KR20200110797A - Clutch actuator - Google Patents

Abstract

The present invention relates to a clutch actuator (1), the clutch actuator comprising a casing (2), an electric motor (8) fixed to the casing and comprising a rotation output shaft (14), and a shaft of the electric motor (8). Rotation-linear type of motion- comprising an input member 21 that is rotationally driven by 14, and an output member 35 that drives a translational motion of the pushing member capable of displacing the fluid in the pressure chamber 47. It comprises a conversion device (21, 35), the pushing member is movable between the deployed position and the retracted position, the pressure chamber (47) is an annular peripheral wall (53) extending along the translation axis (B) of the pushing member. ) And an end wall 54, said pressure chamber 47 comprising a fluid outlet 55 intended to be connected to a pipe 58.

Description

Clutch actuator

The invention relates in particular to a clutch actuator for a transmission system of an automobile.

The present invention, in particular, but not exclusively, is the operation of a single or double clutch, in which the state at rest can be normally engaged or always disengaged, the operation of the gearbox synchronization device for manual shifting, the operation of the semi-automatic gearbox. , The operation of the double-clutch manual gearbox, or the operation of the clutch used to couple the combustion engine and the electric machine when the combustion engine and electric machine form part of the hybrid vehicle drive system.

The clutch actuator makes it possible for the transmission system to transition from an engaged state that allows transmission of torque or motion to a disengaged state in which such transmission is not performed. The clutch actuator also makes it possible to keep the system in an engaged or disengaged state.

Document WO 2015/090316 is a casing and an electric motor mounted on the casing, wherein the output shaft of the electric motor is rotationally coupled to the first pinion, and the electric motor and the second pinion engaged with the first pinion are supported. Disclosed is a clutch actuator comprising a rotation-linear type movement-conversion device comprising a screw and a nut. The nut cooperates with the screw and is rotationally coupled and translationally coupled to a pushing member. The pushing member allows the master-cylinder piston to move so as to be able to displace a predetermined amount of oil.

Thus, the rotation of the motor shaft causes the piston to move through the pinion and motion-transformer device.

Such actuators are said to be hydrostatic so long as they allow a certain amount of fluid to be displaced without creating a flow of hydraulic fluid, since a certain amount of fluid is effectively maintained in a state that is virtually unchanged over time. .

In order to improve the miniaturization of such an actuator, document FR 2 721 264 in the name of the applicant's company describes an electric motor fixed to the casing and comprising a rotating output shaft, a screw rotationally driven by the shaft of the electric motor, and a retracted position. A clutch actuator comprising a rotation-linear type of motion-conversion device comprising a nut for driving the translational motion of the piston between the position and the deployed position is proposed. The piston can displace the fluid in the pressure chamber. The pressure chamber includes an annular wall and an end wall extending along an axis of movement of the pushing member. The pressure chamber includes a fluid outlet intended to be connected to a pipe, the fluid outlet extending from the surrounding wall. The pushing member may extend axially towards the fluid outlet during translational movement towards the deployed position. In order not to obstruct the circulation of fluid as the piston approaches the deployed position, the piston comprises a portion of a smaller diameter than the pressure chamber, located on the side of the free end of the piston, the end facing the end of the pressure chamber. have. This portion extends over a significant length of the piston. Thus, fluid located between the end of the pressure chamber and the free end of the piston can be discharged toward the fluid outlet through an annular volume located radially between the peripheral wall of the piston and the peripheral wall of the pressure chamber. Such a structure makes it possible to limit the axial size of the actuator, but the reduced diameter of the piston hinders the effective guidance of the piston by the peripheral wall of the pressure chamber.

The present invention seeks to overcome this drawback while limiting the axial size of the clutch actuator.

For this purpose, the present invention relates to a clutch actuator, which clutch actuator,

-With casing,

-An electric motor fixed to the casing and comprising a rotating output shaft,

-A rotation-linear type motion-conversion device comprising an input member rotationally driven by a shaft of an electric motor and an output member driving a translational motion of a pushing member capable of pressurizing a fluid in the pressure chamber, and pushing The member can be moved between the deployed position and the retracted position,

The pressure chamber comprises an annular peripheral wall extending along the translational axis of the pushing member and an end wall, the pressure chamber comprising a fluid outlet intended to be connected to a pipe, the fluid outlet extending from the peripheral wall , The pushing member may extend axially toward the fluid outlet during the translational movement toward the deployed position, characterized in that a fluid flow duct is formed in the peripheral wall of the pressure chamber.

