Drive device for electric vehicles

Abstract

In an electric vehicle drive unit capable of switching between high and low reduction ratios, a configuration is achieved that allows for smooth mode switching of the rotational transmission state switching device even during regenerative driving when regenerative torque acts on the drive motor. The control unit of the electric vehicle drive unit is equipped with a coordination control function that performs a pre-shift procedure. This pre-shift procedure involves, as the reduction ratio switching function switches the mode of the two-stage transmission (3), pressing one of the first engagement claws (94 or 97) that extends radially or axially from the base (93 (or 96)) of the second engagement claw (75) supported by the pivot on the second component (75) towards the other side in the circumferential direction through the protrusion (100) to disengage it from the engagement recess (77), while reducing the regenerative torque of the drive motor (2) and increasing the braking force of the friction brake device (5).

Description

Technical Field

[0001] This disclosure relates to a drive unit for an electric vehicle that increases the output torque of an electric motor (decelerates rotation) and transmits it to the drive wheels. Background Technology

[0002] With the trend of reducing fossil fuel consumption in recent years, research on electric vehicles and hybrid vehicles has made progress and some have been implemented. The electric motor, which is the power source of electric vehicles and hybrid vehicles, is different from the internal combustion engine (engine) that works by directly burning fossil fuels. The torque and rotation speed characteristics of the output shaft are preferred for automobiles (usually, the maximum torque is generated at start-up). Therefore, it is not necessary to install a transmission like that of a conventional automobile with an internal combustion engine as the drive source.

[0003] However, even when using an electric motor as the drive source, acceleration and high-speed performance can be improved by incorporating a transmission. Specifically, by incorporating a transmission, the relationship between vehicle speed and acceleration can be made smoother, approaching that of a car equipped with a gasoline engine and a transmission in its power transmission system. For more information, see [link to relevant documentation]. Figure 36 Please provide an explanation.

[0004] For example, if a power transmission device with a large reduction ratio is configured between the output shaft of the electric motor and the input part of the differential gear connected to the drive wheel, then the relationship between the acceleration (G) and the driving speed (km / h) of the electric vehicle becomes... Figure 36 As shown by solid line a. That is, it has excellent acceleration performance at low speeds, but cannot perform high-speed driving. In contrast, if a power transmission device with a small reduction ratio is arranged between the above-mentioned output shaft and the above-mentioned input section, then this relationship becomes Figure 36 Like the dashed 'b'. That is, it can travel at high speeds, but its acceleration performance at low speeds is compromised.

[0005] In contrast, if a gearbox is installed between the output shaft and the input section, and the reduction ratio of the gearbox is changed according to the vehicle speed, a characteristic can be obtained where the portion to the left of point P in solid line a and the portion to the right of point P in dashed line b are continuous. It can be seen that this characteristic is similar to... Figure 36 The vehicles with similar output levels, as shown by the dashed line c, are roughly the same. In terms of acceleration and high-speed performance, they can achieve the same performance as gasoline engine vehicles with a transmission in the power transmission system.

[0006] International Publication No. 2023 / 135870 discloses a structure for a drive unit for an electric vehicle. This drive unit uses a two-stage transmission to increase the output torque of a drive motor, which serves as the drive source, and transmits it to a differential gear. The two-stage transmission includes: a friction engagement device capable of switching between engagement and disengagement modes; and a rotational transmission state switching device capable of switching between a locking mode, a one-way clutch mode, and a free mode. In this electric vehicle drive unit, by switching between the mode of the friction engagement device and the mode of the rotational transmission state switching device, the two-stage transmission can switch between a low reduction ratio mode (small reduction ratio) and a high reduction ratio mode (larger than the low reduction ratio mode) between the input and output components.

[0007] Specifically, the secondary transmission can be switched to a high reduction ratio mode by switching the electric friction clutch device to the disengagement mode and the aforementioned rotational transmission state switching device to the lock mode. Furthermore, the secondary transmission can be switched to a low reduction ratio mode by switching the electric friction clutch device to the engagement mode and the rotational transmission state switching device to the free mode.

[0008] In the drive system for electric vehicles described in International Publication No. 2023 / 135870, during normal forward driving (power-operated driving), when switching from a high reduction ratio mode to a low reduction ratio mode, after the rotational transmission state switching device is switched from a locked mode to a one-way clutch mode, the friction engagement device is switched from a disengaged mode to an engaged mode. This prevents the occurrence of shock (gear shift shock) during reduction ratio switching.

[0009] The rotational transmission state switching device constituting the drive unit for the electric vehicle includes: a first component, a second component, a mode selection component, a first claw component, a second claw component, a first claw force application component, and a second claw force application component.

[0010] The first component has multiple engaging recesses in the circumferential direction on its outer peripheral surface.

[0011] The second component is arranged coaxially around the first component.

[0012] The mode selection component has radially protruding protrusions at multiple locations in the circumferential direction, and rotates with the rotation of the drive cam used to switch the friction clutch device.

[0013] The first claw component has a first base pivotally supported on the second component and a first engaging claw extending from the first base toward a first side in a circumferential direction.

[0014] The second claw component has a second base pivotally supported on the second component and a second engaging claw extending from the second base toward a second side in a circumferential direction.

[0015] The first claw force-applying component elastically applies force to the first engaging claw in the direction of engaging with the engaging recess.

[0016] The second claw force-applying component elastically applies force to the second engaging claw in the direction of engaging with the engaging recess.

[0017] The rotary transmission state switching device switches between free mode, locked mode, and one-way clutch mode as the mode selection component rotates.

[0018] Specifically, when the rotation transmission state switching device is switched to free mode, the mode selection component is rotated, and the protrusion pushes the first and second engaging claws radially outward and upward to disengage them from the engaging recess. Thus, regardless of the relative rotation direction of the first and second components, the rotation of the first component relative to the second component is allowed.

[0019] When the rotation transmission state switching device is switched to the locking mode, the protrusion is positioned at the portion that is offset from the first and second engaging claws in the circumferential direction, and the first and second engaging claws are engaged with the engaging recess, thereby preventing the first component from rotating relative to the second component regardless of the relative rotation direction of the first and second components.

[0020] When the rotation transmission state switching device is switched to the one-way clutch mode, the protrusion pushes the second engagement pawl radially outward and upward to disengage it from the engagement recess, thereby allowing only the first component to rotate in a predetermined direction relative to the second component and preventing rotation in the opposite direction.

[0021] Existing technical documents

[0022] Patent documents

[0023] Patent Document 1: International Publication No. 2023 / 135870 Summary of the Invention

[0024] The problem that the invention aims to solve

[0025] In the drive unit for electric vehicles described in International Publication No. 2023 / 135870, during regenerative driving when regenerative torque acts on the drive motor, when switching from a high reduction ratio mode to a low reduction ratio mode, it is necessary to switch the rotational transmission state switching device from a locked mode to a one-way clutch mode, and then to a free mode.

[0026] Here, when the vehicle is regenerating forward in a high reduction ratio mode, the first component is subjected to torque in the opposite direction to the predetermined direction, i.e., the direction in which rotation is prevented by the rotation transmission state switching device. Therefore, the circumferential side of the engagement recess of the first component is forcefully pushed by the front end of the first engagement pawl. Consequently, the force required to press the first engagement pawl radially outward using the protrusion to switch the rotation transmission state switching device from the locked mode to the one-way clutch mode may become excessive, and in significant cases, it may be impossible to switch the rotation transmission state switching device mode.

[0027] If a high-output motor is used as the shift motor to drive the drive cam, the rotational transmission state switching device can be switched during forward regeneration travel in high reduction ratio mode, regardless of the torque applied to the first component. However, this results in a larger shift motor.

[0028] In view of the above, the present disclosure aims to achieve a structure in which, in a drive unit for an electric vehicle capable of switching between high and low reduction ratios, during regenerative driving when regenerative torque acts on the drive motor, the mode switching can be performed smoothly when switching from a low reduction ratio mode to a high reduction ratio mode.

[0029] Solution for solving the problem

[0030] One aspect of the present invention provides a drive unit for an electric vehicle, comprising a drive motor, a two-stage transmission, a torque transmission mechanism, a friction braking device, and a control device.

[0031] The aforementioned drive motor has a motor output shaft.

[0032] The aforementioned two-stage transmission includes an input component, an output component, a rotating component, an electric friction clutch device, and a rotation state switching device.

[0033] The aforementioned input component is an input component capable of transmitting torque between itself and the output shaft of the aforementioned motor.

[0034] The output component is supported so that it can rotate relative to the input component.

[0035] The aforementioned rotating component is supported so that it can rotate relative to the aforementioned input component and the aforementioned output component.

[0036] The aforementioned electric friction clutch device includes: a first clutch component, a second clutch component, a friction engagement part, a cam device, and an electric actuator.

[0037] The aforementioned first clutch component rotates integrally with the aforementioned rotating component, or is constituted by the rotating component itself;

[0038] The second clutch component is coaxial with the first clutch component and is supported relative to the first clutch component, and rotates integrally with the input component or the output component, or is constituted by the input component or the output component itself.

[0039] The aforementioned friction engagement portion has at least one first friction plate and at least one second friction plate supported to allow for axial relative displacement, and is disposed between the aforementioned first clutch component and the aforementioned second clutch component.

[0040] The aforementioned cam device has a driving cam and a driven cam supported for relative rotation and axial displacement relative to the driving cam. As the driving cam rotates, the axial distance between the driving cam and the driven cam expands / contracts.

[0041] The aforementioned electric actuator has a shift motor and a reducer, and the shift motor drives the aforementioned drive cam to rotate via the reducer.

[0042] The aforementioned electric friction clutch device is configured to switch between a connection mode and a disengagement mode by expanding / reducing the axial dimension of the aforementioned cam device. The connection mode transmits torque between the first clutch component and the second clutch component by pressing the at least one first friction plate and the at least one second friction plate together. The disengagement mode does not transmit torque between the first clutch component and the second clutch component by releasing the force that presses the at least one first friction plate and the at least one second friction plate together.

[0043] The aforementioned rotary transmission state switching device comprises: a first component, a second component, a mode selection component, a first claw component, a second claw component, a first claw force application component, and a second claw force application component.

[0044] The aforementioned first component has multiple engaging recesses in the circumferential direction.

[0045] The second component is coaxially arranged with the first component.

[0046] The aforementioned mode selection component has protrusions that extend radially or axially at multiple locations in the circumferential direction, and rotates or displaces axially as the aforementioned drive cam rotates.

[0047] The first claw component has a first base pivotally supported on the second component and a first engaging claw extending from the first base toward a first side in a circumferential direction.

[0048] The second claw component has a second base pivotally supported on the second component and a second engaging claw extending from the second base toward a second side in the circumferential direction.

[0049] The first claw force-applying component applies elastic force to the first engaging claw in the direction that makes it engage with the engaging recess.

[0050] The second claw force-applying component applies force elastically to the second engaging claw in the direction that makes it engage with the engaging recess.

[0051] One of the aforementioned first and second components rotates integrally with the aforementioned rotating component, or is constituted by the aforementioned rotating component itself. Furthermore, the other of the aforementioned first and second components is supported so that it cannot rotate relative to a fixed portion that does not rotate even during use.

[0052] The aforementioned rotary transmission state switching device is configured to switch between at least one of the locking mode and the one-way clutch mode, and the free mode.

[0053] The aforementioned locking mode positions the protrusion at a position offset from the first and second engaging claws in the circumferential or axial direction, thereby engaging the first and second engaging claws with the engaging recess and preventing relative rotation between the first and second components regardless of their relative rotation direction.

[0054] The aforementioned one-way clutch mode involves pressing only one of the first and second engaging claws radially or axially through the protrusion to disengage it from the engaging recess, while engaging the other engaging claw with the engaging recess. This allows only one component to rotate in a predetermined direction relative to the other component, while preventing one component from rotating in a direction opposite to the predetermined direction relative to the other component.

[0055] The aforementioned free mode involves pressing the first and second engaging claws radially or axially through the protrusions to disengage them from the engaging recesses, thereby allowing relative rotation between the first and second components regardless of their relative rotational direction.

[0056] The torque transmission mechanism described above transmits torque between the output component and the drive wheel.

[0057] The aforementioned friction braking device is disposed between the aforementioned output component and the aforementioned drive wheel to brake the rotation of the aforementioned drive wheel.

[0058] The aforementioned control device has reduction ratio switching function and coordination control function.

[0059] The aforementioned reduction ratio switching function is based on the rotation of the drive cam by the electric actuator to switch the mode of the friction engagement part and the mode of the rotation transmission state switching device, thereby switching the secondary transmission to a high reduction ratio mode with a large reduction ratio between the input component and the output component, and a low reduction ratio mode with a small reduction ratio between the input component and the output component.

[0060] The aforementioned coordinated control function performs a pre-shift procedure, which involves, when torque is transmitted from the output component side to the input component side through the secondary transmission, and when a torque is applied to one component to cause that component to rotate relative to the other component in a circumferential direction, and the rotational transmission state switching device prevents the rotation of one component relative to the other component in a circumferential direction, before the mode of the secondary transmission is switched by the reduction ratio switching function, the protrusion presses one of the first and second engagement claws, which is pivotally supported at the base of the second component and extends in a circumferential direction, outward from the engagement recess, radially or axially, causing it to disengage from the engagement recess. Simultaneously, the regenerative torque of the drive motor is reduced while the braking force of the friction braking device is increased.

[0061] In one aspect of the electric vehicle drive device of the present invention, the regenerative torque of the drive motor can be reduced to 0 during the pre-shifting process.

[0062] In a drive system for an electric vehicle according to one aspect of the present invention, the secondary transmission can be configured to switch to the locked mode. In this case, the reduction ratio switching function can switch the secondary transmission to the high reduction ratio mode by switching the electric friction clutch device to the disengaged mode and the rotational transmission state switching device to the locked mode, and switch the secondary transmission to the low reduction ratio mode by switching the electric friction clutch device to the engaged mode and the rotational transmission state switching device to the free mode.

[0063] In one aspect of the electric vehicle drive system of the present invention, the two-stage transmission can be configured to switch to the one-way clutch mode. In this case, the coordination control function can be performed during the switching of the two-stage transmission from the high reduction ratio mode to the low reduction ratio mode and before the rotational transmission state switching device switches from the locking mode to the one-way clutch mode.

[0064] In a drive device for an electric vehicle according to one aspect of the present invention, the aforementioned coordinated control function can perform the aforementioned pre-shifting process and further execute an inertial process, which is that after the aforementioned one engaging claw is pressed radially or axially out of the aforementioned engaging recess by the aforementioned protrusion, the driving torque of the aforementioned drive motor in the same direction as the regenerative torque acting on the aforementioned drive motor is increased, thereby promoting the reduction of the rotational speed of the aforementioned motor output shaft, and then, after the rotational speed of the aforementioned motor output shaft begins to decrease, the driving torque of the aforementioned drive motor is reduced.

[0065] In a drive device for an electric vehicle according to one aspect of the present invention, the aforementioned coordinated control function can perform a shift completion process after the aforementioned inertial process. This shift completion process involves making the clamping force of the friction engagement portion such that the torque that can be transmitted between the at least one first friction plate and the at least one second friction plate without slipping against each other is greater than or equal to the torque transmitted through the friction engagement portion after the switching of the secondary transmission to the low reduction ratio mode is completed. Then, the braking force of the friction braking device is further reduced while the regenerative torque of the drive motor is increased.

[0066] In a drive device for an electric vehicle according to one aspect of the present invention, the electric friction clutch device can be equipped with a return spring that elastically applies force in the direction that separates the at least one first friction plate and the at least one second friction plate from each other.

[0067] In a drive device for an electric vehicle according to one aspect of the present invention, the electric friction clutch device is further provided with an elastic force application mechanism, which is provided between the first clutch component or the second clutch component and the friction engagement portion, and applies force elastically in the direction of pushing the at least one first friction plate and the at least one second friction plate together.

[0068] Alternatively, in a drive device for an electric vehicle according to one aspect of the present invention, the electric friction clutch device may further include an elastic force application mechanism disposed between the friction engagement portion and the driven cam, and elastically apply force in the direction that separates the friction engagement portion and the driven cam from each other.

[0069] In a drive unit for an electric vehicle according to one aspect of the present invention, the aforementioned two-stage transmission may further include: a sun gear; a ring gear arranged coaxially with the sun gear around it; a planetary carrier supported to be rotatable relative to the sun gear and the ring gear; and a planetary gear mechanism having a plurality of planetary gears meshing with the sun gear and the ring gear, and being rotatably supported on the planetary carrier about its own central axis.

[0070] In this case, the input element, which is any one of the sun gear, the ring gear, and the planetary gear carrier, is connected to the input component in a manner that allows it to rotate integrally with the input component.

[0071] An output element, which is any one of the aforementioned sun gear, ring gear, and planetary carrier and is different from the aforementioned input element, is connected to the aforementioned output component in a manner that allows it to rotate integrally with the output component.

[0072] Rotating elements, which are the remaining elements of the sun gear, the ring gear, and the planetary gear carrier (excluding the input and output elements), are connected to the rotating component in a manner that they rotate integrally with the rotating component.

[0073] Invention Effects

[0074] According to one aspect of the present disclosure, the drive device for an electric vehicle can smoothly switch modes of the rotational transmission state switching device during regenerative driving when regenerative torque acts on the drive motor. Attached Figure Description

[0075] Figure 1 This is a block diagram illustrating a first example of a drive unit for an electric vehicle according to an embodiment of the present disclosure.

[0076] Figure 2 This is a schematic cross-sectional view of a drive unit for an electric vehicle, representing the first example.

[0077] Figure 3 (A) is a diagram showing the torque transmission path in the low reduction ratio mode of the first example of the two-stage transmission, and (B) is a diagram showing the torque transmission path in the high reduction ratio mode of the first example of the two-stage transmission.

