Speed changer

Abstract

To provide a speed changer that is loaded on a vehicle provided with an internal combustion engine and an electric motor, which can be downsized.SOLUTION: A speed changer 10 is provided with: an input shaft 13 that transmits power outputted from an internal combustion engine 3; an electric motor connection shaft 60 that is connected to an electric motor 4; a switching shaft 30 that transmits power between the input shaft 13 and the electric motor connection shaft 60; an intermediate shaft 41 provided between the switching shaft 30 and the input shaft 13; and a first reverse idler gear 42 provided on the intermediate shaft 41. The switching shaft 30 is provided with a switching mechanism 70 and a switching shaft gear 32 that can transmit power to the electric motor connection shat 60. The electric motor connection shaft 60 is provided with an electric motor connection shaft gear 61. The electric motor connection shaft gear 61 and the first reverse idler gear 42 are provided in a region whose height is below a height of the switching shaft gear 32.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a transmission mounted on a vehicle equipped with an internal combustion engine and an electric motor as power sources. [Background technology]

[0002] Conventionally, hybrid vehicles equipped with an electric motor and an internal combustion engine are known (for example, see Patent Document 1). In such hybrid vehicles, one or both of the electric motor and the internal combustion engine are used as drive sources. Furthermore, the electric motor in a hybrid vehicle functions as a generator that generates electricity using regenerative torque during vehicle braking. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-241331 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in vehicles such as those described in the above-mentioned prior art patent document 1, the size of the transmission increases when viewed from the internal combustion engine side, resulting in poor mountability. Specifically, in vehicles equipped with an internal combustion engine and an electric motor, a low gear is required on the side from the electric motor toward the internal combustion engine to ensure the engine's startability. Therefore, in the power transmission path between the electric motor and the internal combustion engine, the gear diameter of the gear provided for power transmission increases in a portion of the path. This results in a problem that transmissions used in vehicles equipped with an electric motor and an internal combustion engine tend to be large in size. Furthermore, in front-engine, rear-wheel-drive (FR) vehicles, adopting the transmission structure described in Patent Document 1 requires a large floor tunnel, which raises concerns that the driver's foot space will expand toward the passenger compartment, thereby compressing the driver's cab. Furthermore, in FR commercial vehicles, adopting the transmission structure described in Patent Document 1 requires a high luggage compartment, which reduces marketability.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to reduce the size of a transmission mounted on a vehicle equipped with an internal combustion engine and an electric motor. [Means for solving the problem]

[0006] (1) A transmission of the present invention is used in a vehicle equipped with an internal combustion engine and an electric motor, and includes an input shaft that transmits power output from the internal combustion engine, an output shaft that transmits the power to drive wheels of the vehicle, an electric motor connection shaft that is connected to the electric motor, a switching shaft (first driven shaft) that transmits power between the input shaft and the electric motor connection shaft, an intermediate shaft (second driven shaft) provided intermediate the switching shaft and the input shaft, and an intermediate shaft gear (second driven gear) provided on the intermediate shaft, The shaft is provided with a switching mechanism that switches between an input side connection state that enables the transmission of the power between the motor connection shaft and the input shaft and an output side connection state that enables the transmission of the power between the motor connection shaft and the output shaft, and a switching shaft gear (first driven gear) that can transmit the power to the motor connection shaft, and the motor connection shaft is provided with a motor connection shaft gear, and the motor connection shaft gear and the intermediate shaft gear are provided in an area below the height of the switching shaft gear.

[0007] As described above in (1), the transmission of the present invention is configured such that the motor connecting shaft gear provided on the motor connecting shaft connected to the electric motor and the intermediate shaft gear provided on the intermediate shaft are provided in an area below the height of the switching shaft gear provided on the switching shaft. As a result, the transmission of the present invention can prevent the motor connecting shaft gear and the intermediate shaft gear from being increased in height in order to accommodate the switching shaft gear, while making the gear diameter of the switching shaft gear provided in the middle of the power transmission path through which power is transmitted between the electric motor and the internal combustion engine a size necessary to achieve the desired gear ratio.

[0008] (2) In the transmission of the present invention, it is preferable that the axial centers of the motor connection shaft gear, the switching shaft gear, and the intermediate shaft gear are arranged so as to be aligned along a predetermined imaginary line.

[0009] By adopting the configuration described in (2) above, the transmission of the present invention can minimize the distance between the motor connection shaft gear, the switching shaft gear, and the intermediate shaft gear. This allows the transmission of the present invention to achieve a large gear ratio while minimizing the gear diameter of the switching shaft gear. This further prevents the transmission of the present invention from becoming large in height.

[0010] (3) In the transmission of the present invention, the electric motor connecting shaft gear, the switching shaft gear, and the intermediate shaft gear are arranged in this order, and the axial center position of the switching shaft gear is lower than the axial center position of the electric motor connecting shaft gear, and the axial center position of the intermediate shaft gear is lower than the axial center position of the switching shaft gear.

[0011] In the transmission of the present invention, as described above in (3), the motor connecting shaft gear, the switching shaft gear, and the intermediate shaft gear are arranged in descending order, thereby allowing oil to flow smoothly through the motor connecting shaft gear, the switching shaft gear, and the intermediate shaft gear in that order.

