Patent Grant
8511410
1. Field of the Invention
The present invention relates to a travel system for a hybrid type motor vehicle.
2. Description of the Prior Art
Hybrid type motor vehicles combine, as a traction or propulsion drive means, a thermal engine which is generally an internal-combustion engine, and a rotary electric machine connected to an electric source, such as one or more electric accumulators. This combination allows the performance of the vehicle to be optimized, notably by limiting the discharge of pollutants to the atmosphere and by decreasing the fuel consumption of the entire device.
As it is already known, notably from French Patent Application No. 2,670,440, hybrid vehicles comprise a drive system with a thermal engine including an output shaft connected to a speed variation device and an electric machine connected to an electric battery. This system also comprises two clutches with a first clutch between the thermal engine and the electric machine and a second clutch between the electric machine and the speed variation device.
Thus, when the vehicle is to be driven with a high torque available over a wide speed range while limiting exhaust gas and noise generation, as in an urban site, the electric machine is preferably used for driving the motive axle of the vehicle.
On the other hand, for uses where a high driving power and a wide operating range are required, the thermal engine is used for driving the motive axle and thus providing powering of the vehicle.
Although satisfactory, this drive system however involves some significant drawbacks.
In fact, when only the electric machine is used to drive the vehicle, sufficient torque is required therefrom for driving the vehicle as well as overcoming all the resistances (inertia, friction, . . . ) inherent in the vehicle and in the speed variation device.
Furthermore, during vehicle braking, part of the energy released thereby is absorbed by the speed variation device and only a minor part of this energy is recovered which is then converted to electric power by the electric machine.
The present invention overcomes the aforementioned drawbacks with a simple drive system with devices constantly providing transfer to the motive axle and vice versa.
The invention therefore relates to a travel system for a hybrid type motor vehicle comprising a thermal engine with a shaft, an electric machine with a rotor connected to electric accumulators, a drive shaft controlled in rotation by the machine and/or the engine for rotating the motive axle of the vehicle, and a rotating speed variation device between the drive shaft and the engine shaft, which the speed variation device comprises at least two alternate paths for motion transmission to the motive axle which are each controlled by at least one disengageable coupling.
One of the transmission paths can comprise the engine shaft and a disengageable coupling for connection in rotation with the drive shaft.
The other transmission path can comprise the engine shaft, an engine shaft rotating speed reduction device and another disengageable coupling for connection in rotation between the device and the drive shaft.
The rotating speed reduction device can comprise a speed-reducer motion transmission device between the shaft and at least one of the camshafts, and another speed-reducer motion transmission device between this camshaft and the disengageable coupling.
The rotating speed reduction device can comprise a speed-reducer motion transmission device between the shaft and a rotary axle carried by a fixed part of the vehicle, and another speed-reducer motion transmission device between this axle and the disengageable coupling.
The other speed-reducer motion transmission device can comprise a disengageable coupling providing rotating motion transmission between the rotary axle and the disengageable coupling.
The other speed-reducer motion transmission device can comprise a disengageable coupling providing rotating motion transmission between the rotor of the electric machine and the disengageable coupling.
The rotating speed reduction device can comprise an epicyclic train whose inner planetary gear is carried by the engine shaft, the outer planetary gear is carried by a fixed part of the vehicle and the satellites are carried by the disengageable coupling.
The drive shaft can carry a disengageable coupling for transmission of its rotating motion to the motive axle.
The drive shaft can carry an actuator for operating one or the other of the couplings.
The drive shaft can comprise the rotor of the electric machine or a shaft independent of the engine and/or of the electric machine.
The drive shaft can be connected to the motive axle by a motion transmission device.
The invention also relates to a method of travel of a hybrid type motor vehicle comprising a thermal engine with a shaft, an electric machine with a rotor connected to electric accumulators, a drive shaft controlled by the machine and/or the engine for rotating the motive axle of the vehicle, and a speed variation device between said drive shaft and the engine shaft, wherein the engine shaft is connected to the motive axle drive shaft by at least two alternate paths for rotary motion transmission which are each controlled by at least one disengageable coupling.
The method can provide one of the rotary motion transmission paths with a device for reducing the rotating speed of the shaft so as to obtain a drive shaft rotation with a different rotating speed from that of the other path.
The method can start the thermal engine by supplying the electric machine from the accumulators and connect the rotor of the machine to the engine shaft through one of the motion transmission paths.