[0078] Figure 4 This is a three-dimensional diagram of the first example representing the aforementioned two-stage transmission.

[0079] Figure 5 This is a cross-sectional view of the first example, representing the aforementioned two-stage transmission.

[0080] Figure 6This is a perspective view showing the first example of removing the planetary gear mechanism from the aforementioned two-stage transmission.

[0081] Figure 7 This is a cross-sectional view showing the first example of removing the planetary gear mechanism from the aforementioned two-stage transmission.

[0082] Figure 8 This is an exploded perspective view showing the first example of removing the planetary gear mechanism from the aforementioned two-stage transmission.

[0083] Figure 9 This is an exploded perspective view showing the first example of removing the worm gear and two support bearings from the electric friction clutch device that constitutes the above-mentioned two-stage transmission.

[0084] Figure 10 This is an exploded perspective view showing the removal of the first and second friction plates from the aforementioned electric friction clutch device in the first example.

[0085] Figure 11 yes Figure 5 Enlarged view of the X-section.

[0086] Figure 12 This is a perspective view showing the first example of removing the drive cam from the aforementioned electric friction clutch device.

[0087] Figure 13 This is an exploded perspective view showing the first example of the electric friction clutch device from which the driven cam and rolling elements are removed.

[0088] Figure 14 (A) is a perspective view showing the removal of the flange and pressing member of the rotating component from the aforementioned two-stage transmission in the first example, and (B) is an exploded perspective view showing the removal of the aforementioned flange and pressing member.

[0089] Figure 15 (A) to (D) are schematic diagrams of the cam mechanism of the above-mentioned electric friction clutch device viewed from the radial outside.

[0090] Figure 16 This is a perspective view of the first example of the rotary transmission state switching device constituting the above-mentioned two-stage transmission, viewed from the other side of the axial direction.

[0091] Figure 17 This is an exploded perspective view of the aforementioned rotary transmission state switching device in the first example.

[0092] Figure 18 This is an end view of the aforementioned rotary transmission state switching device viewed from the other side of the axial direction after the cover is removed in the first example.

[0093] Figure 19 yes Figure 18 Enlarged view of the Y-section.

[0094] Figure 20 (A) is a schematic diagram showing the engagement relationship of the first and second engaging pawls, the engaging recess and the protrusion in the free mode of the above-mentioned rotary transmission state switching device, (B) is a schematic diagram showing the engagement relationship in the locked mode, and (C) is a schematic diagram showing the engagement relationship in the one-way clutch mode.

[0095] Figure 21 This is a line diagram schematically illustrating the mode of the electric friction clutch device and the mode of the rotary transmission state switching device in the aforementioned two-stage transmission.

[0096] Figure 22 (A) and (B) are line graphs showing the relationship between the rotation angle of the drive cam and the output torque and current value of the shift motor when the electric friction clutch device is switched from the engagement mode to the disengagement mode in the first example. (A) is a graph showing the case when the first friction plate and the second friction plate are new and unworn. (B) is a graph showing the case when the first friction plate and the second friction plate are significantly worn.

[0097] Figure 23 This is a cross-sectional view of the first example showing the electric friction clutch device switched to the engagement mode.

[0098] Figure 24 This is a cross-sectional view of the first example showing the contact state between the pressing component and the piston during the switching process from the engagement mode to the disengagement mode of the aforementioned electric friction clutch device.

[0099] Figure 25 This is a cross-sectional view of the first example showing the electric friction clutch device switched to the disengaged mode.

[0100] Figure 26 This is a flowchart illustrating the action of switching the aforementioned two-stage transmission from a high reduction ratio mode to a low reduction ratio mode during normal forward driving, as shown in the first example.

[0101] Figure 27 It is a line graph showing the time changes of various parameters when the above-mentioned two-stage transmission is switched from high reduction ratio mode to low reduction ratio mode during normal forward driving, as shown in the first example.

[0102] Figure 28 This is a flowchart illustrating the action of switching the aforementioned two-stage transmission from a high reduction ratio mode to a low reduction ratio mode during regenerative driving when regenerative torque acts on the drive motor, as shown in the first example.

[0103] Figure 29 This is a line graph showing the time changes of various parameters when the above-mentioned two-stage transmission is switched from a high reduction ratio mode to a low reduction ratio mode during the above-mentioned regeneration driving process, as shown in the first example.

[0104] Figure 30 This is a cross-sectional view showing a portion of the comparative example's two-stage transmission.

[0105] Figure 31 This is a line diagram schematically showing the engagement / disengagement states of the first friction engagement device and the second friction engagement device in a comparative example of a two-stage transmission.

[0106] Figure 32 This refers to the equivalent of a two-stage transmission in a variation of the first example. Figure 21 The image.

[0107] Figure 33 This is a cross-sectional view of a drive unit for an electric vehicle, schematically illustrating a second example of an embodiment of the present disclosure.

[0108] Figure 34 (A) is a diagram showing the torque transmission path in the low reduction ratio mode of the two-stage transmission of the electric vehicle drive unit constituting the second example, and (B) is a diagram showing the torque transmission path in the high reduction ratio mode of the two-stage transmission of the second example.

[0109] Figure 35 This is a cross-sectional view showing the second example with the secondary transmission removed.

[0110] Figure 36 It is a line diagram used to illustrate the effect of assembling a transmission into a drive unit that uses an electric motor as its driving source. Detailed Implementation

[0111] [First example]

[0112] Regarding the first example of an implementation of this disclosure, using Figures 1-29 Please provide an explanation.

[0113] The drive unit 1 for electric vehicles includes: a drive motor 2, a two-stage transmission 3, a torque transmission mechanism 4, a friction braking device 5, and a control device 6.

[0114] The drive motor 2 has a motor output shaft 7.

[0115] Furthermore, a positive value for the torque (T2) of the drive motor 2 indicates that it is the output torque (drive torque, power operating torque), while a negative value for the torque (T2) indicates that it is the regenerative torque. In the following explanation, a positive value for the torque (T2) may sometimes be expressed as the output torque, and a negative value for the torque (T2) may be expressed as the regenerative torque.

[0116] The two-stage transmission 3 includes: an input component 8, an output component 9, a rotating component 10, an electric friction clutch device 11, and a rotational transmission state switching device 12.

[0117] Regarding the two-stage transmission 3, unless otherwise stated, axial, radial, and circumferential directions refer to the axial, radial, and circumferential directions of the input component 8. The axial, radial, and circumferential directions of the input component 8 are consistent with the axial, radial, and circumferential directions of the output component 9, and also consistent with the axial, radial, and circumferential directions of the rotating component 10. Furthermore, axial side refers to... Figure 2 , Figure 3 (A), (B) Figure 5 , Figure 7 , Figure 11 , Figure 15 (A)~(D) and Figures 23-25 The right side, the other side of the axis refers to Figure 2 , Figure 3 (A), (B) Figure 5 , Figure 7 , Figure 11 , Figure 15 (A)~(D) and Figures 23-25 On the left side.

[0118] The two-stage transmission 3 is configured to switch the torque transmission path by switching between the mode of the electric friction clutch device 11 and the mode of the rotational transmission state switching device 12. This allows it to switch between a high reduction ratio mode (large reduction ratio) and a low reduction ratio mode (small reduction ratio) between the input component 8 and the output component 9. In this example, the two-stage transmission 3 switches the torque transmission path through the planetary gear mechanism 13 by switching between the mode of the electric friction clutch device 11 and the mode of the rotational transmission state switching device 12, thereby switching between the high reduction ratio mode and the low reduction ratio mode.

[0119] The input component 8 is capable of transmitting torque between itself and the motor output shaft 7. Specifically, the input component 8 has an input gear 16 at its axial end that meshes with the drive gear 15 of the motor output shaft 7 of the drive motor 2.

[0120] In this example, the input component 8 is rotatable relative to the fixed part 14, which does not rotate during use, by a rolling bearing or the like (not shown). The fixed part 14 is composed of a housing or the like that that houses the two-stage transmission 3. In addition, the input component 8 is configured as a cylindrical (hollow) shape.

[0121] The output component 9 is supported so that it can rotate relative to the input component 8.

[0122] In this example, the output component 9 is coaxially arranged with the input component 8, and is supported radially inside the cylindrical input component 8 via rolling bearings (not shown) to allow relative rotation with respect to the input component 8. Additionally, the output component 9 has an output gear 17 at one end on its axial side.

[0123] The rotating component 10 is supported so that it can rotate relative to the input component 8 and the output component 9.

[0124] In this example, the rotating component 10 is coaxially configured with the input component 8 and the output component 9, and is supported relative to the fixed part 14 via the rotation transmission state switching device 12, the cam device 31 constituting the electric friction clutch device 11, and the radial bearing 42 for rotatably supporting the drive cam 38 constituting the cam device 31 relative to the rotating component 10.

[0125] Specifically, the rotating component 10 has a small-diameter flange 18 protruding radially outward at its axial midpoint, and is located on the opposite side axially from the small-diameter flange 18. Figure 2 The left side portion has a flange portion 19 protruding radially outward. The flange portion 19 has: a hollow circular plate-shaped first annular portion 21, a first cylindrical portion 22 bent axially from the radially outer end of the first annular portion 21 to the other side, a hollow circular plate-shaped second annular portion 23 bent radially outward from the axially other end of the first cylindrical portion 22, and a second cylindrical portion 24 bent axially from the radially outer end of the second annular portion 23 to the other side. The first annular portion 21 has partially arc-shaped through holes 20 at multiple locations in its radially central portion, which are used to insert a portion of the cylindrical portion 67 constituting the pressing member 62 of the electric friction clutch device 11.

[0126] In this example, the rotating component 10 is constructed by embedding a stepped cylindrical component 26 fixedly within a shaft component 25 having a small-diameter flange portion 18. That is, as... Figure 14 (A) and Figure 14 As shown in (B), the stepped cylindrical member 26 has: a flange portion 19; and a small-diameter cylindrical portion 27 bent radially inward from the end of the first annular portion 21 of the flange portion 19 toward the other side in the axial direction. The rotating member 10 supports and fixes the stepped cylindrical member 26 to the shaft member 25 by engaging the inner spline portion 28 provided on the inner circumferential surface of the small-diameter cylindrical portion 27 with the outer spline portion spline provided on the outer circumferential surface of the shaft member 25. However, the rotating member can also be constructed by joining and fixing the stepped cylindrical member and the shaft member by pressing, welding, or other methods.

[0127] The electric friction clutch device 11 includes a first clutch component, a second clutch component, a friction engagement portion 29, a cam device 31, and an electric actuator 32, and is positioned between the rotating component 10 and the input component 8 or the output component 9. The electric friction clutch device 11 switches between a torque-transmitting engagement mode and a torque-disengaging disengagement mode between the first clutch component and the second clutch component.

[0128] The aforementioned first clutch component is connected to the rotating component 10 in a manner that allows it to rotate integrally, or it is constituted by the rotating component 10 itself. In this example, the aforementioned first clutch component is constituted by the rotating component 10 itself.

[0129] The second clutch component is supported coaxially with the first clutch component, allowing it to rotate relative to the first clutch component. Furthermore, the second clutch component is either integrally rotatable with the input component 8 or the output component 9, or it is constituted by the input component 8 or the output component 9 itself. In this example, the second clutch component is constituted by the input component 8 itself.

[0130] The friction engagement portion 29 has at least one first friction plate 33 and at least one second friction plate 34 supported to allow for axial relative displacement, and is disposed between the rotating component 10, which is the first clutch component, and the input component 8, which is the second clutch component.

[0131] In this example, at least one first friction plate 33 is composed of multiple first friction plates 33, and at least one second friction plate 34 is composed of multiple second friction plates 34. More specifically, the friction engagement portion 29 is composed of a multi-plate clutch, which is formed by alternately overlapping multiple first friction plates 33 supported on the rotating component 10 and multiple second friction plates 34 supported on the input component 8.

[0132] Multiple first friction plates 33 are supported on the outer peripheral surface of the first cylindrical portion 22 so that they can be axially displaced but cannot rotate relative to the first cylindrical portion 22.

[0133] Multiple second friction plates 34 are supported on the inner circumferential surface of their ends on the opposite side of the input component 8 so that they can be axially displaced but cannot be rotated relative to the input component 8.

[0134] The cam device 31 includes a drive cam 38 and a driven cam 39 supported to be able to rotate relative to the drive cam 38 and to have relative axial displacement. As the drive cam 38 rotates, the axial distance between the drive cam 38 and the driven cam 39 increases or decreases.

[0135] The cam device 31 can adopt any structure as long as it can increase or decrease the axial distance between the driving cam 38 and the driven cam 39, i.e., the axial dimension of the cam device 31, as the driving cam 38 rotates. For example, the cam device can adopt a structure in which the driving cam surface of the driving cam and the driven cam surface of the driven cam slide directly; a structure in which multiple rolling elements are sandwiched between the driving cam surface of the driving cam and the driven cam surface of the driven cam; or a structure in which multiple rolling elements supported on one of the driving cam and the driven cam make rolling contact with the cam surface of the other of the driving cam and the driven cam, etc.

[0136] In this example, the cam device 31, in addition to the driving cam 38 and the driven cam 39, also has a plurality of rolling elements 40, which are supported on the driven cam 39 and have rolling contact with the driving cam surface 52 of the driving cam 38.

[0137] The drive cam 38 is supported relative to the rotating member 10 such that it can rotate relative to the rotating member 10 and the input member 8, but cannot perform axial displacement relative to the rotating member 10. Specifically, as Figure 5 As shown, the drive cam 38 is supported by a cylindrical component 41, a radial bearing 42, and an angular contact ball bearing 43, enabling it to rotate relative to the rotating component 10. Furthermore, in Figures 2-3 In (B), the illustrations of the cylindrical component 41 and the angular contact ball bearing 43 are omitted.

[0138] The cylindrical member 41 has a cylindrical portion 44 and an outwardly bent flange portion 45 extending radially outward from the end of the cylindrical portion 44 on the other side of the axial direction. The cylindrical member 41 supports and fixes the outwardly bent flange portion 45 to the fixed portion 14 by means of threaded fastening or the like.

[0139] The radial bearing 42 includes: an inner ring 46 externally fixed to the axial end of the rotating component 10; an outer ring 47 internally fixed to the cylindrical portion 44 of the cylindrical component 41; and a plurality of rolling elements 48 freely disposed between the inner ring 46 and the outer ring 47. In the illustrated example, the radial bearing 42 is constructed of a multi-row deep groove ball bearing using balls as rolling elements 48. It should be noted that the radial bearing is not particularly limited as long as it can enable the first component and the cam device to rotate relative to each other and can support the axial force of the elastic force-applying mechanism; for example, it can also be constructed of deep groove ball bearings, radial angular contact ball bearings, or radial tapered roller bearings.

[0140] The angular contact ball bearing 43 has: an inner ring 49 externally fixed to the cylindrical portion 44 of the cylindrical member 41; an outer ring 50 internally fixed to the drive cam 38; and a plurality of balls 51 that are freely disposed between the inner ring 49 and the outer ring 50.

[0141] like Figure 12 As shown, the drive cam 38 has a drive cam surface 52 on the radially inner portion of its side on one axial side. This drive cam surface 52 is formed by alternating concave and convex portions of equal number along the circumferential direction. The drive cam surface 52 is configured to... Figure 15 (A) ~ Figure 15 The rolling element 40 is repeated multiple times (three times in this example) from the upper side to the lower side of (D), in the order of first bottom 52a, gently inclined surface 52b, first flat surface 52c, inclined surface 52d, second bottom 52e, first medium inclined surface 52f, second flat surface 52g and second medium inclined surface 52h.

[0142] The first flat surface 52c and the second flat surface 52g in the drive cam surface 52 are located on the far side in the axial direction, that is, at the front end of the protrusion, and the first bottom surface 52a and the second bottom surface 52e are located on the far side in the axial direction. The tilt angle of the first moderately inclined surface 52f and the second moderately inclined surface 52h relative to the imaginary plane P orthogonal to the central axis of the drive cam 38 is greater than the tilt angle of the gently inclined surface 52b relative to the imaginary plane P.

[0143] The tilt angle of the gently tilted surface 52b, as well as the tilt angles of the first and second inclined surfaces 52f and 52h, are all set to a size that allows the rolling body 40 to move both by rolling and by climbing. Furthermore, in this example, the first and second inclined surfaces 52f and 52h have opposite tilt directions and the same tilt angle, but the tilt angles can also be different. Additionally, in this example, the tilt angle of the gently tilted surface 52b can be set to be smaller than the tilt angles of the first and second inclined surfaces 52f and 52h, but the tilt angle of the gently tilted surface 52b can also be set to be the same as the tilt angles of the first and second inclined surfaces 52f and 52h.

[0144] Furthermore, the tilt angle of the tilted face 52d relative to the imaginary plane P can be set to any size as long as it allows the rolling body 40 to climb.

[0145] In this example, the drive cam 38 has teeth 53 on its outer peripheral surface, which are helical gears, and has pins 54 protruding toward the axial side at multiple points (three in the illustrated example) in the circumferential direction of the radially central portion of the side on the axial side.

[0146] The driven cam 39 is disposed around the rotating member 10 with axial displacement only. In this example, the driven cam 39 has a hollow circular plate shape and can be supported on the fixed part 14 with axial displacement. In this example, the driven cam 39 can be supported on the fixed part 14 with axial displacement by engaging the inner spline portion 55 on the inner peripheral surface of the driven cam 39 with the outer spline portion 56 on the outer peripheral surface of the cylindrical part 44 of the cylindrical member 41. It should be noted that the method of supporting the driven cam relative to the fixed part is not particularly limited as long as it can support the driven cam on the fixed part with axial displacement only. For example, the driven cam can also be supported on the fixed part with axial displacement by engaging a protrusion on one of the driven cam and the fixed part with a groove on the other part.

