Speed changer

Abstract

To provide a speed changer which can be downsized as a whole, while securing a gear ratio (a gear diameter) that is required from the viewpoint of securing startability or the like.SOLUTION: A speed changer 10, which is loaded on a vehicle provided with an internal combustion engine 3 and an electric motor 4, is provided with: an input shaft 13 that transmits power outputted from the internal combustion engine 3; an input shaft gear 14; an output shaft 15 that transmits power to a driving wheel; an output shaft gear 16; a primary shaft 21 that transmits power of the input shaft 13; a primary input gear 22; an electric motor connection shaft 60 that is connected to the electric motor 4; an input-side gear 61 supported on the electric motor connection shaft 60; a first driven shaft 30 on which a first driven gear 32 engaging with the input-side gear 61 is supported; and a second driven shaft 35 on which a second driven gear 36 engaging with the first driven gear 32 and with the primary input gear 22 are supported, where the primary input gear 22 engages with the second driven gear 36 and the input shaft gear 14 to transmit power.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a transmission for a vehicle, and more particularly to a transmission for a hybrid 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] Incidentally, when an engine is configured to be started by a motor generator, as in the prior art disclosed in Patent Document 1, a gear of a size corresponding to a gear ratio is required in the transmission to ensure a sufficient gear ratio for starting performance. However, when the overall length of the vehicle and the overall lengths of the engine, propeller shaft, rear axle, transfer case, etc. mounted on the vehicle are taken into consideration, the overall length of the transmission is naturally limited. Therefore, in transmissions for vehicles equipped with an internal combustion engine and an electric motor, a challenge exists as to how to miniaturize the entire transmission while ensuring the gear ratio (gear diameter) required from the perspective of ensuring starting performance, etc.

[0005] SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a transmission that can be made smaller overall while ensuring a gear ratio (gear diameter) required from the standpoint of ensuring startability and the like. [Means for solving the problem]

[0006] (1) The transmission of the present invention, which is provided to solve the above-mentioned problems, is a transmission for 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 output shaft gear supported integrally on the output shaft, and an electric motor connection shaft that is connected to the electric motor, and is provided with a switching mechanism 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 by comprising an output side gear that transmits the power transmitted to the electric motor connection shaft, and an output side idler gear that meshes with the output side gear and the output shaft gear.

[0007] The transmission of the present invention is configured with a switching mechanism that switches between an input-side connection state that enables power transmission between the electric motor connection shaft and the input shaft and an output-side connection state that enables power transmission between the electric motor connection shaft and the output shaft, as described above (1). Because the transmission of the present invention has the switching mechanism described above, it can smoothly start the internal combustion engine and switch between power running and regeneration by the electric motor. Furthermore, by configuring the transmission of the present invention as described above (1), it is not necessary to provide a separate rotating shaft (also referred to as a switching shaft) for the switching mechanism, and the number of gears for power transmission between the electric motor connection shaft and the output shaft can be reduced. In other words, the transmission of the present invention can reduce the number of shafts and gears by at least one compared to when a switching shaft gear is provided on the switching shaft. This allows the transmission of the present invention to be simplified in configuration and compact in size. Furthermore, because the transmission of the present invention can reduce the number of gears, it can improve the power transmission efficiency of the electric motor during regeneration and power running. Therefore, the transmission of the present invention can improve the fuel efficiency of the internal combustion engine and the electricity efficiency of the electric motor. Here, the power during regeneration is transmitted in the following order: output shaft, output shaft gear, output side idler gear, output side gear, electric motor connecting shaft, and electric motor.

[0008] (2) The transmission of the present invention, which is provided to solve the above-mentioned problems, is a transmission for 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 input shaft gear supported integrally on the input shaft, an output shaft that transmits the power to drive wheels of the vehicle, an output shaft gear supported integrally on the output shaft, a primary shaft that transmits the power of the input shaft in the transmission, a primary input gear supported integrally on the primary shaft, an electric motor connection shaft connected to the electric motor, an input side gear supported integrally on the electric motor connection shaft, a first driven shaft on which a first driven gear that meshes with the input side gear is supported, and a second driven shaft on which a second driven gear that meshes with the first driven gear and the primary input gear is supported, and the primary input gear meshes with the second driven gear and the input shaft gear to transmit the power.

