Transmission mounting structure

By offsetting and overlapping the electric motor and internal combustion engine in the fore-and-aft direction and using a flexible coupling, the transmission mounting structure achieves compactness and efficient space utilization, addressing the size and space challenges in hybrid vehicles.

JP7794865B2Active Publication Date: 2026-01-06DAIHATSU MOTOR CO LTD
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Patent Information

Application Number
JP2024022465
Authority / Receiving Office
JP · JP
Patent Type
Patents
Current Assignee / Owner
Filing Date
2024-02-17
Publication Date
2026-01-06
Estimated Expiration
2044-02-17

AI Technical Summary

Technical Problem

Conventional hybrid vehicles with both an internal combustion engine and an electric motor face challenges in mounting due to the large size of the transmission, which can compromise driver space and luggage compartment space, especially in front-engine, rear-wheel-drive vehicles, leading to poor mountability and reduced marketability.

Method used

The transmission mounting structure positions the electric motor and internal combustion engine offset in the fore-and-aft direction of the vehicle, allowing them to overlap vertically, with a flexible coupling connecting the electric motor's shaft to the transmission, and utilizing the space above the oil pan for the connecting shaft, and integrating the switching mechanism efficiently within the transmission.

Benefits of technology

This configuration results in a more compact transmission mounting structure that saves space, improves layout freedom, and prevents the transmission from appearing large from the internal combustion engine's perspective, enhancing mountability and marketability.

✦ Generated by Eureka AI based on patent content.

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Patent Text Reader

Abstract

To provide a loading structure of a speed changer in a vehicle provided with an internal combustion engine and an electric motor, which can be downsized.SOLUTION: A loading structure X is for loading a speed changer 10 on a vehicle provided with an internal combustion engine 3 and an electric motor 4. The speed changer 10 is provided with: an input shaft 13 that transmits power outputted from the internal combustion engine 3; an electric motor connection shaft 60 that is connected to the electric motor 4; a switching shaft 30 that transmits power between the input shaft 13 and the electric motor connection shaft 60; an output shaft 15; and a switching mechanism 70, provided on the switching shaft 30, which switches between an input-side connection state where power can be transmitted between the electric motor connection shaft 60 and the input shaft 13 and an output-side connection state where power can be transmitted between the electric motor connection shaft 60 and the output shaft 15. The electric motor 4 and the internal combustion engine 3 are deviated in a longitudinal direction of the vehicle, at one side in the longitudinal direction of the vehicle with respect to the speed changer 10, and are arranged to be wrapped in a vertical direction.SELECTED DRAWING: Figure 1
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Description

[Technical Field]

[0001] The present invention relates to a transmission mounting structure for 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 a vehicle such as the conventional technology disclosed in Patent Document 1, the size of the transmission becomes large when viewed from the internal combustion engine side, resulting in poor mountability. Specifically, in a vehicle equipped with an internal combustion engine and an electric motor, when the electric motor and the internal combustion engine are collectively arranged on one side of the transmission in the longitudinal direction of the vehicle, a mounting structure in which the electric motor and the internal combustion engine are arranged vertically side by side is conceivable. Adopting such a mounting structure requires a large vertical space, resulting in poor mountability. Furthermore, in a front-engine, rear-wheel-drive vehicle (FR vehicle), adopting the transmission structure described in Patent Document 1 requires a large floor tunnel, which raises concerns that the driver's foot space may expand toward the passenger compartment, compressing the driver's cab. Furthermore, in an FR commercial vehicle, adopting the transmission structure described in Patent Document 1 requires a high luggage compartment, which leads to a problem of reduced marketability.

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

[0006] (1) The present invention is a mounting structure for a transmission in a vehicle equipped with an internal combustion engine and an electric motor, wherein the transmission comprises an input shaft that transmits power output from the internal combustion engine, an electric motor connection shaft connected to the electric motor, a switching shaft that transmits power between the input shaft and the electric motor connection shaft, an output shaft that transmits the power to drive wheels of the vehicle, and a switching mechanism provided on the switching shaft that switches between an input side connection state that enables the transmission of the power between the electric motor connection shaft and the input shaft and an output side connection state that enables the transmission of the power between the electric motor connection shaft and the output shaft, and is characterized in that the electric motor and the internal combustion engine are positioned on one side of the transmission in the fore-and-aft direction of the vehicle, at a position offset in the fore-and-aft direction of the vehicle, and are positioned so as to overlap in the vertical direction.

[0007] The transmission mounting structure of the present invention employs a layout in which the electric motor and the internal combustion engine are disposed together on one side of the transmission in the longitudinal direction of the vehicle, but the electric motor and the internal combustion engine are disposed offset in the longitudinal direction of the vehicle and overlap each other in the vertical direction, thereby enabling the transmission mounting structure of the present invention to have a more compact configuration than a mounting structure in which the electric motor and the internal combustion engine are disposed side by side in the vertical direction.