The flow duct can be designed to allow a fluid to flow between the end of the chamber and the corresponding end of the pushing member on the one hand and the fluid outlet on the other hand.

The creation of a flow duct to the peripheral wall of the pressure chamber allows the fluid outlet to be located on the peripheral wall of the pressure chamber, while the pressure chamber towards the fluid outlet and the free end of the piston when the piston is moved towards the deployed position. It means that it allows fluid to flow from the volume located between the ends of. Further, the pushing member can be effectively guided by the peripheral surface of the pressure chamber.

Within the meaning of the invention, the fluid outlet and the fluid flow duct are separate elements.

According to the invention, the flow duct extends along the axis B at the peripheral wall between the end wall of the pressure chamber and the fluid outlet.

According to another feature of the invention, the flow duct extends along the axis B at the peripheral walls on both sides of the fluid outlet.

The pushing member forms a piston, and the assembly formed by the pushing member and the pressure chamber forms a hydraulic emitter that can cooperate with a hydraulic receiver through a pipe.

The fluid outlet may extend along an axis making an angle of 90° to the axis of movement of the piston. Of course, it is possible to change these angles as needed.

The fluid is for example oil or brake oil.

The actuator comprises at least one first annular seal and at least one second annular seal axially offset from each other with respect to the axis of motion of the pushing member, each seal being between the pushing member and the axially fixed portion of the clutch actuator. To provide a seal, the first seal can be subjected to a fluid pressure created in the pressure chamber, and the second seal can be subjected to a lower fluid pressure.

The second seal can for example be subjected to a pressure close to or equal to atmospheric pressure, while the first seal can be subjected to a high pressure, for example on the order of 30 to 60 bar, preferably on the order of 45 bar.

At least one filling duct may be formed near the free end of the pushing member, the filling duct having a pressure chamber and an area located axially between the first seal and the second seal when the pushing member is positioned in the deployed position. Making it possible to connect, the area being connected to the fluid reservoir.

As mentioned above, the free end of the pushing member is the end facing the end wall of the pressure chamber.

Such a feature makes it possible to use the fluid contained in the reservoir to allow the pressure chamber to be filled, or to compensate for potential fluid losses when the pushing member is placed in the deployed position.

Of course, the movement of the pushing member that allows such connection with the reservoir can be relatively small, so as not to have too much influence on the actuating movement of the pushing member, for example on the order of 1% to 8% of the total movement of the pushing member. have. The actuation movement is defined as being a movement that allows the pressurized fluid to be displaced towards the fluid outlet.

The pushing member may comprise several filling ducts evenly distributed around the axis of the pushing member.

The input member may comprise a screw and the output member comprises a nut. Thus, rotation of the screw causes the nut to move in translation.

The input member can be rotationally driven by a shaft of an electric motor, via a reduction gear set.

The actuator may comprise a guide member at least partially surrounding the pushing member, the pushing member being rotationally coupled to the guide member and capable of being translatable relative to the guide member.

Then, the guide member can be fixed relative to the casing.

The output shaft of the motor may extend along the axis A, and the input member may rotate around an axis B parallel to the axis A.

Such an arrangement ensures good radial miniaturization of the actuator.

The fluid outlet may comprise a connecting means intended to cooperate in a fluidtight manner with a complementary connecting means belonging to the pipe.

The connecting means may comprise an elastic element that can be clipped into the groove of the complementary connecting means, or, conversely, the complementary connecting means can comprise an elastic element that can be clipped into the groove of the connecting means.

The actuator may comprise means for detecting the position of the pushing member.

The detection means may include a magnetic element fixed to the pushing member and a sensor mounted on a fixed portion of the actuator, the sensor capable of detecting the position of the magnet along the moving axis of the pushing member.

The clutch actuator may also include one or more of the following features:

-The pushing member comprises a rotation coupling portion rotationally coupled to the output member.

