Hybrid vehicle

Abstract

To provide a hybrid vehicle, which is configured so that an entire physical size of a transaxle case combined with an engine can be suppressed from enlarging.SOLUTION: A counter driven gear 22a to which power is inputted from a second electric motor MG2, a counter driven gear 22b having a diameter smaller than a diameter of the counter driven gear 22a which drives a differential gear device 24 and a counter shaft 22 constitute a speed reduction mechanism 38, which makes an outer ring gear of a stepped pinion unnecessary. This can suppress an outer diameter of a first case cover 40b at an engine side protruding from a case main body 40a of the transaxle case 40 in order to store the speed reduction mechanism 38 from becoming larger. At least either of a portion of the differential gear device 24 and a portion of the counter shaft 22 is arranged to protrude toward the engine 12 more than a combined surface F of the engine 12 and the transaxle case 40, which can shorten a dimension in a second shaft line CL2 of the transaxle case 40.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a hybrid vehicle equipped with an engine, a first electric motor and a second electric motor that are rotationally driven by the engine, a reduction mechanism that reduces the power of the second electric motor, and a differential to which power is transmitted from the reduction mechanism. [Background technology]

[0002] Hybrid vehicles are known that include an engine, a power split mechanism, a first electric motor, a second electric motor, a reduction mechanism that reduces the power of the second electric motor, and a differential mechanism to which power is transmitted from the reduction mechanism. For example, the hybrid vehicle described in Patent Document 1 is one such example. In the hybrid vehicle described in Patent Document 1, (a) the engine, power split mechanism, and first electric motor are arranged along a first axis, (b) the second electric motor, reduction mechanism, and differential mechanism are arranged along a second axis that is parallel to the first axis, and (c) the second electric motor, reduction mechanism, and differential mechanism are arranged in this order along the second axis from the first electric motor side toward the engine side. The hybrid vehicle described in Patent Document 1 also includes a stepped pinion planetary gear set as the reduction mechanism. A "stepped pinion type planetary gear device" is a planetary gear device that has a large diameter pinion and a small diameter pinion that rotate but cannot rotate relative to each other, with power input to the large diameter pinion from a sun gear that meshes with it, and power output from a carrier to the small diameter pinion that meshes with a ring gear fixed to a non-rotating member. A stepped pinion type planetary gear device is a reduction mechanism that makes it easy to increase the reduction ratio and is less likely to reduce power transmission efficiency. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-79981 Summary of the Invention [Problem to be solved by the invention]

[0004] While an increase in the axial length of a stepped pinion planetary gear set is easily suppressed, its outer diameter relative to the axis tends to increase. Therefore, when an engine, which projects radially about a first axis, and a stepped pinion planetary gear set, which projects radially about a second axis, are positioned so that they overlap in the first axial direction (i.e., the same direction as the second axial direction), the axial distance between the first and second axes may need to be increased to prevent the engine and the stepped pinion planetary gear set from overlapping. Increasing the axial distance between the first and second axes increases the overall size of a transaxle case that houses the engine, which is rotatable about the first axis, the first electric motor, the second electric motor, a reduction mechanism that reduces the power of the second electric motor, and a differential mechanism to which power is transmitted from the reduction mechanism. This can, for example, deteriorate the aerodynamic characteristics of the vehicle or reduce the freedom of vehicle design. This situation applies not only to parallel-type HEV vehicles, but also to split-type or series-type HEV vehicles.

[0005] The present invention was made against the background of the above circumstances, and its purpose is to provide a hybrid vehicle that can prevent the overall size of the engine and transaxle case from becoming larger. [Means for solving the problem]

[0006] The gist of the first invention is that (a) a hybrid vehicle in which, within a transaxle case combined with an engine, a planetary gear device and a first electric motor are arranged so that the crankshaft of the engine can rotate about a first axis, a second electric motor and a differential gear device are arranged so that they can rotate about a second axis parallel to the first axis, and the second electric motor, a reduction mechanism, and a differential gear device are arranged in this order from the first electric motor side to the engine side, (b) the reduction mechanism includes a counter shaft rotatable about a third axis parallel to the first and second axes, a counter driven gear provided on the counter shaft and receiving power from the second electric motor, and a counter drive gear provided on the counter shaft and having a smaller diameter than the counter driven gear for driving the differential gear device, and (c) at least one of a portion of the differential gear device and a portion of the counter shaft is arranged to protrude toward the engine beyond the mating surface between the engine and the transaxle case. [Effects of the Invention]

