Hybrid vehicle drive system

Abstract

Hybrid vehicle drive system that features: a generator (20) which can generate electrical power using the power of an internal combustion engine (4); an electric motor (30) which is driven by electrical power to drive wheels; a housing (40) that accommodates the generator (20) and the electric motor (30); and a power control unit (60) for controlling the generator (20) and the electric motor (30), wherein the generator (20) and the electric motor (30) are arranged side by side on the same axis in the housing (40), wherein the power control unit (60) is mounted on the housing (40) by directly and appropriately connecting a unit-side generator connector (61) and a unit-side motor connector (62) provided on a lower surface of the power control unit (60) to a housing-side generator connector (51) and a housing-side motor connector (52) arranged on the housing (40), wherein the housing (40) is fixed to a vehicle frame element (80) via a mounting element (70), and wherein a fixing point, where the housing (40) and the mounting element (70) are fixed to each other, is arranged near the housing-side generator connector (51) and the housing-side motor connector (52), characterized by that the distance from the fixing point to the housing-side generator connector (51) and the housing-side motor connector (52) is shorter than the distance from the fixing point to a body-side fixing point where the mounting element (70) and the vehicle frame element (80) are attached to each other.

Description

[0001] The present invention relates to a hybrid vehicle drive system and in particular to a hybrid vehicle drive system comprising an internal combustion engine, a generator and an electric motor.

[0002] Traditionally, in a hybrid vehicle drive system comprising an internal combustion engine, a generator and an electric motor, a power control unit (PCU) is provided as a power control device to control the generator and the electric motor.

[0003] The power control unit consists of a generator inverter, which is connected between a battery and the generator to convert an AC voltage to a DC voltage, a motor inverter, which is connected between the battery and the electric motor to convert a DC voltage to an AC voltage or an AC voltage to a DC voltage, and a control unit (CCU) to control the generator inverter and the motor inverter.

[0004] In a conventional hybrid vehicle drive system, a housing containing the generator and electric motor, and the power control unit are mounted separately on a vehicle frame member. The power control unit is connected to the generator and motor via a three-phase cable. This requires only one mounting frame for the power control unit, but also raises concerns about noise generation from the three-phase cable.

[0005] Then, as described in JP 2013-150 472 A or JP 2012-170 177 A, it is proposed that the power control unit be mounted directly onto the chassis. Since the mounting frame for the power control unit and the three-phase cable are not required according to these hybrid vehicle drive systems, such an advantage is provided that not only can vehicle body weight and costs be reduced, but noise generation can also be suppressed.

[0006] From "TOYOTA: Workshop Manual Toyota Prius 2003-2009: P112 Hybrid Control System; Hybrid Transmission Transaxle. Toyota, 2006" a drive system is known in which an electric motor and a generator are arranged in a housing on a common axle. A control unit is mounted on the housing and connected to the electric motor and / or the generator by direct cable connections. A hybrid vehicle is also known from US Patent 2007 / 0145747A1 in which a control unit is connected to the electric motor and / or the generator by means of a cable connection.

[0007] However, because the power control unit is heavy, mounting it directly onto the housing raises the center of gravity, raising concerns about increased housing vibration. This increased vibration, in turn, could lead to contact problems in the connectors and amplified noise transmitted into the passenger compartment of a hybrid vehicle.

[0008] Furthermore, it still needs to be investigated how a housing-side connector and a unit-side connector should be arranged when the power control unit is mounted directly onto the housing.

[0009] Furthermore, if the generator and the electric motor are arranged adjacent to each other, it is still necessary to investigate how the power control unit should be arranged relative to an exhaust pipe of the combustion engine, which forms a heat source.

[0010] The invention was made in view of the problems described above, and one of its objectives is to provide a hybrid vehicle drive system which allows a power control unit to be preferably mounted on a housing that accommodates a generator and an electric motor.

[0011] The invention solves the problem with the subject matter defined in the independent claim. The dependent claims relate to advantageous embodiments.

[0012] In particular, the invention provides the following aspects. According to a first aspect of the invention, a hybrid vehicle drive system (e.g., a hybrid vehicle drive system 100 in an embodiment which will be described later) is provided, comprising: a generator (e.g. a generator 20 in the embodiment) that can generate electrical power using the power of an internal combustion engine (e.g. an internal combustion engine 4 in the embodiment); an electric motor (e.g. an electric motor 30 in the embodiment) which is driven by electrical power to drive wheels; a housing (e.g. a drive system housing 40 in the embodiment) that accommodates the generator and the electric motor; and a power control unit (e.g. a power control unit 60 in the embodiment) for controlling the generator and the electric motor, wherein the generator and the electric motor are arranged side by side on the same axis in the housing, wherein the power control unit is mounted on the housing by directly and appropriately connecting a unit-side generator connector (e.g. a unit-side generator connector 61 in the embodiment) and a unit-side motor connector (e.g. a unit-side motor connector 62 in the embodiment), which are provided on a lower surface of the power control unit, to a housing-side generator connector (e.g. a housing-side generator connector 51 in the embodiment) and a housing-side motor connector (e.g. a housing-side motor connector 52 in the embodiment) which are arranged on the housing, wherein the housing is fixed to a vehicle frame element (e.g. a body frame 80 in the embodiment) via a mounting element (e.g. a mounting element 70 in the embodiment), and wherein a fixing point (e.g. a first fixing point K2 in the embodiment), where the housing and the mounting element are fixed to each other, is arranged near the housing-side generator connector and the housing-side motor connector.

[0013] According to the invention, in the hybrid vehicle drive system according to the first aspect, a distance (e.g., a distance L1 in the embodiment) from the fixing point to the housing-side generator connector and the housing-side motor connector is shorter than a distance (e.g., a distance L2 in the embodiment) from the fixing point to a body-side fixing point (e.g., a body-side fixing point K1 in the embodiment) where the mounting element and the vehicle frame element are attached to each other.

[0014] According to a second aspect of the invention in the hybrid vehicle drive system according to the first aspect or the second aspect is the fixing point between an inner end section (e.g. an inner end section 51e in the embodiment) of the housing-side generator connector and an inner The end section (e.g. an inner end section 52e in the embodiment) of the housing-side motor connector is located when the fixing point is viewed from a direction that is perpendicular to a direction in which the housing-side generator connector and the housing-side motor connector are aligned.

[0015] According to a third aspect of the invention in the hybrid vehicle drive system according to the first or second aspect The fixing point comprises a first fixing point (e.g., a first fixing point K2 in the embodiment) located between an inner end section of the housing-side generator connector and an inner end section of the housing-side motor connector, and furthermore a second fixing point (e.g., a second fixing point K3 in the embodiment) and a third fixing point (e.g., a third fixing point K4 in the embodiment) that differ from the first fixing point, and when the second fixing point and the third fixing point are viewed from a direction perpendicular to a direction in which the housing-side generator connector and the housing-side motor connector are aligned, the second fixing point and the third fixing point are located between an outer end section (e.g.,an outer end section 51f in the embodiment) of the housing-side generator connector and an outer end section (e.g. an outer end section 52f in the embodiment) of the housing-side motor connector.

