Transmission path switching device and two-stage transmission

Abstract

The present invention provides a structure capable of switching a transmission path by using an electric actuator. The transmission path switching device (5) switches between the following modes: a first mode in which the friction engagement device (40) is connected by the rotation of the drive cam (50) and the rotation transmission state switching device (41) is switched to the free mode; a second mode in which the friction engagement device (40) is disconnected and the rotation transmission state switching device (41) is switched to the locked mode; and a switching mode in which the rotation transmission state switching device (41) is switched to the one-way clutch mode and established during the switching from the second mode to the first mode.

Description

Technical Field

[0001] The present invention relates to a transmission path switching device for switching a power transmission path between an input member and an output member, and a two-stage transmission including the transmission path switching device. Background Art

[0002] In recent years, along with the trend of reducing the consumption of fossil fuels, research on electric vehicles and hybrid vehicles has been promoted and partially implemented. Regarding the power source of electric vehicles and hybrid vehicles, namely an electric motor, different from an internal combustion engine (engine) that operates by directly burning fossil fuels, the characteristics of the torque and rotational speed of the output shaft are suitable for use in a motor vehicle (usually generating maximum torque at startup). Therefore, it is not necessary to provide a transmission as in a normal motor vehicle with an internal combustion engine as the drive source. However, when a transmission is provided with an electric motor as the drive source, the acceleration performance and high-speed performance can be improved. Specifically, by providing a transmission, the relationship between the traveling speed and acceleration of the vehicle can be made close to that of a motor vehicle equipped with a fuel engine and having a transmission in the drive system, resulting in smooth performance. This will be described with reference to Figure 39 for illustration.

[0003] For example, when a transmission device with a large reduction ratio is arranged between the output shaft of the electric motor and the input portion of the differential gear connected to the drive wheels, the relationship between the acceleration (G) and the traveling speed (km / h) of the electric vehicle is as shown by the solid line a in Figure 39 . That is, the acceleration performance at low speeds is excellent, but it cannot travel at high speeds. In contrast, if a transmission device with a small reduction ratio is arranged between the above, the relationship is as shown by the dotted line b in Figure 39 . That is, although it can travel at high speeds, the acceleration performance at low speeds is impaired. In contrast, if a transmission is provided between the output shaft and the input portion, and the reduction ratio of the transmission is changed according to the vehicle speed, a characteristic can be obtained that makes the left part of point P in the solid line a continuous with the right part of point P in the dotted line b. As shown by the dashed line c in Figure 39 , this characteristic is substantially the same as that of a fuel engine vehicle with the same level of output, and in terms of acceleration performance and high-speed performance, the same performance as that of a fuel engine vehicle having a transmission in the drive system can be obtained.

[0004] In Japanese Patent Laid-Open No. 5-116549 (Patent Document 1), a structure of a drive device for an electric vehicle is disclosed, in which the torque of the output shaft of an electric motor is transmitted to a differential gear via a two-stage transmission (after deceleration by the two-stage transmission), and the two-stage transmission is composed of a combination of a pair of planetary gear mechanisms and a pair of brakes. In this drive device for an electric vehicle, by switching the connection / disconnection state of the pair of brakes, the structural elements of the pair of planetary gear mechanisms can be switched between a rotatable state and a non-rotatable state, so that the reduction ratio between the output shaft of the electric motor and the differential gear can be switched between two levels of high and low.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Patent Laid-Open No. 5-116549 Summary of the Invention

[0008] Problems to be Solved by the Invention

[0009] The device described in Japanese Patent Laid-Open No. 5-116549 is configured such that servo pistons PL and PH that operate hydraulically press against each other a friction engagement element supported by a structural element of a planetary gear mechanism and a friction engagement element supported by a housing, thereby connecting (engaging) the brakes. However, in electric vehicles and hybrid vehicles, in order to reduce costs and improve electric efficiency performance by system simplification, it is desired to use an electric actuator to switch the reduction ratio of the two-stage transmission without using a hydraulic system.

[0010] An object of the present invention in view of the above problems is to achieve the following structure: a transmission path switching device capable of using an electric actuator to switch a transmission path, and a two-stage transmission equipped with the transmission path switching device.

[0011] Means for Solving the Problems

[0012] The transmission path switching device of the present invention includes:

[0013] a cam device having a drive cam and a driven cam, the drive cam being supported so as to be rotatable and not axially displaceable, the driven cam being supported so as to be relatively rotatable and axially displaceable with respect to the drive cam, and being axially displaced as the drive cam rotates; and

[0014] a friction engagement device having at least one friction plate and one separator plate supported so as to be axially relatively displaceable with respect to each other.

[0015] The friction engagement device is configured to connect by pressing the friction plate and the separation plate against each other based on displacing the driven cam in a direction in which the axial interval from the drive cam is increased, and to disconnect by releasing the force pressing the friction plate and the separation plate against each other based on displacing the driven cam in a direction in which the axial interval from the drive cam is decreased.

[0016] The transmission path switching device of the present invention further includes a rotational transmission state switching device, which has: a first member and a second member coaxially arranged with each other; and a mode selection portion that rotates or axially displaces as the drive cam rotates.

[0017] The rotational transmission state switching device has: at least one of a free mode and a locked mode, the free mode allowing rotation of the first member relative to the second member regardless of the relative rotation direction between the first member and the second member, the locked mode being a locked mode that prevents rotation of the first member relative to the second member regardless of the relative rotation direction between the first member and the second member; and a one-way clutch mode that only allows rotation of the first member relative to the second member in a predetermined direction and prevents rotation of the first member relative to the second member in a direction opposite to the predetermined direction.

[0018] The rotational transmission state switching device is configured to be able to switch between at least one of the free mode and the locked mode and the one-way clutch mode based on rotating or axially displacing the mode selection portion.

[0019] Regarding the transmission path switching device according to one aspect of the present invention, it may be that the rotational transmission state switching device is in the one-way clutch mode during the switching process of the friction engagement device from the connected state to the disconnected state and / or during the switching process of the friction engagement device from the disconnected state to the connected state.

[0020] Regarding the transmission path switching device according to one aspect of the present invention, it may have a first mode that connects the friction engagement device and makes the rotational transmission state switching device in the free mode.

[0021] Regarding the transmission path switching device according to one aspect of the present invention, it may have a second mode that disconnects the friction engagement device and makes the rotational transmission state switching device in the locked mode.

[0022] Regarding the transmission path switching device of one aspect of the present invention, it may be provided with a neutral mode, in which the friction engagement device is disengaged and the rotational transmission state switching device is in the free mode.

[0023] Regarding the transmission path switching device of one aspect of the present invention, it may be

[0024] One of the first member and the second member has engagement recesses at multiple positions in the circumferential direction, and the mode selection portion has protrusions protruding radially or axially at multiple positions in the circumferential direction.

[0025] The rotational transmission state switching device further includes:

[0026] A first claw member having a first base portion and a first engagement claw, the first base portion being pivotally supported by the other of the first member and the second member, and the first engagement claw extending from the first base portion to one side in the circumferential direction;

[0027] A second claw member having a second base portion and a second engagement claw, the second base portion being pivotally supported by the other of the first member and the second member, and the second engagement claw extending from the second base portion to the other side in the circumferential direction;

[0028] A first claw biasing member that elastically biases the first engagement claw in a direction to engage with the engagement recess; and

[0029] A second claw biasing member that elastically biases the second engagement claw in a direction to engage with the engagement recess.

[0030] In the one-way clutch mode, one of the first engagement claw and the second engagement claw is not pushed by the protrusion to engage with the engagement recess, and the other of the first engagement claw and the second engagement claw is pushed by the protrusion not to engage with the engagement recess, thereby allowing only rotation of the first member relative to the second member in a predetermined direction and preventing rotation of the first member relative to the second member in a direction opposite to the predetermined direction.

[0031] When the transmission path switching device of the present invention has the free mode, in the free mode, the first engagement claw is pushed by the protrusion not to engage with the engagement recess, and the second engagement claw is pushed by the protrusion not to engage with the engagement recess, thereby allowing rotation of the first member relative to the second member regardless of the relative rotation direction of the first member and the second member.

[0032] When the transmission path switching device of the present invention has the locking mode, in the locking mode, the first engaging claw is not pushed by the protruding portion to engage with the engaging concave portion, and the second engaging claw is not pushed by the protruding portion to engage with the engaging concave portion, so that the rotation of the first member relative to the second member is blocked regardless of the relative rotation direction of the first member and the second member.

[0033] Regarding the transmission path switching device according to an aspect of the present invention, a selection plate is further provided. The selection plate has the mode selection portion and rotates or is displaced in the axial direction along with the rotation of the drive cam.

[0034] Regarding the transmission path switching device according to an aspect of the present invention, a speed reducer is further provided between the drive cam and the selection plate. The speed reducer decelerates the rotational speed of the drive cam and transmits it to the selection plate.

[0035] Regarding the transmission path switching device according to an aspect of the present invention, it may be

[0036] The speed reducer includes:

[0037] A cam-side gear portion provided on the drive cam;

[0038] A plate-side gear portion provided on the selection plate; and

[0039] A two-stage gear having a first gear portion meshing with the cam-side gear portion and a second gear portion meshing with the plate-side gear portion.

[0040] Alternatively, in the transmission path switching device according to an aspect of the present invention, it may be

[0041] The speed reducer includes:

[0042] A cam-side groove provided on the drive cam and extending more in the radially outward direction as it goes toward one side in the rotational direction;

[0043] A plate-side groove provided on the selection plate and extending more in the radially inward direction as it goes toward one side in the rotational direction; and

[0044] An engagement pin having a first engagement portion and a second engagement portion. The first engagement portion engages with the cam-side groove in a manner capable of displacing along the cam-side groove, and the second engagement portion engages with the plate-side groove in a manner capable of displacing along the plate-side groove.

[0045] The circumferential direction length of the cam-side groove is longer than the circumferential direction length of the plate-side groove.

[0046] At this time, it is possible that the speed reducer further includes a guide plate having a guide groove extending in the radial direction and supported so as not to rotate.

[0047] The engagement pin further has a third engagement portion that engages with the guide groove so as to be displaceable along the guide groove.

[0048] Alternatively, in the transmission path switching device according to an aspect of the present invention,

[0049] it is possible that the protruding portion protrudes in the axial direction.

[0050] It is possible that the selection plate has an engagement groove that includes an inclined portion inclined with respect to the circumferential direction and extends in the circumferential direction.

[0051] It is possible that the drive cam has an engagement pin that protrudes in the radial direction and engages with the engagement groove so as to be displaceable along the engagement groove.

[0052] Regarding the transmission path switching device according to an aspect of the present invention, it is possible that the drive cam has the mode selection portion.

[0053] Regarding the transmission path switching device according to an aspect of the present invention, it is possible that an elastic member is further provided, the elastic member is disposed between the driven cam and the friction engagement device, and elastically biases in a direction in which the driven cam and the friction engagement device are separated from each other.

[0054] Regarding the transmission path switching device according to an aspect of the present invention, the friction engagement device further has a return spring that elastically biases in a direction in which the friction plate and the separation plate are separated from each other.

[0055] Regarding the transmission path switching device according to an aspect of the present invention, it is possible that the cam device includes a plurality of rollers having a rotation axis in the radial direction and clamped between the drive cam and the driven cam.

[0056] The roller is supported by the driven cam so as to freely rotate about the rotation axis.

[0057] Regarding the two-stage speed reducer of the present invention, it is possible to include:

[0058] An input member;

[0059] An output member coaxially disposed with the input member;

[0060] A planetary gear mechanism disposed between the input member and the output member in the power transmission direction; and

[0061] A transmission path switching device that switches the transmission path between the input component and the output component.

[0062] Especially in the two-stage transmission of the present invention, the transmission path switching device further includes an electric actuator, which is the transmission path switching device of the present invention, and the transmission path switching device rotates and drives the drive cam.

[0063] The planetary gear mechanism includes:

[0064] A sun gear, which is connected to the input component so as to rotate integrally with the input component;

[0065] A ring gear, which is coaxially arranged around the sun gear;

[0066] A planet carrier, which is coaxially arranged with the sun gear and is connected to the output component so as to rotate integrally with the output component; and

[0067] A plurality of pinions, which mesh with the sun gear and the ring gear and are supported by the planet carrier to rotate freely about their own central axes.

[0068] One of the friction plate and the separation plate is supported on the sun gear or the input component in a manner that allows relative axial displacement but does not allow relative rotation.

[0069] The other of the friction plate and the separation plate is supported on the planet carrier or the output component in a manner that allows relative axial displacement but does not allow relative rotation.

[0070] One of the first component and the second component is supported on a non-rotating part even during use in a manner that does not allow relative rotation.

[0071] The other of the first component and the second component is supported on the ring gear in a manner that does not allow relative rotation.

[0072] Regarding a two-stage transmission according to one aspect of the present invention, it may be that

[0073] The drive cam has a toothed portion on its outer peripheral surface.

[0074] The electric actuator includes a worm that meshes with the toothed portion, and a speed-changing motor that rotates and drives the worm.

[0075] Effects of the invention

[0076] Regarding the transmission path switching device of the present invention, the disconnection and connection states of the friction engagement device and the mode of the rotation transmission state switching device are switched by rotating a driving cam. In short, according to the transmission path switching device of the present invention, the driving cam is rotationally driven by using one electric actuator including an electric motor or the like, so that the transmission path can be switched. In addition, the two-stage transmission of the present invention includes the transmission path switching device of the present invention. According to the two-stage transmission of the present invention, the reduction ratio between the input component and the output component can be switched between a high stage and a low stage by using an electric actuator. BRIEF DESCRIPTION OF THE DRAWINGS

[0077] Figure 1 FIG. is a perspective view of a two-stage transmission showing a first example of an embodiment of the present invention.

[0078] Figure 2 FIG. is a cross-sectional view of the two-stage transmission of the first example.

[0079] Figure 3 FIG. is a schematic diagram of the two-stage transmission of the first example.

[0080] Figure 4 (A) of FIG. is a schematic diagram showing the transmission path in the low reduction ratio mode, Figure 4 (B) of FIG. is a schematic diagram showing the transmission path in the high reduction ratio mode.

[0081] Figure 5 FIG. is a cross-sectional view showing the transmission path switching device taken out for the first example.

[0082] Figure 6 FIG. is an exploded perspective view showing the transmission path switching device taken out for the first example.

[0083] Figure 7 FIG. is an exploded perspective view showing the cam device and the rotation transmission state switching device taken out.