[0009] The transmission of the present invention, configured as described above in (2), allows the primary shaft, the first driven shaft, and the second driven shaft to be positioned close to each other. In other words, the transmission of the present invention allows the first driven gear and the second driven gear to overlap in the radial direction, thereby reducing the size of the transmission (transmission case) and achieving (ensuring) the gear ratio (gear diameter) required, for example, when starting an internal combustion engine (e.g., an engine). This improves the ease of mounting the transmission of the present invention on a vehicle. Furthermore, the transmission of the present invention allows the mating surface between the transmission case 10A and the torque converter case (also referred to as a torque converter case) to be small, thereby simplifying the tools used to connect the internal combustion engine and the transmission (for example, eliminating the need for a tool with a universal joint).

[0010] (3) In the transmission of the present invention, the first driven gear comprises a third driven gear arranged on the internal combustion engine side and a fourth driven gear arranged on the opposite side of the axial direction of the first driven shaft from the internal combustion engine side, and the third driven gear meshes with the input side gear, the fourth driven gear meshes with the second driven gear, and the second driven gear radially wraps around the third driven gear.

[0011] By configuring the transmission of the present invention as described above in (3), the third driven gear, which is coaxially supported on the first driven shaft, and the second driven gear, which is supported on the fourth driven gear, can be positioned offset from each other in the axial direction of the first driven shaft. Therefore, the transmission of the present invention can cause the second driven gear and the third driven gear to overlap in the radial direction by meshing the fourth driven gear with the second driven gear. This reduces interference between the third driven gear and the second driven gear. Furthermore, the transmission of the present invention can further reduce the size of the transmission (transmission case) and can secure (secure) a gear ratio (gear diameter) required, for example, when starting an internal combustion engine (e.g., internal combustion engine). Furthermore, the transmission of the present invention improves vehicle mountability.

[0012] (4) The transmission of the present invention comprises a reverse idler shaft that transmits the power for reverse travel, and a reverse idler gear supported integrally on the reverse idler shaft, and the third driven gear is positioned at a different position from the reverse idler gear in the axial direction of the first driven shaft, and the third driven gear and the reverse idler gear preferably overlap in the radial direction.

[0013] By configuring the transmission of the present invention as described above in (4), the third driven gear and the reverse idler gear can be positioned offset from each other in the axial direction of the first driven shaft. This allows the third driven gear and the reverse idler gear to overlap in the radial direction. Therefore, the transmission of the present invention can suppress interference between the third driven gear and the reverse idler gear. This allows the transmission of the present invention to be compact in size (transmission case) and to secure (secure) a gear ratio (gear diameter) required, for example, when starting an internal combustion engine (e.g., internal combustion engine). Furthermore, the transmission of the present invention improves ease of installation on a vehicle.

[0014] (5) In the transmission of the present invention, the third driven gear may be formed to have a larger diameter than the fourth driven gear.

[0015] By adopting the configuration described in (5) above, the transmission of the present invention can more reliably ensure the radial overlap between the third driven gear and the second driven gear. As a result, the transmission of the present invention can further increase (secure) the gear ratio (gear diameter) required when starting the internal combustion engine. Furthermore, the transmission of the present invention can be more easily mounted on a vehicle.

[0016] (6) In the transmission of the present invention, the reverse idler gear comprises a first reverse idler gear and a second reverse idler gear having a smaller diameter than the first reverse idler gear, and the second reverse idler gear is disposed at a different position from the first reverse idler gear in the axial direction of the reverse idler shaft, and the first reverse idler gear is disposed at a different position from the third driven gear in the axial direction of the reverse idler shaft and radially wraps around the third driven gear.

[0017] By adopting the configuration described above in (6), the transmission of the present invention can more reliably ensure a radial overlap between the first reverse idler gear and the third driven gear. This allows the transmission of the present invention to be made more compact and improves the ease of installation on a vehicle. Furthermore, by adopting the configuration described above in (6), the transmission of the present invention can easily ensure a desired gear ratio. [Effects of the Invention]

[0018] According to the present invention, a transmission that solves the above-mentioned problems can be provided. [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 side view of an internal combustion engine connected to a transmission of the present invention, viewed from the direction of the internal combustion engine. [Figure 4] 2 is a side view of the transmission of FIG. 1 coupled to the internal combustion engine, as viewed from the direction of the internal combustion engine. FIG. [Figure 5] 2 is a schematic skeleton diagram of one embodiment of the transmission of FIG. 1. [Figure 6] FIG. 2 is an enlarged view of a main part of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0020] A transmission 10 according to one embodiment of the present invention will be described in detail below with reference to the drawings. Note that each drawing is a schematic representation for ease of understanding, and may differ from the actual shape, size, and arrangement of components. Note also that the fact that each shaft is supported by an appropriate bearing or the like and is rotatable may be omitted. In the following description, the front side of the vehicle may be referred to as the front Fr, and the rear side may be referred to as the rear Rr.

