Clutch actuating device for a motorcycle and actuation method therefor
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2026-02-06
- Publication Date
- 2026-08-13
Smart Images
Figure IB2026051145_13082026_PF_FP_ABST
Abstract
Description
[0001] DESCRIPTION
[0002] CLUTCH ACTUATING DEVICE FOR A MOTORCYCLE AND ACTUATION METHOD THEREFOR
[0003] Technical field
[0004] The present invention relates to an actuating device for actuating a clutch and a method therefor.
[0005] Background art
[0006] In the sector of clutch actuating devices, there are different solutions. The most high-performing solutions, to which the present invention belongs, are semi-automatic solutions with electronic control, in which an electric actuator is actuated to allow an engagement and a disengagement of the clutch.
[0007] Generally, in these solutions, the presence is in fact known of an electric rotary actuator and of a linear control actuator, the displacement of which results in the displacement of a controlled linear actuator, in turn connected with the clutch. Between the electric rotary actuator and the linear control actuator a transformation assembly is present, which transforms the rotation of the rotary actuator into a translation of the linear control actuator.
[0008] Some of these systems use solutions that include discs with cam tracks of a helical or spiral shape. Such solutions are not very compact and are particularly sensitive to wear of the mechanical parts, which may nevertheless give rise to clearances such as to reduce the efficiency of the clutch.
[0009] Solutions of this kind are, for example, described in document DE102019118754.
[0010] According to other solutions, the use is contemplated of other conversion systems which, for example, employ screws. Such systems, provide a direct connection to the drive shaft of the linear actuator, with resulting little controlover actuation and lower reliability, as well as a reduced engagement force. Such solutions are further characterized by a motion transmission from the control actuator to the controlled actuator, always of a mechanical nature, and, therefore, as anticipated above, they present wear issues that cause a loss of the initial calibration, to the detriment of the engagement effectiveness.
[0011] Solutions of this type are described, for example, in document EP3150877B1.
[0012] In general, the known solutions are therefore lacking in reliability, compactness and responsiveness.
[0013] Object of the invention
[0014] It is the object of the present invention to provide an actuating device and an actuation method therefor, which solve the aforesaid issues of the prior art.
[0015] Said object is fully achieved by the device and the method of the present invention, which are characterized by the contents of the following claims. According to an aspect of the present description, the present invention provides an actuating device for actuating a clutch for a motorcycle.
[0016] The device comprises a containment body.
[0017] The device comprises an electric actuator. The electric actuator is constrained to the containment body. The electric actuator includes a drive member, rotating about an axis of rotation.
[0018] The device comprises a linear control actuator. The linear control actuator includes a fixed portion, constrained to the containment body, and a movable portion, slidable with respect to the fixed portion along a first actuation axis.
[0019] Said linear control actuator is configured to connect to a controlled linear actuator, connected to the clutch and movable along a second actuation axis, to actuate said clutch.
[0020] The device comprises a transformation assembly. The transformationassembly comprises a rotating member, connected to the drive member, and a translating member, associated (constrained in both translation directions, or only in one translation direction oriented toward the movable portion of the linear control actuator) to the movable portion of the linear control actuator. Thereby, the transformation assembly is configured to transform a rotation of the drive member into a displacement of the movable portion along the first actuation axis.
[0021] Advantageously, the first actuation axis is parallel (preferably coaxial) to the axis of rotation of the electric actuator. This ensures a particular compactness of the device.
[0022] The device comprises a transmission assembly. The transmission assembly is connected to the electric actuator. The transmission assembly is connected to the transformation assembly. The transmission assembly is configured to transmit a rotation of the drive member to the rotating member of the transformation assembly.
[0023] The speed of rotation of the rotating member is lower than the speed of rotation of the drive member.
[0024] The above configuration allows a particularly effective trade off between compactness of the system, due to the alignment of the components thereof, reliability, due to the transmission assembly allowing an adjustment of the speed of rotation and an increase of the torque, and durability, due to the disengagement from the wear of the components.
[0025] In an embodiment, the drive member is a drive shaft. Furthermore, the transmission assembly is arranged, along the axis of rotation, between the transformation assembly and the electric actuator.
[0026] This further increases the slenderness of the system, which has a very limited radial size.
[0027] In an embodiment, the transmission assembly comprises a central gear, connected to the drive shaft. The central gear includes a central gear profile, obtained on an outer surface of the central gear.
[0028] Furthermore, the transmission assembly comprises an outer crown. Theouter crown is connected to the containment body (preferably fixed to the containment body). The outer crown includes an outer gear profile, formed on an inner surface of the outer crown facing the central gear along a radial direction, perpendicular to the axis of rotation.
[0029] In such an embodiment, the transmission assembly comprises a plurality of satellite gears. Each of said satellite gears is interposed, along the radial direction, between the outer crown and the central gear. Said satellite gears are angularly spaced apart from each other. Said satellite gears are configured to rotate about a respective satellite axis.
[0030] The transmission assembly comprises a planet carrier. Said satellite gears are rotatably connected to the planet carrier. The planet carrier rotates, about the axis of rotation, as a result of a rolling of the satellites of said plurality on the outer crown.
[0031] Preferably the transmission assembly comprises an epicyclic gear train. The use of such a transmission assembly as the one described above allows the coaxiality of the axes to be maintained, with particularly small overall dimensions and a very high robustness of the system.
[0032] Alternatively, the transmission assembly comprises a mechanism with planetary screws.
[0033] In an embodiment, the transformation assembly comprises a threaded screw, elongated along the axis of rotation between a first end and a second end. The transformation assembly comprises a head tube, internally threaded and screwed about the threaded screw.
[0034] In an embodiment, the threaded screw defines the translating member and the head tube defines the rotating member.
[0035] In such an embodiment, the head tube is constrained to the planet carrier and defines the rotating member of the transformation assembly, and the threaded screw is constrained to the movable portion of the linear control actuator and defines the translating member.
[0036] In an alternative embodiment, the threaded screw defines the rotating member and the head tube defines the translating member.In such an embodiment, the threaded screw is constrained to the planet carrier and defines the rotating member of the transformation assembly and the head tube is constrained to the movable portion of the linear control actuator and defines the translating member.