[0008] (2) In the transmission mounting structure of the present invention, the electric motor connection shaft and the rotating shaft of the electric motor are preferably connected by a shaft connecting structure that can transmit power while allowing eccentric rotation.

[0009] By adopting the configuration according to (2) above, the transmission mounting structure according to the present invention can position the electric motor relative to the transmission without aligning the axial center positions of the electric motor connecting shaft and the electric motor rotating shaft. This improves the degree of freedom in the layout of the electric motor relative to the transmission, and allows for even more compactness in the transmission mounting structure according to the present invention.

[0010] (3) In the transmission mounting structure of the present invention, the electric motor connection shaft and the rotating shaft of the electric motor are preferably connected to each other via a flexible coupling.

[0011] The transmission mounting structure according to the present invention is configured such that the electric motor connecting shaft and the rotating shaft of the electric motor are connected via a flexible coupling as described above in (3), so that the electric motor can be connected to the transmission without the need to align the axial centers of the electric motor connecting shaft and the rotating shaft. This allows the transmission mounting structure according to the present invention to have greater freedom in the layout of the electric motor relative to the transmission, making it possible to achieve even more compactness.

[0012] (4) The transmission mounting structure of the present invention is preferably such that the motor connecting shaft and the connecting shaft connecting the rotating shaft of the motor are arranged to pass through an area above the oil pan arrangement area in which the oil pan is arranged in the internal combustion engine.

[0013] The transmission mounting structure according to the present invention takes advantage of the fact that the oil pan is located at a lower position in the internal combustion engine and employs the configuration according to (4) above. The transmission mounting structure according to the present invention utilizes the area above the oil pan location for arranging the electric motor connecting shaft and the connecting shaft that connects the electric motor rotating shaft. Therefore, the transmission mounting structure according to the present invention can be made more compact in the vertical direction.

[0014] (5) The mounting structure of the transmission of the present invention is preferably such that the switching shaft has 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 disposed between the output side gear and the switching shaft gear, and between the input side gear and the output side gear.

[0015] The transmission mounting structure of the present invention, by adopting the configuration according to (5) above, 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 mounting structure of the present invention can dispose the switching shaft gear closer to the internal combustion engine. As a result, the transmission mounting structure of the present invention can dispose the electric motor in a position close to the internal combustion engine, and can prevent the external dimensions of the transmission from becoming large when viewed from the internal combustion engine.

[0016] (6) In the mounting structure of 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.

[0017] By configuring the transmission mounting structure of the present invention as described above in (6), it is possible to smoothly switch between the input side connection state and the output side connection state in the transmission by switching the connection state of the clutch. [Effects of the Invention]

[0018] According to the present invention, it is possible to provide a transmission mounting structure that solves the above-mentioned problems. [Brief explanation of the drawings]

[0019] [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

[0020] The mounting structure X of the 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.

[0021] As shown in FIGS. 1 and 3 , the mounting structure X according to this embodiment has an internal combustion engine 3 and an electric motor 4 connected to a transmission 10. The internal combustion engine 3 is configured by 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 through the input shaft 13.

[0022] 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.

[0023] 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, forward clutches 5, 1 (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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] The continuously variable transmission 20 is provided with a primary shaft 21, a secondary shaft 23, a primary pulley 26, a secondary pulley 27, and a belt 28.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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).

[0033] 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 .

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] In the mounting structure X for the transmission 10 of this embodiment, the internal combustion engine 3 and the electric motor 4 are mounted on a vehicle with the transmission 10 as described above connected to them so as to be able to transmit power. As shown in FIGS. 1, 3, etc., in the mounting structure X, the internal combustion engine 3 and the electric motor 4 are disposed on one side of the transmission 10 in the front-to-rear direction of the vehicle (the front Fr side in this embodiment) at a position offset from the front-to-rear direction of the vehicle. Furthermore, as shown in FIGS. 1, 3, 5, etc., the internal combustion engine 3 and the electric motor 4 are disposed so as to overlap each other in the vertical direction. Specifically, in this embodiment, the electric motor 4 is disposed on the front side of the vehicle relative to the internal combustion engine 3 and above the internal combustion engine 3. Furthermore, when viewed from the front-to-rear direction of the vehicle, the internal combustion engine 3 and the electric motor 4 are disposed so as to overlap each other in the vertical direction (overlapping state).

[0049] 1 and 3, in the mounting structure X, the rotating shaft 4A of the electric motor 4 and the electric motor connecting shaft 60 of the transmission 10 are connected by a shaft connecting structure 80. 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. The shaft connecting structure 80 may be, for example, one that connects the rotating shaft 4A and the electric motor connecting shaft 60 via a flexible shaft, or one that connects a shaft body disposed between the rotating shaft 4A and the electric 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 disposed between the rotating shaft 4A and the electric 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 electric motor connecting shaft 60 is connected to the other end of the connecting shaft 82 via a second universal joint 86.

