JP2008281174A

JP2008281174A - Electric linear motion actuator and electric brake device

Info

Publication number: JP2008281174A
Application number: JP2007128150A
Authority: JP
Inventors: Tatsuya Yamazaki; 達也山崎; Masaaki Eguchi; 雅章江口
Original assignee: NTN Corp; NTN Toyo Bearing Co Ltd
Current assignee: NTN Corp
Priority date: 2007-05-14
Filing date: 2007-05-14
Publication date: 2008-11-20

Abstract

<P>PROBLEM TO BE SOLVED: To form a cover of a casing in a thin and simple shape, in an electric linear motion actuator of arranging a rotary shaft so as not to become coaxial with a rotor shaft of an electric motor. <P>SOLUTION: The rotary shaft 4 is arranged in parallel to the rotor shaft 2a of the electric motor 2, and a ball bearing 14 supporting the rotary shaft 4 is installed in a bearing support member 15 fixed between an outer race member 5 and a retaining ring 13 installed on an inner diameter surface of the casing 1 so as to receive reaction in the axial direction of the linear motion actuator generated in the outer race member 5, to thereby dispense with installation of the bearing in the cover 1c of the casing 1, and the cover 1c can be formed in the thin and simple shape. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

本発明は、電動モータの回転運動を直線運動に変換して被駆動物を直線駆動する電動式直動アクチュエータと、電動式直動アクチュエータを用いてブレーキ部材を被制動部材に押圧する電動式ブレーキ装置に関する。 The present invention relates to an electric linear motion actuator that linearly drives a driven object by converting the rotational motion of an electric motor into linear motion, and an electric brake that presses a brake member against the braked member using the electric linear motion actuator Relates to the device.

電動モータの回転運動を直線運動に変換して被駆動物を直線駆動する電動式直動アクチュエータには、運動変換機構としてボールねじ機構やボールランプ機構を採用したものが多く、小容量の電動モータで大きな直線駆動力が得られるように、遊星歯車減速機構等の歯車減速機構を組み込んだものが多い（例えば、特許文献１参照）。 Many of the electric linear actuators that convert the rotational motion of the electric motor into linear motion to drive the driven object linearly employ a ball screw mechanism or a ball ramp mechanism as the motion conversion mechanism. In many cases, a gear reduction mechanism such as a planetary gear reduction mechanism is incorporated so that a large linear driving force can be obtained (see, for example, Patent Document 1).

上述した電動式直動アクチュエータに採用されているボールねじ機構やボールランプ機構は、リードを有するねじ筋や傾斜カム面に沿わせる運動変換機構によって、ある程度の増力機能を有するが、電動式ブレーキ装置等で必要とされるような大きな増力機能は確保できない。このため、これらの運動変換機構を採用した電動式直動アクチュエータでは、遊星歯車減速機構等の別途の減速機構を組み込んで駆動力を増力しているが、このように別途の減速機構を組み込むことは、電動式直動アクチュエータのコンパクトな設計を阻害する。 The ball screw mechanism and the ball ramp mechanism employed in the electric linear actuator described above have a certain degree of boosting function by a motion conversion mechanism along the lead screw thread and the inclined cam surface. It is not possible to secure a large boosting function that is necessary for the above. For this reason, in the electric linear actuator that employs these motion conversion mechanisms, a separate reduction mechanism such as a planetary gear reduction mechanism is incorporated to increase the driving force. In this way, a separate reduction mechanism is incorporated. Impedes the compact design of the electric linear actuator.

このような問題に対して、本発明者らは、別途の減速機構を組み込むことなく大きな増力機能を確保でき、直動ストロークが小さい電動式ブレーキ装置にも好適な電動式直動アクチュエータとして、電動モータのロータ軸から回転を伝達される回転軸と、この回転軸の外径側でケーシングの内径面に固定された外輪部材との間に、キャリヤに回転自在に支持された複数の遊星ローラを介在させて、これらの各遊星ローラが回転軸の回転に伴って回転軸の周りを自転しながら公転するようにし、回転軸の外径面または外輪部材の内径面に螺旋凸条を設け、各遊星ローラの外径面に、螺旋凸条と同一ピッチで螺旋凸条が嵌まり込む周方向溝、または螺旋凸条と同一ピッチでリード角が異なり螺旋凸条が嵌まり込む螺旋溝を設けて、回転軸の周りを自転しながら公転する各遊星ローラを支持するキャリヤを軸方向へ相対移動させ、回転軸の回転運動をキャリヤの直線運動に変換する機構を先に提案している（特許文献２、３参照）。 With respect to such a problem, the present inventors can secure a large boosting function without incorporating a separate speed reduction mechanism, and as an electric linear actuator suitable for an electric brake device having a small linear stroke, A plurality of planetary rollers rotatably supported by a carrier are provided between a rotating shaft to which rotation is transmitted from the rotor shaft of the motor and an outer ring member fixed to the inner surface of the casing on the outer diameter side of the rotating shaft. By interposing, each of these planetary rollers revolves while rotating around the rotation shaft as the rotation shaft rotates, and provided with spiral ridges on the outer diameter surface of the rotation shaft or the inner diameter surface of the outer ring member, The outer circumferential surface of the planetary roller is provided with a circumferential groove in which the spiral ridges are fitted at the same pitch as the spiral ridges, or a spiral groove in which the spiral ridges are fitted at the same pitch as the spiral ridges but with different lead angles. Around the axis of rotation The carrier for supporting the respective planetary rollers to rolling while revolving by relatively moved in the axial direction, has proposed a mechanism for converting the rotary motion of the rotary shaft into a linear motion of the carrier previously (see Patent Documents 2 and 3).