[0012] (4) In the transmission of the present invention, the axial center position of the electric motor connection shaft may be located in an area above an oil pan arrangement area in which an oil pan is arranged in the internal combustion engine.

[0013] By configuring the transmission of the present invention as described in (4) above, the area above the oil pan, which is located low in the internal combustion engine, can be utilized to directly or indirectly connect the electric motor to the electric motor connecting shaft. Therefore, the transmission of the present invention can make the mounting structure in which the electric motor is connected to the electric motor connecting shaft and mounted on a vehicle more compact in the vertical direction.

[0014] (5) In the transmission of the present invention, it is preferable that the connecting shaft that connects the electric motor connecting shaft and the rotating shaft of the electric motor is connected in an area above an oil pan arrangement area in which an oil pan is arranged in the internal combustion engine.

[0015] By configuring the transmission of the present invention as described above in (5), the area above the oil pan arrangement area, which is located low in the internal combustion engine, can be utilized as space for connecting the electric motor to the electric motor connecting shaft via the connecting shaft. Therefore, the transmission of the present invention can make the mounting structure in which the electric motor is connected to the electric motor connecting shaft and mounted on a vehicle more compact in the vertical direction.

[0016] (6) In the transmission of the present invention, the switching shaft preferably includes an output side gear capable of transmitting the power to the output shaft and an input side gear capable of transmitting the power of the input shaft, and the switching mechanism is preferably arranged between the output side gear and the switching shaft gear, and between the input side gear and the output side gear.

[0017] By adopting the configuration according to (6) above, the transmission of the present invention can accommodate the switching mechanism inside the transmission with high space efficiency. Furthermore, by disposing the switching mechanism between the switching shaft gear and the output gear as described above, the transmission of the present invention can dispose the switching shaft gear closer to the internal combustion engine. This allows the electric motor to be disposed in close proximity to the internal combustion engine, preventing the external dimensions of the transmission from becoming too large when viewed from the internal combustion engine.

[0018] (7) In the transmission of the present invention, the switching shaft is provided with an output side gear capable of transmitting the power to the output shaft and an input side gear capable of transmitting the power of the input shaft, and the switching mechanism has a clutch, and by switching the connection state of the clutch, the input side connection state and the output side connection state of the switching mechanism are switched.

[0019] By configuring the transmission of the present invention as described above in (7), the transmission can smoothly switch between the input side connection state and the output side connection state by switching the clutch connection state. [Effects of the Invention]

[0020] According to the present invention, a transmission that solves the above-mentioned problems can be provided. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 2 is an overall front view of a transmission according to an embodiment of the present invention, with a cover cut away. [Figure 2] FIG. 2 is a side view of the transmission in FIG. 1 as seen from the direction of the internal combustion engine. [Figure 3] 1 is a schematic skeleton diagram of a transmission according to an embodiment of the present invention; [Figure 4] FIG. 2 is an explanatory diagram showing the positional relationship between an internal combustion engine and a transmission. [Figure 5] FIG. 2 is an explanatory diagram showing the positional relationship between an internal combustion engine and an electric motor. DETAILED DESCRIPTION OF THE INVENTION

[0022] A transmission 10 according to one embodiment of the present invention will be described in detail below with reference to the drawings. Note that each drawing is a schematic representation for ease of understanding, and may differ from the actual shape, size, and arrangement of components. Note also that the fact that each shaft is supported by an appropriate bearing or the like and is rotatable may be omitted. In the following description, the front side of the vehicle may be referred to as the front Fr, and the rear side may be referred to as the rear Rr.

[0023] As shown in Figures 1 and 3, a transmission 10 according to this embodiment is mounted on a vehicle with an internal combustion engine 3 and an electric motor 4 connected to it. The internal combustion engine 3 is configured as an engine such as a gasoline engine or a diesel engine. A drive shaft (not shown) of the internal combustion engine 3 is connected to an input shaft 13 of the transmission 10. Therefore, the power output by the internal combustion engine 3 is input to the transmission 10 via the input shaft 13.

[0024] The electric motor 4 is configured, for example, as a motor generator, and is capable of outputting driving force and generating electricity. The electric motor 4 has a rotating shaft 4A (see FIG. 3) connected to an electric motor connecting shaft 60 in the transmission 10 via a shaft coupling structure 80. Therefore, the power output by the electric motor 4 is input to the transmission 10 via the electric motor connecting shaft 60. As will be described in detail later, regenerative power (regenerative energy) from drive wheels (not shown) and power from the internal combustion engine 3 are input to the electric motor 4 via the electric motor connecting shaft 60 and can be used to generate electricity.

[0025] The transmission 10 has a plurality of gears, and is configured to change the speed of the power generated by the internal combustion engine 3 and the electric motor 4, and to transmit regenerated energy to the electric motor 4. The transmission 10 is equipped with a torque converter 12, an input shaft 13, a continuously variable transmission 20 (CVT 20), a reverse transmission mechanism 40, a forward clutch 51 (clutch device 50), and a reverse clutch 55 (clutch device 50). In addition to the above, the transmission 10 is also equipped with a switching shaft 30, an electric motor connecting shaft 60, a switching mechanism 70, etc.