[0021] As shown in FIGS. 1 and 5, an internal combustion engine 3 and an electric motor 4 are connected to the transmission 10. The internal combustion engine 3 is constituted by, for example, a gasoline engine, a diesel engine, or the like. A drive shaft (not shown) of the internal combustion engine 3 is connected to an input shaft 13 of the transmission 10. Therefore, power output by the internal combustion engine 3 is input to the transmission 10 through the input shaft 13. FIG. 3 is a side view of the internal combustion engine 3 as seen from the direction of the internal combustion engine. The internal combustion engine 3 is housed in an internal combustion engine case 3A (partially omitted in the drawing). FIG. 4 is a side view of the internal combustion engine 3 and the transmission 10 in a coupled (connected) state as seen from the direction of the internal combustion engine 3. The internal combustion engine case 3A is formed to be large enough to surround the transmission case 10A of the transmission 10 in a cross-sectional view.

[0022] 1 and 5, the electric motor 4 is configured as, for example, a motor generator, and is capable of outputting driving force and generating electricity. The electric motor 4 has a motor shaft 4A (see FIG. 5) connected to an electric motor connecting shaft 60 in the transmission 10 via a universal joint 5. 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, changes the speed of power generated by the internal combustion engine 3 and the electric motor 4, and transmits regenerated energy to the electric motor 4. As shown in FIG. 4, the transmission 10 is housed in a transmission case 10A. The transmission case 10A and the internal combustion engine case 3A are connected at their mating surfaces (not shown) with appropriate bolts (not shown) or the like. As shown in FIGS. 1 and 5, 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), a reverse clutch 55 (clutch device 50), and an output shaft 15. The transmission 10 also includes an electric motor connecting shaft 60, a primary shaft 21, a secondary shaft 23, a first driven shaft 30, a second driven shaft 35, a reverse idler shaft 41, a switching mechanism 70, etc. In addition to the above, the transmission 10 is equipped with an electric motor connecting shaft gear 61 (also referred to as the input side gear 61), a first driven gear 32 (third driven gear 32A, fourth driven gear 32B), a second driven gear 36, a primary input gear 22, an output side gear 33, an output shaft gear 16, etc.

[0024] As shown in FIGS. 1 and 5, 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 includes 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 (also referred to as a driven gear 22) is attached to the primary shaft 21 so as to be able to rotate relative to the primary shaft 21. The primary input gear 22 is in mesh with the input shaft gear 14 and a second driven gear 36, which will be described later. Therefore, the primary input gear 22 can transmit power transmitted from the input shaft 13 to the primary shaft 21 and a second driven shaft 35, which will be described later.

[0029] 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 rotate relative to the secondary shaft 23. The secondary output gear 25 meshes with an output shaft gear 16 provided on the output shaft 15.

[0030] 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.

[0031] 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 a reverse idler shaft 41 and a reverse idler gear 42 (a first reverse idler gear 42A and a second reverse idler gear 42B).

[0032] As shown in FIG. 2, the reverse idler shaft 41 is a shaft provided midway between the secondary shaft 23 and a first driven shaft 30 (described later). As shown in FIG. 1, the reverse idler shaft 41 is rotatably supported at both ends by a front bearing 44 and a rear bearing 46. The front bearing 44 and the rear bearing 46 are each held in the transmission case 10A. The front bearing 44 is provided at the end of the reverse idler shaft 41 on the first reverse idler gear 42A side. The rear bearing 46 is provided at the end on the second reverse idler gear 42B side.

[0033] As shown in FIGS. 1 and 5, the first reverse idler gear 42A is formed integrally with the reverse idler shaft 41 and meshes with the input shaft gear 14. That is, the first reverse idler gear 42A can reverse the rotational direction of the input shaft gear 14 (input shaft 13). The first reverse idler gear 42A has a larger diameter than the second reverse idler gear 42B. The first reverse idler gear 42A is displaced (disposed at a different position) in the axial direction of the reverse idler shaft 41 (toward the rear in the axial direction in this embodiment) with respect to a third driven gear 32A, which will be described later. Therefore, the first reverse idler gear 42A overlaps (overlaps) with the third driven gear 32A in the radial direction. That is, the transmission 10 of the present invention can suppress interference between the first reverse idler gear 42A and the third driven gear 32A. Furthermore, the transmission 10 of the present invention can be made compact because the reverse idler shaft 41 and the first driven shaft 30 can be arranged close to each other. Note that the first reverse idler gear 42A may be meshed with an electric motor connecting shaft gear 61 of the electric motor connecting shaft 60 (described later) as needed, so as to transmit the power of the electric motor 4 in the reverse direction.

