JPH02199330A - Power transmission mechanism - Google Patents

Abstract

PURPOSE:To prevent lowering of torque transmission by providing the second working piston which is assembled slidably in the axial direction between a retainer and the first working piston to be brought into contact with the first working piston and in which a compartment communicating with a circular clutch chamber is formed at the part on the opposite side to the first working piston. CONSTITUTION:In a power transmission mechanism 10, when the number of differential rotations of both propeller shafts 25 and 26 is large, as a frictional clutch 10b is frequently frictionally-engaged and frictional engaging force is large, the temperature inside a clutch chamber R1 becomes high. Therefore, pressure in the chamber R1 is raised, but as the chamber R1 communicates with a compartment R2, pressure in the compartment R2 becomes the same as that pressure. As a result, the pressure in the compartment R2 pressurizes the second working piston 14 and pressurizes the first working piston 13, but since this pressurizing force is almost the same as the pressurizing force that the pressure in the chamber R1 pressurizes the piston 13, and since both the pressurizing forces working on the piston 13 are offset by each other, lowering of torque transmission caused by pressure rise in the chamber R1 can be prevented.

Description

【発明の詳細な説明】 （産業上の利用分野） 本発明は、同軸的かつ相対回転可能に位置する内外両回
転部材間に配設されて、これら両部材間のトルク伝達を
行う動力伝達機構に関する。Detailed Description of the Invention (Industrial Application Field) The present invention relates to a power transmission mechanism that is disposed between an inner and an outer rotating member that are coaxially and relatively rotatably located, and that transmits torque between these members. Regarding.

（従来技術） かかる動力伝達機構は、駆動側回転部材と従動側回転部
材間に配設されてこれら両部材の相対回転時これら両部
材を互にトルク伝達可能に連結して、従動側回転部材を
駆動させる連結機構として使用されるものと、駆動側お
よび従動側回転部材間、両駆動側回転部材間または両従
動側回転部材間に配設されてこれら両部材の相対回転時
これら両部材を互にトルク伝達可能に連結して、これら
両部材間の回転差を制限させる差動制限機構として使用
されるもの等に大別される。前者の連結機構は主として
リャルタイム式の四輪駆動車における一方の動力伝達系
路に配設され、また後者の差動制限機構は主として車両
における各ディファレンシャルに配設される。(Prior Art) Such a power transmission mechanism is arranged between a driving side rotating member and a driven side rotating member, and connects these two members so that torque can be transmitted to each other when these two members rotate relative to each other. A coupling mechanism that is used as a coupling mechanism to drive the drive side and a driven side rotating member, or between both driving side rotating members, or between both driven side rotating members, and when these two members rotate relative to each other. These members are broadly classified into those used as differential limiting mechanisms that are connected to each other so as to transmit torque and limit the rotational difference between these two members. The former coupling mechanism is mainly disposed on one power transmission path in a real-time four-wheel drive vehicle, and the latter differential limiting mechanism is mainly disposed on each differential in the vehicle.

しかして、従来の動力伝達機構としては特開昭６３−２
４０４２９号公報に示されているように、同軸的かつ相
対回転可能に位置する内外両回転部材間に配設され、こ
れら両回転部材の相対回転により作動して両回転部材を
トルク伝達可能に連結する摩擦係合力を発生させるとと
もに付与される押圧力に応じて前記摩擦係合力を増減さ
せる湿式摩擦クラッチ、および両回転部材の相対回転に
応じた押圧力を発生させて前記摩擦クラッチに付与する
押圧力発生手段を備え、同押圧力発生手段を、前記両回
転部材間に液密的に軸方向へ摺動可能かつ外側回転部材
に一体回転可能に組付けられて前記摩擦クラッチに当接
する作動ピストンと、前記外側回転部材に一体回転可能
に設けられて前記作動ピストンとの間に軸方向に所定間
隔を有して粘性流体が封入される流体室を形成するリテ
ーナと、半径方向へ延びる１または複数のベーン部を備
え前記流体室にて内側回転部材に一体的に組付けられた
ロータとにより構成してなる動力伝達機構がある。However, as a conventional power transmission mechanism, JP-A-63-2
As shown in Japanese Patent No. 40429, it is disposed between both the inner and outer rotating members that are coaxially and relatively rotatably located, and is actuated by the relative rotation of these two rotating members to connect the two rotating members so that torque can be transmitted. A wet friction clutch that generates a frictional engagement force and increases or decreases the frictional engagement force according to the applied pressing force, and a pressing force that generates a pressing force corresponding to the relative rotation of both rotating members and applies to the friction clutch. an actuating piston comprising a pressure generating means, the pressing force generating means being able to slide liquid-tightly in the axial direction between the two rotary members and integrally rotatable with the outer rotary member, and abutting the friction clutch; a retainer that is provided to be integrally rotatable with the outer rotary member and that has a predetermined distance between it and the actuating piston and forms a fluid chamber in which a viscous fluid is sealed; There is a power transmission mechanism including a rotor having a plurality of vane parts and integrally assembled to an inner rotating member in the fluid chamber.