[0026] The torque converter 12 includes a pump impeller 12A, a turbine runner 12B, and a lockup mechanism 12C. An input shaft 13 is connected to the pump impeller 12A and is rotatable integrally with the input shaft 13 about the same rotational axis. The turbine runner 12B is rotatable about the same rotational axis as the pump impeller 12A. The lockup mechanism 12C is provided to directly connect / disconnect the pump impeller 12A and the turbine runner 12B. When the lockup mechanism 12C is engaged (lockup on), the pump impeller 12A and the turbine runner 12B are directly connected, and when the lockup mechanism 12C is released (lockup off), the pump impeller 12A and the turbine runner 12B are disconnected.

[0027] The input shaft 13 is disposed so that its axis coincides with the rotation axis of the torque converter 12. The input shaft 13 is capable of transmitting power output from the internal combustion engine 3. An input shaft gear 14 is formed integrally with the input shaft 13. A front Fr end of the input shaft 13 is inserted into the torque converter 12.

[0028] The output shaft 15 is disposed rearwardly relative to the input shaft 13 with a gap therebetween. The output shaft 15 is disposed so that its axis is aligned with the axis of the input shaft 13. Although not shown, the output shaft 15 can transmit power to the driving wheels of the vehicle via a drive shaft or the like. An output shaft gear 16 is formed integrally with the output shaft 15. The output shaft gear 16 is in mesh with a secondary output gear 25, which will be described later.

[0029] The continuously variable transmission 20 includes a primary shaft 21, a secondary shaft 23, a primary pulley 26, a secondary pulley 27, and a belt 28.

[0030] A primary input gear 22 is attached to the primary shaft 21 so as to be rotatable relative to the primary shaft 21. The primary input gear 22 meshes with the input shaft gear 14. A secondary input gear 24 and a secondary output gear 25 are attached to the secondary shaft 23. The secondary input gear 24 is rotatable relative to the secondary shaft 23. The secondary output gear 25 is attached so as not to be rotatable relative to the secondary shaft 23. The secondary output gear 25 meshes with an output shaft gear 16 provided on the output shaft 15.

[0031] In the continuously variable transmission 20, a belt 28 is stretched between a primary pulley 26 and a secondary pulley 27. In the continuously variable transmission 20, the oil pressure supplied to each oil pressure chamber (not shown) of the primary pulley 26 and the secondary pulley 27 is controlled to change the groove width of each of the primary pulley 26 and the secondary pulley 27, thereby continuously and infinitely changing the belt speed ratio (pulley ratio between the primary pulley 26 and the secondary pulley 27) within a certain speed ratio range. The rotational force (power) of the secondary shaft 23 whose speed has been changed is transmitted to the output shaft 15 via the secondary output gear 25 and the output shaft gear 16, and the drive wheels (not shown) are driven.

[0032] The reverse transmission mechanism 40 is a mechanism that transmits the power (rotation) of the input shaft 13 to the secondary input gear 24. The reverse transmission mechanism 40 is provided with an intermediate shaft 41, a first reverse idler gear 42 (intermediate shaft gear), and a second reverse idler gear 43.

[0033] The intermediate shaft 41 is a shaft provided intermediate the switching shaft 30 and the input shaft 13. The intermediate shaft 41 is provided substantially parallel to the switching shaft 30 and the input shaft 13. The intermediate shaft 41 is capable of transmitting power between the switching shaft 30 and the input shaft 13 via a first reverse idler gear 42 and a second reverse idler gear 43, which will be described later.

[0034] The first reverse idler gear 42 is formed integrally with the intermediate shaft 41 and meshes with the input shaft gear 14. That is, the first reverse idler gear 42 can reverse the rotation direction of the input shaft gear 14 (input shaft 13). The first reverse idler gear 42 also meshes with the input side gear 31 provided on the switching shaft 30 and can reverse the rotation direction of the input side gear 31 (switching shaft 30).

[0035] The second reverse idler gear 43 is formed integrally with the intermediate shaft 41 at a position Rr rearward of the first reverse idler gear 42 and is in mesh with the secondary input gear 24 .

[0036] The forward clutch 51 (clutch device 50) is provided to allow / prohibit rotation of the primary input gear 22 relative to the primary shaft 21. Although not shown, the forward clutch 51 forms the clutch device 50 which includes a clutch drum, a clutch piston, friction material, a hydraulic chamber, etc. The forward clutch 51 controls the supply of oil into the hydraulic chamber according to the output value of a solenoid (not shown), thereby controlling clutch engagement.

[0037] When forward clutch 51 is engaged (engaged state), relative rotation of primary input gear 22 with respect to primary shaft 21 is prohibited. In other words, engagement of forward clutch 51 causes primary shaft 21 and primary input gear 22 to rotate integrally. As a result, forward driving force is transmitted to output shaft 15 via continuously variable transmission 20, and drive wheels (not shown) are driven in the forward direction. On the other hand, when forward clutch 51 is disengaged (disengaged state), relative rotation of primary input gear 22 with respect to primary shaft 21 is permitted. Therefore, even if primary input gear 22 rotates, the rotation is not transmitted to primary shaft 21.

[0038] The reverse clutch 55 (clutch device 50) is provided to allow / prohibit rotation of the secondary input gear 24 relative to the secondary shaft 23. The reverse clutch 55 has a similar configuration to the forward clutch 51, and therefore a detailed description thereof will be omitted.

