Automotive drive systems

Abstract

In a drive system for hybrid vehicles, the objective is to ensure acceleration performance at low speeds, achieve miniaturization, enable continuously variable transmission with minimal shift shock, and improve fuel efficiency. [Solution] The system consists of an engine 1, an input shaft 10, an output shaft 12, a first MG 30, a second MG 32, a planetary gear 20 consisting of three rotating elements: a sun gear 22, a ring gear 24, and a carrier 28, and a first and second gear shifting mechanism 3 and a second gear shifting mechanism 4, respectively, which obtain high and low gear ratios. The input shaft 10 is connected to the carrier 28, the output shaft 12 is connected to the ring gear 24 and can also be connected to the second MG 32, the first MG 30 is connected to the sun gear 22, the first gear shifting mechanism 3 is located between the output shaft 12 and the second MG 32, and the second gear shifting mechanism 4 is located between the input shaft 10 and the output shaft 12.

Description

Technical Field

[0001] The present invention relates to a drive device for an automobile, and more particularly to a drive device for a so-called hybrid automobile having an engine and a motor generator (hereinafter referred to as “MG”) as power sources.

Background Art

[0002] Conventionally, as a drive device for this type of automobile, there is a planetary gear (power split planetary gear) having three rotating elements, a sun gear, a ring gear, and a carrier, for splitting an input torque, an input shaft connected to the carrier among them, a first MG connected to the sun gear, an output shaft connected to the ring gear, and a second MG connectable to this output shaft. An electric continuously variable transmission (hereinafter referred to as “CVT”) is configured using the planetary gear and the two MGs, and a transmission is provided between the output shaft and the second MG so that the second MG drives the output shaft to decelerate at low speed to obtain a large output torque. An example of such a configuration is known (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above conventional drive device for an automobile, the transmission provided between the output shaft and the second MG includes at least two friction elements (B1, B2 in FIG. 7), and the transmission is switched by switching the engagement of these friction elements, so that a large output torque can be obtained at low speed and a second MG with a small capacity can be used.

[0005] However, friction elements have drawbacks: drag friction occurs when they are not engaged, resulting in energy loss during power transmission, low power transmission efficiency, and shift shock occurs when switching between friction elements.

[0006] The problems we are trying to solve are that the low power transmission efficiency is disadvantageous in terms of fuel economy, and the shifting shock in the transmission is not negligible. The objective of this invention is to improve fuel efficiency and enable continuously variable transmission that minimizes shifting shocks. [Means for solving the problem]

[0007] The automotive drive system of the present invention comprises an input shaft capable of receiving power from an engine, an output shaft, a first motor-generator, a second motor-generator, a planetary gear consisting of three rotating elements: a sun gear, a ring gear, and a carrier, and a first and second gear shift mechanism for obtaining high and low gear ratios, respectively. The input shaft is connected to the carrier, the output shaft is connected to the ring gear and can be connected to the second motor-generator, the first motor-generator is connected to the sun gear, the first gear shift mechanism is provided between the output shaft and the second motor-generator, and the second gear shift mechanism is provided between the input shaft and the output shaft. [Effects of the Invention]

[0008] As configured as described above, the automotive drive system of the present invention improves fuel efficiency and allows driving in drive modes including continuously variable transmission, which reduces shifting shock. [Brief explanation of the drawing]

[0009] [Figure 1] This is a skeleton diagram showing the main parts of an automobile drive system according to Embodiment 1 of the present invention. [Figure 2] This is a diagram showing the operation table for Example 1. [Figure 3] This is a skeleton diagram showing the main parts of an automobile drive system according to Embodiment 2 of the present invention. [Figure 4] This is a diagram showing the operation table for Example 2. [Figure 5] This is a skeleton diagram showing the main parts of an automobile drive system according to Embodiment 3 of the present invention. [Figure 6] This is a diagram showing the operation table for Example 3. [Figure 7] This is a skeleton diagram showing the main parts of an automobile drive system according to Embodiment 4 of the present invention. [Figure 8] This is a diagram showing the operation table for Example 4. [Modes for carrying out the invention]