[0007] According to the first aspect of the present invention, the reduction mechanism includes a counter shaft provided with a counter driven gear that receives power from the second electric motor and a counter drive gear that drives the differential gear device and has a smaller diameter than the counter driven gear, thereby eliminating the need for a ring gear on the outside of the stepped pinion and preventing the outer diameter of the engine-side case cover that protrudes from the transaxle case to accommodate the differential mechanism from becoming larger. Also, because at least one of a portion of the differential gear device and a portion of the counter shaft is positioned to protrude toward the engine beyond the mating surface between the engine and the transaxle case, the dimension of the transaxle case in the second axial direction can be reduced.

[0008] The gist of the second invention is that in the first invention, a planetary gear set is disposed between the engine and the first electric motor, the planetary gear set having a sun gear connected to a rotor shaft of the first electric motor, a carrier connected to a crankshaft of the engine, and a ring gear meshing with a planetary gear supported by the carrier, the outer teeth of the ring gear meshing with the counter driven gear. This allows the planetary gear set to function as a power split mechanism and to drive the vehicle using direct torque from the engine, thereby shortening the axial length of the transaxle case in the direction of the second axis in a split-type HEV vehicle.

[0009] The gist of the third invention is that, in the first invention, a planetary gear set is disposed between the engine and the first electric motor, the planetary gear set having a sun gear connected to the first electric motor, a carrier connected to the engine, planetary gears rotatably supported by the carrier, and a ring gear meshing with the planetary gears supported by the carrier, and the ring gear is fixed to the transaxle case. This allows the axial length of the transaxle case to be shortened in the direction of the second axis in a series-type HEV vehicle in which the engine drives the first electric motor via the planetary gear set functioning as a speed-increasing transmission and the second electric motor is driven using electric power generated by the first electric motor. Another advantage is that a small-diameter, high-speed electric motor can be used as the first electric motor.

[0010] The gist of the fourth invention is that in the first invention, the engine and the second electric motor are directly connected. This allows the axial length of the transaxle case to be shortened in the first axial direction and the second axial direction in a series-type HEV vehicle in which the engine drives the directly connected first electric motor and the second electric motor is driven using electric power generated by the first electric motor. Another advantage is that a large-diameter, low-speed electric motor can be used as the first electric motor. [Brief explanation of the drawings]

[0011] [Figure 1]1 is a schematic diagram of a split-type hybrid vehicle according to a first embodiment of the present invention; [Figure 2] FIG. 10 is a schematic configuration diagram of a series hybrid vehicle according to a second embodiment of the present invention. [Figure 3] FIG. 10 is a schematic configuration diagram of a series hybrid vehicle according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, each embodiment of the present invention will be described in detail with reference to the drawings. Note that unless otherwise specified, the drawings have been appropriately simplified or modified, and the dimensional ratios and shapes of the various parts are not necessarily accurately depicted. [Example]

[0013] FIG. 1 is a diagram illustrating the schematic configuration of a split-type hybrid vehicle 10 (hereinafter simply referred to as "vehicle 10") according to a first embodiment of the present invention. In FIG. 1, arrows indicate the upper and lower directions in the vertical direction of the vehicle 10 and the left and right directions in the vehicle width direction. FIG. 1 is a diagram of the vehicle 10 viewed from the rear to the front, and the devices shown in a transaxle case 16 are shown reflecting their relative positional relationships in the up-down and left-right directions. FIG. 1 is a development view passing through a first axis CL1, a third axis CL3, and a second axis CL2.

[0014] The vehicle 10 is equipped with an engine 12, which is a well-known internal combustion engine, a crankshaft 14, a damper 16 that absorbs torque fluctuations, an input shaft 18, a planetary gear device 20, and a first electric motor MG1, all of which are rotatable about a first axis CL1, a countershaft 22 which is rotatable about a third axis CL3 which is parallel to the first axis CL1, and a second electric motor MG2, a differential gear device 24, a pair of axles 30, 32, and a pair of drive wheels 34, 36 which are rotatable about a second axis CL2 which is parallel to the first axis CL1.