この種形式の動力伝達機構においては、両回転部材間に
相対回転が生じると外側回転部材に一体回転可能に組付
けた作動ピストンおよびリテーナと、内側回転部材に一
体的に組付けたロータとの間に相対回転が生じ、流体室
の前記ロータのベーン部にて区画された粘性流体封入室
内の粘性流体が強制的に流動させられ、封入室内では流
動抵抗等に起因して圧力が発生する。すなわち、押圧力
発生手段に差動回転数に応じた圧力が発生する。In this type of power transmission mechanism, when relative rotation occurs between both rotating members, an operating piston and a retainer are integrally assembled to the outer rotating member and a rotor is integrally assembled to the inner rotating member. Relative rotation occurs during this time, and the viscous fluid in the viscous fluid enclosure chamber defined by the vane portion of the rotor of the fluid chamber is forced to flow, and pressure is generated within the enclosure chamber due to flow resistance or the like. That is, a pressure corresponding to the differential rotation speed is generated in the pressing force generating means.

この圧力は作動ピストンを軸方向に押圧して摩擦クラッ
チを押圧させ、同クラッチに両回転部材をトルク伝達可
能に連結する摩擦係合力を発生させる。かかる摩擦係合
力は差動回転数に比例し、両回転部材間では差動回転数
に比例したトルクが一方から他方へ伝達される。従って
、当該動力伝達機構は四輪駆動車の一方の動力伝達系路
における駆動側回転部材と従動側回転部材との連結機構
として機能するとともに、駆動側および従動側回転部材
間、両駆動側回転部材間または両従動側回転部材間の差
動制限機構としても機能する。This pressure pushes the actuating piston in the axial direction, causing the friction clutch to be pressed and generating a frictional engagement force in the clutch that connects both rotating members in a torque-transmitting manner. This frictional engagement force is proportional to the differential rotation speed, and a torque proportional to the differential rotation speed is transmitted between the two rotating members from one side to the other. Therefore, the power transmission mechanism functions as a coupling mechanism between the driving-side rotating member and the driven-side rotating member in one power transmission path of the four-wheel drive vehicle, and also functions as a coupling mechanism between the driving-side and driven-side rotating members. It also functions as a differential limiting mechanism between members or between both driven rotating members.

（発明が解決しようとする課題） ところで、上記した形式の動力伝達機構においては、両
回転部材間の相対回転が増大すると摩擦クラッチの頻繁
な摩擦係合と摩擦係合力の増大によりクラッチ室内のク
ラッチオイルが高温となり、同クラッチ室内の気体が増
太しがっ膨張して内圧が上昇し、この内圧が作動ピスト
ンを逆方向に押圧して同ピストンの摩擦クラッチに対す
る押圧力を低下させ、トルク伝達を低下させる。クラッ
チ室の内圧上昇は経時的に増大するクラッチオイルの分
解ガスによっても生じトルク伝達を低下させる。(Problems to be Solved by the Invention) In the above-mentioned type of power transmission mechanism, when the relative rotation between the two rotating members increases, the frictional engagement of the friction clutch increases and the frictional engagement force increases, causing the clutch in the clutch chamber to As the oil becomes hot, the gas inside the clutch chamber increases in size and expands, increasing the internal pressure. This internal pressure pushes the operating piston in the opposite direction, reducing the piston's pressing force against the friction clutch, and transmitting torque. decrease. The increase in internal pressure in the clutch chamber is also caused by decomposed gas from clutch oil that increases over time, reducing torque transmission.

