JP2008267523A - Ball screw mechanism - Google Patents

Ball screw mechanism Download PDF

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JP2008267523A
JP2008267523A JP2007112775A JP2007112775A JP2008267523A JP 2008267523 A JP2008267523 A JP 2008267523A JP 2007112775 A JP2007112775 A JP 2007112775A JP 2007112775 A JP2007112775 A JP 2007112775A JP 2008267523 A JP2008267523 A JP 2008267523A
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groove
ball
screw
circulation
circulation groove
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JP2008267523A5 (en
JP4978887B2 (en
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Toru Harada
徹 原田
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NSK Ltd
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NSK Ltd
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H25/00—Gearings comprising primarily only cams, cam-followers and screw-and-nut mechanisms
    • F16H25/18—Gearings comprising primarily only cams, cam-followers and screw-and-nut mechanisms for conveying or interconverting oscillating or reciprocating motions
    • F16H25/20—Screw mechanisms
    • F16H25/22—Screw mechanisms with balls, rollers, or similar members between the co-operating parts; Elements essential to the use of such members
    • F16H25/2204—Screw mechanisms with balls, rollers, or similar members between the co-operating parts; Elements essential to the use of such members with balls
    • F16H25/2214—Screw mechanisms with balls, rollers, or similar members between the co-operating parts; Elements essential to the use of such members with balls with elements for guiding the circulating balls
    • F16H25/2223—Cross over deflectors between adjacent thread turns, e.g. S-form deflectors connecting neighbouring threads

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ball screw mechanism for securing smooth operation while suppressing abnormal noises and vibration. <P>SOLUTION: Both side faces 4c are inclined faces to be opened as approaching a male screw groove 1a. So, a step between a rolling passage formed by the male screw groove 1a and a female screw groove 2a and a circulation groove 4a is reduced to secure smooth operation while suppressing the generation of noises and vibration when a ball 3 transfers between the rolling passage and the circulation groove 4a. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

本発明は、一般産業用機械に組付けられたり、或いは自動車や船舶に使用されたりするボールねじ機構に関するものである。   The present invention relates to a ball screw mechanism that is assembled to a general industrial machine or used in an automobile or a ship.

近年、車両等の省力化が進み、例えば自動車のトランスミッションやパーキングブレーキなどを手動でなく、電動モータの力により行うシステムが開発されている。そのような用途に用いる電動アクチュエータには、電動モータから伝達される回転運動を高効率で軸線方向運動に変換するために、ボールねじ機構が用いられる場合がある。   In recent years, labor saving of vehicles and the like has progressed, and for example, a system has been developed in which a transmission, a parking brake, and the like of an automobile are performed not by hand but by the power of an electric motor. An electric actuator used for such an application may use a ball screw mechanism in order to convert the rotational motion transmitted from the electric motor into the axial motion with high efficiency.

しかるに、通常、ボールねじ機構は、ねじ軸と、ナットと、両者間に形成された転走路内を転動するボールとからなるが、いわゆるコマ式のボールねじ機構においては、転走路の一端から他端へとボールを戻すために、コマをナットに取り付けている（特許文献１参照）。
特開平１１−２７０６４８号公報 However, normally, the ball screw mechanism is composed of a screw shaft, a nut, and a ball that rolls in a rolling path formed between the two. In the so-called top-type ball screw mechanism, the ball screw mechanism starts from one end of the rolling path. In order to return the ball to the other end, a top is attached to the nut (see Patent Document 1).
JP 11-270648 A

