JP2009216046A

JP2009216046A - Oil pump structure

Info

Publication number: JP2009216046A
Application number: JP2008062801A
Authority: JP
Inventors: Kei Aida; 圭会田
Original assignee: Fuji Heavy Industries Ltd
Current assignee: Subaru Corp
Priority date: 2008-03-12
Filing date: 2008-03-12
Publication date: 2009-09-24
Anticipated expiration: 2028-03-12
Also published as: JP4970317B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide the oil pump structure effectively preventing a fretting phenomenon to be generated between a rotor and a side surface of a rotor housing part, by restricting vibration of a driving shaft in the axial direction. <P>SOLUTION: The oil pressure of oil, which flows from an opening 22a side of a discharge port 22 to an opening 21a side of a suction port 21 along a side surface 17 of a cover 16 of an oil pump 1, is applied to an oil pressure receiving surface formed by a stage difference part 43 of a driving shaft 41, and a step part 45 formed in the driving shaft 41 is pushed by energization to a ball bearing 38 arranged in a housing 11 so as to prevent vibration of the driving shaft 41 in the axial direction (a). With this structure, generation of vibration of an inner rotor 31 in the axial direction (a) to be caused by vibration of the driving shaft 41 in the axial direction (a) is restricted, and a fretting phenomenon to be generated between an inner rotor 31, an outer rotor 33 and side surfaces 13, 17 of the cover 16 and the housing 11 is effectively prevented. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

本発明は、オイルポンプ構造に関し、特にフレッティング現象防止が得られるオイルポンプ構造に関する。 The present invention relates to an oil pump structure, and more particularly to an oil pump structure that can prevent fretting phenomenon.

例えば自動変速機に組み込まれるオイルポンプは、自動変速機の内部機構を潤滑し、油圧制御回路を作動させ、クラッチ等の内部機構を油圧駆動させる。 For example, an oil pump incorporated in an automatic transmission lubricates an internal mechanism of the automatic transmission, operates a hydraulic control circuit, and hydraulically drives an internal mechanism such as a clutch.

この種のオイルポンプの一例を、図６を参照して説明する。図６はトランスミッションケース内に収容されたオイルポンプ１０１の概要を示す断面図である。 An example of this type of oil pump will be described with reference to FIG. FIG. 6 is a sectional view showing an outline of the oil pump 101 housed in the transmission case.

オイルポンプ１０１は、ハウジング１０２の中央部に凹設された側面１０３ａ及び周面１０３ｂを有するロータ収容部１０３内に、インナロータ１１１及びアウタロータ１１２を噛み合わせて配置し、カバー１０５と共にトランスミッションケース内を区画する隔壁１００ａに固定される。 The oil pump 101 is arranged by engaging the inner rotor 111 and the outer rotor 112 in a rotor accommodating portion 103 having a side surface 103 a and a peripheral surface 103 b that are recessed in the center of the housing 102, and partitions the transmission case together with the cover 105. Fixed to the partition wall 100a.

カバー１０５はハウジング１０２に凹設されたロータ収容部１０３の側面１０３ａに対向する側面１０３ｃを有すると共に、側面１０３ｃに開口する吸入ポート１０７及び吐出ポート１０８が形成される。ロータ収容部１０３の周面１０３ｂはアウタロータ１１２をインナロータ１１１に対して偏心状態に位置決めして回転自在に保持する。アウタロータ１１２はロータ収容部１０３の側面１０３ａとカバー１０５の側面１０３ｃとの間及び周面１０３ｂによって囲まれた収容部１０３内でインナロータ１１１に噛み合って従動回転する。 The cover 105 has a side surface 103c that faces the side surface 103a of the rotor accommodating portion 103 that is recessed in the housing 102, and a suction port 107 and a discharge port 108 that open to the side surface 103c. The peripheral surface 103b of the rotor accommodating portion 103 positions the outer rotor 112 in an eccentric state with respect to the inner rotor 111 and holds it rotatably. The outer rotor 112 meshes with the inner rotor 111 and is driven to rotate in the housing portion 103 surrounded by the circumferential surface 103b between the side surface 103a of the rotor housing portion 103 and the side surface 103c of the cover 105.

ハウジング１０２及びカバー１０５の中央にそれぞれ形成された軸支孔１０４、１０６にニードルベアリング１０４ａ、１０６ａを介して駆動軸１１０の一端側をロータ収容部１０３内を貫通させて回転自在に軸支する。ロータ収容部１０３を貫通する駆動軸１１０にはインナロータ１１１の軸孔１１１ａが貫通すると共に半月キー１１３によって相対回転を拘束する。 One end side of the drive shaft 110 passes through the inside of the rotor housing portion 103 through the needle bearings 104a and 106a and is rotatably supported in shaft support holes 104 and 106 formed at the centers of the housing 102 and the cover 105, respectively. A shaft hole 111 a of the inner rotor 111 passes through the drive shaft 110 that passes through the rotor housing portion 103, and relative rotation is restricted by the half moon key 113.

