JPH0545820B2

JPH0545820B2 -

Info

Publication number: JPH0545820B2
Application number: JP2329589A
Authority: JP
Inventors: Hideaki Kawahara
Original assignee: Bando Chemical Industries Ltd
Current assignee: Bando Chemical Industries Ltd
Priority date: 1989-01-31
Filing date: 1989-01-31
Publication date: 1993-07-12
Also published as: JPH02203053A

Description

【発明の詳細な説明】（産業上の利用分野）本発明は、タイミングベルトの張力を駆動力に
応じて自動的に調整して、そのスキツプ現象を抑
制するベルト伝動装置の改良に関するものであ
る。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in a belt transmission device that automatically adjusts the tension of a timing belt according to driving force to suppress the skip phenomenon. .

（従来の技術）従来より、歯付プーリにタイミングベルト（シ
ンクロベルト）を巻き掛けてベルト伝動を行うベ
ルト伝動装置においては、ベルトの張力が低下す
ると、ベルトの歯部とプーリの歯部との噛合がな
くなつていわゆるスキツプ現象が生じるという問
題がある。(Prior art) Conventionally, in belt transmission devices that perform belt transmission by winding a timing belt (synchronous belt) around a toothed pulley, when the tension of the belt decreases, the contact between the teeth of the belt and the teeth of the pulley increases. There is a problem that a so-called skip phenomenon occurs due to loss of engagement.

このようなスキツプ現象を抑制する装置として
は、ベルトの緩み側背面をばね等で付勢されたテ
ンシヨンローラにより押圧して、ベルトにその駆
動力に応じた張力を与えるようにしたテンシヨン
機構が知られている。しかし、このものでは、ベ
ルトがテンシヨンローラによつて通常の屈曲方向
とは逆の背面方向に屈曲されるため、ベルト心体
の疲労が促進され、ベルトの耐久性が低下すると
いう不具合がある。また、大きいトルクが加わつ
た場合や、経時変化に伴つてベルトに伸びが生じ
た場合には、テンシヨンローラの戻りによりその
押圧力が低下し、スキツプ現象の発生は確実に阻
止し得ないこととなる。 A device for suppressing this kind of skipping phenomenon is a tension mechanism that applies tension to the belt in accordance with the driving force by pressing the back surface of the slack side of the belt with a tension roller biased by a spring or the like. Are known. However, with this method, the belt is bent by the tension roller in the back direction, which is opposite to the normal bending direction, which accelerates fatigue of the belt core and reduces the durability of the belt. . Additionally, if a large torque is applied or if the belt stretches over time, the tension roller returns and its pressing force decreases, making it impossible to reliably prevent the occurrence of the skip phenomenon. becomes.

このため、上記スキツプ現象を確実に阻止し得
るようにしたベルト伝動装置として、従来、特公
昭58−47592号公報に開示されるものが知られて
いる。 For this reason, a belt transmission device disclosed in Japanese Patent Publication No. 58-47592 is known as a belt transmission device capable of reliably preventing the above-mentioned skip phenomenon.

すなわち、このものは、互いに平行な１対の回
転軸にそれぞれ支持された歯付プーリからなる駆
動及び従動プーリと、該両プーリ間に巻き掛けら
れて両回転軸間で動力を伝達するタイミングベル
トとを設け、上記駆動又は従動プーリのいずれか
一方を、回転軸に回転一体に支持されかつ外周に
ギヤを有する第１プーリ部材と、該第１プーリ部
材の外周に第１プーリ部材の軸心に対して偏心可
能に配置され、上記第１プーリ部材のギヤに噛合
するギヤを内周に有し、外周に上記タイミングベ
ルトに噛み合う歯部を有する第２プーリ部材とで
構成し、上記両プーリ部材のギヤ同士の噛合で動
力伝達を行わせることにより、駆動及び従動プー
リ間の軸間距離を駆動力に応じて変位させて最適
なベルト張力を自動的に得るようにし、ベルトの
スキツプ現象を防止してその耐久性の向上を図る
ようにしたものである。 That is, this device includes driving and driven pulleys each consisting of a toothed pulley supported by a pair of mutually parallel rotating shafts, and a timing belt that is wound between the two pulleys and transmits power between the two rotating shafts. a first pulley member which is rotationally integrally supported by the rotating shaft and has a gear on the outer periphery; and an axial center of the first pulley member on the outer periphery of the first pulley member. a second pulley member that is arranged eccentrically relative to the belt, has a gear on its inner periphery that meshes with the gear of the first pulley member, and a second pulley member that has teeth on its outer periphery that mesh with the timing belt; By transmitting power by meshing the gears of the members, the distance between the shafts of the driving and driven pulleys is changed according to the driving force, and the optimal belt tension is automatically obtained, thereby eliminating the belt skipping phenomenon. The purpose is to prevent this and improve its durability.

しかしながら、この従来のものでは、駆動プー
リ側を第１及び第２プーリ部材で構成した場合、
該両プーリ部材の径の違いにより必然的に第２プ
ーリ部材側のギヤの数が第１プーリ部材のギヤの
数よりも多くなり、回転軸の回転が減速されて第
２プーリ部材つまりベルトに伝達されることとな
る。このため、駆動プーリから従動プーリに回転
を増速して伝達する必要のある自転車の駆動系に
適用すると、その増速伝達の確保のために、上記
減速分を見越して駆動プーリの直径を必要以上に
大きくせねばならず、その配置スペースが大きく
なつたり、重量が増加したりする等の難点があつ
た。 However, in this conventional device, when the drive pulley side is composed of the first and second pulley members,
Due to the difference in the diameters of both pulley members, the number of gears on the second pulley member side is inevitably greater than the number of gears on the first pulley member, and the rotation of the rotating shaft is decelerated and the second pulley member, that is, the belt. It will be transmitted. For this reason, when applied to a bicycle drive system that requires increased speed transmission of rotation from the drive pulley to the driven pulley, the diameter of the drive pulley must be increased in anticipation of the above deceleration in order to ensure the increased speed transmission. However, it had to be made larger than this, which resulted in problems such as an increase in the installation space and an increase in weight.

そこで、こうした不具合を解消するベルト伝動
装置として、特開昭63−6261号公報に開示される
ものがある。このものは、例えば第１１図に示す
ように、基本的には上記従来の構造と同様で、駆
動軸ａ上の駆動プーリｃと従動軸ｂ上の従動プー
リｄとの間に歯付伝動ベルトｅが巻回されたもの
である。その特徴として、上記駆動プーリｃは、
外周端面に歯付ベルトｅが噛み合う無端状の外歯
（図示せず）を有する環状従動輪ｆと、該環状従
動輪ｆの内周側に配置され、中心に上記駆動軸ａ
を一体に有し、環状従動輪ｆの内径よりも小径の
駆動デイスクｇと、上記環状従動輪ｆの側面に一
体に取り付けられ、中心部に上記駆動軸ａを遊動
可能に貫通させる窓h₁を有する側面板ｈと、上記
駆動デイスクｇの側面に駆動軸ａを中心として等
角度間隔で突設された複数のブツシユｉ，ｉ，…
と、上記側面板ｈにその中心と同心状態に等角度
間隔で開口され、上記複数のブツシユｉ，ｉ，…
をそれぞれ遊嵌合可能な複数のブツシユ窓ｊ，
ｊ，…とを備えている。そして、駆動デイスクｇ
の各ブツシユｉが側面板ｈの各ブツシユ窓ｊの周
縁部を摺接しながら押すことによつて駆動デイス
クｇから環状従動輪ｆへの動力伝達が行われる構
成とされている。この構成により、駆動力に応じ
て最適なベルト張力を自動的に得ることができ、
ベルトｅのスキツプ現象を確実に防止することが
できることに加え、駆動デイスクｇ（駆動軸ａ）
と環状従動輪ｆとの回転比率が等しいために、増
速伝達を要する自転車の駆動系に適用した場合で
も、環状従動輪ｆ延いては駆動プーリｃの直径を
小さくすることができる。 Therefore, a belt transmission device that solves these problems is disclosed in Japanese Patent Application Laid-Open No. 63-6261. For example, as shown in FIG. 11, this device has basically the same structure as the conventional structure described above, and has a toothed power transmission belt between a drive pulley c on a drive shaft a and a driven pulley d on a driven shaft b. e is wound. As its characteristics, the drive pulley c is as follows:
An annular driven wheel f having endless external teeth (not shown) with which a toothed belt e meshes with the outer peripheral end surface, and an annular driven wheel f disposed on the inner peripheral side of the annular driven wheel f, with the drive shaft a at the center.
a drive disk g having a smaller diameter than the inner diameter of the annular driven wheel f, and a window _h1 integrally attached to the side surface of the annular driven wheel f and allowing the drive shaft a to freely pass through the center thereof. a side plate h having a side plate h, and a plurality of bushes i, i, .
A plurality of bushes i, i, . . . are opened at equal angular intervals concentrically with the center of the side plate h,
Multiple button windows that can be fitted loosely,
It is equipped with j,... And drive disk g
Each bush i slides against and pushes the peripheral edge of each bush window j of the side plate h, thereby transmitting power from the drive disk g to the annular driven wheel f. With this configuration, the optimal belt tension can be automatically obtained according to the driving force.
In addition to being able to reliably prevent the belt e from skipping, the drive disk g (drive shaft a)
Since the rotation ratios of the annular driven wheel f and the annular driven wheel f are equal, even when applied to a bicycle drive system that requires increased speed transmission, the diameter of the annular driven wheel f and the drive pulley c can be reduced.

