Vehicle drive device

Abstract

To enhance the power performance of a hybrid vehicle.SOLUTION: A vehicle driving apparatus mounted on a hybrid vehicle includes: an engine coupled to wheels via a power transmission path; a transmission mechanism provided on the power transmission path; a motor generator provided on a path coupling the engine and the transmission mechanism in the power transmission path; a first power transmission mechanism provided on a path coupling the engine and the motor generator in the power transmission path; and a second power transmission mechanism provided on a path coupling the motor generator and the transmission mechanism in the power transmission path.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a vehicle drive device mounted on a hybrid vehicle.

Background Art

[0002] Hybrid vehicles are equipped with a vehicle drive device having an engine and a motor generator as power sources (see Patent Documents 1 and 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in order to improve the power performance of a hybrid vehicle while ensuring the fuel consumption performance of the hybrid vehicle, it is necessary to increase the motor torque. In this case, it is common to increase the size of the motor generator, but increasing the size of the motor generator is a factor that increases the cost and weight of the hybrid vehicle. For this reason, it is required to improve the power performance of the hybrid vehicle while suppressing an increase in the size of the motor generator.

[0005] An object of the present invention is to improve the power performance of a hybrid vehicle while suppressing an increase in the size of a motor generator.

Means for Solving the Problems

[0006] A vehicle drive device according to an embodiment is a vehicle drive device mounted on a hybrid vehicle, and includes an engine connected to wheels via a power transmission path, and provided in the power transmission path , comprising an input shaft for speed change and an output shaft for speed change A transmission mechanism, and a motor generator provided in a path connecting the engine and the transmission among the power transmission paths Input shaft and a first power transmission mechanism provided in a path connecting the engine and the motor generator among the power transmission paths, including a first large-diameter rotating body connected to the engine and a first small-diameter rotating body connected to the motor generator It has. The vehicle drive device A first power transmission mechanism provided in a path connecting the engine and the motor generator among the power transmission paths, including a first large-diameter rotating body connected to the engine and a first small-diameter rotating body connected to the motor generator It has. The vehicle drive device A second power transmission mechanism provided in a path connecting the motor generator and the transmission among the power transmission paths, including a second small-diameter rotating body connected to the motor generator and a second large-diameter rotating body connected to the transmission Input shaft A second power transmission mechanism provided in a path connecting the motor generator and the transmission among the power transmission paths, including a second small-diameter rotating body connected to the motor generator and a second large-diameter rotating body connected to the transmission Input shaft A second power transmission mechanism provided in a path connecting the motor generator and the transmission among the power transmission paths, including a second small-diameter rotating body connected to the motor generator and a second large-diameter rotating body connected to the transmission It has. The engine, the first power transmission mechanism, the second power transmission mechanism, and the input shaft for speed change are arranged in series.

Advantages of the Invention

[0007] The vehicle drive device according to one embodiment has a first power transmission mechanism provided in a path connecting the engine and the motor generator, and a second power transmission mechanism provided in a path connecting the motor generator and the transmission mechanism. Thereby, while suppressing the increase in size of the motor generator, the power performance of the hybrid vehicle can be improved.

Brief Description of the Drawings

[0008]

Figure 1

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Embodiments for Carrying Out the Invention

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, the same or substantially the same components and elements are denoted by the same reference numerals, and repeated descriptions are omitted.

[0010] [Power Train Configuration] FIG. 1 is a diagram showing a configuration example of a hybrid vehicle 11 equipped with a vehicle drive device 10 according to an embodiment of the present invention. As shown in FIG. 1, the hybrid vehicle 11 is equipped with a vehicle drive device 10 constituted by a power train 12 or the like. The power train 12 has an engine 13, a motor generator 14, and a transmission mechanism 15. Further, a rear wheel 19r is connected to a rear wheel output shaft 16 of the power train 12 via a propeller shaft 17 and a rear differential mechanism 18. Furthermore, a front differential mechanism 20 is incorporated in the power train 12, and a front wheel 19f is connected to the front differential mechanism 20. Note that the illustrated power train 12 is an all-wheel drive power train that drives both the front wheels 19f and the rear wheels 19r, but is not limited thereto. For example, it may be a front-wheel drive power train that drives only the front wheels 19f, or a rear-wheel drive power train that drives only the rear wheels 19r.

[0011] FIG. 2 is a diagram showing a configuration example of the power train 12. As shown in FIG. 2, the power train 12 has an engine 13, a motor generator 14, a transmission mechanism 15, a forward / reverse switching mechanism 21, and a center differential mechanism 22. A torque converter 24 is connected to a crankshaft 23 of the engine 13, and a rotor 14r of the motor generator 14 is connected to a turbine shaft 25 of the torque converter 24 via a first gear train 31 and an engine clutch 26. Further, a transmission input shaft 27 of the transmission mechanism 15 is connected to the rotor 14r of the motor generator 14 via a second gear train 32. Note that the illustrated transmission mechanism 15 is an automatic transmission mechanism constituted by a plurality of planetary gear trains 40, clutches 41, and brakes 42, but is not limited thereto, and may be a transmission mechanism such as a continuously variable transmission mechanism composed of a pair of pulleys.

