POWER GENERATION ASSEMBLY AND SERIES HYBRID VEHICLE

A power generation assembly includes: an engine including a crank shaft having an axial direction extending vertically; and an axial gap power generator located at one side of the engine in the axial direction and including a rotor connected to the crank shaft so as to be rotatable about a rotation axis extending in the axial direction and a stator opposed to the rotor in the axial direction while being spaced apart from the rotor in the axial direction.

BACKGROUND OF THE INVENTION

Field of the Invention

The present disclosure relates to a power generation assembly and a series hybrid vehicle.

Description of the Related Art

U.S. Pat. No. 9,038,754 discloses a series hybrid vehicle including: a traveling electric motor driven by electric power supplied from a battery; and a power generation engine that drives a power generator to charge the battery. The engine and the power generator are integrated with each other to form a power generation assembly. The engine is located such that a crank shaft is directed in a vertical direction, and the power generator is located under the engine.

SUMMARY OF THE INVENTION

The size of the power generation assembly in the vertical direction is desired to be further reduced depending on uses. However, when the size of the power generator or the engine in the vertical direction is simply reduced, the power generation performance deteriorates.

An object of the present disclosure is to make an entire power generation assembly compact without deteriorating power generation performance.

A power generation assembly according to one aspect of the present disclosure includes: an engine including a crank shaft having an axial direction extending vertically; and an axial gap power generator located at one side of the engine in the axial direction and including a rotor connected to the crank shaft so as to be rotatable about a rotation axis extending in the axial direction and a stator opposed to the rotor in the axial direction while being spaced apart from the rotor in the axial direction.

According to the above configuration, the power generator is located at one vertical-direction side of the engine including the crank shaft extending in the vertical direction. Therefore, an occupied space of the power generation assembly in a horizontal direction is reduced. The power generator is of an axial gap type and is located such that the rotor rotates about the rotation axis extending in the vertical direction. Therefore, the occupied space of the power generation assembly in the vertical direction is also reduced. Thus, the entire power generation assembly can be made compact without deteriorating the power generation performance.

A series hybrid vehicle according to one aspect of the present disclosure includes: a power generation assembly; a battery that is charged by electric power generated by the power generation assembly; an electric motor that is driven by the electric power supplied from the battery and generates traveling power; at least one wheel; and a vehicle body supported by the wheel. The power generation assembly includes: an engine including a crank shaft extending in a vertical direction; and an axial gap power generator located at one side of the engine in the vertical direction and including a rotor connected to the crank shaft so as to be rotatable about a rotation axis extending in an axial direction of the crank shaft and a stator opposed to the rotor in the axial direction while being spaced apart from the rotor in the axial direction. The power generation assembly is mounted on the vehicle body such that a lower end of the axial gap power generator is located lower than an upper end of the wheel.

According to the above configuration, the hybrid vehicle having high space efficiency can be provided by the compact power generation assembly.

DETAILED DESCRIPTION

Hereinafter, an embodiment will be described with reference to the drawings. A power generation assembly1described below includes a crank shaft22extending in a vertical direction (upper-lower direction). In other words, the upper-lower direction of the power generation assembly1is a direction in which the crank shaft22extends, and a direction in a plane which is orthogonal to the crank shaft22is a horizontal direction of the power generation assembly1.

FIG.1is a plan view of the power generation assembly1according to the embodiment.FIG.2is a sectional view taken along line II-II ofFIG.1showing the power generation assembly1. As shown inFIGS.1and2, the power generation assembly1includes an engine unit2and an axial gap power generator3driven by the engine unit2. The engine unit2includes: an engine10that is an internal combustion engine; and an upper cover11located at an upper side of the engine10.

The engine10of the engine unit2is a multiple cylinder engine, and for example, is a V-twin engine. The engine10includes a crank case21, the crank shaft22, a pair of cylinders23, and a valve gear24. The crank shaft22is accommodated in the crank case21while being rotatably supported by the crank case21. A rotation axis X of the crank shaft22extends in the vertical direction. The crank shaft22rotates in association with reciprocating movements of pistons in the cylinders23. The crank shaft rotates a connection target to give kinetic energy to the connection target. Each of the cylinders23extends in the horizontal direction when viewed from the crank shaft22.