（発明が解決しようとする課題）ところが、この提案のものでは、作動原理上、
駆動デイスクｇの各ブツシユｉが側面板ｈの各ブ
ツシユ窓ｊの周縁部を滑りながら押すことによつ
て駆動デイスクｇから環状従動輪ｆへの動力伝達
が行われる構造であるので、ブツシユｉ又はブツ
シユ窓ｊ周縁部が早期磨耗しないようにするため
に、実際の使用段階では各ブツシユｉ上にローラ
を回転自在に支持すること等が必要不可欠とされ
る。このため、構造が複雑になり、装置の組立工
数が増加してコストアツプを招く難がある。(Problem to be solved by the invention) However, in this proposal, due to the operating principle,
The structure is such that power is transmitted from the drive disk g to the annular driven wheel f by each bush i of the drive disc g slidingly pushing against the peripheral edge of each bush window j of the side plate h. In order to prevent premature wear of the peripheral edge of the bush window j, it is essential to rotatably support a roller on each bush i during actual use. Therefore, the structure becomes complicated and the number of man-hours for assembling the device increases, leading to an increase in cost.

また、大きな負荷が急激に加わつた場合にはロ
ーラが破損したり、ブツシユｉが折損したりする
虞れがある。 Furthermore, if a large load is applied suddenly, there is a risk that the rollers may be damaged or the bushings i may break.

さらには、ブツシユｉやローラの摺動摩擦によ
るトルクロスが生じるのは避けられ得ない。 Furthermore, it is unavoidable that torque loss occurs due to sliding friction of the bush i and rollers.

また、駆動デイスクｇの側面にブツシユｉ，
ｉ，…が突設されているため、駆動プーリｃの厚
さが増大してベルト伝動装置が厚くなる等の問題
もある。 In addition, there are buttons i on the side of the drive disk g.
Since the protruding portions i, .

本発明は斯かる諸点に鑑みてなされたものであ
り、その目的は、上記のベルト伝動装置におい
て、回転軸に結合支持される側のプーリ部材とベ
ルトに噛合連結される側のプーリ部材との駆動力
伝達構造を改良することにより、ベルト伝動装置
の構造を簡単にして組立工数の低減及びそれに伴
うコストダウン化を図り、急激な大負荷に対する
耐久性を高め、トルクロスを低減するとともに、
ベルト伝動装置の薄肉化を図ることにある。 The present invention has been made in view of the above points, and its object is to improve the connection between the pulley member on the side that is coupled and supported by the rotating shaft and the pulley member on the side that is meshed and connected to the belt in the above-mentioned belt transmission device. By improving the driving force transmission structure, we have simplified the structure of the belt transmission device, reducing assembly man-hours and associated costs, increasing durability against sudden large loads, and reducing torque loss.
The objective is to make the belt transmission device thinner.

（課題を解決するための手段）この目的を達成するために、本発明の解決手段
は、基本的に、駆動側プーリにおける回転軸側と
プーリ側とをボールやローラ等の転動体を用いた
係合機構によつて連結する。(Means for Solving the Problem) In order to achieve this object, the solving means of the present invention basically consists of using rolling elements such as balls and rollers between the rotating shaft side and the pulley side of the driving pulley. Connected by an engagement mechanism.

すなわち、請求項１記載の発明では、互いに平
行な１対の回転軸と、該回転軸にそれぞれ支持さ
れた歯付プーリからなる駆動及び従動プーリと、
該両プーリ間に巻き掛けられて両回転軸間で動力
を伝達するタイミングベルトとを備えたベルト伝
動装置に対し、上記駆動プーリを、回転軸に回転
一体に支持された円板状の第１プーリ部材と、該
第１プーリ部材に係合された第２プーリ部材とか
らなるものとする。 That is, in the invention according to claim 1, a pair of rotating shafts parallel to each other, and a driving and driven pulley each consisting of a toothed pulley supported by the rotating shafts, respectively;
For a belt transmission device including a timing belt that is wound between both pulleys and transmits power between both rotating shafts, the drive pulley is connected to a disc-shaped first belt that is rotatably supported by the rotating shaft. It consists of a pulley member and a second pulley member engaged with the first pulley member.

そして、上記第１プーリ部材は、内周が上記回
転軸に回転一体に取り付けられた円板からなるデ
イスク部を備えた構成とする。 The first pulley member is configured to include a disk portion having an inner periphery formed of a disk rotatably attached to the rotating shaft.

一方、上記第２プーリ部材は、第１プーリ部材
の外周に配置され、かつ内径がデイスク部の外径
よりも大に形成され、外周に上記タイミングベル
トに噛み合う歯部を有する略リング状のプーリ部
と、上記デイスク部の両側にデイスク部を挟み込
むように配置され、かつ外周縁が上記プーリ部に
回転一体に固定され、中心に上記回転軸を挿通可
能な貫通孔を有する円板からなる１対の側面板と
を備えた構成とする。 On the other hand, the second pulley member is a generally ring-shaped pulley disposed on the outer periphery of the first pulley member, the inner diameter of which is larger than the outer diameter of the disc portion, and the outer periphery of which has teeth that mesh with the timing belt. and a disk 1 which is arranged on both sides of the disk part so as to sandwich the disk part, whose outer periphery is rotationally fixed to the pulley part, and has a through hole in the center through which the rotation shaft can be inserted. The configuration includes a pair of side plates.

さらに、上記一方の側面板の内側面には複数の
有底の第２プーリ側案内穴を側面板と同心円周上
にかつ等角度間隔をあけて設ける。また、上記デ
イスク部において上記一方の側面板の内側面に対
向する一側面には上記第２プーリ側案内穴と略同
径の複数の有底の第１プーリ側案内穴を第２プー
リ側案内穴に対応して設ける。 Furthermore, a plurality of bottomed second pulley-side guide holes are provided on the inner surface of the one side plate on a circumference concentric with the side plate and spaced at equal angular intervals. Further, in one side surface of the disk portion opposite to the inner surface of the one side plate, a plurality of bottomed first pulley side guide holes having approximately the same diameter as the second pulley side guide holes are provided for second pulley side guide holes. Provide corresponding to the hole.

また、上記互いに対向する両案内穴には案内穴
の開口径よりも小径の転動体を各半部がそれぞれ
両案内穴に臨むように嵌装する。そして、上記各
転動体の案内穴での転動により第２プーリ部材を
第１プーリ部材に対し所定量偏心可能に構成す
る。 Moreover, rolling elements having a smaller diameter than the opening diameter of the guide holes are fitted into the mutually opposing guide holes so that each half faces each of the guide holes. The second pulley member is configured to be eccentric by a predetermined amount with respect to the first pulley member by rolling of each of the rolling elements in the guide holes.

請求項２記載の発明では、上記請求項１記載の
発明の構成において、第１プーリ部材のデイスク
部の他側面にも同様の第１プーリ部材側案内穴を
設け、一方、デイスク部両側面にそれぞれ対向す
る側面板の内側面に第２プーリ部材側案内穴を設
ける。 In the invention set forth in claim 2, in the configuration of the invention set forth in claim 1, a similar first pulley member side guide hole is provided on the other side of the disk portion of the first pulley member, and on the other hand, a similar first pulley member side guide hole is provided on both sides of the disk portion. A second pulley member side guide hole is provided on the inner side surface of the opposing side plates.