[0050] 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 set appropriately taking into consideration 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 Figures 4 and 5, the oil pan is disposed at a position on the lower side of the internal combustion engine 3, and a gap is formed above the oil pan arrangement area 3A where the oil pan is disposed, at a position lower than the surrounding area, and this gap is utilized as an area for disposing the connecting shaft 82.

[0051] The above is one embodiment of the mounting structure X of the transmission 10 of the present invention. Next, the effects achieved by the mounting structure X of the transmission 10 of the present invention will be described below.

[0052] <Action and effect> The above-described transmission 10 has the following characteristic configurations (a) to (f). Therefore, the mounting structure X for the transmission 10 according to the present invention can achieve the following unique effects that cannot be achieved by conventional techniques.

[0053] (a) The mounting structure X of the transmission 10 exemplified in this embodiment is for mounting the transmission 10 in a vehicle equipped with an internal combustion engine 3 and an electric motor 4, and the transmission 10 includes an input shaft 13 that transmits power output from the internal combustion engine 3, an electric motor connecting shaft 60 connected to the electric motor 4, a switching shaft 30 that transmits power between the input shaft 13 and the electric motor connecting shaft 60, an output shaft 15 that transmits power to the drive wheels of the vehicle, and a switching mechanism 70 that is provided on the switching shaft 30 and switches between an input side connection state that enables power transmission between the electric motor connecting shaft 60 and the input shaft 13 and an output side connection state that enables power transmission between the electric motor connecting shaft 60 and the output shaft 15, and is characterized in that the electric motor 4 and the internal combustion engine 3 are positioned on one side of the transmission 10 in the fore-and-aft direction of the vehicle, at a position offset from the fore-and-aft direction of the vehicle, and are positioned so as to overlap in the up-and-down direction.

[0054] The mounting structure X of the transmission 10 according to this embodiment employs a layout in which the electric motor 4 and the internal combustion engine 3 are arranged together on one side of the transmission 10 in the longitudinal direction of the vehicle, but the electric motor 4 and the internal combustion engine 3 are arranged offset in the longitudinal direction of the vehicle and overlap each other in the vertical direction. As a result, the mounting structure X of the transmission 10 according to this embodiment can be made more compact than a mounting structure X in which the electric motor 4 and the internal combustion engine 3 are arranged next to each other in the vertical direction.

[0055] (b) In the mounting structure X of the transmission 10 of this embodiment, the electric motor connecting shaft 60 and the rotating shaft 4A of the electric motor 4 are connected by a shaft connecting structure 80 that is capable of transmitting power while allowing eccentric rotation.

[0056] By adopting the configuration according to (b) above, the mounting structure X for the transmission 10 according to this embodiment can place the electric motor 4 relative to the transmission 10 without aligning the axial center positions of the electric motor connecting shaft 60 and the rotating shaft 4A of the electric motor 4. This improves the degree of freedom in the layout of the electric motor 4 relative to the transmission 10, and allows for even more compactness in the mounting structure X for the transmission 10 according to this embodiment.

[0057] (c) In the mounting structure X of the transmission 10 of this embodiment, the electric motor connecting shaft 60 and the rotating shaft 4A of the electric motor 4 are axially connected via flexible couplings (first universal joint 84 and second universal joint 86 in this embodiment).

[0058] The mounting structure X for the transmission 10 according to this embodiment is configured such that the electric motor connecting shaft 60 and the rotating shaft 4A of the electric motor 4 are axially connected via a flexible coupling as described above in (c), so that the electric motor 4 can be connected to the transmission 10 without aligning the axial centers of the electric motor connecting shaft 60 and the rotating shaft 4A. This improves the degree of freedom in the layout of the electric motor 4 relative to the transmission 10, and allows for even more compactness in the mounting structure X for the transmission 10 according to this embodiment.

[0059] (d) In the mounting structure X of 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 arranged to pass through an area above the oil pan arrangement area 3A in which the oil pan is arranged in the internal combustion engine 3.

[0060] The mounting structure X for the transmission 10 according to this embodiment employs the configuration according to (d) above, taking into account that the oil pan is disposed at a lower position in the internal combustion engine 3. The mounting structure X for the transmission 10 according to this embodiment utilizes the area above the oil pan disposition area 3A to dispose of the electric motor connecting shaft 60 and the connecting shaft 82 that connects the rotating shaft 4A of the electric motor 4. Therefore, the mounting structure X for the transmission 10 according to this embodiment can be made more compact in the vertical direction.

[0061] (e) In the mounting structure X of the transmission 10 of this embodiment, the switching shaft 30 has 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.

