IMPROVED WET CLUTCH FOR A MOTORIZED DRIVE SYSTEM

Description

[0001] [The present invention relates to an improved wet clutch for a powertrain system. The invention also relates to a dual wet clutch and a triple wet clutch comprising this improved wet clutch.]

[0002] The present invention relates to the field of powertrain systems for vehicles, such as motor vehicles or industrial vehicles, particularly those arranged between a heat engine and a gearbox.

[0003] The invention relates for example to a triple wet clutch for a hybrid type motor vehicle in which a rotating electric machine is disposed in the powertrain system.

[0004] In the prior art, hybrid vehicles are known to include a dual wet clutch positioned between an internal combustion engine and a gearbox, a rotating electric machine, and a torque-deleting clutch, also known as a "K0 clutch." An actuation mechanism for this torque-deleting clutch allows the rotation of a crankshaft of the internal combustion engine to be coupled or uncoupled to a rotor of the rotating electric machine. This enables the internal combustion engine to be shut off each time the vehicle stops and restarted using the rotating electric machine. The rotating electric machine can also act as an electric brake or provide additional power to the internal combustion engine to assist it or prevent it from stalling. When the internal combustion engine is running, the electric machine can function as a generator.The rotating electric machine can also provide vehicle drive independently of the internal combustion engine.

[0005] One technical solution for reducing radial space requirements involves offsetting the rotating electric machine relative to the main transmission axis. This means that the rotation axis of the rotating electric machine's rotor is parallel to the rotation axis of the clutches, as described in document WO2020 / 099136 A1. In this configuration, the rotating electric machine's rotor is kinematically connected to a torque transmission disc carrier of the triple clutch via a toothed drive ring. The rotational guidance of this disc carrier is crucial for minimizing noise at the toothed drive ring. Specifically, the torque transmission disc carrier is guided in rotation directly relative to the rotating electric machine's housing by means of a radial guide bearing, in this example, a needle bearing.

[0006] In this so-called "off-line" architecture, the axial position of the toothed drive ring must be close to the radial guide bearing, whose function is to support the radial loads within the wet triple clutch. Therefore, precisely positioning this radial guide bearing relative to the toothed drive ring is critical to minimizing nutation of the wet triple clutch. Furthermore, ensuring the lubrication of this radial guide bearing is essential to guarantee the reliability of the wet triple clutch throughout the powertrain system's lifespan.

[0007] The invention aims to improve the design presented in patent application WO2020 / 099136 A1 by ensuring stable guidance of the toothed drive ring of the wet triple clutch and by providing proper lubrication of the radial guide bearing supporting this toothed drive ring. Documents DE102020102359 A1 and DE102019104074 A1 also demonstrate the prior art.

[0008] The invention aims in particular to provide a simple, effective and economical solution to this problem.

[0009] The aim of the present invention is in particular to propose a wet clutch which makes it possible to resolve at least in part the aforementioned disadvantages of the prior art.

[0010] For this purpose, the invention proposes, according to one of its aspects, a wet clutch for a powertrain system comprising around an axis X at least: a multi-disc assembly consisting of flanges and friction discs; a torque transmission disc carrier supporting the wet clutch multi-disc assembly, comprising: a cylindrical portion, a flange extending radially from the cylindrical portion, an annular cavity with axis X disposed on one side of the flange and arranged to receive an actuating piston for the multi-disc assembly, a radial guide bearing attached to the torque transmission disc carrier on the other side of the flange and arranged to guide the wet clutch in rotation relative to the powertrain system, in which the torque transmission disc carrier includes at least one outlet portion of a lubrication channel of the radial guide bearing which opens radially below the radial guide bearing, the outlet portion of the lubrication channel is oriented in the opposite direction to that of the annular cavity and inclined with respect to the X axis at an angle between 0 and 60 degrees.

[0011] This wet clutch, according to the invention, has the advantage of lubricating the radial guide bearing of the wet clutch with a suitable oil flow rate. The service life of the radial guide bearing is improved.

[0012] For the purposes of this application, a wet clutch is a clutch that is adapted to operate in an oil bath.

[0013] The radial guide bearing can be a needle bearing.

[0014] According to one variant of the invention, the radial guide bearing can be a ball bearing.

[0015] According to another variant of the invention, the radial guide bearing can be a roller bearing.

[0016] Preferably, the torque transmission disc carrier can include several lubrication channel outlet portions distributed around the X axis of rotation.

[0017] Advantageously, the torque transmission disc carrier may include a cylindrical flange inside which the radial guide bearing is inserted, the cylindrical flange extending axially in the opposite direction to that of the annular cavity.

[0018] Preferably, the wet clutch may include an axial guide bearing disposed radially below the radial guide bearing, said output portion opening radially below the axial guide bearing.

[0019] Advantageously, the axial guide bearing can be supported on the torque transmission disc carrier in a receiving housing, the receiving housing being oriented axially in the opposite direction to that of the annular cavity.

[0020] Advantageously, the receiving housing for the axial guide bearing can be formed by the cylindrical collar, the flange and the cylindrical portion of the torque transmission disc carrier.

[0021] Preferably, a drive cover can be attached to the outer periphery of the flange of the torque transmission disc carrier and include a toothed ring suitable for being rotationally linked with an electrical machine rotating around an axis parallel to the axis of rotation X.

