FR2862025A1 - Transmission unit for hybrid type parallel pull chain, has wet friction type clutch for connection between input and output shafts, and jaw type clutch for connection between rotor and output shaft - Google Patents

Abstract

The unit has an input shaft (37) connected to a thermal engine, and an output shaft (39) connected to a transmission. An electric engine (31) has a stator (61) and a rotor (63), and a clutch (33) is provided for connection between the input and output shafts. A clutch (35) is provided for connection between the rotor and the output shaft. The clutch (33) is of wet friction type and the clutch (35) is of jaw clutch type. An independent claim is also included for a motor vehicle.

Description

The invention relates to a transmission element for a chain of

  parallel hybrid type traction.

  "Parallel hybrid traction train" means a traction chain supplying a wheel shaft with mechanical energy from at least one irreversible type engine (generally a heat engine) and at least one reversible type engine ( usually an electric motor), and in which the energy node from both motors is mechanical in nature.

  FIG. 1 schematically shows a parallel hybrid traction chain of known type to which the invention more particularly applies.

  Such a traction chain 1 therefore essentially comprises a heat engine (or more generally an irreversible motor) 3, a transmission element 5, and a gearbox 7 whose input is connected to the transmission element 5 and the output to a wheel shaft 9.

  The transmission element 5 comprises an electric motor (or more generally a reversible motor) 11 of the hybrid traction system, as well as a first clutch 13 connecting the heat engine 3 and the box input shaft 7. , and a second clutch 15 connecting the electric motor 11 and the gearbox input shaft 7.

  The invention therefore relates more particularly to a transmission element for a parallel hybrid-type power train, said element comprising a movement input shaft intended to be connected to a heat engine, a movement output shaft intended to be connected. to a gearbox, an electric motor having a stator and a rotor, a first linkage clutch between the input shaft and the output shaft, and a second linkage clutch between the rotor and the output shaft .

  In the known hybrid drive chains, of the type previously described, the two connecting clutches, respectively to the engine and the electric motor, are of the same type, in general friction, more precisely dry or wet.

  To minimize wear and ensure efficient clutch cooling, some designers choose to use two wet clutches.

  This choice, which has the advantages mentioned above vis-à-vis the dry clutch solution, nevertheless has certain disadvantages. In particular, wet clutches have a relatively large axial size, due to the stacking of a large number of friction discs. In addition, wet clutches are associated with hydraulic circuits of lubrication and cooling complex and penalizing in terms of size.

  The invention aims to overcome the aforementioned drawbacks, and to provide a transmission element of the aforementioned type, one of the clutches is of wet friction type, and which is of smaller axial size and less complexity.

  For this purpose, according to the invention, the other of said clutches is of jaw type.

  According to other features of the invention, taken alone or in any technically feasible combination: the first clutch is of wet friction type, and the second clutch is of jaw type; the two clutches are arranged radially inside the electric motor; and - the transmission element comprises a casing having a first half-shell rotatably supporting the input shaft, and a second half-shell rotatably supporting the output shaft, these two half-shells defining a housing in which are coaxially mounted both clutches and the electric motor.

  With this arrangement, the transmission element according to the invention can adapt to a conventional single-source traction chain, and replace a simple clutch, to form a parallel hydride type traction chain, without major modification. other elements of the power train.

  According to still other optional features of the invention: the first half-shell is integral with the stator and rotatably supports the rotor; - the housing is sealed to a lubricating fluid and / or cooling; the second clutch is returned to the engaged position; the first clutch is returned to the disengaged position; and the claw clutch is provided with a synchronization device.

  The invention also relates to a motor vehicle comprising a parallel hydride type traction chain, said traction chain comprising a heat engine, a gearbox, and a transmission element as described above, connecting the heat engine to the transmission box. speeds.

  Particular embodiments of the invention will now be described in more detail with reference to FIGS. 2 and 3 of the accompanying drawings, in which: FIG. 2 is a partial view in axial section of a transmission element according to a first embodiment of the invention; and FIG. 3 is a similar view of a transmission element according to a second embodiment of the invention.

  In Figure 2, there is shown a transmission element 25 according to a first embodiment of the invention for connecting, as the element 5 in Figure 1, a thermal engine to a gearbox. Like the element 5, the element 25 of the invention comprises an electric motor 31, a first clutch 33, and a second clutch 35.

  The transmission member 25 further includes a motion input shaft 37 and an X-axis coaxial motion output shaft 39. The X axis is oriented from the input to the output for the convenience of description. who will follow.

  Upstream and downstream terms will refer to this orientation.

  The input shaft 37 is integral in rotation with the crankshaft of the heat engine, a part of which, or nose, is shown in FIG. 2 under the reference 41.

  In the example shown, the crankshaft 41 is provided with a flywheel 43, and connected to the input shaft 37 via a damping device 45.

