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 gear shift mechanism 3 and a second gear shift mechanism 4, respectively, which obtain high and low gear ratios. The input shaft 10 is connected to or can be connected to the carrier 28, the output shaft 12 is connected to the ring gear 24 and can be connected to the second MG 32, the first MG 30 is connected to the sun gear 22, the first gear shift mechanism 3 is located between the output shaft 12 and the second MG 32, and the second gear shift 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 of 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 or can be 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 arrangement of each axis in Example 3. [Figure 7] This is a diagram showing the operation table for Example 3. [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, the carrier 28 is connected to the input shaft 10, and the ring gear 24 is integrated with the first gear 24a.

[0013] The first gear 24a is connected to the output shaft 12 via the second gear 12a which 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 an 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 the sixth gear 14b and seventh gear 14c 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 and operation common to other sleeves described later will be explained using the first sleeve 14d as an example. Specifically, the first sleeve 14d is positioned radially outward of the first hub 14e, which is integrated with the counter shaft 14, and its rotational direction is integrated with the first hub 14e, while its axial direction is shiftable. The dog teeth 14f and 14g formed on the surfaces of the sixth gear 14b and the seventh gear 14c facing the first sleeve 14d, respectively, selectively engage with one of them when the first sleeve 14d shifts. Figure 1 shows the neutral position, where neither the dog teeth 14f nor the dog teeth 14g are engaged. The engagement between the first sleeve 14d and 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 it is 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 signs such as hubs and dog teeth are omitted.

[0017] The input shaft 10 has the eighth gear 10a rotatably supported thereon, 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 in the axial direction. 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 speed change 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 sake of the following description, the above gear ratios are taken as examples 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 driven 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, providing two types of drive: H-lo and H-hi. The HV mode also includes ML and MH modes, which are not electromechanical CVTs but are mechanically driven from the input shaft 10 by the second transmission mechanism 4.

[0025] First, although it 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 H-lo or H-hi in the operating 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 H-lo 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 0. 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. ML is a mechanical drive 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 H-hi.

[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 H-lo and H-hi 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 H-hi, the gear ratio decreases, and the rotational speed of the first MG30 decreases until it stops. This state is called H-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 as described above, during cruising such as H-hi, when the second MG 32 is driven in an inefficient state at low load operation, 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 this regard, the parking gear 12e is integrated with the second gear 12a. The other configurations are basically the same as in Embodiment 1.

[0040] The above describes the configuration of this embodiment. Here, the gear ratios described in Embodiment 1 are used as an example as follows. Lm:2.40 Hm:0.87 Le:2.20 He: 1.60 ρ:0.35

[0041] Next, regarding the operation and function of Example 2, Figure 4 shows the operation table. As mentioned above, the configuration of the second transmission mechanism 4 is different, and the gear ratios for each drive mode are different in relation to the gear ratios described above. Other than this, it is basically the same as in Example 1, so a detailed explanation will be omitted.

[0042] 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. As a result, by optimizing each gear ratio to match the vehicle and engine, acceleration performance and fuel efficiency are improved. [Examples]

[0043] 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 part of the automobile drive system according to Embodiment 3 of the present invention, and Figure 6 shows the arrangement of each shaft in Figure 5 as viewed from the engine 1 side. Note that Figure 5 is drawn as a cross-section along line AA in Figure 6, and the second counter shaft 18, which will be described later, is drawn further down. Although they are separated in Figure 5, the 8th gear 10a and the 16th gear 10f and the 12th gear 18a and the 13th gear 18b are meshing with each other. Also, in Figure 6, the reference numerals of each shaft or symbolic rotating body are attached to the center of each shaft, and the outlines of the main gears are shown with dashed lines. Furthermore, Figure 6 shows the PTO gear 19, which will be described later, and is not shown in Figure 5.

[0044] This section will focus on the differences between Examples 1 and 2, and will omit explanations for parts that are substantially the same, using essentially the same names and reference numerals. Example 3 has a configuration similar to Example 2, with the second MG32 mounted on the fifth shaft, but with an additional second counter shaft 18 mounted in the position shown in Figure 6, and a new third speed control mechanism 5 mounted on the second counter shaft 18, input shaft 10, and carrier shaft 28a. Furthermore, the input shaft 10 and the motor drive shaft 16 can be connected via the counter shaft 14. These will be described in detail below.