[0022] Advantageously, the cylindrical flange supporting the radial guide bearing can be positioned geometrically directly above the drive cover. This limits the nutation movements of the triple wet clutch at the connection with the rotating electrical machine by placing the radial guide bearing close to the drive cover.

[0023] Preferably, the lubrication channel can be supplied with lubricating fluid via channels machined directly into the second driven shaft of the powertrain system's gearbox, with the machined channels guiding the lubricating oil supply flow toward the torque transmission disc carrier. For example, the lubricating oil flow can pass between the central bore of the torque transmission disc carrier and the outer surface of the second driven shaft.

[0024] According to a first embodiment of the invention, the lubrication channel may open radially into a central bore with axis X of the torque transmission disc carrier. The inlet of the lubrication channel communicating directly with the central bore of the torque transmission disc carrier may include a machined counterbore whose diameter is larger than the diameter of the outlet portion.

[0025] Advantageously, the lubrication channel can open radially into a reservoir area with a diameter larger than the central X-axis bore of the torque transmission disc carrier, the inlet of the lubrication channel being axially offset from the edges of the reservoir area by a Y-value between 1 and 10 mm. The reservoir area creates a lubrication oil reservoir for the radial guide bearing, improving the flow rate in the outlet portion.

[0026] This wet clutch according to the first variant of the invention has the advantage of reducing the distance traveled by the lubricating oil before reaching the radial guide bearing. Lubrication efficiency is improved.

[0027] According to a second embodiment of the invention, the lubrication channel can open radially into a central bore along the X-axis of the torque transmission disc carrier. The lubrication channel can also open radially into a reservoir area having a larger diameter than the central bore along the X-axis of the torque transmission disc carrier. The inlet of the lubrication channel is offset axially from the edges of the reservoir area by a Y-value between 1 and 10 mm. The inlet of the lubrication channel, which communicates directly with the central bore, has the same diameter as the outlet portion. The reservoir area creates a lubrication oil reservoir for the radial guide bearing, improving the flow rate in the outlet portion.

[0028] According to a third variant of the invention, the outlet portion of the lubrication channel can be oriented along an axis perpendicular to the X axis and pass completely through the cylindrical portion.

[0029] This wet clutch, according to the third variant of the invention, has the advantage of reducing the distance traveled by the lubricating oil before reaching the radial guide bearing and of lubricating the radial guide bearing of the wet clutch with an appropriate oil flow rate. The service life of the radial guide bearing is improved.

[0030] According to a fourth variant of the invention, the wet clutch may include an actuating piston of the multi-disc assembly, axially movable relative to the torque transmission disc carrier between an engaged position and a disengaged position of the wet clutch, the actuating piston being controlled in displacement by means of a control chamber, delimited in part by the actuating piston and the annular cavity, to which is associated a balancing chamber delimited in part by the actuating piston, said lubrication channel communicating with the balancing chamber.

[0031] Optionally, the lubrication channel can communicate with a central X-axis bore of the torque transmission disc carrier.

[0032] This wet clutch according to the fourth variant of the invention has the advantage of reducing the number of machining operations required to produce the lubrication channel.

[0033] According to a fifth embodiment of the invention, the wet clutch may include an actuating piston for the multi-disc assembly, which is axially movable relative to the torque transmission disc carrier between an engaged and a disengaged position of the wet clutch. The actuating piston is actuated by means of a control chamber, partially delimited by the actuating piston and the annular cavity, to which is associated a balancing chamber, also partially delimited by the actuating piston. The lubrication channel communicates with the balancing chamber. The lubrication channel may be common to a cooling channel supplying oil to the balancing chamber and includes a bifurcation forming the outlet portion.

[0034] Advantageously, the cooling channel may include an oil inlet port radially located within the outlet portion and an oil outlet port opening into the balancing chamber, the cooling channel passing through the torque transmission disc carrier.

[0035] Preferably, the outlet portion can be arranged axially between the oil inlet port and the oil outlet port of the cooling channel.

[0036] This wet clutch according to the fifth variant of the invention has the advantage of providing a substantial flow of lubricating oil towards the radial guide bearing.

[0037] The invention also relates, according to another aspect, to a dual wet clutch for a powertrain system comprising at least one X-axis: a first wet clutch incorporating all or part of the previously mentioned characteristics, of the multi-disc type, controlled to selectively couple a driving shaft to a first driven shaft; a second wet clutch, of the multi-disc type, controlled to selectively couple a driving shaft to a second driven shaft; the first and second clutches being arranged radially one above the other.

[0038] Preferably, the torque transmission disc carrier of the first clutch can be common with the second clutch and support the multi-disc assembly of the second wet clutch.

[0039] Advantageously, the torque transmission disc carrier can support the multi-disc assemblies of the first and second clutches and include a second annular cavity designed to receive an actuating piston for the second clutch. In this cavity, the lubrication channel outlet portion passes through the flange and opens radially below the radial guide bearing in the opposite direction to the cavities. This arrangement is particularly well-suited to wet dual-clutch systems where a compact radial design is preferred.

[0040] Preferably, the first annular cavity can be arranged radially beyond the second annular cavity. This dual wet clutch according to the invention has the advantage, thanks to the radial interlocking of the control chambers of the actuating pistons, of reducing its overall size.

[0041] Advantageously, the lubrication channels are arranged angularly between the oil channels opening into the first and second annular cavities.