  The output shaft 39 is rotatably connected to the input gearbox input shaft, a portion of which is shown in FIG. 2 as 47.

  The transmission element 25 comprises a housing consisting essentially of a first half-shell 51 and a second half-shell 52, assembled by fixing means 54 distributed on the periphery of the housing. The housing half-shells 51, 52 internally delimit a housing 53, inside which are arranged the electric motor 31, the clutches 33, 35 and the input shafts 37 and 39 output, coaxially.

  The input shaft 37 and the output shaft 39 are rotatably mounted relative to the housing 51, 52.

  The input shaft 37 is a splined shaft complementary to a hollow shaft 55 of the damping device 45, and an end portion of the input shaft 37 protrudes axially from the first half-shell 51 towards the outside. The input shaft 37 is rotatably mounted on the first half-shaft 51 via rolling bearings 57.

  The output shaft 39 is a hollow shaft with internal splines, of complementary shape to the box input shaft end 47. To be engaged with the output shaft 39, the end of the Box input shaft 47 projects into housing 53.

  The electric motor 31 comprises a stator 61 secured to the first housing half-shell 51, a collector 62 integral with the stator, and a rotor 63 rotatably mounted on the first half-shell 51 via a bearing 65. rotor 63 is arranged radially inside the stator 61.

  The input shaft 37 is formed, preferably in one piece, with a radial wall 95 which extends inside the housing 53, and which has at the periphery an axial ring 97.

  Correspondingly, the output shaft 39 is formed, preferably in one piece, with a radial wall 105 which extends inside the housing 53, and which has at the periphery an axial ring 107. The axial ring 107 extends coaxially and radially outer with respect to the ring 97.

  The first clutch 33 is arranged between the axial rings 97 and 107.

  The transmission element 25 further comprises a first piston 111 for actuating the first clutch 33, and a spring member 115 urging the first piston 111 under pressure on the first clutch 33.

  The first clutch 33 essentially consists of a first series of disks 121, rotatably connected to the ring gear 97 and axially displaceable thereon under the effect of the piston 111, and a second series of disks 122, connected in rotation. to the ring 107 and axially movable on the latter. The first 121 and second 122 disks are interleaved alternately.

  The discs 121, 122 are stopped axially by a stop 123 opposite the piston 111.

  It will be understood that the discs 121, 122 can move from a disengaged position, in which the first discs 121 do not make contact with the second discs 122, to an engaged position, in which the first 121 and second 122 discs are clamped together. against others.

  In the disengaged position, the input shaft 37 and the output shaft 39 are free to rotate relative to each other.

  The spring member 115 is constituted, in the example shown, a spring washer, of the type for example Belleville washer, and urges the piston 111 in the engaged position.

  The second clutch 35 comprises a pair of coaxial X-axis wheels 131, 132 with axial jaws which are engageable with each other.

  The first clutch wheel 131, connected in rotation with the rotor 63, is capable of axial displacement against a spring 137, under the effect of a second piston 141.

  The second piston 141 is connected in rotation to the output shaft 39 by a finger 142 passing through the radial wall 105.

  The spring 137 urges the jaw wheel 131 towards the wheel 132, in the engagement position of the claws 133, 134, that is to say in the engaged position of the clutch 35.

  Also under the effect of the return spring 137, the wheel 131 is permanently supported by a peripheral edge protruding axially on the piston 141.

  The clutch 35 is further provided with a synchronizing device 145 consisting essentially, in known manner, of two complementary parts 146, 147 having respective axial frustoconical surfaces 148, 149 that can cooperate by friction. A first 146 of these parts is integral with the first clutch wheel 131, while the second 147 of these parts is secured to the second clutch wheel 132. During a mutual engagement phase jaws 133, 134, frustoconical complementary surfaces 148, 149 mutually engage friction, so that the jaw wheels 131, 132 are progressively brought to the same speed of rotation, before positive engagement jaw 133, 134.

  We will now describe the arrangements for moving the pistons (or plateaux) pressure 111, 141, and thus to move the clutches 33, 35 from one position to another among their engaged and disengaged positions.

  The second housing shell 52 is formed with two control fluid supply channels 151, 152 connected to a control fluid circuit (not shown).

  The first supply channel 151 opens into a first pressure-sealed pressure chamber 201 formed between the first piston 111 and the radial wall 105. It is understood that the pressurized control fluid supply of this first chamber 201 via the first channel 151 causes the upstream displacement of the piston 111, against the reaction of the spring 115. This movement of the piston 111 causes the clamping of the disk stacks 121, 122, and the passage to the position engaged with the first clutch 35. When the control fluid is discharged from the first pressure chamber 201, via the same feed channel 151, the piston 111 moves downstream under the effect of the spring 115, by loosening the Stacks of discs 121, 122. The clutch 33 then resumes its so-called naturally open position, that is to say disengaged, in the absence of supply of the pressure chamber 201 control fluid.

