Clutch mechanism and unit

Abstract

[Problem] To provide a structure that contributes to miniaturization of a clutch mechanism. [Solution] This clutch mechanism comprises: a first claw part that rotates about a first shaft; a second claw part that rotates about a second shaft; and a slide member that slides along the axial direction of the first shaft and the second shaft. The rotation angle of the first claw part and the rotation angle of the second claw part change as the sliding member slides along the axial direction.

Description

Clutch mechanism and unit

[0001] The present invention relates to a clutch mechanism and a unit including the clutch mechanism.

[0002] Patent Documents 1 to 3 disclose bicycle drive units equipped with clutch mechanisms.

[0003] JP 09-249181 JP 09-286371 JP 2008-174227

[0004] An object of the present invention is to provide a structure that contributes to making the clutch mechanism more compact.

[0005] According to one aspect of the present invention, the clutch mechanism comprises a first claw portion that rotates around a first axis, a second claw portion that rotates around a second axis, and a slide member that slides along the axial direction of the first axis and the second axis, and the rotation angle of the first claw portion and the rotation angle of the second claw portion change as the slide member slides along the axial direction.

[0006] According to one aspect of the present invention, the rotation angles of the multiple pawls change when a single slide member slides, eliminating the need for multiple slide members. This reduces the number of parts, providing a structure that contributes to making the clutch mechanism more compact.

[0007] FIG. 1 is a side view illustrating an outline of an electrically assisted bicycle to which a unit including a clutch mechanism according to an embodiment of the present invention is applied. FIG. 2 is a configuration diagram of the unit. FIG. 3 is a skeleton diagram of the unit. FIG. 4 is a diagram illustrating the meshing relationship of each gear in a planetary gear mechanism. FIG. 5 is a collinear diagram of the unit. FIG. 6 is a skeleton diagram illustrating the clutch mechanism and the planetary gear mechanism. FIG. 7 is a diagram illustrating the configuration of the clutch mechanism, showing a state in which power is being transmitted. FIG. 8 is a diagram illustrating the configuration of the clutch mechanism, showing a state in which power is not being transmitted. FIG. 9 is a diagram illustrating a state in which the gear position of the unit has been shifted to first gear. FIG. 10 is a diagram illustrating a state in which the gear position of the unit has been shifted to second gear. FIG. 11 is a diagram illustrating a state in which the gear position of the unit is being shifted from second gear to third gear. FIG. 12 is a diagram illustrating a state in which the gear position of the unit has been shifted to third gear. FIG. 13 is a diagram illustrating a first modified example of the clutch mechanism, showing a state in which the gear position of the unit has been shifted to second gear. Fig. 14 is a diagram illustrating a first modified example of the clutch mechanism, showing a state in which the gear position of the unit is switched to third gear. Fig. 15 is a diagram illustrating a second modified example of the clutch mechanism, showing a state in which the gear position of the unit is switched to second gear. Fig. 16 is a diagram illustrating a second modified example of the clutch mechanism, showing a state in which the gear position of the unit is switched to third gear.

[0008] Below, with reference to the drawings, we will explain an electric assist unit 100 as a unit equipped with a clutch mechanism 40 according to an embodiment of the present invention, and an electric assist bicycle (hereinafter simply referred to as a "bicycle") 1 to which the electric assist unit 100 is applied.

[0009] First, the overall configuration of a bicycle 1 will be described with reference to FIG.

[0010] FIG. 1 is a side view illustrating an outline of a bicycle 1 to which an electric assist unit 100 is applied.

[0011] As shown in Figure 1, the bicycle 1 comprises a frame 2, a front wheel 3a, a rear wheel 3b as a drive wheel, a handlebar 4, a saddle 5, a drive sprocket 6a, a driven sprocket 6b as a sprocket, a chain 6c, a pair of pedals 7, crank arms 7b as a pair of crank portions, a crankshaft 7c, a support shaft 8 as a fixed element, a controller 9a, a power storage unit 9b, and an electric assist unit 100.

[0012] The bicycle 1 is driven by a rider sitting astride the saddle 5 and pedaling the crank arms 7b via pedals 7. The bicycle 1 drives the rear wheel 3b with a pedaling force (driving torque) transmitted from the crank arms 7b to the crankshaft 7c, and a driving force (assist torque) from the electric assist unit 100, the magnitude of which corresponds to the pedaling force.

[0013] The frame 2 is a so-called diamond frame that is generally parallelogram-shaped in side view. A front wheel 3a and a rear wheel 3b are rotatably mounted on the frame 2. The frame 2 has a front fork 2a that supports the front wheel 3a.

[0014] The front wheel 3a is steered left and right by rotating the front fork 2a through the operation of the handlebars 4 by the rider.

[0015] The rear wheel 3b rotates around a support shaft 8. A driven sprocket 6b and an electric assist unit 100 are attached to the rear wheel 3b. The driven sprocket 6b corresponds to the input element.

[0016] The driving torque is transmitted to the driven sprocket 6b via a chain 6c that is wound around the driving sprocket 6a, to which the driving force from the crank arm 7b is input.

[0017] The electric assist unit 100 generates an assist torque according to the pedal force applied by the driver. The electric assist unit 100 can switch between three gears: a first gear (lowest gear), a second gear, and a third gear (highest gear). The electric assist unit 100 will be described in detail later.