[0034] The second reverse idler gear 42B is formed to have a smaller diameter than the first reverse idler gear 42A. The second reverse idler gear 42B is formed integrally with the reverse idler shaft 41 on the rear side Rr of the first reverse idler gear 42A, and is in mesh with the secondary input gear 24.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] As shown in Fig. 2, the motor connection shaft 60 is arranged laterally and in parallel with the first driven shaft 30 with a gap therebetween. As shown in Figs. 1 and 5, a universal joint 5 is connected to the front end (front Fr side) of the motor connection shaft 60. A motor shaft 4A (see Fig. 5) of an electric motor 4 (for example, a motor generator) is connected to the front end side (Fr side) of the universal joint 5. The motor connection shaft 60 is provided with an electric motor connection shaft gear 61, an output side gear 33, and a switching mechanism 70.

[0040] The motor connecting shaft gear 61 is journaled to the front end side (front Fr side) of the motor connecting shaft 60, and is in mesh with the third driven gear 32A of the first driven shaft 30. Therefore, when the electric motor 4 is driven, the power output from the electric motor 4 is transmitted to the first driven shaft 30. As will be described in detail later, when the first driven shaft 30 is driven by the internal combustion engine 3, the power output from the internal combustion engine 3 is transmitted to the first driven shaft 30 and then used to generate power for the electric motor 4 via the motor connecting shaft gear 61 and the electric motor connecting shaft 60.

[0041] 2 and 4, the first driven shaft 30 is provided between the motor connection shaft 60 and the input shaft 13. As shown in Fig. 6, the front end side (front Fr side) and the rear end side (rear Rr side) of the first driven shaft 30 are rotatably supported by bearings 31, 31, respectively. In addition, a first driven gear 32 is journaled to the middle of the first driven shaft 30.

[0042] The first driven gear 32 includes a third driven gear 32A and a fourth driven gear 32B disposed on the rear side Rr of the third driven gear 32A. That is, the third driven gear 32A and the fourth driven gear 32B are disposed at different positions (shifted positions) in the axial direction of the first driven shaft 30.

[0043] The third driven gear 32A has a larger diameter than the fourth driven gear 32B. The third driven gear 32A meshes with the motor connection shaft gear 61. Therefore, the first driven shaft 30 can transmit the power output from the motor connection shaft 60. Here, the third driven gear 32A is disposed at a different position (shifted position) from the first reverse idler gear 42A in the axial direction of the first driven shaft 30 so as not to interfere with the first reverse idler gear 42A (see FIG. 1). Therefore, the third driven gear 32A and the first reverse idler gear 42A overlap each other in the radial direction (see FIGS. 2 and 4).

[0044] The fourth driven gear 32B has a smaller diameter than the third driven gear 32A. The fourth driven gear 32B is disposed on the axial side of the first driven shaft 30 opposite the internal combustion engine 3 (on the transmission 10 side). The fourth driven gear 32B meshes with a second driven gear 36 journaled on a second driven shaft 35 (described later). In other words, the second driven gear 36 meshes with the fourth driven gear 32B radially inside the third driven gear 32A. In other words, the second driven gear 36 overlaps (overlaps) with the third driven gear 32A in the radial direction (see FIGS. 2 and 4). That is, by overlapping at least a portion of the second driven gear 36 and the third driven gear 32A, the transmission 10 of the present invention can arrange the first driven shaft 30 and the second driven shaft 35 close to each other, thereby achieving a compact design.

[0045] 1 and 5, the second driven shaft 35 is disposed in parallel to and spaced apart from the first driven shaft 30. A second driven gear 36 is journaled on the second driven shaft 35.

[0046] The second driven gear 36 is in mesh with the primary input gear 22 (driven gear 22) and the fourth driven gear 32B. Therefore, the second driven gear 36 can rotate integrally with the second driven shaft 35 as the primary shaft 21 rotates. That is, the power output from the internal combustion engine 3 is transmitted to the electric motor connection shaft 60 via the primary shaft 21, the second driven shaft 35, and the first driven shaft 30, and is used to generate electricity in the electric motor 4. Furthermore, the second driven gear 36 can rotate integrally with the second driven shaft 35 as the first driven shaft 30 rotates. That is, the power output from the electric motor 4 is transmitted to the first driven shaft 30, the second driven shaft 35, and the input shaft 13, and is used to start the internal combustion engine 3.