-The coupling part is also rotationally coupled to the guide member.

-The coupling part is guided translationally by a guide member.

-The pushing member comprises a non-cylindrical radially inner part mounted around a non-cylindrical part of, for example, a round cross-section and a shape complementary to the output member.

-The pushing member comprises at least one rib or spline, eg four ribs, mounted in at least one complementary groove or spline belonging to the guide member.

-The pushing member comprises a piston which is fixed translationally to the output member and/or the coupling part.

The piston comprises a tubular cylindrical portion comprising a free end wall at a first end and an annular rim extending radially outward at the other end.

-The annular rim of the piston is interposed in the radial direction of the coupling part of the pushing member, for example axially between the annular part and the radial surface of the output member, ie the nut.

-The coupling part of the pushing member and the piston can be rotationally coupled. Thus, precise angular positioning of the magnetic element intended to detect the axial position of the pushing member relative to the corresponding sensor is ensured in particular.

-The annular rim of the piston may comprise at least one non-cylindrical region, for example two diametrically opposite non-cylindrical regions, cooperating with regions of complementary shape belonging to the coupling part to provide rotational coupling of the parts. .

-The coupling part can be made of a thermoplastic material, for example a polyamide material containing a dry lubricant such as PTFE, for example 15% PTFE. The thermoplastic material may contain, for example, reinforcing fibers such as glass fibers, carbon fibers or aramid fibers, and/or inorganic fillers.

-The piston can be made of thermosetting material. It reduces roughness and makes it possible to avoid jamming the mounted seal around the pushing part.

-The actuator includes an electronic board housed in an electronic housing.

-The motor comprises a body that is at least partially metallic, electrically grounded to the electronic board.

-A rolling member is mounted between the screw thread and the nut thread, and the rolling member is lubricated.

-The clutch actuator comprises a casing and a cover defining a housing for at least partially receiving the reduction gear set.

-The input member is pivotally mounted to the guide member via a bearing, for example a ball bearing.

-The electronic housing is oriented perpendicular to the axis (A) and axis (B). Such a structure makes it possible to reduce the size in the axial size, ie in the direction of the axes A and B.

-The electronic housing is fixed to the motor casing.

-The electronic housing and/or the electronic board comprise heat sink means.

-The electronic housing includes a body and a cover.

-The body of the electronic housing is made of, for example, a reinforced thermoplastic resin, and the cover of the electronic housing is made of, for example, an aluminum alloy. Aluminum alloys allow better heat dissipation.

-The casing comprises a first part forming a housing defining an inner volume, and a hollow second part extending along the axis B from the first part.

-The second part opens into the inner volume of the first part.

-The first part contains the opening of the axis B.

-The inner volume of the first part, for example by clip fastening, screw fastening or welding, the first part It is closed by a cover that can be fixed in minutes.

-The casing and cover are made of plastic and are welded to each other by laser welding or ultrasonic welding.

-The casing of the actuator is fixed to the casing of the gearbox, for example via a bracket.

-The electric motor is a brushless permanent magnet motor.

-The motor comprises a body or a stator forming a mounting plate or a fixing flange, which plate or flange allows the body of the motor to be fixed to the casing, for example using screws fitted into the tapped holes of the casing. .

-The main body includes a cylindrical centering part that is centered and coupled to the opening of the axis A of the casing.

-An annular seal is created between the opening of the casing and the outer periphery of the cylindrical portion of the body.

-The shaft of the motor extends along the axis B through the opening of the casing and enters the inner volume of the first part of the casing.

-The shaft of the motor supports a first pinion including a plurality of teeth (Z1).

-The second pinion is mounted so as to idle about the shaft or pin, ie to rotate freely.

-The shaft supporting the second pinion, the first end is mounted in the hole of the first part of the casing and the second end is mounted in the hole of the cover.

-The shaft is mounted in the corresponding hole without a gap.

-The second pinion is engaged with the first pinion supported by the motor.

-The third pinion of the shaft B rotates as one with the first end of the screw of the motion-conversion means.

-The third pinion directly engages with the second pinion, and includes a plurality (Z2) of teeth.

-3 pinions are accommodated in the inner volume of the housing.