[0016] According to a fourth aspect of the invention in the hybrid vehicle drive system according to one of the first to third aspects The power control unit and the housing are bolted together, and at least four bolt mounting points (e.g., bolt mounting points T5, T6, T7, T8 in the embodiment), where the power control unit and the housing are bolted together, are provided to surround the housing-side generator connector and the housing-side motor connector in such a way that a rectangular shape is formed around it.

[0017] According to a fifth aspect of the invention in the hybrid vehicle drive system according to one of the first to third aspects The housing-side generator connector and the housing-side motor connector are fixed to the housing by a connector retaining element (e.g. a connector retaining element 53 in the embodiment), The power control unit is fixed to the connector retaining element, and a fixing point (e.g. a fixing point K5 in the embodiment), where the power control unit and the connector retaining element are fixed to each other, is arranged near the fixing point where the housing and the mounting element are fixed to each other.

[0018] According to a sixth aspect of the invention, in the hybrid vehicle drive system according to the fifth aspect, the connector retaining element and the housing are fastened to each other with a bolt, and When a bolt fixing point (e.g., bolt fixing points T1, T2 in the embodiment), where the connector retaining element and the housing are attached to each other by the bolt, is viewed from a direction in which the housing-side generator connector and the housing-side motor connector are aligned, the bolt fixing point is located between the fixing point where the power control unit and the connector retaining element are fixed to each other and the fixing point where the housing and the mounting element are fixed to each other.

[0019] According to a seventh aspect of the invention in the hybrid vehicle drive system according to one of the first to sixth aspects Lengths (e.g., lengths L11, L12 in the embodiment) of the power control unit are shorter than lengths (e.g., lengths 21, 22 in the embodiment) of the housing in an axial direction and in a direction perpendicular to the axial direction.

[0020] According to an eighth aspect of the invention in the hybrid vehicle drive system according to one of the first to seventh aspects The generator and the electric motor, which are arranged side by side in the housing, are arranged together with the internal combustion engine in an internal combustion engine compartment, and in a state in which the housing is fixed to the vehicle frame element via the mounting element, the control unit is arranged such that an upper surface of the power control unit is inclined upwards from a front towards its rear to follow a shape of a hood covering the internal combustion engine compartment.

[0021] According to a ninth aspect of the invention, in the hybrid vehicle drive system according to the eighth aspect, the power control unit has a water cooling jacket, and the water cooling jacket is connected to a venting reservoir (e.g. a venting reservoir 69 in the embodiment) which is provided behind it.

[0022] According to a tenth aspect of the invention in the hybrid vehicle drive system according to one of the first to ninth aspects The power control unit is mounted on a power control unit bearing section (e.g. a power control unit bearing section 42k in the embodiment) which is provided on an upper surface of the housing with a space defined between them, and a recessed section (e.g. a recessed section 42m in the embodiment) is formed on the housing to be adjacent to the power control unit bearing section.

[0023] According to a first example, a hybrid vehicle drive system (e.g., the hybrid vehicle drive system 100 in the embodiment) is provided, which includes: a generator (e.g. generator 20 in the embodiment) that can generate electrical power using the power of an internal combustion engine (e.g. internal combustion engine 4 in the embodiment); an electric motor (e.g. the electric motor 30 in the embodiment) which is driven by electrical power to drive wheels; a housing (e.g. the drive system housing 40 in the embodiment) that accommodates the generator and the electric motor; and a power control unit (e.g. the power control unit 60 in the embodiment) for controlling the generator and the electric motor, wherein the generator and the electric motor are arranged side by side on the same axis in the housing, wherein the power control unit is mounted on the housing by directly and appropriately connecting a unit-side generator connector (e.g. the unit-side generator connector 61 in the embodiment) and a unit-side motor connector (e.g. the unit-side motor connector 62 in the embodiment), which are provided on a lower surface of the power control unit, to a housing-side generator connector (e.g. the housing-side generator connector 51 in the embodiment) and a housing-side motor connector (e.g. the housing-side motor connector 52 in the embodiment) which are arranged on the housing, wherein the housing-side generator connector and the housing-side motor connector are arranged side by side along a direction that is at right angles to an axial direction, between a center of the generator in the axial direction and a center of the electric motor in the axial direction.

[0024] According to a second example in the hybrid vehicle drive system according to the first example, a generator rotary encoder (e.g. a generator rotary encoder 24 in the embodiment) and a motor rotary encoder (e.g. a motor rotary encoder 34 in the embodiment) are provided in a radial direction inwards from a coil transition section (e.g. a coil transition section 23b in the embodiment) of the generator and a coil transition section (e.g. a coil transition section 33b in the embodiment) of the electric motor and in the axial direction between the generator and the electric motor, and a generator rotary signal stator (e.g. a rotary signal stator 24b in the embodiment) which forms the generator rotary signal, and a motor rotary signal stator (e.g. a rotary signal stator 34b in the In the embodiment), which forms the motor rotation indicator, are held on a partition (e.g. a partition 44 in the embodiment) that divides an interior of the housing into a generator receiving section and an electric motor receiving section.

[0025] According to a third example in the hybrid vehicle drive system according to the first or second example are a generator rotary encoder (e.g. the generator rotary encoder 24 in the embodiment) and a motor rotary encoder (e.g. the motor rotary encoder 34 in the embodiment) in a radial direction inwards from a coil transition section (e.g. the coil transition section 23b in the embodiment) of the generator and a coil transition section (e.g. the coil transition section 33b in the embodiment) of the electric motor and in the axial direction between the generator and the electric motor, A rotary signal connector (e.g. a rotary signal connector 35 in the embodiment) is provided on the housing, and The rotary encoder connector is provided on a surface (e.g., a front surface in the embodiment) of the housing that is different from a surface where the housing-side generator connector and the housing-side motor connector are provided.

[0026] According to a fourth example, a hybrid vehicle drive system (e.g., the hybrid vehicle drive system 100 in the embodiment) is provided, which includes: an internal combustion engine (e.g. the internal combustion engine 4 in the embodiment); an exhaust pipe (e.g., an exhaust pipe 4b in the embodiment) connected to the internal combustion engine; a generator (e.g., generator 20 in the embodiment) capable of generating electrical power using the power of the internal combustion engine; an electric motor (e.g., electric motor 30 in the embodiment) driven by electrical power to drive wheels; a housing (e.g. the drive system housing 40 in the embodiment) that accommodates the generator and the electric motor; and a power control unit (e.g. the power control unit 60 in the embodiment) for controlling the generator and the electric motor, wherein the generator and the electric motor are arranged side by side on the same axis in the housing, wherein the internal combustion engine is arranged adjacent to the housing in a lateral direction of a vehicle, wherein the exhaust pipe extends from a front towards a rear of the vehicle while passing below the internal combustion engine, wherein the power control unit is mounted on the housing by directly and appropriately connecting a unit-side generator connector (e.g. the unit-side generator connector 61 in the embodiment) and a unit-side motor connector (e.g. the unit-side motor connector 62 in the embodiment), which are provided on a lower surface of the power control unit, to a housing-side generator connector (e.g. the housing-side generator connector 51 in the embodiment) and a housing-side motor connector (e.g. the housing-side motor connector 52 in the embodiment) which are arranged on the housing, and wherein the power control unit is arranged such that it is offset in the lateral direction against a projection zone (e.g. an exhaust pipe projection zone H in the embodiment) in which the exhaust pipe projects in an up-down direction.

