Power transmission device

Abstract

To provide a power transmission device capable of switching each state of power transmission while suppressing cost increase.SOLUTION: A power transmission device 16 includes (a) a planetary gear mechanism 20 including a carrier CA to which an engine 12 is connected, a sun gear S to which a first electric motor MG1 is connected, and a ring gear R, and (b) an engagement mechanism 30 having a single actuator 70 capable of selecting any one of a first state in which a relay gear 38 to which a second electric motor MG2 and a pair of driving wheels 14 are connected is non-connected to any of a ring gear R and a case 18, a second state in which the relay gear 38 is connected to the ring gear R and the case 18, and a third state in which the relay gear 38 is connected to both the ring gear R and the case 18.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a power transmission device including a planetary gear mechanism including rotating elements to which an engine and a first electric motor are respectively connected, and a connecting gear to which a second electric motor and a pair of drive wheels are connected. [Background technology]

[0002] Power transmission devices are known that include a planetary gear mechanism including rotating elements to which an engine and a first electric motor are respectively connected, and a connecting gear to which a second electric motor and a pair of drive wheels are connected. For example, the power transmission device described in Patent Document 1 is such a device. The power transmission device described in Patent Document 1 is provided with a clutch that connects and disconnects a ring gear of the planetary gear mechanism and the connecting gear, and a parking lock mechanism that allows or restricts rotation of the connecting gear. Therefore, this power transmission device can be selected from one of a first state in which the connecting gear is disconnected from the ring gear and the parking lock mechanism is inactive, a second state in which the connecting gear is connected to the ring gear and the parking lock mechanism is inactive, and a third state in which the connecting gear is connected to the ring gear and the parking lock mechanism is inactive. The first state, second state, and third state are respective states of power transmission in the power transmission device. As a result, in the first state, the power transmission device enables the vehicle to run as a BEV (Battery Electric Vehicle) using only the second electric motor as a power source for running, in the second state, it enables the vehicle to run as an HEV (Hybrid Electric Vehicle) using the engine and the second electric motor as power sources for running, and in the third state, it makes it possible to restrict the rotation of a pair of drive wheels. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-129330 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, the power transmission device described in Patent Document 1 is provided with separate actuators: one for controlling the clutch that connects and disconnects the ring gear and connecting gear of the planetary gear mechanism, and the other for switching the parking lock mechanism between an activated state and a deactivated state. Because independent actuators are provided for each, there is a risk of increased costs for switching the power transmission states in the power transmission device.

[0005] The present invention has been made in light of the above circumstances, and an object of the present invention is to provide a power transmission device that can switch between various power transmission states while suppressing increases in cost. [Means for solving the problem]

[0006] The gist of the present invention is a power transmission device comprising: (a) a planetary gear mechanism including a first rotating element connected to an engine, a second rotating element connected to a first electric motor, and a third rotating element; (b) a connecting gear connected to a second electric motor and a pair of drive wheels; and (c) an engagement mechanism having a single actuator that can select one of a first state in which the connecting gear is not connected to either the third rotating element or a non-rotating member; a second state in which the connecting gear is connected to the third rotating element and not connected to the non-rotating member; and a third state in which the connecting gear is connected to both the third rotating element and the non-rotating member. [Effects of the Invention]

[0007] The power transmission device of the present invention includes: (a) a planetary gear mechanism including a first rotating element connected to an engine, a second rotating element connected to a first electric motor, and a third rotating element; (b) a connecting gear connected to a second electric motor and a pair of drive wheels; and (c) an engagement mechanism having a single actuator capable of selecting one of a first state in which the connecting gear is disconnected from both the third rotating element and a non-rotating member; a second state in which the connecting gear is connected to the third rotating element and is disconnected from the non-rotating member; and a third state in which the connecting gear is connected to both the third rotating element and the non-rotating member. Thus, the power transmission in the power transmission device can be selected between the first state, the second state, and the third state by the single independent actuator. Therefore, the power transmission device can switch between each power transmission state while suppressing an increase in cost. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram illustrating a schematic configuration of a vehicle equipped with a power transmission device according to a first embodiment. [Figure 2] 4A and 4B are diagrams illustrating states of an engagement mechanism that realizes a first state of the power transmission device. [Figure 3] 10A and 10B are diagrams illustrating the state of an engagement mechanism that realizes a second state of the power transmission device. [Figure 4] 10A and 10B are diagrams illustrating the state of an engagement mechanism that realizes a third state of the power transmission device. [Figure 5] FIG. 10 is a diagram illustrating a schematic configuration of a vehicle equipped with a power transmission device according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, each embodiment of the present invention will be described in detail with reference to the drawings. Note that in each embodiment, the drawings are appropriately simplified or modified, and the dimensional ratios and shapes of each part are not necessarily drawn accurately. [Example]

[0010] FIG. 1 is a diagram illustrating a schematic configuration of a vehicle 10 equipped with a power transmission device 16 according to a first embodiment.

