Valve with thermally insulating coupling and exhaust line comprising such a valve

A valve comprises a kinematic chain having a rotary driving member, a rotary driven member, and an intermediate member. The driving member has a driving contact element in flat or linear abutment on a complementary driving contact element of the intermediate member. The driven member has a driven contact element in flat or linear abutment on a complementary driven contact element of the intermediate member. The complementary driving contact element and the complementary driven contact element (49) together form an angle between 45° and 135°.A driving elastic member urges the driving contact element against the complementary driving contact element.A driven elastic member urges the driven contact element against the complementary driven contact element.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the US national phase of PCT/FR2017/050652, filed Mar. 20, 2017.

TECHNICAL FIELD

The present invention generally relates to valves intended to be used in high-temperature circuits, such as exhaust lines.

More specifically, according to a first aspect, the invention relates to a valve of the type comprising an actuator having a motor shaft, a flap having a drive shaft, and a kinematic chain coupling the drive shaft to the motor shaft in rotation, the kinematic chain comprising:a driving member rotating around a first rotation axis, and connected in rotation to the motor shaft; anda driven member rotating around a second rotation axis substantially aligned with the first rotation axis, and connected in rotation to the drive shaft.

BACKGROUND

Such a valve is, for example, known from WO 2010/103249. This document describes a valve whereof the drive shaft is coupled to the motor shaft by a joint of the Oldham type. Such a joint makes it possible to thermally uncouple the actuator from the drive shaft. It makes it possible to transmit the movement from the motor shaft to the drive shaft while absorbing the geometric variations of the kinematic chain, for example any misalignment of the shafts.

Conversely, when the actuator is equipped with a position sensor, it is not possible to precisely know the position of the flap by using the sensor. Furthermore, the flap of the valve may begin to vibrate, which is a source of noise.

SUMMARY

A valve is provided that does not have the above flaws.

Specifically, a valve of the aforementioned type, further includes a kinematic chain comprising:an intermediate member positioned axially between the driving member and the driven member, the driving member having a driving contact element in planar or linear bearing on a complementary driving contact element of the intermediate member, the driven member having a driven contact element in planar or linear bearing on a complementary driven contact element of the intermediate member, the complementary driving contact element and the complementary driven contact element forming an angle with one another comprised between 45° and 135°;a driving elastic member inserted between the driving member and the intermediate member and urging the driving contact element against the complementary driving contact element;a driven elastic member inserted between the driven member and the intermediate member and biasing the driven contact element against the complementary driven contact element.

Thus, the driving elastic member forces the driving contact element to remain in bearing against the complementary driving contact element. The transmission of movement from the driving member to the intermediate member is homokinetic. Likewise, the driven elastic member forces the driven contact element to remain in bearing against the complementary driven contact element. The transmission of movement between the intermediate member and the driven member is also homokinetic. As a result, it is possible to make an extremely precise determination of the position of the valve flap by using a position sensor located at the actuator.

Furthermore, at the end of travel of the flap, the driving elastic and driven members make it possible to impose a torque on the flap. The latter is urged against the seat serving as end-of-travel stop for the flap. This contributes to reducing the noises emitted by the valve during operation.

Due to the fact that the contact between the driving member, the intermediate member and the driven member is limited to planar or linear areas, the transmission of heat from the drive shaft to the motor shaft is reduced.

The fact that the complementary driving contact element and the complementary driven contact element are substantially perpendicular to one another makes the kinematic chain capable of absorbing assembly allowances, in particular related to the fact that the first rotation axis is not strictly parallel to and aligned with the second rotation axis.