[0018] The pedal 7 is used by the driver to input driving torque, and is connected to a crankshaft 7c via a crank arm 7b.

[0019] The support shaft 8 is attached to the frame 2. The support shaft 8 is provided so as to be unable to rotate relative to the frame 2.

[0020] The controller 9a is composed of a microcomputer equipped with a CPU, RAM, ROM, input / output interface, etc. The controller 9a can also be composed of multiple microcomputers. The controller 9a performs various processes by having the CPU read and execute programs stored in the ROM. Specifically, the controller 9a calculates an assist torque based on an electrical signal corresponding to the magnitude of the pedal depression force input from a torque sensor (not shown), which will be described later, and outputs a command signal so that the electric motor 90 generates the assist torque.

[0021] The power storage unit 9b is a rechargeable secondary battery such as a nickel-metal hydride battery or a lithium-ion battery, etc. The power storage unit 9b is provided so as to be detachable from the frame 2.

[0022] Next, the configuration of the electric assist unit 100 will be described with reference to FIGS.

[0023] Fig. 2 is a configuration diagram of the electric assist unit 100. Fig. 3 is a skeleton diagram of the electric assist unit 100. Fig. 4 is a diagram showing the meshing relationship of each gear in the planetary gear mechanism 30. Fig. 5 is a collinear diagram of the electric assist unit 100. Arrows in Fig. 2 indicate power transmission paths.

[0024] As shown in FIG. 2 , the electric assist unit 100 includes a case 10 , a speed change mechanism 20 , an electric motor 90 as a motor, and a reduction mechanism 91 .

[0025] The case 10 supports the rear wheel 3b rotatably relative to the support shaft 8. The case 10 is fixed to a ring gear 39 (described later) of the planetary gear mechanism 30. The case 10 corresponds to an output element.

[0026] The case 10 supports the rear wheel 3b rotatably relative to the support shaft 8. The rear wheel 3b is attached to the outer periphery of the case 10 via spokes (not shown). The case 10 supports the ring gear 39 of the planetary gear mechanism 30 rotatably relative to the support shaft 8 around the axis of the ring gear 39, and rotates together with the ring gear 39 relative to the support shaft 8. The case 10 rotates together with the rear wheel 3b relative to the support shaft 8 around the support shaft 8.

[0027] As shown in FIG. 3, the transmission mechanism 20 has a planetary gear mechanism 30, a low brake 31 as a first brake, a second brake 32 as a second brake, a clutch 33, and a clutch mechanism 40 (see FIG. 2).

[0028] The planetary gear mechanism 30 includes a small diameter sun gear 34, a large diameter sun gear 35, a short planetary gear 36 as a first planetary gear, a long planetary gear 37 as a second planetary gear, a carrier 38 as a shared carrier, and a ring gear 39.

[0029] 4, the planetary gear mechanism 30 has, as rotating elements, a small-diameter sun gear 34, a large-diameter sun gear 35, short planetary gears 36, long planetary gears 37, a carrier 38, and a ring gear 39. The planetary gear mechanism 30 functions as a so-called Ravigneaux-type planetary gear mechanism that has both a double pinion and a single pinion.

[0030] The carrier 38 rotatably supports the short planetary gears 36 and the long planetary gears 37. The short planetary gears 36 mesh with both the small-diameter sun gear 34 and the long planetary gears 37. The long planetary gears 37 mesh with the large-diameter sun gear 35 and the ring gear 39. The large-diameter sun gear 35 is adjacent to the small-diameter sun gear 34 in the axial direction. The long planetary gears 37 also mesh with the short planetary gears 36. The short planetary gears 36 and the long planetary gears 37 are arranged adjacent to each other in the circumferential direction and mesh with each other.

[0031] 3, the pedal force applied by the driver is input to the small diameter sun gear 34. The large diameter sun gear 35 has a larger diameter than the small diameter sun gear 34.

[0032] The short planetary gear 36 meshes with the small diameter sun gear 34. The long planetary gear 37 meshes with the short planetary gear 36 and also with the large diameter sun gear 35.

[0033] The carrier 38 connects the short planetary gear 36 and the long planetary gear 37 and supports them rotatably.

[0034] The ring gear 39 meshes with the long planetary gear 37. A case 10 (see FIG. 2) that supports the rear wheel 3b rotatably about the support shaft 8 is fixed to the ring gear 39.

[0035] Low brake 31 can lock the rotation of carrier 38. Second brake 32 can lock the rotation of large diameter sun gear 35. Clutch 33 connects small diameter sun gear 34 and carrier 38 in a detachable manner.

[0036] When the gear is switched to the first gear, which is the lowest gear, the low brake 31 fixes the carrier 38 to the support shaft 8, locking it so that it cannot rotate. The driving torque input from the driven sprocket 6b is transmitted from the small sun gear 34 to the short planetary gears 36, and from the short planetary gears 36 to the ring gear 39 via the long planetary gears 37. At this time, because the carrier 38 is locked so that it cannot rotate, the pedal force input from the small sun gear 34 is reduced in speed and transmitted from the ring gear 39 to the rear wheel 3b via the case 10. Therefore, the driver's pedal force is transmitted to the rear wheel 3b at the largest reduction ratio (see FIG. 5).