[0011] The vehicle 10 is a hybrid vehicle equipped with an engine 12, a first electric motor MG1, and a second electric motor MG2, which function as power sources for traveling. The engine 12 is a well-known internal combustion engine. The first electric motor MG1 and the second electric motor MG2 are, for example, rotating electric machines having a prime mover function and a generator function, and are so-called motor generators. Note that the first electric motor MG1 and the second electric motor MG2 may be rotating electric machines without a generator function as long as they have a prime mover function. The vehicle 10 is equipped with a power transmission device 16 between these power sources and a pair of drive wheels 14.

[0012] The power transmission device 16 includes, in order from the engine 12 side, a crankshaft 24, a planetary gear mechanism 20, a mesh clutch 32, a relay gear 38, a large-diameter gear 42, a countershaft 40, a small-diameter gear 44, a differential gear 22, and a pair of axles 50 in a power transmission path between the engine 12 and a pair of drive wheels 14. The engine 12, the crankshaft 24, the relay gear 38, the large-diameter gear 42, the countershaft 40, the small-diameter gear 44, the differential gear 22, the pair of axles 50, and the pair of drive wheels 14 each have a well-known configuration. The differential ring gear 22r is a differential ring gear of the differential gear 22. The first axis C1 is the rotational center line of the engine 12, the crankshaft 24, the relay gear 38, and the first electric motor MG1. The second axis C2 is the rotational center line of the second electric motor MG2. The second axis C2 is parallel to, for example, the first axis C1. The third axis C3 is the rotation center line of the countershaft 40. The third axis C3 is parallel to the first axis C1 and the second axis C2. The large diameter gear 42 and the small diameter gear 44 are fixed to the countershaft 40 so as not to rotate relative to each other.

[0013] The power transmission device 16 includes, in a power transmission path between the second electric motor MG2 and the pair of drive wheels 14, an output gear 46, a large-diameter gear 42, a countershaft 40, a small-diameter gear 44, a differential gear 22, and a pair of axles 50, in that order from the second electric motor MG2 side. The output gear 46 is a gear that outputs the power of the second electric motor MG2 and is fixed to the rotor shaft MG2r of the second electric motor MG2 so as not to rotate relative to it. The large-diameter gear 42 meshes with both the relay gear 38 and the output gear 46. The relay gear 38 is connected to the second electric motor MG2 via the large-diameter gear 42 and the output gear 46, and is also connected to the pair of drive wheels 14 via the large-diameter gear 42, the countershaft 40, the small-diameter gear 44, the differential gear 22, and the pair of axles 50. In other words, the relay gear 38 is connected to the second electric motor MG2 and the pair of drive wheels 14. The relay gear 38 corresponds to the “connecting gear” in the present invention. The vehicle 10 also includes an actuator 70, an inverter 60, a battery 62, and an electronic control device 90. The dog clutch 32 and the actuator 70 constitute an engagement mechanism 30.

[0014] The planetary gear mechanism 20 is, for example, a single-pinion planetary gear device, and includes, as rotating elements, a sun gear S, a pinion P, a carrier CA that supports the pinion P so that it can rotate and revolve, and a ring gear R that meshes with the sun gear S via the pinion P. A rotor shaft MG1r of a first electric motor MG1 is connected to the sun gear S, and the carrier CA is connected to the engine 12 via a crankshaft 24. The sun gear S, carrier CA, and ring gear R in the planetary gear mechanism 20 are each rotatable about a first axis C1. The planetary gear mechanism 20 functions, for example, as a power split mechanism that mechanically splits power input from the engine 12 to the first electric motor MG1 and the ring gear R. The first electric motor MG1 generates electricity using the power of the engine 12 split by the first electric motor MG1. The power Wmg1 generated by the first electric motor MG1 is charged to the battery 62, and all or a part of the generated power Wmg1, or power from the battery 62 in addition to the generated power Wmg1, is used to rotate the second electric motor MG2. The planetary gear mechanism 20 functions as an electric continuously variable transmission in which the differential state of the planetary gear mechanism 20 is controlled by controlling the operating state of the first electric motor MG1. The carrier CA, sun gear S, and ring gear R correspond to the "first rotating element," "second rotating element," and "third rotating element" in this invention, respectively. Meshing teeth Ro are provided on the outer periphery of a rotating member having the ring gear R provided on its inner periphery. The meshing teeth Ro are positioned so as to be meshable with meshing teeth 36b (described later). The meshing teeth Ro are meshing teeth that transmit the power of the engine 12, which is divided into the ring gear R, to the relay gear 38 via the meshing teeth 36b, and correspond to the "power transmission meshing teeth" in this invention.