また、請求項３記載の発明では、上記請求項１
記載の発明の構成とは逆に、駆動プーリにおける
第１プーリ部材を、軸線方向に所定間隔をあけて
対向配置され、かつ内周が上記回転軸に回転一体
に取り付けられた円板からなる１対の側面板を備
える構成とする。一方、第２プーリ部材は、第１
プーリ部材の外周に配置され、かつ内径が側面板
の外径よりも大に形成され、外周に上記タイミン
グベルトに噛み合う歯部を有する略リング状のプ
ーリ部と、上記両側面板間に遊嵌合され、かつ外
周縁が上記プーリ部に回転一体に固定され、中心
に上記回転軸を挿通可能な貫通孔を有する円板か
らなるデイスク部とを備えてなるものとする。 In addition, in the invention as claimed in claim 3, the above-mentioned claim 1
Contrary to the structure of the invention described above, the first pulley member of the drive pulley is made of a disc which is disposed facing each other at a predetermined interval in the axial direction and whose inner periphery is integrally attached to the rotation shaft. The configuration includes a pair of side plates. On the other hand, the second pulley member
A generally ring-shaped pulley part is disposed on the outer periphery of the pulley member, has an inner diameter larger than the outer diameter of the side plate, and has teeth on the outer periphery that mesh with the timing belt, and is loosely fitted between the both side plates. and a disk portion having an outer peripheral edge rotatably fixed to the pulley portion and having a through hole in the center through which the rotating shaft can be inserted.

そして、上記一方の側面板の内側面に複数の有
底の第１プーリ側案内穴を側面板と同心円周上に
かつ等角度間隔をあけて設ける一方、上記デイス
ク部において上記一方の側面板の内側面に対向す
る一側面に、上記第１プーリ側案内穴と略同径の
複数の有底の第２プーリ側案内穴を第１プーリ側
案内穴に対応して設ける。 A plurality of bottomed first pulley-side guide holes are provided on the inner surface of the one side plate on a circumference concentric with the side plate and spaced at equal angular intervals, and in the disc portion, the first pulley side guide holes are provided on the inner surface of the one side plate. A plurality of bottomed second pulley-side guide holes having substantially the same diameter as the first pulley-side guide holes are provided on one side surface opposite to the inner surface, corresponding to the first pulley-side guide holes.

さらに、上記互いに対向する両案内穴に転動体
を各半部がそれぞれ両案内穴に臨むように嵌装
し、各転動体の案内穴での転動により第２プーリ
部材を第１プーリ部材に対し所定量偏心可能に構
成する。 Further, the rolling elements are fitted into the mutually opposing guide holes so that each half faces the two guide holes, and the second pulley member is connected to the first pulley member by rolling of each rolling element in the guide hole. The structure is configured such that it can be eccentric by a predetermined amount.

請求項４記載の発明では、上記請求項３記載の
発明の構成において、第２プーリ部材のデイスク
部の他側面にも同様の第２プーリ部材側案内穴を
設け、一方、デイスク部両側面にそれぞれ対向す
る側面板の内側面に第１プーリ部材側案内穴を設
ける。 In the invention set forth in claim 4, in the configuration of the invention set forth in claim 3, a similar second pulley member side guide hole is provided on the other side of the disc portion of the second pulley member, and on the other hand, a similar second pulley member side guide hole is provided on both sides of the disk portion. First pulley member side guide holes are provided on the inner surfaces of the opposing side plates.

さらに、請求項５記載の発明では、上記請求項
１、２、３又は４記載の発明の構成において、デ
イスク部と側面板との間に、転動体を転動可能に
保持する保持孔を有する転動体保持板を配設す
る。 Furthermore, in the invention set forth in claim 5, in the structure of the invention set forth in claim 1, 2, 3, or 4, a holding hole is provided between the disk portion and the side plate for rollably holding the rolling element. Install a rolling element retaining plate.

そして、具体的に、請求項６記載の発明では、
上記請求項１、２、３、４又は５記載の発明の構
成において転動体をボールとする。 Specifically, in the invention according to claim 6,
In the structure of the invention according to claim 1, 2, 3, 4 or 5, the rolling elements are balls.

一方、請求項７記載の発明では、上記請求項
１、２、３、４又は５記載の発明の構成において
転動体をローラ（ころ）とする。 On the other hand, in the invention set forth in claim 7, in the structure of the invention set forth in claim 1, 2, 3, 4, or 5, the rolling elements are rollers.

また、請求項８記載の発明では、上記請求項７
記載の記載の発明の構成において、ローラを円柱
状、円錐状又は鼓形状とする。 In addition, in the invention as claimed in claim 8, the above-mentioned claim 7
In the described embodiment of the invention, the roller is cylindrical, conical or drum-shaped.

（作用）上記の構成により、請求項１、２、３又は４記
載の発明では、駆動及び従動プーリ間にタイミン
グベルトが巻き掛けられると、該タイミングベル
トの曲げ剛性と第２プーリ部材の自重とにより、
第２プーリ部材の軸心が第１プーリ部材の軸心に
対し従動プーリ側でかつベルト緩み側に偏心す
る。この偏心に伴い、第２プーリ部材の案内穴が
それと対応する第１プーリ側案内穴に対して同様
の方向に偏心するが、この両案内穴間には転動体
が介在されているため、偏心は転動体に規制され
て止まる。すなわち、無負荷状態では第２プーリ
部材は最大量偏心する。この状態では、第２プー
リ側案内穴が第１プーリ側案内穴に対して従動プ
ーリ側でかつベルト緩み側に偏心しているため、
第１プーリ部材に駆動力を与えた場合、第２プー
リ部材に駆動力を伝達するのは、偏心方向が第１
プーリ部材の円周方向と一致する位置、つまり第
１プーリ部材の軸心に対し従動プーリ側でかつベ
ルト緊張側部分のみとなる。従つて、駆動プーリ
の１回転中、複数の案内穴及び転動体が第１プー
リ部材の軸心に対し従動プーリ側でかつベルト緊
張側部分を横切るときにのみ、駆動力が第１プー
リ部材から第２プーリ部材に伝達される。(Function) With the above configuration, in the invention according to claim 1, 2, 3 or 4, when the timing belt is wound between the driving and driven pulleys, the bending rigidity of the timing belt and the dead weight of the second pulley member are reduced. According to
The axis of the second pulley member is eccentric with respect to the axis of the first pulley member on the driven pulley side and on the belt slack side. Along with this eccentricity, the guide hole of the second pulley member becomes eccentric in the same direction with respect to the corresponding guide hole on the first pulley side, but since a rolling element is interposed between both guide holes, the eccentricity is regulated by the rolling elements and stops. That is, in the no-load state, the second pulley member is eccentric by the maximum amount. In this state, the second pulley side guide hole is eccentric to the driven pulley side with respect to the first pulley side guide hole and toward the belt slack side.
When a driving force is applied to the first pulley member, the driving force is transmitted to the second pulley member in the eccentric direction.
It is located only at a position that coincides with the circumferential direction of the pulley member, that is, on the driven pulley side with respect to the axis of the first pulley member and on the belt tension side. Therefore, during one rotation of the drive pulley, the driving force is released from the first pulley member only when the plurality of guide holes and rolling elements cross the belt tension side portion on the driven pulley side with respect to the axis of the first pulley member. is transmitted to the second pulley member.

回転軸に駆動力が与えられた場合、第１プーリ
部材から第２プーリ部材への駆動力の伝達は第１
プーリ部材の軸心に対し従動プーリ側でかつベル
ト緊張側部分に位置する転動体のみで行われ、そ
の力の方向は第１プーリ部材の円周方向となる。
この方向は第２プーリ部材の軸心から第１プーリ
部材の軸心に向かう方向と略一致しているので、
上記駆動力により第２プーリ部材は第１プーリ部
材側へ移動して偏心量は減少する。ところが、こ
の第２プーリ部材の移動により、、タイミングベ
ルトの巻き掛かるピツチ周長が増大するので、無
負荷状態で緩み状態にあつたタイミングベルトは
引つ張られ、これにより第２プーリ部材の移動が
規制される。同時に、モーメントの釣合いにによ
り、第１プーリ部材の軸心に対し従動プーリ側で
かつベルト緊張側部分に位置する転動体からそれ
ぞれベルトの緊張側及び緩み側の各スパンまでの
垂直距離に応じた比率でベルトの緊張側及び緩み
側に張力が付与される。また、駆動力の大きさが
変化しても、その駆動力を伝達する転動体の位置
及び力の方向は変化せず、力の大きさのみが駆動
力に応じて変化するため、タイミングベルトの緊
張側及び緩み側には常に一定の比率で張力が与え
られる。以上により、タイミングベルトのスキツ
プ現象を抑制して、その耐久性を高めることがで
きる。 When a driving force is applied to the rotating shaft, the driving force is transmitted from the first pulley member to the second pulley member.
This force is applied only by the rolling elements located on the driven pulley side and belt tensioning side with respect to the axis of the pulley member, and the direction of the force is in the circumferential direction of the first pulley member.
Since this direction substantially coincides with the direction from the axis of the second pulley member toward the axis of the first pulley member,
The driving force causes the second pulley member to move toward the first pulley member, and the amount of eccentricity decreases. However, due to the movement of the second pulley member, the pitch circumference around which the timing belt is wound increases, so the timing belt, which was loose under no load, is pulled, and this causes the movement of the second pulley member. is regulated. At the same time, due to moment balance, the vertical distance from the rolling element located on the driven pulley side and belt tension side portion with respect to the axis of the first pulley member to each span on the tension side and slack side of the belt, respectively. Tension is applied to the tension side and slack side of the belt in proportion. In addition, even if the magnitude of the driving force changes, the position of the rolling elements that transmit the driving force and the direction of the force do not change, and only the magnitude of the force changes according to the driving force, so the timing belt Tension is always applied to the tension side and the slack side at a constant ratio. As described above, it is possible to suppress the timing belt skipping phenomenon and improve its durability.