The upper cover11of the engine unit2is fixed to the crank case21so as to cover the crank case21from above. The upper cover11has an inverted U-shaped section that is open downward. The upper cover11defines an internal space together with the crank case21. An upper portion of the crank shaft22which projects upward from the crank case21is located in the internal space of the upper cover11. A cooling fan12and a sub-power generator14are located above the engine10and in the internal space of the upper cover11.

The sub-power generator14is attached to the upper portion of the crank shaft22. To be specific, the sub-power generator14generates electric power in such a manner that a rotor (not shown) thereof rotates in association with the crank shaft22. The electric power generated by the sub-power generator14is used as electric power necessary to drive the engine10. For example, the electric power generated by the sub-power generator14is supplied to a below-described electronic control unit4, and the like.

The cooling fan12is attached to the upper portion of the crank shaft22so as to be located above the sub-power generator14. An inflow opening11ais located at an upper plate portion of the upper cover11. A fan cover13is detachably attached to the upper cover11so as to cover the inflow opening11a. The fan cover13has, for example, a net structure that prevents foreign matters from passing therethrough but allows air to pass therethrough.

An outflow opening11bis located at a side plate portion of the upper cover11. A louver may be located at the outflow opening11b. When the cooling fan12rotates in association with the crank shaft22, air is sucked through the fan cover13and the inflow opening11a. The sucked air cools the sub-power generator14and the engine10and is discharged through the outflow opening11bto an outside.

The valve gear24includes a camshaft24aextending in the vertical direction and opens and closes intake/exhaust valves (not shown) of the cylinders23in mechanical association with the crank shaft22. The configuration of the valve gear24is publicly known and is not especially limited. The rotation of the crank shaft22is transmitted to the camshaft24athrough a gear25. In the horizontal direction, the valve gear24is located at one side of the rotation axis X of the crank shaft22at which the cylinders23exist. To be specific, the valve gear24is located in one (the side at which the cylinders23exist) of two regions obtained by dividing a space by a virtual vertical plane which includes the rotation axis X of the crank shaft22and is perpendicular to a virtual line connecting the rotation axis X and the center of gravity of the pair of cylinders23.

The engine unit2includes an air cleaner15that purifies intake air to be supplied to the engine10. An upper end of the air cleaner15is located higher than an upper end of the engine10. Specifically, the upper end of the air cleaner15is located higher than an upper surface of the upper cover11. The air cleaner15includes an air cleaner case28and a cleaner element29(filter) accommodated in the air cleaner case28.

Specifically, the air cleaner case28includes a tubular peripheral wall portion and end wall portions which close both ends of the peripheral wall portion. The air cleaner case28is located such that an axis thereof is directed in the horizontal direction. The cleaner element29has a cylindrical shape. A radially inner side of the cleaner element29is a clean side, and a radially outer side of the cleaner element29is a dirty side.

A duct16projects upward from the peripheral wall portion of the air cleaner case28. The duct16communicates with the dirty side of the air cleaner15. A suction opening16ais located at an upper end of the duct16. To be specific, the suction opening16ais located higher than the air cleaner case28and the cleaner element29. A filter may be located at the suction opening16a. Outside air sucked through the suction opening16ais guided to the dirty side located at a radially outer side of the cleaner element29, flows through the cleaner element29to be purified, and is guided to the clean side located at a radially inner side of the cleaner element29.

An intake air pipe17that communicates with the clean side located at the radially inner side of the cleaner element29is connected to the end wall portion of the air cleaner case28. The intake air pipe17includes a first portion17aand a second portion17b. The first portion17aextends in the horizontal direction. The second portion17bhas a U shape that extends downward, makes a U-turn, and extends upward. Therefore, the length of an intake air passage of the intake air pipe17is made long in a small space. A downstream end of the second portion17bof the intake air pipe17is located such that the intake air can be supplied to combustion chambers of the cylinders23. The second portion17bmay have an inverted U shape that extends upward, makes a U-turn, and extends downward.

