Drive unit

Abstract

This drive unit is a unit which is mounted in a vehicle and in which an inverter, a motor that receives power supply from the inverter, and a gear box having a shaft gear provided on the shaft of the motor are unitized. The drive unit includes a gear chamber which is provided in the gear box and in which a shaft gear having a diameter smaller than the outer diameter dimension of the motor is accommodated. The drive unit includes a housing chamber which is provided in the gear box and which is formed as a space different from the gear chamber by the dimensional difference between the outer diameter dimension of the motor and the outer diameter dimension of the shaft gear. At least some of the components of the inverter are housed in the housing chamber.

Description

Drive unit

[0001] The present invention relates to a drive unit.

[0002] JP2017-184523A discloses a drive device.

[0003] The drive device includes a left-side electric motor and a right-side electric motor. A reducer housing of the reducer unit is provided between the left-side electric motor and the right-side electric motor. An inverter housing of the inverter unit is provided above the reducer housing. The inverter housing accommodates the components that make up the inverter.

[0004] In this drive device, the inverter unit is provided above the reduction gear unit, which causes a problem of increased size.

[0005] The present invention has been made in view of the above problems, and has as its object to provide a drive unit that can be made smaller.

[0006] According to one aspect of the present invention, there is provided a drive unit mounted on a vehicle, which unitizes an inverter, a motor receiving power supply from the inverter, and a gearbox having a shaft gear attached to the shaft of the motor, and which comprises: a gear chamber attached to the gearbox and accommodating a shaft gear having a smaller diameter than the outer diameter of the motor; and a storage chamber attached to the gearbox and formed as a space different from the gear chamber due to the dimensional difference between the outer diameter of the motor and the outer diameter of the shaft gear, and in which at least some of the components of the inverter are accommodated.

[0007] In this drive unit, the gearbox has an accommodation chamber formed as a space separate from the gear chamber due to the difference in outer diameter between the motor and the shaft gear. This accommodation chamber accommodates at least some of the inverter components. This allows the drive unit to be more compact than if all of the inverter components were located outside the gearbox.

[0008] FIG. 1 is a perspective view of a drive unit according to this embodiment, showing a state in which a gear box cover is removed. FIG. 2 is a cross-sectional view of a main portion of the drive unit according to this embodiment, showing a state in which a motor housing is cut away. FIG. 3 is a schematic diagram used to explain the drive unit according to this embodiment. FIG. 4 is a schematic diagram used to explain a drive unit according to a first modified example of this embodiment. FIG. 5 is a perspective view of a drive unit according to a second modified example of this embodiment, showing a state in which a gear box cover is removed. FIG. 6 is a schematic diagram used to explain the function of a reservoir of a drive unit according to a second modified example of this embodiment. FIG. 7 is a schematic diagram used to explain the function of cooling a semiconductor device of a drive unit according to a second modified example of this embodiment. FIG. 8 is a schematic diagram used to explain the function of cooling a heat-generating component of a drive unit according to a second modified example of this embodiment.

[0009] First Embodiment Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0010] Fig. 1 is a perspective view showing a drive unit 10 according to this embodiment, with a cover (not shown) of a gear box 12 removed. Fig. 2 is a cross-sectional view of a main part of the drive unit 10 according to this embodiment, with a motor housing 14 cut away. Fig. 3 is a schematic diagram used to explain the drive unit 10 according to this embodiment.

[0011] 1, a drive unit 10 is used in, for example, an electric vehicle. The drive unit 10 is mounted on the vehicle and drives the drive wheels provided on the vehicle. The drive unit 10 is disposed on the front side F of the vehicle and drives the front wheels of the vehicle.

[0012] The drive unit 10 includes an inverter 20, a motor 22 (see FIG. 2) that receives power from the inverter 20, and a gearbox 12 that has a shaft gear 26 provided on a shaft 24 of the motor 22. The inverter 20, the motor 22 (see FIG. 2), and the gearbox 12 are unitized.

[0013] When mounted on a vehicle, the drive unit 10 is disposed so that a shaft 24 extending from the motor 22 extends in the vehicle width direction W. In addition, in the drive unit 10, a differential gear 55 (see FIG. 3) that drives a drive shaft (not shown) that drives the drive wheels is disposed rearward R of the shaft 24 of the motor 22.