[0042] Preferably, the torque transmission disc carrier can support a radial and / or axial guide bearing arranged to guide the wet dual clutch in rotation relative to the powertrain system, the flange of the torque transmission disc carrier comprising at least one outlet portion of a lubrication channel oriented in the opposite direction to that of the cavities, said outlet portion opening radially below the radial and / or axial guide bearing.

[0043] The invention also relates, according to another aspect, to a triple wet clutch for a powertrain system comprising a multi-disc type torque-cutting clutch, controlled to selectively couple a shaft leading to a rotating electrical machine, and a double wet clutch incorporating all or part of the characteristics mentioned above, the torque-cutting clutch being arranged radially above the double wet clutch.

[0044] Advantageously, the triple wet clutch may include the torque transmission disc carrier of the dual wet clutch which is also common to the torque cut-off clutch, said torque transmission disc carrier comprising an annular cavity arranged radially beyond the dual wet clutch and arranged to receive an actuating piston of the torque cut-off clutch, said torque transmission disc carrier comprising an attached drive cover arranged to be driven in rotation by a rotating electrical machine, the drive cover forming in part the annular cavity of the torque cut-off clutch.

[0045] Advantageously, the drive cover can surround the outer perimeter of the flange.

[0046] Thanks to this wet triple clutch architecture, the clutches are concentric and arranged radially in the same plane. The axial footprint of such a wet triple clutch within a powertrain system is thus reduced.

[0047] Positioning the drive cover on the outer edge of the torque transmission disc carrier minimizes nutation of the wet triple clutch. The overhang of the drive cover relative to the radial guide bearing is reduced. Backlash at the kinematic linkage with the rotating electric machine rotor is minimized. This results in reduced noise levels within the transmission.

[0048] In one embodiment, the drive cover may include a connection area suitable for rotationally linking with an electrical machine rotating about an axis parallel to the axis of rotation X. The connection area may be axially offset from the disconnect clutch and / or the first and second clutches. The rotating electrical machine is then said to be "off-line".

[0049] Preferably, the drive cover may include a groove arranged to receive the multi-disc assembly of the torque-cutting clutch, said groove being formed from the same material as the drive cover or attached to the drive cover.

[0050] Advantageously, the drive cover may include a toothed ring suitable for being rotationally linked with an electrical machine rotating around an axis parallel to the axis of rotation X.

[0051] This arrangement allows the rotating electric machine to be positioned according to the available space within the vehicle's torque transmission chain. Specifically, this arrangement avoids having to position the electric machine axially following the clutches, which would negatively impact axial compactness. Similarly, this arrangement avoids having to position the rotating electric machine radially beyond the clutches, which would also negatively impact radial compactness.

[0052] Alternatively, a chain or belt may be used to connect the rotating electrical machine to the connection area.

[0053] The invention will be better understood, and other aims, details, characteristics and advantages thereof will appear more clearly during the following description of a particular embodiment of the invention, given solely for illustrative and non-limiting purposes, with reference to the appended figures. there [ Figure 1 ] represents an axial cross-sectional view of a triple wet clutch according to a first embodiment of the invention. the [ Figure 2 ] represents a detailed axial cross-sectional view of the wet clutch according to the first embodiment of the invention of the [ Figure 1 ]. there [ Figure 3 ] represents a detailed axial cross-sectional view of a wet clutch according to a second embodiment of the invention. the [ Figure 4 ] represents a detailed axial cross-sectional view of a wet clutch according to a third embodiment of the invention. the [ Figure 5 ] represents a detailed axial cross-sectional view of a triple wet clutch according to a fourth embodiment of the invention. the [ Figure 6 ] represents a detailed axial cross-sectional view of a triple wet clutch according to a fifth embodiment of the invention.

[0054] In the following description and claims, the terms "front" or "rear" will be used, without limitation and to facilitate understanding, according to the direction with respect to an axial orientation determined by the main X axis of rotation of the transmission of the motor vehicle and the terms "inside / internal" or "outside / external" with respect to the X axis and along a radial orientation, orthogonal to said axial orientation.

[0055] We have represented on the figures 1 And 2a first embodiment of a wet clutch E1 according to the invention integrated within a triple wet clutch 1. The triple wet clutch 1 is represented within a motor vehicle powertrain system by means of a gearbox housing 120 equipped with two driven torque output shafts A1, A2.

[0056] On the figure 1 We observe a triple wet clutch 1 comprising: a multi-disc type torque-cutting clutch K0, controlled to selectively couple a shaft driving a rotating electrical machine, a first wet torque-output clutch E1 and a second wet torque-output clutch E2 respectively of multi-disc type, controlled to selectively couple the electrical machine and / or the shaft driving a first driven shaft and a second driven shaft, the first and second wet clutches E1, E2 being arranged radially one above the other, and a torque transmission disc carrier 100 having the function of introducing the torque into the clutches and the other function of supplying oil to the control chambers and the balancing chambers of the torque-cutting clutch K0, the first wet clutch E1 and the second wet clutch E2.

[0057] The first wet clutch E1 is a multi-disc type and operates in a wet environment. The first wet clutch E1 includes, in particular, a multi-disc assembly consisting of friction plates 11 and discs 12, and the torque transmission disc carrier 100 arranged to receive the multi-disc assembly via an attached disc support 110. The disc support 110 is fixedly attached to the torque transmission disc carrier 100, for example by welding.

