸の焼付きを防止できるので、張出軸受のメンテナンス作業頻度や作業コストの低減を実現できる。
【００２１】
【発明の実施形態】
以下、本発明を図に示した実施例を用いて詳細に説明する。但し、この実施例に記載されている構成部品の寸法、材質、形状、その相対位置などは、特定的な記載が特にない限り、この発明の範囲をそれのみに限定する趣旨ではなく、単なる説明例にすぎない。
（実施形態１）
図１は本発明の実施形態１に係る張出軸受の構成を示す説明図であり、（Ａ）は軸心線に沿う断面図、（Ｂ）は（Ａ）におけるＡ−Ａ線断面図である。
本実施形態は、プロペラ重量が大きい場合、張出軸受の軸受本体６が長いためにプロペラ軸２に撓みが生じ、該プロペラ軸２の荷重を受ける部分が軸受の船首側と船尾側の両端に集中し、その部分の軸受摩耗が著しいことに鑑みて提案するものである。
図１において、軸受本体６はプロペラ軸２が貫通できるように円筒形状をしており、図７に示すブラケット３の中に装着される。該軸受本体６の材質は、潤滑性を持つリグナムバイタ、ゴム、合成樹脂等である。前記合成樹脂の種類はフェノール樹脂、ナイロン、テフロン（デュポン社商標）等が好適である。
【００２２】
前記軸受本体６の内面には、軸方向に一定の幅を持った給水溝８を周方向に等間隔に配置する。このとき、軸受本体６の上側内面には軸受の全長に渡って、下側内面には中央部寄りに配置する。前記給水溝８は、軸受本体６の内面を削り取って設けてもよいし、細長い平板状の潤滑性材料を軸受本体６内面に取り付けて形成してもよい。該平板状の潤滑性材料は軸受本体６の軸方向長さと同一にする必要は無く、複数の平板を長辺方向に並べて充当してもよい。
軸受本体６の中央部内面には周方向に円周溝９を１つ設ける。更に、該軸受本体６の外周面から該円周溝９に連通するように給水口７を穿孔する。
また、軸受本体６の中央部寄り下側内面に設けた給水溝８の端部を周方向に連通させる第２円周溝１１を該給水溝８の両端にそれぞれ設ける。
前記給水溝８、円周溝９、第２円周溝１１の溝の幅、深さ、及び給水溝８の数は任意でよい。プロペラ軸２の寸法や運転条件によって軸受への負荷条件が異なり、要求される冷却能力も異なるからである。
【００２３】
次に、以上のように構成した張出軸受を用いた船舶の運転状況について説明する。船舶運航時には、船舶が取水した海水（又は船舶に貯蔵している水でもよい）を給水口７から連続的に或いは間欠的に注入する。注入された海水は円周溝９を介して、船首方向、船尾方向の給水溝８に通っていく。該海水は第２の円周溝１１に達すると、軸受の周方向に巡るとともに、軸受端部に向って上側内面の給水溝８を通っていき、端部に達すると海中へ排出される。
一方、軸受両端部の下側内面の軸受面１０とプロペラ軸２の外面との微小な隙間には、第２円周溝や給水溝８から漏れ出た海水が浸透し、海水の薄い皮膜を作る。この皮膜はプロペラ軸２と軸受面１０の潤滑材として機能する。
【００２４】
以上のように軸受本体６の内部で撓むプロペラ軸２に対して、軸受本体６両端部には軸受面１０を設けているので、最も荷重の掛かる部分の負荷能力を維持することができる。更に、前記荷重の軽減される中央部寄りの部位では給水溝８を全周に渡って設けているので、下側内面を全て軸受面１０とした場合に比べて冷却能力が向上する。その結果、荷重の大きい部分の軸受摩耗を軽減し、或いはプロペラ軸２の焼付きを防止できるので、張出軸受のメンテナンス作業頻度や作業コストの低減が実現できる。
【００２５】
（実施形態２）
図２は本発明の実施形態２に係る張出軸受の構成を示す説明図であり、（Ａ）は軸心線に沿う断面図、（Ｂ）は（Ａ）におけるＢ−Ｂ線断面図である。
本実施形態は、プロペラ重量が大きい場合、張出軸受の軸受本体６が長いためにプロペラ軸２に撓みが生じ、該プロペラ軸２の荷重を受ける部分が軸受の船首側と船尾側の両端に集中し、その部分の軸受摩耗が著しいことに鑑みて提案された。
実施形態２の装置構成を実施形態１との差異で説明する。この実施形態では図１に示した実施形態１における２つの第２円周溝１１を省き、軸受中央部下側内面の給水溝８の深さを、両側の軸受面１０に向って軸方向に徐々に浅くなるように構成した。その他の構成は実施形態１と同様である。
【００２６】
次に、以上のように構成した第２実施形態に係る張出軸受を用いた船舶の運転状況について説明する。船舶運航時には、船舶が取水した海水（又は船舶に貯蔵している水でもよい）を給水口７から連続的に或いは間欠的に注入する。注入された海水は円周溝９を介して、船首方向、船尾方向の給水溝８に通っていく。軸受上側内面の給水溝８に入った海水は軸受両端部まで達すると海中に排出される。一方、軸受中央部下側内面の給水溝８に入った海水は、軸方向に通じても排出される先が無いため、給水圧力を保持する。
前記給水圧力を保持することによって、プロペラ軸２と軸受面１０の微小な隙間に一定水圧を持って海水が浸透していくので、該海水の潤滑材としての機能と冷却媒質としての機能とが確実に働き、負荷能力維持と軸受の冷却に寄与する。その結果、荷重の大きい部分の軸受摩耗を軽減し、プロペラ軸の焼付きを防止できるので、張出軸受のメンテナンス作業頻度や作業コストの低減が実現できる。
【００２７】
（実施形態３）
図３は本発明の実施形態３に係る張出軸受の構成を示す説明図であり、（Ａ）は軸心線に沿う断面図、（Ｂ）は（Ａ）におけるＣ−Ｃ線断面図である。
本実施形態は、軸受の船首側と船尾側で受けるプロペラ軸２の荷重がそれぞれで異なる場合、軸受摩耗量が不均等になり、摩耗量が局所的に最も多い軸受部分に律速されて、軸受をメンテナンスしなければならないことに鑑みて提案された。
実施形態３の装置構成を、実施形態１との差異で説明する。この実施形態では図１に示した実施形態１における円周溝９と給水口７を省き、該円周溝９を挟んで設けられていた２つの第２円周溝１１を２つの円周溝９とし、それぞれに給水口７を接続した。その他の構成は実施形態１と同様である。
【００２８】
次に、以上のように構成した第３実施形態に係る張出軸受を用いた船舶の運転状況について説明する。
船舶運航時には、船舶が取水した海水（又は船舶に貯蔵している水でもよい）を２ヵ所の給水口７から連続的に或いは間欠的に注入する。注入された海水は２つの円周溝９を介して、船首方向、船尾方向の給水溝８に通っていく。軸受上側内面の給水溝８に入った海水は軸受両端部まで達すると海中に排出される。
この場合、給水口７への給水圧力に差を設けると、軸受中央部下側内面の給水溝８に入った海水は、２つの円周溝９のどちらかに戻って上側内面の給水溝８に入り軸受端部に向う。軸受中央部下側内面の給水溝８に入った海水が２つの円周溝９の何れに戻るかは、２つの円周溝９内の水圧力の差によって決まり、水圧力の低い円周溝９へ戻る。軸受内全体の円周溝９と給水溝８に沿って水圧力分布がつくので、軸受内部に海水が滞留する部分がなくなる。２つの円周溝９の水圧力が等しい場合、実施形態２と同じく、軸受中央部下側内面の給水溝８の水圧力は、円周溝９の水圧力に保持される。
【００２９】
２つの給水口７への給水圧力に差を設けると、給水圧力を高く設定した円周溝９から船首側と船尾側に向って海水の流れが生じる。船首側と船尾側の軸受面１０の軸荷重が異なる場合、軸荷重が大きい側の給水口７の給水圧力を高くすることによって、軸荷重が大きい側の給水溝８に、温度上昇がより少ない海水を供給できる。従って、軸荷重の大小に応じて給水圧力に差を設けることによって、軸荷重が比較的大きい箇所に対する冷却能力をより高く、軸荷重が比較的小さい箇所に対する冷却能力をより低くできる。その結果、軸受内面に局所的に加熱される箇所が生ぜず、軸受全体の温度分布が均等になるので、局所的な加熱損傷に対するメンテナンスが不要になるので、張出軸受のメンテナンス作業頻度や作業コストの低減が実現できる。
【００３０】
一方、船首側と船尾側の軸荷重がほぼ等しいため、２つの給水口７に対する給水圧力を等しくした場合、軸受中央部下側内面の給水溝８の水圧力は円周溝９の水圧力と同じに保持される。従って、実施形態２と同じ作用が生じ、円周溝９からプロペラ軸２と軸受面１０の微小な隙間に一定水圧を持って海水が浸透していくので、海水の潤滑材と冷却媒質としての機能が確実に働き、軸受の冷却と負荷能力維持に寄与する。その結果、軸受摩耗を軽減したり、プロペラ軸の焼付きを防止できるので、張出軸受のメンテナンス作業頻度や作業コストの低減が実現できる。
