Speed change device

Abstract

The present invention reduces the time during which both rotational torque and thrust of an actuator act on a bearing. The transmission device includes a first planetary gear mechanism, a second planetary gear mechanism, a first coupling mechanism, a second coupling mechanism, and a third coupling mechanism, and the third coupling mechanism includes: a pressing portion that couples a coupling element; a spring that urges the pressing part in the coupling direction; an actuator that generates a thrust force in a release direction and releases the coupling element by displacing the pressing portion in the release direction by the thrust force; a bearing which, when releasing the coupling element, bears the load of the spring compressed by the thrust, couples the first coupling mechanism and releases the second coupling mechanism and the third coupling mechanism in the first transmission stage, and couples the second coupling mechanism and releases the first coupling mechanism and the third coupling mechanism in the second transmission stage, the first gear stage is selected during emergency travel in which a larger driving force than during normal start-up is required.

Description

Technical Field

[0001] This invention relates to a speed change device. Background Technology

[0002] Patent Document 1 discloses a speed change device. The speed change device changes the speed of rotation input from a motor via an input shaft and outputs the rotation via a differential mechanism on the output shaft. The speed change device includes multiple planetary gear mechanisms and multiple connecting elements. By switching the connection and release of the multiple connecting elements, the speed change device can switch the transmission path of rotation in the multiple planetary gear mechanisms, thereby achieving multiple speed levels.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Chinese Patent Application Publication No. 107178585 Summary of the Invention

[0006] The technical problem that the invention aims to solve

[0007] For example, a normally closed clutch can be used as the connecting element. In a normally closed clutch, the piston pressing the friction plate is forced in the engagement direction by a spring. When releasing the clutch, the piston is displaced in the release direction by a thrust in the release direction applied by an actuator.

[0008] The rotating element of the clutch is supported rotatably on a stationary element, for example via a bearing. The bearing receives rotational torque from the rotating element and acts as the actuator thrust when the clutch is released.

[0009] When the rotational torque and the actuator thrust act on the bearing for a longer period of time, the friction increases, which may affect the durability of the bearing.

[0010] In transmission systems, it is required to reduce the time that both the rotational torque and the actuator thrust act on the bearing.

[0011] Technical solutions for solving technical problems

[0012] A transmission device according to one aspect of the present invention comprises: a first planetary gear mechanism having a first sun gear connected to an input shaft, a first planet carrier connected to an output shaft, and a first ring gear; a second planetary gear mechanism having a second sun gear connected to the input shaft, a second planet carrier connected to the first ring gear, and a second ring gear; a first coupling mechanism capable of coupling the first ring gear and the second planet carrier to a first fixed element; a second coupling mechanism capable of coupling the second ring gear to a second fixed element; and a third coupling mechanism capable of coupling the second ring gear to the input shaft, the third coupling mechanism comprising: a coupling element connected to the second ring gear and the input shaft; a pressing part for engaging the coupling element by pressing the coupling element toward one axial end of the input shaft, i.e., the coupling direction; a spring for applying force to the pressing part in the coupling direction; and an actuator for generating a thrust at the other axial end of the input shaft, i.e., the release direction, thereby causing the pressing part to engage the input shaft. The release direction is shifted, thereby releasing the connecting element; the bearing, which supports the rotating element of the third connecting mechanism, bears the load of the spring compressed by the thrust when the connecting element is released. By switching the connection and release of the first connecting mechanism, the second connecting mechanism, and the third connecting mechanism, a first gear stage, a second gear stage, and a third gear stage are realized. In the first gear stage, the first connecting mechanism is connected, and the second connecting mechanism and the third connecting mechanism are released. In the second gear stage, the second connecting mechanism is connected, and the first connecting mechanism and the third connecting mechanism are released. In the third gear stage, the third connecting mechanism is connected, and the first connecting mechanism and the second connecting mechanism are released. The second gear stage is selected during normal start-up and low-speed driving, the third gear stage is selected during medium-speed driving and high-speed driving, and the first gear stage is selected during emergency driving when a greater driving force than that required during normal start-up is needed.

[0013] Invention Effects

[0014] According to one aspect of the present invention, in a transmission device, the time during which both the rotational torque and the actuator thrust act on the bearing can be reduced. Attached Figure Description

[0015] Figure 1 This is a schematic diagram representing a power transmission device.

[0016] Figure 2 This is a diagram showing the structure of a clutch.

[0017] Figure 3 It is a diagram showing the clutch release state, and a collinear diagram showing the rotational speeds (rotational speeds) of the components of the gear mechanism from 1st to 3rd speed.

[0018] Figure 4A This is a schematic diagram illustrating a cam mechanism.

[0019] Figure 4B This is a schematic diagram illustrating a cam mechanism.

[0020] Figure 5 It is a connection table for speeds 1 to 3.

[0021] Figure 6 It is a collinear diagram showing the rotational speeds of the components of the transmission device from speed 1 to speed 3.

[0022] Figure 7 This is a diagram showing the power transmission path at speed 1.

[0023] Figure 8 This is a diagram showing the power transmission path at 2 speeds.

[0024] Figure 9 This is a diagram showing the power transmission path at 3 speeds. Detailed Implementation

[0025] In the following description, an example of applying a transmission device according to a certain aspect of the present invention to a power transmission device mounted in a vehicle will be described. The power transmission device is a device comprising an electric motor as a rotary motor and a power transmission mechanism that transmits power from the electric motor to the drive wheels. The power transmission mechanism may include, for example, a gear mechanism and / or a differential mechanism (differential gear mechanism).

[0026] Furthermore, in the following description, when a second element (component, part, etc.) is described as connected to the first element (component, part, etc.), connected downstream of the first element (component, part, etc.), or connected upstream of the first element (component, part, etc.), it means that the first element and the second element are connected in a manner capable of transmitting power. The power input side is called upstream, and the power output side is called downstream. Additionally, the first element and the second element may also be connected via other elements (clutch, other gear mechanisms, etc.).

[0027] "Overlapping when viewed from a specified direction" means that multiple elements are arranged in a specified direction, which is synonymous with the description "overlapping in a specified direction". "Specified direction" includes, for example, axial, radial, gravitational direction, vehicle travel direction (vehicle forward direction, vehicle backward direction), etc.

[0028] When multiple elements (components, parts, etc.) are shown in the accompanying drawings arranged in a specified direction, the description in the instruction manual can be regarded as including the content that overlaps when viewed from the specified direction.

[0029] "Non-overlapping when viewed from a specified direction" and "offset when viewed from a specified direction" refer to the arrangement of multiple elements in a specified direction, which are synonymous with the descriptions "non-overlapping in a specified direction" and "offset in a specified direction." "Specified direction" can be, for example, axial, radial, gravitational direction, or vehicle travel direction (forward or backward).

[0030] In cases where multiple elements (components, parts, etc.) are not arranged in a specified direction as shown in the accompanying drawings, the description in the instruction manual may be considered as indicating that they do not overlap when viewed from the specified direction.

[0031] "When viewed from a specified direction, the first element (component, part, etc.) is located between the second element (component, part, etc.) and the third element (component, part, etc.)" means that, when viewed from a specified direction, the first element can be observed to be located between the second and third elements. "Specified direction" refers to axial, radial, gravitational direction, vehicle travel direction (vehicle forward direction, vehicle backward direction), etc.

[0032] For example, when the second element, the first element, and the third element are arranged sequentially along the axial direction, it can be said that, viewed radially, the first element is located between the second and third elements. In the accompanying drawings, where the first element is shown to be located between the second and third elements when viewed from a specified direction, this can be considered as having the content described in the specification that the first element is located between the second and third elements when viewed from a specified direction.

[0033] When viewed from the axial direction, the two elements (components, parts, etc.) are coaxial when they overlap.

[0034] "Axial" refers to the axial direction of the rotation axis of the component constituting the device. "Radial" refers to the direction orthogonal to the rotation axis of the component constituting the device. Examples of such components include electric motors, gear mechanisms, and differential gear mechanisms.

[0035] Figure 1 This is a schematic diagram showing the power transmission device 1.

[0036] like Figure 1 As shown, the power transmission device 1 has an electric motor 2 (rotary motor) as the power source for driving the vehicle. The power transmission device 1, as a power transmission mechanism for transmitting the output rotation of the electric motor 2, includes an input shaft 31, a speed change device 4, an output shaft 32, a differential mechanism 9, and a drive shaft D.

[0037] The input shaft 31, the transmission device 4, the output shaft 32, and the rotation shaft X of the motor 2 are arranged coaxially. That is, the "rotation shaft X direction" corresponds to the "axial direction of the input shaft 31", and the "radial direction of the rotation shaft X" corresponds to the "radial direction of the input shaft 31". The motor 2 is arranged at one end of the power transmission device 1 in the rotation shaft X direction (right side in the figure), and the transmission device 4 is arranged at the other end of the rotation shaft X direction (left side in the figure). The motor 2 is connected to the transmission device 4 via the input shaft 31. The transmission device 4 is connected to the differential mechanism 9 via the output shaft 32. The rotation shaft X extends along the vehicle width direction.

[0038] Furthermore, in the following explanation, the case of "one end of the rotation axis in the X direction" can be regarded as the right side of the figure, and the case of "the other end of the rotation axis in the X direction" can be regarded as the left side of the figure.

[0039] The output shaft 32 is connected to the differential mechanism 9 via a reduction gear, a counting gear, etc. (not shown). The reduction gear, the counting gear, etc. are arranged parallel to each other at intervals in a direction orthogonal to the rotation axis X, i.e., in the vehicle's front-to-back direction.

[0040] The differential mechanism 9 is connected to the left and right drive wheels K, K' of the vehicle via the drive shaft D. The drive shaft D extends along the axis X5, which is parallel to the rotation axis X.

[0041] The electric motor 2 has: a rotor core 21, which rotates integrally with the input shaft 31; and a stator core 25, which surrounds the outer periphery of the rotor core 21 at intervals.