[0015] The mesh clutch 32 can connect and disconnect power transmission between the relay gear 38 and the ring gear R, and can connect and disconnect power transmission between the relay gear 38 and meshing teeth 18fx1 (described later). The mesh clutch 32 has a first sleeve 34 and a second sleeve 36 that are rotatable about a first axis C1. The first axis C1 corresponds to the "axis" in this invention.

[0016] The first sleeve 34 has a smaller diameter than the second sleeve 36 and is immovable in the direction of the first axis C1. The first sleeve 34 is coupled to the relay gear 38 so as to be immovable relative to the relay gear 38. The first sleeve 34 is supported by the case 18, for example, via a bearing (not shown). Interlocking teeth 34a are provided on the outer periphery of the first sleeve 34. The interlocking teeth 34a are provided at positions where they can mesh with interlocking teeth 36a, which will be described later. Interlocking teeth 18fx1 are provided on the case 18, which is a non-rotating member. The interlocking teeth 18fx1 are provided at positions where they can mesh with interlocking teeth 36c, which will be described later. The interlocking teeth 34a correspond to the "first interlocking teeth" in this invention. The case 18 corresponds to the "non-rotating member" in this invention, and the interlocking teeth 18fx1 correspond to the "fixing interlocking teeth" in this invention.

[0017] The second sleeve 36 is movable in the direction of the first axis C1. From one side to the other in the direction of the first axis C1, meshing teeth 36a and meshing teeth 36b are provided on the inner periphery of the second sleeve 36, and a groove 36d and meshing teeth 36c are provided on the outer periphery of the second sleeve 36. The groove 36d is formed as a groove extending in the circumferential direction. The meshing teeth 36a are always in mesh with the meshing teeth 34a of the first sleeve 34, and can mesh with the meshing teeth Ro so as to be non-rotatable relative to each other. That is, the meshing teeth 34a can be brought into mesh with and disengaged from the meshing teeth Ro. The meshing teeth 36b can be brought into mesh with the meshing teeth Ro so as to be non-rotatable relative to each other. That is, the meshing teeth 36b can be brought into mesh with and disengaged from the meshing teeth Ro. The meshing teeth 36c can mesh with the meshing teeth 18fx1 so as to be unable to rotate relative to each other. That is, the meshing teeth 36c can be brought into a meshed state with the meshing teeth 18fx1 and brought into a non-meshed state. The meshing teeth 36a, 36b, and 36c correspond to the "second meshing teeth" in this invention.

[0018] The mesh clutch 32 can be selected from a first state, a second state, and a third state. Here, the "first state" refers to a state in which the relay gear 38 is not connected to either the ring gear R or the case 18. The "second state" refers to a state in which the relay gear 38 is connected to the ring gear R and not connected to the case 18. The "third state" refers to a state in which the relay gear 38 is connected to both the ring gear R and the case 18. The first state, the second state, and the third state correspond to the respective power transmission states of the power transmission device 16. The first state, the second state, and the third state of the mesh clutch 32 are controlled by an actuator 70. The configuration and control of the actuator 70 will be described later.

[0019] The inverter 60 is a well-known power supply circuit that is provided between the first electric motor MG1 and the second electric motor MG2 and the battery 62, and that converts direct current to alternating current and vice versa under the control of the electronic control device 90. The output torque of the first electric motor MG1 and the output torque of the second electric motor MG2 are each controlled by the inverter 60, which is controlled by the electronic control device 90.

[0020] The electronic control device 90 is a controller including a control device that controls each part in the vehicle 10, and is configured to include, for example, a so-called microcomputer in which a CPU processes signals according to a program pre-stored in a ROM while utilizing the temporary storage function of a RAM. The electronic control device 90 outputs various command signals (for example, an engine control signal Se for controlling the engine 12, an electric motor control signal Smg for controlling the first electric motor MG1 and the second electric motor MG2, a step motor control signal Ssm for controlling the rotational position of the step motor 72, etc.) to each device provided in the vehicle 10 (for example, the engine 12, the inverter 60, a step motor 72 described later, etc.).