[0015] The first electric motor MG1 and the second electric motor MG2 are so-called motor generators that function as electric motors and as generators.

[0016] The planetary gear set 20 includes a sun gear 20s coupled or connected to a first rotor shaft 21 of the first electric motor MG1, a carrier 20c that supports planetary gears 20p meshing with the sun gear 20s so that the planetary gears 20p can rotate and revolve and is coupled or connected to the engine 12, and a ring gear 20r that has inner teeth 20ig that mesh with the planetary gears 20p and outer teeth 20og that mesh with the counter driven gear 22a. In this embodiment, the input torque from the engine 12 is distributed to the first electric motor MG1 and the ring gear 20r, so the planetary gear set 20 functions as a power split mechanism.

[0017] The counter shaft 22 is provided with a relatively large-diameter counter driven gear 22a and a relatively small-diameter counter drive gear 22b. The counter driven gear 22a meshes with outer peripheral teeth 20og of the ring gear 20r and a second output gear 28 provided on a second rotor shaft 26 of the second electric motor MG2, the second output gear 28 having a smaller diameter than the counter driven gear 22a. The counter drive gear 22b meshes with a differential input gear 24b, the second output gear 28 having a larger diameter than the counter drive gear 22b, and the counter shaft 22. The gear pair of the counter driven gear 22a and the second output gear 28, the gear pair of the counter drive gear 22b and the differential input gear 24b, and the counter shaft 22 constitute a reduction mechanism 38 that reduces the rotation of the second rotor shaft 26 of the second electric motor MG2 and transmits the reduced rotation to the differential case 24a. In this embodiment, the speed reduction mechanism 38 reduces the rotation of the ring gear 20r and transmits it to the differential case 24a.

[0018] The differential gear device 24 comprises a differential case 24a rotatably supported around the second axis CL2, a pair of side gears 24c, 24d rotatably supported within the differential case 24a while connected to the axial ends of a pair of axles 30, 32, and a pinion 24e arranged within the differential case 24a around an axis perpendicular to the second axis CL2 and meshing with the pair of side gears 24c, 24d between them.

[0019] One axle 30 of the pair of axles 30, 32 passes through the tubular second rotor shaft 26 of the second electric motor MG2 and connects one of the pair of drive wheels 34, 36 to one of the pair of side gears 24c, 24d, the side gear 24c, and the other axle 32 connects the other drive wheel 36 to the other side gear 24d.

[0020] The damper 16, planetary gear set 20, first electric motor MG1, countershaft 22, second electric motor MG2, and differential gear set 24 are housed in a liquid-tight transaxle case 40 consisting of a case body 40a, a first case cover 40b on the engine side, and a second case cover 40c on the opposite side from the engine 12. The engine 12 is assembled and fixed to the case body 40a via an assembly surface F. In FIG. 1, the devices shown in the transaxle case 16 are shown reflecting their relative positional relationships in the vertical and horizontal directions.

[0021] The hybrid vehicle 10 configured as described above constitutes a so-called split-type HEV vehicle. In the power transmission mechanism of this hybrid vehicle 10, power output from the engine 12 passes through a damper 16 and an input shaft 18 and is split by a planetary gear set 20 to a first electric motor MG1 and a ring gear 20r. The first electric motor MG1 outputs a reaction torque by regeneration (electric power generation) in response to the torque of the engine 12 split to the first electric motor MG1 by the planetary gear set 20, and controls the direct torque to the counter drive gear 22b. The first electric motor MG1 and the planetary gear set 20 function as an electric continuously variable transmission in which the differential state of the planetary gear set 20 is controlled by controlling the operating state of the first electric motor MG1. The electric power generated by the first electric motor MG1 is used to charge a battery (not shown) or to drive a second electric motor MG2.

