Speed changer

Abstract

To provide a speed changer which can suppress an entire length thereof from lengthening, 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 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 of the input shaft 13; and an output shaft 15 that transmits power to a driving wheel of a vehicle. The switching shaft 30 is provided with: a switching mechanism 70 that switches between an input-side connection state where power can be transmitted between the electric motor connection shaft 60 and the input shaft 13 and an output-side connection state where power can be transmitted between the electric motor connection shaft 60 and the output shaft 15; and a switching gear 32 that can transmit power to the electric motor connection shaft 60. A switching shaft bearing 35 that bears the switching shaft 30 rotatably and the switching gear 32 are wrapped in an axis line direction of the switching shaft 30.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 a transmission for a vehicle equipped with an internal combustion engine and an electric motor, a challenge exists as to how to reduce the overall length of the 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 reduce the overall length while ensuring the gear ratio (gear diameter) required from the viewpoint 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 electric motor connection shaft connected to the electric motor, a switching shaft that transmits power from the input shaft, and an output shaft that transmits the power to drive wheels of the vehicle, wherein the switching shaft 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 a switching shaft gear that can transmit the power to the electric motor connection shaft, and wherein a switching shaft bearing that rotatably supports the switching shaft and the switching shaft gear wrap in the axial direction of the switching shaft.

[0007] The transmission of the present invention is configured such that the switching shaft bearing and the switching shaft gear are overlapped in the axial direction of the switching shaft as described above in (1). This allows the transmission of the present invention to employ a switching shaft gear having a gear diameter necessary to ensure a gear ratio suitable for starting while keeping the overall length small.

[0008] (2) The transmission of the present invention preferably includes an intermediate shaft provided intermediate between the switching shaft and the input shaft, an intermediate shaft gear provided on the intermediate shaft, and an intermediate shaft bearing that rotatably supports the intermediate shaft, and the intermediate shaft gear and the intermediate shaft bearing are preferably wrapped around the intermediate shaft in the axial direction.

[0009] By configuring the transmission of the present invention as described above in (2), the overall length can be reduced and the transmission can be made compact, even when the transmission is configured such that the intermediate shaft and the intermediate shaft gear are disposed between the switching shaft and the input shaft via the intermediate shaft and the intermediate shaft.

[0010] (3) In the transmission of the present invention, the switching shaft gear and the intermediate shaft bearing may preferably overlap in the radial direction.

[0011] By configuring the transmission of the present invention as described above in (3), it is possible to ensure the strength of the intermediate shaft bearing while ensuring the gear ratio (gear diameter) required from the standpoint of ensuring starting performance, etc.

[0012] (4) In the transmission of the present invention, the switching shaft gear and the intermediate shaft gear may preferably overlap in the radial direction.

[0013] By configuring the transmission of the present invention as described above in (4), the gear diameters of the switching shaft gear and the intermediate shaft gear can be made to be the sizes required to ensure the required gear ratio, while still achieving a compact configuration.

[0014] (5) The transmission of the present invention preferably has a retainer that holds the intermediate shaft bearing, and the retainer is formed so as to avoid an area where the switching shaft gear is disposed.

[0015] The transmission of the present invention has the configuration described in (5) above, which allows the switching shaft gear and the intermediate shaft bearing to overlap in the radial direction, thereby ensuring the gear ratio (gear diameter) required from the standpoint of ensuring starting performance, etc., while also ensuring the strength of the intermediate shaft bearing.

[0016] (6) In the transmission of the present invention, the switching shaft may have an input gear capable of transmitting power from the input shaft, and the input gear may be in mesh with the intermediate shaft gear.

[0017] By adopting the configuration of (6) above, the transmission of the present invention can utilize the intermediate shaft gear for extracting power from the input gear, eliminating the need for a separate gear. Therefore, by adopting the configuration of (6) above, the transmission of the present invention can be made more compact and less expensive.

[0018] (7) In the transmission of the present invention, the switching shaft preferably includes an output side gear capable of transmitting the power to the output shaft and an input side gear capable of transmitting the power of the input shaft, and the switching mechanism is disposed between the output side gear and the switching shaft gear, and between the input side gear and the output side gear.