ハウジング１０２の軸支孔１０４から突出する駆動軸１１０の他端側は一対のボールベアリング１１５ａ、１１５ｂを介してトランスミッションケースに形成された軸支部１００ｂに回転自在に支持されると共に、スプロケット１１６が固設され、チェーン１１７を介して図示しないトルクコンバータのスリーブ等によって回転駆動される。 The other end side of the drive shaft 110 protruding from the shaft support hole 104 of the housing 102 is rotatably supported by a shaft support portion 100b formed in the transmission case via a pair of ball bearings 115a and 115b, and the sprocket 116 is fixed. And is rotationally driven by a sleeve of a torque converter (not shown) through a chain 117.

このように構成されたオイルポンプ１０１は、トルクコンバータのスリーブ等の回転に伴ってチェーン１１７及びスプロケット１１６を介して駆動軸１１０が回転駆動されてインナロータ１１１が回転する。インナロータ１１１の回転に伴って互いに回転するインナロータ１１１の歯部とアウタロータ１１２の歯部によって形成される閉込部によって吸入ポート１０７からオイルが吸引され、インナロータ１１１の歯部とアウタロータ１１２の歯部との間の閉込部内に囲い込まれたオイルはインナロータ１１１及びアウタロータ１１２の回転に伴って吐出ポート１０８側へ運ばれ、吐出ポート１０８から各部に送油される。 In the oil pump 101 configured as described above, the drive shaft 110 is rotationally driven via the chain 117 and the sprocket 116 as the sleeve of the torque converter rotates, and the inner rotor 111 rotates. Oil is sucked from the suction port 107 by a closed portion formed by the teeth of the inner rotor 111 and the teeth of the outer rotor 112 that rotate with each other as the inner rotor 111 rotates, and the teeth of the inner rotor 111 and the teeth of the outer rotor 112 The oil enclosed in the confinement portion between the two is conveyed to the discharge port 108 side as the inner rotor 111 and the outer rotor 112 rotate, and is sent from the discharge port 108 to each portion.

一方、吸入ポート１０７から吐出ポート１０８に至るまでのインナロータ１１１とアウタロータ１１２よって形成される閉込部内の油圧変動が大きく、かつ駆動軸１１０の回転駆動に伴って、駆動軸１１０に発生する軸方向ａの移動及び振動は、駆動軸１１０の端部１１０ａが対向するトランスミッションケースの隔壁１００ａとの当接及び駆動軸１１０を回転自在に支持するボールベアリング１１５ａ、１１５ｂによって規制される。しかし、円滑な駆動軸１１０の回転を確保するために駆動軸１１０の端部１１０ａと隔壁１００ａとの間に微細な隙間を要し、かつベアリング１１５ａ、１１５ｂのアウタレース及びインナレースに形成された転動溝とボールとの間に微細な間隙を要求される。これらの微細な間隙に起因して駆動軸１１０には周期的な軸方向ａの振動が発生する。駆動軸１１０の軸方向ａの振動に伴って駆動軸１１０に固設されたインナロータ１１１及びインナロータ１１１に噛合するアウタロータ１１２が軸方向ａに振動して収容部１０３の側面１０３ａ及び１０３ｃに繰り返し接触し、インナロータ１１１、アウタロータ１１２及びロータ収容部１０３の側面１０３ａ、１０３ｃにフレッティング現象が発生することが懸念される。特に軽量化のためにハウジング１０２及びカバー１０５がアルミニウム合金等によって形成されオイルポンプにあってはフレッティング現象による損傷が発生する。 On the other hand, the hydraulic pressure fluctuation in the confining portion formed by the inner rotor 111 and the outer rotor 112 from the suction port 107 to the discharge port 108 is large, and the axial direction generated in the drive shaft 110 as the drive shaft 110 rotates. The movement and vibration of “a” are restricted by contact with the partition wall 100a of the transmission case opposed to the end 110a of the drive shaft 110 and ball bearings 115a and 115b that rotatably support the drive shaft 110. However, in order to ensure smooth rotation of the drive shaft 110, a fine gap is required between the end 110a of the drive shaft 110 and the partition wall 100a, and the outer race and the inner race of the bearings 115a and 115b are formed. A fine gap is required between the dynamic groove and the ball. Due to these fine gaps, periodic vibrations in the axial direction a are generated on the drive shaft 110. As the drive shaft 110 vibrates in the axial direction a, the inner rotor 111 fixed to the drive shaft 110 and the outer rotor 112 meshing with the inner rotor 111 vibrate in the axial direction a and repeatedly contact the side surfaces 103 a and 103 c of the housing portion 103. There is a concern that the fretting phenomenon may occur on the inner rotor 111, the outer rotor 112, and the side surfaces 103a and 103c of the rotor accommodating portion 103. In particular, in order to reduce the weight, the housing 102 and the cover 105 are formed of an aluminum alloy or the like, and the oil pump is damaged by a fretting phenomenon.

