Drive shaft coupling system

Abstract

Title of the invention: Transmission shaft coupling system The present invention relates to a transmission shaft coupling system (1) comprising: - a support housing (50); - a first transmission shaft (2) guided in rotation relative to the support housing by means of a first guide bearing (100); and - a second transmission shaft (3), coaxial with the first shaft (2), guided in rotation relative to the support housing by means of a second guide bearing (200); and - a dog clutch sleeve (30) comprising at least a first connecting spline (33) adapted to drive the first shaft in rotation about a first axis of rotation (X) and a second connecting spline (34) adapted to drive the second shaft in rotation; in which the first shaft (2) and the second shaft (3) are guided relative to each other by means of a third guide bearing (300). Figure from the summary: Figure 1

Description

Title of the invention: Transmission shaft coupling system

[0001] The present invention relates to the field of transmission shaft coupling systems used in a motor vehicle transmission.

[0002] The drive shaft coupling system is, for example, integrated into an electric transmission of a motor vehicle, which comprises an electric machine and an associated speed reducer, the coupling system being placed, in particular, between the output of the speed reducer and the wheel of the vehicle. The motor vehicle may be electric or hybrid.

[0003] In a motor vehicle with a hybrid transmission comprising an internal combustion engine and an electric transmission, such coupling systems can be used to connect the electric transmission to the rear wheels of the vehicle when its use becomes necessary to supplement the internal combustion engine, which provides torque and power to the front wheels. Such a driveshaft coupling system is known from document WO2016 / 096769 AL

[0004] In this document, the transmission shaft coupling system is interposed between a transmission drive shaft comprising a first internal spline and a transmission driven shaft coaxial to the drive shaft comprising a second external spline.

[0005] The coupling system also includes a double-grooved dog clutch sleeve adapted to connect the driving shaft to the driven shaft when the use of the electric transmission becomes necessary. The dog clutch sleeve is mounted longitudinally on the driven transmission shaft. The dog clutch sleeve is driven along a first axis of rotation of the driven transmission shaft by means of an actuation device comprising an electric motor associated with a speed reduction device, for example, an epicyclic gear train.

[0006] The driving shaft, the driven shaft, and the dog clutch sleeve are contained within a support housing that surrounds these three elements. The driven shaft is guided in rotation relative to this support housing by means of a guide bearing.

[0007] When the coupling system is in an uncoupling position, the outer spline of the connector is not engaged in the first inner spline of the driving shaft.

[0008] The driving shaft is guided relative to the driven shaft at a distance from the double-grooved joint of the dog clutch sleeve. This design allows While correctly guiding the drive and driven shafts relative to the support housing, this does not prevent the possibility of flexing between the drive and driven shafts. This flexing puts stress on the splines of the dog clutch sleeve, increasing the resisting forces required to move it axially relative to the support housing.

[0009] In addition, the driving and driven shafts can be at an angle to each other due to spline clearances and internal clearances in the guide bearings when it comes to bearings.

[0010] The present invention aims to overcome these drawbacks by proposing a transmission shaft coupling system in which the rotational guidance of the driving and driven shafts within the coupling system housing is improved.

[0011] To this end, according to a first aspect of the invention, a transmission shaft coupling system is proposed comprising:

[0012] - support housing;

[0013] - a first transmission shaft guided in rotation relative to the support housing via a first guide bearing which includes a first transmission spline; and

[0014] - a second transmission shaft, coaxial with the first shaft, guided in rotation by relative to the support housing via a second guide bearing and which includes a second transmission spline; and

[0015] - a dog clutch sleeve comprising at least one first groove of connection capable of driving the first shaft in rotation around a first axis of rotation and a second splined connection capable of driving the second shaft in rotation;

[0016] in which the support housing has a general shape of revolution about the first axis of rotation surrounding the first shaft, the second shaft and the dog clutch sleeve which is arranged to move axially inside said support housing about the first axis of rotation between a first extreme disengagement position and a second extreme engagement position,

[0017] and in which the first shaft and the second shaft are guided relative to each other by means of a third guide bearing, one of the first guide bearing or the other of the second guide bearing radially overlaps the third guide bearing at least partially.

[0018] This transmission shaft coupling system limits the play between the first shaft and the second shaft by placing the third guide bearing as close as possible to either the first or second guide bearing. This alignment of the guide bearings limits the effect of misalignment between the first and second shafts, which is related to compensating for operating clearances within the shaft. of the transmission shaft coupling system. The bending of the first and second shafts is also limited at the first and second splines of the dog clutch sleeve connection.

[0019] It is thus possible to reduce the effort required to move the dog clutch sleeve by limiting friction between splines. The actuation device responsible for axially moving the dog clutch sleeve can be optimized in terms of motor torque, and the gear ratio of the speed reduction device can be adapted to reduce the actuation time required to move the dog clutch sleeve between the first disengagement position and the second engagement position.