[0147] like Figure 13 As shown, the driven cam 39 has rectangular holes 57 extending axially at multiple points (three in the illustrated example) in the circumferential direction of its radially central portion, and has generally semi-circular plate-shaped support plates 58a and 58b protruding from their respective radially opposite sides toward the other side of the axial direction. The radially outer support plate 58a has a radially extending circular hole, i.e., a support hole 59, and the radially inner support plate 58b has a support recess 60 with a circular opening on its radially outer side.

[0148] In this example, the multiple rolling elements 40 consist of three rolling elements 40. It should be noted that the multiple rolling elements 40 can also consist of two or more rolling elements 40.

[0149] The rolling elements 40 are each cylindrical in shape and are supported on support plates 58a and 58b via a cylindrical support shaft 68 and a plurality of rollers 69. Specifically, the radially outer end of the support shaft 68, centered on the central axis of the driven cam 39, is fitted and fixed to the support hole 59 of the radially outer support plate 58a, and the radially inner end of the support shaft 68, centered on the central axis of the driven cam 39, is fitted and fixed to the support recess 60 of the radially inner support plate 58b. The plurality of rollers 69 are rotatably held between the inner circumferential surface of the rolling element 40 and the outer circumferential surface of the axially intermediate portion of the support shaft 68. Thus, the rolling element 40 is supported on the driven cam 39 in a manner that allows it to rotate freely about its rotation axis C, which is oriented in a radial direction centered on the central axis of the driven cam 39.

[0150] With the rolling element 40 supported on the driven cam 39, the axial side portion of the rolling element 40 is disposed inside the rectangular hole 57. The outer peripheral surface of the rolling element 40 makes rolling contact with the driving cam surface 52 on the other axial side of the driving cam 38.

[0151] The cam device 31 drives the drive cam 38 by rotating to increase or decrease the amount of the rolling element 40 climbing from the first bottom 52a or the second bottom 52e in the drive cam surface 52, thereby causing the driven cam 39 to move axially, and thus expanding or shrinking the axial distance between the drive cam 38 and the driven cam 39, i.e., the axial dimension of the cam device 31.

[0152] The electric actuator 32 has a shift motor 70 and a reducer 71, through which the shift motor 70 rotates the drive cam 38 of the drive cam device 31 via the reducer 71.

[0153] In this example, the reducer 71 is a worm gear reducer. That is, the reducer 71 is formed by meshing the worm teeth on the outer peripheral surface of the worm 72 connected to the output shaft of the shift motor 70 with the gear teeth 53 on the outer peripheral surface of the drive cam 38. The worm 72 is rotatably supported on the fixed part 14 by a pair of support bearings 73a, 73b. It should be noted that the reducer 71 can also be formed by meshing the spur gear or bevel gear on the output shaft of the electric motor with the spur gear or bevel gear on the drive cam, or by using a belt or chain between the output shaft of the electric motor and the drive cam.

[0154] The electric friction clutch device 11 is configured to switch between a connection mode and a disengagement mode by expanding / reducing the axial dimension of the cam device 31. In the connection mode, torque is transmitted between the first clutch component and the second clutch component by pressing the first friction plate 33 and the second friction plate 34 together. In the disengagement mode, no torque is transmitted between the first clutch component and the second clutch component by releasing the force that presses the first friction plate 33 and the second friction plate together.

[0155] In this example, the drive cam 38 is rotated by the electric actuator 32, which expands the axial dimension of the cam device 31, i.e. the axial distance between the drive cam 38 and the driven cam 39, and the first friction plate 33 and the second friction plate 34 are pressed together. The force that presses the first friction plate 33 and the second friction plate 34 together is released by reducing the axial dimension of the cam device 31.

[0156] The electric friction clutch device 11 can further include an elastic force application mechanism 30 as an arbitrary structural element. The elastic force application mechanism 30 is provided between the first clutch component, i.e., the rotating component 10, or the second clutch component, i.e., the input component 8, and the friction engagement portion 29, and applies elastic force in the direction that pushes the first friction plate 33 and the second friction plate 34 together.

[0157] In this case, the electric friction clutch device 11 is configured such that, based on the relative displacement of the driven cam 39 in the direction of increasing the axial distance between it and the drive cam 38, the elastic force application mechanism 30 is pressed in the direction of releasing the force that pushes the first friction plate 33 and the second friction plate 34 together, and based on the relative displacement of the driven cam 39 in the direction of decreasing the axial distance between it and the drive cam 38, the elastic force application mechanism 30 is pressed in the direction of pushing the first friction plate 33 and the second friction plate 34 together.

[0158] Alternatively, the electric friction clutch device 11 may further include an elastic force application mechanism as an arbitrary structural element, which is disposed between the friction engagement portion 29 and the driven cam 39 and applies elastic force in the direction that separates the friction engagement portion 29 and the driven cam 39 from each other.

[0159] In this case, the electric friction clutch device 11 is configured such that, based on the relative displacement of the driven cam 39 in the direction of increasing the axial distance between it and the drive cam 38, the driven cam 39 is pressed in the direction of pressing the first friction plate 33 and the second friction plate 34 together by the elastic force application mechanism 30, and based on the relative displacement of the driven cam 39 in the direction of decreasing the axial distance between it and the drive cam 38, the force that presses the first friction plate 33 and the second friction plate 34 together is released.

[0160] In this example, the electric friction clutch device 11 has an elastic force application mechanism 30, which is provided between the first clutch component, i.e., the rotating component 10, or the second clutch component, i.e., the input component 8, and the friction engagement portion 29, and applies force elastically in the direction of pressing the first friction plate 33 and the second friction plate 34 together.

[0161] In this example, the elastic force application mechanism 30 has a piston 36 and an elastic member 37.

[0162] The piston 36 is supported to allow axial displacement relative to the rotating member 10. The piston 36 is configured as a hollow circular plate and is supported around the portion of the rotating member 10 between the axially oriented small-diameter flange 18 and flange 19, allowing for axial displacement relative to the rotating member 10. The piston 36 has its radially outer end face facing the axially opposite side of either the first friction plate 33 or the second friction plate 34, located on the most axial side.

[0163] An elastic member 37 is disposed between the rotating member 10 and the piston 36. In this example, the elastic member 37 is held in an elastically compressed state between the side of the small-diameter flange 18 on the other side of the axial direction and the side of the piston 36 on one side of the axial direction. That is, the elastic force application mechanism 30 uses the force that the elastic member 37 wants to elastically recover to press the first friction plate 33 or the second friction plate 34 on the most axial side toward the other side of the axial direction via the piston 36, thereby elastically applying force in the direction that pushes the first friction plate 33 and the second friction plate 34 together.

[0164] The specific structure of the elastic component is not particularly limited. In this example, the elastic component 37 is composed of at least one disc spring, and in the illustrated example, it is composed of two disc springs. It should be noted that the elastic component can also be composed of at least one helical spring or other elastic components.

[0165] The elastic force application mechanism 30 in this example also includes a thrust bearing 61, a pressing component 62, and a preload unit 65 between the driven cam 39 and the piston 36.

[0166] A thrust bearing 61 is disposed between a pressing member 62, which is opposite to the piston 36, and a driven cam 39 of the cam device 31. The thrust bearing 61 has: a pair of track rings 63a, 63b; and a plurality of rolling elements 64 which are freely disposed between the pair of track rings 63a, 63b. The track ring 63b on the axially opposite side of the pair of track rings 63a, 63b is supported and fixed to the driven cam 39.

[0167] The pressing member 62 has: a cylindrical base 66; and a partially cylindrical portion 67 protruding circumferentially (three in the illustrated example) from one end of the base 66 on one side. One of a pair of track rings 63a and 63b of a thrust bearing 61 is fixedly supported at the other end of the base 66 on the axial side. The partially cylindrical portion 67 is inserted into the through hole 20 of the rotating member 10, and the front end (the end on one side of the axial direction) of this partially cylindrical portion 67 is opposite to the radially central portion of the side surface of the piston 36 on the other side of the axial direction.

[0168] A preload-applying unit 65 is disposed between the pressing member 62 and the rotating member 10, and applies preload to the thrust bearing 61. The preload-applying unit 65 is held in an elastically compressed state between the pressing member 62 and the side of the first annular portion 21 constituting the flange portion 19 of the rotating member 10 on the opposite side of the axial direction. Thus, as... Figure 3 As shown in (B), even when the piston 36 is pressed towards the axial side against the elastic restoring force of the elastic member 37, a preload is applied to the thrust bearing 61, preventing the thrust bearing 61 from dislodging from the elastic force application mechanism 30 and the cam device 31. Furthermore, the elastic force of the preload application unit 65 is smaller than the elastic restoring force of the elastic member 37. The preload application unit 65 can be composed, for example, of an elastic member such as rubber, one or more disc springs, one or more helical springs, or other springs.

[0169] The electric friction clutch device 11 in this example includes a return spring 35 as an arbitrary structural element. This return spring 35 is disposed between the first friction plate 33 and the second friction plate 34, and elastically applies force in the direction of widening the distance between the first friction plate 33 and the second friction plate 34. Thus, after releasing the force that pressed the first friction plate 33 and the second friction plate 34 together, the first friction plate 33 and the second friction plate 34 are reliably separated. The elastic force of the return spring 35 is smaller than the elastic restoring force of the elastic member 37 of the elastic force application mechanism 30.

[0170] In this example, the electric friction clutch device 11 uses the electric actuator 32 to drive the cam 38 to rotate, thereby expanding / reducing the axial dimension of the cam device 31 and causing the piston 36 of the elastic force application mechanism 30 to be axially displaced relative to the rotating component 10. This allows switching between a cut-off mode where no torque is transmitted between the rotating component 10 and the input component 8 and a connection mode where torque is transmitted.

[0171] First, when the electric friction clutch device 11 is switched to a disengagement mode in which no torque is transmitted between the rotating member 10 and the input member 8, the drive cam 38 can be rotated using the electric actuator 32, as follows: Figure 15 (B) and Figure 15 As shown in (D), the rolling element 40 is positioned on the first flat surface 52c or the second flat surface 52g of the drive cam surface 52, or the amount of climb towards the gently inclined surface 52b, the inclined surface 52d, the first medium inclined surface 52f, or the second medium inclined surface 52h is increased.

[0172] Therefore, by moving the driven cam 39 in the direction of increasing the axial distance from the driving cam 38 (i.e., on the axial side), the piston 36 of the elastic force application mechanism 30 is pressed towards the axial side via the thrust bearing 61 and the pressing member 62, and the elastic member 37 is elastically compressed. When the elastic member 37 is elastically compressed, the force that pushes the first friction plate 33 and the second friction plate 34 together decreases and is eventually lost. As a result, by the action of the return spring 35, the distance between the first friction plate 33 and the second friction plate 34 increases, the friction engagement portion 29 is disengaged, and the electric friction clutch device 11 switches to the disengagement mode.

[0173] In contrast, when the electric friction clutch device 11 is switched to a connection mode that transmits torque between the rotating component 10 and the input component 8, the drive cam 38 can be rotated using the electric actuator 32, as follows: Figure 15 (A) and Figure 15 As shown in (C), the rolling element 40 is positioned at the first bottom 52a or the second bottom 52e of the drive cam surface 52, or the amount of climb toward the gently inclined surface 52b, the inclined surface 52d, the first intermediate inclined surface 52f, or the second intermediate inclined surface 52h is reduced.

[0174] Therefore, by moving the driven cam 39 in the direction of reducing the axial distance from the driving cam 38, i.e., to the other side of the axial direction, the force pressing the piston 36 of the elastic force application mechanism 30 toward the axial direction is reduced. Thus, primarily through the elastic restoring force of the first friction plate 33 and the elastic member 37, the piston 36, the thrust bearing 61, and the pressing member 62 are pressed toward the other side of the axial direction, and through the piston 36, either the first friction plate 33 or the second friction plate 34 on the far axial side is pressed toward the other side of the axial direction. As a result, the first friction plate 33 and the second friction plate 34 press against each other, the friction engagement portion 29 is connected, and the electric friction clutch device 11 switches to the engagement mode.

[0175] In this example, when the electric friction clutch device 11 is maintained in the disengaged mode, the shift motor 70 needs to be continuously energized to prevent the piston 36 from moving axially to the other side due to the elastic force of the elastic member 37. Conversely, when the electric friction clutch device 11 is maintained in the engaged mode, the piston 36 is pressed axially to the other side by the elastic force of the elastic member 37, thereby pressing the first friction plate 33 and the second friction plate 34 together. Therefore, when the electric friction clutch device 11 is maintained in the engaged mode, it is not necessary to continuously energize the shift motor 70. That is, the electric friction clutch device 11 in this example is a normally closed clutch device.

[0176] The rotary transmission state switching device 12 includes: a first component 74 having engagement recesses 77 at multiple locations in the circumferential direction; a second component 75 coaxially disposed with the first component 74; and a mode selection component 76 that rotates or is axially displaced as the drive cam 38 rotates.

[0177] One of the first component 74 and the second component 75 is integrally rotatably connected to the rotating component 10, or is constituted by the rotating component 10 itself. Furthermore, the other component of the first component 74 and the second component 75 is supported on the fixed portion 14, which does not rotate even during use, and cannot rotate relative to it. In this example, the first component 74 is integrally rotatably connected to the rotating component 10, and the second component 75 is supported on the fixed portion 14, which does not rotate even during use, and cannot rotate relative to it. Additionally, the mode selection component 76 rotates with the rotation of the drive cam 38.

[0178] The rotational transmission state switching device 12 has a free mode and a locked mode that are switched based on the rotation or axial displacement of the mode selection component 76. The free mode allows the first component 74 to rotate relative to the second component 75 regardless of the relative rotation direction of the first component 74 and the second component 75. The locked mode prevents the relative rotation of the first component 74 and the second component 75 regardless of the relative rotation direction of the first component 74 and the second component 75.

[0179] The rotational transmission state switching device 12 is configured to switch to a free mode by releasing the engagement of the engaging member relative to at least one of the first member 74 and the second member 75 based on the rotation or axial displacement of the mode selection member 76, and to switch to a locked mode by engaging the engaging member with both the first member 74 and the second member 75.

[0180] In addition to free mode and locked mode, the rotary transmission state switching device 12 can also have a one-way clutch mode, which only allows rotation of the first component 74 relative to the second component 75 in a predetermined direction. In this example, the rotary transmission state switching device 12 has a one-way clutch mode. Specifically, the rotary transmission state switching device 12 can switch between free mode, locked mode, and one-way clutch mode based on the rotation of the mode selection component 76.

[0181] When the rotary transmission state switching device 12 has a one-way clutch mode, the aforementioned engaging member can include: a first engaging member, which, when mounted on the first member 74 and the second member 75, allows rotation of one member relative to the other member in a predetermined direction and prevents rotation in the opposite direction; and a second engaging member, which, when mounted on the first member 74 and the second member 75, prevents rotation of one member relative to the other member in the opposite direction to the predetermined direction and allows rotation in the predetermined direction.

[0182] The rotary transmission state switching device 12 switches to a free mode by disengaging the first engaging member from at least one of the first component 74 and the second component 75, and by disengaging the second engaging member from at least one of the first component 74 and the second component 75. The rotary transmission state switching device 12 switches to a locked mode by engaging both the first engaging member and the second engaging member with both the first component 74 and the second component 75. Furthermore, the rotary transmission state switching device 12 switches to a one-way clutch mode by engaging the first engaging member with both the first component 74 and the second component 75, and by disengaging the second engaging member from at least one of the first component 74 and the second component 75.

[0183] In this example, the first component 74 has multiple engaging recesses 77 in the circumferential direction on its outer peripheral surface. That is, the first component 74 has gear-shaped concave-convex portions 79 on its outer peripheral surface, which are formed by alternating engaging recesses 77 and protrusions 78 in the circumferential direction.

[0184] Furthermore, the first component 74 has an outer diameter-side interlocking portion 80 on its inner circumferential surface, which consists of alternating recesses and protrusions arranged in the circumferential direction. The first component 74 is supported relative to the rotating component 10 and cannot rotate relative to it by engaging the outer diameter-side interlocking portion 80 with the inner diameter-side interlocking portion 81 on the outer circumferential surface of the second cylindrical portion 24 of the rotating component 10. That is, the first component 74 rotates integrally with the rotating component 10.

[0185] The second component 75 is supported around the first component 74 and is coaxial with the first component 74, and is capable of relative rotation relative to the first component 74. That is, the inner circumferential surface of the second component 75 faces the outer circumferential surface of the first component 74, i.e., the front end face of the protrusion 78, with a gap. The second component 75 has an inner diameter-side concave-convex engagement portion 82 on its outer circumferential surface, which is formed by alternating concave and convex portions in the circumferential direction. The second component 75 is supported relative to the fixed portion 14 and cannot rotate relative to it by engaging the inner diameter-side concave-convex engagement portion 82 with the outer diameter-side concave-convex engagement portion on the inner circumferential surface of the fixed portion 14. That is, the second component 75 does not rotate even when the two-stage transmission 3 is in use.

[0186] The second component 75 includes: a base 83 having a rectangular cross-sectional shape; and a cylindrical portion 84 that protrudes circumferentially from the radially outer end of the side of the base 83 on one axial side toward the axial side.

[0187] The base 83 has a plurality of first retaining recesses 85 and second retaining recesses 86 arranged alternately in the circumferential direction (six in the illustrated example).

[0188] Each first retaining recess 85 has an opening on the inner circumferential surface of the base 83 and on the side on the opposite axial side. Each first retaining recess 85 includes a spring retaining portion 87a and a base portion 88a. Viewed from the opposite axial side, the spring retaining portion 87a has its long axis extending towards the circumferential direction ( Figures 18-20 The pedestal portion 88a has a generally rectangular opening shape that extends towards the radially outward direction from the front side in the clockwise direction. The pedestal portion 88a has an opening shape that is generally circular when viewed from the other side in the axial direction, and on the other side in the circumferential direction of the spring retaining portion 87a ( Figures 18-20 Adjacent to each other (clockwise rear side).