なお、ギヤポンプのフレッティング現象防止に関しては、特許文献１のオイルポンプ構造がある。この特許文献１のオイルポンプ装置について要部断面図を示す図７を参照して説明する。 In addition, there exists an oil pump structure of patent document 1 regarding prevention of the fretting phenomenon of a gear pump. The oil pump device of Patent Document 1 will be described with reference to FIG.

駆動機１２１のケーシング１２２とオイルポンプ１２５のケーシングフランジ１２６との嵌合及び駆動機１２１の駆動軸１２３とオイルポンプ１２５のポンプ軸１２７との嵌合によって駆動機１２１に結合されるオイルポンプ装置１２０において、駆動機１２１のケーシング１２２とオイルポンプフランジ１２６との嵌合面のはめあい隙間を、駆動軸１２３とポンプ軸１２７との嵌合面１２８のはめあい隙間より小さく形成して、駆動軸１２３とポンプ軸１２７との軸間相対接触を防止することによって該部のフレッティング現象を防止するものである。しかし、ロータとロータ収容部との接触によるフレッティング現象に対しては考慮されていない。 The oil pump device 120 coupled to the drive unit 121 by fitting the casing 122 of the drive unit 121 and the casing flange 126 of the oil pump 125 and fitting the drive shaft 123 of the drive unit 121 and the pump shaft 127 of the oil pump 125. , The fitting gap between the fitting surface of the casing 122 and the oil pump flange 126 of the driving machine 121 is formed to be smaller than the fitting gap between the fitting surfaces 128 of the driving shaft 123 and the pump shaft 127, so that the driving shaft 123 and the pump By preventing relative contact between the shaft 127 and the shaft 127, the fretting phenomenon of the portion is prevented. However, no consideration is given to the fretting phenomenon caused by contact between the rotor and the rotor housing portion.

特開昭６０−１８４９８３号公報Japanese Unexamined Patent Publication No. 60-184983

従って、かかる点に鑑みなされた本発明の目的は、駆動軸の軸方向の振動を抑制して、フレッティング現象を有効的に防止できるオイルポンプ構造を提供することにある。 Accordingly, an object of the present invention made in view of such a point is to provide an oil pump structure capable of effectively preventing a fretting phenomenon by suppressing vibration in the axial direction of a drive shaft.

上記目的を達成する請求項１に記載のオイルポンプ構造の発明は、アウタロータとインナロータを収容する第１のケース部材と、上記アウタロータインナロータを側面からカバーする第２ケース部材と、上記インナロータを支持する駆動軸とを備えたオイルポンプにおいて、上記第２ケース部材の側面に吸入ポート及び吐出ポートが開口し、上記駆動軸は、第１ケース部材に形成された軸支孔に支持部材を介して軸支される第１軸部と、上記インナロータを支持するロータ軸部と、上記第２ケース部材に形成された軸支孔に軸支される第２軸部が形成されると共に、上記ロータ軸部の一端に上記吐出ポート側から吸入ポート側に流れるオイルの油圧が作用する受圧面が形成され、他端に上記支持部材に当接する当接部が形成されたことを特徴とする。 The invention of the oil pump structure according to claim 1, which achieves the above object, includes a first case member that accommodates the outer rotor and the inner rotor, a second case member that covers the outer rotor inner rotor from a side surface, and the inner rotor. In the oil pump including the drive shaft, the suction port and the discharge port are opened on the side surface of the second case member, and the drive shaft is inserted into a shaft support hole formed in the first case member via a support member. A first shaft portion that is pivotally supported, a rotor shaft portion that supports the inner rotor, a second shaft portion that is pivotally supported by a shaft support hole formed in the second case member, and the rotor shaft The pressure receiving surface on which the oil pressure of the oil flowing from the discharge port side to the suction port side acts is formed at one end of the portion, and the contact portion that contacts the support member is formed at the other end. To.

この発明によると、第２ケース部材の側面に沿って吐出ポートの開口部側から吸入ポートの開口部側に流れるオイルの油圧が、駆動軸の受圧面に作用し、駆動軸に形成された当接部が第１ケース部材に配置された支持部材に押圧付勢されて駆動軸の軸方向の振動が防止される。これにより駆動軸の軸方向の振動に起因するインナロータの軸方向の振動発生が抑制されてインナロータ及びアウタロータと第１ケース部材及び第２ケース部材の側面との間の繰り返し接触がなくなり、インナロータ、アウタロータ及び第１ケース部材及び第２ケース部材の側面との間に発生するフレッティング現象の発生が有効的に防止できる。 According to the present invention, the oil pressure of the oil flowing from the opening side of the discharge port along the side surface of the second case member to the opening side of the suction port acts on the pressure receiving surface of the driving shaft and is formed on the driving shaft. The contact portion is pressed and urged by the support member disposed on the first case member, so that vibration in the axial direction of the drive shaft is prevented. As a result, the occurrence of axial vibration of the inner rotor due to the axial vibration of the drive shaft is suppressed, and repeated contact between the inner rotor and the outer rotor and the side surfaces of the first case member and the second case member is eliminated, and the inner rotor and outer rotor are eliminated. In addition, it is possible to effectively prevent the fretting phenomenon that occurs between the side surfaces of the first case member and the second case member.