[0020] A radial superposition at least partial implies that there is at least one overlap between one of the rings of the third guide bearing and one of the rings of the first guide bearing or the other of the rings of the second guide bearing.

[0021] Advantageously, the first shaft, the second shaft and the support housing are nested within each other at a geometric plane perpendicular to the first axis of rotation passing through the third guide bearing.

[0022] Preferably, the outside diameter of the third guide bearing is less than the outside diameter of the first guide bearing and / or the second guide bearing.

[0023] Advantageously, the first shaft, the second shaft and the dog clutch sleeve are partially nested within each other.

[0024] According to one aspect of the invention, the transmission shaft coupling system comprises an actuating device supported by the support housing, said actuating device comprising an interface component inserted within a receiving housing formed in the dog clutch sleeve, the interface component being arranged to axially move the dog clutch sleeve between the first extreme disengagement position and the second extreme coupling position.

[0025] According to a variant of the invention, the first guide bearing is radially superimposed on the third guide bearing so that a geometric plane perpendicular to the first axis of rotation passes through the first guide bearing and the third guide bearing.

[0026] Advantageously, the receiving housing for the dog clutch sleeve is located between the second guide bearing and the geometric plane passing through the first and third guide bearings. In this way, the actuation forces required on the actuating device are limited. The actuating device responsible for axially moving the dog clutch sleeve can be sized with a reduced power rating for the electric motor.

[0027] According to another variant of the invention, the second guide bearing is radially superimposed on the third guide bearing so that a geometric plane perpendicular to the first axis of rotation passes through the second guide bearing and the third guide bearing.

[0028] Advantageously, the receiving housing for the dog clutch sleeve is located between the first guide bearing and the geometric plane passing through the second and third guide bearings. In this way, the actuation forces required on the actuating device are limited. The actuating device responsible for axially moving the dog clutch sleeve can be sized with a reduced power rating for the electric motor.

[0029] According to one aspect of the invention, the actuation device comprises an output shaft rotating about a second axis of rotation, the interface component being disposed at the end of the output shaft and arranged to pivot within the receiving housing formed in the dog clutch sleeve between the first extreme disengagement position and the second extreme coupling position when the output shaft pivots according to a predetermined angular actuation sector.

[0030] Preferably, the predetermined angular actuation sector is between 20° and 180°.

[0031] The interface component of the actuation device is, for example, an actuation cam or an eccentric actuation rod.

[0032] According to one aspect of the invention, the interface component of the actuating device is an actuating cam pivoting about the second axis of rotation of the actuating device. The actuating cam comprises three actuating faces formed in the form of cylindrical segments, and the three centers of these cylindrical segments form an isosceles triangle. The actuating cam has two contact areas arranged to bear against lateral edges of the receiving housing. The geometry of the contact areas of the actuating cam uses large-diameter cylindrical segments, thereby reducing the contact pressure with the clutch sleeve.

[0033] For example, the principal vertex of the isosceles triangle can be coincident with the second axis of rotation of the output shaft.

[0034] Preferably, the actuating cam may have a symmetrical actuation profile whose axis of symmetry passes through the bisector of the isosceles triangle, the bisector of the isosceles triangle corresponding to the midpoint of the second angular sector. The actuating cam thus has a symmetrical profile passing through the second axis of rotation of the output shaft.

[0035] According to one aspect of the invention, the interface component is an eccentric actuating rod with respect to the second axis of rotation of the actuating device, the eccentric actuating rod being a cylindrical component which is inserted into the receiving housing of the dog clutch sleeve.

[0036] The eccentric actuating rod can be a plain bearing or a rolling bearing, for example, a ball bearing or a roller bearing. This allows a part to rotate freely around the eccentric axis, for example, the outer ring of the ball bearing, ensuring non-slip contact with the clutch sleeve, but for which lubrication of the contact with the eccentric axis remains necessary. In this way, heating at the contact point is reduced between the interface component of the actuating device and the clutch sleeve. The rotation of the outer ring of the ball or roller bearing on one of the two parallel flat surfaces of the receiving housing limits heating at the contact point.

[0037] According to one aspect of the invention, the actuation device comprises an actuation fork, the interface component being disposed at one end of the actuation fork, the dog clutch sleeve being able to move axially inside the support housing along the first axis of rotation between a first extreme disengagement position and a second extreme coupling position when the end of the actuation fork moves axially according to a predetermined value.

[0038] Preferably, the predetermined value is between 2 and 10 mm.

[0039] According to one variant of the invention, the first connecting groove of the dog clutch sleeve is, for example, an internal groove, an external groove or, for example, a series of dog clutches distributed regularly around the first axis of rotation.

[0040] According to one variant of the invention, the second connecting groove of the dog clutch sleeve is, for example, an internal groove, an external groove or, for example, a series of dog clutches distributed regularly around the first axis of rotation.

[0041] The series of dog clutches is arranged at one end of the dog clutch sleeve.

