Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D29/00—Clutches and systems of clutches involving both fluid and magnetic actuation
  • F16D29/005—Clutches and systems of clutches involving both fluid and magnetic actuation with a fluid pressure piston driven by an electric motor
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D23/00—Details of mechanically-actuated clutches not specific for one distinct type
  • F16D23/12—Mechanical clutch-actuating mechanisms arranged outside the clutch as such
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D25/00—Fluid-actuated clutches
  • F16D25/08—Fluid-actuated clutches with fluid-actuated member not rotating with a clutching member
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D28/00—Electrically-actuated clutches
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H1/00—Toothed gearings for conveying rotary motion
  • F16H1/02—Toothed gearings for conveying rotary motion without gears having orbital motion
  • F16H1/20—Toothed gearings for conveying rotary motion without gears having orbital motion involving more than two intermeshing members
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D23/00—Details of mechanically-actuated clutches not specific for one distinct type
  • F16D23/12—Mechanical clutch-actuating mechanisms arranged outside the clutch as such
  • F16D2023/123—Clutch actuation by cams, ramps or ball-screw mechanisms
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D25/00—Fluid-actuated clutches
  • F16D25/08—Fluid-actuated clutches with fluid-actuated member not rotating with a clutching member
  • F16D2025/081—Hydraulic devices that initiate movement of pistons in slave cylinders for actuating clutches, i.e. master cylinders
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D2121/00—Type of actuator operation force
  • F16D2121/18—Electric or magnetic
  • F16D2121/24—Electric or magnetic using motors

Definitions

• the present invention relates to a clutch actuator, in particular for a transmission system of a motor vehicle.
• the invention applies particularly, but not exclusively, to the actuation of a single or double clutch whose idle state can be normally engaged or normally disengaged, the actuation of a gearbox synchronizer for manual transmission, when actuating a robotized gearbox, the actuation of a manual gearbox with a double clutch, or the actuation of a coupling clutch of a heat engine with a machine when the latter two are part of a propulsion system of a hybrid vehicle.
• the clutch actuator makes it possible to move from an engaged state, in which the transmission system makes it possible to transmit a torque or a movement, to a disengaged state, in which such transmission is not performed.
• the clutch actuator also keeps the system in the engaged or disengaged state.
• WO2015 / 090316 discloses a clutch actuator comprising a housing, an electric motor mounted on the housing and whose output axis is coupled in rotation to a first gear, a roto-linear type motion transformation device comprising a screw carrying a second pinion meshing with the first pinion and having a nut. The nut cooperates with the screw and is coupled both in rotation and in translation with a thrust member. The thrust member allows to actuate the displacement of a piston of a master cylinder, so as to move a volume of oil.
• Such an actuator is said to be hydrostatic in that it allows the displacement of a volume of fluid, without, however, generating a flow of hydraulic fluid, the volume of fluid remaining in effect virtually unchanged over time.
• the axis of the motor is secured to a first pinion, meshing with a second pinion mounted idle, that is to say free to rotate, about an axis mounted in the housing, the screw of the device roto-linear type of motion transformation being secured to a third pinion meshing with the second pinion.
• the second gear comprises two teeth axially offset from one another and having diameters and numbers of teeth different from one to the other toothing.
• a first gear of the second gear meshes with the first gear and a second gear of the second gear meshes with the third gear.
• the second pinion thus has a complex structure and a large axial size.
• the axis of the second pinion is supported only at one of its ends by the housing. It may then be difficult to keep the axis of the second gear parallel to the axes of the first and third gears, which may cause premature wear of the gears.
• the invention relates to a clutch actuator comprising a housing, an electric motor fixed to the housing and comprising a rotating shaft of axis A, a roto-linear type motion transformation device comprising input movable in rotation about an axis B parallel to the axis A and an output member movable in translation along the axis B, the input member being rotated by the shaft of the electric motor , by means of a gearbox, the gearbox comprising a first toothed gear integral with the motor shaft, a second toothed gear idler about an axis parallel to the axes A and B and meshing with the first gear, and a third toothed gear integral with the input member and meshing with the second gear, characterized in that the second gear comprises a single toothing meshing with both the first gear and the third gear.
