JP2004181991A

JP2004181991A - Electric power steering device

Info

Publication number: JP2004181991A
Application number: JP2002347884A
Authority: JP
Inventors: Hiroyuki Shigemura; 博之重村; Masafumi Uota; 雅史魚田; Wataru Yamada; 渉山田; Yoshihito Shibamura; 祥仁柴村
Original assignee: Koyo Seiko Co Ltd
Current assignee: Koyo Seiko Co Ltd
Priority date: 2002-11-29
Filing date: 2002-11-29
Publication date: 2004-07-02
Anticipated expiration: 2022-11-29
Also published as: JP4032945B2

Abstract

<P>PROBLEM TO BE SOLVED: To smoothly move a bearing member, the movement of which is restricted in a direction to cross with the direction where a distance between rotating centers becomes long and short, in the direction where the distance between the rotating centers becomes long and short. <P>SOLUTION: This electric power steering device is provide with the bearing member 8 having a bearing hole 81 into which a shaft 3b of a worm 3 is inserted and free to move in the direction where the distance H between the rotating centers of the worm 3 and a worm wheel 4 becomes long and short, a supporting member 7 having a storage hole 75 to store the bearing member 8 in it, ring grooves 82, 83 into which an elastic ring 17 to contact with a peripheral surface of the storage hole 75 is inserted and a communicating groove 84 to communicate to the ring grooves by a groove deeper than the ring grooves from both sides of the ring grooves 82, 83 and to communicate both ends 8a, 8b on the moving side of the bearing member 8 to each other. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は操舵補助力の発生源としてモータを用いてなる電動式パワーステアリング装置に関する。
【０００２】
【従来の技術】
車両用の電動式パワーステアリング装置は、操舵補助用のモータ及び該モータの回転力を舵取手段に伝える減速歯車機構を備えており、操舵手段の回転に応じた舵取手段の動作を前記モータの回転により補助し、舵取りのための運転者の労力負担を軽減するように構成されている。
【０００３】
減速歯車機構はその一端部が前記モータの出力軸に継合される駆動歯車と、該駆動歯車に噛合し、舵取手段に繋がる従動歯車と、前記駆動歯車の他端部が挿入される軸受孔を有し、駆動歯車及び従動歯車の回転中心間距離が長短となる方向への移動が可能な円柱形の軸受部材と、該軸受部材を収容する収容孔を有する支持部材とを備え、軸受部材を移動操作することにより、駆動歯車及び従動歯車の回転中心間距離を調整し、駆動歯車及び従動歯車の噛合部のバックラッシュ量を少なくして転舵時のバックラッシュによる歯打ち音をなくするように構成されている。（例えば、特許文献１。）
【０００４】
また、減速歯車機構のウォーム歯車等は回転中心線に対しその歯すじが回転方向へ捩じれており、ウォームからウォームホイールへ回転トルクが加わるとき、換言すればモータの回転によって操舵補助する場合、ウォームがウォームホイールの歯すじに沿って径方向へ動くように分力（以下噛合反力と云う）が発生する。この噛合反力によりウォームが径方向へ押圧され、この押圧力により前記軸受部材が前記収容孔内で前記回転中心間距離が長短となる方向と交差する方向へ動き、該軸受部材が収容孔に当接して音鳴りすることになる。このため、特許文献１にあっては、前記軸受部材の周面で前記軸受孔に対し両側位置に環状溝を設け、各環状溝にＯリングからなる弾性環を挿入保持することにより、軸受部材の動きを制限し、前記した音鳴りをなくするように構成されている。
【０００５】
【特許文献１】
特開２００２−２１９４３号公報
【０００６】
【発明が解決しようとする課題】
ところが、特許文献１のように軸受部材の周面に弾性環が設けられた電動式パワーステアリング装置にあっては、弾性環が収容孔の周面に接触し、軸受部材及び収容孔の周面間で収容孔内が弾性環によって隔離されるため、軸受部材の動き側の端と収容孔との間に密封空間が発生する。従って、軸受部材が前記回転中心間距離が長短となる方向へ移動する場合、密封空間内の空気が圧縮され、密封空間の内圧が上昇することになり、軸受部材の移動が抑制されることになり、改善策が要望されていた。
【０００７】
本発明は斯かる事情に鑑みてなされたものであり、弾性体によって回転中心間距離が長短となる方向と交差する方向への動きが制限された軸受部材を回転中心間距離が長短となる方向へスムーズに移動させることができる電動式パワーステアリング装置を提供することを目的とする。
【０００８】
【課題を解決するための手段】