[0037] The use of a screw with the respective head tube allows for a slim and coaxial solution with the electric actuator, to the advantage of the compactness of the device.
[0038] Preferably, the transformation assembly comprises a ball screw, including a plurality of balls, interposed between the threaded screw and the head tube and configured to slide therein in response to the rotation of the threaded screw and / or of the head tube.
[0039] The use of the ball screw allows for a reduction in friction and therefore reduced wear of the components involved, to the advantage of the reliability and durability of the device.
[0040] In an embodiment, the linear control actuator is a control piston cylinder assembly. The control piston cylinder assembly comprises a control piston, defining the movable portion, and a control cylinder, defining the fixed portion and defining a control volume, variable according to the position of the control piston. Preferably, the piston cylinder is of the hydraulic type. The use of a piston cylinder assembly reduces the mechanical components that may wear.
[0041] The cylinder comprises a control port, hydraulically connectable to the controlled linear actuator, defined by a respective controlled piston cylinder assembly, including a controlled cylinder and a controlled piston. By means of the control port, the liquid is conveyed under pressure from the control cylinder to the controlled cylinder.
[0042] In an embodiment, the device comprises a reserve of liquid.
[0043] The device comprises an exhaust port, configured to hydraulically connect the control volume of the control cylinder with the reserve of liquid.
[0044] The control piston is slidable along the first actuation axis between a first limit position, in which the volume of the control cylinder is equal to a firstvalue, and a second limit position, in which the volume of the control cylinder is equal to a second value, lower than the first value.
[0045] The exhaust port is open to the control volume in the first limit position of the piston.
[0046] The exhaust port allows the pressure to be released when it is necessary to disengage the clutch, thus improving the responsiveness of the device. In an embodiment, the translating member of the transformation assembly is constrained to translate with the control piston in both directions.
[0047] In a more advantageous embodiment, the transformation assembly comprises a pusher member. The thrust member extends along the axis of rotation between a first end, constrained to the translating member of the transformation unit, and a second end, which contacts the control piston. The control piston comprises a head surface, facing the control volume, and a tail surface, opposite the head surface and facing the transformation assembly.
[0048] The control piston comprises a thrust seat, formed on the tail surface. The second end of the pusher is inserted inside the thrust seat.
[0049] The displacement of the pusher along the first actuation axis results in a corresponding displacement of the control piston, only in a motion transfer direction, oriented from the tail surface to the head surface of the control piston.
[0050] In other words, the translation of the translating member results in a translation of the pusher in the motion transfer direction. Said translation results in a thrust of the second end of the pusher on a bottom of the thrust seat of the piston, which results in a corresponding translation of the control piston. Conversely, when the translating member moves rearwards (translates in a direction opposite the motion transfer direction), the pusher does not drag the control piston therewith, but comes out from the thrust seat.
[0051] In such a case, therefore, the rearward movement of the control piston occurs (at least) due to the fluid pressure inside the control volume which,no longer finding an abutment from the pusher, results in a rearward movement of the control piston until the exhaust port is opened.
[0052] Thereby, it is avoided that a negative pressure may be generated inside the control volume, which would occur in the case where the control piston were dragged back by the movement of the translating member actuated by the electric motor.
[0053] In an embodiment, the second end of the pusher has a spherical shape. Furthermore, a thrust seat bottom has a concave shape, to receive the spherical second end of the pusher.
[0054] The thrust seat has a preferably conical shape, converging in the motion transfer direction. This facilitates the insertion and accommodation of the pusher in the thrust seat, avoiding unpleasant snags.
[0055] In an embodiment, the control cylinder comprises a bottom surface, perpendicular to the first actuation axis and facing toward the control piston. The device comprises an elastic element, interposed between the bottom surface and the head surface of the control piston. The elastic element is configured to exert an elastic force along the first actuation axis, oriented so as to move the bottom surface away from the head surface.
[0056] The use of the elastic element allows a return of the piston to the first limit position, when it is necessary to re-engage the clutch. This facilitates the sliding of the piston pushed by the pressure of the fluid and further improves the responsiveness and reliability of the device.
[0057] In an embodiment, the device comprises a position sensor, configured to detect a position signal, representative of an angular position of the drive member.
[0058] In an embodiment, the position sensor is an encoder integrated in the motor member. In an embodiment, the position sensor is a position transducer, arranged externally to the drive member to directly detect the position of the linear control actuator.
[0059] The device comprises a control unit, configured to receive the position signal. The control unit is configured to derive, on the basis of the positionsignal, a position of the movable portion of the linear control actuator.
[0060] The control unit is configured to control the rotation of the electric actuator according to the position signal.
[0061] Even more preferably, the device comprises a pressure sensor, configured to detect a pressure signal, representative of a pressure of the fluid within the actuation cylinder. The pressure of the fluid in the control cylinder is directly correlated (and with less influence of other parameters) to the force applied on the clutch to overcome the resistance of the clutch springs (to disengage it).
[0062] The control unit is configured to receive the pressure signal. The control unit is configured to derive, on the basis of the pressure signal, a position of the movable portion of the linear control actuator.
[0063] The control unit is configured to control the rotation of the electric actuator according to the pressure signal.
[0064] These controls, in particular the one on the pressure, allow obtaining feedback on the actual force applied against the clutch springs and, therefore, on the status of the clutch, thus ensuring an adequate and reliable operation of the device.
[0065] According to an aspect of the present description, the present invention provides a clutch assembly.
[0066] The clutch assembly comprises a clutch, movable between an engaged position, in which it is configured to transmit a torque, and a disengaged position.
[0067] The clutch assembly comprises an actuator member. The actuator member is connected to the clutch. The actuator member is movable along a direction of actuation between an engaged position, to which the engaged position of the clutch corresponds, and a disengaged position, to which the disengaged position of the clutch corresponds.
[0068] The clutch assembly comprises a controlled linear actuator, including a respective fixed portion, constrained to the containment body, and a respective movable portion, constrained to the actuator member andslidable with respect to the fixed portion along a second actuation axis, to displace the actuator member between the engaged position and the disengaged position.