[0012] On the speed change output shaft 43 of the speed change mechanism 15, a forward and reverse switching mechanism 21 composed of a planetary gear train 44, a forward clutch 45, and a reverse brake 46 is connected. Further, on the forward and reverse output shaft 47 of the forward and reverse switching mechanism 21, a center differential mechanism 22 composed of a compound planetary gear train 48 and a differential limiting clutch 49 is connected. A hollow shaft 51 is provided on the differential carrier 50 of the center differential mechanism 22, and a front wheel output shaft 53 is connected to this hollow shaft 51 via a transfer gear train 52. A pinion 54 is provided at the tip of the front wheel output shaft 53, and a bevel gear 55 of the front differential mechanism 20 meshes with this pinion 54. Further, a front wheel 19f is connected to a front axle 56 extending from the front differential mechanism 20. Note that the pinion 54 and the bevel gear 55 that mesh with each other are configured as a spiral bevel gear or a hypoid (registered trademark) gear having curved teeth. Also, a rear wheel 19r is connected to the rear wheel output shaft 16 of the center differential mechanism 22 via a propeller shaft 17 and a rear differential mechanism 18 as shown in FIG. 1 described above.

[0013] FIG. 3 is a diagram briefly showing the configuration of the vehicle drive device 10. As shown in FIG. 3, the engine 13 and the center differential mechanism 22 are connected to each other via a power transmission path 60 including a torque converter 24, a first gear train 31, an engine clutch 26, a motor generator 14, a second gear train 32, a speed change mechanism 15, a forward and reverse switching mechanism 21, and the like. Also, the center differential mechanism 22 and the front wheel 19f are connected to each other via a power transmission path 61 including a transfer gear train 52, a front wheel output shaft 53, and a front differential mechanism 20. Further, the center differential mechanism 22 and the rear wheel 19r are connected to each other via a power transmission path 62 including a propeller shaft 17 and a rear differential mechanism 18.

[0014] That is, the engine 13 and the front wheels (wheels) 19f are connected to each other via a power transmission path 70 constituted by power transmission paths 60 and 61. A transmission mechanism 15 is provided in this power transmission path 70, and a motor generator 14 is provided in a path 70a that connects the engine 13 and the transmission mechanism 15 among the power transmission path 70. Further, a first gear train 31 is provided in a path 70b that connects the engine 13 and the motor generator 14 among the power transmission path 70, and a second gear train 32 is provided in a path 70c that connects the motor generator 14 and the transmission mechanism 15 among the power transmission path 70. Furthermore, an engine clutch (clutch mechanism) 26 is provided in a path 70d that connects the first gear train 31 and the motor generator 14 among the power transmission path 70, and a front differential mechanism (differential mechanism) 20 is provided in a path 70e that connects the transmission mechanism 15 and the front wheels 19f among the power transmission path 70.

[0015] Similarly, the engine 13 and the rear wheels (wheels) 19r are connected to each other via a power transmission path 71 constituted by power transmission paths 60 and 62. A transmission mechanism 15 is provided in this power transmission path 71, and a motor generator 14 is provided in a path 71a that connects the engine 13 and the transmission mechanism 15 among the power transmission path 71. Further, a first gear train 31 is provided in a path 71b that connects the engine 13 and the motor generator 14 among the power transmission path 71, and a second gear train 32 is provided in a path 70c that connects the motor generator 14 and the transmission mechanism 15 among the power transmission path 71. Furthermore, an engine clutch 26 is provided in a path 71d that connects the first gear train 31 and the motor generator 14 among the power transmission path 71.

[0016] In addition, the first gear train (first power transmission mechanism) 31 provided in the paths 70b and 71b connecting the engine 13 and the motor generator 14 includes a first small-diameter gear (first small-diameter rotating body) 31a connected to the motor generator 14 via the engine clutch 26, and a first large-diameter gear (first large-diameter rotating body) 31b connected to the engine 13 via the torque converter 24. The first small-diameter gear 31a and the first large-diameter gear 31b that constitute the first gear train 31 mesh with each other, and the engine 13 and the motor generator 14 are connected to each other via the first gear train 31. Also, since the number of teeth of the first large-diameter gear 31b is more than the number of teeth of the first small-diameter gear 31a, the rotational speed of the motor generator 14 (hereinafter referred to as the motor rotational speed) is higher than the rotational speed of the engine 13 (hereinafter referred to as the engine rotational speed). For example, the gear ratio of the first gear train 31 (First gear ratio) is set to "0.5".

