transmission

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 of a vehicle. More specifically, it relates to a transmission in a hybrid vehicle equipped with an internal combustion engine and an electric motor as power sources.

Background Art

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

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when configured such that an engine can be started by a motor generator as in the prior art according to Patent Document 1 described above, in order to ensure a sufficient gear ratio for ensuring starting performance, it is necessary to provide a gear of a size corresponding to the gear ratio in the transmission. On the other hand, considering the overall length of the vehicle and the overall lengths of the engine, propeller shaft, rear axle, transfer, etc. mounted on the vehicle, there are naturally restrictions on the overall length of the transmission. Therefore, in a transmission in a vehicle equipped with an internal combustion engine and an electric motor, there is a problem of how to miniaturize the entire transmission while ensuring the gear ratio (gear diameter) required from the viewpoint of ensuring starting performance and the like.

[0005] Therefore, the present invention aims to provide a transmission that can be made smaller overall while ensuring the gear ratio (gear diameter) required from the viewpoint of ensuring starting performance and other such viewpoints. [Means for solving the problem]

[0006] (1) The transmission of the present invention, provided to solve the above-mentioned problems, is a transmission for a vehicle equipped with an internal combustion engine and an electric motor, comprising: an input shaft for transmitting power output from the internal combustion engine; an output shaft for transmitting the power to the drive wheels of the vehicle; an output shaft gear integrally supported on the output shaft; and an electric motor connection shaft connected to the electric motor, wherein a switching mechanism is provided to switch 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 further comprising: an output-side gear for transmitting 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] As described in (1) above, the transmission of the present invention is configured to have 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 the said power between the motor connection shaft and the output shaft. In this way, the transmission of the present invention has a switching mechanism as described above, so that it can smoothly switch between starting the internal combustion engine and motor-driven acceleration and regeneration. Furthermore, as described in (1) above, the transmission of the present invention does not require a separate rotating shaft (also called a switching shaft) for providing the switching mechanism, so the number of gears for power transmission between the motor connection shaft and the output shaft can be reduced. In other words, the transmission of the present invention can reduce at least one shaft and gear compared to the case in which a switching shaft gear is provided on the switching shaft. As a result, the transmission of the present invention can be simplified in configuration and made smaller. Furthermore, since the number of gears can be reduced, the transmission of the present invention can improve the power transmission efficiency in motor-driven acceleration and regeneration. Therefore, the transmission of the present invention can improve fuel efficiency in internal combustion engines and electric efficiency in electric motors. Here, the power during regeneration is transmitted in the following order: output shaft, output shaft gear, output side idler gear, output side gear, motor connection shaft, and electric motor.

[0008] (2) The transmission of the present invention, provided to solve the above-mentioned problems, is a transmission for a vehicle equipped with an internal combustion engine and an electric motor, and is characterized by comprising: an input shaft for transmitting power output from the internal combustion engine; an input shaft gear integrally supported on the input shaft; an output shaft for transmitting the power to the drive wheels of the vehicle; an output shaft gear integrally supported on the output shaft; a primary shaft for transmitting the power from the input shaft in the transmission; a primary input gear integrally supported on the primary shaft; an electric motor connection shaft connected to the electric motor; an input side gear integrally supported on the electric motor connection shaft; a first driven shaft supporting a first driven gear that meshes with the input side gear; and a second driven shaft supporting a second driven gear that meshes with the first driven gear and the primary input gear, wherein 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, by having the configuration described in (2) above, allows the primary shaft, the first driven shaft, and the second driven shaft to be arranged in close proximity. That is, the transmission of the present invention allows the first driven gear and the second driven gear to overlap radially, so that the size of the transmission (transmission case) can be reduced, and the gear ratio (gear diameter) required when starting an internal combustion engine (e.g., an engine) can be increased (secured). As a result, the transmission of the present invention is easier to mount 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 called the torque converter case) to be reduced, so that the tools used when connecting the internal combustion engine and the transmission can be simplified (for example, tools with universal joints can be eliminated).

[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 from the internal combustion engine side in the axial direction of the first driven shaft, wherein 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 overlaps the third driven gear radially.