[0042] When the motor 2 is driven and the rotor core 21 rotates around the rotation axis X, the input shaft 31 rotates integrally with the rotor core 21. The rotation of the input shaft 31 is changed by the speed change device 4 and output to the output shaft 32. The rotation output to the output shaft 32 is slowed down by reduction gears, counting gears, etc. (not shown) and transmitted to the differential mechanism 9. The rotation transmitted to the differential mechanism 9 is transmitted to the left and right drive wheels K and K' of the vehicle via the drive shaft D.

[0043] The speed changer 4 is located downstream of the motor 2 in the power transmission path that transmits the rotational force of the motor 2. The differential mechanism 9 is located downstream of the speed changer 4 in the power transmission path.

[0044] The output shaft 32 can be, for example, a hollow cylindrical shape. The input shaft 31, extending from the motor 2 along the rotation axis X, passes through the interior of the output shaft 32 and connects to the transmission device 4. The input shaft 31 and output shaft 32 are configured to rotate relative to each other about the rotation axis X. When viewed radially from the rotation axis X, a portion of the input shaft 31 overlaps with the output shaft 32. In other words, the power transmission device 1 has a structure in which the input shaft 31 extends from the motor 2 towards the transmission device 4, and the output shaft 32 is folded back from the transmission device 4 towards the motor 2.

[0045] With this folding structure, the output shaft 32 is positioned between the motor 2 located at one end of the rotation axis X direction of the power transmission device 1 and the transmission device 4 located at the other end. In other words, the output shaft 32 is positioned at the center of the power transmission device 1.

[0046] Furthermore, the differential mechanism 9, which is connected to the output shaft 32 via a reduction gear, a counting gear, etc. (not shown), is located at the center of the drive shaft D in the X5 direction (vehicle width direction).

[0047] like Figure 1 As shown, the power transmission device 1 includes an electric motor housing 11, a gear housing 12, and a clutch housing 13. The electric motor housing 11 houses the electric motor 2. The gear housing 12 and clutch housing 13 house the transmission device 4. The gear housing 12 is located at the other end of the electric motor housing 11 along the rotation axis X direction and engages with the electric motor housing 11. The clutch housing 13 is located at the other end of the gear housing 12 along the rotation axis X direction and engages with the gear housing 12. The electric motor housing 11, gear housing 12, and clutch housing 13 are arranged in the rotation axis X direction to form an integral housing. The input shaft 31 and output shaft 32 penetrate the interior of the housing and are supported by the housing via bearing B. Furthermore, although not shown in the figure, the differential mechanism 9 is, for example, housed in an axle axle housing separate from the housing.

[0048] The transmission device 4 can have multiple gear mechanisms and multiple connecting mechanisms with different gear ratios. By operating the connection and release of multiple connecting mechanisms, the transmission device 4 switches the rotation transmission path in multiple gear mechanisms to achieve multiple speed stages with different speed ratios.

[0049] The transmission device 4 comprises multiple gear mechanisms, such as a first planetary gear mechanism 40 (hereinafter also simply referred to as "first gear mechanism 40") and a second planetary gear mechanism 50 (hereinafter also simply referred to as "second gear mechanism 50"). The first gear mechanism 40 and the second gear mechanism 50 are arranged on the rotation axis X. The first gear mechanism 40 is positioned between the motor 2 and the second gear mechanism 50 in the direction of the rotation axis X. When viewed from the direction of the rotation axis X, the first gear mechanism 40 and the second gear mechanism 50 overlap with the motor 2.

[0050] The first gear mechanism 40 includes: a first sun gear 41; a pinion 43 that meshes with the outer periphery of the first sun gear 41; a first planet carrier 45 that supports the pinion 43; and a first gear ring 42 that meshes with the pinion 43 on its inner periphery.

[0051] The first sun gear 41 is fixed to the outer periphery of the input shaft 31.

[0052] The first planetary carrier 45 has a pinion shaft 45a that rotatably supports the pinion 43 and a planetary carrier plate 45b that supports the pinion shaft 45a. The inner circumferential side of the planetary carrier plate 45b is connected to the output shaft 32. The first ring gear 42 is connected to the second planetary carrier 55 via the planetary carrier plate 55b, which will be described later. The first ring gear 42 is rotatable integrally with the second planetary carrier 55.

[0053] Thus, in the first gear mechanism 40, the first sun gear 41 fixed to the input shaft 31 is the input element, and the first planetary carrier 45 connected to the output shaft 32 is the output element.

[0054] The second gear mechanism 50 includes: a second sun gear 51; a pinion 53 that meshes with the outer periphery of the second sun gear 51; a second planetary carrier 55 that supports the pinion 53; and a second gear ring 52 that meshes with the pinion 53 on its inner periphery.

[0055] The second sun gear 51 is fixed to the outer periphery of the input shaft 31. In other words, the input shaft 31 is arranged such that it passes through the inner periphery of the first sun gear 41 and the second sun gear 51 in the direction of the rotation axis X.

[0056] The second planetary carrier 55 has a pinion shaft 55a that rotatably supports the pinion 53 and a planetary carrier plate 55b that supports the pinion shaft 55a. The second planetary carrier 55 is connected to the first gear ring 42 of the first gear mechanism 40 via the planetary carrier plate 55b.

[0057] The second gear ring 52 is connected to the clutch drum 75 of the clutch 70 (described later) via the connecting part 52a.

[0058] Thus, in the second gear mechanism 50, the second sun gear 51 fixed to the input shaft 31 is the input element, and the second planetary carrier 55 connected to the first gear ring 42 of the first gear mechanism 40 is the output element.

[0059] The transmission device 4, as a connecting mechanism, includes a selectable one-way clutch 61 (first connecting mechanism) and a selectable one-way clutch 62 (second connecting mechanism). Hereinafter, the selectable one-way clutch 61 will also be referred to as "SOWC61". Hereinafter, the selectable one-way clutch 62 will also be referred to as "SOWC62". SOWC61 and SOWC62 are mounted on the gear housing 12. SOWC61 and SOWC62 connect the components of the gear mechanism, respectively, to the gear housing 12 (first fixed element and second fixed element).

[0060] SOWC61 is located between the first gear ring 42 and the gear housing 12. The area of ​​the gear housing 12 that supports the first gear ring 42 constitutes the first fixing element. As described above, the first gear ring 42 is connected to the second planet carrier 55 via the planet carrier plate 55b. Therefore, the first gear ring 42 and the second planet carrier 55 are supported on the gear housing 12 (the first fixing element) via SOWC61.

[0061] The SOWC61 has three operating states (connected, released, and engaged). The operating state of the SOWC61 is switched between the connected, released, and engaged states via an actuator (not shown).

[0062] When SOWC61 is in the engaged state, the first gear ring 42 is fixed to the gear housing 12 via SOWC61. Therefore, the first gear ring 42 is fixed to the gear housing 12 together with the second planetary carrier 55, and their respective rotations are restricted.

[0063] When SOWC61 is in the released state, the first gear ring 42 and the second planetary carrier 55 can also rotate in either one direction or the other direction in the circumferential direction about the rotation axis X.

[0064] When SOWC61 is engaged, the first gear ring 42 and the second planetary carrier 55 can only rotate in one direction.

[0065] SOWC62 is located between the second gear ring 52 and the gear housing 12. The area of ​​the gear housing 12 that supports the second gear ring 52 constitutes the second fixing element.

[0066] The SOWC62 also has three operating states (connected, released, and engaged). The operating states of the SOWC62 are switched between the connected, released, and engaged states by an actuator (not shown).

[0067] When SOWC62 is in the connected state, the second gear ring 52 is fixed to the gear housing 12 via SOWC62. Therefore, the second gear ring 52 is fixed to the gear housing 12, and the rotation of the second gear ring 52 is restricted.

[0068] When SOWC62 is in the released state, the second gear ring 52 can rotate in either one direction or the other direction around the rotation axis X in the circumferential direction.

[0069] When SOWC62 is engaged, the second gear ring 52 can only rotate in one direction.

[0070] SOWC61 and 62 may, for example, include a waiting mechanism composed of a spring or the like. The waiting mechanism is a mechanism that stores the thrust applied from the actuator. SOWC61 and 62 can quickly switch between a released state, a connected state, and a locked state via the waiting mechanism.

[0071] The transmission 4 includes a clutch 70 as a third coupling mechanism. The clutch 70 is a direct-connect clutch that directly connects the second ring gear 52 to the input shaft 31. When the second ring gear 52 is directly connected to the input shaft 31, the first sun gear 41 and the second sun gear 51, fixed to the input shaft 31, rotate integrally with the second ring gear 52. Details will be described later. The clutch 70 functions as a direct-connect clutch for synchronizing the rotational speeds of the input shaft 31 and the output shaft 32.

[0072] Figure 2 This is a diagram showing the structure of clutch 70. Figure 2 This indicates the engagement status of clutch 70.

[0073] Figure 3 This is a diagram showing the released state of clutch 70.

[0074] like Figure 2 As shown, the clutch 70 is housed in the clutch housing 13. The clutch housing 13 has a peripheral wall portion 131 surrounding the rotational shaft X. One end of the peripheral wall portion 131 in the rotational shaft X direction (right side in the figure) of the clutch housing 13 is fitted into the gear housing 12. A cover member 14 is fitted into the other end (left side in the figure). The opening on the other end (left side in the figure) of the clutch housing 13 is closed by the cover member 14. In addition, one end of the peripheral wall portion 131 is formed to have a thickness on the inner diameter side compared to the other end. Therefore, a stepped surface 131a extending towards the inner diameter side is formed on the inner peripheral side of the peripheral wall portion 131. An annular plate member 15, described later, is mounted on the stepped surface 131a in the rotational shaft X direction.

[0075] The clutch housing 13 has a wall portion 132 located in the region embedded in the gear housing 12. The wall portion 132 extends from the region embedded in the gear housing 12 in the peripheral wall portion 131 toward the inner diameter side of the peripheral wall portion 131. The wall portion 132 is a partition wall that separates the space inside the gear housing 12 and the space inside the clutch housing 13 in the direction of the rotation axis X.