そして、この発明の場合、案内穴と転動体との
係合により駆動力を伝達する構造であるため、ブ
ツシユ及びローラを使用する場合に比べ、構造が
簡単となり、組立工数の減少によつてコストダウ
ンを図ることができる。また、転動体による伝達
であるので、大きな負荷が急激に加わつた場合で
も転動体の損傷がなく、高い耐久性を得ることが
できる。さらに、転動体の案内穴内での転動によ
りその抵抗が小さく、トルクロスを低減すること
ができる。しかも転動体が案内穴内で転動するの
で、駆動プーリ側の厚さを薄くでき、ベルト伝動
装置のコンパクト化を図ることができる。 In the case of this invention, since the driving force is transmitted through the engagement between the guide hole and the rolling element, the structure is simpler than when using bushes and rollers, and the assembly man-hours are reduced, resulting in lower costs. You can try to bring it down. Furthermore, since the transmission is by rolling elements, even if a large load is suddenly applied, the rolling elements will not be damaged and high durability can be achieved. Furthermore, due to the rolling of the rolling elements within the guide holes, the resistance is small and torque loss can be reduced. Furthermore, since the rolling elements roll within the guide hole, the thickness of the driving pulley side can be reduced, and the belt transmission device can be made more compact.

また特に、請求項２又は４記載の発明では、案
内穴及び転動体が第１プーリ部材又は第２プーリ
部材のデイスク部における表裏側面に配設されて
いるので、第１プーリ部材から第２プーリ部材へ
駆動力を伝達する際の力のバランスが良くなり、
トルクロスを低減できるとともに、大きな駆動力
を伝達することができる。 Particularly, in the invention according to claim 2 or 4, since the guide hole and the rolling element are arranged on the front and back sides of the disk portion of the first pulley member or the second pulley member, Improves the balance of force when transmitting driving force to components,
Torque loss can be reduced and large driving force can be transmitted.

さらに、請求項５記載の発明では、転動体の位
置規制を行う転動体保持板が付設されているの
で、案内穴内での転動体の遊びを有効に規制で
き、駆動プーリのより安定した回転を得ることが
できる。 Furthermore, in the invention set forth in claim 5, since the rolling element holding plate for regulating the position of the rolling element is attached, play of the rolling element within the guide hole can be effectively restricted, and more stable rotation of the drive pulley can be achieved. Obtainable.

（実施例）以下、本発明の実施例を図面に基づいて説明す
る。(Example) Hereinafter, an example of the present invention will be described based on the drawings.

第３図及び第４図は本発明の第１実施例の全体
構成を示し、１は自転車のクランクペダル（図示
せず）に連結された駆動軸、２は自転車の後車輪
（図示せず）を支持する従動軸であつて、これら
駆動軸１及び従動軸２は互いに平行に配置されて
いる。上記駆動軸１には歯付きの駆動プーリ３が
回転一体に取り付けられている。従動軸２には駆
動プーリ３よりも小径で外周に歯部１６ａを有す
る従動プーリ１６が支持され、この従動プーリ１
６は図示しないワンウエイクラツチ機構によつて
駆動回転方向（図で反時計回り方向）にのみ従動
軸２に回転一体に連結される。そして上記両プー
リ３，１６間には底面（内周面）に歯部B₁を有
するタイミングベルトＢが巻き掛けられており、
このベルトＢによつて駆動軸１から従動軸２に動
力を伝達するようになされている。 3 and 4 show the overall configuration of the first embodiment of the present invention, in which 1 is a drive shaft connected to a bicycle crank pedal (not shown), 2 is a rear wheel of the bicycle (not shown) The drive shaft 1 and the driven shaft 2 are arranged parallel to each other. A toothed drive pulley 3 is rotatably attached to the drive shaft 1. A driven pulley 16 is supported on the driven shaft 2 and has a diameter smaller than that of the driving pulley 3 and has teeth 16a on the outer periphery.
6 is rotatably connected to the driven shaft 2 only in the drive rotation direction (counterclockwise in the figure) by a one-way clutch mechanism (not shown). A timing belt B having teeth _B1 on the bottom surface (inner peripheral surface) is wound between the pulleys 3 and 16.
Power is transmitted from the drive shaft 1 to the driven shaft 2 by this belt B.

上記駆動プーリ３は、駆動軸１に回転一体に支
持された小径円板状の第１プーリ部材４と、該第
１プーリ部材４の外周に配置され、第１プーリ部
材４の軸心O₁すなわち駆動軸１の回転中心に対
して偏心可能な軸心O₂を有する第２プーリ部材
７と、両プーリ部材４，７を連結する係合機構１
２とで構成されている。 The drive pulley 3 includes a first pulley member 4 in the form of a small diameter disc that is rotatably supported by the drive shaft 1, and is arranged around the outer periphery of the first pulley member 4, with an axis O ₁ of the first pulley member 4. That is, a second pulley member 7 having an axis O ₂ that can be eccentric with respect to the rotation center of the drive shaft 1, and an engagement mechanism 1 that connects both pulley members 4 and 7.
It is composed of 2.

上記駆動プーリ３の具体構造について第１図及
び第２図により説明すると、上記第１プーリ部材
４は、駆動軸１に回転一体に結合されたボス部５
と、該ボス部５の外周に一体形成された円板から
なるデイスク部６とで構成されている。 The specific structure of the drive pulley 3 will be explained with reference to FIGS. 1 and 2. The first pulley member 4 has a boss portion 5 rotatably coupled to the drive shaft 1.
and a disk portion 6 formed of a circular plate integrally formed on the outer periphery of the boss portion 5.

一方、上記第２プーリ部材７は、略リング状の
プーリ部８と、該プーリ部８に外周部にてピン
９，９，…により回転一体に固定された表裏１対
の側面板１０，１１とを備えてなる。上記プーリ
部８は第１プーリ部材４の外周に配置され、その
内径がデイスク部６の外径よりも大に形成され、
外周には上記タイミングベルトＢに噛み合う歯部
８ａが形成されている。一方、１対の側面板１
０，１１は上記デイスク部６の両側にデイスク部
６を挟み込むように対向配置され、外周部はプー
リ部８よりも半径方向外側に突出していて、駆動
プーリ３の対向シエイブを構成しており、中心に
は上記ボス部５（駆動軸１）を挿通可能な貫通孔
１０ａ，１１ａが形成されている。 On the other hand, the second pulley member 7 includes a substantially ring-shaped pulley part 8 and a pair of front and back side plates 10, 11 which are integrally fixed to the pulley part 8 by pins 9, 9, . It will be equipped with. The pulley part 8 is arranged on the outer periphery of the first pulley member 4, and has an inner diameter larger than the outer diameter of the disc part 6,
A tooth portion 8a that meshes with the timing belt B is formed on the outer periphery. On the other hand, a pair of side plates 1
0 and 11 are arranged opposite to each other on both sides of the disc part 6 so as to sandwich the disc part 6, and the outer circumferential part protrudes outward in the radial direction from the pulley part 8, and constitutes an opposing sheave of the drive pulley 3. Through holes 10a and 11a are formed at the center, through which the boss portion 5 (drive shaft 1) can be inserted.