請求項２に記載の発明は、請求項１に記載のオイルポンプ構造において、上記ロータ軸部にインナロータが２面嵌合で嵌合支持されたことを特徴とする。 According to a second aspect of the present invention, in the oil pump structure according to the first aspect, an inner rotor is fitted and supported on the rotor shaft portion by two-surface fitting.

この発明によると、駆動軸のロータ軸部とインナロータが２面嵌合して駆動軸とインナロータが強固に結合され、インナロータとアウタロータよって形成される閉込部内の油圧変動が大きいときでも安定したインナロータ及びアウタロータの回転駆動が確保され、良好なポンプ機能が維持できる。また、ロータ軸部と第２軸部との間に形成される受圧面の受圧面積が効率的に確保できる。 According to the present invention, the rotor shaft portion of the drive shaft and the inner rotor are fitted into two surfaces so that the drive shaft and the inner rotor are firmly coupled, and the inner rotor is stable even when the hydraulic pressure fluctuation in the confinement portion formed by the inner rotor and the outer rotor is large. And the rotation drive of an outer rotor is ensured and a favorable pump function can be maintained. Further, the pressure receiving area of the pressure receiving surface formed between the rotor shaft portion and the second shaft portion can be efficiently ensured.

請求項３に記載の発明は、請求項１または２のオイルポンプ構造において、上記第１ケース部材の軸支孔に配置される支持部材は、アウタレースが該軸支孔に嵌合支持されたボールベアリングであり、上記当接部が該ボールベアリングのインナレースに当接することを特徴とする。 The invention according to claim 3 is the oil pump structure according to claim 1 or 2, wherein the support member disposed in the shaft support hole of the first case member is a ball in which an outer race is fitted and supported in the shaft support hole. It is a bearing, The said contact part contact | abuts to the inner race of this ball bearing, It is characterized by the above-mentioned.

この発明は、第１ケース部材に配置されるベアリングをボールベアリングとすることで、駆動軸の当接部をボールベアリングのインナレースによって効率的に受け止めることができる。 According to the present invention, since the bearing disposed on the first case member is a ball bearing, the contact portion of the drive shaft can be efficiently received by the inner race of the ball bearing.

請求項４に記載の発明は、請求項３のオイルポンプ構造において、第１ケース部材の軸支持孔にクリップ係止溝が形成され、該クリップ係止溝にボールベアリングのアウタレースを係止保持するクリップが装着されたことを特徴とする。 According to a fourth aspect of the present invention, in the oil pump structure of the third aspect, a clip locking groove is formed in the shaft support hole of the first case member, and the outer race of the ball bearing is locked and held in the clip locking groove. A clip is attached.

この発明によると、ボールベアリングのアウタレースがクリップ係止溝に装着したクリップによって確実に保持され、駆動軸の当接部をボールベアリングのインナレースによって効率的に受け止めることができる。 According to this invention, the outer race of the ball bearing is securely held by the clip mounted in the clip locking groove, and the contact portion of the drive shaft can be efficiently received by the inner race of the ball bearing.

本発明によると、第２ケース部材の側面に沿って吐出ポートの開口部側から吸入ポートの開口部側に流れるオイルの油圧が、駆動軸の受圧面に作用し、駆動軸に形成された当接部が第１ケース部材に配置されたベアリングに押圧付勢されて駆動軸の軸方向の振動が防止され、駆動軸の軸方向の振動に起因するインナロータ及びアウタロータと第１ケース部材及び第２ケース部材の側面との間に発生するフレッティング現象の発生が有効的に防止できる。 According to the present invention, the hydraulic pressure of the oil flowing from the discharge port opening side to the suction port opening side along the side surface of the second case member acts on the pressure receiving surface of the drive shaft and is formed on the drive shaft. The contact portion is pressed and urged by a bearing disposed on the first case member to prevent the axial vibration of the drive shaft, and the inner rotor, the outer rotor, the first case member, and the second due to the axial vibration of the drive shaft. It is possible to effectively prevent the fretting phenomenon occurring between the side surface of the case member.

本発明に係るオイルポンプ構造の実施の形態を、自動変速機のトランスミッションケース内に配置される内接型オイルポンプを例に、図１乃至図５を参照して説明する。 An embodiment of an oil pump structure according to the present invention will be described with reference to FIGS. 1 to 5 by taking an inscribed oil pump disposed in a transmission case of an automatic transmission as an example.