[0037] When the gear position is switched to second gear, second brake 32 fixes large-diameter sun gear 35 to support shaft 8, locking it so that it cannot rotate. Driving torque input from driven sprocket 6b is transmitted from small-diameter sun gear 34 to short planetary gear 36, and from short planetary gear 36 to ring gear 39 via long planetary gear 37. At this time, because large-diameter sun gear 35 is locked so that it cannot rotate, the pedal force input from small-diameter sun gear 34 is reduced in speed and transmitted from ring gear 39 to rear wheel 3b via case 10. Therefore, the driver's pedal force is transmitted to rear wheel 3b at a smaller reduction ratio than when the gear position is first gear (see FIG. 5).

[0038] When the gear is switched to the third gear, which is the highest gear, the clutch 33 connects the small-diameter sun gear 34 and the carrier 38 and they rotate together, so that the rotational speeds of the small-diameter sun gear 34 and the ring gear 39 are the same (see FIG. 5). Therefore, while the first and second gears are reduction gears, when the gear is the third gear, the pedal force input from the small-diameter sun gear 34 is transmitted from the ring gear 39 to the rear wheel 3b via the case 10 at a constant speed without being reduced.

[0039] As shown in Fig. 2, the clutch mechanism 40 is disposed on the radially inner periphery of the planetary gear mechanism 30 (see Fig. 2). This makes it easy to shorten the radial length of the clutch mechanism 40 and accommodate it on the radially inner periphery of the planetary gear mechanism 30, thereby contributing to making the clutch mechanism 40 more compact in the axial direction. The clutch mechanism 40 will be described in detail later with reference to Figs. 6 to 8.

[0040] The electric motor 90 assists the driving force in accordance with the pedal force applied by the driver. The electric motor 90 is driven by a command from the controller 9 a. The electric motor 90 generates an assist torque using electric power supplied from the power storage unit 9 b.

[0041] The reduction mechanism 91 transmits the driving force output from the electric motor 90 to the ring gear 39. The reduction mechanism 91 reduces the rotational speed of the output shaft of the electric motor 90 and transmits the reduced rotational speed to the ring gear 39. The reduction mechanism 91 may be a planetary gear mechanism or a reducer formed by combining multiple gears.

[0042] The power of the electric motor 90 is transmitted to the case 10 via the reduction mechanism 91. The power of the driven sprocket 6b is transmitted to the case 10 without passing through the reduction mechanism 91. When viewed in the direction of the rotation axis of the planetary gear mechanism 30 (the left-right direction in FIG. 2 ), the electric motor 90 and the reduction mechanism 91 overlap with the planetary gear mechanism 30.

[0043] In this way, the planetary gear mechanism 30 overlaps the compact clutch mechanism 40 in the radial direction, while the electric motor 90 and the reduction mechanism 91, which tend to be large in size, are arranged side by side in the axial direction without overlapping in the radial direction. This allows the layout of the entire electric assist unit 100 to be compact.

[0044] Next, a specific configuration of the clutch mechanism 40 in the transmission mechanism 20 will be described with reference to Figures 6 to 8. Note that the planetary gear mechanism 30 has the same configuration as that shown in Figure 3, so a detailed description thereof will be omitted here.

[0045] Fig. 6 is a skeleton diagram illustrating the clutch mechanism 40 and the planetary gear mechanism 30. Fig. 7 is a diagram illustrating the configuration of the clutch mechanism 40, showing a state in which power is being transmitted. Fig. 8 is a diagram illustrating the configuration of the clutch mechanism 40, showing a state in which power is not being transmitted.

[0046] 6, the transmission mechanism 20 has a first one-way clutch 30a and a second one-way clutch 30b. In the transmission mechanism 20, an input from the driven sprocket 6b, which serves as an input element, is transmitted to the case 10, which serves as an output element, via the clutch mechanism 40 and the planetary gear mechanism 30.

[0047] The first one-way clutch 30a constitutes the low brake 31. The first one-way clutch 30a is connected to a carrier 38 serving as a third element of the planetary gear mechanism 30. The first one-way clutch 30a is provided between the support shaft 8 and the carrier 38. The first one-way clutch 30a is in an engaged state when the first claw portion 41 and the planetary gear mechanism 30 are not engaged and the second claw portion 42 and the planetary gear mechanism 30 are not engaged. The first one-way clutch 30a is in a disengaged state when at least one of the first claw portion 41 and the second claw portion 42 is engaged with the planetary gear mechanism 30.

[0048] By providing the first one-way clutch 30a, when multiple gears are achieved with the clutch mechanism 40, at least one gear is achieved by the first one-way clutch 30a, which is another clutch, thereby shortening the axial length of the clutch mechanism 40. Furthermore, by arranging the first one-way clutch 30a, which is another clutch, in a dead space, this contributes to making the entire electric assist unit 100 more compact.

[0049] Furthermore, by selecting the first one-way clutch 30a as the other clutch, the engagement state of the first one-way clutch 30a can be indirectly controlled by the slide member 43, eliminating the need to provide an actuator or the like dedicated to the other clutch. Therefore, not providing an actuator can contribute to making the entire electric assist unit 100 more compact.