[0076] exist Figure 2 In this configuration, the second gear mechanism 50 is located on the right side of the wall portion 132. The clutch 70 is located on the left side of the wall portion 132. The clutch 70 and the second gear mechanism 50 are adjacent to each other across the wall portion 132.

[0077] An opening 133 is provided in the wall portion 132 in the region intersecting with the rotation axis X. The opening 133 is formed with an opening diameter that allows the connection portion 753 on the clutch 70 side to pass through. In this embodiment, the connection portion 753 on the clutch 70 side is supported by the wall portion 132 via the bearing B2. The connection portion 753 extends transversely through the opening 133 from the clutch housing 13 side to the gear housing 12 side. Inside the gear housing 12, the connection portion 753 is connected to the second gear ring 52 (see reference) of the second gear mechanism 50 in a manner that prevents relative rotation. Figure 1 ) is connected to the connecting part 52a.

[0078] The clutch 70 has a clutch hub 74 that rotates integrally with the input shaft 31, a clutch drum 75 that rotates integrally with the second gear ring 52 of the second gear mechanism 50, and a plurality of friction plates 71 as connecting elements. As a mechanism for switching the engagement and disengagement of the plurality of friction plates 71, the clutch 70 also has a piston 76 that is stressed by a disc spring 77 and an electric actuator 80.

[0079] The clutch hub 74 is disposed on the outer periphery of the input shaft 31. The clutch hub 74 has a cylindrical peripheral wall portion 741, a bottom portion 742 extending from one end of the peripheral wall portion 741 in the rotation axis X direction toward the inner diameter side, and a connecting portion 743 connected to the input shaft 31.

[0080] The connecting part 743 is a cylindrical portion that is inserted into the input shaft 31. The connecting part 743 engages with the spline on the outer periphery of the input shaft 31 and rotates integrally with the input shaft 31.

[0081] The bottom 742 extends radially outward from the outer periphery of the wall portion 132 side of the connecting portion 743.

[0082] The peripheral wall portion 741 is a cylindrical portion surrounding the rotation shaft X. The inner circumference of the peripheral wall portion 741 and the outer circumference of the input shaft 31 are radially spaced apart from each other on the rotation shaft X. A drive plate 72 constituting a friction plate 71 is splinedly fitted onto the outer circumference of the peripheral wall portion 741. The drive plate 72 is capable of displacement in the direction of the rotation shaft X (left-right direction in the figure) while its relative rotation with the peripheral wall portion 741 is restricted.

[0083] The peripheral wall portion 751 of the clutch drum 75 is located on the outer diameter side of the peripheral wall portion 741.

[0084] The clutch drum 75 has a peripheral wall portion 751 that surrounds the outer periphery of the peripheral wall portion 741 at intervals, and a bottom portion 752 that extends from one end of the peripheral wall portion 751 in the rotation axis X direction toward the inner diameter side. The end of the clutch drum 75 on the inner diameter side of the bottom portion 752 is connected to the aforementioned connecting portion 753.

[0085] A driven plate 73 constituting a friction plate 71 is fitted into the inner periphery spline of the peripheral wall portion 751. The driven plate 73 is able to move in the rotation axis X direction (left and right direction in the figure) while its relative rotation with the peripheral wall portion 751 is restricted.

[0086] The driven plate 73 and the driving plate 72 are arranged alternately in the direction of the rotation axis X.

[0087] Viewed from the friction plate 71, the piston 76 is located on the opposite side of the bottom 752 of the clutch drum 75 (left side in the figure).

[0088] The piston 76 has a cylindrical base 761. A pressing portion 762 is provided at one end of the base 761 in the rotation axis X direction. Viewed from the rotation axis X direction, the pressing portion 762 is plate-shaped and extends radially outward from the outer periphery of the base 761. The outer periphery of the pressing portion 762 engages with the inner periphery spline of the peripheral wall portion 751 on the side of the clutch drum 75.

[0089] The piston 76 is supported in a manner that allows it to move along the rotational axis X while its relative rotation with the clutch drum 75 is restricted.

[0090] A circular plate-shaped opposing part 763 is externally fixed to the other end of the base 761 in the X direction of the rotation axis.

[0091] In the clutch drum 75, a retainer 78 is provided on the inner circumference of the peripheral wall portion 751. The retainer 78 includes an annular retaining portion 781 whose outer circumference is splinedly engaged with the peripheral wall portion 751 of the clutch drum 75, and a cylindrical portion 782 connected to the inner circumference of the retaining portion 781. The retaining portion 781, such as a retaining ring, restricts movement in the X direction of the rotation axis.

[0092] The cylindrical portion 782 extends from the outer diameter side of the base 761 of the piston 76 toward the other end (left side in the figure) in the direction of the rotation axis X. The cylindrical portion 782 is inserted into the opening 151 of the plate member 15 in the direction of the rotation axis X. The outer periphery of the cylindrical portion 782 is supported by the plate member 15 via the bearing B1.

[0093] A bushing Bs is fitted between the inner circumference of the cylinder 782 and the outer circumference of the base 761 of the piston 76. The piston 76 is capable of relative movement in the direction of the rotation axis X and relative displacement in the circumferential direction about the rotation axis X relative to the retainer 78. Alternatively, a bearing may be fitted instead of the bushing Bs.

[0094] A disc spring 77 is disposed between the retaining part 781 of the retainer 78 and the pressing part 762 of the piston 76.

[0095] The disc spring 77 is ring-shaped when viewed from the rotation axis X direction, and conical in cross-section along the rotation axis X direction. The disc spring 77 is inserted into the base 761 of the piston 76. In the rotation axis X direction, the disc spring 77 is configured such that its outer diameter side contacts the pressing part 762, and its inner diameter side contacts the holding part 781 of the retainer 78.

[0096] The disc spring 77 is held in a pre-compressed state between the retaining portion 781 on the retainer 78 side and the pressing portion 762 on the piston 76 side. As described above, the movement of the retainer 78 in the rotation axis X direction is restricted. Therefore, the piston 76 is forced towards the friction plate 71 side by the elastic force of the disc spring 77.

[0097] In this embodiment, the piston 76 is pressed against the friction plate 71 in the direction of rotation X by the force exerted by the disc spring 77. In this state, the driven plate 73 and the drive plate 72 are compressed in the direction of rotation X and connected in a manner that prevents them from rotating relative to each other.

[0098] When the driven plate 73 and the drive plate 72 are connected in a manner that prevents them from rotating relative to each other, the clutch hub 74 on the drive plate 72 side and the clutch drum 75 on the driven plate 73 side are connected in a manner that prevents them from rotating relative to each other.

[0099] In this embodiment, the piston 76 is displaced away from the wall 132 (left side in the figure) by the driving force of the electric actuator 80, which will be described later. Therefore, during the period when the driving force of the electric actuator 80 is not applied, the piston 76 is restricted from relative rotation between the driven plate 73 and the drive plate 72 by the force acting from the disc spring 77 (spring).

[0100] That is, the clutch 70 is a so-called normally closed clutch 70, which maintains the engagement state without actuating the electric actuator 80.

[0101] As described above, in the clutch 70, the clutch hub 74 is connected to the input shaft 31 in a manner that prevents relative rotation, and the clutch drum 75 is connected to the connecting portion 52a of the second gear ring 52 via the connecting portion 753 in a manner that prevents relative rotation.

[0102] Therefore, with the clutch hub 74 and clutch drum 75 connected in a manner that prevents relative rotation, the input shaft 31 and the second gear ring 52 are connected in a manner that allows rotation to be transmitted. Thus, rotation of the input shaft 31 is input to the second gear ring 52 via the clutch 70.

[0103] like Figure 3As shown, when the driving force of the electric actuator 80 (described later) releases the piston 76 from pressing against the plurality of friction plates 71, the connection between the drive plate 72 and the driven plate 73 is released, allowing them to rotate relative to each other. Consequently, the clutch hub 74 and the clutch drum 75 can also rotate relative to each other, cutting off the rotational transmission from the input shaft 31 to the second gear ring 52 via the clutch 70.

[0104] like Figure 2 As shown, the electric actuator 80 has an actuator motor 81, a shaft 82, a drive gear 83, a first driven gear 84, and a second driven gear 85 (driven gear).

[0105] The actuator motor 81 is disposed outside the clutch housing 13. The actuator motor 81 is mounted, for example, on a cover component 14 that encloses the clutch housing 13. The output shaft 81a of the actuator motor 81 rotates about an axis X1 parallel to the rotation axis X by a driving force supplied from a drive source (not shown). The actuator motor 81 is capable of switching the direction of rotation of the output shaft 81a between one direction and another about the axis X1.

[0106] A shaft 82 is inserted outside the output shaft 81a of the actuator motor 81. The shaft 82 is connected to the output shaft 81a in a non-rotatable manner via a hollow assembly H. Therefore, the rotation of the actuator motor 81 is output from the output shaft 81a to the shaft 82. The shaft 82 extends along the axis X1, passing through the cover member 14 and extending inside the clutch housing 13. The end of the shaft 82 on the opposite side of the actuator motor 81 in the axis X1 direction is rotatably supported on the plate member 15 via a bearing B3.

[0107] A drive gear 83 is integrally formed on shaft 82. The drive gear 83 is located between cover member 14 and plate member 15 in the direction of axis X1. The drive gear 83 is positioned to overlap with the base 761 and the opposing portion 763 of piston 76 in the radial direction of the rotation axis X. Gear teeth Gt are formed on the outer peripheral surface of the drive gear 83. A first driven gear 84 and a second driven gear 85 mesh with the gear teeth Gt of the drive gear 83.

[0108] The first driven gear 84 and the second driven gear 85 are annular when viewed from the rotation axis X, and are inserted into the base 761 of the piston 76. The first driven gear 84 and the second driven gear 85 are located radially between the base 761 of the piston 76 and the drive gear 83 on the rotation axis X. The first driven gear 84 and the second driven gear 85 are arranged in the rotation axis X direction between the opposing portion 763 of the piston 76 and the plate member 15.

