transmission

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 Art

[0002] Conventionally, a hybrid vehicle equipped with an electric motor (motor) and an internal combustion engine (engine) is known (for example, Patent Document 1). In such a hybrid vehicle, one or both of the electric motor and the internal combustion engine are used as a drive source. Further, the electric motor in a hybrid vehicle is supposed to exhibit a function as a generator that generates electricity by regenerative torque during vehicle braking.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Incidentally, in vehicles like the one described in Patent Document 1, the size of the transmission as seen from the internal combustion engine side becomes large, resulting in poor mounting capacity. In other words, in vehicles equipped with an internal combustion engine and an electric motor, it is necessary to use a lower gear on the side from the electric motor to the internal combustion engine in order to ensure the starting performance of the internal combustion engine. As a result, in the power transmission path where power is transmitted between the electric motor and the internal combustion engine, there is a part where the gear diameter of the gear provided for power transmission becomes larger. This leads to the problem that transmissions used in vehicles equipped with electric motors and internal combustion engines tend to be large in size. Furthermore, in front-engine, rear-wheel-drive (FR) vehicles, if the structure of the transmission described in Patent Document 1 is adopted, it is necessary to enlarge the floor tunnel, raising concerns that the foot space in the driver's seat will bulge outwards into the passenger compartment, thus compressing the driver's seat. Also, in FR commercial vehicles, if the structure of the transmission described in Patent Document 1 is adopted, it is necessary to set the cargo area higher, which leads to a decrease in marketability.

[0005] Therefore, the present invention aims to miniaturize the transmission mounted on a vehicle equipped with an internal combustion engine and an electric motor. [Means for solving the problem]

[0006] (1) The transmission of the present invention is used in a vehicle equipped with an internal combustion engine and an electric motor, and comprises an input shaft that transmits power output from the internal combustion engine, an output shaft that transmits the power to the drive wheels of the vehicle, an electric motor connection shaft 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 between the switching shaft and the input shaft, and an intermediate shaft gear (second driven gear) provided on the intermediate shaft, and the switching The shaft is provided with a switching mechanism that 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, 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 a region below the height of the switching shaft gear.

[0007] As described in (1) above, the transmission of the present invention has an electric motor connection shaft gear provided on the electric motor connection shaft connected to the electric motor, and an intermediate shaft gear provided on the intermediate shaft, both located in a region below the height of the switching shaft gear provided on the switching shaft. This allows the transmission of the present invention to set the gear diameter of the switching shaft gear provided in the power transmission path between the electric motor and the internal combustion engine to the size necessary to achieve the desired gear ratio, while suppressing the need to increase the height of the electric motor connection shaft gear and the intermediate shaft gear to accommodate the switching shaft gear.

[0008] (2) The transmission of the present invention is preferably arranged such that the axial positions of the motor connecting shaft gear, the switching shaft gear, and the intermediate shaft gear are 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 connecting shaft gear, the switching shaft gear, and the intermediate shaft gear. As a result, the transmission of the present invention can achieve a large gear ratio while minimizing the gear diameter of the switching shaft gear. This further suppresses the increase in size in the height direction of the transmission of the present invention.

[0010] (3) The transmission of the present invention is arranged such that the motor connecting shaft gear, the switching shaft gear, and the intermediate shaft gear are in that order, and the axis of the switching shaft gear is lower than the axis of the motor connecting shaft gear, and the axis of the intermediate shaft gear is lower than the axis of the switching shaft gear.

[0011] As described in (3) above, the transmission of the present invention allows oil to flow smoothly in the order of the motor connecting shaft gear, the switching shaft gear, and the intermediate shaft gear by arranging them in that order from lowest to highest.

[0012] (4) The transmission of the present invention is preferable such that the axial center of the motor connecting shaft is located in a region above the oil pan arrangement region in the internal combustion engine where the oil pan is arranged.

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

[0014] (5) The transmission of the present invention is preferably such that the motor connecting shaft and the connecting shaft that connects the motor's rotating shaft are connected in a region above the oil pan arrangement region where the oil pan is located in the internal combustion engine.

[0015] By having the configuration described in (5) above, the transmission of the present invention can utilize the area above the oil pan location, which is located at a low position in the internal combustion engine, as space for connecting the electric motor to the electric motor connection shaft via a 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 connection shaft and mounted on the vehicle, more compact in the vertical direction.