一方、車両用ブレーキ装置としては油圧式のものが多く採用されてきたが、近年、ＡＢＳ(Antilock Brake System)等の高度なブレーキ制御の導入に伴い、これらの制御を複雑な油圧回路なしに行うことができる電動式ブレーキ装置が注目されている。電動式ブレーキ装置は、ブレーキペダルの踏み込み信号等で電動モータを作動させ、上述したような電動式直動アクチュエータをキャリパボディに組み込んでブレーキ部材を被制動部材に押圧するものである（例えば、特許文献２参照）。通常、電動式ブレーキ装置は車両のばね下に取り付けられるので、路面からの振動を受けても安定して作動し、かつ、コンパクトに設計できるものが望まれる。 On the other hand, many hydraulic brake devices have been adopted, but in recent years, with the introduction of advanced brake control such as ABS (Antilock Brake System), these controls are performed without a complicated hydraulic circuit. Electric brake devices that can do this are attracting attention. The electric brake device operates an electric motor in response to a brake pedal depression signal or the like, and incorporates an electric linear actuator as described above into a caliper body to press a brake member against a member to be braked (for example, a patent) Reference 2). Usually, since the electric brake device is attached under the spring of the vehicle, it is desired that the electric brake device operates stably even when subjected to vibration from the road surface and can be designed compactly.

特開平６−３２７１９０号公報JP-A-6-327190 特開２００７−３２７１７号公報JP 2007-32717 A 特開２００７−３７３０５号公報JP 2007-37305 A 特開２００３−３４３６２０号公報JP 2003-343620 A

特許文献２、３に記載された電動式直動アクチュエータは、別途の減速機構を組み込むことなく、コンパクトな設計で大きな増力機能を確保できるが、電動モータのロータ軸と直動アクチュエータの回転軸を同軸上に直列に配置しているので、全体の軸方向長さ寸法が長くなる問題があり、本発明者らは、直動アクチュエータの回転軸を電動モータのロータ軸と同軸にならないように配置して、全体の軸方向長さをコンパクトにすることを先に提案している（特願２００６−２７０８１７）。 The electric linear actuators described in Patent Documents 2 and 3 can secure a large boosting function with a compact design without incorporating a separate reduction mechanism, but the rotor shaft of the electric motor and the rotary shaft of the linear actuator are Since it is arranged in series on the same axis, there is a problem that the overall length in the axial direction becomes long, and the present inventors have arranged the rotation axis of the linear actuator not to be coaxial with the rotor axis of the electric motor. Thus, it has been proposed to make the entire axial length compact (Japanese Patent Application No. 2006-270817).

特願２００６−２７０８１７で提案したものでは、前記回転軸を支持する軸受を、直動アクチュエータのケーシングの後端側を閉塞する蓋に組み付けている。このため、このケーシングの蓋が、軸受を組み付けるための厚みと強度を必要とし、かつ、軸受の組み付け部が突出する複雑な形状となって、蓋の重量が重くなるとともに、製造コストが高くなる問題がある。 In the one proposed in Japanese Patent Application No. 2006-270817, the bearing that supports the rotating shaft is assembled to a lid that closes the rear end side of the casing of the linear actuator. For this reason, the cover of this casing requires the thickness and intensity | strength for assembling a bearing, and also becomes the complicated shape from which the assembly part of a bearing protrudes, and the weight of a cover becomes heavy and manufacturing cost becomes high. There's a problem.

そこで、本発明の課題は、回転軸を電動モータのロータ軸と同軸にならないように配置した電動式直動アクチュエータにおける、ケーシングの蓋を薄肉で簡単な形状とすることである。 Therefore, an object of the present invention is to make the casing lid thin and simple in an electric linear motion actuator in which the rotation shaft is arranged so as not to be coaxial with the rotor shaft of the electric motor.