ここで、コマについて説明する。ボールねじ機構においては、ねじ軸とナットとが軸線方向に相対移動する際に、ボールを循環させる機構が本来的に必要である。コマ式ボールねじ機構においては、ナットに取り付けられているコマが、ボールねじの１リード分に相当する軸線方向の転走路のずれを補うべく、軸線回りに３４０度前後延在する転走路の一端と他端とを連結するＳ字状に蛇行した循環溝を有している。従って、ボールは、転走路に沿って転動した後、ねじ軸のランド部を乗り越えるようにして、転走路の一端からコマの循環溝内に導かれ、その後循環溝から転走路の他端へと戻されるようになっている。   Here, the frame will be described. In the ball screw mechanism, a mechanism for circulating the ball when the screw shaft and the nut relatively move in the axial direction is inherently necessary. In the top type ball screw mechanism, the top attached to the nut has one end of a rolling path extending about 340 degrees around the axis to compensate for the deviation of the rolling path in the axial direction corresponding to one lead of the ball screw. And a circulation groove meandering in an S shape connecting the other end. Accordingly, after rolling along the rolling path, the ball is guided from one end of the rolling path into the circulation groove of the coma so as to get over the land portion of the screw shaft, and then from the circulation groove to the other end of the rolling path. It is supposed to be returned.

しかるに、ボールねじ機構においては、ボールの転動は極力スムーズに行うようにすることが、異音や振動の発生を抑制し、ひいてはボールねじの効率や耐久性などを確保する上で重要となる。このため従来技術では、ボールとコマとの隙間を比較的余裕を持って設定していた。ところが、この隙間が大きすぎると、循環構内でボールの蛇行（千鳥）が発生し、場合によっては、循環溝においてボール詰まりを起こし、ボールねじ寿命低下の原因となる恐れがある。更に、この隙間設定のため、循環溝とねじ溝との間に比較的大きな段差を与えることになり、上記のボール蛇行と同様にボールねじ寿命の低下につながる恐れがある。   However, in the ball screw mechanism, it is important to make the ball roll as smoothly as possible to suppress the generation of noise and vibration, and to ensure the efficiency and durability of the ball screw. . For this reason, in the prior art, the gap between the ball and the piece is set with a relatively large margin. However, if this gap is too large, meandering of the ball (staggered) occurs in the circulating premises, and in some cases, the ball is clogged in the circulating groove, which may cause a reduction in the life of the ball screw. Further, since this clearance is set, a relatively large step is provided between the circulation groove and the screw groove, and there is a possibility that the life of the ball screw may be reduced like the above-described ball meandering.

本発明は、かかる従来技術の問題点に鑑みてなされたものであり、異音や振動を抑制し、円滑な動作を確保できるボールねじ機構を提供することを目的とする。   The present invention has been made in view of the problems of the prior art, and an object of the present invention is to provide a ball screw mechanism that can suppress abnormal noise and vibration and ensure a smooth operation.

第１の本発明のボールねじ機構は、
外周面に雄ねじ溝を形成したねじ軸と、
前記ねじ軸を包囲するように配置され且つ内周面に雌ねじ溝を形成したナットと、
対向する両ねじ溝間に形成された転走路に沿って転動自在に配置された複数のボールと、
前記ナットの取り付け孔内に挿入され、前記転走路の一端から他端へと循環する前記ボールが転動するための循環溝を備えたコマと、を有し、
前記循環溝を通過するボールの進行方向に沿った軸線に対して直交する方向に前記コマを切断した切断面をとったとき、前記循環溝の側面の少なくとも一方は、その溝底から離れる方向に向かうにつれて側面の他方に対して開くような斜面を有することを特徴とする。 The ball screw mechanism according to the first aspect of the present invention comprises:
A screw shaft having a male screw groove formed on the outer peripheral surface;
A nut disposed so as to surround the screw shaft and having an internal thread formed on an inner peripheral surface thereof;
A plurality of balls arranged to freely roll along a rolling path formed between opposing screw grooves;
A piece that is inserted into the mounting hole of the nut and has a circulation groove for rolling the ball that circulates from one end to the other end of the rolling path, and
When taking a cut surface obtained by cutting the piece in a direction perpendicular to the axis along the traveling direction of the ball passing through the circulation groove, at least one of the side surfaces of the circulation groove is in a direction away from the groove bottom. It has a slope that opens with respect to the other side as it goes.