[0016] (6) The transmission of the present invention is preferably configured such that the switching shaft comprises an output gear capable of transmitting the power to the output shaft and an input gear capable of transmitting the power of the input shaft, and the switching mechanism is located between the output gear and the switching shaft gear, and between the input gear and the output gear.

[0017] The transmission of the present invention, by having the configuration described in (6) above, can efficiently house the switching mechanism inside the transmission. Furthermore, as described above, the transmission of the present invention can position the switching shaft gear closer to the internal combustion engine by arranging the switching mechanism between the switching shaft gear and the output gear. As a result, the transmission of the present invention can position the electric motor in close proximity to the internal combustion engine, and can suppress an increase in the external size of the transmission as seen from the internal combustion engine side.

[0018] (7) The transmission of the present invention is preferable in which the switching shaft comprises an output gear capable of transmitting the power to the output shaft and an input gear capable of transmitting the power of the input shaft, and the switching mechanism has a clutch, and the switching of the input side connection state and the output side connection state in the switching mechanism is performed by switching the connection state of the clutch.

[0019] By adopting the configuration described in (7) above, the transmission of the present invention can smoothly switch between the input-side connection state and the output-side connection state in the transmission 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 Description of the Drawings

[0021] [Figure 1] It is an overall front view with a notch in the cover of the transmission according to an embodiment of the present invention. [Figure 2] It is a side view of the transmission in FIG. 1 as viewed from the internal combustion engine direction. [Figure 3] It is a schematic skeleton view of the transmission according to an embodiment of the present invention. [Figure 4] It is an explanatory diagram showing the positional relationship between the internal combustion engine and the transmission. [Figure 5] It is an explanatory diagram showing the positional relationship between the internal combustion engine and the electric motor.

Modes for Carrying Out the Invention

[0022] Hereinafter, the transmission 10 according to an embodiment of the present invention will be described in detail with reference to the drawings. Note that each drawing is schematically represented for easy understanding and may be different from the actual shape, size, and arrangement of components. Also, it should be noted that it may be omitted that each axis is supported by an appropriate bearing or the like and is rotatable. Also, hereinafter, 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 FIGS. 1 and 3, the transmission 10 according to the present embodiment is mounted on a vehicle with the internal combustion engine 3 and the electric motor 4 connected. The internal combustion engine 3 is composed of, for example, 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 the input shaft 13 in the transmission 10. Therefore, the power output by the internal combustion engine 3 is input to the transmission 10 through the input shaft 13.

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

[0025] The transmission 10 has multiple 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 the regenerated energy to the electric motor 4. The transmission 10 includes 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 also includes a switching shaft 30, an electric motor connection shaft 60, and a switching mechanism 70, etc.

[0026] The torque converter 12 includes a pump impeller 12A, a turbine runner 12B, and a lock-up mechanism 12C. The input shaft 13 is connected to the pump impeller 12A, and the pump impeller 12A is capable of rotating integrally with the input shaft 13 around the same axis of rotation. The turbine runner 12B is rotatable around the same axis of rotation as the pump impeller 12A. The lock-up mechanism 12C is provided to directly connect / disconnect the pump impeller 12A and the turbine runner 12B. When the lock-up mechanism 12C is engaged (lock-up on), the pump impeller 12A and the turbine runner 12B are directly connected, and when the lock-up mechanism 12C is released (lock-up off), the pump impeller 12A and the turbine runner 12B are separated.

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

[0028] The output shaft 15 is positioned at a rearward (Rr) distance from the input shaft 13. The output shaft 15 is positioned so that its axis aligns with the axis of the input shaft 13. Although not shown in the illustration, the output shaft 15 can transmit power to the vehicle's drive wheels via a drive shaft or the like. An output shaft gear 16 is integrally formed with the output shaft 15. The output shaft gear 16 meshes with a secondary output gear 25, which will be described later.

[0029] 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.

