FR2975640A1 - Power train for hybrid motor vehicle, has movement transmission track comprising toothed wheels and transmitting movement to powered axle, and additional epicyclic gear train connecting epicyclic drive train to movement transmission track - Google Patents

Abstract

The power train has a speed variation device (14) comprising an epicyclic drive train (26) having a sun gear (36) and a ring (50), where the sun gear and the ring are connected to a shaft (12) of a heat engine (10) via controlled clutches (28, 30). A movement transmission track comprises toothed wheels (120, 122), and transmits movement to a powered axle (16). An additional epicyclic gear train connects the epicyclic drive train to the movement transmission track. A coupling surface (130) is carried by an epicyclic gear (96).

Description

The present invention relates to a powertrain for driving a hybrid type of motor vehicle.

As is already known, this type of vehicle comprises a powertrain that uses alone or in combination, an internal combustion engine with a speed variation device and a rotary electrical machine connected to an electrical source, such as one or several batteries, to achieve its displacement.

This combination has the advantage of optimizing the performance of this vehicle, including reducing emissions of pollutants into the atmosphere and reducing fuel consumption.

Thus, when it is desired to move the vehicle with a large torque over a wide range of speeds while limiting the generation of exhaust gas and noise, as in an urban site, the use of the electric machine is preferred for drive this vehicle on the move. By cons, the heat engine is used, alone or in combination with the electric machine, to move this vehicle in applications where high drive power and high operating autonomy are required.

As is better described in the French patent application No. 10 / 03,002 of the applicant, the speed variation device of this type of hybrid vehicle comprises unidirectional couplings and controlled-control clutches associated with a double epicyclic train, each of these trains comprising a ring gear, a sun gear and a planet carrier for controlling the movement of the vehicle through its drive axle.

This thus makes it possible to obtain two gear ratios when the vehicle is driven by the electric motor and three gear ratios for the drive by the heat engine.

In a constant effort to improve, the applicant has further perfected this variable speed transmission device by offering the possibility of being able to drive the vehicle by the engine at an additional speed ratio.

With this speed ratio, the engine is used on a better operating point while having a torque to the larger wheel.

For this purpose, the invention relates to a powertrain of a hybrid type of motor vehicle comprising an electric machine, a heat engine with a motor shaft, a speed variation device comprising two coaxial planetary gear trains, each with a ring gear, a sun gear. and satellites carried by a planet carrier, and two clutches, characterized in that it comprises a rotational movement transmission path parallel to the motor shaft for the connection between the motor shaft and the crown of the engine. one of the planetary gear trains.

The transmission path may comprise a transmission shaft carrying rotational connection means with the shaft and the crown.

The transmission shaft may comprise two half-shafts interconnected by a unidirectional coupling. Advantageously, the unidirectional coupling may comprise a freewheel.

Preferably, the means for connection with the shaft may comprise a gear. The connection means with the crown may comprise a gear wheel cooperating with an external toothing carried by the headband of said crown.

The transmission shaft can be supported by bearings carried by a fixed part of the powertrain.

The other features and advantages of the invention will now appear on reading the following description, given solely by way of illustration and without limitation, and to which is appended the single figure which is a diagram showing a powertrain according to US Pat. invention applied to a drive system of a hybrid vehicle.

In FIG. 1, the powertrain comprises a heat engine 10, in particular an internal combustion engine, with a motor shaft 12 coming from the crankshaft of this engine and a speed variation device 14. This powertrain also comprises an electric machine 16 with a rotor 18. This machine can function as an electric drive motor for the vehicle or as a generator of electrical energy and more particularly as an alternator for charging the batteries (not shown).

This group is associated with a driving axle 20 which drives the driving wheels 22 of the vehicle, advantageously via a differential bridge 24.

The speed variation device 14 comprises a main planetary gear train 26, called motor epicyclic gear train, another additional epicyclic gear train 28, hereinafter referred to as the epicyclic machine train description, two controlled-control clutches 30, 32, two couplings unidirectional automatic, here freewheels 34, 36, and a rotational movement transmission path 38.