さらに上記係合機構１２について説明するに、
上記第２プーリ部材７における裏側（第１図で左
側）の側面板１１の内側面には複数（図では16
個）の有底円形状の第２プーリ側ボール案内穴１
４，１４，…が側面板１１と同心円周上にかつ等
角度間隔をあけて凹設されている。一方、上記第
１プーリ部材４のデイスク部６において上記裏側
側面板１１の内側面に対向する裏面には上記第２
プーリ側ボール案内穴１４，１４，…と略同径の
複数の有底円形状の第１プーリ側ボール案内穴１
３，１３，…がそれぞれ両プーリ部材４，７の同
心状態で各第２プーリ側ボール案内穴１４に対応
して形成されている。この各ボール案内穴１３，
１４は深さが開口部の直径に比べて小さい浅穴に
設定されている。 Further, to explain the engagement mechanism 12,
The inside surface of the side plate 11 on the back side (left side in FIG. 1) of the second pulley member 7 has a plurality of
round bottomed ball guide hole 1 on the second pulley side
4, 14, . . . are recessed on a circumference concentric with the side plate 11 and spaced at equal angular intervals. On the other hand, in the disk portion 6 of the first pulley member 4, the second
A plurality of first pulley-side ball guide holes 1 each having a circular shape with a bottom and having approximately the same diameter as the pulley-side ball guide holes 14, 14, .
3, 13, . . . are formed concentrically with both pulley members 4, 7, corresponding to each second pulley side ball guide hole 14, respectively. Each ball guide hole 13,
14 is a shallow hole whose depth is smaller than the diameter of the opening.

さらに、上記互いに対向する第１プーリ側ボー
ル案内穴１３と第２プーリ側ボール案内穴１４と
の各々には各ボール案内穴１３，１４の開口径よ
りも小径でその略半分程度の直径を有するボール
１５（転動体）が各半部をそれぞれ両ボール案内
穴１３，１４に臨ませて嵌装されている。 Further, each of the first pulley-side ball guide hole 13 and the second pulley-side ball guide hole 14 facing each other has a diameter smaller than the opening diameter of each ball guide hole 13, 14, and approximately half the opening diameter thereof. A ball 15 (rolling element) is fitted with each half facing both ball guide holes 13 and 14, respectively.

そして、この各ボール１５のボール案内穴１
３，１４での転動により第２プーリ部材７が第１
プーリ部材４に対し所定量偏心可能に構成されて
いる。 Then, the ball guide hole 1 of each ball 15
3 and 14, the second pulley member 7 moves to the first
It is configured to be eccentric by a predetermined amount with respect to the pulley member 4.

また、上記駆動軸１及び従動軸２の軸心O₁，
O₃同士を結ぶ直線l_Aと、該直線l_Aに直交しかつ上
記第１プーリ部材４の軸心O₁を通る直線l_Bとによ
り区画された緩み側偏心ゾーンＺに、上記第２プ
ーリ部材７の軸心O₂が所定量偏心して位置する
よう、上記タイミングベルトＢの長さが設定され
ている。 Further, the axis O ₁ of the driving shaft 1 and the driven shaft 2,
The _second pulley is placed in a slack side eccentric zone Z defined by a straight line _lA connecting the O3s and _{a straight line lB} _that is perpendicular to the straight line lA and passes through the axis _O1 of the first pulley member 4. The length of the timing belt B is set so that the axis _O2 of the member 7 is eccentrically positioned by a predetermined amount.

したがつて、上記実施例においては、駆動及び
従動プーリ３，１６間で動力伝達が行われない無
負荷状態では、第３図に示すように、タイミング
ベルトＢの張力がほぼ零になり、駆動プーリ３に
おける第２プーリ部材７の軸心O₂が第１プーリ
４の軸心O₁に対し最大量偏心する。 Therefore, in the above embodiment, in a no-load state where no power is transmitted between the drive and driven pulleys 3 and 16, the tension in the timing belt B becomes almost zero, as shown in FIG. The axis O ₂ of the second pulley member 7 in the pulley 3 is eccentric by the maximum amount with respect to the axis O ₁ of the first pulley 4 .

この状態から駆動軸１に駆動力が加わつて負荷
状態になると、第４図に示すように、その駆動力
は第１プーリ部材４から、該第１プーリ部材４の
軸心O₁に対しほぼ従動プーリ１６側でかつベル
ト緊張側部分（図で駆動プーリ３の右上側部分）
に位置するボール１５を介して第２プーリ部材７
に伝達される。このため、第２プーリ部材７は両
プーリ部材４，７の軸心O₁，O₂を通る平面ｐに
沿つてタイミングベルトＢの緊張側に移動すると
ともに、この移動によつてタイミングベルトＢの
緊張側と緩み側とに一定の比率で張力が分配され
る。その結果、タイミングベルトＢのスキツプ現
象を有効に抑え、その耐久性を向上させることが
できる。 When a driving force is applied to the drive shaft 1 from this state and it becomes a loaded state, as shown in _FIG. The part on the driven pulley 16 side and the belt tension side (the upper right part of the drive pulley 3 in the figure)
The second pulley member 7 is connected to the second pulley member 7 via the ball 15 located at
transmitted to. Therefore, the second pulley member 7 moves to the tension side of the timing belt B along the plane p passing through the axes O ₁ and O ₂ of both pulley members 4 and 7, and this movement causes the timing belt B to move toward the tension side. Tension is distributed between the tension side and the slack side at a constant ratio. As a result, the skipping phenomenon of the timing belt B can be effectively suppressed and its durability can be improved.

そして、タイミングベルトＢの回行状態では、
上記両プーリ部材４，７の軸心O₁，O₂同士がほ
ぼ一致し、このことにより駆動プーリ３をスムー
ズに回転させることができる。 Then, when the timing belt B is running,
The axes O ₁ and O ₂ of both pulley members 4 and 7 substantially coincide with each other, thereby allowing the drive pulley 3 to rotate smoothly.

この場合、上記第１及び第２プーリ部材４，７
がボール案内穴１３，１４及びボール１５からな
る係合機構１２により連結されているので、駆動
プーリ３に対しその駆動軸１の回転を１：１の伝
達比で伝達でき、駆動プーリ３の回転を増速して
従動プーリ１６に伝動する場合であつても駆動プ
ーリ３の径を必要以上に大きくせずとも済み、よ
つて駆動プーリ３の配置スペースを縮小しかつそ
の重量をも軽減することができる。 In this case, the first and second pulley members 4, 7
are connected by an engagement mechanism 12 consisting of ball guide holes 13, 14 and balls 15, so the rotation of the drive shaft 1 can be transmitted to the drive pulley 3 at a transmission ratio of 1:1, and the rotation of the drive pulley 3 Even when the speed of the drive pulley 3 is increased and the power is transmitted to the driven pulley 16, the diameter of the drive pulley 3 does not need to be increased more than necessary, thereby reducing the installation space of the drive pulley 3 and its weight. I can do it.

また、ボール案内穴１３，１４とボール１５と
の係合により駆動力を伝達する構造であるため、
ブツシユ及びローラを使用する場合に比べ、構造
が簡単となり、組立工数の減少によつてコストダ
ウンを図ることができる。 In addition, since the structure is such that driving force is transmitted through engagement between the ball guide holes 13 and 14 and the ball 15,
Compared to the case where a bush and rollers are used, the structure is simpler and costs can be reduced by reducing the number of assembly steps.

さらに、ボール１５による伝達であるので、大
きな負荷が急激に加わつた場合でもボール１５の
損傷がなく、高い耐久性を得ることができる。 Furthermore, since the transmission is via the balls 15, even if a large load is suddenly applied, the balls 15 will not be damaged and high durability can be achieved.

さらにまた、ボール１５は案内穴１３，１４内
で転動するので、トルクロスを低減することがで
きる。 Furthermore, since the balls 15 roll within the guide holes 13 and 14, torque loss can be reduced.

加えて、ボール１５がボール案内穴１３，１４
内で転動するので、駆動プーリ３側の厚さを薄く
でき、ベルト伝動装置のコンパクト化を図ること
ができる。 In addition, the ball 15 is inserted into the ball guide holes 13 and 14.
Since the belt rotates within the belt, the thickness on the driving pulley 3 side can be reduced, and the belt transmission device can be made more compact.

また、第３図に示すように、無負荷状態ではタ
イミングベルトＢの張力が零であるので、該タイ
ミングベルトＢの装着の際に初張力を与える必要
がなく、その装着を容易に行うことができる。 Furthermore, as shown in Fig. 3, the tension of the timing belt B is zero in the no-load state, so there is no need to apply initial tension when installing the timing belt B, making it easy to install the timing belt B. can.

本発明は以上の第１実施例以外に種々の他の実
施例を包含するものであり、以下、その各々につ
いて説明する。尚、各実施例では、第１実施例に
対応する部分については同じ符号を符してその詳
細な説明は省略する。 The present invention includes various other embodiments in addition to the first embodiment described above, and each of them will be described below. In each embodiment, parts corresponding to those in the first embodiment are denoted by the same reference numerals, and detailed explanation thereof will be omitted.