The valve may further have one or more of the features below, considered individually or according to any technical possible combination(s):the driving contact element is substantially radial relative to the first rotation axis and the driven contact element is substantially radial relative to the second rotation axis;the driving member comprises another driving contact element in planar or linear bearing on a complementary driving contact element of the intermediate member, the driven member comprising another driven contact element in planar or linear bearing on another complementary driven contact element of the intermediate member;the complementary driving contact element and the other complementary driving contact element are substantially in the extension of one another;the complementary driven contact element and the other complementary driven contact element are substantially in the extension of one another;the driving elastic member biases the other driving contact element against the other complementary driving contact element;the driven elastic member biases the other driven contact element against the other complementary driven contact element;the driving elastic member biases the driving contact element against the complementary driving contact element along a first direction, and biases the other driving contact element against the other complementary driving contact element along the same first direction;the driven elastic member biases the driven contact element against the complementary driven contact element along a second direction, and biases the other driven contact element against the other complementary driven contact element along the same second direction;the first and second directions are substantially perpendicular to one another.the driving contact element and the other driving contact element are positioned symmetrically relative to the first rotation axis, the driven contact element and the other driven contact element being positioned symmetrically relative to the second rotation axis;the driving elastic member and/or the driven elastic member are preloaded and only deform if a torque greater than 0.1 N·m is transmitted respectively between the driving member and the intermediate member and/or between the driven member and the intermediate member;the flap can be moved by the actuator between extreme positions, the flap abutting against a seat in at least one of the extreme positions;the kinematic chain comprises an elastic device axially biasing the driven member so as to separate it from the driving member.the intermediate member is a plate;the intermediate member includes driving and driven orifices cut out in the plate, the complementary driving contact element and the complementary driven contact element being edges respectively of the driving orifice and the driven orifice, respectively;the driving member and the driven member are plates;the driving contact element and the driven contact element are tabs cut out in the driving member and the driven member, respectively, and engaged in the driving and driven orifices, respectively;the driving contact element and/or the driven contact element include stops limiting the axial movement of the intermediate member relative to the driving and/or driven members;the driving member and the driven member are identical;the driving elastic member and the driven elastic member are identical;the intermediate member has first and second faces opposite one another, these first and second faces being symmetrical to one another such that the intermediate member is capable of being mounted indifferently with the first face facing the driving member and the second face facing the driven member or with the first face facing the driven member and the second face facing the driving member;the intermediate member comprises a fastener of the driving elastic member and/or of the driven elastic member on the intermediate member;the driving elastic member and the driven elastic member are respectively alongside against the driving contact element and against the driven contact element by curved areas, with no protruding edges;the driving and driven members are each an integral sheet;the elastic device is kept in position on the driving member and on the driven member by raised areas of the driving member and the driven member.

According to a second aspect, the invention relates to an exhaust line comprising a valve having the above features.

DETAILED DESCRIPTION

The valve1shown inFIG. 1is suitable for being inserted typically on a vehicle exhaust line. This vehicle is typically a motor vehicle, for example a car or truck.

In a variant, this valve is used in any other high-temperature fluid circuit.

In an exhaust line, the valve1preferably fulfills one of the functions below:improving the acoustics of the vehicle by opening or closing, partially or fully, a duct of the exhaust line, based on the duty point of the engine;improving pollutant emissions, in particular nitrogen oxides, by adjusting the back pressure in the exhaust line, so as to regulate the recirculation rate of the exhaust gases in the engine;orienting the exhaust gases selectively inside or outside an energy recovery member, for example a heat exchanger;orienting the exhaust gases selectively inside or outside and exhaust gas pollution control member.

The valve1comprises an actuator3having a motor shaft5, a flap7having a drive shaft9, and a kinematic chain11rotatably coupling the drive shaft9to the motor shaft5.

Typically, the valve1includes a valve body13inwardly forming a passage14traveled by the high-temperature fluid. The flap7is placed inside the valve body13, and rotated by the actuator3relative to the valve body13.

Typically, the actuator3is fastened to the valve body13by one or several tabs15.

The actuator3is of any suitable type. Typically it is a gear motor, preferably an electric gear motor.

The valve1is, for example, an on-off valve. In this case, the flap7is able to adopt a first extreme position in which the flap prohibits the circulation of the fluid through the valve body. It is also able to adopt a second extreme position, in which the circulation of the fluid through the valve body is allowed.

In a variant, the valve is of the adjustable type, the flap being able to adopt a plurality of intermediate positions partway between the first and second extreme positions. Each intermediate position corresponds to a degree of partial opening, making it possible to vary the passage section offered to the fluid traveling through the valve body13.