従って、本発明の目的は、かかる形式の動力伝達機構に
おいてクラッチ室内の圧力上昇に起因するトルク伝達の
低下を防止することにある。Therefore, an object of the present invention is to prevent a decrease in torque transmission due to an increase in pressure within the clutch chamber in this type of power transmission mechanism.

（課題を解決するための手段） 本発明は上記した形式の動力伝達機構であって前記押圧
力発生手段を、前記両回転部材間に液密的かつ外側回転
部材に一体的または一体回転可能に設けたリテーナと、
前記外側回転部材に一体回転可能かつ軸方向へ摺動可能
に組付けられて前記摩擦クラッチに当接するとともに前
記リテーナとの間に軸方向に所定間隔を有して粘性流体
が封入される流体室を形成する第１の作動ピストンと、
半径方向へ延びる１まなは複数のベーン部を備え前記流
体室にて内側回転部材に一体的に組付けられたロータと
、前記リテーナと第１の作動ピストン間に軸方向へ摺動
可能に組付けられて同作動ピストンに当接するとともに
同作動ピストンとは反対側の部位にて前記リテーナとの
間に前記摩擦クラッチを収容する環状のクラッチ室に連
通ずる隔室を形成する第２の作動ピストンにより構成し
てなる動力伝達機構にある。(Means for Solving the Problems) The present invention provides a power transmission mechanism of the type described above, in which the pressing force generating means is fluid-tight between the two rotating members and integrally or rotatably with the outer rotating member. With the provided retainer,
a fluid chamber that is attached to the outer rotating member so as to be integrally rotatable and slidable in the axial direction, abuts the friction clutch, and is spaced apart from the retainer by a predetermined distance in the axial direction, and is filled with a viscous fluid; a first actuating piston forming a
A rotor including one or more vane portions extending in the radial direction and integrally assembled to the inner rotating member in the fluid chamber, and a rotor that is slidably assembled in the axial direction between the retainer and the first working piston. a second actuating piston that is attached and abuts the actuating piston, and forms a compartment communicating with the annular clutch chamber that accommodates the friction clutch between the actuating piston and the retainer at a portion opposite to the actuating piston; The power transmission mechanism is comprised of:

（発明の作用・効果） かかる構成によれば、クラッチ室内の圧力が上昇すると
クラッチ室に連通ずるリテーナおよび第２の作動ピスト
ン間の隔室内の圧力も上昇し、これら両室内の圧力は常
に路間−となる。従って、クラッチ室内の圧力に対する
第１の作動ピストンの受圧面積と隔室内の圧力に対する
第２の作動ピストンの受圧面積とを路間−にすれば、ク
ラッチ室内の圧力による第１の作動ピストンの押圧力に
起因するトルク伝達の低下が防止される。また、両作動
ピストンの受圧面積を路間−に形成しなくとも、上記し
たトルク伝達の低下は十分に抑制される。(Operations and Effects of the Invention) According to this configuration, when the pressure in the clutch chamber increases, the pressure in the compartment between the retainer and the second actuating piston, which communicate with the clutch chamber, also increases, and the pressure in both chambers is always maintained at a constant level. Between. Therefore, if the pressure-receiving area of the first actuating piston with respect to the pressure in the clutch chamber and the pressure-receiving area of the second actuating piston with respect to the pressure in the compartment are set to be -, the pressure in the first actuating piston due to the pressure in the clutch chamber will be reduced. A reduction in torque transmission due to pressure is prevented. Further, even if the pressure receiving area of both working pistons is not formed between the pistons, the above-mentioned decrease in torque transmission can be sufficiently suppressed.

（実施例） 以下本発明の実施例を図面に基づいて説明するに、第１
図には本発明にかかる動力伝達機構の一実施例が示され
ている。当該動力伝達機構１０は第３図に示すように、
リャルタイム式の四輪駆動車の後輪側動力伝達系路に配
設される。(Example) Examples of the present invention will be described below based on the drawings.
The figure shows an embodiment of the power transmission mechanism according to the present invention. The power transmission mechanism 10, as shown in FIG.
It is installed in the rear wheel power transmission line of real-time four-wheel drive vehicles.