[0069] The clutch assembly comprises an actuating device according to any one of the features described in the present invention. The linear control actuator is connected to the controlled linear actuator so that a displacement of the movable portion of the linear control actuator along the first actuation axis results in a displacement of the movable portion of the controlled linear actuator along the second actuation axis.
[0070] According to an aspect of the present description, the present invention provides a method for actuating a clutch in a motorcycle.
[0071] The method comprises a step of providing a containment body.
[0072] The method comprises a step of rotating a drive member of an electric actuator about an axis of rotation.
[0073] The method comprises a step of displacing a movable portion of a linear control actuator, along a first actuation axis with respect to a fixed portion of the linear control actuator.
[0074] The method comprises a step of displacing a movable portion of a controlled linear actuator, along a second actuation axis with respect to a fixed portion of the controlled linear actuator, in response to the displacement of the linear control actuator.
[0075] The method comprises a step of actuating the clutch in response to the displacement of the controlled linear actuator.
[0076] The method comprises a step of transforming the rotation of the drive member into a displacement of the movable portion of the linear control actuator along the first actuation axis, by means of a transformation assembly, comprising a rotating member, connected to the drive member, and a translating member, associated (constrained to the translation in at least one direction) to the movable portion of the linear control actuator. The first actuation axis is parallel (preferably coaxial) to the axis of rotation of the electric actuator.The method comprises a transmission step, in which a transmission assembly connected to the electric actuator and to the transformation assembly transmits a rotation of the drive member to the rotating member of the transformation assembly. The speed of rotation of the rotating member is lower than the speed of rotation of the drive member.
[0077] In an embodiment of the method, the transmission step comprises a step of rotating a central gear, connected to the drive shaft and including a central gear profile, obtained on an outer surface of the central gear.
[0078] The transmission step comprises a step of providing an outer crown, connected to the containment body and including an outer gear profile, obtained on an inner surface of the outer crown facing the central gear along a radial direction, perpendicular to the axis of rotation.
[0079] The transmission step comprises a step of rotating a plurality of satellite gears, each interposed, along the radial direction, between the outer crown and the central gear, about respective satellite axes.
[0080] The transmission step comprises a step of rolling said plurality of satellite gears on the outer crown.
[0081] The transmission step comprises a step of rotating a planet carrier, on which said satellite gears are rotatably connected about the axis of rotation, due to the step of rotating the satellites of said plurality on the outer crown. According to an embodiment of the method, the transformation step comprises a step of rotating a threaded screw about the axis of rotation. The transformation step comprises a step of translating a head tube, internally threaded and screwed about the threaded screw, along the first actuation axis.
[0082] According to an alternative embodiment, the transformation step comprises a step of rotating the head tube about the axis of rotation.
[0083] The transformation step comprises a step of translating the threaded screw along the first actuation axis.
[0084] Brief description of the drawingsThis and other features will be more apparent from the following description of a preferred embodiment, shown merely byway of a non-limiting example in the accompanying drawings, in which:
[0085] - Figure 1 shows a sectional view of a clutch assembly including a clutch actuating device according to the present invention;
[0086] - Figure 2 shows a detail of an actuator and of a transmission assembly of the device shown in Figure 1 ;
[0087] - Figure 3 shows a perspective sectional detail of a transformation assembly of the device shown in Figure 1 ;
[0088] - Figure 4A shows a section of the actuating device of Figure 1 in a first position, in which the linear control actuator is in a first limit position;
[0089] - Figure 4B shows a section of the actuating device of Figure 1 in a second position, in which the linear control actuator is in an isolation position;
[0090] - Figure 4C shows a section of the actuating device of Figure 1 in a third position, in which the linear control actuator is in a second limit position; - Figures 5A and 5B show a sectional detail of an embodiment of the actuating device, in a first position, in which the control actuator is in a first limit position, and in a second position, in which the control actuator is in a second limit position;
[0091] - Figure 6 shows a sectional detail of an engagement head of a piston of the control actuator or of a pusher of the actuating device.
[0092] Detailed description of preferred embodiments of the invention With reference to the accompanying Figures, reference 1 designates an actuating device for actuating a clutch F, preferably in the context of a twowheeled vehicle.
[0093] Preferably, the actuating device 1 is a semi-automatic actuating device. Preferably, the actuating device 1 is a powered actuating device.
[0094] The actuating device 1 comprises a containment body 10. The containment body 10 is configured to connect to the two-wheeled vehicle and to support the other components of the actuating device 1.Preferably, the containment body 10 has a tubular shape within which one or more components of the actuating device 1 are included. More in detail, the containment body 10 extends along an axis of rotation R between a first end 10A and a second end 10B.
[0095] Preferably, the containment body 10 has a variable diameter along the axis of rotation A. The containment body 10 comprises a support seat 101 , configured to receive a rolling bearing, for the rotating support of the rotating components of the actuating device 1. In particular, the actuating device 1 may comprise a support rolling bearing 102, accommodated in the support seat.
[0096] The actuating device 1 comprises an electric actuator 2. The electric rotary actuator 2 comprises a drive member 21 , i.e., a drive shaft 21 , which rotates about the axis of rotation A due to the torque generated by the electric motor.
[0097] The electric actuator 2 is arranged at the first end 10A of the containment body 10, with the drive shaft 21 facing toward the second end 10B.
[0098] The electric actuator 2 may be an electric motor with brushes or without brushes.
[0099] The actuating device 1 comprises a transmission assembly 3. The transmission assembly 3 is connected to the drive shaft 21 to receive the machine torque generated by the electric motor 2.
[0100] According to an illustrative but non-limiting embodiment, the transmission assembly 3 comprises an epicyclic gear train 3’.
[0101] In particular, the transmission assembly 3 comprises a central gear 31 , connected to the drive shaft 21. The central gear 31 rotates integrally with the drive shaft 21. The central gear 31 comprises a central gear profile 311 , obtained on an outer surface of the central gear 31.
[0102] The transmission assembly 3 comprises an outer crown 33. The outer crown 33 is connected to the containment body 10. The outer crown 33 includes an outer gear profile 331. The outer gear profile 331 is obtained on an inner surface of the outer crown 33. The outer gear profile 331 faces thecentral gear 31 along a radial direction R, perpendicular to the axis of rotation A.