  In a similar manner, the second supply channel 152 opens into a second pressure-tight pressure-controlled chamber 202 formed between the piston 141 and a radial wall 205, integral with the output shaft 39 and spaced axially from the radial wall 105. It is understood that the supply of pressurized control fluid of the second chamber 202 causes the axial displacement upstream of the piston 141. Thus, the piston 141 integrally moves the wheel 131 upstream, to the against the reaction of the spring 137, so that the jaws 133, 134 move from an initial position of mutual engagement to an unobstructed position. When the pressurized fluid supply of the second chamber 202 is interrupted and the fluid therein is discharged via the same channel 152, the dog wheel 131 resumes its initial position, in which the jaws 133, 134 are in position. mutual engagement, under the effect of the spring 137. The second clutch 35 then resumes its so-called naturally closed position, that is to say, engaged, in the absence of supply of the pressure chamber 202 control fluid.

  The transmission element 25 operates, as understood from the above, as follows: - First case: the pressure chambers 201, 202 are not powered The first clutch 33 is open, while the second clutch 35 is closed, so that the heat engine does not provide power to the wheel shaft, and the electric machine 31 provides power to the wheel shaft, or receives it so as to recharge the source (l accumulator) of electrical energy. We are then in a pure electrical operating mode.

  - Second case: the two pressure chambers 201, 202 are fed The first clutch 33 is closed, while the second clutch 35 is open, so that only the engine provides power to the wheel shaft, the machine electric 31 being mechanically isolated. We are then in a pure thermal operating mode.

  - Third case: the first pressure chamber 201 is energized and the second pressure chamber 202 is not energized The two clutches 33, 35 are in the closed position, so that the heat engine provides power to the pressure shaft. wheel, and the electric machine 31 also provides, or withdraws for charging the power source. We are in a hybrid mode of operation.

  - Fourth case: the first pressure chamber 30 201 is not energized and the second pressure chamber 202 is energized The two clutches 33, 35 are then in the open position, so that neither the engine nor the electric machine 31 do not provide (or with respect to the electric machine) mechanical energy to the wheel shaft.

  In Figure 3, there is shown an alternative embodiment of the invention, which differs essentially from the embodiment shown in Figure 2 in that the second clutch 35 is devoid of synchronization device. In this embodiment, the jaws 333, 334 are formed directly on the one hand on the piston 141, and on the other hand on a portion integral with the rotor. In the example shown, the jaws 333, 334 are formed of radial teeth, or frontal type.

  When the claws 333, 334 are mutually engaged, as illustrated in FIG. 3, the rotor 63 and the output shaft 39 are connected in rotation via the piston 141. A downstream displacement of the piston 141, to from the position shown, causes the release of jaws 333, 334, and thus the release of the rotational connection of the rotor 63 and the output shaft 39.

Claims (10)

  A transmission element for a parallel hybrid-type power train, said element (25) comprising a motion input shaft (37) for connection to a heat engine, a motion output shaft (39) for to be connected to a gearbox, an electric motor (31) having a stator (61) and a rotor (63), a first clutch (33) connecting the input shaft (37) and the shaft outlet (39), and a second clutch (35) connecting the rotor (63) and the output shaft (39), one (33) of said clutches being of wet friction type, characterized in that the other (35) of said clutches is of jaw type.   2. Transmission element according to claim 1, characterized in that the first clutch (33) is wet friction type, and the second clutch (35) is jaw type.   3. Transmission element according to claim 1 or 2, characterized in that the two clutches (33, 35) are arranged radially inside the electric motor (31).   4. Transmission element according to any one of claims 1 to 3, characterized in that it comprises a housing having a first half-shell (51) rotatably supporting the input shaft (37), and a second half-shell (52) rotatably supporting the output shaft (39), these two half-shells (51, 52) defining a housing (53) in which are coaxially mounted the two clutches (33, 35) and the motor electric (31).   5. transmission element according to any one of claims 1 to 4, characterized in that the first half-shell (51) is integral with the stator (61) and rotatably supports the rotor (63).   6. Transmission element according to any one of claims 1 to 5, characterized in that the housing (53) is sealingly closed to a lubricating fluid and / or cooling.   7. Transmission element according to any one of claims 1 to 6, characterized in that the second clutch (35) is biased into the engaged position.   8. Transmission element according to any one of claims 1 to 7, characterized in that the first clutch (33) is biased to the disengaged position.   9. Transmission element according to any one of claims 1 to 8, characterized in that the jaw clutch (35) is provided with a synchronization device (45).   10. A motor vehicle comprising a parallel hydride-type traction chain, said traction chain comprising a heat engine (3), a gearbox (7), and a transmission element (25) according to any one of claims 1 to 9 connecting the heat engine (3) to the gearbox (7).