当該車両は前輪側が常時駆動するとともに後輪側が必要
時駆動するもので、エンジン２１の一側に組付けたトラ
ンスアクスル２２はトランスミッションおよびトランス
ファを備え、エンジン２１からの動力をアクスルシャフ
ト２３に出力して前輪２４を駆動させるとともに、第１
プロペラシヤフト２５に出力する。第１プロペラシヤフ
ト２５は動力伝達機構１０を介して第２プロペラシヤフ
ト２６に連結していて、これら両シャフト２５．２６が
動力伝達可能な場合動力がリヤディファレンシャル２，
７を介してアクスルシャフト２８に出力され、後輪２９
が駆動する。In this vehicle, the front wheels are always driven and the rear wheels are driven when necessary. A transaxle 22 attached to one side of an engine 21 is equipped with a transmission and a transfer, and outputs power from the engine 21 to an axle shaft 23. to drive the front wheels 24, and the first
Output to propeller shaft 25. The first propeller shaft 25 is connected to the second propeller shaft 26 via the power transmission mechanism 10, and when both shafts 25 and 26 can transmit power, the power is transmitted to the rear differential 2,
7 to the axle shaft 28, and the rear wheel 29
is driven.

しかして、動力伝達機構１０はアウタケース１１および
インナシャフト１２からなる環状の作動室内に押圧力発
生手段１０ａおよび摩擦クラッチ１０ｂを備えている。Thus, the power transmission mechanism 10 includes a pressing force generating means 10a and a friction clutch 10b within an annular working chamber made up of an outer case 11 and an inner shaft 12.

アウタケース１１は所定長さの筒部１１ａの一端に内向
フランジ部１１ｂを備えてなり、筒部］１ａの他端が開
口していて他端側内周にネジ部１１ｃが形成されている
。インナシャフト１２は所定長さの段付きの筒部１２ａ
の中間部外周に外向フランジ部１２ｂを備えてなり、フ
ランジ部１２ｂの外周には軸方向へ延びる外スプライン
部１２Ｃが形成され、かつ筒部１２ａの一端側内周には
軸方向へ延びる内スプライン部１２ｄが形成されている
。かかるインナシャフト１２においては、その節部１２
ａの一端がアウタケース１１の内向フランジ部１１ｂの
内孔内に液密的かつ回転可能に嵌合されていて、筒部１
２ａの他端側外周に組付けた後述の押圧力発生手段１０
ａの構成部材を介してアウタケース１１に回転可能に支
持されている。インナシャフト１２はその内スプライン
１２ｄにて第２プロペラシヤフト２６の先端部のスプラ
イン２６ａに嵌合して固定され、かつアウタケース１１
は第１プロペラシヤフト２５の後端に固定されている。The outer case 11 includes an inward flange portion 11b at one end of a cylindrical portion 11a having a predetermined length, the other end of the cylindrical portion 1a is open, and a threaded portion 11c is formed on the inner periphery of the other end. The inner shaft 12 has a stepped cylindrical portion 12a having a predetermined length.
An outward flange portion 12b is provided on the outer periphery of the intermediate portion of the flange portion 12b, and an outer spline portion 12C extending in the axial direction is formed on the outer periphery of the flange portion 12b, and an inner spline portion 12C extending in the axial direction is formed on the inner periphery of one end side of the cylindrical portion 12a. A portion 12d is formed. In such an inner shaft 12, the knot portion 12
One end of a is fluid-tightly and rotatably fitted into the inner hole of the inward flange portion 11b of the outer case 11, and the cylindrical portion 1
Pushing force generating means 10, which will be described later, is assembled on the outer periphery of the other end of 2a.
It is rotatably supported by the outer case 11 via the component a. The inner shaft 12 is fixed at its inner spline 12 d by fitting into the spline 26 a at the tip of the second propeller shaft 26 , and the outer case 11
is fixed to the rear end of the first propeller shaft 25.