A throttle device18including a throttle valve is located at the intake air pipe17. A fuel supplier19is located at the intake air pipe17. The fuel supplier19is, for example, an injector or a carburetor. Specifically, the throttle device18and the fuel supplier19are located at the second portion17bof the intake air pipe17and upstream of a U-turn portion17ba. Therefore, the intake air passage extending from the throttle device18and the fuel supplier19to the cylinders23is made long.

An oil pan26that is open upward is located at a lower portion of the crank case21. Specifically, the oil pan26is located at a lower portion of the internal space of the crank case21. The oil pan26is located at such a height as to overlap the crank shaft22in a direction (vertical direction) along the rotation axis X of the crank shaft22. In the horizontal direction, the oil pan26is located at a side of the rotation axis X of the crank shaft22which is opposite to the side at which the valve gear24exists.

To be specific, the oil pan26is located in the other (the side at which the cylinders23do not exist) of the two regions obtained by dividing the space by the virtual vertical plane which includes the rotation axis X of the crank shaft22and is perpendicular to the virtual line connecting the rotation axis X and the center of gravity of the pair of cylinders23. The oil pan26may be expanded so as to reach a vertically lower side of the valve gear24. Moreover, a lower case21bmay also serve as the oil pan.

The axial gap power generator3is located at a lower side of the engine10. The axial gap power generator3may be located at an upper side of the engine10. The axial gap power generator3is located under the oil pan26. The axial gap power generator3is attached to a lower surface of the engine10. The axial gap power generator3is located lower than the entire engine unit2.

As described below, the axial gap power generator3includes a substantially plate-shaped stator33and substantially plate-shaped rotors34and35. The stator33and the rotors34and35are lined up in an axial direction of a rotating shaft32such that main surfaces of the stator33and the rotors34and35are opposed to each other. To be specific, in the axial gap power generator3, a main direction of magnetic flux of the rotors34and35is the axial direction of the rotating shaft32. Therefore, the dimension of the axial gap power generator3in the axial direction of the rotating shaft32can be reduced.

The axial gap power generator3, the cooling fan12, and the sub-power generator14are located coaxially with the crank shaft22. The axial gap power generator3is larger than the sub-power generator14. Specifically, the volume of the axial gap power generator3is larger than the volume of the sub-power generator14. In a top view of the power generation assembly1, an area occupied by the axial gap power generator3is larger than an area occupied by the sub-power generator14. A rated output (power generation capability per unit time) of the axial gap power generator3is larger than a rated output (power generation capability per unit time) of the sub-power generator14.

The dimension of the axial gap power generator3in the vertical direction is larger than the dimension of the sub-power generator14in the vertical direction. The dimension of the axial gap power generator3in the vertical direction is smaller than the dimension of the axial gap power generator3in the horizontal direction. The dimension of the axial gap power generator3in the vertical direction is smaller than the dimension of the engine10in the vertical direction. When viewed from a direction in which the rotation axis X extends, the axial gap power generator3is located inside an outer shape of the engine10(seeFIG.1). When viewed from the direction in which the rotation axis X extends, the axial gap power generator3may protrude outward from the outer shape of the engine10.

The axial gap power generator3includes a power generator case31, the rotating shaft32, the stator33, the first rotor34, and the second rotor35. The rotating shaft32extending in the vertical direction is supported by the power generator case31so as to be rotatable. In a plan view, the power generator case31has a circular outer shape. The rotating shaft32is located at a lower side of the crank shaft22. A rotation axis of the rotating shaft32coincides with the rotation axis X of the crank shaft22. The rotating shaft32is coupled to the crank shaft22so as to rotate integrally with the crank shaft22.

The first rotor34, the stator33, and the second rotor35are line up in this order from an upper side to a lower side. The stator33includes a stator core41and a coil42located at the stator core41. The coil42is connected to a terminal of the axial gap power generator3. The stator33is rotatable relative to the rotating shaft32and is supported in a stationary state relative to the power generator case31.

The first rotor34includes a first rotor core43and a first magnet44. The first rotor core43has a circular plate shape and is externally fitted to the rotating shaft32so as to rotate integrally with the rotating shaft32. The first magnet44is located at the first rotor core43so as to be opposed to an upper surface of the stator33. The second rotor35includes a second rotor core45and a second magnet46. The second rotor core45has a circular plate shape and is externally fitted to the rotating shaft32so as to rotate integrally with the rotating shaft32. The second magnet46is located at the second rotor core45so as to be opposed to a lower surface of the stator33.