-The reduction ratio of the reduction gear set formed by the first pinion and the third pinion, that is, the ratio Z1/Z2 is composed of 1 to 5.

-The pinion is lubricated with oil or grease.

-The third pinion is fixed to the rear end of the screw of the motion-conversion means, ie the end located on the cover side.

-The screw includes a flat cylindrical part and a threaded part.

-The thread of the screw has a pitch and profile compatible with the use of a ball coupled to the thread.

-The casing and/or cover is made of aluminum, steel or plastic.

-Pinions are made of metal or plastic.

-The screw is supported near the first end by a bearing, for example a ball bearing.

-The bearing includes an inner ring surrounding the screw and an outer ring accommodated in the guide member.

-The guide member is made of steel, aluminum or plastic.

-The guide member comprises, at a first end, a first portion comprising a recess extending radially outwardly and comprising a hole allowing engagement of the screw.

-The screw is attached to a hole in a fixing plate, for example of a generally square shape, mounted in the inner volume of the first part of the casing.

-Each screw is attached to the thread of the casing.

-The guide member is fixed to the casing.

-The guide member comprises a tubular second part of the shaft B comprising splines or grooves on the opposite side of the cover with respect to the first part of the casing.

-The input member, output member, guide member and/or pushing member are at least partially received in the tubular second part of the casing.

-The guide member is fixed against the tubular second part of the casing.

-The second part of the casing comprises at least one groove, rib or spline cooperating with at least one complementary rib, groove or spline belonging to the guide member.

-The guide member comprises a third part of a generally cylindrical shape located in front of the second part and having a diameter smaller than that of the second part.

-An annular radial shoulder is defined between the second and third parts.

-The nut has a tapped thread, and the pitch and profile of the tapped thread are compatible with the use of balls joined to the thread.

-The threads of balls, screws and tapped threads of nuts are lubricated with grease.

-The nut of the motion-conversion means is received in the coupling part of the pushing member.

-The piston of the pushing member is engaged at the front end to the third part of the guide member.

-The outer diameter of the piston of the pushing member substantially corresponds to the inner diameter of the third part of the guide member.

-The movement of the piston causes a certain amount of hydraulic fluid, for example oil, to be displaced in the pipe, actuating a hydraulic receiver that itself can actuate the clutch.

-The cover of the housing is fixed or clipped onto the main body of the housing.

By reading the description of Haga given as a non-limiting example and with reference to the accompanying drawings, the invention will be better understood, and further details, features and advantages of the invention will become apparent:
1 is a perspective view of a clutch actuator according to an embodiment of the present invention,
2 is an exploded perspective view of the actuator,
3 and 4 are axial cross-sectional views of the actuator,
5 is an exploded perspective view of the pushing member,
6 is a perspective view of the pushing member,
7 is a radial cross-sectional view of the actuator,
8 is a radial cross-sectional view of the actuator,
9 is a detailed view showing the means for connecting the pipe and the fluid outlet according to the first embodiment of the present invention
10 is a diagram corresponding to FIG. 8, showing a second embodiment of the present invention,
11 is an axial cross-sectional view of the actuator.

1 to 8 show a clutch actuator 1 according to an embodiment of the present invention. The clutch actuator 1 forms a housing defining an inner volume and extends along the axis B from the first part 2a with an opening 3 in the axis A (Fig. 2). And a casing 2 comprising a tubular second part 2b. The second part 2b opens into the inner volume of the first part 2a. Axis B is parallel to axis A and is offset with respect to axis A.

The inner volume of the first part 2a can be closed by a cover 4 which can be attached to the first part 2a by clip fastening, screw fastening or any other suitable means. The casing 2 and the cover 4 are made of plastic, for example, and it is possible for these elements 2, 4 to be welded to each other by laser welding or ultrasonic welding.

The fixed extension 5 extends axially from the first part 2a. A fixing lug 6 extends radially from the second part 2b. The fixed extension 5 and the fixed lug 6 have a tapped hole 7 (Fig. 2).

For example, the casing 2 of the actuator 1 is intended to be fixed to the casing of the gearbox, for example via a bracket (not shown).

