JP3053796B2 - Screw drive - Google Patents
Screw driveInfo
- Publication number
- JP3053796B2 JP3053796B2 JP10127556A JP12755698A JP3053796B2 JP 3053796 B2 JP3053796 B2 JP 3053796B2 JP 10127556 A JP10127556 A JP 10127556A JP 12755698 A JP12755698 A JP 12755698A JP 3053796 B2 JP3053796 B2 JP 3053796B2
- Authority
- JP
- Japan
- Prior art keywords
- nut
- screw
- screw shaft
- thread
- case
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Landscapes
- Sliding-Contact Bearings (AREA)
- Transmission Devices (AREA)
- Connection Of Motors, Electrical Generators, Mechanical Devices, And The Like (AREA)
Description
【０００１】[0001]
【産業上の利用分野】この発明は、ねじ軸とこれにねじ
係合したナットを用いて電動機の回転運動を直線運動に
変換するねじ駆動装置に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw shaft and a screw shaft.
It relates screw drive apparatus for converting the linear motion rotary motion of an electric motor using engaged nut.
【０００２】[0002]
【従来の技術】この種のねじ駆動装置として、特開昭６
４−６５３６０号公報に記載されたボールねじ装置が従
来から知られている。2. Description of the Related Art Japanese Patent Laid-Open Publication No.
The ball screw device sub described in 4-65360 JP
Known since the beginning .
【０００３】この装置は、図４に示すように、ナット２
２の両端部を転がり軸受２４、２４を介してケース２１
に回転自在に支持し、そのナット２２の外周にモータの
回転子２５を、ケース２１にモータの固定子２６をそれ
ぞれ取付け、ナット２２の内側にボール２７を介してね
じ軸２３を螺合して構成されている。[0003] As shown in FIG.
2 at both ends by rolling bearings 24, 24
The rotor 22 of the motor is attached to the outer periphery of the nut 22, the stator 26 of the motor is attached to the case 21, and the screw shaft 23 is screwed into the nut 22 via a ball 27. It is configured.
【０００４】[0004]
【発明が解決しようとする課題】ところが、上記の構造
では、ケース２１内部に軸受２４、２４を介してナット
２２を支持しているため、ケース２１の外形寸法が必然
的に大きくなり、装置全体の重量増加も引き起こす問題
を有している。However, in the above structure, since the nut 22 is supported inside the case 21 via the bearings 24, 24, the external dimensions of the case 21 are inevitably large, and the entire device is There is a problem that also causes an increase in the weight of the tire.
【０００５】また、ナット２２とねじ軸２３をボール２
７を介して螺合させる構造では、使用中の温度環境の変
化によってナットとねじ軸の熱膨脹量に差が生じた場
合、ボール２７とねじ山との間にガタが生じ、駆動精度
が悪化する問題がある。The nut 22 and the screw shaft 23 are connected to the ball 2
In the structure in which the nut is screwed through 7, if a difference occurs in the thermal expansion between the nut and the screw shaft due to a change in the temperature environment during use, backlash occurs between the ball 27 and the screw thread, and the driving accuracy deteriorates. There's a problem.
【０００６】この発明の第１の目的は、ナットを支持す
る転がり軸受を不要にし、装置外形をコンパクトに形成
できるねじ駆動装置を提供することにある。A first object of the present invention is to provide a screw drive device which does not require a rolling bearing for supporting a nut, and which can form a compact outer shape of the device.
【０００７】また、この発明の第２の目的は、使用時に
熱変化があってもナットとねじ軸間の運動精度を良好に
維持できるねじ駆動装置を提供することである。A second object of the present invention is to provide a screw drive device capable of maintaining good movement accuracy between a nut and a screw shaft even when there is a thermal change during use.
【０００８】[0008]
【課題を解決するための手段】上記第１の目的を達成す
るため、この発明は、ねじ軸と螺合するナットをケース
に回転自在に支持し、そのナットの外周にモータの回転
子を、ケースにモータの固定子をそれぞれ取付けたねじ
駆動装置において、上記ナットをポリイミド系合成樹脂
で形成し、そのナットの表面にケースとすべり接触する
軸受面を設けた構造としたのである。In order to achieve the first object, according to the present invention, a nut rotatably supported by a screw shaft is rotatably supported on a case, and a rotor of the motor is provided on the outer periphery of the nut. In the screw drive device in which the stator of the motor is attached to the case, the nut is made of a polyimide synthetic resin, and the surface of the nut is provided with a bearing surface that comes into sliding contact with the case.
【０００９】なお、上記構造において、上記ねじ軸又は
ナットのねじ山の表面に、摩擦係数の小さい樹脂層を被
覆するようにしてもよい。In the above structure, the surface of the thread of the screw shaft or the nut may be coated with a resin layer having a small friction coefficient.