The motor epicyclic gear train 26 comprises a sun gear 40 with a ribbon 42 toothed externally carried by a flange 44. This flange is fixedly mounted on a shaft 46, here a hollow shaft, said sun gear shaft, placed in the extension of the shaft motor 12 being free in rotation but fixed in translation relative thereto. The free end 48 of this sun gear shaft is supported in a bearing 50 carried by a fixed portion 52 of the powertrain of the vehicle through the freewheel 34, said freewheel.

This train also comprises a ring 54 with an internally toothed ring 56, placed concentrically with the sun gear 40, and a sail 58 connected to an end 59 of a hollow shaft 60, called a crown shaft. The crown shaft surrounds the sun gear shaft while being free to rotate but fixed in translation relative thereto. The ring gear 54 is connected via the ring gear shaft 60 to a bearing 62 of a fixed part of the power unit of the vehicle by the free wheel 36, called free wheel crown.

Of course, the two freewheels 34 and 36 are arranged in such a way that the ring gear and the sun gear can rotate only in the same direction and preferably in the same direction as that of the motor shaft 12.

This epicyclic motor train 26 further comprises a planet carrier 66 preferably comprising three externally toothed satellites 68 advantageously placed in the same angular interval relative to each other (here at 120 °) and meshing with the crown and the planetary. This planet carrier comprises a vertical wall 70 from which are derived axes 72 carrying the satellites 68 and a tubular bearing 74, said bearing planet carrier, surrounding the sun gear shaft 46 being free to rotate but fixed in translation on it.

The free ends of the shafts of the sun gear 46 and the ring gear 60 which are opposite ends 48 and 59 each carry a controlled-control coupling 30 and 32, preferably a friction clutch. Thus the clutch 30, called the sun gear clutch, comprises a friction disc 76, fixedly mounted in rotation but free in axial translation on the sun gear shaft 46, a reaction plate 78 fixedly mounted in translation and in rotation on the motor shaft 12, a pressure plate 80, movable in translation relative to said reaction plate while being fixed in rotation therewith, and a release actuator 82 for acting on the pressure plate, here in the form of a rocking lever on a fixed point of the powertrain and support rods subjected to return springs. . The other clutch 32, referred to as the crown clutch, comprises a friction disc 84, coaxial with the friction disc 76, which is fixedly mounted in rotation and free in axial translation by a horizontal wall 86 coming from the reaction plate 78 of FIG. the clutch 30. The friction disc 84 of the crown clutch is able to be clamped between a reaction plate 88 fixedly mounted in translation and in rotation on the free end of the crown shaft 60. and a pressure plate 90 movable in axial translation under the action of another declutching actuator 92, here also in the form of a rocking lever and bearing rods subjected to return springs.

The vertical wall 70 of the planet carrier 66 of the motor epicyclic gear train 26 carries, on its outer periphery and beyond the planet axes 72, a horizontal strip 94 toothed internally and externally. This strip is part of the ring gear 96 of the electric machine epicyclic gear train 28. Thus the wall 70 is a common element to the planet carrier 66 of the epicyclic motor gear train and to the ring gear 96 of the machine epicyclic gear train 28.

This epicyclic gear train 28, which is placed coaxially with the epicyclic motor gear 26 by surrounding the sun gear shaft 46, comprises a planet carrier 98, here with three satellites 100 in the form of an externally-toothed wheel carried by satellite axes 102. and placed in the same angular interval with respect to each other (here at 1200). These satellites meshing with the internal toothing of the strip 94 of the ring gear 96. These satellites also mesh with a sun gear 104 which comprises a strip 106 toothed externally and carried by a flange 108. This flange is fixedly mounted on one end of a tubular shaft 110, said additional sun gear shaft, which surrounds, freely in rotation but fixedly in translation, the sun gear shaft 46 of the epicyclic motor train 26. The free end of the tubular shaft 110 fixedly bears an external gear wheel 112 which cooperates with another externally toothed wheel 114, called the rotor wheel, fixedly supported by the rotor 18 of the electric machine 16.