[0109] The first driven gear 84 and the second driven gear 85 are arranged in the direction of the rotation axis X. The first driven gear 84 is located at one end of the second driven gear 85 in the direction of the rotation axis X. Gear teeth are formed on the outer periphery of the first driven gear 84 and the second driven gear 85, and mesh with the gear teeth Gt of the drive gear 83. Thus, the rotation of the drive gear 83 is transmitted to the first driven gear 84 and the second driven gear 85, which rotate in the circumferential direction about the rotation axis X.

[0110] Here, the first driven gear 84 and the second driven gear 85 are formed with different numbers of teeth. Therefore, when transmitting the rotation of the drive gear 83, the rotation of the first driven gear 84 and the second driven gear 85 produces a phase difference.

[0111] like Figure 3 As shown, cylindrical connecting portions 841 and 851 are respectively provided on the inner circumference of the first driven gear 84 and the second driven gear 85. Connecting portions 841 and 851 protrude towards one end in the direction of the rotation axis X. Connecting portion 851 is located on the inner diameter side of connecting portion 841. Connecting portions 841 and 851 are radially opposite each other on the rotation axis X, and a bushing Bs is sandwiched between connecting portions 841 and 851.

[0112] The base 761 of the piston 76 is located on the inner diameter side of the connecting portion 851. A bearing B4 is sandwiched between the connecting portion 851 and the base 761 of the piston 76. That is, the first driven gear 84 and the second driven gear 85 are supported on the base 761 of the piston 76 in a rotatable manner via the bearing B4.

[0113] The first driven gear 84 is opposite to the plate component 15 at one end in the direction of the rotation axis X. A needle roller bearing NB is clamped between the first driven gear 84 and the plate component 15, and the first driven gear 84 is capable of rotating relative to the plate component 15.

[0114] The second driven gear 85 is opposite to the opposing portion 763 of the piston 76 at its other end in the X direction of the rotation axis. A needle roller bearing NB is sandwiched between the second driven gear 85 and the opposing portion 763. Thus, the second driven gear 85 can rotate relative to the opposing portion 763.

[0115] like Figure 3 As shown, the surface at the other end of the first driven gear 84 in the X direction of its rotation axis becomes the opposing surface 842 opposite to the second driven gear 85. The surface at one end of the second driven gear 85 in the X direction of its rotation axis becomes the opposing surface 852 opposite to the first driven gear 84.

[0116] Cam grooves 843 and 853 are provided on opposite surfaces 842 and 852, respectively. Cam grooves 843 and 853 are recessed in the direction of separation from each other in the rotation axis X direction.

[0117] Cam grooves 843 and 853 are formed within a specified angle range along the circumference of the rotation axis X. Although the illustration is omitted, multiple cam grooves 843 and 853 are provided at equal intervals along the circumference on the opposite surfaces 842 and 852. As an example, three cam grooves 843 and 853 can be provided at 120° intervals along the circumference on the opposite surfaces 842 and 852.

[0118] Cam grooves 843 and 853 on opposite surfaces 842 and 852 are formed at equal radial distances from the rotation axis X and are positioned opposite each other in the direction of the rotation axis X. Although in Figure 2 and Figure 3 The diagram is omitted, but rolling elements are maintained between the cam grooves 843 and 853 on opposite surfaces 842 and 852. The first driven gear 84 and the second driven gear 85 are displaced in the X direction along the rotation axis as the rolling elements move within the cam grooves 843 and 853, as detailed later. That is, the cam grooves 843 and 853 of the first driven gear 84 and the second driven gear 85 and the rolling elements constitute a cam mechanism.

[0119] In this embodiment, the cam mechanism converts the rotational motion input from the actuator motor 81 into linear motion along the rotation axis X via the first driven gear 84 and the second driven gear 85. That is, the electric actuator 80, the first driven gear 84, and the second driven gear 85 constitute a linear actuator.

[0120] Figure 4A and Figure 4B This is a schematic diagram illustrating a cam mechanism. Figure 4A This indicates that the rolling element Rb is held between the locking portions Ca and Ca. Figure 4B This indicates that the rolling element Rb is held between the locking portions Cb and Cb.

[0121] Figure 4A and Figure 4B This indicates the state in which the cam groove 843 of the first driven gear 84 and the cam groove 853 of the second driven gear 85 are cut along the circumferential direction about the rotation axis X and viewed radially from the rotation axis X. Furthermore, in Figure 4A and Figure 4B In this context, the rolling element Rb is represented as a spherical ball, but it can also be a cylindrical or conical roller.

[0122] like Figure 4AAs shown, the cam groove 843 of the first driven gear 84 is formed by recessing one end of the opposing surface 842 in the direction of the rotation axis X. The cam groove 843 consists of an inclined surface Is on which the rolling element Rb can roll and locking portions Ca and Cb that lock the rolling element Rb. The locking portion Ca is provided on one side of the inclined surface Is in the circumferential direction (lower side in the figure), and the locking portion Cb is provided on the other side (upper side in the figure). The locking portions Ca and Cb are hemispherical recesses with a radius of curvature matching the outer periphery of the rolling element Rb. The locking portion Ca has a depth Da (Da≈r) in the direction of the rotation axis X that matches the radius r of the rolling element Rb. The locking portion Cb has a depth Db (Db<Da) in the direction of the rotation axis X that is shallower than that of the locking portion Ca.

[0123] The inclined surface Is of the cam groove 843 is inclined such that it is located at one end from the locking part Ca toward the locking part Cb in the direction of rotation axis X. That is, the cam groove 843 is formed such that the groove gradually becomes shallower as it moves from the locking part Ca toward the locking part Cb.

[0124] The cam groove 853 of the second driven gear 85 is formed by recessing the opposing surface 852 towards the other end in the direction of the rotation axis X. The cam groove 853 has a shape that reverses the cam groove 843 in the direction of the rotation axis X and in the circumferential direction. The cam groove 853 is composed of an inclined surface Is on which the rolling element Rb can roll and locking portions Cb and Ca that lock the rolling element Rb. The locking portion Cb is provided on one side (lower side in the figure) of the inclined surface Is in the circumferential direction, and the locking portion Ca is provided on the other side (upper side in the figure). The inclined surface Is of the cam groove 853 is inclined in such a way that it is located at one end from the other end in the direction of the rotation axis X as it moves from the locking portion Ca toward the locking portion Cb. That is, the cam groove 853 is formed such that the groove gradually becomes shallower as it moves from the locking portion Ca toward the locking portion Cb.

[0125] When the actuating motor 81 (refer to) is activated Figure 2 When the drive gear 83 rotates around axis X1, the first driven gear 84 and the second driven gear 85, which mesh with the drive gear 83, rotate circumferentially around the rotation axis X. Here, as described above, the first driven gear 84 and the second driven gear 85 have different numbers of teeth, thus creating a phase difference in their rotation. In this embodiment, the first driven gear 84 has more teeth than the second driven gear 85. Therefore, when the drive gear 83 rotates, the first driven gear 84 rotates faster than the second driven gear 85.

[0126] Figure 4AThis indicates a state where the actuator motor 81 is not driven and the first driven gear 84 and the second driven gear 85 are not rotating (no phase difference is generated). In the state where no phase difference is generated, the first driven gear 84 and the second driven gear 85 are configured such that the locking portion Ca of the cam groove 843 and the locking portion Ca of the cam groove 853 are opposite to each other in the direction of the rotation axis X. The rolling element Rb is held between the locking portions Ca and Ca.

[0127] The locking portions Ca and Ca have depths Da at distances of 842 and 852 from the opposing surfaces, respectively.

[0128] The depth Da of the locking part Ca is set to match the radius r of the rolling element Rb. For example... Figure 4A As shown, if the locking portions Ca and Ca are opposite each other in the direction of the rotation axis X, a space with a depth 2Da, equivalent to the diameter 2r of the rolling element Rb, is formed between the two locking portions Ca and Ca. That is, when the rolling element Rb is held between the locking portions Ca and Ca, the entire rolling element Rb is housed between the locking portions Ca and Ca. As a result, the opposing surfaces 842 of the first driven gear 84 and the opposing surfaces 852 of the second driven gear 85 are in abutting state. Figure 2 (The state shown).

[0129] When the actuator motor 81 drives the drive gear 83 to rotate around axis X1, a phase difference is generated between the first driven gear 84 and the second driven gear 85. Specifically, since the first driven gear 84 has more teeth than the second driven gear 85, the first driven gear 84 rotates faster than the second driven gear 85. This results in a phase difference between the first driven gear 84 and the second driven gear 85. Furthermore, the amount of the phase difference is generated by the relative movement of the cam grooves 843 and 853 of the first driven gear 84 and the second driven gear 85 to one side and the other side in the circumferential direction.

[0130] like Figure 4B As shown, in this embodiment, the first driven gear 84 rotates faster than the second driven gear 85. Therefore, the cam groove 843 of the first driven gear 84 is displaced relative to the cam groove 853 of the second driven gear 85 in the circumferential direction (marked by the shaded arrow in the figure). Due to this circumferential displacement of the cam groove 843, the rolling element Rb disengages from the respective locking portions Ca of the cam grooves 843 and 853 and rolls towards the locking portion Cb on the inclined surface Is.

[0131] Here, as Figure 3 As shown, since the plate member 15 is located at one end of the first driven gear 84 in the X direction of the rotation axis, the movement of the first driven gear 84 to one end is restricted. The opposing portion 763 supporting the second driven gear 85, together with the piston 76, allows movement in the X direction of the rotation axis.

[0132] like Figure 4B As shown, the inclined surface Is of the cam groove 843 is inclined such that it extends from the locking portion Ca toward the locking portion Cb and is located at one end in the direction of the rotation axis X to the other end. Therefore, the rolling element Rb rolls on the inclined surface Is and moves toward the other end in the direction of the rotation axis X. As a result, the second driven gear 85, which holds the rolling element Rb by the cam groove 853 at the other end, is pressed by the rolling element Rb and moves toward the other end (marked by the hollow arrow in the figure).

[0133] Furthermore, the inclined surface Is of the cam groove 853 is inclined from the locking portion Ca in such a way that it is located on one end side from the other end side in the direction of the rotation axis X. Therefore, as the rolling element Rb rolls in the cam groove 853 from the locking portion Ca toward the locking portion Cb, the amount by which the rolling element Rb presses the second driven gear 85 toward the other end side increases.

