Power transmission device

Abstract

To provide a power transmission device capable of reducing the number of parts and being miniaturized.SOLUTION: A power transmission device 1 includes a motor shaft 17 of an electric motor, a first transmission mechanism 9 having a first gear set 33 capable of transmitting power to the motor shaft 17, a second transmission mechanism 11 capable of transmitting power to an engine and having a second gear set 53, a generator shaft 25 of a generator driven via the second gear set 53, a third transmission mechanism 13 capable of transmitting power to the second transmission mechanism 11 via a third gear set 75, and a differential mechanism 15 capable of transmitting power via the first transmission mechanism 9 and the third transmission mechanism 13. An electric motor and a generator are arranged on one side in a rotary shaft direction of a first transmission mechanism 9, a second transmission mechanism 11 and a third transmission mechanism 13, and a motor gear part 23 constituting a first gear set 33 and a generator gear part 29 constituting a second gear set 53 are respectively arranged on respective shaft ends of a motor shaft 17 and a generator shaft 25.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a power transmission device. [Background technology]

[0002] A conventional power transmission device includes a motor shaft of an electric motor, a first transmission mechanism having a first gear set capable of transmitting power between the motor shaft and the first transmission mechanism, and a second transmission mechanism having a second gear set capable of transmitting power between the motor shaft and the engine.The power transmission device also includes a generator shaft of a generator driven via the second gear set and a third transmission mechanism capable of transmitting power between the generator shaft and the second transmission mechanism via a third gear set.A power transmission device including a differential mechanism capable of transmitting power via the first transmission mechanism and the third transmission mechanism is also known (see Patent Document 1).

[0003] In this power transmission device, a third input member is connected to an end of the motor shaft so as to rotate integrally with the motor shaft. The third input member is provided with an eighth gear that constitutes a first gear set. A first input member is connected to an end of the generator shaft so as to rotate integrally with the generator shaft. The first input member is provided with a first gear that constitutes a second gear set.

[0004] In this power transmission device, the driving force of the electric motor is output from the third input member via the first transmission mechanism to the differential mechanism, while the driving force of the engine is input from the second transmission mechanism via the first input member to drive the generator. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2021 / 039134 Summary of the Invention [Problem to be solved by the invention]

[0006] In the power transmission device of Patent Document 1, rotating shaft members provided with gear portions constituting a first gear set and a second gear set are respectively connected to the shaft ends of the motor shaft and the generator shaft so as to be rotatable together. This requires two rotating shaft members, which increases the number of parts. In addition, a space is required to accommodate the two rotating shaft members, which increases the size of the device.

[0007] The present invention has been made in view of the problems inherent in the prior art, and an object of the present invention is to provide a power transmission device that can reduce the number of parts and can be made smaller. [Means for solving the problem]

[0008] The power transmission device of this embodiment comprises a motor shaft of an electric motor, a first transmission mechanism having a first gear set capable of transmitting power between the motor shaft, a second transmission mechanism capable of transmitting power between the motor shaft and an engine and having a second gear set, a generator shaft of a generator driven via the second gear set, a third transmission mechanism capable of transmitting power between the second transmission mechanism via a third gear set, and a differential mechanism capable of transmitting power via the first transmission mechanism and the third transmission mechanism, wherein the electric motor and the generator are arranged on one side of the rotational axis direction of the first transmission mechanism, the second transmission mechanism, and the third transmission mechanism, and a motor gear portion constituting the first gear set and a generator gear portion constituting the second gear set are provided at the respective axial ends of the motor shaft and the generator shaft. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a power transmission device that can reduce the number of parts and can be made smaller. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a cross-sectional view of a power transmission device according to an embodiment of the present invention. [Figure 2] 1 is a schematic diagram of a power transmission device according to an embodiment of the present invention when viewed from the side; DETAILED DESCRIPTION OF THE INVENTION

[0011] The power transmission device according to this embodiment will be described in detail below with reference to the drawings. Note that the dimensional proportions in the drawings are exaggerated for the sake of explanation and may differ from the actual proportions.