【００３１】
（実施形態４）
図４は本発明の実施形態４に係る張出軸受の構成を示す説明図であり、（Ａ）は軸心線に沿う断面図、（Ｂ）は（Ａ）におけるＤ−Ｄ線断面図である。
プロペラ４の回転が高速になれば、相対的にプロペラ軸２の軸径が細くなるので、張出軸受内部で軸が凸状に屈曲し易くなる。そのため、本発明は、プロペラ軸２が軸受本体６の船首側と船尾側の下側内面に加えて、軸受本体６の中央部上側内面にも当たる可能性が生じることに鑑みて提案された。
本実施形態は、実施形態３に示した軸受構造から、２つの円周溝９で挟まれた、軸受上側内面の給水溝８を除いたものである。
【００３２】
次に、以上のように構成した第４実施形態に係る張出軸受を用いた船舶の運転状況について説明する。
船舶運航時には、船舶が取水した海水（又は船舶に貯蔵している水でもよい）を２ヵ所の給水口７から連続的に或いは間欠的に注入する。注入された海水は２つの円周溝９を介して、軸受上側内面の給水溝８に入り、さらに該海水はそれぞれ船首方向、船尾方向の給水溝８に通っていき、軸受両端部まで達すると海中に排出される。軸受下側内面の給水溝８に入った海水は、円周溝９の圧力差に従って、どちらかの円周溝９に戻る。
軸受本体６の中央部上側内面の給水溝８を省いて軸受面１０を設けたことで、該中央部上側内面の軸受負荷能力を向上することができる。そのため、プロペラ軸２が軸受内部で凸状に撓み、軸受中央部でプロペラ軸２が持ち上がった場合においても軸受作用により軸を押し返すことができる。その結果、軸受摩耗を軽減したり、プロペラ軸の焼付きを防止できるので、張出軸受のメンテナンス作業頻度や作業コストの低減が実現できる。
【００３３】
（実施形態５）
図５は本発明の実施形態５にかかる張出軸受の構成を示す説明図であり、（Ａ）は軸心線に沿う断面図、（Ｂ）は（Ａ）におけるＥ−Ｅ線断面図である。
本実施形態は、船体１の船尾にある船尾管軸受（不図示）とブラケット３内部にある張出軸受までの距離を比較的短くとれる場合、船尾管軸受と張出軸受の位置関係によっては、軸荷重は張出軸受の船尾側のみにかかることに鑑みて提案された。
実施形態５の装置構成を、従来例を示す図８との差異で説明する。本実施形態では図８の円周溝９とそれに連通する給水口７の位置を、軸受中央部から船尾側寄りに設定する。更に、該円周溝９と軸受の船尾側端部との間の下側内面に軸受面１０を設ける。その他の構成は図８と同様である。
【００３４】
次に、以上のように構成した第５実施形態に係る張出軸受を用いた船舶の運転状況について説明する。
船舶運航時には、船舶が取水した海水（又は船舶に貯蔵している水でもよい）を給水口７から連続的に或いは間欠的に注入する。注水された海水は円周溝９を通り、船首側と船尾側の給水溝８に流れ、軸受の船首側と船尾側の端部から海中に排出される。
プロペラ軸２の荷重が張出軸受の船尾側に偏る場合、軸受の船尾側下側内面の軸受面１０でその荷重を支えることができる。その際、荷重が集中する船尾側に軸受面１０を設ければよいので、円周溝９とそれに連通する給水口７は、荷重条件に従ってなるべく船尾側に位置すればよい。円周溝９から船首側には、給水溝８を軸受内面全周に渡って設けているのでプロペラ軸２と軸受の冷却能力を低下させることがない。また、荷重が集中する箇所が船尾側の１ヵ所なので、実施形態１から４のように該集中箇所が２ないし３ヶ所ある場合に比べて、冷却用水の流量を減らすことができる。その結果、軸受摩耗を軽減したり、プロペラ軸２の焼付きを防止したり、軸受冷却用水量を減らすことができるので、張出軸受のメンテナンス作業頻度や作業コストの低減が実現できる。
【００３５】
（実施形態６）
図６は本発明の実施形態６に係る張出軸受の構成を示す説明図であり、（Ａ）は軸心線に沿う断面図、（Ｂ）は（Ａ）におけるＦ−Ｆ線断面図である。
本実施形態は、船体１の後尾にある船尾管軸受（不図示）とブラケット３内部にある張出軸受までの距離を比較的短くとれるために、船尾管軸受と張出軸受の位置関係によっては、軸荷重が張出軸受の船尾側のみにかかる場合、かつ船速が早い場合を鑑みて提案された。
実施形態６の装置構成は、図５の張出軸受構造から円周溝９とそれに連通する給水口７を省き、軸受の上側内面の給水溝を船首側から船尾側にかけて通じさせたものである。その他の構成は図５と同様である。
【００３６】
次に、以上のように構成した第６実施形態に係る張出軸受を用いた場合の運転状況について説明する。
船舶運航時には、海水が軸受の船首側端部から給水溝８に連続的に入り、船尾側端部から海中に排出される。
船速が早い場合、ポンプを利用して圧力をかけて冷却用水を給水口７に注入する替わりに、給水溝８に船速相当で流入する海水をそのまま冷却用水としても、プロペラ軸２と軸受の冷却能力を賄える。但し、船首側に軸受面１０を設けた軸受構造であると、軸受面１０が存在する周方向の給水溝８には冷却水が通じないので不適である。その結果、軸受構造から円周溝９、給水口７、給水に用いるポンプ及び冷却水用配管を廃したので軸受の構造を簡素化でき、軸受の製造コストの、また、海水を取水するポンプと取水した海水や予め用意した冷却用水を貯蔵するタンクが不要なので、軸受の周辺機器を設置するコストの低減が実現できる。更に、船舶運航時にこれらのポンプを運転するコストも不要とできる。加えて、軸受摩耗を軽減し、プロペラ軸の焼付きを防止したり、張出軸受のメンテナンス作業頻度や作業コストの低減が実現できる。
【００３７】
（実施形態７）
図示を省略した本発明の実施形態７は、プロペラ軸２とプロペラ４の自重以外の荷重を軸受が受けることを鑑みて提案された。この実施形態では、前記実施形態１ないし６の張出軸受において、プロペラ運転中にプロペラ軸２の自重、及びプロペラフォースのベクトル方向を含む周方向範囲に面した給水溝８を廃した構造とする。
プロペラ軸とプロペラの自重による軸受下側内面への荷重、およびプロペラ軸の撓みによる軸受上側内面への荷重だけでなく、船舶の旋回や海水の運動によってプロペラが受ける任意の方向の流体力に対しても軸受負荷能力を低下させることがない。その結果、軸受摩耗を軽減したり、プロペラ軸の焼付きを防止できるので、張出軸受のメンテナンス作業頻度や作業コストの低減が実現する。
【００３８】
（実施形態８）
図示を省略した本発明の実施形態８は、前記実施形態１、２の張出軸受において、軸受両端部へのプロペラ軸荷重が不均等な場合を鑑みて提案された。本実施形態は、円周溝９と該円周溝９に連通する給水口７の軸受軸方向位置を、軸受全長に対して船尾側から２０％ないし５０％、または船首側から１０％ないし５０％の範囲とした構造とする。船尾側からは２０％、船首側からは１０％とした理由は、船尾側にはプロペラ４が装着されるので、船尾側荷重が船首側荷重に比べて大きくなる。そのため、その大きくなる割合だけ軸受面１０の面積をより広く確保しなければならないので、円周溝９とそれに連通する給水口７との船尾側の設置位置の範囲は狭くなる。
本実施形態によれば、軸受両端部にプロペラ軸２の荷重が不均等に掛かる場合、軸受負荷能力を維持できるように軸受両端部の軸受面１０の面積を最低限確保し、それ以外の内面には軸受全周に給水溝８を配することで冷却能力を確保する。その結果、軸受摩耗を軽減したり、プロペラ軸の焼付きを防止できるので、張出軸受のメンテナンス作業頻度や作業コストの低減が実現する。
【００３９】
（実施形態９）
図示を省略した本発明の実施形態９は、前記実施形態３、４の張出軸受において、軸受両端部へのプロペラ軸荷重が不均等な場合を鑑みて提案された。本実施形態は、円周溝９と該円周溝９に連通する給水口７の軸受軸方向位置を、軸受全長に対して船尾側から２０％ないし５０％、及び船首側から１０％ないし５０％の範囲とした構造とする。船尾側からは２０％、船首側からは１０％とした理由は、船尾側にはプロペラ４が装着されるので、船尾側荷重が船首側荷重に比べて大きくなる。そのため、その大きくなる割合だけ軸受面１０の面積をより広く確保しなければならないので、円周溝９とそれに連通する給水口７との船尾側の設置位置の範囲は狭くなる。
本実施形態によれば、軸受両端部にプロペラ軸２の荷重が不均等に掛かる場合、軸受負荷能力を維持できるように軸受両端部の軸受面１０の面積を最低限確保し、それ以外の内面には軸受全周に給水溝８を配することで冷却能力を確保する。その結果、軸受摩耗を軽減したり、プロペラ軸の焼付きを防止できるので、張出軸受のメンテナンス作業頻度や作業コストの低減が実現する。