[0019] By adopting the configuration according to (7) above, the transmission of the present invention can accommodate the switching mechanism inside the transmission with high space efficiency. Furthermore, by disposing the switching mechanism between the switching shaft gear and the output gear as described above, the transmission of the present invention can dispose the switching shaft gear closer to the internal combustion engine. This allows the electric motor to be disposed in close proximity to the internal combustion engine, preventing the external dimensions of the transmission from becoming larger when viewed from the internal combustion engine side.

[0020] (8) In the transmission of the present invention, the switching shaft is provided with an output side gear capable of transmitting the power to the output shaft and an input side gear capable of transmitting the power of the input shaft, and the switching mechanism has a clutch, and by switching the connection state of the clutch, the input side connection state and the output side connection state of the switching mechanism are switched.

[0021] By adopting the configuration according to (8) above, the transmission of the present invention can smoothly switch between the input side connection state and the output side connection state by switching the connection state of the clutch. [Effects of the Invention]

[0022] According to the present invention, a transmission that solves the above-mentioned problems can be provided. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 2 is an overall front view of a transmission according to an embodiment of the present invention, with a cover cut away. [Figure 2] FIG. 2 is a side view of the transmission in FIG. 1 as seen from the direction of the internal combustion engine. [Figure 3]1 is a schematic skeleton diagram of a transmission according to an embodiment of the present invention; [Figure 4] FIG. 2 is an enlarged view of a main part of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0024] 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.

[0025] As shown in Figures 1 and 3, an internal combustion engine 3 and an electric motor 4 are connected to a transmission 10. The internal combustion engine 3 is configured as an engine such as a gasoline engine or a diesel engine. A drive shaft (not shown) of the internal combustion engine 3 is connected to an input shaft 13 of the transmission 10. Therefore, the power output by the internal combustion engine 3 is input to the transmission 10 through the input shaft 13.

[0026] The electric motor 4 is configured, for example, as a motor generator, and is capable of outputting driving force and generating electricity. The electric motor 4 has a motor shaft 4A (see FIG. 3) 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.

[0027] The transmission 10 has a plurality of gears, and is configured to change the speed of the power generated by the internal combustion engine 3 and the electric motor 4, and to transmit regenerated energy to the electric motor 4. The transmission 10 is equipped with a torque converter 12, an input shaft 13, a continuously variable transmission 20 (CVT 20), a reverse transmission mechanism 40, a forward clutch 51 (clutch device 50), and a reverse clutch 55 (clutch device 50). In addition to the above, the transmission 10 is also equipped with a switching shaft 30, an electric motor connecting shaft 60, a switching mechanism 70, etc.

[0028] 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.

[0029] 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.

[0030] 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 drive wheels of the vehicle via a propeller 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.

[0031] 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.

[0032] A primary input gear 22 is attached to the primary shaft 21 so as to be rotatable relative to the primary shaft 21. The primary input gear 22 meshes with the input shaft gear 14. A secondary input gear 24 and a secondary output gear 25 are attached to the secondary shaft 23. The secondary input gear 24 is rotatable relative to the secondary shaft 23. The secondary output gear 25 is attached so as not to be rotatable relative to the secondary shaft 23. The secondary output gear 25 meshes with an output shaft gear 16 provided on the output shaft 15.

[0033] 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.

[0034] The reverse transmission mechanism 40 is a mechanism that transmits the power (rotation) of the input shaft 13 to the secondary input gear 24. The reverse transmission mechanism 40 is provided with an intermediate shaft 41, a first reverse idler gear 42 (intermediate shaft gear), and a second reverse idler gear 43.

[0035] The intermediate shaft 41 is a shaft provided midway between the switching shaft 30 and the input shaft 13. As shown in FIGS. 1 and 4, the intermediate shaft 41 is rotatably supported by an intermediate shaft bearing 44 and an other-end intermediate shaft bearing 46. The intermediate shaft bearing 44 and the other-end intermediate shaft bearing 46 are each held via a retainer 48 relative to a transmission case 11 that constitutes the transmission 10. The intermediate shaft bearing 44 is provided at the end of the intermediate shaft 41 on the first reverse idler gear 42 side. The other-end intermediate shaft bearing 46 is provided on the opposite side of the switching shaft 30 in the axial direction (the second reverse idler gear 43 side) from the switching shaft bearing 35.