[0062] By adopting the configuration according to (e) above, the mounting structure X of 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 mounting structure X of the transmission 10 of this embodiment can dispose the switching shaft gear 32 closer to the internal combustion engine. As a result, the mounting structure X of the transmission 10 of this embodiment disposes the electric motor 4 in a position close to the internal combustion engine 3, and can prevent the external dimensions of the transmission 10 from becoming large when viewed from the internal combustion engine side.

[0063] (f) In the mounting structure X of the transmission 10 of this embodiment, the switching shaft 30 has 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, and by switching the connection state of the clutch, the input side connection state and the output side connection state of the switching mechanism 70 are switched.

[0064] By configuring the mounting structure X of the transmission 10 of this embodiment as described above in (f), it is possible to smoothly switch between the input side connection state and the output side connection state in the transmission 10 by switching the connection state of the clutch.

[0065] <<Variations>> The above are the effects obtained by the mounting structure X of the transmission 10 according to one embodiment of the present invention. However, the mounting structure X of the transmission 10 is not limited to the above embodiment and can be variously modified within the scope of the present invention. For example, the mounting structure X of 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. 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 can be used as the electric motor 4, not just motor generators. Furthermore, various types of electric motors 4, shapes, and sizes can be used. 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 invention. For example, the transmission 10 can be configured without some or all of the configurations described above in (b) to (f), or can be configured with some or all of the configurations described above in (b) to (f) and other configurations.

[0066] Specifically, the mounting structure X for the transmission 10 described above has been exemplified as a configuration in which the electric motor connecting shaft 60 of the transmission 10 and the rotating shaft 4A of the electric motor 4 are connected by the shaft connecting structure 80, as in (b) above, but the present invention is not limited to this. For example, the mounting structure X can also be one in which the electric motor connecting shaft 60 and the rotating shaft 4A of the electric motor 4 are connected by a shaft that does not allow eccentric rotation, by aligning the axial center positions of the electric motor connecting shaft 60 and the rotating shaft 4A.

[0067] The mounting structure X for the transmission 10 described above is exemplified as one in which the motor connecting shaft 60 and the rotating shaft 4A are connected via a flexible coupling as described above (c), but the present invention is not limited to this. For example, as described above, the mounting structure X can also be one in which the rotating shaft 4A and the motor connecting shaft 60 are connected via a flexible shaft, or one in which the shafts are connected via a flexible coupling other than a universal joint such as a Cardan joint, a bellows coupling, or an Oldham coupling.

[0068] The mounting structure X for the transmission 10 described above is exemplified as one in which the connecting shaft 82 is arranged to pass through an area above the oil pan arrangement area 3A, as shown in (d) above, but the present invention is not limited to this. For example, the mounting structure X may be one in which the connecting shaft 82 is arranged to pass through an area above the internal combustion engine 3 at a location other than the oil pan arrangement area 3A.

[0069] In the mounting structure X of the transmission 10 described above, as in (e) 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 mounting structure X 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.

[0070] In the transmission 10 described above, the input-side connection state and the output-side connection state of the switching mechanism 70 are switched by switching the connection state of the clutch 71 as described above (f), but the present invention is not limited to this. The mounting structure X can employ various switching devices and mechanisms different from 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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]

[0075] 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]

[0076] 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 60: Motor connection shaft 70: Switching mechanism 80: Shaft connection structure 82:Connection shaft 84: First universal joint 86: Second universal joint X: Mounting structure

Claims

1. A transmission mounting structure for a vehicle equipped with an internal combustion engine and an electric motor, The transmission is an input shaft that transmits power output from the internal combustion engine; 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 output shaft that transmits the power to drive wheels of the vehicle; a switching mechanism provided on the switching shaft, which switches between an input-side connection state that enables the transmission of power between the motor connection shaft and the input shaft and an output-side connection state that enables the transmission of power between the motor connection shaft and the output shaft; It is equipped with A transmission mounting structure characterized in that the electric motor and the internal combustion engine are arranged on one side of the transmission in the fore-and-aft direction of the vehicle, at a position offset from the fore-and-aft direction of the vehicle, and are arranged so as to overlap in the vertical direction.

2. 2. The transmission mounting structure according to claim 1, wherein the electric motor connecting shaft and the rotating shaft of the electric motor are connected by a shaft connecting structure that can transmit power while allowing eccentric rotation.

3. 3. The transmission mounting structure according to claim 1, wherein the electric motor connection shaft and the rotating shaft of the electric motor are axially connected via a flexible coupling.

4. 3. The transmission mounting structure according to claim 1, wherein the electric motor connecting shaft and the connecting shaft that connects the rotating shaft of the electric motor are arranged so as to pass through an area above an oil pan arrangement area in which an oil pan is arranged in the internal combustion engine.

Citation Information

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