[0047] The output side gear 33 is journaled to the rear end side (rear Rr side) of the motor connection shaft 60. The output side gear 33 is meshed with an output transmission shaft gear 18 (also referred to as an output side idler gear 18) journaled to an output transmission shaft 17 (described later) (in the drawing, the output side gear 33 and the output transmission shaft 17 are shown as being spaced apart, but it should be noted that in reality they are meshed with each other).

[0048] The output transmission shaft 17 is disposed parallel to and spaced apart from the electric motor connection shaft 60. An output transmission shaft gear 18 is journaled on 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 gear 33 on the first driven shaft 30. The output transmission shaft gear 18 also meshes with the output shaft gear 16 on the output shaft 15. Therefore, the output transmission shaft 17 can transmit the power of the first driven shaft 30 to the output shaft 15 as the first driven shaft 30 rotates.

[0049] The switching mechanism 70 is provided in the middle portion of the motor connecting shaft 60. Specifically, the switching mechanism 70 is disposed between the motor connecting shaft gear 61 and the output side gear 33. The switching mechanism 70 includes a clutch 71 and the like.

[0050] The switching mechanism 70 can switch 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, by switching the connection state of the clutch 71 using hydraulic pressure or the like. Specifically, the electric motor connecting shaft 60 is divided into a front Fr side and a rear Rr side via the clutch 71 of the switching mechanism 70, and an electric motor connecting shaft gear 61 is arranged on the front Fr side of the electric motor connecting shaft 60, and an output side gear 33 is arranged on the rear Rr side of the electric motor connecting shaft 60.

[0051] Therefore, in the "input side connected state," the rear Rr side of the electric motor connecting shaft 60 is disengaged (the rear Rr side of the clutch 71 is disengaged), and only the front Fr side of the electric motor connecting shaft 60 rotates. That is, the electric motor connecting shaft gear 61 (input side gear 61) rotates in accordance with the rotation of the front Fr side of the electric motor connecting shaft 60. Therefore, when the internal combustion engine 3 is driven in the "input side connected state," the power output from the internal combustion engine 3 is supplied to the electric motor 4 for generating electricity via the input shaft 13, the primary shaft 21, the second driven shaft 35, the first driven 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, the first driven shaft 30, the second driven shaft 35, the primary shaft 21, and the input shaft 13.

[0052] Furthermore, in the "output side connected state," the clutch 71 is engaged, so that the rear Rr side of the motor connecting shaft 60 is connected, and the front Fr side and rear Rr side of the motor connecting shaft 60 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 (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 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.

[0053] In this embodiment, as described above, the third driven gear 32A and the second driven gear 36 are radially overlapped, thereby reducing the size of the transmission 10. Therefore, as shown in FIG. 4, the upper side of the transmission case 10A (the upper side of the third driven gear 32A and the first reverse idler gear 42A) can be set to a low position. In other words, the transmission case 10A can be reduced in size in the vertical direction. Therefore, when fastening the internal combustion engine 3 and the transmission 10 with bolts, a tool with, for example, a universal joint, which has conventionally been required, can be eliminated. In addition, it is possible to store wiring by utilizing the space formed in the upper part of the transmission case 10A.

[0054] The above is one embodiment of the transmission 10 of the present invention. Next, the effects achieved by the transmission 10 of the present invention will be described below.

[0055] <Action and effect> The above-described transmission 10 has the following characteristic configurations (a) to (f). Therefore, the transmission 10 of the present invention can achieve the following unique effects that cannot be achieved by conventional techniques.

[0056] (a) The above-mentioned transmission 10 is a transmission 10 for a vehicle equipped with an internal combustion engine 3 and an electric motor 4, and comprises an input shaft 13 that transmits the power output from the internal combustion engine 3, an output shaft 15 that transmits the power to the drive wheels of the vehicle, an output shaft gear 16 supported integrally on the output shaft 15, and an electric motor connecting shaft 60 that is connected to the electric motor 4, and is provided with a switching mechanism 70 that switches between an input side connection state that enables the transmission of the power between the electric motor connecting shaft 60 and the input shaft 13 and an output side connection state that enables the transmission of the power between the electric motor connecting shaft 60 and the output shaft 15, and is characterized by comprising an output side gear 33 that transmits the power transmitted to the electric motor connecting shaft 60, and an output side idler gear 18 that meshes with the output side gear 33 and the output shaft gear 16.