第１発明に係る電動式パワーステアリング装置は、モータの出力軸に軸継手を介して継合され、反モータ側に軸部を有する駆動歯車と、該駆動歯車に噛合し、舵取手段に繋がる従動歯車と、前記軸部を支持し駆動歯車及び従動歯車の回転中心間距離が長短となる方向への移動が可能な軸受部材と、該軸受部材を収容する収容孔を有する支持部材と、前記軸受部材及び収容孔間に配置された弾性環とを備え、前記モータの回転によって操舵補助するようにした電動式パワーステアリング装置において、前記軸受部材又は支持部材は前記弾性環が挿入された環状溝と、該環状溝の両側から環状溝よりも深い溝で環状溝に連通し、前記軸受部材の移動側両端部を連通させる連通溝とを有することを特徴とする。
【０００９】
第１発明にあっては、軸受部材及び収容孔の周面間で収容孔内が弾性環によって隔離されているが、弾性環が挿入された環状溝の両側から環状溝よりも深い溝で環状溝に連通し、軸受部材の移動側両端部を連通させる連通溝を有するため、前記回転中心間距離が長短となる方向へ軸受部材が移動する場合、該軸受部材をスムーズに移動させることができる。また、連通溝は環状溝を有する部材に設けられているため、軸受部材が前記回転中心間距離が長短となる方向へ移動する場合の弾性環の連通溝による損傷をなくすることができ、弾性環の耐久性を高めることができる。また、連通溝にはグリース等の潤滑剤を溜めることができるため、軸受部材が前記回転中心間距離が長短となる方向へ移動する場合の弾性環及び該弾性環が接触する周面の摩耗を低減でき、耐久性を高めることができる。
【００１０】
第２発明に係る電動式パワーステアリング装置は、モータの出力軸に軸継手を介して継合され、反モータ側に軸部を有する駆動歯車と、該駆動歯車に噛合し、舵取手段に繋がる従動歯車と、前記軸部が挿入された軸受孔を有し駆動歯車及び従動歯車の回転中心間距離が長短となる方向への移動が可能な軸受部材と、該軸受部材を収容する収容孔を有する支持部材と、前記軸受部材及び収容孔間に配置された弾性環とを備え、前記モータの回転によって操舵補助するようにした電動式パワーステアリング装置において、前記軸受部材は移動側両端部から前記軸受孔にかけて貫通する孔を有することを特徴とする。
【００１１】
第２発明にあっては、軸受部材及び収容孔の周面間で収容孔内が弾性環によって隔離されているが、軸受部材の移動側両端部及び収容孔間の空間内と軸受孔とは孔により連通しているため、前記回転中心間距離が長短となる方向へ軸受部材が移動する場合、該軸受部材をスムーズに移動させることができる。また、孔は軸受部材の移動側端部から軸受孔にかけて貫通しているため、軸受部材が前記回転中心間距離が長短となる方向へ移動する場合の弾性環の孔による損傷をなくすることができ、弾性環の耐久性を高めることができる。また、軸受部材の孔にはグリース等の潤滑剤を溜めることができるため、軸受孔に挿入支持される駆動歯車の軸受部材との接触抵抗を低減できる。
【００１２】
第３発明に係る電動式パワーステアリング装置は、モータの出力軸に軸継手を介して継合され、反モータ側に軸部を有する駆動歯車と、該駆動歯車に噛合し、舵取手段に繋がる従動歯車と、前記軸部が挿入された軸受孔を有し駆動歯車及び従動歯車の回転中心間距離が長短となる方向への移動が可能な軸受部材と、該軸受部材を収容する収容孔を有する支持部材と、前記軸受部材及び収容孔間に配置された弾性環とを備え、前記モータの回転によって操舵補助するようにした電動式パワーステアリング装置において、前記軸受部材又は支持部材は前記弾性環が挿入された環状溝と、該環状溝の両側から環状溝よりも深い溝で環状溝に連通し、前記軸受部材の移動側両端部を連通させる連通溝とを有しており、前記軸受部材は移動側両端部から前記軸受孔にかけて貫通する孔を有することを特徴とする。
【００１３】
第３発明にあっては、軸受部材及び収容孔の周面間で収容孔内が弾性環によって隔離されているが、環状溝の両側から環状溝よりも深い溝で環状溝に連通する連通溝と、軸受部材の移動側両端部から軸受孔にかけて貫通する孔とを有するため、前記回転中心間距離が長短となる方向へ軸受部材が移動する場合、該軸受部材をより一層スムーズに移動させることができる。
【００１４】
また、連通溝は環状溝を有する部材に設けられており、孔は軸受部材に設けられているため、軸受部材が前記回転中心間距離が長短となる方向へ移動する場合の弾性環の連通溝及び孔による損傷をなくすることができ、弾性環の耐久性を高めることができる。また、連通溝及び孔にはグリース等の潤滑剤を溜めることができるため、軸受部材が前記回転中心間距離が長短となる方向へ移動する場合の弾性環及び該弾性環が接触する周面の摩耗を低減でき、さらに、軸受孔に挿入支持される駆動歯車の軸受部材との接触抵抗を低減できる。
【００１５】
【発明の実施の形態】
以下本発明をその実施の形態を示す図面に基づいて詳述する。
実施の形態１
図１は本発明に係る電動式パワーステアリング装置の減速歯車機構部分の構成を示す拡大断面図、図２は電動式パワーステアリング装置の全体構成を示す断面図、図３は軸受部材部分を拡大した横断平面図、図４は軸受部材の構成を示す側面図、図５は軸受部材部分を拡大した横断平面図である。
【００１６】
電動式パワーステアリング装置は、操舵補助用のモータ１と、該モータ１の出力軸１ａに雄形継手部２１及び雌形継手部２２を有する軸継手２を介して継合される駆動歯車としてのウォーム３及び該ウォーム３に噛合する従動歯車としてのウォームホイール４を有する減速歯車機構Ａと、該減速歯車機構Ａに繋がる舵取手段５とを備えている。
【００１７】
この舵取手段５は、一端部が舵取りのための操舵輪Ｂに繋がり、他端部に筒部５１ａを有する第１の操舵軸５１と、筒部５１ａ内に挿入されてその一端部が第１の操舵軸５１の筒部５１ａに連結され、操舵輪Ｂに加わる操舵トルクの作用によって捩れるトーションバー５２と、他端部がトーションバー５２の他端部に連結され、減速歯車機構Ａに繋がる第２の操舵軸５３とを備え、該第２の操舵軸５３がユニバーサルジョイントを介して例えばラックピニオン式の舵取機構（不図示）に繋がる。
【００１８】
減速歯車機構Ａのウォーム３は両端に軸部３ａ，３ｂを有しており、一端の軸部３ａが転がり軸受６を介して支持部材７に回転自在に支持された状態でモータ１の出力軸１ａに継合され、他端の軸部３ｂが円柱形の軸受部材８を介して支持部材７に支持されている。尚、軸部３ａは転がり軸受６の内輪６ａに圧入されている。軸部３ａの途中には転がり軸受６の内輪６ａの一端と向き合い、ウォーム３の内輪６ａとの相対移動を規制するフェールセーフとしてのＣ形リング等の規制環９が着脱可能に取付けられている。ウォームホイール４は第２の操舵軸５３の途中に嵌合固定されている。
【００１９】
支持部材７はウォーム３を収容し、該ウォーム３の軸部３ａ，３ｂを、転がり軸受６及び軸受部材８を介して回転自在に支持した第１収容部７ａと、ウォームホイール４を収容し、該ウォームホイール４を第２の操舵軸５３及び該第２の操舵軸５３に嵌合された２つの転がり軸受１０，１１を介して支持した第２収容部７ｂとを有する。
【００２０】