There is a gap between the first rotor34and the stator33in a direction along the rotation axis. Moreover, there is a gap between the second rotor35and the stator33in the direction along the rotation axis. The first rotor34and the second rotor35are connected to the crank shaft22through the rotating shaft32so as to rotate about the rotation axis X in association with the crank shaft22. The configuration of the axial gap power generator3is not especially limited. For example, one rotor and a pair of stators may be included, or rotors and stators may be included. Or, one rotor and one stator may be included.

In the axial gap power generator3, the first rotor34and the second rotor35are rotated by the crank shaft22, and this generates a current at the coil42(power generation function). In the axial gap power generator3, the first rotor34and the second rotor35are rotated by a magnetic field generated by supplying a current to the coil42, and this generates rotational power that rotates the crank shaft22(motor function). The axial gap power generator3is an integrated starter generator (ISG) that has both of a power generation function of generating electric power by the rotational power of the crank shaft22of the engine10and a starter motor function of starting the engine10.

FIG.3is a block diagram of a hybrid vehicle50on which the power generation assembly1ofFIG.2is detachably mounted. As shown inFIG.3, the power generation assembly1includes an inverter5(regulator) electrically connected to the axial gap power generator3. The inverter5is integrally connected to the axial gap power generator3. The inverter5convers AC power, generated by the axial gap power generator3, into DC power, adjusts the voltage of the DC power, and charges a battery51. In addition, the inverter5converts the DC power, discharged from the below-described battery51, into the AC power, adjusts the voltage of the AC power, and supplies the AC power to the axial gap power generator3.

The power generation assembly1includes the electronic control unit4. The electronic control unit4controls the engine10and the inverter5. The electronic control unit4controls the engine10such that the output of the engine10is constant. The power generation assembly1also includes a regulator (not shown) that converts the AC power, generated by the sub-power generator14, into the DC power and adjusts the voltage of the DC power. In the power generation assembly1, the engine10, the axial gap power generator3, the electronic control unit4, the inverter5, the sub-power generator14, a cooling medium pump P2, and the like are fixed to each other and integrated with each other.

The hybrid vehicle50includes the battery51, an inverter52, a traction motor53, an electronic control unit54, and the like. The vehicle50is a series hybrid vehicle. The traction motor53generates traveling power and drives driving wheels (for example, rear wheels RW). The inverter52converts the DC power, discharged from the battery51, into the AC power, adjusts the voltage of the AC power, and supplies the AC power to the traction motor53. In addition, the inverter52converts the AC power, regenerated by the traction motor53, into the DC power, adjusts the voltage of the DC power, and charges the battery51. The electronic control unit54controls the inverter52. The electronic control unit54can control traveling torque of the hybrid vehicle50.

The power generation assembly1includes an electric interface6. The electric interface6electrically connects the inverter5of the power generation assembly1to the battery51located outside the power generation assembly1. In the case of contact power supply, the electric interface6is a detachable terminal or a detachable electric power connector. In the case of non-contact power supply, the electric interface6is a coil.

The power generation assembly1includes a communication interface8. The communication interface8communicably connects the electronic control unit4of the power generation assembly1to the electronic control unit54located outside the power generation assembly1. In the case of wired communication, the communication interface8is a detachable terminal or a detachable communication connector. In the case of wireless communication, the communication interface8is a known wireless communicator.

The hybrid vehicle50includes an oil pump P1, an oil control valve unit55, and a hydraulic actuator56. The oil pump P1discharges oil when rotational driving power is input to a driven shaft of the oil pump P1. The hydraulic actuator56is, for example, a hydraulic cylinder that generates braking power. The oil control valve unit55opens and closes a passage between the oil pump P1and the hydraulic actuator56to control hydraulic pressure to be applied to the hydraulic actuator56. The operation of the oil control valve unit55is controlled by the electronic control unit54.

