FR3069596A1 - CLUTCH ACTUATOR - Google Patents

Abstract

The invention relates to a clutch actuator (1) comprising an electric motor (8) comprising an output shaft (17) rotating with axis A, a roto-linear type motion transformation device (25, 53), having an input member (25) movable in rotation about an axis B parallel to the axis A and an output member (53) movable in translation along the axis B relative to the member of input (25), the input member (25) being rotated by the shaft (17) of the electric motor (8), the output member (53) driving the translational movement of a thrust (55) delimiting an internal volume with the output member (53), the input member (25) being housed, at least in part, in said internal space, characterized in that the thrust member ( 55) is traversed by at least one vent port (67).

Description

Clutch actuator

The present invention relates to a clutch actuator, in particular for a transmission system of a motor vehicle.

The invention applies in particular, but not exclusively, to the actuation of a single or double clutch whose idle state can be normally engaged or normally disengaged, to the actuation of a gearbox synchronizer for manual transmission, when actuating a robotic gearbox, when actuating a manual dual-clutch gearbox, or when actuating a clutch coupling a heat engine with a machine electric when the latter two are part of a propulsion chain of a hybrid vehicle.

The clutch actuator makes it possible to pass from a engaged state, in which the transmission system allows the transmission of a torque or a movement, to a disengaged state, in which such a transmission is not carried out. The clutch actuator also keeps the system in the engaged or disengaged state.

Document WO2015 / 090316 discloses a clutch actuator comprising a casing, an electric motor mounted on the casing and the output axis of which is coupled in rotation to a first pinion, a rotary-linear type movement transformation device comprising a screw carrying a second pinion meshing with the first pinion and comprising a nut. The nut cooperates with the screw and is coupled both in rotation and in translation with a thrust member. The thrust member makes it possible to actuate the displacement of a piston of a master cylinder, so as to be able to displace a volume of oil.

The rotation of the axis of the engine thus causes the displacement of the piston, by means of the pinions and the movement transformation device.

Such an actuator is said to be hydrostatic in that it allows the displacement of a volume of fluid, without however generating a flow rate of hydraulic fluid, the volume of fluid effectively remaining almost unchanged over time.

The screw is partially housed in the thrust member. When the screw moves relative to the nut, the volume of air inside the thrust member varies. The air then passes through, in particular, the threads of the nut and the screw. There is a need to best manage the evacuation and the introduction of air into the internal volume of the thrust member, which is difficult to achieve through the threads.

To this end, the invention relates to a clutch actuator comprising an electric motor comprising a rotating output shaft of axis A, a device for transforming movement of the roto-linear type, comprising an input member movable in rotation around an axis B parallel to the axis A and an output member movable in translation along the axis B relative to the input member, the input member being driven in rotation by the shaft of the electric motor, the outlet member causing the translational movement of a thrust member defining an internal volume with the outlet member, the inlet member being housed, at least in part, in said internal space, characterized in that the thrust member is traversed by at least one vent orifice.

The vent orifice makes it possible to communicate the internal volume of the thrust member with the volume external to said thrust member. In this way, air can pass through the vent orifice when the inlet member moves in the thrust member, varying the dimensions of said internal volume.

The inlet member may include a screw cooperating with a nut of the outlet member.

Rolling members can be mounted between the screw thread and the nut thread, said rolling members being lubricated.

The rolling members are for example balls or rollers. Lubrication is for example carried out with grease. In such a case, since the air can escape through the vent hole, this does not pollute the grease or the lubricating oil. This guarantees the proper functioning of the actuator.

The clutch actuator may comprise a hydraulic transmitter comprising a piston movable in translation along the axis B, the thrust member comprising an end surface bearing on the piston, the vent orifice being formed in said end surface, said end surface further comprising at least one groove connecting the vent orifice to the radially outer periphery of the end surface.

Air can thus pass through the vent orifice and the groove so as to communicate the internal volume of the thrust member and the radially external periphery of the end surface.

The clutch actuator may include a guide member at least partially surrounding the push member, the push member being coupled in rotation to the guide member and being able to be moved in translation along the axis B relative to said guide member, the volume defined between the guide member and the thrust member communicating with the internal volume of the thrust member, in particular through the vent orifice.