第１収容部７ａはウォーム３の軸長方向に長くなっており、その長手方向一端部には転がり軸受６を嵌合支持する支持孔７１及び該支持孔７１に連なるねじ孔７２及びモータ取付部７３が設けられており、ねじ孔７２に転がり軸受６を固定するためのねじ環１２が螺着されている。また、モータ取付部７３にモータ１が取付けられている。
【００２１】
モータ１の出力軸１ａとウォーム３の軸部３ａとはセレーションを有する雄形継手部２１及び雌形継手部２２を介して継合されている。雄形継手部２１は軸部３ａの周面にセレーションを設けることにより構成されており、また、雌形継手部２２は出力軸１ａに嵌合固定された筒部材２３の内側にセレーションを設けることにより構成されており、雄形継手部２１と雌形継手部２２との間に径方向隙間ができるように雄形継手部２１及び雌形継手部２２がセレーション嵌合されている。
【００２２】
雄形継手部２１のモータ側端面、換言すればウォーム３の一端には軸長方向へ窪んだ凹所２１ｂが設けられている。この凹所２１ｂには出力軸１ａの端面にその一端が当接してウォーム３を反モータ側へ付勢する付勢手段としてのコイルバネ１３が収容されている。コイルバネ１３の付勢力が軸部３ａから規制環９を介して転がり軸受６の内輪６ａに伝動され、転がり軸受６の軸長方向隙間をなくする。
【００２３】
第１収容部７ａの他端部には、ウォーム３の他端の軸部３ｂが挿入される凹孔７４及び該凹孔７４の内面に臨み、ウォーム３及びウォームホイール４の回転中心間距離Ｈが長短となる方向に穿設された円柱形の収容孔７５が設けられている。この収容孔７５には軸部３ｂが回転自在に嵌合される軸受部材８と、該軸受部材８をウォームホイール４の方向へ付勢するコイルバネからなる弾性体１４と、収容孔７５の外部への開放部を閉じる閉孔部材１５とが収容されている。また、収容孔７５の外部への開放側にはねじ部７６が設けられており、該ねじ部７６に閉孔部材１５が螺着されている。この閉孔部材１５と軸受部材８との間には軸受部材８の回転中心間距離Ｈが長くなる方向への移動を許容する空間Ｃ１が発生するようにしてある。
【００２４】
収容孔７５は、支持部材７の内側となる一端、換言すれば軸受部材８に対して閉孔部材１５と反対側の端を第２収容部７ｂと連通しない閉鎖部７７とし、この閉鎖部７７と軸受部材８との間に軸受部材８の回転中心間距離Ｈが短くなる方向への移動を許容する空間Ｃ２が発生するようにしてある。
【００２５】
軸受部材８はその軸長方向の中間位置、換言すれば収容孔７５に沿って移動する移動方向両端の途中に回転中心間距離Ｈが長短となる方向と直交するように穿設された軸受孔８１と、移動側端部８ａ，８ｂ及び軸受孔８１間の周面に凹設された２つの環状溝８２，８３とを備えており、軸受孔８１に軸部３ｂが回転可能に挿入されたすべり軸受１６を設けてあり、該すべり軸受１６を介して軸部３ｂを軸受部材８に支持してある。環状溝８２，８３には収容孔７５の周面に接触し、軸受部材８が収容孔７５内で回転中心間距離Ｈが長短となる方向と交差する方向へ動くのを制限するＯリングからなる弾性環１７，１７が挿入保持されている。
【００２６】
軸受部材８の周面には環状溝８２，８３の両側となる移動側端部８ａ，８ｂから環状溝８２，８３よりも深い溝で環状溝８２，８３に連通する連通溝８４が周方向に離隔して４個設けられている。各連通溝８４は軸受孔８１の両移動側端部８ａ，８ｂと連通するように等間隔で設けられている。このため、空間Ｃ１とＣ２とが連通溝８４により連通される。図３、図５により明らかなように各連通溝８４の幅方向両端縁は湾曲しており、連通溝８４による弾性環１７，１７の損傷をなくするようにしてある。なお、連通溝８４は１又は複数個であればよく、個数は特に制限されない。
【００２７】
また、軸受部材８の一方の移動側端部８ａには弾性体１４を収容支持する円柱形の凹所８ｃと、該凹所８ｃの開口縁に連なる浅底の環状凹部８ｄとが設けられており、該環状凹部８ｄにゴム製の環状の弾性板１８が挿入支持されている。この弾性板１８は、金属製の軸受部材８が金属製の閉孔部材１５に直接当接するのを防いでいる。
【００２８】
尚、支持部材７内には、トーションバー５２の捩れに応じた操舵軸５１、５３の相対回転変位量によって操舵輪Ｂに加わる操舵トルクを検出するトルクセンサ１９が内装されており、該トルクセンサ１９が検出したトルク等に基づいてモータ１が駆動制御されるように構成されている。
【００２９】
以上のように構成された電動式パワーステアリング装置は、ウォーム３を組込む場合、支持部材７の収容孔７５に軸受部材８を挿入し、支持部材７の第１収容部７ａに収容するウォーム３の軸部３ｂを凹孔７４から軸受部材８のすべり軸受１６に挿入する。
【００３０】
このようにウォーム３及び軸受部材８を組込んだ後、弾性体１４、閉孔部材１５を収容孔７５に挿入し、該閉孔部材１５の回転操作により弾性体１４を介して軸受部材８を移動させ、さらに、すべり軸受１６を介してウォーム３を揺動させ、該ウォーム３をウォームホイール４の歯面に接触させ、ウォーム３及びウォームホイール４の回転中心間距離Ｈを調整し、ウォーム３及びウォームホイール４の噛合部のバックラッシュ量をなくすることができる。この場合、軸受部材８の周面に設けられた弾性環１７，１７が収容孔７５の周面に接触し、軸受部材８及び収容孔７５の周面間で収容孔７５内が弾性環１７，１７によって隔離され、軸受部材８の移動側端部８ａ，８ｂ及び収容孔７５間に空間Ｃ１，Ｃ２が発生する。また、軸受部材８と閉孔部材１５との間に介在された弾性体１４がウォーム３をウォームホイール４に向けて付勢し、該ウォーム３のウォームホイール４との噛合部に予圧を加えている。
【００３１】
操舵補助によってウォーム３がウォームホイール４の歯すじに沿うように径方向へ押圧され、この押圧力、換言すれば前記噛合反力が軸部３ｂから軸受部材８の軸受孔８１に加わった場合、軸受部材８の周面に設けられた弾性環１７，１７によって軸受部材８の前記噛合反力による動きを抑制することができる。従って、軸受部材８が支持部材７の収容孔７５に当接することを防止でき、この当接による音鳴りをなくすることができる。
【００３２】
また、前記噛合反力によって軸受部材８が回転中心間距離Ｈが長くなる方向へ移動する場合、軸受部材８の移動側端部８ａ及び収容孔７５間の空間Ｃ１内の空気は、軸受部材８の周面に設けられた連通溝８４から軸受部材８の移動側端部８ｂ及び収容孔７５間の空間Ｃ２と軸受孔８１とに流出する。従って、軸受部材８をスムーズに移動させることができる。また、弾性体１４の弾性復元力によって軸受部材８が回転中心間距離Ｈが短くなる方向へ移動する場合、軸受部材８の移動側端部８ｂ及び収容孔７５間の空間Ｃ２内の空気は、軸受部材８の周面に設けられた連通溝８４から軸受部材８の移動側端部８ａ及び収容孔７５間の空間Ｃ１と軸受孔８１とに流出する。従って、軸受部材８をスムーズに移動させることができる。
【００３３】