[0057] The transmission 10 of the present invention is configured with a switching mechanism 70 that 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, as described above (a). Because the transmission 10 of the present invention has the switching mechanism 70 described above, it can smoothly switch between starting the internal combustion engine 3 and power running and regeneration by the electric motor 4. Furthermore, by configuring the transmission 10 of the present invention as described above (a), it is not necessary to provide a separate rotating shaft (also referred to as a switching shaft) for providing the switching mechanism 70, and therefore the number of gears for power transmission between the electric motor connecting shaft 60 and the output shaft 15 can be reduced. In other words, the transmission 10 of the present invention can reduce the number of shafts and gears by at least one compared to when a switching shaft gear is provided on the switching shaft. This simplifies the configuration of the transmission 10 of the present invention and enables it to be made smaller. Furthermore, the transmission 10 of the present invention can reduce the number of gears, thereby improving the power transmission efficiency during regeneration and power running of the electric motor 4. As a result, the transmission 10 of the present invention can improve the fuel efficiency of the internal combustion engine 3 and the electricity efficiency of the electric motor 4. Here, the power during regeneration is transmitted in the following order: output shaft 15, output shaft gear 16, output side idler gear 18, output side gear 33, electric motor connecting shaft 60, and electric motor 4.

[0058] (b) The transmission 10 described above is a transmission 10 for a vehicle equipped with an internal combustion engine 3 and an electric motor 4, and includes an input shaft 13 that transmits power output from the internal combustion engine 3, an input shaft gear 14 integrally supported on the input shaft 13, an output shaft 15 that transmits the power to driving wheels of the vehicle, an output shaft gear 16 integrally supported on the output shaft 15, a primary shaft 21 that transmits the power of the input shaft 13 in the transmission 10, and a primary input gear 22 (drive gear) integrally supported on the primary shaft 21. the primary input gear 22 meshes with the second driven gear 36 and the input shaft gear 14 to transmit the power.

[0059] By adopting the configuration (b) above, the transmission 10 of the present invention can arrange the primary shaft 21, the first driven shaft 30, and the second driven shaft 35 in close proximity to each other. That is, the transmission 10 of the present invention can overlap the first driven gear 32 and the second driven gear 36 in the radial direction, thereby reducing the size of the transmission 10 (transmission case 10A) and achieving (ensuring) the gear ratio (gear diameter) required, for example, when starting the internal combustion engine 3 (e.g., engine). This improves the mountability of the transmission 10 of the present invention in a vehicle. Furthermore, the transmission 10 of the present invention can reduce the mating surface between the transmission case 10A and the torque converter case (also referred to as a torque converter case), thereby simplifying the tools used to connect the internal combustion engine 3 and the transmission 10 (for example, eliminating the need for a tool with a universal joint).

[0060] (c) In the transmission 10 of the present invention, the first driven gear 32 comprises a third driven gear 32A arranged on the internal combustion engine 3 side and a fourth driven gear 32B arranged on the opposite side of the axial direction of the first driven shaft 30 from the internal combustion engine 3 side, and the third driven gear 32A is meshed with the input side gear 61, the fourth driven gear 32B is meshed with the second driven gear 36, and the second driven gear 36 is radially wrapped around the third driven gear 32A.

[0061] By adopting the configuration (c) above, the transmission 10 of the present invention can displace the third driven gear 32A, which is coaxially supported on the first driven shaft 30, and the second driven gear 36, which is supported on the fourth driven gear 32B, from each other in the axial direction of the first driven shaft 30. Therefore, in the transmission 10 of the present invention, the second driven gear 36 and the third driven gear 32A can be overlapped in the radial direction by meshing the fourth driven gear 32B with the second driven gear 36. This makes it possible for the transmission 10 of the present invention to suppress interference between the third driven gear 32A and the second driven gear 36. Furthermore, the transmission 10 of the present invention can further reduce the size of the transmission 10 (transmission case 10A) and can achieve (secure) a gear ratio (gear diameter) required, for example, when starting the internal combustion engine 3 (e.g., engine). Furthermore, the transmission 10 of the present invention can be easily mounted on a vehicle.

[0062] (d) The transmission 10 of the present invention comprises a reverse idler shaft 41 that transmits the power for reverse travel and a reverse idler gear 42 that is integrally supported on the reverse idler shaft 41, and the third driven gear 32A is positioned at a different position from the reverse idler gear 42 in the axial direction of the first driven shaft 30, and the third driven gear 32A and the reverse idler gear 42 overlap in the radial direction.

