JP2016511190A - Drivetrain for hybrid vehicles - Google Patents

Abstract

The present invention includes an internal combustion engine (ICE), at least one electric motor (EM1, EM2), and a power split transmission (4) having three connection systems (4a, 4b, 4c). The connection system (4a) is at least one electric motor (EM2), the second connection system (4b) is an internal combustion engine (ICE), and preferably a third connection system (4c) formed by a thumb shaft (S). Relates to an output shaft (2) of the vehicle and a drive train (1) for a hybrid vehicle that is connected in driving. Furthermore, the first connection system (4a) is connected to a torque control module (5) formed by a two-course four-axis transmission.

Description

  The present invention includes an internal combustion engine, at least one electric motor, and a power split type transmission having three connection systems, wherein the first connection system is at least one electric motor and the second connection system is an internal combustion engine. The third connection system, preferably formed by a thumb shaft, relates to a vehicle output shaft and a drive train for a hybrid vehicle that is drivingly connected to each other.

  A battery has a lower weight energy density than a fossil fuel and takes a relatively long time to charge, so that the cruising distance of an electric vehicle is generally shorter than that of an internal combustion engine vehicle. Therefore, in electric vehicles, so-called cruising distance extension devices are often used to ensure an acceptable cruising distance with an equivalent total vehicle weight. At that time, the internal combustion engine directly drives a generator for supplying auxiliary energy to the battery when necessary. In such a structural concept, no mechanical power transmission path is provided between the internal combustion engine and the drive wheels. This provides the advantage that an optimal design of the internal combustion engine and an optimal battery size design based on some operating points can be made at reduced cost and at a lower cost. However, since mechanical power transmission is not performed between the internal combustion engine and the drive wheels, the internal combustion engine − is generated by frequent energy conversion between the internal combustion engine → the generator → the high pressure system → the battery → the high pressure system → the motor → the transmission. High losses will occur in the power transmission path. The electric motor forms the drive and must be designed for high power.

  In the power split type hybrid drive, a part of the power supplied from the internal combustion engine is directly mechanically transmitted to the drive wheels via the two-course power split type transmission. In order to meet the system's static requirements (moment balance-support moment), the transmission must either be powered or pulled off depending on the driving conditions. This is performed by motor operation or power generation operation of the electric motor. Therefore, the power split is performed through a pure electric power transmission path.

  In order to be able to operate the internal combustion engine at a single operating point, the power supply from the power split of the required driving power must be adapted by motor operation or power generation operation of another electric motor. Therefore, in principle, reactive power flows through the electrical power transmission path in accordance with the operating state and power requirements.

Possible reactive power flows:
-Electric motor 1 → high voltage system → battery → high voltage system → electric motor 2.
-Electric motor 2 → high pressure system → battery → high pressure system → electric motor 1.

  As a result, it is possible to integrate the advantages of the mechanical power transmission path of the internal combustion engine and the optimum design of the internal combustion engine based on some operating points and the reduction in vehicle mass due to the downsizing of the battery. However, the disadvantage is that the power split is performed purely electrically, which causes high loss due to frequent energy conversion. The reactive power flow that can occur in the electrical power transfer path results in low efficiency. In addition, high control costs are incurred by the system.

  German Patent Publication No. 199090924 discloses a hybrid transmission for a vehicle comprising a drive shaft, an output shaft, a continuously variable control device, and a mechanical superimposed transmission mechanism. The superimposing transmission mechanism is a five-axis planetary gear mechanism having a carrier shaft as a transmission output shaft. The carrier carries a plurality of planetary gear sets that mesh with each other. These planetary gears mesh with two internal gears and two sun gears. The two sun gears are connected to each other via an electric continuously variable control device. The first internal gear is fixedly connected to the internal combustion engine. The second internal gear can be connected to the gear box via a brake.

  EP 1279545 A1 comprises a planetary gear mechanism with four elements and two degrees of freedom, consisting of two sun gears, one planetary gear carrier and at least one internal gear. A hybrid drivetrain for a vehicle is disclosed. The internal gear and the planetary gear carrier are connected to the drive shaft of the internal combustion engine. Each of the two sun gears is connected to an electric motor.