[0021] When the dog clutch 32 is switched to the first state, the relay gear 38 is disconnected from both the ring gear R and the case 18, and the power transmission device 16 can achieve BEV driving using only the second electric motor MG2 as a driving power source. In this case, the power output from the second electric motor MG2 is transmitted to the pair of drive wheels 14 via the rotor shaft MG2r, the output gear 46, the large diameter gear 42, the counter shaft 40, the small diameter gear 44, the differential gear 22, and the pair of axles 50 in this order.

[0022] When the mesh clutch 32 is switched to the second state, the relay gear 38 is connected to the ring gear R and disconnected from the case 18, allowing the power transmission device 16 to achieve HEV driving using the engine 12 and the second electric motor MG2 as a driving power source. In this case, for example, power output from the engine 12 is input to the planetary gear mechanism 20, which functions as a power split mechanism, and the power of the engine 12 divided by the ring gear R is transmitted to the pair of drive wheels 14 via the mesh clutch 32, the relay gear 38, the large-diameter gear 42, the countershaft 40, the small-diameter gear 44, the differential gear 22, and a pair of axles 50 in that order. In addition, power output from the second electric motor MG2 is transmitted to the pair of drive wheels 14 via the rotor shaft MG2r, the output gear 46, the large-diameter gear 42, the countershaft 40, the small-diameter gear 44, the differential gear 22, and a pair of axles 50 in that order.

[0023] When the mesh clutch 32 is switched to the third state, the relay gear 38 is connected to both the ring gear R and the case 18, and therefore the power transmission device 16 can achieve an activated state of the parking lock mechanism in which rotation of the relay gear 38 and the ring gear R is restricted. In this case, the relay gears 38 connected to the ring gear R and the pair of drive wheels 14 are both made unable to rotate.

[0024] Now, the specific configuration and control of the actuator 70 will be described.

[0025] Fig. 2 is a diagram illustrating the state of the engagement mechanism 30 that realizes a first state of the power transmission device 16. Fig. 3 is a diagram illustrating the state of the engagement mechanism 30 that realizes a second state of the power transmission device 16. Fig. 4 is a diagram illustrating the state of the engagement mechanism 30 that realizes a third state of the power transmission device 16. Note that the planetary gear mechanism 20, the dog clutch 32, and the relay gear 38 are each configured approximately symmetrically with respect to the first axis C1, and the lower half of the first axis C1 is omitted in Figs. 2 to 4.

[0026] The actuator 70 includes a shift fork 76 fitted to the second sleeve 36, a holding member 74 that holds the shift fork 76, and a step motor 72 (see FIG. 1).

[0027] The holding member 74 is, for example, a cylindrical member extending along a fourth axis C4. The fourth axis C4 is parallel to the first axis C1. The holding member 74 is disposed so as to extend in the direction of the fourth axis C4. In the direction of the fourth axis C4, one end of the holding member 74 is inserted into a guide hole 18gd1 with a bottom provided in the case 18, and the other end of the holding member 74 is inserted into a guide hole 18gd2 with a bottom provided in the case 18. The guide holes 18gd1 and 18gd2 are holes of a size that allow the one end and the other end of the holding member 74 to be inserted therethrough, respectively, and support the holding member 74. For example, the case 18 is prepared as separate members, namely, a first case member provided with the guide hole 18gd1 and a second case member provided with the guide hole 18gd2. Then, with one end and the other end of the holding member 74 inserted into the guide holes 18gd1 and 18gd2, respectively, the first case member and the second case member are fastened together with fasteners such as bolts.

[0028] A wave-shaped portion 74w is provided on the outer periphery of the holding member 74 in a portion that is not inserted into the guide holes 18gd1 and 18gd2.

[0029] The shift fork 76 is held at the fastening portion 70j by a holding member 74 so as to be immovable relative to the second sleeve 36. A fitting portion 76a is provided at the tip of the shift fork 76. The fitting portion 76a fits into a groove 36d provided in the second sleeve 36.

[0030] The step motor 72 moves the retaining member 74 in the direction of the fourth axis C4 in accordance with the travel mode selected by the electronic control device 90 and the selection of P range (parking range) in a shift operation device (not shown). The step motor 72 corresponds to the "drive device" in this invention. A drive gear 72g is connected to the output shaft of the step motor 72. The drive gear 72g meshes with the waveform-shaped portion 74w. When the step motor 72 is rotated, the retaining member 74 and the shift fork 76 are moved in the direction of the fourth axis C4. This moves the second sleeve 36 in the direction of the first axis C1.