[0012] As shown in FIG. 1, a power transmission device 1 according to this embodiment is disposed, for example, in a power transmission path of a vehicle, between a drive source and left and right drive wheels. The drive source includes an electric motor 3 (see FIG. 2) and an engine 5 (see FIG. 2). The drive force of the electric motor 3 is transmitted to a differential mechanism 15 via a first transmission mechanism 9, and the drive force is distributed to the left and right drive wheels via a pair of output shafts (not shown). The drive force of the engine 5 is transmitted to the differential mechanism 15 via a third transmission mechanism 13, and the drive force is distributed to the left and right drive wheels via a pair of output shafts. Meanwhile, the drive force of the engine 5 drives a generator 7 (see FIG. 2) via a second transmission mechanism 11, and charges a power source such as a battery or a storage battery.

[0013] As shown in Figures 1 and 2, the power transmission device 1 includes an electric motor 3, an engine 5, a generator 7, a first transmission mechanism 9, a second transmission mechanism 11, a third transmission mechanism 13, and a differential mechanism 15.

[0014] The electric motor 3 includes a stator (not shown) and a motor shaft 17 serving as a rotor. The stator is disposed outside the casing 19 on one side in the direction of the rotation axis of the first transmission mechanism 9, the second transmission mechanism 11, and the third transmission mechanism 13. The stator is electrically connected to a controller (not shown) that controls the energization and to a power source that supplies electric power. The motor shaft 17 is disposed rotatably via bearings 21 (only one of which is shown) on the outer periphery on both axial sides. The motor shaft 17 is rotated by energizing the stator. One end of the motor shaft 17 is disposed so as to protrude into the interior of the casing 19.

[0015] A motor gear portion 23 that outputs the driving force of the electric motor 3 to the first transmission mechanism 9 is provided at the end of the motor shaft 17 disposed inside the casing 19. By providing the motor gear portion 23 at the end of the motor shaft 17, it is possible to eliminate a rotating shaft member that is independently supported by the casing 19 and has a gear portion that is integrally rotatably connected to the motor shaft 17, thereby reducing the number of parts. In addition, it is possible to reduce the installation space required for arranging the rotating shaft member, thereby achieving a reduction in size and weight. The motor gear portion 23 is formed as a single member that is continuous with the motor shaft 17, which is the rotor. Therefore, in this embodiment, the number of parts can be reduced and the structure can be simplified compared to a structure in which the motor shaft 17 and the motor gear portion 23 are formed separately and then integrally connected.

[0016] The engine 5 is disposed outside the casing 19 on the other side of the first transmission mechanism 9, the second transmission mechanism 11, and the third transmission mechanism 13 in the direction of the rotation axis. An output shaft (not shown) of the engine 5 is disposed so as to be able to transmit power to the second transmission mechanism 11 via an interrupter (not shown) such as a dry single-plate clutch. The driving force of the engine 5 is output to the second transmission mechanism 11 via the interrupter in the connected state.

[0017] The generator 7 includes a stator (not shown) and a generator shaft 25 serving as a rotor. The stator is disposed outside the casing 19 on one side in the direction of the rotation axis of the first transmission mechanism 9, the second transmission mechanism 11, and the third transmission mechanism 13. The stator is electrically connected to a controller (not shown) that controls the energization and to a power source to be charged. The generator shaft 25 is disposed rotatably via bearings 27 (only one of which is shown) on the outer periphery on both axial sides. The generator shaft 25 is rotated by the driving force of the engine 5 via the second transmission mechanism 11, and charges the power source via the stator. One end of the generator shaft 25 is disposed so as to protrude into the inside of the casing 19.