【００４０】
【発明の効果】
以上記載の如く、請求項１ないし５の発明によれば、給水溝を軸受本体の上側内面及び中央部下側内面に設け、該中央部下側内面の給水溝の両側に位置する端部下側内面を平滑な軸受面に構成したので、プロペラ軸の軸受本体の軸受負荷能力を低下させることなく該軸受本体の冷却効率を向上させることができる。これによって、軸受摩耗を軽減したり、プロペラ軸の焼付きを防止できるので、張出軸受のメンテナンス作業頻度や作業コストの低減に寄与する。
また、請求項６ないし７の発明によれば、軸受本体の片側端部の下側内面を平滑な軸受面に構成し、該軸受本体の内面の他の部位に前記給水溝を設けたので、張出軸受の軸受本体の船尾側端部における軸受負荷能力を維持できるとともに、軸受全体の冷却ができる。これによって、軸受摩耗を軽減したり、プロペラ軸の焼付きを防止できるので、張出軸受のメンテナンス作業頻度や作業コストの低減を実現できる。
【００４１】
また、請求項８の発明によれば、給水溝の一部を軸受面に直接開口したので、軸受構造を簡素化できる。これによって、軸受本体の製造コストの低減に寄与する。さらに、プロペラ軸と軸受の冷却に用いる冷却水用ポンプや周辺機器を不要とできるので、軸受周辺機器の製造コストや運転コストの低減に寄与する。
また、請求項９の発明によれば、プロペラ運転中にプロペラ軸の荷重を受ける方向に面した部位を平滑な軸受面としたので、船舶の旋回や海水の運動によってプロペラが受ける任意の方向の流体力に対しても軸受負荷能力を維持できる。これによって、軸受摩耗を軽減したり、プロペラ軸の焼付きを防止できるので、張出軸受のメンテナンス作業頻度や作業コストの低減を実現できる。
また、請求項１０の発明によれば、円周溝と該円周溝に連通する給水口との軸受軸方向位置を、軸受全長に対して船尾側から２０％ないし５０％の範囲、及び船首側から１０％ないし５０％の範囲の何れか一方または双方の範囲としたので、軸受本体の両端部へのプロペラ軸荷重が不均等な場合にも、軸受全体を均等に冷却できる。これによって、軸受摩耗を軽減したり、プロペラ軸の焼付きを防止できるので、張出軸受のメンテナンス作業頻度や作業コストの低減を実現できる。
【図面の簡単な説明】
【図１】本発明の実施形態１にかかる張出軸受の構成を示す説明図である。
【図２】本発明の実施形態２にかかる張出軸受の構成を示す説明図である。
【図３】本発明の実施形態３にかかる張出軸受の構成を示す説明図である。
【図４】本発明の実施形態４にかかる張出軸受の構成を示す説明図である。
【図５】本発明の実施形態５にかかる張出軸受の構成を示す説明図である。
【図６】本発明の実施形態６にかかる張出軸受の構成を示す説明図である。
【図７】張出軸受を設置する船体後部の構成を示す説明図である。
【図８】張出軸受の従来技術を示す説明図である。
【図９】張出軸受の従来技術を示す説明図である。
【符号の説明】
６　軸受本体
７　給水口
８　給水溝
９　円周溝
１０　軸受面
１１　第２円周溝[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an overhang bearing for a marine propeller shaft, which is used for a propeller bearing of a ship and has a water supply groove on the inner surface of the bearing body for allowing water such as seawater to cool the bearing body and the shaft.
[0002]
[Prior art]
FIG. 7 shows a stern structure in which an overhang bearing is used in a ship. In the figure, a propeller shaft 2 is installed so as to penetrate a stern portion of a hull 1 and a bracket 3 which is attached to the hull 1 so as to protrude from the hull 1, and a propeller 4 is mounted on an end of the stern side. A rudder 5 is installed on the hull 1 at a position on the stern side of the propeller 4. In this overhang bearing, the bearing body has a cylindrical shape and is provided inside the bracket 3 to support the propeller shaft load.
[0003]
The propeller shaft load mainly includes the following two types.
(1) Weight of propeller shaft 2 and propeller 4
(2) Fluid force when the ship turns
The weight of the propeller shaft 2 and the propeller 4 in (1) above is a load directed downward by the hull due to gravity. The fluid force at the time of turning the ship in the above (2) is a lateral load applied to the propeller 4 by seawater resistance in a direction perpendicular to the direction of movement of the ship. Therefore, excluding the load in any direction received by the movement of the seawater itself, the overhang bearing receives the own weight of the propeller shaft 2 and the propeller 4 when the ship goes straight, and when the ship turns, the overhang bearing generates the combined force of the own weight and the fluid force at the time of turning. receive.
[0004]
Since the entire bearing is submerged in the overhang bearing, a bearing mechanism having a movable portion that supports a propeller shaft load by a hydraulic mechanism is not generally used. Therefore, in order to support the axial load of the propeller shaft 2 by the bearing structure itself, a lignum bitter or rubber material having elasticity and lubricity is used for the material of the bearing inner surface. Lignum vita is a natural tree that grows in the tropics, is full of resin, has dense fibers, and has excellent self-lubricating properties.