第２の本発明のボールねじ機構は、
外周面に雄ねじ溝を形成したねじ軸と、
前記ねじ軸を包囲するように配置され、内周面に雌ねじ溝と、前記雌ねじ溝の両端を連結する循環路とを形成したナットと、
対向する両ねじ溝間に形成された転走路に沿って転動自在に配置された複数のボールと、を有し、
前記循環溝を通過するボールの進行方向に沿った軸線に対して直交する方向に前記ナットを切断した切断面をとったとき、前記循環溝の側面の少なくとも一方は、その溝底から離れる方向に向かうにつれて側面の他方に対して開くような斜面を有することを特徴とする。 The ball screw mechanism of the second invention is
A screw shaft having a male screw groove formed on the outer peripheral surface;
A nut that is disposed so as to surround the screw shaft, and has a female screw groove formed on an inner peripheral surface thereof, and a circulation path that connects both ends of the female screw groove;
A plurality of balls arranged to roll along a rolling path formed between both opposing screw grooves, and
When taking a cut surface obtained by cutting the nut in a direction perpendicular to the axis along the traveling direction of the ball passing through the circulation groove, at least one of the side surfaces of the circulation groove is in a direction away from the groove bottom. It has a slope that opens with respect to the other side as it goes.

本発明によれば、前記循環溝を通過するボールの進行方向に沿った軸線に対して直交する方向に前記コマ又は前記ナットを切断した切断面をとったとき、前記循環溝の側面の少なくとも一方は、その溝底から離れる方向に向かうにつれて側面の他方に対して開くような斜面を有するので、前記循環溝と前記ボールとの隙間を小さく設定することによりボールの蛇行を抑えることができ、更に隙間を小さくしても、循環溝とねじ溝との間の段差を抑えることができるので、異音や振動を抑制し、円滑な動作を確保できる。   According to the present invention, when taking a cut surface obtained by cutting the top or the nut in a direction orthogonal to the axis along the traveling direction of the ball passing through the circulation groove, at least one of the side surfaces of the circulation groove Has a slope that opens with respect to the other side surface as it goes away from the groove bottom, so that the meandering of the ball can be suppressed by setting a small gap between the circulation groove and the ball, Even if the gap is reduced, the step between the circulation groove and the screw groove can be suppressed, so that abnormal noise and vibration can be suppressed and smooth operation can be ensured.

前記切断面における前記循環溝の溝底の半径と、前記ボールの半径と差は、０．０５ｍｍ以上、０．１ｍｍ以下であると好ましい。   The difference between the radius of the bottom of the circulation groove on the cut surface and the radius of the ball is preferably 0.05 mm or more and 0.1 mm or less.

次に、本発明の実施の形態を図面を参照して説明する。図１は、本実施の形態であるボールねじ機構の側面図であり、図２は、図１の構成をII-II線で切断して矢印方向に見た図であり、図３は、図１の構成を、循環溝を通過するボールの進行方向に沿った軸線に対して直交する方向に向かうIII-III線で切断して矢印方向に見た図であり、図４は、ナットから一方のコマを分解した状態を示す斜視図である。   Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a side view of the ball screw mechanism according to the present embodiment, FIG. 2 is a view of the configuration of FIG. 1 taken along line II-II and viewed in the direction of the arrow, and FIG. Fig. 4 is a view of the configuration of Fig. 1 taken along the line III-III that is perpendicular to the axis along the traveling direction of the ball passing through the circulation groove and viewed in the direction of the arrow. It is a perspective view which shows the state which decomposed | disassembled the top.