[0103] The transmission assembly 3 comprises a plurality of satellite gears 32. Each satellite gear 32 is interposed, along the radial direction R, between the outer crown 33 and the central gear 31. Said satellite gears 32 are angularly spaced apart from one another. Said satellite gears 32 are configured to rotate about a respective satellite axis AS, parallel to the axis of rotation A.
[0104] The transmission assembly 3 comprises a planet carrier 34. Said satellite gears 32 are rotatably connected on said planet carrier 34. The planet carrier 34 rotates, about the axis of rotation A, as a result of a rolling of the satellite gears 32 of said plurality on the outer crown 33. The axis of rotation of the planet carrier 34 and the axis of rotation of the drive shaft 21 are coaxial.
[0105] The transmission assembly 3 comprises an intermediate bearing 35, interposed between the central gear 31 and the planet carrier 34, to allow a relative rotation therebetween.
[0106] The planet carrier 34 comprises a plurality of radial arms 341, each associated with a respective satellite gear 32. In detail, each of said radial arms comprises a respective receiving hole 342. The planet carrier 34 comprises a plurality of interference-fit pins 343, configured to be inserted within a respective receiving hole 342 and into a hub of a corresponding satellite gear 32.
[0107] Preferably, the planet carrier 34 extends along the axis of rotation A between a first end 34A, where said radial arms 341 are positioned, and a second end 34B, opposite the first end 34A.
[0108] In an embodiment, the planet carrier 34 comprises a support surface 344, arranged, along the axis of rotation A, downstream of the radial arms 341 in a motion transfer direction VTM, oriented from the first end 34A to the second end 34B of the planet carrier 34.
[0109] The support surface 344 is radially aligned with the support seat 101 of thecontainment body and is configured to accommodate the inner crown of the support rolling bearing 102.
[0110] In an embodiment, the planet carrier 34 comprises a central hole 345. The central hole 345 is elongated along the axis of rotation A starting from the second end 34 B toward the first end 34A.
[0111] In a preferred embodiment, the central hole 345 goes through the planet carrier 34, along the axis of rotation A.
[0112] The actuating device 1 comprises a transformation assembly 4. The transformation assembly 4 is configured to transform a rotation of the planet carrier 34 (i.e., of the transmission assembly 3) into a translational motion, to be transferred to a linear control actuator 5, which will be described in greater detail below.
[0113] In an embodiment, the transformation assembly 4 comprises a rotating member 41. Furthermore, the transformation assembly 4 comprises a translating member 42. The rotation of the rotating member 41 results in a corresponding translation of the translating member 42, by virtue of the kinematic coupling that exists between the rotating member 41 and the translating member 41.
[0114] According to a particularly advantageous embodiment, the rotating member 41 is a screw 411. The screw 411 is preferably a ball screw.
[0115] The screw 411 extends along the axis of rotation A between a first end 411 A and a second end 411 B.
[0116] The screw 411 is connected to the planet carrier 34 at the first end 411 A thereof. In particular, the screw 411 is inserted into the central hole 345 of the planet carrier 34. Therefore, the screw 411 comprises a first portion 411 ’, which is inserted into the central hole 345 and which extends from the first end 411 A towards the second end, and a second portion 411”, arranged externally to the central hole 345 and which extends from the second end 411 B up to the first portion 411 ’.
[0117] The screw 411 comprises a helical thread 411 F, within which, in the embodiment in which the screw is a ball screw, the screws slide. The helicalthread 411 F is arranged in the second portion 411 ”.
[0118] In an embodiment, the translating member 42 is a head tube 421 (namely a screw nut 421). The head tube 421 comprises an internal thread 421 F, configured to engage with the helical thread 411 F of the screw 411. In an embodiment, between the internal thread 421 F of the head tube 421 and the helical thread 411 F of the screw 411 , the balls are interposed.
[0119] The head tube 421 extends along the axis of rotation A between a first end 421 A and a second end 421 B. The first end 421 A faces toward the transmission assembly 3. The head tube 421 comprises a respective first portion 42T, where the presence of the internal thread 421 F is provided, and a respective second portion 421”, configured to connect to the linear control actuator 5 or to an intermediate element allowing a contact, a connection, or an interaction with the linear control actuator.
[0120] To this end, the head tube 421 comprises an engagement profile 421 P, arranged at the second portion 421 ” of the head tube 421.
[0121] Preferably, the engagement profile 421 P is obtained on an outer surface of the head tube 421.
[0122] In an embodiment, the engagement profile 421 P comprises a circumferential protrusion PC, projecting from the outer surface of the second portion 421” of the head tube 421. The circumferential protrusion PC, in a radial section, comprises a lead-in wall PC1, inclined with respect to the axis of rotation A, converging with the axis of rotation A in the motion transfer direction VTM, and an abutment wall PC2, substantially perpendicular to the axis of rotation A.
[0123] In an embodiment, the engagement profile 421 P connects directly to a control piston of the linear control actuator while, in other cases, it connects to a pusher 425 that will be better described below.
[0124] In an embodiment, the head tube 421 comprises a guide pin 422. The guide pin 422 is constrained to the head tube and protrudes from the outer surface of the head tube 421. In particular, the guide pin 422 is connected at the first portion 42T of the head tube 421. The guide pin 422 protrudes alongthe radial direction R.
[0125] The containment body 10 comprises a guide groove 103. The guide groove 103 is aligned along the radial direction R with the guide pin 422. In particular, the guide pin 422 is arranged internally to the guide groove 103. The guide pin 422 is configured to slide within the guide groove 103 along a direction parallel to the axis of rotation. The length along a direction parallel to the axis of rotation A of the guide groove 103 is at least equal to a stroke traveled by the head tube 421 along the axis of rotation A as a result of the rotation of the screw 411.
[0126] The presence of the guide pin 422 prevents the head tube from being rotated by the screw 411. Therefore, being unable to rotate with the screw 411 , the head tube 421 is forced to translate.
[0127] This configuration allows the insertion of an engagement head of the linear control actuator 5, which deforms by virtue of the lead-in wall PC1 , and the subsequent inhibited extraction, by virtue of the abutment against the abutment wall PC2.