[0018] A generator gear unit 29, to which the driving force of the engine 5 is input from the second transmission mechanism 11, is provided at the axial end of the generator shaft 25 disposed inside the casing 19. By providing the generator gear unit 29 at the axial end of the generator shaft 25, it is possible to eliminate a rotating shaft member that is independently supported by the casing 19 and has a gear unit connected to the generator shaft 25 so as to be rotatable integrally therewith, thereby reducing the number of parts. In addition, it is possible to reduce the installation space required for the rotating shaft member, thereby achieving a reduction in size and weight. The generator gear unit 29 is formed as a single member that is continuous with the generator shaft 25, which is the rotor. Therefore, in this embodiment, the number of parts can be reduced and the structure can be simplified compared to a structure in which the generator shaft 25 and the generator gear unit 29 are formed separately and then connected integrally.

[0019] The first transmission mechanism 9 is disposed on a power transmission path between the electric motor 3 and the differential mechanism 15. The first transmission mechanism 9 includes a first rotating shaft 31, a first gear set 33, a motor clutch unit 35, a first output gear unit 37, and a park lock gear unit 39.

[0020] The first rotating shaft 31 is rotatably supported on both axial ends of the outer periphery thereof by the casing 19 via bearings 41 and 43. The first rotating shaft 31 is disposed such that its rotation axis is parallel to the rotation axis of the motor shaft 17.

[0021] The first gear set 33 is made up of the motor gear portion 23 and a motor-side large-diameter gear portion 45 that is formed with a larger diameter than the motor gear portion 23 and meshes with the motor gear portion 23. The motor-side large-diameter gear portion 45 is formed separately from the first rotating shaft 31 and is disposed on the outer periphery of the first rotating shaft 31 via a bearing so as to be rotatable relative to the first rotating shaft 31. The first gear set 33 transmits the driving force from the electric motor 3 from the motor shaft 17 to the first rotating shaft 31 after reducing the speed.

[0022] The motor-side large-diameter gear portion 45 of the first gear set 33 is disposed on one side of the differential mechanism 15 in the direction of the rotation axes of the first transmission mechanism 9, the second transmission mechanism 11, and the third transmission mechanism 13. This allows a large amount of space to be secured on the other side of the first transmission mechanism 9, the second transmission mechanism 11, and the third transmission mechanism 13 in the direction of the rotation axes, thereby improving the degree of freedom in designing the differential mechanism 15.

[0023] The motor clutch unit 35 includes an interrupting portion formed between the motor-side large-diameter gear portion 45 and the hub 47, and a sleeve 49 that interrupts the interrupting portion. The hub 47 is formed in an annular shape separately from the first rotating shaft 31, is disposed adjacent to the motor-side large-diameter gear portion 45 in the axial direction of the first rotating shaft 31, and is connected to the outer periphery of the first rotating shaft 31 so as to be rotatable integrally with the first rotating shaft 31. The interrupting portion includes a plurality of concave-convex engaging portions provided in the circumferential direction of the motor-side large-diameter gear portion 45, and a connecting portion provided in a splined shape on the outer periphery of the hub 47. The sleeve 49 is formed in an annular shape and is connected to the connecting portion of the hub 47 so as to be axially movable relative to the connecting portion and rotatable integrally with the hub 47. A fork (not shown) of an actuator (not shown) engages with the outer periphery of the sleeve 49, and the sleeve 49 is moved axially.

[0024] When the sleeve 49 of the motor clutch portion 35 moves axially toward the motor-side large-diameter gear portion 45, the sleeve 49 engages with the engaging portion of the motor-side large-diameter gear portion 45, and the interrupting portion is brought into an engaged state. When the interrupting portion is engaged, the motor-side large-diameter gear portion 45 and the first rotating shaft 31 become rotatable as a unit, and the driving force from the electric motor 3 is transmitted to the first transmission mechanism 9 via the first gear set 33.

[0025] When the sleeve 49 moves axially toward the hub 47, the motor clutch portion 35 disengages the sleeve 49 from the engaging portion of the motor-side large-diameter gear portion 45, and the disconnecting portion enters a disconnected state. When the disconnecting portion is disconnected, the motor-side large-diameter gear portion 45 and the first rotating shaft 31 become relatively rotatable, and power transmission between the electric motor 3 and the first transmission mechanism 9 is interrupted.