[0010] Hereinafter, an automobile drive system according to an embodiment of the present invention will be described with reference to the figures based on an example. [Examples]

[0011] Figure 1 is a skeleton diagram of the main components of an automobile drive system according to Embodiment 1 of the present invention. The automobile drive system of Embodiment 1 consists of four parallel shafts, which, from bottom to top in Figure 1, are the first shaft which is the output shaft 12, the second shaft which is the input shaft 10 and on which the planetary gear 20 and the first MG 30 are arranged, the third shaft which is the counter shaft 14, and the fourth shaft which is the motor drive shaft 16 and connected to the second MG 32. Although Figure 1 shows these four shafts arranged on a plane, they do not necessarily have to be on a plane in reality. Also, the circles in the figure illustrate the arrangement of bearings, although their explanation is omitted.

[0012] The input shaft 10 is connected to the crankshaft 1a of the power source engine 1 via a damper 1b. The planetary gear 20 is generally called a single-pinion type and has three rotating elements: a sun gear 22, a ring gear 24, and a carrier 28. The sun gear 22 is connected to the first MG 30, and the carrier 28 is connected to the input shaft 10.

[0013] The first gear 24a, which is integrated with the ring gear 24, is connected to the output shaft 12 via the second gear 12a that meshes with it, and is also connected to the counter shaft 14 via the third gear 14a. In other words, the output shaft 12 is connected to the ring gear 24 and the counter shaft 14 via these gears. The output shaft 12 outputs power from the integrated output gear 12b to drive the wheels of the automobile via a differential gear (not shown). A parking gear 12e is also provided integrally with the output shaft 12, but this is well known so its explanation is omitted.

[0014] Between the motor drive shaft 16 connected to the second MG32 and the counter shaft 14, there is a first speed change mechanism 3 that enables two speed settings, high and low, as described later. Specifically, in the first speed change mechanism 3, the fourth gear 16b and fifth gear 16c, which are integrated with the motor drive shaft 16, mesh with the sixth gear 14b and seventh gear 14c, which are rotatably supported on the counter shaft 14. The counter shaft 14 and one of the sixth gear 14b and seventh gear 14 can be selectively connected by shifting the first sleeve 14d, which is provided on the counter shaft 14, in the axial direction.

[0015] Here, the configuration of the first sleeve 14d is common to that of the other sleeves described later, so the first sleeve 14d will be explained as a representative example. The first sleeve 14d is positioned radially outward of the first hub 14e, which is integrated with the counter shaft 14, and rotates in the same direction as the first hub 14e, but is shiftable in the axial direction. The dog teeth 14f and 14g formed on the faces of the sixth gear 14b and seventh gear 14c facing the first sleeve 14d, respectively, selectively engage with one of them when the first sleeve 14d shifts in either the left or right direction. Figure 1 shows the neutral position where neither the dog teeth 14f nor the dog teeth 14g are engaged. The engagement of the first sleeve 14d with the dog teeth 14f and 14g is achieved by controlling the rotational speed difference between them to be close to zero, and conversely, the disengagement is achieved by controlling the torque transmission between them to be close to zero.

[0016] Thus, when the first sleeve 14d is shifted to the right in FIG. 1, a low (Lm) gear ratio is obtained, and when shifted to the left, a high (Hm) gear ratio is obtained. The countershaft 14 and the output shaft 12 are connected via the first gear 24a. The shift of the first sleeve 14d is performed by a shift fork and an actuator not shown, but since these configurations are well-known, the drawings and their descriptions are omitted. Also, for each of the subsequent sleeves, the illustration and description of symbols such as hubs and dog teeth are omitted.

[0017] On the input shaft 10, the eighth gear 10a is rotatably supported, and the eighth gear 10a meshes with the ninth gear 12c integral with the output shaft 12. The second sleeve 10d provided on the input shaft 10 can be selectively connected to the first gear 24a and the eighth gear 10a by shifting axially. These obtain two-stage gear ratios between the input shaft 10 and the output shaft 12. That is, when the second sleeve 10d is shifted to the right in FIG. 1, it has a low (Le) gear ratio, and when shifted to the left, it has a high (He) gear ratio, and constitutes the second transmission mechanism of the present invention between the input shaft 10 and the output shaft 12.