[0050] The second one-way clutch 30b is provided between the driven sprocket 6b and the small diameter sun gear 34. The second one-way clutch 30b transmits the pedal force applied by the driver to the small diameter sun gear 34. The second one-way clutch 30b does not transmit the rotation of the small diameter sun gear 34 to the pedals 7.

[0051] The clutch mechanism 40 includes a first engagement member 40a, a second engagement member 40b, a first claw portion 41, a second claw portion 42, and a slide member 43. The first engagement member 40a and the first claw portion 41 constitute the second brake 32. The second engagement member 40b and the second claw portion 42 constitute the clutch 33.

[0052] The first engagement member 40a is provided on the inner periphery of the large-diameter sun gear 35. The first engagement member 40a is formed in an annular shape. As shown in Figures 7 and 8, the first engagement member 40a has a plurality of first engagement portions 40c with which second end portions 41b (described later) of the first claw portions 41 engage.

[0053] The first engaging portions 40c are arranged at equal angular intervals on the inner circumference of the first engaging member 40a, which is formed in an annular shape. When the first claws 41 are engaged with the first engaging portions 40c, the first engaging member 40a is fixed so as not to rotate via the first claws 41 (the state shown in FIG. 7). When the first claws 41 are not engaged with the first engaging portions 40c, the first engaging member 40a rotates integrally with the large-diameter sun gear 35 (the state shown in FIG. 8).

[0054] As shown in Fig. 6, the second engaging member 40b is provided on the inner periphery of the carrier 38. The second engaging member 40b is formed in an annular shape. As shown in Figs. 7 and 8, the second engaging member 40b has a plurality of second engaging portions 40d that engage with second end portions 42b (described later) of the second claw portions 42.

[0055] The second engaging portions 40d are arranged at equal angular intervals on the inner circumference of the second engaging member 40b, which is formed in an annular shape. When the second pawls 42 are engaged with the second engaging portions 40d, the second engaging member 40b receives power from the driven sprocket 6b via the second pawls 42 (the state shown in FIG. 7). When the second pawls 42 are not engaged with the second engaging portions 40d, the second engaging member 40b rotates integrally with the carrier 38 (the state shown in FIG. 8).

[0056] The first claws 41 rotate around a first axis A1 fixed to the support shaft 8. A plurality of first claws 41 are provided on the outer periphery of the slide member 43. The first claws 41 are provided to be engageable with the large-diameter sun gear 35, which serves as the first element of the planetary gear mechanism 30. The first claws 41 have a first end 41a and a second end 41b. The rotation angle of the first claws 41 changes as the slide member 43 slides along the axial direction. The rotation angle of the first claws 41 changes between a direction in which the second end 41b approaches the slide member 43 and a direction in which the second end 41b moves away from the slide member 43. The first claws 41 are biased by a biasing member (not shown) in a direction in which the second end 41b moves away from the slide member 43 (the state shown in FIG. 7 ).

[0057] The second claws 42 rotate around the second axis A2, which is connected to the driven sprocket 6b. A plurality of second claws 42 are provided on the outer periphery of the slide member 43. The second claws 42 are engageable with the carrier 38, which serves as the second element of the planetary gear mechanism 30. The second claws 42 have a first end 42a and a second end 42b. The rotation angle of the second claws 42 changes as the slide member 43 slides along the axial direction. The rotation angle of the second claws 42 changes between the direction in which the second end 42b approaches the slide member 43 and the direction in which the second end 42b moves away from the slide member 43. The second claws 42 are biased by a biasing member (not shown) in the direction in which the second end 42b moves away from the slide member 43 (the state shown in FIG. 7 ).

[0058] As shown in FIG. 6 , the slide member 43 is movable axially around the outer periphery of the support shaft 8, and switches between three gear positions (first, second, and third) depending on its axial position. The axial position of the slide member 43 is changed based on the rider's operation. This allows the rider to change gears by operating a lever or the like, similar to shifting gears on a regular bicycle. The slide member 43 is formed in a substantially cylindrical shape surrounding the outer periphery of the support shaft 8. The slide member 43 slides along the axial direction of the first axis A1 and the second axis A2. The slide member 43 has a first convex portion 44, a second convex portion 45, a first recessed portion 46, a second recessed portion 47, a first inclined portion 48, and a second inclined portion 49.

[0059] The first protrusion 44 is provided in an annular shape on the outer periphery of the slide member 43. The first protrusion 44 is formed with a large diameter so as to protrude from the outer periphery of the slide member 43.

[0060] The second convex portion 45 is provided in an annular shape on the outer periphery of the slide member 43. The second convex portion 45 is formed with a large diameter so as to protrude from the outer periphery of the slide member 43. The second convex portion 45 is formed with the same outer diameter as the first convex portion 44. The second convex portion 45 is provided so as to be spaced apart from the first convex portion 44 in the axial direction. A first recess 46, a second recess 47, a first inclined portion 48, and a second inclined portion 49 are provided between the second convex portion 45 and the first convex portion 44.

[0061] The first recess 46 is provided in an annular shape on the outer periphery of the slide member 43. The first recess 46 is formed to have a smaller diameter than the first protrusion 44 and the second protrusion 45. The first recess 46 is provided between the first protrusion 44 and the second protrusion 45 in the axial direction.