The planet axes 102 are carried by a plate 116 forming part of the planet carrier and comprising a tubular bearing 118 freely rotating but fixedly in translation with the sun shaft tubular shaft 110. This bearing 118 fixedly bears a gear wheel 120 which co-operates with a gear 122 connected to the differential bridge 24 associated with the driving axle 20.

The epicyclic gear train 28 also carries a controlled-control coupling 124 making it possible to connect its crown 96, either to the plate 116 of the planet carrier 98, or to a fixed part of the powertrain. Advantageously, this coupling comprises a claw actuator 126 with two meshing positions 1, 2 and a neutral position N. This actuator is rotatably supported by the outer surface of the strip 94 of the ring 96 while being movable in axial translation on it. This actuator is intended to cooperate, either with a fixed coupling surface 128 carried by a fixed part of the power unit, or with another coupling surface 130 carried by the peripheral end of the plate 116 beyond the axes of satellites 102.

For this, the actuator is subjected to a control means 132 enabling it to mate with the fixed part 128 of the powertrain (position 1), with the plate 116 (position 2) or to be in a neutral position ( position N) without being connected to either of the two mating surfaces.

The rotational movement transmission path 38 of this speed variation device comprises a rotational movement transmission shaft 134 substantially parallel to the motor shaft 12 as well as the crown gear 60 and the sun gear 46.. This shaft consists of two parts 136 and 138 (or half-shafts) interconnected by a unidirectional coupling 140, here in the form of a freewheel. Each half-shaft 136, 138 is carried by a bearing 142, respectively 144, from a fixed part of the powertrain and the wheel Iibre140 is located between these two bearings. This shaft carries means of connection in rotation with the shaft 12 and the ring gear 96 of the train 28. Thus, the half-shaft 136 carries on its end facing the motor 10 a gear 146 which cooperates with a toothed wheel 148 by the motor shaft 12 and which is located between this motor and the clutch 30 thus forming a gear ensuring the means of connection in rotation with the shaft 12.

The other half-shaft 138 also carries a toothed wheel 150 which cooperates meshing with the external toothing of the strip 94 of the ring gear 96 of the machine epicyclic gear train 28 also constituting means of connection in rotation with this ring gear. Of course, it may be envisaged to use all other systems to ensure the connection to rotation such as toothed belts, chains, ... As is better seen in the figure, the free end of one half -trees carries a cage 152 in which is placed the free wheel while the free end of the other of these half-shafts bears on the inner diameter of this freewheel. This makes it possible to obtain simultaneous rotation of the two half-shafts only in one direction of rotation.

The different operating configurations of the entire powertrain will now be described below.

As regards the drive of the vehicle in the electrical operating mode where only the electric machine 16 is used, in particular as a driving machine of the vehicle, the two clutches 28 and 30 are inactive, the actuator 126 is in neutral position (N) not being engaged with either of the two mating surfaces 128 or 130. As soon as the electrical machine 22 is electrically powered, its rotor 24 is rotated and this machine functions as an electric motor. After the rotation of the rotor, the actuator 126 is controlled in one of the positions 1 or 2 to ensure the rotational drive of the axle 20 of the vehicle. Thus, in the position 1, the actuator is engaged with the coupling surface 128 of the fixed part by immobilizing in rotation the ring gear 96 of the machine epicyclic gear train 96. The rotational movement of the rotor wheel 114 is transmitted to the toothed wheel 112 and the sun gear 104 by the sun gear shaft 110. This rotation 20 of the sun gear is then transmitted to the satellites 100 which, taking into account the immobilization in rotation of the ring gear 94, meshes thereon. driving the planet carrier 98 in rotation. This rotational movement is then transmitted to the toothed wheel 120 by the tubular bearing 118. The rotation of this toothed wheel 120, which cooperates by meshing with the toothed wheel 122, 25 is then transmitted to the axle 20 to drive the wheels 22 of the vehicle.