[0084] Figure 8 FIG. is a cross-sectional view showing the friction engagement device taken out.

[0085] Figure 9 FIG. is a perspective view showing the state of the rotation transmission state switching device taken out and viewed from one side in the axial direction.

[0086] Figure 10 FIG. is an exploded perspective view showing the rotation transmission state switching device taken out.

[0087] Figure 11 FIG. is an end view showing the state of the selection plate removed from the rotation transmission state switching device and viewed from one side in the axial direction.

[0088] Figure 12 isFigure 11 Enlarged view of the X part.

[0089] Figure 13 It is a schematic diagram showing the engagement relationship of the first engaging claw, the second engaging claw, the engaging concave part, and the protruding part. Figure 13 (A) of is a schematic diagram showing the engagement relationship in the free mode. Figure 13 (B) of is a schematic diagram showing the engagement relationship in the locked mode. Figure 13 (C) of is a schematic diagram showing the engagement relationship in the one-way clutch mode.

[0090] Figure 14 It is a line diagram schematically showing the disconnection state of the friction engagement device and the state switching device of the rotational transmission.

[0091] Figure 15 It is a cross-sectional view showing the transmission path switching device of the comparative example.

[0092] Figure 16 It is a line diagram schematically showing the disconnection state of the first friction engagement device and the second friction engagement device in the transmission path switching device of the comparative example.

[0093] Figure 17 (A) of is related to the first example of the modification related to the first example of the embodiment of the present invention and is Figure 14 equivalent to the figure. Figure 17 (B) of is related to the second example of the modification related to the first example of the embodiment of the present invention and is Figure 14 equivalent to the figure.

[0094] Figure 18 It is a cross-sectional view showing the transmission path switching device taken out for the second example of the embodiment of the present invention.

[0095] Figure 19 It is an exploded perspective view showing the transmission path switching device taken out for the second example.

[0096] Figure 20 It is an exploded perspective view showing the drive cam, the two-stage gear, and the selection plate taken out.

[0097] Figure 21 It is a cross-sectional view showing the transmission path switching device taken out for the third example of the embodiment of the present invention.

[0098] Figure 22 It is an exploded perspective view showing the transmission path switching device taken out for the third example.

[0099] Figure 23 It is a cross-sectional view showing the transmission path switching device taken out for the fourth example of the embodiment of the present invention.

[0100] Figure 24 It is a perspective view of the drive cam, guide plate, and selection plate taken out and viewed from one axial side.

[0101] Figure 25 It is a perspective view of the drive cam, guide plate, and selection plate taken out and viewed from the other axial side.

[0102] Figure 26 It is a schematic diagram showing the engagement state of the cam side groove, guide groove, and plate side groove with the engagement pin. Figure 26 (A) of it is a schematic diagram showing the engagement state in the free mode. Figure 26 (B) of it is a schematic diagram showing the engagement state in the locked mode. Figure 26 (C) of it is a schematic diagram showing the engagement state in the one-way clutch mode.

[0103] Figure 27 It is a perspective view showing the engagement pin taken out.

[0104] Figure 28 It is a cross-sectional view showing the transmission path switching device taken out for the fifth example of the embodiment of the present invention.

[0105] Figure 29 It is an exploded perspective view showing the transmission path switching device taken out for the fifth example.

[0106] Figure 30 It is an exploded perspective view showing the drive cam and selection plate taken out.

[0107] Figure 31 It is a perspective view showing the selection plate, first claw member, second claw member, and engagement pin taken out.

[0108] Figure 32 It is Figure 31 An enlarged view of part Y.

[0109] Figure 33 It is a cross-sectional view showing the two-stage transmission for the sixth example of the embodiment of the present invention.

[0110] Figure 34 It is Figure 33 An enlarged view of part Z.

[0111] Figure 35 It is an exploded perspective view showing the cam device taken out for the sixth example.

[0112] Figure 36 It is a cross-sectional view showing the two-stage transmission for the seventh example of the embodiment of the present invention.

[0113] Figure 37 It is a perspective view showing the drive cam taken out for the seventh example.

[0114] Figure 38 It is an enlarged view of the main part for showing the extraction and representation of the rotation transmission state in the seventh example.

[0115] Figure 39 It is a line graph for explaining the effect achieved by assembling a transmission in a driving device with an electric motor as the driving source. Detailed implementation mode

[0116] [The first example of the implementation mode]

[0117] Refer to Figures 1 to 14 The first example of the implementation mode of the present invention will be described. The two-stage transmission 1 in this example is arranged, for example, between the output shaft of an electric motor, which is the power source of an electric vehicle or a hybrid vehicle, and a differential gear, and increases (decelerates) the torque of the output shaft of the electric motor and then transmits it to the differential gear, or directly transmits it to the differential gear without increasing (decelerating). The two-stage transmission in this example includes: an input member 2, an output member 3, a planetary gear mechanism 4, and a transmission path switching device 5, and is configured to be able to switch the reduction ratio between the input member 2 and the output member 3 between two levels of high and low.

[0118] The input member 2 is connected to a drive shaft (not shown) such as the output shaft of an electric motor and inputs torque (power). In this example, the input member 2 includes: an input cylindrical portion 6, and an input flange portion 7 bent outward in the radial direction from the end portion on one axial side ( Figures 2 to 8 the right side) of the input cylindrical portion 6. The drive shaft is, for example, embedded in the inner peripheral surface of the input cylindrical portion 6 in a manner capable of transmitting torque, or is connected to the input flange portion 7 by bolting or the like in a manner capable of transmitting torque.

[0119] The output member 3 is coaxially arranged with the input member 2 and is connected to a driven shaft such as a differential gear or a propeller shaft (not shown), and outputs torque to the driven shaft. In this example, the output member 3 includes: an output cylindrical portion 9 having an internal spline portion 8 on the inner peripheral surface, and an output flange portion 10 bent outward in the radial direction from the end portion on the other axial side ( Figures 2 to 8 the left side) of the output cylindrical portion 9. The driven shaft is connected to the output member 3 in a manner capable of transmitting torque by spline engagement of an external spline portion provided on the outer peripheral surface of the front end portion with the internal spline portion 8 of the output cylindrical portion 9.

[0120] As Figures 2 to 4 (B) shown, the planetary gear mechanism 4 is arranged between the input member 2 and the output member 3 in the power transmission direction, and includes: a sun gear 11, a ring gear 12, a planet carrier 13, and a plurality of pinions 14.

[0121] The sun gear 11 is connected to the input member 2 in a manner that enables it to rotate integrally with the input member 2. In this example, the sun gear 11 includes: a small-diameter cylindrical portion 15 on one axial side, a large-diameter cylindrical portion 16 on the other axial side, and a flange portion 17 that is bent radially outward from the end portion on the other axial side of the large-diameter cylindrical portion 16. The sun gear 11 has a sun-gear-side external spline portion 18 on the outer peripheral surface of the large-diameter cylindrical portion 16, and has a spur gear or helical gear, i.e., a gear portion 19, on the outer peripheral surface of the flange portion 17. The sun gear 11 externally fits the small-diameter cylindrical portion 15 onto the input cylindrical portion 6 of the input member 2 by means of a structure capable of transmitting torque, such as spline engagement.

[0122] The ring gear 12 is supported around the sun gear 11 coaxially therewith and capable of relative rotation with respect to the sun gear 11. In this example, the ring gear 12 includes: a small-diameter cylindrical portion 20 on one axial side, a large-diameter cylindrical portion 21 on the other axial side, and an annular portion 22 that connects the end portion on the other axial side of the small-diameter cylindrical portion 20 to the end portion on the one axial side of the large-diameter cylindrical portion 21. The ring gear 12 has a ring-gear-side external spline portion 23 on the outer peripheral surface of the small-diameter cylindrical portion 20, and has a spur gear or helical gear, i.e., a gear portion 24, on the inner peripheral surface of the large-diameter cylindrical portion 21.

[0123] The planet carrier 13 is supported coaxially with the sun gear 11 and the ring gear 12, and is connected to the output member 3 in a manner that enables it to rotate integrally with the output member 3. In this example, the planet carrier 13 includes: a pair of rim portions 25a, 25b that are each annular and arranged at intervals in the axial direction; columns 26 that are erected between multiple locations in the circumferential direction that match each other on the pair of rim portions 25a, 25b; and a cylindrical portion 27 that projects integrally in the axial direction from a radially intermediate portion of the axial-side surface of the axial-side rim portion 25a of the pair of rim portions 25a, 25b.

[0124] The planet carrier 13 has through-holes 28a that penetrate axially at multiple locations in the circumferential direction of the portion of the axial-side rim portion 25a that is radially outside the cylindrical portion 27, and has a planet-carrier-side internal spline portion 29 on the inner peripheral surface of the cylindrical portion 27. In addition, the planet carrier 13 has through-holes 28b that penetrate axially at a portion of the axial-other-side rim portion 25b of the pair of rim portions 25a, 25b that matches the through-holes 28a of the axial-side rim portion 25a. The planet carrier 13 is configured to be able to rotate integrally with the output member 3 by connecting the axial-other-side rim portion 25b to the output flange portion 10 of the output member 3 by means of a structure capable of transmitting torque, such as spline engagement.

[0125] Each pinion gear 14 meshes with the sun gear 11 and the ring gear 12 respectively, and the planet carrier 13 is supported so as to be able to rotate freely about its own central axis. In this example, each pinion gear 14 is supported around the axial middle portion of the cylindrical support shaft 30 so that the cylindrical main body portion 31 can rotate freely by means of a radial needle bearing 32. The main body portion 31 has a gear portion 33 on its outer peripheral surface which is a spur gear or a helical gear and meshes with the gear portion 19 of the sun gear 11 and the gear portion 24 of the ring gear 12. The end portions on both axial sides of the support shaft 30 are respectively inserted and fixed in the circular holes 28a, 28b of the planet carrier 13.

[0126] In addition, in this example, the other axial side surface of the spacer portion 35 which is prevented from displacing to one axial side by the snap ring 34a engaged with the outer peripheral surface of the axial middle portion of the large-diameter cylindrical portion 16 of the sun gear 11 abuts against the one axial side surface of the radially inner portion of the one axial side rim portion 25a via a thrust bearing 36a. In addition, the one axial side surface of the radially inner portion of the pressing plate 37 which is prevented from displacing to the other axial side by the snap ring 34b engaged with the inner peripheral surface of the end portion on the other axial side of the large-diameter cylindrical portion 21 of the ring gear 12 abuts against the other axial side surface of the radially inner portion of the other axial side rim portion 25b (output flange portion 10 of the output member 3) via a thrust bearing 36b. Thus, in the state where the planetary gear mechanism 4 is assembled, separation of the sun gear 11, the ring gear 12, the planet carrier 13 and the pinion gears 14 can be prevented respectively. In short, the planetary gear mechanism 4 can be handled integrally as a sub-assembly.

[0127] The transmission path switching device 5 switches the transmission path between the input member 2 and the output member 3. The transmission path switching device 5 of this example includes: a housing 38 that does not rotate even during use, a cam device 39, a friction engagement device 40, and a rotational transmission state switching device 41.

[0128] The housing 38 includes: an inner diameter side cylindrical portion 42, an outer diameter side cylindrical portion 43, and an annular side plate portion 44 that connects the end portion on one axial side of the inner diameter side cylindrical portion 42 and the end portion on one axial side of the outer diameter side cylindrical portion 43. The housing 38 has a fixed side external spline portion 45 on the outer peripheral surface of the inner diameter side cylindrical portion 42, and a fixed side internal spline portion 46 on the inner peripheral surface of the outer diameter side cylindrical portion 43. In addition, the housing 38 further has a through hole 47 that penetrates radially and extends in the circumferential direction in a portion on one axial side of the outer diameter side cylindrical portion 43.

[0129] In this example, a radial needle bearing 48 is disposed between the inner peripheral surface of the inner diameter side cylindrical portion 42 of the housing 38 and the outer peripheral surface of the input cylindrical portion 6 of the input member 2, and a thrust needle bearing 49 is disposed between the axial one side surface of the side plate portion 44 and the axial other side surface of the input flange portion 7, whereby the input member 2 is rotatably supported relative to the housing 38.

[0130] As Figure 5 and Figure 7 shown, the cam device 39 includes: a drive cam 50 supported in a rotatable and axially non-displaceable manner, a driven cam 51 supported in a manner capable of relative rotation and axial displacement with respect to the drive cam 50 and displaced axially as the drive cam 50 rotates, and a plurality (five in the illustrated example) of engagement pins 52.

[0131] The drive cam 50 has an annular shape and is supported on the outer peripheral surface of the end portion on the axial one side of the inner diameter side cylindrical portion 42 of the housing 38 so as to be freely rotatable via an angular contact ball bearing 53 capable of supporting radial loads and thrust loads and axially non-displaceable.

[0132] The drive cam 50 has a drive cam surface 54 in the radially inner part of the axial other side surface in which the number of concave portions and convex portions is the same and they are alternately arranged in the circumferential direction. The drive cam surface 54 has a flat surface portion orthogonal to the central axis of the drive cam 50 at the front end portion of the convex portion.

[0133] The drive cam 50 has cam-side engagement holes 56 opening to the axial other side surface at a plurality of equally spaced positions in the circumferential direction in the radially outer part (five positions in the illustrated example), and has a helical gear with a chord-wound tooth rib, i.e., a tooth portion 57, on the outer peripheral surface.

[0134] The drive cam 50 is rotationally driven by an electric actuator 58. As Figure 1 and Figure 6 shown, the electric actuator 58 includes: a worm 59 and a reduction motor 60. The worm 59 has a worm wheel portion 61 on the outer peripheral surface of the axial intermediate portion that meshes with the portion of the tooth portion 57 of the drive cam 50 exposed from the through hole 47 of the housing 38. The reduction motor 60 rotationally drives the worm 59. That is, the drive cam 50 is rotationally driven by the reduction motor 60 via a worm gear reducer formed by meshing the tooth portion 57 with the worm wheel portion 61.

[0135] As Figure 5 and Figure 7As shown, the driven cam 51 is arranged so as to axially oppose the radially inner portion of the driving cam 50. The driven cam 51 has a driven cam surface 62 on the axially one side surface opposing the driving cam surface 54 of the driving cam 50, in which the concave portions and convex portions are respectively the same number (five in this example) as those of the concave portions and convex portions of the driving cam surface 54 and are alternately arranged in the circumferential direction. However, the driven cam surface 62 opposing the driving cam surface 54 may also be constituted by a flat surface orthogonal to the central axis.