The actuator 1 further comprises an electric motor 8, in particular a brushless permanent magnet motor, mounted on the casing 2. The motor 8 comprises a body 9 or a stator forming a mounting plate or a fixing flange 10, which plate or flange 10 is, for example, a screw 11 fitted in a tapped hole 7 By using, it is possible to fix the body 9 of the motor 8 to the casing 2. The body 9 further comprises a cylindrical centering portion 13 (Fig. 4) that is coupled and centered to the cylindrical opening 3 of the casing 2. The body 9 also comprises at least one connector.

The motor 8 further includes a rotating shaft 14 fixed to the rotor of the motor 8. The shaft 14 extends along the axis A through the opening 3 and enters the inner volume of the first part 2a of the casing 2. The shaft 14 supports a first pinion 15 comprising a plurality (Z1) of teeth. The second pinion 16 is mounted so as to idly rotate relative to the shaft or pin 17, ie to rotate freely. The shaft 17 has its first end mounted in the hole 18 in the first part 2a of the casing 2, and the second end in the hole 19 in the cover 4 (Fig. 3). . The shaft 17 can be mounted in the holes 18 and 19 without gaps. The second pinion 16 meshes with the first pinion 15 supported by the motor 8.

The third pinion 20 of the shaft B rotates as one with the first end 22 of the screw 21. The third pinion 20 directly engages the second pinion 16 and includes a plurality of teeth (Z2). The three pinions 15, 16, 20 are accommodated in the inner volume of the housing 2a. The reduction ratio, i.e. the ratio Z1/Z2, consists of 1 to 5 in this embodiment, for example. Pinions 15, 16, 20 can be lubricated with oil or grease.

The third pinion 20 is fixed to the rear end 22 of the screw 21, that is, the end positioned on the cover 4 side.

The screw 21 comprises a flat cylindrical rear portion 22 and a threaded front portion 23.

Here, the thread of the screw 21 has a pitch and profile compatible with the use of the ball 24 coupled to the thread.

The casing 2 and/or the cover 4 can be made of aluminum, steel or plastic, for example. Pinions 15, 16, 20 are made of plastic or steel, for example.

The screw 21 is supported near the first or rear end 22 by a bearing, in this example a ball bearing 25. The bearing 25 includes an inner race 26 surrounding the screw 21 and an outer race 27 accommodated in the guide member 28.

The guide member 28 is made of, for example, steel, aluminum or plastic. The guide member 28 comprises a tubular rear portion 30 of the shaft B comprising a rib or groove 31 coupled to a groove or rib 31a of a complementary shape belonging to the portion 2b of the casing. . The guide member 28 is generally cylindrical in shape and further comprises a front portion 32 having a diameter smaller than that of the rear portion 30. Thus, the annular radial shoulder 33 is defined between the rear portion 30 and the front portion 32.

The outer ring 27 of the bearing 25 is received in the rear portion 30 of the guide member 28.

The ring 34 is mounted axially between the inner ring 26 of the bearing 25 and the rear end of the thread 23. The nut 35 is screwed onto the threaded portion 23 of the screw 21. The nut 35 has a tapped thread, and the pitch and profile of the tapped thread is compatible with the use of a ball 24 that is coupled to the thread of the nut 35 and screw 21. The radially outer periphery of the nut 35 comprises two grooves 36 (Fig. 2) oriented along the axis B and on opposite sides. Each groove 36 has an arc-shaped cross section.

Therefore, the assembly formed by the nut 35, the screw 21 and the ball 24 is a rotation-linear type of motion-conversion system, that is, the rotational motion of the screw 21 is converted to the translational motion of the nut 35 to minimize friction. In other words, it forms a motion-conversion system that can convert with maximum efficiency. The thread of the ball 24, the screw 21 and the tapped thread of the nut 35 may be lubricated with grease.

The nut 35 is rotationally coupled to the pushing member 37. The pushing member 37 comprises a first part or coupling part 38 of a generally cylindrical shape located at the rear and a second part or piston 39 located at the front. The two parts 38 and 39 are formed by two separate components.