上記の課題を解決するために、電動モータのロータ軸から回転を伝達される回転軸と、この回転軸の外径側でケーシングの内径面に固定された外輪部材との間に、キャリヤに回転自在に支持された複数の遊星ローラを介在させて、これらの各遊星ローラが前記回転軸の回転に伴って回転軸の周りを自転しながら公転するようにし、前記回転軸の外径面または前記外輪部材の内径面に螺旋凸条を設け、前記各遊星ローラの外径面に、前記螺旋凸条と同一ピッチで螺旋凸条が嵌まり込む周方向溝、または螺旋凸条と同一ピッチでリード角が異なり螺旋凸条が嵌まり込む螺旋溝を設けて、前記回転軸の周りを自転しながら公転する各遊星ローラを支持するキャリヤを軸方向へ相対移動させ、前記回転軸の回転運動を前記キャリヤの直線運動に変換して、被駆動物を直線駆動する電動式直動アクチュエータにおいて、前記回転軸を前記電動モータのロータ軸と同軸にならないように配置し、この回転軸を支持する軸受を、前記ロータ軸からの回転伝達部と前記遊星ローラとの間の軸方向部位に配設した構成を採用した。 In order to solve the above problem, the carrier rotates between the rotating shaft that transmits the rotation from the rotor shaft of the electric motor and the outer ring member that is fixed to the inner surface of the casing on the outer diameter side of the rotating shaft. By interposing a plurality of planetary rollers supported freely, each of these planetary rollers revolves while rotating around the rotation shaft as the rotation shaft rotates, and the outer diameter surface of the rotation shaft or the A spiral ridge is provided on the inner surface of the outer ring member, and a circumferential groove in which the spiral ridge is fitted at the same pitch as the spiral ridge on the outer diameter surface of each planetary roller, or a lead at the same pitch as the spiral ridge. A spiral groove in which a spiral protrusion is fitted at a different angle is provided, the carrier supporting each planetary roller that revolves while rotating around the rotation shaft is relatively moved in the axial direction, and the rotational movement of the rotation shaft is Converted into linear motion of the carrier In the electric linear actuator that linearly drives the driven object, the rotation shaft is disposed so as not to be coaxial with the rotor shaft of the electric motor, and a bearing that supports the rotation shaft is transmitted from the rotor shaft. The structure arrange | positioned in the axial direction site | part between a part and the said planetary roller was employ | adopted.

すなわち、直動アクチュエータの回転軸を電動モータのロータ軸と同軸にならないように配置し、この回転軸を支持する軸受を、ロータ軸からの回転伝達部と遊星ローラとの間の軸方向部位に配設することにより、ケーシングの蓋に軸受を組み付けることを不要とし、蓋を薄肉で簡単な形状にできるようにした。 In other words, the rotation shaft of the linear actuator is arranged so as not to be coaxial with the rotor shaft of the electric motor, and the bearing that supports the rotation shaft is disposed in the axial direction portion between the rotation transmission portion from the rotor shaft and the planetary roller. By disposing it, it is not necessary to assemble the bearing to the lid of the casing, and the lid can be made thin and simple.

前記外輪部材を固定するケーシングの内径面を円筒面で形成して、この円筒面で形成したケーシングの内径面に、前記外輪部材に発生する直動アクチュエータの軸方向反力を受ける止め輪を装着したものでは、前記回転軸を支持する軸受を、この止め輪と前記外輪部材との間で前記ケーシングの内径面に固定した軸受支持部材に組み付けることができる。 The inner surface of the casing for fixing the outer ring member is formed by a cylindrical surface, and a retaining ring for receiving the axial reaction force of the linear actuator generated on the outer ring member is mounted on the inner surface of the casing formed by the cylindrical surface. In this case, the bearing that supports the rotating shaft can be assembled to a bearing support member that is fixed to the inner diameter surface of the casing between the retaining ring and the outer ring member.

前記軸受支持部材には、前記キャリヤが軸受支持部材側へ後退移動したときに、キャリヤまたはキャリヤと一緒に後退移動する部材に軸方向で当接され、前記キャリヤの後退位置を規制するストッパ部を設けることができる。 The bearing support member is provided with a stopper portion that abuts the carrier or a member that moves backward together with the carrier in the axial direction when the carrier moves backward toward the bearing support member, and regulates the backward position of the carrier. Can be provided.

前記回転軸の外径面または外輪部材の内径面に設けた螺旋凸条を、これらの回転軸の外径面または外輪部材の内径面に設けた螺旋溝に周着した条部材で形成することにより、螺旋凸条を容易に精度よく形成することができる。 The spiral ridges provided on the outer diameter surface of the rotating shaft or the inner diameter surface of the outer ring member are formed by the strip members that surround the spiral grooves provided on the outer diameter surface of the rotating shaft or the inner diameter surface of the outer ring member. Thus, the spiral ridge can be easily formed with high accuracy.