[0039] When reverse clutch 55 is engaged (engaged state), relative rotation of secondary input gear 24 with respect to secondary shaft 23 is prohibited. In other words, when reverse clutch 55 is engaged, secondary shaft 23 and secondary input gear 24 rotate integrally. As a result, a driving force in the reverse direction is transmitted to output shaft 15, and the drive wheels (not shown) are driven in the reverse direction. On the other hand, when reverse clutch 55 is disengaged (disengaged state), relative rotation of secondary input gear 24 with respect to secondary shaft 23 is permitted. Therefore, even if secondary input gear 24 rotates, the rotation is not transmitted to secondary shaft 23.

[0040] The switching shaft 30 is a shaft that transmits power between the input shaft 13 and the electric motor connection shaft 60. Specifically, an input side gear 31 that meshes with a first reverse idler gear 42 (intermediate shaft gear) is fixed to the switching shaft 30. The first reverse idler gear 42 is also meshed with an input shaft gear 14 that is fixed to the input shaft 13. Therefore, the power output from the input shaft 13 is transmitted to the switching shaft 30. The switching shaft 30 is also provided with a switching shaft gear 32. The switching shaft gear 32 is fixed to the front end side (the internal combustion engine 3 side, the front Fr side) of the switching shaft 30. In other words, the switching shaft gear 32 is fixed to the internal combustion engine 3 side in the axial direction of the switching shaft 30. The switching shaft gear 32 is in mesh with an electric motor connection shaft gear 61 (described later) and can transmit the power of the switching shaft 30 to the electric motor connection shaft 60.

[0041] Although details will be described later, the switching shaft 30 is provided with an output gear 33 and a switching mechanism 70 in addition to the input gear 31 and switching shaft gear 32 described above. Also, an output transmission shaft 17 is provided parallel to and spaced from the switching shaft 30.

[0042] The output side gear 33 is journaled to the rear end side (rear Rr side) of the switching shaft 30. The output side gear 33 is meshed with an output transmission shaft gear 18 journaled to an output transmission shaft 17, which will be described later.

[0043] An output transmission shaft gear 18 is journalled to the output transmission shaft 17. The output transmission shaft gear 18 is meshed with the output shaft gear 16 of the output shaft 15. The output transmission shaft gear 18 is also meshed with the output side gear 33 of the switching shaft 30. The output transmission shaft gear 18 is also meshed with the output shaft gear 16 of the output shaft 15. Therefore, the output transmission shaft 17 can transmit the power of the switching shaft 30 to the output shaft 15 as the switching shaft 30 rotates.

[0044] As shown in Fig. 2, the electric motor connecting shaft 60 is arranged laterally and in parallel with the switching shaft 30 at a distance. As shown in Figs. 1 and 3, a universal joint 5 is connected to the front end (front Fr side) of the electric motor connecting shaft 60. A rotating shaft 4A (see Fig. 3) of an electric motor 4 (for example, a motor generator) is connected to the front end side (Fr side) of the universal joint 5. In addition, an electric motor connecting shaft gear 61 is journaled to the electric motor connecting shaft 60.

[0045] The electric motor connecting shaft gear 61 meshes with the switching shaft gear 32 on the switching shaft 30. Therefore, when the electric motor 4 is driven, the power output from the electric motor 4 is transmitted to the switching shaft 30. As will be described in detail later, when the switching shaft 30 is driven by the internal combustion engine 3, the power output from the internal combustion engine 3 is transmitted to the switching shaft 30 and then used to generate power in the electric motor 4 via the electric motor connecting shaft gear 61 and the electric motor connecting shaft 60.

[0046] The switching mechanism 70 is provided in the middle portion of the switching shaft 30. Specifically, the switching mechanism 70 is disposed between the output side gear 33 and the switching shaft gear 32, and between the input side gear 31 and the output side gear 33. The switching mechanism 70 includes a clutch 71 and the like.

[0047] The switching mechanism 70 can switch between an "input side connected state" that enables power transmission between the electric motor connection shaft 60 and the input shaft 13 and an "output side connected state" that enables power transmission between the electric motor connection shaft 60 and the output shaft 15, by switching the connection state of the clutch 71 using hydraulic pressure or the like. Specifically, the switching shaft 30 is divided into a front Fr side and a rear Rr side via the clutch 71 of the switching mechanism 70, and a switching shaft gear 32 and an input side gear 31 are disposed on the front Fr side of the switching shaft 30, and an output side gear 33 is provided on the rear Rr side of the switching shaft 30.

[0048] Therefore, in the "input side connected state," the rear Rr side of the switching shaft 30 is not connected (the rear Rr side of the clutch 71 is disengaged), and only the front Fr side of the switching shaft 30 rotates. That is, the switching shaft gear 32 and the input side gear 31 rotate as the front Fr side of the switching shaft 30 rotates. Therefore, when the internal combustion engine 3 is running in the "input side connected state," the power output from the internal combustion engine 3 is supplied to the electric motor 4 for power generation via the switching shaft 30 and the electric motor connecting shaft 60. On the other hand, when the internal combustion engine 3 is stopped in the "input side connected state," the power output from the electric motor 4 is supplied to the start of the internal combustion engine 3 via the electric motor connecting shaft 60 and the switching shaft 30.