[0134] When the rolling element Rb rolls on the inclined surface Is of the cam grooves 843 and 853 and reaches the locking parts Cb, as Figure 4B As shown, it is held between the locking portions Cb and Cb.

[0135] like Figure 4A As shown, the depth Db of the locking portion Cb is set to be smaller than the depth Da of the locking portion Ca. That is, the depth Db of the locking portion Cb is smaller than the radius r of the rolling element Rb. In other words, when the rolling element Rb is held between the locking portions Cb and Cb, the rolling element Rb cannot be completely contained within the locking portions Cb and Cb, and becomes partially protruding from the locking portions Cb and Cb. That is, when the rolling element Rb is held between the locking portions Cb and Cb, it becomes a state where the opposing surface 842 of the first driven gear 84 is separated from the opposing surface 852 of the second driven gear 85. Figure 3 (as shown in the diagram). Here, the interval between the opposing surfaces 842 of the first driven gear 84 and 852 of the second driven gear 85 is a distance (2r-2Db) corresponding to the difference between the radius of the rolling element Rb and the depth Db of the locking portion Cb. This difference can be appropriately set according to the amount of displacement required by the piston 76 when the friction plate 71 is released.

[0136] like Figure 3 As shown, when the second driven gear 85 is moved toward the other end in the direction of the rotation axis X by the actuator motor 81, the second driven gear 85 presses against the opposing portion 763 of the piston 76. As a result, a thrust is applied to the piston 76 as a whole toward the other end in the direction of the rotation axis X (release direction). That is, the piston 76 moves toward the other end in the direction of the rotation axis X (release direction) by the thrust of the electric actuator 80 overcoming the force of the disc spring 77. The pressing portion 762 of the piston 76, which is connected to the friction plate 71, moves toward the other end, thereby releasing the clutch 70.

[0137] like Figure 3 As shown, the pressing part 762 of the piston 76 presses against the outer diameter side of the disc spring 77 while moving to the other end. Here, the retainer 78 supporting the inner diameter side of the disc spring 77 is supported on the plate member 15 via the bearing B1, and splinedly engaged with the inner circumference of the clutch drum 75 in a state where its movement in the X direction of the rotation axis is restricted.

[0138] That is, the movement of the retainer 78 toward the other end in the direction of the rotation axis X is restricted. Therefore, when a thrust is applied from the electric actuator 80 toward the other end in the direction of the rotation axis X, the outer diameter side of the disc spring 77 supported by the pressing part 762 approaches the inner diameter side supported by the retainer 78. As a result, the disc spring 77 is further compressed compared to when the clutch 70 is in the released state.

[0139] The load generated by the compression of the disc spring 77 also acts on bearing B1 via retainer 78, and on bearing B2 via retainer 78 and clutch drum 75.

[0140] In other words, when the clutch 70 switches from engagement to disengagement, the thrust of the electric actuator 80 acts as a load on the compressed disc spring 77, which is also applied to the bearings B1 and B2.

[0141] When the clutch 70 is re-engaged, the actuator motor 81 and the drive gear 83 rotate in the opposite direction to when it was released. In this case, since the first driven gear 84 rotates in the opposite direction faster than the second driven gear 85, a phase difference is generated between the rotations of the first driven gear 84 and the second driven gear 85. Therefore, the cam groove 843 of the first driven gear 84 is circumferentially opposite to the cam groove 853 of the second driven gear 85. Figure 4B The upper side of the middle is relatively shifted.

[0142] Therefore, the rolling element Rb causes the locking portions Cb and Cb of the cam grooves 843 and 853 (refer to...) Figure 4B It disengages, rolls on inclined surfaces Is, and returns to the locking parts Ca, Ca (see reference). Figure 4A Between ), at this time, the second driven gear 85 passes through the disc spring 77 (refer to) Figure 3 The restoring force of the piston 76 causes it to move towards one end of the rotation axis X along with the piston 76, bringing it back into contact with the first driven gear 84. The pressing part 762 of the piston 76, through the force of the disc spring 77, presses the friction plate 71 towards one end of the rotation axis X (connection direction). Thus, the clutch 70 is engaged again.

[0143] like Figure 1As shown, the transmission 4 includes a control unit CU that operates multiple connecting mechanisms (SOWC61, 62 and clutch 70) to control the switching of transmission levels. The control unit CU can, for example, function as a part of an ECU (Electronic Control Unit) that comprehensively controls the vehicle's movements. The control unit CU determines whether a gear shift is needed based on a preset gear diagram, vehicle speed, and accelerator pedal depressor position, and operates SOWC61, 62 and clutch 70 based on the determination result.

[0144] As described above, the transmission device 4 has multiple gear mechanisms (first gear mechanism 40, second gear mechanism 50) with different gear ratios.

[0145] In the transmission device 4 of this embodiment, as an example, the gear ratio of the first gear mechanism 40 is set to be larger than the gear ratio of the second gear mechanism 50.

[0146] In a planetary gear mechanism, the smaller the value (λ value) obtained by dividing the number of teeth of the sun gear by the number of teeth of the ring gear, the larger the gear ratio. That is, the λ value of the first gear mechanism 40 (the number of teeth of the first sun gear 41 / the number of teeth of the first ring gear 42) is set to be less than the λ value of the second gear mechanism 50 (the number of teeth of the second sun gear 51 / the number of teeth of the second ring gear 52).

[0147] The transmission device 4 consists of three transmission stages with different transmission ratios (output speed / input speed), namely the first transmission stage, the second transmission stage, and the third transmission stage.

[0148] The first gear, known as the emergency low gear, is selected for emergency driving situations requiring greater driving force than usual for starting. "Emergency driving" includes both the initial start and subsequent driving. Examples of emergency driving include starting on a steep incline, starting with a heavy load, or driving on rough roads such as mud.

[0149] The second gear is selected for normal starts and low-speed driving. Normal starts refer to starting on a flat road, starting without a heavy load, and driving on a paved road. The third gear is selected for medium-speed and high-speed driving. That is, in the transmission 4, the second and third gears are specifically selected, and the selection time of the first gear in emergency low-speed gear is significantly shortened compared to the second and third gears.

[0150] Here, medium speed driving refers to a speed faster than low speed driving, and high speed driving refers to a speed faster than medium speed driving. Low speed driving, medium speed driving, and high speed driving are not limited to specific speed ranges, but are appropriately set according to vehicle specifications, driving environment, etc.

[0151] In addition, in the following explanations, "first gear", "second gear" and "third gear" will also be referred to as "1st speed", "2nd speed" and "3rd speed".

[0152] Figure 5 It is a connection table for speeds 1 to 3.

[0153] exist Figure 5 In the display, components in the connected state are shown with a black circle. Components in the released state have an empty column.

[0154] Figure 6 This is a collinear diagram showing the rotational speeds of each component in the transmission device 4 at speeds 1 to 3. A value of 0 on each vertical axis represents a rotational speed of 0. The direction above 0 represents rotation in one direction DA (described later), and the direction below 0 represents rotation in the other direction DB (described later). Furthermore, for ease of explanation, the rotational speeds of the input shaft 31 in speeds 1 to 3 are assumed to be the same.

[0155] Figure 7 This is a diagram showing the power transmission path at speed 1.

[0156] Figure 8 This is a diagram showing the power transmission path at 2 speeds.

[0157] Figure 9 This is a diagram showing the power transmission path at 3 speeds.

[0158] Figures 7-9 The power transmission path is indicated by thick lines. Additionally, in SOWC61, 62, and clutch 70, components in the engaged state are indicated by shading. Furthermore, in the first gear mechanism 40 and the second gear mechanism 50, components that are fixed and cannot rotate are indicated by shading.

[0159] like Figure 6 As shown, the rotational speeds of the first sun gear 41 and the second sun gear 51 are equivalent to the input rotational speed (IN) from the input shaft 31 to the transmission 4. The rotational speed of the first planetary carrier 45 is equivalent to the output rotational speed (OUT) from the transmission 4 to the output shaft 32. In the transmission 4, the gear ratio (OUT / IN) of speed 1 is set to be the smallest, and the gear ratio of speed 3 is set to be the largest. The gear ratio of speed 2 is set to be greater than speed 1 and less than speed 3. Speed ​​3 is set to a gear ratio of 1 where the input and output rotational speeds are the same.

[0160] like Figure 5 As shown, in the first speed, SOWC61 is engaged, SOWC62 is disengaged, and clutch 70 is disengaged.

[0161] Through motor 2 (refer to) Figure 1 The driver, such as Figure 7 As shown, the input shaft 31 rotates in one direction DA about the rotation axis X. Direction DA refers to the direction of rotation when the vehicle is moving forward. Direction DA can be set to, for example, counterclockwise. When direction DA is set counterclockwise, the other direction DB is clockwise.

[0162] By setting SOWC61 to the engaged state, the first gear ring 42 of the first gear mechanism 40 and the second planetary carrier 55 of the second gear mechanism 50 connected to the first gear ring 42 are fixed to the gear housing 12 without rotation. Therefore, the pinion 53 held on the second planetary carrier 55 does not revolve around the sun but rotates in the opposite direction DB. Additionally, in Figures 7-9 In the diagram, pinions 43 and 53 only indicate the direction of their revolution with arrows, omitting the diagram of their rotation direction.

[0163] The second gear ring 52 rotates freely in the other direction DB by the rotation of the pinion 53.

[0164] Thus, in speed 1, the second planetary carrier 55 and the first ring gear 42 are fixed, so the rotation of the second sun gear 51 input to the second gear mechanism 50 is not output to the first gear mechanism 40.

[0165] In the first gear mechanism 40, the first sun gear 41 rotates in one direction DA, while the first ring gear 42 is fixed and cannot rotate. The pinion 43, meshing with the first sun gear 41 and the first ring gear 42, revolves in one direction DA while rotating on its own axis in the other direction DB. Through the revolution of the pinion 43, the first planet carrier 45 rotates in one direction DA. The rotation of the first planet carrier 45 is output to the output shaft 32.