[0030] A primary input gear 22 is mounted on the primary shaft 21 so as to be rotatable relative to it. The primary input gear 22 meshes with the input shaft gear 14. A secondary input gear 24 and a secondary output gear 25 are mounted on the secondary shaft 23. The secondary input gear 24 is rotatable relative to the secondary shaft 23. The secondary output gear 25 is mounted so as not to be rotatable relative to the secondary shaft 23. The secondary output gear 25 meshes with the output shaft gear 16, which is located 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 hydraulic pressure supplied to the hydraulic chambers (not shown) of the primary pulley 26 and the secondary pulley 27 is controlled, and the groove widths of the primary pulley 26 and the secondary pulley 27 are changed, thereby continuously changing the belt gear ratio (pulley ratio between the primary pulley 26 and the secondary pulley 27) within a constant gear ratio range. The rotational force (power) of the shifted secondary shaft 23 is transmitted to the output shaft 15 via the secondary output gear 25 and the output shaft gear 16, driving the drive wheels (not shown).

[0032] The reverse transmission mechanism 40 is a mechanism that transmits power (rotation) from 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 located between the switching shaft 30 and the input shaft 13. The intermediate shaft 41 is provided approximately 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 the first reverse idler gear 42 and the second reverse idler gear 43, which will be described later.

[0034] The first reverse idler gear 42 is integrally formed with the intermediate shaft 41 and meshes with the input shaft gear 14. In other words, the first reverse idler gear 42 can reverse the rotation direction of the input shaft gear 14 (input shaft 13). Furthermore, the first reverse idler gear 42 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 the rear Rr of the first reverse idler gear 42 and meshes with the secondary input gear 24.

[0036] The forward clutch 51 (clutch device 50) is provided to allow / prevent the rotation of the primary input gear 22 relative to the primary shaft 21. The forward clutch 51 forms a clutch device 50 that includes a clutch drum, clutch piston, friction material, and hydraulic chamber, although these are not shown in the figures. The forward clutch 51 controls the engagement of the clutch by controlling the supply of oil to the hydraulic chamber according to the output value of a solenoid (not shown).

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

[0038] The reverse clutch 55 (clutch device 50) is provided to allow / prevent the rotation of the secondary input gear 24 relative to the secondary shaft 23. Since the reverse clutch 55 has the same configuration as the forward clutch 51, a detailed explanation is omitted.

[0039] When the reverse clutch 55 is engaged (engaged state), relative rotation of the secondary input gear 24 with respect to the secondary shaft 23 is prohibited. In other words, the engagement of the reverse clutch 55 causes the secondary shaft 23 and the secondary input gear 24 to rotate together. This transmits a driving force in the reverse direction to the output shaft 15, and drives the drive wheels (not shown) in the reverse direction. On the other hand, when the reverse clutch 55 is released (released state), relative rotation of the secondary input gear 24 with respect to the secondary shaft 23 is permitted. Therefore, even if the secondary input gear 24 rotates, that rotation is not transmitted to the secondary shaft 23.

[0040] The switching shaft 30 is a shaft that transmits power between the input shaft 13 and the motor connection shaft 60. Specifically, the input side gear 31, which meshes with the first reverse idler gear 42 (intermediate shaft gear), is mounted on the switching shaft 30. The first reverse idler gear 42 meshes with the input shaft gear 14, which is mounted on 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 mounted on the front end side (internal combustion engine 3 side, front Fr side) of the switching shaft 30. In other words, the switching shaft gear 32 is mounted on the internal combustion engine 3 side in the axial direction of the switching shaft 30. The switching shaft gear 32 meshes with the motor connection shaft gear 61, which will be described later, and can transmit power from the switching shaft 30 to the motor connection shaft 60.

[0041] As will be described in more detail 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 mentioned above. Furthermore, an output transmission shaft 17 is provided parallel to the switching shaft 30 at a distance from it.

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

[0043] An output transmission shaft gear 18 is mounted to the output transmission shaft 17. The output transmission shaft gear 18 meshes with the output shaft gear 16 on the output shaft 15. The output transmission shaft gear 18 also meshes with the output side gear 33 on the switching shaft 30. Furthermore, the output transmission shaft gear 18 meshes with the output shaft gear 16 on the output shaft 15. Therefore, the output transmission shaft 17 can transmit power from the switching shaft 30 to the output shaft 15 as the switching shaft 30 rotates.

[0044] As shown in Figure 2, the motor connection shaft 60 is positioned parallel to the switching shaft 30 with a gap between them. As shown in Figures 1 and 3, a universal joint 5 is connected to the front end (front Fr side) of the motor connection shaft 60. The rotating shaft 4A (see Figure 3) of the electric motor 4 (for example, a motor generator) is connected to the front end (Fr side) of the universal joint 5. A motor connection shaft gear 61 is also fixed to the motor connection shaft 60.