[0049] Furthermore, in the "output side connected state," the clutch 71 is engaged, so that the rear Rr side of the switching shaft 30 is connected, and the front Fr side and rear Rr side of the switching shaft 30 rotate integrally. Therefore, when the electric motor 4 is driving in the "output side connected state," the power output from the electric motor 4 is provided to drive the drive wheels (not shown) via the electric motor connecting shaft 60 and the switching shaft 30 (EV driving state or assisted driving (HEV driving) state). On the other hand, when the drive wheels are braked (decelerated) in the "output side connected state," the braking force acting on the output shaft 15 is provided to the electric motor 4 for regeneration (electric power generation) via the switching shaft 30 and the electric motor connecting shaft 60. Note that, when the clutch 71 is disengaged (also referred to as a disengaged state), the switching mechanism 70 can also block the transmission of power between the electric motor connecting shaft 60 and the input shaft 13 and between the electric motor connecting shaft 60 and the output shaft 15.

[0050] 2 and 4, in the transmission 10 of this embodiment, the secondary shaft 23, intermediate shaft 41, switching shaft 30, and electric motor connection shaft 60 of the continuously variable transmission 20 are arranged in parallel to one another. A second reverse idler gear 43 provided on the intermediate shaft 41 meshes with a secondary input gear 24 provided on the secondary shaft 23, and an input gear 31 of the switching shaft 30 meshes with a first reverse idler gear 42 (intermediate shaft gear) provided on the intermediate shaft 41. Furthermore, an electric motor connection shaft gear 61 provided on the electric motor connection shaft 60 meshes with the switching shaft gear 32 provided on the switching shaft 30. As a result, in the transmission 10, a power transmission path (power transmission system) is formed between the secondary shaft 23, the intermediate shaft 41, the switching shaft 30, and the electric motor connection shaft 60, allowing power to be transmitted via the gears provided thereon.

[0051] In the transmission 10, the electric motor connection shaft gear 61 and the first reverse idler gear 42 (intermediate shaft gear) are provided in an area below the height of the switching shaft gear 32 located therebetween. That is, the upper end positions of the electric motor connection shaft gear 61 and the first reverse idler gear 42 are provided in an area below the upper end position of the switching shaft gear 32. In addition, in the transmission 10, the electric motor connection shaft gear 61, the switching shaft gear 32, and the first reverse idler gear 42 are arranged in this order. The axial position of the switching shaft gear 32 (switching shaft 30) is lower than the axial position of the electric motor connection shaft gear 61 (electric motor connection shaft 60). In addition, the axial position of the first reverse idler gear 42 is lower than the axial position of the switching shaft gear 32. Furthermore, in this embodiment, the secondary input gear 24 (secondary shaft 23) is disposed on the opposite side of the first reverse idler gear 42 (intermediate shaft 41) from the switching shaft gear 32 (switching shaft 30). The axial center position of the secondary input gear 24 (secondary shaft 23) is located lower than that of the first reverse idler gear 42 (intermediate shaft 41). Therefore, in the transmission 10, the oil contained in the case 11 of the transmission 10 flows from the electric motor connecting shaft gear 61 (electric motor connecting shaft 60) side, through the switching shaft gear 32 (switching shaft 30) and the first reverse idler gear 42 (intermediate shaft 41) in this order, and then can flow smoothly toward the secondary input gear 24 (secondary shaft 23).

[0052] The electric motor connection shaft gear 61, the switching shaft gear 32, and the first reverse idler gear 42 are arranged so that their axial center positions are aligned along a predetermined imaginary line L. In other words, assuming that an imaginary line L connects the axial center positions of the electric motor connection shaft gear 61 and the first reverse idler gear 42, the axial center position of the switching shaft gear 32 is located on the imaginary line L. As a result, in the transmission 10, the distance (inter-shaft distance) between the electric motor connection shaft gear 61 (electric motor connection shaft 60), the switching shaft gear 32 (switching shaft 30), and the first reverse idler gear 42 (intermediate shaft 41) is minimized. As a result, the transmission 10 is able to achieve a large gear ratio while preventing the gear diameter of the switching shaft gear 32 from becoming excessively large.

[0053] The transmission 10 of this embodiment is mounted on a vehicle with the internal combustion engine 3 and the electric motor 4 connected to each other so as to be able to transmit power. As shown in FIGS. 1 and 3 , the transmission 10 has an electric motor connecting shaft 60 connected to the rotating shaft 4A of the electric motor 4 via a shaft connecting structure 80. The transmission 10 can be configured such that the electric motor connecting shaft 60 and the rotating shaft 4A are arranged with their axial centers aligned and connected together, but in this embodiment, the axial centers of the electric motor connecting shaft 60 and the rotating shaft 4A are misaligned. Therefore, the shaft connecting structure 80 enables power transmission between the rotating shaft 4A and the electric motor connecting shaft 60 while allowing the rotating shaft 4A and the electric motor connecting shaft 60 to rotate eccentrically relative to each other.