In order to achieve recharging of the accumulators, the method can consist in connecting the engine shaft to the rotor of the electric machine with one of the motion transmission paths.
During braking phases of the vehicle, the method can recover the mechanical energy of the motive axle so as to transmit it to the engine shaft by connecting the drive shaft to the shaft with one of the motion transmission paths.
Other features and advantages of the invention will be clear from reading the description hereafter, given by way of non limitative example, with reference to the accompanying figures wherein:
As illustrated in
As it is well known, shaft 12 of the thermal engine drives in rotation at least one camshaft 18, two camshafts here, which control the exhaust and intake valves (not shown) of this engine by means of a speed-reducer rotating motion transmission device 20. Usually, this device comprises a driving wheel 22 fixedly mounted on engine shaft 12, a receiving wheel 24 of larger diameter than the driving wheel fixedly mounted on each camshaft and a transmission belt 26 (or a transmission chain or a gear train) connecting these two wheels in rotation.
As better illustrated in this figure, the end of engine shaft 12 carries, fixed in rotation but mobile in axial translation, an element 28 of a disengageable friction coupling 30 between this shaft 12 and rotor 16 of machine 14. This element, forming the reaction plate of this coupling, is arranged opposite another plate 32 that makes up the pressure plate fixed in rotation an in translation with rotor 16. These two plates are to be contacted with each other so as to be secured in rotation under the action of an actuator 34 carried by rotor 16 while being free in translation on this rotor.
Thus, when this coupling 30 is effective, the rotor is in direct gear with the engine shaft with a rotating motion transmission path VT1, which is referred to as the long path, corresponding to a speed equal to that of the engine crankshaft.
Another disengageable friction coupling 36 is provided to ensure alternately transmission of the rotating motion from shaft 12 of the thermal engine, via camshafts 28, to rotor 16. The camshafts therefore fixedly carry a driving pulley 38 arranged opposite wheel 24 and belonging to another speed-reducer rotating motion transmission device 39. This pulley is connected by a transmission belt (or a transmission chain or a gear train) to a receiving pulley 42 (of larger diameter than the driving pulley) mounted free in rotation on engine shaft 12 while being axially fixed thereon. This pulley, arranged opposite driving wheel 22, is connected to a housing 44 surrounding coupling 30 between the rotor and the engine shaft. This housing carries an axially mobile reaction plate 46 facing actuator 34 and it is intended to ensure connection in rotation with another fixed pressure plate 48 carried by rotor 16, under the action of actuator 34, thus forming the other disengageable friction coupling 36.
When this other coupling is operational, rotor 16 is connected in rotation to shaft 12 of the thermal engine with a rotating motion transmission path VT2, which is referred to as the short path, which corresponds to the reduction in the rotating speed of this shaft 12 by speed reduction device 49. This reduction device thus comprises speed reducer device 39 and speed reducer device 20.
The rotor of the electric machine can thus be driven in rotation by the thermal engine by two alternate transmission paths VT1 or VT2, through engaging of one or the other of couplings 30 or 36.
Rotor 16 can therefore be driven in rotation at different speeds, either at high speed by shaft 12 or at low speed by a reduction in the rotating speed of shaft 12 through speed reduction device 49.
As can be better seen in this figure, rotor 16 carries another disengageable coupling 50, a mesh coupling here, comprising a plate 2 fixed in translation while being mounted free in rotation on the rotor. This plate comprises recesses 54 for cooperation with fingers 56 of an actuator 58 mounted fixedly in rotation on the rotor but freely in translation thereon.
In order to provide rotating motion transmission between this rotor and a motive axle 60, a motion transmission device 62 is arranged between this rotor and this axle. Preferably, a transmission belt 64 is arranged between plate 52 and a fixed pulley 66 placed on this axle. This pulley thus allows driving wheels 68 of the vehicle a transmission, such as a differential 70.
Of course, electric machine 14 is connected to electric accumulators 72 while being controlled by a control device (not shown) for feeding the engine and/or charging these accumulators.
Similarly, actuators 34 and 58 are controlled by any control means (not shown), such as jacks, allowing their displacement on rotor 16 for the desired engaging of couplings 30, 36, 50, under the effect of a control unit such as the powertrain calculator (not shown) any vehicle is equipped with.
Thus, speed variation device 13 comprises a first speed stage made up of path VT1 and a second speed stage, shorter than the long path VT2.
The various configurations of the drive system hereinafter described according to the traction mode used and/or to the operation of the thermal engine and of the electric machine.