[0045] The motor connecting shaft gear 61 meshes with the switching shaft gear 32 on the switching shaft 30. Therefore, when the motor 4 is driven, the power output from the 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 electricity for the motor 4 via the motor connecting shaft gear 61 and the motor connecting shaft 60.

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

[0047] The switching mechanism 70 can switch between an "input-side connection state" that enables power transmission between the motor connection shaft 60 and the input shaft 13 and an "output-side connection state" that enables power transmission between the motor connection shaft 60 and the output shaft 15 by switching the connection state of the clutch 71 by hydraulics 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. The switching shaft gear 32 and the input-side gear 31 are located on the front Fr side of the switching shaft 30, and the 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 not engaged), 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 used to generate electricity for the electric motor 4 via the switching shaft 30 and the electric motor connection 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 used to start the internal combustion engine 3 via the electric motor connection shaft 60 and the switching shaft 30.

[0049] Furthermore, in the "output-side connected state," the rear Rr side of the switching shaft 30 is connected by the engagement of the clutch 71, and the front Fr side and rear Rr side of the switching shaft 30 rotate together. Therefore, when the motor 4 is driven in the "output-side connected state," the power output from the motor 4 is used to drive the drive wheels (not shown) via the motor connection 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 used for regeneration (power generation) of the motor 4 via the switching shaft 30 and the motor connection shaft 60. The switching mechanism 70 can also interrupt the transmission of power between the motor connection shaft 60 and the input shaft 13, and between the motor connection shaft 60 and the output shaft 15, when the clutch 71 is disengaged (also referred to as the unengaged state).

[0050] As shown in Figures 2 and 4, in the transmission 10 of this embodiment, the secondary shaft 23, intermediate shaft 41, switching shaft 30, and motor connection shaft 60 of the continuously variable transmission 20 are arranged in parallel with each other. Furthermore, the second reverse idler gear 43 provided on the intermediate shaft 41 meshes with the secondary input gear 24 provided on the secondary shaft 23, and the input side gear 31 of the switching shaft 30 meshes with the first reverse idler gear 42 (intermediate shaft gear) provided on the intermediate shaft 41. In addition, the motor connection shaft gear 61 provided on the 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, intermediate shaft 41, switching shaft 30, and motor connection shaft 60, through the gears provided on each of them, enabling power transmission.

[0051] In the transmission 10, the motor connecting shaft gear 61 and the first reverse idler gear 42 (intermediate shaft gear) are located in a region below the height of the switching shaft gear 32, which is situated between them. That is, the upper end positions of the motor connecting shaft gear 61 and the first reverse idler gear 42 are located in a region below the upper end position of the switching shaft gear 32. In the transmission 10, the motor connecting shaft gear 61, the switching shaft gear 32, and the first reverse idler gear 42 are arranged in that order. The axial center position of the switching shaft gear 32 (switching shaft 30) is lower than the axial center position of the motor connecting shaft gear 61 (motor connecting shaft 60). Also, the axial center position of the first reverse idler gear 42 is lower than the axial center position of the switching shaft gear 32. Furthermore, in this embodiment, the secondary input gear 24 (secondary shaft 23) is positioned on the opposite side of the switching shaft gear 32 (switching shaft 30) from the first reverse idler gear 42 (intermediate shaft 41). The axial center position of the secondary input gear 24 (secondary shaft 23) is even 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 can flow from the motor connection shaft gear 61 (motor connection shaft 60) side, through the switching shaft gear 32 (switching shaft 30), and then through the first reverse idler gear 42 (intermediate shaft 41), before flowing smoothly towards the secondary input gear 24 (secondary shaft 23).

[0052] The axial positions of the motor connecting shaft gear 61, the switching shaft gear 32, and the first reverse idler gear 42 are arranged to align along a predetermined imaginary line L. That is, when an imaginary line L is assumed to connect the axial position of the motor connecting shaft gear 61 and the axial position of the first reverse idler gear 42, the axial position of the switching shaft gear 32 is located on the imaginary line L. As a result, the transmission 10 minimizes the distance between the motor connecting shaft gear 61 (motor connecting shaft 60), the switching shaft gear 32 (switching shaft 30), and the first reverse idler gear 42 (intermediate shaft 41). Consequently, the transmission 10 is designed to allow for a large gear ratio while suppressing the excessively large gear diameter of the switching shaft gear 32.