[0026] The first output gear portion 37 is disposed adjacent to the hub 47 in the axial direction of the first rotating shaft 31. The first output gear portion 37 is formed of a single member that is continuous with the outer periphery of the first rotating shaft 31. The first output gear portion 37 outputs the driving force of the electric motor 3, which is transmitted to the first rotating shaft 31, to the differential mechanism 15.

[0027] The park lock gear portion 39 is disposed on the opposite side of the hub 47 in the axial direction of the first rotating shaft 31, with the first output gear portion 37 sandwiched therebetween. The park lock gear portion 39 is formed in an annular shape separately from the first rotating shaft 31, and is coupled to the outer periphery of the first rotating shaft 31 so as to be rotatable integrally with the first rotating shaft 31. The park lock gear portion 39 is engageable with a lock member (not shown) of a parking lock mechanism (not shown). When engaged with the lock member, the park lock gear portion 39 prevents rotation of the first rotating shaft 31, preventing the vehicle from moving while parked.

[0028] The second transmission mechanism 11 is disposed on a power transmission path between the engine 5 and the generator 7 and the third transmission mechanism 13. The second transmission mechanism 11 includes a second gear set 53. The second gear set 53 is provided on a second rotating shaft 51 of the third transmission mechanism 13, which will be described later in this embodiment. Note that the second rotating shaft 51 of the third transmission mechanism 13, the high reduction clutch unit 55, and the low reduction clutch unit 57 will also be described below.

[0029] The second rotating shaft 51 is rotatably supported on the outer periphery on both axial sides by the casing 19 via bearings 59 and 61. The second rotating shaft 51 is disposed so that its rotation axis is parallel to the rotation axis of the generator shaft 25.

[0030] The second gear set 53 is made up of the generator gear portion 29 and a generator-side large-diameter gear portion 63 that is formed with a larger diameter than the generator gear portion 29 and meshes with the generator gear portion 29. The generator-side large-diameter gear portion 63 is formed separately from the second rotating shaft 51 and is connected to the outer periphery of the second rotating shaft 51 so as to be rotatable integrally with the second rotating shaft 51. The second gear set 53 transmits the driving force from the engine 5 from the second rotating shaft 51 to the generator shaft 25 at an increased speed.

[0031] The generator-side large-diameter gear portion 63 of the second gear set 53 is disposed on one side of the differential mechanism 15 in the direction of the rotation axes of the first transmission mechanism 9, the second transmission mechanism 11, and the third transmission mechanism 13. This allows a large amount of space to be secured on the other side of the first transmission mechanism 9, the second transmission mechanism 11, and the third transmission mechanism 13 in the direction of the rotation axes, thereby improving the degree of freedom in designing the differential mechanism 15.

[0032] The high reduction clutch portion 55 includes a high reduction gear portion 65 , a hub 67 , a discontinuous portion formed between the high reduction gear portion 65 and the hub 67 , and a sleeve 69 .

[0033] The high-reduction gear portion 65 is formed separately from the second rotating shaft 51 and is disposed on the outer periphery of the second rotating shaft 51 via a bearing so as to be rotatable relative to the second rotating shaft 51. The hub 67 is disposed adjacent to the high-reduction gear portion 65 in the axial direction of the second rotating shaft 51 and is formed as a single member that is continuous with the outer periphery of the second rotating shaft 51. The discontinuous portion consists of a plurality of concave-convex engaging portions provided in the circumferential direction of the high-reduction gear portion 65 and a connecting portion provided in a spline pattern on the outer periphery of the hub 67. The sleeve 69 is formed in an annular shape and is connected to the connecting portion of the hub 67 so as to be movable in the axial direction relative to the connecting portion of the hub 67 and to be rotatable integrally with the hub 67. A fork (not shown) of an actuator (not shown) engages with the outer periphery of the sleeve 69, and the sleeve 69 is moved axially.