[0018] The above is the configuration of this embodiment. Here, for the following description, taking the above gear ratios as examples, they are as follows. Lm (rotation speed of the second MG32 / rotation speed of the output shaft 12): 1.50 Hm (same as above): 0.6 Le (rotation speed of the input shaft 10 / rotation speed of the output shaft 12): 1.55 He (same as above): 1.02 Also, taking the ratio of the number of teeth of the sun gear 22 to the number of teeth of the ring gear 24 of the planetary gear 20 as ρ, ρ is set to 0.4. In the following description, the rotation direction of the engine 1 is defined as "forward rotation", and the rotation opposite to it is defined as "reverse rotation".

[0019] Next, the operation and function of the automotive drive system shown in Figure 1 will be explained in accordance with the operation table shown in Figure 2. In the operation table in Figure 2, each drive mode described below is assigned to the vertical direction, and the operating status and gear ratio of the two sleeves and two MGs are assigned to the horizontal direction. Specifically, the first sleeve 14d is designated as S1, the second sleeve 10d as S2, the first MG30 as MG1, and the second MG32 as MG2. The arrows indicated in the table for each sleeve represent the shift direction of that sleeve. In the case of the MGs, power generation is represented as G and drive as D. The gear ratio value is the rotational speed of the second MG32 / the rotational speed of the output shaft 12 in EV mode, and the high-efficiency drive in HV mode is the rotational speed of the input shaft 10 / the rotational speed of the output shaft 12. Furthermore, the # shown in the table for the first sleeve 14d indicates that a shift of the first sleeve 14d is possible in that drive mode.

[0020] Although not shown in the diagram, the automotive drive system shown in Figure 1 is equipped with a battery, various sensors, a controller, an inverter, a shift lever, etc., as needed, in addition to the aforementioned shift fork and actuator, in order to operate it, and the following operations are basically performed based on the instructions of the controller.

[0021] The drive modes of the drive system shown in Figure 1 include "EV mode" when engine 1 is stopped and "HV mode" when engine 1 is running. In EV mode, the vehicle is driven as an EV (electric vehicle) by the second MG32, while in HV mode, except for ML and MH described later, the vehicle is driven as an electromechanical CVT.

[0022] First, let's explain the EV mode, which uses electricity stored in the battery as the power source. In EV mode, power is supplied from the battery to the second MG32 for driving, or during braking called regenerative braking, the second MG32 generates electricity to charge the battery. As described above, the first transmission mechanism 3 provides a two-stage gear ratio between the second MG32 and the output shaft 12. For starting and low-speed driving, the gear ratio Lm (EL) is selected, and for high-speed driving, the gear ratio Hm (EH) is selected.

[0023] Switching between EL and EH is done by setting the torque of the second MG32 to 0. However, to avoid the drive torque or braking torque becoming temporarily 0, it is also possible to switch to the HV mode described later and then switch between the gear ratios Lm and Hm while driving in HV mode. Note that in EV mode, reverse is the same EL in the operation table, and the rotation direction of the second MG32 is the opposite of that in forward.

[0024] Next, the HV mode of drive by engine 1 will be described. The HV mode primarily operates as an electromechanical CVT (continuously variable transmission) using planetary gears 20, the first MG 30, and the second MG 32. A first transmission mechanism 3 is interposed between the second MG 32 and the output shaft 12, resulting in two types of drive: HL and HH. The HV mode also includes ML and MH, which are not electromechanical CVTs but are mechanically driven from the input shaft 10 by the second transmission mechanism 4.

[0025] First, although the procedure for starting engine 1 is well known, when the vehicle is stopped, the first MG30 is rotated in reverse in the HL state shown in Figure 2, and when the vehicle is in motion, the first MG30 is used to generate electricity regardless of the drive mode.