[0042] According to one aspect of the invention, the second internal connecting groove of the The dog clutch sleeve is made in the form of a series of internal splines spaced axially with a regular pitch, for example, four internal splines spaced axially with a pitch between 2 and 10 mm, and the second external spline of the second shaft is made in the form of a series of external splines spaced axially with the same regular pitch. This dog clutch sleeve exhibits a high torque transmission capacity while remaining axially compact.

[0043] According to another embodiment of the invention, the first connecting spline of the dog clutch sleeve is constantly engaged with the first transmission spline of the first shaft, and the second connecting spline of the dog clutch sleeve is free to rotate relative to the second transmission spline of the second shaft when the dog clutch sleeve is in the first extreme disengagement position.

[0044] According to another embodiment of the invention, the second connecting spline of the dog clutch sleeve is constantly engaged with the second transmission spline of the second shaft, and the first connecting spline of the dog clutch sleeve is free to rotate relative to the first transmission spline of the first shaft when the dog clutch sleeve is in the first extreme disengaged position.

[0045] According to a variant of the invention, the dog clutch sleeve comprises a first internal connecting groove arranged to drive the first shaft in rotation and a second internal connecting groove arranged to drive the second shaft in rotation, the first and second internal grooves being engaged respectively in a first external transmission groove of the first shaft and a second external transmission groove of the second shaft when the dog clutch sleeve is in the second extreme coupling position.

[0046] According to another embodiment of the invention, the dog clutch sleeve comprises at least a first external connecting groove arranged to drive the first shaft in rotation and a second internal connecting groove arranged to drive the second shaft in rotation, the first external connecting groove and the second internal connecting groove being engaged respectively in a first internal transmission groove of the first shaft and a second external transmission groove of the second shaft when the dog clutch sleeve is in the second extreme coupling position.

[0047] The transmission shaft coupling system according to the invention may have one or more of the characteristics described below, either combined or taken independently of each other:

[0048] - the first guide bearing is a ball bearing, or a roller bearing, or a smooth bearing;

[0049] - the second guide bearing is a ball bearing, or a bearing rollers, or a plain bearing;

[0050] - the third guide bearing is a ball bearing, or a roller bearing, or a smooth bearing;

[0051] - the actuation device is attached to the support housing;

[0052] - the support housing has a general shape of revolution surrounding the first shaft, the second shaft and the dog clutch sleeve along the first axis of rotation;

[0053] - the support housing includes a bearing surface for the actuation device;

[0054] - the receiving housing is an annular groove comprising two flat surfaces parallels formed on the two lateral edges;

[0055] - the receiving housing for the dog clutch sleeve is in the form of a The groove consists of two lateral rims and a cylindrical bottom and receives the interface component of the output shaft.

[0056] - the spline play between the first transmission shaft and the sleeve of The dog clutch measured on the side of the teeth of the first transmission spline is greater than the spline clearance between the dog clutch sleeve and the second transmission shaft measured on the side of the teeth of the second transmission spline.

[0057] - the spline play between the first transmission shaft and the sleeve of The dog clutch measured on the side of the teeth of the first transmission spline is less than the spline clearance between the dog clutch sleeve and the second transmission shaft measured on the side of the teeth of the second transmission spline.

[0058] The invention also relates to a vehicle transmission, for example hybrid or electric, comprising a transmission shaft coupling system as previously mentioned.

[0059] For example, the first shaft is a drive shaft of a transmission fixed in rotation to a differential output shaft and the second shaft is a driven shaft of a transmission fixed in rotation to a wheel shaft of the vehicle.

[0060] For example, the first shaft is a drive shaft of a transmission fixed in rotation to an intermediate transmission shaft and the second shaft is a driven shaft of a transmission fixed in rotation to a transmission output pinion.

[0061] The invention also relates to a motor vehicle with hybrid or electric transmission comprising a transmission shaft coupling system and / or a transmission as previously mentioned.

[0062] Other features, details and advantages of the invention will become clearer upon reading the following description on the one hand, and the illustrative and non-limiting examples of embodiments given with reference to the accompanying drawings on the other hand, in which:

[0063] [Fig-1] is a cross-sectional view of a transmission shaft coupling system according to a first embodiment of the invention;

[0064] [Fig.2] is an isometric view of the transmission shaft coupling system according to the first embodiment of the invention of [Fig.1];

[0065] [Fig.3] is a simplified view of the interface end of the output shaft of the actuation device of the [Fig.1];

[0066] [Fig.4] is a cross-sectional view of a transmission shaft coupling system according to a second embodiment of the invention;

[0067] [Fig.5] is a cross-sectional view of a transmission shaft coupling system according to a third embodiment of the invention;

[0068] [Fig.6] is an isometric view of the transmission shaft coupling system according to the third embodiment of the invention of [Fig.5];

[0069] [Fig.7] is a cross-sectional view of a transmission shaft coupling system according to a fourth embodiment of the invention;

[0070] [Fig.8] is an isometric view of the transmission shaft coupling system according to the fourth embodiment of the invention of [Fig.7];

[0071] [Fig.9] is a cross-sectional view of a transmission shaft coupling system according to a fifth embodiment of the invention.