[0031] In Fig. 2, when the drive gear 72g rotates in the direction of the solid arrow shown in Fig. 2, the power transmission device 16 switches to the state shown in Fig. 3. In Fig. 3, when the drive gear 72g rotates in the direction of the solid arrow shown in Fig. 3, the power transmission device 16 switches to the state shown in Fig. 4.

[0032] In Fig. 4, when the drive gear 72g rotates in the direction of the dashed arrow shown in Fig. 4, the power transmission device 16 is switched to the state shown in Fig. 3. In Fig. 3, when the drive gear 72g rotates in the direction of the dashed arrow shown in Fig. 3, the power transmission device 16 is switched to the state shown in Fig. 2.

[0033] In Fig. 2, when the drive gear 72g attempts to rotate in the direction of the dashed arrow shown in Fig. 2, the movement of the holding member 74 in the direction of the fourth axis C4 is blocked by the bottom of the guide hole 18gd2. In Fig. 4, when the drive gear 72g attempts to rotate in the direction of the solid arrow shown in Fig. 4, the movement of the holding member 74 in the direction of the fourth axis C4 is blocked by the bottom of the guide hole 18gd1.

[0034] The outer periphery of the other end of the holding member 74 is provided with an uneven portion 74o, the outer diameter of which periodically changes in a wave-like pattern. The uneven portion 74o is provided with a plurality of recesses P1 (see FIG. 2), P2 (see FIG. 3), and P3 (see FIG. 4). The case 18 is provided with a through hole 82 that communicates with the guide hole 18gd2. A ball 84 is inserted into the through hole 82, and a lid 88 is fitted into the through hole 82. A spring 86 is inserted between the ball 84 and the lid 88 to bias the ball 84 toward the uneven portion 74o of the holding member 74. In this manner, the ball 84 is pressed so as to fall into one of the plurality of recesses P1, P2, or P3 of the holding member 74. The uneven portion 74o provided on the outer periphery of the other end of the holding member 74, the ball 84 pressed against the uneven portion 74o of the holding member 74, and the like constitute a positioning mechanism 80. In this manner, the actuator 70 has the positioning mechanism 80.

[0035] The retaining member 74 has a recess P1 in the direction in which the ball 84 is biased and pressed in the state shown in Figure 2, a recess P2 in the direction in which the ball 84 is biased and pressed in the state shown in Figure 3, and a recess P3 in the direction in which the ball 84 is biased and pressed in the state shown in Figure 4.

[0036] 2, the meshing teeth 36a are in mesh with the meshing teeth 34a, the meshing teeth 36a and 36b are both out of mesh with the meshing teeth Ro, and the meshing teeth 36c are out of mesh with the meshing teeth 18fx1. In this state, the meshing teeth 34a of the first sleeve 34 to which the relay gear 38 is connected are in mesh with the meshing teeth 36a of the second sleeve 36, but the meshing teeth 36a and 36b of the second sleeve 36 are both out of mesh with the meshing teeth Ro, so the relay gear 38 connected to the first sleeve 34 is not connected to the ring gear R. In addition, the meshing teeth 36c of the second sleeve 36 are not in mesh with the meshing teeth 18fx1, so the relay gear 38 connected to the first sleeve 34 is not connected to the case 18. That is, in the state shown in FIG. 2, the first state in which the relay gear 38 is not connected to either the ring gear R or the case 18 is realized.

[0037] 3, the meshing teeth 36a are in mesh with the meshing teeth 34a, the meshing teeth 36b are in mesh with the meshing teeth Ro, and the meshing teeth 36c are in a disengagement state with the meshing teeth 18fx1. In this state, the meshing teeth 34a of the first sleeve 34 to which the relay gear 38 is connected are in mesh with the meshing teeth 36a of the second sleeve 36, and the meshing teeth 36b of the second sleeve 36 are in mesh with the meshing teeth Ro, so the relay gear 38 connected to the first sleeve 34 is in a connected state with the ring gear R. In addition, the meshing teeth 36c of the second sleeve 36 are in a disengagement state with the meshing teeth 18fx1, so the relay gear 38 connected to the first sleeve 34 is in a disconnected state from the case 18. That is, in the state shown in FIG. 3, the relay gear 38 is connected to the ring gear R and is not connected to the case 18, which is the second state.