The guide member and the thrust member may comprise grooves of complementary shapes making it possible to couple them in rotation and to ensure the translational movement of the thrust member relative to the guide member. The air is able to circulate between said grooves.

The input member can be driven in rotation by the shaft of the electric motor, by means of a speed reducer, the clutch actuator comprising a casing and a cover delimiting a housing housing at least in part said speed reducer.

The volume of the housing can be in communication with the internal volume of the thrust member, in particular by means of the vent orifice and / or of the volume delimited between the guide member and the thrust member.

The housing and / or the cover may include an area provided with an air permeable membrane impermeable to oil and grease, so as to allow the passage of air between the internal volume of the housing and the outside through said permeable membrane.

Such a membrane is for example a porous membrane, for example a hydrophobic membrane made of PTFE material.

The inlet member can be pivotally mounted in the guide guide member by means of a bearing, the air being able to bypass said bearing.

The bearing is for example a ball bearing comprising an inner ring and an outer ring, the air being able to pass between said rings and between the balls.

The actuator according to the invention may also include one or more of the following characteristics:

The actuator comprises an electronic card housed in an electronic box, said electronic box being oriented parallel to the axis A and to the axis B. Such a structure makes it possible to reduce the space requirement, in particular the radial space requirement, it i.e. in the direction perpendicular to axes A and B.

- The electronic unit has a connector connected directly to a connector complementary to the electric motor. Such a characteristic makes it possible to reduce the bulk and limit the electromagnetic disturbances. This avoids the use of shielding means, which reduces costs.

- The electronic unit is removed from the engine, with the exception of the area containing the connector. This avoids thermal bridges and limits heating of the housing by conduction.

- The electronic unit is fixed to the housing.

- The electronic unit and / or the electronic card include means for dissipating heat.

- The electronic unit has a body and a cover. The housing body is for example made of reinforced thermoplastic, the housing cover being for example made of reinforced thermoplastic.

- The guide member is fixed relative to the housing.

- The thrust member is coupled in rotation and in translation to the nut.

- The housing comprises a first part forming a housing delimiting an internal volume, and a second generally cylindrical part, extending along the axis B from the first part;

- The second part leads into the internal volume of the first part.

- The first part has a B axis opening.

- The internal volume of the first part is closed by a cover capable of being fixed on the first part, for example by snap-fastening, screwing or welding.

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

- Said permeable membrane is located on the cover of the casing.

- Said membrane is located at one end of an orifice, in particular an orifice in the cover.

- Partitions or fins extend from the radially outer surface of the second part of the housing.

- Said partitions or fins extend along the axis B and circumferentially.

- The actuator housing is fixed to a gearbox housing, for example by means of a support.

- The electric motor is a permanent magnet motor without brushes or "brushless" motor.

- The motor comprises a body or stator forming a plate or a fixing flange, said plate or flange allowing the fixing of the motor body on the casing, for example by means of screws engaged in threads of the second part of the casing .

- The body has a cylindrical centering part, engaged and centered in the opening of axis A of the casing.

- An O-ring is formed between said opening of the casing and the external periphery of the cylindrical part of the body.

- The body comprises at least one electrical connector, comprising one or more pins.

- The axis of the motor extends along axis A through the opening of the housing, and opens into the internal volume of the first part of the housing.

- The axis of the motor carries a first pinion comprising a number Z1 of teeth.

- A second pinion is mounted idler, that is to say freely in rotation, around an axis or a pin.

- Said axis supporting the second pinion is mounted in a hole in the first part of the housing, at a first end, and in a hole in the cover, at a second end.

- The mounting of said axis in the corresponding holes is carried out without play.

- The second pinion meshes with the first pinion supported by the motor.

- A first washer, for example metallic, is mounted around the axis, between the cover and the pinion.

- A second washer, for example metallic, is mounted between the pinion and the first part of the housing.

- A third pinion, of axis B, is integral in rotation with a first end of the screw of the movement transformation means.

- The third pinion meshes directly with the second pinion and has a number Z2 of teeth.

- The three pinions are housed in the internal volume of the housing.

- The reduction ratio of the reducer formed by the first pinion and by the third pinion, that is to say the ratio Z1 / Z2 is between 1 and 5,

- The sprockets are lubricated with oil or grease.