German Patent Application Publication No. 199090924 European Patent Application No. 1279545

  An object of the present invention is to improve efficiency and reduce control costs.

  According to the present invention, the above object is achieved by connecting a torque control module formed by a two-course four-axis transmission to a first connection system.

  A power split type two-course (degree of motion = 2) transmission is generally understood as a transmission having two kinematic degrees of freedom. By presetting the number of revolutions on the two axes, the movement of the system is uniquely defined. Furthermore, if torque is preset on the connecting shaft, the system is fully established statically. In general, a transmission / sub-transmission that transmits power must at least always have one more connecting shaft than its kinematic freedom. Therefore, the simplest two course transmission has exactly three connecting shafts. The planetary gear mechanism / planetary gear mechanism forms the simplest embodiment of a two-course three-axis transmission. From the condition that the sum of all moments becomes zero, the connection moment of the two-course transmission must be partially positive and partially negative. There will always be one moment with the opposite sign and two moments with the same sign, one single moment being equal to the sum of the other two moments. The axis having a single moment is referred to as the thumb shaft, and the other two axes are referred to as the differential shaft.

  If the planetary gear mechanism has a negative gear ratio, and therefore a so-called negative transmission, the two central shafts are simultaneously differential shafts and the carrier shaft is a thumb shaft. On the other hand, if the planetary gear mechanism has a positive gear ratio when stopped, it is generally a plus transmission. In this case, one central shaft and the carrier shaft are differential shafts, and the remaining central shaft is a thumb shaft.

  Preferably, the torque control module has four connection systems, the first module connection system is a first motor, the second module connection system is a second motor, and the other module connection system is a power split. The first transmission system and the second connection system of the transmission system are respectively connected in driving. The torque control module consists of two two-course three-axis transmissions, the differential shafts of these two three-axis transmissions are connected to each other, and the thumb shaft of the first two-course three-axis transmission forms the first module connection system However, if the thumb shaft of the second two-course three-axis transmission forms the second module connection system, it is possible to achieve particularly high efficiency and low control cost.

  The two two-course three-axis transmissions jointly form a two-course four-axis transmission having four connection systems by double connection, and one of these connection systems is the first sub-transmission. And a further connection system forms the thumb shaft of the second sub-transmission, and the remaining two module connection systems form a coupled differential shaft train of the two sub-transmissions.

  In this case, the two differential shafts of the first and second three-shaft transmissions of the torque control module are directly connected to form a positive differential shaft train, which is a further difference between the first and second two-course three-shaft transmissions. These two differential shafts may be connected to each other via a reverse rotation mechanism to form a negative differential shaft train. Thereby, the positive differential shaft train forms a positive gear ratio between the two sub-transmissions, and the negative differential shaft train forms a negative gear ratio between the two sub-transmissions.

  The first sub-transmission functions as an open differential that distributes the drive moment of the first module connection system to the module connection system connected by the differential shaft train at a constant ratio. The torque applied to the second connection system redistributes the drive moment of the connection system connected to the differential shaft train.

  Basically, the moment distribution can be performed by the torque control module on the drive side or output side.

  In the first embodiment of the present invention, the differential shaft of one differential shaft train of the torque control module is a first connection system of a power split type transmission, and the other differential shaft of the other differential shaft train is a power split type. Each drive connection is made with a second connection system of the transmission. In this case, the first connection system of the power split transmission is connected to the module connection system of the positive differential shaft train or the negative differential shaft train. On the contrary, the second connection system of the power split transmission is connected to the negative differential shaft train or the positive differential shaft train of the torque control module.

  In the second embodiment of the present invention, the differential shaft of one differential shaft train of the torque control module is the second connection system of the power split transmission, and the differential shaft of the other differential shaft train is the first of the power split transmission. Each of the three connection systems is drivingly connected.