The first part 38 is made of a thermoplastic material, for example PTFE, for example a polyamide material containing 15% PTFE. The thermoplastic material may contain reinforcing fibers and/or inorganic fillers, for example glass fibers. The second part is made of a thermosetting material. It reduces roughness and makes it possible to avoid jamming the mounted seal around the pushing part.

The first part 38 has a rib 38a that cooperates through a shape complementary to the groove 31 of the guide member 28. In this way, the pushing member 37 and more particularly the first part 38 is coupled by the guide member 28 and the rotation is fixed, sliding relative to the guide member 28 along the axis B. can do.

The nut 35 is received in the first part 38. The first portion 38 includes a protruding region that engages each groove 36 of the nut 35 to rotationally couple the nut 35 and the first portion 38 of the pushing member 37. The front end of the first portion 38 of the pushing member 37 comprises a portion 42 extending radially inwardly.

The second part 39 of the pushing member 37 is generally cylindrical and tubular in shape and comprises a free end wall 40 at the first end and an annular rim 41 extending radially outward at the other end. . The annular rim 41 of the second part 39 is axially interposed between the radial part 42 and the radial front surface of the nut 35.

The second part 39 of the pushing member 37 has its front end coupled to the front part 32 of the guide member 28. In particular, the diameter of the second portion 39 of the pushing member 37 substantially corresponds to the diameter of the front portion 32 of the guide member 28 to provide translational guidance.

The first and second parts 38, 39 comprise a rotational coupling means, in this case a groove of complementary cross-section in the form of an arc and protruding regions 43 (Fig. 5), located opposite to each other. The first portion 38 also comprises a radially deformable region that allows the first portion 38 to be axially fixed on the nut 35 by means of a clip fastening.

A magnet 44 is received in the free end wall 40 of the second portion 39 of the pushing member 37. The magnet is offset from the axis B of the pushing member 37 and is located near the cylindrical peripheral wall 45 of the second part 39. The peripheral wall 45 is a filling duct or port extending along the axis B and evenly distributed around the circumference and opening onto the front end face 40 of the second part 39 of the pushing member 37. It further includes (46). The filling duct 46 extends over a short length portion of the second part 39, for example a distance of 0.5 mm to 3 mm, for example a distance of the order of 1.5 mm.

The second part 2b of the casing 2 accommodates the screw 21, the nut 35, the pushing member 37 and the guide member 28. The second part 2b also forms a pressure chamber 47 (FIGS. 3 and 4) in front, and in the pressure chamber 47 the front end of the second part 39 of the pushing member 37 is Is located.

A first annular seal 48, for example a lip seal, is located radially between the casing 2 and the second part 39 of the pushing member 37. The first seal 48 is fixed axially with respect to the casing 2.

A second annular seal 49, for example a lip seal, is radially between the second part 39 of the pushing member 37 and the front part 32 of the guide member 28, the first seal 48 Is located at the rear of the The second seal 49 is axially fixed to the guide member 28 and the casing 2. One or more annular rings 50 are axially interposed between seals 48 and 49.

The fluid reservoir opens through a port 51 and a duct 52 into an annular area located axially between the seals 48 and 49.

The pressure chamber 47 is connected to the cylindrical peripheral wall 53 of the casing 2, the end wall 54 of the casing 2, the end wall 40 of the pushing member 37 and the second annular seal 49. Limited by

The fluid outlet 55 extends from the cylindrical peripheral wall 53 of the pressure chamber 47 along an axis C, in this case oriented perpendicular to the axis B and offset rearwardly with respect to the end wall 54 do. The fluid flow duct 56 allows fluid to flow between the end 54 of the chamber 47 and the front end 40 of the pushing member 37 on the one hand and the fluid outlet 55 on the other hand. It is formed on the peripheral wall 53 so as to be. The flow duct 56 extends along the axis B. The flow duct 56 extends along an axis B between the fluid outlet 55 and the end wall 54 of the pressure chamber 47. The flow duct 56 also extends along the axis B at the peripheral walls 53 on either side of the fluid outlet 55.

On the outside of the casing 2 a position sensor 57 is mounted, and the sensor 57 can detect the position of the magnet 44 and thus the position of the pushing member 37 in a non-contact manner.

The fluid outlet 55 is connected to the pipe 58 via complementary connection means 59.