[0036] The retainer 48 is formed so as to avoid the area where the switching shaft gear 32 provided on the switching shaft 30, which will be described in detail later, is disposed. The retainer 48 has a shape in which a portion corresponding to the area where the switching shaft gear 32 is disposed is cut out. This enables the retainer 48 to hold the intermediate shaft bearing 44 in a position close to the switching shaft gear 32 in the axial direction of the intermediate shaft 41 while avoiding interference with the switching shaft gear 32. In other words, by shaping the retainer 48 as described above, the switching shaft gear 32 can be disposed so as to be wedged into the retainer 48.

[0037] The first reverse idler gear 42 is formed integrally with the intermediate shaft 41 and meshes with the input shaft gear 14. That is, the first reverse idler gear 42 can reverse the rotation direction of the input shaft gear 14 (input shaft 13). The first reverse idler gear 42 also meshes with the input side gear 31 provided on the switching shaft 30 and can reverse the rotation direction of the input side gear 31 (switching shaft 30).

[0038] The second reverse idler gear 43 is formed integrally with the intermediate shaft 41 at a position Rr rearward of the first reverse idler gear 42 and is in mesh with the secondary input gear 24 .

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] The switching shaft 30 can transmit the power of the input shaft 13. Specifically, an input side gear 31 that meshes with a first reverse idler gear 42 (intermediate shaft gear) is journaled on the switching shaft 30. The first reverse idler gear 42 also meshes with an input shaft gear 14 that is journaled on the input shaft 13. Therefore, the power output from the input shaft 13 is transmitted to the switching shaft 30.

[0044] As shown in FIGS. 1 and 4 , the switching shaft 30 is rotatably supported by a switching shaft bearing 35 provided on one axial end and an output-side switching shaft bearing 37 provided on the other axial end. The switching shaft bearing 35 and the output-side switching shaft bearing 37 are each mounted to a transmission case 11 that forms the outer shell of the transmission 10. The switching shaft bearing 35 is provided at the end of the switching shaft 30 on the power input side (the side on which the internal combustion engine 3 and the electric motor 4 are disposed in this embodiment). The output-side switching shaft bearing 37 is provided on the opposite side of the switching shaft 30 in the axial direction from the switching shaft bearing 35. The output-side switching shaft bearing 37 is provided at the end of the switching shaft 30 on the power output side. As will be described in detail later, the switching shaft 30 is provided with a switching shaft gear 32, an output-side gear 33, and a switching mechanism 70 in addition to the input-side gear 31 described above. Furthermore, an output transmission shaft 17 is provided parallel to and spaced from the switching shaft 30.

[0045] The switching shaft gear 32 is attached to the front end side (the internal combustion engine 3 side, the front Fr side) of the switching shaft 30. In other words, the switching shaft gear 32 is attached to the internal combustion engine 3 side in the axial direction of the switching shaft 30. The switching shaft gear 32 meshes with an electric motor connecting shaft gear 61, which will be described later, and can transmit power in the switching shaft 30 to the electric motor connecting shaft 60.

[0046] The switching shaft gear 32 is arranged so as to overlap the switching shaft bearing 35 in the axial direction of the switching shaft 30. That is, the switching shaft gear 32 is arranged so as to overlap the switching shaft bearing 35 when viewed from the axial direction of the switching shaft 30. The switching shaft gear 32 is also arranged so as to overlap the intermediate shaft bearing 44 provided on the intermediate shaft 41 in the radial direction (a direction intersecting the axial direction). Furthermore, the switching shaft gear 32 is arranged so as to overlap the first reverse idler gear 42 (intermediate shaft gear) in the radial direction. In this way, the switching shaft gear 32 is arranged so as to overlap in the axial direction and radial direction in relation to the switching shaft bearing 35, the intermediate shaft bearing 44, and the first reverse idler gear 42 arranged around it. As a result, the transmission 10 has a configuration in which the switching shaft gear 32, the switching shaft bearing 35, the intermediate shaft bearing 44, and the first reverse idler gear 42 are compactly arranged.