[0136] The driven cam 51 has a driven-side internal spline portion 63 on the inner peripheral surface, and is supported relative to the housing 38 so as to be axially displaceable only by spline-engaging the driven-side internal spline portion 63 with the fixed-side external spline portion 45 of the housing 38.

[0137] The cam device 39 further includes a plurality (five in the illustrated example) of rolling elements 64 that are arranged so as to be freely rollable between the driving cam surface 54 and the driven cam surface 62. That is, in this example, as the driving cam 50 rotates, the amounts by which the rolling elements 64 are lifted from the bottoms of the concave portions of the driving cam surface 54 and the amounts by which they are lifted from the bottoms of the concave portions of the driven cam surface 62 increase and decrease, whereby the driven cam 51 is displaced axially. Further, in this example, spheres are used as the rolling elements 64, but rollers or tapered rollers may also be used as the rolling elements.

[0138] Each engagement pin 52 is non-loosely inserted (engaged) with the cam-side engagement hole 56 of the driving cam 50 by the end portion on the axially one side, so that the portion on the axially other side protrudes from the axially other side surface of the driving cam 50 toward the axially other side.

[0139] As Figure 5 and Figure 8 shown, the friction engagement device 40 respectively has a plurality of friction plates 65 and separation plates 66. The friction plates 65 and the separation plates 66 are each substantially annular and are alternately arranged in the axial direction.

[0140] The friction engagement device 40 is configured such that the friction plates 65 and the separation plates 66 are pressed against each other for connection by displacing the driven cam 51 of the cam device 39 in the direction in which the axial interval from the driving cam 50 is increased, and the force pressing the friction plates 65 and the separation plates 66 against each other is released for disconnection by displacing the driven cam 51 in the direction in which the axial interval from the driving cam 50 is decreased.

[0141] In this example, the friction engagement device 40 is disposed between the sun gear 11 and the carrier 13. That is, by connecting the friction engagement device 40, the sun gear 11 and the carrier 13, which are each a rotating body, are integrally rotated, and by disconnecting the friction engagement device 40, the sun gear 11 and the carrier 13 are relatively rotated with respect to each other. In short, the friction engagement device 40 functions as a clutch to switch the transmission connection / disconnection state between the sun gear 11 and the carrier 13.

[0142] Each friction plate 65 has an internal spline portion on its inner peripheral surface, and by spline-engaging the internal spline portion with the sun gear side external spline portion 18 of the sun gear 11, it is supported with respect to the sun gear 11 so as to be displaceable only in the axial direction.

[0143] Each separator plate 66 has an external spline portion on its outer peripheral surface, and by spline-engaging the external spline portion with the carrier side internal spline portion 29 of the carrier 13, it is supported with respect to the carrier 13 so as to be displaceable only in the axial direction.

[0144] The separator plate 66 that is the most axially other side among the separator plates 66 is prevented from displacing axially by a snap ring 67 that is engaged with the axially other end of the cylindrical portion 27 of the carrier 13.

[0145] Between the separator plate 66 that is the most axially one side among the separator plates 66 and the driven cam 51, an elastic member 68 and a thrust ball bearing 69 are sequentially interposed from the axial one side. The elastic member 68 elastically biases the friction engagement device 40 and the driven cam 51 in the axially separating directions. In addition, in this example, the elastic member 68 is constituted by a disc spring. However, the elastic member 68 may also be constituted by a torsion helical spring or the like.

[0146] As Figure 8 shown, the friction engagement device 40 further includes a return spring 70 that elastically biases in a direction to separate the friction plate 65 and the separator plate 66 from each other and release the force pressing the friction plate 65 and the separator plate 66 against each other. In this example, the return spring 70 is installed between the separator plate 66 that is the most axially one side and the separator plate 66 that is the most axially other side, and elastically biases the separator plate 66 that is the most axially one side and the separator plate 66 that is the most axially other side in the axially separating directions.

[0147] As Figures 9 to 12 shown, the rotation transmission state switching device 41 includes: a first member 71 and a second member 72 that are coaxially arranged with each other, a first claw member 73 and a second claw member 74, a first claw biasing member 75 and a second claw biasing member 76, and a selection plate 77.

[0148] The first component 71 has engaging recesses 78 at multiple locations in the circumferential direction on its outer peripheral surface. That is, the first component 71 has a gear-shaped uneven portion 80 on its outer peripheral surface in which the engaging recesses 78 and the convex portions 79 are alternately arranged in the circumferential direction. In addition, the first component 71 has an internal spline portion 81 on its inner peripheral surface. The first component 71 is supported relative to the ring gear 12 so as not to be relatively rotatable by spline-engaging the internal spline portion 81 with the outer spline portion 23 on the ring-gear side of the ring gear 12. That is, the first component 71 rotates integrally with the ring gear 12.

[0149] The second component 72 is supported around the first component 71 coaxially therewith and is capable of relative rotation with respect to the first component 71. That is, the inner peripheral surface of the second component 72 faces the outer peripheral surface (the front end surface of the convex portion 79) of the first component 71 with a gap therebetween. The second component 72 has an external spline portion 82 on its outer peripheral surface. The second component 72 is supported relative to the housing 38 so as not to be relatively rotatable by spline-engaging the external spline portion 82 with the fixed-side internal spline portion 46 of the housing 38.

[0150] The second component 72 includes a base portion 83 having a rectangular cross-sectional shape and a cylindrical portion 84 that projects integrally around the circumference from the end portion on the radially outer side of the axially one side surface of the base portion 83 toward the axially one side.

[0151] The base portion 83 has first holding recesses 85 and second holding recesses 86 that are alternately arranged in the circumferential direction, each being plural (six each in the illustrated example).

[0152] Each of the first holding recesses 85 opens to the inner peripheral surface and the axially one side surface of the base portion 83. Each of the first holding recesses 85 includes a spring holding portion 87a and a pedestal portion 88a. The spring holding portion 87a, when viewed from the axially one side, has a substantially rectangular opening shape in which the major axis is arranged in a direction extending radially outward as it goes toward the circumferential direction side ( Figure 11 the clockwise front side in ). The pedestal portion 88a has a substantially circular opening shape when viewed from the axially one side and is arranged adjacent to the other side in the circumferential direction of the spring holding portion 87a ( Figure 11 the clockwise rear side).

[0153] Each second holding recess 86 opens to the inner circumferential surface and one axial side surface of the base 83. When each second holding recess 86 is viewed from one axial side, it has a shape symmetric with respect to a virtual plane containing the central axis of the second member 72 with respect to the first holding recess 85. That is, each second holding recess 86 includes a spring holding portion 87b and a pedestal portion 88b. The spring holding portion 87b, when viewed from one axial side, has a substantially rectangular opening shape in which a major axis is arranged in a direction extending toward the radially outer side as it goes toward the other side in the circumferential direction. The pedestal portion 88b has a substantially circular opening shape when viewed from one axial side and is arranged adjacent to the circumferential direction side of the spring holding portion 87a.

[0154] The first claw member 73 includes a first base portion 89 and a first engaging claw 90.

[0155] The first base portion 89 is configured to be substantially cylindrical and is supported (pivotally supported) by the pedestal portion 88a of the first holding recess 85 so as to be able to swing about a pivot parallel to the central axis of the second member 72.

[0156] The first engaging claw 90 is configured to be substantially flat and extends from the first base portion 89 toward the other side in the circumferential direction. The first engaging claw 90 opposes (engages) the outer peripheral surface of the annular convex portion 91 of the selection plate 77 with the one axial side portion, and opposes the uneven portion 80 of the first member 71 with the other axial side portion (engages so as to be able to engage and disengage with respect to the engaging recess 78).

[0157] The second claw member 74 includes a second base portion 92 and a second engaging claw 93.

[0158] The second base portion 92 is configured to be substantially cylindrical and is supported by the pedestal portion 88b of the second holding recess 86 so as to be able to swing about a pivot parallel to the central axis of the second member 72.

[0159] The second engaging claw 93 is configured to be substantially flat and extends from the second base portion 92 toward the other side in the circumferential direction. The second engaging claw 93 opposes the outer peripheral surface of the annular convex portion 91 of the selection plate 77 with the one axial side portion, and opposes the uneven portion 80 of the first member 71 with the other axial side portion.

[0160] The first claw biasing member 75 elastically biases the first engaging claw 90 of the first claw member 73 in a direction of engaging with the engaging recess 78 of the first member 71. That is, the first claw biasing member 75 biases the first claw member 73 so that the first claw member 73 rotates about the central axis (pivot) of the first base portion 89 Figure 12The force in the clockwise swinging direction. Specifically, the first claw biasing member 75 is composed of an elastic member such as a torsion coil spring and is held in an elastically compressed state between the bottom surface (the surface facing radially inward) of the spring holding portion 87a of the first holding recess 85 and the radially outer side surface of the first engaging claw 90.

[0161] The second claw biasing member 76 elastically biases the second engaging claw 93 of the second claw member 74 in the direction of engaging with the engaging recess 78 of the first member 71. That is, the second claw biasing member 76 provides the second claw member 74 with a force in the direction of swinging counterclockwise about the central axis of the second base portion 92. Figure 12 The force in the counterclockwise swinging direction. Specifically, the second claw biasing member 76 is composed of an elastic member such as a torsion coil spring and is held in an elastically compressed state between the bottom surface (the surface facing radially inward) of the spring holding portion 87b of the second holding recess 86 and the radially outer side surface of the second engaging claw 93.

[0162] As Figure 10 shown, the selection plate 77 includes: a substrate portion 94 having a substantially annular plate shape, and an annular convex portion 91 that projects integrally around the axial direction from a radially intermediate portion on the other axial side surface of the substrate portion 94.

[0163] The substrate portion 94 has plate-side engaging holes 95 that open to one axial side surface at a plurality of circumferentially equally spaced positions in the radial intermediate portion (five positions in the illustrated example). The other axial end portions of the respective engaging pins 52 are snugly fitted (engaged) in the respective plate-side engaging holes 95. That is, the selection plate 77 rotates integrally (in the same direction at the same speed) with the drive cam 50.

[0164] The annular convex portion 91 has projecting portions 96 that project radially outward at a plurality of positions in the circumferential direction on the outer peripheral surface. That is, the annular convex portion 91 has an uneven portion 97 formed by alternately arranging the projecting portions 96 and recesses in the circumferential direction on the outer peripheral surface. In this example, the uneven portion 97 constitutes the mode selection portion.

[0165] The first member 71, the second member 72, and the selection plate 77 are combined by a cover body 98 and a snap ring 99 so as to be capable of relative rotation and not capable of relative axial displacement (not accidentally separating axially), thereby constituting the rotational transmission state switching device 41.

[0166] That is, with the first member 71 disposed radially inward of the axially other-side portion of the base 83 of the second member 72, the annular cover 98 is supported and fixed by screw fixation on the axially other side surface of the second member 72, and the axially one side surface of the radially inner portion of the cover 98 faces the axially other side surface of the first member 71. Thereby, displacement of the first member 71 relative to the second member 72 in the axially other direction is prevented.

[0167] Further, the annular protrusion 91 of the selection plate 77 is disposed radially inward of the axially one-side portion of the base 83 of the second member 72, the front end surface (axially other side surface) of the annular protrusion 91 is in sliding contact with or close to facing the axially one side surface of the first member 71, and with the axially other side surface of the radially outer portion of the substrate portion 94 in sliding contact with or close to facing the axially one side surface of the base 83 of the second member 72, a snap ring 99 is engaged with the axially one-side end portion of the inner circumferential surface of the cylindrical portion 84 of the second member 72. Thereby, displacement of the first member 71 and the selection plate 77 relative to the second member 72 in the axially one direction is prevented.

[0168] The rotation transmission state switching device 41 supports and fixes the second member 72 relative to the housing 38 so as not to be relatively rotatable and axially displaceable. Specifically, the external spline portion 82 provided on the outer circumferential surface (the outer circumferential surfaces of the base 83 and the cylindrical portion 84) of the second member 72 is spline-engaged with the fixed-side internal spline portion 46 of the housing 38, and the second member 72 and the cover 98 are clamped from both axial sides by a pair of snap rings 101a, 101b engaged with the inner circumferential surface of the outer diameter side cylindrical portion 43 of the housing 38.

[0169] The rotation transmission state switching device 41 of this example has: a free mode in which the first member 71 and the second member 72 can relatively rotate in two directions, a locked mode in which the first member 71 and the second member 72 cannot relatively rotate, and a one-way clutch mode in which only rotation of the first member 71 in a predetermined direction relative to the second member 72 is allowed. The rotation transmission state switching device 41 is configured to switch between the following engaged states by rotation of the selection plate 77, that is, the engaged state of the first engagement claw 90 of the first claw member 73 with the engagement recess 78 of the first member 71 and the engaged state of the second engagement claw 93 of the second claw member 74 with the engagement recess 78, so that it is possible to switch between the free mode, the locked mode, and the one-way clutch mode.

[0170] <Free mode>

[0171] In the free mode, the phase of the selection plate 77 in the circumferential direction relative to the second member 72 is adjusted, as Figure 13As shown in (A), the protrusion 96 is used to lift the first engaging claw 90 radially outward against the elastic force of the first claw biasing member 75, and to lift the second engaging claw 93 radially outward against the elastic force of the second claw biasing member 76. Thereby, the engagement between the engaging recess 78 of the first member 71 and the first engaging claw 90 and the second engaging claw 93 is disengaged. In this state, regardless of the relative rotation direction between the first member 71 and the second member 72, rotation of the first member 71 relative to the second member 72 is permitted. That is, regardless of the rotation direction of the first member 71, rotation of the first member 71 relative to the housing 38 is permitted. In other words, regardless of the rotation direction of the ring gear 12, rotation of the ring gear 12 relative to the housing 38 is permitted.

[0172] <Locking mode>

[0173] In the locking mode, the phase of the selection plate 77 in the circumferential direction relative to the second member 72 is adjusted. As Figure 13 shown in (B), the protrusion 96 is positioned at a portion offset in the circumferential direction from the first engaging claw 90 of the first claw member 73 and the second engaging claw 93 of the second claw member 74. In other words, in the circumferential direction, the recess in the concavo-convex portion 97 is made to be in phase with the first engaging claw 90 and the second engaging claw 93. Thereby, the engaging recess 78 of the first member 71 is engaged with the first engaging claw 90 and the second engaging claw 93. In this state, regardless of the relative rotation direction between the first member 71 and the second member 72, rotation of the first member 71 relative to the second member 72 is blocked. That is, regardless of the rotation direction of the first member 71, rotation of the first member 71 relative to the housing 38 is blocked.