In the first embodiment, which can be seen in Fig. 9, the connecting means 59 of the pipe 58 comprises a groove 60, and the connecting means 59 of the fluid outlet 55 are generally spring clip-shaped and have a groove ( 60) includes an elastic member 61 intended to be clip-fastened. In this embodiment, the corresponding end of the pipe 58 is coupled inside the connecting means 59 of the fluid outlet 55.

As shown in Fig. 10, the opposite can also be envisioned, in which the connection means 59 of the fluid outlet 55 comprise a groove 60, and the connection means 59 of the pipe 58 A second embodiment is shown comprising an elastic member 61 intended to be clipped into this groove 60. In this embodiment, the corresponding end of the fluid outlet 55 is coupled inside the connecting means 59 of the pipe 58.

Movement of the pushing member 37 causes hydraulic fluid, e.g., oil, to displace in the pipe 58, which, as known per se, activates a hydraulic receiver capable of operating the clutch itself. .

The actuator 1 further comprises a housing 63 for accommodating a power and/or control electronic board, which housing 63 is fixed to the casing 2, for example by screws. This screw may be the same as the screw 11 used to attach the flange 10 of the motor 8.

The electronic board and housing 63 includes a connector 64 that allows the board to be electrically connected to the electric motor 8 and/or to at least one component (not shown) of the vehicle.

This connector 64 is also used to control the electric motor from the vehicle's engine control unit (ECU) and/or clutch control unit (CCU), so that the electronic board is connected to a power source, for example, a battery and/or CAN (Controller Area Network) can be connected to a bus, and these units can run vehicle shift system monitoring software. One of the connectors 64 also includes at least one sensor of the vehicle, for example a sensor providing information about the position of the clutch pedal, a sensor providing information about the position of the gear lever, regarding the position of an element of the gearbox It may be connected to a sensor that provides information and/or a sensor that provides the position of a hydraulic receiver associated with the actuator 1 or a sensor that provides the position of a magnet.

The housing 63 is oriented in a plane extending perpendicular to the axes A and B to promote the axial miniaturization of the actuator 1.

The housing 63 includes a body 65 and a cover 66 fixed or clipped on the body. The housing 63 includes heat sink means in the cover 66 in this example. The heat sink means comprise fins or protruding elements 67, for example cones, to increase the surface area for heat exchange with ambient air.

During operation, the electric motor 8 is controlled by an electronic board to drive the rotation of the shaft 14 and the first pinion 15. Then, the first pinion 15 drives the second pinion 16, the third pinion 20, and the screw 21 to rotate. The rotational speed of the screw 21 is a function of the rotational speed of the motor 8 and the reduction ratio Z2/Z1.

The rotation of the screw 21 causes the nut 35 to move along the axis B. Since the nut 35 is seated in the axial direction relative to the pushing member 37, the pushing member 37 is thus positioned along the axis B between the first retracted position and the deployed position as seen in FIGS. 3 and 4. Is moved. These two extreme positions correspond for example to the engaged and disengaged positions of the clutch.

Movement of the nut 35 and the pushing member 37 causes displacement of the hydraulic fluid in such a way as to actuate the hydraulic receiver through the pipe 58.

It will be noted that the duct 56 makes it possible to supply the fluid outlet 55 regardless of the position of the pushing member 37. Moreover, when the pushing member 37 reaches the retracted position, the filling duct 46 connects the pressure chamber 47 with the region located axially between the first seal 48 and the second seal 49 Thus, the fluid contained in the reservoir is used to fill the pressure chamber 47 and compensate for any fluid loss.

According to one embodiment not shown, the assembly formed by the screw 21, ball 24 and nut 35 may be replaced by a conventional screw-nut type system having a shorter or longer pitch. In such a case, the reduction ratio needs to be adjusted.

The apparent pitch may be smaller (multiple threads), but not the actual pitch (or helical pitch), and the actual pitch is usually larger to provide an accurate output.

The ball screws 21, 24 can also be replaced by roller screws.

In addition, the reduction gear set consisting of three pinions (15, 16, 20) is a first pinion rotationally coupled to the shaft 14 of the motor 8, and a rotational coupling to the rear end 22 of the screw 21. It can be replaced by a reduction gear set comprising a ringed second pinion, the first pinion directly engaging the second pinion.