[0047] The output side gear 33 is journaled to the rear end side (rear Rr side) of the switching shaft 30. The output side gear 33 is meshed with an output transmission shaft gear 18 journaled to an output transmission shaft 17, which will be described later.

[0048] An output transmission shaft gear 18 is journalled to the output transmission shaft 17. The output transmission shaft gear 18 is meshed with the output shaft gear 16 of the output shaft 15. The output transmission shaft gear 18 is also meshed with the output side gear 33 of the switching shaft 30. The output transmission shaft gear 18 is also meshed with the output shaft gear 16 of the output shaft 15. Therefore, the output transmission shaft 17 can transmit the power of the switching shaft 30 to the output shaft 15 as the switching shaft 30 rotates.

[0049] As shown in Fig. 2, the electric motor connecting shaft 60 is arranged laterally and in parallel with the switching shaft 30 at a distance. As shown in Figs. 1 and 3, a universal joint 5 is connected to the front end (front Fr side) of the electric motor connecting shaft 60. A motor shaft 4A (see Fig. 3) of an electric motor 4 (for example, a motor generator) is connected to the front end side (Fr side) of the universal joint 5. In addition, an electric motor connecting shaft gear 61 is journaled to the electric motor connecting shaft 60.

[0050] The electric motor connecting shaft gear 61 meshes with the switching shaft gear 32 on the switching shaft 30. Therefore, when the electric motor 4 is driven, the power output from the electric motor 4 is transmitted to the switching shaft 30. As will be described in detail later, when the switching shaft 30 is driven by the internal combustion engine 3, the power output from the internal combustion engine 3 is transmitted to the switching shaft 30 and then used to generate power in the electric motor 4 via the electric motor connecting shaft gear 61 and the electric motor connecting shaft 60.

[0051] The switching mechanism 70 is provided in the middle portion of the switching shaft 30. Specifically, the switching mechanism 70 is disposed between the output side gear 33 and the switching shaft gear 32, and between the input side gear 31 and the output side gear 33. The switching mechanism 70 includes a clutch 71 and the like.

[0052] The switching mechanism 70 can switch between an "input side connected state" that enables power transmission between the electric motor connection shaft 60 and the input shaft 13 and an "output side connected state" that enables power transmission between the electric motor connection shaft 60 and the output shaft 15, by switching the connection state of the clutch 71 using hydraulic pressure or the like. Specifically, the switching shaft 30 is divided into a front Fr side and a rear Rr side via the clutch 71 of the switching mechanism 70, and a switching shaft gear 32 and an input side gear 31 are disposed on the front Fr side of the switching shaft 30, and an output side gear 33 is provided on the rear Rr side of the switching shaft 30.

[0053] Therefore, in the "input side connected state," the rear Rr side of the switching shaft 30 is not connected (the rear Rr side of the clutch 71 is disengaged), and only the front Fr side of the switching shaft 30 rotates. That is, the switching shaft gear 32 and the input side gear 31 rotate as the front Fr side of the switching shaft 30 rotates. Therefore, when the internal combustion engine 3 is running in the "input side connected state," the power output from the internal combustion engine 3 is supplied to the electric motor 4 for power generation via the switching shaft 30 and the electric motor connecting shaft 60. On the other hand, when the internal combustion engine 3 is stopped in the "input side connected state," the power output from the electric motor 4 is supplied to the start of the internal combustion engine 3 via the electric motor connecting shaft 60 and the switching shaft 30.

[0054] Furthermore, in the "output side connected state," the clutch 71 is engaged, so that the rear Rr side of the switching shaft 30 is connected, and the front Fr side and rear Rr side of the switching shaft 30 rotate integrally. Therefore, when the electric motor 4 is driving in the "output side connected state," the power output from the electric motor 4 is provided to drive the drive wheels (not shown) via the electric motor connecting shaft 60 and the switching shaft 30 (EV driving state or assisted driving (HEV driving) state). On the other hand, when the drive wheels are braked (decelerated) in the "output side connected state," the braking force acting on the output shaft 15 is provided to the electric motor 4 for regeneration (electric power generation) via the switching shaft 30 and the electric motor connecting shaft 60. Note that, when the clutch 71 is disengaged (also referred to as a disengaged state), the switching mechanism 70 can also block the transmission of power between the electric motor connecting shaft 60 and the input shaft 13 and between the electric motor connecting shaft 60 and the output shaft 15.