The power generation assembly1includes a mechanical interface7. The mechanical interface7can output the rotational power of the crank shaft22as mechanical energy. The mechanical interface7is, for example, a PTO shaft including an engaging portion (such as a spline groove or a keyway) that can be engaged with a mating member so as not to be rotatable relative to the mating member. A power transmitting path9(such as a gear mechanism, a chain-sprocket mechanism, or a belt-pulley mechanism) that transmits the rotational power of the crank shaft22to the mechanical interface7is located between the crank shaft22and the mechanical interface7. The axial gap power generator3is mechanically connected to the power transmitting path9.

The rotational power generated by the axial gap power generator3can be output from the mechanical interface7through the power transmitting path9. The mechanical interface7is detachably connected to the driven shaft of the oil pump P1. To be specific, the oil pump P1is driven by the rotational power supplied from the mechanical interface7. Moreover, a driven shaft of the cooling medium pump P2is mechanically connected to the power transmitting path9.

The rotational power generated by the engine10and the rotational power generated by the axial gap power generator3can be superimposed on each other at the power transmitting path9. When a predetermined condition is satisfied (for example, when there is a request from the electronic control unit54), the electronic control unit4drives the engine10and also drives the axial gap power generator3as a motor. Therefore, the rotational power generated by both of the engine10and the axial gap power generator3is output from the mechanical interface7through the power transmitting path9. At this time, while controlling the engine10such that the output of the engine10is constant, the electronic control unit4controls the inverter5so as to change the driving torque of the axial gap power generator3. Thus, the electronic control unit4can adjust the output from the mechanical interface7.

The electric interface6, the mechanical interface7, and the communication interface8are detachable from the hybrid vehicle50. Therefore, the power generation assembly1is easily attachable to and detachable from the hybrid vehicle50.

FIG.4is a block diagram of a modified example of a cooling structure of the power generation assembly1ofFIG.2. As shown inFIG.4, the power generation assembly1includes a cooling passage70. The cooling passage70includes an engine cooling passage70athat cools the engine10. The engine cooling passage70ais a circulation passage through which a cooling medium (for example, water) discharged from the cooling medium pump P2is guided to the engine10, and the cooling medium having cooled the engine10is returned to the cooling medium pump P2. A filter71and a radiator72are located at the engine cooling passage70a.

The cooling passage70includes a power generator cooling passage70bthat cools the axial gap power generator3. The power generator cooling passage70bbranches from the engine cooling passage70a, guides the cooling medium (for example, water) to the axial gap power generator3, and returns the cooling medium, having cooled the axial gap power generator3, to the engine cooling passage70a. The cooling passage70includes an inverter cooling passage70cthat cools the inverter5. The inverter cooling passage70cbranches from the engine cooling passage70aor the power generator cooling passage70b, guides the cooling medium (for example, water) to the inverter5, and returns the cooling medium, having cooled the inverter5, to the engine cooling passage70aor the power generator cooling passage70b. The cooling passage70may not include the inverter cooling passage70cand may not include the engine cooling passage70a.

FIG.5is a schematic diagram of the hybrid vehicle50ofFIG.3.FIG.6is a side view of the hybrid vehicle50ofFIG.5. As shown inFIGS.5and6, the hybrid vehicle50includes a pair of left and right front wheels FW and a pair of left and right rear wheels RW. The hybrid vehicle50is not limited to a four-wheeled vehicle and may be, for example, a two-wheeled vehicle or a three-wheeled vehicle. The hybrid vehicle50includes a vehicle body57supported by the front wheels FW and the rear wheels RW. The vehicle body57defines a vehicle internal space51that is separated from a vehicle external space S2.

The vehicle internal space51includes an occupant space S1ain which a user gets. The occupant space Sla is opened and closed by a door58attached to the vehicle body57. The vehicle internal space51includes a front accommodating space S1bthat is separated from the occupant space Sla. The front accommodating space S1bis located in front of the occupant space Sla. The front accommodating space S1bis opened and closed by a hood60(bonnet) which is located in front of a windshield59and attached to the vehicle body57. The front accommodating space S1bincludes a region located between the left front wheel FW and the right front wheel FW.