[0027] Although vibration from the power control unit is transmitted into the passenger compartment via the housing, mounting element, and vehicle frame element, it is possible, according to the first aspect, to reduce the vibration transmitted into the passenger compartment by mounting the power control unit directly onto the housing containing the generator and electric motor via the housing-side generator connector and the housing-side motor connector. This is because the power control unit and the housing form a single rigid element, and the power control unit is positioned near the fixing point where the housing and mounting element are joined. As a result, it is possible to reduce noise transmitted from the power control unit into the passenger compartment.Since the fixing point, where the housing and the mounting element are fixed to each other, is also located near the housing-side generator connector and the housing-side motor connector, it is possible to obtain a large vibration damping effect in the housing-side generator connector and the housing-side motor connector, which are located close to the fixing point, thus making it possible to prevent a contact failure of the connectors that would otherwise be caused by a vibration.

[0028] According to the first aspect, the fixing point where the housing and the mounting element are fixed to each other can be located near the housing-side generator connector and the housing-side motor connector.

[0029] According to the second aspect, the fixing point where the housing and the mounting element are fixed to each other can be arranged in such a way as to maintain a good balance with respect to the housing-side generator connector and the housing-side motor connector, thereby making it possible to further reduce the vibration of the housing-side generator connector and the housing-side motor connector.

[0030] According to the third aspect, the three fixing points where the housing and the mounting element are fixed to each other can be arranged in such a way as to maintain a good balance with respect to the housing-side generator connector and the housing-side motor connector, thereby making it possible to reduce the vibration of the housing-side generator connector and the housing-side motor connector much more.

[0031] Since, according to the fourth aspect, the rigidity of the housing is improved by integrating the power control unit with the housing by attaching them to each other with the bolt, it is possible to reduce the vibration of the housing more.

[0032] Since, according to the fifth aspect, the fixing point where the connector retaining element, which is fixed to the housing, and the power control unit are fixed to each other is located near the fixing point where the housing and the mounting element are fixed to each other, the connector retaining element, the power control unit and the housing can be integrated together near the fixing point.

[0033] Since, according to the sixth aspect, the bolt fixing point, where the connector retaining element and the housing are attached to each other with the bolt, is located between the fixing point, where the power control unit and the connector retaining element are fixed to each other, and the fixing point, where the housing and the mounting element are fixed to each other, the integration of the connector retaining element, the power control unit and the housing can be promoted.

[0034] According to the seventh aspect, the lengths of the power control unit in the axial direction and in the direction perpendicular to the axial direction are shorter than the lengths of the housing, and therefore it is possible to avoid the danger of the power control unit, which is a high-voltage element, forming a first point of impact when the vehicle is involved in a collision.

[0035] Since the power control unit is arranged according to the eighth aspect in such a way that the upper surface of the power control unit is inclined upwards from the front to its rear in order to follow the shape of the hood covering the internal combustion engine, the installation capability of the power control unit in the internal combustion engine compartment and the venting capability of a coolant flowing through the control unit can be improved.

[0036] Since, according to the ninth aspect, the water cooling jacket of the power control unit is connected to the vent tank provided at the rear, air in the coolant can be recovered into the tank with better efficiency through the synergy between the connection of the water cooling jacket with the vent tank and the upward tilt of the power control unit towards the rear.

[0037] Since, according to the tenth aspect, the recessed section on the housing is designed to be adjacent to the power control unit bearing section, the drainage of water remaining in the power control unit bearing section can be improved by directing the water into the recessed section. Furthermore, since the power control unit rests on the power control unit bearing section with the space defined between them, thermal interference between them can be prevented. Additionally, the lower surface of the power control unit can be cooled by air flowing through this space.

[0038] Since, according to the first example, the housing-side generator connector and the housing-side motor connector are arranged side by side along the direction that is perpendicular to the axial direction between the center of the generator in the axial direction and the center of the electric motor in the axial direction, not only can the housing-side generator connector and the housing-side motor connector be arranged close to each other in the position that is either close to the generator or the electric motor, but the connector retaining element can also be formed from the single element that is used for both connectors.

[0039] According to the second example, not only can the generator rotary encoder and the motor rotary encoder be arranged by utilizing the dead space defined radially inwards from the coil transition sections, but the partition wall can also be used as the retaining wall that is used jointly for the generator rotary encoder and the motor rotary encoder.

[0040] According to the third example, the rotary encoder connector can be arranged with a high degree of freedom by avoiding interference with the power control unit.

[0041] According to the fourth example, the balance of weights is improved by aligning the internal combustion engine, generator, and electric motor in the lateral direction. Furthermore, the influence of heat from the exhaust pipe can be suppressed by placing the power control unit, which requires heat dissipation, on the opposite side of the housing from where the exhaust pipe is located.

[0042] Furthermore, the influence of heat from the exhaust pipe can be further suppressed by arranging the power control unit in such a way that it is offset against the protruding zone of the exhaust pipe. - Fig. Figure 1 is a perspective view of a hybrid vehicle drive system according to an embodiment of the invention. Fig. Figure 2 is a block diagram of the hybrid vehicle drive system according to the embodiment of the invention. Fig. Figure 3 is a sectional view showing an inner section of a drive system housing of the hybrid vehicle drive system according to the embodiment of the invention. Fig. Figure 4 is a sectional view of a main part showing an interior of the drive system part and an interior of a power control unit of the hybrid vehicle drive system according to the embodiment of the invention. Fig. Figure 5 is a perspective exploded view of the hybrid vehicle drive system according to the embodiment of the invention. Fig. 6A is a side view of the power control unit. Fig. Figure 6B shows a side view of a housing-side connector. Fig. 6C is a side view of the drive system housing. Fig. 7A is a top view of the power control unit. Fig. Figure 7B shows a top view of the housing-side connector. Fig. 7C is a top view of the drive system housing. Fig. Figure 8 is a sectional view showing the power control unit of the hybrid vehicle drive system according to the embodiment of the invention. Fig. Figure 9 is a lower perspective view showing the power control unit of the hybrid vehicle drive system according to the embodiment of the invention. Fig. Figure 10 is a top view of the hybrid vehicle drive system according to the embodiment of the invention, showing a state in which a mounting element is mounted on the drive system housing. Fig. Figure 11 is a perspective view showing a venting reservoir mounted on the power control unit of the hybrid vehicle drive system according to the embodiment of the invention. Fig. Figure 12 is a schematic top view of the hybrid vehicle drive system according to the embodiment of the invention.

[0043] - A hybrid vehicle according to an embodiment of the invention is described below based on the accompanying drawings.

[0044] As in Fig. Figure 1 shows that in a hybrid vehicle drive system 100 according to an embodiment of the invention, an internal combustion engine 4 and a drive system housing 40, which accommodates a generator 20 and an electric motor 30, are arranged adjacent to each other in an internal combustion engine compartment not shown, and a power control unit 60, which controls the generator 20 and the electric motor 30, is mounted on the drive system housing 40.