前記螺旋凸条を螺旋溝に周着した条部材で形成したものでは、前記軸受支持部材に前記外輪部材側への環状突出部を形成し、この環状突出部に前記条部材で形成した螺旋凸条の外径面または内径面を案内する案内面を設けることにより、条部材が端部より脱落するのを防止することができる。 In the case where the spiral protrusion is formed of a strip member that is attached to the spiral groove, an annular protrusion toward the outer ring member is formed on the bearing support member, and the spiral protrusion formed of the stripe member on the annular protrusion. By providing a guide surface for guiding the outer diameter surface or inner diameter surface of the strip, it is possible to prevent the strip member from falling off the end portion.

前記回転軸を前記電動モータのロータ軸と並列に配置することにより、全体の軸方向長さ寸法を最も短くして、かつ、外形を凹凸の少ないコンパクトな形態とすることができる。また、前記軸受の長さ分のスペースだけ電動モータの長さ寸法を大きくすることができ、モータのトルクを増大するか、またはモータの外径寸法を小さくすることができる。 By arranging the rotating shaft in parallel with the rotor shaft of the electric motor, the overall axial length can be minimized, and the outer shape can be reduced to a compact form with little unevenness. Further, the length of the electric motor can be increased by a space corresponding to the length of the bearing, and the torque of the motor can be increased or the outer diameter of the motor can be reduced.

また、本発明の電動式ブレーキ装置は、電動モータの回転運動を直線運動に変換してブレーキ部材を直線駆動する電動式直動アクチュエータを備え、前記直線駆動されるブレーキ部材を被制動部材に押圧する電動式ブレーキ装置において、前記電動式直動アクチュエータに上述したいずれかの電動式直動アクチュエータを用いる構成を採用した。 The electric brake device according to the present invention includes an electric linear actuator that linearly drives the brake member by converting the rotational motion of the electric motor into a linear motion, and presses the brake member that is linearly driven against the member to be braked. In the electric brake device, the configuration using any one of the electric linear actuators described above as the electric linear actuator is adopted.

本発明の電動式直動アクチュエータは、直動アクチュエータの回転軸を電動モータのロータ軸と同軸にならないように配置し、この回転軸を支持する軸受を、ロータ軸からの回転伝達部と遊星ローラとの間の軸方向部位に配設したので、ケーシングの蓋に軸受を組み付けることを不要とし、蓋を薄肉で簡単な形状とすることができ、蓋の重量を軽くできるとともに、製造コストを低減することができる。 The electric linear motion actuator of the present invention is arranged so that the rotation shaft of the linear motion actuator is not coaxial with the rotor shaft of the electric motor, and the bearing that supports the rotation shaft is connected to the rotation transmission portion from the rotor shaft and the planetary roller. Since it is disposed in the axial direction between the housing and the bearing, it is not necessary to assemble the bearing to the casing lid, the lid can be made thin and simple, the lid weight can be reduced, and the manufacturing cost is reduced. can do.

前記螺旋凸条を螺旋溝に周着した条部材で形成したものでは、前記軸受支持部材に外輪部材側への環状突出部を形成し、この環状突出部に条部材で形成した螺旋凸条の外径面または内径面を案内する案内面を設けることにより、条部材が端部より脱落するのを防止することができる。 In the case where the spiral ridge is formed of a strip member that surrounds the spiral groove, an annular protrusion toward the outer ring member is formed on the bearing support member, and the spiral protrusion formed of the strip member on the annular protrusion is formed. By providing the guide surface for guiding the outer diameter surface or the inner diameter surface, it is possible to prevent the strip member from falling off the end portion.

前記回転軸を電動モータのロータ軸と並列に配置することにより、全体の軸方向長さ寸法を最も短くして、かつ、外形を凹凸の少ないコンパクトな形態とすることができる。また、前記軸受の長さ分のスペースだけ電動モータの長さ寸法を大きくすることができ、モータのトルクを増大するか、またはモータの外径寸法を小さくすることができる。 By arranging the rotating shaft in parallel with the rotor shaft of the electric motor, the overall axial length can be made the shortest and the outer shape can be made compact with less unevenness. Further, the length of the electric motor can be increased by a space corresponding to the length of the bearing, and the torque of the motor can be increased or the outer diameter of the motor can be reduced.