[0026] Next, although electromechanical CVTs are well known, their overview will be explained. The carrier 28, driven from the input shaft 10 by the power of the engine 1, transmits its torque to the sun gear 22 and the ring gear 24. The torque acting on the ring gear 24 mechanically drives the output shaft 12. Meanwhile, the torque acting on the sun gear 22 generates electricity in the first MG 30, which supplies the resulting power to the second MG 32, which drives the output shaft 12 via the first transmission mechanism 3. In other words, the torque of the sun gear 22 is electrically transmitted to the output shaft 12. The rotational speed ratio between the input shaft 10 and the output shaft 12 changes steplessly according to the vehicle-side drive load acting on the output shaft 12 and the engine power. Note that in HV mode, reverse is the same HL in the operation table, and the rotation direction of the second MG 32 is the opposite of that in forward mode.

[0027] In actual driving, the vehicle is often in EV mode when starting. In that case, it starts in EL mode, and when the driving load increases or the battery charge decreases, it switches to HV mode by starting engine 1 as described above.

[0028] When the vehicle speed increases while driving in HL mode, and the gear ratio (rotational speed of input shaft 10 / rotational speed of output shaft 12) reaches Le, the speed difference between the second sleeve 10d and the eighth gear 10a becomes zero. At this point, the second sleeve 10d is shifted to the right, and the generation and driving of the first MG30 and second MG32 are stopped, switching to driving with gear ratio Le by the eighth gear 10a and the ninth gear 12c. This is ML mode. ML mode is mechanically driven and has no energy loss associated with electrical transmission.

[0029] Furthermore, while running in ML mode, the rotational speeds of the first MG30 and the second MG32 can be freely changed, allowing the first transmission mechanism 3 to be switched between low (Lm) and high (Lh). Then, with the first transmission mechanism 3 switched to high, the power generation and drive of the first MG30 and the second MG32 are restored using the reverse procedure described above, and when the transmission torque of the second sleeve 10d becomes 0, the second sleeve 10d is returned to neutral, switching to HH mode.

[0030] Similarly, when the gear ratio reaches He while driving, shifting the second sleeve 10d to the left switches to the mechanically driven MH. And even while driving in MH mode, the first gear mechanism 3 can be switched.

[0031] Thus, ML and MH are drive positions that allow switching of the first transmission mechanism 3 while driving in HV mode. Whether to switch between HL and HH in ML or MH should be determined by the vehicle's speed and the state of the drive load. Furthermore, the gear ratio does not change when switching from HV mode to ML and HH, or when switching back to HV mode.

[0032] After switching to HH, the gear ratio decreases, and the rotational speed of the first MG30 decreases until it stops. This state is called HS, and the gear ratio is He / (1+ρ), which corresponds to 0.73 in the gear ratio-tooth ratio described above. When the first MG30 stops, it does not generate electricity and the electrical drive becomes 0, so it is considered a mechanical drive, and this gear ratio is called the mechanical point, and is considered a high-efficiency drive. In this case, when the gear ratio is close to 0.73, it automatically becomes a high-efficiency drive, so there is no need to switch the sleeve. The above three high-efficiency drives are suitable for use in cruising, and in order to improve fuel efficiency during cruising, the first sleeve 14d can be set to neutral and the second MG32 can be stopped.

[0033] The above explains the switching process during acceleration from a standstill to high speed. Conversely, switching during deceleration is basically the same as switching during acceleration, but in the reverse order.