[0174] <One-way clutch mode>

[0175] In the one-way clutch mode, the phase of the selection plate 77 in the circumferential direction relative to the second member 72 is adjusted. As Figure 13 shown in (C), the protrusion 96 is used to lift only the second engaging claw 93 radially outward against the elastic force of the second claw biasing member 76. Thereby, the engaging recess 78 of the first member 71 is engaged with the first engaging claw 90, and the engagement between the engaging recess 78 and the second engaging claw 93 is disengaged. In this state, only rotation of the first member 71 relative to the second member 72 in the said predetermined direction ( Figure 13 the clockwise direction in (C)) is permitted, and rotation in the direction opposite to the said predetermined direction ( Figure 13 the counterclockwise direction in (C)) is blocked.

[0176] That is, when the first member 71 is about to rotate in the predetermined direction relative to the second member 72, the convex portion 79 of the uneven portion 80 causes the first engaging claw 90 to lift radially outward against the elastic force of the first claw biasing member 75. As a result, rotation of the first member 71 in the predetermined direction is permitted. In contrast, when the first member 71 is about to rotate in the direction opposite to the predetermined direction relative to the second member 72, the rotation of the first member 71 in the direction opposite to the predetermined direction is blocked by the engagement of the engaging recess 78 and the first engaging claw 90. In short, the rotation transmission state switching device 41 operates as a ratchet type one-way clutch.

[0177] In addition, the predetermined direction is the same as the forward rotation direction of the input member 2. The forward rotation direction of the input member 2 refers to the rotation direction of the input member 2 when the motor vehicle is moving forward.

[0178] The transmission path switching device 5 of this example rotationally drives the drive cam 50 using the electric actuator 58, thereby axially displacing the driven cam 51. While switching the connection / disconnection state of the friction engagement device 40, the phase of the selection plate 77 relative to the second member 72 in the circumferential direction is adjusted, thereby switching the mode of the rotation transmission state switching device 41, and thus switching the operation mode. The transmission path switching device 5 includes: a first mode in which the friction engagement device 40 is connected and the rotation transmission state switching device 41 is in the free mode; a second mode in which the friction engagement device 40 is disconnected and the rotation transmission state switching device 41 is in the locked mode; a third mode in which the rotation transmission state switching device 41 is in the one-way clutch mode is established during the switching from the disconnection state to the connection state of the friction engagement device 40; and a fourth mode in which the friction engagement device 40 is disconnected and the rotation transmission state switching device 41 is in the free mode. Each mode will be described below.

[0179] <First mode>

[0180] To switch the transmission path switching device 5 to the first mode, the drive cam 50 is rotationally driven using the electric actuator 58, thereby connecting the friction engagement device 40 and setting the rotation transmission state switching device 41 to the free mode.

[0181] That is, by rotating the drive cam 50, the amount by which the rolling element 64 is lifted from the bottom of the recess of the drive cam surface 54 and the amount by which it is lifted from the bottom of the recess of the driven cam surface 62 are increased, so that the driven cam 51 is displaced in the direction in which the axial interval from the drive cam 50 is enlarged (the other side in the axial direction). Thereby, the separation plate 66 closest to the axial one side is pressed toward the other side in the axial direction via the elastic member 68 and the thrust rolling bearing 69. As a result, the friction plate 65 and the separation plate 66 are pressed against each other, thereby connecting (fastening) the friction engagement device 40 (the fastening force of the friction engagement device 40 is increased), and the sun gear 11 and the planet carrier 13 rotate integrally.

[0182] In the above-described manner, while connecting the friction engagement device 40, the phase of the selection plate 77 with respect to the second member 72 in the circumferential direction is adjusted, so that as shown in (A) of Figure 13 , the first engagement claw 90 is lifted toward the radially outer side by the protrusion 96, and the second engagement claw 93 is lifted toward the radially outer side. Thereby, the engagement between the engagement recess 78 of the first member 71 and the first engagement claw 90 and the second engagement claw 93 is disengaged, and the rotation transmission state switching device 41 is switched to the free mode that allows the first member 71 to rotate relative to the second member 72 regardless of the relative rotation direction between the first member 71 and the second member 72.

[0183] <Second Mode>

[0184] In order to switch the power transmission path switching device 5 to the second mode, the drive cam 50 is rotationally driven by the electric actuator 58, so that the friction engagement device 40 is disengaged and the rotation transmission state switching device 41 is in the locked mode.

[0185] That is, by rotating the drive cam 50, the amount by which the rolling element 64 is lifted from the bottom of the recess of the drive cam surface 54 and the amount by which it is lifted from the bottom of the recess of the driven cam surface 62 are decreased, so that the driven cam 51 is displaced in the direction in which the axial interval from the drive cam 50 is reduced (one side in the axial direction). Thereby, the force pressing the friction plate 65 and the separation plate 66 against each other is released. As a result, by the action of the return spring 70, the interval between the separation plate 66 closest to the axial one side and the separation plate 66 closest to the other side in the axial direction is enlarged, so that the friction engagement device 40 is disengaged (the fastening force of the friction engagement device 40 disappears).

[0186] In the above-described manner, while disconnecting the friction engagement device 40, the phase of the selection plate 77 with respect to the second member 72 in the circumferential direction is adjusted, so that as shown in Figure 13As shown in (B) thereof, the protruding portion 96 is positioned at a portion that is offset in the circumferential direction from the first engaging claw 90 of the first claw member 73 and the second engaging claw 93 of the second claw member 74. Thereby, the engaging concave portion 78 of the first member 71 is engaged with the first engaging claw 90 and the second engaging claw 93, and regardless of the relative rotation direction of the first member 71 and the second member 72, it is switched to a locked mode in which the rotation of the first member 71 relative to the second member 72 is blocked.

[0187] <Third Mode>

[0188] The transmission path switching device 5 in this example is configured to switch to the third mode during the switching process from the cut-off state to the connected state of the friction engagement device 40, that is, on the way from the second mode to the first mode.

[0189] During the switching process from the cut-off state to the connected state of the friction engagement device 40, by the rotation of the drive cam 50, as the amount of elevation of the rolling body 64 from the bottom of the concave portion of the drive cam surface 54 and the amount of elevation from the bottom of the concave portion of the driven cam surface 62 gradually increase, the force with which the friction plate 65 and the separation plate 66 are pressed against each other gradually increases (the tightening force of the friction engagement device 40 gradually increases). At this time, the friction plate 65 and the separation plate 66 slide (sliding contact) the axially both side surfaces of the friction plate 65 and the axially both side surfaces of the separation plate 66 against each other and rotate in the same direction, gradually achieving synchronization (the rotational speeds gradually become the same).

[0190] Regarding the transmission path switching device 5 in this example, before starting to switch the friction engagement device 40 from the cut-off state to the connected state by the rotation of the drive cam 50, that is, before the force with which the friction plate 65 and the separation plate 66 are pressed against each other increases, the rotation transmission state switching device 41 is switched to the one-way clutch mode. In order to switch the rotation transmission state switching device 41 to the one-way clutch mode, as Figure 13 shown in (C) thereof, only the second engaging claw 93 is lifted toward the radially outer side against the elastic force of the second claw biasing member 76 by using the protruding portion 96. Thereby, only the first engaging claw 90 is engaged with the engaging concave portion 78 of the first member 71, and the rotation transmission state switching device 41 only allows the rotation of the first member 71 relative to the second member 72 in the predetermined direction, and blocks the rotation in the direction opposite to the predetermined direction.

[0191] In this example, by the rotation of the drive cam 50, while completing the mode switching of the rotation transmission state switching device 41 to the one-way clutch, the switching from the cut-off state to the connected state of the friction engagement device 40 is started, so that the transmission path switching device 5 is switched to the third mode.

[0192] In addition, in this example, in a state where the transmission path switching device 5 is in the third mode, by rotating the drive cam 50, while completing the switching of the friction engagement device 40 to the connected state, the rotation transmission state switching device 41 starts to switch from the one-way clutch mode to the free mode.

[0193] <Fourth Mode>

[0194] In order to switch the transmission path switching device 5 to the fourth mode, the drive cam 50 is rotationally driven by the electric actuator 58, thereby disconnecting the friction engagement device 40 and setting the rotation transmission state switching device 41 to the free mode.

[0195] That is, by rotating the drive cam 50, the driven cam 51 is displaced in a direction (axial side) in which the axial interval from the drive cam 50 is reduced, and the force pressing the friction plate 65 and the separation plate 66 against each other is released. And, due to the action of the return spring 70, the interval between the separation plate 66 closest to the axial side and the separation plate 66 closest to the axial other side is enlarged, disconnecting the friction engagement device 40.

[0196] In the above manner, while disconnecting the friction engagement device 40, the phase of the selection plate 77 relative to the second component 72 in the circumferential direction is adjusted, so that as Figure 13 shown in (A) of, the protrusion 96 causes the first engaging claw 90 to lift radially outward against the elastic force of the first claw biasing member 75, and the second engaging claw 93 to lift radially outward against the elastic force of the second claw biasing member 76. Thus, the engagement between the engaging recess 78 of the first component 71 and the first engaging claw 90 and the second engaging claw 93 is separated, and the first component 71 is allowed to rotate relative to the housing 38 regardless of the rotation direction of the first component 71.

[0197] The two-stage transmission 1 of this example switches the operation mode of the transmission path switching device 5, so that as Figure 14 shown, it is possible to switch between a low reduction ratio mode where the reduction ratio between the input member 2 and the output member 3 is small (reduction ratio is 1), and a high reduction ratio mode where the reduction ratio is larger than that of the low reduction ratio mode. In addition, the two-stage transmission 1 of this example passes through a reduction ratio switching mode during the switching from the high reduction ratio mode to the low reduction ratio mode. Furthermore, the two-stage transmission 1 of this example can also be switched to a neutral mode where power is not transmitted between the input member 2 and the output member 3. The following explains each case.

[0198] <Low Reduction Ratio Mode>

[0199] To switch the two-stage transmission 1 to the low reduction ratio mode, the drive cam 50 is rotationally driven by the electric actuator 58, so that the transmission path switching device 5 is switched to the first mode in which the friction engagement device 40 is connected and the rotation transmission state switching device 41 is in the free mode. When the transmission path switching device 5 is switched to the first mode, as shown in (A) of Figure 4 , by connecting the friction engagement device 40, the sun gear 11 and the carrier 13 rotate integrally, and the rotation transmission state switching device 41 is switched to the free mode, thereby allowing the ring gear 12 to rotate relative to the housing 38. In such a low reduction ratio mode, the rotation directions and rotation speeds of the sun gear 11, the ring gear 12, and the carrier 13 are the same, and the entire planetary gear mechanism 4 rotates integrally, that is, in a so-called attached state. Therefore, the power of the input member 2 is transmitted to the output member 3 through the path shown in (A) below.

[0200] (A) Input member 2 → Carrier 13 → Output member 3

[0201] In this way, in the low reduction ratio mode, the power of the input member 2 is directly transmitted to the output member 3 without being decelerated. In other words, in the low reduction ratio mode, the reduction ratio between the input member 2 and the output member 3 is 1.

[0202] <High reduction ratio mode>

[0203] To switch the two-stage transmission 1 to the high reduction ratio mode, the drive cam 50 is rotationally driven by the electric actuator 58, so that the transmission path switching device 5 is switched to the second mode in which the friction engagement device 40 is disconnected and the rotation transmission state switching device 41 is in the locked mode. When the transmission path switching device 5 is switched to the second mode, as shown in (B) of Figure 4 , the friction engagement device 40 is disconnected, so that the sun gear 11 and the carrier 13 can rotate relative to each other, and the rotation transmission state switching device 41 is switched to the locked mode, thereby preventing the ring gear 12 from rotating relative to the housing 38. In such a high reduction ratio mode, the power of the input member 2 is transmitted to the output member 3 through the path shown in (B) below.

[0204] (B) Input member 2 → Sun gear 11 → Autonomous rotation of pinion 14 → Revolution of pinion 14 based on meshing with ring gear 12 → Carrier 13 → Output member 3

[0205] In this way, in the high reduction ratio mode, the power of the input member 2 is decelerated by the planetary gear mechanism 4 and transmitted to the output member 3. In addition, in the high reduction ratio mode, the reduction ratio between the input member 2 and the output member 3 is determined by the gear ratio of the ring gear 12 to the sun gear 11 (number of teeth of gear portion 24 of ring gear 12 / number of teeth of gear portion 19 of sun gear 11).

[0206] As described above, regarding the two-stage transmission 1 of this example, an electric actuator 58 is used to rotationally drive a drive cam 50, thereby switching the operation mode of the transmission path switching device 5, that is, switching the disconnection / connection state of the friction engagement device 40 and the mode of the rotation transmission state switching device 41, so that the reduction ratio between the input member 2 and the output member 3 can be switched between a high stage and a low stage. Specifically, for example, in a region where the power input to the input member 2 is low speed and high torque, the two-stage transmission 1 is switched to the high reduction ratio mode, and in a region of high speed and low torque, it is switched to the low reduction ratio mode. Therefore, the acceleration performance and high-speed performance of an electric vehicle or a hybrid vehicle when traveling only with an electric motor as the drive source can be made to have the characteristic that the portion to the left of the ratio point P in the solid line a of the foregoing Figure 39 is continuous with the portion to the right of the ratio point P in the dash-dotted line b, that is, it is close to Figure 39 the fuel engine vehicle shown by the dashed line c.

[0207] In particular, regarding the transmission path switching device 5 of this example, the speed-changing motor 60 of the electric actuator 58 is energized, and the drive cam 50 is rotated via the worm 59, thereby switching the disconnection / connection state of the friction engagement device 40 and the mode of the rotation transmission state switching device 41. That is, in the transmission path switching device 5 of this example, a hydraulic system for controlling friction engagement devices such as clutches and brakes is not required. Therefore, in an electric vehicle or a hybrid vehicle, the system can be simplified, the cost can be reduced, and the electric efficiency performance can be improved.

[0208] <Reduction Ratio Switching Mode>

[0209] Regarding the two-stage transmission 1 of this example, when the input member 2 rotates in the forward rotation direction, during the switching from the high reduction ratio mode to the low reduction ratio mode, the transmission path switching device 5 is set to the third mode, thereby switching to the reduction ratio switching mode.