[0058] The 100-axis X-axis torque transmission disc carrier includes: a cylindrical portion 104, a flange 105 extending radially from the cylindrical portion 104, a first annular cavity 101 disposed on the side of the flange and arranged to receive an actuating piston 15 of the first clutch E1, a second annular cavity 102 disposed on the same side of the flange as the first annular cavity and arranged to receive an actuating piston 25 of the second clutch E2, a third annular cavity 103 disposed radially beyond the other two annular cavities and arranged to receive an actuating piston 5 of the torque cut-off clutch K0, and oil channels 54a, 54b and 54c formed in the torque transmission disc carrier 100 passing through the cylindrical portion 104 and the flange 105, and opening separately into the annular cavities.

[0059] The annular cavities 103, 101, and 102 of the torque-cutting clutch K0, the first clutch E1, and the second clutch E2 are oriented in the same direction, for example, towards the drive shaft, i.e., towards the internal combustion engine of the powertrain system. The annular cavities 103, 101, and 102 serve as control chambers for the respective clutches K0, E1, and E2.

[0060] The triple wet clutch 1 has, around its axis of rotation X, at least one torque input element 2 which is rotationally linked to a driving shaft (not shown). The input element 2 is located at the front of the triple wet clutch 1.

[0061] In the first embodiment, the input element 2, generally having an "L" shape, comprises a radial orientation part formed by a torque input web 3 and an axial orientation part formed by a splined hub 4. The torque input element 2 is guided in rotation inside a housing 121 fixed relative to the powertrain system.

[0062] The input element 2 of the torque input is for example linked in rotation by means of splines formed at the output of a damping device (such as a double flywheel damper, etc.) whose input is linked, in particular by means of a flywheel, to the driving shaft formed by a crankshaft which is driven in rotation by a thermal engine equipping the motor vehicle.

[0063] The torque input veil 3 has, at its external radial end, a groove arranged to receive the multi-disc assembly of the torque cut-off clutch K0.

[0064] In the example considered, the triple wet clutch 1 further includes a torque-cutting clutch K0 selectively coupling by friction the torque input web 3 and an intermediate disc carrier 91 of the torque-cutting clutch K0 rotationally fixed with the torque transmission disc carrier 100.

[0065] The K0 torque-cutting clutch comprises a multi-disc assembly including several friction discs 7, equipped with friction linings, which are rotationally fixed to the torque input disc 3, and several flanges 6 arranged respectively on either side of each friction disc 7, which are rotationally fixed to the intermediate disc carrier 81. The K0 torque-cutting clutch is actuated by an axially movable actuating piston 5, here moving from rear to front, between a disengaged position and an engaged position, which correspond respectively to the open and closed states of the K0 torque-cutting clutch. The actuating piston 5 clamps the friction linings so as to transmit torque between the torque input disc 3 and the intermediate disc carrier 91.

[0066] The flanges 6 of the multi-disc assembly of the torque cut-off clutch K0 are rotationally linked to the torque transmission disc carrier 100 via a spline and the friction discs 7 are rotationally linked to the input element 2.

[0067] The wet triple clutch 1 includes a drive cover 90 mounted on the outer periphery of the torque transmission disc carrier 100 and arranged to be rotated by the rotating electric machine. The drive cover 90 is mounted on the outer circumference of the flange 105. In this case, the drive cover 90 partially forms the annular cavity 57. The torque transmission disc carrier 100 transmits torque within the wet triple clutch 1. For this purpose, the drive cover 90 is rotationally fixed to the intermediate disc carrier 91, in this case by means of a welded connection.

[0068] The drive cover 90 includes a connection area 92 suitable for rotationally linking with a rotating electrical machine. In this case, the electrical machine rotates about an axis parallel to the axis of rotation X. The electrical machine is described as "off-line" because it is not concentric with the drive shaft but aligned along a parallel shaft. The connection area 92 is suitable for direct interaction with a pinion of the rotating electrical machine.

[0069] The connection zone 92 can be in the form of a ring gear suitable for direct or indirect (belt, chain, etc.) engagement with a pinion of the rotating electrical machine (not visible). The ring gear may have helical teeth with a shape complementary to the pinion of the rotating electrical machine.

[0070] The 100 torque transmission disc carrier is capable of transmitting torque from two separate sources: thermal and electrical. When the torque-cutting clutch K0 is closed, the torque from the internal combustion engine can then be transmitted to the coaxial gearbox shafts A1 and A2, depending on whether one of the first clutch E1 or the second clutch E2 is closed.

[0071] The first driven shaft A1 is driven in rotation when said first clutch E1 is closed and the second driven shaft A2 is driven in rotation when said second clutch E2 is closed.

[0072] The multi-disc assembly of the first clutch E1 comprises flanges 11 rotationally linked to the disc support 110 attached to the torque transmission disc carrier 100 and friction discs 12 rotationally linked to a first output disc carrier 13. The friction discs 12 are, individually, axially interposed between two successive flanges 11.

[0073] The first output disc carrier 13 of the first clutch E1 is rotationally linked by meshing with the friction discs 12 and by a splined connection with said first driven shaft A1. The inner radial end of the first output disc carrier 13 is fixed to a splined output hub.

[0074] The multi-disc assembly of the second clutch E2 comprises flanges 21 rotationally linked to the disc support 110 attached to the torque transmission disc carrier 100 and friction discs 22 rotationally linked to a second output disc carrier 23. The friction discs 22 are individually axially interposed between two successive flanges 21.