[0034] The low-speed clutch portion 57 includes a low-speed gear portion 71 , a hub 67 , a discontinuous portion formed between the low-speed gear portion 71 and the hub 67 , and a sleeve 69 .

[0035] The low-reduction gear portion 71 is formed with a larger diameter than the high-reduction gear portion 65. The low-reduction gear portion 71 is formed separately from the second rotating shaft 51 and is arranged on the opposite side of the hub 67 from the high-reduction gear portion 65 in the axial direction of the second rotating shaft 51, and is arranged on the outer periphery of the second rotating shaft 51 via a bearing so as to be rotatable relative to the second rotating shaft 51. The intermittent portion consists of a plurality of concave-convex engaging portions provided in the circumferential direction of the low-reduction gear portion 71 and a connecting portion provided in a spline pattern on the outer periphery of the hub 67.

[0036] The high reduction clutch unit 55 and the low reduction clutch unit 57 are set to different reduction ratios and are engaged and disengaged depending on the running conditions of the vehicle when the engine 5 is used as the drive source.

[0037] For example, when the vehicle is traveling at low speeds, such as when starting, the sleeve 69 is moved axially toward the high reduction gear section 65, and the sleeve 69 engages with the engaging section of the high reduction gear section 65, bringing the intermittent section of the high reduction clutch section 55 into an engaged state. When the intermittent section of the high reduction clutch section 55 is engaged, the high reduction gear section 65 and the second rotating shaft 51 can rotate integrally, and the driving force from the engine 5 is transmitted to the high reduction gear section 65.

[0038] For example, when the vehicle is traveling stably at high speed, the sleeve 69 is moved axially toward the low-reduction gear unit 71, the sleeve 69 engages with the engaging portion of the low-reduction gear unit 71, and the intermittent portion of the low-reduction clutch unit 57 is brought into an engaged state. When the intermittent portion of the low-reduction clutch unit 57 is engaged, the low-reduction gear unit 71 and the second rotating shaft 51 can rotate integrally, and the driving force from the engine 5 is transmitted to the low-reduction gear unit 71.

[0039] For example, when the vehicle is traveling using only the driving force of the electric motor 3, the sleeve 69 is located in a neutral position at the hub 67. When the sleeve 69 is in the neutral position, the sleeve 69 is disengaged from the engaging portions of the high reduction gear unit 65 and the low reduction gear unit 71, and the intermittent portions of the high reduction clutch unit 55 and the low reduction clutch unit 57 are in a disengaged state. When the intermittent portions of the high reduction clutch unit 55 and the low reduction clutch unit 57 are in a disengaged state, the high reduction gear unit 65 and the low reduction gear unit 71 are rotatable relative to the second rotating shaft 51, and power transmission between the engine 5 and the differential mechanism 15 is interrupted.

[0040] The third transmission mechanism 13 described in detail in this embodiment is disposed on a power transmission path between the engine 5 (second transmission mechanism 11) and the differential mechanism 15. The third transmission mechanism 13 includes a second rotating shaft 51, a high reduction clutch unit 55, a low reduction clutch unit 57, a third rotating shaft 73, a third gear set 75, and a third output gear unit 77.

[0041] The third rotating shaft 73 is rotatably supported on both axial ends of the outer periphery by the casing 19 via bearings 79 and 81. The third rotating shaft 73 is arranged such that its rotation axis is parallel to the rotation axes of the generator shaft 25 and the second rotating shaft 51.

[0042] The third gear set 75 includes a high reduction gear set 83 and a low reduction gear set 85 .

[0043] The high-reduction gear set 83 is made up of the high-reduction gear portion 65 and a high-reduction large-diameter gear portion 87 which is formed with a larger diameter than the high-reduction gear portion 65 and which meshes with the high-reduction gear portion 65. The high-reduction large-diameter gear portion 87 is formed of a single member which is continuous with the third rotating shaft 73 on the outer periphery of the third rotating shaft 73. The high-reduction gear set 83 transmits the driving force from the engine 5 transmitted to the second transmission mechanism 11 to the third rotating shaft 73 at a speed ratio which results in high reduction.