For simplification reasons, in the description below, coupling 30 between shaft 12 and rotor 16 is referred to as the “high-speed coupling”, the other friction coupling 36 is referred to as the “low-speed coupling” and mesh coupling 50 is referred to as the “jaw coupling”.
The configuration of
Neither of the two couplings, namely the high-speed 30 or the low-speed 36, is thus engaged whereas jaw coupling 50 is in gear through the displacement of actuator 58 allowing engagement of fingers 56 into recesses 54 of plate 52. Therefore, as soon as electric machine 14 is fed by accumulators 72, rotor 16 is driven in rotation and transmits its rotary motion to actuator 58 that is connected in rotation to plate 52. This rotation is then transmitted to motive axle 60 by belt 64 of motion transmission device 62.
This configuration allows the vehicle to run in forward or reverse gear while leaving the possibility for engine 10 remaining in operation, notably for driving vehicle auxiliaries (power steering pump, air conditioning compressor, etc.).
In another configuration illustrated in
Once rotation of rotor 16 obtained, high-speed coupling 30 is engaged through displacement of actuator 34 to the right (considering
As soon as engine starting is achieved, actuator 34 is controlled to the left so as to make the high-speed coupling inoperative, without engaging low-speed coupling 36. The engine thus remains in operation, notably to drive its auxiliaries, as mentioned above.
Electric machine 14 therefore has a double function, traction of the vehicle and starting of the thermal engine while the vehicle is moving, and without disturbing the operation of this electric machine used for driving the vehicle.
In the configuration of
In this case, jaw coupling 50 is engaged, as described above in connection with
Simultaneously, one of the high-speed 30 or low-speed 36 couplings (in thick line or dotted line) is engaged by actuator 34, thus connecting shaft 12 to rotor 16. As a result of this connection, the power generated by this engine is transmitted by shaft 12 to rotor 16, thus coming on top of that transmitted by electric machine 14.
It is considered in this configuration that the engine has already been started, either as described in connection with
In the layout of
Jaw coupling 50 is therefore not operational and high-speed coupling 30 is engaged under the action of actuator 34.
As soon as electric machine is supplied by accumulators 72, its rotor 16 is driven in rotation. Considering the link, through coupling 30, between this rotor and shaft 12, the latter is driven in rotation by the rotor. The engine is thus started under the control of the controller.
Of course, as soon as engine start is achieved, the high-speed coupling is made inoperative under the action of actuator 34 and the engine remains in operation.
Other operating modes of the thermal engine and of the electric machine are described hereinafter in connection with the figures already described.
For driving the vehicle only with thermal engine 10, the configuration used is that of
This allows establishing a high or low-speed rotation link between shaft 12 and rotor 16. The vehicle is thus driven by the thermal engine according to two different speeds. Rotation of rotor 16 can be used to convert electric machine 14 to a current generator (or alternator) notably for recharging accumulators 72.
In another operating mode with a configuration corresponding to
The link in rotation between rotor 16 and shaft 12 is provided by actuating one of friction couplings 30, 36 and the jaw coupling is disengaged.
Rotor 16 of machine 14 is driven in rotation by shaft 12 and this machine is thus used as a current generator for recharging the accumulators and/or supplying vehicle accessories.
As regards brake energy recovery, the configuration used corresponds to that of
During braking, the energy to be recovered comes from motive axle 60 that drives in rotation rotor 16 via transmission device 62. This rotation is thus used for converting electric machine 14 to a current generator for recharging the accumulators and/or supplying the vehicle accessories.
According to the configuration illustrated in
High-speed coupling 30 is operational, as well as jaw coupling 50. The energy coming from axle 60 is thus transmitted to rotor 16 by motion transmission device 62 by driving this rotor in rotation, as mentioned above. Considering the link in rotation between the rotor and engine shaft 10, the engine shaft transmits a negative torque and slows down the rotor rotation. This slowing down is then transmitted to the motive axle by transmission device 62.
Of course, only engine braking can be used by deactivating the controller of the electric machine. This allows letting the rotor to rotate freely without any effect on the accumulators 72.