[0022] The first electric motor MG1 and the second electric motor MG2 are arranged at positions where they overlap in the direction of the second axis CL2 (= the same direction as the direction of the first axis CL1). That is, when viewed in a radial direction centered on the second axis CL2, the second electric motor MG2 is arranged at a position where it overlaps with the first electric motor MG1. In this embodiment, the second electric motor MG2 is arranged directly below the first electric motor MG1. In the direction of the second axis CL2, the second electric motor MG2 and the differential gear device 24 are arranged in this order from the first electric motor MG1 side toward the engine 12 side. In the direction of the second axis CL2, the engine 12 and a portion of the differential gear device 24 are arranged at positions where they overlap with each other. That is, when viewed in a radial direction centered on the second axis CL2, a portion of the differential gear device 24 and a portion of the countershaft 22 are arranged at positions where they overlap with the underside of the engine 12. In this embodiment, a portion of the differential gear device 24 is arranged directly below the engine 12. That is, in the direction of the second axis CL2, a part of the differential gear unit 24 and a part of the countershaft 22 are disposed directly below the engine 12 and protrude further toward the engine 12 than the mating surface F of the engine 12.

[0023] Since a portion of the differential gear unit 24 and a portion of the countershaft 22 are positioned to protrude toward the engine 12 beyond the mating surface F of the engine 12, and another portion of the differential gear unit 24 and another portion of the countershaft 22 are housed within the case main body 40a, the protruding length L1 of the first case cover 40b on the engine side and the diameter dimension D1 of the first case cover 40b excluding the outer peripheral flange for assembly are significantly reduced.

[0024] According to this embodiment, (a) in a transaxle case 40 combined with the engine 12, the planetary gear set 20 and the first electric motor MG1 are arranged so that the crankshaft 14 of the engine 12 can rotate about the first axis CL1, the second electric motor MG2 and the differential gear set 24 are arranged so that they can rotate about the second axis CL2 parallel to the first axis CL1, and the second electric motor MG2, the reduction mechanism 38, and the differential gear set 24 are arranged in this order from the first electric motor MG1 side to the engine 12 side, (b) the reduction mechanism 38 is arranged on a third axis CL1 parallel to the first axis CL1 and the second axis CL2. The transaxle case 40 includes a counter shaft 22 rotatably mounted around a line CL3, a counter driven gear 22a mounted on the counter shaft 22 and receiving direct torque from the engine 12 and torque from the second electric motor MG2, and a counter drive gear 22b mounted on the counter shaft 22 and having a smaller diameter than the counter driven gear 22a, which drives the differential gear device 24; and (c) at least one of a portion of the differential gear device 24 and a portion of the counter shaft 22 is arranged to protrude toward the engine 12 beyond the mating plane F between the engine 12 and the transaxle case 40. As a result, the reduction gear mechanism 38 includes the counter shaft 22 provided with the counter driven gear 22a that receives power from the second electric motor MG2 and the counter drive gear 22b that drives the differential gear device 24 and has a smaller diameter than the counter driven gear 22a, eliminating the need for a ring gear on the outside of the stepped pinion and preventing the outer diameter of the first case cover 40b that protrudes from the case body 40a of the transaxle case 40 toward the engine in order to accommodate the differential mechanism from becoming larger. Also, because at least one of a portion of the differential gear device 24 and a portion of the counter shaft 22 is disposed to protrude toward the engine 12 beyond the mating plane F between the engine 12 and the transaxle case 40, the dimension of the transaxle case 40 in the direction of the second axis CL2, i.e., the protruding length L1 of the first case cover 40b, can be shortened.

[0025] Next, another embodiment of the present invention will be described with reference to Figures 2 and 3. In the following embodiment, parts common to the above-mentioned embodiment will be given the same reference numerals and description thereof will be omitted. [Example]

[0026] 2 is a schematic diagram of a hybrid vehicle 100 (hereinafter simply referred to as "vehicle 100") according to a second embodiment of the present invention. In FIG. 2, as in FIG. 1, arrows indicate the upper and lower sides of the vehicle 110 in the direction of a vertical line and the left and right sides in the vehicle width direction, respectively, and the view is of the vehicle 110 viewed from the rear to the front.

[0027] The vehicle 100 has substantially the same configuration as the vehicle 10 according to the first embodiment described above, but differs in that the power of the engine 12 is not transmitted to the pair of drive wheels 50. Therefore, the following description will focus on the differences from the first embodiment.

[0028] The vehicle 100 differs from the planetary gear set 20 in the vehicle 10 of the first embodiment in that the ring gear 20r does not have outer peripheral teeth 20og and is fixed to a non-rotating member, such as the case main body 40a. The planetary gear set 20 to which the ring gear 20r is fixed increases the rotation from the engine 12 and transmits it to the first rotor shaft 21 of the first electric motor MG1 connected to the sun gear 20s. In other words, the planetary gear set 20 of this embodiment functions as a speed-increasing transmission.