• the single-toothed structure of the second pinion according to the invention is less complex, which reduces costs.
• the second gear also has a smaller axial size.
• the teeth of the pinions are for example helical or straight teeth.
• the housing may define a housing with a cover fixed to the housing, said gears being housed in said housing, the axis of the second gear being supported by the housing at one end and the cover at a second end.
• the axis of the second pinion is thus supported at both ends so as to ensure the parallelism between the axes of the different gears. This prevents premature wear of the gears.
• the axis of the second gear is mounted in a hole of the housing and in a hole of the cover, the mounting of said axis in said holes being made without play.
• the axis is suitable for centering or positioning the cover on the housing, before fixing said cover to the housing, for example by welding.
• a washer for example metal is mounted around the axis of the second gear, axially between the second gear and the housing.
• a washer, for example metal may be mounted around the axis of the second gear, axially between the second gear and the cover.
• Each washer is for example metallic.
• the metal washer can be secured to the second pinion or housing, for example by fitting or overmolding.
• the metal washer can be secured to the second pinion or cover, for example by fitting or overmolding.
• the actuator may comprise a guiding member fixed relative to the casing, the output member being coupled in rotation to the guiding member and being able to be displaced in translation relative to the guiding member, along the B axis.
• the output member and the guide member may comprise complementary splines adapted to perform the coupling in rotation between said elements, while allowing their relative displacement in translation.
• the input member of the motion transformation device may be a screw, the output member being formed by a nut cooperating with said screw.
• the output member may comprise a thrust member coupled in rotation and in translation to the nut.
• the actuator may comprise a hydraulic transmitter comprising a movable piston and actuated by the displacement along the axis B of the output member of the motion transformation device.
• Said 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, that is to say in the direction perpendicular to the axes A and B.
• the electronic unit comprises a connector connected directly to a complementary connector of the electric motor.
• control unit is removed from the motor, except for the area with the connector. This avoids thermal bridges and limits the heating of the electronic unit by conduction.
• the electronics box is attached to the housing.
• the electronic box and / or the electronic card comprise means of heat dissipation.
• the electronic box has a body and a lid.
• the body of the electronic housing is for example made of reinforced thermoplastic, the lid of the electronic housing being for example made of reinforced thermoplastic.
• the housing comprises a first portion forming the housing and defining an internal volume, and a second generally cylindrical portion extending along the axis B from the first portion;
• the second part opens into the internal volume of the first part.
• the first part has an opening axis B.
• the internal volume of the first part is closed by a cover adapted to be fixed on the first part, for example by snapping, screwing or welding.
• the housing and cover are made of plastic and are welded to each other by laser welding or ultrasonic welding.
• the housing comprises at least one breathable zone but impervious to liquids, for example water, or oil, or impermeable to grease.
• Said permeable zone is formed on the cover of the housing.
• Said permeable zone is produced by a porous membrane, for example a hydrophobic membrane made of
• Said membrane is located at one end of an orifice of the housing, in particular an orifice of the lid.
• Partitions or fins extend from the radially outer surface of the second part of the housing.
• the said partitions or fins extend along the axis B and circumferentially.
• the casing of the actuator is fixed to a casing of a gearbox, for example by means of a support.
• the electric motor is a brushless permanent magnet motor or brushless motor.
• the motor comprises a body or stator forming a plate or a mounting flange, said plate or flange for fixing the motor body on the housing, for example by means of screws engaged in threads of the second part of the housing .
• the body has a cylindrical centering portion, engaged and centered in the opening of axis A of the housing.
• An O-ring is provided between said housing opening and the outer periphery of the cylindrical portion of the body.
• the body comprises at least one electrical connector, having one or more pins.
• the axis of the motor extends along the axis A through the opening of the housing, and opens into the internal volume of the first part of the housing.
• the first pinion comprises a number Z1 of teeth
• the third pinion comprises a number Z2 of teeth
• the reduction ratio of the reducer formed by the first pinion and by the third pinion that is to say the ratio Z1 / Z2; being between 1 and 5
• the axis of the second pinion is formed by a pin.
• the sprockets are lubricated with oil or grease.
• the third pinion is fixed to the rear end of a screw, that is to say at the end located on the side of the lid, by means of a screw and a washer.