The flap7abuts against a seat or a stop in at least one of the extreme positions, typically both extreme positions.

The flap7is arranged in any way possible on the drive shaft9.

For example, the valve1is of the butterfly type, the flap7being fastened to the drive shaft9along a median line of said flap7(seeFIG. 1). In a variant, the valve is of the gate type, the flap being fastened to the drive shaft along an edge of said flap.

The valve body13has any suitable shape. For example, it has a tubular shape, with a circular or rectangular section, or any other suitable section.

In the example shown inFIG. 1, the valve body13is a tube with a circular section.

The valve1comprises at least a first bearing17, arranged so as to guide a first end part19of the drive shaft9in rotation relative to the valve body13.

Typically, the valve further includes a second bearing21, arranged to guide the rotation of a second end part23of the drive shaft9in rotation relative to the valve body13.

The or each bearing17,21is rigidly fastened to the valve body13.

The valve1advantageously includes a sealing member25, rigidly fastened to the first end part19of the shaft.

The sealing member25cooperates with an additional sealing member27to prevent the exhaust gases from leaving the valve and spreading into the environment by passing between the drive shaft9and the first bearing17. The complementary sealing member27belongs to the bearing17or is attached on the bearing17. The sealing member25has a sealing step29bearing slidably against a complementary sealing step31formed on the member27(FIG. 2). The steps29and31completely surround the drive shaft9and are biased axially against one another as will be described below.

The complementary sealing member27has a sealing step30bearing slidably against a complementary sealing step32formed on the bearing17(FIG. 2). The steps30and32completely surround the drive shaft9and are biased axially against one another as will be described below.

The kinematic chain11comprises:a driving member33rotating around a first rotation axis R1, and rotated by the motor shaft5;a driven member35rotating around a second rotation axis R2substantially aligned with the first rotation axis R1, the driven member35rotating the drive shaft9; andan intermediate member37, arranged axially between the driving member33and the driven member35.

Typically, the first rotation axis R1corresponds to the rotation axis of the motor shaft5, the driving member33being fastened to the motor shaft5. In a variant, the first rotation axis R1does not correspond to the rotation axis of the motor shaft5, the driving member33then being rotated by the motor shaft5by a coupling of any suitable type, such as a reduction gear.

Likewise, the second rotation axis R2typically corresponds to the rotation axis of the drive shaft9, the driven member35being fastened to the drive shaft9. In a variant, the second rotation axis R2does not correspond to the rotation axis of the drive shaft9, the driven member35being coupled to the drive shaft9by a coupling of any suitable type, for example a reduction gear.

In the present description, the axial direction corresponds to the direction defined by the first and second axes of rotation R1, R2, which are substantially aligned with one another. This means that the first and second axes of rotation R1, R2together form an angle of less than 10°, preferably less than 5°, and still more preferably less than 3°.

So as to ensure the transmission of the rotational movement from the driving member33to the intermediate member37, the driving member33comprises a driving contact element39in planar or linear bearing on a complementary driving contact element41of the intermediate member37(FIG. 3). Preferably, the driving member33comprises another driving contact element43in planar or linear bearing on another complementary driving contact element45of the intermediate member37(seeFIGS. 3 to 8).

Here, planar or linear bearing refers to a connection with five degrees of freedom, two in translation and three in rotation. The contact between the two contact elements of a same pair is done along a surface substantially having the form of a line or a plane.

The driven member35comprises a driven contact element47in planar or linear bearing on a complementary driven contact element49of the intermediate member37. Advantageously, the driven member35comprises another driven contact element51in planar or linear bearing on another complementary driven contact element53of the intermediate member37.

The driving contact element39and the other driving contact element43are in the extension of one another. More specifically, they fit in a same plane. Typically, they are arranged symmetrically relative to the first rotation axis R1.

Likewise, the driven contact element47and the other driven contact element51are placed in the extension of one another, and more specifically in the same plane. They are typically arranged symmetrically relative to the second rotation axis R2.