[0054] The shaft coupling structure 80 may be, for example, one that couples the rotating shaft 4A and the motor connecting shaft 60 via a flexible shaft, or one that couples a shaft to a shaft body arranged between the rotating shaft 4A and the motor connecting shaft 60 via a flexible coupling such as a universal joint, a Cardan joint, a bellows coupling or an Oldham coupling. In this embodiment, a connecting shaft 82 is arranged between the rotating shaft 4A and the motor connecting shaft 60, and the rotating shaft 4A is connected to one end of the connecting shaft 82 via a first universal joint 84, and the motor connecting shaft 60 is connected to the other end of the connecting shaft 82 via a second universal joint 86.

[0055] In the mounting structure X, the connecting shaft 82 may be disposed, for example, so as to pass above the internal combustion engine 3, and may be appropriately set in consideration of the relative positions of the internal combustion engine 3, the electric motor 4, the transmission 10, and other components. In this embodiment, as shown in FIG. 4, the axial center position of the electric motor connecting shaft 60 is located in an area above the oil pan arrangement area 3A in which the oil pan is arranged in the slant-mounted internal combustion engine 3. Also, as shown in FIG. 5, in the mounting structure X, the oil pan is disposed in a position on the lower side of the internal combustion engine 3, and a gap is formed above the oil pan arrangement area 3A in which the oil pan is arranged, at a position lower than the surrounding area. This embodiment focuses on the formation of such a gap, and by disposing the connecting shaft 82 in the gap and connecting the electric motor connecting shaft 60 to the connecting shaft 82, the transmission 10 is mounted on the vehicle.

[0056] The above is one embodiment of the transmission 10 of the present invention. Next, the effects achieved by the transmission 10 of the present invention will be described below.

[0057] <Action and effect> The above-described transmission 10 has the following characteristic configurations (a) to (g). Therefore, the transmission 10 according to the present invention can achieve the following unique effects that cannot be achieved by conventional techniques.

[0058] (a) The transmission 10 of this embodiment is used in a vehicle equipped with an internal combustion engine 3 and an electric motor 4, and includes an input shaft 13 that transmits power output from the internal combustion engine 3, an output shaft 15 that transmits the power to drive wheels of the vehicle, an electric motor connecting shaft 60 that is connected to the electric motor 4, a switching shaft 30 (first driven shaft) that transmits power between the input shaft 13 and the electric motor connecting shaft 60, an intermediate shaft 41 (second driven shaft) that is provided between the switching shaft 30 and the input shaft 13, and a first reverse idler gear 42 (intermediate shaft gear / second driven gear) that is provided on the intermediate shaft 41. ) and the switching shaft 30 is provided with a switching mechanism 70 that switches between an input side connection state that enables power transmission between the motor connecting shaft 60 and the input shaft 13 and an output side connection state that enables power transmission between the motor connecting shaft 60 and the output shaft 15, and a switching shaft gear 32 (first driven gear) that can transmit power to the motor connecting shaft 60, and the motor connecting shaft 60 is provided with a motor connecting shaft gear 61, and the motor connecting shaft gear 61 and the first reverse idler gear 42 are provided in an area below the height of the switching shaft gear 32.

[0059] As described above in (a), in the transmission 10 of this embodiment, the electric motor connecting shaft gear 61 provided on the electric motor connecting shaft 60 connected to the electric motor 4, and the first reverse idler gear 42 provided on the intermediate shaft 41 are provided in an area equal to or lower than the height of the switching shaft gear 32 provided on the switching shaft 30. As a result, in the transmission 10 of this embodiment, in the power transmission path through which power is transmitted between the electric motor 4 and the internal combustion engine 3, the gear diameter of the switching shaft gear 32 provided in the middle of the power transmission path is set to a size necessary to achieve a desired gear ratio, while preventing the electric motor connecting shaft gear 61 and the first reverse idler gear 42 from being increased in size in the height direction in order to arrange the switching shaft gear 32.

[0060] (b) In the transmission 10 of this embodiment, the motor connecting shaft gear 61, the switching shaft gear 32, and the first reverse idler gear 42 are arranged so that their axial centers are aligned along a predetermined imaginary line L.

[0061] By adopting the configuration as described above in (b), the transmission 10 of this embodiment can minimize the center distance between the electric motor connecting shaft gear 61, the switching shaft gear 32, and the first reverse idler gear 42. This makes it possible for the transmission 10 of this embodiment to achieve a large gear ratio while minimizing the gear diameter of the switching shaft gear 32. This further prevents the transmission 10 of this embodiment from becoming large in height.

[0062] (c) In the transmission 10 of this embodiment, the electric motor connecting shaft gear 61, the switching shaft gear 32, and the first reverse idler gear 42 are arranged in this order, and the axial position of the switching shaft gear 32 is lower than the axial position of the electric motor connecting shaft gear 61, and the axial position of the first reverse idler gear 42 is lower than the axial position of the switching shaft gear 32.

[0063] In the transmission 10 of this embodiment, as shown in (c) above, the electric motor connecting shaft gear 61, the switching shaft gear 32, and the first reverse idler gear 42 are arranged in descending order, thereby allowing oil to flow smoothly through the electric motor connecting shaft gear 61, the switching shaft gear 32, and the first reverse idler gear 42 in that order.

[0064] (d) In the transmission 10 of this embodiment, the axial center position of the electric motor connecting shaft 60 is located in an area above the oil pan arrangement area 3A in which the oil pan of the internal combustion engine 3 is arranged.