[0014] 2, the motor 22 is housed in a rectangular motor housing 14. The motor housing 14 has a motor housing bottom surface 14A and a motor housing front wall surface 14B extending from the edge of the motor housing bottom surface 14A on the vehicle front F side. The motor housing 14 also has a motor housing rear wall surface 14C extending from the edge of the motor housing bottom surface 14A on the vehicle rear R side, and a motor housing top surface 14D connecting the motor housing front wall surface 14B and the motor housing rear wall surface 14C.

[0015] The motor housing front wall 14B has a front opening 30, which is closed by a cover 32.

[0016] The motor 22 includes a motor case 22A. The motor case 22A is coupled to the motor housing 14 and holds the motor 22 in the motor housing 14. A stator 22B is provided in the motor case 22A along the inner wall surface of the motor case 22A. A rotor 22C is rotatably provided inside the stator 22B. A shaft 24 is provided on the rotor 22C. The shaft 24 passes through a partition wall 40 that separates the motor housing 14 and the gear box 12 and extends into the gear box 12. In this embodiment, the outer diameter dimension D1 of the motor 22 is determined by the outer diameter of the stator 22B.

[0017] The motor 22 is a so-called rotating electric machine that functions as an electric motor that receives power supply to rotate the drive wheels and as a generator that receives rotational force from the drive wheels to generate electricity (regenerate).

[0018] 1, the gearbox 12 includes a gearbox housing 50. The gearbox housing 50 includes a shaft gear 26 provided on the shaft 24 of the motor 22, an intermediate gear 52 that meshes with the shaft gear 26, and a final gear 54 (see FIG. 3) that meshes with the intermediate gear 52.

[0019] The gear box 12 includes a gear mechanism 56 consisting of a shaft gear 26, an intermediate gear 52, and a final gear 54. The shaft gear 26, the intermediate gear 52, and the final gear 54 that make up the gear mechanism 56 are arranged in the horizontal direction. The intermediate gear 52 has a larger diameter than the shaft gear 26. The gear mechanism 56 constitutes a speed reduction mechanism. Note that the gear mechanism 56 may also constitute a speed increase mechanism.

[0020] The final gear 54 transmits the driving force to a differential gear 55 (see FIG. 3) that constitutes a differential device. The differential gear 55 drives a drive shaft (not shown).

[0021] The gearbox housing 50 includes a box main body 60 that houses the shaft gear 26, and a box extension 62 that extends from the box main body 60 toward the rear R of the vehicle. The box extension 62 has a shape that corresponds to the outer shapes of the intermediate gear 52 and the differential gear 55 (see FIG. 3). The box extension 62 has a peripheral wall 62A that follows the outer peripheries of the intermediate gear 52 and the differential gear 55.

[0022] The box main body 60 and the box extension 62 are provided with bolt insertion portions 66 through which bolts are inserted to fasten the motor housing 14 and the gearbox housing 50 and to attach a cover (not shown) to the gearbox housing 50.

[0023] In order to increase the rigidity of the connection between the gearbox housing 50 and the motor housing 14 , bolt insertion portions 66 are arranged at corners 68 of the box body 60 of the gearbox housing 50 .

[0024] The box main body 60 includes a main body bottom surface 60A, a main body front wall surface 60B extending from the edge of the main body bottom surface 60A on the front F side of the vehicle, and a main body rear wall surface 60C connecting the edge of the main body bottom surface 60A on the rear R side of the vehicle and the peripheral wall 62A of the box extension portion 62. The box main body 60 also includes a main body top surface 60D connecting the main body front wall surface 60B and the peripheral wall 62A of the box extension portion 62. As a result, the box main body 60 is formed with a rectangular cross section with a portion that contacts the box extension portion 62 missing.

[0025] A main body bottom surface 60A of the box main body 60 extends in an extension of the motor housing bottom surface 14A (see FIG. 2 ) of the motor housing 14. A main body front wall surface 60B of the box main body 60 extends to a position toward the vehicle rear R beyond the motor housing front wall surface 14B of the motor housing 14. A main body top surface 60D of the box main body 60 extends at a height position lower than the motor housing top surface 14D of the motor housing 14.

[0026] The gear box 12 includes a gear chamber 70 that accommodates the shaft gear 26, which has a diameter smaller than the outer diameter D1 (see FIG. 2 or FIG. 3) of the motor 22. The gear box 12 also includes an accommodation chamber 72 that is formed as a space different from the gear chamber 70 due to the difference in size between the outer diameter D1 of the motor 22 and the outer diameter D2 (see FIG. 3) of the shaft gear 26.