- The third pinion is fixed to the rear end of a screw, that is to say the end located on the side of the cover, by means of a screw and a washer.

- The third pinion can be fixed to the rear end of the screw by fitting and crimping.

- The screw has a smooth cylindrical part and a part having a thread.

- The thread of said screw has a pitch and a profile compatible with the use of balls engaged in the threads.

- The housing and / or the cover are made of aluminum, steel or plastic.

- The gables are made of plastic.

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

- The bearing has an inner ring surrounding the screw and an outer ring housed in the guide member.

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

The guide member has a first end situated on the side of the first part of the casing, and a second end opposite the first end, the guide member comprising, at its first end, a radially internal cylindrical part and a radially outer cylindrical part, connected by a radially extending connecting zone.

- Centering pads extend radially outward from the radially outer cylindrical part.

- Each centering stud has two lateral surfaces oblique to the axis B, the stud tapering towards the front.

- The guide member may include a cylindrical centering zone for positioning the bearing. Advantageously, the cylindrical centering zone is discontinuous in order to allow the air to bypass said bearing.

- The guide member has, at its first end, lugs extending radially outward from the connection zone.

- Said tabs have holes allowing the engagement of screws.

- Said screws are engaged in holes in a fixing plate, for example of generally square shape, mounted in the internal volume of the first part.

- Each screw is engaged in a thread on the housing.

- The guide member is integral with the casing.

- The guide member comprises, in front of the first part, that is to say opposite the cover with respect to the first part, a second cylindrical part of axis B, having grooves.

- Each groove has sides in the form of an involute of a circle.

- The guide member comprises a third part, located in front of the second part, of generally cylindrical shape and with a diameter less than the diameter of the second part.

- An annular radial shoulder is delimited between the second part and the third part.

- Openings are provided in said shoulder, for example four openings regularly distributed over the circumference.

- Each opening having an oblong shape.

- The outer ring is housed with minimal play in the radially inner cylindrical part of the first part of the guide member.

- The radially external surface of the studs bears on the internal surface of the second part of the casing.

- The connecting part provides flexibility allowing good centering of the radially inner and outer cylindrical parts of the guide member.

- An internal ring is mounted axially between the internal ring of the bearing and the front end of the thread.

- An outer ring is mounted axially between the outer ring of the bearing and the nut.

- Said nut has a thread whose pitch and profile are compatible with the use of balls engaged in the threads.

- The radially outer periphery of the nut has a groove oriented along the axis B.

- Said groove has a section in the form of a circular arc.

- The balls, the thread of the screw and the thread of the nut are lubricated with grease.

- The thrust member comprises a first part located at the rear, of generally cylindrical shape, and a second part located at the front, of general cylindrical shape and of smaller diameter than the first part.

- The first part and the second part of the pushing member thus define an annular shoulder extending radially.

- The first part of the thrust member comprises grooves cooperating by shape cooperation with the grooves of the guide member.

- The nut is housed in the first part of the thrust member.

- The first part of the thrust member comprises a rib engaged in the groove of the nut, so as to couple the nut and the thrust member in rotation.

- The front end of the nut is supported on the radial shoulder.

- Said shoulder has protruding studs, the studs being for example four in number and being regularly distributed over the circumference.

- Said studs have a shape similar to that of the openings of the guide member and are capable of passing through said openings.

- The second part of the thrust member is engaged at its front end in the third part of the guide member.

- The diameter of the second part of the thrust member corresponds substantially to the diameter of the third part of the guide member.

- The front end of the thrust member comprises connecting means capable of connecting the internal volume of the second part and the space located between the guide member and the casing, in particular the second part of the casing.

- The hydraulic transmitter is a master cylinder and has a body fixed on the casing, in particular on the front end of the second part of the casing, for example by means of a fixing ring.

- The piston of the hydraulic transmitter is movable along the axis B relative to the body.

- The piston is returned towards the rear by a return spring axially interposed between the corresponding end of the piston and the body.

- The body also includes a connection zone used to connect a pipe.

- The displacement of the piston causes the displacement of a volume of hydraulic fluid in the pipe, for example oil, so as to actuate a hydraulic receiver, itself capable of actuating a clutch.