[0210] In the reduction ratio switching mode, the rotation transmission state switching device 41 is switched to the one-way clutch mode, thereby allowing only the rotation of the ring gear 12 in the predetermined direction with respect to the housing 38 and preventing the rotation in the direction opposite to the predetermined direction.

[0211] In addition, in the reduction ratio switching mode, the fastening force of the friction engagement device 40 gradually increases, so that the rotation of the sun gear 11 and the rotation of the carrier 13 gradually reach synchronization. During the rotation of the input member 2 in the forward rotation direction, the fastening force of the friction engagement device 40 gradually increases. When the rotation of the sun gear 11 and the rotation of the carrier 13 gradually reach synchronization, the torque applied to the first member 71 of the rotation transmission state switching device 41 in the direction opposite to the predetermined direction gradually decreases. In addition, in the reduction ratio switching mode, the rotation transmission state switching device 41 switches to the one-way clutch mode. Therefore, even when a torque in the direction opposite to the predetermined direction is applied to the first member 71, the first member 71 does not rotate.

[0212] After the torque applied to the first member 71 in the direction opposite to the predetermined direction gradually decreases to 0, the direction of the torque applied to the first member 71 is reversed (applying the torque in the predetermined direction to the first member 71), and at this moment, the rotation of the first member 71 in the predetermined direction is permitted. Therefore, according to the two-stage transmission 1 of this example, it is possible to suppress the shift shock based on mode switching and suppress the torque loss in the two-stage transmission 1. For the reasons, refer to Figure 15 and Figure 16 for description.

[0213] Figure 15 Fig. shows the transmission path switching device 5z of the comparative example. The transmission path switching device 5z includes: a first friction engagement device 40a that switches the sun gear 11 and the carrier 13 between a state where they can rotate relative to each other and a state where they cannot rotate relative to each other, and a second friction engagement device 40b that switches the ring gear 12 between a rotatable state and a non-rotatable state. That is, regarding the transmission path switching device 5z of the comparative example, instead of the rotation transmission state switching device 41 of the transmission path switching device 5 of this example, a second friction engagement device 40b that switches the connection / disconnection state by pressing or separating the friction plate 65a and the separation plate 66a is adopted.

[0214] Regarding the transmission path switching device 5z of the comparative example, the drive cam 50z of the cam device 39z is rotationally driven by an electric actuator, and the first driven cam 51a and the second driven cam 51b are displaced axially, thereby switching the connection / disconnection state of the first friction engagement device 40a and the second friction engagement device 40b. The first driven cam 51a and the second driven cam 51b are displaced with different phases as the drive cam 50z rotates (displacing in the axial direction in opposite directions to each other (advancing and retreating)).

[0215] Regarding the two-stage transmission equipped with the transmission path switching device 5z of the comparative example, during the switching process from the high reduction ratio mode with a large reduction ratio to the low reduction ratio mode with a small reduction ratio, as Figure 16As shown, the tightening force of the first friction engagement device 40a gradually increases, and the tightening force of the second friction engagement device 40b gradually decreases. Therefore, during the switching from the high reduction ratio mode to the low reduction ratio mode, when the tightening force of the second friction engagement device 40b gradually decreases to an insufficient level, the ring gear 12 is dragged and slips by the revolution of the pinion 14, resulting in a loss of torque.

[0216] In addition, regarding the two-stage transmission equipped with the transmission path switching device 5z of the comparative example, as the tightening force of the first friction engagement device 40a gradually increases, the rotation of the sun gear 11 and the rotation of the carrier 13 reach synchronization. After the torque in the direction opposite to the predetermined direction applied to the ring gear 12 gradually decreases to 0, the direction of the torque applied to the ring gear 12 flips. However, regarding the transmission path switching device 5z of the comparative example, when the direction of the torque applied to the ring gear 12 flips, at the moment when the revolution direction of the pinion 14 is the same as the rotation direction of the ring gear 12, the tightening force of the second friction engagement device 40b cannot be large enough. Therefore, the ring gear 12 drags and slips relative to the housing 38, resulting in a loss of torque.

[0217] In contrast, regarding the two-stage transmission 1 of this example, in order to switch from the high reduction ratio mode to the low reduction ratio mode by the rotation of the drive cam 50, before starting to switch the friction engagement device 40 from the cut-off state to the connected state, the rotation transmission state switching device 41 is set to the one-way clutch mode. Therefore, in order to switch the friction engagement device 40 from the cut-off state to the connected state, the tightening force of the friction engagement device 40 is gradually increased, so that the rotation of the sun gear 11 and the rotation of the carrier 13 gradually reach synchronization, and thus at the moment when the direction of the torque applied to the ring gear 12 flips, the rotation of the ring gear 12 in the predetermined direction can be tolerated. Therefore, it is possible to suppress the shift shock based on the mode switching and suppress the torque loss in the two-stage transmission 1.

[0218] Furthermore, in the reduction ratio switching mode, regarding the reduction ratio between the input member 2 and the output member 3, in a state where the tightening force of the friction engagement device 40 is such that no torque loss occurs at the engagement portion between the friction plate 65 and the separation plate 66, it is the same as the reduction ratio in the high reduction ratio mode. On the other hand, in a state where the tightening force of the friction engagement device 40 increases to a level where it does not slip at the contact portion between the friction plate 65 and the separation plate 66 and can transmit torque, it is the same as the reduction ratio in the low reduction ratio mode, which is 1. On the other hand, in a state where the tightening force of the friction engagement device 40 is at a level where slipping occurs at the contact portion between the friction plate 65 and the separation plate 66, the reduction ratio between the input member 2 and the output member 3 becomes a value corresponding to the magnitude of the input torque, the rotational speed, etc.

[0219] In addition, regarding the two-stage transmission 1 of this example, when the input member 2 rotates in the reverse direction, that is, when the motor vehicle reverses, the vehicle basically does not travel at high speed. Therefore, when the input member 2 rotates in the reverse direction, when switching from the high reduction ratio mode to the low reduction ratio mode, there is no need to be able to select a reduction ratio switching mode in the power transmission path switching device 5. In addition, when switching from the low reduction ratio mode to the high reduction ratio mode, mainly the vehicle is in a decelerated state. In this state, power is not transmitted from the input member 2 to the output member 3, so there is no need to select a reduction ratio switching mode in the power transmission path switching device 5.

[0220] <Neutral mode>

[0221] In addition, regarding the two-stage transmission 1 of this example, it has a neutral mode in which power is not transmitted between the input member 2 and the output member 3. In order to switch the two-stage transmission 1 to the neutral mode, the drive cam 50 is rotationally driven by the electric actuator 58, so that the power transmission path switching device 5 is switched to a third mode in which the friction engagement device 40 is disengaged and the rotation transmission state switching device 41 is in a free mode. When the power transmission path switching device 5 is switched to the third mode, the friction engagement device 40 is disengaged, so that the sun gear 11 and the planet carrier 13 rotate relative to each other, and the rotation transmission state switching device 41 is switched to the free mode, so that the ring gear 12 rotates relative to the housing 38.

[0222] In addition, during the switching process from the low reduction ratio mode to the neutral mode, regarding the reduction ratio between the input member 2 and the output member 3, during the period when the fastening force of the friction engagement device 40 is such that it does not slip at the contact portion between the friction plate 65 and the separation plate 66 and can transmit torque, it is the same as the reduction ratio of the low reduction ratio mode, which is 1. On the other hand, in a state where the fastening force of the friction engagement device 40 is reduced to such an extent that no torque loss occurs in the engagement portion between the friction plate 65 and the separation plate 66, power is not transmitted between the input member 2 and the output member 3. In a state where the fastening force of the friction engagement device 40 slips at the contact portion between the friction plate 65 and the separation plate 66, the reduction ratio between the input member 2 and the output member 3 becomes a value corresponding to the magnitude of the input torque, the rotational speed, etc.

[0223] In addition, in a state where the input member 2 rotates in the forward direction, that is, during the switching process from the high reduction ratio mode to the reduction ratio switching mode, a torque in a direction opposite to the predetermined direction is applied to the first member 71 of the rotation transmission state switching device 41. Here, regarding the rotation transmission state switching device 41, the rotation of the first member 71 in a direction opposite to the predetermined direction is also blocked during the switching from the locked mode to the one-way clutch mode. That is, during the switching process from the high reduction ratio mode to the reduction ratio switching mode, the reduction ratio between the input member 2 and the output member 3 is the same as the reduction ratio of the high reduction ratio mode.

[0224] When the input member 2 rotates in the forward rotation direction, that is, during the switching process from the reduction ratio switching mode to the low reduction ratio mode, a torque in the predetermined direction is applied to the first member 71 of the rotation transmission state switching device 41. Here, with respect to the rotation transmission state switching device 41, the rotation of the first member 71 in the predetermined direction is also permitted during the switching from the one-way clutch mode to the free mode. That is, during the switching process from the reduction ratio switching mode to the low reduction ratio mode, the reduction ratio between the input member 2 and the output member 3 is the same as the reduction ratio in the low reduction ratio mode.

[0225] Regarding the transmission path switching device 5 of this example, an elastic member 68 is disposed between the separation plate 66 on the most axially outer side and the driven cam 51. Therefore, the assembly error of the transmission path switching device 5 and the offset accompanying the wear of the friction plate 65 and the separation plate 66 can be absorbed by the elastic member 68. Therefore, by controlling the force for pushing the driven cam 51 (the pressing force of the driven cam 51 toward the other side in the axial direction with respect to the separation plate 66 on the most axially outer side), the fastening force of the friction engagement device 40 can be controlled. As a result, in the low reduction ratio mode, the fastening force of the friction engagement device 40 can be sufficiently ensured.

[0226] In this example, in the state where the transmission path switching device 5 is switched to the first mode and the friction engagement device 40 is connected, the rolling body 64 rides over the flat surface portion provided on the front end surface of the convex portion of the drive cam surface 54. Therefore, according to the transmission path switching device 5 of this example, after the mode switching is completed, even if the power supply to the speed change motor 60 is stopped, the connected state of the friction engagement device 40 can be maintained, and thus the electric efficiency performance can also be improved.

[0227] In addition, instead of the method of providing the flat surface portion on the front end surface of the convex portion of the drive cam surface 54, or in addition to providing the flat surface portion, the worm gear reducer composed of the tooth portion 57 of the drive cam 50 and the worm wheel portion 61 of the worm 59 may be provided with a self-locking function, so that the connected state of the friction engagement device 40 can be maintained even after the power supply to the speed change motor 60 is stopped.

[0228] In addition, regarding the two-stage transmission 1 of this example, the planetary gear mechanism 4 is arranged around the output member 3, and the transmission path switching device 5 is arranged around the input member 2. However, when implementing the two-stage transmission of the first aspect of the present invention, it is not limited to this, and various structures can be adopted. For example, the planetary gear mechanism can be arranged around the input member, and the transmission path switching device can be arranged around the output member. Or, it can also be arranged in such a way that the planetary gear mechanism and / or the transmission path switching device do not overlap with the input member or the output member in the radial direction. In short, the shapes of the respective parts can be appropriately changed according to their respective structures.

[0229] In addition, regarding the cam device 39 of the transmission path switching device 5 of this example, a rolling element 64 is clamped between the driving cam 50 and the driven cam 51. However, when implementing the transmission path switching device of the present invention, it is not limited to the structure of this example. As long as the cam device can displace the driven cam axially by the rotation of the driving cam, various structures can be adopted. For example, it is also possible to directly slide the driving cam surface provided on the driving cam and the driven cam surface provided on the driven cam in contact with each other.

[0230] In addition, in this example, regarding the rotation transmission state switching device 41, the second member 72 is arranged around the first member 71, and the first claw member 73 and the second claw member 74 are supported relative to the second member 72 so as to be swingable. However, when implementing the present invention, there is no particular limitation as long as the rotation transmission state switching device is a structure that can switch the rotation transmission state between the first member and the second member. For example, the first claw member and the second claw member can be supported relative to the first member arranged radially inward so as to be swingable, or the first member and the second member can be arranged to face each other axially.

[0231] [Regarding the first and second examples of the modification of the first example of the embodiment]

[0232] Refer to Figure 17 of (A) and Figure 17 of (B) to describe the first and second examples of the modification of the first example of the embodiment of the present invention.

[0233] The rotation transmission state switching device 41 of the first example of the modification (refer to Figures 9 to 12 ) does not have a free mode in which the first member 71 and the second member 72 can rotate relative to each other in two directions. That is, as Figure 17As shown in (A) of FIG. , the rotation transmission state switching device 41 only has: a locking mode in which the first member 71 and the second member 72 cannot rotate relative to each other; a one-way clutch mode that only allows rotation of the first member 71 relative to the second member 72 in a predetermined direction. Specifically, it is configured such that by adjusting the circumferential setting position and the circumferential length of the protrusion 96 of the selection plate 77, the rotation transmission state switching device 41 can be switched between the two modes of the locking mode and the one-way clutch mode.

[0234] Regarding the two-stage transmission 1 of the first example of the modification, similar to the two-stage transmission of the first example of the embodiment, one drive cam 50 is rotationally driven by one electric actuator 58, so that the high reduction ratio mode, the reduction ratio switching mode, the low reduction ratio mode, and the neutral mode can be switched.

[0235] In this modification, the low reduction ratio mode is achieved by connecting the friction engagement device 40 and setting the rotation transmission state switching device 41 to the one-way clutch mode. That is, in the reduction ratio switching mode, after the friction engagement device 40 is switched from the disengaged state to the engaged state, the rotation transmission state switching device 41 is maintained in the one-way clutch mode. Here, in the state where the rotation transmission state switching device 41 is in the one-way clutch mode, rotation of the first member 71 in a predetermined direction is allowed. Therefore, when the input member 2 rotates in the forward rotation direction, the rotation directions and rotation speeds of the sun gear 11, the ring gear 12, and the carrier 13 are the same, and the entire planetary gear mechanism 4 rotates integrally, and the power of the input member 2 is directly transmitted to the output member 3 without being decelerated.

[0236] In addition, by disconnecting the friction engagement device 40 and setting the rotation transmission state switching device 41 to the one-way clutch mode, when the two-stage transmission 1 is switched to the neutral mode, rotation in the predetermined direction is not transmitted between the input member 2 and the output member 3.