At least part of the power generation assembly1is located in the front accommodating space S1b. The power generation assembly1is supported by the vehicle body57in such a posture that the axial gap power generator3is located under the engine unit2. The power generation assembly1is located in a space sandwiched between the left front wheel FW and the right front wheel FW. In a side view, at least part of the power generation assembly1overlaps the front wheel FW. The power generation assembly1is mounted on the vehicle body57such that a lower end of the axial gap power generator3is located lower than upper ends of the front wheels FW (when the hybrid vehicle50is in a stop state and an empty state). At least part of the power generation assembly1may be located in a rear accommodating space located behind the occupant space Sla instead of the front accommodating space S1b.

FIG.7is a schematic sectional view showing the power generation assembly1of the hybrid vehicle50ofFIG.6and its vicinity which are viewed from front. As shown inFIG.7, the axial gap power generator3is located at a lower side of a bottom plate61of the vehicle body57. At least part of the axial gap power generator3is exposed to the vehicle external space S2located outside the bottom plate61. The axial gap power generator3may be located in both of the vehicle internal space S1(in the present embodiment, the front accommodating space S1b) and the vehicle external space S2, or the entire axial gap power generator3may be located in the vehicle external space S2.

The bottom plate61includes a recess62that is recessed upward. An upper plate portion62aof the recess62includes an opening H. The power generation assembly1extends through the opening H. The engine unit2is accommodated in the front accommodating space S1b. The axial gap power generator3is accommodated in the recess62. The lower end of the axial gap power generator3is located at a height equal to or higher than the height of a lower surface of a portion of the bottom plate61which is adjacent to the recess62.

The bottom plate61may not include the recess62that accommodates the axial gap power generator3. To be specific, the axial gap power generator3may be located so as to project downward from the bottom plate61. The entire power generation assembly1may be located in the vehicle internal space S1(front accommodating space S1b). Air (traveling wind) in the vehicle external space S2during traveling may be guided to the axial gap power generator3. Moreover, the air (traveling wind) in the vehicle external space S2during traveling may also be guided to the engine unit2.

According to the above configuration, the axial gap power generator3is located at one vertical-direction side of the engine10including the crank shaft22extending in the vertical direction. Therefore, an occupied space of the power generation assembly1in the horizontal direction is reduced. The power generator3is of an axial gap type and is located such that the rotors34and35rotate about the rotation axis X extending in the vertical direction. Therefore, the occupied space of the power generation assembly1in the vertical direction is also reduced. Thus, the entire power generation assembly1can be made compact without deteriorating the power generation performance.

Moreover, the axial gap power generator3is located at a lower side of the engine10. Therefore, the amount of heat transferred from the engine10to the axial gap power generator3can be made smaller than when the axial gap power generator3is located at an upper side of the engine10.

Moreover, since the cooling fan12is located at an opposite side of the axial gap power generator3across the engine10, the cooling fan12and the axial gap power generator3which operate in association with the crank shaft22are prevented from interfering with each other, and the cooling fan12can be easily located.

Moreover, the cooling fan12requires maintenance in which when foreign matters are sucked, the fan cover13is detached, and the foreign matters are removed. The air cleaner15requires maintenance in which the air cleaner case28is disassembled, and the cleaner element29is replaced. Herein, the upper end of the air cleaner15is located higher than the upper end of the engine10. Therefore, the cooling fan12and the air cleaner15which are assumed to have high maintenance frequency are located at the same side (upper side) of the engine10in the vertical direction. Thus, the devices having high maintenance frequency are collectively positioned, and this can improve the convenience of the maintenance.

Moreover, the oil pan26is located above the axial gap power generator3located at the lower side of the engine10and is located at the lower portion of the crank case21of the engine10. Therefore, a passage through which the oil from the engine10is guided to the oil pan26does not have to bypass the axial gap power generator3, and therefore, the power generation assembly1can be kept compact.

Moreover, in the horizontal direction, the valve gear24is located at one side of the rotation axis X, and the oil pan26is located at the other side of the rotation axis X. To be specific, the valve gear24and the oil pan26are located so as to sandwich the rotation axis X. Therefore, the valve gear24and the oil pan26can coexist while keeping the power generation assembly1compact.