[0189] Each second retaining recess 86 has an opening on the inner circumferential surface of the base 83 and on the side surface on the other side of the axial direction. When viewed from the other side of the axial direction, each second retaining recess 86 has a shape symmetrical to the first retaining recess 85 about an imaginary plane containing the central axis of the second component 75. That is, each second retaining recess 86 includes a spring retaining portion 87b and a pedestal portion 88b. When viewed from the other side of the axial direction, the spring retaining portion 87b has a generally rectangular opening shape in which the major axis extends towards the radially outward direction the further towards the other side of the circumferential direction. The pedestal portion 88b has a generally circular opening shape when viewed from the other side of the axial direction and is arranged adjacent to the spring retaining portion 87a on the circumferential side.

[0190] The rotary transmission state switching device 12 in this example includes: a first claw member 89 as a first engaging member and a second claw member 90 as a second engaging member; and a first claw force application member 91 and a second claw force application member 92. In this example, the rotary transmission state switching device 12 has multiple first claw members 89 and second claw members 90, and multiple first claw force application members 91 and second claw force application members 92, and each has the same number.

[0191] Each first claw component 89 has a first base 93 and a first engaging claw 94.

[0192] The first base 93 is configured to be generally cylindrical and is supported (pivot-supported) on the pedestal portion 88a of the first retaining recess 85 in a pivotal manner centered on a pivot parallel to the central axis of the second component 75.

[0193] The first engaging claw 94 is generally flat and extends from the first base 93 toward the circumferential direction. The first engaging claw 94 engages with the outer peripheral surface of the annular protrusion 95 of the mode selection member 76 on the other axial side, and engages with the concave-convex portion 79 of the first member 74 on the axial side (capable of engaging / disengaging with respect to the engaging recess 77).

[0194] Each second claw component 90 has a second base 96 and a second engaging claw 97.

[0195] The second base 96 is configured to be generally cylindrical and is supported on the pedestal 88b of the second retaining recess 86, which is capable of swinging about a pivot parallel to the central axis of the second component 75.

[0196] The second engaging claw 97 is generally flat and extends from the second base 96 toward the other side in the circumferential direction. The second engaging claw 97 has its axial portion facing the outer periphery of the annular protrusion 95 of the mode selection member 76, and its axial portion facing the concave-convex portion 79 of the first member 74.

[0197] The first claw force-applying component 91 elastically applies force to the first engaging claw 94 of the first claw component 89 in the direction that it engages with the engaging recess 77 of the first component 74. That is, the first claw force-applying component 91 applies force to the first claw component 89 such that the first claw component 89, centered on the central axis (pivot) of the first base 93, moves along... Figure 19 The force exerted is in the direction of clockwise swing. Specifically, the first claw force-applying component 91 is made of an elastic component such as a helical spring, and is held in an elastically compressed state between the bottom surface (the radially inward surface) of the spring holding portion 87a of the first holding recess 85 and the radially outer surface of the first engaging claw 94.

[0198] The second claw force-applying component 92 elastically applies force to the second engaging claw 97 of the second claw component 90 in the direction that it engages with the engaging recess 77 of the first component 74. That is, the second claw force-applying component 92 applies force to the second claw component 90 such that the second claw component 90, centered on the central axis of the second base 96, moves along... Figure 19 The force exerted is in the direction of counterclockwise swing. Specifically, the second claw force-applying component 92 is made of an elastic component such as a helical spring, and is held in an elastically compressed state between the bottom surface (the radially inward surface) of the spring holding portion 87b of the second holding recess 86 and the radially outer surface of the second engaging claw 97.

[0199] like Figure 17 As shown, the mode selection component 76 includes: a base 98 in the shape of a generally circular plate; and an annular protrusion 95 that protrudes circumferentially from the radial center of the side of the base 98 toward the other side of the axial direction.

[0200] The base 98 has multiple, equally spaced (three in the illustrated example) plate-side engaging holes 99 in the radially central portion of its side surface on the opposite side of the axial direction. The end of the pin 54 on one side is fitted (engaged) into each plate-side engaging hole 99 without wobbling. That is, the mode selection component 76 rotates integrally with the drive cam 38 (in the same direction and at the same speed).

[0201] The annular protrusion 95 has multiple protrusions 100 that protrude radially outward in the circumferential direction on its outer peripheral surface. That is, the annular protrusion 95 has gear-shaped protrusions and concave portions 101 on its outer peripheral surface, which are formed by alternating protrusions 100 and concave portions in the circumferential direction.

[0202] The first component 74, the second component 75, and the mode selection component 76 are combined by means of the cover 102 and the retaining ring 103, which can rotate relative to each other but cannot be displaced axially (so that they will not accidentally separate in the axial direction), to form a rotation transmission state switching device 12.

[0203] Specifically, with the first component 74 positioned radially inside the axial side of the base 83 of the second component 75, the annular cover 102 is threadedly fastened to the axial side of the second component 75, such that the axial side of the radially inner portion of the cover 102 faces the axial side of the first component 74. This prevents axial displacement of the first component 74 relative to the second component 75.

[0204] With the annular protrusion 95 of the mode selection component 76 positioned radially inside the axially opposite side of the base 83 of the second component 75, such that the front end face (the side surface on the axial side) of the annular protrusion 95 slides into contact with or nearly opposes the side surface on the axially opposite side of the first component 74, and with the side surface on the axial side of the radially outer portion of the base 98 sliding into contact with or nearly opposing the side surface on the axially opposite side of the base 83 of the second component 75, the retaining ring 103 is secured to the end of the inner circumferential surface of the cylindrical portion 84 of the second component 75 on the axially opposite side. This prevents displacement of the first component 74 and the mode selection component 76 relative to the second component 75 to the axially opposite side.

[0205] The rotation transmission state switching device 12 in this example is configured to switch the engagement state of the first engaging pawl 94 of the first pawl member 89 and the engagement recess 77 of the first member 74, and the engagement state of the second engaging pawl 97 of the second pawl member 90 and the engagement recess 77, based on the rotation of the mode selection member 76, thereby enabling switching between free mode, locked mode and one-way clutch mode.

[0206] <Free Mode>

[0207] In free mode, adjust the phase of the mode selection component 76 relative to the second component 75 in the circumferential direction, such as... Figure 20 As shown in (A), the protrusion 100 pushes the first engaging claw 94 radially outward against the elastic force of the first claw applying member 91, and pushes the second engaging claw 97 radially outward against the elastic force of the second claw applying member 92. This releases the engagement between the engaging recess 77 of the first member 74 and the first and second engaging claws 94 and 97. In this state, rotation of the first member 74 relative to the second member 75 is permitted regardless of the relative rotation direction of the first member 74 and the second member 75. That is, rotation of the first member 74 relative to the fixed portion 14 is permitted regardless of the rotation direction of the first member 74.

[0208] <Locked Mode>

[0209] In locked mode, adjust the phase of the mode selection component 76 relative to the second component 75 in the circumferential direction, such as... Figure 20 As shown in (B), the protrusion 100 is positioned at a point in the circumferential direction that deviates from the first engaging claw 94 of the first claw member 89 and the second engaging claw 97 of the second claw member 90. That is, in the circumferential direction, the recess in the protrusion-recession 101 is aligned with the phase of the first engaging claw 94 and the second engaging claw 97. Thus, the engaging recess 77 of the first member 74 engages with the first engaging claw 94 and the second engaging claw 97. In this state, regardless of the relative rotation direction of the first member 74 and the second member 75, rotation of the first member 74 relative to the second member 75 is prevented. That is, regardless of the rotation direction of the first member 74, rotation of the first member 74 relative to the fixed portion 14 is prevented.

[0210] <One-way clutch mode>

[0211] In one-way clutch mode, the phase of the mode selection component 76 relative to the second component 75 in the circumferential direction is adjusted, such as... Figure 20 As shown in (C), the protrusion 100 pushes the second engaging claw 97 radially outward and upward against the elastic force of the second claw applying member 92. This engages the engaging recess 77 of the first member 74 with the first engaging claw 94, and disengages the engaging recess 77 from the second engaging claw 97. In this state, only the aforementioned predetermined direction of the first member 74 relative to the second member 75 is permitted. Figure 20 The rotation of (C) in a clockwise direction, and prevents the direction opposite to the predetermined direction ( Figure 20 The rotation of (C) in the counterclockwise direction.

[0212] That is, when the first component 74 wants to rotate relative to the second component 75 in the predetermined direction, the first engaging pawl 94 is pushed radially outward by the protrusion 78 of the protrusion 79, overcoming the elastic force of the first pawl force-applying component 91. As a result, rotation of the first component 74 in the predetermined direction is allowed. Conversely, when the first component 74 wants to rotate relative to the second component 75 in the opposite direction, rotation of the first component 74 in the opposite direction is prevented by the engagement of the engaging recess 77 with the first engaging pawl 94. In summary, the rotation transmission state switching device 12 operates as a ratchet-type one-way clutch.

[0213] Furthermore, the aforementioned predetermined direction is consistent with the forward rotation direction of the input component 8. The forward rotation direction of the input component 8 refers to the direction of rotation of the input component 8 when the car is moving forward.

[0214] The two-stage transmission 3 can switch between a high reduction ratio mode with a large reduction ratio between the input component 8 and the output component 9 and a low reduction ratio mode with a small reduction ratio between the input component 8 and the output component 9 by switching between the mode of the electric friction clutch device 11 and the mode of the rotational transmission state switching device 12.

[0215] The two-stage transmission 3 in this example also includes a planetary gear mechanism 13 as an arbitrary structural element. That is, the two-stage transmission 3 in this example switches the transmission path of the torque transmitted in the planetary gear mechanism 13 by switching the mode of the electric friction clutch device 11 and the mode of the rotational transmission state switching device 12, thereby enabling switching between a high reduction ratio mode and a low reduction ratio mode.

[0216] The planetary gear mechanism 13 has a sun gear 104, a ring gear 105, a planet carrier 106, and multiple planetary gears 107.

[0217] The ring gear 105 is arranged coaxially with the sun gear 104 around it.

[0218] The planetary gear carrier 106 is supported coaxially with the sun gear 104 and the ring gear 105, and is capable of rotating relative to the sun gear 104 and the ring gear 105.

[0219] Multiple planetary gears 107, along with a sun gear 104 and a ring gear 105, are supported on a planetary gear carrier 106 and are capable of rotation (self-rotation) around their own central axis.

[0220] The plurality of planetary gears 107 can be composed of planetary gears that mesh with both the sun gear 104 and the ring gear 105. That is, the planetary gear mechanism 13 can be composed of a single-pinion planetary gear mechanism. Alternatively, the plurality of planetary gears 107 can also have: a first planetary gear that meshes with the sun gear 104; and a second planetary gear that meshes with the ring gear and also with the first planetary gear. That is, the planetary gear mechanism 13 can be composed of a double-pinion planetary gear mechanism.

[0221] In the two-stage transmission 3, the input component 8, the output component 9, the first friction plate 33 and the second friction plate 34 of the electric friction clutch device 11, and the first component 74 and the second component 75 of the rotational transmission state switching device 12 are connected to the sun gear 104, the ring gear 105, the planetary gear carrier 106, or the fixed part 14, so that by switching the mode of the electric friction clutch device 11 and the mode of the rotational transmission state switching device, the reduction ratio between the input component 8 and the output component 9 can be switched between high and low stages.

[0222] Specifically, an input element, which is any one of the sun gear 104, ring gear 105, and planetary carrier 106, is connected to the input member 8 in a manner that allows it to rotate integrally with the input member 8. An output element, which is any one of the sun gear 104, ring gear 105, and planetary carrier 106 and is different from the aforementioned input element, is connected to the output member 9 in a manner that allows it to rotate integrally with the output member 9. Furthermore, rotating elements, which are the remaining elements of the sun gear 104, ring gear 105, and planetary carrier 106 other than the aforementioned input and output elements, are connected to the rotating member 10 in a manner that allows them to rotate integrally with the rotating member 10.

[0223] For example, the ring gear 105 can be connected to the input component 8 in a manner that rotates integrally with the input component 8, the planetary gear carrier 106 can be connected to the output component 9 in a manner that rotates integrally with the output component 9, and the sun gear 104 can be connected to the rotating component 10 in a manner that rotates integrally with the rotating component 10.

[0224] Alternatively, the sun gear 104 can be connected to the input component 8 in a manner that rotates integrally with the input component 8, the planetary gear carrier 106 can be connected to the output component 9 in a manner that rotates integrally with the output component 9, and the ring gear 105 can be connected to the rotating component 10 in a manner that rotates integrally with the rotating component 10.

[0225] Alternatively, the sun gear 104 can be connected to the input component 8 in a manner that rotates integrally with the input component 8, the ring gear 105 can be connected to the output component 9 in a manner that rotates integrally with the output component 9, and the planetary gear carrier 106 can be connected to the rotating component 10 in a manner that rotates integrally with the rotating component 10.

[0226] In this example, the ring gear 105 is connected to the input component 8 in a manner that rotates integrally with the input component 8, the planetary gear carrier 106 is connected to the output component 9 in a manner that rotates integrally with the output component 9, and the sun gear 104 is connected to the rotating component 10 in a manner that rotates integrally with the rotating component 10.

[0227] More specifically, the sun gear 104 is provided at the end of the rotating member 10 on one side of the axis.

[0228] The ring gear 105 is mounted on the axial middle part of the input component 8.

[0229] The planetary gear carrier 106 and the output component 9 are integrated into one unit.

[0230] Furthermore, multiple planetary gears 107 mesh with both the sun gear 104 and the ring gear 105, and are supported on the planetary gear carrier 106 in a rotational manner around their own central axis. That is, in this example, the planetary gear mechanism 13 is composed of a single-pinion type planetary gear mechanism.

[0231] The torque transmission mechanism 4 transmits torque between the output component 9 and the drive wheel 108.

[0232] In this example, the torque transmission mechanism 4 is composed of a differential device that distributes the rotational torque of the output component 9 to a pair of drive wheels 108. By engaging the output gear 17 of the output component 9 with the ring gear 117 constituting the differential device of the torque transmission mechanism 4, torque can be transmitted between the output component 9 and the drive wheels 108.

[0233] The friction braking device 5 is disposed between the output component 9 and the drive wheel 108 to brake the rotation of the drive wheel 108.

[0234] In this example, the friction braking device 5 is configured to brake the rotation of the drive wheel 108 by pressing friction components such as brake pads and brake shoes against a rotating body 110 such as a rotor or roller that is supported and fixed to the differential device constituting the torque transmission mechanism 4.

[0235] Control device 6 has reduction ratio switching function and coordination control function.

[0236] In this example, the control device 6 is configured to control the drive motor 2, the secondary transmission 3, and the friction brake device 5 based on signals from various sensors, such as the accelerator pedal opening sensor 111 that detects the amount of operation of the accelerator pedal, the input rotation sensor 112 that detects the rotation speed of the motor output shaft 7, and the output rotation sensor 113 that detects the rotation speed of the drive wheel 108, in order to realize the reduction ratio switching function and the coordinated control function.

[0237] In addition, the control device 6 includes: a TCU (Transmission Control Unit) 114 for controlling the two-stage transmission 3; and a VCU (Vehicle Control Unit) 116 for controlling various components of the vehicle, including an inverter 115 for supplying power to the TCU 114 and the drive motor 2.

[0238] First, the reduction ratio switching function of control device 6 will be explained.

[0239] The reduction ratio switching function is based on the use of the electric actuator 32 to rotate the drive cam 38, switching the mode of the electric friction clutch device 11 and the mode of the rotational transmission state switching device 12. This switches the two-stage transmission 3 to a high reduction ratio mode with a large reduction ratio between the input component 8 and the output component 9, and a low reduction ratio mode with a small reduction ratio between the input component 8 and the output component 9. In the electric vehicle drive unit 1 of this example, the control unit 6, based on instructions from the VCU 116, uses the TCU 114 to control the electric actuator 32, thereby switching the mode of the electric friction clutch device 11 and the mode of the rotational transmission state switching device 12, thus executing the reduction ratio switching function.

[0240] <Low Reduction Ratio Mode>

[0241] In order to switch the secondary transmission 3 to a low reduction ratio mode, the electric friction clutch device 11 is switched to the engagement mode, and the rotational transmission state switching device 12 is switched to the free mode.

[0242] Specifically, the electric friction clutch device 11 is switched to engagement mode by expanding the axial dimension of the cam device 31 through the rotation of the cam 38 driven by the electric actuator 32. As a result, the input component 8 and the rotating component 10 rotate as a unit, and the sun gear 104 and the ring gear 105 rotate as a unit.

[0243] Simultaneously with switching the electric friction clutch device 11 to the engagement mode, based on adjusting the phase of the mode selection component 76 relative to the second component 75 in the circumferential direction by rotating the drive cam 38, the rotation transmission state switching device 12 is switched to a free mode that allows the rotation of the first component 74 relative to the second component 75 regardless of the relative rotation direction of the first component 74 and the second component 75. As a result, rotation of the rotating component 10 relative to the fixed portion 14 is permitted, and rotation of the sun gear 104 is permitted.

[0244] In the low reduction ratio mode, the sun gear 104, ring gear 105, and planetary gear carrier 106 rotate in the same direction and at the same speed, resulting in a so-called "adhesive" state where the planetary gear mechanism 13 rotates as a whole. Therefore, as Figure 3 As shown in bold in (A), the rotational torque of the input component 8 is transmitted in the order of input component 8, planetary gear carrier 106, and output component 9, and is taken out from output component 9.