押圧力発生手段１０ａは第１、第２作動ピストン１３．
１４、ロータ１５および第１、第２リテーナ１６．１７
からなり、かつ摩擦クラッチ１０ｂは湿式多板クラッチ
式のもので、多数のクラッチプレート１８ａおよびクラ
ッチディスク１８ｂからなる。各クラッチプレート１８
ａはその外周の凸起部をアウタケース１１の内周に設け
た溝部ｌｉｄに嵌合されて、同ケース１１に一体回転可
能かつ軸方向へ移動可能に組付けられている。各クラッ
チディスク１８ｂはその内周の凸起部をインナシャフト
１２の外スプライン部１２ｃに嵌合されて各クラッチプ
レート１８ａ間に位置し、同シャフト１２に一体回転可
能かつ軸方向へ移動可能に組付けられている。これらの
クラッチプレート１８ａおよびクラッチディスク１８ｂ
を収容するクラッチ室Ｒ１には、クラッチ用オイルと気
体とが所定量封入されている。The pressing force generating means 10a includes first and second working pistons 13.
14, rotor 15 and first and second retainers 16.17
The friction clutch 10b is of a wet type multi-plate clutch type, and consists of a large number of clutch plates 18a and clutch discs 18b. Each clutch plate 18
The protrusion on the outer periphery of a is fitted into a groove lid provided on the inner periphery of the outer case 11, and is assembled to the case 11 so as to be integrally rotatable and movable in the axial direction. Each clutch disk 18b has a convex portion on its inner circumference fitted into an outer spline portion 12c of the inner shaft 12, and is positioned between each clutch plate 18a, and is assembled to the shaft 12 so as to be rotatable integrally and movable in the axial direction. It is attached. These clutch plates 18a and clutch discs 18b
A predetermined amount of clutch oil and gas are sealed in the clutch chamber R1 that accommodates the clutch.

押圧力発生手段１０ａを構成する第１作動ピストン１３
はアウタケース１１の筒部１１ａ内周に一体回転可能か
つ軸方向へ摺動可能に、またインナシャフト１２に対し
てはその外周に液密的に回転可能かつ軸方向へ摺動可能
にそれぞれ組付けられていて、その−側面１３ａにて最
他端のクラッチプレート１８ａに当接している。ロータ
１５は第１図および第２図に示すように、環状ボス部１
５ａの外周の互に１８０°離れた部位にて半径方向へ延
びる２枚のベーン部１５ｂを備えてなり、環状ボス部１
５ａにてインナシャフト１２の筒部１２ａ外周に嵌合さ
せてインナシャフト１２に一体的に組付けられている。First actuating piston 13 constituting the pressing force generating means 10a
are mounted on the inner periphery of the cylindrical portion 11a of the outer case 11 so as to be integrally rotatable and slidable in the axial direction, and on the outer periphery of the inner shaft 12 in a liquid-tight manner so as to be rotatable and slidable in the axial direction. The clutch plate 18a at the other end is in contact with the clutch plate 18a at its negative side 13a. As shown in FIGS. 1 and 2, the rotor 15 has an annular boss portion 1.
The annular boss portion 1 is provided with two vane portions 15b extending in the radial direction at portions 180° apart from each other on the outer periphery of the annular boss portion 1.
It is integrally assembled to the inner shaft 12 by being fitted onto the outer periphery of the cylindrical portion 12a of the inner shaft 12 at 5a.

かかるロータ１５においては、その厚みが第１作動ピス
トン１３の他側に設けた環状の小径凹所１３ｂの深さと
略同じ厚みに形成されていて、小径凹所１３ｂ内に嵌合
している。第１リテーナ１６は第１作動ピストン１３の
環状の大径凹所１３ｃ内に液密的に嵌着され、インナシ
ャフト１２の外周に対しては液密的かつ回転可能に嵌合
されている。第２作動ピストン１４は筒部１４ａの他端
に内向フランジ部１４ｂを備えた筒状のもので、筒部１
４ａがアウタケース１１の内周と第１作動ピストン１３
の外周間に液密的かつ軸方向へ摺動可能に嵌合され、ま
た内向フランジ部１４ｂが第１リテーナ１６の筒部１６
ａの外周に液密的かつ軸方向へ摺動可能に嵌合されてい
て、第１作動ピストン１３に当接している。The rotor 15 has a thickness substantially equal to the depth of an annular small-diameter recess 13b provided on the other side of the first working piston 13, and is fitted into the small-diameter recess 13b. The first retainer 16 is fluid-tightly fitted into the annular large-diameter recess 13c of the first working piston 13, and is fluid-tightly and rotatably fitted to the outer periphery of the inner shaft 12. The second actuating piston 14 has a cylindrical shape with an inward flange 14b at the other end of the cylindrical portion 14a.
4a is the inner circumference of the outer case 11 and the first working piston 13
The inward flange portion 14b is fitted liquid-tightly and slidably in the axial direction between the outer peripheries of the first retainer 16.
It is fitted onto the outer periphery of the piston a in a fluid-tight manner and slidable in the axial direction, and is in contact with the first actuating piston 13.