図１はオイルポンプの断面図、図２は図１のＡ部拡大図、図３は図２のＩ−Ｉ線断面図、図４は図２のＩＩ−ＩＩ線断面図、図５は駆動軸の斜視図である。 1 is a cross-sectional view of an oil pump, FIG. 2 is an enlarged view of a portion A in FIG. 1, FIG. 3 is a cross-sectional view taken along a line II in FIG. 2, FIG. It is a perspective view of a shaft.

オイルポンプ１は、第１ケース部材となるハウジング１１の中央部に凹設された平面状の側面１３及び円筒状の周面１４を有するロータ収容部１２内に、外周面に歯部３１ａが形成されたインナロータ３１及び内周面に歯部３３ａが形成されたアウタロータ３２が、互いの歯部３１ａと３３ａとを噛み合わされた状態で配置され、第２ケース部材となるカバー１６と共にトランスミッションケース内を区画する隔壁６１にボルト１９によって固定される。これらハウジング１１及びカバー１６によってロータ収容部１２内に配置されたインナロータ３１及びアウタロータ３２を軸方向ａの両側から側面１３と側面１７によって挟み込むポンプハウジング１０を構成する。 In the oil pump 1, a tooth portion 31 a is formed on the outer peripheral surface in the rotor housing portion 12 having a planar side surface 13 and a cylindrical peripheral surface 14 that are recessed in the central portion of the housing 11 serving as a first case member. The inner rotor 31 and the outer rotor 32 having the teeth 33a formed on the inner peripheral surface are disposed in a state where the teeth 31a and 33a are meshed with each other, and the cover 16 serving as the second case member is disposed in the transmission case. The partition wall 61 is partitioned by bolts 19. The housing 11 and the cover 16 constitute the pump housing 10 in which the inner rotor 31 and the outer rotor 32 disposed in the rotor accommodating portion 12 are sandwiched between the side surface 13 and the side surface 17 from both sides in the axial direction a.

カバー１６は、ハウジング１１に凹設されたロータ収容部１２の側面１３と対向する側面１７を有すると共に、側面１７に対向して開口部２１ａ及び２２ａが開口する吸入ポート２１及び吐出ポート２２が形成される。 The cover 16 has a side surface 17 that faces the side surface 13 of the rotor accommodating portion 12 that is recessed in the housing 11, and a suction port 21 and a discharge port 22 that open the openings 21 a and 22 a so as to face the side surface 17. Is done.

ロータ収容部１２の周面１４は、アウタロータ３３をインナロータ３１に対して偏心状態に位置決めしてアウタロータ３３の外周面を回転自在に保持する。アウタロータ３３はロータ収容部１２の側面１３とカバー１６の側面１７との間及び周面１４によって囲まれたロータ収容部１３内でインナロータ３１に噛み合って従動回転する。 The circumferential surface 14 of the rotor accommodating portion 12 positions the outer rotor 33 in an eccentric state with respect to the inner rotor 31 and rotatably holds the outer circumferential surface of the outer rotor 33. The outer rotor 33 meshes with the inner rotor 31 in the rotor housing portion 13 surrounded by the circumferential surface 14 between the side surface 13 of the rotor housing portion 12 and the side surface 17 of the cover 16 and is driven to rotate.

ハウジング１１及びカバー１６のそれぞれの中央に、駆動軸４１をボールベアリング３８及びニードルベアリング３９を介在して回転自在に軸支する軸支孔１５、１８が形成される。ハウジング１１の軸支孔１５はロータ収容部１２に連続形成されて後述する駆動軸４１のロータ軸部４４が摺動可能に嵌合する軸保持孔１５ａと、軸保持孔１５ａに段部１５ｂを介して連続形成されてボールベアリング３８のアウタレース３８ａが嵌合するベアリング保持孔１５ｃとが連続形成される。ベアリング保持孔１５ｃには、ベアリング保持孔１５ｃに収容されたボールベアリング３８のアウタレース３８ａに当接してボールベアリング３８を保持するクリップ２０が嵌合するクリップ係止溝１５ｄが形成されている。 In the center of each of the housing 11 and the cover 16, shaft support holes 15 and 18 are formed that rotatably support the drive shaft 41 with a ball bearing 38 and a needle bearing 39 interposed therebetween. The shaft support hole 15 of the housing 11 is continuously formed in the rotor accommodating portion 12, and a shaft holding hole 15a in which a rotor shaft portion 44 of a drive shaft 41 described later is slidably fitted, and a step portion 15b is formed in the shaft holding hole 15a. Thus, a bearing holding hole 15c that is continuously formed through which the outer race 38a of the ball bearing 38 is fitted is continuously formed. In the bearing holding hole 15c, a clip locking groove 15d is formed in which the clip 20 holding the ball bearing 38 is fitted in contact with the outer race 38a of the ball bearing 38 accommodated in the bearing holding hole 15c.