[0017] In addition, the second gear train (second power transmission mechanism) 32 provided in the path connecting the motor generator 14 and the transmission mechanism 15 includes a second small-diameter gear (second small-diameter rotating body) 32a connected to the rotor 14r of the motor generator 14, and a second large-diameter gear (second large-diameter rotating body) 32b connected to the transmission input shaft 27 of the transmission mechanism 15. The second small-diameter gear 32a and the second large-diameter gear 32b that constitute the second gear train 32 mesh with each other, and the motor generator 14 and the transmission mechanism 15 are connected to each other via the second gear train 32. Also, since the number of teeth of the second large-diameter gear 32b is more than the number of teeth of the second small-diameter gear 32a, the motor rotational speed is higher than the rotational speed of the transmission input shaft 27 (hereinafter referred to as the transmission input rotational speed). For example, the gear ratio of the second gear train 32 (Second gear ratio) is set to "2.0".

[0018] [Engine Control] FIG. 4 is a diagram showing an example of a power train 12 and a control system 80 included in a vehicle drive device 10. As shown in FIG. 4, a throttle valve 82 for adjusting the intake air amount is provided in an intake manifold 81 of an engine 13. Further, an injector 83 for injecting fuel into an intake port and a cylinder is provided in the engine 13, and an ignition device 84 including an igniter and an ignition plug is provided. Furthermore, a starter motor 85 for starting and rotating a crankshaft 23 via a torque converter 24 is provided in the engine 13. In addition, an engine control unit CU1, which is an electronic control unit, is connected to the throttle valve 82, the injector 83, the ignition device 84, the starter motor 85, etc. to control the operating state of the engine 13.

[0019] [Hydraulic control] As shown in FIG. 4, a valve unit 86 including a plurality of electromagnetic valves and oil passages is provided in the power train 12 to control an engine clutch 26, a transmission mechanism 15, etc. of the power train 12. Further, an oil pump 87 driven by the engine 13 and a transmission input shaft 27 and an oil pump 89 driven by an electric motor 88 are provided in the power train 12. The hydraulic oil discharged from the oil pumps 87 and 89 has its supply destination, pressure, etc. controlled by the valve unit 86 and is supplied to the engine clutch 26, the transmission mechanism 15, etc. In addition, a transmission control unit CU2, which is an electronic control unit, is connected to the valve unit 86 and the electric motor 88 to control the operating state of the power train 12 using the valve unit 86 and to control the operating state of the oil pump 89 using the electric motor 88.

[0020] As shown in Fig. 2, the oil pump 87 is connected to the pump shell 91 of the torque converter 24 via a chain mechanism 90 equipped with a one-way clutch. Also, the oil pump 87 is connected to the transmission input shaft 27 via a chain mechanism 92 equipped with a one-way clutch. When the engine 13 is in an operating state, a driving force is transmitted from the pump shell 91 to the oil pump 87 via the chain mechanism 90. On the other hand, even when the engine 13 stops and the transmission input shaft 27 rotates, a driving force is transmitted from the transmission input shaft 27 to the oil pump 87 via the chain mechanism 92.

[0021] [Battery Control] As shown in Fig. 4, a battery module 94 is connected to the motor generator 14 via an inverter 93. A plurality of battery cells 96 constituting a battery 95 such as a lithium-ion battery are incorporated in the battery module 94. Further, the battery module 94 is provided with a main relay 97 for opening and closing an energization line, and a battery sensor 98 for detecting the charge and discharge current, terminal voltage, temperature, etc. of the battery 95. Also, a battery control unit CU3, which is an electronic control unit, is connected to the battery module 94. The battery control unit CU3 has a function of monitoring the charge and discharge of the battery 95 and controlling the main relay 97 and the like. Also, the battery control unit CU3 has a function of calculating the state of charge (SOC) of the battery 95 based on the charge and discharge current, terminal voltage, etc. detected by the battery sensor 98. Note that the SOC of the battery 95 is a ratio indicating the remaining electrical amount of the battery 95, and is the ratio of the stored electrical amount to the full charge capacity of the battery 95.

[0022] [Motor Control] As shown in FIG. 4, a motor control unit CU4, which is an electronic control unit, is connected to an inverter 93 connected to a stator 14s of a motor generator 14. The motor control unit CU4 controls the operating state of the motor generator 14 by controlling the inverter 93 composed of a plurality of switching elements and the like. When controlling the motor generator 14 to the power running state, the DC power from the battery 95 is converted into AC power via the inverter 93 and supplied to the stator 14s. On the other hand, when controlling the motor generator 14 to the power generation state, the AC power from the stator 14s is converted into DC power via the inverter 93 and supplied to the battery 95.

[0023] [Control System] As shown in FIG. 4, a control system 80 composed of a plurality of electronic control units is provided in the vehicle drive device 10 to control the power train 12. As the electronic control units constituting the control system 80, there are the above-described engine control unit CU1, transmission control unit CU2, battery control unit CU3, and motor control unit CU4. Further, as an electronic control unit constituting the control system 80, there is a vehicle control unit CU5 that outputs control signals to each of the control units CU1 to CU4. These control units CU1 to CU5 are communicably connected to each other via an in-vehicle network 100 such as a CAN (Controller Area Network).