The vehicle is driven in displacement by traction / electric propulsion only on a short gear ratio and that as well in forward and reverse. In the case where the claw actuator 126 is engaged with the mating surface 130 of the plate 116 (position 2), the ring 94 is rotatably connected therewith. Under the impulse of the rotational movement of the gears 114 and 112, the sun gear 104 is rotated. This rotation is transmitted to the satellites 100 which themselves transmit it to the ring 94. By the connection with the plate 116, the rotation of this ring is transmitted to the toothed wheel 120 which cooperates with the toothed wheel 122 of the bridge 24. thus making it possible to drive the wheels of the vehicle in rotation. In this configuration, the sun gear shaft 110, the bearing 118 of the plate 116 and the bearing 66 of the planet carrier 58 connected to the ring 94 rotate at the same speed.

The rotation of the ring 96 is transmitted to the half-shaft 138 by meshing with the toothed wheel 150 but, because of the presence of the free wheel 140, this rotation is not transmitted back to the half-shaft 134.

By this, the vehicle is driven in traction / electric propulsion on a long speed ratio with possibility of energy recovery during decelerations of the vehicle in forward.

For starting the heat engine, the clutches 30 and 32 are in the active position, the coupling 124 is in the neutral position N and the machine 16 is fed by the batteries, which has the effect of rotating the rotor 18 This rotation of the rotor drives the sun gear 104 via the gear wheels 114 and 112, and the ring gear 94 is rotated by means of the satellites 100. The two clutches 30 and 32 being closed, the ring gear 96 all of the elements of the motor epicyclic gear train 26 by means of the planet carrier 66. As a result, this train 26 rotates the shaft 12 of the engine 10 thus making it possible to start the engine.

Of course, as soon as the starting of the heat engine is obtained, one and / or the other of the clutch actuators 82 and / or 92 may be controlled so as to disengage the motor shaft 12 from the machine 22. rendering the clutch 30 and / or 32 inactive.

The other configurations will now be described to illustrate the traction / propulsion of the vehicle by the heat engine 10 according to different speed ratios, here 4 different ratios, and the different possibilities of using the electric machine 22 as an electric generator.

In these configurations, the actuator 126 is either in the neutral position N or in the position 2 and the clutches 30 and 32 are either in the active position or one in the active position.

In the configuration where the two clutches 30 and 32 are in the active position, the rotation of the shaft 12 of the heat engine 10 rotates the shaft 60 with the ring gear 54, the shaft 46 with the sun gear 40 and consequently the planet carrier 66. This rotation of the planet carrier is then transmitted through the wall 70 to the ring gear 96 of the machine epicyclic gear train 28.

Thus, when the claw actuator 126 is in position 2, the sun gear shaft 110, the bearing 118 of the plate 116 and the bearing 74 of the planet carrier 66 20 connected to the ring gear 94 rotate at the same speed. The planet carrier 98 of this epicyclic machine train then drives the axle 20 via the wheels 120 and 122, while the sun gear 104 drives the electric machine 22 in rotation through the wheels 112 and 114. 25 In this thermal traction mode, the electric machine 16 can be used, either in engine operation with the powers of the electric machine and the combustion engine combined to be transmitted to the axle 20, or in generator operation to supply the batteries or all vehicle electrical accessories. When the claw actuator 126 is in the neutral position N, the torque transmitted by the shaft 12 of the heat engine to the ring gear 94 is transferred to the planet carrier 98 via the satellites 100 using the reaction of the sun gear 104 The planet carrier 98 then drives the axle 20 through the wheels 120 and 122, while the sun gear 104 drives the electric machine 22 in rotation through the wheels 112 and 114.