[0245] <High Reduction Ratio Mode>

[0246] In order to switch the secondary transmission 3 to a high reduction ratio mode, the electric friction clutch device 11 is switched to the disengagement mode, and the rotational transmission state switching device 12 is switched to the locking mode.

[0247] Specifically, the electric friction clutch device 11 is switched to the disengaged mode by reducing the axial dimension of the cam device 31 by rotating the cam 38 using the electric actuator 32. As a result, the input component 8 and the rotating component 10 rotate relative to each other, and the sun gear 104 and the ring gear 105 rotate relative to each other.

[0248] Simultaneously with switching the electric friction clutch device 11 to the disengagement mode, the rotation transmission state switching device 12 is switched to a locking mode by rotating the drive cam 38, which prevents the rotation of the first component 74 relative to the second component 75 regardless of the relative rotation direction of the first component 74 and the second component 75. As a result, the rotation of the rotating component 10 relative to the fixed part 14 is prevented, and the rotation of the sun gear 104 is also prevented.

[0249] In high reduction ratio mode, such as Figure 3 As shown in bold in (B), the rotational torque of the input component 8 is transmitted sequentially through the rotational motion of the input component 8, the ring gear 105, the planetary gear 107, the revolution of the planetary gear 107 meshing with the sun gear 104, the planet carrier 106, and the output component 9, and is extracted from the output component 9. In high reduction ratio mode, the reduction ratio between the input component 8 and the output component 9 is determined by the gear ratio of the ring gear 105 to the sun gear 104 (number of teeth on the ring gear 105 / number of teeth on the sun gear 104).

[0250] In the electric vehicle drive unit 1 of this example, by using an electric actuator 32 to rotate and drive a drive cam 38, the modes of the electric friction clutch device 11 and the rotational transmission state switching device 12 are switched, thereby enabling two-stage switching of the reduction ratio between the input component 8 and the output component 9. Specifically, for example, in the region where the power input to the input component 8 is low speed and high torque, the two-stage transmission 3 is switched to a high reduction ratio mode, while in the region of high speed and low torque, it is switched to a low reduction ratio mode. Therefore, the acceleration performance and high-speed performance of electric vehicles and hybrid vehicles when driven solely by an electric motor are improved to achieve the aforementioned... Figure 36 The solid line a, which is continuous to the left of point P, and the dashed line b, which is continuous to the right of point P, and with... Figure 36 The characteristic of gasoline engine vehicles approaching each other is shown by the dashed line c.

[0251] In the electric vehicle drive unit 1 of this example, a hydraulic system for controlling friction engagement devices such as clutches and brakes is not required. Therefore, in electric vehicles and hybrid vehicles, the system can be simplified, costs reduced, and energy efficiency improved.

[0252] In the electric vehicle drive unit 1 disclosed herein, the two-stage transmission 3 is capable of having a reduction ratio switching mode for smoothly switching from a high reduction ratio mode to a low reduction ratio mode during normal forward driving (powered driving). Additionally or alternatively, the two-stage transmission 3 can have: a neutral mode in which no torque is transmitted between the input component 8 and the output component 9, and / or a parking mode that locks the rotation of the output component 9. In this example, the two-stage transmission 3, in addition to the low reduction ratio mode and the high reduction ratio mode, also has a reduction ratio switching mode, a neutral mode, and a parking mode.

[0253] <Reduction Ratio Switching Mode>

[0254] During normal forward driving, when the secondary transmission 3 begins to switch from a high reduction ratio mode to a low reduction ratio mode, firstly, based on the phase of the mode selection component 76 relative to the second component 75 in the circumferential direction, such as... Figure 20 As shown in (C), the protrusion 100 pushes the second engaging pawl 97 radially outward against the elastic force of the second pawl force-applying member 92. Thus, only the first engaging pawl 94 engages with the engaging recess 77 of the first member 74, and the rotational transmission state switching device 12 switches to a one-way clutch mode, which only allows the first member 74 to engage in the aforementioned predetermined direction relative to the second member 75. Figure 20 The rotation of (C) in the predetermined direction, and prevents rotation in the opposite direction to the predetermined direction.

[0255] Simultaneously with or after switching the rotational transmission state switching device 12 to one-way clutch mode, the switching of the electric friction clutch device 11 from disengagement mode to engagement mode begins. During the switching of the electric friction clutch device 11 from disengagement mode to engagement mode, based on the rotation of the drive cam 38, such as... Figure 15 (B) Figure 15 As shown in (A), the rolling element 40 descends on the gently inclined surface 52b of the drive cam surface 52. Then, as the amount of ascent of the rolling element 40 from the first bottom 52a of the drive cam surface 52 gradually decreases, the force of the first friction plate 33 and the second friction plate 34 pressing against each other gradually increases (the fastening force F of the friction engagement portion 29 gradually increases). At this time, the input component 8 rotates while sliding (sliding contact) the axial sides of the second friction plate 34 relative to the axial sides of the first friction plate 33.

[0256] During the rotation of the input component 8 in the forward direction, as the clamping force F of the friction engagement part 29 gradually increases, the torque applied to the second component 75 of the rotation transmission state switching device 12 in the direction opposite to the predetermined direction gradually decreases. At this time, the rotation transmission state switching device 12 is switched to a one-way clutch mode, so even if torque is applied to the second component 75 in the direction opposite to the predetermined direction, the second component 75 will not rotate. After the torque applied to the second component 75 in the direction opposite to the predetermined direction gradually decreases to 0, when the direction of the torque applied to the second component 75 reverses (the torque in the predetermined direction is applied to the second component 75), at that instant, rotation of the second component 75 in the predetermined direction is permitted.

[0257] <Neutral Mode>

[0258] In order to switch the secondary transmission 3 to neutral mode, the electric friction clutch device 11 is switched to disengagement mode, and the rotational transmission state switching device 12 is switched to free mode.

[0259] Therefore, by using the electric actuator 32 to rotate the drive cam 38, the rolling element 40 is positioned on the second flat surface 52g of the drive cam surface 52, causing the driven cam 39 to displace in the direction of increasing axial distance from the drive cam 38 (axial side). This causes the piston 36 of the elastic force application mechanism 30 to be pressed axially towards the axial side via the thrust bearing 61 and the pressing member 62, thereby elastically compressing the elastic member 37 and dissipating the force that presses the first friction plate 33 and the second friction plate 34 together. Then, by the action of the return spring 35, the distance between the first friction plate 33 and the second friction plate 34 increases, the friction engagement portion 29 is disengaged, and the electric friction clutch device 11 is switched to the disengaged mode. As a result, the input member 8 and the rotating member 10 rotate relative to each other, and the sun gear 104 and the ring gear 105 can rotate relative to each other.

[0260] Simultaneously with switching the electric friction clutch device 11 to the engagement mode, the phase of the adjustment mode selection component 76 relative to the second component 75 in the circumferential direction is adjusted, such as... Figure 20 As shown in (A), the protrusion 100 pushes the first engaging pawl 94 radially outward and the second engaging pawl 97 radially outward. This releases the engagement between the engaging recess 77 of the first component 74 and the first and second engaging pawls 94 and 97, and the rotation transmission state switching device 12 switches to a free mode. This free mode allows the first component 74 to rotate relative to the second component 75 regardless of the relative rotation direction of the first component 74 and the second component 75. As a result, the rotation of the rotating component 10 relative to the fixed portion 14 is allowed, and the rotation of the sun gear 104 is permitted.

[0261] In this neutral mode, the input component 8 and the output component 9 rotate freely relative to each other, and no torque is transmitted between the input component 8 and the output component 9.

[0262] <Parking Lock Mode>

[0263] In order to switch the secondary transmission 3 to the parking lock mode, the electric friction clutch device 11 is switched to the engagement mode, and the rotational transmission state switching device 12 is switched to the lock mode.

[0264] Therefore, by using the electric actuator 32 to rotate the drive cam 38, the rolling element 40 is positioned at the second bottom 52e of the drive cam surface 52, causing the driven cam 39 to displace in the direction of decreasing axial distance from the drive cam 38 (to the other side of the axial direction). This causes the force that presses the piston 36 of the elastic force application mechanism 30 toward one side of the axial direction to be lost. Then, mainly by the elastic restoring force of the first friction plate 33 and the elastic member 37, the piston 36, the thrust bearing 61, and the pressing member 62 are pressed toward the other side of the axial direction, and the piston 36 presses either the first friction plate 33 or the second friction plate 34 on the outermost axial side toward the other side of the axial direction.

[0265] Thus, by pressing the first friction plate 33 and the second friction plate 34 together, the friction engagement part 29 is connected, thereby switching the electric friction clutch device 11 into the engagement mode. As a result, the rotation of the input part 8 relative to the rotating part 10 is prevented, and the rotation of the ring gear 105 relative to the sun gear 104 is prevented.

[0266] Simultaneously with switching the electric friction clutch device 11 to the engagement mode, the phase of the mode selection component 76 relative to the second component 75 in the circumferential direction is adjusted, such as... Figure 20 As described in (B), the protrusion 100 is positioned at a portion offset from the first engaging pawl 94 and the second engaging pawl 97 in the circumferential direction. Consequently, the engaging recess 77 of the first component 74 engages with the first engaging pawl 94 and the second engaging pawl 97, and the rotation transmission state switching device 12 switches to a locking mode. This locking mode prevents the rotation of the first component 74 relative to the second component 75 regardless of the relative rotational direction of the first component 74 and the second component 75. As a result, the rotation of the rotating component 10 relative to the fixed portion 14 is prevented, and the rotation of the sun gear 104 is also prevented.

[0267] In this parking lock mode, the rotation of input component 8 and output component 9 is locked.

[0268] In this example, the drive unit 1 for an electric vehicle is configured such that, during normal forward driving, when switching from a high reduction ratio mode to a low reduction ratio mode, in order to prevent discontinuous (abrupt) changes in the rotational torque of the output component 9 and thus prevent gear shift shock, the output torque and speed R of the drive motor 2 are controlled. s And the rotational speed (rotational amount) of the shift motor 70. As an example of this control, using... Figure 26 and Figure 27 The following example illustrates how the rotational torque of the output component 9 is maintained at approximately constant before and after switching from a high reduction ratio mode to a low reduction ratio mode.

[0269] When switching from a high reduction ratio mode to a low reduction ratio mode based on conditions such as vehicle speed and accelerator opening, firstly, the electric actuator 32 rotates the drive cam 38, thereby switching the rotational transmission state switching device 12 to a one-way clutch mode, and causing the phase of the drive cam 38 in the rotational direction to move to the clutch engagement point θ. f (S1). Clutch contact point θ f This is the point at which the elastic force-applying mechanism 30 begins to generate the force that pushes the first friction plate 33 and the second friction plate 34 together.

[0270] In other words, the clutch contact point θ f The point where the end of piston 36 on the other side of the axial direction begins to contact the first friction plate 33 or the second friction plate 34 located on the most axial side, i.e., the clutch clearance C. f (Reference Figure 25 The point where θ is 0. In this example, the clutch engagement point θ f The clutch contact point is pre-determined using the clutch contact point detection function.

[0271] When the phase of the drive cam 38 in the rotational direction is moved to the clutch engagement point θ f Then, the process transitions to the torque stage (S2). In the torque stage, the drive cam 38 is rotated at a predetermined speed (rotational speed) by the electric actuator 32, causing the amount of rise of the rolling element 40 from the first bottom 52a to decrease, thereby gradually increasing the pushing force between the first friction plate 33 and the second friction plate 34, i.e., the fastening force F of the friction engagement portion 29. At the same time, the output torque (drive torque, power operating torque) of the drive motor 2 is gradually increased.

[0272] That is, assuming the output torque of the drive motor 2 is kept constant, during the torque phase, as the clamping force F of the friction engagement part 29 increases, the torque transmitted to the friction engagement part 29 increases, and therefore, the rotational torque of the output component 9 decreases. Therefore, in this example of the two-stage transmission 3, the output torque of the drive motor 2 is gradually increased based on the increase in the clamping force F of the friction engagement part 29, i.e., the amount of rotation of the drive cam 38, in a manner that allows the rotational torque of the output component 9 to be kept approximately constant regardless of the increase in the clamping force F of the friction engagement part 29.

[0273] Furthermore, the relationship between the rotational amount of the drive cam 38 and the increase in the output torque of the drive motor 2 is determined in advance through experiments and calculations. In this example, the rotational speed of the drive cam 38 in S2 is made smaller than that of the drive cam 38 in S1. It should be noted that the rotational speed of the drive cam 38 in S2 can also be the same as that of the drive cam 38 in S1, or it can be larger than that of the drive cam 38 in S1.

[0274] In S2, more specifically, while rotating the drive cam 38 by a predetermined angle, the output torque of the drive motor 2 is increased by an amount corresponding to the rotation of the drive cam 38. Then, in the following S3, it is determined whether the torque phase has ended.

[0275] That is, during the torque phase, as the clamping force F of the friction engagement portion 29 increases, the clutch torque transmitted to the friction engagement portion 29 increases, and the torque applied to the second component 75 of the rotational transmission state switching device 12 in the direction opposite to the predetermined direction gradually decreases. The torque applied to the second component 75 in the direction opposite to the predetermined direction gradually decreases until it becomes 0.

[0276] In this example, during normal forward driving, when switching from a high reduction ratio mode to a low reduction ratio mode, the secondary transmission 3 is switched to reduction ratio switching mode. Therefore, when the torque applied to the second component 75 in the direction opposite to the predetermined direction becomes 0, and then the direction of the torque applied to the second component 75 is reversed (the torque in the predetermined direction is applied to the second component 75), at that instant, rotation of the second component 75 in the predetermined direction is permitted, and rotation of the sun gear 104 is permitted. When the sun gear 104 rotates, the rotational speed R of the motor output shaft 7 of the drive motor 2... s It begins to decrease.

[0277] Therefore, in this example, the rotational speed R of the motor output shaft 7 is determined based on the output signal of the input rotation sensor 112 installed on the motor output shaft 7 of the drive motor 2. s If the torque level decreases by more than a predetermined value, the torque phase is considered to have ended. This determination is based on the input rotation sensor 112 installed on the motor output shaft 7 of the drive motor 2.

[0278] The rotational speed R of the motor output shaft 7 is determined. s The speed R of the motor output shaft 7 is approximately constant. s If the decrease is smaller than the predetermined value and the torque phase has not ended, return to S2.

[0279] In S3, the speed R of the motor output shaft 7 is determined. s When the reduction is greater than the predetermined value, and the torque stage ends, the process transitions to the inertia stage (S4-1~S4-3).

[0280] During the inertia phase, firstly, the output torque of the drive motor 2 is rapidly reduced, increasing the rotational speed R of the motor output shaft 7. s Further reduction (S4-1). The reduction in output torque of drive motor 2 is only sufficient to increase the rotational speed R of motor output shaft 7. sThere are no particular limitations on further reduction. Specifically, for example, it is possible to reduce the output torque of the drive motor 2 to 0 or a negative value.

[0281] At the rotational speed R of the motor output shaft 7 s After the reduction begins, the output torque of the drive motor 2 is increased so that the rotational torque of the input component 8 becomes the target torque that the output component 9 should output when the switching from the high reduction ratio mode to the low reduction ratio mode of the two-stage transmission 3 is completed (S4-2). In this example, the rotational torque of the output component 9 is set to be approximately constant before and after the switching from the high reduction ratio mode to the low reduction ratio mode. Therefore, the output torque of the drive motor 2 is increased until the rotational torque of the input component 8 is equal to the rotational torque of the output component 9 at the start of the switching from the high reduction ratio mode to the low reduction ratio mode.

[0282] There is no particular limitation on the rate at which the output torque of the drive motor 2 is increased, as long as the rotational torque of the input component 8 is increased to the target torque before the inertia phase is completed. For example, it can be increased according to the rotational speed R of the input component 8. in The rotational speed R of the output component 9 out The difference (rotation difference) ΔR controls the output torque of the drive motor 2. More specifically, it can be controlled as follows: as the rotational speed R of the motor output shaft 7 increases... s The reduction in speed R of input component 8 causes the speed of input component 8 to decrease. in The rotation difference ΔR decreases, which in turn increases the output torque of the drive motor 2. When the rotation difference ΔR becomes 0, the rotation torque of the input component 8 becomes the target torque.

[0283] Next, in S4-3, the rotational speed R of the input component 8 is determined. in and the rotational speed R of output component 9 out Are they equal? ​​Specifically, determine the rotational speed R of input component 8. in The rotational speed R of the output component 9 out Whether the difference (rotation difference) ΔR is within a predetermined range. This determination is based on the output signal of the input rotation sensor 112 or the output signals of the rotation sensors installed on the input component 8 and the output component 9, respectively.

[0284] If the rotational difference ΔR is determined to be outside the predetermined range, i.e., the rotational speed R of input component 8 is... in The rotational speed R of the output component 9 out If they are not equal, S4-3 will be executed again after a predetermined time has elapsed.

[0285] When the rotational difference ΔR is determined to be within a predetermined range, i.e., the rotational speed R of input component 8 is... in The rotational speed R of the output component 9 outIf they are equal, the inertial phase is considered to have ended, and the process moves to the next S5.

[0286] In S5, the drive cam 38 is rotated to a predetermined circumferential phase by the electric actuator 32, causing the rolling element 40 to be located at the first bottom 52a of the drive cam surface 52, and causing the driven cam 39 to be displaced in the direction of decreasing axial distance from the drive cam 38, i.e., on the other side of the axial axis. This ensures the piston clearance C between the end of the pressing member 62 on one side of the axial axis and the side of the piston 36 on the other side of the axial axis. p In other words, the piston clearance C p If the value is 0 or higher, it is preferred to be greater than 0.