[0237] On the other hand, the rotation transmission state switching device 41 of the second example of the modification does not have a locking mode in which the first member 71 and the second member 72 cannot rotate relative to each other. That is, the rotation transmission state switching device 41 only has: a free mode in which the first member 71 and the second member 72 can rotate relative to each other in two directions; a one-way clutch mode that only allows rotation of the first member 71 relative to the second member 72 in a predetermined direction. Specifically, it is configured such that by adjusting the circumferential setting position and the circumferential length of the protrusion 96 of the selection plate 77, the rotation transmission state switching device 41 can be switched between the two modes of the free mode and the one-way clutch mode.

[0238] Regarding the two-stage transmission 1 of the second example of the modification, similar to the two-stage transmission of the first example of the embodiment and the two-stage transmission of the first example of the modification, one drive cam 50 is rotationally driven by one electric actuator 58, so that the high reduction ratio mode, the reduction ratio switching mode, the low reduction ratio mode, and the neutral mode can be switched.

[0239] In this modification, the high reduction ratio mode is achieved by cutting off the friction engagement device 40 and setting the rotation transmission state switching device 41 to the one-way clutch mode. That is, in the state where the rotation transmission state switching device 41 is in the one-way clutch mode, the rotation of the first component 71 in the direction opposite to the predetermined direction is blocked. Therefore, in the state where the input component 2 rotates in the forward rotation direction, the sun gear 11 and the planet carrier 13 can rotate relative to each other, and the rotation of the ring gear 12 relative to the housing 38 is blocked. Therefore, the power of the input component 2 is decelerated by the planetary gear mechanism 4 and transmitted to the output component 3.

[0240] When switching the two-stage transmission 1 from the high reduction ratio mode to the low reduction ratio mode, the rotation transmission state switching device 41 is kept in the one-way clutch mode, and the tightening force of the friction engagement device 40 is started to increase, so that the reduction ratio switching mode can be switched. And when the connection of the friction engagement device 40 is completed and the rotation transmission state switching device 41 is in the free mode, the two-stage transmission 1 can be switched to the low reduction ratio mode.

[0241] In addition, by cutting off the friction engagement device 40 and setting the rotation transmission state switching device 41 to the one-way clutch mode, when the two-stage transmission 1 is switched to the neutral mode, the rotation in the predetermined direction is not transmitted between the input component 2 and the output component 3.

[0242] Regarding the first and second examples of the modification of the first example of the above-described embodiment, by switching the friction engagement device 40 between the connected state and the cut-off state and switching the rotation transmission state switching device 41 between two modes, the two-stage transmission 1 can be switched to the high reduction ratio mode, the reduction ratio switching mode, the low reduction ratio mode, and the neutral mode. Therefore, compared with the two-stage transmission 1 of the first example of the embodiment, the two-stage transmission 1 of the first and second examples of the modification can simplify the control. The structures and functions of other parts are the same as those of the first example of the embodiment.

[0243] [Second Example of the Embodiment]

[0244] Refer to Figures 18 to 20A second example of the embodiment of the present invention will be described. The transmission path switching device 5a in this example includes a speed reducer 102 that reduces the rotational speed of the drive cam 50a and transmits it to the selection plate 77a between the drive cam 50a and the selection plate 77a. That is, the transmission path switching device 5a in this example does not include the engagement pin 52 provided between the drive cam 50 and the selection plate 77 as in the first example of the embodiment, and is configured to be able to transmit the rotation of the drive cam 50a to the selection plate 77a via the speed reducer 102.

[0245] The speed reducer 102 includes: a cam side gear portion 103 provided on the drive cam 50a, a plate side gear portion 104 provided on the selection plate 77a, and a two-stage gear 105.

[0246] The drive cam 50a includes: a base portion 106 configured to be substantially in the shape of an annular plate and having a drive cam surface 54 in a radially inner portion on the other axial side surface, and a cylindrical portion 107 protruding integrally toward the other axial side from a radially intermediate portion on the other axial side surface of the base portion 106. In addition, the drive cam 50a has the cam side gear portion 103 integrally on the outer peripheral surface of the cylindrical portion 107.

[0247] The selection plate 77a includes: a stepped cylindrical base portion 127, and an annular convex portion 91 protruding integrally toward the other axial side from a radially intermediate portion on the other axial side surface of the base portion 127. The base portion 127 has a small diameter portion 128 on one axial side and a large diameter portion 129 on the other axial side. In this example, the selection plate 77a has the plate side gear portion 104 integrally on the outer peripheral surface of the small diameter portion 128. In this example, the plate side gear portion 104 has a larger pitch diameter compared to the pitch diameter of the cam side gear portion 103, and has a larger number of teeth compared to the number of teeth of the cam side gear portion 103.

[0248] The two-stage gear 105 has: a first gear portion 108 meshing with the cam side gear portion 103, and a second gear portion 109 meshing with the plate side gear portion 104. The first gear portion 108 has a larger pitch diameter than the pitch diameter of the second gear portion 109, and has a larger number of teeth than the number of teeth of the second gear portion 109. The two-stage gear 105 in this example includes: a central shaft 110 supported relative to the housing 38a; and a main body portion 111 having the first gear portion 108 integrally on the outer peripheral surface of the one axial side portion and having the second gear portion 109 integrally on the outer peripheral surface of the other axial side portion, and being supported around the central shaft 110 so as to be rotatable freely.

[0249] According to the transmission path switching device 5a in this example, even without using a particularly high-output speed-changing motor 60, it is possible to sufficiently ensure the allowable load torque of the rotation transmission state switching device 41a. The reason for this will be described by comparing with the transmission path switching device 5 of the first example of the embodiment.

[0250] Regarding the transmission path switching device 5 of the first example of the embodiment, in order to fully ensure the allowable load torque of the rotation transmission state switching device 41, it is effective to increase the number of the first claw members 73 and the second claw members 74. However, when the number of the first claw members 73 and the second claw members 74 is increased, the rotation angle of the drive cam 50 when switching between the first mode and the second mode is reduced. Even if the rotation angle of the drive cam 50 at the time of mode switching is reduced, in order to fully ensure the displacement amount (stroke) in the axial direction of the driven cam 51 and thereby fully ensure the fastening force of the friction engagement device 40, it is necessary to increase the inclination angle (lead angle) of the drive cam surface 54 and / or the driven cam surface 62 with respect to the virtual plane orthogonal to the central axis of the cam device 39. However, when the inclination angle of the drive cam surface 54 and / or the driven cam surface 62 is increased, in order to smoothly roll the rolling elements 64 between the drive cam surface 54 and the driven cam surface 62, it is necessary to use a variable-speed motor 60 with a higher output.

[0251] In contrast, the transmission path switching device 5a of this example includes a speed reducer 102 between the drive cam 50a and the selection plate 77a. Therefore, the rotation angle of the selection plate 77a per rotation of the drive cam 50a can be made smaller than the rotation angle of the driven cam 51 per rotation of the drive cam 50a. Therefore, in order to fully ensure the allowable load torque of the rotation transmission state switching device 41a, even when the number of the first claw members 73 and the second claw members 74 is increased, it is not necessary to increase the inclination angle of the drive cam surface 54 and / or the driven cam surface 62 in order to fully ensure the displacement amount in the axial direction of the driven cam 51. In short, it is not necessary to use a variable-speed motor 60 with a particularly high output. Regarding the structure and the function and effect of other parts, they are the same as those of the first example of the embodiment.

[0252] [Third Example of the Embodiment]

[0253] Refer to Figure 21 and Figure 22 The third example of the embodiment of the present invention will be described. Similar to the transmission path switching device 5a of the second example of the embodiment, the transmission path switching device 5d of this example includes a speed reducer 102b that reduces the rotational speed of the drive cam 50d and transmits it to the selection plate 77d.

[0254] The speed reducer 102b includes: a cam side gear portion 103a provided on the drive cam 50d, a plate side gear portion 104a provided on the selection plate 77d, and a two-stage gear 105.

[0255] The drive cam 50b is configured to be substantially in the shape of an annular plate, and has a cam-side gear portion 103a on a part of its outer peripheral surface. Specifically, the drive cam 50b has a small-diameter portion 130 with an outer diameter smaller than the rest in a part in the circumferential direction (a range of about 2 / 3 of the entire circumference), and has a cam-side gear portion 103a on a part of the outer peripheral surface of the small-diameter portion 130 (a range of about 1 / 2 of the length dimension in the circumferential direction).

[0256] The selection plate 77d has: an annular plate-shaped base portion 94a, and an annular convex portion 91 that projects integrally toward the other axial side from a radially intermediate portion on the other axial side surface of the base portion 94a. In addition, the selection plate 77d has a partial cylindrical portion 131 that projects toward the axial side from a part in the circumferential direction (a range of about 1 / 3 of the entire circumference) in the radially intermediate portion on the axial one side surface of the base portion 94a, and has a plate-side gear portion 104a on the radially outer side surface (outer peripheral surface) of the partial cylindrical portion 131.

[0257] The two-stage gear 105 has: a first gear portion 108 that meshes with the cam-side gear portion 103a, and a second gear portion 109a that meshes with the plate-side gear portion 104.

[0258] Similar to the transmission path switching device 5a of the second example of the embodiment, the transmission path switching device 5d according to this example can make the rotation angle of the selection plate 77d per revolution of the drive cam 50d smaller than the rotation angle of the driven cam 51 per revolution of the drive cam 50d. In addition, regarding the transmission path switching device 5d of this example, the drive cam 50d is reciprocally rotated by the electric actuator 58 to switch the mode.

[0259] In addition, in this example, a pair of snap rings 101a, 101b that are fixed to the inner peripheral surface of the outer diameter side cylindrical portion 43 of the housing 38 are used to clamp the second member 72 and the selection plate 77d from both axial sides. That is, the outer peripheral surface of the selection plate 77d is fitted into the inner peripheral surface of the outer diameter side cylindrical portion 43 so as to be relatively rotatable, and the radially outer portion on the axial one side surface of the selection plate 77d is slidably abutted against the snap ring 101b on the axial one side. The second member 72 spline-engages the outer spline portion 82 provided on the outer peripheral surface with the fixed-side inner spline portion 46 of the housing 38, and the axial one side surface of the base portion 83 is in sliding contact with or close to and opposed to the radially outer portion of the base portion 94a of the selection plate 77d. In this state, the radially outer portion on the other axial side surface of the second member 72 is abutted against the snap ring 101a on the other axial side.

[0260] In summary, in this example, the rotation transmission state switching device 41d does not have the cover body 98 and the snap ring 99 that the rotation transmission state switching device 41a of the second example of the embodiment has. Therefore, compared with the structure of the second example of the embodiment, the number of parts can be reduced. The structures and functions of other parts are the same as those of the first and second examples of the embodiment.

[0261] [Fourth Example of the Embodiment]

[0262] Refer to Figures 23 to 27 The fourth example of the embodiment of the present invention will be described. The transmission path switching device 5b in this example includes a speed reducer 102a between the drive cam 50b and the selection plate 77b. The speed reducer 102a includes: a cam-side groove 112 provided in the drive cam 50b, a plate-side groove 113 provided in the selection plate 77b, a guide plate 114, and a plurality (three in the illustrated example) of engagement pins 115.

[0263] The cam-side groove 112 is formed at multiple locations (three in the illustrated example) in the circumferential direction on the other axial side of the radially outer portion of the drive cam 50b so as to extend in a direction of moving radially outward as it moves toward the circumferential direction side when viewed from the other axial side. On the other hand, the plate-side groove 113 is formed at multiple locations (three in the illustrated example) in the circumferential direction on the one axial side of the selection plate 77b so as to extend in a direction of moving radially outward as it moves toward the circumferential direction side when viewed from the one axial side. In other words, the cam-side groove 112 extends in a direction of moving radially outward as it moves toward one side in the rotation direction of the drive cam 50b and the selection plate 77b, while the plate-side groove 113 extends in a direction of moving radially inward as it moves toward one side in the rotation direction of the drive cam 50b and the selection plate 77b.

[0264] The cam-side groove 112 has the same radial length as the radial length (the amount of elongation in the radial direction) of the plate-side groove 113, and has a longer circumferential length (the amount of elongation in the circumferential direction) than the circumferential length of the plate-side groove 113.

[0265] The guide plate 114 has guide grooves 116 that extend radially at multiple locations (three in the illustrated example) in the circumferential direction. Specifically, the guide plate 114 is configured to be substantially annular and has an external spline portion 117 over the entire outer peripheral surface, and has convex portions 118 that project radially inward at multiple locations in the circumferential direction on the inner peripheral surface. In addition, the guide plate 114 has guide grooves 116 that open to the radially inner side surface and both axial side surfaces and extend radially at the circumferential center positions of the respective convex portions 118. The guide grooves 116 have the same radial length as the radial length of the cam-side groove 112 and the radial length of the plate-side groove 113.

[0266] The guide plate 114 is axially disposed (clamped) between the drive cam 50b and the selection plate 77b, and is supported so as not to rotate relative to the housing 38 by spline-engaging the external spline portion 117 with the fixed-side internal spline portion 46 of the housing 38.

[0267] As Figure 27 shown, each engagement pin 115 has a first engagement portion 119 at one end in the axial direction, a second engagement portion 120 at the other end in the axial direction, and a third engagement portion 121 at the axial intermediate portion.

[0268] The first engagement portion 119 engages with the cam-side groove 112 of the drive cam 50b so as to be displaceable along the cam-side groove 112.

[0269] The second engagement portion 120 engages with the plate-side groove 113 of the selection plate 77b so as to be displaceable along the plate-side groove 113.

[0270] The third engagement portion 121 engages with the guide groove 116 of the guide plate 114 so as to be displaceable along the guide groove 116.

[0271] To switch the transmission path switching device 5b to the first mode, the drive cam 50b is rotationally driven by the electric actuator 58, thereby connecting the friction engagement device 40 and switching the rotational transmission state switching device 41b to the free mode. In this example, by engaging the engagement pin 115 as Figure 26 shown in (A), with the radially outer portion of the cam-side groove 112, the radially outer portion of the plate-side groove 113, and the radially outer portion of the guide groove 116, the rotational transmission state switching device 41b is switched to the free mode. In the state shown in (A) of Figure 26 , the first engagement claw 90 and the second engagement claw 93 are lifted radially outward by the protrusion 96 of the selection plate 77b and do not engage with the engagement recess 78 of the first member 71.