[0072] The features, variants and different embodiments of the invention can be combined with each other in various combinations, provided that they are not incompatible or mutually exclusive.

[0073] Throughout the description, elements common to several figures retain the same reference.

[0074] In the description and claims, the terms "external" and "internal" and the orientations "axial" and "radial" shall be used to designate, according to the definitions given in the description, elements of the transmission system. By convention, the "radial" orientation is directed orthogonally to the first axis of rotation X of the coupling system determining the "axial" orientation, and, from the inside out and away from said axis, the "circumferential" orientation is directed orthogonally to the first axis of rotation X and orthogonally to the radial direction.

[0075] Figures 1 to 3 illustrate a portion of an electric transmission 80 of a motor vehicle comprising an electric machine (not shown), an associated speed reducer 5 and a transmission shaft coupling system located in particular between the output of the speed reducer and the wheel of the vehicle. The motor vehicle may be of the electric or hybrid type.

[0076] The driveshaft coupling system 1 is here a connecting clutch between two shafts 2, 3 which is used, in the transmission 80 of a vehicle, to transmit torque from a thermal or electric motor, not shown, to a wheel shaft 7 of a motor vehicle. Such a driveshaft coupling system can, for example, be part of a secondary drive chain capable of transmitting torque from a secondary motor of the vehicle, such as an electric motor, to a rear or front axle of a vehicle, while a primary drive chain is capable of transmitting torque from a main motor, for example a thermal engine, to the wheel shafts of another vehicle axle. When the reversible electric machine associated with the speed reducer is inactive, there is no advantage to leaving said electric machine connected to the vehicle wheel. The connecting clutch is then disengaged.

[0077] The transmission shaft coupling system 1 is kinematically interposed between the speed reducer 5 and the wheel shaft 7 of the vehicle. The output of the speed reducer is rotationally fixed to a first transmission shaft 2 about a first axis of rotation X. The first shaft 2 will be referred to in the remainder of this description as the "driving shaft 2" because it is rotationally fixed to the output of the differential of the transmission speed reducer 5.

[0078] The transmission drive shaft 2 includes a first transmission spline 2a machined on its end, the first transmission spline 2a is in this example external.

[0079] The transmission shaft coupling system 1 also includes a second transmission shaft 3, coaxial with the driving shaft 2, comprising a second transmission spline 3a, the second transmission spline 3a being external in this example. The second shaft 3 will be referred to in the remainder of this description as the "driven shaft 3" because it is rotationally fixed to the wheel shaft 7 of the vehicle.

[0080] The transmission shaft coupling system 1 also includes a support housing 50. The transmission drive shaft 2 is guided in rotation relative to the support housing 50 by means of a first guide bearing 100, and the driven shaft 3 is guided in rotation relative to the support housing 50 by means of a second guide bearing 200.

[0081] The driven shaft 3 is inserted into the driving shaft 2 and guided in rotation by means of a third guide bearing 300 around the first axis of rotation X. The driven transmission shaft 3 also includes an internal torque output spline 3b rotationally linked with the wheel shaft 7 of the vehicle.

[0082] The first guide bearing 100 is a ball bearing.

[0083] The second guide bearing 200 is a ball bearing.

[0084] The third guide bearing 300 is a ball bearing.

[0085] The transmission shaft coupling system 1 uses a dog clutch sleeve 30 to connect the two driving and driven shafts 2, 3. The dog clutch sleeve 30 is axially movable about the first axis of rotation X and includes a first connecting spline 33 suitable for rotating the driving shaft 2 and a second connecting spline 34 suitable for rotating the driven shaft 3. In this example, the first and second connecting splines 33, 34 are external and are complementary to the first and second transmission splines 2a, 3a.

[0086] In this example, the first connecting spline 33 of the dog clutch sleeve 30 is constantly engaged with the first transmission spline 2a of the driving shaft 2 and the second connecting spline 34 of the dog clutch sleeve 30 is free to rotate relative to the second transmission spline 3a of the driven shaft 3 when the dog clutch sleeve 30 is in the first extreme disengaged position.

[0087] To actuate the transmission shaft coupling system 1, an electrically powered actuating device 10 is used. The actuating device 10 comprises an electric motor 11 kinematically linked to a speed reduction device 13, an output shaft 40 of the speed reduction device rotating about a second axis of rotation Y, and an interface component 20, for example an actuating cam, disposed at the end of the output shaft which interacts with the dog clutch sleeve 30. The interface component 20 is arranged, in particular, to pivot within a receiving housing 31 formed directly in the dog clutch sleeve 30. The receiving housing 31 of the dog clutch sleeve 30 is in the form of a groove composed of two lateral edges 32 and a cylindrical bottom 35 and receives the interface component of the output shaft.