[0055] 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.

[0056] <Action and effect> The above-described transmission 10 has the following characteristic configurations (a) to (h). Therefore, the transmission 10 of the present invention can achieve the following unique effects that cannot be achieved by conventional techniques.

[0057] (a) The above-described transmission 10 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 electric motor connecting shaft 60 connected to the electric motor 4, a switching shaft 30 that transmits power from the input shaft 13, and an output shaft 15 that transmits power to the drive wheels of the vehicle. The switching shaft 30 is provided with a switching mechanism 70 that switches between an input side connection state that enables power transmission between the electric motor connecting shaft 60 and the input shaft 13 and an output side connection state that enables power transmission between the electric motor connecting shaft 60 and the output shaft 15, and a switching shaft gear 32 that can transmit power to the electric motor connecting shaft 60. A switching shaft bearing 35 that rotatably supports the switching shaft 30 and the switching shaft gear 32 wrap around the switching shaft 30 in the axial direction.

[0058] As described above in (a), the transmission 10 has a configuration in which the switching shaft bearing 35 and the switching shaft gear 32 are overlapped in the axial direction of the switching shaft 30. This allows the transmission 10 to employ a switching shaft gear 32 having a gear diameter necessary to ensure a gear ratio suitable for starting, while keeping the overall length small.

[0059] (b) The transmission 10 has an intermediate shaft 41 provided between the switching shaft 30 and the input shaft 13, a first reverse idler gear 42 (intermediate shaft gear) provided on the intermediate shaft 41, and an intermediate shaft bearing 44 that rotatably supports the intermediate shaft 41, and the first reverse idler gear 42 (intermediate shaft gear) and the intermediate shaft bearing 44 wrap around the intermediate shaft 41 in the axial direction.

[0060] By configuring the transmission 10 as described above in (b), the overall length can be reduced and the transmission can be made compact, even if the transmission 10 is configured such that the intermediate shaft 41 and the first reverse idler gear 42 (intermediate shaft gear) are arranged between the switching shaft 30 and the input shaft 13 via the intermediate shaft 41.

[0061] (c) In the transmission 10, the switching shaft gear 32 and the intermediate shaft bearing 44 overlap in the radial direction.

[0062] By configuring the transmission 10 as described above in (c), it is possible to ensure the strength of the intermediate shaft bearing 44 while ensuring the gear ratio (gear diameter) required from the standpoint of ensuring startability, etc.

[0063] (d) In the transmission 10, the switching shaft gear 32 and the first reverse idler gear 42 (intermediate shaft gear) overlap each other in the radial direction.

[0064] By configuring the transmission 10 as described above in (d), the gear diameters of the switching shaft gear 32 and the first reverse idler gear 42 (intermediate shaft gear) can be made to be the size required to ensure the required gear ratio, while still allowing for a compact configuration.

[0065] (e) The transmission 10 has a retainer 48 that holds the intermediate shaft bearing 44, and the retainer 48 is formed so as to avoid the area where the switching shaft gear 32 is disposed.

[0066] By configuring the transmission 10 as described in (e) above, the switching shaft gear 32 and the intermediate shaft bearing 44 can be overlapped in the radial direction. This allows the transmission 10 to ensure the strength of the intermediate shaft bearing 44 while ensuring the gear ratio (gear diameter) required from the standpoint of ensuring startability, etc.

[0067] (f) In the transmission 10, the switching shaft 30 has an input gear 31 capable of transmitting the power of the input shaft 13, and the input gear 31 is in mesh with a first reverse idler gear 42 (intermediate shaft gear).

[0068] By configuring the transmission 10 as in (f) above, the first reverse idler gear 42 (intermediate shaft gear) can be used to extract power from the input gear 31, eliminating the need for a separate gear. Therefore, by configuring the transmission 10 as in (f) above, costs can be reduced and the transmission can be made more compact.