[0024] The vehicle control unit CU5 sets the operation target of the power train 12 based on the input information from various control units CU1 to CU4 and various sensors described later. Then, control signals corresponding to the operation target of the power train 12 are generated, and these control signals are output to various control units. As sensors connected to the vehicle control unit CU5, there is a vehicle speed sensor 101 that detects the vehicle speed, which is the traveling speed of the hybrid vehicle 11, an accelerator sensor 102 that detects the operation amount of the accelerator pedal, and a brake sensor 103 that detects the operation amount of the brake pedal. In addition, a start switch 104 operated by the driver when starting the control system 80 is connected to the vehicle control unit CU5.

[0025] Figure 5 is a diagram briefly showing the basic structure of each control unit CU1 to CU5. As shown in Figure 5, each control unit CU1 to CU5 has a microcontroller 112 in which a processor 110, a memory 111, etc. are incorporated. A predetermined program is stored in the memory 111, and the program instruction set is executed by the processor 110. The processor 110 and the memory 111 are connected to be communicable with each other. In the illustrated example, one processor 110 and one memory 111 are incorporated in the microcontroller 112, but it is not limited to this, and a plurality of processors 110 may be incorporated in the microcontroller 112, or a plurality of memories 111 may be incorporated in the microcontroller 112.

[0026] In addition, each control unit CU1 to CU5 is provided with an input conversion circuit 113, a drive circuit 114, a communication circuit 115, an external memory 116, a power supply circuit 117, and the like. The input conversion circuit 113 converts a signal input from various sensors into a signal that can be input to the microcontroller 112. The drive circuit 114 generates a drive signal for an actuator such as the valve unit 86 described above based on a signal output from the microcontroller 112. The communication circuit 115 converts a signal output from the microcontroller 112 into a communication signal directed to another control unit. Further, the communication circuit 115 converts a communication signal received from another control unit into a signal that can be input to the microcontroller 112. Furthermore, the power supply circuit 117 supplies a stable power supply voltage to the microcontroller 112, the input conversion circuit 113, the drive circuit 114, the communication circuit 115, the external memory 116, and the like. Also, data and the like that should be retained even when not powered are stored in the external memory 116 such as a non-volatile memory.

[0027] [Travel Mode] FIG. 6 is a travel mode map showing an example of the execution regions of the EV mode and the HEV mode. FIG. 7 is a diagram showing the execution status of the EV mode, and FIG. 8 is a diagram showing the execution status of the HEV mode. Also, FIG. 9 is a diagram showing the vehicle acceleration in the EV mode, and FIG. 10 is a diagram showing the high-efficiency operation region of the motor generator 14.

[0028] The control system 80 has, as driving modes, an EV (Electric Vehicle) mode and an HEV (Hybrid Electric Vehicle) mode. The EV mode is a driving mode in which the engine 13 is stopped and the motor generator 14 is operated, and the HEV mode is a driving mode in which the engine 13 and the motor generator 14 are operated. As shown in FIG. 6, a boundary line L1 that demarcates the execution regions of the EV mode and the HEV mode is set in the driving mode map. Note that the required driving force shown in FIG. 6 is the driving force required for the power train 12. The control system 80 can set the required driving force based on, for example, the accelerator opening, which is the operation amount of the accelerator pedal. That is, as the accelerator opening increases, the required driving force is set larger, and as the accelerator opening decreases, the required driving force is set smaller.

[0029] As shown in FIG. 6, when the operation region based on the required driving force and the vehicle speed is in the EV region below the boundary line L1, the EV mode is selected by the control system 80. As shown in FIG. 7, when the EV mode is selected, the control system 80 controls the engine clutch 26 to the released state, controls the engine 13 to the stopped state, and controls the motor generator 14 to the power running state. Thereby, as indicated by the arrow X1 in FIG. 7, the power running torque from the motor generator 14 (hereinafter referred to as the motor torque) can be transmitted to the front and rear wheels 19f, 19r, and the hybrid vehicle 11 can be driven using the motor generator 14. Note that when the hybrid vehicle 11 is decelerated, the motor generator 14 is controlled to the regenerative power generation state, and the kinetic energy of the hybrid vehicle 11 is converted into electric energy and stored in the battery 95.

[0030] Here, the motor generator 14 and the transmission mechanism 15 are connected to each other via the second gear train 32. As a result, since the motor torque can be increased by the second gear train 32, it is possible to suppress the increase in the size of the motor generator 14 and enhance the acceleration performance, i.e., the power performance, in the EV mode. That is, as shown by the solid line L2 in FIG. 9, the vehicle acceleration in the low vehicle speed range can be significantly increased. Note that the dashed line L3 shown in FIG. 9 indicates the vehicle acceleration of a hybrid vehicle in which the motor generator 14 and the transmission mechanism 15 are directly connected, i.e., the vehicle acceleration of a hybrid vehicle not equipped with the second gear train 32.