以下、図面に基づき、本発明の実施形態を説明する。この電動式直動アクチュエータは、図１乃至図３に示すように、ケーシング１の円筒部１ａの後端側で瓢箪形を形成するように張り出すフランジ１ｂが設けられて、このフランジ１ｂに電動モータ２が円筒部１ａに沿わせて取り付けられ、電動モータ２のロータ軸２ａの回転が歯車３ａ、３ｂ、３ｃによって、ロータ軸２ａと並列に円筒部１ａの中心に配置された回転軸４に伝達されるようになっており、回転軸４と円筒部１ａの円筒面とされた内径面に固定された外輪部材５との間に、キャリヤ６の支持軸６ａに回転自在に支持された３個の遊星ローラ７が介在し、各遊星ローラ７が回転軸４の回転に伴って、その周りを自転しながら公転するようになっている。また、隣接する各遊星ローラ７の間には、両側の遊星ローラ７の外径面に摺接して、潤滑剤としてのグリースを塗布する３個の扇形状の潤滑剤塗布部材８が配設されている。各潤滑剤塗布部材８は、キャリヤ６の支持軸６ａに取り付けられた有底部分円筒状のケース９に収納されている。 Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIGS. 1 to 3, this electric linear actuator is provided with a flange 1 b protruding so as to form a bowl shape on the rear end side of the cylindrical portion 1 a of the casing 1, and the flange 1 b is electrically driven. The motor 2 is attached along the cylindrical portion 1a, and the rotation of the rotor shaft 2a of the electric motor 2 is rotated by the gears 3a, 3b, 3c to the rotating shaft 4 arranged in the center of the cylindrical portion 1a in parallel with the rotor shaft 2a. 3 is rotatably supported by the support shaft 6a of the carrier 6 between the rotary shaft 4 and the outer ring member 5 fixed to the inner surface of the cylindrical portion 1a. A plurality of planetary rollers 7 are interposed, and each planetary roller 7 revolves while rotating around the rotating shaft 4 as the rotating shaft 4 rotates. In addition, between the adjacent planetary rollers 7, three fan-shaped lubricant application members 8 for applying grease as a lubricant are disposed in sliding contact with the outer diameter surfaces of the planetary rollers 7 on both sides. ing. Each lubricant application member 8 is housed in a bottomed partial cylindrical case 9 attached to the support shaft 6 a of the carrier 6.

前記ケーシング１の後端側には蓋１ｃが取り付けられており、歯車３ａ、３ｂ、３ｃは、蓋１ｃで覆われた空間に、軸方向同一断面内で噛み合うように配設されている。ロータ軸２ａの歯車３ａおよび回転軸４の歯車３ｃと噛み合う中間歯車３ｂは、フランジ１ｂと蓋１ｃに差し渡された軸ピン１０に玉軸受１１で支持されている。 A lid 1c is attached to the rear end side of the casing 1, and the gears 3a, 3b, and 3c are arranged so as to mesh with each other in the same cross section in the axial direction in the space covered with the lid 1c. An intermediate gear 3b that meshes with the gear 3a of the rotor shaft 2a and the gear 3c of the rotating shaft 4 is supported by a ball bearing 11 on a shaft pin 10 that is passed between the flange 1b and the lid 1c.

前記ケーシング１の円筒部１ａの内径面には環状溝１２が設けられ、この環状溝１２に、外輪部材５に発生する直動アクチュエータの軸方向反力を受ける止め輪１３が装着され、この止め輪１３と外輪部材５との間で、回転軸４を支持する玉軸受１４を組み付けた軸受支持部材１５が円筒部１ａの内径面に固定されている。したがって、止め輪１３と外輪部材５との間で玉軸受１４を組み付けた分だけケーシング１の円筒部１ａの長さが長くなり、円筒部１ａに沿わせて取り付けられた電動モータ２の長さ寸法を、円筒部１ａから突出させることなく大きくすることができる。 An annular groove 12 is provided on the inner diameter surface of the cylindrical portion 1 a of the casing 1, and a retaining ring 13 that receives an axial reaction force of the linear actuator generated in the outer ring member 5 is attached to the annular groove 12. Between the ring 13 and the outer ring member 5, a bearing support member 15 assembled with a ball bearing 14 for supporting the rotating shaft 4 is fixed to the inner diameter surface of the cylindrical portion 1a. Accordingly, the length of the cylindrical portion 1a of the casing 1 is increased by the amount of the ball bearing 14 assembled between the retaining ring 13 and the outer ring member 5, and the length of the electric motor 2 attached along the cylindrical portion 1a. The dimensions can be increased without protruding from the cylindrical portion 1a.

前記各遊星ローラ７は、回転軸４に外嵌されたキャリヤ６の支持軸６ａに２列の針状ころ軸受１６で回転自在に支持されて、その自転がスラストころ軸受１７でキャリヤ６に支持され、各遊星ローラ７と一緒に公転するキャリヤ６には直線駆動部材１８がスラストころ軸受１９で支持されており、各遊星ローラ７の直線運動がキャリヤ６を介して直線駆動部材１８に伝達されるようになっている。 Each of the planetary rollers 7 is rotatably supported by two rows of needle roller bearings 16 on a support shaft 6a of a carrier 6 fitted on the rotary shaft 4, and the rotation of the planetary rollers 7 is supported by the carrier 6 by a thrust roller bearing 17. A linear drive member 18 is supported by a thrust roller bearing 19 on the carrier 6 that revolves together with each planetary roller 7, and the linear motion of each planetary roller 7 is transmitted to the linear drive member 18 via the carrier 6. It has become so.