[0128] Preferably, the head tube 421 defines a tube open both at the first end 421 A and at the second end 421 B. In other embodiments, the tube may also be open only at the first end 421 A.
[0129] As also previously anticipated, the actuating device 1 comprises a linear control actuator 5.
[0130] The linear control actuator 5 (hereinafter, for brevity, also referred to as control actuator) comprises a control piston 51 and a control cylinder 52. The control cylinder 52 is connected to the containment body 10 or, in other versions of the present invention, the cylinder is defined by the shape itself of the containment body 10, including a compartment defining the control cylinder 52.
[0131] The control piston 51 extends along the axis of rotation A, between a first end 51 A, facing the transformation assembly 4, and a second end 51 B, opposite the first end 51 A.
[0132] The control cylinder 52 defines a control volume VI, variable according tothe position of the control piston 51.
[0133] The control piston 51 comprises a head surface 51 T, facing the control volume VI.
[0134] In an embodiment, the device comprises an engagement head 511. The engagement head 511 comprises an engagement crown, including an inner surface 511 S facing the engagement profile 421 P of the head tube 421. On the inner surface 511S an engagement protrusion PA is present. The engagement protrusion PA comprises an insertion wall PA1, which is inclined with respect to the axis of rotation A so as to be convergent with the axis of rotation A in the motion transfer direction VTM. Furthermore, the engagement protrusion PA comprises an abutment wall PA2, substantially perpendicular to the axis of rotation A and configured to abut against the abutment wall PC2 of the head tube 421 in the motion transfer direction VTM.
[0135] This allows an insertion of the head tube 421 into the engagement head and inhibits the slipping off in the transfer motion direction VTM.
[0136] In a first embodiment, the engagement head 511 is obtained on the first end 51 A of the control piston 51.
[0137] In a second embodiment (which has specific advantages related to maintaining the pressure in the control volume VI), the control piston 51 comprises a tail surface 51 C, opposite the head surface 51 T and oriented toward the transformation assembly 4. In such an embodiment, the transformation assembly 4 comprises a pusher 425, interposed, along the axis of rotation A, between the translating member 42 and the control piston 51. In particular, the pusher 425 extends along the axis of rotation A between a first end 425A, in (at least temporary) contact with the control piston 51 , and a second end 425B, constrained to the head tube 421. In particular, in such an embodiment, the engagement head 511 is formed at the second end 425B of the pusher 425, so as to connect it to the engagement profile 421 P of the head tube 421.
[0138] In such an embodiment, the control piston 51 comprises a thrust seat 513,obtained on the tail surface 51 C. In particular, the thrust seat 513 is a hole formed on the tail surface 51 C. The thrust seat has a conical profile converging in the motion transfer direction VTM.
[0139] The thrust seat has a bottom having a preferably curved and preferably concave shape.
[0140] The first end 425A of the pusher 425 has a spherical shape, so as to be able to be inserted in the bottom of the thrust seat 513, which has a complementary shape.
[0141] When the head tube 421 slides along the first actuation direction AT1 in the motion transfer direction VTM, the pusher 425 pushes on the bottom of the thrust seat 513, causing a dragging of the control piston 51 , until the pusher 425 itself meets a first end-of-stroke wall FC1. Conversely, when the head tube 421 retracts and translates along the direction opposite the motion transfer direction VTM, the pusher 425 does not drag along the control piston 51 , but comes out of the thrust seat 513 until the head tube 421 abuts against a second end-of-stroke wall FC2.
[0142] Therefore, the control piston 51 moves rearward due to the fluid pressure in the control volume (but possibly also with other auxiliary means that will be described below), which, pushing onto the control piston 51 , which, no longer having the pusher 425 to abut against it, moves rearward until it in fact abuts again against the pusher 425.
[0143] The control piston 51 slides within the control cylinder 52 along a first actuation axis AT1 , which is preferably coincident with the axis of rotation A.
[0144] The control cylinder 52 comprises a cylindrical wall 521. The control cylinder 52 comprises a bottom wall 522, facing toward the control piston 51 along the first actuation axis AT1. The control piston 51 comprises a seal 512, configured to achieve a hydraulic seal of an actuation fluid contained in the control cylinder 52, to prevent leakage. The control piston 51 slides in the control cylinder 52 with the seal 512 in sliding contact with the cylindrical wall 521 of the cylinder 52.The cylinder 52 comprises a control port 523. The control port 523 is hydraulically connectable to a controlled linear actuator 6 (which will be described hereinafter), to convey pressurized liquid from the control cylinder to the controlled cylinder. The control port 523 is proximal to the bottom surface 522 of the cylinder.
[0145] The cylinder 52 comprises an exhaust port 524. The actuating device 1 comprises a reserve of liquid RS, in selective communication with the control volume VI of the cylinder for receiving or dispensing liquid from and into the control volume VI of the cylinder 52. The pressure of the liquid within the reserve of liquid RS is ambient pressure.
[0146] In particular, the exhaust port 524 is configured to hydraulically connect the control volume of the control cylinder 52 with the reserve of liquid RS.
[0147] The control piston 51 is slidable along the first actuation axis AT1 between a first limit position PP1 , in which the control volume VI of the control cylinder 52 is equal to a first value, and a second limit position PP2, in which the control volume VI of the control cylinder 52 is equal to a second value, lower than the first value.
[0148] In the first limit position PP1 of the control piston 51 , the exhaust port 524 is open onto the control volume VI.
[0149] The control port 523 is open onto the control volume VI both in the first limit position PP1 and in the second limit position PP2 of the control piston 51. Furthermore, in the sliding thereof along the first actuation axis AT1 , the control piston 51 defines a hydraulic isolation position PIS, in which the seal 512 is arranged, along the first actuation axis AT1 , downstream of the exhaust port 524 in the motion transfer direction VTM, to isolate the control volume VI with respect to the reserve of liquid RS, so as to start the pressurization of the control volume VI.