Moreover, the small sub-power generator14is located at an upper side of the engine10, and the large axial gap power generator3is located at a lower side of the engine10. Therefore, the center of gravity of the power generation assembly1is lowered, and this can improve arrangement stability. Furthermore, the sub-power generator14that is smaller than the axial gap power generator3is located at the upper side of the engine10. Therefore, the sub-power generator14can be easily accommodated in the upper cover11while avoiding the cooling fan12located at the upper side of the engine10and being located close to the engine10. Thus, the power generation assembly1can be made compact.

Moreover, when viewed from the axial direction X, the axial gap power generator3is located inside the outer shape of the engine10. Therefore, the size of the power generation assembly1in the horizontal direction can be prevented from increasing.

Moreover, the power generation capability can be improved by using the multiple cylinder engine as the engine10, and the power generation assembly1can be reduced in size in the vertical direction by the axial gap power generator3which can reduce the occupied space in the vertical direction. Especially, since the engine10includes the cylinders23located on the same horizontal plane and extending in different directions, the power generation assembly1can be suitably reduced in size in the vertical direction.

Moreover, the inverter5serves as part of the power generation assembly1and is integrally connected to the axial gap power generator3. Therefore, the power generation assembly1capable of easily supplying stable DC power to an outside can be provided.

Moreover, the axial gap power generator3is the integrated starter generator having both of the power generation function and the starter motor function. Therefore, a starter motor does not have to be included, and this can reduce the size of the power generation assembly1.

Moreover, the axial gap power generator3is cooled by the cooling medium flowing through the cooling passage70, and this can improve the power generation performance. In addition, the cooling medium that cools the engine10and the cooling medium that cools the axial gap power generator3are the same as each other, and therefore, the power generation assembly1can be reduced in size.

Moreover, according to the power generation assembly1, the mechanical energy output from the mechanical interface7by the rotational power of the engine10can be increased by an assist realized by the driving power of the axial gap power generator3serving as a motor. Since torque adjustment of the motor is easier than that of the engine, the torque of the rotational power output from the mechanical interface7can be easily and quickly adjusted.

Moreover, in the hybrid vehicle50, the lower end of the axial gap power generator3is located lower than the upper ends of the front wheels FW. Therefore, the hybrid vehicle50having high space efficiency and low center of gravity can be provided by the compact power generation assembly1.

Moreover, the axial gap power generator3is located at a lower side of the vehicle body57such that at least part thereof is exposed to the vehicle external space S2. Therefore, the axial gap power generator3is easily exposed to traveling wind, and this can efficiently cool the axial gap power generator3.

Moreover, since the axial gap power generator3is located between the left front wheel FW and the right front wheel FW, an arrangement space for the other on-vehicle parts in the entire vehicle can be secured.

FIG.8is a block diagram of a power generation assembly101of First Modified Example. As shown inFIG.8, the oil pump P1is included in the power generation assembly101of First Modified Example. The power generation assembly101includes a fluid interface107instead of the mechanical interface7. The fluid interface107outputs the oil, discharged from the oil pump P1, to an outside.

Specifically, a pipe connected to an inflow port of the oil control valve unit55of a vehicle150is detachably connected to the fluid interface107. The oil discharged from the oil pump P1is output through the fluid interface107to the oil control valve unit55located outside the power generation assembly101.

According to this configuration, since the oil pump P1is included in the power generation assembly101, the configuration of the vehicle150except for the power generation assembly101can be simplified. Moreover, since the power generation assembly101outputs fluid energy in addition to electric energy that is high in versatility, high output energy is easily supplied to external devices, and the external devices can easily perform high-load work. Moreover, when the fluid interface107of the power generation assembly101is connected to the external hydraulic actuator56that requires hydraulic pressure, the hydraulic pressure can be supplied to the hydraulic actuator56. Therefore, the power generation assembly101that can easily supply the fluid energy and is of a cassette type can be provided. Since the other components are the same as those of the above embodiment, the same reference signs are used, and explanations thereof are omitted.