- The connection area extends parallel to axis B and offset from said axis B.

- The front end of the pushing member is in plan support on the rear end of the piston.

- The surface of the front end of the thrust member and the surface of the rear end of the piston are radially oriented surfaces.

- The front end surface of the pushing member is crossed by at least one vent orifice, for example two diametrically opposite vent orifices, opening on the one hand into the internal volume of the second part of the thrust member and on the other hand in grooves or grooves connecting each orifice to the outer periphery of the front end surface.

- Said surface has radial grooves, for example six in number.

- Said surface has grooves in the form of a circular arc, connecting at least some of the grooves.

- The electronic card and the electronic unit include connectors, making it possible to electrically connect the card to the electric motor and to at least one member of the vehicle.

- At least one connector of the electronic unit makes it possible to connect the electronic card to a source of electrical energy, for example to the battery of the on-board network of the vehicle and / or to a CAN bus (Controller Area Network) so as to control the electric motor from the engine control unit (ECU) and / or the vehicle clutch control unit (CCU), these units being able to implement software for monitoring the vehicle transmission system.

- One of the connectors is connected to at least one vehicle sensor, for example a sensor providing information on the position of a clutch pedal, a sensor providing information on the position of a gear lever, a sensor providing information on the position of an element of the gearbox and / or a sensor providing information on the position of an element of an element of the hydraulic transmitter or of the associated hydraulic receiver.

- The cover of the electronic box is fixed or snapped onto the body of the electronic box.

- The heat dissipation means of the electronic unit are located at the level of the cover.

- The heat dissipation means comprise projecting elements, for example fins or cones.

- The electronic unit is located in an area of the actuator which is spaced from the gearbox housing.

- The rotary type movement transformation device comprises a conventional screw-nut type system or using a ball screw or a roller screw.

- The speed reducer comprises a first pinion coupled in rotation to the motor shaft and a second pinion coupled in rotation to the screw, the first pinion directly meshing with the second pinion.

- The speed reducer comprises one or more reduction stages, for example two reduction stages.

- The opening of the casing used for mounting the engine mounting comprises zones oriented along an axis C forming an angle between 5 and 25 ° with axis A and bearing surfaces oriented along axis A.

The invention will be better understood and other details, characteristics and advantages of the invention will appear on reading the following description given by way of nonlimiting example with reference to the appended drawings in which:

FIGS. 1 and 2 are perspective views of a clutch actuator according to an embodiment of the invention,

- Figure 3 is an axial sectional view of the actuator,

- Figures 4 and 5 are exploded perspective views of the actuator,

- Figures 6 and 7 are perspective views of the thrust member

FIG. 8 is a view in axial section of the thrust member,

FIG. 9 is a perspective view of the guide member,

- Figures 10 to 12 are views illustrating different successive positions of the engine when it is mounted on the housing of a clutch actuator according to another embodiment.

Figures 1 to 9 illustrate a clutch actuator 1 according to an embodiment of the invention. This comprises a casing 2 comprising a first part 2a forming a housing delimiting an internal volume and having an opening 3 of axis A, and a second part 2b generally cylindrical, extending along an axis B from the first part. The second part 2b opens into the internal volume of the first part 2a. Axis B is parallel to axis A and is offset from said axis A.

The internal volume of the first part 2a can be closed by a cover 4 able to be fixed by snap-fastening, screwing or any other suitable means on the first part 2a. The casing 2 and the cover 4 are for example made of plastic, these elements 2, 4 being able to be welded to each other by laser welding or by ultrasonic welding.

The cover 4 and / or the casing 2 may comprise at least one zone 5 which is permeable to air but impermeable to liquids, for example to water, to oil, or even impermeable to grease. Such a zone 5 is for example produced by a porous membrane (visible in FIG. 3), for example a hydrophobic membrane produced in expanded PTFE material, said membrane being located at the end of an orifice 6 of the cover 4.

Partitions or fins 7 extend from the radially outer surface of the second part 2b. Said partitions 7 extend along the axis B and / or circumferentially.

The casing 2 of the actuator 1 is for example intended to be fixed to a casing of a gearbox, for example by means of a support not shown.