Thus, in the case of the example described in connection with
This variant differs from
The transmission path VT2 comprises a driving wheel 74, advantageously a gear wheel, mounted fixedly on shaft 12 of engine 10. Wheel 74 drives by engaging, a receiving gear wheel 76 of larger diameter than the driving wheel and mounted fixedly on a receiving axle 78 rotating freely on a fixed part of the vehicle such as the engine. Driving wheel 74 associated with receiving wheel 76 thus form a speed-reducer rotating motion transmission device. This axle carries fixedly a transmission pulley 80 that drives in rotation receiving pulley 42 carrying housing 44 with the this receiving pulley having a larger diameter than pulley 80. Advantageously, transmission pulley 80 and receiving pulley 42 are gear wheels that engage onto one another, thus forming another speed-reducer rotating motion transmission device.
Advantageously, the device controlling camshafts 18 that control the exhaust and intake valves is the same as the device described above in connection with
Transmission path VT2 comprises an epicyclic train 82, forming a speed-reducer rotating motion transmission device, with a rotary inner planetary gear 84 fixedly carried by shaft 12 of engine 10, a fixed outer planetary gear 86 carried by a fixed element of the engine or of the vehicle, and satellites 88 carried by housing 44 of coupling 36 and cooperating with the planetary gears.
The various configurations of the drive system according to the traction mode used and/or to the operation of the thermal engine and of the electric machine for the variants of
In the variant of
Plate 152 of jaw coupling 150, identical to jaw coupling 50 described above, is fixedly linked to rotor 16 of electric machine 14. This plate cooperates in rotation, advantageously by engaging, with receiving pulley 42 carrying housing 44 for low-speed coupling 36. The electric machine with its rotor 16 is therefore arranged substantially parallel to independent shaft 90.
Actuator 158 of jaw coupling 150 is carried freely in translation but fixedly in rotation by a turning axle 98 supported by a fixed part of the engine such as the engine case. A receiving wheel 100 is arranged fixedly on this axle and it cooperates, preferably through engaging, with a driving wheel 102 carried fixedly by engine shaft 12.
Similar to
Similarly, when low-speed coupling 36 is actuated and the jaw coupling engaged, independent shaft 90 is connected in rotation to engine shaft 12 with the short transmission path VT2. Short path VT2 comprises driving wheel 102, receiving wheel 100, plate 152 and receiving pulley 42 with speed reduction between shaft 12 and independent shaft 90.
Independent shaft 90 can therefore be driven in rotation at different speeds, either at high speed by shaft 12 with the long path VT1, or at low speed by means of the speed reduction from short transmission path VT2.
The various operating stages of this variant are substantially identical to those of
Thus, for the electric traction mode where electric machine 14 is supplied by accumulators 72 (
The vehicle thus operates under traction conditions of electric origin, in forward or reverse gear, while leaving the possibility for engine 10 remaining in operation, notably for driving vehicle auxiliaries (power steering pump, air conditioning compressor, etc.).
In order to associate this electric traction mode with the optional engine starting (when it is not running), jaw coupling 150 is engaged and rotor 16 is connected in rotation to axle 98. The rotation of this axle causes rotation of receiving wheel 100, which in turn rotates wheel 102. The rotation of this wheel, linked to shaft 12, thus allows the engine to be started (
Of course, once the engine started, the jaw coupling is disengaged and the engine keeps running so as to drive notably its auxiliaries.
For the example of
For high-speed driving, only coupling 30 is operational under the action of actuator 34. The rotation of shaft 12 is transmitted by coupling 30 directly to independent shaft 90 that drives motive axle 60 through device 92.
For low speed, jaw coupling 150 is engaged while securing plate 152 to axle 98, and low-speed coupling 36 is controlled by actuator 34 (as shown in dotted line in the figure). The rotation of shaft 12 is transmitted to independent shaft 90 by driving wheel 102, receiving wheel 100, plate 152, pulley 42 and coupling 36 while being geared down.
In the example illustrated in
Jaw coupling 150 is therefore engaged and neither couplings 30 and 36 are operational.
As soon as electric machine 14 is supplied by accumulators 72, its rotor 16 is driven in rotation. Due to the link with axle 98, wheel 100 is driven in rotation. This rotation is transmitted to driving wheel 102 that drives shaft 12 so as to allow engine 10 to start.
All the other configurations of the drive system are also possible with this variant according to the traction mode are used and/or to operate the thermal engine and of the electric machine, as already described in connection with
For the electric traction by machine 14 combined with thermal traction by engine 10, the configuration corresponds to that of
Jaw coupling 150 is engaged and low-speed coupling 36 is operational.