• the third pinion can be attached to the rear end of the screw by fitting and crimping.
• the screw has a smooth cylindrical portion and a portion having a thread.
• the thread of said screw has a pitch and a profile compatible with the use of balls engaged in the nets.
• the housing and / or the cover are made of aluminum, steel or plastic.
• the gears are made of plastic.
• the screw is supported by a bearing, for example a ball bearing, near the first end.
• a bearing for example a ball bearing
• the bearing comprises an inner ring surrounding the screw and an outer ring housed in the guide member.
• the guide member is steel, aluminum or plastic.
• the guide member has a first end located on the side of the first portion of the housing, and a second end opposite the first end, the guide member having, at its first end, a cylindrical portion radially internal and a radially external cylindrical part, connected by a radially extending connection zone.
• Centering studs extend radially outwardly from the radially outer cylindrical portion.
• Each centering stud has two lateral surfaces oblique with respect to the axis B, the stud narrowing towards the front.
• the guide member comprises, at its first end, tabs extending radially outwardly from the connecting zone.
• the said tabs have holes for the engagement of screws.
• - Said screws are engaged in holes of 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 of the housing.
• the guide member is integral with the housing.
• the guide member comprises, in front of the first part, that is to say opposite the lid relative to the first part, a second cylindrical portion of axis B, having splines.
• Each groove has flanks in the form of involute circle.
• the guide member comprises a third portion, located in front of the second portion, of generally cylindrical shape and a diameter smaller than the diameter of the second portion.
• An annular radial shoulder is defined between the second portion and the third portion.
• Openings are formed in said shoulder, for example four regularly distributed openings on the circumference.
• Each opening having an oblong shape.
• the outer ring is housed with a minimum clearance in the radially inner cylindrical portion of the first portion of the guide member.
• the radially outer surface of the pads is supported on the inner surface of the second part of the housing.
• the connecting portion provides flexibility to ensure a good centering of the cylindrical portions radially inner and outer of the guide member.
• An inner ring is mounted axially between the inner 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 nets.
• 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 tapping of the nut are lubricated with grease.
• the thrust member comprises a first portion located at the rear, of generally cylindrical shape, and a second portion at the front, generally cylindrical in shape and smaller in diameter than the first part.
• the first part and the second part of the thrust member thus delimit an annular shoulder extending radially.
• the first part of the thrust member has splines 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 in rotation the nut and the thrust member.
• the front end of the nut is supported on the radial shoulder.
• - Said shoulder comprises projecting pads, the pads being for example four in number and being evenly distributed on the circumference.
• - Said pads have a shape similar to that of the openings of the guide member and are adapted to pass 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 portion of the urging member substantially corresponds to the diameter of the third portion of the guide member.
• the front end of the thrust member comprises connecting means adapted to connect the internal volume of the second part and the space between the guide member and the housing, in particular the second part of the housing.
• the hydraulic transmitter is a master cylinder and comprises a body fixed on the housing, in particular on the front end of the second part of the housing, 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 biased back by a return spring interposed axially between the corresponding end of the piston and the body.
• the body further comprises a connection area for connecting a pipe.
• the movement 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 able to actuate a clutch.
• connection area extends parallel to the axis B and offset from said axis B.
• the front end of the thrust member is in plane 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 thrust member is traversed by at least one vent orifice, for example two vent holes diametrically opposed, opening on the one hand in the internal volume of the second portion 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 comprises radial grooves, for example six in number.
• Said surface comprises grooves in the shape of a circular arc, connecting at least some of the grooves.
• the electronic card and the housing have connectors for electrically connecting the card to the electric motor and at least one body of the vehicle.
• At least one connector of the box makes it possible to connect the electronic card to a source of electrical energy, for example to the battery of the on-board vehicle network and / or to a CAN bus (Controller Area Network) so as to control the motor; electrical power from the engine control unit (ECU) and / or the clutch control unit (CCU) of the vehicle, these units can implement a monitoring software of the vehicle transmission system.
• a source of electrical energy for example to the battery of the on-board vehicle network and / or to a CAN bus (Controller Area Network) so as to control the motor; electrical power from the engine control unit (ECU) and / or the clutch control unit (CCU) of the vehicle, these units can implement a monitoring software of the vehicle transmission system.