[0045] As in Fig. 2 and Fig. As shown in Figure 3, an input shaft 1, an intermediate shaft 2, and an output shaft 3, arranged parallel to each other, are provided inside the drive system housing 40. In the intermediate shaft 2, an inner circumferential shaft 2a is surrounded by an outer circumferential shaft 2b to rotate relative to each other. In the following description, an axial direction means a direction parallel to the axes of rotation of the input shaft 1, the intermediate shaft 2, and the output shaft 3. The hybrid vehicle drive system 100 is located inside the combustion engine compartment, such that the axial direction forms a lateral direction of the vehicle, and a direction intersecting the axial direction at right angles forms a front-to-back direction of the vehicle.

[0046] As in Fig. 1 and Fig. As shown in Figure 12, in the hybrid vehicle drive system 100, which is arranged inside the combustion engine compartment, an exhaust pipe 4b is connected to a front surface of the combustion engine 4, and the exhaust pipe 4b extends downwards along the front surface of the combustion engine 4 and then extends rearwards along a lower surface of the combustion engine 4. Fig. 1 and Fig. 12 designate reference signs, such as Fr, Rr, L, R, U and D, respectively forward, backward, left, right, upward and downward directions that result when a driver of the vehicle is sitting in a driver's seat while looking in front of the vehicle.

[0047] The input shaft 1, which is connected to a crankshaft 4a of the internal combustion engine 4, is connected to the inner circumferential shaft 2a via a generator drive gear pair 5 on an axle on which the generator 20 is mounted. The outer circumferential shaft 2b, on whose axle the electric motor 30 is mounted, is connected to the output shaft 3 via an electric motor drive power transmission gear pair 6, and the input shaft 1 and the output shaft 3 are connected to each other via an internal combustion engine drive power transmission gear pair 7. The output shaft 3 and a differential gear unit 8 are connected to each other via a final gear pair 9, and the differential gear unit 8 is connected to drive gears 11 and 112 via differential shafts 10.A clutch 12 is provided on the input shaft 1, and this clutch 12 engages or disengages to initiate or interrupt a power transmission between the input shaft 1 and the output shaft 3 via the internal combustion engine drive force transmission gear pair 7.

[0048] The hybrid vehicle drive system 100, which is constructed in the manner already described herein, comprises a transmission line through which a driving force of the electric motor 30 is transmitted to the drive wheels 11, 11 to cause the vehicle to move, and a transmission line through which a driving force of the internal combustion engine 4 is transmitted to the drive wheels 11, 11 to cause the vehicle to move, and is constructed to drive by selecting one of the two transmission lines or by using the two transmission lines in parallel.

[0049] When the transmission line is used, through which the driving force of the electric motor 30 is transmitted to the drive wheels 11, 11 to cause the vehicle to move, the internal combustion engine 4 is driven with the clutch 12 disengaged. An internal combustion engine driving force, which is fed from the input shaft 1 into the inner circumferential shaft 2a of the intermediate shaft 2 via the generator drive gear pair 5, rotates the inner circumferential shaft 2a and also rotates the generator 20, which is fixed to the inner circumferential shaft 2a, together with the inner circumferential shaft 2a, causing the generator 20 to produce electrical power. The electric motor 30, which is connected to the outer circumferential shaft 2b, which rotatably surrounds the inner circumferential shaft 2a, receives electrical power generated by the generator 20 to rotate the outer circumferential shaft 2b and transmits its driving force to the output shaft 3 by means of the electric motor drive force transmission gear pair 6.The drive force transmitted to the output shaft 3 is then transferred to the drive wheels 11, 112 via the final gear pair 9, the differential gear unit 8 and the differential shafts 10. This enables the vehicle to move via a series drive, in which the entire drive force of the internal combustion engine 4 is converted into electricity at the generator 20.

[0050] On the other hand, if the transmission line is used through which the driving force of the internal combustion engine 4 is transmitted to the drive wheels 11, 11 to cause the vehicle to move, the internal combustion engine 4 is driven, with the clutch 12 being applied. The internal combustion engine driving force is transmitted from the input shaft 1, is then transmitted to the output shaft 3 by means of the internal combustion engine driving force transmission gear pair 7, and is then transmitted to the drive wheels 11, 11 by means of the differential gear pair 9, the differential gear unit 8 and the differential shafts 10.Since in this situation the input shaft 1 and the inner circumferential shaft 2a are always connected to each other by means of the generator drive gear pair 5, electrical power is generated at the generator 20, and the electric motor 30 is rotated by means of the electrical power generated at the generator 20, thus making it possible to cause the vehicle to drive by parallel drive. It is also possible to cause the vehicle to drive by means of the motive power of the internal combustion engine 4 by simply minimizing the slippage loss while the generator 20 and the electric motor 30 are controlled to generate zero torque.

[0051] Next, with reference to Fig. 3 in particular an arrangement of the generator 20 and the electric motor 30 in the drive system housing 40 according to the embodiment is described.

[0052] The drive system housing 40 according to this embodiment consists of first and second housings 42, 43, which are arranged sequentially from the side of the internal combustion engine 4. The input shaft 1, the intermediate shaft 2, and the output shaft 3 are arranged parallel to each other inside the housing. As described above, the intermediate shaft 2 comprises the inner circumferential shaft 2a and the outer circumferential shaft 2b. The electric motor 30 is connected to the outer circumferential shaft 2, and the generator 20 is connected to the inner circumferential shaft 2a by a connecting shaft 2c, which is keyed to the inner circumferential shaft 2a.

[0053] Specifically, the generator 20 and the internal combustion engine 30 are housed inside the drive system housing 40 to be aligned on the same axis. A generator mounting section GS, which houses the generator 20, and an electric motor mounting section MS, which houses the electric motor 30, are separated by a partition 44, and this partition 44 rotatably holds the outer circumferential shaft 2b and the connecting shaft 2c by means of bearings 2d and 2e.

[0054] The generator 20 consists of a rotor 21, which is fixed to the connecting shaft 2c, and a stator 22, which is arranged opposite the rotor 21. Coils 23 for three phases (U-phase, V-phase, W-phase) are wound around the stator 22. The coil 23 has a coil winding section 23a, which is wound around a toothed section of the stator 22, and coil transition sections 23b, through which the coil winding section 23a is connected to adjacent coil winding sections 23a. The coil transition sections 23b project axially from the stator 22. Because of this, a dead space is normally defined radially inward from the coil transition sections 23b of the generator 20.

[0055] The electric motor 30 consists of a rotor 31, which is fixed to the outer circumferential shaft 2b, and a stator 32, which is arranged opposite the rotor 31. Coils 33 for three phases (U-phase, V-phase, W-phase) are wound around the stator 32. The coil 33 has a coil winding section 33a, which is wound around a toothed section of the stator 32, and coil transition sections 33b, through which the coil winding section 33a is connected to adjacent coil winding sections 33a. The coil transition sections 33b project axially from the stator 32. Because of this, a dead space is normally defined radially inward from the coil transition sections 33b of the electric motor 30.

[0056] A generator rotation sensor 24, which detects a rotation angle of the generator 20, and a motor rotation sensor 34, which detects a rotation angle of the electric motor 30, are arranged radially inwards from the coil transition sections 23b of the generator 20 and the coil transition sections 33b of the electric motor 30, where the dead spaces are normally defined, and axially between the generator 20 and the electric motor 30.