[0075] The second output disc carrier 23 of the second clutch E2 is rotationally linked by meshing with the friction discs 22 and by a splined connection with said second driven shaft A2. The inner radial end of the second output disc carrier 23 is fixed to a splined output hub.

[0076] The annular disc support 110 has an external spline 111 which meshes with the multi-disc assembly of the first clutch E1 and an internal spline 112 which meshes with the multi-disc assembly of the second clutch E2. The disc support 110 common to the first clutch E1 and the second clutch E2 is fixedly assembled to the torque transmission disc carrier 100 by means of a welded connection located on the inner periphery of said disc support.

[0077] In an alternative not shown, the internal and external splines engaging with the multi-disc assemblies of the E1 and E2 clutches can be distributed over two separate disc supports and attached to the torque transmission disc carrier 100.

[0078] From a general operating point of view, the triple wet clutch 1 is hydraulically controlled via a pressurized fluid, usually oil.

[0079] To selectively control the change of state of the torque-cutting clutch K0, the first clutch E1, and the second clutch E2, a wet triple-clutch control unit manages the pressurized oil supply within separate control chambers. The control unit is generally integrated into the gearbox housing 120. The control unit is connected to the torque-transmission disc carrier 100, which has pressurized oil lines 54a, 54b, and 54c, for example, three of them as shown in the diagram. figure 1 . The oil lines 54a, 54b and 54c are distributed angularly around the cylindrical portion 104.

[0080] Each of the oil channels 54a, 54b and 54c consists of substantially radial and axial bores directed towards the control chambers of the torque cut-off clutch K0, of the first and second clutches E1, E2.

[0081] For example, the oil line 54c, whose inlet port is located axially at the rear end of the cylindrical portion 104, is associated with the control chamber 56 of the first wet clutch E1. The oil line 54c is formed by drilling successive axial and radial channels within the torque transmission disc carrier 100. The channels open into one another and are arranged to supply pressurized fluid to the control chamber 56.

[0082] The first clutch E1 comprises an actuating piston 15 which is axially movable, here from rear to front, between a disengaged position and an engaged position, corresponding respectively to the open and closed states of the first clutch E1. The multi-disc assembly of the first clutch E1 is directly actuated by the first actuating piston 15, which is made from a stamped steel sheet. The actuating piston 15 is axially movable relative to the first annular cavity 101 of the torque transmission disc carrier 100.The actuating piston 15 is actuated by means of the control chamber 56 and a balancing chamber 46. The actuating piston 15 alternately clamps the multi-disc assembly axially in an engaged position against reaction means 19 located on the free end of the external spline 111 of the disc support 110, and axially releases the multi-disc assembly in a disengaged position. The reaction means 19 may be, for example, an elastic ring.

[0083] The control chamber 56 is delimited in part by the actuating piston 15 and the torque transmission disc carrier 100, to which is associated a balancing chamber 46 delimited in part by the actuating piston 15 and the disc support 110.

[0084] The oil line 54b, machined in the torque transmission disc carrier 100, is associated with the control chamber 55 of the second clutch E2. The oil line 54b is formed by drilling successive axial and radial channels within the torque transmission disc carrier 100. The channels open into one another and are arranged to supply pressurized fluid to the control chamber 55 of the second clutch E2. The oil line 54b opens into the second annular cavity 102.

[0085] The second clutch E2 includes an actuating piston 25 which is axially mobile, here from rear to front, between a disengaged position and an engaged position which correspond respectively to the open and closed states of the second clutch E2. The actuating piston 25 is controlled in movement by means of the control chamber 55 and a balancing chamber 45, said actuating piston 25 alternately axially clamping in an engaged position the multi-disc assembly against the reaction means 19 arranged on the free end of the internal spline 112 of the disc support 110 and axially releasing the multi-disc assembly in a disengaged position.

[0086] In the first embodiment, the oil channels 54a, 54b and 54c open onto the outer perimeter of the flange 105 and are closed by the drive cover 90.

[0087] As is known in the operation of a wet clutch, a balancing chamber is associated with each control chamber. The balancing chambers are supplied with fluid, for example, coolant. The coolant flows through cooling channels 54d separate from the oil lines 54a, 54b, and 54c. These separate cooling channels 54d are also formed in the torque transmission disc carrier 100.

[0088] To facilitate the control of the actuating piston 15, the first clutch E1 uses the balancing chamber 46, which is supplied with cooling fluid. The balancing chamber 46 is arranged radially beyond the control chamber 55 of the second clutch E2. The cooling channel 54d opens into the annular balancing chamber 46, which is formed partly by the cylindrical portion 104 of the torque transmission disc carrier 100 and partly by the disc support 110 attached to the flange 105.

[0089] We will now explain how the triple wet clutch 1 is guided in rotation relative to the gearbox casing 120 in order to reduce noise at the point of engagement of the drive cover 90 with the rotor of the rotating electrical machine (not shown).

[0090] In particular, the triple wet clutch 1 is guided in rotation relative to the gearbox housing 120 by means of an axial guide bearing 8 and a radial guide bearing 9 bearing on the torque transmission disc carrier 100. The torque transmission disc carrier 100 includes in particular a cylindrical flange 107 inside which the radial guide bearing 9 is inserted, the flange 107 extending axially in the opposite direction to that of the annular cavities 103, 101, 102.