[0166] like Figure 6 As shown, in speed 1, the first ring gear 42 is fixed and rotates at 0, thus the gear ratio (OUT / IN) becomes smaller. Consequently, in speed 1, the rotation input by the first sun gear 41 is significantly reduced, and the output speed is the lowest among speeds 1 to 3.

[0167] like Figure 5 As shown, in 2nd speed, SOWC61 is in the released state, SOWC62 is in the engaged state, and clutch 70 is in the released state.

[0168] like Figure 8 As shown, the first sun gear 41 of the first gear mechanism 40 and the second sun gear 51 of the second gear mechanism 50 rotate integrally with the input shaft 31 in one direction DA.

[0169] By setting SOWC62 to the connected state, the second gear ring 52 of the second gear mechanism 50 is fixed to the gear housing 12 in a non-rotatable manner.

[0170] The pinion 53, which meshes with the second sun gear 51 rotating in one direction DA and the fixed second ring gear 52, revolves in one direction DA while rotating on its own axis in the other direction DB. The second planet carrier 55 rotates in one direction DA through the revolution of the pinion 53. The first ring gear 42 of the first gear mechanism 40, which is connected to the second planet carrier 55, also rotates in one direction DA. That is, the rotation output from the second planet carrier 55 of the second gear mechanism 50 is input to the first ring gear 42 of the first gear mechanism 40.

[0171] The rotation input to the first gear ring 42 is speed-changed by a small gear ratio of the second gear mechanism 50. Therefore, as... Figure 6 As shown, the rotational speed of the first ring gear 42 is lower than that of the first sun gear 41.

[0172] like Figure 8 As shown, due to the difference in rotational speed between the first sun gear 41 and the first ring gear 42, the pinion 43 revolves in one direction DA while rotating on its own axis in the other direction DB. The first planetary carrier 45 rotates in one direction DA through the revolution of the pinion 43. The rotation of the first planetary carrier 45 is output to the output shaft 32.

[0173] Thus, at speed 2, the rotational speed reduced by the second gear mechanism 50 is input to the first ring gear 42 of the first gear mechanism 40 via the second planetary carrier 55. Therefore, the first ring gear 42 rotates at a speed lower than the input speed. Consequently, as... Figure 3 As shown, at speed 2, compared to speed 1 where the first gear ring 42 is fixed and does not rotate, the gear ratio (OUT / IN) is larger. The output rotational speed of speed 2 is higher than that of speed 1, but lower than the output rotational speed of speed 3 which has the same input rotational speed.

[0174] Additionally, at 2 speeds, SOWC61 can be in an engaged state instead of an unengaged state. In this case, the second planetary carrier 55 and the first ring gear 42 can only rotate in one direction, DA.

[0175] like Figure 5 As shown, at 3rd speed, SOWC61 and SOWC62 are in the released state, and clutch 70 is in the engaged state.

[0176] like Figure 9 As shown, the first sun gear 41 of the first gear mechanism 40 and the second sun gear 51 of the second gear mechanism 50 rotate together with the input shaft 31 in one direction DA.

[0177] like Figure 2 As shown, the clutch hub 74 of the clutch 70 is connected to the clutch drum 75, and the second gear ring 52 connected to the clutch drum 75 is directly connected to the input shaft 31 connected to the clutch hub 74.

[0178] The second sun gear 51 and the second ring gear 52 rotate in one direction DA at the same rotational speed, while the pinion 53 does not rotate on its own axis but revolves in the same direction DA. The second planetary carrier 55 and the first ring gear 42 connected to the second planetary carrier 55 rotate in one direction DA at the same rotational speed as the input shaft 31 through the revolution of the pinion 53.

[0179] That is, the first sun gear 41 and the first ring gear 42 of the first gear mechanism 40 rotate in one direction DA at the same rotational speed as the input shaft 31. The pinion 43, which meshes with the first sun gear 41 and the first ring gear 42, does not rotate on its own axis but revolves in one direction DA. The first planet carrier 45 rotates in one direction DA at the same rotational speed as the input shaft 31 through the revolution of the pinion 43. The rotation of the first planet carrier 45 is output to the output shaft 32.

[0180] Thus, at speed 3, all six components, including the first gear mechanism 40 and the second gear mechanism 50, rotate at the same speed as the input shaft 31.

[0181] Thus, clutch 70 functions as a direct-connection clutch that equalizes the rotational speeds of input shaft 31 and output shaft 32. Figure 6 As shown, at speed 3, the first gear ring 42 rotates at the same speed as the input shaft 31, thus the gear ratio becomes the maximum of 1. The output speed of speed 3, which matches the input speed, is the highest among speeds 1 to 3.

[0182] At 3rd speed, SOWC61 and 62 can be in an engaged state instead of an unengaged state. In this case, the second planetary carrier 55 and the second ring gear 52 can only rotate in one direction, DA.

[0183] A large amount of torque is required when the vehicle starts and during acceleration. Even greater torque is needed during emergency driving. Torque can also be increased by increasing the output of electric motor 2, but this may negatively impact the vehicle's fuel efficiency.

[0184] Here, the larger the reduction ratio (input speed / output speed) in the transmission 4, the greater the output torque. As mentioned above, in speed 1, the first gear ring 42 is fixed and its speed is 0, so the reduction ratio is the largest among speeds 1 to 3. That is, in the transmission 4, by increasing the reduction ratio to increase torque, the output of the motor 2 can be reduced, and the large torque required for emergency driving can be obtained.

[0185] On the other hand, when the vehicle is cruising at high speed, large torque is not required, but it is preferable to reduce the meshing loss of the gears in the transmission 4. Therefore, at 3rd speed, the clutch 70 is engaged, and the gear ratio 1 is set so that all components of the first gear mechanism 40 and the second gear mechanism 50 rotate at the same speed.

[0186] As described above, clutch 70 is a normally closed clutch 70, which operates without actuating the electric actuator 80, via disc spring 77 (see reference). Figure 2 The clutch 70 is engaged due to the force exerted by the electric actuator 80. When the clutch 70 is changed to the released state, the thrust of the electric actuator 80 acts as a load on the compressed disc spring 77 on the bearing B1 of the support retainer 78 and the bearing B2 of the support clutch drum 75.

[0187] Here, when the thrust generated by the electric actuator 80 and the torque generated by the circumferential rotation about the rotation axis X act on bearings B1 and B2, the friction of bearings B1 and B2 increases, which may affect the power consumption of the electric actuator 80 used to maintain the released state of the clutch 70. In addition, the longer the thrust and rotational torque of the electric actuator 80 act together, the more likely it is to affect the durability of bearings B1 and B2.

[0188] like Figure 7 As shown, at speed 1, clutch 70 is in the released state. Clutch drum 75, connected to the second gear ring 52, rotates in the opposite direction DB. Retainer 78, splinedly engaged with clutch drum 75, also rotates in the opposite direction DB. That is, at speed 1, the thrust and rotational torque of electric actuator 80 act simultaneously on bearings B1 and B2.

[0189] like Figure 8 As shown, at speed 2, clutch 70 is in the released state. Because SOWC 62 is engaged, the second gear ring 52 is fixed and cannot rotate. Therefore, the clutch drum 75 connected to the second gear ring 52 and the retainer 78 spline-fitted with the clutch drum 75 do not rotate. That is, at speed 2, only the thrust of the electric actuator 80 acts on bearings B1 and B2; rotational torque does not act on bearings B1 and B2.

[0190] like Figure 9 As shown, clutch 70 is engaged at 3rd speed. Clutch drum 75, connected to the second gear ring 52, rotates in one direction DA, and retainer 78, splinedly engaged with clutch drum 75, rotates in one direction DA. That is, at 3rd speed, only rotational torque acts on bearings B1 and B2, and no thrust from electric actuator 80 acts on them.

[0191] Thus, in the transmission device 4, only at speed 1, the thrust and rotational torque generated by the electric actuator 80 act on bearings B1 and B2. In this embodiment, speed 1 is set as an emergency low gear and is not selected during normal driving. That is, in the transmission device 4 of this embodiment, the transmission level is set such that the time for the thrust and rotational torque generated by the electric actuator 80 to act on bearings B1 and B2 is shortened.

[0192] Here, the clutch 70 can also be configured to directly connect the second planetary carrier 55 and the input shaft 31. However, in this case, the clutch 70 is not connected to the second bearing, which cannot rotate at 2 speeds. Therefore, at 2 speeds, both thrust and rotational torque act on bearings B1 and B2.

[0193] That is, by configuring the clutch 70 and setting the transmission stages, the transmission device 4 of this embodiment can reduce the time during which the thrust and rotational torque of the electric actuator 80 act on the bearings B1 and B2. This reduces friction in the bearings B1 and B2, thereby reducing the power consumption of the electric actuator 80. Furthermore, it reduces the impact on the durability of the bearings B1 and B2.

[0194] Hereinafter, examples of the speed change device 4 in one aspect of the present invention are given.

[0195] (1) The transmission 4 has a first planetary gear mechanism 40, a second planetary gear mechanism 50, SOWC61 (first connecting mechanism), SOWC62 (second connecting mechanism) and a clutch 70 (third connecting mechanism).

[0196] The first planetary gear mechanism 40 has a first sun gear 41 connected to the input shaft 31, a first planet carrier 45 connected to the output shaft 32, and a first gear ring 42.

[0197] The second planetary gear mechanism 50 has a second sun gear 51 connected to the input shaft 31, a second planet carrier 55 connected to the first ring gear 42, and a second ring gear 52.

[0198] SOWC61 can connect the first gear ring 42 and the second planetary carrier 55 to the gear housing 12 (first fixed element).

[0199] SOWC62 can connect the second gear ring 52 to the gear housing 12 (second fixing element).

[0200] The clutch 70 can connect the second gear ring 52 to the input shaft 31.

[0201] The clutch 70 has a friction plate 71 (connecting element), a pressing part 762, a disc spring 77 (spring), an electric actuator 80 (actuator), and bearings B1 and B2 (bearings).