[0272] To switch the transmission path switching device 5b to the second mode, the drive cam 50b is rotationally driven by the electric actuator 58, thereby disconnecting the friction engagement device 40 and switching the rotational transmission state switching device 41b to the locked mode. In this example, by engaging the engagement pin 115 as Figure 26 shown in (B), with the radially inner portion (the other portion in the rotational direction) of the cam-side groove 112, the radially inner end portion (the one portion in the rotational direction) of the plate-side groove 113, and the radially inner end portion of the guide groove 116, the rotational transmission state switching device 41b is switched to the locked mode. When Figure 26In the state shown in (B), the protrusion 96 of the selection plate 77b is located at a portion offset in the circumferential direction from the first engaging claw 90 and the second engaging claw 93, and the first engaging claw 90 and the second engaging claw 93 are engaged with the engaging recess 78 of the first member 71.

[0273] In the intermediate mode of the transmission path switching device 5b established during the switching from the second mode to the first mode, the rotation transmission state switching device 41b is switched to the one-way clutch mode. In this example, by making the engaging pin 115 as Figure 26 shown in (C), engage with the radial intermediate portion (intermediate portion in the rotational direction) of the cam side groove 112, the radial intermediate portion (intermediate portion in the rotational direction) of the plate side groove 113, and the radial intermediate portion of the guide groove 116, the rotation transmission state switching device 41b is switched to the one-way clutch mode. When Figure 26 in the state shown in (A), the protrusion 96 of the selection plate 77b is used to lift only the second engaging claw 93 toward the radially outer side, only the first engaging claw 90 is engaged with the engaging recess 78 of the first member 71, and the second engaging claw 93 is not engaged with the engaging recess 78.

[0274] That is, regarding the transmission path switching device 5b of this example, when the drive cam 50b is rotationally driven by the electric actuator 58, the engaging pin 115 moves radially by the engagement of the first engaging portion 119 with the cam side groove 112 of the drive cam 50b and the engagement of the third engaging portion 121 with the guide groove 116 of the guide plate 114. When the engaging pin 115 moves radially, the selection plate 77b is rotationally driven by the engagement of the second engaging portion 120 with the plate side groove 113 of the selection plate 77b. And, by adjusting the phase of the selection plate 77b in the circumferential direction, the protrusion 96 is used to lift the first engaging claw 90 and the second engaging claw 93 toward the radially outer side, or to release the lifting force, thereby switching the mode of the rotation transmission state switching device 41b.

[0275] In this example, the circumferential length of the cam side groove 112 is made longer than the circumferential length of the plate side groove 113, so that the rotation of the drive cam 50b is decelerated and transmitted to the selection plate 77b. Therefore, according to the transmission path switching device 5b of this example, even without using a particularly high-output speed-changing motor 60, it is possible to sufficiently ensure the allowable load torque of the rotation transmission state switching device 41b.

[0276] In addition, regarding the transmission path switching device 5b of this example, unlike the transmission path switching device 5a of the second example of the embodiment, the two-stage gear 105 is not arranged on the radially outer side of the drive cam 50a and the selection plate 77a. Therefore, the outer diameter dimension of the transmission path switching device 5b of this example can be more easily suppressed to be smaller than that of the transmission path switching device 5a of the second example of the embodiment. The structures and functions of other parts are the same as those of the first and second examples of the embodiment.

[0277] [Fifth Example of the Embodiment]

[0278] Refer to Figures 28 to 32 The fifth example of the embodiment of the present invention will be described. The transmission path switching device 5c of this example is configured such that the drive cam 50c is rotationally driven by the electric actuator 58, so that the selection plate 77c is displaced axially, thereby switching the mode of the rotational transmission state switching device 41c.

[0279] The selection plate 77c includes: a substrate portion 94a that is substantially in the shape of an annular plate, and a cylindrical portion 122 that projects integrally in the circumferential direction from an end portion on the radially inner side of the axially one side surface of the substrate portion 94a. In addition, the selection plate 77c has an engagement groove 123 that includes an inclined portion inclined with respect to the circumferential direction, integrally formed on the outer circumferential surface of the cylindrical portion 122.

[0280] In addition, on the radially intermediate portion of the axially other side surface of the substrate portion 94a, in the circumferential direction, a plurality of protruding portions 96a having a longer axial length and protruding portions 96b having a shorter axial length are alternately arranged. The front end portion of the protruding portion 96a having a longer axial length faces the second engaging claw 93 of the second claw member 74, and the front end portion of the protruding portion 96b having a shorter axial length faces the first engaging claw 90 of the first claw member 73. In this example, the protruding portions 96a and 96b, each being plural, constitute a mode selection portion.

[0281] The drive cam 50c includes: a base portion 106a that is configured to be substantially in the shape of an annular plate and has a drive cam surface 54 on the radially inner portion of the axially other side surface, and a cylindrical portion 124 that projects integrally in the axial direction from the radially outer portion of the axially other side surface of the base portion 106a. In addition, the drive cam 50c has an engagement hole 125 that penetrates in the radial direction in the cylindrical portion 124.

[0282] Regarding the transmission path switching device 5c of this example, the radial middle part of the cylindrical engagement pin 126 is snugly fitted into the engagement hole 125 of the drive cam 50c, and the end portion on the radially inner side of the engagement pin 126 is engaged with the engagement groove 123 of the selection plate 77c so as to be displaceable along the engagement groove 123. Therefore, regarding the transmission path switching device 5c of this example, when the drive cam 50c is rotationally driven by the electric actuator 58, the selection plate 77c is axially moved by the engagement between the end portion on the radially inner side of the engagement pin 126 and the engagement groove 123.

[0283] In this example, when the rotation transmission state switching device 41c is switched to the free mode in order to switch the transmission path switching device 5c to the first mode, the selection plate 77c is moved toward the other side in the axial direction. As a result, the second engagement claw 93 is lifted toward the radially outer side against the elastic force of the second claw biasing member 76 by the protruding portion 96a having a longer axial length, and the first engagement claw 90 is lifted toward the radially outer side against the elastic force of the first claw biasing member 75 by the protruding portion 96b having a shorter axial length. As a result, the engagement recess 78 of the first member 71 is disengaged from the engagement with the first engagement claw 90 and the second engagement claw 93, and rotation of the first member 71 relative to the second member 72 is permitted regardless of the relative rotation direction of the first member 71 and the second member 72.

[0284] When the rotation transmission state switching device 41c is switched to the locked mode in order to switch the transmission path switching device 5c to the second mode, the selection plate 77c is moved toward one side in the axial direction. As a result, the protruding portion 96a having a longer axial length is retracted to a portion axially offset from the second engagement claw 93, and the protruding portion 96b having a shorter axial length is retracted to a portion axially offset from the first engagement claw 90. As a result, the engagement recess 78 of the first member 71 is engaged with the first engagement claw 90 and the second engagement claw 93 (see Figure 12 ), and rotation of the first member 71 relative to the second member 72 is prevented regardless of the relative rotation direction of the first member 71 and the second member 72.

[0285] In the intermediate mode of the transmission path switching device 5c established during the switching from the second mode to the first mode, only the second engagement claw 93 is lifted toward the radially outer side against the elastic force of the second claw biasing member 76 by the protruding portion 96a having a longer axial length. As a result, the engagement recess 78 of the first member 71 is engaged with the first engagement claw 90, and the engagement between the engagement recess 78 and the second engagement claw 93 is disengaged. As a result, only rotation of the first member 71 in a predetermined direction relative to the second member 72 is permitted, and rotation in the direction opposite to the predetermined direction is prevented. The structures and functions of other parts are the same as those of the first example of the embodiment.

[0286] [Sixth Example of Embodiment]

[0287] Refer to Figures 33 to 35 The sixth example of the embodiment of the present invention will be described. Regarding the transmission path switching device 5e of this example, the structure of the cam device 39e is different from that of the cam device 39 in the first example of the embodiment. The cam device 39e includes: a drive cam 50e, a driven cam 51c, a plurality (five in the illustrated example) of engagement pins 52, and a plurality (three in the illustrated example) of rolling elements 64a. In particular, in this example, rollers are used as the rolling elements 64a that constitute the cam device 39e. The rolling element 64a has a rotation axis C in the radial direction centered on the central axis of the driven cam 51c, and the driven cam 51c is supported so as to be freely rotatable (self-rotatable) about the rotation axis C.

[0288] The drive cam 50e is configured as a hollow circular plate shape, and has a drive cam surface 54a in which the number of concave portions and convex portions is the same and they are alternately arranged in the circumferential direction in the radially inner portion on the other axial side. In addition, the drive cam 50e has cam-side engagement holes 56 that open to the other axial side at multiple equally spaced positions in the circumferential direction in the radially outer portion, and has a gear portion 57 on the outer peripheral surface. The drive cam 50e is supported on the outer peripheral surface of the end portion on one axial side of the inner diameter side cylindrical portion 42 of the housing 38 so as to be freely rotatable via an angular contact ball bearing 53 and not axially displaceable.

[0289] The driven cam 51c is configured as a hollow circular plate shape, and has a plurality (three at equally spaced positions in the circumferential direction in the illustrated example) of rectangular holes 132 penetrating in the axial direction in the circumferential direction in the radially outer portion, and has substantially semi-circular plate-shaped support plate portions 133a, 133b protruding from both radially inner and outer portions of each rectangular hole 132 toward one axial side. Among the support plate portions 133a, 133b, the radially outer support plate portion 133a has a circular hole penetrating in the radial direction, that is, a support hole 134, and the radially inner support plate portion 133b has a support recess 135 having a circular opening on the radially outer surface.

[0290] The driven cam 51c is supported so as to be axially displaceable only relative to the housing 38 by spline-engaging the driven-side internal spline portion 63 provided on the inner peripheral surface with the fixed-side external spline portion 45 of the housing 38.

[0291] Each engagement pin 52 has its end portion on one axial side non-loosely embedded in the cam-side engagement hole 56 of the drive cam 50e, so that the other axial side portion protrudes from the other axial side surface of the drive cam 50e toward the other axial side. The end portion on the other axial side of each engagement pin 52 is embedded in a plate-side engagement hole 95 provided on the one axial side surface of the substrate portion 94 constituting the selection plate 77.

[0292] Each rolling element 64a has a cylindrical shape and is supported by a cylindrical support shaft 136 and a plurality of rollers 137 so as to be freely rotatable with respect to the support plate portions 133a and 133b of the driven cam 51c. That is, the end portion on one axial side of the support shaft 136 (the end portion on the outer side in the radial direction centered on the central axis of the driven cam 51c) is fitted and fixed in the support hole 134 of the radially outer support plate portion 133a, and the end portion on the other axial side of the support shaft 136 (the end portion on the inner side in the radial direction centered on the central axis of the driven cam 51c) is fitted and fixed in the support recess 135 of the radially inner support plate portion 133b. The plurality of rollers 137 are clamped between the inner peripheral surface of the rolling element 64a and the outer peripheral surface of the intermediate portion in the axial direction of the support shaft 136 so as to be freely rollable. Thus, the rolling element 64a is supported by the driven cam 51c so as to be freely rotatable about the rotation axis C in the radial direction centered on the central axis of the driven cam 51c (self-rotation).

[0293] In addition, in a state where the rolling element 64a is supported by the driven cam 51c, the portion on the other axial side of the rolling element 64a is disposed inside the rectangular hole 132. Further, each rolling element 64a has its outer peripheral surface in rolling contact with the drive cam surface 54a provided on the other axial side surface of the drive cam 50e.

[0294] According to this example as described above, by rotating the drive cam 50e, the driven cam 51c can be reliably displaced in the axial direction. That is, regarding the cam device 39 of the first example of the embodiment, since a sphere is used as the rolling element 64, when the drive cam 50 rotates, slippage may occur at the rolling contact portion between the surface of the rolling element 64 and the drive cam surface 54 and / or the driven cam surface 62. When slippage occurs at the rolling contact portion between the surface of the rolling element 64 and the drive cam surface 54 and / or the driven cam surface 62, it may cause the driven cam 51 to be unable to be displaced in the axial direction, or the axial displacement amount of the driven cam 51 with respect to the rotation amount of the drive cam 50 may not be sufficiently ensured.

[0295] In contrast, in this example, a roller having a cylindrical shape is used as the rolling element 64a, and the rolling element 64a is supported by the driven cam 51c so as to be freely rotatable and does not rotate during use. Therefore, when the drive cam 50e rotates, slippage at the rolling contact portion between the outer peripheral surface of the rolling element 64a and the drive cam surface 54a can be effectively prevented, and by rotating the drive cam 50e, the driven cam 51c can be reliably displaced in the axial direction. As a result, the disconnection and connection states of the friction engagement device 40 can be reliably switched, and thus the mode switching of the transmission path switching device 5e can be reliably performed. The structures and functions of the other parts are the same as those of the first example of the embodiment.

[0296] [Seventh Example of Embodiment]

[0297] Use Figures 36 to 38 A seventh example of the embodiment of the present invention will be described. Regarding the transmission path switching device 5f of this example, the drive cam 50f has a concavo-convex portion 97a that constitutes a mode selection portion for switching the mode of the rotation transmission state switching device 41e. That is, the drive cam 50f integrally has, as in the first example of the embodiment: the drive cam 50 that constitutes the cam device 39, and the selection plate 77 that constitutes the rotation transmission state switching device 41.

[0298] The drive cam 50f is configured as a hollow circular plate shape, and has a drive cam surface 54a in which the number of concave portions and convex portions is the same and they are alternately arranged in the circumferential direction in the radially inner portion on the other axial side surface, and has a gear portion 57 on the outer peripheral surface. In addition, the drive cam 50f has an annular convex portion 91a that projects integrally toward the other axial side in the radially outer portion on the other axial side surface.

[0299] The annular convex portion 91a has concave portions 138 that are recessed radially inward at multiple locations in the circumferential direction on the other axial side portion of the outer peripheral surface, and portions between adjacent concave portions 138 in the circumferential direction project radially outward more than the portions adjacent in the circumferential direction on both sides. That is, the annular convex portion 91a has a concavo-convex portion 97a in which the concave portions 138 and the projecting portions 96c are alternately arranged in the circumferential direction on the outer peripheral surface of the other axial side portion. The concavo-convex portion 97a constitutes a mode selection portion for switching the mode of the rotation transmission state switching device 41e in the same manner as the concavo-convex portion 97 of the first example of the embodiment.

[0300] In addition, in this example, the second member 72a that constitutes the rotation transmission state switching device 41e does not have a cylindrical portion 84 as in the second member 72 of the first example of the embodiment. That is, in this example, the second member 72a is composed only of a base portion 83 having a rectangular cross-sectional shape. The base portion 83 has first holding concave portions 85 and second holding concave portions 86 that are alternately arranged in the circumferential direction.