The reduction gear set may comprise one or more reduction stages, for example two reduction stages, as known for example from document EP 2 841 869.

Regardless of which embodiment is envisioned, such an actuator 1 has a compact structure that exhibits a small bulkiness along the axes A and B and in the direction perpendicular to the axis. It is also possible to use a number of commercially available components such as, for example, ball screws 21 and 24. In addition, the cost of such an actuator 1 is relatively inexpensive and can be easily integrated into an existing propulsion system.

Claims (12)

As a clutch actuator 1,
With casing (2),
An electric motor (8) fixed to the casing and comprising a rotating output shaft (14),
The input member 21 rotationally driven by the shaft 14 of the electric motor 8, and the output member 35 driving the translational motion of the pushing member 37 capable of displacing the fluid in the pressure chamber 47 ) Comprising a rotation-linear type of motion-conversion device (21, 35),
The pushing member 37 can move between the deployed position and the retracted position,
The pressure chamber 47 includes an annular peripheral wall 53 extending along the translation axis B of the pushing member 37 and an end wall 54, the pressure chamber 47 comprising a pipe ( 58) configured to be connected to a fluid outlet 55, the fluid outlet 55 extending from the peripheral wall 53, and the pushing member 37 during a translational movement towards the deployed position. In the clutch actuator (1), which can extend axially toward 55),
A fluid flow duct 56 is formed in the peripheral wall 53 of the pressure chamber 47.
Clutch actuator. The method of claim 1,
The flow duct (56) is characterized in that it extends along the axis (B) at the peripheral wall (53) between the end wall (54) of the pressure chamber (47) and the fluid outlet (55).
Clutch actuator. The method according to claim 1 or 2,
The flow duct 56 is characterized in that it extends along the axis (B) in the peripheral wall (53) on both sides of the fluid outlet (55).
Clutch actuator. The method according to any one of claims 1 to 3,
At least one first annular seal 48 and at least one second annular seal 49 axially offset from each other with respect to the movement axis B of the pushing member 37, each seal 48 , 49) provides a seal between the pushing member 37 and the axially fixed portion of the clutch actuator 1, and the first seal 48 is subjected to the fluid pressure generated in the pressure chamber 47. And the second seal 49 is capable of receiving a lower fluid pressure.
Clutch actuator. The method of claim 1,
At least one filling duct 46 is formed in the vicinity of the free end 40 of the pushing member 37, and the filling duct 46 is the first when the pushing member 37 is positioned in the deployed position. Characterized in that it is possible to connect the pressure chamber 47 with an area axially located between the seal 48 and the second seal 49, the area being connected to a fluid reservoir.
Clutch actuator. The method according to any one of claims 1 to 5,
The input member comprises a screw (21), characterized in that the output member comprises a nut (35)
Clutch actuator. The method according to any one of claims 1 to 6,
The input member 21 is rotationally driven by a shaft 14 of the electric motor 8 via a reduction gear set 15, 16, 20.
Clutch actuator. The method according to any one of claims 1 to 7,
And a guide member 28 that at least partially surrounds the pushing member 37, wherein the pushing member 37 is rotationally coupled to the guide member 28 and to be translated relative to the guide member 28. Characterized by being able to
Clutch actuator. The method according to any one of claims 1 to 8,
The output shaft 14 of the electric motor 8 extends along an axis A, and the input member 21 can rotate around an axis B parallel to the axis A. With
Clutch actuator. The method according to any one of claims 1 to 9,
The fluid outlet (55) comprises a connecting means (59) configured to cooperate in an oiltight manner with a complementary connecting means (59) belonging to the pipe (58).
Clutch actuator. The method of claim 10,
The connecting means (59) comprises an elastic element (61) that can be clipped into the groove (60) of the complementary connecting means (59), or, conversely, the complementary connecting means (59) comprises the connecting means (59). ), characterized in that it comprises an elastic element (61) that can be clipped into the groove (60)
Clutch actuator. The method according to any one of claims 1 to 11,
Characterized in that it comprises means (57) for detecting the position of the pushing member (37).
Clutch actuator.

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