[0150] In an embodiment, the cylinder 52 comprises a secondary seal 525. The secondary seal 525 is arranged, along the first actuation axis AT 1 , upstream of the exhaust port 524 in the motion transfer direction VTM. The secondary seal 525 is constrained to the cylinder 52. The secondary seal 525 slideson the control piston 51 while this translates along the first actuation axis AT1.
[0151] In an embodiment, the control cylinder 52 comprises an equalization hole 526. The equalization hole 526 is interposed, along the first actuation axis AT1 , between the seal 512 and the secondary seal 525.
[0152] The equalization hole 526 is fluidly connected to the reserve of liquid RS. In particular, in the first limit position PP1 of the control piston 51 , the equalization hole 526 is interposed, along the first actuation axis AT1 , between the seal 512 and the secondary seal 525, while the exhaust hole is connected to the control volume VI. Instead, in the second limit position PP2 of the control piston 51 , both the exhaust port 524 and the equalization hole 526 are interposed, along the first actuation axis AT 1 , between the seal 512 and the secondary seal 525.
[0153] As it is known, the equalization hole 526 allows, during the return steps of the control piston 51 , to maintain the pressure upstream of the seal 512 always at a value greater than or equal to ambient pressure. This allows avoiding a negative pressure in the control cylinder 52, which may create cavitation issues and create bubbles in the control cylinder 52.
[0154] According to a more performing embodiment, the actuating device 1 comprises an elastic element 6. The elastic element 6 is interposed between the second end 51 B of the control piston 51 and the bottom surface 522 of the control cylinder 52.
[0155] The elastic element 6 is configured to exert a separating elastic force between the control piston 51 and the bottom surface 522 of the control cylinder 52, along the first actuation axis AT 1.
[0156] In an embodiment, the elastic element 6 is a torsion spring.
[0157] In an embodiment, the elastic element 6 is a preloaded spring, configured to exert a separating force between the control piston 51 and the bottom surface 522 of the control cylinder 52, also in the first limit position PP1. This ensures, on one hand, a more substantial return force of the control piston 51 and, on the other hand, also a holding force in the first limit position PP1of the control piston 51 , thus avoiding unintentional pressurization of the control cylinder 52.
[0158] In an embodiment, the device 1 comprises a control unit UC. The control unit UC is configured to receive an engagement signal SI or a disengagement signal SD by a user, to control an engagement or a disengagement of the clutch FR, respectively.
[0159] The control unit UC, in response to the reception of the engagement signal SI or of the disengagement signal SD, is configured to generate a control signal SC.
[0160] The control unit UC is configured to send the control signal SC to the electric actuator 2 to control it to rotate in a first direction or in a second direction opposite the first one, on the basis of the reception of the engagement signal SI or of the disengagement signal SD.
[0161] According to an aspect of the present description, the present invention provides a clutch assembly 100 comprising an actuating device 1 according to any of the features described above. Furthermore, the clutch assembly 100 comprises a controlled linear actuator 7 (hereinafter also defined as controlled actuator 7).
[0162] In an exemplary embodiment, the controlled actuator 7 comprises a respective controlled cylinder 71 , including a controlled volume VC. The controlled actuator comprises a respective controlled piston 72.
[0163] The controlled volume VC of the controlled cylinder 71 is hydraulically connected to the control volume VI of the control cylinder by means of the control port 523.
[0164] Therefore, the movement of the control cylinder 51 results in a transfer of fluid from the control volume VI to the controlled volume VC. The increase in controlled volume VC results in the displacement of the controlled piston 72, which slides within the controlled cylinder 71 along a second actuation axis AT2 (preferably misaligned from the first actuation axis AT1.
[0165] The clutch assembly 100 comprises a clutch FR, movable between an engaged position, in which it is configured to transmit a torque, and adisengaged position.
[0166] The clutch assembly 100 comprises an actuator member 8. The actuator member 8 is connected to the clutch FR. In particular, a displacement of the actuator member 8 along the second actuation axis AT2 results in a displacement of the clutch FR from the engaged position to the disengaged position. The actuator member 8 is movable along the second actuation axis AT2 in reciprocating motion.
[0167] The actuator member 8 is connected to the controlled piston 72, so as to move integrally with the controlled piston 72.
[0168] In particular, the actuator member 8 is movable (preferably along the second actuation direction AT2) between an engaged position, to which the engaged position of the clutch FR corresponds, and a disengaged position, to which the disengaged position of the clutch FR corresponds.
[0169] The clutch assembly 100 comprises a return element 9. The return element 9 is configured to exert a return force on the controlled piston 72, so as to return the clutch FR to the disengaged position.
[0170] The return element 9 is interposed between the controlled piston 72 and a respective bottom surface 711 of the controlled cylinder 71.
[0171] In the following, the operation of the system in terms of method is described, namely how the clutch FR is operatively actuated.
[0172] Preferably, the control unit automatically determines when to disengage the clutch FR. Alternatively or in addition, the user of the vehicle sends a disengagement signal SD, to disengage the clutch FR. The control unit of the vehicle sends a control signal SC to the electric actuator 2, controlling a rotation thereof in a first direction.
[0173] The rotation of the electric actuator 2, namely of the drive member 21, results in the rotation of the central gear 31 and, by means of the transmission assembly, the speed of rotation of the drive shaft is transmitted to the planet carrier 34. The speed of the planet carrier 34 will be lower than that of the drive shaft 21 and the transmitted torque will instead be greater. The rotation of the planet carrier 34 puts the screw 411 into rotation. As aresult of the rotation of the screw 411 , the head tube 421 translates along the axis of rotation A.
[0174] In this condition, the control piston 51 is in the first limit position PP1. The rotation of the screw 411 results in a translation of the head tube 421 and, consequently, a displacement of the control piston 51 , which is constrained to the head tube 421 at least in translation along the motion transfer direction VTM. The displacement of the control piston 51 entails a closing of the exhaust port 524 (closing the hydraulic connection between the control volume VI and the reserve of liquid RS).
[0175] At this point, the movement of the control piston 51 results in a transfer of liquid from the control volume VI of the linear control actuator 5, to the controlled volume VC of the controlled linear actuator 7.