[0011] The transmission of the present invention, by having the configuration described in (3) above, allows the third driven gear, which is coaxially supported with respect to the first driven shaft, and the second driven gear, which is supported by the fourth driven gear, to be positioned offset from each other in the axial direction of the first driven shaft. Therefore, by meshing the fourth driven gear and the second driven gear, the transmission of the present invention can cause the second driven gear and the third driven gear to overlap radially. As a result, the transmission of the present invention can suppress interference between the third driven gear and the second driven gear. Furthermore, the transmission of the present invention can be made smaller in size (transmission case) and can achieve (secure) the gear ratio (gear diameter) required when starting an internal combustion engine (e.g., an engine). In addition, the transmission of the present invention improves the mountability on vehicles.

[0012] (4) The transmission of the present invention comprises a reverse idler shaft for transmitting the power for reverse movement, and a reverse idler gear integrally supported on the reverse idler shaft, wherein the third driven gear is positioned at a different location from the reverse idler gear in the axial direction of the first driven shaft, and the third driven gear and the reverse idler gear overlap radially.

[0013] The transmission of the present invention, by having the configuration described in (4) above, allows the third driven gear and the reverse idler gear to be positioned offset from each other in the axial direction of the first driven shaft. As a result, the transmission of the present invention allows the third driven gear and the reverse idler gear to overlap radially. Therefore, the transmission of the present invention can suppress interference between the third driven gear and the reverse idler gear. As a result, the transmission of the present invention can be made smaller in size (transmission case) and can also be made to obtain (secure) the gear ratio (gear diameter) required when starting an internal combustion engine (e.g., an engine). Furthermore, the transmission of the present invention improves the mountability on vehicles.

[0014] (5) In the transmission of the present invention, the third driven gear is preferably 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 secure 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 an internal combustion engine. Furthermore, the transmission of the present invention offers improved mountability in vehicles.

[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, wherein the second reverse idler gear is positioned at a different location from the first reverse idler gear in the axial direction of the reverse idler shaft, and the first reverse idler gear is positioned at a different location from the third driven gear in the axial direction of the reverse idler shaft and overlaps the third driven gear radially.

[0017] The transmission of the present invention, by having the configuration described in (6) above, can more reliably ensure radial overlap between the first reverse idler gear and the third driven gear. As a result, the transmission of the present invention can be made smaller and its mountability in vehicles can be improved. Furthermore, the transmission of the present invention, by having the configuration described in (6) above, can easily ensure the 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 drawing]

[0019] [Figure 1] This is an overall front view with a cutout of the transmission cover according to one embodiment of the present invention. [Figure 2] Figure 1 is a side view of the transmission as seen from the direction of the internal combustion engine. [Figure 3]It is a side view of an internal combustion engine connected to the transmission of the present invention as seen from the internal combustion engine direction. [Figure 4] It is a side view of the transmission of FIG. 1 in a state where it is coupled to an internal combustion engine as seen from the internal combustion engine direction. [Figure 5] It is a schematic skeleton diagram according to an embodiment of the transmission of FIG. 1. [Figure 6] It is an enlarged view of the main part of FIG. 1.

Embodiments for Carrying Out the Invention

[0020] Hereinafter, the transmission 10 according to an embodiment of the present invention will be described in detail with reference to the drawings. Note that each figure is schematically shown for easy understanding, and it should be noted that it may be different from the actual shape, size, and arrangement of components. Also, it should be noted that it may be omitted that each axis is supported by an appropriate bearing or the like and is rotatable. Also, hereinafter, the front side of the vehicle may be referred to as the front Fr and the rear side may be referred to as the rear Rr.

[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 composed of, for example, an engine such as a gasoline engine or a diesel engine. The drive shaft (not shown) of the internal combustion engine 3 is connected to the input shaft 13 in the transmission 10. Therefore, the power output by the internal combustion engine 3 is input to the transmission 10 through the input shaft 13. FIG. 3 is a side view of the internal combustion engine 3 as seen from the internal combustion engine direction. The internal combustion engine 3 is housed in an internal combustion engine case 3A (partially omitted and shown). 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 in a size that surrounds the transmission case 10A of the transmission 10 in a cross-sectional view.

[0022] As shown in Figures 1 and 5, the electric motor 4 is configured, for example, as a motor generator, and can output driving force and generate electricity. The motor shaft 4A (see Figure 5) of the electric motor 4 is connected to the motor connection 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 motor connection shaft 60. As will be described in detail later, regenerative power (regenerative energy) from the drive wheels (not shown) and power from the internal combustion engine 3 are input to the electric motor 4 via the motor connection shaft 60 and can be used for power generation.