• ECU engine control unit
• CCU clutch control unit
• One of the connectors is connected to at least one sensor of the vehicle, 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 a gearbox element and / or a sensor providing information on the position of an element of an element of the hydraulic transmitter or the associated hydraulic receiver.
• 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 a gearbox element and / or a sensor providing information on the position of an element of an element of the hydraulic transmitter or the associated hydraulic receiver.
• the electronic box cover is fixed or snapped onto the housing body.
• the heat dissipation means of the electronic unit are located at the cover.
• the heat dissipation means comprise projecting elements, for example fins or cones.
• the control unit is located in an area of the actuator that is separated from the gearbox housing.
• the roto-linear type motion transformation device comprises a conventional screw-nut type system or using a ball screw or a roller screw.
• the gearbox comprises a first pinion coupled in rotation to the motor shaft and a second pinion coupled in rotation to the screw, the first pinion meshing directly with the second pinion.
• the gearbox comprises one or more reduction stages, for example two reduction stages.
• the opening of the housing used to mount the motor assembly has areas oriented along an axis C forming an angle between 5 and 25 ° with the axis A and bearing surfaces oriented along the axis A.
• FIGS. 1 and 2 are perspective views of a clutch actuator according to one embodiment of the invention.
• FIG. 3 is an axial sectional view of the actuator
• FIGS. 4 and 5 are exploded views, in perspective, of the actuator
• FIGS. 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
• FIGS. 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.
• FIGS 1 to 9 illustrate a clutch actuator 1 according to one embodiment of the invention.
• This comprises a housing 2 comprising a first portion 2a forming a housing defining an internal volume and having an opening 3 of axis A, and a second portion 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.
• the axis B is parallel to the axis A and is offset with respect to said axis A.
• the internal volume of the first part 2a can be closed by a cover 4 adapted to be fixed by snapping, screwing or any other appropriate means on the first part 2a.
• the housing 2 and the cover 4 are for example plastic, these elements 2, 4 can be welded to one another by laser welding or ultrasonic welding.
• the lid 4 and / or the casing 2 may comprise at least one zone 5 permeable to air but impervious to liquids, for example water, or oil, or even impermeable to grease.
• a zone 5 is for example made by a porous membrane (visible in FIG. 3), for example a hydrophobic membrane made of expanded PTFE material, said membrane being situated at one end of an orifice 6 of the lid 4.
• Partitions or fins 7 extend from the radially outer surface of the second portion 2b. Said partitions 7 extend along the axis B and / or circumferentially.
• the housing 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 furthermore comprises an electric motor 8, in particular a brushless permanent magnet motor or brushless motor, mounted on the housing 2.
• the motor 8 comprises a body 9 or stator forming a plate or a mounting flange 10, said plate or flange 10 for fixing the body 9 of the motor 8 on the casing 2, for example by means of screws 1 1 engaged in threads 12 (FIG. at the level of the second portion 2b of the casing 2.
• the body 9 also comprises a cylindrical centering portion 13, engaged and centered in the cylindrical opening 3 of the casing 2.
• An O-ring 14 may be formed between said opening 3 and the outer periphery of the cylindrical portion 13 of the body 9.
• the body 9 also comprises at least one electrical connector 15, comprising one or more pins 16 (FIG. 5).
• the motor 8 further comprises a rotating shaft 17 secured to 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 portion 2a of the housing 2.
• the shaft 17 carries a first pinion 18 having a number Z1 of teeth.
• a second pinion 19 is mounted idle, that is to say freely rotating, about an axis or a pin 20.
• Said pin 20 is mounted in a hole 21 of the first portion 2a of the housing 2, to a first end, and in a hole 22 of the cover 4, at a second end ( Figure 3).
• the mounting of the shaft 20 in the holes 21, 22 can be achieved without play.
• the second pinion 19 meshes with the first pinion 18 supported by the motor 8.
• a third pinion 24, of axis B, is rotatably connected to 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 gears 18, 19, 24 are housed in the internal volume of the housing 2a.
• the reduction ratio that is to say the ratio Z1 / Z2 is for example between 1 and 5, in this embodiment.
• the pinions 18, 19, 24 can be lubricated with oil or grease.