The actuator 1 further comprises an electric motor 8, in particular a brushless permanent magnet motor or so-called “brushless” motor, mounted on the casing 2. The motor 8 comprises a body 9 or stator forming a plate or a flange of fixing 10, said plate or flange 10 allowing the body 9 of the motor 8 to be fixed on the casing 2, for example by means of screws 11 engaged in internal threads 12 (FIG. 5) located at the level of the second part 2b of the casing 2. The body 9 also comprises a cylindrical centering part 13, engaged and centered in the cylindrical opening 3 of the casing 2. An O-ring 14 can be formed between said opening 3 and the external periphery of the cylindrical part 13 of the body 9.

The body 9 also includes at least one electrical connector 15, comprising one or more pins 16 (FIG. 5).

The motor 8 also comprises a rotary axis 17, integral with the rotor of the motor 8. The axis 17 extends along the axis A through the opening 3, and opens into the internal volume of the first part 2a of the casing 2. The axis 17 carries a first pinion 18 comprising a number Z1 of teeth. A second pinion 19 is mounted idly, that is to say freely in rotation, about an axis or a pin 20. Said axis 20 is mounted in a hole 21 in the first part 2a of the casing 2, at a first end, and in a hole 22 of the cover 4, at a second end (Figure 3). The mounting of the axis 20 in the holes 21, 22 can be carried out without play. The second pinion 19 meshes with the first pinion 18 supported by the motor 8.

A first washer 23, for example metallic, is mounted around the axis 20 between the second pinion 19 and the first part 2a of the casing 2. A second washer, for example metallic, can be mounted around the axis 20, between cover 4 and pinion 19.

A third pinion 24, of axis B, is integral in rotation with a first end 26 of a screw 25. The third pinion 24 meshes directly with the second pinion 19 and has a number Z2 of teeth. The three pinions 18, 19, 24 are housed in the internal volume of the housing 2a. The reduction ratio, that is to say the Z1 / Z2 ratio is for example between 1 and 5, in this embodiment. The sprockets 18, 19, 24 can be lubricated with oil or grease.

The third pinion 24 is fixed to the rear end 26 of the screw 25, that is to say the end situated on the side of the cover 4, by means of a screw 27 and a washer 28.

The screw 25 has a smooth cylindrical rear part 26 and a front part 29 having a thread.

The thread of said screw 25 here has a pitch and a profile compatible with the use of balls 30 engaged in the threads.

The casing 2 and / or the cover 4 can be made of aluminum, steel or plastic for example. The pinions 18, 19, 24 are for example made of plastic or steel.

The screw 25 is supported by a bearing, here a ball bearing 31, near the first end 26. The bearing 31 has an internal ring 32 surrounding the screw 25 and an external ring 33 housed in a guide member 34.

The guide member 34 is for example made of steel, aluminum or plastic. This comprises a first part 35 located on the side of the first part 2a of the casing 2, and a second part 36 opposite the first part 35.

The guide member 34 comprises, at its first part 35, a radially internal cylindrical part 37 and a radially external cylindrical part 38, connected by a connecting region 39 extending radially (FIG. 4). Centering pads 40 (see in particular FIG. 9) extend radially outward from the radially external cylindrical part 38. Each centering pad 40 has two oblique lateral surfaces 41 relative to the axis B, the pad 40 narrowing forward. As a variant, the stud 40 can narrow backwards.

The guide member 34 further comprises, at its first part 35, lugs 42 extending radially outward from the connection zone 40, said lugs 42 having holes 43 allowing the engagement of screws 44 Said screws 44 are also engaged in holes in a fixing plate 45, here of generally square shape, mounted in the internal volume of the first part 2a. Each screw 44 is engaged in a thread of the casing 2. The guide member 34 is thus secured to the casing 2.

The second part 36 is cylindrical with axis B and has grooves 46. Each groove 46 has flanks 47 in the form of an involute of a circle (FIG. 9). Other forms can be considered.

The guide member 34 further comprises a third part 48, located in front of the second part 36, of generally cylindrical shape and with a diameter less than the diameter of the second part 36. An annular radial shoulder 49 is thus delimited between the second part 36 and the third part 48. Openings 50 are formed in said shoulder 49, here four openings 50 regularly distributed over the circumference, each opening 50 having an oblong shape.