また、前記軸受支持部材１５には、キャリヤ６と一緒に直線運動するケース９に軸方向で当接され、ケーシング１の後端側へのキャリヤ６の後退位置を規制する環状に突出したストッパ部１５ａが設けられている。この環状に突出したストッパ部１５ａの外径面には、後述する条部材５ｂで形成された螺旋凸条の内径面を案内する案内面１５ｂも形成されている。 Further, the bearing support member 15 is in contact with the case 9 that moves linearly together with the carrier 6 in the axial direction, and an annularly protruding stopper portion that restricts the retracted position of the carrier 6 toward the rear end side of the casing 1. 15a is provided. A guide surface 15b for guiding an inner diameter surface of a spiral protrusion formed by a strip member 5b described later is also formed on the outer diameter surface of the annularly protruding stopper portion 15a.

図４（ａ）、（ｂ）に示すように、前記各遊星ローラ７が転接する外輪部材５の内径面には２条の螺旋溝５ａが設けられ、各螺旋溝５ａに周着された条部材５ｂで、外輪部材５の内径面に２条の螺旋凸条が形成されている。また、遊星ローラ７の外径面には、条部材５ｂで形成された螺旋凸条が嵌まり込み、螺旋凸条と同一ピッチでリード角の異なる１条の螺旋溝７ａが設けられている。なお、外輪部材５の螺旋凸条と遊星ローラ７の螺旋溝７ａの螺旋の向きは、互いに逆向きになっているように見えるが、図４（ａ）に示された螺旋凸条は、図４（ｂ）に示された螺旋溝７ａの裏側の部分に螺合するので、両者の螺旋の向きは同じである。したがって、回転軸４の周りを自転しながら公転し、その螺旋溝７ａが外輪部材５の螺旋凸条と螺合する各遊星ローラ７は、螺旋凸条と螺旋溝７ａとのリード角の差によって軸方向へ直線運動する。 As shown in FIGS. 4 (a) and 4 (b), two spiral grooves 5a are provided on the inner surface of the outer ring member 5 to which the planetary rollers 7 are brought into rolling contact, and the strips circumferentially attached to the spiral grooves 5a. Two spiral ridges are formed on the inner diameter surface of the outer ring member 5 by the member 5b. Further, the outer surface of the planetary roller 7 is fitted with a spiral projection formed by the strip member 5b, and is provided with a single spiral groove 7a having the same pitch as the spiral projection and having a different lead angle. Although the spiral ridges of the outer ring member 5 and the spiral grooves 7a of the planetary roller 7 appear to be opposite to each other, the spiral ridges shown in FIG. Since the screw is engaged with the portion on the back side of the spiral groove 7a shown in 4 (b), the directions of the spirals are the same. Accordingly, each planetary roller 7 that revolves while rotating around the rotation shaft 4 and whose spiral groove 7a is screwed with the spiral protrusion of the outer ring member 5 has a difference in lead angle between the spiral protrusion and the spiral groove 7a. Move linearly in the axial direction.

図５に拡大して示すように、前記遊星ローラ７の外径面の螺旋溝７ａは、溝幅が溝底側から溝縁側へ広がるように両側の側壁が傾斜し、条部材５ｂで形成された外輪部材５の内径面の螺旋凸条は、基部側から頂部側へ条幅が狭まるように、両側の側面が螺旋溝７ａの側壁の傾斜角と等しい角度で傾斜しており、外輪部材５の螺旋凸条がリード角の異なる遊星ローラ７の螺旋溝７ａに嵌まり込むときに、螺旋凸条が螺旋溝７ａの溝縁部に接触しないようになっている。 As shown in an enlarged view in FIG. 5, the spiral groove 7a on the outer diameter surface of the planetary roller 7 is formed by strip members 5b with inclined side walls so that the groove width extends from the groove bottom side to the groove edge side. Further, the spiral protrusions on the inner diameter surface of the outer ring member 5 are inclined at an angle equal to the inclination angle of the side wall of the spiral groove 7a so that the width of the spiral protrusion is narrowed from the base side to the top side. When the spiral ridges are fitted into the spiral grooves 7a of the planetary rollers 7 having different lead angles, the spiral ridges do not come into contact with the groove edges of the spiral grooves 7a.