• the pinions 18, 19, 24 each have helical teeth. Of course, other types of teeth (right, ...) can be considered.
• the third pinion 24 is fixed to the rear end 26 of the screw 25, that is to say the end located on the side of the lid 4, by means of a screw 27 and a washer 28.
• the screw 25 has a smooth cylindrical rear portion 26 and a front portion 29 having a thread.
• the threading of said screw 25 here comprises a pitch and a profile compatible with the use of balls 30 engaged in the threads.
• the casing 2 and / or the cover 4 may 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 comprises an inner ring 32 surrounding the screw 25 and an outer ring 33 housed in a guide member 34.
• the guide member 34 is for example made of steel, aluminum or plastic. This includes a first portion 35 located on the side of the first portion 2a of the housing 2, and a second portion 36 opposite the first portion 35.
• the guide member 34 comprises, at its first portion 35, a radially inner cylindrical portion 37 and a radially outer cylindrical portion 38, connected by a connecting zone 39 extending radially ( Figure 4).
• Centering studs 40 (see in particular FIG. 9) extend radially outwardly from the radially outer cylindrical portion 38.
• Each centering stud 40 has two oblique lateral surfaces 41 with respect to the B axis, the stud 40 narrowing forward. Alternatively, the stud 40 can shrink backwards.
• the guide member 34 further comprises, at its first portion 35, tabs 42 extending radially outwardly from the connection zone 40, said tabs 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 housing 2.
• the guide member 34 is thus integral with the housing 2.
• the second portion 36 is cylindrical with axis B and has splines 46. Each groove 46 has flanks 47 in the form of involute circle ( Figure 9). Other forms can be envisaged.
• the guide member 34 further comprises a third portion 48, located in front of the second portion 36, of generally cylindrical shape and of a diameter smaller than the diameter of the second portion 36.
• An annular radial shoulder 49 is thus delimited between the second portion 36 and the third portion 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 inner cylindrical portion 37 of the first portion 35 of the guide member 34. Furthermore, the radially outer surface of the studs 40 bears on the inner surface. of the second portion 2b of the housing 2.
• the connecting portion 40 provides a certain flexibility to ensure a good centering of the radially inner and outer cylindrical portions 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 nets.
• the radially outer periphery of the nut 53 has a groove 54 ( Figure 4) oriented along the axis B.
• Said groove 54 has a section in the form of an arc.
• the assembly formed by the nut 53, the screw 25 and the balls 30 thus form a roto-linear type of motion transformation system, that is to say capable of transforming the rotational movement of the screw 25. in a translational movement of the nut 53, with minimum friction, that is to say with a maximum yield.
• 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 thrust member 55.
• Said thrust member 55 has a first portion 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 portion 56.
• the first portion 56 and the second portion 57 of the thrust member 55 thus define an annular shoulder 58 extending radially.
• the first part 56 comprises splines 59 cooperating by shape cooperation with the splines 46 of the guide member 34.
• the thrust member 55 is rotatably coupled to the guide member 34 and is adapted to slide relative to it along the B axis.
• 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 couple in rotation the nut 53 and the thrust member 55. Moreover, 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 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 able to pass through said openings 50.
• the second portion 57 of the thrust member 55 is engaged at its front end in the third portion 48 of the guide member 34.
• the diameter of the second portion 57 of the thrust member 55 substantially corresponds to the diameter of the third portion 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 between the guide member 34 and the casing 2, in particular the second part 2b of housing 2.
• the actuator 1 further comprises a hydraulic transmitter 62, which is here a master cylinder. It comprises a body 63 fixed on the casing 2, and in particular on 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 comprises a connection zone 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 able to actuate a clutch, as is known per se.
• the front end of the thrust member 55 is in plane support on the rear end of the piston 65.
• the surface of the front end of the thrust member 55 and the surface of the rear end of the piston, are radially oriented surfaces. Such a plane support allows a possible offset of the piston and the thrust member 55, so as to avoid constraining the piston and avoid any risk of leakage between the piston and the body.
• the front end surface of the thrust member 55 is traversed by at least one vent orifice 67, here two vent holes 67 diametrically opposed ( Figure 7), opening on the one hand in the internal volume of the second portion 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.