[0057] The generator rotary encoder 24 comprises a rotary encoder rotor 24a, which is fixed to the connecting shaft 2c, and a rotary encoder stator 24, which is arranged opposite the rotary encoder rotor 24a. The motor rotary encoder 34 comprises a rotary encoder rotor 34a, which is fixed to the outer circumferential shaft 2b, and a rotary encoder stator 34b, which is arranged opposite the rotary encoder rotor 34a. The rotary encoder stators 24a and 34b of the generator rotary encoder 24 and the motor rotary encoder 34 are both held on the partition 44 described above. By using the above-described structure, not only can the generator rotary encoder 24 and the motor rotary encoder 34 be arranged taking advantage of the dead spaces that are normally radially inward from the coil transition sections 23b, 33b, but the partition wall 44 can also be used as a retaining wall that is used together to hold the generator rotary encoder 24 and the motor rotary encoder 34.Coils (not shown) drawn from the rotary encoder stators 24b, 34b are connected to a rotary encoder connector 35 which is arranged on a front surface of the drive system housing 40, and the rotary encoder connector 35 and the power control unit 60 are connected to each other by means of a cable harness 37.

[0058] As in Fig. 3 and Fig. As shown in Figure 4, the coils 23 of three phases (U-phase, V-phase, W-phase) of the generator 20 are connected to each other at one end, and the other ends of the coils 23 are individually pulled out of the stator 22 as coil terminals 23c to be connected to a housing-side generator connector 51 inside the drive system housing 40. Furthermore, the coils 33 of three phases of the electric motor 30 are connected to each other at their ends, and the other ends of the coils 33 are individually pulled out of the stator 32 as terminals 33c to be connected to a housing-side motor connector 52 inside the drive system housing 40.

[0059] The housing-side generator connector 51 and the housing-side motor connector 52 are arranged such that they are aligned side by side along a direction perpendicular to the axial direction, between the center of the generator 20 in the axial direction and the center of the electric motor 30 in the axial direction. The housing-side generator connector 51 and the housing-side motor connector 52 of this embodiment are then connected to each other by means of the connector retaining element 53 to form an integrated housing-side connector 50, and are fixed to the drive system housing 40 by means of the connector retaining element 53.

[0060] To describe in particular the housing-side generator connector 51 and the housing-side motor connector 52, the housing-side generator connector 51 and the housing-side motor connector 52 in this embodiment, as in Fig. 4 to Fig. Figure 7 shows connector sections 51a, 52a projecting from an upper surface of the connector retaining element 53, which has a plate-like shape, and coil connection sections 51b, 52b projecting from a lower surface of the connector retaining element 53. The connector sections 51a, 52a have an elliptical cylindrical shape, and connector terminals 51c, 52c for three phases (U-phase, V-phase, W-phase) are arranged in the corresponding connector sections 51a, 52a. The coil connection sections 51b, 52b have an elliptical cylindrical shape, and coil connection terminals 51d, 52d for three phases are provided on the outer surface of the corresponding coil connection sections 51b, 52b, and the coil connection terminals 51d, 52d are electrically connected to the connector terminals 51c, 52c.

[0061] The housing-side generator connector 51 and the housing-side motor connector 52 of the embodiment, which are constructed in the manner described above, are mounted on the drive system housing 40 in such a state that the connector retaining element 53 follows an upper surface of the drive system housing 40, and that the coil connection sections 51b, 52b fit into connector holes 42a, 42b formed on the upper surface of the drive system housing 40. Then, in the drive system housing 40, the coil terminals 23c of the three phases of the generator 20 are connected to the coil connection terminals 51d of the housing-side generator connector 51, and the coil terminals 33c of three phases of the electric motor 30 are connected to the coil connection terminals 52d of the housing-side motor connector 52 (see Figure 5). Fig. 4).

[0062] As in Fig. As shown in Figure 8, the power control unit 60 of this embodiment comprises an inverter 64, a control unit 65 (CCU) that controls the inverter 64, and a current sensor (not shown). The inverter 64 comprises a generator inverter, which is connected between a DC-DC converter (not shown), located outside an internal combustion engine compartment, and the generator 20, and which converts an AC voltage to a DC voltage, and a motor inverter, which is connected between the DC-DC converter (not shown) and the electric motor 30, and which converts a DC voltage to an AC voltage or an AC voltage to a DC voltage.

[0063] As in Fig. 4, Fig. 8 and Fig. As shown in Figure 9, a unit-side generator connector 61 and a unit-side motor connector 62 are provided on a lower surface of the power control unit 60, and the power control unit 60 can control the generator 20 and the electric motor 30 by electrically connecting the unit-side generator connector 61 and the unit-side motor connector 62 to the housing-side generator connector 51 and the housing-side motor connector 52.

[0064] To describe in particular the unit-side generator connector 61 and the unit-side motor connector 62, the unit-side generator connector 61 and the unit-side motor connector 62 have elliptical locating holes 61a, 62a that fit onto the connector sections 51a, 52b of the housing-side generator connector 51 and the housing-side motor connector 52, connector sections 61b, 62b that are provided such that they project into the interior of the locating holes 61a, 62a and fit into the connector sections 51a, 52a of the housing-side generator connector 51 and the housing-side motor connector 52, and connector terminals 61c, 62c that are arranged inside the connector sections 61b, 62b and that are in contact with the connector terminals 51c, 52c of the housing-side generator connector 51 and the housing-side motor connector 52 are brought to be electrically connected to them.

[0065] The power control unit 60 of this embodiment, which is constructed as described above, is mounted on the drive system housing 40 by directly connecting the unit-side generator connector 61 and the unit-side motor connector 62, which are arranged on the lower surface of the power control unit 60, to the housing-side generator connector 51 and the housing-side motor connector 52, which are arranged on the drive system housing 40.

[0066] As in Fig. As shown in Figure 10, the drive system housing 40 is fixed to the body frame 80 by means of a mounting element 70. The mounting element 70 comprises a vehicle-side fixing element 71, which is fixed to the body frame 80, a housing-side fixing element 72, which is fixed to an outer edge of the upper surface of the drive system housing 40, and a vibration damping element (not shown), which fixes the vehicle-side fixing element 71 and the housing-side fixing element 72 to each other. The vehicle-side fixing element 71 is fixed to the body frame 80 by a bolt 71a, and the housing-side fixing element 72 is fixed to the drive system housing 40 by bolts 72a, 72b, and 72c.Although the drive system housing 40 may also be connected to the body frame 80 at another section or sections by means of a mounting element or mounting elements 70, here the fixing of the drive system housing 40 to the body frame 80 is described, with a focus on a fixing assembly used near the connector retaining element 53.

[0067] In particular, a fixing point K1 (referred to below as a body-side fixing point K1) is established between the mounting element 70 and the body frame 80 by tightening a bolt 71a in a (not shown) mounting hole formed in the body frame 80 by means of a (not shown) through-hole formed by the vehicle-side fixing element 71. Then, the fixing points K2, K3, K4 (referred to below as a first fixing point, K3 as a second fixing point, and K4 as a third fixing point) between the mounting element 70 and the drive system housing 40 are established by tightening bolts 72a, 72b, 72c in the mounting holes 43a, 43b, 43c (see Figure 1). Fig. 1, Fig. 7C) are generated in the drive system housing 40 by means of (not shown) through holes formed by the housing-side fixing element 72.