[0053] The transmission 10 of this embodiment is mounted on a vehicle with the internal combustion engine 3 and the electric motor 4 connected in a manner that enables power transmission. Furthermore, as shown in Figures 1 and 3, the transmission 10 is configured such that the electric motor connecting shaft 60 is connected to the rotating shaft 4A of the electric motor 4 via a shaft coupling structure 80. The transmission 10 can be configured such that the electric motor connecting shaft 60 and the rotating shaft 4A are aligned and shaft-connected, but in this embodiment, the axial positions of the electric motor connecting shaft 60 and the rotating shaft 4A are misaligned. Therefore, the shaft coupling structure 80 is configured to allow power transmission between the rotating shaft 4A and the electric motor connecting shaft 60 while allowing eccentric rotation of the rotating shaft 4A and the electric motor connecting shaft 60 relative to each other.

[0054] The shaft connection structure 80 may be, for example, one that connects the rotating shaft 4A and the motor connecting shaft 60 via a flexible shaft, or one that connects a shaft body positioned between the rotating shaft 4A and the motor connecting shaft 60 via a flexible coupling such as a universal joint, cardan joint, bellows coupling, or Oldham coupling. In this embodiment, a connecting shaft 82 is positioned between the rotating shaft 4A and the motor connecting shaft 60, with the rotating shaft 4A connected to one end of the connecting shaft 82 via a first universal joint 84, and the motor connecting shaft 60 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 described above can be positioned, for example, to pass above the internal combustion engine 3, and should be set appropriately considering the relative positions of the internal combustion engine 3, the electric motor 4, the transmission 10, or other components. In this embodiment, as shown in Figure 4, the axial center of the electric motor connecting shaft 60 is located in a region above the oil pan arrangement region 3A where the oil pan is located in the slant-arranged internal combustion engine 3. Also, as shown in Figure 5, in the mounting structure X, the oil pan is positioned below the internal combustion engine 3, and a gap is formed above the oil pan arrangement region 3A where the oil pan is located, at a lower position than the surrounding area. This embodiment focuses on the formation of such a gap, and the connecting shaft 82 is positioned in this gap, and the electric motor connecting shaft 60 is connected to the connecting shaft 82, thereby mounting the transmission 10 on the vehicle.

[0056] The above describes one embodiment of the transmission 10 of the present invention. Next, the effects and advantages realized by the transmission 10 according to the present invention will be described below.

[0057] <Effects> The transmission 10 described above 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 with the prior art.

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

[0059] In this embodiment, as described in (a) above, the transmission 10 has a motor connection shaft gear 61 provided on the motor connection shaft 60 connected to the electric motor 4, and a first reverse idler gear 42 provided on the intermediate shaft 41, both located in a region below the height of the switching shaft gear 32 provided on the switching shaft 30. As a result, in the power transmission path where power is transmitted between the electric motor 4 and the internal combustion engine 3, the transmission 10 of this embodiment can achieve the desired gear ratio while keeping the gear diameter of the switching shaft gear 32 located in the middle of the power transmission path small enough to accommodate the switching shaft gear 32, while suppressing the need to increase the height of the motor connection shaft gear 61 and the first reverse idler gear 42 to accommodate the switching shaft gear 32.

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

[0061] By configuring the transmission 10 of this embodiment as described in (b) above, the distance between the motor connecting shaft gear 61, the switching shaft gear 32, and the first reverse idler gear 42 can be minimized. As a result, the transmission 10 of this embodiment can have a large gear ratio while minimizing the gear diameter of the switching shaft gear 32. This further suppresses the increase in size in the height direction of the transmission 10 of this embodiment.

[0062] (c) The transmission 10 of this embodiment is arranged in the order of motor connecting shaft gear 61, switching shaft gear 32, and first reverse idler gear 42, with the axis of the switching shaft gear 32 being lower than the axis of the motor connecting shaft gear 61, and the axis of the first reverse idler gear 42 being lower than the axis of the switching shaft gear 32.

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

[0064] (d) In this embodiment, the transmission 10 has the axial center of the motor connecting shaft 60 located in a region above the oil pan arrangement region 3A in the internal combustion engine 3 where the oil pan is located.