From this, either of the clutches can be placed in the inactive position to obtain other gear ratios. For the inactive position of the clutch 30 and active clutch 32, the rotation of the shaft 12 of the heat engine 10 rotates the shaft 60 with the ring 54 which rotates the satellites 68 and the holder satellites 66. This rotation of the planet carrier is then transmitted through the wall 70 to the ring gear 96 of the machine epicyclic gear train 28.

Thus, when the claw actuator 126 is in position 2, the rotational movement of the ring gear 94 is transmitted to the plate 116 and then to the toothed wheel 120 by the bearing 118. This wheel then drives the axle 20 by through the wheel 122, while the sun gear 104 drives the electric machine 22 in rotation through the wheels 112 and 114. When the claw actuator 126 is in the neutral position N, the rotation of the ring 94 is transferred to the planet carrier 98 via the satellites 100 using the reaction of the sun gear 104. The planet carrier 98 then drives the axle 20 through the wheels 120 and 122, while the sun gear 104 drives the machine. 22 for rotation in rotation through the wheels 112 and 114 For the inactive position of the clutch 32 and the active clutch 30, the rotation of the shaft 12 of the heat engine 10 drives in rotation the sun gear shaft 46 with the plan silence 40. The rotation of the sun causes the satellite 68 in rotation and then the planet carrier 66. This rotation of the planet carrier is then transmitted through the wall 70 to the ring gear 96 of the epicyclic gear machine 28.

From this configuration, we find the same path of the motion transmission as described in relation to the inactive position of the clutch 30 for the positions N or 2 of the claw actuator 126.

To obtain another gear ratio made outside the planetary gear trains 26 and 28, this is achieved through the transmission path 38 with the clutches 30 and 32 in the inactive position and the coupling 124 in the N or 2 position. The rotational movement of the shaft 12 of the motor 10 is transmitted to the half-shaft 136 by the gear formed by the gears 148 and 146. This rotational movement of this half-shaft is then transferred to the other half. shaft 138 through the freewheel 140 which is then active so as to drive in the same direction of rotation the other half-shaft 138. The rotation of this half-shaft is transmitted to the ring 96 by the toothed wheel 150.

As previously described, we find, from this configuration, the same path of the transmission of movement of the ring gear 96 towards the toothed wheel 112 for the positions N or 2 of the claw actuator 126.

This thus makes it possible to achieve another gear ratio without using the motor epicyclic gear train 26 and shunting thereof, while using the machine epicyclo'idal train 26.

Claims (7)

CLAIMS1) A hybrid motor vehicle power train comprising an electric machine (16), a heat engine (10) with a motor shaft (12), a speed variation device (14) comprising two coaxial epicyclic gear trains (26, 28), each with a ring gear (54, 96), a sun gear (40, 104) and satellites (68, 100) carried by a planet carrier (66, 98), and two clutches (30, 32), characterized in that it comprises a rotational movement transmission path (38) parallel to the motor shaft (12) for the connection between said shaft and the ring gear (96) of one (28) of the epicyclic gear trains. 2) Power train according to claim 1, characterized in that said path comprises a transmission shaft (134) carrying rotational connection means (146, 148; 150) with the shaft (12) and the ring (96). 3) Powertrain according to claim 2, characterized in that the transmission shaft (134) comprises two half-shafts (134, 138) interconnected by a unidirectional coupling (140). 4) power train according to claim 3, characterized in that the unidirectional coupling comprises a free wheel (140). 5) Power train according to claim 2, characterized in that the linkage means with the shaft (12) comprise a gear (146, 148) (26). 6) Powertrain according to claim 2, characterized in that the connecting means with the ring gear (96) comprise a toothed wheel (150) cooperating with an external toothing carried by the strip (94) of said crown. 7) Powertrain according to one of claims 2 to 6, characterized in that the transmission shaft (134) is supported by bearings (142, 144) carried by a fixed part (52) of said group.