【００１０】一方、第２の目的を達成するため、この発
明は、ナットをポリイミド系合成樹脂製とするのに加え
て、ねじ軸をナットと同種のポリイミド系合成樹脂で形
成したものである。On the other hand, in order to achieve the second object, the present invention has a nut formed of a polyimide synthetic resin and a screw shaft formed of the same kind of polyimide synthetic resin as the nut .
【００１１】[0011]
【作用】上記第１の手段においては、ポリイミド系合成
樹脂のもつ自己潤滑性によりナットとケースの接触部の
摩擦抵抗を小さくできるため、転がり軸受を用いずにナ
ットを円滑に回転支持することができる。In the first means, the frictional resistance of the contact portion between the nut and the case can be reduced by the self-lubricating property of the polyimide synthetic resin, so that the nut can be smoothly rotated and supported without using a rolling bearing. it can.
【００１２】一方、第２の手段では、ナットとねじ軸を
共にポリイミド系合成樹脂とすることにより、両者の線
膨脹係数が等しくなり、使用時の環境が熱変化しても両
者のねじ山間のすき間が一定に維持される。On the other hand, in the second means, since both the nut and the screw shaft are made of a polyimide synthetic resin, the linear expansion coefficients of the two become equal, and even if the environment during use changes thermally, the distance between the two screw threads is increased. The gap is kept constant.
【００１３】[0013]
【実施例】図１は実施例のねじ駆動装置を示している。FIG. 1 shows a screw driving device according to an embodiment.
【００１４】図において、１はケース、２はナットであ
り、ナット２の外周面に回転子（マグネット）５が、ケ
ース１の内周面に固定子（ステータコイル）６がそれぞ
れ取付けられ、この両者によりナット２を回転駆動する
モータ４を構成している。In FIG. 1, reference numeral 1 denotes a case, 2 denotes a nut, and a rotor (magnet) 5 is mounted on an outer peripheral surface of the nut 2 and a stator (stator coil) 6 is mounted on an inner peripheral surface of the case 1, respectively. The two constitute a motor 4 for rotating the nut 2.
【００１５】上記ナット２は、ポリイミド（ＰＩ）系の
合成樹脂によって成形されており、その両端部の外周面
に、ケース１の内面とすべり接触するラジアル軸受面
７、７が形成されている。また、ナット２の中央部分に
設けた段差の両端面には、ケース１の内側端面とすべり
接触するスラスト軸受面８、８が形成されている。[0015] The nut 2, polyimide (PI) are formed form by the synthetic resin system, the outer peripheral surface of both ends, the radial bearing surface 7, 7 sliding contact with the casing 1 of the inner surface is formed ing. Thrust bearing surfaces 8, 8 that are in sliding contact with the inner end surface of the case 1 are formed on both end surfaces of the step provided in the central portion of the nut 2.
【００１６】上記ナット２の内径には、ねじ山９が形成
され、このねじ山９に、ねじ軸３のねじの谷１０が螺合
している。このねじ軸３は、鋼やアルミニウム合金など
の金属材で形成され、そのねじ谷１０の表面に、ポリテ
トラフルオロエチレン（以下ＰＴＦＥとする）から成る
樹脂層１１がコーティングされている。A thread 9 is formed in the inner diameter of the nut 2, and a thread root 10 of the screw shaft 3 is screwed into the thread 9. The screw shaft 3 is formed of a metal material such as steel or an aluminum alloy, and the surface of the screw valley 10 is coated with a resin layer 11 made of polytetrafluoroethylene (hereinafter referred to as PTFE).
【００１７】また、図２に示すように、ナット２のねじ
山９は断面が半円形の形状で形成され、これに対してね
じ軸３のねじ谷１０は、ナット２のねじ山９に対して対
称に傾斜する２つの傾斜面１２、１３で形成されてお
り、ねじ山９とねじ谷１０はねじの進行方向に２点で線
接触している。As shown in FIG. 2, the thread 9 of the nut 2 is formed to have a semicircular cross section, whereas the thread root 10 of the screw shaft 3 is formed with respect to the thread 9 of the nut 2. The thread 9 and the thread root 10 are in line contact with each other at two points in the traveling direction of the screw.
【００１８】上記の構造で成る実施例のねじ駆動装置に
おいては、ケース１を固定した状態でナット２を回転さ
せると、ねじ軸３が軸方向に移動する。逆に、ねじ軸３
を固定した状態でナット２を回転させると、ナット２と
ケース１が直線移動する。In the screw driving device of the embodiment having the above structure, when the nut 2 is rotated with the case 1 fixed, the screw shaft 3 moves in the axial direction. Conversely, screw shaft 3
When the nut 2 is rotated in a state in which is fixed, the nut 2 and the case 1 move linearly.