Further, in order to remove heating due to friction between the propeller shaft 2 and the inner surface of the bearing main body and to prevent seizure of the propeller shaft 2, seawater or fresh water is passed through a clearance between the propeller shaft 2 and the inner surface of the bearing main body to cool.
[0005]
Next, the structure of the overhang bearing will be described. FIG. 8A is a cross-sectional view of the bearing body 6 along the axis, and FIG. 8B is a side view of FIG. The bearing body 6 is made of rubber or resin, and a water supply groove 8 for passing seawater in the axial direction is formed on the inner surface of the bearing body 6. The water supply groove 8 is communicated in the circumferential direction by a circumferential groove 9 provided at the center of the bearing, and a water supply port 7 is provided in the circumferential groove 9 so that water can be supplied from outside the bearing body 6.
During the operation of the ship, when the seawater taken in is supplied to the water supply port 7, the seawater flows into the water supply groove 8 through the circumferential groove 9, and is discharged into the sea from the bearing ends on the stern side and the bow side. When the water supply to the water supply port 7 is stopped or the water supply pressure is reduced, the seawater flows into the water supply groove 8 from the bearing end on the bow side, and is discharged from the stern side end. By flowing seawater on the inner surface of the bearing body 6 in this way, the bearing body 6 and the propeller shaft 2 are cooled, and a seawater film is formed in a gap between the inner surface of the bearing other than the water supply groove 8 and the outer surface of the propeller shaft 2. This seawater film plays the role of lubrication.
[0006]
A bearing in which the circumferential groove 9 and the water supply groove 8 are removed from the bearing structure of FIG. 8 is disclosed in Japanese Patent Application Laid-Open No. 2000-266047. In this example, a plurality of lubrication grooves are formed at predetermined intervals by bending a thin plate-like sliding material into a shape protruding in the thickness direction, and this sliding material is bent into a cylindrical shape and concentric with the inner periphery of the bearing. Are arranged in a way. Then, the seawater enters the lubrication groove from the bow end of the bearing and escapes from the stern end, whereby the seawater plays a role of lubrication between the propeller and the thin plate-shaped sliding member.
[0007]
Instead of cutting grooves in the axial direction of the bearing body 6, elongated flat plates made of a material having lubricity are arranged at equal intervals in the circumferential direction on the inner surface of the bearing. It has been disclosed. In this example, a rectangular parallelepiped elastic body having a predetermined size is provided on the inner peripheral portion of a cylindrical outer cylinder. In this case, the thickness of the flat plate becomes the depth of the groove.
[0008]
9A is a cross-sectional view along the axis of the bearing main body 6 with the lower inner surface of FIG. 8 as the bearing surface 10, and FIG. 9B is a side view of FIG. In the case of this structure, the load capacity of the bearing supporting the propeller shaft 2 is improved as compared with the case of FIG. 8, and the formation of a water film between the bearing surface 10 and the propeller shaft 2 by the rotation of the propeller shaft is easy. become.
However, since there is no water supply groove 8, the ability to cool the bearing and the propeller shaft 2 is reduced, so that the bearing wears faster.
In any of the overhang bearings shown in FIGS. 8 and 9, since the load capacity of the bearing supporting the propeller shaft 2 is a load per unit area of the bearing surface, the water supply groove 8 is provided as shown in FIG. 8. In this case, if the structure is equal in the axial direction, the propeller shaft 2 is supported by an area obtained by subtracting the circumferential width of the plurality of water supply grooves 8 from the inner circumferential length of the bearing body.
Propeller shaft bearings are described in detail in the "Grade 1 Marine Engine Mechanic Guide" (Nippon Foundation Business Result Library, Japan Marine Engine Maintenance Association, 1996).
[0009]
[Problems to be solved by the invention]
The overhang bearing according to the conventional technique described above has the following problems.
When a heavy propeller 4 is supported, the propeller shaft 2 hits against the stern of the overhang bearing. Further, since the distance from the stern tube bearing (not shown) in the hull to the bracket 3 is long, the propeller shaft 2 is bent in the bracket 3, and a large load is applied to both the bow side and the stern side of the overhang bearing. Occurs.
In this case, in the structure shown in FIG. 8, since the water supply groove 8 is provided on the inner surface on the lower side of the bearing, the bearing load capacity is lower and the wear rate of the bearing is faster than in a case where the water supply groove 8 is not provided.
In the structure shown in FIG. 9, although the bearing load capacity is maintained, the bow side and stern side ends that generate a large load are located farthest from the circumferential groove 9, and there is no water supply groove 8 on the load surface side. Therefore, there is a possibility that the cooling efficiency of the propeller shaft 2 and the bearing body 6 is poor, the wear rate of the bearing is increased, or seizure occurs.
[0010]
In view of the drawbacks of the related art, the present invention is applied to a propeller bearing of a marine vessel, and in an overhang bearing in which a plurality of water supply grooves are provided at equal intervals on an inner surface in an axial direction, a bearing without lowering the bearing load capacity of the bearing. Providing an overhang bearing that reduces wear and improves the cooling efficiency of the bearing to prevent seizure between the bearing and the propeller shaft, thereby reducing the maintenance work frequency and work cost of the overhang bearing. Aim.
[0011]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the present invention provides an overhanging bearing according to claim 1, wherein a propeller shaft of a ship is supported, and a plurality of water supply grooves are provided along an axial direction on an inner surface of a bearing body. Grooves are provided on the upper inner surface and the lower inner surface of the central portion of the bearing main body, and the lower end inner surfaces located on both sides of the water supply groove of the lower central inner surface are formed as smooth bearing surfaces. suggest.
According to the first aspect of the present invention, the cooling capacity of the lower inner surface of the bearing can be improved by providing the water supply groove in the lower inner surface of the central portion of the bearing without lowering the bearing load capacity at both ends of the bearing. As a result, bearing wear can be reduced and seizure of the propeller shaft can be prevented, so that the frequency of maintenance work and the cost of the overhang bearing can be reduced.
[0012]
According to a second aspect of the present invention, in the first aspect of the present invention, a circumferential groove connecting the water supply grooves on the upper inner surface and the lower inner surface at the center in the circumferential direction is provided, and is communicated with the outer peripheral surface of the bearing body. A water supply port is connected to the circumferential groove, and a second circumferential groove is provided for connecting both side openings of the water supply groove on the lower inner surface of the central portion in a circumferential direction. According to the second aspect of the present invention, in addition to the first aspect, the second circumferential groove which connects the openings at both ends of the water supply groove on the lower inner surface of the center of the bearing in the circumferential direction is provided. Seawater penetrates into the bearing surface between the groove and the bearing end, and the function of the seawater as a lubricant and the function of a cooling medium work to maintain and cool the load capacity of the bearing. As a result, bearing wear can be reduced and seizure of the propeller shaft can be prevented, so that the frequency of maintenance work and the cost of the overhang bearing can be reduced.
[0013]
According to a third aspect of the present invention, in the first aspect of the present invention, a circumferential groove connecting the water supply grooves on the upper inner surface and the lower inner surface at the center in the circumferential direction is provided, and is communicated with the outer peripheral surface of the bearing body. A water supply port is connected to the circumferential groove, and a depth of the water supply groove on the lower inner surface of the central portion is formed so as to be shallower from the circumferential groove toward the bearing surface.