[0044] The low-reduction gear set 85 is made up of a low-reduction gear section 71 and a low-reduction large-diameter gear section 89 that is larger in diameter than the low-reduction gear section 71 but smaller in diameter than the high-reduction large-diameter gear section 87 and that meshes with the low-reduction gear section 71. The low-reduction large-diameter gear section 89 is formed separately from the third rotating shaft 73 and is connected to the outer periphery of the third rotating shaft 73 so as to be rotatable integrally with the third rotating shaft 73. The high-reduction gear set 83 transmits the driving force from the engine 5, which has been transmitted to the second transmission mechanism 11, to the third rotating shaft 73 at a reduction ratio that results in low reduction.

[0045] Because the third gear set 75 has the high-reduction gear set 83 and the low-reduction gear set 85, the driving force transmitted from the engine 5 to the differential mechanism 15 can be selected according to the running conditions of the vehicle. The high-reduction gear set 83 and the low-reduction gear set 85 are arranged on the other side of the motor gear unit 23 and the generator gear unit 29 in the direction of the rotation axis of the first transmission mechanism 9, the second transmission mechanism 11, and the third transmission mechanism 13. Therefore, the high-reduction gear set 83 and the low-reduction gear set 85 do not overlap with the motor gear unit 23 and the generator gear unit 29 in the radial direction, which improves the degree of freedom in designing them.

[0046] The third output gear portion 77 is disposed between the high-reduction large-diameter gear portion 87 and the low-reduction large-diameter gear portion 89 in the axial direction of the third rotating shaft 73. The third output gear portion 77 is formed separately from the third rotating shaft 73, and is coupled to the outer periphery of the third rotating shaft 73 so as to be rotatable integrally with the third rotating shaft 73. The third output gear portion 77 outputs the driving force of the engine 5 transmitted to the third rotating shaft 73 to the differential mechanism 15.

[0047] The differential mechanism 15 is disposed on a power transmission path between the electric motor 3 (first transmission mechanism 9) and the engine 5 (third transmission mechanism 13) and the left and right drive wheels. The differential mechanism 15 includes a differential case 91, a pinion shaft 93, a pinion gear 95, and a pair of side gears 97, 99.

[0048] The differential case 91 is rotatably supported on the casing 19 via bearings 105, 107 at the outer peripheries of bosses 101, 103 formed on both axial sides. A flange portion 111 to which a ring gear 109 is fixed is formed on the differential case 91. The flange portion 111 is arranged so that at least a portion of its radial extent overlaps with the high-reduction large-diameter gear portion 87 and the low-reduction large-diameter gear portion 89 of the third transmission mechanism 13 when viewed from the rotational axis direction. This allows the third transmission mechanism 13 and the differential mechanism 15 to be arranged close to each other in the radial direction, thereby enabling the radial size to be reduced.

[0049] The ring gear 109 is in mesh with the first output gear portion 37 of the first transmission mechanism 9 and the third output gear portion 77 of the third transmission mechanism 13. The driving forces of the electric motor 3 and the engine 5 are input to the ring gear 109, which rotates and drives the differential case 91. The differential case 91 houses a pinion shaft 93, a pinion gear 95, and a pair of side gears 97, 99.

[0050] The pinion shafts 93 include one long pinion shaft and two short pinion shafts. Both ends of the long pinion shaft are engaged with holes formed in the differential case 91 to prevent disengagement, and the long pinion shafts are driven to rotate integrally with the differential case 91. One end of the short pinion shaft is engaged with a hole formed in the middle of the long pinion shaft, and the other end is engaged with a hole formed in the differential case 91 to prevent disengagement, and the short pinion shafts are driven to rotate integrally with the differential case 91. Pinion gears 95 are supported on the outer end sides of the pinion shafts 93, respectively.