[0031] Also, since the motor generator 14 and the transmission mechanism 15 are connected via the second gear train 32, the motor speed can be increased from the low vehicle speed range. Here, as shown by the hatching in FIG. 10, the energy efficiency of the motor generator 14 is higher in the high rotation range α than in the low rotation range. That is, by increasing the motor speed using the second gear train 32, the motor generator 14 can be controlled to approach the high rotation range α from the low vehicle speed range. Thereby, the energy efficiency of the motor generator 14 can be increased, and the fuel consumption performance of the hybrid vehicle 11 can be enhanced.

[0032] Also, as shown in FIG. 6, when the driving region based on the required driving force and the vehicle speed is the HEV region above the boundary line L1, the control system 80 selects the HEV mode. As shown in FIG. 8, when the HEV mode is selected, the control system 80 controls the engine clutch 26 to the engaged state, controls the engine 13 to the operating state, and controls the motor generator 14 to the power running state. Thereby, as shown by the arrows X1 and X2 in FIG. 8, the engine torque and the motor torque can be transmitted to the front and rear wheels 19f and 19r, and the hybrid vehicle 11 can be driven using the engine 13 and the motor generator 14. Note that when the hybrid vehicle 11 is decelerated, the motor generator 14 is controlled to the regenerative power generation state, and the kinetic energy of the hybrid vehicle 11 is converted into electrical energy and stored in the battery 95.

[0033] As described above, since the motor generator 14 and the transmission mechanism 15 are connected via the second gear train 32, even in the HEV mode, the motor speed can be increased from the low vehicle speed range, similarly to the EV mode. That is, even in the HEV mode, since the motor speed can be increased by the second gear train 32, the motor generator 14 can be controlled to approach the high rotation range α from the low vehicle speed range. Thereby, the energy efficiency of the motor generator 14 can be increased, and the fuel consumption performance of the hybrid vehicle 11 can be improved.

[0034] [Engine start in EV mode] As shown by the arrow A in FIG. 6, when the required driving force or the vehicle speed increases so as to exceed the boundary line L1 in the EV mode, the control system 80 starts the stopped engine 13 to switch the driving mode from the EV mode to the HEV mode. Here, FIG. 11 is a diagram showing the engine start situation in the EV mode. As shown in FIG. 11, the control system 80 controls the engine clutch 26 to be in the engaged state during traveling in the EV mode, and transmits the motor torque from the motor generator 14 to the engine 13 as shown by the arrow X3, and starts the rotation of the engine 13 by the motor torque. Here, the engine 13 and the motor generator 14 are connected to each other via the first gear train 31. Thereby, since the motor torque can be increased by the first gear train 31, the engine start performance in the EV mode can be improved while suppressing the increase in size of the motor generator 14.

[0035] [Mounting of power train] FIG. 12 is a cross-sectional view briefly showing the power train 12 along the line A-A of FIG. 1. As shown in FIG. 12, the hybrid vehicle 11 is equipped with the power train 12, and the power train 12 is accommodated in the floor tunnel 118 of the vehicle body. Further, since the engine 13 and the motor generator 14 are connected via the first gear train 31, the rotation center axis C1 of the motor generator 14 is located above the rotation center axis C2 of the engine 13 in the vertical direction. Thereby, the front differential mechanism 20 can be arranged below the motor generator 14, and the degree of freedom in designing the power train 12 can be increased from the viewpoint of ensuring mountability.

[0036] Also, since the engine 13 and the motor generator 14 are connected via the first gear train 31, as indicated by the reference sign W1, the rotation center axis C2 of the engine 13 and the rotation center axis C1 of the motor generator 14 are displaced from each other in the vehicle width direction. In this way, since the motor generator 14 can be displaced in the vehicle width direction with respect to the engine 13, the motor generator 14 can be arranged without interfering with the floor tunnel 118, the power supply cable, etc. Also from this point, the degree of freedom in designing the power train 12 can be increased.

[0037] In the examples shown in FIGS. 7 and 12 etc., the rotation center axis C2 of the engine 13 and the rotation center axis C3 of the transmission mechanism 15 coincide with each other, but it is not limited to this, and the rotation center axis C2 of the engine 13 and the rotation center axis C3 of the transmission mechanism 15 may be displaced from each other. Note that the rotation center axis C2 of the engine 13 is an axis that coincides with the center line of the crankshaft 23, the rotation center axis C1 of the motor generator 14 is an axis that coincides with the center line of the rotor 14r, and the rotation center axis C3 of the transmission mechanism 15 is an axis that coincides with the center line of the transmission input shaft 27.

[0038] [Other Embodiments of the Vehicle Drive Device] The vehicle drive device is not limited to the vehicle drive device 10 having the structure shown in FIG. 2, and a vehicle drive device having another structure may be used. FIGS. 13 to 16 are diagrams showing vehicle drive devices 120, 130, 140, and 150 according to other embodiments.