[0065] In this embodiment, the transmission 10, with the configuration described in (d) above, can utilize the area above the oil pan arrangement area 3A, which is located at a low position in the internal combustion engine 3, to directly or indirectly connect the electric motor 4 to the electric motor connection shaft 60. Therefore, in this embodiment, the transmission 10, with the electric motor 4 connected to the electric motor connection shaft 60 and mounted on the vehicle, can be made more compact in the vertical direction.

[0066] (e) In this embodiment, the transmission 10 has a motor connecting shaft 60 and a connecting shaft 82 that connects the motor 4's rotating shaft 4A, which are connected in a region above the oil pan arrangement region 3A where the oil pan is located in the internal combustion engine 3.

[0067] In this embodiment, the transmission 10, by having the configuration described in (e) above, can utilize the area above the oil pan arrangement area 3A, which is located at a low position in the internal combustion engine 3, as space for connecting the electric motor 4 to the electric motor connection shaft 60 via the connecting shaft 82. Therefore, in this embodiment, the transmission 10, with the electric motor 4 connected to the electric motor connection shaft 60 and mounted on the vehicle, can be made more compact in the vertical direction.

[0068] (f) The transmission 10 of this embodiment has a switching shaft 30 comprising an output gear 33 capable of transmitting power to the output shaft 15 and an input gear 31 capable of transmitting power to the input shaft 13, and a switching mechanism 70 is located between the output gear 33 and the switching shaft gear 32, and between the input gear 31 and the output gear 33.

[0069] In this embodiment, by adopting the configuration described in (f) above, the transmission 10 can efficiently house the switching mechanism 70 inside the transmission 10. Furthermore, in this embodiment, by arranging the switching mechanism 70 between the switching shaft gear 32 and the output side gear 33 as described above, the transmission 10 can be positioned closer to the internal combustion engine. As a result, in this embodiment, the electric motor 4 can be positioned close to the internal combustion engine 3, and the external dimensions of the transmission 10 as seen from the internal combustion engine side can be suppressed.

[0070] (g) The transmission 10 of this embodiment has a switching shaft 30 which includes an output gear 33 capable of transmitting power to the output shaft 15 and an input gear 31 capable of transmitting power to the input shaft 13, and a switching mechanism 70 which includes a clutch 71, and 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.

[0071] The transmission 10 of this embodiment, by having the configuration described in (g) above, can 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 71.

[0072] ≪Variations≫ The above describes the effects and advantages obtained by the transmission 10 according to one embodiment of the present invention. However, the transmission 10 is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention. For example, the transmission 10 can be as described in (a) above, and can be formed in various shapes and sizes. In addition, the internal combustion engine 3 connected to the transmission 10 can be of various types, shapes and sizes. For example, the internal combustion engine 3 can be a gasoline engine, a diesel engine, or various other types. In this embodiment, the case in which a motor generator is used for the electric motor 4 is illustrated, but the electric motor 4 can be a motor generator or various other types of motors and generators. In addition, the electric motor 4 can be of various types, shapes and sizes. Furthermore, within the scope of the invention, the transmission 10 of the present invention can be modified by increasing or decreasing the number of rotating shafts as appropriate. For example, the transmission 10 may not have some or all of the components described in (b) to (g) above, or it may have some or all of the components described in (b) to (g) above, along with other components.

[0073] Specifically, as described in (b) above, the transmission 10 is arranged such that the axial positions of the 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 can also be arranged such that the axial position of the switching shaft gear 32 is offset upward with respect to the imaginary line L which connects the axial positions of the motor connecting shaft gear 61 and the first reverse idler gear 42.

[0074] The transmission 10 described above is not limited to the arrangement shown in (c) above, in which the motor connecting shaft gear 61, the switching shaft gear 32, and the first reverse idler gear 42 are arranged in an order in which the axial positions become lower. For example, the transmission 10 may be configured such that the axial position of either or both of the motor connecting shaft gear 61 and the first reverse idler gear 42 is at the same height as the axial position of the switching shaft gear 32, or at a position offset vertically within a certain range.

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

[0076] As described above, the transmission 10 utilizes the area above the oil pan arrangement area 3A as space for a connecting shaft 82 to connect the electric motor 4 to the electric motor connecting shaft 60, as shown in (e) above. However, the present invention is not limited to this. The transmission 10 may have the connecting shaft 82 positioned in a location different from the area above the oil pan arrangement area 3A.