[0063] By adopting the configuration (d) above, the transmission 10 of the present invention can displace the third driven gear 32A and the reverse idler gear 42 from each other in the axial direction of the first driven shaft 30. This allows the third driven gear 32A and the reverse idler gear 42 to overlap in the radial direction in the transmission 10 of the present invention. Therefore, the transmission 10 of the present invention can suppress interference between the third driven gear 32A and the reverse idler gear 42. This allows the transmission 10 of the present invention to be compact in size (transmission case 10A) and to secure (secure) a gear ratio (gear diameter) required, for example, when starting the internal combustion engine 3 (e.g., engine). Furthermore, the transmission 10 of the present invention improves mountability on a vehicle.

[0064] (e) The transmission 10 of the present invention is characterized in that the third driven gear 32A has a larger diameter than the fourth driven gear 32B.

[0065] By adopting the configuration as described above in (e), the transmission 10 of the present invention can more reliably ensure the radial overlap between the third driven gear 32A and the second driven gear 36. This allows the transmission 10 of the present invention to further increase (secure) the gear ratio (gear diameter) required when starting the internal combustion engine 3. Furthermore, the transmission 10 of the present invention can be more easily mounted on a vehicle.

[0066] (f) In the transmission 10 of the present invention, the reverse idler gear 42 comprises a first reverse idler gear 42A and a second reverse idler gear 42B having a smaller diameter than the first reverse idler gear 42A, and the second reverse idler gear 42B is positioned at a different position from the first reverse idler gear 42A in the axial direction of the reverse idler shaft 41, and the first reverse idler gear 42A is positioned at a different position from the third driven gear 32A in the axial direction of the reverse idler shaft 41 and is radially wrapped around the third driven gear 32A.

[0067] By adopting the configuration as described in (f) above, the transmission 10 of the present invention can more reliably ensure the radial overlap between the first reverse idler gear 42A and the third driven gear 32A. This allows the transmission 10 of the present invention to be made more compact and improves the ease of installation on a vehicle. By adopting the configuration as described in (f) above, the transmission 10 of the present invention can easily ensure the gear ratio.

[0068] <<Variations>> The above are the effects obtained by the transmission 10 according to one embodiment of the present invention. However, the transmission 10 is not limited to the above embodiment and can be modified in various ways within the scope of the present invention. For example, the transmission 10 may be formed in various shapes and sizes as long as it is as described in (a) or (b) above. 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, not just motor generators, can be used as the electric motor 4. Furthermore, various types of motors, shapes, and sizes can be used as the electric motor 4. Furthermore, the transmission 10 of the present invention can have an increased or decreased number of rotating shafts as appropriate within the scope of the invention. For example, the transmission 10 can be configured without some or all of the configurations described above in (c) to (f), or can be configured with some or all of the configurations described above in (c) to (f) and other configurations. Furthermore, the shape and size of the internal combustion engine case 3A (internal combustion engine side mating surface 3B) and the transmission case 10A (transmission side mating surface 10B) are not limited to those of this embodiment, and can be changed as appropriate depending on the arrangement of each shaft and gear.

[0069] Specifically, in the above-described transmission 10, as shown in (c) above, the second driven gear 36 overlaps the third driven gear 32A in the radial direction, but the radial overlap can be set to an extent that the second driven gear 36 (including the second driven shaft 35) and the third driven gear 32A (including the first driven shaft 30) do not interfere with each other and that ensures the required gear ratio.

[0070] In the transmission 10 described above, as described in (d) above, the third driven gear 32A and the reverse idler gear 42 overlap in the radial direction, but the radial overlap of the third driven gear 32A and the reverse idler gear 42 can be set to various overlap amounts. The axial positions and diameters of the third driven gear 32A (including the first driven shaft 30) and the reverse idler gear 42 (including the reverse idler shaft 41) can be set to such an extent that they do not interfere with each other and that the required gear ratio can be secured.

[0071] In the transmission 10 described above, as shown in (e) above, the third driven gear 32A has a larger diameter than the fourth driven gear 32B, but the present invention is not limited to this. For example, the third driven gear 32A and the fourth driven gear 32B may be interchanged, or the third driven gear 32A and the fourth driven gear 32B may have the same diameter. Furthermore, the third driven gear 32A and the fourth driven gear 32B may be set to various diameters.

[0072] In the transmission 10 described above, the reverse idler gear 42 is divided into a first reverse idler gear 42A and a second reverse idler gear 42B as described in (f) above, but the present invention is not limited to this. For example, the reverse idler gear 42 may be configured as a single gear. Furthermore, in the transmission 10 described above, the first reverse idler gear 42A is formed to have a larger diameter than the second reverse idler gear 42B. However, the first reverse idler gear 42A can be formed to have various diameters as long as it does not interfere with the third driven gear 32A. Therefore, the first reverse idler gear 42A and the third driven gear 32A can also be configured not to overlap in the radial direction. Furthermore, the first reverse idler gear 42A can be disposed at various positions in the axial direction of the reverse idler shaft 41 as long as it does not interfere with the third driven gear 32A.