[0091] The axial guide bearing 8 is arranged radially below the radial guide bearing 9. The axial guide bearing 8 bears against the torque transmission disc carrier 100 in a receiving recess 106, the receiving recess 106 being oriented axially in the opposite direction to that of the annular cavities 103, 101, 102. The guide bearings 8 and 9 bear against a portion of the gearbox housing 120.

[0092] This arrangement of the radial guide bearing 9 ensures rotational stability of the wet triple clutch 1 within the powertrain system. Nutational movements of the wet triple clutch are reduced.

[0093] The radial guide bearing 9 is a needle bearing. Alternatively, the radial guide bearing can be a ball bearing or a roller bearing.

[0094] The axial guide bearing 8 is a needle bearing.

[0095] According to one variant, an angular contact ball bearing can be used as an axial and radial guide bearing.

[0096] The guide bearings 8, 9 are lubricated by a supply of lubricating oil disposed between the driven shafts A1, A2 of the gearbox 120. For example, the driven shaft A2 may include machined channels 119 guiding the supply of lubricating oil towards the torque transmission disc carrier 100. The lubricating oil flows between the central bore 108 of the torque transmission disc carrier 100 and the outer surface of the second driven shaft A2. A lubrication channel 80 opens radially into the central bore 108 along the X-axis of the torque transmission disc carrier. In order to create a reservoir of lubricating oil at the central bore 108, it is possible to machine a reservoir zone 109 having a diameter enlarged relative to the central bore 108 of axis X. The reservoir zone 109 is annular in shape.The reserve area 109 is located at the outlet of the lubrication oil supply flow from the driven shafts A1, A2.

[0097] In order to lubricate the radial guide bearing 9 of the wet clutch with an appropriate oil flow, the torque transmission disc carrier 100 includes an outlet portion 81 of a lubrication channel 80 oriented in the opposite direction to that of the cavities 103, 101, 102, said outlet portion 81 opens radially below the axial guide bearing 8 and the radial guide bearing 9. In this way, the service life of the guide bearings is improved.

[0098] More specifically, the outlet portion 81 opens into the receiving housing 106 of the axial guide bearing 8 formed by the cylindrical collar 107, the flange 105 and the cylindrical portion 104 of the torque transmission disc carrier 100. In this way, the lubricating oil is directed directly towards the axial guide bearing 8, then passes through the radial guide bearing 9.

[0099] To improve the flow of the lubricating oil, the outlet portion 81 of the lubrication channel can be inclined with respect to the X-axis at an angle Δ between 0 and 60 degrees. In the example of the figures 1 And 2The angle Δ is 45° with respect to the X-axis. This inclination also facilitates machining of the lubrication channel 80. The torque transmission disc carrier includes, in particular, several outlet portions 81 of lubrication channels 80 distributed around the axis of rotation X, for example, six outlet portions 81 spaced angularly every 60 degrees. The lubrication channels 80 are arranged angularly between the oil channels 54b, 54c opening into the first and second annular cavities 101, 102.

[0100] The flow of lubricating oil through the radial guide bearing 9 depends on the machining diameter of said output portion 81 and the number of lubrication channels 80.

[0101] To maintain a constant flow rate of lubricating oil, the inlet of the lubrication channel 80, which communicates directly with the central bore 108 of the torque transmission disc carrier 100, includes a machined counterbore 82 with a diameter larger than the diameter of the outlet portion 81. The machined counterbore 82 opens radially into the reservoir zone 109, the inlet of the lubrication channel 80 being axially offset from the edge of the reservoir zone 109. This wet clutch according to the first embodiment of the invention has the advantage of reducing the distance traveled by the lubricating oil before reaching the radial guide bearing. Lubrication efficiency is improved.

[0102] We will now present other embodiments of lubrication for the radial guide bearing of the triple wet clutch 1. All these embodiments fulfill the same function of lubricating the radial guide bearing of the wet clutch with a suitable oil flow rate. The service life of the radial guide bearing is improved.

[0103] There figure 3 presents a wet clutch according to a second embodiment of the invention similar to the first embodiment at least in its general operation.

[0104] This second embodiment differs from the one described in reference to figures 1 And 2 in that the inlet of the lubrication channel 80 communicating directly with the central bore 108 is of the same diameter as the outlet portion 81. This simplification of shape facilitates the machining of the lubrication channel 80.

[0105] To improve the flow of the lubricating oil, the outlet portion 81 of the lubrication channel is inclined with respect to the X axis at an angle Δ of 45° with respect to the X axis. This inclination also facilitates the machining of the lubrication channel 80.

[0106] To ensure a homogeneous flow of lubricating oil, the inlet of the lubrication channel 80 is axially offset from the edge of the reservoir zone 109 by a value Y between 1 and 10 mm, for example, 5 mm. Depending on the value of the offset Y, the flow rate at the outlet portion is increased. For example, an offset Y of 0 mm results in an insufficient flow rate at the outlet.

[0107] This second embodiment has the advantage of reducing the distance traveled by the lubricating oil before reaching the radial guide bearing. Lubrication efficiency is improved.

[0108] There figure 4 presents a wet clutch according to a third embodiment of the invention similar to the first embodiment at least in its general operation.

[0109] This third embodiment differs from that described in reference to figures 1 And 2 in that the outlet portion 81 of the lubrication channel 80 is oriented along an axis perpendicular to the X axis and passes through the cylindrical portion 104 of the torque transmission disc carrier 100.