[0027] 3, the outer diameter D2 of the shaft gear 26 is smaller than the outer diameter D1 of the motor 22. Therefore, in the gearbox housing 50 formed to fit the motor housing 14, a space exists between the shaft gear 26 and the wall surface of the gearbox housing 50 due to the difference in size between the outer diameter D1 of the motor 22 and the outer diameter D2 of the shaft gear 26. The accommodation chamber 72 is formed in this space.

[0028] 1, the accommodation chamber 72 is surrounded by the main body bottom surface 60A, the main body front wall surface 60B, the main body rear wall surface 60C of the gearbox housing 50, and a partition wall 80 connecting the main body rear wall surface 60C and the main body front wall surface 60B. As a result, the accommodation chamber 72 is located below the shaft gear 26 and is formed in a corner of the gearbox 12.

[0029] The partition wall 80 is formed with a partition wall extension portion 80A that extends from the middle of the main body front wall surface 60B toward the shaft gear 26 and along the main body bottom surface 60A, and a curved partition wall curved portion 80B that extends from the partition wall extension portion 80A. The partition wall 80 also has an inclined partition wall portion 80C that connects the partition wall curved portion 80B and the main body rear wall surface 60C.

[0030] The partition curved portion 80B is formed to have an arcuate cross section that curves along the shaft gear 26. The partition curved portion 80B supports a bearing 82, which rotatably supports the tip end of the shaft 24, from below.

[0031] The partition curved portion 80B is formed so that the portion below the central axis of the shaft 24 is lowest. As a result, a first reservoir 84 that stores lubricating oil for lubricating each gear of the gear mechanism 56 is formed by the partition curved portion 80B on the surface of the partition 80 facing the gear chamber 70. The lubricating oil stored in the first reservoir 84 is scooped up by the rotating shaft gear 26.

[0032] The partition wall inclined portion 80C extends obliquely downward from the partition wall curved portion 80B toward the main body rear wall surface 60C. As a result, a second reservoir 86 for storing lubricating oil is formed by the partition wall inclined portion 80C on the surface of the partition wall 80 facing the gear chamber 70. The lubricating oil stored in the second reservoir 86 is scooped up by the rotating final gear 54 or differential gear 55.

[0033] A parking lock actuator 90 is provided on the main body top surface 60D of the box main body 60 of the gearbox 12. An operating shaft 90A of the parking lock actuator 90 extends into the gear chamber 70 and engages with an operating plate 92. An engaging pawl 92A that engages with teeth 94A of a lock gear 94 provided on the shaft 24 is provided at the tip of the operating plate 92.

[0034] When the park lock actuator 90 establishes the locked state, the operating shaft 90A rotates the operating plate 92 about the support shaft 92B, and the engaging pawl 92A is inserted between the teeth 94A of the lock gear 94. As a result, the park lock actuator 90 prevents the shaft gear 26 from rotating.

[0035] When the park lock actuator 90 is in the unlocked state, the operating shaft 90A rotates the operating plate 92, and pulls the engaging pawl 92A out from between the teeth 94A of the lock gear 94. As a result, the park lock actuator 90 allows the shaft gear 26 to rotate.

[0036] The accommodation chamber 72 accommodates at least some of the components that make up the inverter 20 .

[0037] The inverter 20 includes a smoothing capacitor 100 that smoothes the voltage supplied from the battery via the high-voltage unit. The inverter 20 also includes a semiconductor device 102 that generates three-phase AC from the voltage smoothed by the smoothing capacitor 100 to drive the motor 22, which is a three-phase motor. The inverter 20 also includes a three-phase electrode unit 104 that outputs the three-phase AC generated by the semiconductor device 102 to the motor 22.

[0038] In the drive unit 10 of this embodiment, the smoothing capacitor 100 , the semiconductor device 102 , and the three-phase electrode section 104 that constitute the inverter 20 are all housed in the housing chamber 72 .

[0039] In the drive unit 10 of this embodiment, a case will be described in which all of the components of the inverter 20 are accommodated in the accommodation chamber 72, but the drive unit 10 is not limited to this configuration. For example, the drive unit 10 of this embodiment may accommodate only some of the components of the inverter 20 in the accommodation chamber 72.

[0040] A smoothing capacitor 100 is disposed in the accommodation chamber 72 on the vehicle rear R side of the semiconductor device 102. A three-phase electrode unit 104 is disposed on the vehicle front F side of the semiconductor device 102. The three-phase electrode unit 104 forms, for example, a bus bar.