[0069] (g) The transmission 10 has a switching shaft 30 equipped with an output side gear 33 capable of transmitting power to the output shaft 15 and an input side gear 31 capable of transmitting power from the input shaft 13, and the switching mechanism 70 is arranged between the output side gear 33 and the switching shaft gear 32, and between the input side gear 31 and the output side gear 33.

[0070] By adopting the configuration according to (g) above, the transmission 10 can accommodate the switching mechanism 70 with high spatial efficiency inside the transmission 10. Furthermore, by disposing the switching mechanism 70 between the switching shaft gear 32 and the output gear 33 as described above, the transmission 10 can dispose the switching shaft gear 32 closer to the internal combustion engine. This allows the electric motor 4 to be disposed in close proximity to the internal combustion engine 3, and prevents the external dimensions of the transmission 10 from becoming larger when viewed from the internal combustion engine side.

[0071] (h) In the transmission 10, the switching shaft 30 has an output side gear 33 capable of transmitting power to the output shaft 15 and an input side gear 31 capable of transmitting power from the input shaft 13, and the switching mechanism 70 has a clutch 71, and by switching the connection state of the clutch 71, the switching mechanism 70 switches between the input side connection state and the output side connection state.

[0072] By adopting the configuration according to (h) above, the transmission 10 can smoothly switch between the input side connection state and the output side connection state by switching the connection state of the clutch 71.

[0073] <<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 can be formed in various shapes and sizes as long as it is as described above in (a). Furthermore, various types of internal combustion engines 3 can be used that are connected to the transmission 10. For example, various types of internal combustion engines, such as gasoline engines and diesel engines, can be used as the internal combustion engine 3. Furthermore, while the present embodiment illustrates a case in which a motor generator is used as the electric motor 4, various types of motors and generators, not just motor generators, can be used as the electric motor 4. Furthermore, various types of 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 (b) to (h), or can be configured with some or all of the configurations described above in (b) to (h) and other configurations.

[0074] Specifically, in the above-described transmission 10, the first reverse idler gear 42 (intermediate shaft gear) and the intermediate shaft bearing 44 overlap in the axial direction of the intermediate shaft 41 as in (b) above, but the present invention is not limited to this. For example, the transmission 10 may also be one in which the first reverse idler gear 42 (intermediate shaft gear) and the intermediate shaft bearing 44 do not overlap in the axial direction of the intermediate shaft 41.

[0075] In the transmission 10 described above, the switching shaft gear 32 and the intermediate shaft bearing 44 overlap in the radial direction as in (c) above, but the present invention is not limited to this. The transmission 10 may also be one in which the switching shaft gear 32 and the intermediate shaft bearing 44 do not overlap in the radial direction.

[0076] In the transmission 10 described above, the switching shaft gear 32 and the first reverse idler gear 42 (intermediate shaft gear) overlap in the radial direction as described above (d), but the present invention is not limited to this. For example, the transmission 10 may be configured such that the switching shaft gear 32 and the first reverse idler gear 42 (intermediate shaft gear) do not overlap in the radial direction.

[0077] In the transmission 10 described above, the retainer 48 is formed so as to avoid the area where the switching shaft gear 32 is disposed, as described above in (e), but the present invention is not limited to this. For example, the transmission 10 may be configured so that the retainer 48 is provided at a location away from the switching shaft gear 32 so as not to interfere with the switching shaft gear 32. Also, in the transmission 10, the retainer 48 is formed so as to avoid the area where the switching shaft gear 32 is disposed by cutting out the retainer 48, but the present invention is not limited to this, and it is also possible to prevent the retainer 48 from interfering with the switching shaft gear 32 by using a structure other than a cutout.

[0078] The transmission 10 described above has been exemplified as having an input gear 31 capable of transmitting the power of the input shaft 13 provided on the switching shaft 30, as described above in (f), and having the input gear 31 meshed with the first reverse idler gear 42 (intermediate shaft gear), but the present invention is not limited to this. The transmission 10 can also be configured to transmit the power of the input shaft 13 to the switching shaft 30 without using the input gear 31 or the first reverse idler gear 42.