The driving contact element39is in a substantially radial plane relative to the first rotation axis R1. The other contact element43is therefore also preferably in a substantially radial plane relative to the axis R1.

The driven contact element47, and preferably also the other driven contact element51, is/are in a radial plane relative to the second rotation axis R2.

As a result, the complementary driving contact element41and the other complementary driving contact element45are also in the extension of one another, more specifically aligned with one another. The complementary driven contact element49and the other complementary driven contact element53are substantially in the extension of one another, and more specifically are typically aligned with one another.

The contact elements41and45are preferably arranged symmetrically relative to the center C of the intermediate member37. The contact elements49and53are also arranged symmetrically relative to the center C. The center C is normally located on the first and second axes of rotation R1, R2, when the latter are aligned and when the kinematic chain11is at rest.

The complementary driving contact element41and the complementary driven contact element49together form an angle of between 45° and 135°, preferably between 60° and 120°, still more preferably between 80° and 100°.

Ideally, the complementary driving contact element41and the complementary driven contact element49are substantially perpendicular to one another. In other words, and as shown inFIG. 5, the contact elements41,49,45and53are arranged at 90° with respect to one another, around the center C.

Furthermore, the kinematic chain11includes a driving elastic member55, interposed between the driving member33and the intermediate member37, and biasing the driving contact element39against the complementary driving contact element41.

Typically, the driving elastic member55also biases the other driving contact element43against the other complementary driving contact element45.

The driving elastic member55biases the driving contact elements39,43against the complementary elements41,45along a same first direction D1(seeFIG. 5). The direction D1is substantially perpendicular to the first and second axes of rotation R1, R2.

The kinematic chain11further includes a driven elastic member57interposed between the driven member35and the intermediate member37. The latter biases the driven contact element47against the complementary driven contact element49.

Typically, it also biases the other driven contact element51against the other complementary driven contact element53.

The driven elastic member57typically biases the driven contact element47and the other driven contact element51against the complementary contact areas49,53along the same second direction D2(seeFIG. 5). The direction D2is typically perpendicular to the axes of rotation R1, R2.

Advantageously, the first and second directions D1, D2are substantially perpendicular to one another.

Advantageously, the intermediate member37is a plate.

This plate has any type of shape, for example circular like in the illustrated examples, or rectangular, or any other suitable shape.

The intermediate member37is more specifically a thin metal plate, with a thickness smaller than 3 mm, preferably smaller than 2 mm, and still more preferably smaller than 1 mm.

The plate is substantially perpendicular to the axes of rotation R1and R2.

The intermediate member37includes, in one preferred embodiment, driving and driven orifices59,61, cut out in the plate. Typically, the intermediate member37includes two driving orifices59and two driven orifices61.

The complementary driving contact element41is an edge of the one of the driving orifices59. The other complementary driving contact element45is an edge of the other driving orifices59.

Likewise, the driven contact element49is an edge of one of the driven orifices61. The other complementary driven contact element53is an edge of the other driven orifices61.

Typically, the driving and driven orifices59,61are arranged at 90° relative to one another around the center C of the intermediate member37.

The driving member33and/or the driven member35are also advantageously plates, typically thin metal plates. Each one has a thickness smaller than 3 mm, preferably smaller than 2 mm, and still more preferably smaller than 1 mm.

The or each plate is substantially perpendicular to the axes of rotation R1, R2.

The driving contact element39is a tab cut out in the driving member33(FIGS. 7 and 8). Typically, the other driving contact element43is another tab, also cut out in the driving member33.

The tabs are typically bent substantially perpendicular to the plate.

Likewise, the driven contact element47and/or the other driven contact element51are tabs respectively cut out in the driven member35. These tabs are typically bent perpendicular to the plate.

The tabs are engaged in the driving and driven orifices59and61.

Advantageously, the driving contact element39and/or the driven contact element47include stops limiting the axial movement of the intermediate member37relative respectively to the driving and/or driven members33,35.