[0088] As illustrated in [Fig.2], the interface component 20 is fixed securely to the output shaft 40 which pivots in a protective housing 18 of the actuation device 10.

[0089] The protective housing 18 protects the electric motor 11 and supports the speed reduction device 13. The protective housing 18 is mounted on the support housing 50. The support housing 50 is cylindrical in shape with its axis coinciding with the first axis of rotation X and has an opening for the output shaft 40 of the actuation device. The support housing 50 thus has a general shape of revolution about the first axis of rotation X surrounding the first shaft 2, the second shaft 30, and the dog clutch sleeve 30.

[0090] As illustrated in Figures 2 and 3, the dog clutch sleeve 30 moves axially between two extreme positions of disengagement and engagement when the output shaft 40 pivots about its second axis of rotation Y according to a predetermined angular sector of actuation a. The dog clutch sleeve 30 moves axially by a value Dx relative to the driven transmission shaft 3, which is axially fixed.

[0091] When the dog clutch sleeve 30 is in the first extreme disengagement position, the second connecting spline 34 is disengaged from the second transmission spline of the driven shaft 3. The second connecting spline 34 is broken to reduce the engagement stroke.

[0092] When the dog clutch sleeve 30 is in the second extreme coupling position, the first and second connecting splines 33, 34 are engaged respectively in the first transmission spline 2a of the driving shaft 2 and the second transmission spline 3a of the driven shaft 3.

[0093] The receiving housing 31 of the dog clutch sleeve 30 is in the form of a groove composed of two lateral edges 32 and a cylindrical bottom 35 and receives the interface component 20 of the actuating device. The two lateral edges 32 support two parallel flat surfaces 32a which are formed from the same material as the dog clutch sleeve.

[0094] In this first embodiment of the invention, the actuating cam 20 has, in cross-section perpendicular to the second axis of rotation Y, a general Reuleaux triangle profile. The actuating cam 20 has two contact areas 20a, 20b bearing on the parallel flat surfaces 32a of the receiving housing; a bearing width L1 along the first axis of rotation X separating the two contact areas is constant throughout the rotation of the output shaft 40 to move from the first extreme disengagement position to the second extreme engagement position.

[0095] To ensure a free movement of the actuating cam 20 within the annular groove without undue friction, an operating clearance is defined between the bearing width L1 of the actuating cam and the distance D separating axially along the first axis of rotation X the two parallel flat surfaces 32a of the receiving housing 31.

[0096] As illustrated in [Fig. 3], the actuating cam 20 comprises three actuating faces 21 formed in the form of cylindrical segments. The three centers 22 of these cylindrical segments form an isosceles triangle, the principal vertex of the isosceles triangle coinciding with the second axis of rotation Y of the output shaft 40. The geometry of the contact areas 20a, 20b of the actuating cam utilizes large-diameter cylindrical segments to reduce the contact pressure with the parallel surfaces of the receiving housing. During rotation of the actuating cam, the actuating face 21 slides on one of the parallel surfaces 32a. In this first embodiment, the actuating cam 20 has a symmetrical actuating profile whose axis of symmetry passes through the bisector 37 of the isosceles triangle. The isosceles triangle has an altitude H and a principal angle [3 for example between 15° and 165°.The actuation cam 20 thus has a symmetrical profile passing through the second axis of rotation Y.

[0097] To ensure free movement of the actuating cam 20 within the receiving housing 31 without unwanted friction, the actuating faces 21 of the actuating cam 20 are connected to each other by a cylindrical connecting face 23 of radius R2 less than the radius RI of the cylindrical portions, the connection radius being between 0.5 and 5 mm. During rotation of the actuating cam, the cylindrical connection face 23 is also made to slide on one of the parallel surfaces 32. The contact areas 20a, 20b of the actuating cam are alternately formed by an actuating face 21 and / or a cylindrical connection face 23. The geometry of the contact area 20a, 20b then has a radius RI or a radius R2.

[0098] The actuating cam 20 also includes an end radius R3 arranged to interact with the parallel flat surfaces 32a of the dog clutch sleeve 30 and tangentially connecting two actuating faces 21, the center of this end radius R3 being concentric with the axis of rotation Y.

[0099] We will now describe the operation of the actuation device allowing the transition from the first extreme uncoupling position to the second extreme coupling position with a reduced actuation time.

[0100] When it is desired to engage the teeth of the internal spline of the dog clutch sleeve 30 within the second transmission spline 3a of the driven shaft 3, the rotational speed of the driving shaft 2 is adjusted with the instruction to be as close as possible to the rotational speed of the driven shaft 3, while maintaining a slight speed differential between the two shafts 2, 3. When the speed instruction of the driving shaft 2 is reached, the teeth of the internal spline of the dog clutch sleeve 30 are inserted by rotating the output shaft 40 and the associated actuating cam 20 through a predetermined angular sector of actuation a between 20° and 180°.