[0068] The first fixing point K2 to the third fixing point K4, where the drive system housing 40 and the mounting element 70 are fixed to one another, are arranged near the housing-side generator connector 51 and the housing-side motor connector 52. In particular, a distance L1, defined in the axial direction from the first fixing point K2 to the housing-side generator connector 51 and the housing-side motor connector 52, is shorter than a distance L2, defined in the axial direction from the first fixing point K2 to the body-side fixing point K1, where the mounting element 70 and the body frame 80 are fixed to one another.Furthermore, a distance L3, defined in the axial direction from the second fixing point K3 and the third fixing point K4 to the housing-side generator connector 51 and the housing-side motor connector 52, is made shorter than a distance L4, defined from the second fixing point K3 and the third fixing point K4 to the body-side fixing point K1, where the mounting element 70 and the body frame 80 are fixed to each other in the axial direction.

[0069] Since, according to the above-described setup, when mounting the power control unit 60 directly onto the drive system housing 40 using the housing-side generator connector 51 and the housing-side motor connector 52, the first fixing point K2 to the third fixing point K4, where the drive system housing 40 and the mounting element 70 are fixed to each other, are located near the housing-side generator connector 51 and the housing-side motor connector 52, a large vibration suppression effect can be obtained in the housing-side generator connector 51 and the housing-side motor connector 52, which are located near the first fixing point K2 to the third fixing point K4.

[0070] Furthermore, if the first fixing point K2 is considered in a direction (the axial direction) that is perpendicular to the direction in which the housing-side generator connector 51 and the housing-side motor connector 52 are aligned, it is preferred that the first fixing point K2 be located between an inner end section 51e of the housing-side generator connector 51 and an inner end section of the housing-side motor connector 52. In this way, by arranging the first fixing point K2 such that a good balance is maintained with respect to the housing-side generator connector 51 and the housing-side motor connector 52, it is possible to further reduce the vibration in the housing-side generator connector 51 and the housing-side motor connector 52.

[0071] Furthermore, if the second fixing point K3 and the third fixing point K4 are considered in the direction (the axial direction) that is perpendicular to the direction in which the housing-side generator connector 51 and the housing-side motor connector 52 are aligned, it is preferred that the second fixing point K3 and the third fixing point K4 are located between an outer end section 51f of the housing-side generator connector 51 and an outer end section 52f of the housing-side motor connector 52. In this way, by arranging the three fixing points, that is, from the first fixing point K2 to the third fixing point K4, such that a good balance is maintained with respect to the housing-side generator connector 51 and the housing-side motor connector 52, it is possible to reduce vibration in the housing-side generator connector 51 and the housing-side motor connector 52 much further.

[0072] Next, a fixing assembly between the power control unit 60 and the connector retaining element 53, a fixing assembly between the connector retaining element 53 and the drive system housing 40 and a fixing assembly between the power control unit 60 and the drive system housing 40 are described.

[0073] The power control unit 60 is fixed to the connector retaining element 53 by means of a fixing point K5. The connector retaining element 53 holds the housing-side generator connector 51 and the housing-side motor connector 52. Specifically, the fixing point K5, where the power control unit 60 and the connector retaining element 53 are fixed to one another, is created by tightening a bolt 60b in a fastening hole 53a formed in the connector retaining element 53 by means of a through-hole 60a formed by the power control unit 60. This fixing point K5 is then arranged near the first fixing point K2, where the drive system housing 40 and the mounting element 70 are fixed to one another. It is preferred that the fixing point K5 is arranged between the housing-side generator connector 51 and the housing-side motor connector 52.By using this setup, the power control unit 60, the connector retaining element 53 and the drive system housing 40 can be integrated together near the first fixing point K2, where the drive system housing 40 and the mounting element 70 are fixed to each other.

[0074] The connector retaining element 53 is fixed to the drive system housing 40 by bolting or fastening with bolts. In particular, bolt fastening points T1, T2, T3, T4, where the connector retaining element 53 and the drive system housing 40 are bolted together, are created by tightening bolts 53f, 53g, 53h, 53i in fastening holes 42c, 42d, 42e, 42f, which are formed in the drive system housing 40 by means of through holes 53b, 53c, 53d, 53e formed by the connector retaining element 53.Then, at bolt mounting points T1, T2, T3, T4, the bolt mounting points T1 and T2, where a central section of the connector retaining element 53 is fixed to the drive system housing 40, are located between the fixing point K5, where the power control unit 60 and the connector retaining element 53 are fixed to each other, and the first fixing point K2, where the drive system housing 40 and the mounting element 70 are fixed to each other, when viewed in the direction in which the housing-side generator connector 51 and the housing-side motor connector 52 are aligned. Using this configuration facilitates the integration of the power control unit 60, the connector retaining element 53, and the drive system 40 near the fixing point K2.

[0075] Furthermore, the power control unit 60 is attached to the drive system housing 40 by means of at least four bolts. In particular, bolt attachment points T5, T6, T7, T8, where the power control unit 60 and the drive system housing 40 are bolted together, are created by tightening bolts 60g, 60h, 60i (not shown), 60j (not shown) in mounting holes 42g, 42h, 42i, 42j, which are formed in the drive system housing 40 by means of through holes 60c, 60d, 60e, 60f formed by the power control unit 60. The attachment sections of the power control unit 60, where the through holes 60c, 60d, 60e, 60f are formed, are manufactured in such a way that they protrude slightly downwards from the lower surface of the power control unit 60, so that only the attachment sections are brought into contact with the drive system housing 40.The four bolt mounting points T5, T6, T7, T8 are then arranged such that they surround the housing-side generator connector 51 and the housing-side motor connector 52 in such a way that they form a rectangular shape around them. Since using this configuration improves the rigidity of the drive system housing 40 by integrating the power control unit 60 with the drive system housing 40 through bolting them together, it is possible to further reduce the vibration of the drive system housing 40.

[0076] Next, a mounting position and a cooling structure of the power control unit 60 are described.

[0077] As in Fig. 5 to Fig. As shown in Figure 7C, a power control unit bearing section 42k is formed on an upper surface of the drive system housing 40. The power control unit 60 is attached to the drive system housing 40 and the connector retaining element 53 by being fastened together with the bolts in such a way that only the mounting sections where the through holes 60c, 60d, 60e, 60f are formed bear against the power control unit bearing section 42k, and that the power control unit 60 rests on the power control unit bearing section 42k, with a space defined between them. The power control unit bearing section 42k of this embodiment is designed such that it projects upward from the upper surface of the drive system housing 40, and in conjunction with the projection of the power control unit bearing section 42k, a recessed section 42m ( Fig. 3, Fig. 10), which is manufactured deeper than the power control unit bearing section 42k, is formed in a zone adjacent to the power control unit bearing section 42k. By using this design, even if water penetrates the interior of the combustion engine compartment, the water can be directed into the recessed section 42m, thereby improving water drainage. Furthermore, since the power control unit 60 is mounted on the power control unit bearing section 42k with the space defined between them, disruptive heat between them can be prevented. Additionally, the lower surface of the power control unit 60 can be cooled by air flowing through the space.