More specifically, the tab forming the driving contact element39includes tongues71,73cut and bent such that these tongues no longer extend in the main plane in which the tab fits. When the tab is engaged in the corresponding driving orifice59, the tongue71is placed between the intermediate member37and the driving member33. On the contrary, the tongue73is placed between the intermediate member37and the driven member35.

The tongues71,73are bent on one side of the tab forming the element39(FIG. 7), so as to be placed in line with the edge of the driving orifice59defining the complementary driving contact element41.

Likewise, the tab forming the driven contact element47has tongues75,77cut and bent also so as not to fit in the same plane as the rest of the tab. When the tab is engaged in the driven orifice61, the tongue75is placed between the driven member35and the intermediate member37. The tongue77is placed between the intermediate member37and the driving member33. The tongues75and77are bent on one side of the tab forming the element47(FIG. 10), so as to be placed in line with the edge of the driven orifice61defining the complementary driven contact element49.

Advantageously, the other driven contact element43and/or the other driven contact element51also have stops, of the same type as described above.

Thus, the driving member33, the driven member35and the intermediate member37are each an integral sheet.

The driving member33and the driven member35are obtained by stamping, cutting and bending of the sheet. This is also true for the intermediate member37.

Advantageously, the driving elastic member55is a spring leaf.

The driving elastic member55includes a central part79by which the driving elastic member55is fastened on the intermediate member37, and two end parts81and83cooperating with the contact elements39and43.

The intermediate member37includes a fastener85of the driving elastic member. Typically, this fastener is a cut and bent tab, having a shape making it possible to pinch the central part79of the driving elastic member55against the intermediate member37.

The driving elastic member55is configured so as to be alongside against the contact elements39,43by curved areas, with no protruding edges.

Thus, as shown byFIG. 3, the end parts81and83of the driving elastic member55form bowed portions, which bear against the large faces of the tabs respectively located opposite the complementary contact elements41and45.

The driving elastic member55is braced between the tab85on the one hand and the contact elements39and43on the other hand.

The driven elastic member57is of the same type as the driving elastic member55.

The intermediate member37has a tab87for fastening the driven elastic member57on the intermediate member37. This tab87pinches a central portion89of the driven elastic member57against the intermediate member37. The end parts91and93of the driven elastic member57are in bearing against the tabs making up the driven contact elements47,51, and more specifically against the large faces of these tabs opposite the complementary contact elements49and53. The driven elastic member57is braced between the tab87and the driven contact elements47and51, and biases these elements along the second direction D2against the edges of the driven orifices61that define the complementary contact elements49and53.

The driven elastic member57is alongside against the driven contact elements47,51by curved areas, with no protruding edges. These curved areas correspond to the end parts91and93of the member57. InFIG. 3, only one of the two end parts91is visible.

The driving elastic member55and/or the driven elastic member57are preloaded. Thus, they only deform if a torque greater than 0.1 N·m, preferably greater than 0.3 N·m, is transmitted respectively between the driving member33and the intermediate member37and between the driven member35and the intermediate member37.

The valve1further includes an elastic device94, biasing the driven member35so as to move it axially away from the driving member33.

The elastic device94advantageously comprises a helical spring95.

The intermediate member37then has a central opening97, passed through by the helical spring95.

The helical spring95is kept in position on the driving member33and on the driven member35by raised areas99,101, respectively formed on the driving member33and the driven member35.

The raised areas99,101are typically stamped. The end turns of the helical spring95are in bearing around the raised areas99,101. Thus, the ends of the helical spring95are blocked in translation along the driving and driven members33,35.

The operation of the valve1will now be described.

In order to drive the flap7toward a first end position, the actuator3is turned on. The driving member33is rotated in the direction of rotation T1(FIGS. 1 and 5) by the motor shaft5. The other driving contact element43is in bearing directly against the other complementary driving contact element45, such that the intermediate member37is also rotated, in the same direction. The complementary driven contact element49bears directly against the driven contact element47, such that the driven member35is rotated by the intermediate member37, in the direction T1. The driving33, intermediate37and driven35members have the same rotation speed as long as the flap7is not at the end of travel, in bearing against the corresponding seat. Indeed, the motor torque remains below 0.1 N·m, the driving elastic55and driven57members keeping the contact elements in bearing against one another.