また、軸受部材８及び収容孔７５間の隙間にはグリース等の潤滑剤が塗布されるが、この潤滑剤の一部を連通溝８４に溜めることができる。従って、前記隙間の潤滑剤が減少した場合においても連通溝８４内の潤滑剤を弾性環１７の外周部に供給することができ、弾性環１７及び収容孔７５の摩耗を長期間に亘って低減できる。
【００３４】
実施の形態２
図６は電動式パワーステアリング装置の実施の形態２の構成を示す要部の断面図である。
この実施の形態２の電動式パワーステアリング装置は、実施の形態１のように軸受部材８の周面に連通溝８４を設ける代わりに、凹所８ｃから軸受孔８１にかけて貫通する第１の孔８５、軸受部材８の移動側端部８ｂから軸受孔８１にかけて貫通する第２の孔８６を設け、軸受部材８の移動側端部８ａ，８ｂ及び収容孔７５間の空間Ｃ１，Ｃ２内の空気を軸受孔８１に流出させるようにしたものである。
【００３５】
実施の形態２において、第１の孔８５は軸受部材８の凹所８ｃから軸受孔８１の両端部、換言すれば非すべり軸受部分にかけて軸受孔８１の中心と交差するように穿設してある。第２の孔８６は軸受部材８の移動側端部８ｂから軸受孔８１の両端部、換言すれば非すべり軸受部分にかけて軸受孔８１の中心と交差するように穿設してある。第１及び第２の孔８５，８６は夫々２つとしてあるが、該孔８５，８６の個数は特に制限されない。また、各孔８５，８６は軸受孔８１の中心と交差するように穿設する他、軸受孔８１の中心と直交的に穿設してもよい。なお、第１の孔８５は軸受孔８１から移動側端部８ａにかけて設けてもよい。
【００３６】
実施の形態２にあっては、前記噛合反力によって軸受部材８が回転中心間距離Ｈが長くなる方向へ動く場合、軸受部材８の移動側端部８ａ及び収容孔７５間の空間Ｃ１内の空気は、第１の孔８５から軸受孔８１に流出する。従って、軸受部材８をスムーズに移動させることができる。また、弾性体１４の弾性復元力によって軸受部材８が回転中心間距離Ｈが短くなる方向へ移動する場合、軸受部材８の移動側端部８ｂ及び収容孔７５間の空間Ｃ２内の空気は、第２の孔８６から軸受孔８１に流出する。従って、軸受部材８をスムーズに移動させることができる。
その他の構成及び作用は実施の形態１と同様であるため、同様の部品については同じ符号を付し、その詳細な説明及び作用効果の説明を省略する。
【００３７】
実施例の形態３
図７は電動式パワーステアリング装置の実施の形態３の構成を示す要部の拡大断面図である。
この実施の形態３の電動式パワーステアリング装置は、軸受部材８に実施の形態１の連通溝８４と、実施の形態２の第１及び第２の孔８５，８６とを設けたものである。
その他の構成及び作用は実施の形態１、２、５と同様であるため、同様の部品については同じ符号を付し、その詳細な説明及び作用効果の説明を省略する。
【００３８】
尚、以上説明した実施の形態では軸受部材８に環状溝８２，８３及び連通溝８４を設けたが、その他、この環状溝８２，８３及び連通溝８４は収容孔７５に設けてもよい。この場合、連通溝８４は空間Ｃ１，Ｃ２に連通させる。
【００３９】
また、以上説明した実施の形態では軸受部材８の周面に軸長方向に離隔する２つの環状溝８２，８３を設けたが、その他、この環状溝８２，８３は何れか１つであってもよい。また、連通溝８４は軸受部材８の移動側端部（移動側端面）から環状溝８２，８３にかけて設ける他、軸受部材８の移動側端面と離隔した位置から環状溝８２，８３にかけて設けてもよい。この場合、例えば軸受部材８及び収容孔７５の周面間の隙間の寸法を、移動側端面から環状溝８２，８３にかけて設けるものに比べて大きい寸法とし、空間Ｃ１の空気は環状溝８２に連通する連通溝８４及び隙間を経て環状溝８３に連通する連通溝８４から空間Ｃ２へ流出し、空間Ｃ２の空気は環状溝８３に連通する連通溝８４及び隙間を経て環状溝８２に連通する連通溝８４から空間Ｃ１へ流出するように構成する。
また、以上説明した実施の形態では、ウォーム３である駆動歯車及びウォームホイール４である従動歯車を備えたウォーム歯車である他、ベベルギヤ、ハイポイドギヤであってもよい。
【００４０】
【発明の効果】
以上詳述したように第１発明、第２発明、第３発明によれば、回転中心間距離が長短となる方向へ軸受部材が動く場合、軸受部材の移動側両端部を連通させることができ、弾性環によって回転中心間距離が長短となる方向と交差する方向への動きが制限された軸受部材を回転中心間距離が長短となる方向へスムーズに移動させることができ、しかも、弾性環の耐久性を高めることができる。
【図面の簡単な説明】
【図１】本発明に係る電動式パワーステアリング装置の実施の形態１の構成を示す減速歯車機構部分の拡大断面図である。
【図２】本発明に係る電動式パワーステアリング装置の全体構成を示す断面図である。
【図３】本発明に係る電動式パワーステアリング装置の軸受部材部分を拡大した横断平面図である。
【図４】本発明に係る電動式パワーステアリング装置の軸受部材の構成を示す側面図である。
【図５】本発明に係る電動式パワーステアリング装置の軸受部材部分を拡大した横断平面図である。
【図６】本発明に係る電動式パワーステアリング装置の実施の形態２の構成を示す要部の断面図である。
【図７】本発明に係る電動式パワーステアリング装置の実施の形態３の構成を示す要部の拡大断面図である。
【符号の説明】
１モータ
１ａ出力軸
２軸継手
３ウォーム（駆動歯車）
３ｂ軸部
４ウォームホイール（従動歯車）
７支持部材
７５収容孔
８軸受部材
８ａ，８ｂ移動側端部
８１軸受孔
８２，８３環状溝
８４連通溝
８５，８６孔
１７弾性環
Ｃ１，Ｃ２空間
Ｈ回転中心間距離[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electric power steering device using a motor as a source of a steering assist force.
[0002]
[Prior art]
An electric power steering apparatus for a vehicle includes a motor for assisting steering and a reduction gear mechanism for transmitting a rotational force of the motor to a steering unit. The operation of the steering unit according to the rotation of the steering unit is controlled by the motor. , And is configured to reduce the labor burden on the driver for steering.