図６は、上述した電動式直動アクチュエータを採用した電動式ブレーキ装置を示す。この電動式ブレーキ装置は、キャリパボディ２１の内部で被制動部材としてのディスクロータ２２の両側に、ブレーキ部材としてのブレーキパッド２３を対向配置したディスクブレーキであり、キャリパボディ２１に電動式直動アクチュエータのケーシング１が固定され、その直線駆動部材１８でブレーキパッド２３がディスクロータ２２に押圧されるようになっている。なお、この図では、電動式直動アクチュエータが図１で示した断面と直交する断面で示されており、直線駆動部材１８は押圧する側のブレーキパッド２３に爪２４で回り止めされている。 FIG. 6 shows an electric brake device that employs the electric linear actuator described above. This electric brake device is a disc brake in which brake pads 23 as brake members are arranged oppositely on both sides of a disc rotor 22 as a braked member inside the caliper body 21, and the electric linear actuator is connected to the caliper body 21. The brake pad 23 is pressed against the disc rotor 22 by the linear drive member 18. In this figure, the electric linear actuator is shown in a cross section orthogonal to the cross section shown in FIG. 1, and the linear drive member 18 is prevented from rotating by a claw 24 on a brake pad 23 on the pressing side.

上述した実施形態では、外輪部材の内径面に螺旋凸条を設け、遊星ローラの外径面にこの螺旋凸条と同一ピッチでリード角が異なる螺旋溝を設けたが、螺旋凸条は回転軸の外径面に設けることもでき、遊星ローラの外径面には、螺旋凸条と同一ピッチの周方向溝を設けることもできる。 In the embodiment described above, the spiral protrusion is provided on the inner diameter surface of the outer ring member, and the spiral groove having the same pitch as the spiral protrusion and the lead angle is different on the outer diameter surface of the planetary roller. The outer circumferential surface of the planetary roller can be provided with circumferential grooves having the same pitch as the spiral ridges.

電動式直動アクチュエータの実施形態を示す縦断面図A longitudinal sectional view showing an embodiment of an electric linear actuator 図１のII−II線に沿った断面図Sectional view along the line II-II in FIG. 図１のIII−III線に沿った断面図Sectional view along line III-III in FIG. ａ、ｂは、それぞれ図１の外輪部材の螺旋凸条と遊星ローラの螺旋溝を示す正面図a and b are front views showing the spiral ridge of the outer ring member and the spiral groove of the planetary roller in FIG. 図１の外輪部材の螺旋凸条と遊星ローラの螺旋溝の係合部を拡大して示す断面図Sectional drawing which expands and shows the engaging part of the spiral protrusion of the outer ring member of FIG. 1, and the spiral groove of a planetary roller 図１の電動式直動アクチュエータを採用した電動式ブレーキ装置を示す縦断面図1 is a longitudinal sectional view showing an electric brake device employing the electric linear actuator of FIG.

符号の説明Explanation of symbols

１ケーシング
１ａ円筒部
１ｂフランジ
１ｃ蓋
２電動モータ
２ａロータ軸
３ａ、３ｂ、３ｃ歯車
４回転軸
５外輪部材
５ａ螺旋溝
５ｂ条部材
６キャリヤ
６ａ支持軸
７遊星ローラ
７ａ螺旋溝
８潤滑剤塗布部材
９ケース
１０軸ピン
１１玉軸受
１２環状溝
１３止め輪
１４玉軸受
１５軸受支時部材
１５ａストッパ部
１５ｂ案内面
１６針状ころ軸受
１７スラストころ軸受
１８直線駆動部材
１９スラストころ軸受
２１キャリパボディ
２２ディスクロータ
２３ブレーキパッド
２４爪 DESCRIPTION OF SYMBOLS 1 Casing 1a Cylindrical part 1b Flange 1c Cover 2 Electric motor 2a Rotor shaft 3a, 3b, 3c Gear 4 Rotating shaft 5 Outer ring member 5a Spiral groove 5b Strip member 6 Carrier 6a Support shaft 7 Planetary roller 7a Spiral groove 8 Lubricant application member 9 Case 10 Shaft pin 11 Ball bearing 12 Annular groove 13 Retaining ring 14 Ball bearing 15 Bearing support member 15a Stopper portion 15b Guide surface 16 Needle roller bearing 17 Thrust roller bearing 18 Linear drive member 19 Thrust roller bearing 21 Caliper body 22 Disc rotor 23 Brake pad 24 Claw