[0077] As described above, the transmission 10 has a switching mechanism 70 positioned between the output gear 33 and the switching shaft gear 32, and between the input gear 31 and the output gear 33, as described in (f) above. However, the present invention is not limited to this. For example, the transmission 10 can be modified by changing the arrangement of the switching shaft gear 32, the input gear 31, and the output gear 33 that constitute the switching mechanism 70.

[0078] As described above, the transmission 10 switches the input-side connection state and the output-side connection state of the switching mechanism 70 by switching the connection state of the clutch 71, but the present invention is not limited to this. The transmission 10 can employ various switching devices and mechanisms different from the clutch 71 for switching the state of the switching mechanism 70. Furthermore, the switching of the clutch 71 is not limited to hydraulic operation; various methods, such as electrical operation, can also be used.

[0079] In this embodiment, when the internal combustion engine 3 is operating with the input side connected, the power output from the internal combustion engine 3 is used to generate electricity for the electric motor 4 via the switching shaft 30 and the electric motor connection shaft 60. However, the transmission 10 of the present invention is not limited to this. The power output from the internal combustion engine 3 may be used to generate electricity for the electric motor 4 as needed. For example, it is also possible to disengage the clutch 71 and use the power output from the internal combustion engine 3 only to drive the drive wheels.

[0080] Furthermore, in this embodiment, when the motor 4 is driven in the output-side connected state, the power output from the motor 4 is used to drive the drive wheels via the motor connection shaft 60 and the switching shaft 30. However, the transmission 10 of the present invention is not limited to this. The power output from the motor 4 may be used to drive the drive wheels as needed. For example, the clutch 71 may be disengaged, and the power output from the motor 4 may be used to drive something other than the drive wheels. Also, in this embodiment, when the drive wheels are braked in the output-side connected state, the braking force is used to regenerate power to the motor 4. However, regeneration may be performed as needed. For example, when the charge is abundant, regeneration may not be performed.

[0081] In this embodiment, the intermediate shaft 41 and the first reverse idler gear 42 (intermediate shaft gear) are shared to transmit power from 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 going through the switching shaft 30.

[0082] The above describes various embodiments and modifications of the transmission according to the present invention. However, the present invention is not limited to those exemplified in the embodiments and modifications described above, and it will be readily apparent to those skilled in the art that other embodiments may exist in the spirit and nature of the teachings, without departing from the scope of the claims. [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 placement area 4:Electric motor 4A: Rotation axis 10: Transmission 13: Input axis 15: Output axis 30: Switching axis 31: Input gear 32: Switching shaft gear 33: Output gear 41: Intermediate axis 42: First reverse idler gear (intermediate shaft gear) 60: Motor connecting shaft 61: Motor connecting shaft gear 70: Switching mechanism 71: Clutch 82:Connection shaft L: virtual line X: Mounting structure

Claims

1. A transmission in 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 the drive wheels of the vehicle, The motor connection shaft connected to the aforementioned motor, A switching shaft that transmits power between the input shaft and the motor connection shaft, An intermediate shaft provided between the switching shaft and the input shaft, An intermediate shaft gear provided on the aforementioned intermediate shaft, It has, The aforementioned switching shaft includes: A switching mechanism that 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, A switching shaft gear capable of transmitting the power to the motor connection shaft, A system is in place, The motor connecting shaft is provided with a motor connecting shaft gear. A transmission characterized in that the upper end position of the motor connecting shaft gear and the upper end position of the intermediate shaft gear are located in a region below the upper end position of the switching shaft gear.

2. The transmission according to claim 1, characterized in that the axial centers of the motor connecting shaft gear, the switching shaft gear, and the intermediate shaft gear are arranged to align along a predetermined imaginary line.

3. The motor connecting shaft gear, the switching shaft gear, and the intermediate shaft gear are arranged in that order. The axis of the switching shaft gear is lower than the axis of the motor connecting shaft gear. The transmission according to claim 1 or 2, characterized in that the axial center position of the intermediate shaft gear is lower than the axial center position of the switching shaft gear.

4. The transmission according to claim 1 or 2, characterized in that the axial center position of the motor connecting shaft is located in a region above the oil pan arrangement region in the internal combustion engine where the oil pan is arranged.

5. The transmission according to claim 1 or 2, characterized in that the motor connecting shaft and the motor rotating shaft are connected in a region above the oil pan arrangement region where the oil pan is located in the internal combustion engine.

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