[0110] In this example, the guide bearings 8, 9 are lubricated by a supply of lubricating oil located between the driven shafts A1, A2 of the gearbox 120. The lubricating oil flow is oriented perpendicular to the axis of rotation of the driven shaft A2 towards the torque transmission disc carrier 100. The lubricating oil flow passes between the central bore 108 of the torque transmission disc carrier 100 and the outer surface of the second driven shaft A2, then directly through the lubrication channel 80. To create a reservoir of lubricating oil at the central bore 108, a reservoir area 109 can be machined with a diameter larger than that of the central bore 108 along the X-axis. The reservoir area 109 is annular in shape. The reserve area 109 is located at the outlet of the lubrication oil supply flow from the driven shafts A1, A2.

[0111] In order to lubricate the radial guide bearing 9 of the wet clutch with an appropriate oil flow, the lubrication channel 80 is oriented along an axis perpendicular to the X axis and passes completely through the cylindrical portion 104 of the torque transmission disc carrier 100. The outlet portion 81 opens radially below the axial guide bearing 8 and the radial guide bearing 9. In this way, the service life of the guide bearings is improved.

[0112] More specifically, the outlet portion 81 opens into the receiving housing 106 of the axial guide bearing 8 formed by the cylindrical collar 107, the flange 105 and the cylindrical portion 104 of the torque transmission disc carrier 100. In this way, the lubricating oil is directed directly towards the axial guide bearing 8, then passes through the radial guide bearing 9.

[0113] There figure 5 presents a wet clutch according to a fourth embodiment of the invention similar to the first embodiment at least in its general operation.

[0114] This fourth embodiment differs from that described in reference to figures 1 And 2 in that the lubrication channel 80 communicates with the balancing chamber 46 of the first clutch E1.

[0115] In this fourth embodiment, the balancing chamber 46 is supplied with fluid, for example, cooling fluid. The cooling fluid flows through a separate cooling channel (not shown) distinct from the oil lines 54a, 54b, and 54c. A portion of the fluid in the balancing chamber is transferred to the lubrication channel 80 via additional bores 115 in the torque transmission disc carrier 100. Thus, the cooling fluid from the cooling channel 54d is common to the lubricating oil flowing through the lubrication channel 80 and the radial guide bearing 9.

[0116] As illustrated on the figure 5 The lubrication channel 80 communicates with the balancing chamber 46 and the central bore 108 of the X-axis of the torque transmission disc carrier 100 by means of an additional bore 115 extending radially through the flange 105. This additional bore 115 is plugged by the drive cover 90. Thus, a large part of the lubrication oil supply flow returns to the central bore 108 and a small part of the lubrication oil supply flow uses the lubrication channel 80. For example, the flow rate of lubrication oil exiting radially below the radial guide bearing is between 0.01 and 0.1 liters per minute.

[0117] Alternatively, the lubrication channel 80 can communicate with the balancing chamber 47 of the torque cut-off clutch K0 or with the balancing chamber 45 of the second clutch E2.

[0118] In an alternative not shown, the additional hole 115 may be non-through in the central bore 108 of the torque transmission disc carrier 100.

[0119] There figure 6 presents a wet clutch according to a fifth embodiment of the invention similar to the first embodiment at least in its general operation.

[0120] This fifth embodiment differs from that described in reference to figures 1 And 2 in that the lubrication channel 80 communicates with the balancing chamber 46 of the first clutch E1 by means of the cooling channel 54d

[0121] In this fifth embodiment, the balancing chamber 46 is supplied with fluid, for example, coolant. The coolant flows through a cooling channel 54d separate from the oil lines 54a, 54b, and 54c. The cooling channel 54d opens into the annular balancing chamber 46, which is formed partly by the cylindrical portion 104 of the torque transmission disc carrier 100 and partly by the disc support 110 attached to the flange 105. The coolant from the cooling channel 54d is common to the lubricating oil flowing through the lubrication channel 80 and the radial guide bearing 9.

[0122] As illustrated on the figure 6 , the lubrication channel 80 is common with the cooling channel 54d supplying oil to the balancing chambers 47, 46, 45 of the various clutches K0, E1, E2 and includes a bifurcation forming the outlet portion 81.

[0123] The cooling channel 54d includes an oil inlet port 117 whose location is arranged radially inside the outlet portion 81 and an oil outlet port 118 opening into the balancing chamber 46, the cooling channel 54d passing through the torque transmission disc carrier 100. The outlet portion 81 is arranged axially between the oil inlet port 117 and the oil outlet port 118 of the cooling channel 54d.

[0124] This wet clutch according to the fifth embodiment of the invention has the advantage of providing a substantial flow of lubricating oil towards the radial guide bearing. For example, the flow rate of lubricating oil exiting radially below the radial guide bearing is between 0.1 and 1 liter per minute. The adjustment of the outlet flow rate depends on the machining diameter of said outlet portion 81.

[0125] Although the invention has been described in connection with several particular embodiments, it is clearly evident that it is by no means limited to them and that it includes all technical equivalents of the means described as well as their combinations if these fall within the scope defined by the claims of the invention.

[0126] It is clear from the foregoing that the present invention proposes a triple wet clutch in which the clutches are concentric and arranged radially in the same plane. The axial footprint of such a triple wet clutch within a torque transmission chain is reduced.