[0045] First, the second counter shaft 18 integrates the 12th gear 18a and the 13th gear 18b. The 12th gear 18a meshes with the 8th gear 10a on the input shaft 10, and the 13th gear 18b meshes with the 16th gear 10f, which is integrated with the 15th gear 10e on the carrier shaft 28a. The third sleeve 28d, provided on the carrier shaft 28a, connects to the 16th gear 10f when shifted to the left, and to the input shaft 10 when shifted to the right, thereby obtaining the low (Lc) and high (Hc) gear ratios. These constitute the third gear shift mechanism of the present invention. Furthermore, the 15th gear 10e and the 16th gear 10f mesh with the 9th gear 12c and the 11th gear 12d, supported on the output shaft 12. Similar to the case of Embodiment 2, the second sleeve 10d, positioned on the output shaft 12, is shifted to obtain the low (Le) and high (He) gear ratios, thus constituting the second gear shift mechanism of the present invention.

[0046] Furthermore, the eighth gear 10a meshes with the seventeenth gear 14h, which is supported on the counter shaft 14, and the fourth sleeve 14j provided on the seventh gear 14c shifts to the right, connecting the seventeenth gear 14h and the seventh gear 14c. As a result, the input shaft 10 and the motor drive shaft 16 are connected via the seventeenth gear 14h and the seventh gear 14c. In this way, the torque of the input shaft 10 can drive the output shaft 12 via the first speed change mechanism 3.

[0047] Embodiment 3 has four sleeves, but the first sleeve 14d and the fourth 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 three actuators.

[0048] Next, Figure 6 shows only the PTO gear 19, which is retrofitted to mesh with the fifth gear 16c in Figure 5, but detailed illustrations have been omitted. Its function will be described later.

[0049] The above describes the configuration of this embodiment. For the purpose of the explanation described later, the gear ratios mentioned above will be used as an example as follows. Lm:2.43 Hm:0.83 Le:2.40 He: 1.73 Lc (rotational speed of input shaft 10 / rotational speed of carrier 28): 2.00 Hc (same as above): 1.0 (direct connection) ρ:0.45

[0050] Next, the operation and function of Embodiment 3 will be described. Figure 7 shows the operation table for Embodiment 3, corresponding to Figures 2 and 4. As described above, a third sleeve 28d (S3) and a fourth sleeve 16f (S4) have been added. Note that arrows in parentheses indicate that the sleeves are shifting but are not involved in power transmission. Here again, explanations of parts that are basically the same as in Embodiments 1 and 2 will be omitted. Also, what was said in the description of the configuration above will be omitted. That is, the EV mode and the switching of the first transmission mechanism 3 in CVT drive are the same as in Embodiments 1 and 2, so the explanation will be omitted.

[0051] First, the CVT drive has two gears, HL and HH, because the third transmission mechanism 5 intervenes between the input shaft 10 and the carrier 28 to provide two gears, low (Lc) and high (Hc). Then, the first transmission mechanism 3 of the second MG 32 combines these with two gears, low (Lm) and high (Hm). Basically, these are combinations of low gears and high gears, but the drive is performed in three types: HL, which is a combination of low gears Lc and Lm; H-Lh, which is a combination of Lc and Hm; and HH, which is a combination of high gears.

[0052] Furthermore, the ML and MH modes provided by the highly efficient second transmission mechanism 4 are basically the same as in the case of Embodiment 2, but the M-LL and M-HH modes, which are performed by shifting the fourth sleeve 16f, differ from those in Embodiments 1 and 2. Specifically, when the gear ratio reaches 4.06 during HL driving, shifting the fourth sleeve 14j causes the torque transmitted from the input shaft 10 to the motor drive shaft 16 to drive the output shaft 12 via the first transmission mechanism 3 at a gear ratio of 4.06. Similarly, when the gear ratio reaches 1.73 during HH driving, shifting the fourth sleeve 14j switches to M-HH driving with a gear ratio of 1.73. M-LL and M-HH have distinctive features. M-LL allows driving at the full power of the engine 1 regardless of the capacity of the first MG 30, and M-HH allows switching of the third transmission mechanism 5 during that driving.