[0051] A plurality of pinion gears 95 (four in this example) are arranged at equal intervals around the circumferential direction of the differential case 91. Each of the plurality of pinion gears 95 is supported on the end side of the pinion shaft 93 and revolves with the rotation of the differential case 91. The pinion gear 95 is rotatably supported on the pinion shaft 93 so as to be rotationally driven when a differential rotation occurs between a pair of meshed side gears 97, 99. The pinion gear 95 transmits the driving force input to the differential case 91 to the pair of side gears 97, 99.

[0052] The pair of side gears 97, 99 are housed in the differential case 91 so as to be rotatable relative to one another. The pair of side gears 97, 99 are each meshed with a pinion gear 95. On the inner circumferential sides of the pair of side gears 97, 99, spline-shaped output portions 113, 115 are provided which output the driving force transmitted to the pair of side gears 97, 99. A pair of output shafts (not shown) which are connected to left and right drive wheels so as to be rotatable together are connected to the output portions 113, 115 so as to be rotatable together.

[0053] In the differential mechanism 15, driving force from the electric motor 3 and the engine 5, which serve as driving sources, is input to a differential case 91. The driving force input to the differential case 91 is transmitted to a pair of side gears 97, 99 via a pinion gear 95. The driving force transmitted to the pair of side gears 97, 99 is distributed and output to the left and right drive wheels.

[0054] Here, the third rotating shaft 73 of the third transmission mechanism 13 is constantly rotating via the third output gear unit 77 when the differential case 91 of the differential mechanism 15 is rotating. The third rotating shaft 73 is disposed below the motor shaft 17, the generator shaft 25, the first rotating shaft 31, the second rotating shaft 51, and the rotation axis of the differential case 91. Therefore, the third rotating shaft 73 is disposed at the lowest position of all the rotating shafts disposed in parallel. By disposing the third rotating shaft 73 at the lowest position, the third gear set 75 of the third rotating shaft 73 can constantly scoop up the lubricating oil contained in the casing 19, thereby improving lubrication.

[0055] The power transmission device 1 includes a motor shaft 17 of the electric motor 3, a first transmission mechanism 9 having a first gear set 33 capable of transmitting power between the motor shaft 17, and the first transmission mechanism 9, and a second transmission mechanism 11 having a second gear set 53 capable of transmitting power between the motor shaft 17 and the engine 5. The power transmission device 1 also includes a generator shaft 25 of the generator 7 driven via the second gear set 53, and a third transmission mechanism 13 capable of transmitting power between the generator shaft 25 and the second transmission mechanism 11 via a third gear set 75. The power transmission device 1 also includes a differential mechanism 15 capable of transmitting power via the first transmission mechanism 9 and the third transmission mechanism 13. The electric motor 3 and the generator 7 are disposed on one side of the first transmission mechanism 9, the second transmission mechanism 11, and the third transmission mechanism 13 in the rotational axis direction. The motor gear portion 23 constituting the first gear set 33 and the generator shaft 25 are provided at the respective shaft ends thereof, and the generator gear portion 29 constituting the second gear set 53.

[0056] By providing the motor gear portion 23 and the generator gear portion 29 at the shaft ends of the motor shaft 17 and the generator shaft 25, it is possible to eliminate the need for a rotating shaft member having a gear portion that is connected to the motor shaft 17 and the generator shaft 25 so as to be rotatable together with them. This makes it possible to reduce the number of parts, and also to reduce the space required to arrange the rotating shaft member, resulting in a more compact design.

[0057] Therefore, in such a power transmission device 1, the number of parts can be reduced, and the size can be reduced.

[0058] At least one of the motor gear portion 23 and the generator gear portion 29 is formed from a single member that is continuous with the rotor side.

[0059] Therefore, there is no need to form the rotor and the motor gear section 23 or the generator gear section 29 separately and provide a structure that connects the rotor and the motor gear section 23 or the generator gear section 29 together, which allows the number of parts to be reduced and the structure to be simplified.