[0003]
The reduction gear mechanism has a drive gear having one end connected to the output shaft of the motor, a driven gear that meshes with the drive gear and is connected to steering means, and a bearing into which the other end of the drive gear is inserted. A bearing member having a hole, a cylindrical bearing member capable of moving in a direction in which the distance between the rotation centers of the drive gear and the driven gear becomes longer and shorter, and a support member having an accommodation hole for accommodating the bearing member; By moving the members, the distance between the centers of rotation of the driving gear and the driven gear is adjusted, the backlash amount of the meshing part of the driving gear and the driven gear is reduced, and the rattling noise due to the backlash during steering is eliminated. It is configured to (For example, Patent Document 1)
[0004]
Further, the worm gears and the like of the reduction gear mechanism have their tooth traces twisted in the rotational direction with respect to the rotation center line. A component force (hereinafter referred to as a meshing reaction force) is generated so that the gear moves in the radial direction along the tooth trace of the worm wheel. The worm is pressed in the radial direction by the meshing reaction force, and the pressing force moves the bearing member in the accommodation hole in a direction intersecting the direction in which the distance between the rotation centers becomes longer and shorter. It will make a sound in contact. For this reason, in Patent Literature 1, by providing annular grooves on both sides of the bearing hole on the peripheral surface of the bearing member and inserting and holding an elastic ring formed of an O-ring in each annular groove, the bearing member is provided. Is restricted so as to eliminate the above-mentioned sound.
[0005]
[Patent Document 1]
JP, 2002-21943, A
[Problems to be solved by the invention]
However, in an electric power steering apparatus in which an elastic ring is provided on the peripheral surface of a bearing member as in Patent Document 1, the elastic ring contacts the peripheral surface of the housing hole, and the peripheral surfaces of the bearing member and the housing hole. Since the inside of the accommodation hole is isolated by the elastic ring, a sealed space is created between the end on the movement side of the bearing member and the accommodation hole. Therefore, when the bearing member moves in a direction in which the distance between the rotation centers becomes longer or shorter, the air in the sealed space is compressed, and the internal pressure in the sealed space increases, whereby the movement of the bearing member is suppressed. In other words, improvement measures were requested.
[0007]
The present invention has been made in view of the above circumstances, and a bearing member whose movement in a direction intersecting with a direction in which the distance between the rotation centers is longer or shorter is restricted by an elastic body in a direction in which the distance between the rotation centers is shorter or longer. It is an object of the present invention to provide an electric power steering device capable of smoothly moving the electric power steering device.
[0008]
[Means for Solving the Problems]
An electric power steering apparatus according to a first aspect of the present invention is connected to an output shaft of a motor via a shaft coupling, has a drive gear having a shaft portion on a side opposite to the motor, meshes with the drive gear, and is connected to steering means. A driven gear, a bearing member that supports the shaft portion, and is movable in a direction in which the distance between the rotation centers of the driving gear and the driven gear becomes longer and shorter, a supporting member having a receiving hole for receiving the bearing member, An electric power steering device comprising a bearing member and an elastic ring disposed between the receiving holes, wherein the rotation of the motor assists the steering, wherein the bearing member or the supporting member has an annular groove into which the elastic ring is inserted. And a communication groove communicating from both sides of the annular groove with the annular groove at a depth deeper than the annular groove, and communicating with both ends on the moving side of the bearing member.
[0009]
In the first invention, the inside of the receiving hole is isolated by the elastic ring between the peripheral surfaces of the bearing member and the receiving hole, but is formed by a groove deeper than the annular groove from both sides of the annular groove in which the elastic ring is inserted. Since there is a communication groove that communicates with the groove and communicates both ends of the bearing member on the moving side, when the bearing member moves in a direction in which the distance between the rotation centers becomes longer or shorter, the bearing member can be moved smoothly. . Further, since the communication groove is provided in the member having the annular groove, it is possible to eliminate damage due to the communication groove of the elastic ring when the bearing member moves in the direction in which the distance between the rotation centers becomes longer and shorter, The durability of the ring can be increased. Further, since a lubricant such as grease can be stored in the communication groove, wear of the elastic ring and the peripheral surface with which the elastic ring contacts when the bearing member moves in the direction in which the distance between the rotation centers becomes longer and shorter is reduced. Can be reduced and durability can be increased.
[0010]
An electric power steering apparatus according to a second aspect of the present invention is connected to an output shaft of a motor via a shaft coupling, and has a driving gear having a shaft portion on the side opposite to the motor, and meshes with the driving gear to be connected to steering means. A driven gear, a bearing member having a bearing hole in which the shaft portion is inserted, the bearing member being movable in a direction in which the distance between the rotation centers of the driving gear and the driven gear becomes longer and shorter, and a receiving hole for receiving the bearing member. An electric power steering apparatus comprising: a support member having an elastic ring disposed between the bearing member and the housing hole; and the steering assisted by the rotation of the motor. It is characterized by having a hole passing through the bearing hole.
[0011]
In the second invention, the inside of the receiving hole is isolated by the elastic ring between the peripheral surfaces of the bearing member and the receiving hole. When the bearing member moves in a direction in which the distance between the rotation centers becomes longer or shorter, the bearing member can be smoothly moved. Further, since the hole penetrates from the moving side end of the bearing member to the bearing hole, it is possible to eliminate damage caused by the hole of the elastic ring when the bearing member moves in the direction in which the distance between the rotation centers becomes longer or shorter. It is possible to enhance the durability of the elastic ring. Further, since lubricant such as grease can be stored in the hole of the bearing member, the contact resistance of the driving gear inserted and supported in the bearing hole with the bearing member can be reduced.
[0012]
An electric power steering device according to a third aspect of the present invention is connected to an output shaft of a motor via a shaft coupling, and has a drive gear having a shaft portion on the side opposite to the motor, and meshes with the drive gear to be connected to steering means. A driven gear, a bearing member having a bearing hole in which the shaft portion is inserted, the bearing member being movable in a direction in which the distance between the rotation centers of the driving gear and the driven gear becomes longer and shorter, and a receiving hole for receiving the bearing member. An electric power steering apparatus comprising a support member having the elastic ring disposed between the bearing member and the housing hole, and assisting steering by rotation of the motor, wherein the bearing member or the support member includes the elastic ring. And a communication groove communicating from both sides of the annular groove to the annular groove at a depth deeper than the annular groove to communicate both ends of the bearing member on the moving side. Is from both ends of the moving side And having a hole penetrating toward serial bearing hole.