According to the third aspect of the present invention, in addition to the first aspect, the depth of the water supply groove on the lower inner surface of the center portion of the bearing is formed so as to be shallower from the circumferential groove toward the bearing surface. The cooling water supplied to the water supply groove is not drained through the circumferential groove, and by maintaining the water pressure drop in the axial direction in the water supply groove, the water pressure is supplied to the minute gap between the propeller shaft and the bearing surface. We can supply water. Therefore, seawater permeates into the bearing surface between the circumferential groove and the bearing end, and functions as a lubricant for the seawater and a function as a cooling medium, thereby maintaining and cooling the load capacity of the bearing. . As a result, bearing wear can be reduced and seizure of the propeller shaft can be prevented, so that the frequency of maintenance work and the cost of the overhang bearing can be reduced.
[0014]
The invention according to claim 4 is provided with two circumferential grooves connecting circumferentially the opening at both ends of the water supply groove on the lower inner surface of the central portion and the water supply groove on the upper inner surface, and on the outer peripheral surface of the bearing body. It is characterized in that the communicating water supply port is connected to each circumferential groove.
According to the fourth aspect of the present invention, in addition to the first aspect, the water supply pressure to the two water supply ports 7 is increased while monitoring the load state of the propeller shaft on the bearing surface formed on the lower inner surface of both ends of the bearing. The adjustment allows the entire bearing to be cooled evenly. As a result, uneven bearing wear in the axial direction can be suppressed, and local seizure of the propeller shaft can be prevented, so that the maintenance work frequency and work cost of the overhang bearing can be reduced.
[0015]
A fifth aspect of the present invention is characterized in that, in the fourth aspect of the present invention, a central upper inner surface sandwiched between the two circumferential grooves is a smooth bearing surface.
According to the fifth aspect of the present invention, in addition to the first and fourth aspects, it is possible to improve the bearing load capacity of the upper inner surface of the central portion of the bearing in response to the case where the propeller shaft bends inside the bearing body. it can. As a result, bearing wear can be reduced and seizure of the propeller shaft can be prevented, so that the frequency of maintenance work and the cost of the overhang bearing can be reduced.
[0016]
According to a sixth aspect of the present invention, there is provided an overhang bearing in which a propeller shaft of a ship is supported and a plurality of water supply grooves are provided along an axial direction on an inner surface of a bearing body, wherein a lower inner surface of one end of the bearing body is provided. The present invention is characterized in that it is formed on a smooth bearing surface, and the water supply groove is provided in another portion of the inner surface of the bearing body.
According to the invention described in claim 6, when the distance between the overhang bearing and the stern tube bearing installed in the hull is short, the load on the propeller shaft becomes the largest, and the stern-side end of the bearing body of the overhang bearing. , The bearing load capacity can be maintained, and the entire bearing can be cooled. As a result, bearing wear can be reduced and seizure of the propeller shaft can be prevented, so that the frequency of maintenance work and the cost of the overhang bearing can be reduced.
[0017]
The invention according to claim 7 is characterized in that, in the invention according to claim 6, each of the water supply grooves is connected in a circumferential direction, and a circumferential groove whose one side is open to the bearing surface is provided.
According to the seventh aspect of the present invention, in addition to the sixth aspect, seawater permeates from the circumferential groove to the bearing surface, and functions as a lubricant for the seawater and a function as a cooling medium, and Load capacity and cooling. As a result, bearing wear can be reduced and seizure of the propeller shaft can be prevented, so that the frequency of maintenance work and the cost of the overhang bearing can be reduced.
[0018]
The invention according to claim 8 is the invention according to claim 6, wherein a part of the water supply groove is directly opened to the bearing surface.
According to the eighth aspect of the present invention, in addition to the sixth aspect, the bearing can be cooled by seawater flowing into the water supply groove from the bow-side end of the bearing body. As a result, the structure of the bearing is simplified, and equipment such as a pump necessary for water supply is not required, so that the occurrence of troubles of the bearing is reduced, and the maintenance work frequency and work cost of the overhang bearing can be reduced.
[0019]
According to a ninth aspect of the present invention, in the first aspect of the present invention, a portion of the propeller shaft facing the direction in which the load is applied during the propeller operation is a smooth bearing surface. I do.
According to the ninth aspect of the present invention, in addition to any one of the first to eighth aspects, the load on the lower inner surface of the bearing due to the weight of the propeller shaft and the propeller, and the upper inner surface of the bearing due to the bending of the propeller shaft. The bearing load capacity can be maintained not only for the load but also for the fluid force in any direction that the propeller receives due to the turning of the ship or the motion of the seawater. As a result, bearing wear can be reduced and seizure of the propeller shaft can be prevented, so that the frequency of maintenance work and the cost of the overhang bearing can be reduced.
[0020]
According to a tenth aspect of the present invention, in the invention according to any one of the first and ninth aspects, a position in the bearing axial direction of the circumferential groove and the water supply port communicating with the circumferential groove is set to a total bearing length. On the other hand, the range is 20% to 50% from the stern side and / or 10% to 50% from the bow side.
According to the tenth aspect of the present invention, in addition to any one of the first to ninth aspects, when the propeller shaft loads on the both ends of the bearing body are uneven, the circumferential groove and the circumferential groove are different from each other. The entire bearing can be cooled uniformly by changing the position of the water supply port communicating with the water supply port. As a result, bearing wear can be reduced and seizure of the propeller shaft can be prevented, so that the frequency of maintenance work and the cost of the overhang bearing can be reduced.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail using embodiments shown in the drawings. However, the dimensions, materials, shapes, relative positions, and the like of the components described in this embodiment are not intended to limit the scope of the present invention thereto, unless otherwise specified. It is only an example.
(Embodiment 1)
1A and 1B are explanatory diagrams showing a configuration of an overhang bearing according to Embodiment 1 of the present invention, in which FIG. 1A is a cross-sectional view along an axis, and FIG. 1B is a cross-sectional view taken along line AA in FIG. is there.
In this embodiment, when the propeller weight is large, the propeller shaft 2 is bent because the bearing body 6 of the overhanging bearing is long, and the parts receiving the load of the propeller shaft 2 are located at both the bow and stern sides of the bearing. It is proposed in view of the fact that the bearings are concentrated and wear of the bearing is remarkable.
In FIG. 1, the bearing main body 6 has a cylindrical shape so that the propeller shaft 2 can pass therethrough, and is mounted in the bracket 3 shown in FIG. The material of the bearing body 6 is lignum vita having lubricity, rubber, synthetic resin or the like. The type of the synthetic resin is preferably phenol resin, nylon, Teflon (trademark of DuPont) or the like.
[0022]
Water supply grooves 8 having a constant width in the axial direction are arranged at equal intervals in the circumferential direction on the inner surface of the bearing body 6. At this time, the bearing body 6 is disposed near the center on the lower inner surface over the entire length of the bearing on the upper inner surface of the bearing body 6. The water supply groove 8 may be formed by shaving the inner surface of the bearing body 6 or may be formed by attaching an elongated flat lubricating material to the inner surface of the bearing body 6. The flat lubricating material does not need to be the same as the axial length of the bearing body 6, and a plurality of flat plates may be arranged and applied in the long side direction.
One circumferential groove 9 is provided on the inner surface of the central portion of the bearing body 6 in the circumferential direction. Further, a water supply port 7 is formed so as to communicate with the circumferential groove 9 from the outer peripheral surface of the bearing body 6.
In addition, second circumferential grooves 11 are provided at both ends of the water supply groove 8 for connecting the ends of the water supply grooves 8 provided on the lower inner surface near the center of the bearing body 6 in the circumferential direction.
The width and depth of the water supply groove 8, the circumferential groove 9, and the second circumferential groove 11, and the number of the water supply grooves 8 may be arbitrary. This is because the load condition on the bearing varies depending on the dimensions and operating conditions of the propeller shaft 2, and the required cooling capacity also varies.
[0023]
Next, an operation state of a ship using the overhang bearing configured as described above will be described. During the operation of the ship, the seawater taken by the ship (or the water stored in the ship) is continuously or intermittently injected from the water supply port 7. The injected seawater passes through the circumferential groove 9 into the water supply groove 8 in the bow direction and the stern direction. When the seawater reaches the second circumferential groove 11, the seawater travels in the circumferential direction of the bearing, passes through the water supply groove 8 on the upper inner surface toward the bearing end, and is discharged into the sea when reaching the end.