[0202] Friction plate 71 is connected to the second gear ring 52 and the input shaft 31. Specifically, friction plate 71 has a drive plate 72 and a driven plate 73. Drive plate 72 is connected to input shaft 31, and driven plate 73 is connected to the second gear ring 52.

[0203] The pressing part 762 presses the friction plate 71 toward one end in the X direction of the rotation axis (the axial direction of the input shaft 31), i.e., the connection direction, thereby connecting the friction plate 71.

[0204] The disc spring 77 applies force to the pressing part 762 in the connecting direction.

[0205] The electric actuator 80 generates a thrust on the other end of the rotation axis X direction, i.e. the release direction, and uses this thrust to displace the pressing part 762 in the release direction, thereby releasing the friction plate 71.

[0206] Bearings B1 and B2 support the retainer 78 and clutch drum 75, which are rotating elements of the clutch 70, and bear the load of the disc spring 77 compressed by the thrust when the friction plate 71 is released.

[0207] In transmission 4, the first, second, and third gear stages are achieved by switching the engagement and disengagement of SOWC61, SOWC62, and clutch 70.

[0208] In the first gearing stage, engage SOWC61 and disengage SOWC62 and clutch 70.

[0209] In the second gearing stage, engage SOWC62 and disengage SOWC61 and clutch 70.

[0210] In the third gearing stage, clutch 70 is engaged, and SOWC61 and SOWC62 are disengaged.

[0211] The second gear is selected for normal starting and low-speed driving.

[0212] The third gear is selected for both medium and high speed driving.

[0213] The first gear is selected for emergency driving situations where greater driving force than is required for a normal start.

[0214] The friction plate 71 of the clutch 70 is engaged by being pressed by a pressing part 762, which is subjected to force in the engagement direction by a disc spring 77. When the clutch 70 is released, it is released by displacing the pressing part 762 in the release direction using the thrust of the actuator.

[0215] Bearings B1 and B2 support the retainer 78 and clutch drum 75, which are rotating elements of the clutch 70. Therefore, when these rotating elements rotate, rotational torque is input to bearings B1 and B2.

[0216] Furthermore, when the clutch 70 is released, the disc spring 77 is compressed by the thrust of the electric actuator 80, and therefore bearings B1 and B2 bear the load of the compressed disc spring 77. That is, when the clutch 70 is released, the thrust of the electric actuator 80 acts as a load on bearings B1 and B2 as the disc spring 77.

[0217] When the rotational torque and the thrust of the electric actuator 80 act on bearings B1 and B2, the friction of bearings B1 and B2 increases. That is, the longer the rotational torque and the thrust of the electric actuator 80 act together, the more likely it is to affect the durability of bearings B1 and B2.

[0218] In this embodiment, clutch 70 is a direct-connect clutch that directly connects the second gear ring 52 to the input shaft 31. Furthermore, clutch 70 is disengaged in the first and second transmission stages and engaged in the third transmission stage. In the second transmission stage, SOWC 62 is engaged, thus fixing the second gear ring 52 so that it cannot rotate.

[0219] That is, in this embodiment, only in the first transmission stage, both the rotational torque and the electric actuator 80 act on the bearings B1 and B2 of the clutch 70.

[0220] Furthermore, in this embodiment, the first gear is set as an emergency low-speed gear, meaning it is selected only during emergency driving. Therefore, compared to setting the first gear for normal starting and low-speed driving, this embodiment reduces the time that the rotational torque and the electric actuator 80 act on bearings B1 and B2. That is, it reduces the time of high friction in bearings B1 and B2, mitigating the decrease in the durability of bearings B1 and B2.

[0221] (2) The clutch 70 has a piston 76 and a retainer 78.

[0222] The piston 76 has a pressing part 762. The pressing part 762 is disposed opposite to the friction plate 71 on the other end side in the rotation axis X direction.

[0223] The retainer 78 is disposed opposite to the pressing part 762 on the other end side of the rotation axis X direction, and holds the disc spring 77 between itself and the pressing part 762.

[0224] The clutch 70 includes a bearing B1 (first bearing) that supports a retainer 78, which is a rotating element, on the clutch housing 13 (third fixed element).

[0225] The actuator is an electric actuator 80 that displaces the piston 76 in the direction of the rotation axis X. The electric actuator 80 has a portion that overlaps with the piston 76 when viewed from the direction of the rotation axis X.

[0226] The retainer 78, acting as a rotating element, holds the disc spring 77 between itself and the pressing part 762. Therefore, the rotational torque generated by the rotation of the retainer 78 and the thrust generated by the electric actuator 80 act on the bearing B1 supporting the retainer 78. As described above, in this embodiment, the time during which both the thrust and rotational torque of the electric actuator 80 act simultaneously on the bearing B1 is reduced. Therefore, the impact on the durability of the bearing B1 can be reduced.

[0227] Alternatively, the actuator that displaces the piston 76 can be, for example, a hydraulic actuator. A hydraulic actuator has an oil chamber between the clutch drum 75 and the piston 76, and supplies oil pressure to the oil chamber to displace the piston 76. Therefore, when using a hydraulic actuator, a hydraulic supply circuit needs to be provided in the transmission 4. Furthermore, to supply sufficient oil pressure for the displacement of the piston 76, the oil chamber needs to be enlarged, thus there is a tendency to increase the size of the clutch drum 75 and the piston 76.

[0228] In this embodiment, an electric actuator 80 is used as the actuator. Therefore, it is not necessary to provide a hydraulic supply circuit in the transmission 4. In addition, since an oil chamber is not required, the size of the clutch drum 75 and piston 76 can be reduced.

[0229] Furthermore, in this embodiment, the electric actuator 80 is configured to have a portion that overlaps with the piston 76 when viewed from the rotation axis X direction. That is, the electric actuator 80 is configured to be parallel to the friction plate 71 and the piston 76 in the rotation axis X direction. As a result, the size of the transmission device 4 in the radial direction of the rotation axis X can be reduced.

[0230] (3) The clutch 70 is a rotating element and has a clutch hub 74 and a clutch drum 75.

[0231] The clutch hub 74 is connected to the input shaft 31.

[0232] The clutch drum 75 is located on the outer periphery of the clutch hub 74 and is connected to the second gear ring 52.

[0233] The friction plate 71 has: a drive plate 72 (first friction plate), which is disposed in the radial direction of the rotation shaft X (radial direction of the input shaft 31) between the clutch hub 74 and the clutch drum 75 and engages with the clutch hub 74; and a driven plate 73 (second friction plate), which is disposed in the radial direction of the rotation shaft X between the clutch hub 74 and the clutch drum 75 and engages with the clutch drum 75.

[0234] The pressing part 762 and the retainer 78 of the piston 76 engage with the inner circumference of the clutch drum 75, and are configured opposite to the drive plate 72 and the driven plate 73 on the other end side of the rotation axis X direction.

[0235] The bearing has a bearing B2 (second bearing) that supports the clutch drum 75 on the clutch housing 13.

[0236] In the clutch 70 of this embodiment, a clutch hub 74 is housed within the inner circumference of the clutch drum 75, and a drive plate 72 and a driven plate 73 are arranged between the clutch drum 75 and the clutch hub 74. That is, the rotating element connected to the second gear ring 52, i.e., the clutch drum 75, and the rotating element connected to the input shaft 31, i.e., the clutch hub 74, are arranged overlapping in the radial direction of the rotation axis X. As a result, the transmission device 4 can reduce the dimensional expansion in the direction of the rotation axis X.

[0237] The retainer 78 and piston 76 of the disc spring 77 engage with the clutch drum 75, which is a rotating element. Therefore, the rotational torque generated by the rotation of the clutch drum 75 and the thrust generated by the electric actuator 80 act on the bearing B2 supporting the clutch drum 75. As described above, in this embodiment, the time during which both the thrust and rotational torque of the electric actuator 80 act simultaneously on the bearing B2 is reduced. Therefore, the impact on the durability of the bearing B2 can be reduced.

[0238] (4) The transmission device 4 has a plate component 15 connected to the clutch housing 13 and located on the other side of the rotation axis X direction relative to the retainer 78.

[0239] The retainer 78 has a retaining portion 781 and a cylindrical portion 782. The retaining portion 781 is located between the pressing portion 762 and the plate member 15 in the rotation axis X direction, and retains the disc spring 77 between itself and the pressing portion 762. The cylindrical portion 782 is provided on the inner periphery of the retaining portion 781 and extends to the other end in the rotation axis X direction.

[0240] The piston 76 has a base 761 that is connected to the inner diameter side of the pressing part 762 and extends along the rotation axis X direction.

[0241] The inner circumference of the cylinder 782 is inserted into the base 761 of the piston 76 in a rotatable manner, and the outer circumference of the cylinder 782 is supported on the plate member 15 via the bearing B1 (first bearing).

[0242] Viewed radially from the rotation axis X, bearing B1 is positioned to overlap with the cylindrical portion 782 of retainer 78 and the base 761 of piston 76.

[0243] The piston 76 and retainer 78 are arranged along the rotation axis X. When the piston 76 and retainer 78 are tilted relative to the rotation axis X, the piston 76 may come into contact with the friction plate 71 when the clutch 70 is in the released state. In this case, a drag torque may be generated on the friction plate 71, increasing the power consumption of the motor 2. In this embodiment, viewed radially from the rotation axis X, the cylindrical portion 782 of the retainer 78 and the base 761 of the piston 76 are arranged to overlap with the bearing B1. In other words, both the cylindrical portion 782 of the retainer 78 and the base 761 of the piston 76 are supported by the bearing B1. This reduces the tilt of the piston 76 and retainer 78 relative to the rotation axis X.

[0244] (5) The electric actuator 80 has a drive gear 83, a first driven gear 84 and a second driven gear 85 (driven gears) and a cam mechanism. Specifically, the cam mechanism consists of a cam groove 843 of the first driven gear 84, a cam groove 853 of the second driven gear 85, and a rolling element Rb held between the cam grooves 843 and 853.

[0245] The drive gear 83 is disposed on the outer periphery of the base 761 of the piston 76 and rotates about the axis X1 along the rotation axis X direction.