The rotation of rotor 16 of the electric machine is transmitted to independent shaft 90 by plate 152, pulley 42 and coupling 36. Simultaneously, the rotation of shaft 12 is transmitted to pulley 42 by driving wheel 102, receiving wheel 100 and plate 152.
It is possible to make high-speed coupling 30 operational instead of coupling 36. In this case, the rotation of shaft 12 is directly transmitted to independent shaft 90.
Electric traction of the vehicle is then provided through transmission of the rotation of rotor 16 to independent shaft 90 through wheel 100 and wheel 102, jaw coupling 150 being engaged.
The thermal traction of the vehicle with recharging of the accumulators by machine 14 corresponds to the configuration of
With the configuration of jaw coupling 150 being engaged and low-speed coupling 30 being is operational, the rotation of shaft 12 of engine 10 is transmitted both to electric machine 14 and to independent shaft 90.
The rotary transmission to machine 14 is achieved by driving wheel 102, receiving wheel 100 and jaw coupling 150 connected to rotor 16. The rotation of the rotor 16 allows this machine to be used as a current generator for recharging accumulators 72.
The rotation of plate 152 of the jaw coupling is transmitted to receiving pulley 42, then to independent shaft 90 through coupling 36.
In the option where high-speed coupling 30 is operational instead of low-speed coupling 36, transmission of the rotating motion of shaft 12 to rotor 16 is achieved as mentioned above with, in addition thereto, free rotation of pulley 42. This transmission of the rotating motion of shaft 12 is also achieved through the direct link with independent shaft 90 through coupling 30.
In the case of low speed with coupling 36 being operational, the rotation of rotor 16 of the electric machine is obtained through the rotation of shaft 12, wheels 100 and 102, and of plate 152. Simultaneously, the rotation of shaft 12 is transmitted to independent shaft 90 by driving wheel 102, receiving wheel 100, plate 152, pulley 42 and coupling 36.
Recharging of the accumulators by machine 14 corresponds to the configuration of
Brake energy recovery corresponds to the configuration of
Jaw coupling 150 is not engaged and low-speed coupling 36 is engaged under the action of actuator 34.
Motive axle 60 drives in rotation independent shaft 90 via transmission device 92. This rotation is then transmitted to rotor 16 by coupling 36, pulley 42 and plate 152 connected to this rotor. This rotor rotation allows electric machine 14 to be used as a current generator for recharging the accumulators and/or for supplying vehicle accessories.
In cases where jaw coupling 150 is already engaged under the action of actuator 158, this also allows achieving engine braking, in addition to energy recovery. In fact, the rotation of plate 152 is transmitted to shaft 12 of the engine by wheels 100 and 102. Considering the connection between independent shaft 90 and plate 152, slowing down thereof through shaft 12 of the engine leads to slowing down of independent shaft 90 and, consequently, of motive axle 60.
It is also possible to achieve engine braking in addition to energy recovery by making high-speed coupling 30 operational. Axle 60 therefore drives shaft 12 through the agency of coupling 30, which itself drives rotor 16 through wheel 102, wheel 100 and plate 152 under the action of jaw coupling 150 that is engaged.
It is also possible to consider using only engine braking by making only friction coupling 30 operational. The rotation of independent shaft 90 is thus slowed down by shaft 12 through high-speed coupling 30.
The example illustrated in
This example differs from the example of
Furthermore, rotary axle 98 of
Advantageously, receiving pulley 42 is connected by a belt 40 to plate 152 of jaw coupling 150.
In this configuration, the long transmission path VT1, as described above, has shaft 12 connected by high-speed coupling 30 to independent drive shaft 90. The short transmission path VT2 has speed-reducer rotation transmission system 20 and of another speed-reducer rotation transmission system with plate 152 (jaw coupling 150 engaged), belt 40, receiving pulley 42 and low-speed coupling 36.
The operation of this other illustration of the drive system is substantially identical to that described in connection with
The present invention is not limited to the examples described and it encompasses any variant or equivalent without departing from the scope of the invention as defined above.
| Number | Date | Country | Kind |
|---|---|---|---|
| 09 03474 | Jul 2009 | FR | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 6258006 | Hanyu et al. | Jul 2001 | B1 |
| 6502474 | Sakamoto et al. | Jan 2003 | B2 |
| 7238139 | Roethler et al. | Jul 2007 | B2 |
| Number | Date | Country |
|---|---|---|
| 2 670 440 | Oct 1990 | FR |
| Number | Date | Country | |
|---|---|---|---|
| 20110011655 A1 | Jan 2011 | US |