• said surface 70 has radial grooves 69, here six in number, and grooves 68 in the shape of a circular arc, connecting at least one of the grooves 69.
• the actuator 1 further comprises a housing 71 housing an electronic card power and / or control, 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 directly connected to the connector 15 of the motor 8, so as to reduce the space requirement and to limit the electromagnetic disturbances.
• the connector 72 is oriented perpendicular to the housing 71 and to the electronic card.
• the connector 72 can also connect the ground of the motor 8 to the ground of a clutch control unit (CCU) for example, in addition to the phases of the motor 8 and the position and switching signals of the motor 8.
• CCU clutch control unit
• 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 vehicle network and / or to a CAN (Controller Area Network) bus so as to control the electric motor at from the engine control unit (ECU) and / or the clutch control unit (CCU) of the vehicle, these units can implement a monitoring software of the vehicle transmission system.
• One of the connectors can also be connected to at least one sensor of the vehicle, 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 a gearbox element and / or a sensor providing information on the position of an element of an element of the hydraulic transmitter 62 or the associated hydraulic receiver.
• the housing 71 is spaced from the motor 8, so as to avoid thermal bridges and limit heating of the housing 71 and 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 cover.
• the heat dissipation means comprise fins or projecting elements, for example cones 76, so as to improve the heat exchange surface with the surrounding air.
• the housing 71 is located in an area of the actuator 1 which is spaced from the housing of the gearbox, this housing forming a heat source.
• the electric motor 8 is controlled by means of the electronic card, causing the rotation of the shaft 17 and the first pinion 18. The latter then drives in rotation 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 rotation speed of the motor 8 and the reduction ratio Z2 / Z1.
• the hydraulic transmitter 62 used may be a standard commercial transmitter.
• the displacement in translation along the axis B of the nut 53 and the thrust member 55 causes the piston 65 and the hydraulic fluid to move in such a way as to control the hydraulic receiver 62.
• the assembly formed by the screw 25, the balls 30 and the nut 53 can be replaced by a conventional screw-nut type system, whose pitch is smaller or larger. In such a case, it is necessary to adapt the reduction ratio.
• the apparent pitch may be smaller (several threads), but the actual pitch (or helical pitch) is usually larger to ensure proper yield.
• the ball screw 25, 30 could also be replaced by a roller screw.
• gearbox composed of three pinions 18, 19, 24 can be replaced by a gearbox comprising a first coupled pinion 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 gear unit may comprise one or more reduction stages, for example two reduction stages, as is known from EP 2 860 869 for example.
• FIGS. 10 to 12 illustrate another embodiment of the invention in which the opening 3 of the housing comprises zones 3a oriented along an axis C forming an angle of between 5 and 25 ° with the axis A and bearing surfaces 3b. oriented along the axis A.
• the motor 8 When mounting the motor 8 on the casing 2, the motor 8 is engaged along the axis C, from front to rear, so that the shaft 17 carrying the first pinion 18 and the cylindrical centering portion 13 of the body 9 are engaged in the opening 3 ( Figures 10 and 1 1). The motor 8 is then pivoted so as to extend along the axis A, the cylindrical portion 13 of the body 9 then resting on the bearing surfaces 3b of the housing 2 (FIG. 12).
• the screws 1 1 can then be fixed in the casing 2, in particular in the threads 12 formed in the second part 2a of the casing 2.
• 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 commercial elements, 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 on existing propulsion systems.

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Electromagnetism (AREA)
• Transmission Devices (AREA)
• General Details Of Gearings (AREA)

Applications Claiming Priority (2)

Publications (1)

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ID=60020113

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• 2017
  • 2017-07-31 FR FR1757331A patent/FR3069594B1/fr not_active Expired - Fee Related
• 2018
  • 2018-07-11 WO PCT/FR2018/051749 patent/WO2019025686A1/fr unknown
  • 2018-07-11 KR KR1020207002961A patent/KR20200032112A/ko not_active Application Discontinuation
  • 2018-07-11 EP EP18750251.3A patent/EP3662170A1/fr not_active Withdrawn
  • 2018-07-11 CN CN201880050253.6A patent/CN111194387A/zh active Pending

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