  In this case, the third connection system of the power split transmission is connected to the direct differential shaft train or the opposite differential shaft train of the torque control module. Conversely, the second connection system of the power split transmission is connected to the opposite differential shaft train or the direct differential shaft train of the torque control module.

Thus, the drive train has two basic units with different functions:
1) Power split type two course transmission for CVT function (CVT = Continuous Variable Transmission) 2) Torque control module (TVM = Tork-Vectoring-Modul) for system dynamic power distribution.

  All advantages of a hybrid drive with a power split transmission according to the present invention-for example the realization of a mechanical power transmission path for an internal combustion engine, the optimal design of the internal combustion engine depending on some operating points and the vehicle mass due to the miniaturization of the battery In addition, the frequency of energy conversion can be reduced. Therefore, a reduction in energy loss by the mechanical power split method and a relatively high efficiency resulting therefrom can be realized. Furthermore, the required control costs are significantly reduced.

  Hereinafter, the present invention will be described in detail with reference to the drawings. Each figure shows the following:

It is a figure which shows 1st embodiment of the drive train by this invention. It is a figure which shows the 1st modification of embodiment shown in FIG. It is a figure which shows the 2nd modification of embodiment shown in FIG. It is a figure which shows 2nd embodiment of the drive train by this invention. It is a figure which shows the 1st modification of embodiment shown in FIG. It is a figure which shows the 2nd deformation | transformation aspect of embodiment shown in FIG. It is a figure which shows 3rd embodiment of the drive train by this invention. It is a figure which shows the 1st modification of embodiment shown in FIG. It is a figure which shows the 2nd deformation | transformation aspect of embodiment shown in FIG. It is a figure which shows 4th embodiment of the drive train by this invention. It is a figure which shows the 1st modification of embodiment shown in FIG. It is a figure which shows the 2nd modification of embodiment shown in FIG.

  In the series of embodiments and variations, functionally identical parts are given the same reference numerals.

  Each figure shows a drive train 1 having a series of power sources formed by an internal combustion engine ICE, a first electric motor EM1 and a second electric motor EM2, and at least one of the vehicles via an output shaft 2. Two drive wheels 3 are driven. In the drive train 1, a power split transmission 4 having three connection systems 4a, 4b and 4c is arranged. The first connection system 4a is connected to the first and second electric motors EM1, EM2 via the torque control module 5 having four module connection systems 5a, 5b, 5c, 5d. The second connection system 4b is connected to the drive shaft 6 of the internal combustion engine ICE.

  The power split transmission 4 is formed as a two course transmission having a kinematic degree of freedom. This type of triaxial transmission formed by the planetary gear mechanism L always has two axes having the same sign with respect to the axial moment and one axis having the opposite sign. An axis having the same sign is referred to as a differential shaft, and an axis having the opposite sign is referred to as a thumb shaft. An axis that can transmit only the coupling power is called a carrier shaft, and an axis that can transmit both the coupling power and the roll power is called a central shaft. The triaxial transmission has a unique moment and rotational speed behavior for the differential shaft and the thumb shaft. The so-called stop gear ratio is used to represent the movement of the triaxial transmission. The stop gear ratio is defined as the gear ratio between the two central shafts when the carrier shaft is stopped. The stopping gear ratio may be positive or negative, which again requires a distinction between so-called plus transmission and minus transmission.

The minus transmission means a three-axis transmission in which two central shafts are simultaneously differential shafts and the remaining carrier shaft is a thumb shaft.
The plus transmission means a three-axis transmission in which the carrier shaft and one of the two central shafts are a differential shaft, and the remaining central shaft is a thumb shaft.

  In a simple planetary gear mechanism having only one planetary gear meshing with the sun gear on the one hand and with the internal gear on the other hand, the two central shafts-the sun gear and the internal gear-are differential shafts, the carrier shaft is It is a thumb shaft. This planetary gear mechanism has a minus transmission movement.