[0078] It is preferred that lengths L11, L12 of the power control unit 60 be shorter in the axial direction (the lateral direction) and in a direction (the longitudinal direction) that is perpendicular to the axial direction than lengths L21, L22 of the drive system housing 40. By using this design, it is possible to avoid the risk that the power control unit 60, which is a high-voltage component, would form a first point of impact in the event of a collision involving the vehicle.

[0079] Furthermore, it is preferred that the power control unit 60, in a state where the drive system housing 40 is fixed to the body frame 80 by means of the mounting element 70, is inclined upwards from the front towards its rear, so that its upper surface follows a (not shown) engine hood covering the combustion engine compartment. Using this configuration improves the installability of the power control unit 60 within the combustion engine compartment and the venting capability of a coolant flowing through the interior of the power control unit 60.

[0080] A water cooling jacket (not shown), which forms a flow path for the coolant, is located inside the power control unit 60. As shown in Fig. 4 and Fig. As shown in Figure 11, an inlet pipe 66, connected to an inlet opening of the water cooling jacket, is provided at a front end (a lower inclined side) of the power control unit 60, and an outlet pipe 67, connected to an outlet opening of the water cooling jacket, is provided at a rear end (an upper inclined side) of the power control unit 60. Coolant is then supplied to the power control unit 60 at all times by providing a coolant supply line extending from a radiator (not shown) to reach the inlet pipe 66 and a coolant return line extending from the outlet pipe 67 to reach the radiator, thereby cooling an electronic component inside the power control unit 60.

[0081] Furthermore, a vent tank 69, inserted into the coolant return line, is provided on the rear (upper inclined side) of the power control unit 60. This allows air in the coolant to be efficiently recovered into the vent tank 69, since the water cooling jacket of the power control unit 60 is in contact with the vent tank 69 on its upper inclined side.

[0082] Furthermore, the power control unit 60 is, as in Fig.Figure 12 shows the power control unit 60 arranged such that it is offset in the lateral direction against the exhaust pipe projection zone H, where the exhaust pipe 4b projects in an up-down direction. By using this arrangement, the power control unit 60, which must be provided with a heat countermeasure, is located on the opposite side of the drive system housing 40 from the side where the exhaust pipe 4b, which forms a heat source, is located, thereby suppressing the influence of heat.

[0083] Furthermore, the influence of heat can be further suppressed by arranging the power control unit 60 in such a way that it is offset in the width direction against the exhaust pipe projection zone H.

[0084] Thus, the embodiment, as already described here, provides at least the following aspect under (1). (2) and (3) describe two examples. (1) Hybrid vehicle drive system 100 comprising: the generator 20, which can generate electrical power using the power from the internal combustion engine 4; the electric motor 30, which drives the wheels; the drive system housing 40, which accommodates the generator 20 and the electric motor 30; and the power control unit 60 for controlling the generator 20 and the electric motor 30, wherein the generator 20 and the electric motor 30 are arranged side by side on the same axis in the drive system housing 40, wherein the power control unit 60 is mounted on the drive system housing 40 by directly and appropriately connecting the unit-side generator connector 61 and the unit-side motor connector 62, which are provided on the lower surface of the power control unit 60, to the housing-side generator connector 51 and the housing-side motor connector 52, which are arranged on the drive system housing 40, wherein the drive system housing 40 is fixed to the vehicle frame element 80 via the mounting element 70, and wherein the first fixing point K2, where the drive system housing 40 and the mounting element 70 are fixed to each other, is located near the housing-side generator connector 51 and the housing-side motor connector 52.

[0085] Although vibrations from the power control unit 60 are transmitted into the passenger compartment via the drive system housing 40, the mounting element 70 and the body frame 80, these vibrations can be reduced as a result of the power control unit 60 being mounted directly onto the drive system housing 40, which accommodates the generator 20 and the electric motor 30, by means of the housing-side generator connector 51 and the housing-side motor connector 52. This is because the power control unit 60 and the drive system housing 40 are integrated into a single rigid element and the power control unit 60 is located near the first fixing point K2, where the drive system housing 40 and the mounting element 70 are fixed to each other.As a result, not only can damage to internal components of the power control unit 60 caused by vibrations be prevented, but noise transmitted from the power control unit 60 into the passenger compartment can also be reduced. Furthermore, since the first fixing point K2, where the drive system housing 40 and the mounting element 70 are fixed to one another, is located near the housing-side generator connector 51 and the housing-side motor connector 52, a significant vibration damping effect can be achieved in these connectors, which are situated near fixing point K2. This prevents contact failures of the connectors that would otherwise be caused by vibrations.

[0086] (2) Hybrid vehicle drive system 100, comprising: the generator 20, which can generate electrical power using the power from the internal combustion engine 4; the electric motor 30, which drives the wheels; the drive system housing 40, which accommodates the generator 20 and the electric motor 30; and the power control unit 60 for controlling the generator 20 and the electric motor 30, wherein the generator 20 and the electric motor 30 are arranged side by side on the same axis in the drive system housing 40, wherein the power control unit 60 is mounted on the drive system housing 40 by directly and appropriately connecting the unit-side generator connector 61 and the unit-side motor connector 61, which are provided on the lower surface of the power control unit 60, to the housing-side generator connector 52 and the housing-side motor connector 52, which are arranged on the drive system housing 40, wherein the housing-side generator connector 51 and the housing-side motor connector 52 are arranged side by side along the direction which is perpendicular to the axial direction between the center of the generator 20 in the axial direction and the center of the electric motor 30 in the axial direction.

[0087] Since the housing-side generator connector 51 and the housing-side motor connector 52 are arranged side by side along the direction perpendicular to the axial direction between the center of the generator 20 in the axial direction and the center of the electric motor 30 in the axial direction, not only can the housing-side generator connector 51 and the housing-side motor connector 52 be arranged close to each other in the position near both the generator 20 and the electric motor 30, but the connector retaining element can also consist of the single element that is used jointly for the two connectors.

[0088] (3) Hybrid vehicle drive system 100, comprising: the internal combustion engine 4; the exhaust pipe 4b, which is connected to the internal combustion engine 4; the generator 20, which can generate electrical power using the power from the internal combustion engine 4; the electric motor 30, which is driven by electrical power to drive wheels; the drive system housing 40, which accommodates the generator 20 and the electric motor 30; and the power control unit 60 for controlling the generator 20 and the electric motor 30, wherein the generator 20 and the electric motor 30 are arranged side by side on the same axis in the drive system housing 40, wherein the internal combustion engine 4 is arranged adjacent to the drive system housing 40 in the lateral direction of the vehicle, wherein the exhaust pipe 4b extends from the front towards the rear of the vehicle 4, passing below the internal combustion engine 4, wherein the power control unit 60 is mounted on the drive system housing 40 by connecting the unit-side generator connector 61 and the unit-side motor connector 62, which are on a lower surface of the power control unit 60, are directly and appropriately connected to the housing-side generator connector 51 and the housing-side motor connector 52, which are arranged on the drive system housing 40, and wherein the power control unit 60 is arranged such that it is offset in the lateral direction against the projection zone H in which the exhaust pipe 4b projects in an up-down direction.