[0023] The transmission 10 has multiple gears and is configured to change the speed of the power generated by the internal combustion engine 3 and the electric motor 4, and to transmit the regenerated energy to the electric motor 4. As shown in Figure 4, the transmission 10 is housed in the transmission case 10A. The transmission case 10A and the internal combustion engine case 3A are joined together at their respective mating surfaces (not shown) with appropriate bolts (not shown). As shown in Figures 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 connection 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, and a switching mechanism 70. In addition to the above, the transmission 10 includes 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, and the like.

[0024] As shown in Figures 1 and 5, the torque converter 12 includes a pump impeller 12A, a turbine runner 12B, and a lock-up mechanism 12C. The input shaft 13 is connected to the pump impeller 12A, and the pump impeller 12A is capable of rotating integrally with the input shaft 13 around the same axis of rotation. The turbine runner 12B is rotatable around the same axis of rotation as the pump impeller 12A. The lock-up mechanism 12C is provided to directly connect / disconnect the pump impeller 12A and the turbine runner 12B. When the lock-up mechanism 12C is engaged (lock-up on), the pump impeller 12A and the turbine runner 12B are directly connected, and when the lock-up mechanism 12C is released (lock-up off), the pump impeller 12A and the turbine runner 12B are separated.

[0025] The input shaft 13 is positioned so that its axis coincides with the rotation axis of the torque converter 12. The input shaft 13 can transmit power output from the internal combustion engine 3. An input shaft gear 14 is integrally formed on the input shaft 13. The front end Fr of the input shaft 13 is inserted into the torque converter 12.

[0026] The output shaft 15 is positioned at a rearward (Rr) distance from the input shaft 13. The output shaft 15 is positioned so that its axis aligns with the axis of the input shaft 13. Although not shown in the illustration, the output shaft 15 can transmit power to the vehicle's drive wheels via a drive shaft or the like. An output shaft gear 16 is integrally formed with the output shaft 15. The output shaft gear 16 meshes with a secondary output gear 25, which will be described later.

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

[0028] A primary input gear 22 (also referred to as a driven gear 22) is mounted on the primary shaft 21 so as to be rotatable relative to it. The primary input gear 22 meshes with the input shaft gear 14 and the 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 the second driven shaft 35, which will be described later.

[0029] A secondary input gear 24 and a secondary output gear 25 are mounted on the secondary shaft 23. The secondary input gear 24 is rotatable relative to the secondary shaft 23. The secondary output gear 25 is mounted so as not to 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 hydraulic pressure supplied to the hydraulic chambers (not shown) of the primary pulley 26 and the secondary pulley 27 is controlled, and the groove widths of the primary pulley 26 and the secondary pulley 27 are changed, thereby continuously changing the belt gear ratio (pulley ratio between the primary pulley 26 and the secondary pulley 27) within a constant gear ratio range. The rotational force (power) of the shifted secondary shaft 23 is transmitted to the output shaft 15 via the secondary output gear 25 and the output shaft gear 16, driving the drive wheels (not shown).

[0031] The reverse transmission mechanism 40 is a mechanism that transmits power (rotation) from the input shaft 13 to the secondary input gear 24. The reverse transmission mechanism 40 is equipped with a reverse idler shaft 41 and reverse idler gears 42 (first reverse idler gear 42A and second reverse idler gear 42B).

[0032] The reverse idler shaft 41 is a shaft located midway between the secondary shaft 23 and the first driven shaft 30, which will be described later, as shown in Figure 2. As shown in Figure 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 located at the end of the reverse idler shaft 41 on the side of the first reverse idler gear 42A. The rear bearing 46 is located at the end on the side of the second reverse idler gear 42B.