On the other hand, seawater leaking from the second circumferential groove or the water supply groove 8 penetrates into a minute gap between the bearing surface 10 on the lower inner surface of the both ends of the bearing and the outer surface of the propeller shaft 2, and a thin film of seawater is formed. create. This film functions as a lubricant for the propeller shaft 2 and the bearing surface 10.
[0024]
As described above, since the bearing surfaces 10 are provided at both ends of the bearing main body 6 with respect to the propeller shaft 2 which bends inside the bearing main body 6, it is possible to maintain the load capacity of the portion where the load is most applied. Further, since the water supply groove 8 is provided over the entire circumference at the portion near the center where the load is reduced, the cooling capacity is improved as compared with the case where the entire lower inner surface is the bearing surface 10. As a result, it is possible to reduce bearing wear in a portion where a large load is applied, or to prevent seizure of the propeller shaft 2, so that it is possible to reduce the maintenance work frequency and work cost of the overhang bearing.
[0025]
(Embodiment 2)
2A and 2B are explanatory diagrams illustrating a configuration of an overhang bearing according to a second embodiment of the present invention. FIG. 2A is a cross-sectional view along an axis, and FIG. 2B is a cross-sectional view taken along line BB in FIG. is there.
In this embodiment, when the propeller weight is large, the propeller shaft 2 is bent because the bearing body 6 of the overhanging bearing is long, and the parts receiving the load of the propeller shaft 2 are located at both the bow and stern sides of the bearing. It was proposed in view of the fact that the bearings were concentrated and the wear of the bearing was remarkable.
The device configuration of the second embodiment will be described with reference to differences from the first embodiment. In this embodiment, the two second circumferential grooves 11 in the first embodiment shown in FIG. 1 are omitted, and the depth of the water supply groove 8 on the lower inner surface of the central part of the bearing is gradually reduced in the axial direction toward the bearing surfaces 10 on both sides. To be shallow. Other configurations are the same as in the first embodiment.
[0026]
Next, an operation state of a boat using the overhang bearing according to the second embodiment configured as described above will be described. During the operation of the ship, the seawater taken by the ship (or the water stored in the ship) is continuously or intermittently injected from the water supply port 7. The injected seawater passes through the circumferential groove 9 into the water supply groove 8 in the bow direction and the stern direction. The seawater that has entered the water supply groove 8 on the inner surface of the bearing is discharged into the sea when it reaches both ends of the bearing. On the other hand, since the seawater that has entered the water supply groove 8 on the lower inner surface of the center part of the bearing has no destination to be discharged even if it is passed in the axial direction, the water supply pressure is maintained.
By maintaining the water supply pressure, seawater permeates with a constant water pressure into the minute gap between the propeller shaft 2 and the bearing surface 10, so that the function as a lubricant for the seawater and the function as a cooling medium are improved. It works reliably and contributes to maintenance of load capacity and cooling of bearings. As a result, it is possible to reduce bearing wear in a portion where a large load is applied and prevent seizure of the propeller shaft, thereby realizing a reduction in maintenance work frequency and work cost of the overhang bearing.
[0027]
(Embodiment 3)
3A and 3B are explanatory diagrams illustrating a configuration of an overhang bearing according to Embodiment 3 of the present invention. FIG. 3A is a cross-sectional view along an axis, and FIG. 3B is a cross-sectional view taken along line CC in FIG. is there.
In this embodiment, when the load of the propeller shaft 2 received on the bow side and the stern side of the bearing is different from each other, the amount of wear of the bearing becomes uneven, and the speed is controlled by the bearing portion where the amount of wear is locally largest, and It has been suggested in view of the need to maintain.
The device configuration of the third embodiment will be described with reference to differences from the first embodiment. In this embodiment, the circumferential groove 9 and the water supply port 7 in the first embodiment shown in FIG. 1 are omitted, and the two second circumferential grooves 11 provided so as to sandwich the circumferential groove 9 are replaced with two circumferential grooves. 9, and the water supply port 7 was connected to each. Other configurations are the same as in the first embodiment.
[0028]
Next, an operation state of a boat using the overhang bearing according to the third embodiment configured as described above will be described.
During the operation of the ship, the seawater taken by the ship (or the water stored in the ship) is continuously or intermittently injected from two water supply ports 7. The injected seawater passes through the two circumferential grooves 9 into the water supply grooves 8 in the bow direction and the stern direction. The seawater that has entered the water supply groove 8 on the inner surface of the bearing is discharged into the sea when it reaches both ends of the bearing.
In this case, if a difference is made in the water supply pressure to the water supply port 7, the seawater that has entered the water supply groove 8 on the lower inner surface of the center of the bearing returns to one of the two circumferential grooves 9 and returns to the water supply groove 8 on the upper inner surface. Facing the end of the bearing. Which of the two circumferential grooves 9 the seawater that has entered the water supply groove 8 on the lower inner surface of the bearing central portion is determined by the difference between the water pressures in the two circumferential grooves 9, and the circumferential groove 9 having a low water pressure. Return to Since a water pressure distribution is formed along the circumferential groove 9 and the water supply groove 8 throughout the bearing, there is no portion where seawater stays inside the bearing. When the water pressures of the two circumferential grooves 9 are equal to each other, the water pressure of the water supply groove 8 on the lower inner surface of the central part of the bearing is maintained at the water pressure of the circumferential groove 9 as in the second embodiment.
[0029]
If there is a difference between the water supply pressures to the two water supply ports 7, the seawater flows toward the bow and stern side from the circumferential groove 9 where the water supply pressure is set high. When the axial load on the bow-side and stern-side bearing surfaces 10 is different, the water supply pressure of the water supply port 7 on the side with the large axial load is increased, so that the water supply groove 8 on the side with the large axial load has a lower temperature rise. Can supply seawater. Therefore, by providing a difference in water supply pressure according to the magnitude of the shaft load, the cooling capacity for a portion where the shaft load is relatively large can be higher, and the cooling capacity for a portion where the shaft load is relatively small can be lower. As a result, there is no locally heated area on the inner surface of the bearing, and the temperature distribution of the entire bearing becomes uniform, so that maintenance for local heating damage is not required. Cost reduction can be realized.
[0030]
On the other hand, since the axial loads on the bow side and the stern side are almost equal, when the water supply pressure to the two water supply ports 7 is made equal, the water pressure in the water supply groove 8 on the lower inner surface of the central part of the bearing is the same as the water pressure in the circumferential groove 9. Is held. Therefore, the same action as in the second embodiment occurs, and seawater permeates with a constant water pressure from the circumferential groove 9 into the minute gap between the propeller shaft 2 and the bearing surface 10, so that the seawater lubricant and the cooling medium serve as a cooling medium. Functions work reliably, contributing to bearing cooling and maintaining load capacity. As a result, bearing wear can be reduced and seizure of the propeller shaft can be prevented, so that the frequency of maintenance work and the cost of the overhang bearing can be reduced.
[0031]
(Embodiment 4)
4A and 4B are explanatory diagrams illustrating a configuration of an overhang bearing according to Embodiment 4 of the present invention, in which FIG. 4A is a cross-sectional view along an axis, and FIG. 4B is a cross-sectional view taken along line DD in FIG. is there.
If the rotation speed of the propeller 4 becomes higher, the diameter of the propeller shaft 2 becomes relatively smaller, so that the shaft is easily bent in a convex shape inside the overhang bearing. Therefore, the present invention has been proposed in view of the possibility that the propeller shaft 2 may hit not only the lower inner surfaces of the bow and stern sides of the bearing main body 6 but also the inner upper surface of the central part of the bearing main body 6.