図１において、不図示の被駆動部材に連結され、回転不能且つ軸線方向にのみ移動可能に支持されたねじ軸１の外周面には、雄ねじ溝１ａ（一部簡略図示）が形成されている。不図示のハウジングに対して回転のみ可能に支持された円筒状のナット２は、ねじ軸１を包囲するように配置され且つ内周面に雌ねじ溝２ａ（図２参照）を形成している。複数のボール３（図２参照）が、対向する両ねじ溝間に形成された螺旋状の転走路内を転動自在となるように配置されている。   In FIG. 1, a male screw groove 1a (partially simplified) is formed on the outer peripheral surface of a screw shaft 1 that is connected to a driven member (not shown) and is supported so as not to rotate but to move only in the axial direction. . A cylindrical nut 2 supported so as to be rotatable only with respect to a housing (not shown) is arranged so as to surround the screw shaft 1 and forms a female screw groove 2a (see FIG. 2) on an inner peripheral surface thereof. A plurality of balls 3 (see FIG. 2) are arranged so as to be able to roll in a spiral rolling path formed between the opposing screw grooves.

ナット２の外周に形成された長円断面の貫通穴（取り付け孔）２ｂ内には、コマ４が配置されている。コマ４は、貫通穴２ｂに取り付けた状態で、内側にＳ字状の循環溝４ａを形成している（図４参照）。   A top 4 is arranged in a through hole (attachment hole) 2b having an elliptical cross section formed on the outer periphery of the nut 2. The top 4 is formed with an S-shaped circulation groove 4a inside (see FIG. 4) while being attached to the through hole 2b.

図３，４を参照して、雄ねじ溝１ａと雌ねじ溝２ａとで形成される転走路は、ねじ軸１の周囲を１周弱巻き回したところで、コマ４によって分断されており、各々の一端と他端とを、コマ４の循環溝４ａが連結している。なお、隣接する雄ねじ溝１ａ間には、ランド部１ｃが形成されている。   Referring to FIGS. 3 and 4, the rolling path formed by male thread groove 1a and female thread groove 2a is divided by frame 4 when it is wound slightly around the circumference of screw shaft 1, and each end thereof is cut. The circulation groove 4a of the top 4 is connected to the other end. A land portion 1c is formed between adjacent male screw grooves 1a.

本実施の形態のボールねじ機構の動作を説明すると、不図示の電動モータによりナット２が回転駆動されると、転走路を転動するボール３により、かかる回転運動がねじ軸１の軸線方向運動に効率よく変換され、それに連結された不図示の被駆動部材を軸線方向に移動させることができる。この際に、図３に示すように、転走路から循環溝４ａに侵入したボール３は、循環溝４ａに沿って転動することでランド部１ｃを乗り越えて、転走路の一端から他端へと移動できるようになっている。   The operation of the ball screw mechanism of the present embodiment will be described. When the nut 2 is rotationally driven by an electric motor (not shown), the rotational movement of the screw shaft 1 is caused by the ball 3 rolling on the rolling path. The driven member (not shown) connected thereto can be moved in the axial direction. At this time, as shown in FIG. 3, the ball 3 that has entered the circulation groove 4a from the rolling road rolls along the circulation groove 4a, gets over the land portion 1c, and moves from one end to the other end of the rolling path. And can be moved.

更に、図３と同様な位置で切断した図５に示す比較例を参照して、本実施の形態の効果について説明する。比較例においては、コマ４’の循環溝４ａ’は、溝底４ｂ’と、それに接続する一対の平行な側面４ｃ’とを有している。溝底４ｂ’の半径はＲ２であり、ボール３の半径をｒとすると、循環溝４ａ’とボール３との隙間Δ２は、（Ｒ２−ｒ）である。   Furthermore, the effect of this embodiment will be described with reference to a comparative example shown in FIG. 5 cut at the same position as in FIG. In the comparative example, the circulation groove 4a 'of the top 4' has a groove bottom 4b 'and a pair of parallel side surfaces 4c' connected thereto. The radius of the groove bottom 4b 'is R2, and when the radius of the ball 3 is r, the gap Δ2 between the circulation groove 4a' and the ball 3 is (R2-r).