[0033] As shown in Figures 1 and 5, the first reverse idler gear 42A is integrally formed 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 rotation direction of the input shaft gear 14 (input shaft 13). The first reverse idler gear 42A is formed with a larger diameter than the second reverse idler gear 42B. The first reverse idler gear 42A is positioned offset (positioned in a different location) from the third driven gear 32A, which will be described later, in the axial direction of the reverse idler shaft 41 (towards the rear in this embodiment). Therefore, the first reverse idler gear 42A overlaps radially with the third driven gear 32A. That is, the transmission 10 of the present invention can suppress mutual 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 more compact because the reverse idler shaft 41 and the first driven shaft 30 can be arranged in close proximity. The first reverse idler gear 42A may, if necessary, mesh with the motor connection shaft gear 61 of the motor connection shaft 60, which will be described later, to transmit the power of the motor 4 in reverse.

[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 at the rear Rr of the first reverse idler gear 42A and meshes with the secondary input gear 24.

[0035] The forward clutch 51 (clutch device 50) is provided to allow / prevent the rotation of the primary input gear 22 relative to the primary shaft 21. The forward clutch 51 forms a clutch device 50 that includes a clutch drum, clutch piston, friction material, and hydraulic chamber, although these are not shown in the figures. The forward clutch 51 controls the engagement of the clutch by controlling the supply of oil to the hydraulic chamber according to the output value of a solenoid (not shown).

[0036] When the forward clutch 51 is engaged (engaged state), relative rotation of the primary input gear 22 with respect to the primary shaft 21 is prohibited. In other words, the engagement of the forward clutch 51 causes the primary shaft 21 and the primary input gear 22 to rotate together. As a result, a driving force in the forward direction is transmitted to the output shaft 15 via the continuously variable transmission 20, and the drive wheels (not shown) are driven in the forward direction. On the other hand, when the forward clutch 51 is disengaged (disengaged state), relative rotation of the primary input gear 22 with respect to the primary shaft 21 is permitted. Therefore, even if the primary input gear 22 rotates, that rotation is not transmitted to the primary shaft 21.

[0037] The reverse clutch 55 (clutch device 50) is provided to allow / prevent the rotation of the secondary input gear 24 relative to the secondary shaft 23. Since the reverse clutch 55 has the same configuration as the forward clutch 51, a detailed explanation is omitted.

[0038] When the reverse clutch 55 is engaged (engaged state), relative rotation of the secondary input gear 24 with respect to the secondary shaft 23 is prohibited. In other words, the engagement of the reverse clutch 55 causes the secondary shaft 23 and the secondary input gear 24 to rotate together. This transmits a driving force in the reverse direction to the output shaft 15, and drives the drive wheels (not shown) in the reverse direction. On the other hand, when the reverse clutch 55 is released (released state), relative rotation of the secondary input gear 24 with respect to the secondary shaft 23 is permitted. Therefore, even if the secondary input gear 24 rotates, that rotation is not transmitted to the secondary shaft 23.

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

[0040] The motor connecting shaft gear 61 is fixed to the front end (front Fr side) of the motor connecting shaft 60 and meshes with the third driven gear 32A on the first driven shaft 30. Therefore, when the motor 4 is driven, the power output from the 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 electricity for the motor 4 via the motor connecting shaft gear 61 and the motor connecting shaft 60.

[0041] As shown in Figures 2 and 4, the first driven shaft 30 is located between the motor connection shaft 60 and the input shaft 13. As shown in Figure 6, the front end (front Fr side) and rear end (rear Rr side) of the first driven shaft 30 are rotatably supported by bearings 31, 31, respectively. A first driven gear 32 is also fixed to the middle of the first driven shaft 30.

[0042] The first driven gear 32 comprises a third driven gear 32A and a fourth driven gear 32B positioned 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 positioned at different (staggered) positions in the axial direction of the first driven shaft 30.

[0043] The third driven gear 32A is formed with 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 power output from the motor connection shaft 60. Here, the third driven gear 32A is positioned at a different position (offset position) from the first reverse idler gear 42A (see Figure 1) in the axial direction of the first driven shaft 30 so as not to interfere with each other. Therefore, the third driven gear 32A and the first reverse idler gear 42A overlap radially (see Figures 2 and 4).

[0044] The fourth driven gear 32B is formed with a smaller diameter than the third driven gear 32A. The fourth driven gear 32B is located on the opposite side of the first driven shaft 30 from the internal combustion engine 3 side (the transmission 10 side) in the axial direction of the first driven shaft 30. The fourth driven gear 32B meshes with the second driven gear 36, which is fixed to the second driven shaft 35, which will be described later. In other words, the second driven gear 36 meshes with the fourth driven gear 32B radially inside the third driven gear 32A. To put it another way, the second driven gear 36 overlaps radially with the third driven gear 32A (see Figures 2 and 4). That is, the transmission 10 of the present invention can be made more compact because the first driven shaft 30 and the second driven shaft 35 can be placed in close proximity by overlapping at least a portion of the second driven gear 36 and the third driven gear 32A.