上記第１実施例では、第１プーリ部材４の裏面
及び該裏面に対向する裏側の側面板１１の内面に
それぞれボール案内穴１３，１４を凹設して、該
各ボール穴１３，１４にボール１５を嵌装した
が、これに代え、ボール案内穴１３，１４及びボ
ール１５を駆動軸プーリ３の表面側に設けてもよ
い。 In the first embodiment, the ball guide holes 13 and 14 are formed in the back surface of the first pulley member 4 and the inner surface of the side plate 11 on the back side opposite to the back surface, and the ball guide holes 13 and 14 are provided in the respective ball holes 13 and 14. 15, but instead of this, the ball guide holes 13, 14 and the ball 15 may be provided on the surface side of the drive shaft pulley 3.

また、第１プーリ部材４の表裏面及び該表裏面
に対向する表裏側の側面板１１の内面にそれぞれ
ボール案内穴を凹設して、該各ボール案内穴にボ
ールを嵌装した構造とすることも可能である（第
２実施例）。この例の場合、ボール案内穴及びボ
ールが駆動ーリ３の表裏側双方に設けられるの
で、第１プーリ部材４から第２プーリ部材７への
駆動力の伝達の際、スラスト方向の力のバランス
が良くなり、トルクロスをさらに低減できるとと
もに、伝達可能な駆動力を増大できる利点があ
る。 Further, ball guide holes are formed in the front and back surfaces of the first pulley member 4 and the inner surfaces of the side plates 11 on the front and back surfaces opposite to the front and back surfaces, and balls are fitted into each of the ball guide holes. It is also possible (second embodiment). In this example, since the ball guide hole and the balls are provided on both the front and back sides of the drive pulley 3, when the driving force is transmitted from the first pulley member 4 to the second pulley member 7, the force in the thrust direction is balanced. This has the advantage that the torque loss can be further reduced and the transmittable driving force can be increased.

第５図は第３実施例を示し、上記第１実施例で
は、第１プーリ部材４にデイスク部６を、第２プ
ーリ部材７に側面板１０，１１をそれぞれ形成し
たのに代え、第１プーリ部材４に側面板１０′，
１１′を、第２プーリ部材７にデイスク部６′をそ
れぞれ形成したものである。すなわち、この実施
例では、駆動プーリ３′における第１プーリ部材
４′は、駆動軸１と回転一体のボス部５と、軸線
方向に所定間隔をあけて対向配置され、かつ内周
がピン９′，９′，…により上記ボス部５に回転一
体に固定された円板からなる表裏１対の側面板１
０′，１１′とで構成されている。 FIG. 5 shows a third embodiment, in which, instead of forming the disk portion 6 on the first pulley member 4 and the side plates 10 and 11 on the second pulley member 7 in the first embodiment, the first A side plate 10' is attached to the pulley member 4,
11', a disk portion 6' is formed on the second pulley member 7, respectively. That is, in this embodiment, the first pulley member 4' of the drive pulley 3' is disposed facing the boss portion 5, which is rotatably integral with the drive shaft 1, at a predetermined interval in the axial direction, and has an inner circumference formed by the pin 9. A pair of front and back side plates 1 consisting of a circular plate rotatably fixed to the boss portion 5 by ', 9', . . .
0' and 11'.

一方、第２プーリ部材７′は、外周に歯部８ａ
を有する略リング状のプーリ部８と、上記第１プ
ーリ部材４の両側面板１０′，１１′間に遊嵌合さ
れ、かつ外周縁が上記プーリ部８に回転一体に固
定され、中心に上記ボス部５（駆動軸１）を挿通
可能な貫通孔６a′を有する円板からなるデイスク
部６′とで構成されている。 On the other hand, the second pulley member 7' has teeth 8a on the outer periphery.
A substantially ring-shaped pulley portion 8 having A disk portion 6' is formed of a circular plate having a through hole 6a' through which the boss portion 5 (drive shaft 1) can be inserted.

さらに、上記表裏側の両側面板１０′，１１′の
内側面にはそれぞれ複数の有底の第１プーリ側ボ
ール案内穴１３′，１３′，…が側面板１０′，１
１′と同心円周上にかつ等角度間隔をあけて設け
られている一方、上記デイスク部６′の両側面に
はそれぞれ上記第１プーリ側ボール案内穴１３′，
１３′と略同径の複数の有底の第２プーリ側ボー
ル案内穴１４′，１４′が第１プーリ側ボール案内
穴１３′に対応して設けられている。 Further, a plurality of bottomed first pulley side ball guide holes 13', 13', .
The first pulley side ball guide holes 13' are provided on both side surfaces of the disk portion 6', respectively, on a circumference concentric with the disk portion 1' and spaced at equal angular intervals.
A plurality of bottomed second pulley-side ball guide holes 14', 14' having substantially the same diameter as 13' are provided corresponding to the first pulley-side ball guide hole 13'.

そして、上記互いに対向する両ボール案内穴１
３′，１４′にはボール案内穴１３′，１４′の開口
径よりも小径のボール１５が各半部をそれぞれ両
ボール案内穴１３′，１４′に臨ませて嵌装されて
いて、各ボール１５のボール案内穴１３′，１
４′での転動により第２プーリ部材７が第１プー
リ部材４に対し所定量偏心可能に構成されてい
る。 Both ball guide holes 1 facing each other are provided.
A ball 15 having a smaller diameter than the opening diameter of the ball guide holes 13' and 14' is fitted into each of the holes 3' and 14' with each half facing each ball guide hole 13' and 14'. Ball guide hole 13', 1 of ball 15
The second pulley member 7 is configured to be eccentric by a predetermined amount with respect to the first pulley member 4 by rolling at 4'.

したがつて、この第３実施例でも、上記第２実
施例と同様の作用効果を奏することができる。 Therefore, this third embodiment can also provide the same effects as the second embodiment.

尚、この第３実施例の構成において、駆動プー
リ３′のボール案内穴１３′，１４′とボール１５
との組合せを駆動プーリ３′の表裏側のいずれか
一方に限定してもよく、上記第１実施例と同様の
作用効果を奏することが可能である。 In the configuration of this third embodiment, the ball guide holes 13' and 14' of the drive pulley 3' and the ball 15
The combination may be limited to either the front or back side of the drive pulley 3', and it is possible to achieve the same effects as in the first embodiment.

さらに、第６図に示すように、上記デイスク部
６（又は６′）と側面板１０，１１（又は１０′，
１１′）との間に、ボール１５を転動可能に保持
する円形保持孔１７ａ，１７ａ，…を有するボー
ル保持板１７を配設してもよい。この場合、ボー
ル１５の位置規制を行うボール保持板１７によ
り、各ボール案内穴１３，１４（又は１３′，１
４′）内でのボール１５の遊びを有効に規制でき、
駆動プーリ３，３′のより安定した回転を得るこ
とができる利点がある。 Furthermore, as shown in FIG. 6, the disk portion 6 (or 6') and the side plates 10, 11 (or 10',
11') may be provided with a ball holding plate 17 having circular holding holes 17a, 17a, . . . for holding the balls 15 in a rollable manner. In this case, each ball guide hole 13, 14 (or 13', 1
4'), the play of the ball 15 within the ball 15 can be effectively restricted.
There is an advantage that more stable rotation of the drive pulleys 3, 3' can be obtained.

以上の実施例では、転動体としてボール１５を
使用したが、このボール１５に代えて円柱状、円
錐状、鼓形状のローラを用いることもできる。 In the above embodiment, balls 15 were used as rolling elements, but instead of balls 15, cylindrical, conical, or drum-shaped rollers may be used.

すなわち、第７図及び第８図は第４実施例を示
しており、この実施例では、上記第１実施例の構
成（第１図〜第４図参照）において、各ボール案
内穴１３，１４をローラ案内穴１８，１９に、ボ
ール１５を円柱状ローラ２０にそれぞれ代えた構
成とされている。したがつて、この実施例の場
合、第１実施例と同様の作用効果を奏することが
できることに加え、ボール１５をローラ２０に代
えたことによつて耐久性を向上させることがで
き、より一層有利である。 That is, FIGS. 7 and 8 show a fourth embodiment, and in this embodiment, in the configuration of the first embodiment (see FIGS. 1 to 4), each ball guide hole 13, 14 is The roller guide holes 18 and 19 are replaced by roller guide holes 18 and 19, and the ball 15 is replaced by a cylindrical roller 20. Therefore, in the case of this embodiment, in addition to being able to achieve the same effects as in the first embodiment, durability can be improved by replacing the ball 15 with the roller 20, and the durability can be further improved. It's advantageous.