[0065] By configuring the transmission 10 of this embodiment as described in (d) above, the area above the oil pan arrangement area 3A, which is located at a low position in the internal combustion engine 3, can be utilized to directly or indirectly connect the electric motor 4 to the electric motor connecting shaft 60. Therefore, the transmission 10 of this embodiment can make the mounting structure X, in which the electric motor 4 is connected to the electric motor connecting shaft 60 and mounted on a vehicle, more compact in the vertical direction.

[0066] (e) In the transmission 10 of this embodiment, the connecting shaft 82 that connects the electric motor connecting shaft 60 and the rotating shaft 4A of the electric motor 4 is connected in an area above the oil pan arrangement area 3A in which the oil pan is arranged in the internal combustion engine 3.

[0067] By configuring the transmission 10 of this embodiment as described in (e) above, the area above the oil pan arrangement area 3A, which is located at a low position in the internal combustion engine 3, can be utilized as space for connecting the electric motor 4 to the electric motor connecting shaft 60 via the connecting shaft 82. Therefore, the transmission 10 of this embodiment can make the mounting structure X, in which the electric motor 4 is connected to the electric motor connecting shaft 60 and mounted on a vehicle, more compact in the vertical direction.

[0068] (f) In the transmission 10 of this embodiment, the switching shaft 30 is provided with an output side gear 33 capable of transmitting power to the output shaft 15, and an input side gear 31 capable of transmitting power from the input shaft 13, and the switching mechanism 70 is arranged between the output side gear 33 and the switching shaft gear 32, and between the input side gear 31 and the output side gear 33.

[0069] By adopting the configuration according to (f) above, the transmission 10 of this embodiment can accommodate the switching mechanism 70 with high spatial efficiency inside the transmission 10. Furthermore, by disposing the switching mechanism 70 between the switching shaft gear 32 and the output gear 33 as described above, the transmission 10 of this embodiment can dispose the switching shaft gear 32 closer to the internal combustion engine. This allows the transmission 10 of this embodiment to dispose the electric motor 4 in a position close to the internal combustion engine 3, and prevents the external dimensions of the transmission 10 from becoming large when viewed from the internal combustion engine side.

[0070] (g) In the transmission 10 of this embodiment, the switching shaft 30 is provided with an output side gear 33 capable of transmitting power to the output shaft 15 and an input side gear 31 capable of transmitting power from the input shaft 13, and the switching mechanism 70 has a clutch 71, and by switching the connection state of the clutch 71, the input side connection state and the output side connection state of the switching mechanism 70 are switched.

[0071] By configuring the transmission 10 of this embodiment as described above in (g), the transmission 10 can smoothly switch between the input side connection state and the output side connection state by switching the connection state of the clutch 71.

[0072] <<Variations>> The above are the effects achieved by the transmission 10 according to one embodiment of the present invention. However, the transmission 10 is not limited to the above embodiment and can be modified in various ways within the scope of the present invention. For example, the transmission 10 may be formed in various shapes and sizes as long as it is as described above in (a). Furthermore, various types of internal combustion engines 3 can be used that are connected to the transmission 10. For example, various types of internal combustion engines, such as gasoline engines and diesel engines, can be used as the internal combustion engine 3. Furthermore, while the present embodiment illustrates a case in which a motor generator is used as the electric motor 4, various types of motors and generators, not just motor generators, can be used as the electric motor 4. Furthermore, various types of electric motors, shapes, and sizes can be used as the electric motor 4. Furthermore, the transmission 10 of the present invention can have an increased or decreased number of rotating shafts as appropriate within the scope of the present invention. For example, the transmission 10 may not have some or all of the configurations described above in (b) to (g), or it may have some or all of the configurations described above in (b) to (g) plus other configurations.

[0073] Specifically, as shown in (b) above, the transmission 10 described above is arranged so that the axial positions of the electric motor connecting shaft gear 61, the switching shaft gear 32, and the first reverse idler gear 42 are aligned along the imaginary line L, but the present invention is not limited to this. For example, the transmission 10 may be arranged so that the axial position of the switching shaft gear 32 is offset upward from the imaginary line L connecting the axial positions of the electric motor connecting shaft gear 61 and the first reverse idler gear 42.

[0074] The above-described transmission 10 is not limited to the one in which the motor connecting shaft gear 61, the switching shaft gear 32, and the first reverse idler gear 42 are arranged in this order with their shaft center positions descending as shown in (c) above. For example, the transmission 10 may be one in which the shaft center positions of either or both of the motor connecting shaft gear 61 and the first reverse idler gear 42 are at the same height as the shaft center position of the switching shaft gear 32, or are offset from that position in the vertical direction by a certain range.

[0075] The above-described transmission 10 is not limited to the one in which the axial center position of the electric motor connecting shaft 60 is located in an area above the oil pan arrangement area 3A in which the oil pan is arranged in the internal combustion engine 3, as in (d) above. For example, the transmission 10 may have the axial center position of the electric motor connecting shaft 60 located in a position outside the area above the oil pan arrangement area 3A.

[0076] As described above in (e), the transmission 10 utilizes the area above the oil pan arrangement area 3A as a space for arranging the connecting shaft 82 for connecting the electric motor 4 to the electric motor connecting shaft 60, but the present invention is not limited to this. The transmission 10 may also have the connecting shaft 82 arranged in a position other than the area above the oil pan arrangement area 3A.