[0045] As shown in Figures 1 and 5, the second driven shaft 35 is positioned parallel to the first driven shaft 30, with a gap between them. The second driven gear 36 is mounted to the second driven shaft 35.

[0046] The second driven gear 36 meshes with the primary input gear 22 (driven gear 22) and the fourth driven gear 32B. Therefore, the second driven gear 36 can rotate together 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 motor connection shaft 60 via the primary shaft 21, the second driven shaft 35, and the first driven shaft 30, and used for power generation by the motor 4. Also, the second driven gear 36 can rotate together with the second driven shaft 35 as the first driven shaft 30 rotates. That is, the power output from the motor 4 is transmitted to the first driven shaft 30, the second driven shaft 35, and the input shaft 13, and used for starting the internal combustion engine 3.

[0047] The output gear 33 is fixed to the rear end (rear Rr side) of the motor connection shaft 60. The output gear 33 meshes with the output transmission shaft gear 18 (also called the output idler gear 18), which is fixed to the output transmission shaft 17, described later (although the diagram shows the output gear 33 and the output transmission shaft 17 as being separated, note that they are actually meshed with each other).

[0048] The output transmission shaft 17 is mounted parallel to the motor connection shaft 60, with a gap between them. An output transmission shaft gear 18 is mounted 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 side 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 power from the first driven shaft 30 to the output shaft 15 as the first driven shaft 30 rotates.

[0049] The switching mechanism 70 is located in the middle section of the motor connection shaft 60. Specifically, the switching mechanism 70 is positioned between the motor connection 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 motor connection shaft 60 and the input shaft 13, and an "output-side connection state" that enables power transmission between the motor connection shaft 60 and the output shaft 15, by switching the connection state of the clutch 71 by hydraulics or the like. Specifically, the motor connection shaft 60 is divided into a front Fr side and a rear Rr side via the clutch 71 of the switching mechanism 70, with the motor connection shaft gear 61 located on the front Fr side of the motor connection shaft 60 and the output-side gear 33 located on the rear Rr side of the motor connection shaft 60.

[0051] Therefore, in the "input-side connected state," the rear Rr side of the motor connection shaft 60 is not connected (the rear Rr side of the clutch 71 is not engaged), and only the front Fr side of the motor connection shaft 60 rotates. That is, the motor connection shaft gear 61 (input-side gear 61) rotates in conjunction with the rotation of the front Fr side of the motor connection 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 used to generate electricity for the motor 4 via the input shaft 13, primary shaft 21, second driven shaft 35, first driven shaft 30, and motor connection shaft 60. On the other hand, when the internal combustion engine 3 is stopped in the "input-side connected state," the power output from the motor 4 is used to start the internal combustion engine 3 via the motor connection shaft 60, first driven shaft 30, second driven shaft 35, primary shaft 21, and input shaft 13.

[0052] Furthermore, in the "output-side connected state," the rear Rr side of the motor connection shaft 60 is connected by the engagement of the clutch 71, and the front Fr side and rear Rr side of the motor connection shaft 60 rotate together. Therefore, when the motor 4 is driven in the "output-side connected state," the power output from the motor 4 is used to drive the drive wheels (not shown) via the motor connection shaft 60 (EV driving state or assisted driving (HEV driving) state). On the other hand, when the drive wheels are braked (decelerated) in the "output-side connected state," the braking force acting on the output shaft 15 is used for regeneration (power generation) of the motor 4 via the motor connection shaft 60. The switching mechanism 70 can also interrupt the transmission of power between the motor connection shaft 60 and the input shaft 13, and between the motor connection shaft 60 and the output shaft 15, when the clutch 71 is disengaged (also referred to as the unengaged state).