【００１９】この駆動においては、ナット２のねじ山９
とねじ軸３のねじ谷１０は２点で線接触し、これにナッ
ト２を形成するポリイミド系合成樹脂とねじ軸３を被覆
したＰＴＦＥ樹脂層１１の潤滑性が加わることにより、
ねじ山９とねじ谷１０の摺接部分の摩擦抵抗は極めて小
さなものとなる。このため、ねじ山９とねじ谷１０の摺
動時に生じるトルクが大幅に低減され、ボールねじを用
いた場合と同様にトルク変動の少ない円滑な駆動力伝達
を行なうことができる。In this drive, the thread 9 of the nut 2
And the screw root 3 of the screw shaft 3 are in line contact at two points, and the polyimide synthetic resin forming the nut 2 and the lubricating property of the PTFE resin layer 11 covering the screw shaft 3 are added to this.
The frictional resistance at the sliding contact between the thread 9 and the thread root 10 is extremely small. For this reason, the torque generated when the thread 9 and the thread root 10 slide is greatly reduced, and a smooth driving force transmission with little torque fluctuation can be performed as in the case of using the ball screw.
【００２０】図３はねじ山の他の実施例を示す。この例
では、ねじ軸３のねじ谷１０を、ナット２のねじ山９の
曲率半径Ｒ1 よりも大きく、かつ中心が互いに偏心する
曲率半径Ｒ2 、Ｒ2 を備えた２つの円弧面１４、１５で
形成している。このようにねじ谷１０をゴシック形状と
しても、ねじ山９とねじ谷１０を２点で線接触させるこ
とができ、駆動力伝達時のトルク損失を小さくすること
ができる。FIG. 3 shows another embodiment of the thread. In this example, the thread root 10 of the screw shaft 3 is formed with two arcuate surfaces 14 having curvature radii R 2 , R 2 that are larger than the radius of curvature R 1 of the thread 9 of the nut 2 and whose centers are eccentric to each other. 15. Thus, even if the thread root 10 is formed in a Gothic shape, the thread 9 and the thread root 10 can be brought into line contact at two points, and the torque loss at the time of driving force transmission can be reduced.
【００２１】なお、上記のねじ軸３は、ナット２と同種
のポリイミド系合成樹脂で形成することができる。この
ようにねじ軸３とナット２を共に同種の樹脂材料で形成
すると、両者の線膨脹係数が等しくなり、温度環境が変
化してもねじ軸とナットのねじ山間の係合すき間が一定
に維持されるため、精度の高いねじ駆動を行なうことが
できる。また、合成樹脂で形成されたねじ山同士が接触
することにより、接触部分の摩擦抵抗が著しく小さくな
り焼付きが防止されるため、ねじ軸の表面にＰＴＦＥ樹
脂層等のコーティングを施さなくても、スムーズで安定
した駆動を行なうことができる。The screw shaft 3 can be formed of the same kind of polyimide synthetic resin as the nut 2. When the screw shaft 3 and the nut 2 are both made of the same kind of resin material in this manner, the linear expansion coefficients of the two become equal, and the engagement gap between the screw shaft and the thread of the nut is kept constant even when the temperature environment changes. Therefore, highly accurate screw driving can be performed. Also, since the threads formed of the synthetic resin come into contact with each other, the frictional resistance of the contact portion is significantly reduced and seizure is prevented, so that the surface of the screw shaft does not need to be coated with a PTFE resin layer or the like. Thus, smooth and stable driving can be performed.
【００２２】また、上記の実施例では、ナットのねじ山
を半円形の形状に形成したが、逆にねじ軸のねじ山を半
円形に形成し、ナットのねじ山をそれに線接触する面で
形成してもよい。In the above embodiment, the thread of the nut is formed in a semicircular shape. Conversely, the thread of the screw shaft is formed in a semicircular shape, and the thread of the nut is formed on the surface in line contact therewith. It may be formed.
【００２３】また、合成樹脂で形成したナット又はねじ
軸のねじ山の表面に、さらにＰＴＦＥ樹脂層などの摩擦
抵抗の低い樹脂層をコーティングすることもできる。Further, the surface of the thread of the nut or screw shaft formed of a synthetic resin may be further coated with a resin layer having a low frictional resistance such as a PTFE resin layer.
【００２４】[0024]
【効果】以上のように、この発明の第１の手段では、ポ
リイミド系合成樹脂から成るナットに軸受面を設けたこ
とにより、ポリイミド系合成樹脂は自己潤滑性を有する
ため、ねじ軸とナットの滑りおよびナットとケースのす
べりを両立させることができる。このため、ナットとケ
ースの間から転がり軸受を省くことができるので、装置
の外径寸法のコンパクト化と重量低減を図ることができ
る利点がある。[Effect] As described above, in the first means of the invention, port
The bearing surface is provided on a nut made of polyimide synthetic resin.