[0034] The above describes the operation of Example 1, and the following effects can be obtained in Example 1. As described above, since the first transmission mechanism 3 is provided, the capacity of the second MG required to obtain the output torque at low speeds can be reduced, as in the conventional example, and since the gear ratio is determined by the first transmission mechanism 3, which consists of two pairs of gears, there is a high degree of freedom in setting the gear ratio. For example, it is easy to increase the driving force in the low-speed range and when reversing by increasing Lm, and to reduce the rotational loss of the MG2 at high speeds by decreasing Hm. Furthermore, since the gear ratio switching of the first transmission mechanism 3 is performed while the ML or MH of the second transmission mechanism is being driven, the gear ratio does not change during switching, and therefore no shift shock occurs, resulting in a smooth switch. In addition, since a friction clutch or hydraulic pump is not required for switching, the power transmission efficiency is high and fuel efficiency can be improved. Furthermore, fuel efficiency can be further improved by using ML and MH during cruising. In that case, by neutralizing the first sleeve 14d and stopping the second MG32, energy loss due to the rotation of the second MG32 can be avoided, further improving fuel efficiency.

[0035] Furthermore, although not shown in the diagram, it is well known that if the output shaft 12 drives the front wheels of the vehicle, a small MG for rear-wheel drive and a separate output shaft for the rear wheels, distinct from the output shaft 12, can be provided to create a four-wheel drive system. In that case, because the ratio of electrical power transmission is low, during cruising such as HH, when the second MG 32 is driven in a low-load, low-efficiency state, the first sleeve 14d can be put into neutral to stop the second MG 32, and the electricity generated by the first MG 30 can be supplied to the MG for rear-wheel drive, thereby allowing it to function as a mechanical-electric CVT. This reduces energy loss when rotating the large-capacity second MG 32 and improves fuel efficiency.

[0036] Furthermore, as can be seen in Figure 1, the first transmission mechanism 3 and the second transmission mechanism 4 can be easily arranged to overlap in the axial direction, which reduces the overall axial length of the device and makes it highly suitable for installation in FF vehicles (front-wheel drive vehicles) where the engine 1 is mounted transversely. [Examples]

[0037] Next, an automobile drive system according to Embodiment 2 of the present invention will be described. Figure 3 is a skeleton diagram of the main parts of the automobile drive system according to Embodiment 2 of the present invention. Here, the parts that differ from Embodiment 1 will be described in detail, and parts that are substantially the same as those in Embodiment 1 will be given basically the same names and reference numerals and their descriptions will be omitted.

[0038] The first difference between Example 2 and Example 1 is that the number of axes has increased by one. That is, if we consider the axes from bottom to top in Figure 3, the axes from the first to the third are the same as in Example 1, but the fourth axis consists only of the motor drive shaft 16, and the second MG32 is placed on the motor shaft 32b, which is the fifth axis. The second MG32 is connected to the motor drive shaft 16 by a drive gear 32a that is integrally provided with the motor shaft 32b, which meshes with the fifth gear 16c.

[0039] The second difference between Embodiment 2 and Embodiment 1 is the configuration of the second gear shift mechanism 4. Specifically, the eighth gear 10a and the tenth gear 10b, which are integrated with the input shaft 10, mesh with the ninth gear 12c and the eleventh gear 12d, which are rotatably supported on the output shaft 12. When the second sleeve 10d, which is positioned on the output shaft 12, is shifted to the right, it connects with the ninth gear 12c, and when shifted to the left, it connects with the tenth gear 10b, thereby obtaining the low (Le) and high (He) gear ratios. Therefore, these four gears and the second sleeve 10d constitute the second gear shift mechanism of the present invention. In relation to this, the parking gear 12e is integrated with the second gear 12a.

[0040] The third difference between Embodiment 2 and Embodiment 1 is that the input shaft 10 and the motor drive shaft 16 can be connected via the seventh gear 14c on the counter shaft 14. That is, the twelfth gear 10e, which is integrated with the input shaft 10, meshes with the thirteenth gear 14h, which is supported on the counter shaft 14, and the third sleeve 14j, which is provided on the thirteenth gear 14h, connects to the seventh gear 14c by shifting to the right. In other words, the input shaft 10 and the motor drive shaft 16 can be connected via the seventh gear 14c. Furthermore, if the third sleeve 14j is shifted to the right and the first sleeve 14d is shifted to the left, the thirteenth gear h connects to the counter shaft 14, and if the first sleeve 14d is shifted to the right, the seventh gear 14c connects to the sixth gear 14b via the motor drive shaft 16. Therefore, the input shaft 10 is connected to the output shaft 12 via the motor drive shaft 16 and the first speed change mechanism 3 to obtain a two-stage speed ratio. The other configurations are basically the same as in Example 1.