[0041] This drive unit 10 receives power supplied from a battery via a smoothing capacitor 100 and inputs it to the PN terminal of the semiconductor device 102. The drive unit 10 also outputs the output from the UVW terminals of the semiconductor device 102 to the motor 22 via a three-phase electrode unit 104 that forms a bus bar. This makes it easier to arrange the wiring compared to when the components of the inverter 20 are arranged in the order of, for example, the semiconductor device 102, the smoothing capacitor 100, and the three-phase electrode unit 104.

[0042] In addition, the smoothing capacitor 100, the semiconductor device 102, and the three-phase electrode section 104 are arranged in this order from the rear R of the vehicle in the accommodation chamber 72, and the PN terminals of the smoothing capacitor 100 and the semiconductor device 102 to which the smoothing capacitor 100 is connected are arranged on the rear R side of the vehicle.

[0043] Therefore, in this embodiment in which the drive unit 10 is positioned on the front F side of the vehicle, the distance from the battery, which is positioned on the rear R side of the vehicle relative to the drive unit 10, to the PN terminal of the semiconductor device 102 can be shortened, making it possible to shorten the wiring extending from the battery.

[0044] When the drive unit 10 is disposed at the rear R of the vehicle, the positions of the smoothing capacitor 100 and the three-phase electrode unit 104 are reversed.

[0045] (Operations and Effects) As described above, the drive unit 10 of the first embodiment is a unit mounted on a vehicle. The drive unit 10 is a unit that combines the inverter 20, the motor 22 that receives power supply from the inverter 20, and the gearbox 12 that has the shaft gear 26 attached to the shaft 24 of the motor 22. The drive unit 10 includes a gear chamber 70 that is attached to the gearbox 12 and that houses the shaft gear 26, the shaft gear 26 having a diameter smaller than the outer diameter dimension D1 of the motor 22. The drive unit 10 includes an accommodation chamber 72 that is attached to the gearbox 12 and that is formed as a space different from the gear chamber 70 due to the dimensional difference between the outer diameter dimension D1 of the motor 22 and the outer diameter dimension D2 of the shaft gear 26. The accommodation chamber 72 accommodates at least some of the components of the inverter 20.

[0046] As a result, the excess space generated in the gearbox housing 50 due to the difference in size between the outer diameter D1 of the motor 22 and the outer diameter D2 of the shaft gear 26 can be effectively utilized as the accommodation chamber 72. At least some of the components of the inverter 20 are accommodated in this accommodation chamber 72. Therefore, the drive unit 10 can be made more compact than if all of the components of the inverter 20 were arranged outside the gearbox 12.

[0047] In the drive unit 10 of this embodiment, all of the components of the inverter 20 are housed in the housing chamber 72 of the gearbox 12. This allows for further miniaturization compared to when some of the components of the inverter 20 are disposed externally.

[0048] Furthermore, the center of gravity of the drive unit 10 can be lowered compared to when the inverter unit, which houses some of the components of the inverter 20, is disposed on top of the motor housing 14 or the gearbox housing 50. This reduces lateral shaking of the drive unit 10 during driving, thereby suppressing vibration and improving driving stability.

[0049] In addition, when the drive unit 10 of this embodiment is mounted on a vehicle, various gears including the shaft gear 26 (the shaft gear 26, the intermediate gear 52, and the final gear 54) are arranged horizontally in the gearbox 12. The accommodation chamber 72 is located below the shaft gear 26 and in a corner of the gearbox 12.

[0050] In this configuration, the components of the inverter 20 are disposed at a lower position than the shaft gear 26. This allows the center of gravity of the drive unit 10 to be lower than when the components of the inverter 20 are disposed at a higher position than the shaft gear 26 and excess space remains below the shaft gear 26. This reduces lateral shaking of the drive unit 10 during driving, thereby suppressing vibration and improving driving stability.

[0051] The components of the inverter 20 are arranged in a housing chamber 72 formed in a corner of the gearbox 12 .

[0052] Here, the motor housing 14 and the gearbox housing 50 are joined at corners 68 to increase rigidity, and the components of the inverter 20 are housed in housing chambers 72 formed on the corner sides of the gearbox 12. Therefore, the components of the inverter 20 can be arranged in the corners where the joint rigidity is high.

[0053] <First Modification> Next, a drive unit 200 according to a first modification will be described.