[0062] The second recess 47 is provided in an annular shape on the outer periphery of the slide member 43. The second recess 47 is formed to have the same outer diameter as the first recess 46. The second recess 47 is provided between the first protrusion 44 and the second protrusion 45 in the axial direction. In the slide member 43, the second recess 47 is formed integrally with the first recess 46.

[0063] In this way, by forming the two recesses 46 and 47 into a common recess, the axial length of the slide member 43 can be shortened, which contributes to making the slide member 43 more compact.

[0064] When the first end 41a of the first claw portion 41 is positioned radially opposite the first convex portion 44 of the slide member 43, the second end 41b of the first claw portion 41 is rotated in a direction approaching the slide member 43. When the first end 41a of the first claw portion 41 is positioned radially opposite the first concave portion 46 of the slide member 43, the second end 41b of the first claw portion 41 is rotated in a direction away from the slide member 43.

[0065] Furthermore, even when the first end 41a of the first claw portion 41 is positioned radially opposite the second protrusion 45 of the slide member 43, the second end 41b of the first claw portion 41 is rotated in a direction approaching the slide member 43.

[0066] When the first end 42a of the second claw portion 42 is positioned radially opposite the second convex portion 45 of the slide member 43, the second end 42b of the second claw portion 42 is rotated in a direction approaching the slide member 43. When the second end 42b of the second claw portion 42 is positioned radially opposite the second concave portion 47 of the slide member 43, the second end 42b of the second claw portion 42 is rotated in a direction away from the slide member 43.

[0067] This allows the rotation angle of the claws 41 and 42 to be controlled by the unevenness of the slide member 43.

[0068] The first inclined portion 48 is provided in an annular shape on the outer periphery of the slide member 43. The first inclined portion 48 is formed to be inclined from the large-diameter first convex portion 44 toward the small-diameter first concave portion 46. The outer diameter of the first inclined portion 48 gradually decreases from the position continuous with the first convex portion 44 toward the position continuous with the first concave portion 46.

[0069] The second inclined portion 49 is provided in an annular shape on the outer periphery of the slide member 43. The second inclined portion 49 is formed to be inclined from the large-diameter second convex portion 45 toward the small-diameter second concave portion 47. The outer diameter of the second inclined portion 49 gradually decreases from the position continuous with the second convex portion 45 toward the position continuous with the second concave portion 47.

[0070] When the first end 41 a of the first claw 41 is positioned radially opposite the first inclined portion 48, the second end 41 b of the first claw 41 rotates in a direction away from the slide member 43. When the first end 42 a of the second claw 42 is positioned radially opposite the second inclined portion 49, the second end 42 b of the second claw 42 rotates in a direction away from the slide member 43.

[0071] Next, the shifting of the gear position of the electric assist unit 100 using the clutch mechanism 40 will be described with reference to FIGS. 9 to 12. FIG.

[0072] Fig. 9 is a diagram showing a state in which the gear position of the electric assist unit 100 has been switched to first gear. Fig. 10 is a diagram showing a state in which the gear position of the electric assist unit 100 has been switched to second gear. Fig. 11 is a diagram showing a state in which the gear position of the electric assist unit 100 is in the process of being switched from second gear to third gear. Fig. 12 is a diagram showing a state in which the gear position of the electric assist unit 100 has been switched to third gear.

[0073] As shown in Figure 9, when the gear position of the electric assist unit 100 is switched to the first gear position, the first end 41a of the first claw 41 is positioned radially opposite the second protrusion 45 of the slide member 43, and the second end 41b is rotated in a direction approaching the slide member 43 (the state shown in Figure 8). The second claw 42 is positioned radially opposite the second protrusion 45 of the slide member 43, and the second end 42b is rotated in a direction approaching the slide member 43 (the state shown in Figure 8).

[0074] At this time, the first claw portion 41 is not engaged with the first engaging member 40a, so the first engaging member 40a is rotatable integrally with the large-diameter sun gear 35. The second claw portion 42 is not engaged with the second engaging member 40b, so the second engaging member 40b is rotatable integrally with the carrier 38. The first one-way clutch 30a is in an engaged state because the first claw portion 41 is not engaged with the planetary gear mechanism 30 and the second claw portion 42 is not engaged with the planetary gear mechanism 30. Therefore, the low brake 31 fixes the carrier 38 to the support shaft 8 and locks it so that it cannot rotate.

[0075] 10 , when the gear position of the electric assist unit 100 is switched to the second gear, the first end 41 a of the first claw 41 is positioned radially opposite the first recess 46 of the slide member 43, and the second end 41 b is rotated in a direction away from the slide member 43 (the state shown in FIG. 7 ). The second claw 42 is positioned radially opposite the second protrusion 45 of the slide member 43, and the second end 42 b is rotated in a direction approaching the slide member 43 (the state shown in FIG. 8 ).

[0076] At this time, the first claw 41 is engaged with the first engaging member 40a, and therefore the first engaging member 40a is fixed so as not to rotate via the first claw 41. The second claw 42 is not engaged with the second engaging member 40b, and therefore the second engaging member 40b is rotatable integrally with the carrier 38. Therefore, the second brake 32 fixes the large diameter sun gear 35 to the support shaft 8, locking it so as not to rotate.