[0101] In this first embodiment of the invention, the driving shaft 2 and the driven shaft 3 are guided relative to each other by means of the third guide bearing 300, and the first guide bearing 100 is radially superimposed on the third guide bearing 300. This limits the beat of the driving shaft with the driven shaft by placing the third guide bearing as close as possible to the first guide bearing.

[0102] This alignment of the guide bearings limits the deflection of the first and second shafts at the first and second connecting splines 33, 34 of the dog clutch sleeve. The force required to move the dog clutch sleeve 30 is reduced by limiting friction between the splines.

[0103] As illustrated in [Fig.1], the first guide bearing 100 is radially superimposed on the third guide bearing 300 so that a geometric plane P perpendicular to the first axis of rotation X passes through the first guide bearing 100 and the third guide bearing 300. The outside diameter of the third guide bearing 300 is less than the outside diameter of the first guide bearing 100.

[0104] The receiving housing 31 of the dog clutch sleeve 30 is disposed between the second guide bearing 200 and the geometric plane P passing through the first guide bearing and the third guide bearing.

[0105] The driving shaft 2, the driven shaft 3 and the support housing 50 are nested within each other at the level of the geometric plane P perpendicular to the first axis of rotation X passing through the third guide bearing 300.

[0106] It will be noted that the driving shaft 2, the driven shaft 3 and the dog clutch sleeve 30 are partially nested within each other.

[0107] We will now describe, with reference to [Fig.4], a second embodiment of the invention, which differs from the first embodiment in that the dog clutch sleeve 30 comprises a first external connection spline 33 arranged to drive the first shaft 2 in rotation and a second internal connection spline 34 arranged to drive the second shaft 3 in rotation, the first external connection spline 33 and the second internal connection spline 34 being engaged respectively in a first internal transmission spline 2a of the first shaft 2 and a second external transmission spline 3a of the second shaft 3 when the dog clutch sleeve 30 is in the second extreme coupling position.

[0108] The first tree 2 will be referred to in the rest of the description of this second mode as "leading tree 2" and the second tree 3 will be referred to as "led tree 3".

[0109] The drive shaft 2 of the transmission is guided in rotation relative to the support housing 50 by means of a first guide bearing 100, and the driven shaft 3 is guided in rotation relative to the support housing 50 by means of a second guide bearing 200.

[0110] In this second embodiment of the invention, the driving shaft 2 and the driven shaft 3 are guided relative to each other by means of the third guide bearing 300, and the first guide bearing 100 is radially superimposed on the third guide bearing 300. This limits the beat of the driving shaft with the driven shaft by placing the third guide bearing as close as possible to the first guide bearing.

[0111] The first guide bearing 100 is a ball bearing.

[0112] The second guide bearing 200 is a ball bearing.

[0113] The third guide bearing 300 is a plain bearing.

[0114] As illustrated in [Fig.4], the first guide bearing 100 is radially superimposed on the third guide bearing 300 so that a geometric plane P perpendicular to the first axis of rotation X passes through the first guide bearing 100 and the third guide bearing 300. The outside diameter of the third guide bearing 300 is less than the outside diameter of the first guide bearing 100.

[0115] The receiving housing 31 of the dog clutch sleeve 30 is disposed between the second guide bearing 200 and the geometric plane P passing through the first guide bearing and the third guide bearing.

[0116] The driving shaft 2, the driven shaft 3 and the support housing 50 are nested within each other at the level of the geometric plane P perpendicular to the first axis of rotation X passing through the third guide bearing 300.

[0117] It will be noted that the driving shaft 2, the driven shaft 3 and the dog clutch sleeve 30 are partially nested within each other at the level of a second geometric plane P' perpendicular to the first axis of rotation X.

[0118] This second embodiment of the invention also differs from the first embodiment in that the interface component 20 is an eccentric actuation rod with respect to the second axis of rotation Y of the actuation device.

[0119] Generally, the eccentric actuating rod 20 is a cylindrical component that is inserted into the receiving housing 31 of the dog clutch sleeve 30. The eccentric actuating rod 20 is a roller bearing whose axis of rotation is parallel and distant from the second axis of rotation Y.

[0120] The rotation of the eccentric control rod 20 around the second axis of rotation Y of the speed reduction device 13 of the actuation device 10 allows the dog clutch sleeve 30 to be moved longitudinally.

[0121] We will now describe, with reference to Figures 5 and 6, a third embodiment of the invention, which differs from the first embodiment in that the first connecting groove 33 of the dog clutch sleeve 30 is a series of dog clutches distributed regularly around the first axis of rotation X. The series of dog clutches is arranged at the end of the dog clutch sleeve oriented towards the second shaft 2.

[0122] The first tree 2 will be referred to in the following description of this third mode as "leading tree 2" and the second tree 3 will be referred to as "led tree 3".