[0041] Embodiment 2 has three sleeves, but the first sleeve 14d and the third sleeve 14j are in a cooperative relationship, so they can be shifted in conjunction with a single actuator. These are well known, so they are not shown or described. Therefore, all sleeves can be operated with a total of two actuators.

[0042] The above describes the configuration of this embodiment. Here, the gear ratios described in Embodiment 1 are used as an example as follows. Lm:2.20 Hm:0.74 Le:2.20 He: 1.67 ρ:0.35

[0043] Next, regarding the operation and function of Example 2, the operation table corresponding to Figure 2 is shown in Figure 4. As described above, compared to Example 1, the configuration of the second transmission mechanism 4 is different, and the third sleeve 14j is added as S3, and in connection with this, the number of high-efficiency drive modes has increased. In addition, the names of the drive modes in high-efficiency drive are M-1 and M-4, but otherwise it is the same as in Example 1. Specifically, when driving in HL mode, if the gear ratio reaches 3.805, shifting the third sleeve 14j will switch to M-1, and when driving in HH mode, if the gear ratio reaches 1.280, shifting the third sleeve 14j will switch to M-4. This is basically the same as ML and MH, so a detailed explanation will be omitted.

[0044] In this embodiment, in addition to the effects described in Embodiment 1, the following advantages are available. Specifically, since the second MG32 is positioned on the motor shaft 32b, which is the fifth shaft, the radial size of the first MG30 and the second MG32 can be increased, and the tooth ratio of the drive gear 32a and the fifth gear 16c can be freely set. Furthermore, because the configuration of the second transmission mechanism has been changed, the degree of freedom in setting the gear ratio of each transmission mechanism is also increased. In addition, two more high-efficiency drive modes are added by shifting the third sleeve 14j. As a result, for example, in M-1, acceleration and uphill driving are possible with the full power of engine 1 at a gear ratio equivalent to the first gear of a typical 5-speed automatic transmission, and in M-4, fuel efficiency is improved during cruising in urban areas. [Examples]

[0045] Next, an automobile drive system according to Embodiment 3 of the present invention will be described. Figure 5 is a skeleton diagram of the main parts of the automobile drive system according to Embodiment 3 of the present invention. Here, the parts that differ from Embodiments 1 and 2 will be described in detail, and parts that are substantially the same will be given basically the same names and reference numerals and their descriptions will be omitted. Embodiment 3 is composed of the first to fifth axes, similar to Embodiment 2, but the contents of each axis are different. That is, the first axis is the output shaft 12, and the arrangement of each gear has changed, but it is the same as in Embodiment 2. In the second axis, the arrangement of the input shaft 10, planetary gear 20, and first MG 30 is the same as in Embodiments 1 and 2, but the ring gear shaft 24b, which is integrated with the ring gear 24, extends to the right and has the role of the counter shaft 14 in Embodiments 1 and 2. The third axis is the motor drive shaft 16, and it forms a first speed change mechanism between itself and the ring gear shaft 24b. The fourth and fifth axes are equipped with an intermediate gear 17 and a drive gear 32a, respectively, which connect the second MG32 and the motor drive shaft 16. The second speed change mechanism 4 between the input shaft 10 and the output shaft 12 is basically the same as in the case of Embodiment 2.

[0046] Furthermore, the third gear shift mechanism 5 of the present invention is positioned between the input shaft 10 and the motor drive shaft 16. That is, the motor drive shaft 16 supports the 14th gear 16e and the 15th gear 16f, which mesh with the 8th gear 10a and the 10th gear 10b, which are integrated with the input shaft 10, respectively, and also has a third sleeve 14j. In other words, the input shaft 10 and the output shaft 12 can be connected via the third gear shift mechanism 5 and the first gear shift mechanism 3, and each is capable of two-stage gear shifting, so four gear ratios M-1, M-2, M-3, and M-4, which will be described later, can be obtained.