[0039] <Other Embodiment 1> As shown in FIG. 13, the vehicle drive device 120 includes an engine 13, a motor generator 14, and a transmission mechanism 15. The engine 13 and the wheels 121 are connected to each other via a power transmission path 122. The transmission mechanism 15 is provided in the power transmission path 122, and the motor generator 14 is provided in a path 122a that connects the engine 13 and the transmission mechanism 15 in the power transmission path 122. Further, a first chain mechanism 123 is provided in a path 122b that connects the engine 13 and the motor generator 14 in the power transmission path 122, and a second chain mechanism 124 is provided in a path 122c that connects the motor generator 14 and the transmission mechanism 15 in the power transmission path 122. Furthermore, an engine clutch 26 is provided in a path 122d that connects the first chain mechanism 123 and the motor generator 14 in the power transmission path 122.

[0040] In addition, the first chain mechanism (first power transmission mechanism) 123 provided in the path connecting the engine 13 and the motor generator 14 includes a first small-diameter sprocket (first small-diameter rotating body) 123a connected to the motor generator 14 via the engine clutch 26, and a first large-diameter sprocket (first large-diameter rotating body) 123b connected to the engine 13 via the torque converter 24. A chain 123c is wound around the first small-diameter sprocket 123a and the first large-diameter sprocket 123b, and the engine 13 and the motor generator 14 are connected to each other via the first chain mechanism 123. Further, since the number of teeth of the first large-diameter sprocket 123b is larger than the number of teeth of the first small-diameter sprocket 123a, the motor rotation speed is higher than the engine rotation speed.

[0041] Also, a second chain mechanism (second power transmission mechanism) 124 provided in the path connecting the motor generator 14 and the transmission mechanism 15 includes a second small-diameter sprocket (second small-diameter rotating body) 124a connected to the rotor 14r of the motor generator 14, and a second large-diameter sprocket (second large-diameter rotating body) 124b connected to the transmission input shaft 27 of the transmission mechanism 15. A chain 124c is wound around the second small-diameter sprocket 124a and the second large-diameter sprocket 124b, and the motor generator 14 and the transmission mechanism 15 are connected to each other via the second chain mechanism 124. Further, since the number of teeth of the second large-diameter sprocket 124b is larger than the number of teeth of the second small-diameter sprocket 124a, the motor rotation speed is higher than the transmission input rotation speed.

[0042] Thus, even in the vehicle drive device 120 provided with the first and second chain mechanisms 123 and 124, it can function in the same manner as the above-described vehicle drive device 10. That is, the power performance of the hybrid vehicle 11 can be enhanced without causing an increase in the size of the motor generator 14. Also, the engine starting performance can be enhanced without causing an increase in the size of the motor generator 14. Further, the rotation center axis C1 of the motor generator 14 and the rotation center axis C2 of the engine 13 can be arranged to be offset from each other, and the design freedom of the vehicle drive device 120 can be enhanced.

[0043] <Other Embodiment 2> As shown in FIG. 14, the vehicle drive device 130 includes an engine 13, a motor generator 14, and a transmission mechanism 15. The engine 13 and the wheels 131 are connected to each other via a power transmission path 132. The transmission mechanism 15 is provided in this power transmission path 132, and the motor generator 14 is provided in a path 132a that connects the engine 13 and the transmission mechanism 15 among the power transmission path 132. Further, a first gear train 31 is provided in a path 132b that connects the engine 13 and the motor generator 14 among the power transmission path 132, and a second gear train 32 is provided in a path 132c that connects the motor generator 14 and the transmission mechanism 15 among the power transmission path 132. Furthermore, an engine clutch 26 is provided in a path 132d that connects the first gear train 31 and the motor generator 14 among the power transmission path 132, and a damper mechanism 133 is provided in a path 132e that connects the engine 13 and the first gear train 31 among the power transmission path 132. The damper mechanism 133 includes a first disk 134 connected to the crankshaft 23, a second disk 135 connected to the first large-diameter gear 31b, and a spring 136 attached between both disks 134 and 135.

[0044] Thus, even in the vehicle drive device 130 incorporating the damper mechanism 133 instead of the torque converter 24, it can function in the same manner as the above-described vehicle drive device 10. That is, without causing the motor generator 14 to become larger in size, the power performance of the hybrid vehicle 11 can be enhanced. Also, without causing the motor generator 14 to become larger in size, the engine starting performance can be enhanced. Further, the rotational center axis C1 of the motor generator 14 and the rotational center axis C2 of the engine 13 can be arranged so as to be offset from each other, and the degree of freedom in the design of the vehicle drive device 130 can be increased. Also, in the vehicle drive device 130 incorporating the damper mechanism 133 instead of the torque converter 24, the engine 13 can be started without using the starter motor 85. That is, even when the vehicle is stopped, by controlling the engine clutch 26 to the engaged state and controlling the motor generator 14 to the power running state, the engine 13 can be started and rotated using the motor generator 14. When starting the engine 13 using the motor generator 14 while the vehicle is stopped, the forward clutch 45 and the reverse brake 46 of the forward / reverse switching mechanism 21 described above are released.