  One or more planetary gear pairs, where each first planetary gear meshes with the sun gear and the second planetary gear, and the second planetary gear meshes with the internal gear and the first planetary gear. In the planetary gear mechanism, the sun gear as the carrier shaft and the first central shaft is a differential shaft, and the internal gear as the second central shaft is a thumb shaft. Therefore, this planetary gear mechanism has a plus transmission movement.

  In the two-course power split transmission 4 provided here, for example, a minus transmission can be used. By presetting the number of revolutions in two axes, the movement of this system is defined. Furthermore, if the torque is preset by the connection system, the system is fully established statically.

  In this example, the first and second connection systems 4a and 4b of the power split transmission 4 are formed by a differential shaft d, and the third connection system 4c is formed by a thumb shaft s.

The torque control module 5 is formed by two of the two courses triaxial transmission (sub transmission) T ₁ and T _2, which are sub-transmissions jointly, by a double coupling, the module connection system 5a, 5b, and 5c and 5d Having a two-course four-shaft transmission.
The first module connecting system 5a, which is connected to the first electric motor EM1 is formed by sum shaft S ₁ of the first triaxial transmission T _1. The second module connection system 5b which is connected to the electric motor EM2 is formed by sum shaft S ₂ of the second triaxial transmission T _2. First triaxial transmission T ₁ of the differential shaft d ₁ ⁺ a and the second triaxial transmission T ₂ of the differential shaft d ₂ ⁺ are connected to form a ⁺ positive differential shaft train D together. The differential shafts d ₁ ⁻ and d ₂ ^{− of} the first and second three-axis transmissions T ₁ and T ₂ are connected via a reverse rotation mechanism U to form a negative differential shaft train D ⁻ .

Sub transmission T ₁ acts as an open differential for distributing to the module connection system 5c and 5d to scale the drive moment of the first module connecting system 5a. The torque applied to the second module connection system 5b redistributes the drive moments of the connection systems 5c and 5d.

The above series of figures can basically be divided into two groups.
1 to 6 relate to the first group of embodiments and variants in which the torque control module 5 performs the drive side moment distribution.
FIGS. 7 to 12 show the second group of embodiments and variations in which the output side moment distribution is performed by the torque control module 5.
In this case, FIG. 1 shows the first basic embodiment, FIG. 4 shows the second basic embodiment, FIG. 7 shows the third basic embodiment, and FIG. 10 shows the fourth basic embodiment. . In each basic embodiment, there are sub-variants shown in FIGS. 2 and 3, 5 and 6, 8 and 9 to 11 and 12.

  The display of the basic embodiment shown in FIG. 1, FIG. 4, FIG. 7 and FIG. 10 is performed with a so-called wolf symbol. Each planetary gear mechanism has a housing represented by a circle and three connection systems represented by lines. Has been. The carrier shaft is represented by a line penetrating the circle, and the thumb shaft is represented by a double line.

  Reference numeral 7 denotes a drive transmission or a vehicle differential.

In the torque control module 5 in all embodiments, respectively, the first triaxial transmission T ₁ is as positive transmission, the second triaxial transmission T ₂ is formed as a minus transmission. 2 and 3, FIG. 5 and FIG. 6, FIG. 8 and FIG. 9, and FIG. 11 and FIG. 12 are different in that the central shaft of the power split transmission 4 is replaced. Figure 2, in a variant embodiment shown in FIGS. 5, 8 and 11, the sun gear L _S of the planetary gear mechanism L of the power-split type transmission 4 is connected to the drive shaft 6 of the internal combustion engine ICE. On the other hand, the internal gear L _H is connected to the carrier T _1St of the first three-axis transmission T ₁ of the torque control module 5.

3, 6, 9, and 12, the drive shaft 6 of the internal combustion engine ICE is connected to the internal gear L _H of the planetary gear mechanism L of the power split transmission 4. The sun gear L _S is connected to the carrier T _1St of the first three-axis transmission T ₁ .