[0176] Said transfer of fluid thus results in a displacement of the controlled piston 72 and a pressurization of the control volume VI and of the controlled volume VC (in hydraulic communication therebetween). The displacement of the controlled piston 72 results in a corresponding displacement of the actuator member 8 to a disengaged position and, therefore, a displacement of the clutch to a disengaged position.
[0177] When the user wants to re-engage the clutch, the user sends an engagement signal SI to the control unit. In response to the receipt of the engagement signal SI, the control unit generates a control signal SC, to control a rotation of the electric actuator 2, in a second direction opposite the first direction.
[0178] Said rotation of the drive shaft 21 is transmitted by means of the transfer assembly to the screw 411. The screw 411 rotating in the opposite direction determines a translation of the head tube 421 in a direction opposite the motion transmission direction VTM.
[0179] In fact, therefore, the head tube 421 approaches the transmission assembly 3.
[0180] At this point, two embodiments are envisaged. In a first embodiment, during the rearward movement thereof, the head tube 421 , which is constrained tothe control piston 51 , determines a displacement of the control piston 51 from the second limit position PP2 to the first limit position PP1. In such displacement, the liquid present in the controlled volume VC returns into the control volume until, with the sliding of the control piston 51 , the exhaust port 524 re-enters into hydraulic communication with the control volume VI. When this occurs, the pressure within the control volume VI and in the controlled volume VC drops to ambient pressure.
[0181] Therefore, the return element 9 allows the actuator member 8 to be brought into engaged position, namely, the clutch FR into engaged position.
[0182] In a particularly advantageous embodiment, when the head tube 421 moves rearwards, the control piston 51 no longer has an abutment in the direction opposite the motion transfer direction VTM. Therefore, the fluid pressure in the control volume VI determines a displacement of the control piston 51 up to the first limit position PP1 , i.e., until the exhaust port 524 is opened and the fluid pressure in the control volume VI returns to the ambient pressure. In the rearward movement thereof, the control piston 51 is also pushed by the elastic element 6. Also in this case, when the pressure in the control volume VI and in the controlled volume VC drops to ambient pressure, the return element 9 allows the actuator member 8 to be brought into engaged position, namely, the clutch FR into engaged position.
Claims
CLAIMS1. An actuating device (1) for actuating a clutch (FR) for a motorcycle, comprising:- a containment body (10);- an electric actuator (2), constrained to the containment body (10) and including a drive member (21), rotating about an axis of rotation (A);- a linear control actuator (5), including a fixed portion (52), constrained to the containment body (10), and a movable portion (51), slidable with respect to the fixed portion (52) along a first actuation axis (AT1), said linear control actuator (5) being configured to connect to a controlled linear actuator (7), connected to the clutch (FR) and movable along a second actuation axis (AT2), to actuate said clutch (FR);- a transformation assembly (4), comprising a rotating member (41), connected to the drive member (21), and a translating member (42), connected to the movable portion (51) of the linear control actuator (5), to transform a rotation of the drive member (21) into a displacement of the movable portion (51) along the first actuation axis (AT1),wherein the first actuation axis (AT1) is parallel to the axis of rotation (A) of the electric actuator (2),characterized in that it comprises a transmission assembly (3), connected to the electric actuator (2) and to the transformation assembly (4) and configured to transmit a rotation of the drive member (21) to the rotating member (41) of the transformation assembly (4),wherein the speed of rotation of the rotating member (41) is less than the speed of rotation of the drive member (21).
2. A device (1) according to claim 1 , wherein the drive member (21) is a drive shaft and wherein the transmission assembly (3) is arranged, along the axis of rotation (A), between the transformation assembly (4) and the electric actuator (2).
3. A device (1) according to claim 2, wherein the transmission assembly (3) comprises:- a central gear (31), connected to the drive shaft (21) and including a central gear profile (311), obtained on an outer surface of the central gear (31); - an outer crown (33), connected to the containment body (10) and including an outer gear profile (331), obtained on an inner surface of the outer crown (33) facing the central gear (31) along a radial direction (R), perpendicular to the axis of rotation (A);- a plurality of satellite gears (32), each interposed, along the radial direction (R), between the outer crown (33) and the central gear (31), said satellite gears (32) being angularly spaced apart from one another and configured to rotate about a respective satellite axis (AS);- a planet carrier (34), on which said satellite gears (32) are rotatably connected, and rotating, about the axis of rotation (A), as a result of a rolling of said satellite gears (32) of said plurality on the outer crown (33).
4. A device (1) according to any one of the preceding claims, wherein the transformation assembly (4) comprises:- a threaded screw (411), elongated along the axis of rotation between a first (411 A) and a second (411B) end;- a head tube (421), internally threaded and screwed about the threaded screw (411),wherein the threaded screw (411) defines the translating member (42) or the rotating member (41) and, vice versa, the head tube (421) defines the rotating (41) or translating (42) member.
5. A device (1) according to claim 4, wherein the threaded screw (411) is constrained to the planet carrier (34) and defines the rotating member (41) of the transformation assembly (4) and wherein the head tube (421) is associated with the movable portion (51) of the linear control actuator (5) and defines the translating member (42) of the transformation assembly (4).
6. A device (1) according to claim 4, wherein the head tube (421) is constrained to the planet carrier (34) and defines the rotating member (41) of the transformation assembly (4) and wherein the threaded screw (411) is associated with the movable portion (51) of the linear control actuator (5) and defines the translating member (42).
7. A device (1) according to any one of claims 4 to 6, wherein the transformation assembly (4) comprises a ball screw, including a plurality of balls, interposed between the threaded screw (411) and the head tube (421) and configured to slide therein in response to the rotation of the threaded screw (411) and / or of the head tube (421).
8. A device (1) according to any one of the preceding claims, wherein the linear control actuator (5) is a control cylinder-piston assembly, comprising a control piston (51), defining the movable portion (51), and a control cylinder (52), defining the fixed portion (52) and defining a control volume (VI), variable according to the position of the control piston (51), wherein the piston cylinder (52) is of the hydraulic type.