第２リテーナ１７はその他端側外周にネジ部１７ａを備
え、インナシャフト１２の筒部１２ａの他端側外周に液
密的に軸方向へ摺動可能かつ回転可能に嵌合され、アウ
タケース１１に対してはそのネジ部１７ａをアウタケー
ス１１のネジ部１１．　Ｃに進退可能に螺着され、かつ
液密的となっている。The second retainer 17 has a threaded portion 17a on the outer periphery of the other end, and is fluid-tightly fitted to the outer periphery of the other end of the cylindrical portion 12a of the inner shaft 12 so as to be slidable and rotatable in the axial direction. , the threaded portion 17a is connected to the threaded portion 11. of the outer case 11. It is screwed onto C so that it can move forward and backward, and is liquid-tight.

かかるリテーナ１７においては、軸方向の位置調整がな
されてアウタケース１１にカシメ手段にて固定されると
ともに、第１リテーナＪ６の筒部１６ａの他端外周部に
液密的に嵌着されている。これにより、第２リテーナ１
７の一側面と第２作動ピストン１４の他側面間に第１隔
室Ｒ２が形成されているとともに、第２作動ピストン１
４の一側面と第１リテーナ１６の他側面間に第２隔室Ｒ
３が形成されており、かつ第１リテーナ１６の一側面と
第１作動ピストン１３の小径凹所１３ｂとによりロータ
１５が位置する流体室を形成している。In this retainer 17, the position in the axial direction is adjusted and fixed to the outer case 11 by caulking means, and the retainer 17 is fitted in a liquid-tight manner to the outer circumference of the other end of the cylindrical portion 16a of the first retainer J6. . As a result, the second retainer 1
A first compartment R2 is formed between one side of the second working piston 14 and the other side of the second working piston 14.
4 and the other side of the first retainer 16.
3 is formed, and one side of the first retainer 16 and the small diameter recess 13b of the first working piston 13 form a fluid chamber in which the rotor 15 is located.

この流体室内にはシリコンオイル等高粘性流体が所定量
封入されており、またロータ１５はそのベーン部１５ｂ
の外周を小径凹所１３ｂの内周に液密的に接触させ、か
つベーン部１５ｂの両側面と小径凹所１３ｂの他側面お
よびリテーナ１５の一側面間に微小間隙を形成して、流
体室内を２つの滞留室Ｒ４に区画している。また、第１
隔室Ｒ２は第２作動ピストン１４の筒部１４ａの外周に
設けた軸方向に延びる凹溝１４ｃを通してクラッチ室Ｒ
１に連通し、かつ第２隔室Ｒ３は第１リテーナ１６の筒
部１６ａに設けた通孔１６ｂおよびインナシャフト１２
の筒部１２ａに設けた通孔１２ｅを通して外部に連通し
ている。A predetermined amount of highly viscous fluid such as silicone oil is sealed in this fluid chamber, and the rotor 15 has its vane portion 15b.
The outer periphery of the vane portion 15b is brought into liquid-tight contact with the inner periphery of the small diameter recess 13b, and a minute gap is formed between both sides of the vane portion 15b, the other side of the small diameter recess 13b, and one side of the retainer 15, so that the fluid chamber is divided into two retention chambers R4. Also, the first
The compartment R2 is connected to the clutch chamber R through an axially extending concave groove 14c provided on the outer periphery of the cylindrical portion 14a of the second actuating piston 14.
1, and the second compartment R3 is connected to the through hole 16b provided in the cylindrical portion 16a of the first retainer 16 and the inner shaft 12.
It communicates with the outside through a through hole 12e provided in the cylindrical portion 12a.