[0287] After the rolling element 40 is moved to the first bottom 52a, the process ends. Through this process, the secondary transmission 3 is switched from a high reduction ratio mode to a low reduction ratio mode. Then, by maintaining the phase of the drive cam 38 in the circumferential direction, the secondary transmission 3 is maintained in the low reduction ratio mode.

[0288] As described above, in the electric vehicle drive unit 1 of this example, by controlling the drive motor 2 and the shift motor 70, even when switching between high and low reduction ratio modes during normal forward driving, a rapid change in the rotational torque of the output component 9 can be prevented, thus preventing shift shock. It should be noted that, in order to prevent shift shock, the output torque and speed R of the drive motor 2 are controlled... s The timing of the shift motor speed (rotation amount) 70 is also important.

[0289] For example, if the phase of the drive cam 38 in the rotational direction has not reached the clutch engagement point θ f If the current path is still transferred to S2, increasing the output torque of drive motor 2, then it is possible that... Figure 27 As shown by the dashed line in (F), the rotational torque of output component 9 unexpectedly increased.

[0290] Here, as the wear of the first friction plate 33 and the second friction plate 34 increases with the use of the secondary transmission 3, the necessary pressing amount by the elastic force application mechanism 30, used to switch the electric friction clutch device 11 to the engagement mode, on either the first friction plate 33 or the second friction plate 34 on the most axial side towards the other side increases. In other words, the necessary pressing amount by the cam device 31 on the piston 36 towards the axial side when switching the electric friction clutch device 11 to the disengagement mode decreases. As a result, the relationship between the rotation angle θ of the drive cam 38 and the current value A of the shift motor 70 is... Figure 22 (A) Figure 22 The order of (B) changes as shown. That is, as according to Figure 22 (A) and Figure 22As can be seen from (B), when the wear of the first friction plate 33 and the second friction plate 34 increases, the clutch contact point θ f It gets smaller.

[0291] Figure 22 (A) and Figure 22 (B) is a graph showing the relationship between the rotation angle θ of the drive cam 38 and the output torque T and current value A of the shift motor 70 when the electric friction clutch device 11 is switched from the engagement mode to the disengagement mode. Figure 22 (A) indicates the case where the first friction plate 33 and the second friction plate 34 are new and unworn. Figure 22 (B) indicates that the first friction plate 33 and the second friction plate 34 are significantly worn.

[0292] In addition, as according to Figure 22 (A) and Figure 22 As can be seen from (B), when the wear of the first friction plate 33 and the second friction plate 34 increases, the piston contact point θ p It also becomes smaller. When the drive cam 38 is rotated in the direction that switches the friction engagement part 29 from the connected state to the disconnected state, the piston contact point θ p The point where the elastic force-applying mechanism 30 begins to press in the direction of releasing the force that pushes the first friction plate 33 and the second friction plate 34 together. In other words, when the drive cam 38 is rotated in the direction that switches the friction engagement part 29 from the cut-off state to the connected state, the piston contact point θ... p The piston gap C is the distance between the end of the pressing member 62 on one axial side and the side of the piston 36 on the other axial side. p (Reference Figure 23 ) point.

[0293] In the electric vehicle drive unit 1 of this example, the control device 6 has a function to prevent transmission shock regardless of the wear of the first friction plate 33 and the second friction plate 34. Specifically, the control device 6 also has a piston contact point detection function to detect the piston contact point θ. p Clutch contact point detection function, detects the clutch contact point θ. f ; and the touch point adjustment function, which adjusts the piston touch point θ when switching between high and low reduction ratio modes. p and / or clutch contact point θ f Adjust the rotation of drive cam 38.

[0294] According to Figure 22 (A) and Figure 22As can be seen from (B), during mode switching of the electric friction clutch device 11, the output torque T of the shift motor 70 and the current value A of the shift motor 70 change with the same tendency. In this example, the two-stage transmission 3 detects the piston contact point θ based on the current value A of the shift motor 70 when switching the electric friction clutch device 11 from the engagement mode to the disengagement mode. p and clutch contact point θ f .

[0295] When the electric friction clutch device 11 is switched to the engagement mode, the rolling element 40 of the cam device 31 is located at the first bottom 52a of the drive cam surface 52. In this state, as... Figure 23 As shown, a piston gap C exists between the end of the pressing member 62 on one axial side and the side of the piston 36 on the other axial side. p Based on the piston clearance C p The presence of the piston 36 allows for displacement to the other side of the axial direction. Therefore, by means of the elastic force desired by the elastic member 37, the piston 36 is elastically pressed to the other side of the axial direction, and through the piston 36, either the first friction plate 33 or the second friction plate 34 on the most axial side is pressed towards the other side of the axial direction, thereby pushing the first friction plate 33 and the second friction plate 34 together.

[0296] In order to switch the electric friction clutch device 11 from the engagement mode to the disengagement mode, based on the energization of the shift motor 70, the drive cam 38 is rotated in the predetermined direction, increasing the amount of rise of the rolling element 40 from the first bottom 52a. At this time, the current value A of the shift motor 70 is approximately constant, except for the temporary starting current. Figure 22 (A) and Figure 22 (B) in the range α).

[0297] When the pressing member 62 moves toward one side by increasing the amount of rise of the rolling element 40 from the first bottom 52a, such as Figure 24 As shown, one axial end of the pressing member 62 contacts the other axial side of the piston 36. In other words, the piston clearance C p Become 0.

[0298] When from Figure 24From the state shown, when the drive cam 38 is further driven to rotate in the predetermined direction by the shift motor 70, the driven cam 39, via the pressing member 62, presses the piston 36 against the elastic restoring force of the elastic member 37 toward the axial side. In this state, a portion of the elastic restoring force of the elastic member 37 is supported by the cam device 31 via the pressing member 62 and the thrust bearing 61, and the remaining portion is supported by the fixed part 14 via the friction engagement part 29 and the rotation transmission state switching device 12. When the piston 36 is pressed toward the axial side, the force that pushes the first friction plate 33 and the second friction plate 34 together gradually decreases, mainly based on the elastic restoring force of the second friction plate 34 and the elastic member 37. That is, the fastening force F of the friction engagement part 29 gradually decreases.

[0299] During the period when the fastening force F of the friction engagement part 29 is gradually reduced, the current value A of the shift motor 70 increases at a substantially constant rate (slope). Figure 22 (A) and Figure 22 (B) in the range β). That is, the rate of increase of the current value A in the range β is greater than the rate of increase of the current value A in the range α.

[0300] Therefore, the control device 6, through the piston contact point detection function, detects the phase (rotation angle from the reference position (e.g., the initial position where the rolling element 40 is located at the bottom of the recess) θ of the drive cam 38 in the rotational direction when the current value A of the shift motor 70 begins to increase at a predetermined first threshold rate after the shift motor 70 is energized to switch the electric friction clutch device 11 from the engagement mode to the disengagement mode), using the piston clearance C. p The piston contact point θ becomes 0 p The first threshold can be determined in advance through experiments, simulations, etc.

[0301] Furthermore, the rate of increase of the current value A is the amount ΔA of the increase of the current value A per unit rotation angle Δθ of the drive cam 38. Additionally, when the drive cam 38 rotates at a constant speed in the predetermined direction, the amount ΔA of the increase of the current value A per unit time can also be used for determination.

[0302] When the fastening force F of the friction engagement part 29 gradually decreases and becomes 0, from that instant onwards, as... Figure 25 As shown, a clutch clearance C is generated between the end of the piston 36 on the other side of the axial direction and the first friction plate 33 or the second friction plate 34 located on the most axial side. f When clutch clearance C begins to form f At this time, almost all of the elastic restoring force of the elastic member 37 is supported by the cam device 31 via the pressing member 62 and the thrust bearing 61. This initiates the clutch clearance C.f Afterwards, the current value A of the shift motor 70 increases slowly and logarithmically. Figure 22 (A) and Figure 22 (B) in the range γ). That is, the rate of increase of the current value A in the range γ is smaller than the rate of increase of the current value A in the range β.

[0303] Control device 6, through its clutch contact point detection function, determines when the electric friction clutch device 11 is switched from engagement mode to disengagement mode that the phase of the drive cam 38 in the rotational direction exceeds the piston contact point θ. p Then, the phase θ in the rotational direction of the drive cam 38 when the rate of increase of the current value A of the shift motor 70 falls below a predetermined second threshold is used as the clutch clearance C. f The clutch contact point θ becomes 0 f Furthermore, the second threshold is smaller than the first threshold. The second threshold can be determined in advance through experiments, simulations, etc.

[0304] In addition, piston contact point θ p and clutch contact point θ f The detection can be performed at any time as long as it does not obstruct the driving of the vehicle equipped with the two-stage transmission 3. Specifically, it can be performed, for example, immediately after the ignition switch is turned on, during downshifting and acceleration, or when the engine brakes, such as when switching the two-stage transmission from a low gear ratio mode to a high gear ratio mode. It should be noted that when performing the above operation while the vehicle is in motion, there is a problem that the drive cam 38 cannot be driven at any rotational speed. Therefore, the piston contact point θ p and clutch contact point θ f The test is preferably performed immediately after the ignition switch is turned on and the vehicle has come to a complete stop.

[0305] In the electric vehicle drive unit 1 of this example, when the control unit 6 switches between high reduction ratio mode and low reduction ratio mode, it bases the piston contact point θ detected by the piston contact point detection function on the piston contact point detection function. p And / or the clutch contact point θ detected by the clutch contact point detection function f The rotation of the drive cam 38, which is driven by the shift motor 70 via the reducer 71, is adjusted. Specifically, for example, when maintaining the rotational torque of the output component 9 approximately constant before and after switching from a high reduction ratio mode to a low reduction ratio mode, in S1, the clutch contact point θ detected by the clutch contact point detection function is used. f The target value of the phase of the drive cam 38 in the rotational direction.

[0306] Thus, in the electric vehicle drive unit 1 of this example, even as the first friction plate 33 and the second friction plate 34 wear down, the piston contact point θ...p and clutch contact point θ f Even if the initial position changes, it is still possible to base the corrected piston contact point θ. p and clutch contact point θ f Variable speed control is implemented. Therefore, according to the drive unit 1 for electric vehicles in this example, regardless of the wear of the first friction plate 33 and the second friction plate 34, the occurrence of variable speed shock can be prevented.

[0307] In the electric vehicle drive unit 1 of this example, during normal forward driving, the transition from a high reduction ratio mode to a low reduction ratio mode involves a reduction ratio switching mode. Therefore, it is possible to suppress both the shift shock associated with the mode switch and torque loss. For the reason behind this, please refer to... Figure 30 and Figure 31 Please provide an explanation.

[0308] Figure 30 This represents a portion of a comparative example two-stage transmission. The comparative example two-stage transmission includes: a first friction engagement device 201, which switches whether the input component 8 and the rotating component 10 can rotate relative to each other; in other words, whether the ring gear 105 and the sun gear 104 can rotate relative to each other; and a second friction engagement device 202, which switches whether the rotating component 10 can rotate relative to the fixed portion 14; in other words, whether the sun gear 104 can rotate. That is, the comparative example two-stage transmission uses the second friction engagement device 202, which switches modes by pressing or separating the first friction plate 33 and the second friction plate 34, instead of the rotational transmission state switching device 12 of the two-stage transmission in this example.

[0309] In the comparative example, the driving cam 38z of the driving cam device 31z is rotated by an electric actuator, causing the first driven cam 203 and the second driven cam 204 to be displaced axially, thereby switching the mode of the first friction engagement device 201 and the mode of the second friction engagement device 202. The first driven cam 203 and the second driven cam 204 are displaced with different phases relative to each other as the driving cam 38z rotates (displaced axially in opposite directions (forward and backward)).

[0310] In the comparative example of the two-stage transmission, the switching from a high reduction ratio mode with a large reduction ratio to a low reduction ratio mode with a small reduction ratio, such as... Figure 31 As shown, the clamping force of the first friction engagement device 201 gradually increases, while the clamping force of the second friction engagement device 202 gradually decreases. Therefore, during the switch from a high reduction ratio mode to a low reduction ratio mode, when the clamping force of the second friction engagement device 202 gradually decreases and becomes insufficient, the sun gear 104 is dragged by the revolution of the planetary gear 107, resulting in a torque loss between the rotating part 10 and the stationary part 14.

[0311] Furthermore, in the comparative example of the two-stage transmission, as the clamping force of the first friction engagement device 201 gradually increases, the torque applied to the sun gear 104 in the direction opposite to the predetermined direction gradually decreases, and after reaching zero, the direction of the torque applied to the sun gear 104 reverses. However, in the comparative example of the two-stage transmission, at the instant when the direction of the torque applied to the sun gear 104 reverses and the revolution direction of the planetary gear 107 is aligned with the rotation direction of the sun gear 104, the clamping force of the second friction engagement device 202 cannot be large enough. Therefore, the sun gear 104 is dragged relative to the fixed portion 14, resulting in a torque loss between the sun gear 104 and the fixed portion 14.

[0312] In contrast, in this example, based on the rotation of the drive cam 38, before switching the electric friction clutch device 11 from the disengaged mode to the engaged mode to switch from a high reduction ratio mode to a low reduction ratio mode, the rotational transmission state switching device 12 is set to one-way clutch mode. Therefore, in order to switch the electric friction clutch device 11 from the disengaged mode to the engaged mode, the clamping force F of the friction engagement portion 29 gradually increases, allowing the sun gear 104 to rotate in the predetermined direction at the instant the direction of the torque applied to the sun gear 104 reverses. Thus, it is possible to suppress both the shift shock accompanying mode switching and torque loss in the secondary transmission 3.

[0313] Furthermore, in the reduction ratio switching mode, the reduction ratio between the input component 8 and the output component 9 is the same as the reduction ratio in the high reduction ratio mode when the clamping force F of the friction engagement part 29 is small enough that no torque loss occurs at the contact points between the axial sides of the first friction plate 33 and the axial sides of the second friction plate 34. On the other hand, when the clamping force F of the friction engagement part 29 is increased to the point that torque is transmitted smoothly without slippage at the contact points between the axial sides of the first friction plate 33 and the axial sides of the second friction plate 34, the reduction ratio is the same as the reduction ratio in the low reduction ratio mode, which is 1.

[0314] When the fastening force F of the friction engagement part 29 is such that the contact portion between the axial sides of the first friction plate 33 and the axial sides of the second friction plate 34 causes sliding, the reduction ratio between the input part 8 and the output part 9 is a value corresponding to the magnitude of the input torque or the rotational speed.

[0315] When the input component 8 is rotating in the forward direction, and during the switch from the high reduction ratio mode to the reduction ratio switching mode, torque is applied to the second component 75 of the rotational transmission state switching device 12 in the opposite direction to the predetermined direction. Here, the rotation of the second component 75 in the rotational transmission state switching device 12 in the opposite direction to the predetermined direction is also prevented during the switch from the locking mode to the one-way clutch mode. That is, the reduction ratio between the input component 8 and the output component 9 during the switch from the high reduction ratio mode to the reduction ratio switching mode is the same as the reduction ratio in the high reduction ratio mode.

[0316] When the input component 8 rotates in the forward direction, and during the switch from the reduction ratio switching mode to the low reduction ratio mode, the second component 75 of the rotational transmission state switching device 12 is subjected to torque in the predetermined direction. Here, in the rotational transmission state switching device 12, the rotation of the second component 75 in the predetermined direction is also permitted during the switch from the one-way clutch mode to the free mode.

[0317] Furthermore, when the input component 8 rotates in the reverse direction, i.e., when the vehicle equipped with the electric vehicle drive unit 1 in this example is reversing, the vehicle will hardly travel at high speed. Therefore, when the input component 8 rotates in the reverse direction, it is not necessary to switch to the reduction ratio switching mode as is required when rotating in the forward direction. This reduction ratio switching mode allows the rotation of the sun gear 104 at the instant the direction of the torque applied to the sun gear 104 reverses by making the electric friction clutch device 11 a one-way clutch mode. In addition, even when the input component 8 rotates in the forward direction, the vehicle is mainly in a deceleration state when switching from the low reduction ratio mode to the high reduction ratio mode. In this case, since there is no power transmission from the input component 8 to the output component 9, it is also unnecessary to switch the secondary transmission 3 to the reduction ratio switching mode.

[0318] Next, the coordination control function of the control device 6 will be explained. This coordination control function performs a pre-shifting process, which is that when the torque is flowing from the output component 9 to the input component 8 through the secondary transmission 3, and a torque is applied to the first component 74 to rotate it relative to the second component 75 in the circumferential direction, and the rotation of the first component 74 relative to the second component 75 is prevented by the rotation transmission state switching device 12, before the second engagement pawl 97 is radially pressed by the protrusion 100 to disengage it from the engagement recess 77 by the mode switching of the secondary transmission 3 with the aforementioned reduction ratio switching function, the regenerative torque of the drive motor 2 is reduced while the braking force of the friction brake device 5 is increased.

[0319] That is, when the torque is transmitted from the output component 9 to the input component 8 in the secondary transmission 3, that is, when the secondary transmission 3 is switched from a high reduction ratio mode to a low reduction ratio mode during vehicle regeneration, it is necessary to switch the electric friction clutch device 11 from the cut-off mode to the connection mode, and switch the rotational transmission state switching device 12 from the locked mode to the one-way clutch mode, and then to the free mode.

[0320] Here, when the vehicle equipped with the electric vehicle drive unit 1 is regenerating forward in a high reduction ratio mode, the first component 74 of the rotary transmission state switching device 12 is subjected to a torque intended to rotate the first component 74 relative to the second component 75 in the circumferential direction. Therefore, the circumferential side of the inner surface of the engagement recess 77 of the first component 74 is pressed by the front end face of the second engagement pawl 97. Thus, during the switching of the secondary transmission 3 from a high reduction ratio mode to a low reduction ratio mode, in order to switch the rotary transmission state switching device 12 from a locked mode to a one-way clutch mode, the force required to press the second engagement pawl 97 radially outward through the protrusion 100 of the mode selection component 76 to release the engagement between the engagement recess 77 and the second engagement pawl 97 may become excessive.