[0045] <Other Embodiment 3> As shown in Fig. 15, the vehicle drive device 140 has an engine 13, a motor generator 14, and a transmission mechanism 15. The engine 13 and the wheels 141 are connected to each other via a power transmission path 142. A transmission mechanism 15 is provided in this power transmission path 142, and a motor generator 14 is provided in a path 142a that connects the engine 13 and the transmission mechanism 15 in the power transmission path 142. Further, a first gear train 31 is provided in a path 142b that connects the engine 13 and the motor generator 14 in the power transmission path 142, and a second gear train 32 is provided in a path 142c that connects the motor generator 14 and the transmission mechanism 15 in the power transmission path 142. Furthermore, a first engine clutch (clutch mechanism) 143 is provided in a path 142d that connects the first gear train 31 and the motor generator 14 in the power transmission path 142, and a second engine clutch 144 is provided in a path 142e that connects the engine 13 and the first gear train 31 in the power transmission path 142. Also, a damper mechanism 133 is provided in a path 142f that connects the engine 13 and the second engine clutch 144 in the power transmission path 142.

[0046] Thus, even in the vehicle drive device 140 provided with a plurality of engine clutches 143 and 144, it can function in the same manner as the above-described vehicle drive device 10. That is, the power performance of the hybrid vehicle 11 can be enhanced without causing an increase in the size of the motor generator 14. Also, the engine starting performance can be enhanced without causing an increase in the size of the motor generator 14. Furthermore, the rotational center axis C1 of the motor generator 14 and the rotational center axis C2 of the engine 13 can be displaced from each other, and the degree of freedom in the design of the vehicle drive device 140 can be increased. Moreover, since a plurality of engine clutches 143 and 144 are provided, the load acting on each of the engine clutches 143 and 144 can be reduced, and the durability of the vehicle drive device 140 can be enhanced.

[0047] <Other Embodiment 4> In the example shown in FIG. 1, the vehicle drive device 10 is mounted vertically on the hybrid vehicle 11, but it is not limited to this, and the vehicle drive device may be mounted horizontally on the hybrid vehicle 11.

[0048] As shown in FIG. 16, the vehicle drive device 150 has an engine 13, a motor generator 14, and a transmission mechanism 15. The engine 13 and the wheels 151 are connected to each other via a power transmission path 152. The transmission mechanism 15 is provided in this power transmission path 152, and the motor generator 14 is provided in a path 152a that connects the engine 13 and the transmission mechanism 15 among the power transmission paths 152. Also, a first gear train 31 is provided in a path 152b that connects the engine 13 and the motor generator 14 among the power transmission paths 152, and a second gear train 32 is provided in a path 152c that connects the motor generator 14 and the transmission mechanism 15 among the power transmission paths 152. Further, an engine clutch 26 is provided in a path 152d that connects the first gear train 31 and the motor generator 14 among the power transmission paths 152, and a torque converter 24 is provided in a path 152e that connects the engine 13 and the first gear train 31 among the power transmission paths 152.

[0049] Thus, even the vehicle drive device 150 mounted horizontally on the hybrid vehicle 11 can function in the same manner as the above-described vehicle drive device 10. That is, the power performance of the hybrid vehicle 11 can be enhanced without causing an increase in the size of the motor generator 14. Also, the engine starting performance can be enhanced without causing an increase in the size of the motor generator 14. Further, the rotational center axis C1 of the motor generator 14 and the rotational center axis C2 of the engine 13 can be displaced from each other, and the design freedom of the vehicle drive device 150 can be enhanced.

[0050] The present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made without departing from the gist thereof. In the example shown in FIG. 2, the engine clutch 26 is provided in the path 70d that connects the first gear train 31 and the motor generator 14 among the power transmission paths 70. However, the present invention is not limited to this, and the engine clutch 26 may be provided in the path that connects the engine 13 and the first gear train 31 among the power transmission paths 70. That is, it is sufficient that the engine clutch 26 is provided in the path 70a that connects the engine 13 and the motor generator 14 among the power transmission paths 70. In the vehicle drive devices 120, 130, and 150 shown in FIGS. 13, 14, and 16, the engine clutch 26 may be provided on the engine side rather than the first chain mechanism 123 or the first gear train 31. Further, the engine clutch 26 may be a friction clutch or a meshing clutch. In the example shown in FIG. 2, the forward / reverse switching mechanism 21 is provided on the output side of the transmission mechanism 15, that is, the wheel side. However, the present invention is not limited to this, and the forward / reverse switching mechanism 21 may be provided on the input side of the transmission mechanism 15, that is, the engine side. For example, the forward / reverse switching mechanism 21 can be provided between the torque converter 24 and the first gear train 31.