The elastic device94biases the driven member35axially toward the first bearing17. This axial urging is transmitted by the driven member35to the sealing member25. Thus, the sealing step29of the sealing member25is pressed against the complementary sealing step31of the complementary sealing member27, and the sealing step30of the complementary sealing member27is pressed against the complementary sealing step32of the bearing17. This guarantees sealing with respect to the exhaust gases.

When the flap7reaches its first end position, it abuts against the corresponding seat or stop. The rotational movement of the driven member35is then blocked. Conversely, the actuator continues to rotate the driving member33, with an increasing torque.

When the torque transmitted from the intermediate member37to the driven member35exceeds 0.1 N·m, the other complementary driven contact element53loosens at least partially from the driven contact element51.

At the same time, or shortly thereafter, the other complementary driving contact element41loosens from the driving contact element39.

These loosenings are accompanied by a complex movement of the intermediate member37, in a plane perpendicular to the axes of rotation R1, R2.

This movement is possible due to the fact that the orifices59,61radially have a length greater than that of the contact elements39,43,47,51and circumferentially have a width greater than the thickness of said contact elements. Thus, it is possible for the contact elements to travel within the orifices59,61.

The actuator3stops when the driving member33has performed a rotation of several degrees relative to the driven member35. As a result, at the end of travel, the flap7is kept pressed against its seat with a significant torque. This prevents the vibrations of the flap7in this first extreme position.

The stopping of the actuator3is caused by the contact elements39,43,47,51coming into contact with the edges of the orifices59,61opposite the edges defining the complementary contact elements41,45,49and53.

The stopping of the actuator3can also be caused when a predefined torque is reached. This torque is preferably greater than 0.1 N·m.

When the flap7must be driven along a second direction of rotation T2opposite the first, the operation of the valve, in particular that of the kinematic chain11, is completely symmetrical.

The valve described above has multiple advantages.

The driving member33, the driven member35and the intermediate member37assume the form of plates. These plates have a large surface area, such that they serve as fins dissipating the heat transmitted by the drive shaft into the ambient air.

Furthermore, these plates form a shield with respect to the thermal radiation emitted by the body of the valve13toward the actuator3.

These plates also form a shield limiting the convection of the heated air in contact with the valve body13toward the actuator3.

The elastic device94guarantees the contact between the sealing steps29and31, as well as between the sealing steps30and32, and therefore prevents exhaust gas from leaking from the inside of the valve body13toward the environment.

The driving elastic55and driven57members ensure constant contact between the driving member33and the intermediate member37on the one hand, and between the intermediate member37and the driven member35on the other hand. These elastic elements guarantee a homokinetic transmission of the rotational movement from the motor shaft5to the drive shaft9. They nevertheless allow, at the end of travel, the appearance of play between the driving contact element(s) and the complementary driving contact element(s), and between the driving contact element(s) and the complementary driving contact element(s).

The intermediate member37can move in translation relative to the driven member35without the contact between the driven contact element(s) and the complementary driven contact element(s) being broken in translation in the direction Dl.

Likewise, the intermediate member37can move in translation relative to the driving member33without the contact between the driving contact element(s) and the complementary driving contact element(s) being broken in translation in the direction D2.

The contact elements39,43,45and51cooperate with the corresponding slits to perform the following four functions:Transmission of the torque between the driving member33, the intermediate member37and the driven member35;Limitation of the axial translational travel of the intermediate member37relative to the driving33and driven35members, both toward the driving member and toward the driven member;Limitation of the travel of the intermediate member37in a plane perpendicular to the axes of rotation R1, R2, in all directions;Limitation of the angle of rotation of the intermediate member37relative to the driven member35, and of the driving member33relative to the intermediate member37, in the case where the flap7is blocked in rotation and where the actuator3applies a torque greater than the taring of the elastic members.

Advantageously, the driving member33and the driven member35are identical to one another. This reduces the manufacturing costs.

Likewise, the driving elastic member33and the driven elastic member35are advantageously identical to one another, which also contributes to reducing the manufacturing costs.