The outer ring 33 of the bearing 31 is housed with a minimum clearance in the radially internal cylindrical part 37 of the first part 35 of the guide member 34. Furthermore, the radially external surface of the studs 40 is supported on the internal surface of the second part 2b of the casing 2. The connecting part 40 provides a certain flexibility allowing good centering of the radially internal and external cylindrical parts 37, 38 of the guide member 34.

An inner ring 51 is mounted axially between the inner ring 32 of the bearing 31 and the front end of the thread 29. An outer ring 52 is mounted axially between the outer ring 38 of the bearing 31 and a nut 53. Said nut 53 has a thread whose pitch and profile are compatible with the use of balls 30 engaged in the threads. The radially outer periphery of the nut 53 has a groove 54 (FIG. 4) oriented along the axis B. Said groove 54 has a section in the shape of an arc of a circle.

The assembly formed by the nut 53, the screw 25 and the balls 30 thus form a movement transformation system of the rotolinear type, that is to say capable of transforming the rotational movement of the screw 25 into a translational movement of the nut 53, with minimum friction, that is to say with maximum efficiency. The balls 30, the thread of the screw 25 and the thread of the nut 53 can be lubricated with grease.

The nut 53 is coupled in rotation to a pushing member 55. Said pushing member 55 comprises a first part 56 located at the rear, of generally cylindrical shape, and a second part 57 located at the front, of general shape cylindrical and of smaller diameter than the first part 56. The first part 56 and the second part 57 of the pushing member 55 thus delimit an annular shoulder 58 extending radially.

The first part 56 comprises splines 59 cooperating by shape cooperation with the grooves 46 of the guide member

34. In this way, the thrust member 55 is coupled in rotation to the guide member 34 and is capable of sliding relative to the latter along the axis B.

The nut 53 is housed in the first part 56. The first part 56 comprises a rib 60 (FIG. 6) engaged in the groove 54 of the nut 53 so as to rotate the nut 53 and the thrust member 55. Furthermore, the front end of the nut 53 bears on the radial shoulder 58.

Said shoulder 58 comprises studs 61 projecting, the studs 61 being here four in number and being regularly distributed over the circumference. The studs 61 have a shape similar to that of the openings 50 of the guide member 34 and are capable of passing through said openings 50.

The second part 57 of the pushing member 55 is engaged at its front end in the third part 48 of the guide member 34. In particular, the diameter of the second part 57 of the pushing member 55 corresponds substantially to the diameter of the third part 48 of the guide member 34.

The front end of the thrust member 55 comprises connecting means capable of connecting the internal volume of the second part 57 and the space located between the guide member 34 and the casing 2, in particular the second part 2b housing 2.

The actuator 1 further comprises a hydraulic transmitter 62, which is here a master cylinder. This comprises a body 63 fixed to the casing 2, and in particular to the front end of the second part 2a of the casing 2, by means of a fixing ring 64. The latter also comprises a piston 65 (Figure 3) movable along the axis B relative to the body 63. The piston 65 is biased backwards by a return spring 66 interposed axially between the front end of the piston 65 and the body 63. The body 63 further includes a connection area 66a for connecting a pipe. The displacement of the piston 65 causes the displacement of a volume of hydraulic fluid in the pipe, for example oil, so as to actuate a hydraulic receiver, itself suitable for actuating a clutch, as is known per se.

The front end of the pushing member 55 is in plane support on the rear end of the piston 65. The surface of the front end of the pushing member 55 and the surface of the rear end of the piston are radially oriented surfaces. Such a flat support authorizes a possible offset of the piston and of the thrust member 55, so as to avoid forcing the piston and to avoid any risk of leakage between the piston and the body.

The front end surface of the pushing member 55 is crossed by at least one vent orifice 67, here two vent orifices 67 diametrically opposed (FIG. 7), opening on the one hand into the internal volume of the second part 57 of the thrust member 55 and on the other hand in grooves 68 or grooves 69 connecting each orifice 67 to the radially outer periphery of the front end surface 70. In particular, said surface 70 has radial grooves 69, here six in number, and grooves 68 in the form of an arc of a circle, connecting at least some of the grooves 69.