[0127] The invention is not limited to the means and configurations described and illustrated herein, and also extends to any equivalent means or configuration and to any technical combination operating such means, always within the scope defined by the claims. In particular, the shape of the lubrication channel may be modified without prejudice to the invention, provided that these components ultimately fulfill the same functionalities as those described and defined in the claims.

Claims

1. Wet clutch (K0, E1, E2) for a powertrain system comprising, about an axis (X), at least: - a multi-disc assembly (K0, E1, E2) composed of flanges (6, 11, 21) and friction discs (7, 12, 22); - a torque-transmitting disc carrier (100) supporting the multi-disc assembly of the wet clutch, comprising: • a cylindrical portion (104), • a flange (105) extending radially from the cylindrical portion (104), • an annular cavity (103, 101, 102) of axis (X) positioned on one side of the flange (105) and designed to receive an actuating piston (5, 15, 25) for actuation of the multi-disc assembly (K0, E1, E2), - a radial guide bearing (9) attached to the torque-transmitting disc carrier (100) on the other side of the flange and arranged to guide the wet clutch in rotation relative to the powertrain system, wherein the torque-transmitting disc carrier (100) comprises at least one outlet portion (81) of a lubrication channel (80) for lubricating the radial guide bearing which opens out radially below the radial guide bearing (9), characterized in that the outlet portion (81) of the lubrication channel (80) is oriented in the opposite direction to the direction of the annular cavity (103, 101, 102) and inclined relative to the axis (X) by an angle (Δ) of between 0 and 60 degrees.

2. Wet clutch (K0, E1, E2) according to the preceding Claim, wherein the lubrication channel (80) opens out radially in a central bore (108) of axis (X) of the torque-transmitting disc carrier (100).

3. Wet clutch (K0, E1, E2) according to Claim 2, wherein the inlet of the lubrication channel (80) communicating directly with the central bore (108) of the torque-transmitting disc carrier (100) comprises a machined counterbore (82) the diameter of which is greater than the diameter of the outlet portion (81).

4. Wet clutch (K0, E1, E2) according to Claims 1 to 3, wherein the lubrication channel (80) opens out radially in a reserve area (109) having a diameter that is enlarged with respect to the central bore (108) of axis (X) of the torque-transmitting disc carrier (100), the inlet of the lubrication channel being offset axially relative to the edges of the reserve area (109) by a value (Y) of between 1 and 10 mm.

5. Wet clutch (K0, E1, E2) according to Claim 1, comprising an actuating piston (5, 15, 25) for actuation of the multi-disc assembly, which is axially movable relative to the torque-transmitting disc carrier (100) between an engaged position and a disengaged position of the wet clutch, the actuating piston being controlled in movement by means of a control chamber (57, 56, 55), partially delimited by the actuating piston (5, 15, 25) and the annular cavity (103, 101, 102), with which a balancing chamber (47, 46, 45) partially delimited by the actuating piston (5, 15, 25) is associated, said lubrication channel (80) communicating with the balancing chamber.

6. Wet clutch (K0, E1, E2) according to Claim 5, wherein the lubrication channel (80) communicates with a central bore (108) of axis (X) of the torque-transmitting disc carrier (100).

7. Wet clutch (K0, E1, E2) according to Claim 5, wherein the lubrication channel (80) is common to a cooling channel (54d) supplying the balancing chamber (47, 46, 45) with oil and comprises a fork forming the outlet portion (81).

8. Wet clutch (K0, E1, E2) according to the preceding claim, wherein the cooling channel (54d) comprises an oil inlet port (117) located radially internally to the outlet portion (81) and an oil outlet port (118) opening out in the balancing chamber (47, 46, 45), the cooling channel (54d) passing right through the torque-transmitting disc carrier (100).

9. Wet clutch (K0, E1, E2) according to the preceding claim, wherein the outlet portion (81) is arranged axially between the oil inlet port (117) and the oil outlet port (118) of the cooling channel (54d).

10. Wet clutch (K0, E1, E2) according to one of the preceding claims, wherein the torque-transmitting disc carrier (100) comprises a cylindrical collar (107) inside which the radial guide bearing (9) is inserted, the cylindrical collar (107) extending axially in the opposite direction to the direction of the annular cavity (103, 101, 102).

11. Wet clutch (K0, E1, E2) according to the preceding claim, wherein a drive cover (90) is attached to the outer periphery of the flange (105) of the torque-transmitting disc carrier (100) and comprises a ring gear able to be rotatably connected to a rotary electric machine rotating about an axis parallel to the axis of rotation (X), the cylindrical collar (107) supporting the radial guide bearing (9) is arranged geometrically in line with the drive cover (90).

12. Dual wet clutch (E1, E2) for a powertrain system comprising, about an axis (X), at least: - a first wet clutch (E1) according to one of the preceding claims, of multi-disc type, operated in such a way as to selectively couple a drive shaft to a first driven shaft; - a second wet clutch (E2), of multi-disc type, operated in such a way as to selectively couple a drive shaft to a second driven shaft; the first and second clutches (E1, E2) being positioned radially one above the other.

13. Triple wet clutch (1) for a powertrain system, comprising a torque disconnect clutch (K0) of multi-disc type, operated in such a way as to selectively couple a drive shaft to a rotary electric machine, and a dual wet clutch (E1, E2) according to the preceding claim, the torque disconnect clutch (K0) being positioned radially above the dual wet clutch (E1, E2).