[0077] In the transmission 10 described above, as described in (f) above, the switching mechanism 70 is disposed between the output gear 33 and the switching shaft gear 32, and between the input gear 31 and the output gear 33, but the present invention is not limited to this. For example, the transmission 10 may be one in which the positions of the switching shaft gear 32, input gear 31, and output gear 33 that constitute the switching mechanism 70 are changed.

[0078] In the transmission 10 described above, the input-side connected state and the output-side connected state of the switching mechanism 70 are switched by switching the connected state of the clutch 71, as described in (g) above, but the present invention is not limited to this. The transmission 10 can employ various switching devices and mechanisms other than the clutch 71 to switch the state of the switching mechanism 70. Furthermore, the clutch 71 can be switched not only hydraulically but also electrically, and various other types can be used.

[0079] In this embodiment, when the internal combustion engine 3 is operating in the input side connected state, the power output from the internal combustion engine 3 is supplied to the electric motor 4 for power generation via the switching shaft 30 and the electric motor connecting shaft 60, but the transmission 10 of the present invention is not limited to this. The power output from the internal combustion engine 3 may be supplied to the electric motor 4 for power generation as needed, and for example, it is also possible to disengage the clutch 71 and supply the power output from the internal combustion engine 3 only for driving the drive wheels.

[0080] Furthermore, in this embodiment, when the electric motor 4 is driving in the output side connected state, the power output from the electric motor 4 is provided to drive the drive wheels via the electric motor connection shaft 60 and the switching shaft 30, but the transmission 10 of the present invention is not limited to this. The power output from the electric motor 4 may be provided to drive the drive wheels as needed; for example, the clutch 71 may be disengaged and the power output from the electric motor 4 may be used to drive something other than the drive wheels. Furthermore, in this embodiment, when the drive wheels are braked in the output side connected state, the braking force is provided to the electric motor 4 for regeneration; however, regeneration may be performed as needed; for example, it is also possible not to perform regeneration when the battery is abundantly charged.

[0081] In this embodiment, the intermediate shaft 41 and the first reverse idler gear 42 (intermediate shaft gear) are used in common to transmit the power of the input shaft 13 to the switching shaft 30, but the transmission 10 of the present invention is not limited to this. For example, the intermediate shaft 41 and the reverse idler gear 42 may transmit power to the output shaft 15 without passing through the switching shaft 30.

[0082] The above are various embodiments and modifications of the transmission according to the present invention, but the present invention is not limited to the above-mentioned embodiments and modifications, and it will be readily apparent to those skilled in the art that other embodiments are possible within the scope of the claims and the teachings and spirit of the present invention. [Industrial Applicability]

[0083] The present invention can be suitably used as a transmission for a hybrid vehicle equipped with an electric motor and an internal combustion engine. [Explanation of symbols]

[0084] 3: Internal combustion engine 3A: Oil pan location area 4:Electric motor 4A: Rotating shaft 10: Transmission 13: Input shaft 15: Output shaft 30: Switching axis 31: Input gear 32: Switching shaft gear 33: Output gear 41: Intermediate shaft 42: First reverse idler gear (intermediate shaft gear) 60: Motor connection shaft 61: Motor connecting shaft gear 70: Switching mechanism 71: Clutch 82:Connection shaft L: Virtual line X: Mounting structure

Claims

1. A transmission for a vehicle equipped with an internal combustion engine and an electric motor, an input shaft that transmits power output from the internal combustion engine; an output shaft that transmits the power to drive wheels of the vehicle; an electric motor connection shaft connected to the electric motor; a switching shaft that transmits power between the input shaft and the motor connection shaft; an intermediate shaft provided intermediate the switching shaft and the input shaft; an intermediate shaft gear provided on the intermediate shaft; and The switching shaft has a switching mechanism that switches between an input-side connection state that enables the transmission of power between the electric motor connection shaft and the input shaft and an output-side connection state that enables the transmission of power between the electric motor connection shaft and the output shaft; a switching shaft gear capable of transmitting the power to the electric motor connection shaft; is provided, a motor connecting shaft gear is provided on the motor connecting shaft, A transmission characterized in that the electric motor connecting shaft gear and the intermediate shaft gear are provided in an area below the height of the switching shaft gear.

2. 2. The transmission according to claim 1, wherein the electric motor connecting shaft gear, the switching shaft gear, and the intermediate shaft gear are arranged so that their axial centers are aligned along a predetermined imaginary line.

3. the motor connection shaft gear, the switching shaft gear, and the intermediate shaft gear are arranged in this order, the shaft center position of the switching shaft gear is lower than the shaft center position of the electric motor connection shaft gear, 3. The transmission according to claim 1, wherein the axial center of the intermediate gear is lower than the axial center of the switching gear.

4. 3. The transmission according to claim 1, wherein the axial center of the electric motor connecting shaft is located in an area above an oil pan arrangement area in which an oil pan is arranged in the internal combustion engine.

5. 3. The transmission according to claim 1, wherein a connecting shaft that connects the electric motor connecting shaft and the rotating shaft of the electric motor is connected in an area above an oil pan arrangement area in which an oil pan is arranged in the internal combustion engine.

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