[0246] The first driven gear 84 and the second driven gear 85 are arranged radially on the rotating shaft X between the drive gear 83 and the base 761 of the piston 76, and mesh with the drive gear 83.

[0247] The cam mechanism converts the rotational motion input from the drive gear 83 to the first driven gear 84 and the second driven gear 85 into linear motion, causing the second driven gear 85 to move along the rotation axis X direction.

[0248] The piston 76 has a facing portion 763 that extends from the base 761 toward the outer diameter side and is opposite to the second driven gear 85 at the other end in the direction of the rotation axis X.

[0249] The second driven gear 85 is disposed between the plate member 15 and the opposing part 763 of the piston 76.

[0250] The second driven gear 85 moves toward the other end in the direction of the rotation axis X and presses the opposite part 763 of the piston 76, thereby causing the piston 76 to displace toward the other end in the direction of the rotation axis X.

[0251] As an electric actuator 80, by using a linear actuator that converts the rotational motion of the drive gear 83 into the linear motion of the driven gear, the electric actuator 80 can be miniaturized.

[0252] Furthermore, in this embodiment, the first driven gear 84 and the second driven gear 85 are disposed between the opposing portion 763 of the piston 76 and the plate member 15, and the drive gear 83 is disposed on the outer diameter side of the first driven gear 84 and the second driven gear 85. This reduces the size of the transmission device 4 in the X-axis rotation direction.

[0253] (i) The input shaft 31 is connected to the motor 2 (drive source).

[0254] The output shaft 32 is connected to the differential mechanism 9.

[0255] The output shaft 32 has a portion that overlaps with the input shaft 31 in the radial direction of the rotation axis X.

[0256] The differential mechanism 9 is disposed in the direction of the rotation axis X between the electric motor 2 and the first planetary gear mechanism 40 and the second planetary gear mechanism 50.

[0257] The clutch 70 is located on the opposite side of the differential mechanism 9 in the rotation axis X direction relative to the first planetary gear mechanism 40 and the second planetary gear mechanism 50.

[0258] With this structure, the power transmission device 1 can reduce the increase in the radial dimension of the rotation shaft X. In particular, in the structure where the output shaft 32 is folded back towards the input shaft 31, space is easily created on the side of the power transmission device 1 opposite to the input shaft 31 and the output shaft 32 in the direction of the rotation shaft X. For example, by arranging a clutch 70 or an electric actuator 80 in this space, the space can be utilized effectively, which is beneficial for layout.

[0259] Furthermore, between the first planetary gear mechanism 40 or the second planetary gear mechanism 50 and the electric motor 2, an element connected to the differential mechanism 9 is sandwiched in the X direction of the rotation axis. With this structure, the electric motor 2 and the speed change device 4 are arranged on both sides with the differential mechanism 9 as the center, thus improving the weight balance of the entire device.

[0260] In the above implementation methods, such as Figure 1 The diagram illustrates an example of the connection between SOWC61 (first coupling mechanism) and the first gear ring 42, but is not limited to this method. SOWC61 can also be connected to the planet carrier plate 55b of the second planet carrier 55.

[0261] The first gear ring 42 is connected to the planet carrier plate 55b. Therefore, when the SOWC61 is in the connected state by connecting the SOWC61 to the planet carrier plate 55b of the second planet carrier 55, the first gear ring 42 can be fixed in a non-rotatable manner.

[0262] In this embodiment, an example is given of applying the device of a certain aspect of the present invention to a power transmission device 1 mounted in a vehicle, but it is not limited to this approach. The device of a certain aspect of the present invention can also be applied to vehicles. Furthermore, since multiple embodiments and modifications are described in this embodiment, they can be combined arbitrarily.

[0263] The embodiments of the present invention have been described above. However, the above embodiments are merely one example of the application of the present invention and do not imply that the technical scope of the present invention is limited to the specific structures of the above embodiments. Appropriate modifications can be made within the scope of the inventive concept.

[0264] Symbol Explanation

[0265] 1: Power transmission device

[0266] 4: Speed ​​Transmission

[0267] 12: Gear housing (first fixed element, second fixed element)

[0268] 13: Clutch housing (third fixed element)

[0269] 15: Plate components

[0270] 31: Input axis

[0271] 32: Output shaft

[0272] 40: First planetary gear mechanism (first gear mechanism)

[0273] 41: First Sun Gear

[0274] 42: First gear ring

[0275] 45: First Planetary Carrier

[0276] 50: Second planetary gear mechanism (second gear mechanism)

[0277] 51: Second Sun Gear

[0278] 52: Second gear ring

[0279] 55: Second Planetary Carrier

[0280] 61: Optional one-way clutch (SOWC) (first coupling mechanism)

[0281] 62: Optional one-way clutch (SOWC) (second coupling mechanism)

[0282] 70: Clutch (Third Connecting Mechanism)

[0283] 71: Friction plate (connecting element)

[0284] 72: Drive plate (first friction plate)

[0285] 73: Driven plate (second friction plate)

[0286] 74: Clutch hub (rotating element)

[0287] 75: Clutch drum (rotating element)

[0288] 76: Piston

[0289] 761: Base

[0290] 762: Pressing part

[0291] 763: Relative Part

[0292] 77: Disc spring (spring)

[0293] 78: Retainer (rotating element)

[0294] 781: Maintenance Department

[0295] 782: Cylinder section

[0296] 80: Electric actuator (actuator)

[0297] 83: Drive gear

[0298] 84: First driven gear (driven gear)

[0299] 85: Second driven gear (driven gear)

[0300] 843, 853: Cam groove (cam mechanism)

[0301] B1, B2: Bearings

[0302] Rb: Rotating body (cam mechanism)

[0303] X: Rotation axis

[0304] X1: Axis

Claims

1. A variable speed device characterized by, has: a first planetary gear mechanism having a first sun gear connected to an input shaft, a first carrier connected to an output shaft, and a first ring gear; a second planetary gear mechanism having a second sun gear connected to the input shaft, a second carrier connected to the first ring gear, and a second ring gear; a first coupling mechanism capable of coupling the first ring gear and the second carrier to a first fixed element; a second coupling mechanism capable of coupling the second ring gear to a second fixed element; a third coupling mechanism capable of coupling the second ring gear to the input shaft, the third coupling mechanism has: a coupling element connected to the second ring gear and the input shaft; a pressing portion that couples the coupling element by pressing the coupling element toward one end side of the input shaft in an axial direction, i.e., a coupling direction; a spring that applies a force to the pressing portion in the coupling direction; an actuator that generates a thrust force in the other end side of the input shaft in an axial direction, i.e., a release direction, and displaces the pressing portion in the release direction by the thrust force to release the coupling element; a bearing that supports a rotating element of the third coupling mechanism and receives a load of the spring compressed by the thrust force when the coupling element is released, by switching coupling and release of the first coupling mechanism, the second coupling mechanism, and the third coupling mechanism, a first speed stage, a second speed stage, and a third speed stage are realized, in the first speed stage, the first coupling mechanism is coupled, and the second coupling mechanism and the third coupling mechanism are released, in the second speed stage, the second coupling mechanism is coupled, and the first coupling mechanism and the third coupling mechanism are released, in the third speed stage, the third coupling mechanism is coupled, and the first coupling mechanism and the second coupling mechanism are released, the second speed stage is selected at the time of normal start and low-speed travel, the third speed stage is selected at the time of medium-speed travel and high-speed travel, the first speed stage is selected at the time of emergency travel requiring a greater driving force than at the time of normal start.

2. The transmission device according to claim 1, wherein the third coupling mechanism has: a piston disposed opposite the coupling element on the other end side in the axial direction and having the pressing portion; and a retainer disposed opposite the pressing portion on the other end side in the axial direction and holding the spring between the pressing portion, the bearing has a first bearing that supports the retainer as the rotating element of the third coupling mechanism, the actuator is an electric actuator that displaces the piston in the axial direction, and the electric actuator has a portion that overlaps the piston when viewed in the axial direction.

3. The transmission device according to claim 2, wherein the third coupling mechanism has, as the rotating element, a clutch hub connected to the input shaft and a clutch drum disposed on an outer periphery of the clutch hub and connected to the second ring gear, The coupling element has: a first friction plate disposed between the clutch hub and the clutch drum in the radial direction of the input shaft and engaged with the clutch hub; a second friction plate disposed between the clutch hub and the clutch drum in the radial direction of the input shaft and engaged with the clutch drum, The pressing portion of the piston and the retainer are engaged with the inner periphery of the clutch drum, and are disposed opposite the first friction plate and the second friction plate on the other end side in the axial direction, The bearing has a second bearing that supports the clutch drum by the third fixed element.

4. The transmission device according to claim 2 or 3, characterized in that a plate member is connected to the third fixed element and is located on the other end side in the axial direction with respect to the retainer, the retainer has a retaining portion that is located between the pressing portion and the plate member in the axial direction and retains the spring between the pressing portion, and a cylindrical portion that is provided to the inner periphery of the retaining portion and extends to the other end side in the axial direction, the piston has a base portion that is connected to the inner diameter side of the pressing portion and extends in the axial direction, the inner periphery of the cylindrical portion of the retainer is externally inserted into the base portion of the piston in a rotatable manner, and the outer periphery of the cylindrical portion is supported to the plate member via the first bearing, the first bearing is disposed at a position overlapping the cylindrical portion and the base portion in the radial direction of the input shaft.

5. The transmission device according to claim 4, characterized in that the electric actuator has: a drive gear that is disposed to the outer periphery of the base portion of the piston and rotates around an axis in the axial direction; a driven gear that is disposed between the drive gear and the base portion of the piston in the radial direction of the input shaft and engages with the drive gear; a cam mechanism that moves the driven gear in the axial direction by converting a rotational motion input from the drive gear to the driven gear into a linear motion, the piston has an opposite portion that extends outward from the base portion and is opposite the driven gear on the other end side in the axial direction, the driven gear is disposed between the plate member and the opposite portion of the piston, the driven gear moves to the other end side in the axial direction and presses the opposite portion of the piston, thereby displacing the piston to the other end side in the axial direction.

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