また、第９図は第５実施例を示し、上記第３実
施例の構成（第５図参照）において、上記と同様
に各ボール案内穴１３′，１４′をローラ案内穴１
８′，１９′に、ボール１５を円錐状ローラ２０′
にそれぞれ代えたものである。この実施例の場
合、第３実施例と同様の作用効果を奏することが
でき、耐久性を向上させることができる。 Further, FIG. 9 shows a fifth embodiment, in which, in the configuration of the third embodiment (see FIG. 5), each of the ball guide holes 13' and 14' is connected to the roller guide hole 1 in the same way as above.
8' and 19', the ball 15 is connected to the conical roller 20'.
These are the respective replacements. In the case of this embodiment, the same effects as in the third embodiment can be achieved, and durability can be improved.

さらに、第１０図は、上記第６図の実施例と同
様に、デイスク部６（又は６′）と側面板１０，
１１（又は１０′，１１′）との間に、ローラ２０
を転動可能に保持する円形保持孔２１ａ，２１
ａ，…を有するローラ保持板２１を配置したもの
である。この場合、各ローラ案内穴内１８，１９
（又は１８′，１９′）でのローラ２０の遊びを有
効に規制でき、より安定した回転を得ることがで
きる。 Further, FIG. 10 shows the disk portion 6 (or 6'), side plate 10,
11 (or 10', 11'), the roller 20
circular holding holes 21a, 21 that rotatably hold the
A roller holding plate 21 having a, . . . is arranged. In this case, inside each roller guide hole 18, 19
(or 18', 19') can be effectively restricted, and more stable rotation can be obtained.

以上の各実施例は、自転車の駆動系に適用した
場合であるが、本発明はこの他、高い耐久性の要
求される各種のベルト伝動装置に対しても適用す
ることができる。 Although each of the above embodiments is applied to a bicycle drive system, the present invention can also be applied to various belt transmission devices that require high durability.

（発明の効果）以上説明したように、請求項１、２、３又は４
記載の発明によると、タイミングベルトにより従
動プーリとの間で動力を伝達する駆動プーリを、
その回転軸に回転一体に支持された第１プーリ部
材と、該第１プーリ部材の外周に第１プーリ部材
の軸心に対して偏心可能に配置され、かつ第１プ
ーリ部材にボールやローラ等の転動体及びその案
内穴を組み合わせてなる係合機構を介して連結さ
れ、外周にて上記タイミングベルトに噛み合う第
２プーリ部材とで構成し、第１プーリ部材の駆動
力の増大に伴い、第２プーリ部材の第１プーリ部
材に対する偏心量を連続的に減少変化させるよう
にしたことにより、第１プーリ部材の回転を減速
することなく１：１の回転比で第２プーリ部材に
伝達でき、駆動プーリの回転を増速して従動プー
リに伝達する駆動系であつても駆動プーリの直径
を小さく保ち得、駆動プーリひいてはベルト伝動
装置の配置スペースの縮小化及び軽量化を図るこ
とができる。また案内穴と転動体との係合により
駆動力を伝達する構造であるため、ブツシユ及び
ローラを使用する場合に比べ、構造が簡単とな
り、組立工数の減少によつてコストダウンを図る
ことができる。また、転動体による伝達であるの
で、大きな負荷が急激に加わつた場合でも転動体
の損傷がなく、高い耐久性を得ることができる。
さらに、転動体は案内穴内で転動するので、トル
クロスを低減することができる。しかも、転動体
が案内穴内で転動するので、駆動プーリ側の厚さ
を薄くでき、ベルト伝動装置のコンパクト化を図
ることができる。特に、自転車の駆動系に適用し
た場合には、その耐久性を高め得るばかりでな
く、ペダルの踏出し操作力を軽くでき、自転車自
体の軽量化、コンパクト化を図ることができる
等、実用上優れた効果を有するものである。(Effect of the invention) As explained above, claims 1, 2, 3 or 4
According to the described invention, a driving pulley that transmits power between the driven pulley and the driven pulley by a timing belt,
A first pulley member rotatably supported by the rotating shaft; a ball, roller, etc. disposed on the outer periphery of the first pulley member so as to be eccentric with respect to the axis of the first pulley member; and a second pulley member that engages with the timing belt at the outer periphery, and is connected through an engagement mechanism formed by combining the rolling elements and their guide holes, and as the driving force of the first pulley member increases, the second pulley member By continuously decreasing and changing the eccentricity of the two pulley members with respect to the first pulley member, the rotation of the first pulley member can be transmitted to the second pulley member at a rotation ratio of 1:1 without deceleration, Even in the case of a drive system in which the rotation speed of the drive pulley is increased and transmitted to the driven pulley, the diameter of the drive pulley can be kept small, and the installation space and weight of the drive pulley and thus the belt transmission device can be reduced. In addition, since the structure transmits driving force through engagement between the guide hole and the rolling elements, the structure is simpler than when using bushes and rollers, and costs can be reduced by reducing assembly man-hours. . Furthermore, since the transmission is by rolling elements, even if a large load is suddenly applied, the rolling elements will not be damaged and high durability can be achieved.
Furthermore, since the rolling elements roll within the guide hole, torque loss can be reduced. Moreover, since the rolling elements roll within the guide hole, the thickness on the driving pulley side can be reduced, and the belt transmission device can be made more compact. In particular, when applied to the drive system of a bicycle, it not only increases its durability, but also reduces the force required to press the pedals, making the bicycle itself lighter and more compact. It has excellent effects.

また、特に、請求項２又は４記載の発明では、
案内穴及び転動体が第１プーリ部材又は第２プー
リ部材のデイスク部における表裏側面に配設され
ているので、第１プーリ部材から第２プーリ部材
へ駆動力を伝達する際の力のバランスが良くな
り、トルクロスを低減できるとともに、大きな駆
動力を伝達することができる。 Moreover, especially in the invention according to claim 2 or 4,
Since the guide hole and the rolling elements are arranged on the front and back sides of the disk portion of the first pulley member or the second pulley member, the force balance when transmitting the driving force from the first pulley member to the second pulley member is maintained. This makes it possible to reduce torque loss and transmit large driving force.

さらに、請求項５記載の発明では、転動体の位
置規制を行う転動体保持板が付設されているの
で、案内穴内での転動体の遊びを有効に規制で
き、より安定した回転を得ることができる。 Furthermore, in the invention set forth in claim 5, since a rolling element holding plate for regulating the position of the rolling element is attached, play of the rolling element within the guide hole can be effectively restricted, and more stable rotation can be obtained. can.

[Brief explanation of the drawing]

第１図〜第４図は本発明の第１実施例を示し、
第１図は駆動プーリの縦断面図、第２図は同分解
斜視図、第３図は無負荷状態のベルト伝動装置を
示す一部破断正面図、第４図は同負荷状態を示す
一部破断正面図である。第５図は第３実施例を示
す第１図相当図である。第６図はボール保持板の
斜視図である。第７図及び第８図は第４実施例を
示し、第７図は第１図相当図、第８図は第２図相
当図である。第９図は第５実施例における第１図
相当図である。第１０図はローラ保持板の斜視図
である。第１１図は従来例を示す第４図相当図で
ある。１…駆動軸（回転軸）、２…従動軸（回転軸）、
３，３′，３″，３…駆動プーリ、４，４′…第
１プーリ部材、５…ボス部、６，６′…デイスク
部、６a′…貫通孔、７，７′…第２プーリ部材、
８…プーリ部、８ａ…歯部、１０，１０′，１１，
１１′…側面板、１０ａ，１１ａ…貫通孔、１２，
１２′…係合機構、１３，１３′，１４，１４′…
ボール案内穴、１５…ボール（転動体）、１６…
従動プーリ、１７…ボール保持板（転動体保持
板）、１７ａ…保持孔、１８，１８′，１９，１
９′…ローラ案内穴、２０…ローラ（転動体）、２
１…ローラ保持板（転動体保持板）、２１ａ…保
持孔、Ｂ…タイミングベルト、O₁…第１プーリ
部材の軸心、O₂…第２プーリ部材の軸心、O₃…
従動軸の軸心、ｐ…軸心O₁，O₂を通る平面、l_A
…軸心O₁，O₃を結ぶ直線。 1 to 4 show a first embodiment of the present invention,
Fig. 1 is a longitudinal sectional view of the drive pulley, Fig. 2 is an exploded perspective view of the same, Fig. 3 is a partially cutaway front view showing the belt transmission in an unloaded state, and Fig. 4 is a partially cutaway view showing the belt transmission in the same loaded state. FIG. FIG. 5 is a diagram corresponding to FIG. 1 showing the third embodiment. FIG. 6 is a perspective view of the ball holding plate. 7 and 8 show the fourth embodiment, with FIG. 7 being a diagram corresponding to FIG. 1, and FIG. 8 being a diagram corresponding to FIG. 2. FIG. 9 is a diagram corresponding to FIG. 1 in the fifth embodiment. FIG. 10 is a perspective view of the roller holding plate. FIG. 11 is a diagram corresponding to FIG. 4 showing a conventional example. 1... Drive shaft (rotating shaft), 2... Driven shaft (rotating shaft),
3, 3', 3'', 3... Drive pulley, 4, 4'... First pulley member, 5... Boss part, 6, 6'... Disc part, 6a'... Through hole, 7, 7'... Second pulley Element,
8...Pulley part, 8a...Tooth part, 10, 10', 11,
11'...Side plate, 10a, 11a...Through hole, 12,
12'...Engagement mechanism, 13, 13', 14, 14'...
Ball guide hole, 15...Ball (rolling element), 16...
Driven pulley, 17... Ball holding plate (rolling element holding plate), 17a... Holding hole, 18, 18', 19, 1
9'...Roller guide hole, 20...Roller (rolling element), 2
1... Roller holding plate (rolling element holding plate), 21a... Holding hole, B... Timing belt, O ₁ ... Axis center of first pulley member, O ₂ ... Axis center of second pulley member, O ₃ ...
Axis center of driven shaft, p...Plane passing through axes O ₁ and O ₂ , l _A
...A straight line connecting the axes O ₁ and O ₃ .