[0321] Therefore, in the electric vehicle drive unit 1 of this example, when the secondary transmission 3 switches from a high reduction ratio mode to a low reduction ratio mode while the vehicle is in a regenerative driving state, and when the rotary transmission state switching device 12 switches from a locked mode to a one-way clutch mode, the regenerative torque T2 of the drive motor 2 and the braking force BF based on the friction braking device 5 are coordinated and controlled by the coordination control function. This prevents the force required for the mode switching of the rotary transmission state switching device 12 from being too large, while suppressing or preventing discomfort to the occupants.

[0322] In the electric vehicle drive unit 1 of this example, the speed and torque of the drive motor 2 are controlled by the inverter 115 based on signals from various sensors via the VCU 116, the mode of the electric friction clutch device 11 and the mode of the rotational transmission state switching device 12 are controlled via the TCU 114, and the braking force of the friction brake device 5 is controlled, thereby performing a coordinated control function.

[0323] use Figure 28 and Figure 29The following method will be explained: While torque is transmitted from the output unit 9 to the input unit 8 in the two-stage transmission 3, coordinated control is performed to coordinate the rotational speed and torque of the drive motor 2, the mode of the electric friction clutch device 11 and the mode of the rotational transmission state switching device 12, and the braking force of the friction brake device 5, while switching the two-stage transmission 3 from a high reduction ratio mode to a low reduction ratio mode. The following example illustrates the case where the rotational speed of the output unit 9 is maintained approximately constant before and after the switch from a high reduction ratio mode to a low reduction ratio mode.

[0324] When torque is transmitted from the output component 9 to the input component 8 in the two-stage transmission 3, i.e., during vehicle regenerative driving, when switching from a high reduction ratio mode to a low reduction ratio mode begins based on conditions such as vehicle speed, the control device 6 first coordinates the control of the drive motor 2 and the friction brake device 5 as a pre-shift procedure. Specifically, by controlling the energization of the drive motor 2, the regenerative torque T2 of the drive motor 2 is reduced (P1-1), while the braking force BF of the friction brake device 5 is increased (P1-2). Here, when the regenerative torque T2 of the drive motor 2 is reduced, the torque T9 transmitted through the output component 9 in the direction from the drive wheel 108 side to the drive motor 2 side also decreases.

[0325] More specifically, in this example, while reducing the regenerative torque T2 of the drive motor 2 to 0, the braking force BF of the friction brake device 5 is increased to increase the rotational speed R of the output component 9. out Maintain a roughly constant level.

[0326] In this example, the regenerative torque T2 of the drive motor 2 is reduced to 0. However, in the case of implementing the drive device for electric vehicles of this disclosure, as long as the force required to switch the rotation transmission state switching device 12 from the locking mode to the one-way clutch mode in the next first mode switching step (P2) can be reduced, that is, the force required to rotate the drive mode selection member 76 by using the protrusion 100 to push the second engagement pawl 97 against the elastic force of the second pawl force application member 92 radially outward, the regenerative torque T2 can also be greater than 0.

[0327] exist Figure 29 In this context, a negative value for T2 indicates regenerative torque. Increasing the regenerative torque means increasing T2 in the negative direction (increasing the absolute value of the negative value), while decreasing the regenerative torque means making the value of T2 closer to 0 (decreasing the absolute value of the negative value).

[0328] In addition, Figure 29 In order to facilitate understanding of the invention, the braking force BF of the friction braking device 5 is represented by a negative value. Increasing the braking force BF means increasing the braking force BF in a negative direction (increasing the absolute value of the negative value). Figure 29 In the above, a negative value for the torque T9 of the output component 9 means that the torque passes through the output component 9 in the direction from the drive wheel 108 side toward the drive motor 2 side.

[0329] In the pre-shifting process, where the regenerative torque T2 of the drive motor 2 is reduced while the braking force BF of the friction braking device 5 is increased, the drive wheel 108 decelerates due to the combined braking force of the regenerative torque T2 (regenerative braking force) of the drive motor 2 and the friction braking force BF of the friction braking device 5. After the regenerative torque T2 of the drive motor 2 becomes 0, the drive wheel 108 decelerates due to the friction braking force BF of the friction braking device 5.

[0330] In the next first mode switching process (P2), the rotation drive mode selection component 76 rotates the drive cam 38 via the electric actuator 32, thereby switching the rotation transmission state switching device 12 from the locked mode to the one-way clutch mode.

[0331] That is, such as Figure 20 (B) Figure 20 As shown in (C), the phase of the mode selection component 76 relative to the second component 75 in the circumferential direction is adjusted. The protrusion 100 pushes the second engaging claw 97 radially outward against the elastic force of the second claw applying component 92, causing it to disengage from the engaging recess 77. This switches the rotation transmission state switching device 12 to allow only the first component 74 in the aforementioned predetermined direction relative to the second component 75 (…). Figure 20 A one-way clutch mode that prevents rotation in the clockwise direction of (C) and prevents rotation in the opposite direction to the predetermined direction.

[0332] After switching the rotary transmission state switching device 12 to one-way clutch mode, the process moves to the next inertial process (P3~P4).

[0333] In the inertial process, firstly, by controlling the energization of the drive motor 2, the regenerative torque T2 of the drive motor 2 is increased, thereby promoting the rotational speed R of the motor output shaft 7. s The decrease (P3).

[0334] The speed and amount by which the regenerative torque T2 of drive motor 2 increases are sufficient to increase the rotational speed R of motor output shaft 7. s There are no specific limitations on the reduction. It should be noted that, in order to increase the rotational speed R of the motor output shaft 7... s The mode of the secondary transmission 3 is switched quickly by rapidly reducing the load, preferably by increasing the load as quickly as possible without applying an excessive load to the drive motor 2.

[0335] The rotational speed R of the motor output shaft 7 sAfter the reduction begins, the regenerative torque T2 of the drive motor 2 decreases (P4). Specifically, this decreases at the rotational speed R of the motor output shaft 7. s The regenerative torque T2 of drive motor 2 is reduced such that it becomes 0 at the moment it decreases to a predetermined target value. More specifically, in this example, this is achieved by reducing the regenerative torque T2 of drive motor 2 to 0 at a speed R on the motor output shaft 7. s Reduce the speed R of output component 9 to the speed before the mode switch begins in the second-stage transmission 3. out At the moment when the regenerative torque T2 of the drive motor 2 becomes 0, the regenerative torque T2 of the drive motor 2 is reduced.

[0336] In the subsequent inertial phase end determination process (P5), it is determined whether the inertial phase has ended. Specifically, it is determined whether the rotational speed R of the motor output shaft 7 detected by the input rotation sensor 112 has ended. s Whether it has become the target value. More specifically, in this example, determining the rotational speed R of the motor output shaft 7. s Has the output component 9's speed R become the speed R before the start mode switch of the secondary transmission 3? out .

[0337] The rotational speed R of the motor output shaft 7 is determined to be... s If the target value is not reached, the torque stage end determination process (P5) is executed again after a predetermined time has elapsed.

[0338] The rotational speed R of the motor output shaft 7 is determined to be... s If the target value is reached, the inertial process is considered to be over, and the process moves to the next gear shift completion process (P6~P8).

[0339] In the gear shift completion process, firstly, the drive cam 38 is rotated by the electric actuator 32, increasing the clamping force F of the friction engagement portion 29 of the electric friction clutch device 11 to a predetermined value (P6). Specifically, the clamping force F of the friction engagement portion 29 is increased to such that the torque that can be transmitted between the first friction plate 33 and the second friction plate 34 without slipping against each other is greater than, and preferably greater than, the torque transmitted through the friction engagement portion 29 after the shift of the second-stage transmission 3 to the low reduction ratio mode.

[0340] Next, while decreasing the braking force BF of the friction brake device 5 (P7-1), the regenerative torque T2 of the drive motor 2 is increased (P7-2). Specifically, the regenerative torque T2 of the drive motor 2 is increased to the following value: when the braking force BF of the friction brake device 5 becomes 0, the magnitude of the rotational torque T9 of the output component 9 is approximately the same as the magnitude of the rotational torque T9 of the output component 9 at the moment when the mode switching of the secondary transmission 3 begins.

[0341] While decreasing the braking force BF of the friction braking device 5 and increasing the regenerative torque T2 of the drive motor 2, the drive wheel 108 decelerates due to the combined braking force of the regenerative torque T2 (regenerative braking force) of the drive motor 2 and the friction braking force BF of the friction braking device 5. After the braking force BF of the friction braking device 5 becomes 0, the drive wheel 108 decelerates due to the regenerative torque T2 (regenerative braking force) of the drive motor 2.

[0342] After reducing the braking force BF of the friction braking device 5 to 0, the drive cam 38 is rotated by the electric actuator 32, switching the rotational transmission state switching device 12 to free mode, thereby completing the switching of the second-stage transmission 3 to the low reduction ratio mode (P8), and then ending.

[0343] In the electric vehicle drive unit 1 of this example, during vehicle regenerative driving, in order to switch the secondary transmission 3 from a high reduction ratio mode to a low reduction ratio mode, the regenerative torque T2 of the drive motor 2 is reduced before the rotational transmission state switching device 12 is switched from a locked mode to a one-way clutch mode. Therefore, the force that pushes the circumferentially oriented side of the inner surface of the engaging recess 77 of the first component 74 against the front end face of the second engaging claw 97 can be reduced.

[0344] Specifically, in this example, before switching the rotation transmission state switching device 12 from the locking mode to the one-way clutch mode, the regenerative torque T2 of the drive motor 2 is made to be 0. Therefore, the force that pushes the side of the inner surface of the engaging recess 77 toward the front end face of the second engaging claw 97 is lost.

[0345] In this example, the force that pushes the side of the inner surface of the engaging recess 77 toward the front end face of the second engaging pawl 97 in the circumferential direction can be reduced or eliminated. Therefore, the force required to release the engagement between the engaging recess 77 and the second engaging pawl 97 by pressing the second engaging pawl 97 radially outward through the protrusion 100 of the mode selection member 76 to switch the rotary transmission state switching device 12 from the locking mode to the one-way clutch mode can be reduced. As a result, even when switching the secondary transmission 3 from the high reduction ratio mode to the low reduction ratio mode during vehicle regeneration, the mode switching of the rotary transmission state switching device 12 can be performed smoothly.

[0346] Furthermore, in the electric vehicle drive unit 1 of this example, during vehicle regenerative driving, when the two-stage transmission 3 switches from a high reduction ratio mode to a low reduction ratio mode, before the rotational transmission state switching device 12 switches from a locked mode to a one-way clutch mode, the regenerative torque T2 of the drive motor 2 is reduced, and in coordination with this, the braking force BF of the friction braking device 5 on the drive wheel 108 is increased. Therefore, even when the regenerative torque T2 of the drive motor 2 is reduced, the feeling of sudden disappearance of deceleration acceleration (deceleration G) can be suppressed or prevented, and discomfort to occupants, primarily the driver, can be suppressed or prevented.

[0347] Furthermore, in this example, the following situation was described: when the torque is transmitted from the output component 9 side to the input component 8 in the secondary transmission 3, and the secondary transmission 3 is switched from a high reduction ratio mode to a low reduction ratio mode, and the rotational speed of the output component 9 is maintained at approximately constant before and after the mode switch of the secondary transmission 3, however, in the implementation of this disclosure, it is also possible to change the rotational speed of the output component before and after the mode switch of the secondary transmission. Specifically, by adjusting the regenerative torque of the drive motor and / or the braking force of the friction braking device, the rotational speed of the output component after the mode switch of the secondary transmission can be adjusted.

[0348] Furthermore, the drive unit 1 for electric vehicles in this example ensures good torque transmission efficiency. The reasons for this will be explained below.

[0349] When the cam device 31 generates pressing force, that is, when the piston 36 is pressed axially to one side by the driven cam 39 via the thrust bearing 61 and the pressing member 62 ( Figure 3 In the state shown in (B), a force is applied to the thrust bearing 61 toward one axial side. In addition, the reaction force that presses the piston 36 toward one axial side by the driven cam 39 is applied to the radial bearing 42 toward the other axial side via the rolling element 40 and the drive cam 38.

[0350] The track ring 63a on one axial side of the thrust bearing 61 is supported on the rotating member 10 via the pressing member 62 and the piston 36, while the track ring 63b on the other axial side is supported on the fixed part 14 via the cam device 31, the angular contact ball bearing 43, and the cylindrical member 41. Additionally, the inner ring 46 of the radial bearing 42 is externally fixed to the rotating member 10, and the outer ring 47 is supported on the drive cam 38 of the cam device 31 via the cylindrical member 41 and the angular contact ball bearing 43.

[0351] In this example, when the cam device 31 applies pressure—that is, when the piston 36 is pressed towards the axial side, the axial dimension of the elastic member 37 elastically contracts, releasing the force that pushes the first friction plate 33 and the second friction plate 34 together, thus disengaging the electric friction clutch device 11—the rotational transmission state switching device 12 enters the locked mode. In the high reduction ratio mode where the electric friction clutch device 11 is disengaged and the rotational transmission state switching device 12 is switched to the locked mode, the relative rotation of the rotating member 10 relative to the fixed part 14 is prevented. In this state, the track ring 63a on one axial side and the track ring 63b on the other axial side constituting the thrust bearing 61 do not rotate relative to each other, and the inner ring 46 and the outer ring 47 constituting the radial bearing 42 do not rotate relative to each other.

[0352] In summary, in the axial direction ( Figure 2 When the rolling resistance increases due to the force (in the left-right direction of (B)) applied to the thrust bearing 61 and the radial bearing 42, the raceway 63a on one axial side and the raceway 63b on the other axial side of the thrust bearing 61 do not rotate relative to each other, and the inner ring 46 and the outer ring 47 of the radial bearing 42 do not rotate relative to each other. Therefore, torque loss at the thrust bearing 61 and the radial bearing 42 can be prevented.

[0353] Furthermore, the pressing force generated by the cam device 31 is applied axially to the rotating member 10 from the driven cam 39 via the pressing member 62, the thrust bearing 61, the piston 36, and the elastic member 37. Conversely, the reaction force generated by the pressing force of the cam device 31 is applied axially to the rotating member 10 from the driving cam 38 via the radial bearing 42. Thus, the axial forces generated by the pressing force of the cam device 31 are canceled out (balanced) within the rotating member 10.

[0354] On the other hand, when the rotation transmission state switching device 12 switches to free mode, the relative rotation of the rotating component 10 relative to the fixed part 14 is allowed. Figure 3 In the state shown in (A), the electric friction clutch device 11 is engaged, and the cam device 31 does not generate pressing force. In this state, the thrust bearing 61 and the radial bearing 42 are not subjected to the axial ( ) force generated by the pressing force generated by the cam device 31. Figure 3 The force (A) in the left and right directions will not cause the rolling resistance of the thrust bearing 61 and the radial bearing 42 to increase unnecessarily, nor will it cause the torque loss to increase excessively.

[0355] In summary, in the electric vehicle drive unit 1 of this example, except for the short time during mode switching, the thrust bearing 61 and radial bearing 42 will not rotate under the condition that the rolling resistance increases due to the axial force generated by the pressing force produced by the cam device 31. Therefore, excessive torque loss at the thrust bearing 61 and radial bearing 42 can be prevented, and good torque transmission efficiency of the two-stage transmission 3 can be ensured.

[0356] The two-stage transmission disclosed herein can also be applied to a configuration having a rotary transmission state switching device that does not have a one-way clutch mode, i.e., only a free mode and a locked mode. In such a variation, when switching from a high reduction ratio mode to a low reduction ratio mode, such as Figure 32 As shown, after switching the rotary transmission state switching device from the locked mode to the free mode, the electric friction clutch device is switched from the disconnected mode to the connected mode.

[0357] According to the two-stage transmission 3 in this example, the driven cam 39 can be reliably displaced axially by rotating the drive cam 38, thus enabling high-precision mode switching of the two-stage transmission 3.

[0358] That is, when using balls as rolling elements in a cam mechanism, slippage may occur at the rolling contact point between the surface of the rolling element and the surface of the driving cam when the driving cam rotates. If slippage occurs at the rolling contact point between the surface of the rolling element and the surface of the driving cam, the driven cam may be unable to move axially, or the amount of axial displacement of the driven cam relative to the rotation of the driving cam may not be sufficiently guaranteed.

[0359] In contrast, in the two-stage transmission 3 of this example, rollers are used as rolling elements 40, and the rolling elements 40 are supported relative to the driven cam 39 to freely rotate (spin) around a rotation axis C, which is oriented radially towards the central axis of the driven cam 39. Therefore, when the drive cam 38 is rotated, slippage at the rolling contact portion between the outer peripheral surface of the rolling element 40 and the drive cam surface 52 can be prevented, and the driven cam 39 can be reliably displaced axially based on the rotation of the drive cam 38. As a result, mode switching of the two-stage transmission 3 can be performed with high precision. It should be noted that, as described above, balls can also be used as rolling elements constituting the cam device.

[0360] [Second example]

[0361] Regarding the second example of an implementation of this disclosure, using Figures 33-35 The following explanation will be provided. In the electric vehicle drive unit 1a of this example, the construction of the two-stage transmission 3a is different from that of the two-stage transmission 3 in the first example.

[0362] In this example, the two-stage transmission 3a includes: an input component 8a, an output component 9a, a rotating component 10a, an electric friction clutch device 11a, a rotational transmission state switching device 12a, and a planetary gear mechanism 13a.

[0363] In this example, the electric friction clutch device 11a is disposed between the rotating component 10a and the input component 8a, and switches between a torque-transmitting connection mode and a torque-disconnecting mode between the rotating component 10a and the input component 8a. That is, in this example, the second clutch component rotates integrally with the input component 8a. More specifically, the second clutch component is constituted by the input component 8a itself. In addition, the first clutch component is constituted by the rotating component 10a itself.