This embodiment is different from the bearing structure shown in the third embodiment in that the water supply groove 8 on the inner surface of the bearing upper side sandwiched between the two circumferential grooves 9 is removed.
[0032]
Next, an operation state of a ship using the overhang bearing according to the fourth embodiment configured as described above will be described.
During the operation of the ship, the seawater taken by the ship (or the water stored in the ship) is continuously or intermittently injected from two water supply ports 7. The injected seawater enters the water supply groove 8 on the inner side of the bearing via the two circumferential grooves 9, and the seawater passes through the water supply grooves 8 in the bow direction and the stern direction, respectively, and reaches the both ends of the bearing. Released into the sea. The seawater that has entered the water supply groove 8 on the lower inner surface of the bearing returns to one of the circumferential grooves 9 according to the pressure difference of the circumferential groove 9.
By omitting the water supply groove 8 on the upper inner surface of the central portion of the bearing body 6 and providing the bearing surface 10, the bearing load capacity of the inner upper surface of the central portion can be improved. Therefore, even when the propeller shaft 2 bends in a convex shape inside the bearing and the propeller shaft 2 is lifted at the center of the bearing, the shaft can be pushed back by the bearing action. As a result, bearing wear can be reduced and seizure of the propeller shaft can be prevented, so that the frequency of maintenance work and the cost of the overhang bearing can be reduced.
[0033]
(Embodiment 5)
5A and 5B are explanatory views showing a configuration of an overhang bearing according to a fifth embodiment of the present invention, wherein FIG. 5A is a cross-sectional view along an axis, and FIG. 5B is a cross-sectional view taken along line EE in FIG. is there.
In the present embodiment, when the distance between the stern tube bearing (not shown) at the stern of the hull 1 and the overhang bearing inside the bracket 3 can be made relatively short, depending on the positional relationship between the stern tube bearing and the overhang bearing, It was proposed in view of the fact that the shaft load is applied only on the stern side of the overhang bearing.
The device configuration of the fifth embodiment will be described with reference to differences from FIG. 8 showing a conventional example. In this embodiment, the positions of the circumferential groove 9 and the water supply port 7 communicating therewith in FIG. 8 are set closer to the stern side from the center of the bearing. Further, a bearing surface 10 is provided on a lower inner surface between the circumferential groove 9 and the stern end of the bearing. Other configurations are the same as those in FIG.
[0034]
Next, an operation state of a ship using the overhang bearing according to the fifth embodiment configured as described above will be described.
During the operation of the ship, the seawater taken by the ship (or the water stored in the ship) is continuously or intermittently injected from the water supply port 7. The injected seawater passes through the circumferential groove 9, flows into the water supply grooves 8 on the bow side and the stern side, and is discharged into the sea from the bow and stern side ends of the bearing.
When the load of the propeller shaft 2 is biased toward the stern side of the overhang bearing, the load can be supported by the bearing surface 10 on the lower inner surface of the stern side of the bearing. At that time, the bearing surface 10 may be provided on the stern side where the load is concentrated, so that the circumferential groove 9 and the water supply port 7 communicating therewith may be located on the stern side as much as possible according to the load condition. The water supply groove 8 is provided from the circumferential groove 9 to the bow side over the entire inner surface of the bearing, so that the cooling capacity of the propeller shaft 2 and the bearing does not decrease. Further, since the load is concentrated at one location on the stern side, the flow rate of the cooling water can be reduced as compared with the case where the concentration location is two or three as in the first to fourth embodiments. As a result, bearing wear can be reduced, seizure of the propeller shaft 2 can be prevented, and the amount of water for cooling the bearing can be reduced, so that the maintenance work frequency and work cost of the overhang bearing can be reduced.
[0035]
(Embodiment 6)
6A and 6B are explanatory diagrams illustrating a configuration of an overhang bearing according to Embodiment 6 of the present invention, in which FIG. 6A is a cross-sectional view along an axis, and FIG. 6B is a cross-sectional view taken along line FF in FIG. is there.
In this embodiment, since the distance between the stern tube bearing (not shown) at the rear of the hull 1 and the overhang bearing inside the bracket 3 can be made relatively short, depending on the positional relationship between the stern tube bearing and the overhang bearing. It has been proposed in consideration of the case where the shaft load is applied only to the stern side of the overhang bearing and the case where the ship speed is high.
The device configuration of the sixth embodiment is such that the circumferential groove 9 and the water supply port 7 communicating therewith are omitted from the overhang bearing structure of FIG. 5, and the water supply groove on the upper inner surface of the bearing is connected from the bow side to the stern side. . Other configurations are the same as those in FIG.
[0036]
Next, an operation state when the overhang bearing according to the sixth embodiment configured as described above is used will be described.
During the operation of the ship, the seawater continuously enters the water supply groove 8 from the bow-side end of the bearing, and is discharged into the sea from the stern-side end.
When the ship speed is high, instead of using a pump to apply pressure to inject cooling water into the water supply port 7, instead of using seawater flowing into the water supply groove 8 at a speed equivalent to the ship speed as it is as cooling water, the propeller shaft 2 and the bearing Cooling capacity. However, a bearing structure in which the bearing surface 10 is provided on the bow side is not suitable because cooling water does not pass through the circumferential water supply groove 8 where the bearing surface 10 exists. As a result, the circumferential groove 9, the water supply port 7, the pump used for water supply, and the cooling water pipe are eliminated from the bearing structure, so that the structure of the bearing can be simplified, the production cost of the bearing is reduced, and a pump for taking in seawater is provided. Since there is no need for a tank for storing the seawater taken in or the cooling water prepared in advance, it is possible to reduce the cost of installing peripheral devices for the bearing. Furthermore, the cost of operating these pumps when operating a ship can be eliminated. In addition, bearing wear can be reduced, seizure of the propeller shaft can be prevented, and the maintenance work frequency and work cost of the overhang bearing can be reduced.
[0037]
(Embodiment 7)
Embodiment 7 of the present invention, not shown, has been proposed in view of the fact that the bearing receives a load other than its own weight of the propeller shaft 2 and the propeller 4. In this embodiment, in the overhang bearing according to any one of the first to sixth embodiments, the water supply groove 8 facing the circumferential range including the own weight of the propeller shaft 2 and the vector direction of the propeller force during the propeller operation is eliminated. .
Not only the load on the lower inner surface of the bearing due to the propeller shaft and propeller's own weight, and the load on the upper inner surface of the bearing due to the deflection of the propeller shaft, but also the fluid force in any direction that the propeller receives due to the turning of the ship or the movement of seawater However, the bearing load capacity is not reduced. As a result, bearing wear can be reduced and seizure of the propeller shaft can be prevented, so that the frequency of maintenance work and the cost of the overhang bearing can be reduced.
[0038]
(Embodiment 8)
Embodiment 8 of the present invention, not shown, has been proposed in view of the case where the propeller shaft loads on both ends of the bearing are uneven in the overhang bearings of Embodiments 1 and 2. In this embodiment, the position of the circumferential groove 9 and the water supply port 7 communicating with the circumferential groove 9 in the bearing axial direction is 20% to 50% from the stern side or 10% to 50% from the bow side with respect to the entire bearing length. %. The reason for setting 20% from the stern side and 10% from the bow side is that the stern side is mounted with the propeller 4, so that the stern side load is larger than the bow side load. For this reason, the area of the bearing surface 10 must be kept wider by an increasing ratio, so that the range of the installation position on the stern side between the circumferential groove 9 and the water supply port 7 communicating therewith is narrowed.
According to the present embodiment, when the load of the propeller shaft 2 is unevenly applied to both ends of the bearing, the area of the bearing surface 10 at both ends of the bearing is secured to a minimum so that the bearing load capacity can be maintained. The cooling capacity is ensured by arranging a water supply groove 8 all around the bearing. As a result, bearing wear can be reduced and seizure of the propeller shaft can be prevented, so that the frequency of maintenance work and the cost of the overhang bearing can be reduced.