[0301] The drive cam 50f is supported on the outer peripheral surface of the end portion on the one axial side of the inner diameter side cylindrical portion 42 of the housing 38 so as to be freely rotatable via an angular contact ball bearing 53 and not axially displaceable. In a state where the drive cam 50f is supported relative to the housing 38, the annular convex portion 91a provided on the drive cam 50f is disposed radially inward of the portion on the one axial side of the base portion 83 of the second member 72a, and the front end surface (the other axial side surface) of the annular convex portion 91a is in sliding contact or close opposition to the one axial side surface of the first member 71 that constitutes the rotation transmission state switching device 41e.

[0302] The second component 72a is supported and fixed relative to the housing 38 so as not to be rotatable and axially displaced relative to each other. Specifically, an external spline portion 82 provided on the outer peripheral surface of the second component 72a is spline-engaged with a fixed-side internal spline portion 46 provided on the inner peripheral surface of the outer diameter side cylindrical portion 43 of the housing 38, and a pair of snap rings 101a, 101c that are clamped to the inner peripheral surface of the outer diameter side cylindrical portion 43 of the housing 38 are used to clamp the second component 72a and the cover body 98 that is supported and fixed on the other axial side surface of the second component 72a from both axial sides.

[0303] In this example, as the snap ring 101c on the axial one side among the pair of snap rings 101a, 101c, a snap ring having an inner diameter smaller than the outer circumferential diameter of the depth end portion (radial outer end portion) of the first holding recess 85 and the second holding recess 86 provided in the second component 72a and larger than the inner diameter of the second component 72a is used. Therefore, the radially outer portion in the opening on the other axial side of the first holding recess 85 and the second holding recess 86 is covered by the radially inner portion of the snap ring 101c on the axial one side. Thereby, the first claw member 73 and the first claw biasing member 75 held in the first holding recess 85, and the second claw member 74 and the second claw biasing member 76 held in the second holding recess 86 are prevented from falling off from the opening on the other axial side of the first holding recess 85 and the second holding recess 86. Figure 11 and Figure 12 )

[0304] In addition, as the snap ring 101c on the axial one side, a snap ring having an inner diameter larger than the outer circumferential diameter of the depth end portion of the first holding recess 85 and the second holding recess 86 provided in the second component 72a is used, and a washer having an inner diameter smaller than the outer circumferential diameter of the depth end portion of the first holding recess 85 and the second holding recess 86 and larger than the inner diameter of the second component 72a can also be clamped between the snap ring 101c on the axial one side and the second component 72a.

[0305] Regarding the transmission path switching device 5f of this example, the drive cam 50f is provided with a concavo-convex portion 97a that constitutes a mode selection portion for switching the mode of the rotation transmission state switching device 41e. Therefore, compared with the structure in which the concavo-convex portion 97 that constitutes the mode selection portion is provided on the selection plate 77 that is separate from the drive cam 50 as in the first example of the embodiment, the number of parts can be reduced, and the manufacturing cost can be easily reduced. The structures and functions of the other parts are the same as those of the first example and the sixth example of the embodiment.

[0306] For the structures of the first example to the seventh example of the above embodiment, they can be appropriately combined and implemented on the premise of no contradiction.

[0307] Description of reference numerals

[0308] 1—Two-stage transmission; 2—Input component; 3—Output component; 4—Planetary gear mechanism; 5, 5a, 5b, 5c, 5d, 5e, 5f, 5z—Transmission path switching device; 6—Input cylindrical part; 7—Input flange part; 8—Internal spline part; 9—Output cylindrical part; 10—Output flange part; 11—Sun gear; 12—Ring gear; 13—Planet carrier; 14—Pinion; 15—Small-diameter cylindrical part; 16—Large-diameter cylindrical part; 17—Flange part; 18—External spline part on the sun gear side; 19—Gear part; 20—Small-diameter cylindrical part; 21—Large-diameter cylindrical part; 22—Ring part; 23—External spline part on the ring gear side; 24—Gear part; 25a, 25b—Rim part; 26—Column part; 27—Cylindrical part; 28a, 28b—Round hole; 29—Internal spline part on the planet carrier side; 30—Support shaft; 31—Main body part; 32—Radial needle bearing; 33—Gear part; 34a, 34b—Retaining ring; 35—Spacer part; 36a, 36b—Thrust bearing; 37—Pressure plate; 38—Housing; 39, 39a, 39z—Cam device; 40—Friction engagement device; 40a—First friction engagement device; 40b—Second friction engagement device; 41, 41a, 41b, 41c, 41d, 41e—Rotation transmission state switching device; 42—Inner diameter side cylindrical part; 43—Outer diameter side cylindrical part; 44—Side plate part; 45—Fixed side external spline part; 46—Fixed side internal spline part; 47—Through hole; 48—Radial needle bearing; 49—Thrust needle bearing; 50, 50a, 50b, 50c, 50d, 50e, 50f, 50z—Drive cam; 51, 51c—Driven cam; 51a—First driven cam; 51b—Second driven cam; 52—Engagement pin; 53—Angular contact ball bearing; 54, 54a—Drive cam surface; 56—Cam side engagement hole; 57—Tooth part; 58—Electric actuator; 59—Worm; 60—Variable speed motor; 61—Worm gear part; 62—Driven cam surface; 63—Driven side internal spline part; 64, 64a—Rolling element; 65, 65a—Friction plate; 66, 66a—Separation plate; 67—Retaining ring; 68—Elastic member; 69—Thrust rolling bearing; 70—Recovery spring; 71—First component; 72, 72a—Second component; 73—First claw component; 74—Second claw component; 75—First claw biasing member; 76—Second claw biasing member; 77, 77a, 77b, 77c, 77d—Selection plate; 78—Engagement recess; 79—Protrusion; 80—Convex-concave part; 81—Internal spline part; 82—External spline part; 83—Base part; 84—Cylindrical part; 85—First retaining recess; 86—Second retaining recess; 87a, 87b—Spring retaining part; 88a, 88b—Base part; 89—First base; 90—First engagement claw; 91, 91a—Annular protrusion; 92—Second base; 93—Second engagement claw; 94, 94a—Substrate part; 95—Plate side engagement hole; 96, 96a, 96b, 96c—Protrusion;97, 97a - Concave-convex part; 98 - Cover body; 99 - Retaining ring; 101a, 101b, 101c - Retaining ring; 102, 102a, 102b - Reducer; 103, 103a - Cam side gear part; 104, 104a - Plate side gear part; 105 - Two-stage gear; 106, 106a - Base part; 107 - Cylindrical part; 108 - First gear part; 109 - Second gear part; 110 - Central axis; 111 - Main body part; 112 - Cam side groove; 113 - Plate side groove; 114 - Guide plate; 115 - Engaging pin; 116 - Guide groove; 117 - External spline part; 118 - Convex part; 119 - First engaging part; 120 - Second engaging part; 121 - Third engaging part; 122 - Cylindrical part; 123 - Engaging groove; 124 - Cylindrical part; 125 - Engaging hole; 126 - Engaging pin; 127 - Base part; 128 - Small diameter part; 129 - Large diameter part; 130 - Small diameter part; 131 - Partial cylindrical part; 132 - Rectangular hole; 133a, 133b - Support plate part; 134 - Support hole; 135 - Support concave part; 136 - Support shaft; 137 - Roller; 138 - Concave part.;

Claims

1. A transmission path switching device, characterized in that, Comprising: a cam device having a driving cam and a driven cam, the driving cam being supported so as to be rotatable and not axially displaceable, the driven cam being supported so as to be relatively rotatable and axially displaceable with respect to the driving cam, and being displaced axially as the driving cam rotates; and a friction engagement device having at least one friction plate and a separating plate supported so as to be axially relatively displaceable with respect to each other, the friction engagement device being configured such that, based on displacing the driven cam in a direction in which the axial interval from the driving cam is increased, the friction plate and the separating plate are pressed against each other for connection, and based on displacing the driven cam in a direction in which the axial interval from the driving cam is decreased, the force pressing the friction plate and the separating plate against each other is released for disconnection; further comprising a rotational transmission state switching device having: a first member and a second member coaxially arranged with each other; and a mode selection portion that rotates or is axially displaced as the driving cam rotates, the rotational transmission state switching device having at least one of a free mode and a locking mode, the free mode allowing rotation of the first member with respect to the second member regardless of the relative rotation direction between the first member and the second member, the locking mode being a locking mode that prevents rotation of the first member with respect to the second member regardless of the relative rotation direction between the first member and the second member; and a one-way clutch mode that only allows rotation of the first member with respect to the second member in a predetermined direction and prevents rotation of the first member with respect to the second member in a direction opposite to the predetermined direction, and being configured to be able to switch between at least one of the free mode and the locking mode and the one-way clutch mode based on rotating or axially displacing the mode selection portion; In a state where the rotational transmission state switching device is in the one-way clutch mode, the friction engagement device is switched from the disconnection state to the connection state.

2. The transmission path switching device according to claim 1, wherein: it has a first mode in which the friction engagement device is connected and the rotational transmission state switching device is in the free mode.

3. The transmission path switching device according to claim 1 or 2, wherein: it has a second mode in which the friction engagement device is disconnected and the rotational transmission state switching device is in the locking mode.

4. The transmission path switching device according to claim 1 or 2, wherein: it has a neutral mode in which the friction engagement device is disconnected and the rotational transmission state switching device is in the free mode.

5. The transmission path switching device according to claim 1 or 2, wherein: one of the first member and the second member has engagement recesses at multiple locations in the circumferential direction. The mode selection section has protrusions protruding radially or axially at multiple positions in the circumferential direction. The rotation transmission state switching device further includes: A first claw member having a first base portion and a first engaging claw, the first base portion being pivotally supported by the other one of the first member and the second member, and the first engaging claw extending from the first base portion toward one side in the circumferential direction; A second claw member having a second base portion and a second engaging claw, the second base portion being pivotally supported by the other one of the first member and the second member, and the second engaging claw extending from the second base portion toward the other side in the circumferential direction; A first claw biasing member that elastically biases the first engaging claw in a direction to engage with the engaging recess; And A second claw biasing member that elastically biases the second engaging claw in a direction to engage with the engaging recess.

6. The transmission path switching device according to claim 1 or 2, characterized in that It further includes a selection plate having the mode selection section and rotating or displacing axially along with the rotation of the drive cam.

7. The transmission path switching device according to claim 6, characterized in that A speed reducer is further provided between the drive cam and the selection plate, and the speed reducer decelerates the rotational speed of the drive cam and transmits it to the selection plate.

8. The transmission path switching device according to claim 7, characterized in that The speed reducer includes: A cam side gear portion provided on the drive cam; A plate side gear portion provided on the selection plate; and A two-stage gear having a first gear portion meshing with the cam side gear portion and a second gear portion meshing with the plate side gear portion.

9. The transmission path switching device according to claim 7, characterized in that The speed reducer includes: A cam side groove provided on the drive cam and elongating in a direction toward the radially outer side as it goes toward one side in the rotational direction; A plate side groove provided on the selection plate and elongating in a direction toward the radially inner side as it goes toward one side in the rotational direction; And An engaging pin having a first engaging portion and a second engaging portion, the first engaging portion engaging with the cam side groove in a manner capable of displacing along the cam side groove, and the second engaging portion engaging with the plate side groove in a manner capable of displacing along the plate side groove, The circumferential direction length of the cam side groove is longer than the circumferential direction length of the plate side groove.

10. The transmission path switching device according to claim 9, characterized in that The speed reducer further includes a guide plate having a guide groove elongating radially and supported so as not to rotate, The engaging pin further has a third engaging portion that engages with the guide groove in a manner capable of displacing along the guide groove.

11. The transmission path switching device according to claim 5, characterized in that It further includes a selection plate having the mode selection section and rotating or displacing axially along with the rotation of the drive cam.

12. The transmission path switching device according to claim 11, characterized in that The protruding portion protrudes axially. The selection plate has an engaging groove that includes an inclined portion inclined with respect to the circumferential direction and extends in the circumferential direction. The drive cam has an engaging pin that protrudes radially and engages with the engaging groove in such a manner as to be displaceable along the engaging groove.

13. The transmission path switching device according to claim 1 or 2, characterized in that The drive cam has the mode selection portion.

14. The transmission path switching device according to claim 1 or 2, characterized in that An elastic member is further provided, which is disposed between the driven cam and the friction engaging device and elastically biases in a direction in which the driven cam and the friction engaging device are separated from each other.

15. The transmission path switching device according to claim 1 or 2, characterized in that The friction engaging device further has a return spring that elastically biases in a direction in which the friction plate and the separation plate are separated from each other.

16. The transmission path switching device according to claim 1 or 2, characterized in that The cam device includes a plurality of rollers that have a self-rotating shaft facing the radial direction and are clamped between the drive cam and the driven cam. The roller is supported by the driven cam so as to freely rotate about the self-rotating shaft.

17. A two-stage transmission, characterized in that, Comprising: An input member; An output member that is coaxially disposed with the input member; A planetary gear mechanism that is disposed between the input member and the output member in the power transmission direction; and A transmission path switching device that switches the transmission path between the input member and the output member. The transmission path switching device further includes an electric actuator, which is the transmission path switching device according to any one of claims 1 to 16 and rotationally drives the drive cam. The planetary gear mechanism includes: A sun gear that is connected to the input member so as to rotate integrally with the input member. A ring gear that is coaxially disposed around the sun gear. A planet carrier that is coaxially disposed with the sun gear and is connected to the output member so as to rotate integrally with the output member. And A plurality of pinions that mesh with the sun gear and the ring gear and are supported by the planet carrier so as to freely rotate about their own central axes. One of the friction plate and the separation plate is supported by the sun gear or the input member in such a manner as to be axially relatively displaceable and not relatively rotatable. The other of the friction plate and the separation plate is supported by the planet carrier or the output member in such a manner as to be axially relatively displaceable and not relatively rotatable. One of the first member and the second member is supported by a portion that does not rotate even during use in such a manner as to be not relatively rotatable. The other of the first member and the second member is supported by the ring gear in such a manner as to be not relatively rotatable.

18. The two-stage transmission according to claim 17, characterized in that The drive cam has a tooth portion on its outer peripheral surface. The electric actuator includes a worm that meshes with the tooth portion, and a speed-changing motor that rotationally drives the worm.

Images