[0089] In this way, the balance of weights is improved by aligning the internal combustion engine 4, the electric motor 30, and the generator 20 in the lateral direction. Furthermore, the power control unit 60, which must be equipped with a heat-resistant measure, is positioned on the opposite side of the drive system housing 40 from the exhaust pipe 4b, which acts as a heat source, thus suppressing the influence of heat. The influence of heat can also be further suppressed by positioning the power control unit 60 offset from the exhaust pipe projection zone H.

[0090] While the invention has been described, various design changes can therefore be made to it without deviating from the spirit and scope of the invention.

[0091] For example, in this embodiment, the drive system housing 40 and the mounting element 70 are attached to each other at three fixing points, i.e., from the first fixing point K2 to the third fixing point K4. However, the drive system housing 40 and the mounting element 70 can be attached to each other at a single point, i.e., only at fixing point K2, or at two fixing points, i.e., at the second fixing point K3 and the third fixing point K4. Alternatively, four or more fixing points can be provided. If multiple fixing points are provided, at least one fixing point should be located near the housing-side generator connector 51 and the housing-side motor connector 52. Preferably, however, all fixing points are located near the housing-side generator connector 51 and the housing-side motor connector 52. List of reference symbols: 4 Internal combustion engine 4b Exhaust pipe 20 Generator 23b Coil transition section 24 Generator rotary indicators (generator rotary indicators) 24b Rotary signal stator (generator rotary signal stator) 30 electric motor 33b Coil transition section 34 Motor rotation indicators 34b Rotary signal stator (motor rotary signal stator) 40 drive system housings 42k Power Control Unit Bearing Section (Power Control Unit Bearing Section) 42m Deepened Section 44 Partition wall 51 Housing-side generator connector (housing-side generator connector) 51e Inner end section (inner end section of the housing-side generator connector) 51f Outer end section (outer end section of the housing-side generator connector) 52 Housing-side motor connector (housing-side motor connector) 52e Inner end section (inner end section of the housing-side motor connector) 52f Outer end section (outer end section of the housing-side motor connector) 53 Connector retaining element 60 Power control unit 61 Unit-side generator connector (unit-side generator connector) 62 Unit-side motor connector (unit-side motor connector) 69 Venting reservoir 70 Mounting element 80 Body frame (vehicle frame element) 100 hybrid vehicle drive systems K2 First fixation point K3 Second fixation point K4 Third fixation point H Exhaust pipe projection zone

Claims

[1] Hybrid vehicle drive system which features: a generator (20) which can generate electrical power using the power of an internal combustion engine (4); an electric motor (30) which is driven by electrical power to drive wheels; a housing (40) that accommodates the generator (20) and the electric motor (30); and a power control unit (60) for controlling the generator (20) and the electric motor (30), wherein the generator (20) and the electric motor (30) are arranged side by side on the same axis in the housing (40), wherein the power control unit (60) is mounted on the housing (40) by directly and appropriately connecting a unit-side generator connector (61) and a unit-side motor connector (62) provided on a lower surface of the power control unit (60) to a housing-side generator connector (51) and a housing-side motor connector (52) arranged on the housing (40), wherein the housing (40) is fixed to a vehicle frame element (80) via a mounting element (70), and wherein a fixing point, where the housing (40) and the mounting element (70) are fixed to each other, is arranged near the housing-side generator connector (51) and the housing-side motor connector (52), characterized by , that the distance from the fixing point to the housing-side generator connector (51) and the housing-side motor connector (52) is shorter than the distance from the fixing point to a body-side fixing point where the mounting element (70) and the vehicle frame element (80) are attached to each other. [2] Hybrid vehicle drive system according to claim 1, characterized by , that the fixing point is located between an inner end section of the housing-side generator connector (51) and an inner end section of the housing-side motor connector (52) when the fixing point is viewed from a direction that is perpendicular to a direction in which the housing-side generator connector (51) and the housing-side motor connector (52) are aligned. [3] Hybrid vehicle drive system according to one of claims 1 or 2, characterized by , that the fixing point comprises a first fixing point located between an inner end section of the housing-side generator connector (51) and an inner end section of the housing-side motor connector (52), and further comprising a second fixing point and a third fixing point which are different from the first fixing point, and if the second fixing point and the third fixing point are located from a direction that is at right angles to a direction in which the housing-side generator connector (51) and the housing-side motor connector (52) are aligned, the second fixing point and the third fixing point are located between an outer end section of the housing-side generator connector (51) and an outer end section of the housing-side motor connector (52). [4] Hybrid vehicle drive system according to any one of claims 1 to 3, characterized by , that the power control unit (60) and the housing (40) are fastened together with bolts, and at least four bolt fixing points, where the power control unit (60) and the housing (40) are attached to each other, are provided to surround the housing-side generator connector (51) and the housing-side motor connector (52) in such a way as to form a rectangular shape around it. [5] Hybrid vehicle drive system according to any one of claims 1 to 4, characterized by , that the housing-side generator connector (51) and the housing-side motor connector (52) are fixed to the housing (40) by a connector retaining element (53), the power control unit (60) is fixed to the connector retaining element (53), and a fixing point where the power control unit (60) and the connector retaining element (53) are fixed to each other is located near the fixing point where the housing (40) and the mounting element (70) are fixed to each other. [6] Hybrid vehicle drive system according to claim 5, characterized by , that the connector retaining element (53) and the housing (40) are fastened to each other with a bolt, and, When a bolt fixing point, where the connector retaining element (53) and the housing (40) are attached to each other by the bolt, is viewed from a direction in which the housing-side generator connector (51) and the housing-side motor connector (52) are aligned, the bolt fixing point is located between the fixing point where the power control unit (60) and the connector retaining element (53) are fixed to each other and the fixing point where the housing (40) and the mounting element (70) are fixed to each other. [7] Hybrid vehicle drive system according to any one of claims 1 to 6, characterized by , that in an axial direction and in a direction perpendicular to the axial direction, lengths of the power control unit (60) are shorter than lengths of the housing (40). [8] Hybrid vehicle drive system according to any one of claims 1 to 7, characterized by , that the generator (20) and the electric motor (30), which are arranged side by side in the housing (40), are arranged together with the internal combustion engine (4) in an internal combustion engine compartment, and the power control unit (60) is in a state in which the housing (40) is fixed to the vehicle frame via the mounting element (70) such that an upper surface of the power control unit (60) is inclined upwards from a front towards its rear to follow a shape of a hood covering the combustion engine compartment. [9] Hybrid vehicle drive system according to claim 8, characterized by , that the power control unit (60) has a water cooling jacket and the water cooling jacket is connected to a venting reservoir (69) which is provided behind it. [10] Hybrid vehicle drive system according to any one of claims 1 to 9, characterized by , that the power control unit (60) is mounted on a power control unit bearing section (42k) which is provided on an upper surface of the housing (40) with a space defined in between, and a recessed section (42m) is formed on the housing (40) to be adjacent to the power control unit bearing section (42k).

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