[0054] 4 is a schematic diagram used to explain a drive unit 200 according to a first modified example of this embodiment. In the drive unit 200 according to the first modified example, parts that are the same as or equivalent to those in the above-described embodiment are given the same reference numerals and will not be described again, and only the different parts will be described.

[0055] As shown in FIG. 4, a drive unit 200 according to the first modification is different from the embodiment described above in that a coolant passage 210 is provided in the accommodation chamber 72 .

[0056] That is, a coolant path 210 through which a coolant 212 for cooling the inverter 20 flows is provided in the accommodation chamber 72 of the gearbox housing 50. The semiconductor device 102 constituting the inverter 20 is disposed in contact with the coolant path 210. The coolant 212 is formed of, for example, cooling water.

[0057] The coolant passage 210 is provided along the partition wall 80. The coolant passage 210 is formed throughout the accommodation chamber 72 in the vehicle longitudinal direction and the vehicle width direction W (see FIG. 1).

[0058] Coolant path 210 is connected to, for example, a radiator (not shown) provided outside drive unit 10. Coolant 212 circulates between coolant path 210 and the radiator. Coolant 212 cooled by the radiator removes heat from inside accommodation chamber 72 as it passes through coolant path 210. This cools the heated components of inverter 20 and suppresses a temperature rise in the components of inverter 20 that have a lower heat resistance temperature than gear mechanism 56.

[0059] In the first modified example, the case where the coolant passage 210 is formed over the entire area of ​​the accommodation chamber 72 in the vehicle longitudinal direction and the vehicle width direction W is described, but the area where the coolant passage 210 is formed is not limited to this. For example, the position where the coolant passage 210 is provided may be determined depending on the arrangement of the components of the inverter 20 that require cooling.

[0060] (Functions and Effects) The first modified example configured as above provides the same functions and effects as the above-described embodiment with respect to the parts that are the same as or equivalent to those of the above-described embodiment.

[0061] In the first modified example, the gear box 12 is provided with a coolant passage 210 through which a coolant 212 flows to cool the inverter 20 housed in the housing chamber 72 .

[0062] In this configuration, heat from the operating gear mechanism 56 can be transferred, and the components of the inverter 20 inside the accommodation chamber 72, which are prone to heat buildup, can be cooled by the refrigerant 212 in the refrigerant path 210. This suppresses a decrease in efficiency of the inverter 20 due to heat.

[0063] The coolant path 210 is provided along the partition wall 80. The coolant path 210 suppresses the transfer of heat from the gear mechanism 56 to the inverter 20.

[0064] In this modification, the components accommodated in the accommodation chamber 72 include the semiconductor device 102 that constitutes the inverter 20 , and the semiconductor device 102 is disposed in contact with the coolant path 210 .

[0065] In this configuration, by bringing the semiconductor device 102, which generates the most heat among the components of the inverter 20, into contact with the coolant path 210, it is possible to promote cooling of the inverter 20.

[0066] <Second Modification> Next, a drive unit 300 according to a second modification will be described.

[0067] Fig. 5 is a perspective view showing a drive unit 300 according to a second modified example of this embodiment, with a cover (not shown) removed from the gear box 12. Fig. 6 is a schematic diagram used to explain the function of a storage section (first storage section 84) of the drive unit 300 according to the second modified example of this embodiment.

[0068] 7 is a schematic diagram used to explain the function of cooling the semiconductor device 102 of the drive unit 300 according to a second modified example of this embodiment. The semiconductor device 102 is shown in an exaggerated manner in FIG. 7. FIG. 8 is a schematic diagram used to explain the function of cooling the heat-generating component (three-phase electrode section 104) of the drive unit 300 according to the second modified example of this embodiment. The three-phase electrode section 104 constituting the heat-generating component is shown in an exaggerated manner in FIG.

[0069] In the drive unit 300 according to the second modification, the same or equivalent parts as those in the above-described embodiment or the first modification are designated by the same reference numerals and description thereof will be omitted, and only the different parts will be described.

[0070] As shown in Figures 5 and 6, a drive unit 300 according to the second modified example differs significantly from the above-described embodiment or the first modified example in that a partition wall refrigerant passage 310 is formed in the partition wall 80.