[0364] In addition, in this example, the electric friction clutch device 11a has an elastic force application mechanism 30a, which is disposed between the friction engagement portion 29 and the driven cam 39 of the cam device 31, and applies force elastically in the direction that separates the friction engagement portion 29 and the driven cam 39 from each other.

[0365] The elastic force application mechanism 30a has an elastic component 37a and a thrust bearing 61a in sequence from the driven cam 39 side between the friction engagement part 29 and the driven cam 39.

[0366] The elastic component 37a consists of a disc spring.

[0367] The thrust bearing 61a has a pair of raceways 63c, 63d and a plurality of rolling elements 64 which are freely disposed between the pair of raceways 63c, 63d.

[0368] In this example, when the electric friction clutch device 11a is switched to the disengagement mode, where no torque is transmitted between the rotating component 10a and the input component 8a, the drive cam 38 is rotated using the electric actuator 32, causing the driven cam 39 to move in a direction that reduces the axial distance between it and the drive cam 38. As a result, the force that presses the first friction plate 33 and the second friction plate 34 together is lost. Consequently, by the action of the return spring 35, the distance between the first friction plate 33 and the second friction plate 34 increases, the friction engagement portion 29 is disengaged, and the electric friction clutch device 11a is switched to the disengagement mode.

[0369] In contrast, when the electric friction clutch device 11a is switched to a connection mode that transmits torque between the rotating component 10a and the input component 8a, the drive cam 38 is rotated using the electric actuator 32, causing the driven cam 39 to move in a direction that increases the axial distance from the drive cam 38. As a result, the first friction plate 33 and the second friction plate 34 are pressed together via the driven cam 39, through the elastic component 37a and the thrust bearing 61a. Consequently, the first friction plate 33 and the second friction plate 34 are pressed together, the friction engagement portion 29 is engaged, and the electric friction clutch device 11a is switched to the connection mode.

[0370] In this example, when the electric friction clutch device 11a is kept in the engaged mode, the shift motor 70 needs to be continuously energized. Conversely, when the electric friction clutch device 11a is kept in the disengaged mode, the shift motor 70 does not need to be continuously energized. That is, the electric friction clutch device 11 in this example is a normally open type clutch device.

[0371] In this example, the planetary gear mechanism 13a is composed of a single-pinion planetary gear mechanism. Furthermore, in this example, the planet carrier 106a is connected to the output component 9a in a manner that is integrally rotatable with the output component 9a, the sun gear 104a is connected to the input component 8a in a manner that is integrally rotatable with the input component 8a, and the ring gear 105a is connected to the rotating component 10a in a manner that is integrally rotatable with the rotating component 10a.

[0372] In the electric vehicle drive unit 1a of this example, the control unit 6 has a reduction ratio switching function, which switches the two-stage transmission 3a between a high reduction ratio mode with a large reduction ratio between the input component 8a and the output component 9a and a low reduction ratio mode with a small reduction ratio.

[0373] <Low Reduction Ratio Mode>

[0374] To switch the secondary transmission 3a to a low reduction ratio mode, the electric friction clutch device 11a is switched to the engaged mode. As a result, the input component 8a and the rotating component 10a rotate as a unit, and the sun gear 104a and the ring gear 105a rotate as a unit. Furthermore, the rotational transmission state switching device 12a is switched to the free mode. This allows the rotating component 10a to rotate relative to the stationary part 14, and also allows the ring gear 105a to rotate.

[0375] In low reduction ratio mode, the sun gear 104a, ring gear 105a, and planetary gear carrier 106a rotate in the same direction and at the same speed, resulting in a so-called "adhesive" state where the planetary gear mechanism 13a rotates as a whole. Therefore, as Figure 34As shown in bold in (A), the rotational torque of the input component 8a is transmitted in the order of input component 8a, planetary gear carrier 106a, and output component 9a, and is taken out from output component 9a.

[0376] <High Reduction Ratio Mode>

[0377] To switch the secondary transmission 3a to a high reduction ratio mode, the electric friction clutch device 11a is switched to the disengaged mode. This allows the input component 8a and the rotating component 10a to rotate relative to each other, and the sun gear 104a and the ring gear 105a to rotate relative to each other. Additionally, the rotation transmission state switching device 12a is switched to the locking mode. This prevents the rotating component 10a from rotating relative to the fixed part 14, and also prevents the ring gear 105a from rotating.

[0378] In high reduction ratio mode, such as Figure 34 As shown in (B), the rotational torque of the input component 8a is transmitted in the following order: the rotational motion of the input component 8a, the sun gear 104a, the planetary gear 107a, the revolution motion of the planetary gear 107a based on its meshing with the ring gear 105a, the planet carrier 106a, and the output component 9a, and is taken out from the output component 9a.

[0379] Even in this example, the second-stage transmission 3a can switch between reduction ratio switching mode, neutral mode, and parking mode.

[0380] The control device 6 has a coordinated control function for performing a pre-shift procedure. This pre-shift procedure involves, when torque is flowing from the output component 9a towards the input component 8a through the secondary transmission 3a, and the first component 74 is subjected to a torque intended to rotate relative to the second component 75 in a circumferential direction, and the rotation of the first component 74 relative to the second component 75 is prevented from rotating circumferentially by the rotational transmission state switching device 12a, before the second engaging pawl 97 is radially pressed out of the engaging recess 77 by the protrusion 100 during the mode switching of the secondary transmission 3a with the aforementioned reduction ratio switching function, the regenerative torque of the drive motor 2 is reduced while the braking force of the friction brake device 5 is increased. Therefore, even during regenerative driving with regenerative torque acting on the drive motor 2, the mode switching of the rotational transmission state switching device 12a can be performed smoothly.

[0381] The structure and function of the other parts in the second example are the same as those in the first example.

[0382] Symbol Explanation

[0383] 1. 1a—Drive unit for electric vehicles; 2—Drive motor; 3. 3a—Two-stage transmission; 4—Torque transmission mechanism; 5—Friction braking device; 6—Control device; 7—Motor output shaft; 8. 8a—Input component; 9. 9a—Output component; 10. 10a—Rotating component; 11. 11a—Electric friction clutch device; 12. 12a—Rotation transmission state switching device; 13. 13a—Planetary gear mechanism; 14—Fixed part; 15—Drive gear; 16—Input gear; 17—Output gear; 18—Small diameter flange; 19—Flange; 20—Through hole; 21—First annular part; 22—First cylindrical part; 23—Second annular part; 24—Second cylindrical part; 25—Shaft component; 26—Belt Stepped cylindrical component, 27—small diameter cylindrical section, 28—internal spline section, 29—friction engagement section, 30, 30a—elastic force application mechanism, 31, 31z—cam device, 32—electric actuator, 33—first friction plate, 34—second friction plate, 35—return spring, 36—piston, 37, 37a—elastic component, 38, 38z—drive cam, 39—driven cam, 40—rolling element, 41—cylindrical component, 42—radial bearing, 43—angular contact ball bearing, 44—cylindrical section, 45—outer flange section, 46—inner ring, 47—outer ring, 48—rolling element, 49—inner ring, 50—outer ring, 51—ball, 52—drive cam surface, 52a—first bottom, 52b—gradually inclined surface, 52c —First flat surface, 52d—Inclined surface, 52e—Second bottom, 52f—First middle inclined surface, 52g—Second flat surface, 52h—Second middle inclined surface, 53—Gear tooth, 54—Pin, 55—Internal spline, 56—External spline, 57—Rectangular hole, 58a, 58b—Support plate, 59—Support hole, 60—Support recess, 61, 61a—Thrust bearing, 62—Pressing component, 63a, 63b, 63c, 63d—Rail ring, 64—Rolling element, 65—Preload unit, 66—Base, 67—Partial cylindrical part, 68—Support shaft, 69—Roller, 70—Shift motor, 71—Reducer, 72—Worm, 73a, 73b—Support bearing, 74—First part Components: 75—Second component; 76—Mode selection component; 77—Engaging recess; 78—Protrusion; 79—Concave-convex portion; 80—Outer diameter side concave-convex engaging portion; 81—Inner diameter side concave-convex engaging portion; 82—Inner diameter side concave-convex engaging portion; 83—Base; 84—Cylindrical portion; 85—First retaining recess; 86—Second retaining recess; 87a, 87b—Spring retaining portion; 88a, 88b—Base portion; 89—First claw component; 90—Second claw component; 91—First claw applying force component; 92—Second claw applying force component; 93—First base; 94—First engaging claw; 95—Annular protrusion; 96—Second base; 97—Second engaging claw; 98—Base; 99—Plate side engaging hole; 100—Protrusion; 101—Concave-convex portion.102—Cover body; 103—Retaining ring; 104, 104a—Sun gear; 105, 105a—Ring gear; 106, 106a—Planetary gear carrier; 107—Planetary gear; 108—Drive wheel; 109—Drive shaft; 110—Rotating body for braking; 111—Accelerator opening sensor; 112—Input rotation sensor; 113—Output rotation sensor; 114—TCU; 115—Inverter; 116—VCU; 117—Ring gear; 201—First friction engagement device; 202—Second friction engagement device; 203—First driven cam; 204—Second driven cam.

Claims

1. An electric vehicle drive device characterized by comprising: Possessing: a drive motor having a motor output shaft; a two-stage transmission having an input member capable of transmitting torque between the motor output shaft, an output member supported so as to be relatively rotatable with respect to the input member, a rotation member supported so as to be relatively rotatable with respect to the input member and the output member, an electric friction clutch device, and a rotation transmission state switching device; a torque transmission mechanism that transmits torque between the output member and a drive wheel; a friction brake device disposed between the output member and the drive wheel that performs braking of rotation of the drive wheel; and a control device, the electric friction clutch device has: a first clutch member that rotates integrally with the rotation member or is constituted by the rotation member itself; a second clutch member that is supported so as to be relatively rotatable with respect to the first clutch member coaxially with the first clutch member and rotates integrally with the input member or the output member or is constituted by the input member or the output member itself; a friction engagement portion that has at least one first friction plate and at least one second friction plate supported so as to be relatively displaceable in the axial direction and is provided between the first clutch member and the second clutch member; a cam device that has a drive cam and a driven cam supported so as to be relatively rotatable with respect to the drive cam and relatively displaceable in the axial direction with respect to the drive cam and, with rotation of the drive cam, expands / reduces the axial interval between the drive cam and the driven cam; and an electric actuator that has a shift motor and a reducer and, with the shift motor, rotationally drives the drive cam via the reducer, the electric friction clutch device is configured so that, based on expansion / reduction of the axial dimension of the cam device, a connection mode and a disconnection mode can be switched, the connection mode is a mode in which torque is transmitted between the first clutch member and the second clutch member by pressing the at least one first friction plate and the at least one second friction plate against each other, and the disconnection mode is a mode in which torque is not transmitted between the first clutch member and the second clutch member by releasing the force by which the at least one first friction plate and the at least one second friction plate are pressed against each other, the rotation transmission state switching device has: a first member that has engagement recesses at multiple locations in the circumferential direction; a second member disposed coaxially with the first member; a mode selection member that has protrusions protruding in the radial direction or the axial direction at multiple locations in the circumferential direction and rotates or is displaced in the axial direction with rotation of the drive cam; a first claw member that has a first base portion pivotally supported to the second member and a first engagement claw protruding from the first base portion toward a first side in the circumferential direction; a second claw member that has a second base portion pivotally supported to the second member and a second engagement claw protruding from the second base portion toward a second side in the circumferential direction; a first claw urging member that elastically urges the first engagement claw in a direction in which the first engagement claw engages with the engagement recesses; and ​ The second claw force-applying component elastically applies force to the second engaging claw in the direction that causes it to engage with the engaging recess. One of the aforementioned first component and the aforementioned second component rotates integrally with the aforementioned rotating component, or is constituted by the aforementioned rotating component itself, and the other of the aforementioned first component and the aforementioned second component is supported so as not to rotate relative to a fixed part that does not rotate even during use. The aforementioned rotary transmission state switching device is configured to switch between at least one of a locking mode and a one-way clutch mode, and a free mode. In the locking mode, the protrusion is positioned offset from the first and second engaging pawls in the circumferential or axial direction, engaging the first and second engaging pawls with the engaging recess, thereby preventing relative rotation between the first and second components regardless of their relative rotational direction. In the one-way clutch mode, the protrusion engages only one of the first and second engaging pawls. The first and second locking claws are pressed radially or axially to disengage from the locking recess, while the other locking claw engages with the locking recess. This allows rotation of one component relative to the other in a predetermined direction, while preventing rotation of one component relative to the other in the opposite direction. In the free mode, the protrusions press the first and second locking claws radially or axially to disengage from the locking recess, thus allowing relative rotation of the first and second components regardless of their relative rotational direction. The above-mentioned control device has: The reduction ratio switching function, based on the rotational drive of the drive cam by the electric actuator, switches the mode of the electric friction clutch device and the mode of the rotational transmission state switching device, thereby switching the secondary transmission to a high reduction ratio mode with a large reduction ratio between the input and output components and a low reduction ratio mode with a small reduction ratio between the input and output components; and The coordinated control function performs a pre-shift procedure, which is performed when torque is transmitted from the output component side to the input component side through the secondary transmission, and when a torque is applied to one component to cause that component to rotate relative to the other component in the circumferential direction, and the rotational transmission state switching device prevents the rotation of one component relative to the other component in the circumferential direction, before the mode of the secondary transmission is switched by the reduction ratio switching function, the protrusion presses one of the first and second engagement claws, which is pivotally supported at the base of the second component and extends in the circumferential direction, outwards in the circumferential direction, in the radial or axial direction, causing it to disengage from the engagement recess, while reducing the regenerative torque of the drive motor and increasing the braking force of the friction braking device.

2. The drive unit for an electric vehicle according to claim 1, characterized in that, In the aforementioned pre-shifting process, the regenerative torque of the drive motor is reduced to 0.

3. The drive unit for an electric vehicle according to claim 1 or 2, characterized in that, The aforementioned two-stage transmission is configured to switch to the aforementioned locking mode. The aforementioned reduction ratio switching function switches the secondary transmission to the high reduction ratio mode by switching the electric friction clutch device to the disengagement mode and the rotary transmission state switching device to the locking mode, and switches the secondary transmission to the low reduction ratio mode by switching the electric friction clutch device to the engagement mode and the rotary transmission state switching device to the free mode.

4. The drive unit for an electric vehicle according to claim 3, characterized in that, The aforementioned two-stage transmission is configured to switch to the aforementioned one-way clutch mode. The aforementioned control device performs the aforementioned coordination control function during the switching of the aforementioned two-stage transmission from the aforementioned high reduction ratio mode to the aforementioned low reduction ratio mode, and before the aforementioned rotational transmission state switching device switches from the aforementioned locking mode to the aforementioned one-way clutch mode.

5. The drive unit for an electric vehicle according to claim 4, characterized in that, The aforementioned coordinated control function performs the aforementioned pre-shifting procedure and further executes an inertial procedure, which is that after pressing one of the engagement claws radially or axially through the aforementioned protrusion to disengage it from the aforementioned engagement recess, the driving torque of the aforementioned drive motor in the same direction as the regenerative torque acting on the aforementioned drive motor is increased, thereby promoting the reduction of the speed of the aforementioned motor output shaft. Then, after the speed of the aforementioned motor output shaft begins to decrease, the driving torque of the aforementioned drive motor is reduced.

6. The drive unit for an electric vehicle according to claim 5, characterized in that, After performing the inertial process, the aforementioned coordination control function executes a shift completion process. This shift completion process involves making the clamping force of the friction engagement part such that the torque that can be transmitted between the at least one first friction plate and the at least one second friction plate without slipping against each other is greater than the torque through the friction engagement part after the second-stage transmission has switched to the low reduction ratio mode. Then, the braking force of the friction braking device is further reduced while the regenerative torque of the drive motor is increased.

7. The drive unit for an electric vehicle according to any one of claims 1 to 6, characterized in that, The aforementioned electric friction clutch device has a return spring that elastically applies force in the direction that separates the at least one first friction plate and the at least one second friction plate from each other.

8. The drive unit for an electric vehicle according to any one of claims 1 to 7, characterized in that, The aforementioned electric friction clutch device also includes an elastic force application mechanism, which is provided between the first clutch component or the second clutch component and the friction engagement portion, and applies force elastically in the direction of pushing the at least one first friction plate and the at least one second friction plate together.

9. The drive unit for an electric vehicle according to any one of claims 1 to 7, characterized in that, The aforementioned electric friction clutch device also includes an elastic force application mechanism, which is disposed between the friction engagement portion and the driven cam, and applies elastic force in the direction that separates the friction engagement portion and the driven cam from each other.

10. The drive unit for an electric vehicle according to any one of claims 1 to 9, characterized in that, The aforementioned two-stage transmission further comprises: a sun gear; a ring gear, which is coaxially arranged around the sun gear; a planet carrier supported to be rotatable relative to the sun gear and the ring gear; and a planetary gear mechanism having a plurality of planetary gears meshing with the sun gear and the ring gear, and being rotatably supported on the planet carrier about its own central axis. The input element, which is any one of the aforementioned sun gear, ring gear, and planetary carrier, is connected relative to the aforementioned input component in a manner that allows it to rotate integrally with the input component. An output element, which is any one of the aforementioned sun gear, ring gear, and planetary carrier, and is different from the aforementioned input element, is connected to the aforementioned output component in a manner that allows it to rotate integrally with the output component. Rotating elements, which are the remaining elements of the sun gear, the ring gear, and the planetary gear carrier (excluding the input and output elements), are connected to the rotating component in a manner that they rotate integrally with the rotating component.

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