[0047] Although Example 3 has three sleeves, it can be operated with a total of two actuators, similar to Example 2.

[0048] The above describes the configuration of this embodiment. For the purpose of the explanation described later, the gear ratios mentioned above will be set as follows as an example. Note that the gear ratio of the third transmission mechanism 5 is the same as the gear ratio (Le, He) of the second transmission mechanism 4. Lm:2.833 Hm:0.879 Le: 2,500 He: 1.927 ρ:0.50

[0049] Next, the operation and function of Example 3 will be described. Figure 6 shows the operation table for Example 3, corresponding to Figures 2 and 4. As described above, the addition of a two-stage third gear shift mechanism 5 by shifting the third sleeve 28d (S3) increases the number of high-efficiency drive modes. Specifically, for M-1 and M-2, the first gear shift mechanism 3 is set to Lm and the low (Le) and high (He) settings of the third gear shift mechanism 5 are combined, while for M-3 and M-4, the first gear shift mechanism 3 is set to Hm and the low (Le) and high (He) settings of the third gear shift mechanism 5 are combined to obtain the respective gear ratios. The switching operation for each high-efficiency drive mode, excluding H-Hs, is the same as in Examples 1 and 2.

[0050] The above describes the operation of Example 3. In addition to the effects described in Examples 1 and 2, this example offers the following advantages. Specifically, the inclusion of the third transmission mechanism 5 increases the number of modes for high-efficiency driving. M-1 has a gear ratio comparable to the first gear of a typical 7-speed automatic transmission, allowing for full-power acceleration from the engine 1. M-3 and M-4 enable highly efficient driving for cruising in urban areas. As a result, acceleration performance and fuel efficiency are further improved. [Examples]

[0051] Next, an automobile drive system of Embodiment 4 of the present invention will be described. Figure 7 is a skeleton diagram of the main parts of the automobile drive system according to Embodiment 4 of the present invention. Here, the parts that differ from Embodiments 1 to 3 will be described in detail, and parts that are substantially the same will be given basically the same names and reference numerals and their descriptions will be omitted. Embodiment 4 is a drive system suitable for a so-called FR type, in which the engine 1 is located at the front of the automobile and drives the rear wheels, and the input shaft 10, output shaft 12, planetary gear 20, first MG 30, and second MG 32 are arranged on the same axis. Although the arrangement of each shaft and each gear is different, the configuration and function of the first transmission mechanism 3, second transmission mechanism 4, and third transmission mechanism 5 are basically the same as in Embodiment 3.

[0052] In other words, in the axial direction, the first MG30, planetary gear 20, gear train 6, and second MG32 are arranged in that order from the engine 1 side. The first to third axes, which are arranged in parallel from the top in Figure 7, are as follows: the first axis is the second counter axis 18, connected to the output axis 12 by a coupling gear pair 12d. The second axis consists of the input axis 10 and the output axis 12 as described above. The third axis is the motor drive axis 16, connected to the second MG32 by a drive gear 32a and a driven gear 16g.

[0053] A first gear shift mechanism 3 is positioned between the motor drive shaft 16 and the output shaft 12, a second gear shift mechanism 4 is positioned between the input shaft 10 and the second counter shaft 18, and a third gear shift mechanism is positioned between the input shaft 10 and the motor drive shaft 16. Their functions are basically the same as in the third embodiment. Although not specifically shown in the diagram, a third gear, commonly called a power take-off, may be attached to the sixth gear 14b, which rotates in conjunction with the second MG 32, to extract power externally for use in applications other than driving an automobile.

[0054] The above describes the configuration of this embodiment. Here, the gear ratios described above are the same as those in Embodiment 3.

[0055] Next, the operation and function of Example 4 will be described. Figure 8 shows the operation table for Example 4, corresponding to Figure 6. The operation and function are basically the same as in Example 3, except that the shift direction of the first sleeve 14d (S1) is reversed and the gear ratio values ​​are slightly different, so a detailed explanation will be omitted.