[0071] That is, the partition wall 80 separating the gear chamber 70 and the accommodation chamber 72 has a double structure made up of a gear chamber-side wall surface 312 and an accommodation chamber-side wall surface 314. An end of the gear chamber-side wall surface 312 and an end of the accommodation chamber-side wall surface 314 are connected by an end wall 316. As a result, a partition wall refrigerant passage 310 is formed in the partition wall 80, surrounded by the gear chamber-side wall surface 312, the accommodation chamber-side wall surface 314, and the end wall 316. In other words, the partition wall 80 constitutes the partition wall refrigerant passage 310.

[0072] The drive unit 300 may have a coolant passage provided in the partition wall 40 that separates the motor housing 14 from the gearbox housing 50. The drive unit 300 may also have a coolant passage provided in the partition wall 40 at a location corresponding to the accommodation chamber 72.

[0073] A coolant 320 that cools the inside of the accommodation chamber 72 flows through the partition coolant passage 310. The coolant 320 is formed of, for example, cooling water.

[0074] The partition wall refrigerant passage 310 is connected to, for example, a radiator (not shown) provided outside the drive unit 300. The refrigerant 320 circulates between the partition wall refrigerant passage 310 and the radiator. The refrigerant 320 cooled by the radiator reduces the temperature inside the accommodation chamber 72 as it passes through the partition wall refrigerant passage 310. The refrigerant 320 cooled by the radiator also reduces the temperature of the lubricating oil in contact with the gear chamber side wall surface 312.

[0075] 6 , the refrigerant 320 exchanges heat with the lubricating oil stored in the first storage section 84 and the second storage section 86. This allows the drive unit 300 to efficiently cool the lubricating oil that has absorbed heat from the gear mechanism 56.

[0076] Furthermore, the coolant 320 suppresses the transfer of heat between the gear chamber 70 and the accommodation chamber 72. As a result, the coolant 320 suppresses the temperature rise of the components of the inverter 20 that have a lower heat resistance temperature than the gear mechanism 56.

[0077] The semiconductor device 102 accommodated in the accommodation chamber 72 is disposed in contact with the partition wall 80 in which the partition wall coolant passage 310 is provided.

[0078] 7 , the semiconductor device 102 includes a semiconductor device 330. The semiconductor device 330 includes a heat sink 332. Fins of the heat sink 332 are in contact with the housing chamber side wall surface 314 of the partition wall 80 that constitutes the partition wall coolant path 310.

[0079] The three-phase electrode unit 104 housed in the housing chamber 72 generates heat when current is applied. The three-phase electrode unit 104 constitutes a heat-generating component. Furthermore, the smoothing capacitor 100 housed in the housing chamber 72 generates heat when current is applied. The smoothing capacitor 100 constitutes a heat-generating component. The heat-generating component, which is the three-phase electrode unit 104 or the smoothing capacitor 100, is disposed in proximity to the partition wall refrigerant path 310.

[0080] The three-phase electrode unit 104, which is a heat-generating component, will be described in detail using Figure 8. The three-phase electrode unit 104, which is a heat-generating component, includes three electrodes 104A, 104B, and 104C. Each of the electrodes 104A, 104B, and 104C is disposed adjacent to the storage chamber-side wall surface 314 of the partition wall 80 that constitutes the partition wall refrigerant passage 310.

[0081] Here, "close proximity" refers to a state in which each of the electrodes 104A, 104B, and 104C of the three-phase electrode unit 104 is in contact with the accommodation chamber side wall surface 314 of the partition wall 80 that constitutes the partition wall refrigerant passage 310 via the insulating layer 104D. Also, "close proximity" refers to a state in which a gap is formed between each of the electrodes 104A, 104B, and 104C of the three-phase electrode unit 104 and the accommodation chamber side wall surface 314, and the size of this gap is such that heat from each of the electrodes 104A, 104B, and 104C can be transferred to the refrigerant 320 in the partition wall refrigerant passage 310.

[0082] When the heat-generating component is the smoothing capacitor 100, the smoothing capacitor 100 is disposed adjacent to the partition wall refrigerant passage 310 while being mounted on the substrate, as described above.

[0083] (Functions and Effects) The second modified example configured in this manner provides the same functions and effects as the above-described embodiment with respect to the parts that are the same as or equivalent to those of the above-described embodiment.

[0084] In the second modified example, a partition wall coolant passage 310 serving as a coolant passage is provided in the partition wall 80 that separates the gear chamber 70 and the accommodation chamber 72 .

[0085] This allows for a wider use of the accommodation chamber 72 compared to when the refrigerant passage is provided in the accommodation chamber 72 .