With, polyimide synthetic resin has self-lubricating property
The screw shaft and nut and the nut and case
It is possible to balance the slip. Therefore, since the rolling bearing can be omitted from between the nut and the case, there is an advantage that the outer diameter of the device can be reduced in size and the weight can be reduced.
【００２５】また、この発明の第２の手段のように、ナ
ットとねじ軸間の熱膨脹差を無くすことにより、ボール
ねじを用いずにスムーズで精度の高い駆動を行なうこと
ができる。Further, as in the second section in accordance with the present invention, by the thermal expansion difference between the nut and the screw shaft free camphor, can be performed with high accuracy drive smooth without a ball screw.
【図面の簡単な説明】[Brief description of the drawings]
【図１】実施例のねじ駆動装置を示す断面図FIG. 1 is a sectional view showing a screw drive device according to an embodiment.
【図２】同上のナットとねじ軸のねじ山を拡大して示す
断面図FIG. 2 is an enlarged sectional view showing a thread of the nut and a screw shaft of the same.
【図３】同上のねじ山の他の実施例を示す断面図FIG. 3 is a cross-sectional view showing another embodiment of the above screw thread.
【図４】従来例を示す断面図FIG. 4 is a sectional view showing a conventional example.
１ ケース ２ ナット ３ ねじ軸 ４ モータ ５ 回転子 ６ 固定子 ７ ラジアル軸受面 ８ スラスト軸受面 ９ ねじ山 １０ ねじ谷 １１ ＰＴＦＥ樹脂層 DESCRIPTION OF SYMBOLS 1 Case 2 Nut 3 Screw shaft 4 Motor 5 Rotor 6 Stator 7 Radial bearing surface 8 Thrust bearing surface 9 Thread 10 Thread root 11 PTFE resin layer
フロントページの続き (58)調査した分野(Int.Cl.7，ＤＢ名) F16H 25/20 - 25/24 F16C 17/00 - 17/26 Continuation of the front page (58) Field surveyed (Int.Cl. 7 , DB name) F16H 25/20-25/24 F16C 17/00-17/26
Claims (3)
自在に支持し、そのナットの外周にモータの回転子を、
ケースにモータの固定子をそれぞれ取付けたねじ駆動装
置において、上記ナットをポリイミド系合成樹脂で形成
し、そのナットの表面にケースとすべり接触する軸受面
を設けたことを特徴とするねじ駆動装置。A nut rotatably supported by a case is rotatably supported on a case, and a rotor of a motor is mounted on an outer periphery of the nut.
A screw drive device in which a stator of a motor is mounted on a case, wherein the nut is formed of a polyimide synthetic resin, and a surface of the nut is provided with a bearing surface that is in sliding contact with the case.
に、摩擦係数の小さい樹脂層を被覆したことを特徴とす
る請求項１に記載のねじ駆動装置。2. The screw driving device according to claim 1, wherein a surface of the screw thread of the screw shaft or the nut is coated with a resin layer having a small coefficient of friction.
系合成樹脂で形成した請求項１又は２に記載のねじ駆動
装置。3. The screw shaft is made of the same kind of polyimide as a nut.
Screw drive according to claim 1 or 2 was formed in the system synthetic resin.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10127556A JP3053796B2 (en) | 1998-05-11 | 1998-05-11 | Screw drive |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10127556A JP3053796B2 (en) | 1998-05-11 | 1998-05-11 | Screw drive |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP16988898A Division JP3391705B2 (en) | 1998-06-17 | 1998-06-17 | Screw drive |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH1130302A JPH1130302A (en) | 1999-02-02 |
| JP3053796B2 true JP3053796B2 (en) | 2000-06-19 |
Family
ID=14962948
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10127556A Expired - Fee Related JP3053796B2 (en) | 1998-05-11 | 1998-05-11 | Screw drive |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3053796B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103573945A (en) * | 2013-10-10 | 2014-02-12 | 安徽省捷甬达智能机器有限公司 | Screw rod bearing protection device |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7674360B2 (en) * | 2003-12-12 | 2010-03-09 | Applied Materials, Inc. | Mechanism for varying the spacing between sputter magnetron and target |
| DE102007058523A1 (en) | 2007-12-05 | 2009-06-10 | Robert Bosch Gmbh | Adapter element and adjustment drive with adapter element |
-
1998
- 1998-05-11 JP JP10127556A patent/JP3053796B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103573945A (en) * | 2013-10-10 | 2014-02-12 | 安徽省捷甬达智能机器有限公司 | Screw rod bearing protection device |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH1130302A (en) | 1999-02-02 |
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