[0123] In this third mode, the driving shaft 2 and the driven shaft 3 are guided relative to each other by means of the third guide bearing 300, and the first guide bearing 100 is radially superimposed on the third guide bearing 300.

[0124] The first guide bearing 100 is a plain bearing.

[0125] The second guide bearing 200 is a ball bearing.

[0126] The third guide bearing 300 is a plain bearing.

[0127] As illustrated in [Fig. 5], the first guide bearing 100 is radially superimposed on the third guide bearing 300 so that a geometric plane P perpendicular to the first axis of rotation X passes through the first guide bearing 100 and the third guide bearing 300. The outside diameter of the third guide bearing 300 is smaller than the outside diameter of the first guide bearing 100.

[0128] A fourth embodiment of the invention will now be described with reference to Figures 7 and 8, which differs from the previous embodiment in that the first transmission spline 2a of the first shaft 2 is a series of dog clutches distributed regularly around the first axis of rotation X. The series of dog clutches is located at the end of the first shaft 2.

[0129] The first connecting groove 33 of the dog clutch sleeve 30 is also a series of dog clutches distributed regularly around the first axis of rotation X. The series of dog clutches is arranged at the end of the dog clutch sleeve oriented towards the second shaft 2. This improves the radial compactness of the transmission shaft coupling system 1.

[0130] This fourth embodiment of the invention also differs from the previous embodiment in that the interface component 20 is an eccentric actuation rod with respect to the second axis of rotation Y of the actuation device.

[0131] Generally, the eccentric actuating rod 20 is a cylindrical component that is inserted into the receiving housing 31 of the dog clutch sleeve 30. The eccentric actuating rod 20 is a ball bearing whose axis of rotation is parallel and distant from the second axis of rotation Y.

[0132] We will now describe, with reference to [Fig.9], a fifth embodiment of the invention, which differs from the first embodiment in that the first shaft 2 and the second shaft 3 are guided relative to each other by means of a third guide bearing 300 and the second guide bearing 200 is radially superimposed on the third guide bearing 300. This limits the runout of the first shaft with the second shaft by placing the third guide bearing as close as possible to the second guide bearing.

[0133] The first tree 2 will be referred to in the rest of the description of this second mode as "leading tree 2" and the second tree 3 will be referred to as "led tree 3".

[0134] The first guide bearing 100 is a ball bearing.

[0135] The second guide bearing 200 is a ball bearing.

[0136] The third guide bearing 300 is a ball bearing.

[0137] The transmission drive shaft 2 is guided in rotation relative to the support housing 50 via the first guide bearing 100, and the driven shaft 3 is guided in rotation relative to the support housing 50 via the second guide bearing 200.

[0138] As illustrated in [Fig.9], the second guide bearing 200 is radially superimposed on the third guide bearing 300 so that a geometric plane P perpendicular to the first axis of rotation X passes through the second guide bearing 200 and the third guide bearing 300. The outside diameter of the third guide bearing 300 is less than the outside diameter of the second guide bearing 200.

[0139] The receiving housing 31 of the dog clutch sleeve 30 is disposed between the first guide bearing 100 and the geometric plane P passing through the second guide bearing and the third guide bearing.

[0140] The driving shaft 2, the driven shaft 3 and the support housing 50 are nested within each other at the level of the geometric plane P perpendicular to the first axis of rotation X passing through the third guide bearing 300.

[0141] The present invention is not limited to the means and configurations described and illustrated herein and also extends to any equivalent means and configuration as well as to any technically operative combination of such means.

[0142] According to a variant of the invention not shown, the invention relates to an electric vehicle transmission comprising a driveshaft coupling system in which the first shaft is a drive shaft rotationally fixed to an intermediate shaft, and the second shaft is a driven shaft rotationally fixed to a transmission output pinion. In this variant of the invention, the intermediate shaft is kinematically arranged between the rotor shaft of the reversible electric machine and the output shaft of the transmission's speed reducer, which is generally a differential.

[0143] When the reversible electric machine associated with the speed reducer is inactive, there is no advantage to leaving said electric machine connected to the vehicle wheel. The connecting clutch associated with the intermediate shaft is then disengaged.

Claims

Demands

1. A transmission shaft coupling system (1) comprising: - a support housing (50); - a first transmission shaft (2) guided in rotation relative to the support housing by means of a first guide bearing (100) and comprising a first transmission spline (2a); and - a second transmission shaft (3), coaxial with the first shaft (2), guided in rotation relative to the support housing by means of a second guide bearing (200) and comprising a second transmission spline (3a); and - a dog clutch sleeve (30) comprising at least a first connecting spline (33) adapted to drive the first shaft in rotation about a first axis of rotation (X) and a second connecting spline (34) adapted to drive the second shaft in rotation;in which the support housing (50) has a general shape of revolution about the first axis of rotation (X) surrounding the first shaft (2), the second shaft (3) and the dog clutch sleeve (30) which is arranged to move axially inside said support housing (50) about the first axis of rotation between a first extreme disengagement position and a second extreme engagement position, and in which the first shaft (2) and the second shaft (3) are guided relative to each other by means of a third guide bearing (300), one of the first guide bearing (100) or the other of the second guide bearing (200) radially overlaps the third guide bearing (300) at least partially.;

2. Transmission shaft coupling system (1) according to claim 1, wherein the first shaft (2), the second shaft (3) and the support housing (50) are nested within each other at a geometric plane (P) perpendicular to the first axis of rotation (X) passing through the third guide bearing (300).