[0053] In this embodiment, as described above, the third driven gear 32A and the second driven gear 36 are radially overlapped, thus miniaturizing the transmission 10. Therefore, as shown in Figure 4, the upper side of the transmission case 10A (above the third driven gear 32A and the first reverse idler gear 42A) can be set to a lower position. In other words, the transmission case 10A can be miniaturized in the vertical direction. As a result, when fastening the internal combustion engine 3 and the transmission 10 with bolts, tools such as those with universal joints, which were conventionally required, can be eliminated. Furthermore, it is possible to house wiring and other components by utilizing the space formed in the upper part of the transmission case 10A.

[0054] The above describes one embodiment of the transmission 10 of the present invention. Next, the effects and advantages realized by the transmission 10 of the present invention will be described below.

[0055] <Effects> The transmission 10 described above 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 with prior art.

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

[0057] As described in (a) above, the transmission 10 of the present invention is configured to have a switching mechanism 70 that switches between an input-side connection state that enables power transmission between the motor connection shaft 60 and the input shaft 13 and an output-side connection state that enables the transmission of the same power between the motor connection shaft 60 and the output shaft 15. In this way, the transmission 10 of the present invention has the switching mechanism 70 described above, so that it can smoothly switch between starting the internal combustion engine 3 and powering and regenerating power by the motor 4. Furthermore, by configuring the transmission 10 of the present invention as described in (a) above, there is no need to separately provide a rotating shaft (also called a switching shaft) for providing the switching mechanism 70, so the number of gears for power transmission between the motor connection shaft 60 and the output shaft 15 can be reduced. In other words, the transmission 10 of the present invention can reduce at least one shaft and gear compared to the case in which a switching shaft gear is provided on the switching shaft. As a result, the transmission 10 of the present invention can be simplified in structure and made smaller. Furthermore, since the transmission 10 of the present invention can reduce the number of gears, it can improve the power transmission efficiency during regeneration and traction of the electric motor 4. Therefore, the transmission 10 of the present invention can improve fuel efficiency in the internal combustion engine 3 and electric energy consumption in 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 in a vehicle equipped with an internal combustion engine 3 and an electric motor 4, comprising: 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 the drive wheels of the vehicle; an output shaft gear 16 integrally supported on the output shaft 15; a primary shaft 21 that transmits the power from the input shaft 13 in the transmission 10; and a primary input gear 22 (drive) integrally supported on the primary shaft 21. The primary input gear 22 comprises a motor connection shaft 60 connected to the motor 4, an input side gear 61 integrally supported on the motor connection shaft 60, a first driven shaft 30 supporting a first driven gear 32 that meshes with the input side gear 61, and a second driven shaft 35 supporting a second driven gear 36 that meshes with the first driven gear 32 and the primary input gear 22, wherein the primary input gear 22 meshes with the second driven gear 36 and the input shaft gear 14 to transmit the power.

[0059] The transmission 10 of the present invention, by having the configuration described in (b) above, allows the primary shaft 21, the first driven shaft 30, and the second driven shaft 35 to be arranged in close proximity. That is, the transmission 10 of the present invention allows the first driven gear 32 and the second driven gear 36 to overlap radially, so that the size of the transmission 10 (transmission case 10A) can be reduced, and the gear ratio (gear diameter) required when starting the internal combustion engine 3 (e.g., an engine) can be increased (secured). As a result, the transmission 10 of the present invention is easier to mount on a vehicle. In addition, the transmission 10 of the present invention allows the mating surface between the transmission case 10A and the torque converter case (also called the torque converter case) to be reduced, so that the tools used when connecting the internal combustion engine 3 and the transmission 10 can be simplified (for example, tools with universal joints can be eliminated).

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

[0061] The transmission 10 of the present invention, by having the configuration described in (c) above, allows the third driven gear 32A and the second driven gear 36, which are supported on the fourth driven gear 32B, to be positioned offset from each other in the axial direction of the first driven shaft 30, respectively, with respect to the first driven shaft 30. Therefore, the transmission 10 of the present invention can cause the second driven gear 36 and the third driven gear 32A to overlap radially by meshing the fourth driven gear 32B and the second driven gear 36. As a result, the transmission 10 of the present invention can suppress interference between the third driven gear 32A and the second driven gear 36. Furthermore, the transmission 10 of the present invention can be made smaller in size (transmission case 10A), and can also be made to obtain (secure) the gear ratio (gear diameter) required when starting an internal combustion engine 3 (for example, an engine). Furthermore, the transmission 10 of the present invention improves the ease of mounting on a vehicle.