これに対し、本実施の形態においては、図３に示すように、コマ４の循環溝４ａは、溝底４ｂと、それに接続する一対の側面４ｃとを有しているが、両側面４ｃは、溝底４ｂから離れる方向（雄ねじ溝１ａに近づく方向）に向かうにつれて互いに対して開くような斜面となっている。ここで、溝底４ｂの半径はＲ１であり、ボール３の半径をｒとすると、循環溝４ａとボール３との最小隙間Δ１は、（Ｒ１−ｒ）である。しかるに、本実施の形態の溝底４ｂの半径Ｒ１は、比較例の溝底４ｂ’の半径Ｒ２より小さい（Ｒ１＜Ｒ２）ので、本実施の形態の隙間Δ１は、比較例の隙間Δ２より小さくなる。これにより、循環溝４ａを通過するボール３は、循環溝４ａの中心近傍を通るので蛇行を効果的に抑えることができ、ボール詰まりを抑制することができる。   In contrast, in the present embodiment, as shown in FIG. 3, the circulation groove 4a of the top 4 has a groove bottom 4b and a pair of side surfaces 4c connected to the groove bottom 4b. The slopes open toward each other in the direction away from the groove bottom 4b (the direction approaching the male screw groove 1a). Here, the radius of the groove bottom 4b is R1, and when the radius of the ball 3 is r, the minimum gap Δ1 between the circulation groove 4a and the ball 3 is (R1-r). However, since the radius R1 of the groove bottom 4b of the present embodiment is smaller than the radius R2 of the groove bottom 4b ′ of the comparative example (R1 <R2), the gap Δ1 of the present embodiment is smaller than the gap Δ2 of the comparative example. Become. Thereby, since the ball 3 passing through the circulation groove 4a passes through the vicinity of the center of the circulation groove 4a, meandering can be effectively suppressed and ball clogging can be suppressed.

一方、両側面４ｃは、雄ねじ溝１ａに近づくにつれて開くような斜面となっているので、雄ねじ溝１ａ及び雌ねじ溝２ａにより形成される転走路と、循環溝４ａとの段差（図２に示すＳ）が小さくなり、転走路と循環溝４ａとの間をボール３が乗り移るときに生じる騒音や振動を抑えて円滑な動作を確保できる。   On the other hand, since both side surfaces 4c are slopes that open as they approach the male thread groove 1a, a step (S shown in FIG. 2) between the rolling path formed by the male thread groove 1a and the female thread groove 2a and the circulation groove 4a. ) Is reduced, and noise and vibration generated when the ball 3 moves between the rolling path and the circulation groove 4a can be suppressed to ensure smooth operation.

図６は、本実施の形態の変形例にかかる図３と同様な断面図である。本変形例においては、コマを廃止する代わりに、ナット２’の内周に循環溝２ｃを直接形成している。より具体的には、１周未満の雌ねじ溝２ｂの両端を接続するようにして循環溝２ｃを形成し、これに対向する雄ねじ溝１ａと共に閉ループ状の転走路を形成している。このような雌ねじ溝２ｂ及び循環路２ｃは、塑性加工又は自転する刃物をナット２’内で公転させることで形成できる。   FIG. 6 is a cross-sectional view similar to FIG. 3 according to a modification of the present embodiment. In this modification, instead of eliminating the top, the circulation groove 2c is formed directly on the inner periphery of the nut 2 '. More specifically, the circulation groove 2c is formed so as to connect both ends of the female screw groove 2b of less than one round, and a closed loop rolling path is formed together with the male screw groove 1a opposed to the circulation groove 2c. Such female thread groove 2b and circulation path 2c can be formed by plastic working or revolving a rotating tool in the nut 2 '.