[0038] 4, the meshing teeth 36a are in mesh with the meshing teeth 34a, the meshing teeth 36a and 36b are both in mesh with the meshing teeth Ro, and the meshing teeth 36c are in mesh with the meshing teeth 18fx1. In this state, the meshing teeth 34a of the first sleeve 34 to which the relay gear 38 is connected are in mesh with the meshing teeth 36a of the second sleeve 36, and the meshing teeth 36a and 36b of the second sleeve 36 are both in mesh with the meshing teeth Ro, so the relay gear 38 connected to the first sleeve 34 is in a connected state with the ring gear R. In addition, the meshing teeth 36c of the second sleeve 36 are not in mesh with the meshing teeth 18fx1, so the relay gear 38 connected to the first sleeve 34 is in a connected state with the case 18. That is, in the state shown in FIG. 4, the relay gear 38 is connected to both the ring gear R and the case 18, which is the third state.

[0039] The actuator 70 is configured to move the second sleeve 36 in the direction of the first axis C1 using the shift fork 76 so that the meshing teeth 36a, 36b, and 36c of the second sleeve 36 are brought into meshing or disengagement with the meshing teeth 34a, 34b, and 34c, respectively, depending on the first, second, or third state. The actuator 70 is an independent, single actuator. "Independent, single" means that it is controllable independently of other actuators and is one.

[0040] When the positioning mechanism 80 biases the balls 84 and presses them into the recesses P1, P2, and P3, respectively, the holding member 74 is biased in the direction of the fourth axis C4 to positions where it can be switched to the first state, the second state, and the third state, respectively. This biases the second sleeve 36 in the direction of the first axis C1 to positions where it can be switched to the first state, the second state, and the third state, respectively. When the rotation of the drive gear 72g connected to the output shaft of the step motor 72 switches the first state, the second state, and the third state from one to another, the switching is facilitated not only by the rotation of the drive gear 72g but also by the biasing force of the positioning mechanism 80. Furthermore, the positioning mechanism 80 can maintain the position of the second sleeve 36 in the direction of the first axis C1 even when the step motor 72 is not driven.

[0041] The power transmission device 16 of this embodiment includes: (a) a planetary gear mechanism 20 including a carrier CA to which the engine 12 is connected, a sun gear S to which the first electric motor MG1 is connected, and a ring gear R; (b) a relay gear 38 to which the second electric motor MG2 and a pair of drive wheels 14 are connected; and (c) an engagement mechanism 30 having a single actuator 70 that can select one of a first state in which the relay gear 38 is disconnected from both the ring gear R and the case 18; a second state in which the relay gear 38 is connected to the ring gear R and disconnected from the case 18; and a third state in which the relay gear 38 is connected to both the ring gear R and the case 18. In this way, the single independent actuator 70 allows power transmission in the power transmission device 16 to be selected between the first state, the second state, and the third state. Therefore, the power transmission device 16 can switch between each power transmission state while suppressing an increase in cost.

[0042] According to the power transmission device 16 of this embodiment, (a) the engagement mechanism 30 has a first sleeve 34 that is rotatable about the first axis C1 but is immovable in the first axis C1 direction, and a second sleeve 36 that is rotatable about the first axis C1 but is movable in the first axis C1 direction, (b) the ring gear R is provided with meshing teeth Ro, (c) the case 18 is provided with meshing teeth 18fx1, (d) the first sleeve 34 is provided with meshing teeth 34a and is connected to a relay gear 38, (e) the second sleeve 36 is provided with meshing teeth 36a, 36b, and 36c that are meshable with the meshing teeth Ro, the meshing teeth 18fx1, and the meshing teeth 34a but are immovable relative to each other, and (f) in the first state In the first state, the actuator 70 moves the second sleeve 36 in the direction of the first axis C1 so that the meshing teeth 36a are in mesh with the meshing teeth 34a, the meshing teeth 36b are in a non-mesh state with the meshing teeth Ro, and the meshing teeth 36c are in a non-mesh state with the meshing teeth 18fx1; in the second state, the meshing teeth 36a are in mesh with the meshing teeth 34a, the meshing teeth 36b are in mesh with the meshing teeth Ro, and the meshing teeth 36c are in a non-mesh state with the meshing teeth 18fx1; and in the third state, the meshing teeth 36a are in mesh with the meshing teeth 34a, both the meshing teeth 36a and the meshing teeth 36b are in mesh with the meshing teeth Ro, and the meshing teeth 36c are in mesh with the meshing teeth 18fx1. Thus, the power transmission device 16 includes the dog clutch 32 in which the above conditions (a) to (e) are satisfied, and an independent single actuator 70 configured to control the state of the dog clutch 32 as described in the above condition (f) corresponding to each of the first state, second state, and third state. This allows the actuator 70 to select any one of the first state, second state, and third state for power transmission in the power transmission device 16.