[0013]
In the third invention, the inside of the receiving hole is isolated by the elastic ring between the bearing member and the peripheral surface of the receiving hole, but the communicating groove communicating with the annular groove from both sides of the annular groove with a groove deeper than the annular groove. And a hole penetrating from both ends on the moving side of the bearing member to the bearing hole, so that when the bearing member moves in a direction in which the distance between the rotation centers becomes longer or shorter, the bearing member is moved more smoothly. Can be.
[0014]
Further, the communication groove is provided in the member having the annular groove, and the hole is provided in the bearing member. Therefore, the communication groove of the elastic ring when the bearing member moves in the direction in which the distance between the rotation centers becomes longer and shorter. In addition, damage due to holes and holes can be eliminated, and the durability of the elastic ring can be increased. Further, since a lubricant such as grease can be stored in the communication groove and the hole, the elastic ring and the peripheral surface with which the elastic ring contacts when the bearing member moves in the direction in which the distance between the rotation centers becomes longer and shorter. Wear can be reduced, and the contact resistance between the drive gear inserted and supported in the bearing hole and the bearing member can be reduced.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings showing the embodiments.
Embodiment 1
FIG. 1 is an enlarged cross-sectional view showing a configuration of a reduction gear mechanism portion of the electric power steering device according to the present invention, FIG. 2 is a cross-sectional view showing the entire configuration of the electric power steering device, and FIG. FIG. 4 is a cross-sectional plan view, FIG. 4 is a side view showing the configuration of the bearing member, and FIG.
[0016]
The electric power steering apparatus includes a motor 1 for assisting steering and a drive gear connected to an output shaft 1a of the motor 1 via a shaft joint 2 having a male joint 21 and a female joint 22. A reduction gear mechanism A having a worm 3 and a worm wheel 4 as a driven gear meshing with the worm 3, and a steering means 5 connected to the reduction gear mechanism A are provided.
[0017]
This steering means 5 has a first steering shaft 51 having one end connected to a steered wheel B for steering, and having a tubular portion 51a at the other end, and a first steering shaft 51 inserted into the tubular portion 51a and having one end connected to the steering wheel B. The torsion bar 52 is connected to the cylinder portion 51a of the first steering shaft 51, and is twisted by the action of the steering torque applied to the steering wheel B. The other end is connected to the other end of the torsion bar 52, and the reduction gear mechanism A A second steering shaft 53 connected thereto, and the second steering shaft 53 is connected to, for example, a rack and pinion type steering mechanism (not shown) via a universal joint.
[0018]
The worm 3 of the reduction gear mechanism A has shaft portions 3a and 3b at both ends, and the output shaft of the motor 1 in a state where the shaft portion 3a at one end is rotatably supported by a support member 7 via a rolling bearing 6. The shaft 3b at the other end is supported by a support member 7 via a cylindrical bearing member 8. The shaft portion 3a is press-fitted into the inner ring 6a of the rolling bearing 6. A restriction ring 9 such as a C-shaped ring as a fail-safe, which is opposed to one end of the inner ring 6a of the rolling bearing 6 and restricts the relative movement of the worm 3 with the inner ring 6a, is detachably mounted in the middle of the shaft 3a. . The worm wheel 4 is fitted and fixed in the middle of the second steering shaft 53.
[0019]
The supporting member 7 accommodates the worm 3, and accommodates the worm wheel 4 and the first accommodation portion 7 a that rotatably supports the shaft portions 3 a and 3 b of the worm 3 via the rolling bearing 6 and the bearing member 8. The worm wheel 4 includes a second steering shaft 53 and a second housing portion 7b that is supported via two rolling bearings 10 and 11 fitted to the second steering shaft 53.
[0020]
The first housing portion 7a is elongated in the axial direction of the worm 3, and at one end in the longitudinal direction, a support hole 71 for fitting and supporting the rolling bearing 6, a screw hole 72 connected to the support hole 71, and a motor mounting portion. The screw ring 12 for fixing the rolling bearing 6 to the screw hole 72 is screwed. Further, the motor 1 is mounted on the motor mounting portion 73.
[0021]
The output shaft 1a of the motor 1 and the shaft 3a of the worm 3 are joined via a male joint 21 and a female joint 22 having serrations. The male joint 21 is formed by providing serrations on the peripheral surface of the shaft 3a, and the female joint 22 is provided with serrations inside a tubular member 23 fitted and fixed to the output shaft 1a. The male joint part 21 and the female joint part 22 are serrated and fitted so that a radial gap is formed between the male joint part 21 and the female joint part 22.
[0022]
On the motor-side end face of the male joint 21, in other words, on one end of the worm 3, a recess 21 b that is recessed in the axial direction is provided. The recess 21b accommodates a coil spring 13 as an urging means for urging the worm 3 toward the non-motor side with one end thereof abutting on the end face of the output shaft 1a. The urging force of the coil spring 13 is transmitted from the shaft portion 3a to the inner ring 6a of the rolling bearing 6 via the regulating ring 9, and eliminates a gap in the axial direction of the rolling bearing 6.
[0023]
At the other end of the first housing portion 7a, a concave hole 74 into which the shaft portion 3b at the other end of the worm 3 is inserted, and facing the inner surface of the concave hole 74, the distance H between the rotation centers of the worm 3 and the worm wheel 4 is set. Are provided in a column-shaped accommodation hole 75 which is formed in a direction in which the length becomes shorter. A bearing member 8 into which the shaft portion 3b is rotatably fitted, an elastic body 14 composed of a coil spring for urging the bearing member 8 in the direction of the worm wheel 4, and an outside of the housing hole 75. And a closing member 15 that closes the opening portion. A screw portion 76 is provided on the open side of the housing hole 75 to the outside, and the closing member 15 is screwed to the screw portion 76. A space C1 is formed between the closing member 15 and the bearing member 8 to allow the bearing member 8 to move in the direction in which the distance H between the centers of rotation increases.
[0024]
The accommodation hole 75 has one end inside the support member 7, in other words, the end opposite to the hole member 15 with respect to the bearing member 8, as a closing portion 77 not communicating with the second housing portion 7 b. A space C2 that allows movement in a direction in which the distance H between the centers of rotation of the bearing members 8 becomes shorter is generated between the bearing member 8 and the bearing member 8.
[0025]
The bearing member 8 is a bearing hole formed at an intermediate position in the axial length direction, in other words, a bearing hole formed in the middle of both ends in the moving direction moving along the housing hole 75 so as to be orthogonal to the direction in which the distance H between the rotation centers becomes longer and shorter. 81, and two annular grooves 82 and 83 recessed in the peripheral surface between the moving-side ends 8a and 8b and the bearing hole 81. The shaft 3b is rotatably inserted into the bearing hole 81. A sliding bearing 16 is provided, and the shaft portion 3 b is supported by the bearing member 8 via the sliding bearing 16. The annular grooves 82 and 83 are formed of an O-ring that contacts the peripheral surface of the housing hole 75 and restricts the bearing member 8 from moving in the housing hole 75 in a direction intersecting the direction in which the distance H between the rotation centers becomes longer and shorter. The elastic rings 17, 17 are inserted and held.