[0062] (d) The transmission 10 of the present invention comprises a reverse idler shaft 41 for transmitting the power for reverse movement, and a reverse idler gear 42 integrally supported on the reverse idler shaft 41, wherein the third driven gear 32A is positioned differently 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] The transmission 10 of the present invention, by having the configuration described in (d) above, allows the third driven gear 32A and the reverse idler gear 42 to be offset from each other in the axial direction of the first driven shaft 30. As a result, the transmission 10 of the present invention allows the third driven gear 32A and the reverse idler gear 42 to overlap radially. Therefore, the transmission 10 of the present invention can suppress interference between the third driven gear 32A and the reverse idler gear 42. As a result, the transmission 10 of the present invention can be made smaller in size (transmission case 10A) and can also be made to obtain (secure) the gear ratio (gear diameter) required when starting an internal combustion engine 3 (for example, an engine). Furthermore, the transmission 10 of the present invention improves the mountability on a vehicle.

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

[0065] By configuring the transmission 10 of the present invention as described in (e) above, the radial overlap between the third driven gear 32A and the second driven gear 36 can be more reliably secured. As a result, the transmission 10 of the present invention can further increase (secure) the gear ratio (gear diameter) required when starting the internal combustion engine 3. Furthermore, the transmission 10 of the present invention offers improved mountability in vehicles.

[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, wherein the second reverse idler gear 42B is positioned at a different location 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 location from the third driven gear 32A in the axial direction of the reverse idler shaft 41 and overlaps the third driven gear 32A in the radial direction.

[0067] The transmission 10 of the present invention, by having the configuration described in (f) above, can more reliably ensure radial overlap between the first reverse idler gear 42A and the third driven gear 32A. As a result, the transmission 10 of the present invention can be made smaller and its mountability on a vehicle can be improved. The transmission 10 of the present invention, by having the configuration described in (f) above, can easily ensure the gear ratio.

[0068] ≪Variations≫ The above describes the effects and advantages obtained by the transmission 10 according to one embodiment of the present invention. However, the transmission 10 is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention. For example, the transmission 10 may be as described in (a) or (b) above, and can be formed in various shapes and sizes. In addition, the internal combustion engine 3 connected to the transmission 10 can be of various types, shapes, and sizes. For example, the internal combustion engine 3 can be a gasoline engine, a diesel engine, or various other types. In this embodiment, the case in which a motor generator is used for the electric motor 4 is illustrated, but the electric motor 4 can be a motor generator or various other types of motors or generators. In addition, the electric motor 4 can be of various types, shapes, and sizes. Furthermore, within the scope of the invention, the transmission 10 of the present invention can be modified by increasing or decreasing the number of rotating shafts as appropriate. For example, the transmission 10 may not have some or all of the configurations described in (c) to (f) above, or it may have some or all of the configurations described in (c) to (f) above, along with other configurations. Furthermore, 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 the shape and size of this embodiment, and can be appropriately changed according to the arrangement of each shaft and gear.

[0069] Specifically, as described in (c) above, the transmission 10 has a second driven gear 36 that overlaps radially with the third driven gear 32A. The amount of radial overlap can be set to such 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, while ensuring the required gear ratio.

[0070] As described above, in the transmission 10, the third driven gear 32A and the reverse idler gear 42 overlap radially, 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 position and diameter 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 so that they do not interfere with each other and the required gear ratio is secured.

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

[0072] As described above, the transmission 10 has a reverse idler gear 42 that is divided into a first reverse idler gear 42A and a second reverse idler gear 42B, as shown in (f) above, but the present invention is not limited thereto. For example, the reverse idler gear 42 may be composed of a single gear. Also, as described above, the transmission 10 has a first reverse idler gear 42A that is larger in diameter than the second reverse idler gear 42B, but the first reverse idler gear 42A can be formed in 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 not overlap in the radial direction. In addition, the first reverse idler gear 42A can be positioned at various axial positions on 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 connection state and the output-side connection state in the switching mechanism 70 are switched by switching the connection state of the clutch 71, but the present invention is not limited to this. The transmission 10 can employ various switching devices and mechanisms different from the clutch 71 for switching the state of the switching mechanism 70. Also, the switching of the clutch 71 is not limited to hydraulic, but can also be done electrically, and various other methods can be used.