Typically, the intermediate member37is symmetrical. More specifically, the intermediate member37has first and second large faces that are opposite one another, and symmetrical to one another. Thus, the intermediate member37is capable of being mounted indifferently with the first large face facing the driving member33and the second large face facing the driven member35, or with the first large face facing the driven member35and the second large face facing the driving member33. This facilitates the mounting of the valve1.

The respective sizes of the driving and driven orifices59,61and of the contact elements39,43,47,51are such that the intermediate member37can be off-centered relative to the driving member33and the driven member35in all directions.

The axial separation between the tongues71,73and between the tongues75and77is such that a significant axial position allowance exists between the driving member33, the driven member35and the intermediate member37. The machining allowances and the thermal expansions can thus be absorbed without impact on the operation of the valve1.

When the actuator is equipped with a position sensor, the latter can precisely measure the actual position of the flap7of the valve1.

The kinematic chain can absorb the alignment flaws of the motor shaft5and the drive shaft9, as well as the axial distance variations between these shafts.

The valve1can also have multiple variants.

The driving member33can include only the contact element39, and not the other contact element43. Likewise, the driven member35can include only the driven element47, and not the other driven element51. In this case, the intermediate member37includes only one driving59and/or driven61orifice.

The driving member33is, for example, fastened directly on the motor shaft5. In a variant, the driving member33is fastened to an intermediate plate103, which in turn is fastened directly to the motor shaft5. This variant is shown inFIGS. 1 and 2. According to another variant, several intermediate plates, perpendicular to the motor shaft5and superimposed on one another, are interposed between the driving member33and the motor shaft5.

The intermediate plates are separated from one another by an air knife, and are only in contact with one another by a limited number of points, so as to limit the heat transfers by conduction.

This makes it possible to increase the thermal uncoupling between the valve body13and the actuator3.

Symmetrically, the driven member35can be fastened directly to the drive shaft5, or on the contrary by one or several intermediate plates arranged as described above.

These intermediate plates are arranged in planes parallel to one another, and perpendicular to the axes of rotation. They are separated by air knives. They make it possible to increase the thermal uncoupling between the valve body13and the actuator3.

According to another embodiment variant, the sole helical spring95is replaced by two independent elastic members. One of the two elastic members is compressed axially between the driving member33and the intermediate member37, and the other one between the intermediate member37and the driven member35.

The intermediate member37therefore does not have a central opening97, which improves the thermal uncoupling between the valve body13and the actuator3.

According to another embodiment variant, the valve1does not include a helical spring95of the type described above. This spring is replaced by elastic tongues formed in the intermediate member37. These elastic tongues are of the type described in WO2010/103249. These tongues are integral with the intermediate member37. Some tongues protrude relative to the large face of the intermediate member37facing toward the driving member33. Said tongues are compressed axially between the driving member33and the intermediate member37. They bear against the driving member33.

Other tongues protrude axially relative to the large face of the intermediate member37facing toward the driven member35. They bear against the driven member35. They are compressed axially between the intermediate member37and the driven member35.

In this embodiment variant, the intermediate member37does not include a central opening97. The thermal uncoupling between the valve body13and the actuator3is therefore improved. Furthermore, the cost of the valve1is reduced because the helical spring95is eliminated.

According to still another variant, the two tabs of the driving member33and/or the driven member35are replaced by a single tab, with a large width, as shown inFIG. 11.

FIG. 11shows a driving member33with a single tab. The driven member35, if applicable, has substantially the same shape.

FIG. 11shows a median line D passing through the geometric center C of the driving member33and splitting the latter into two equal parts. A transverse line T is also shown that is substantially perpendicular to the median line D. The single tab111extends in a plane substantially perpendicular to the median line D, and containing the transverse direction T. One transverse half of the single tab111is located on one side of the median line D, and the other half is on the other side.

A first transverse end of the single tab111defines the driving contact element39, and the opposite transverse end defines the other driving contact element43. Each of the two transverse ends of the single tab111bears tongues71,73, of the type described above.