Claims

電動モータのロータ軸から回転を伝達される回転軸と、この回転軸の外径側でケーシングの内径面に固定された外輪部材との間に、キャリヤに回転自在に支持された複数の遊星ローラを介在させて、これらの各遊星ローラが前記回転軸の回転に伴って回転軸の周りを自転しながら公転するようにし、前記回転軸の外径面または前記外輪部材の内径面に螺旋凸条を設け、前記各遊星ローラの外径面に、前記螺旋凸条と同一ピッチで螺旋凸条が嵌まり込む周方向溝、または螺旋凸条と同一ピッチでリード角が異なり螺旋凸条が嵌まり込む螺旋溝を設けて、前記回転軸の周りを自転しながら公転する各遊星ローラを支持するキャリヤを軸方向へ相対移動させ、前記回転軸の回転運動を前記キャリヤの直線運動に変換して、被駆動物を直線駆動する電動式直動アクチュエータにおいて、前記回転軸を前記電動モータのロータ軸と同軸にならないように配置し、この回転軸を支持する軸受を、前記ロータ軸からの回転伝達部と前記遊星ローラとの間の軸方向部位に配設したことを特徴とする電動式直動アクチュエータ。 A plurality of planetary rollers rotatably supported by a carrier between a rotating shaft to which rotation is transmitted from the rotor shaft of the electric motor and an outer ring member fixed to the inner diameter surface of the casing on the outer diameter side of the rotating shaft These planetary rollers revolve while rotating around the rotation shaft as the rotation shaft rotates, and spiral ridges are formed on the outer diameter surface of the rotation shaft or the inner diameter surface of the outer ring member. A circumferential groove into which the spiral ridge is fitted at the same pitch as the spiral ridge, or a spiral ridge with a different lead angle at the same pitch as the spiral ridge. Providing a spiral groove to be rotated, relatively moving the carrier supporting each planetary roller that revolves around the rotating shaft in the axial direction, and converting the rotational motion of the rotating shaft into the linear motion of the carrier; Electricity that drives the driven object linearly In the linear actuator, the rotary shaft is disposed so as not to be coaxial with the rotor shaft of the electric motor, and a bearing that supports the rotary shaft is provided between the rotation transmission portion from the rotor shaft and the planetary roller. An electric linear actuator characterized by being disposed in an axial direction part.

前記外輪部材を固定するケーシングの内径面を円筒面で形成して、この円筒面で形成したケーシングの内径面に、前記外輪部材に発生する直動アクチュエータの軸方向反力を受ける止め輪を装着し、前記回転軸を支持する軸受を、この止め輪と前記外輪部材との間で前記ケーシングの内径面に固定した軸受支持部材に組み付けた請求項１に記載の電動式直動アクチュエータ。 The inner surface of the casing for fixing the outer ring member is formed by a cylindrical surface, and a retaining ring for receiving the axial reaction force of the linear actuator generated on the outer ring member is mounted on the inner surface of the casing formed by the cylindrical surface. The electric linear motion actuator according to claim 1, wherein the bearing supporting the rotating shaft is assembled to a bearing support member fixed to the inner diameter surface of the casing between the retaining ring and the outer ring member.

前記軸受支持部材に、前記キャリヤが軸受支持部材側へ後退移動したときに、キャリヤまたはキャリヤと一緒に後退移動する部材に軸方向で当接され、前記キャリヤの後退位置を規制するストッパ部を設けた請求項２に記載の電動式直動アクチュエータ。 The bearing support member is provided with a stopper portion that abuts the carrier or a member that moves backward together with the carrier in the axial direction when the carrier moves backward toward the bearing support member, and regulates the retracted position of the carrier. The electric linear motion actuator according to claim 2.

前記回転軸の外径面または外輪部材の内径面に設けた螺旋凸条を、これらの回転軸の外径面または外輪部材の内径面に設けた螺旋溝に周着した条部材で形成した請求項２または３に記載の電動式直動アクチュエータ。 The spiral protrusion provided on the outer diameter surface of the rotating shaft or the inner diameter surface of the outer ring member is formed by a strip member that is attached to a spiral groove provided on the outer diameter surface of the rotating shaft or the inner diameter surface of the outer ring member. Item 4. The electric linear actuator according to Item 2 or 3.

前記軸受支持部材に前記外輪部材側への環状突出部を形成し、この環状突出部に前記条部材で形成した螺旋凸条の外径面または内径面を案内する案内面を設けた請求項４に記載の電動式直動アクチュエータ。 5. An annular projecting portion toward the outer ring member is formed on the bearing support member, and a guide surface is provided on the annular projecting portion for guiding an outer diameter surface or an inner diameter surface of a spiral protrusion formed by the strip member. The electric linear actuator described in 1.

前記回転軸を前記電動モータのロータ軸と並列に配置した請求項１乃至５のいずれかにに記載の電動式直動アクチュエータ。 The electric linear actuator according to any one of claims 1 to 5, wherein the rotary shaft is arranged in parallel with a rotor shaft of the electric motor.

電動モータの回転運動を直線運動に変換してブレーキ部材を直線駆動する電動式直動アクチュエータを備え、前記直線駆動されるブレーキ部材を被制動部材に押圧する電動式ブレーキ装置において、前記電動式直動アクチュエータに請求項１乃至６のいずれかに記載の電動式直動アクチュエータを用いたことを特徴とする電動式ブレーキ装置。 An electric brake device that includes an electric linear actuator that linearly drives a brake member by converting a rotational movement of the electric motor into a linear movement, and presses the brake member that is linearly driven against the member to be braked. An electric brake device using the electric linear actuator according to any one of claims 1 to 6 as a dynamic actuator.