3. Transmission shaft coupling system (1) according to claim 1 or 2, wherein the outside diameter of the third guide bearing (300) is less than the outside diameter of the first guide bearing (100) and / or the second guide bearing (200).

4. Transmission shaft coupling system (1) according to any one of claims 1 to 3, wherein the first shaft (2), the second shaft (3) and the dog clutch sleeve (30) are partially nested within each other.

5. Transmission shaft coupling system (1) according to any one of claims 1 to 4, wherein the first connecting spline (33) of the dog clutch sleeve (30) is constantly engaged with the first transmission spline (2a) of the first shaft (2) and the second connecting spline (34) of the dog clutch sleeve (30) is free to rotate relative to the second transmission spline (3a) of the second shaft (3) when the dog clutch sleeve (30) is in the first extreme uncoupling position.

6. Transmission shaft coupling system (1) according to any one of claims 1 to 4, wherein the second connecting spline (34) of the dog clutch sleeve (30) is constantly engaged with the second transmission spline (3a) of the second shaft (3) and the first connecting spline (33) of the dog clutch sleeve (30) is free to rotate relative to the first transmission spline (2a) of the first shaft (2) when the dog clutch sleeve (30) is in the first extreme uncoupling position.

7. A drive shaft coupling system (1) according to any one of the preceding claims, comprising an actuating device (10) supported by the support housing (50), said actuating device comprising an interface component (20) inserted within a receiving housing (31) formed in the dog clutch sleeve (30), the interface component (20) being arranged to axially move the dog clutch sleeve between the first extreme disengagement position and the second extreme engagement position.

8. Transmission shaft coupling system (1) according to any one of the preceding claims, wherein the first guide bearing (100) is radially superimposed on the third guide bearing (300) such that a geometric plane perpendicular (P) to the first axis of rotation (X) passes through the first guide bearing (100) and the third guide bearing (300).

9. Transmission shaft coupling system (1) according to the combination of claims 7 and 8, wherein the receiving housing (31) of the dog clutch sleeve (30) is disposed between the second guide bearing (200) and the geometric plane passing through the first guide bearing (100) and the third guide bearing (300).

10. Transmission shaft coupling system (1) according to any one of claims 1 to 7, wherein the second guide bearing (200) is radially superimposed on the third guide bearing (300) such that a geometric plane (P) perpendicular to the first axis of rotation (X) passes through the second guide bearing (200) and the third guide bearing (300).

11. Transmission shaft coupling system (1) according to the combination of claims 7 and 10, the receiving housing (31) of the dog clutch sleeve (30) is disposed between the first guide bearing (100) and the geometric plane (P) passing through the second guide bearing (200) and the third guide bearing (300).

12. Transmission shaft coupling system (1) according to any one of claims 7 to 11, wherein the interface component (20) of the actuating device is an actuating cam pivoting about the second axis of rotation (Y) of the actuating device, the actuating cam comprising three actuating faces (21) made in the form of a portion of a cylinder and the three centers of the portion of a cylinder form an isosceles triangle, the actuating cam (20) has two contact areas (20a, 20b) arranged to press against lateral edges (32) of the receiving housing (31).

13. Transmission shaft coupling system (1) according to any one of claims 7 to 11, wherein the interface component (20) of the actuating device is an eccentric actuating rod with respect to the second axis of rotation (Y) of the actuating device, the eccentric actuating rod being a cylindrical component which is inserted into the receiving housing (31) of the dog clutch sleeve (30).

14. A drive shaft coupling system (1) according to any one of claims 7 to 11, wherein the actuating device (10) comprises an actuating fork, the interface component (20) being disposed at one end of the fork

15. actuation, the dog clutch sleeve (30) can move axially inside the support housing (50) along the first axis of rotation (X) between the first extreme disengagement position and the second extreme coupling position when the end of the actuating fork moves axially according to a predetermined value. Transmission shaft coupling system (1) according to any one of the preceding claims, wherein the dog clutch sleeve (30) comprises at least one first internal connecting spline (33) arranged to drive the first shaft (2) in rotation and a second internal connecting spline (34) arranged to drive the second shaft (3) in rotation, the first and second internal connecting splines (33, 34) being engaged respectively in a first external transmission spline (2a) of the first shaft and a second external transmission spline (3a) of the second shaft when the dog clutch sleeve (30) is in the second extreme coupling position.

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