循環路２ｃの形状は、上述したコマ４の循環溝４ｃの形状と同様である。即ち、循環溝２ｃは、溝底２ｄと、それに接続する一対の側面２ｅとを有しているが、両側面２ｅは、溝底２ｄから離れる方向（雄ねじ溝１ａに近づく方向）に向かうにつれて互いに対して開くような斜面となっている。本変形例によれば、図３の実施の形態と同様な寸法関係を有することにより、循環溝２ｃを通過するボール３は、循環溝２ｃの中心近傍を通るので蛇行を効果的に抑えることができ、ボール詰まりを抑制することができる。又、上述した実施の形態と同様な理由により、転走路と循環溝２ｃとの間をボール３が乗り移るときに生じる騒音や振動を抑えて円滑な動作を確保できる。   The shape of the circulation path 2c is the same as the shape of the circulation groove 4c of the top 4 described above. In other words, the circulation groove 2c has a groove bottom 2d and a pair of side surfaces 2e connected thereto, but the both side surfaces 2e are separated from each other in a direction away from the groove bottom 2d (a direction approaching the male screw groove 1a). On the other hand, the slope is open. According to the present modification, the ball 3 passing through the circulation groove 2c passes through the vicinity of the center of the circulation groove 2c, and the meandering can be effectively suppressed by having the same dimensional relationship as the embodiment of FIG. And clogging of the balls can be suppressed. Further, for the same reason as in the above-described embodiment, it is possible to suppress a noise and vibration generated when the ball 3 moves between the rolling path and the circulation groove 2c, thereby ensuring a smooth operation.

以上、本発明を実施の形態を参照して説明してきたが、本発明は上記実施の形態に限定して解釈されるべきではなく、適宜変更・改良が可能であることはもちろんである。尚、コマは、金属を素材とする場合、焼結加工や鍛造加工によって形成されると好ましく、樹脂を素材とする場合には、射出成形によって形成されると好ましいが、素材や製法がこれらに限られることはない。   The present invention has been described above with reference to the embodiments. However, the present invention should not be construed as being limited to the above-described embodiments, and can be modified or improved as appropriate. The coma is preferably formed by sintering or forging when a metal is used as a raw material, and preferably formed by injection molding when a resin is used as a raw material. There is no limit.

本実施の形態であるボールねじ機構の側面図である。It is a side view of the ball screw mechanism which is this Embodiment. 図１の構成をII-II線で切断して矢印方向に見た図である。It is the figure which cut | disconnected the structure of FIG. 1 by the II-II line | wire, and looked at the arrow direction. 図１の構成をIII-III線で切断して矢印方向に見た図である。It is the figure which cut | disconnected the structure of FIG. 1 by the III-III line | wire, and looked at the arrow direction. ナットから一方のコマを分解した状態を示す斜視図である。It is a perspective view which shows the state which decomposed | disassembled one piece from the nut. 比較例にかかる図３と同様な断面図である。It is sectional drawing similar to FIG. 3 concerning a comparative example. 実施の形態の変形例にかかる図３と同様な断面図である。It is sectional drawing similar to FIG. 3 concerning the modification of embodiment.

符号の説明Explanation of symbols

１ ねじ軸
２ ナット
３ ボール
４ コマ 1 Screw shaft 2 Nut 3 Ball 4 Top

Claims (3)