[0074] In this embodiment, when the internal combustion engine 3 is operating with the input side connected, the power output from the internal combustion engine 3 is used to generate electricity for the electric motor 4 via the electric motor connection shaft 60. However, the transmission 10 of the present invention is not limited to this. The power output from the internal combustion engine 3 may be used to generate electricity for the electric motor 4 as needed. For example, it is also possible to disengage the clutch 71 and use the power output from the internal combustion engine 3 only to drive the drive wheels.

[0075] Furthermore, in this embodiment, when the motor 4 is driven in the output-side connected state, the power output from the motor 4 is used to drive the drive wheels via the motor connection shaft 60. However, the transmission 10 of the present invention is not limited to this. The power output from the motor 4 may be used to drive the drive wheels as needed. For example, the clutch 71 may be disengaged, and the power output from the motor 4 may be used to drive something other than the drive wheels. Also, in this embodiment, when the drive wheels are braked in the output-side connected state, the braking force is used to regenerate power to the motor 4. However, regeneration may be performed as needed. For example, when the charge is abundant, regeneration may not be performed.

[0076] Furthermore, while the transmission 10 of the present invention is exemplified in which the third driven gear 32A and the second driven gear 36 are radially overlapped, and the third driven gear 32A and the first reverse idler gear 42A are radially overlapped, the transmission 10 of the present invention can be configured to overlap each gear radially as needed to prevent interference between each gear and each shaft. In such cases, each gear can be, for example, made into a pair of gears, and the pair of gears can be formed with a large diameter and a small diameter and arranged at different positions in the axial direction.

[0077] The above describes various embodiments and modifications of the transmission according to the present invention. However, the present invention is not limited to those exemplified in the embodiments and modifications described above, and it will be readily apparent to those skilled in the art that other embodiments may exist in the spirit and nature of the teachings, without departing from the scope of the claims. [Industrial applicability]

[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 axis 14: Input shaft gear 15: Output axis 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 Axis 42: Reverse Idler Gear 42A: First reverse idler gear 42B: Second reverse idler gear 60: Motor connecting shaft 61: Motor connecting shaft gear (input side gear) 70: Switching mechanism

Claims

1. A transmission in a vehicle equipped with an internal combustion engine and an electric motor, An input shaft that transmits power output from the internal combustion engine, An input shaft gear integrally supported on the aforementioned input shaft, An output shaft that transmits the power to the drive wheels of the vehicle, An output shaft gear integrally supported on the aforementioned output shaft, In the transmission, the primary shaft transmits the power of the input shaft, A primary input gear integrally supported on the primary shaft, The motor connection shaft connected to the aforementioned motor, The input side gear is integrally supported on the motor connection shaft, A first driven shaft, on which a first driven gear that meshes with the input side gear is supported, A second driven shaft supports the second driven gear that meshes with the first driven gear and the primary input gear, The output gear that transmits the power transmitted to the motor connection shaft, The output side idler gear meshes with the output side gear and the output shaft gear, A reverse idler shaft that transmits the aforementioned power for reverse movement, A reverse idler gear integrally supported on the aforementioned reverse idler shaft, Equipped with, A switching mechanism is provided to switch 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. The primary input gear meshes with the second driven gear and the input shaft gear to transmit the power. The first driven gear is, The third driven gear located on the internal combustion engine side, A fourth driven gear is positioned on the opposite side of the internal combustion engine side in the axial direction of the first driven shaft, Equipped with, The third driven gear is meshed with the input gear. The fourth driven gear meshes with the second driven gear, The second driven gear overlaps radially with the third driven gear, The third driven gear is positioned differently from the reverse idler gear in the axial direction of the first driven shaft. A transmission characterized in that the third driven gear and the reverse idler gear overlap radially.

2. The transmission according to claim 1, characterized in that the third driven gear is formed to have a larger diameter than the fourth driven gear.

3. The aforementioned reverse idler gear is 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 positioned differently from the first reverse idler gear in the axial direction of the reverse idler shaft. The transmission according to claim 1 or 2, characterized in that the first reverse idler gear is positioned at a different location from the third driven gear in the axial direction of the reverse idler shaft and overlaps the third driven gear radially.

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