The actuator 1 further comprises a housing 71 housing an electronic power and / or control card, said housing 71 being fixed on the housing 2, by means of screws for example.

The electronic card and the housing 71 comprise connectors 72, 73 (FIG. 4), making it possible to electrically connect the card to the electric motor 8 and / or to at least one member of the vehicle (not shown). The connector 72 of the housing 71 is connected directly to the connector 15 of the motor 8, so as to reduce the bulk and limit the electromagnetic disturbances. The connector 72 is oriented perpendicular to the housing 71 and to the electronic card.

This avoids the use of shielding means, which reduces costs.

The connector 72 can also connect the ground of the engine 8 to the ground of a clutch control unit (CCU) for example, in addition to the phases of the engine 8 and the position and switching signals of the engine 8.

Other connectors 73 making it possible to connect the electronic card to a source of electrical energy, for example to the battery of the on-board network of the vehicle and / or to a CAN bus (Controller Area Network) so as to control the electric motor at from the engine control unit (ECU) and / or the vehicle clutch control unit (CCU), these units being able to implement software for monitoring the vehicle transmission system. One of the connectors 76 can also be connected to at least one vehicle sensor, for example a sensor providing information on the position of a clutch pedal, a sensor providing information on the position of a gear lever , a sensor providing information on the position of an element of the gearbox and / or a sensor providing information on the position of an element of an element of the hydraulic transmitter 62 or of the associated hydraulic receiver.

Furthermore, apart from the area of the connectors 72 of the housing 71 and of the motor 8, the housing 71 is separated from the motor 8, so as to avoid thermal bridges and limit the heating of the housing 71 and of the electronic card by conduction.

The housing 71 is oriented in a plane extending parallel to the axes A and B, so as to improve the radial compactness of the actuator

1.

The housing 71 comprises a body 74 and a cover 75 fixed or snapped onto the body 74. The housing 71 comprises heat dissipation means, here at the level of the cover. The heat dissipation means comprise fins or projecting elements, for example cones 76, so as to increase the surface area for heat exchange with the surrounding air.

The housing 71 is located in an area of the actuator 1 which is spaced from the gearbox casing, this casing forming a heat source.

In operation, the electric motor 8 is controlled using the electronic card, causing the rotation of the axis 17 and the first pinion 18. The latter then rotates the second pinion 19, the third pinion 24 and the screw 25. The speed of rotation of the screw 25 is a function of the speed of rotation of the motor 8 and of the reduction ratio Z2 / Z1.

The rotation of the screw 25 causes the nut 53 to move along the axis B. The latter being in axial abutment on the shoulder 58, the thrust member 55 is then moved along the axis B between a first position extreme, illustrated in FIG. 3, in which the nut 53 is in abutment on the outer ring 52, and a second extreme position in which the studs 61 of the thrust member 55 are in abutment on the rear radial face of the body 63 of the hydraulic transmitter. These two extreme positions correspond for example to engaged and disengaged positions of the clutch.

The hydraulic transmitter 62 used can be a standard commercial transmitter.

The translational movement, along axis B, of the nut 53 and the thrust member 55, causes the piston 65 and the hydraulic fluid to move so as to control the hydraulic receiver 62.

During the axial displacement of the nut 53, air can pass through the vent orifices 67, the grooves 69 and the grooves 68, so that the air trapped in the internal volume of the second part 57 of the thrust member 55 can escape towards the outside by crossing the space situated between the second part 2b of the casing 2 and the guide member 34 in particular, by crossing the bearing 31 and crossing the zone 5 permeable to the air in the cover 4. In this way, this air is prevented from passing through and polluting the grease allowing the balls 30 to be lubricated.

According to an embodiment not shown, the assembly formed by the screw 25, the balls 30 and the nut 53 can be replaced by a conventional screw-nut type system, the pitch of which is smaller or larger. In such a case, it is necessary to adapt the reduction ratio.

The apparent pitch can be reduced (several threads), but the real pitch (or helical pitch) is generally larger to ensure correct performance.

The ball screw 25, 30 could also be replaced by a roller screw.