[0077] At this time, the first one-way clutch 30a is disengaged because the first pawl 41 is engaged with the planetary gear mechanism 30. In this way, the provision of the first one-way clutch 30a maintains the transmission of power through the first gear until immediately before the gear is shifted from the first gear to the second gear. This makes it possible to prevent interruption of torque transmission when the gear is shifted.

[0078] 11 , when the gear position of the electric assist unit 100 is in the middle of being shifted from second to third, the first end 41a of the first claw 41 is located at a position facing the first inclined portion 48 of the slide member 43 in the radial direction, and the second end 41b is located at a position where it has only partially rotated in a direction away from the slide member 43. The first end 42a of the second claw 42 is located at a position facing the second inclined portion 49 of the slide member 43 in the radial direction, and the second end 42b is located at a position where it has only partially rotated in a direction approaching the slide member 43.

[0079] In this way, the first claw portion 41 and the second claw portion 42 are arranged so that the first end portion 41a of the first claw portion 41 faces the first inclined portion 48 in the radial direction, and the first end portion 42a of the second claw portion 42 faces the second inclined portion 49 in the radial direction.

[0080] This makes it possible to create a simultaneous engagement state of the two claws 41, 42 while the two claws 41, 42 are being switched, thereby preventing interruption in torque transmission when the gear position is being switched.

[0081] 12 , when the gear position of the electric assist unit 100 is switched to the third gear, the first end 41 a of the first claw 41 is positioned radially opposite the first convex portion 44 of the slide member 43, and the second end 41 b is rotated in a direction toward the slide member 43 (the state shown in FIG. 8 ). The second claw 42 is positioned radially opposite the second concave portion 47 of the slide member 43, and the second end 42 b is rotated in a direction away from the slide member 43 (the state shown in FIG. 7 ).

[0082] At this time, the first claw 41 is not engaged with the first engaging member 40a, so the first engaging member 40a can rotate integrally with the large-diameter sun gear 35. The second claw 42 is engaged with the second engaging member 40b, so power is transmitted from the driven sprocket 6b to the carrier 38 via the second claw 42. Therefore, the clutch 33 couples the small-diameter sun gear 34 and the carrier 38 to rotate integrally.

[0083] In this way, the clutch mechanism 40 comprises a first claw portion 41 that rotates around the first axis A1, a second claw portion 42 that rotates around the second axis A2, and a slide member 43 that slides along the axial direction of the first axis A1 and the second axis A2, and as the slide member 43 slides along the axial direction, the rotation angle of the first claw portion 41 and the rotation angle of the second claw portion 42 change.

[0084] As a result, the rotation angles of the plurality of claw portions 41, 42 change when the single slide member 43 slides, eliminating the need for a plurality of slide members 43. This reduces the number of parts, thereby providing a structure that contributes to making the clutch mechanism 40 more compact.

[0085] Next, first and second modified examples of the clutch mechanism 40 will be described with reference to FIGS.

[0086] Fig. 13 is a diagram for explaining a first modified example of the clutch mechanism 40, showing a state in which the gear position of the electric assist unit 100 has been switched to second gear. Fig. 14 is a diagram for explaining a first modified example of the clutch mechanism 40, showing a state in which the gear position of the electric assist unit 100 has been switched to third gear.

[0087] 13 and 14 , the first protrusion 44 and the second protrusion 45 may be provided independently at positions spaced apart in the axial direction, and the first recess 46 and the second recess 47 may be provided independently at positions spaced apart in the axial direction. In this case, too, the rotation angles of the multiple pawls 41, 42 change when a single slide member 43 slides, so there is no need to provide multiple slide members 43. This allows the number of parts to be reduced, providing a structure that contributes to making the clutch mechanism 40 more compact.

[0088] Fig. 15 is a diagram for explaining a second modified example of the clutch mechanism 40, showing a state in which the gear position of the electric assist unit 100 has been switched to second gear. Fig. 16 is a diagram for explaining a second modified example of the clutch mechanism 40, showing a state in which the gear position of the electric assist unit 100 has been switched to third gear.

[0089] 15 and 16, the first protrusion 44 and the second protrusion 45 may be integrally formed, with a first recess 46 and a second recess 47 provided at both axial ends thereof. In this case, too, the rotation angles of the multiple pawls 41, 42 change when a single slide member 43 slides, so there is no need to provide multiple slide members 43. This allows the number of parts to be reduced, providing a structure that contributes to making the clutch mechanism 40 more compact.

[0090] Furthermore, by using a common convex portion for the two convex portions 44 and 45, the axial length of the slide member 43 can be shortened, which contributes to compactness.

[0091] The configuration and effects of the present embodiment will now be described.

[0092] (1) The clutch mechanism 40 includes a first claw portion 41 that rotates around the first axis A1, a second claw portion 42 that rotates around the second axis A2, and a slide member 43 that slides along the axial direction of the first axis A1 and the second axis A2. As the slide member 43 slides along the axial direction, the rotation angle of the first claw portion 41 and the rotation angle of the second claw portion 42 change.

[0093] According to this configuration, the rotation angles of the plurality of claw portions 41, 42 change when the single slide member 43 slides, so there is no need to provide a plurality of slide members 43. Therefore, the number of parts can be reduced, and a structure that contributes to making the clutch mechanism 40 more compact can be provided.