[0043] According to the power transmission device 16 of this embodiment, the actuator 70 includes a shift fork 76 fitted in the second sleeve 36, a retaining member 74 that holds the shift fork 76, and a step motor 72 that moves the retaining member 74 in the direction of the fourth axis C4, which is the same direction as the direction of the first axis C1. In this way, the shift fork 76, the retaining member 74, and the step motor 72 can configure an independent single actuator 70 that can select one of a first state, a second state, and a third state for power transmission in the power transmission device 16.

[0044] According to the power transmission device 16 of this embodiment, the actuator 70 has a positioning mechanism 80 that can maintain the position of the second sleeve 36 in the direction of the first axis C1 depending on the first state, second state, or third state. Compared to a case where the positioning mechanism 80 is not provided, when the positioning mechanism 80 is provided, the position of the second sleeve 36 in the direction of the first axis C1 can be maintained even when the step motor 72 is in a non-driven state. As a result, power consumption can be reduced by maintaining the power transmission state of the power transmission device 16 in any of the first state, second state, or third state while keeping the step motor 72 in a non-driven state. [Example]

[0045] FIG. 5 is a diagram illustrating a schematic configuration of a vehicle 10 equipped with a power transmission device 116 according to a second embodiment. The vehicle 10 according to this embodiment differs in that the power transmission device 116 is provided instead of the power transmission device 16 in the first embodiment. The power transmission device 116 according to this embodiment has substantially the same configuration as the power transmission device 16 in the first embodiment, but differs in that a meshing tooth 36e is provided instead of the meshing teeth 36a, 36b, and 36c, and a meshing tooth 18fx2 is provided instead of the meshing tooth 18fx1. Therefore, the following description will focus on the differences from the first embodiment, and descriptions of substantially common parts will be omitted as appropriate. Note that FIG. 5 illustrates a case where power transmission in the power transmission device 116 is in the second state.

[0046] The case 18, which is a non-rotating member, is provided with meshing teeth 18fx2. The case 18 corresponds to the "non-rotating member" in this invention, and the meshing teeth 18fx2 correspond to the "fixing meshing teeth" in this invention.

[0047] The second sleeve 36 has meshing teeth 36e formed on its inner periphery, and grooves 36d formed on its outer periphery. The meshing teeth 36e are positioned so as to be able to mesh with the meshing teeth 18fx2 and the meshing teeth Ro. The meshing teeth 36e are constantly meshed with the meshing teeth 34a of the first sleeve 34, and can mesh with the meshing teeth Ro while not allowing relative rotation. That is, the meshing teeth 36e can be brought into mesh with and out of mesh with the meshing teeth Ro. The meshing teeth 36e can also be meshed with the meshing teeth 18fx2 while not allowing relative rotation. That is, the meshing teeth 36e can be brought into mesh with and out of mesh with the meshing teeth 18fx2. The meshing teeth 36e correspond to the "second meshing teeth" in this invention.

[0048] In the first state, the meshing teeth 36e are meshed only with the meshing teeth 34a. That is, in the first state, the relay gear 38 is not connected to either the ring gear R or the case 18. In the second state, the meshing teeth 36e are meshed with both the meshing teeth 34a and the meshing teeth Ro, and are not meshed with the meshing teeth 18fx2. That is, in the second state, the relay gear 38 is connected to the ring gear R, and is not connected to the case 18. In the third state, the meshing teeth 36e are meshed with all of the meshing teeth 34a, the meshing teeth Ro, and the meshing teeth 18fx2. That is, the relay gear 38 is connected to both the ring gear R and the case 18.

[0049] As in the above-described first embodiment, the actuator 70 is configured to use the shift fork 76 to move the second sleeve 36 in the direction of the first axis C1 so that the meshing teeth 36e of the second sleeve 36 are meshed or disengaged with the meshing teeth 34a, the meshing teeth Ro, and the meshing teeth 18fx2 depending on the first, second, or third state.

[0050] According to the power transmission device 116 of this embodiment, the same effects as those of the first embodiment described above are achieved.

[0051] The above-described embodiments of the present invention are merely illustrative, and the present invention can be embodied in various forms with various modifications and improvements based on the knowledge of those skilled in the art without departing from the spirit of the present invention.