[0051] In the foregoing description, the gear ratio of the first gear train 31 is set to "0.5" and the gear ratio of the second gear train 32 is set to "2.0", but it is not limited thereto. The gear ratio of the first gear train 31 may be set to be less than "1.0", and the gear ratio of the second gear train 32 may be set to be greater than "1.0". Further, in the foregoing description, the gear ratio of the first gear train 31 is set to "0.5" and the gear ratio of the second gear train 32 is set to "2.0" such that the value obtained by multiplying the gear ratios of both is "1.0", but it is not limited thereto. The gear ratio of the first gear train 31 and the gear ratio of the second gear train 32 may be set such that the value obtained by multiplying the gear ratios of both is greater than "1.0", or the gear ratio of the first gear train 31 and the gear ratio of the second gear train 32 may be set such that the value obtained by multiplying the gear ratios of both is less than "1.0". In the foregoing description, the control system 80 is configured by a plurality of control units CU1 to CU5, but it is not limited thereto. For example, the control system 80 may be configured by one control unit.

Explanation of Signs

[0052] 10 Vehicle drive device 11 Hybrid vehicle 13 Engine 14 Motor generator 15 Transmission mechanism 19r Rear wheel (wheel) 19f Front wheel (wheel) 20 Front differential mechanism (differential mechanism) 26 Engine clutch (clutch mechanism) 31 First gear train (first power transmission mechanism) 31a First small-diameter gear (first small-diameter rotating body) 31b First large-diameter gear (first large-diameter rotating body) 32 Second gear train (second power transmission mechanism) 32a Second small-diameter gear (second small-diameter rotating body) 32b Second large-diameter gear (second large-diameter rotating body) 70 Power transmission path 70a~70e Path 71 Power transmission path Routes 71a to 71e Vehicle drive device 120 Wheel 121 Power transmission path 122 Routes 122a to 122d First chain mechanism (first power transmission mechanism) 123 First small-diameter sprocket (first small-diameter rotating body) 123a First large-diameter sprocket (first large-diameter rotating body) 123b Second chain mechanism (second power transmission mechanism) 124 Second small-diameter sprocket (second small-diameter rotating body) 124a Second large-diameter sprocket (second large-diameter rotating body) 124b Vehicle drive device 130 Wheel 131 Power transmission path 132 Routes 132a to 132e Vehicle drive device 140 Wheel 141 Power transmission path 142 Routes 142a to 142d First engine clutch (clutch mechanism) 143 Vehicle drive device 150 Wheel 151 Power transmission path 152 Routes 152a to 152e

Claims

1. A vehicle drive device mounted on a hybrid vehicle, comprising: an engine connected to a wheel via a power transmission path; a transmission mechanism provided in the power transmission path and having a transmission input shaft and a transmission output shaft; a motor generator provided in a path connecting the engine and the transmission input shaft in the power transmission path; a first power transmission mechanism provided in a path connecting the engine and the motor generator in the power transmission path, the first power transmission mechanism including a first large-diameter rotating body connected to the engine and a first small-diameter rotating body connected to the motor generator; a second power transmission mechanism provided in a path connecting the motor generator and the transmission input shaft in the power transmission path, the second power transmission mechanism including a second small-diameter rotating body connected to the motor generator and a second large-diameter rotating body connected to the transmission input shaft; and the engine, the first power transmission mechanism, the second power transmission mechanism, and the transmission input shaft are arranged in series. A vehicle drive device.

2. The vehicle drive device according to claim 1, further comprising: a clutch mechanism provided in a path connecting the engine and the motor generator in the power transmission path. A vehicle drive device.

3. The vehicle drive device according to claim 1 or 2, wherein: a rotation center axis of the motor generator is located above a rotation center axis of the engine. A vehicle drive device.

4. The vehicle drive device according to any one of claims 1 to 3, wherein: the rotation center axis of the motor generator and the rotation center axis of the engine are offset from each other in a vehicle width direction. A vehicle drive device.

5. The vehicle drive device according to any one of claims 1 to 4, further comprising: a differential mechanism provided in a path connecting the transmission mechanism and the wheel in the power transmission path, and the differential mechanism is located below the motor generator. A vehicle drive device.

6. The vehicle drive device according to claim 1, wherein: the engine and the wheel are connected via one of the power transmission paths, and the second small-diameter rotating body is directly connected to the motor generator. A vehicle drive device.

7. The vehicle drive device according to claim 1, wherein: a first gear ratio, which is a ratio of a rotation speed of the first large-diameter rotating body to a rotation speed of the first small-diameter rotating body, is less than 1.

0. A second gear ratio, which is the ratio of the rotational speed of the second small-diameter rotating body to the rotational speed of the second large-diameter rotating body, is greater than 1.

0. A value obtained by multiplying the first gear ratio and the second gear ratio is 1.

0. A vehicle drive device.

8. In the vehicle drive device according to Claim 7, The first small-diameter rotating body and the motor generator are connected via a clutch mechanism. The motor generator and the second small-diameter rotating body are directly connected. When the clutch mechanism is in a fastened state, the rotational speed of the first small-diameter rotating body and the rotational speed of the second small-diameter rotating body are identical to each other. A vehicle drive device.

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