[0029] The hybrid vehicle 100 configured as described above constitutes a so-called series-type HEV vehicle. In the power transmission mechanism of this hybrid vehicle 100, power output from the engine 12 passes through a damper 16 and an input shaft 18, is accelerated by a planetary gear set 20, and is then transmitted exclusively to a first electric motor MG1. The first electric motor MG1 is rotationally driven by the rotation accelerated by the planetary gear set 20, and outputs generated electric power. The generated electric power is stored in a power storage device (not shown) or supplied to a second electric motor MG2, causing the second electric motor MG2 to generate driving force for the vehicle.

[0030] Similarly, in this embodiment, the first electric motor MG1 and the second electric motor MG2 are disposed at positions overlapping each other in the direction of the second axis CL2. That is, when viewed in a radial direction centered on the second axis CL2, the second electric motor MG2 is disposed at a position overlapping the first electric motor MG1. In this embodiment, the second electric motor MG2 is disposed immediately below the first electric motor MG1. In the direction of the second axis CL2, the second electric motor MG2 and the differential gear device 24 are disposed in this order from the first electric motor MG1 side toward the engine 12 side. In the direction of the second axis CL2, the engine 12 and a portion of the differential gear device 24 are disposed at positions overlapping each other. That is, when viewed in a radial direction centered on the second axis CL2, a portion of the differential gear device 24 and a portion of the countershaft 22 are disposed at positions overlapping the lower side of the engine 12. In this embodiment, a portion of the differential gear device 24 is disposed immediately below the engine 12. That is, in the direction of the second axis CL2, a part of the differential gear unit 24 and a part of the countershaft 22 are disposed directly below the engine 12 and protrude further toward the engine 12 than the mating surface F of the engine 12.

[0031] Since a portion of the differential gear unit 24 and a portion of the countershaft 22 are positioned to protrude toward the engine 12 beyond the assembly surface F of the engine 12, and another portion of the differential gear unit 24 and another portion of the countershaft 22 are housed within the case main body 40a, even in this embodiment, the protruding length L1 and diameter dimension D1 of the first case cover 40b on the engine side are significantly reduced.

[0032] According to this embodiment, similar to the first embodiment described above, (a) the engine 12 and the first electric motor MG1 are arranged to be rotatable about the first axis CL1, (b) the second electric motor MG2 and the differential gear device 24 are arranged to be rotatable about the second axis CL2 that is parallel to the first axis CL1, (c) the second electric motor MG2, the countershaft 22, and the differential gear device 24 are arranged in this order from the first electric motor MG1 side toward the engine 12 side in the direction of the second axis CL2, and (d) at least one of a portion of the differential gear device 24 and a portion of the countershaft 22 is arranged to protrude toward the engine 12 beyond the mating plane F between the engine 12 and the transaxle case 40. This provides the same effects as the first embodiment based on these configurations.

[0033] According to this embodiment, (a) in a transaxle case 40 combined with the engine 12, the planetary gear set 20 and the first electric motor MG1 are arranged so that the crankshaft 14 of the engine 12 can rotate about the first axis CL1, and the second electric motor MG2 and the differential gear set 24 are arranged so that they can rotate about the second axis CL2 parallel to the first axis CL1, and the second electric motor MG2, the reduction mechanism 38, and the differential gear set 24 are arranged in this order from the first electric motor MG1 side to the engine 12 side, (b) the reduction mechanism 38 is arranged so that the counter shaft 22 and the first axis CL1 and The differential gear unit 24 includes a counter shaft 22 rotatably mounted around a third axis CL3 parallel to the second axis CL2, a counter driven gear 22a mounted on the counter shaft 22 and receiving power from the second electric motor MG2, and a counter drive gear 22b having a smaller diameter than the counter driven gear 22a mounted on the counter shaft 22 and driving the differential gear unit 24, (c) at least one of a portion of the differential gear unit 24 and a portion of the counter shaft 22 is positioned to protrude toward the engine 12 beyond the assembly plane F between the engine 12 and the transaxle case 40. As a result, the reduction gear mechanism 38 includes the countershaft 22, the counter driven gear 22a that is provided on the countershaft 22 and receives power from the second electric motor MG2, and the counter drive gear 22b that is provided on the countershaft 22 and has a smaller diameter than the counter driven gear 22a and drives the differential gear device 24, eliminating the need for a ring gear on the outside of the stepped pinion and preventing the outer diameter of the engine-side first case cover 40b that protrudes from the case body 40a of the transaxle case 40 to accommodate the differential mechanism from becoming larger. Also, because at least one of a portion of the differential gear device 24 and a portion of the countershaft 22 is disposed to protrude toward the engine 12 beyond the mating plane F between the engine 12 and the transaxle case 40, the dimension of the transaxle case 40 in the direction of the second axis CL2, i.e., the protruding length L1 of the first case cover 40b, can be shortened.