[0053] Furthermore, in HL, the gear ratio of 1.40 at which the first MG30 stops, as explained in Example 1, is the H-Ls gear ratio, which represents high-efficiency drive. Although this gear ratio and the M-HH gear ratio mentioned earlier are almost the same value, they have different roles. That is, H-Ls enables high-efficiency driving when continuously driving at a gear ratio around 1.40, while M-HH is used when switching the third transmission mechanism 5 from low to high. The four high-efficiency drive positions with sleeve shifts shown in Figure 7 can all be performed without changing the gear ratio, whether switching from CVT drive to high-efficiency drive or vice versa.

[0054] Next, we will explain the power take-off, commonly referred to as PTO, as mentioned above. Power is extracted externally by a PTO gear 19, which is retrofitted to mesh with the fifth gear 16c, which can be driven by the second motor / gear 32, and is used for purposes other than driving the automobile. This PTO gear 19 can be driven in the following ways: Firstly, when the first sleeve 14d and the fourth sleeve 16e are in the neutral position, it can be driven by the second motor / gear 32 by supplying power from the battery. Secondly, by shifting the third sleeve to the left and rotating the engine 1, the power generated by the first motor / gear 30 is supplied to the second motor / gear 32, allowing for long-term power extraction regardless of the battery capacity. In the above cases, power can be extracted at any rotational speed and direction while the vehicle is stationary. Furthermore, while driving, power can be extracted regardless of the drive mode, as the fifth gear 16c is rotating.

[0055] The above describes the operation of Embodiment 3. In addition to the effects described in Embodiments 1 and 2, this embodiment offers the following advantages. Specifically, by providing a third transmission mechanism 5 and enabling the connection between the input shaft 10 and the motor drive shaft 16, the drive in HV mode becomes more versatile and a large driving torque can be achieved. For example, in HV mode, two gear ratios, low (Lc) and high (Hc), are added to the CVT drive, increasing the driving torque and broadening the degree of fuel efficiency improvement. Also, in M-LL mode, the engine 1 can be driven at full power with a gear ratio equivalent to the first gear in a typical automatic transmission. Furthermore, when the engine 1 is stopped during high-speed driving in MH or H-Hs mode, the third sleeve 28d can be set to neutral, preventing the first MG 30 from rotating at high speed, which is advantageous for fuel efficiency. These features are suitable for driving commercial vehicles or SUVs, which have a large range of fluctuations in the driving load. This configuration is also suitable for equipping such vehicles with a PTO.

[0056] 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. It is also possible to provide a one-way clutch between the 15th gear 28b and the carrier shaft 28a in parallel with the third sleeve 28d. [Industrial applicability]

[0057] 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]

[0058] 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 or connectable to the carrier, the output shaft is connected to the ring gear and connectable 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 a third transmission mechanism having two gear ratios is provided between the input shaft and the carrier.

3. 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.

4. The automobile drive unit according to claim 2, characterized in that the automobile drive unit has at least four shafts, which are arranged in parallel and designated as a first shaft, second shaft, third shaft, and fourth shaft in order from one end, a second counter shaft adjacent to the second shaft, the first shaft being the output shaft, the second shaft being the input shaft and arranging the planetary gear and the first motor-generator thereon, the third shaft being the first counter shaft and connected to the ring gear, the fourth shaft being the motor drive shaft and connected to the second motor-generator, the first gear shift mechanism being arranged between the third shaft and the fourth shaft and connecting the input shaft and the second counter shaft, the second gear shift mechanism being arranged between the second counter shaft and the ring gear, and the third gear shift mechanism being arranged between the second counter shaft and the carrier.

5. The automobile drive device according to claim 4, characterized in that the input shaft and the motor drive shaft can be connected via a gear on the counter shaft.

6. The automobile drive system according to any one of claims 1 to 5, 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.

7. The automobile drive system according to any one of claims 4 to 6, characterized in that a power take-off device is attached to one of the gears that rotate in conjunction with the second motor generator.

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