外周面に雄ねじ溝を形成したねじ軸と、
前記ねじ軸を包囲するように配置され且つ内周面に雌ねじ溝を形成したナットと、
対向する両ねじ溝間に形成された転走路に沿って転動自在に配置された複数のボールと、
前記ナットの取り付け孔内に挿入され、前記転走路の一端から他端へと循環する前記ボールが転動するための循環溝を備えたコマと、を有し、
前記循環溝を通過するボールの進行方向に沿った軸線に対して直交する方向に前記コマを切断した切断面をとったとき、前記循環溝の側面の少なくとも一方は、その溝底から離れる方向に向かうにつれて側面の他方に対して開くような斜面を有することを特徴とするボールねじ機構。 A screw shaft having a male screw groove formed on the outer peripheral surface;
A nut disposed so as to surround the screw shaft and having an internal thread formed on an inner peripheral surface thereof;
A plurality of balls arranged to freely roll along a rolling path formed between opposing screw grooves;
A piece that is inserted into the mounting hole of the nut and has a circulation groove for rolling the ball that circulates from one end to the other end of the rolling path, and
When taking a cut surface obtained by cutting the piece in a direction perpendicular to the axis along the traveling direction of the ball passing through the circulation groove, at least one of the side surfaces of the circulation groove is in a direction away from the groove bottom. A ball screw mechanism characterized by having a slope that opens toward the other side as it goes. 外周面に雄ねじ溝を形成したねじ軸と、
前記ねじ軸を包囲するように配置され、内周面に雌ねじ溝と、前記雌ねじ溝の両端を連結する循環路とを形成したナットと、
対向する両ねじ溝間に形成された転走路に沿って転動自在に配置された複数のボールと、を有し、
前記循環溝を通過するボールの進行方向に沿った軸線に対して直交する方向に前記ナットを切断した切断面をとったとき、前記循環溝の側面の少なくとも一方は、その溝底から離れる方向に向かうにつれて側面の他方に対して開くような斜面を有することを特徴とするボールねじ機構。 A screw shaft having a male screw groove formed on the outer peripheral surface;
A nut that is disposed so as to surround the screw shaft, and has a female screw groove formed on an inner peripheral surface thereof, and a circulation path that connects both ends of the female screw groove;
A plurality of balls arranged to roll along a rolling path formed between both opposing screw grooves, and
When taking a cut surface obtained by cutting the nut in a direction perpendicular to the axis along the traveling direction of the ball passing through the circulation groove, at least one of the side surfaces of the circulation groove is in a direction away from the groove bottom. A ball screw mechanism characterized by having a slope that opens toward the other side as it goes. 前記切断面における前記循環溝の溝底の半径と、前記ボールの半径と差は、０．０５ｍｍ以上、０．１ｍｍ以下であることを特徴とする請求項１又は２に記載のボールねじ機構。   3. The ball screw mechanism according to claim 1, wherein a difference between a radius of a groove bottom of the circulation groove on the cut surface and a radius of the ball is 0.05 mm or more and 0.1 mm or less.
JP2007112775A 2007-04-23 2007-04-23 Ball screw mechanism Expired - Fee Related JP4978887B2 (en)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012066693A1 (en) 2010-11-15 2012-05-24 日本精工株式会社 Ball screw
JP2013076463A (en) * 2011-09-15 2013-04-25 Nsk Ltd Ball screw
US8950283B2 (en) 2010-03-31 2015-02-10 Nsk Ltd. Method for manufacturing nut for ball screw and ball screw

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2240077A1 (en) * 1971-08-16 1973-03-01 Skf Ind Trading & Dev NUT FOR BALL SPINDLES
US3815435A (en) * 1972-11-24 1974-06-11 Warner Electric Brake & Clutch Ball screw mechanism with improved ball guide
FR2328138A1 (en) * 1975-10-14 1977-05-13 Verdun Georges Recirculating ball screw drive - with staggered return paths cut in nut wall to improve load distribution
JP2006242252A (en) * 2005-03-02 2006-09-14 Nsk Ltd Ball screw mechanism

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2240077A1 (en) * 1971-08-16 1973-03-01 Skf Ind Trading & Dev NUT FOR BALL SPINDLES
US3815435A (en) * 1972-11-24 1974-06-11 Warner Electric Brake & Clutch Ball screw mechanism with improved ball guide
FR2328138A1 (en) * 1975-10-14 1977-05-13 Verdun Georges Recirculating ball screw drive - with staggered return paths cut in nut wall to improve load distribution
JP2006242252A (en) * 2005-03-02 2006-09-14 Nsk Ltd Ball screw mechanism

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8950283B2 (en) 2010-03-31 2015-02-10 Nsk Ltd. Method for manufacturing nut for ball screw and ball screw
WO2012066693A1 (en) 2010-11-15 2012-05-24 日本精工株式会社 Ball screw
JP2013076463A (en) * 2011-09-15 2013-04-25 Nsk Ltd Ball screw

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