[0034] Furthermore, according to this embodiment, the first electric motor MG1 is connected to the engine 12 via the planetary gear set 20 that functions as a speed-increasing transmission, which makes it easier for the first electric motor MG1 to rotate at high speeds, improving the power generation efficiency of the first electric motor MG1. Preferably, for example, when the first electric motor MG1 is configured to have a small diameter and be capable of efficiently generating power at a high rotational speed, the power generation efficiency of the first electric motor MG1 is improved while an increase in the axial distance between the first axis line CL1 and the second axis line CL2 is more easily suppressed than in other cases. [Example]

[0035] FIG. 3 is a schematic diagram of a hybrid vehicle 110 (hereinafter simply referred to as "vehicle 110") according to a third embodiment of the present invention. In FIG. 3, arrows indicate the upper and lower sides of the vehicle 110 in the direction of a vertical line, and the left and right sides in the vehicle width direction. FIG. 3 is a view of the vehicle 110 as seen from the rear to the front. In FIG. 3, the devices shown inside transaxle case 16 are shown reflecting their relative positional relationships in the up-down and left-right directions.

[0036] The vehicle 110 has substantially the same configuration as the vehicle 100 according to the second embodiment, but differs in that it does not include the planetary gear unit 20 that functions as a speed-increasing transmission. Therefore, the following description will focus on the parts that are different from the second embodiment, and the same reference numerals will be used to denote substantially common parts, and descriptions thereof will be omitted as appropriate.

[0037] The vehicle 110 does not include the speed-increasing planetary gear unit 120 of the vehicle 110 according to the second embodiment, and the input shaft 18 is spline-fitted to the first rotor shaft 21 at a joint C so as to be unable to rotate relative to the first rotor shaft 21. In this manner, the vehicle 110 is directly coupled to the engine 12 so that the engine 12 and the first electric motor MG1 rotate at the same speed. The first electric motor MG1 is driven to rotate by the power of the engine 12. The hybrid vehicle 110 configured as described above constitutes a so-called series-type HEV vehicle.

[0038] According to this embodiment, similarly to the above-described first and second embodiments, (a) the engine 12 and the first electric motor MG1 are rotatably arranged about the first axis CL1, (b) the second electric motor MG2 and the differential gear device 24 are rotatably arranged about the second axis CL2 parallel to the first axis CL1, (c) the second electric motor MG2, the countershaft 22, and the differential gear device 24 are arranged in this order from the first electric motor MG1 side toward the engine 12 side in the direction of the second axis CL2, and (d) at least one of a portion of the differential gear device 24 and a portion of the countershaft 22 is arranged to protrude toward the engine 12 side beyond the mating plane F between the engine 12 and the transaxle case 40. This provides the same effects as those of the first and second embodiments based on these configurations.

[0039] Furthermore, according to this embodiment, the input shaft 18 and the first rotor shaft 21 are directly coupled so that the engine 12 and the first electric motor MG1 have the same rotational speed. This allows the size of the engine 12 and the first electric motor MG1, which are arranged to be rotatable about the first axis line CL1, in the first axis line CL1 direction to be smaller than when the engine 12 and the first electric motor MG1 are not directly coupled but are coupled via, for example, the speed-increasing planetary gear unit 120. Preferably, for example, when the first electric motor MG1 has a large diameter and is configured to be able to generate electricity efficiently at a low rotational speed, the size of the engine 12 and the first electric motor MG1 in the first axis line CL1 direction can be smaller than when this is not the case.