かかる構成の動力伝達機構１０においては、第１、第２
両プロペラシャフト２５．２６間に相対回転が生じてい
ない場合にはこれら両シャフト２５．２６間のトルク伝
達はないが、両シャフト２５．２６間に相対回転が生じ
るとトルク伝達がなされる。すなわち、これら両シャフ
ト２５．２６間に相対回転が生じると、第１プロペラシ
ヤフト２５に一体回転可能に組付けられているアウタケ
ース１１、第１、第２作動ピストン１３．１４および第
１、第２リテーナ１６．１７と、第２１０ベラシヤフト
２６に一体回転可能に組付けられているインナシャフト
１２およびロータ１５との間に相対回転が生じる。従っ
て、押圧力発生手段１０ａの流体室内においては、滞留
室Ｒ４内の粘性流体が相対回転数に比例した速度にて強
制的に流動させられ、周方向に順次相対移行する滞留室
Ｒ４内では流動抵抗に起因してベーン部１５ｂの下流側
端から次のベーン部］、　５　ｂの上流側端に向って漸
次増圧される圧力分布が発生する。この圧力分布の増圧
部分は差動回転数に比例して増大するもので、第１作動
ピストン１３を軸方向へ押圧して摩擦クラッチ１０ｂを
構成する各クラッチプレート１８ａとクラッチディスク
１８ｂをクラッチ用オイルを介して摩擦係合させる。こ
れにより、摩擦クラッチ１０ｂにおいては差動回転数に
比例したトルクをアウタケース１１がらインナシャツ）
１２に伝達し、車両は４輪駆動状態となる。また、この
４輪駆動状態においては前後輪の差動回転を許容し、タ
イトコーナブレーキング現象の発生も防止される。In the power transmission mechanism 10 having such a configuration, the first and second
When there is no relative rotation between the two propeller shafts 25, 26, there is no torque transmission between the two shafts 25, 26, but when there is relative rotation between the two shafts 25, 26, torque is transmitted. That is, when relative rotation occurs between these two shafts 25, 26, the outer case 11, the first and second operating pistons 13, 14, and the first and Relative rotation occurs between the two retainers 16 and 17 and the inner shaft 12 and rotor 15, which are assembled to the 210th bell shaft 26 so as to be able to rotate together. Therefore, in the fluid chamber of the pressing force generating means 10a, the viscous fluid in the retention chamber R4 is forced to flow at a speed proportional to the relative rotational speed, and the viscous fluid in the retention chamber R4 moves relative to each other sequentially in the circumferential direction. Due to the resistance, a pressure distribution is generated in which the pressure is gradually increased from the downstream end of the vane section 15b to the upstream end of the next vane section. The pressure increase portion of this pressure distribution increases in proportion to the differential rotation speed, and presses the first actuating piston 13 in the axial direction to control each clutch plate 18a and clutch disc 18b constituting the friction clutch 10b. Frictional engagement is achieved through oil. As a result, in the friction clutch 10b, a torque proportional to the differential rotation speed is transmitted from the outer case 11 to the inner shirt).
12, and the vehicle enters the four-wheel drive state. Furthermore, in this four-wheel drive state, differential rotation between the front and rear wheels is allowed, and tight corner braking is also prevented from occurring.

ところで、当該動力伝達機構１０においては、両シャフ
ト２５．２６の差動回転数が大きい場合、摩擦クラッチ
１０ｂは頻繁に摩擦係合されるとともに摩擦係合力が大
きいことからクラッチ室Ｒ１内が高温状態になる。この
ため、クラッチ室Ｒ。By the way, in the power transmission mechanism 10, when the differential rotation speed of both shafts 25 and 26 is large, the friction clutch 10b is frequently frictionally engaged and the frictional engagement force is large, so that the inside of the clutch chamber R1 is in a high temperature state. become. For this reason, the clutch chamber R.