Claims

[Claims] 1. A driving and driven pulley consisting of a pair of rotating shafts parallel to each other, toothed pulleys supported by the rotating shafts, and a drive and driven pulley that is wound between the two pulleys and connected between the rotating shafts. and a timing belt for transmitting power, and the driving pulley includes a first pulley member in the shape of a disc that is rotatably supported on a rotating shaft, and a second pulley member that is engaged with the first pulley member. The first pulley member includes a disk portion whose inner periphery is a disk that is rotatably attached to the rotating shaft, while the second pulley member is disposed on the outer periphery of the first pulley member and has an inner diameter. a substantially ring-shaped pulley part formed to be larger than the outer diameter of the disc part and having teeth on the outer periphery that mesh with the timing belt; and a pulley part disposed on both sides of the disc part so as to sandwich the disc part; is rotatably fixed to the pulley portion and includes a pair of side plates consisting of a disc having a through hole in the center through which the rotating shaft can be inserted, and a plurality of side plates are provided on the inner surface of the one side plate. A bottomed second pulley side guide hole is provided on a circumference concentric with the side plate and spaced at equal angular intervals. A plurality of bottomed first pulley side guide holes having approximately the same diameter as the second pulley side guide holes are provided corresponding to the second pulley side guide holes, and guide holes are provided in both of the mutually opposing guide holes. A rolling element having a diameter smaller than the bore diameter is fitted with each half facing both guide holes, and the rolling of each of the rolling elements in the guide hole causes the second pulley member to be eccentric by a predetermined amount with respect to the first pulley member. A belt transmission device having an automatic tension adjustment mechanism. 2. A pair of rotating shafts parallel to each other, driving and driven pulleys each consisting of a toothed pulley supported by the rotating shafts, and a timing belt that is wound between the two pulleys and transmits power between the two rotating shafts. The drive pulley includes a disc-shaped first pulley member rotatably supported by a rotating shaft, and a second pulley member engaged with the first pulley member; The member includes a disk portion whose inner periphery is a disk rotatably attached to the rotating shaft, and the second pulley member is disposed on the outer periphery of the first pulley member and whose inner diameter is the outer diameter of the disk portion. a substantially ring-shaped pulley portion having a tooth portion on its outer periphery that engages with the timing belt; and a pulley portion disposed on both sides of the disc portion so as to sandwich the disc portion, and whose outer periphery rotates on the pulley portion. and a pair of side plates made of a disc that are fixed together and have a through hole in the center through which the rotating shaft can be inserted, and a plurality of bottomed second pulleys are provided on the inner surfaces of each of the side plates. The side guide holes are provided on a circumference concentric with the side plate and spaced at equal angular intervals, while the second guide holes are provided on both sides of the disk portion, respectively.
A plurality of bottomed first pulley side guide holes having approximately the same diameter as the pulley side guide holes are provided corresponding to the second pulley side guide holes, and the mutually opposing guide holes have a diameter larger than the opening diameter of the guide hole. A small diameter rolling element is fitted with each half facing each guide hole, and the second pulley member can be eccentric by a predetermined amount with respect to the first pulley member by rolling of each of the rolling elements in the guide hole. A belt transmission device having an automatic tension adjustment mechanism. 3. A pair of rotating shafts parallel to each other, driving and driven pulleys each consisting of a toothed pulley supported by the rotating shafts, and a timing belt that is wound between the two pulleys and transmits power between the two rotating shafts. The drive pulley includes a disc-shaped first pulley member rotatably supported by a rotating shaft, and a second pulley member engaged with the first pulley member; The member includes a pair of side plates that are arranged opposite to each other at a predetermined interval in the axial direction, and each of which has an inner periphery that is rotatably attached to the rotating shaft. A generally ring-shaped pulley part is disposed on the outer periphery of the pulley member, has an inner diameter larger than the outer diameter of the side plate, and has teeth on the outer periphery that mesh with the timing belt, and is loosely fitted between the both side plates. , and a disk portion having an outer peripheral edge rotatably fixed to the pulley portion and having a through hole in the center through which the rotating shaft can be inserted; A plurality of bottomed first pulley side guide holes are provided on a circumference concentric with the side plate and spaced at equal angular intervals. A plurality of bottomed second pulley side guide holes having approximately the same diameter as the first pulley side guide holes are provided corresponding to the first pulley side guide holes, and the two mutually opposing guide holes have guide holes. A rolling element having a diameter smaller than the opening diameter is fitted with each half facing both guide holes, and the rolling of each of the rolling elements in the guide hole causes the second pulley member to move a predetermined amount relative to the first pulley member. A belt transmission device having an automatic tension adjustment mechanism, characterized in that it is configured to be eccentric. 4 A pair of rotating shafts parallel to each other, driving and driven pulleys each consisting of a toothed pulley supported by the rotating shafts, and a timing belt that is wound between the two pulleys and transmits power between the two rotating shafts. The drive pulley includes a disc-shaped first pulley member rotatably supported by a rotating shaft, and a second pulley member engaged with the first pulley member; The member includes a pair of side plates that are arranged opposite to each other at a predetermined interval in the axial direction, and each of which has an inner periphery that is rotatably attached to the rotating shaft. A generally ring-shaped pulley part is disposed on the outer periphery of the pulley member, has an inner diameter larger than the outer diameter of the side plate, and has teeth on the outer periphery that mesh with the timing belt, and is loosely fitted between the both side plates. , and a disk portion consisting of a disk whose outer peripheral edge is rotatably fixed to the pulley portion and has a through hole in the center through which the rotation shaft can be inserted, and each of the inner surfaces of the both side plates includes a plurality of disc portions. The bottomed first pulley side guide holes are provided on a circumference concentric with the side plate and spaced at equal angular intervals, while the first pulley side guide holes are provided on both sides of the disc portion, respectively.
A plurality of bottomed second pulley-side guide holes having approximately the same diameter as the pulley-side guide holes are provided corresponding to the first pulley-side guide holes, and the mutually opposing guide holes have a diameter larger than the opening diameter of the guide hole. A small diameter rolling element is fitted with each half facing each guide hole, and the second pulley member can be eccentric by a predetermined amount with respect to the first pulley member by rolling of each of the rolling elements in the guide hole. A belt transmission device having an automatic tension adjustment mechanism. 5. Claims 1, 2, and 3, characterized in that a rolling element holding plate having a holding hole for rollably holding the rolling element is disposed between the disk portion and the side plate.
Or a belt transmission device having the automatic tension adjustment mechanism according to 4. 6. A belt transmission device having an automatic tension adjustment mechanism according to claim 1, 2, 3, 4 or 5, wherein the rolling elements are balls. 7. A belt transmission device having an automatic tension adjustment mechanism according to claim 1, 2, 3, 4 or 5, wherein the rolling elements are rollers. 8. The belt transmission device with an automatic tension adjustment mechanism according to claim 7, wherein the roller is cylindrical, conical, or drum-shaped.