In the variant embodiment shown in FIGS. 2 and 3, the sun gear T _1S and T _2S of the first and second triaxial transmission T _1, T ₂ are connected to the drive shaft 6 of the internal combustion engine ICE. The internal gear _{T IH} acts first electric motor EM1. The second electric motor EM2 acting on the second triaxial transmission _{T 2} carrier _{T 2ST.} The internal gear T _{2H of} the second three-axis transmission T ₂ and the carrier T _1St of the first three-axis transmission T ₁ are connected to each other via a reverse _rotation mechanism U. The carrier L _St of the power split transmission 4 is connected to the output shaft 2.

2 and 3, in the embodiment of FIGS. 5 and 6, the central shaft of the split transmission 4 that is not connected to the drive shaft 6 of the internal combustion engine ICE is the same as that of the first three-shaft transmission T ₁ . Both the sun gear T _1S and the sun gear T _{2S of} the second three-axis transmission T ₂ are connected.

As shown in FIGS. 8 and 9, the embodiment having the positive differential shaft train D ⁺ connected to and connected to the drive train 1 on the output side is similar to the power split transmission 4 shown in FIGS. shows a power-split type transmission 4, the arrangement of the central shaft that is not connected to the drive shaft 6 of the internal combustion engine ICE is connected to the first triaxial transmission T _1.
In that case, in FIG. 8, the internal gear L _H of the power split transmission 4 is connected to the carrier T _1St of the first three-axis transmission T ₁ . In contrast, in FIG. 9, the sun gear L _S of the planetary gear mechanism L of the power split transmission 4 is connected to the carrier T _{1St of} the first three-axis transmission T ₁ . Internal gear T _IH of the first triaxial transmission T ₁ is connected to the first electric motor EM1. Each of the sun gear T _1S and T _2S of the first and second triaxial transmission T _1, T ₂ is fixed connected to the output shaft 2. The carrier T _1St is connected to the internal gear T _2H via the reverse _rotation stage U. The second electric motor EM2 acting on the second triaxial transmission _{T 2} carrier _{T 2ST.}

The embodiment shown in FIGS. 11 and 12 shows a modification of the torque control module 5 connected to the drive train 1 on the output side with respect to the power split transmission 4, and in this case, in FIG. The sun gear L _S of the planetary gear mechanism L of the system transmission 4 is connected to the drive shaft 6 of the internal combustion engine ICE, and the internal gear L _H of the planetary gear mechanism L is the first and second three-axis transmissions T ₁ , T _{The two} sun gears T _1S and T _2S are drivingly connected. The carrier L _St of the power split transmission 4 is connected to the carrier T _1St . The carrier T _1St of the first three-axis transmission T ₁ is connected to the internal gear T _{2H of} the second three-axis transmission T ₂ via the reverse _rotation mechanism U. The first three-axis internal gear T _IH of the transmission T ₁ acts first electric motor EM1. The second electric motor EM2 is connected to the carrier T _2St of the second three-axis transmission T ₂ . The embodiment shown in FIG. 12 differs from the arrangement shown in FIG. 11 only in that the central shaft of the power split transmission 4 is replaced. In particular, the drive shaft 6 of the internal combustion engine ICE is connected to the internal gear L _H of the planetary gear mechanism L of the power-split type transmission 4, the sun gear L _S of the planetary gear mechanism L is the first triaxial transmission T ₁ The sun gear T _1S and the sun gear T _{2S of} the second three-axis transmission T ₂ are connected.

  The connection systems 4a, 4b, 4c of the power split transmission 4 and the module connection systems 5a, 5b, 5c, 5d of the torque control module 5 are physically formed connection systems, for example, connection shafts or parts between transmission parts. May be a virtual connection point between isolated or non-isolated transmission elements. Therefore, in FIGS. 2, 3, 5, 6, 8, 9, 11, and 12, the mode of the connection system is only schematically represented.