[0026]
On the peripheral surface of the bearing member 8, a communication groove 84 communicating with the annular grooves 82, 83 at a depth deeper than the annular grooves 82, 83 from the moving side ends 8 a, 8 b on both sides of the annular grooves 82, 83 extends in the circumferential direction. Four are provided at a distance. The communication grooves 84 are provided at equal intervals so as to communicate with both moving-side ends 8a and 8b of the bearing hole 81. Therefore, the spaces C1 and C2 are communicated by the communication groove 84. As is clear from FIGS. 3 and 5, both ends in the width direction of each communication groove 84 are curved so that the elastic rings 17 are not damaged by the communication groove 84. The number of the communication grooves 84 may be one or more, and the number is not particularly limited.
[0027]
A cylindrical recess 8c for accommodating and supporting the elastic body 14 and a shallow annular recess 8d connected to the opening edge of the recess 8c are provided at one moving end 8a of the bearing member 8. An annular elastic plate 18 made of rubber is inserted and supported in the annular recess 8d. The elastic plate 18 prevents the metal bearing member 8 from directly contacting the metal closing member 15.
[0028]
In the support member 7, a torque sensor 19 for detecting a steering torque applied to a steered wheel B based on a relative rotational displacement of the steering shafts 51 and 53 according to the torsion of the torsion bar 52 is provided. The motor 1 is configured to be driven and controlled based on the torque detected by the motor 19 and the like.
[0029]
When the worm 3 is incorporated in the electric power steering apparatus configured as described above, the bearing member 8 is inserted into the accommodation hole 75 of the support member 7, and the worm 3 is accommodated in the first accommodation portion 7 a of the support member 7. The shaft portion 3b is inserted into the slide bearing 16 of the bearing member 8 from the concave hole 74.
[0030]
After the worm 3 and the bearing member 8 are assembled in this manner, the elastic member 14 and the closing member 15 are inserted into the receiving hole 75, and the bearing member 8 is rotated via the elastic member 14 by rotating the closing member 15. The worm 3 is swung through a sliding bearing 16 to bring the worm 3 into contact with the tooth surface of the worm wheel 4, and the distance H between the worm 3 and the rotation center of the worm wheel 4 is adjusted. In addition, the amount of backlash at the meshing portion of the worm wheel 4 can be eliminated. In this case, the elastic rings 17, 17 provided on the peripheral surface of the bearing member 8 come into contact with the peripheral surface of the housing hole 75, and the elastic ring 17, 17 is provided between the bearing member 8 and the peripheral surface of the housing hole 75. The spaces C1 and C2 are generated between the moving-side ends 8a and 8b of the bearing member 8 and the housing hole 75. Further, the elastic body 14 interposed between the bearing member 8 and the closing member 15 urges the worm 3 toward the worm wheel 4, and applies a preload to the meshing portion of the worm 3 with the worm wheel 4. I have.
[0031]
When the worm 3 is radially pressed along the tooth traces of the worm wheel 4 by the steering assist, and when this pressing force, in other words, the meshing reaction force is applied to the bearing hole 81 of the bearing member 8 from the shaft portion 3b, The elastic rings 17 provided on the peripheral surface of the bearing member 8 can suppress the movement of the bearing member 8 due to the meshing reaction force. Therefore, it is possible to prevent the bearing member 8 from contacting the accommodation hole 75 of the support member 7, and it is possible to eliminate the noise caused by this contact.
[0032]
When the bearing member 8 moves in the direction in which the distance H between the rotation centers becomes longer due to the meshing reaction force, the air in the space C1 between the moving-side end 8a of the bearing member 8 and the housing hole 75 is removed by the bearing member 8. Of the bearing member 8 and the space C2 between the housing hole 75 and the bearing hole 81 from the communication groove 84 provided on the peripheral surface of the bearing member 81. Therefore, the bearing member 8 can be moved smoothly. Further, when the bearing member 8 moves in the direction in which the distance H between the centers of rotation is shortened by the elastic restoring force of the elastic body 14, the air in the space C2 between the moving-side end 8b of the bearing member 8 and the accommodation hole 75 is: The fluid flows out from the communication groove 84 provided on the peripheral surface of the bearing member 8 into the space C1 between the moving end 8a of the bearing member 8 and the housing hole 75 and into the bearing hole 81. Therefore, the bearing member 8 can be moved smoothly.
[0033]
A lubricant such as grease is applied to a gap between the bearing member 8 and the housing hole 75, and a part of the lubricant can be stored in the communication groove 84. Therefore, even when the lubricant in the gap decreases, the lubricant in the communication groove 84 can be supplied to the outer peripheral portion of the elastic ring 17, and the wear of the elastic ring 17 and the accommodation hole 75 is reduced over a long period of time. it can.
[0034]
Embodiment 2
FIG. 6 is a cross-sectional view of a main part showing the configuration of the second embodiment of the electric power steering apparatus.
The electric power steering apparatus according to the second embodiment is different from the first embodiment in that the communication groove 84 is provided on the peripheral surface of the bearing member 8, instead of the first hole 85 penetrating from the recess 8 c to the bearing hole 81. A second hole 86 penetrating from the moving end 8b of the bearing member 8 to the bearing hole 81 is provided, and the air in the spaces C1, C2 between the moving end 8a, 8b of the bearing member 8 and the receiving hole 75 is provided. It is designed to flow out into the bearing hole 81.
[0035]
In the second embodiment, the first hole 85 is formed so as to intersect with the center of the bearing hole 81 from the recess 8c of the bearing member 8 to both ends of the bearing hole 81, in other words, from the non-slip bearing portion. . The second hole 86 is formed so as to intersect the center of the bearing hole 81 from the moving end 8b of the bearing member 8 to both ends of the bearing hole 81, in other words, the non-slip bearing portion. Although the first and second holes 85 and 86 are each two, the number of the holes 85 and 86 is not particularly limited. The holes 85 and 86 may be formed so as to intersect with the center of the bearing hole 81, or may be formed so as to be orthogonal to the center of the bearing hole 81. Note that the first hole 85 may be provided from the bearing hole 81 to the moving-side end 8a.