駆動軸４１は、図２に示すと共に図５に斜視図を示すように、ニードルベアリング３９を介在してカバー１６の軸支孔１８に回転自在に嵌合する第２軸部４２と、第２軸部４２に受圧面となる段面部４３を介して連続形成された第２軸部４２より大径のロータ軸部４４と、ロータ軸部４４の端部に当接面となる段部４５を介してボールベアリング３８のインナレース３８ｂに嵌挿する第１軸部４６とが基端４１ａから先端４１ｂ側に一体に連続形成される。駆動軸４１のロータ軸部４４は、外周面４４ａに平行に一対面取りされた２面部４４ｂを有し、図３に示すようにインナロータ３１の２面部３２ａを有する軸孔３２に嵌合して駆動軸４１とインナロータ３１の相対回転を拘束する。ボールベアリング３８から突出する駆動軸４１の先端４１ｂには、中心軸に沿ってスプライン孔４７が穿設される。 As shown in FIG. 2 and a perspective view in FIG. 5, the drive shaft 41 includes a second shaft portion 42 that is rotatably fitted in the shaft support hole 18 of the cover 16 with a needle bearing 39 interposed therebetween, and a second shaft portion 42. A rotor shaft portion 44 having a larger diameter than the second shaft portion 42 continuously formed on the shaft portion 42 via a step surface portion 43 serving as a pressure receiving surface, and a step portion 45 serving as a contact surface at the end of the rotor shaft portion 44 are provided. Thus, the first shaft portion 46 fitted into the inner race 38b of the ball bearing 38 is continuously formed integrally from the proximal end 41a to the distal end 41b. The rotor shaft portion 44 of the drive shaft 41 has two surface portions 44b chamfered in parallel to the outer peripheral surface 44a, and is fitted into the shaft hole 32 having the two surface portions 32a of the inner rotor 31 as shown in FIG. The relative rotation of the drive shaft 41 and the inner rotor 31 is restrained. A spline hole 47 is formed along the central axis at the tip 41 b of the drive shaft 41 protruding from the ball bearing 38.

一方、トランスミッションケースに形成された軸支部６２に一対のボールベアリング６３ａ、６３ｂを介して駆動軸４１と同軸上に延在する入力軸５１の基端部５１ａが回転自在に支持されている。入力軸５１の先端５１ｂに駆動軸４１のスプライン孔４７に嵌合するスプライン歯５２が形成され、入力軸５１の先端５１ｂと駆動軸４１の先端４１ｂが互いに軸方向の相対移動が許容され、かつ動力伝達可能にスプライン嵌合する。更に、入力軸５１は、その基端部５１ａにスプロケット５３が固設され、チェーン５４を介して図示しないトルクコンバータのスリーブ等によって回転駆動される。 On the other hand, a base end portion 51a of an input shaft 51 extending coaxially with the drive shaft 41 is rotatably supported by a shaft support portion 62 formed in the transmission case via a pair of ball bearings 63a and 63b. Spline teeth 52 that fit into the spline hole 47 of the drive shaft 41 are formed at the tip 51b of the input shaft 51, and the tip 51b of the input shaft 51 and the tip 41b of the drive shaft 41 are allowed to move relative to each other in the axial direction. Splined to allow power transmission. Further, the input shaft 51 has a sprocket 53 fixed to the base end portion 51 a thereof, and is rotationally driven via a chain 54 by a sleeve of a torque converter (not shown).

このように構成されたオイルポンプ１は、トルクコンバータのスリーブ等の回転に伴ってチェーン５４及びスプロケット５３を介して入力軸５１が回転駆動される。入力軸５１の回転によって入力軸５１とスプライン嵌合する駆動軸４１が回転し、回転するインナロータ３１の歯部３１ａに歯部３３ａが噛み合うアウタロータ３３が回転する。 In the oil pump 1 configured as described above, the input shaft 51 is rotationally driven via the chain 54 and the sprocket 53 as the sleeve of the torque converter rotates. The drive shaft 41 that is spline-fitted with the input shaft 51 is rotated by the rotation of the input shaft 51, and the outer rotor 33 in which the tooth portion 33 a is engaged with the tooth portion 31 a of the rotating inner rotor 31 is rotated.

互いに回転するインナロータ３１の歯部３１ａとアウタロータ３３の歯部３３ａによって形成される閉込部３４によって吸入ポート２１の開口部２１ａからオイルが閉込部３４内に吸入され、インナロータ３１の歯部３１ａとアウタロータ３３の歯部３３ａとの間の閉込部３４内に囲み込まれたオイルはインナロータ３１及びアウタロータ３３の回転に伴い吐出ポート２２の開口部２２ａへ運ばれ、吐出ポート２２から各部に送り出される。 Oil is sucked into the confining portion 34 from the opening portion 21a of the suction port 21 by the confining portion 34 formed by the tooth portion 31a of the inner rotor 31 and the tooth portion 33a of the outer rotor 33, and the tooth portion 31a of the inner rotor 31. The oil enclosed in the closed portion 34 between the outer rotor 33 and the tooth portion 33a of the outer rotor 33 is carried to the opening 22a of the discharge port 22 as the inner rotor 31 and the outer rotor 33 rotate, and is sent out from the discharge port 22 to each portion. It is.