Claims (11)

An internal combustion engine (ICE), at least one electric motor (EM1, EM2), and a power split transmission (4) having three connection systems (4a, 4b, 4c),
The first connection system (4a) includes at least one electric motor (EM2),
The second connection system (4b) is an internal combustion engine (ICE),
Preferably, the third connection system (4c) formed by the thumb shaft (S) is a vehicle output shaft (2) and a drive train (1) for a hybrid vehicle, each of which is drivingly connected,
The drive train (1), wherein a torque control module (5) formed by a two-course four-axis transmission is connected to the first connection system (4a). The torque control module (5) has four module connection systems (5a, 5b, 5c, 5d),
The first module connection system (5a) includes a first electric motor (EM1),
The second module connection system (5b) includes a second electric motor (EM2),
2. The remaining connection system (5 c, 5 d) is drive-connected to the first or second connection system (4 a, 4 b) of the power split transmission (4), respectively. Drive train (1). The torque control module (5) includes two differential shafts (d ₁ ⁻ , d ₁ ⁺ ; d ₂ ⁻ , d ₂ ⁺ ) and one thumb shaft (S ₁ ; S ₂ ), respectively. with two courses triaxial transmission _(T 1, T _2),
The differential shafts (d ₁ ⁻ , d ₁ ⁺ ; d ₂ ⁻ , d ₂ ⁺ ) of the two three-shaft transmissions (T ₁ , T ₂ ) are connected to each other;
The thumb shaft (S ₁ ) of the first two-course three-axis transmission (T ₁ ) forms the first module connection system (5a),
The drive train according to claim 2, wherein the thumb shaft (S ₂ ) of the second two-course three-axis transmission (T ₂ ) forms the second module connection system (5b). (1). The first three-axis transmission (T ₁ ) is a plus transmission,
The drive train (1) according to claim 3, characterized in that the second three-axis transmission (T ₂ ) is formed as a negative transmission. The two differential shafts (d ₁ ⁺ , d ₂ ⁺ ) of the first and second three-axis transmissions (T ₁ , T ₂ ) of the torque control module (5) are directly connected to each other so as to be positive differentials. Shaft train (D ⁺ ),
The remaining two differential shafts (d ₁ ⁻ , d ₂ ⁻ ) of the first and second two-course three-axis transmissions (T ₁ , T ₂ ) of the torque control module (5) ) To form a negative differential shaft train (D ⁻ ). 5. The drive train (1) according to claim 3, One differential shaft train (D ⁺ ; D ⁻ ) of the torque control module (5) is connected to the first connection system (4a) of the power split transmission (4),
The other differential shaft train (D ⁻ ; D ⁺ ) of the torque control module (5) is drivingly connected to the second connection system (4b) of the power split transmission (4), respectively. The drive train (1) according to claim 5. The first connection system (4a) of the power split transmission (4) includes a positive differential shaft train (D ⁺ ) of the torque control module (5),
Claims, characterized in that a, are connected ^- the power-split mode the second connection system of the transmission (4) (4b) a negative differential shaft train of the torque control module (5) (D) 6. The drive train (1) according to 6. The first connection system (4a) of the power split transmission (4) includes a negative differential shaft train (D ⁻ ) of the torque control module (5),
The second connection system (4b) of the power split transmission (4) is connected to a positive differential shaft train (D ⁺ ) of the torque control module (5), respectively. 6. The drive train (1) according to 6. One differential shaft train (D ⁺ ; D ⁻ ) of the torque control module (5) is connected to the first connection system (4a) of the power split transmission (4),
The other differential shaft train (D ⁻ ; D ⁺ ) of the torque control module (5) is drivingly connected to the third connection system (4c) of the power split transmission (4), respectively. The drive train (1) according to any one of claims 1 to 8. The first connection system (4a) of the power split transmission (4) includes a negative differential shaft train (D ⁻ ) of the torque control module (5),
The third connection system (4c) of the power split transmission (4) is connected to a positive differential shaft train (D ⁺ ) of the torque control module (5), respectively. 9. The drive train (1) according to 9. The first connection system (4a) of the power split transmission (4) includes a positive differential shaft train (D ⁺ ) of the torque control module (5),
Claims, characterized in that a, are connected ^- the power-split mode the third connection system of the transmission (4) (4c) is negative differential shaft train of the torque control module (5) (D) 9. The drive train (1) according to 9.

Images