When the driving member33is formed from a plate, the directions D and T extend in the plane of the plate.

The single tab111is offset along the median line D at a distance from the geometric center C of the driving member33. The two transverse ends of the tab111, making up the contact elements39and43, are therefore not arranged on either side of the geometric center C.

In this embodiment variant, the two driving orifices59are replaced by a single orifice, with a larger width, dimensioned to receive the single tab111.

This single orifice is offset at a distance from the center of the intermediate member37.

The driven member35, if applicable, is as described in reference to the driving member33.

According to another embodiment variant, the driven member35or the driving member33has a bell shape. Such an embodiment variant is shown inFIG. 12. This variant makes it possible to protect the kinematic chain11, the motor shaft5, or the bearing17with respect to water sprays or foreign bodies (gravel), or with respect to streaming water.

In this embodiment variant, the driving member33or the driven member35includes a bottom113bearing the contact element(s), and a skirt115secured to the bottom113and surrounding the bottom113.

The skirt115extends axially toward the driven member35, in the case where the driving member33is bell-shaped. It, for example, extends axially practically up to the driven member35. It therefore completely surrounds the space comprised between the bottom of the driving member33and the driven member35. Conversely, when it is the driven member35that is bell-shaped, the skirt115extends from the bottom of the driven member35toward the driving member33.

It should be noted that the skirt115can be open-worked in order to facilitate the circulation of air, so as to cool the elements of the kinematic chain11.

According to still another embodiment variant, the driving55and driven57elastic members can be replaced by mutually independent helical springs. Each helical spring is arranged so as to urge one of the driving35or driven33contact members against the complementary driving or driven contact element. These springs are typically mounted on the intermediate member37.

According to still another embodiment variant, the driving elastic member is arranged so as to urge the driving contact element39against the complementary driving contact element41in the first direction D1, and to urge the other driving contact element43against the other complementary driving contact element45in a direction opposite the first direction Dl. For example, the driven elastic member57is arranged in the same way. It biases the driven contact element47against the complementary driven contact element49in the second direction D2, and biases the other driven contact element51against the other complementary driven contact element53in a direction opposite the second direction D2.

In this case, when the motor shaft5is rotated in a first rotation direction, the driving contact element(s) abut directly against the complementary driving contact element(s) in order to transmit the torque from the driving member to the intermediate member.

On the contrary, when the motor shaft5is rotated in a second direction opposite the first, the torque is transmitted from the driving member to the intermediate member via the driving elastic member.

According to still another embodiment variant, one or several driving33, driven35and intermediate37members are truncated, to facilitate the assembly.

One or several areas of the plate making up the driving33, driven35or intermediate37member are cut to allow the assembly or travel of the member. The or each area is typically an edge area.

According to still another embodiment variant, one or several driving33, driven35and intermediate37members are provided with a mistake-proofing hole or notch to prevent one or several of said members from being mounted backwards.

According to still another embodiment variant, the driving elastic member55and/or the driven elastic member57are respectively fastened on the driving member33and/or on the driven member35, rather than on the intermediate member37.

According to still another embodiment variant, shown inFIG. 13, the driving member33and/or the driven member35is a fork. In this embodiment variant, the driving member33and/or the driven member35does not include a part in plate form, forming the heat shield. The latter is replaced by a single radial strip117, bearing the contact element(s).

For example, the driving member33is cut in a plate, and arranged in a plate containing the rotation axes. It is generally U-shaped, the two free branches of the U making up the driving contact elements39. The driven member35is made in the same way.

According to still another embodiment variant, one or several of the driving33, driven35and intermediate37members are covered with a layer with a high thermal emissivity, deposited in the form of a coating or a paint. Such a layer makes it possible to increase the quantity of heat discharged by radiation.

According to another embodiment variant, one or several driving33, driven35and intermediate37members has a surface with a low thermal emissivity, for example brilliant or specular. This makes it possible to reduce the transfer of heat by radiation.

According to still another embodiment variant, one or several driving33, driven35and intermediate37members has a non-flat surface, for example embossed or wavy. This makes it possible to increase the surface area of the surface diffusing the heat.