一方、インナロータ３１の側面３１ｂ及びアウタロータ３３の側面３３ｂとカバー１６の側面１７との間にはインナロータ３１及びアウタロータ３３の円滑な回転を確保するため微小な隙間が形成され、吐出ポート２２と吸入ポート２１の圧力差に伴って図４に矢印Ｆで示すようにカバー１６の側面１７に沿って吐出ポート２２の開口部２２ａ側から吸入ポート２１に開口部２１ａに駆動軸４１に沿うオイルの流れが発生する。 On the other hand, a minute gap is formed between the side surface 31b of the inner rotor 31 and the side surface 33b of the outer rotor 33 and the side surface 17 of the cover 16 to ensure smooth rotation of the inner rotor 31 and the outer rotor 33, and the discharge port 22 and the suction port With the pressure difference of 21, the flow of oil along the drive shaft 41 flows from the opening 22 a side of the discharge port 22 to the suction port 21 along the side surface 17 of the cover 16 as indicated by an arrow F in FIG. 4. appear.

このカバー１６の側面１７に沿ってインナロータ３１及びアウタロータ３３の側面３１ｂ、３３ｂとカバー１６の側面１７との隙間を流れるオイルの油圧Ｐが、受圧面となる駆動軸４１の段面部４３に作用し、駆動軸４１を入力軸５１側に押動して当接部となる段部４５がクリップ２０によってアウタレース３８ａが保持されて軸方向ａの移動が規制されたボールベアリング３８のインナレース３８ｂに押圧付勢されて駆動軸４１の軸方向ａの振動が防止される。 The oil pressure P of oil flowing along the side surface 17 of the cover 16 between the side surfaces 31b and 33b of the inner rotor 31 and the outer rotor 33 and the side surface 17 of the cover 16 acts on the step surface portion 43 of the drive shaft 41 serving as a pressure receiving surface. Then, the drive shaft 41 is pushed to the input shaft 51 side, and the stepped portion 45 serving as a contact portion is pressed against the inner race 38b of the ball bearing 38 in which the outer race 38a is held by the clip 20 and the movement in the axial direction a is restricted. The vibration in the axial direction a of the drive shaft 41 is prevented by being biased.

この段部４５がボールベアリング３８のインナレース３８ｂに押圧付勢された駆動軸４１は軸方向ａの振動が防止され、駆動軸４１の振動に起因するインナロータ３１の軸方向の振動の発生が抑制されてインナロータ３１及びアウタロータ３３とロータ収容部１２の側面１３、１７との間の繰り返し接触がなくなり、インナロータ３１、アウタロータ３３及びロータ収容部１２の側面１３、１７との間に発生するフレッティング現象の発生が有効的に防止できる。 The drive shaft 41 in which the stepped portion 45 is pressed and urged against the inner race 38 b of the ball bearing 38 is prevented from vibrating in the axial direction a, and the occurrence of axial vibration of the inner rotor 31 due to the vibration of the driving shaft 41 is suppressed. Thus, the repeated contact between the inner rotor 31 and the outer rotor 33 and the side surfaces 13 and 17 of the rotor accommodating portion 12 is eliminated, and the fretting phenomenon that occurs between the inner rotor 31, the outer rotor 33 and the side surfaces 13 and 17 of the rotor accommodating portion 12. Can be effectively prevented.

また、駆動軸４１のロータ軸部４４とインナロータ３１の軸孔３２が２面嵌合して駆動軸４１とインナロータ３１が強固に支持され、インナロータ３１とアウタロータ３３よって形成される閉込部３４内の油圧が変動が大きいときでも安定したインナロータ３１及びアウタロータ３３の回転駆動が確保され、良好なポンプ機能が維持できる。また、ロータ軸部４４と第２軸部４２との間に形成される受圧面となる断面部４３の面積が確保でき、オイルの受圧面積が効率的に確保できる。 Further, the rotor shaft portion 44 of the drive shaft 41 and the shaft hole 32 of the inner rotor 31 are fitted into two surfaces so that the drive shaft 41 and the inner rotor 31 are firmly supported, and the inside of the confinement portion 34 formed by the inner rotor 31 and the outer rotor 33. Even when the hydraulic pressure of the motor is largely fluctuated, stable rotation of the inner rotor 31 and the outer rotor 33 is ensured, and a good pump function can be maintained. Moreover, the area of the cross-sectional part 43 used as the pressure receiving surface formed between the rotor axial part 44 and the 2nd axial part 42 can be ensured, and the pressure receiving area of oil can be ensured efficiently.