FIG.9is a block diagram of a power generation assembly201of Second Modified Example. As shown inFIG.9, the battery51is included in the power generation assembly201of Second Modified Example. An electric interface206of the power generation assembly201outputs the DC power, discharged from the battery51, to an outside. Specifically, an electric wire connected to the inverter52of a vehicle250is detachably connected to the electric interface206through a terminal or a connector. Non-contact power supply may be performed between the electric interface206and the inverter52. In this case, the electric interface206may be a coil.

The electric power discharged from the battery51is supplied through the electric interface206to the inverter52located outside the power generation assembly201. Moreover, the inverter52charges the battery51through the electric interface206by the electric power regenerated by the traction motor53(FIG.3). The electronic control unit4controls charging and discharging of the battery51in accordance with a signal received from the electronic control unit54through the communication interface8. According to this configuration, since the battery51is included in the power generation assembly201, the configuration of the vehicle250except for the power generation assembly201can be simplified. Since the other components are the same as those in the above embodiment or the above modified example, the same reference signs are used, and explanations thereof are omitted.

FIG.10is a side view of a hybrid vehicle350of a modified example on which the power generation assembly1ofFIG.2is detachably mounted. As shown inFIG.10, the vehicle350includes the pair of left and right rear wheels RW (target wheels). The vehicle350may include the pair of left and right front wheels FW or may include only one front wheel FW. The vehicle350includes: a left swing arm380that connects the left rear wheel RW to a vehicle body357; and a right swing arm380that connects the right rear wheel RW to the vehicle body357. One end portion of each swing arm380is turnably connected to the vehicle body357, and the other end portion of each swing arm380is turnably connected to the rear wheel RW. A suspension (shock absorber) is located between each swing arm380and the vehicle body357.

The vehicle body357defines a vehicle internal space S3that is separated from the vehicle external space S2. The vehicle internal space S3includes an occupant space S3ain which a user gets. The occupant space S3ais opened and closed by a door358attached to the vehicle body357. The vehicle internal space S3includes a rear accommodating space S3bthat is separated from the occupant space S3a. The rear accommodating space S3bis located behind the occupant space S3a. The rear accommodating space S3bis located above the swing arm380.

At least part of the power generation assembly1is located in the rear accommodating space S3b. The power generation assembly1is supported by the vehicle body357in such a posture that the axial gap power generator3is located under the engine unit2. At least part of the axial gap power generator3is located at a lower side of the vehicle body357and exposed to the vehicle external space S2. The axial gap power generator3may be located in both of the vehicle internal space S3(in the present embodiment, the rear accommodating space S3b) and the vehicle external space S2, or the entire axial gap power generator3may be located in the vehicle external space S2. The engine unit2is located in the rear accommodating space S3bbut may be located in the vehicle external space S2.

The power generation assembly1is located between the left and right swing arms380in the left-right direction. In a side view, at least part of the power generation assembly1overlaps the swing arm380. The power generation assembly1is mounted on the vehicle body357such that (when the vehicle350is in a stop state and an empty state) the lower end of the axial gap power generator3is located lower than an upper end of the rear wheel RW. The axial gap power generator3is located such that the lower end thereof is lower than an upper end (front end) of the swing arm380.

In a side view, the axial gap power generator3is located so as to overlap the swing arm380(when the vehicle350is in a stop state and an empty state). The swing arm380is for the rear wheel, but the axial gap power generator3may be located so as to overlap a swing arm for the front wheel in a side view.

According to the above configuration, the axial gap power generator3is located such that the lower end thereof is lower than the upper end of the swing arm380. Therefore, in the vehicle350which includes the swing arms380and in which the vehicle body357largely moves in the upper-lower direction by the suspensions, the center of gravity can be set to be adequately low. Moreover, since the axial gap power generator3is located in a space between the left and right swing arms380, the space of the entire vehicle is efficiently used, and the arrangement space for the other on-vehicle parts can be secured. Since the other components are the same as those in the above embodiment or the above modified example, explanations thereof are omitted.

The present disclosure is not limited to the above embodiment and the modified examples. Modifications, additions, and eliminations may be made with respect to the configurations of the embodiment and the modified examples. For example, some of components or methods in one embodiment or one modified example may be applied to another embodiment or another modified example. Some components in an embodiment or a modified example may be separated and arbitrarily extracted from the other components in the embodiment or the modified example.