[0079] In the transmission 10 described above, as in (g) above, the switching mechanism 70 is disposed between the output gear 33 and the switching shaft gear 32, and between the input gear 31 and the output gear 33, but the present invention is not limited to this. For example, the transmission 10 may be one in which the positions of the switching shaft gear 32, input gear 31, and output gear 33 that constitute the switching mechanism 70 are changed.

[0080] In the transmission 10 described above, the input-side connected state and the output-side connected state of the switching mechanism 70 are switched by switching the connected state of the clutch 71 as described above (h), but the present invention is not limited to this. The transmission 10 can employ various switching devices and mechanisms other than the clutch 71 to switch the state of the switching mechanism 70. Furthermore, the clutch 71 can be switched not only hydraulically but also electrically, and various other types can be used.

[0081] In this embodiment, when the internal combustion engine 3 is operating in the input side connected state, the power output from the internal combustion engine 3 is supplied to the electric motor 4 for power generation via the switching shaft 30 and the electric motor connecting shaft 60, but the transmission 10 of the present invention is not limited to this. The power output from the internal combustion engine 3 may be supplied to the electric motor 4 for power generation as needed, and for example, it is also possible to disengage the clutch 71 and supply the power output from the internal combustion engine 3 only for driving the drive wheels.

[0082] Furthermore, in this embodiment, when the electric motor 4 is driving in the output side connected state, the power output from the electric motor 4 is provided to drive the drive wheels via the electric motor connection shaft 60 and the switching shaft 30, but the transmission 10 of the present invention is not limited to this. The power output from the electric motor 4 may be provided to drive the drive wheels as needed; for example, the clutch 71 may be disengaged and the power output from the electric motor 4 may be used to drive something other than the drive wheels. Furthermore, in this embodiment, when the drive wheels are braked in the output side connected state, the braking force is provided to the electric motor 4 for regeneration; however, regeneration may be performed as needed; for example, it is also possible not to perform regeneration when the battery is abundantly charged.

[0083] In this embodiment, the intermediate shaft 41 and the first reverse idler gear 42 (intermediate shaft gear) are used in common to transmit the power of the input shaft 13 to the switching shaft 30, but the transmission 10 of the present invention is not limited to this. For example, the intermediate shaft 41 and the reverse idler gear 42 may transmit power to the output shaft 15 without passing through the switching shaft 30.

[0084] 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]

[0085] 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]

[0086] 3: Internal combustion engine 4:Electric motor 10: Transmission 13: Input shaft 15: Output shaft 30: Switching axis 31: Input gear 32: Switching shaft gear 33: Output gear 35: Switching shaft bearing 41: Intermediate shaft 42: First reverse idler gear (intermediate shaft gear) 44: Intermediate shaft bearing 48: Retainer 60: Motor connection shaft 70: Switching mechanism 71: Clutch

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 electric motor connection shaft connected to the electric motor; a switching shaft that transmits power from the input shaft; an output shaft that transmits the power to drive wheels of the vehicle; Equipped with The switching shaft has 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 electric motor connection shaft; is provided, A transmission characterized in that a switching shaft bearing that rotatably supports the switching shaft and the switching shaft gear are wrapped around the switching shaft in the axial direction.

2. an intermediate shaft provided intermediate the switching shaft and the input shaft; an intermediate shaft gear provided on the intermediate shaft; an intermediate shaft bearing that rotatably supports the intermediate shaft; and 2. The transmission according to claim 1, wherein the intermediate shaft gear and the intermediate shaft bearing overlap in the axial direction of the intermediate shaft.

3. 3. The transmission according to claim 2, wherein the switching shaft gear and the intermediate shaft bearing overlap in the radial direction.

4. 4. The transmission according to claim 2 or 3, wherein the switching shaft gear and the intermediate shaft gear overlap in the radial direction.

5. a retainer for holding the intermediate shaft bearing; 4. The transmission according to claim 2 or 3, wherein the retainer is formed so as to avoid an area where the switching shaft gear is disposed.

6. the switching shaft has an input side gear capable of transmitting power of the input shaft, 4. The transmission according to claim 2, wherein the input gear is in mesh with the intermediate shaft gear.

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