[0094] (2) When the first end 41a of the first claw portion 41 is positioned radially opposite the first convex portion 44 of the slide member 43, the second end 41b of the first claw portion 41 is rotated in a direction approaching the slide member 43. When the first end 41a of the first claw portion 41 is positioned radially opposite the first concave portion 46 of the slide member 43, the second end 41b of the first claw portion 41 is rotated in a direction away from the slide member 43. When the first end 42a of the second claw portion 42 is positioned radially opposite the second convex portion 45 of the slide member 43, the second end 42b of the second claw portion 42 is rotated in a direction approaching the slide member 43. When the second end 42b of the second claw portion 42 is positioned radially opposite the second concave portion 47 of the slide member 43, the second end 42b of the second claw portion 42 is rotated in a direction away from the slide member 43.

[0095] According to this configuration, the rotation angle of the claw portions 41 and 42 can be controlled by the unevenness of the slide member 43.

[0096] (3) The first recess 46 and the second recess 47 are integrally formed.

[0097] According to this configuration, by using a common recess for the two recesses 46 and 47, the axial length of the slide member 43 can be shortened, which contributes to compactness.

[0098] (4) The first protrusion 44 and the second protrusion 45 are integrally formed.

[0099] According to this configuration, by using a common convex portion for the two convex portions 44 and 45, the axial length of the slide member 43 can be shortened, which contributes to compactness.

[0100] (5) The slide member 43 has a first inclined portion 48 formed so as to extend from the first convex portion 44 to the first concave portion 46, and a second inclined portion 49 formed so as to extend from the second convex portion 45 to the second concave portion 47. The first and second claw portions 41 and 42 are arranged such that when the first end 41a of the first claw portion 41 is positioned radially opposite the first inclined portion 48, the second end 41b of the first claw portion 41 rotates in a direction away from the slide member 43, and when the first end 42a of the second claw portion 42 is positioned radially opposite the second inclined portion 49, the second end 42b of the second claw portion 42 rotates in a direction away from the slide member 43, so that the first end 41a of the first claw portion 41 is radially opposite the first inclined portion 48 and the first end 42a of the second claw portion 42 is radially opposite the second inclined portion 49.

[0101] According to this configuration, a simultaneous engagement state of the two claw portions 41, 42 can be created in the middle of switching between the two claw portions 41, 42, thereby preventing interruption in torque transmission when switching between gear stages.

[0102] (6) The electric assist unit 100 includes a clutch mechanism 40 and a planetary gear mechanism 30, and the input from the driven sprocket 6b is transmitted to the case 10 via the clutch mechanism 40 and the planetary gear mechanism 30. The first claw portion 41 is configured to be engageable with the large-diameter sun gear 35 of the planetary gear mechanism 30, and the second claw portion 42 is configured to be engageable with the carrier 38 of the planetary gear mechanism 30.

[0103] It is preferable to configure a transmission in which the clutch mechanism 40 and the planetary gear mechanism 30 are combined, as in this configuration.

[0104] (7) The electric assist unit 100 further includes a first one-way clutch 30a connected to the carrier 38 of the planetary gear mechanism 30, and the first one-way clutch 30a is in an engaged state when the first claw portion 41 and the planetary gear mechanism 30 are not engaged and the second claw portion 42 and the planetary gear mechanism 30 are not engaged, and is in a disengaged state when at least one of the first claw portion 41 and the second claw portion 42 is engaged with the planetary gear mechanism 30.

[0105] According to this configuration, when multiple gears are achieved with the clutch mechanism 40, at least one of the gears can be achieved with the first one-way clutch 30a, which is another clutch, thereby shortening the axial length of the clutch mechanism 40. Furthermore, by placing the first one-way clutch 30a, which is another clutch, in dead space, this contributes to making the entire electric assist unit 100 more compact.

[0106] Furthermore, by selecting the first one-way clutch 30a as the other clutch, the engagement state of the first one-way clutch 30a can be indirectly controlled by the slide member 43, eliminating the need to provide an actuator or the like dedicated to the other clutch. Therefore, not providing an actuator can contribute to making the entire electric assist unit 100 more compact.

[0107] (8) The clutch mechanism 40 is disposed radially inner around the planetary gear mechanism 30 .

[0108] According to this configuration, the radial length of the clutch mechanism 40 can be easily shortened and can be accommodated within the radial inner periphery of the planetary gear mechanism 30, which contributes to making the clutch mechanism 40 more compact in the axial direction.

[0109] Furthermore, this structure is advantageous when applied to a drive unit that transmits power from the radially inner side to the radially outer side.

[0110] (9) The electric assist unit 100 further includes an electric motor 90 and a reduction mechanism 91, and the power of the electric motor 90 is transmitted to the case 10 via the reduction mechanism 91, while the power of the driven sprocket 6b is transmitted to the case 10 without passing through the reduction mechanism 91. When viewed from the direction of the rotation axis of the planetary gear mechanism 30, the electric motor 90 and the reduction mechanism 91 overlap with the planetary gear mechanism 30.