[0040] The above-described embodiments of the present invention are merely illustrative, and the present invention can be embodied in various forms with various modifications and improvements based on the knowledge of those skilled in the art without departing from the spirit of the present invention.

[0041] In the above-described first, second, and third embodiments, the damper 16 is provided between the engine 12 and the first electric motor MG1, but the present invention is not limited to this. For example, the present invention is also applicable to an embodiment in which the damper 14 is not provided between the engine 12 and the first electric motor MG1.

[0042] In the above-described first, second, and third embodiments, the second axis CL2 passes directly below the engine 12. However, the present invention is not limited to this. For example, the present invention can also be applied to an embodiment in which the second axis CL2 is offset either forward or rearward in the longitudinal direction of the vehicle 10, 100, or 110 with respect to the first axis CL1, and the second axis CL2 does not pass directly below the engine 12. Even in such a case, an increase in the outer diameter of the first case cover 40b about the second axis CL2 is suppressed. This allows the engine 12, which is rotatably disposed about the first axis CL1, and the powertrain devices, which are rotatably disposed about the second axis CL2, to be arranged while suppressing an increase in the inter-axis distance between the first axis CL1 and the second axis CL2. In other words, an increase in the overall size of the engine 12 and the powertrain devices is suppressed.

[0043] In the above-described first, second, and third embodiments, both a portion of the countershaft 22 and a portion of the differential gear device 24 protrude from the combination surface F, but it is also acceptable for only one of them to protrude. In short, it is sufficient that at least one of a portion of the countershaft 22 and a portion of the differential gear device 24 protrudes. [Explanation of symbols]

[0044] 10, 100, 110: Hybrid vehicle, 12: Engine, 14: Crankshaft, 16: Damper, 18: Input shaft, 20: Planetary gear device, 20r: Ring gear, 20s: Sun gear, 20p: Planetary gear, 20c: Carrier, 21: First rotor shaft, 22: Counter shaft, 22a: Counter driven gear, 22b: Counter drive gear, 24: Differential gear device, 24a:, 24b:, 24c:, 24d:, 24e:, 2 6: second rotor shaft, 28: second output gear, 30, 32: axle, 34, 36: drive wheels, 38: reduction gear mechanism, 40: transaxle case, 40a: case body, 40b: first case cover, 40c: second case cover, CL1: first axis, CL2: second axis, CL3: third axis, MG1: first electric motor, MG2: second electric motor, F: mating surface, D1: diameter dimension of first case cover, L1: protrusion length of first case cover

Claims

1. A hybrid vehicle in which a first electric motor and a crankshaft of the engine are rotatably disposed about a first axis within a transaxle case combined with an engine, a second electric motor and a differential gear device are rotatably disposed about a second axis parallel to the first axis, and the second electric motor, a reduction mechanism, and a differential gear device are disposed in this order from the first electric motor side toward the engine side, the reduction mechanism includes: a counter shaft rotatably provided about a third axis parallel to the first axis and the second axis; a counter driven gear provided on the counter shaft and receiving power from the second electric motor; and a counter drive gear provided on the counter shaft and having a smaller diameter than the counter driven gear, for driving the differential gear device, At least one of a portion of the differential gear device and a portion of the countershaft is disposed so as to protrude toward the engine beyond a mating surface between the engine and the transaxle case. A hybrid vehicle characterized by:

2. a planetary gear device is disposed between the engine and the first electric motor, the planetary gear device having a sun gear connected to a rotor shaft of the first electric motor, a carrier connected to a crankshaft of the engine, planetary gears rotatably supported by the carrier, and a ring gear with which the planetary gears supported by the carrier mesh; The outer teeth of the ring gear mesh with the counter driven gear.

2. The hybrid vehicle according to claim 1.

3. a planetary gear device is disposed between the engine and the first electric motor, the planetary gear device having a sun gear connected to a rotor shaft of the first electric motor, a carrier connected to a crankshaft of the engine, planetary gears rotatably supported by the carrier, and a ring gear with which the planetary gears supported by the carrier mesh; The ring gear is fixed to the transaxle case.

2. The hybrid vehicle according to claim 1.

4. The engine and the second electric motor are directly connected.

2. The hybrid vehicle according to claim 1.

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