[0086] In this modification, a first reservoir 84 and a second reservoir 86 are provided on the surface of the partition wall 80 facing the gear chamber 70 as reservoirs for the lubricating oil that lubricates the shaft gear 26 .

[0087] In this configuration, the lubricating oil that has absorbed heat from the gear mechanism 56 including the shaft gear 26 is cooled by heat exchange with the refrigerant 320 in the partition wall refrigerant passage 310 in each reservoir 84, 86. This makes it possible to improve the cooling efficiency of the lubricating oil compared to a case where no lubricating oil reservoir is provided.

[0088] The position or size of each of the storage sections 84 and 86 is preferably determined in accordance with the partition wall refrigerant passage 310 .

[0089] In this modification, the components accommodated in the accommodation chamber 72 include the semiconductor device 102 that constitutes the inverter 20, and the semiconductor device 102 is arranged in contact with the partition wall 80 that constitutes the partition wall refrigerant path 310. That is, the components accommodated in the accommodation chamber 72 include the semiconductor device 102 that constitutes the inverter 20, and the semiconductor device 102 is arranged in contact with the partition wall 80 that constitutes the partition wall refrigerant path 310.

[0090] In this configuration, the semiconductor device 102, which generates the most heat among the components of the inverter 20, is in contact with the partition wall 80 that constitutes the partition wall refrigerant path 310, thereby making it possible to promote cooling of the inverter 20.

[0091] Furthermore, in this modified example, the fins of the heat sink 332 of the semiconductor device 330 constituting the semiconductor device 102 are brought into contact with the chamber side wall surface 314 of the partition 80 constituting the partition refrigerant path 310, thereby making it possible to improve the cooling efficiency of the semiconductor device 102.

[0092] In this modification, the components accommodated in the accommodation chamber 72 include a heat-generating component such as a three-phase electrode section 104 that connects the inverter 20 and the motor 22 or a smoothing capacitor 100 .

[0093] In such a configuration, it is possible to promote cooling of the heat-generating components that make up the inverter 20.

[0094] The above describes embodiments and modifications of the present invention, but the above embodiments and modifications merely illustrate some of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments and modifications.

[0095] The drive units 10, 200, and 300 of the present embodiment and the modified examples described above have been described using an electric vehicle that runs by driving the motor 22 with battery power as an example, but the drive units 10, 200, and 300 are not limited to this. For example, the drive units 10, 200, and 300 may be a series hybrid vehicle in which the motor 22 is driven by power generated by an engine in a vehicle equipped with an engine.

Claims

1. A drive unit mounted on a vehicle, comprising an inverter, a motor that receives power from the inverter, and a gearbox having a shaft gear provided on the motor's shaft, The gearbox includes a gear chamber that houses the shaft gear having a smaller diameter than the outer diameter of the motor, The gearbox is divided and formed to include a housing chamber which is formed as a separate space from the gear chamber due to the difference in dimensions between the outer diameter of the motor and the outer diameter of the shaft gear, At least some of the components of the inverter are housed in the aforementioned housing chamber. Drive unit.

2. The drive unit according to claim 1, When mounted on the aforementioned vehicle, The gearbox has various gears, including the shaft gear, arranged horizontally. The aforementioned housing chamber is located below the shaft gear and is positioned in a corner portion of the gearbox. Drive unit.

3. The drive unit according to claim 1, The gearbox is provided with a refrigerant passage through which a refrigerant that cools the inverter housed in the housing chamber flows. Drive unit.

4. The drive unit according to claim 3, The refrigerant passage is provided in the partition wall separating the gear chamber and the housing chamber. Drive unit.

5. The drive unit according to claim 4, A reservoir for lubricating the shaft gear is provided on the side of the partition wall facing the gear chamber. Drive unit.

6. The drive unit according to claim 3, The components housed in the aforementioned housing chamber include semiconductor devices that constitute the inverter, and the semiconductor devices are arranged in contact with the refrigerant passage. Drive unit.

7. A drive unit according to claim 4 or claim 5, The components housed in the aforementioned housing chamber include semiconductor devices that constitute the inverter, and the semiconductor devices are arranged in contact with the partition wall. Drive unit.

8. A drive unit according to any one of claims 3 to 6, The components housed in the aforementioned housing chamber include a heat-generating component consisting of a three-phase electrode section or a smoothing capacitor that connects the inverter and the motor. Drive unit.