なお、本発明は上記実施の形態に限定されることなく、発明の趣旨を逸脱しない範囲で種々変更可能である。例えば上記実施の形態ではロータ軸部４４とインナロータ３１の軸孔３２とを、互いに係合する２面部３２ａ、４４ｂを備えた２面嵌合により嵌合したが、第２軸部４２より大径のスプライン軸によりロータ軸部４４を形成し、ロータ軸部４４とインナロータ３１の軸孔３２をスプライン孔による形成し互いにスプライン嵌合することもできる。この場合第２軸部４２とスプライン軸によって形成されロータ軸部４４との間の段差部４３が受圧面となる。 In addition, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the meaning of invention. For example, in the above-described embodiment, the rotor shaft portion 44 and the shaft hole 32 of the inner rotor 31 are fitted by two-surface fitting including the two surface portions 32a and 44b that engage with each other, but the diameter is larger than that of the second shaft portion 42. It is also possible to form the rotor shaft portion 44 by the spline shaft, and to form the shaft hole 32 of the rotor shaft portion 44 and the inner rotor 31 by the spline hole so as to be spline fitted to each other. In this case, a stepped portion 43 formed between the second shaft portion 42 and the spline shaft and between the rotor shaft portion 44 serves as a pressure receiving surface.

実施の形態に係るオイルポンプの断面図である。It is sectional drawing of the oil pump which concerns on embodiment. 図１のＡ部拡大図である。It is the A section enlarged view of FIG. 図２のＩ−Ｉ線断面図である。It is the II sectional view taken on the line of FIG. 図２のＩＩ−ＩＩ線断面図である。It is the II-II sectional view taken on the line of FIG. 駆動軸の斜視図である。It is a perspective view of a drive shaft. 従来のオイルポンプの断面図である。It is sectional drawing of the conventional oil pump. 従来のオイルポンプの説明図である。It is explanatory drawing of the conventional oil pump.

Explanation of symbols

１オイルポンプ
１０ポンプハウジング
１１ハウジング（第１ケース部材）
１２ロータ収容部
１３側面
１４周面
１５軸支孔
１５ｃベアリング保持孔
１５ｄクリップ係止溝
１６カバー（第２ケース部材）
１７側面
１８軸支孔
２０クリップ
２１吸入ポート
２１ａ開口部
２２吐出ポート
２２ａ開口部
３１インナロータ
３１ａ歯部
３２軸孔
３３アウタロータ
３３ａ歯部
３４閉込部
３８ボールベアリング
３８ａアウタレース
３８ｂインナレース
３９ニードルベアリング
４１駆動軸
４２第２軸部
４３段差部（受圧面）
４４ロータ軸部
４５段部（当接部）
４６第１軸部 1 Oil pump 10 Pump housing 11 Housing (first case member)
12 Rotor housing part 13 Side surface 14 Peripheral surface 15 Shaft support hole 15c Bearing holding hole 15d Clip locking groove 16 Cover (second case member)
17 Side 18 Shaft support hole 20 Clip 21 Suction port 21a Opening part 22 Discharge port 22a Opening part 31 Inner rotor 31a Tooth part 32 Shaft hole 33 Outer rotor 33a Tooth part 34 Containing part 38 Ball bearing 38a Outer race 38b Inner race 39 Needle bearing 41 Drive Shaft 42 Second shaft portion 43 Stepped portion (pressure receiving surface)
44 Rotor shaft part 45 Step part (contact part)
46 1st shaft

Claims

In an oil pump comprising: a first case member that accommodates an outer rotor and an inner rotor; a second case member that covers the outer rotor and the inner rotor from a side surface; and a drive shaft that supports the inner rotor.
A suction port and a discharge port are opened on a side surface of the second case member;
The drive shaft is formed in a first shaft portion that is supported via a support member in a shaft support hole formed in the first case member, a rotor shaft portion that supports the inner rotor, and the second case member. A second shaft portion that is pivotally supported by the shaft support hole is formed, and a pressure receiving surface is formed at one end of the rotor shaft portion to which oil pressure of oil flowing from the discharge port side to the suction port side acts. An oil pump structure in which an abutting portion that abuts on the support member is formed.

2. The oil pump structure according to claim 1, wherein an inner rotor is fitted and supported on the rotor shaft portion by two-surface fitting.

3. The oil according to claim 1, wherein the support member is a ball bearing in which an outer race is fitted and supported in the shaft support hole, and the contact portion abuts on an inner race of the ball bearing. Pump structure.

The oil pump according to claim 3, wherein a clip locking groove is formed in the shaft support hole of the first case member, and a clip for locking and holding the outer race of the ball bearing is mounted in the clip locking groove. Construction.