[0073] Furthermore, in this embodiment, the input-side connected state and the output-side connected state of the switching mechanism 70 are switched by switching the connected state of the clutch 71, but the present invention is not limited to this. The transmission 10 can employ various switching devices and mechanisms other than the clutch 71 for switching the state of the switching mechanism 70. Furthermore, the clutch 71 can be switched not only by hydraulic means but also by various means such as electrical means.

[0074] 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 to generate electricity via 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 to generate electricity 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 to drive the drive wheels.

[0075] Furthermore, in this embodiment, when the electric motor 4 is in the output-side connected state and driving state, the power output from the electric motor 4 is provided to drive the drive wheels via the electric motor connection shaft 60, 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.

[0076] In addition, although the transmission 10 of the present invention has been exemplified as one in which the third driven gear 32A and the second driven gear 36 are radially wrapped, and the third driven gear 32A and the first reverse idler gear 42A are radially wrapped, the transmission 10 of the present invention can radially wrap the gears so that the gears and shafts do not interfere with each other, as necessary. In such a case, each gear may be formed as a pair of gears, for example, and the pair of gears may be formed with a large diameter and a small diameter and disposed at different positions in the axial direction.

[0077] 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]

[0078] 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]

[0079] 3: Internal combustion engine 4: Electric motor 10: Transmission 13: Input shaft 14: Input shaft gear 15: Output shaft 16: Output shaft gear 18: Output transmission shaft gear (output side idler gear) 21: Primary axis 22: Primary input gear (driven gear) 30: First driven shaft 32: First driven gear 32A: Third driven gear 32B: Fourth driven gear 33: Output gear 35: Second driven shaft 36: Second driven gear 41: Reverse idler shaft 42: Reverse idler gear 42A: First reverse idler gear 42B: Second reverse idler gear 60: Motor connection shaft 61: Motor connection shaft gear (input gear) 70: Switching mechanism

Claims

1. A transmission for a vehicle equipped with an internal combustion engine and an electric motor, an input shaft that transmits power output from the internal combustion engine; an input shaft gear integrally supported on the input shaft; an output shaft that transmits the power to drive wheels of the vehicle; an output shaft gear integrally supported on the output shaft; a primary shaft in the transmission that transmits the power of the input shaft; a primary input gear supported integrally on the primary shaft; an electric motor connection shaft connected to the electric motor; an input gear integrally supported on the electric motor connection shaft; a first driven shaft supporting a first driven gear that meshes with the input gear; a second driven shaft supporting a second driven gear that meshes with the first driven gear and the primary input gear; an output gear that transmits the power transmitted to the electric motor connection shaft; an output side idler gear that meshes with the output side gear and the output shaft gear; Equipped with a switching mechanism is provided that switches between an input side connection state that enables the transmission of power between the electric motor connection shaft and the input shaft and an output side connection state that enables the transmission of power between the electric motor connection shaft and the output shaft, The primary input gear meshes with the second driven gear and the input shaft gear to transmit the power.

2. The first driven gear is a third driven gear disposed on the internal combustion engine side; a fourth driven gear disposed on the opposite side of the first driven shaft from the internal combustion engine in the axial direction of the first driven shaft; Equipped with the third driven gear is in mesh with the input gear, the fourth driven gear meshes with the second driven gear, 2. The transmission according to claim 1, wherein the second driven gear radially overlaps the third driven gear.

3. a reverse idler shaft that transmits the power for reverse travel; a reverse idler gear integrally supported on the reverse idler shaft; Equipped with the third driven gear is disposed at a position different from the reverse idler gear in the axial direction of the first driven shaft, 3. The transmission of claim 2, wherein the third driven gear and the reverse idler gear are radially overlapping.

4. 3. The transmission according to claim 2, wherein the third driven gear has a larger diameter than the fourth driven gear.

5. The reverse idler gear is a first reverse idler gear; a second reverse idler gear having a smaller diameter than the first reverse idler gear; Equipped with the second reverse idler gear is disposed at a position different from that of the first reverse idler gear in the axial direction of the reverse idler shaft, 4. The transmission according to claim 3, wherein the first reverse idler gear is disposed at a position different from that of the third driven gear in the axial direction of the reverse idler shaft and is radially overlapped with the third driven gear.

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