[0060] The first gear set 33 also has a motor-side large-diameter gear portion 45 that meshes with the motor gear portion 23. The second gear set 53 also has a generator-side large-diameter gear portion 63 that meshes with the generator gear portion 29. The motor-side large-diameter gear portion 45 and the generator-side large-diameter gear portion 63 are disposed on one side of the differential mechanism 15 in the direction of the rotation axes of the first transmission mechanism 9, the second transmission mechanism 11, and the third transmission mechanism 13.

[0061] Therefore, a large amount of space can be secured on the other side of the rotational axis direction of the first transmission mechanism 9, the second transmission mechanism 11, and the third transmission mechanism 13, thereby improving the design freedom of the differential mechanism 15.

[0062] The third gear set 75 also has a high-reduction gear set 83 and a low-reduction gear set 85. The high-reduction gear set 83 and the low-reduction gear set 85 are disposed on the other side of the motor gear unit 23 and the generator gear unit 29 in the direction of the rotation axis of the first transmission mechanism 9, the second transmission mechanism 11, and the third transmission mechanism 13.

[0063] Therefore, the high reduction gear set 83 and the low reduction gear set 85 do not overlap with the motor gear section 23 and the generator gear section 29 in the radial direction, which improves the degree of freedom in designing them.

[0064] Although the present embodiment has been described above, the present embodiment is not limited to this, and various modifications are possible within the scope of the gist of the present embodiment.

[0065] For example, in this embodiment, the third gear set 75 is configured by the high reduction gear set 83 and the low reduction gear set 85, but it may be configured with only a single reduction gear set.

[0066] Furthermore, although the third gear set 75 has been described as a three-shaft reduction structure consisting of the second rotating shaft 51, the third rotating shaft 73, and the rotating shaft of the differential mechanism 15, it may also be a two-shaft reduction structure formed between the second rotating shaft 51 and the rotating shaft of the differential mechanism 15. [Explanation of symbols]

[0067] 1 Power transmission device 3 Electric motor 5 Engine 7. Generator 9 First transmission mechanism 11 Second transmission mechanism 13 Third transmission mechanism 15 Differential mechanism 17 Motor shaft 23 Motor gear section 25 Generator axis 29 Generator gear section 33 1st Gear Assembly 45 Large diameter gear on motor side 53 2nd Gear Assembly 63 Generator side large diameter gear 75 3rd Gear Assembly 83 High reduction gear set 85 Low-speed gear set

Claims

1. a motor shaft of the electric motor; a first transmission mechanism having a first gear set capable of transmitting power between the first transmission mechanism and the motor shaft; a second transmission mechanism capable of transmitting power between the engine and the second transmission mechanism and having a second gear set; a generator shaft of a generator driven via the second gear set; a third transmission mechanism capable of transmitting power between the third transmission mechanism and the second transmission mechanism via a third gear set; a differential mechanism capable of transmitting power via the first transmission mechanism and the third transmission mechanism; Equipped with the electric motor and the generator are disposed on one side in the rotation axis direction of the first transmission mechanism, the second transmission mechanism, and the third transmission mechanism, A power transmission device in which a motor gear portion constituting the first gear set and a generator gear portion constituting the second gear set are provided at the respective shaft ends of the motor shaft and the generator shaft.

2. 2. The power transmission device according to claim 1, wherein at least one of the motor gear portion and the generator gear portion is formed from a single member that is continuous with the rotor side.

3. the first gear set has a motor-side large-diameter gear portion that meshes with the motor gear portion, the second gear set has a generator-side large-diameter gear portion that meshes with the generator gear portion, 3. The power transmission device according to claim 1, wherein the motor side large diameter gear portion and the generator side large diameter gear portion are arranged on one side of the differential mechanism in the direction of the rotation axes of the first transmission mechanism, the second transmission mechanism, and the third transmission mechanism.

4. the third gear set includes a high-reduction gear set and a low-reduction gear set, 3. The power transmission device according to claim 1, wherein the high-reduction gear set and the low-reduction gear set are arranged on the other side of the rotational axis direction of the first transmission mechanism, the second transmission mechanism, and the third transmission mechanism from the motor gear section and the generator gear section.

Images