[0036]
In the second embodiment, when the bearing member 8 moves in the direction in which the distance H between the centers of rotation becomes longer due to the meshing reaction force, the bearing member 8 in the space C1 between the moving-side end 8a of the bearing member 8 and the accommodation hole 75 is provided. The air flows out of the first hole 85 into the bearing hole 81. Therefore, the bearing member 8 can be moved smoothly. Further, when the bearing member 8 moves in the direction in which the distance H between the centers of rotation is shortened by the elastic restoring force of the elastic body 14, the air in the space C2 between the moving-side end 8b of the bearing member 8 and the accommodation hole 75 is: It flows out from the second hole 86 to the bearing hole 81. Therefore, the bearing member 8 can be moved smoothly.
Since other configurations and operations are the same as those of the first embodiment, the same reference numerals are given to the same components, and the detailed description and the description of the operation and effects are omitted.
[0037]
Embodiment 3
FIG. 7 is an enlarged sectional view of a main part showing the configuration of the third embodiment of the electric power steering apparatus.
In the electric power steering device according to the third embodiment, the bearing member 8 is provided with the communication groove 84 according to the first embodiment and the first and second holes 85 and 86 according to the second embodiment.
Other configurations and operations are the same as those of the first, second, and fifth embodiments. Therefore, the same reference numerals are given to the same components, and the detailed description and the description of the operation and effects are omitted.
[0038]
In the embodiment described above, the bearing members 8 are provided with the annular grooves 82, 83 and the communication groove 84. However, the annular grooves 82, 83 and the communication groove 84 may be provided in the housing hole 75. In this case, the communication groove 84 communicates with the spaces C1 and C2.
[0039]
In the above-described embodiment, two annular grooves 82 and 83 are provided on the peripheral surface of the bearing member 8 so as to be separated from each other in the axial direction, but in addition, any one of the annular grooves 82 and 83 is provided. Is also good. The communication groove 84 may be provided from the moving-side end (moving-side end surface) of the bearing member 8 to the annular grooves 82 and 83, or may be provided from a position separated from the moving-side end surface of the bearing member 8 to the annular grooves 82 and 83. Good. In this case, for example, the size of the gap between the bearing member 8 and the peripheral surface of the housing hole 75 is made larger than that provided from the moving-side end surface to the annular grooves 82 and 83, and the air in the space C <b> 1 communicates with the annular groove 82. The communication groove 84 communicates with the annular groove 83 through the communication groove 84 via the gap and the space C2, and the air in the space C2 communicates with the communication groove 84 via the communication groove 84 and the gap through the clearance. It is configured to flow out of the space 84 into the space C1.
Further, in the above-described embodiment, a bevel gear or a hypoid gear may be used in addition to the worm gear including the drive gear as the worm 3 and the driven gear as the worm wheel 4.
[0040]
【The invention's effect】
As described in detail above, according to the first, second, and third inventions, when the bearing member moves in a direction in which the distance between the rotation centers becomes longer or shorter, both ends on the moving side of the bearing member can be communicated. The elastic member can smoothly move the bearing member whose movement in the direction intersecting with the direction in which the distance between the rotation centers becomes longer and shorter in the direction in which the distance between the rotation centers becomes longer and shorter. Durability can be increased.
[Brief description of the drawings]
FIG. 1 is an enlarged sectional view of a reduction gear mechanism portion showing a configuration of an electric power steering device according to a first embodiment of the present invention.
FIG. 2 is a cross-sectional view showing the overall configuration of the electric power steering device according to the present invention.
FIG. 3 is an enlarged cross-sectional plan view of a bearing member of the electric power steering device according to the present invention.
FIG. 4 is a side view showing a configuration of a bearing member of the electric power steering device according to the present invention.
FIG. 5 is an enlarged cross-sectional plan view of a bearing member of the electric power steering device according to the present invention.
FIG. 6 is a sectional view of a main part showing a configuration of an electric power steering apparatus according to Embodiment 2 of the present invention.
FIG. 7 is an enlarged sectional view of a main part showing a configuration of an electric power steering apparatus according to Embodiment 3 of the present invention.
[Explanation of symbols]
Reference Signs List 1 motor 1a output shaft 2 shaft coupling 3 worm (drive gear)
3b Shaft 4 Worm wheel (driven gear)
7 Support member 75 Housing hole 8 Bearing member 8a, 8b Moving end 81 Bearing hole 82, 83 Annular groove 84 Communication groove 85, 86 Hole 17 Elastic ring C1, C2 Space H Distance between rotation centers

Claims

A drive gear connected to the output shaft of the motor via a shaft coupling and having a shaft portion on the side opposite to the motor, a driven gear meshing with the drive gear and leading to steering means, and a drive gear supporting the shaft portion and supporting the shaft portion A bearing member movable in a direction in which the distance between the rotation centers of the driven gears becomes longer and shorter, a support member having an accommodation hole for accommodating the bearing member, and an elastic ring disposed between the bearing member and the accommodation hole In the electric power steering apparatus, the steering member is assisted by the rotation of the motor, the bearing member or the support member has an annular groove in which the elastic ring is inserted, and an annular groove from both sides of the annular groove. A communication groove communicating with the annular groove by a deep groove and communicating both ends of the bearing member on the moving side.

A drive gear connected to the output shaft of the motor via a shaft coupling and having a shaft portion on the side opposite to the motor, a driven gear meshing with the drive gear and leading to steering means, and a bearing into which the shaft portion is inserted A bearing member having a hole and capable of moving in a direction in which the distance between the rotation centers of the drive gear and the driven gear becomes longer and shorter, a support member having an accommodation hole for accommodating the bearing member, and between the bearing member and the accommodation hole. And an elastic ring disposed on the power steering apparatus, wherein the bearing member has a hole penetrating from both ends on the moving side to the bearing hole. Electric power steering device.

A drive gear connected to the output shaft of the motor via a shaft coupling and having a shaft portion on the side opposite to the motor, a driven gear meshing with the drive gear and leading to steering means, and a bearing into which the shaft portion is inserted A bearing member having a hole and capable of moving in a direction in which the distance between the rotation centers of the drive gear and the driven gear becomes longer and shorter, a support member having an accommodation hole for accommodating the bearing member, and between the bearing member and the accommodation hole. And an elastic ring disposed on the electric power steering apparatus. The bearing member or the supporting member includes an annular groove in which the elastic ring is inserted, and an annular groove in which the elastic ring is inserted. A communication groove that communicates with the annular groove at a depth deeper than the annular groove from both sides and communicates with both ends of the bearing member on the moving side, and the bearing member penetrates from both ends on the moving side to the bearing hole; Characterized by having holes Electric power steering apparatus to be.