9. A device (1) according to claim 8, comprising a pusher member (425), extending along the axis of rotation (A) between a first end (425A), constrained to the translating member (42) of the transformation assembly (4), and a second end (425B), which contacts the control piston (51), wherein the control piston (51) comprises a head surface (51 T), facing the control volume (VI), and a tail surface (51 C), opposite the head surface (51 T) and facing the transformation assembly (4),wherein the control piston (5) comprises a thrust seat (513), obtained on the tail surface (51 C) and into which the second end (425B) of the pusher (425) is inserted,wherein a displacement of the pusher (425) along the first actuation axis(AT 1 ) results in a corresponding displacement of the control piston (51 ) only in a motion transfer direction (VTM) oriented from the tail surface (51 B) to the head surface (51 T) of the control piston (51).
10. A device (1) according to claim 8 or claim 9, wherein the control cylinder (52) comprises a bottom surface (522), perpendicular to the first actuation axis (AT1) and facing the control piston (51) and wherein the control piston (51) comprises a head surface (51 T), perpendicular to the first actuation axis (AT1) and facing the bottom surface (522) of the control cylinder (52), wherein the device (1) comprises an elastic member (6), interposed between the bottom surface (522) and the head surface, configured to exert an elastic force along the first actuation axis (AT1) and oriented so as to move the bottom surface (522) away from the head surface (51 T).
11. A device (1) according to claim 8, 9 or 10, wherein the control cylinder (52) comprises a control port (523), hydraulically connectable to the controlled linear actuator (7), defined by a respective control cylinder-piston assembly, including a controlled cylinder (71) and a controlled piston (72), for conveying liquid under pressure from the control cylinder (52) to the controlled cylinder (71).
12. A device (1) according to any one of claims 8 to 11 , comprising:- a reserve of liquid (RS);- an exhaust port (524), configured to hydraulically connect the control volume (VI) of the control cylinder (52) with the reserve of liquid (RS), wherein the control piston (51) is slidable along the first actuation axis (AT1) between a first limit position (PP1), wherein the control volume (VI) is equal to a first value, and a second limit position (PP2), wherein the control volume (VI) is equal to a second value, lower than the first value,and wherein the exhaust port (524) is open on the control volume (VI) at the first limit position (PP1) of the control piston (51).
13. A device (1) according to any one of the preceding claims, comprising: - a position sensor, configured to detect a position signal, representative of an angular position of the drive member (21), and / or- a pressure sensor, configured to detect a pressure signal, representative of a fluid pressure within the linear control actuator (5),the device including a control unit (UC), configured to:- receive the position signal and derive, on the basis of the position signal, a position of the movable portion (51) of the linear control actuator (5), and / or- receive the pressure signal and derive, on the basis of the pressure signal, a position of the movable portion (51) of the linear control actuator (5).
14. A device (1) according to any one of the preceding claims, wherein the first actuation axis (AT1) is parallel to the axis of rotation (A) of the electric actuator (2).
15. A clutch assembly (100), comprising:- a clutch (FR), movable between an engaged position, in which it is configured to transmit a torque, and a disengaged position;- an actuator member (8), connected to the clutch (FR) and movable along a direction of actuation between an engaged position, to which the engaged position of the clutch (FR) corresponds, and a disengaged position, to which the disengaged position of the clutch (FR) corresponds;- a controlled linear actuator (7), including a respective fixed portion (71) and a respective movable portion (72), constrained to the actuator member (8) and slidable with respect to the fixed portion (71) along a second actuation axis (AT2), to displace the actuator member (8) between the engaged position and the disengaged position;- an actuation device (1) according to any one of the preceding claims, wherein the linear control actuator (5) is connected to the controlled linearactuator (7) so that a displacement of the movable portion (51) of the linear control actuator (5) along the first actuation axis (AT1) results in a displacement of the movable portion (72) of the controlled linear actuator (7) along the second actuation axis (AT2).
16. A method for actuating a clutch (FR) in a motorcycle, comprising:- providing a containment body (10);- rotating a drive member (21) of an electric actuator (2), about an axis of rotation (A);- displacing a movable portion (51) of a linear control actuator (5), along a first actuation axis (AT1) with respect to a fixed portion (52) of the linear control actuator (5);- displacing a movable portion (72) of a controlled linear actuator (7), along a second actuation axis (AT2) with respect to a fixed portion (71) of the controlled linear actuator (7), in response to the displacement of the linear control actuator (5);- actuating the clutch (FR) in response to the displacement of the controlled linear actuator (7);- transforming the rotation of the drive member (21) into a displacement of the movable portion (51) of the linear control actuator (5) along the first actuation axis (AT1), by means of a transformation assembly (4), comprising a rotating member (41), connected to the drive member (21), and a translating member (42), connected to the movable portion (51) of the linear control actuator (5),wherein the first actuation axis (AT1) is parallel to the axis of rotation (A) of the electric actuator (2),characterized in that the method comprises a transmission step, wherein a transmission assembly (3) connected to the electric actuator (2) and to the transformation assembly (4) transmits a rotation of the drive member (21) to the rotating member (41) of the transformation assembly (4), wherein the speed of rotation of the rotating member (41) is less than thespeed of rotation of the drive member (21).
17. A method according to claim 16, wherein the step of transmitting comprises the following steps:- rotating a central gear (31), connected to the drive shaft (21) and including a central gear profile (311), obtained on an outer surface of the central gear (31);- arranging an outer crown (33), connected to the containment body (10) and including an outer gear profile (331), obtained on an inner surface of the outer crown (33) facing the central gear (31) along a radial direction (R), perpendicular to the axis of rotation (A);- rotating a plurality of satellite gears (32), each interposed, along the radial direction (R), between the outer crown (33) and the central gear (31), about respective satellite axes (32);- rolling said plurality of satellite gears (32) on the outer crown (33);- rotating a planet carrier (34), on which said satellite gears (32) are rotatably connected, about the axis of rotation (A), due to the rolling step of the satellite gears (32) of said plurality on the outer crown (33).
18. A method according to claim 16 or claim 17, wherein the transformation step comprises the following steps:- rotating a threaded screw (411) about the axis of rotation (A);- translating a head tube (421), internally threaded and screwed about the threaded screw (411), along the first actuation axis (AT1),or- rotating the head tube (421) about the axis of rotation (A);- translating the threaded screw (411) along the first actuation axis (AT1).