[0039]
(Embodiment 9)
The ninth embodiment of the present invention, not shown, has been proposed in view of the case where the propeller shaft loads on both ends of the bearing are uneven in the overhang bearings of the third and fourth embodiments. In this embodiment, the position of the circumferential groove 9 and the water supply port 7 communicating with the circumferential groove 9 in the bearing axial direction is 20% to 50% from the stern side and 10% to 50% from the bow side with respect to the entire bearing length. %. The reason for setting 20% from the stern side and 10% from the bow side is that the stern side is mounted with the propeller 4, so that the stern side load is larger than the bow side load. For this reason, the area of the bearing surface 10 must be kept wider by an increasing ratio, so that the range of the installation position on the stern side between the circumferential groove 9 and the water supply port 7 communicating therewith is narrowed.
According to the present embodiment, when the load of the propeller shaft 2 is unevenly applied to both ends of the bearing, the area of the bearing surface 10 at both ends of the bearing is secured to a minimum so that the bearing load capacity can be maintained. The cooling capacity is ensured by arranging a water supply groove 8 all around the bearing. As a result, bearing wear can be reduced and seizure of the propeller shaft can be prevented, so that the frequency of maintenance work and the cost of the overhang bearing can be reduced.
[0040]
【The invention's effect】
As described above, according to the first to fifth aspects of the present invention, the water supply groove is provided on the upper inner surface and the lower inner surface of the central portion of the bearing body, and the lower inner surface of the end located on both sides of the water supply groove on the lower inner surface of the center portion. Because of the smooth bearing surface, the cooling efficiency of the bearing body can be improved without lowering the bearing load capacity of the bearing body of the propeller shaft. As a result, bearing wear can be reduced and seizure of the propeller shaft can be prevented, which contributes to reduction in maintenance work frequency and work cost of the overhang bearing.
According to the invention of claims 6 and 7, the lower inner surface of one end of the bearing body is formed as a smooth bearing surface, and the water supply groove is provided at another portion of the inner surface of the bearing body. The bearing load capacity at the stern end of the bearing body of the overhang bearing can be maintained, and the entire bearing can be cooled. As a result, bearing wear can be reduced and seizure of the propeller shaft can be prevented, so that maintenance work frequency and work cost of the overhang bearing can be reduced.
[0041]
According to the invention of claim 8, a part of the water supply groove is directly opened in the bearing surface, so that the bearing structure can be simplified. This contributes to reducing the manufacturing cost of the bearing body. Further, a cooling water pump and peripheral equipment used for cooling the propeller shaft and the bearing can be omitted, which contributes to a reduction in manufacturing cost and operation cost of the bearing peripheral equipment.
According to the ninth aspect of the present invention, the portion facing the direction receiving the load of the propeller shaft during the operation of the propeller is a smooth bearing surface. The bearing load capacity can be maintained even with respect to the fluid force. As a result, bearing wear can be reduced and seizure of the propeller shaft can be prevented, so that maintenance work frequency and work cost of the overhang bearing can be reduced.
According to the tenth aspect of the present invention, the axial position of the circumferential groove and the water supply port communicating with the circumferential groove is in the range of 20% to 50% from the stern side with respect to the entire bearing length, and the bow. Since either one or both of the ranges of 10% to 50% from the side are set, even when the propeller shaft loads on both ends of the bearing body are uneven, the entire bearing can be uniformly cooled. As a result, bearing wear can be reduced and seizure of the propeller shaft can be prevented, so that maintenance work frequency and work cost of the overhang bearing can be reduced.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing a configuration of an overhang bearing according to a first embodiment of the present invention.
FIG. 2 is an explanatory diagram illustrating a configuration of an overhang bearing according to a second embodiment of the present invention.
FIG. 3 is an explanatory diagram showing a configuration of an overhang bearing according to a third embodiment of the present invention.
FIG. 4 is an explanatory diagram illustrating a configuration of an overhang bearing according to a fourth embodiment of the present invention.
FIG. 5 is an explanatory diagram showing a configuration of an overhang bearing according to a fifth embodiment of the present invention.
FIG. 6 is an explanatory diagram showing a configuration of an overhang bearing according to a sixth embodiment of the present invention.
FIG. 7 is an explanatory view showing a configuration of a rear part of a hull where an overhang bearing is installed.
FIG. 8 is an explanatory view showing a conventional technique of an overhang bearing.
FIG. 9 is an explanatory view showing a conventional technique of an overhang bearing.
[Explanation of symbols]
6 Bearing body
7 water inlet
8 Water supply ditch
9 circumferential groove
10 Bearing surface
11 Second circumferential groove

Claims

In an overhang bearing which supports a propeller shaft of a ship and has a plurality of water supply grooves provided along an axial direction on an inner surface of a bearing body, the water supply grooves are provided on an upper inner surface and a lower inner surface of a center portion of the bearing body. An overhang bearing for a marine propeller shaft, wherein the lower inner surface at the end located on both sides of the water supply groove on the lower inner surface is formed as a smooth bearing surface.

A circumferential groove connecting the water supply grooves on the upper inner surface and the lower inner surface of the central portion in the circumferential direction is provided, and a water supply port communicating with the outer peripheral surface of the bearing body is connected to the circumferential groove, and 2. An overhang bearing for a marine propeller shaft according to claim 1, wherein a second circumferential groove is provided for connecting both side openings of the water supply groove on the inner surface in a circumferential direction.

Providing a circumferential groove connecting the water supply grooves on the upper inner surface and the lower inner surface of the central portion in a circumferential direction, connecting a water supply port communicating with the outer peripheral surface of the bearing body to the circumferential groove, and 2. An overhang bearing for a marine propeller shaft according to claim 1, wherein the depth of the water supply groove on the inner surface is formed so as to be shallower from the circumferential groove toward the bearing surface.

Two circumferential grooves connecting the water supply grooves on both ends of the water supply groove on the lower inner surface of the center portion and the water supply groove on the upper inner surface in a circumferential direction are provided, and a water supply port communicating with the outer peripheral surface of the bearing body is formed in each circle. 2. The overhang bearing for a marine propeller shaft according to claim 1, wherein the overhang bearing is connected to the circumferential groove.

The overhang bearing for a marine propeller shaft according to claim 4, wherein an upper inner surface of a central portion sandwiched between the two circumferential grooves is a smooth bearing surface.

In a projecting bearing in which a propeller shaft of a ship is supported and a plurality of water supply grooves are provided along an axial direction on an inner surface of a bearing body, a lower inner surface of one end of the bearing body is formed as a smooth bearing surface, An overhang bearing for a marine propeller shaft, wherein the water supply groove is provided in another portion of the inner surface of the bearing body.

The overhang bearing for a marine propeller shaft according to claim 6, wherein the water supply groove is connected in a circumferential direction, and a circumferential groove having one side opening in the bearing surface is provided.

7. An overhang bearing for a marine propeller shaft according to claim 6, wherein a part of said water supply groove is opened directly to said bearing surface.

In an overhang bearing that supports the propeller shaft of a ship and has a plurality of water supply grooves along the axial direction on the inner surface of the bearing body, the part facing the direction in which the load on the propeller shaft is applied during propeller operation is a smooth bearing surface. The overhang bearing for a marine propeller shaft according to any one of claims 1 to 8, characterized in that:

In an overhang bearing which supports a propeller shaft of a ship and has a plurality of water supply grooves provided along an axial direction on an inner surface of a bearing body, a position of the water supply port communicating with the circumferential groove and the water supply port in a bearing axial direction. 10. The method according to claim 1, wherein the distance is set in a range of 20% to 50% from the stern side and / or in a range of 10% to 50% from the bow side with respect to the entire bearing length. An overhang bearing for a marine propeller shaft according to any one of the above items.