[0052] In the first and second embodiments described above, the planetary gear mechanism 20 is a single-pinion planetary gear device, the engine 12 is connected to the carrier CA, and the first electric motor MG1 is connected to the sun gear S. However, the present invention is not limited to this. For example, the present invention is also applicable to an embodiment in which the planetary gear mechanism 20 is a double-pinion planetary gear device. For example, the present invention is also applicable to an embodiment in which the engine 12 is connected to the ring gear R, and the first electric motor MG1 is connected to the sun gear S.

[0053] In the above-described first embodiment, the first sleeve 34 has a smaller diameter than the second sleeve 36, but the present invention is not limited to this. For example, the first sleeve 34 may have a larger diameter than the second sleeve 36. In this embodiment, the first sleeve 34 has meshing teeth 34a on its inner periphery, and the second sleeve 36 has meshing teeth 36a on its outer periphery.

[0054] Although the first embodiment described above does not include a synchronization mechanism that synchronizes the rotation of the meshing teeth 36b with the rotation of the meshing teeth Ro, and the second embodiment described above does not include a synchronization mechanism that synchronizes the rotation of the meshing teeth 36e with the rotation of the meshing teeth Ro, the present invention is not limited to these embodiments. For example, the present invention is also applicable to an embodiment in which a known synchromesh mechanism that synchronizes the rotation of the meshing teeth 36b with the rotation of the meshing teeth Ro is included in the first embodiment. The present invention is also applicable to an embodiment in which a known synchromesh mechanism that synchronizes the rotation of the meshing teeth 36e with the rotation of the meshing teeth Ro is included in the second embodiment. [Explanation of symbols]

[0055] 12: engine, 14: pair of drive wheels, 16, 116: power transmission device, 18: case (non-rotating member), 18fx1, 18fx2: meshing teeth (fixing meshing teeth), 20: planetary gear mechanism, 30: engagement mechanism, 34: first sleeve, 34a: meshing teeth (first meshing teeth), 36: second sleeve, 36a-36c, 36e: meshing teeth (second meshing teeth), 38: relay gear (connecting gear), 70: actuator, 72: step motor (drive device), 74: holding member, 76: shift fork, 80: positioning mechanism, C1: first axis (axis), CA: carrier (first rotating element), MG1: first electric motor, MG2: second electric motor, R: ring gear (third rotating element), Ro: meshing teeth (power transmission meshing teeth), S: sun gear (second rotating element)

Claims

1. a planetary gear mechanism including a first rotating element connected to the engine, a second rotating element connected to the first electric motor, and a third rotating element; a connecting gear to which the second electric motor and the pair of drive wheels are connected; an engagement mechanism having a single actuator capable of selecting one of a first state in which the connecting gear is not connected to either the third rotating element or the non-rotating member, a second state in which the connecting gear is connected to the third rotating element and not connected to the non-rotating member, and a third state in which the connecting gear is connected to both the third rotating element and the non-rotating member; A power transmission device comprising:

2. the engagement mechanism includes a first sleeve rotatable about an axis of the third rotating element but not movable in the axial direction, and a second sleeve rotatable about the axis and movable in the axial direction, The third rotating element is provided with power transmission meshing teeth, The non-rotating member is provided with locking meshing teeth, The first sleeve is provided with first meshing teeth and is connected to the connecting gear, the second sleeve is provided with second meshing teeth that can mesh with the power transmission meshing teeth, the fixing meshing teeth, and the first meshing teeth so as not to rotate relative to each other; The actuator is configured to move the second sleeve in the axial direction so that, in the first state, the second meshing teeth are brought into mesh with the first meshing teeth and are not meshed with either the power transmission meshing teeth or the fixing meshing teeth; so that, in the second state, the second meshing teeth are brought into mesh with both the first meshing teeth and the power transmission meshing teeth and are not meshed with the fixing meshing teeth; and so that, in the third state, the second meshing teeth are brought into mesh with either the first meshing teeth, the power transmission meshing teeth, and the fixing meshing teeth.

2. The power transmission device according to claim 1.

3. The actuator includes a shift fork fitted in the second sleeve, a holding member that holds the shift fork, and a drive device that moves the holding member in the axial direction.

3. The power transmission device according to claim 2.

4. The actuator has a positioning mechanism that can hold the position of the second sleeve in the axial direction depending on the first state, the second state, and the third state.

4. The power transmission device according to claim 2 or 3.

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