内の圧力が上昇するが、クラッチ室Ｒ，は第１隔室Ｒ２
に連通しているため同隔室Ｒ２内の圧力もクラッチ室Ｒ
１と略同圧となる。この結果、第１隔室Ｒ２内の圧力が
第２作動ピストン１４を押圧して第１作動ピストン１３
を押圧するが、この押圧力はクラッチ室Ｒ１内の圧力が
第１作動ピストン１３を押圧する押圧力と路間−であっ
て同ピストン１３に作用する両押圧力は互に相殺される
ため、クラッチ室Ｒ１内の圧力上昇は第１作動ピストン
１３に対しては何等影響を及ぼさず、クラッチ室Ｒ１内
の圧力上昇に起因するトルク伝達の低下が防止される。Although the pressure inside increases, the clutch chamber R and the first compartment R2
Because it communicates with the clutch chamber R, the pressure in the same compartment R2 is also connected to the clutch chamber R.
The pressure is approximately the same as 1. As a result, the pressure in the first compartment R2 presses the second working piston 14 and the first working piston 13
However, this pressing force is between the pressure in the clutch chamber R1 and the pressing force that presses the first actuating piston 13, and the two pressing forces acting on the piston 13 cancel each other out. The increase in pressure within the clutch chamber R1 has no effect on the first working piston 13, and a decrease in torque transmission due to the increase in pressure within the clutch chamber R1 is prevented.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は本発明の一実施例に係る動力伝達機構の断面図
、第２図は第１図の矢印■−■綴方肉方向面図、第３図
は同機構を採用した車両の概略図である。 符号の説明 １０・・・動力伝達機構、１０ａ・・・押圧力発生手段
、１０ｂ・・・摩擦クラッチ、１トアウタケース、１２
・・・インナシャフト、１３．１４・・・作動ピストン
、１４ｃ・・・凹溝、１５・・・ロータ、１らｂ・・・
ベーン部、１６．１７・・・リテーナ、１８ａ・・・ク
ラッチプレート、１８ｂ・・・クラッチディスク、２５
，２６・・・プロペラシャフト、Ｒ１・・・クラッチ室
、Ｒ２・・・隔室、Ｒ４・・・滞留室。Fig. 1 is a cross-sectional view of a power transmission mechanism according to an embodiment of the present invention, Fig. 2 is a sectional view in the direction of the arrow ■-■ in Fig. 1, and Fig. 3 is a schematic diagram of a vehicle employing the same mechanism. It is. Explanation of symbols 10...Power transmission mechanism, 10a...Pushing force generating means, 10b...Friction clutch, 1-tooth outer case, 12
... Inner shaft, 13.14... Operating piston, 14c... Concave groove, 15... Rotor, 1b...
Vane part, 16.17... Retainer, 18a... Clutch plate, 18b... Clutch disc, 25
, 26... Propeller shaft, R1... Clutch chamber, R2... Compartment chamber, R4... Retention chamber.

Claims (1)

【特許請求の範囲】[Claims] 　同軸的かつ相対回転可能に位置する内外両回転部材間
に配設され、これら両回転部材の相対回転により作動し
て両回転部材をトルク伝達可能に連結する摩擦係合力を
発生させるとともに付与される押圧力に応じて前記摩擦
係合力を増減させる湿式摩擦クラッチ、および両回転部
材の相対回転に応じた押圧力を発生させて前記摩擦クラ
ッチに付与する押圧力発生手段を備え、同押圧力発生手
段を、前記両回転部材間に液密的かつ外側回転部材に一
体的または一体回転可能に設けたリテーナと、前記外側
回転部材に一体回転可能かつ軸方向へ摺動可能に組付け
られて前記摩擦クラッチに当接するとともに前記リテー
ナとの間に軸方向に所定間隔を有して粘性流体が封入さ
れる流体室を形成する第１の作動ピストンと、半径方向
へ延びる１または複数のベーン部を備え前記流体室にて
内側回転部材に一体的に組付けられたロータと、前記リ
テーナと第１の作動ピストン間に軸方向へ摺動可能に組
付けられて同作動ピストンに当接するとともに同作動ピ
ストンとは反対側の部位にて前記リテーナとの間に前記
摩擦クラッチを収容する環状のクラッチ室に連通する隔
室を形成する第２の作動ピストンにより構成してなる動
力伝達機構。It is disposed between the inner and outer rotating members that are coaxially and relatively rotatably positioned, and is actuated by the relative rotation of these rotating members to generate and apply a frictional engagement force that connects the two rotating members so that torque can be transmitted. A wet friction clutch that increases or decreases the frictional engagement force according to the pressing force, and a pressing force generating means that generates a pressing force corresponding to the relative rotation of both rotating members and applies it to the friction clutch, the pressing force generating means a retainer provided liquid-tightly between the two rotating members and integrally or rotatably with the outer rotating member; and a retainer that is assembled to the outer rotating member so as to be integrally rotatable and slidable in the axial direction, and A first actuating piston that contacts the clutch and has a predetermined distance between it and the retainer in the axial direction to form a fluid chamber in which a viscous fluid is sealed, and one or more vane portions that extend in the radial direction. a rotor that is integrally assembled to the inner rotating member in the fluid chamber; and a rotor that is slidably assembled in the axial direction between the retainer and the first working piston and abuts the first working piston; A power transmission mechanism comprising a second actuating piston forming a compartment communicating with an annular clutch chamber housing the friction clutch between the second actuating piston and the retainer at a portion opposite to the retainer.