Furthermore, the reducer composed of the three pinions 18, 19, 24 can be replaced by a reducer comprising a first pinion coupled in rotation to the shaft 17 of the motor 8 and a second pinion coupled in rotation to the rear end 26 of the screw 25, the first pinion meshing directly with the second pinion.

The reducer may include one or more reduction stages, for example two reduction stages, as is known from document EP 2 860 869 for example.

FIGS. 10 to 12 illustrate another embodiment of the invention in which the opening 3 of the casing comprises zones 3a oriented along an axis C forming an angle between 5 and 25 ° with the axis A and spans 3b oriented along axis A.

When the motor 8 is mounted on the casing 2, the motor 8 is engaged along the axis C, from front to rear, so that the axis 17 carrying the first pinion 18 and the cylindrical centering part 13 of the body 9 are engaged in the opening 3 (Figures 10 and 11). The motor 8 is then tilted so as to extend along the axis A, the cylindrical part 13 of the body 9 then coming to rest on the bearing surfaces 3b of the casing 2 (Figure 12).

The screws 11 can then be fixed in the casing 2, in particular in the threads 12 formed in the second part 2a of the casing 2.

Whatever the embodiment envisaged, such an actuator has a compact structure, having a small footprint along the axes A and B and in the direction perpendicular to said axes. Furthermore, it is possible to use many elements of the trade, such as for example the hydraulic transmitter 62 or the ball screw 25, 30, for example. The cost of such an actuator is also relatively low and can be easily integrated into existing propulsion systems.

Claims (9)

1. clutch actuator (1) comprising an electric motor (8) comprising an output shaft (17) rotating on axis A, a roto-linear type movement transformation device (25, 53), comprising a member inlet (25) movable in rotation about an axis B parallel to the axis A and an outlet member (53) movable in translation along the axis B relative to the inlet member (25 ), the input member (25) being rotated by the shaft (17) of the electric motor (8), the output member (53) causing the translational movement of a thrust member (55 ) delimiting an internal volume with the outlet member (53), the inlet member (25) being housed, at least in part, in said internal space, characterized in that the thrust member (55) is crossed by at least one vent orifice (67). 2. Clutch actuator (1) according to claim 1, characterized in that the input member comprises a screw (25) cooperating with a nut (53) of the output member. 3. clutch actuator (1) according to claim 2, characterized in that rolling members (56) are mounted between the thread of the screw (25) and the thread of the nut (53), said rolling members being lubricated. 4. clutch actuator (1) according to one of claims 1 to 3, characterized in that it comprises a hydraulic transmitter (62) comprising a piston (65) movable in translation along the axis B, the thrust member (55) comprising an end surface (70) bearing on the piston (65), the vent orifice (67) being formed in said end surface (70), said end surface (70) further comprising at least one groove (69) connecting the orifice d vent (67) at the radially outer periphery of the end surface (70). 5. Clutch actuator (1) according to one of claims 1 to 4, characterized in that it comprises a guide member (34) at least partially surrounding the thrust member (55), the thrust member (55) being coupled in rotation to the guide member (34 ) and being able to be moved in translation along the axis B relative to said guide member (34), the volume defined between the guide member (34) and the thrust member (55) communicating with the internal volume of the thrust member (55), in particular through the vent orifice (67). 6. clutch actuator (1) according to one of claims 1 to 5, characterized in that the input member (25) being rotated by the shaft (17) of the electric motor (8), by means of a speed reducer (18, 19, 24), the clutch actuator (1) comprising a casing (2) and a cover (4) delimiting a housing housing at least partially said reducer speeds (18, 19, 24). 7. clutch actuator (1) according to claim 6, characterized in that the volume of the housing is in communication with the internal volume of the thrust member (55), in particular through the orifice vent (67) and / or of the volume delimited between the guide member (34) and the thrust member (55). 8. clutch actuator (1) according to claim 7, characterized in that the housing (2) and / or the cover (4) comprises an area provided with an air permeable and oil impermeable membrane and to grease, so as to allow the passage of air between the internal volume of the housing and the exterior through said permeable membrane. 9. clutch actuator according to one of claims 5 to 8, characterized in that the input member (25) is pivotally mounted in the guide guide member by means of a bearing, l air being able to bypass said bearing.