[0111] With this configuration, the planetary gear mechanism 30 overlaps the compact clutch mechanism 40 in the radial direction, while the electric motor 90 and the reduction mechanism 91, which tend to be large in size, are arranged side by side in the axial direction without overlapping in the radial direction. This allows the layout of the entire electric assist unit 100 to be compact.

[0112] Although an embodiment of the present invention has been described above, the above embodiment merely shows one application example of the present invention, and is not intended to limit the technical scope of the present invention to the specific configuration of the above embodiment.

[0113] For example, in the above embodiment, the electric assist unit 100 is attached to the rear wheel 3b together with the driven sprocket 6b. However, the electric assist unit 100 may also be attached to the crankshaft 7c together with the driving sprocket 6a. In this case, the rider may pedal the crank arm 7b via the pedal 7, and the pedaling force (driving torque) transmitted from the crank arm 7b to the crankshaft 7c may be input to the small-diameter sun gear 34. Alternatively, the output of the electric assist unit 100 may be transmitted from the ring gear 39 through the case 10 to the driving sprocket 6a, and then to the driven sprocket 6b via a chain 6c wound around the driving sprocket 6a, thereby rotating the rear wheel 3b.

[0114] In the above embodiment, the first element of the planetary gear mechanism 30 is the large-diameter sun gear 35, the second element is the carrier 38, and the third element is also the carrier 38. These first, second, and third elements are changed depending on the configuration of the planetary gear mechanism 30, and therefore, for example, the second and third elements may be different members of the planetary gear mechanism 30.

[0115] DESCRIPTION OF SYMBOLS 100 Electric assist unit (unit) 8 Support shaft (fixed element) 10 Case (output element) 30 Planetary gear mechanism 30a First one-way clutch (one-way clutch) 30b Second one-way clutch 34 Small diameter sun gear 35 Large diameter sun gear (first element) 36 Short planetary gear 37 Long planetary gear 38 Carrier (second element, third element) 39 Ring gear 40 Clutch mechanism 41 First claw portion 41a First end 41b Second end 42 Second claw portion 42a First end 42b Second end 43 Slide member 44 First convex portion 45 Second convex portion 46 First recess 47 Second recess 48 First inclined portion 49 Second inclined portion 90 Electric motor (motor) 91 Reduction mechanism A1 First shaft center A2 Second shaft center

Claims

1. A clutch mechanism comprising: a first claw portion that rotates around a first axis; a second claw portion that rotates around a second axis; and a slide member that slides along the axial direction of the first axis and the second axis, wherein the rotation angle of the first claw portion and the rotation angle of the second claw portion change as the slide member slides along the axial direction.

2. A clutch mechanism as claimed in claim 1, wherein when the first end of the first claw portion is positioned radially opposite the first convex portion of the slide member, the second end of the first claw portion is rotated in a direction approaching the slide member; when the first end of the first claw portion is positioned radially opposite the first concave portion of the slide member, the second end of the first claw portion is rotated in a direction away from the slide member; when the first end of the second claw portion is positioned radially opposite the second convex portion of the slide member, the second end of the second claw portion is rotated in a direction approaching the slide member; and when the second end of the second claw portion is positioned radially opposite the second concave portion of the slide member, the second end of the second claw portion is rotated in a direction away from the slide member.

3. A clutch mechanism according to claim 2, wherein the first recess and the second recess are integrally formed.

4. A clutch mechanism according to claim 2, wherein the first protrusion and the second protrusion are integrally formed.

5. A clutch mechanism as claimed in claim 2, wherein the slide member has a first inclined portion formed so as to extend from the first convex portion to the first concave portion, and a second inclined portion formed so as to extend from the second convex portion to the second concave portion, and when the first end of the first claw portion is in a position radially opposing the first inclined portion, the second end of the first claw portion rotates in a direction away from the slide member, and when the first end of the second claw portion is in a position radially opposing the second inclined portion, the second end of the second claw portion rotates in a direction away from the slide member, and the first end of the first claw portion and the second claw portion are arranged so that the first end of the first claw portion is radially opposing the first inclined portion and the first end of the second claw portion is radially opposing the second inclined portion.

6. A unit comprising: a clutch mechanism according to any one of claims 1 to 5; and a planetary gear mechanism, wherein an input from an input element is transmitted to an output element via said clutch mechanism and said planetary gear mechanism, said first claw portion is arranged to be engageable with a first element of said planetary gear mechanism, and said second claw portion is arranged to be engageable with a second element of said planetary gear mechanism.

7. A unit as claimed in claim 6, further comprising a one-way clutch connected to a third element of said planetary gear mechanism, said one-way clutch being in an engaged state when said first claw portion is not engaged with said planetary gear mechanism and said second claw portion is not engaged with said planetary gear mechanism, and being in a disengaged state when at least one of said first claw portion and said second claw portion is engaged with said planetary gear mechanism.

8. A unit according to claim 6, wherein the clutch mechanism is disposed on the radially inner periphery of the planetary gear mechanism.

9. A unit according to claim 8, further comprising: a motor; and a reduction mechanism, wherein the power of the motor is transmitted to the output element via the reduction mechanism, and the power of the input element is transmitted to the output element without passing through the reduction mechanism, and wherein the motor and the reduction mechanism overlap with the planetary gear mechanism when viewed in the direction of the rotation axis of the planetary gear mechanism.

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