[0056] The above describes the operation of Example 4. The effects in this example are basically the same as those in Example 3, except that it is a drive device suitable for the FR type, so the explanation will be omitted.

[0057] The automotive drive system of the present invention can be implemented in a manner that combines control features such as optimal setting of the gear ratio, optimization of the arrangement of shafts, gears and bearings, and a method for selecting the drive mode, based on the general knowledge of those skilled in the art. [Industrial applicability]

[0058] The automotive drive system of the present invention can be applied to passenger cars and commercial vehicles that require smooth gear changes, particularly low running costs, and reduced environmental impact. However, it is not limited to these vehicles and can be applied to a variety of vehicles utilizing internal combustion engines and motor-generators. [Explanation of Symbols]

[0059] 1 Engine 3. First transmission mechanism 4. Second transmission mechanism 5. Third gear mechanism 10 input axes 12 Output shafts 20 Planetary gears 30. First Motor Generator (MG1) 32. Second Motor Generator (MG2)

Claims

1. An input shaft capable of receiving power from the engine, Output shaft and, First motor generator, The second motor generator, A planetary gear system consisting of three rotating elements: a sun gear, a ring gear, and a carrier. A first gear mechanism and a second gear mechanism that obtain high and low gear ratios, respectively, It consists of, The input shaft is connected to the carrier, the output shaft is connected to the ring gear and can be connected to the second motor-generator, and the first motor-generator is connected to the sun gear. An automobile drive system characterized by having the first transmission mechanism between the output shaft and the second motor-generator, and the second transmission mechanism between the input shaft and the output shaft.

2. The automobile drive system according to claim 1, characterized in that the automobile drive system has at least four shafts, which are arranged in parallel and designated as the first shaft, second shaft, third shaft, and fourth shaft in order from one end, the first shaft is the output shaft, the second shaft is the input shaft and the planetary gear and first motor-generator are arranged thereon, the third shaft is the counter shaft and connected to the ring gear, the fourth shaft is the motor drive shaft and connected to the second motor-generator, the first transmission mechanism is arranged between the third shaft and the fourth shaft, and the second transmission mechanism is arranged between the first shaft and the second shaft.

3. The automobile drive device according to claim 2, characterized in that the input shaft and the motor drive shaft can be connected via a gear on the counter shaft.

4. The automobile drive device according to claim 2, characterized in that a third gear shift mechanism having two gear ratios is provided between the input shaft and the motor drive shaft.

5. The automobile drive system according to claim 4, wherein the automobile drive system has at least three shafts, which are arranged in parallel and designated as a first shaft, a second shaft, and a third shaft from one end, the first shaft is the output shaft, the second shaft is the input shaft and a ring gear shaft integrated with the ring gear and the first motor generator connected to the input shaft via the planetary gear are arranged thereon, the third shaft is the motor drive shaft and the first transmission mechanism is arranged between the ring gear shaft and the third shaft, the second transmission mechanism is arranged between the first shaft and the second shaft, and the third transmission mechanism is arranged between the second shaft and the third shaft.

6. The automobile drive system according to claim 4, characterized in that the automobile drive system has at least three shafts, which are arranged in parallel and designated as a first shaft, a second shaft, and a third shaft in order from one end, the first shaft is the motor drive shaft, the second shaft is the input shaft and the output shaft, the planetary gears, the first motor generator and the second motor generator are arranged thereon, the third shaft is the second counter shaft connected to the output shaft and the first gear shift mechanism is arranged between the first shaft and the output shaft, the second gear shift mechanism is arranged between the second shaft and the third shaft and the third gear shift mechanism is arranged thereon.

7. The automobile drive system according to any one of claims 1 to 6, wherein the output shaft drives the front wheels of the automobile, and the system includes a second output shaft having a third motor-generator capable of driving the rear wheels with the third motor-generator, and in cruising conditions, the first transmission mechanism is set to neutral and the power generated by the first motor-generator is supplied to the third motor-generator.

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