JP6896440B2 - Transmission device - Google Patents

Description

The present invention includes a drive shaft connected to a prime mover, a hollow driven shaft that is rotatably fitted to the outer periphery of the drive shaft, a friction clutch that can connect and disconnect the drive shaft and the driven shaft, and a driven shaft to the drive shaft. The present invention relates to a transmission device equipped with a one-way clutch that allows power transmission in only one direction to.

The transmission device is disclosed, for example, in FIG. 2 of Patent Document 1. In this device, the one-way clutch has an outer race concentrically provided on the driven shaft and an inner race fixed to the drive shaft and power is transmitted from the outer race via an engaging element, and also collides with the outer peripheral surface of the outer race. The clutch drum of the friction clutch is fixed to the provided flange with a rivet.

JP-A-2015-190541

By the way, in the above-mentioned conventional structure, since the clutch drum of the friction clutch is fixed to the flange portion on the outer circumference of the outer race with rivets, not only the number of parts increases, but also the work such as riveting hole processing and riveting is specially required, and it is manufactured accordingly. The process is also complicated. Further, since it is necessary to specially provide the flange portion of the outer race, the structure becomes complicated and the weight increases.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a transmission device capable of solving the above-mentioned problems of a conventional structure with a simple structure.

In order to achieve the above object, the present invention connects and cuts off a drive shaft connected to a prime mover, a hollow driven shaft that is rotatably fitted to the outer periphery of the drive shaft, and the drive shaft and the driven shaft. A clutch drum including a possible friction clutch and a one-way clutch that allows power transmission from the driven shaft to the drive shaft in only one direction, and the friction clutch can transmit power from the drive shaft via a friction member. The one-way clutch has a cylindrical outer race concentrically provided on the driven shaft, and an inner race fixed to the drive shaft and power is transmitted from the outer race via an engager. in the clutch drum includes a cylindrical boss portion surrounding said outer race concentrically, which has a drum portion which receives power from and the friction member extending radially outward from the boss portion, said boss part is press-fitted to the outer peripheral surface of the outer race (21), and at least a portion of the engaging member and at least a portion of said boss portion is located in the same region in the axial direction of the driven shaft, the boss portion The inner peripheral surface of the boss portion and the side surface of the drum portion facing forward in the press-fitting direction with respect to the outer race of the boss portion are continuous via a connecting surface whose diameter gradually increases from the inner peripheral surface toward the side surface. the not Rukoto the first feature.

Further, in addition to the first feature, in the present invention, a flange portion capable of contacting the side surface of the engager is projected on the outer peripheral surface of the inner race, and the flange portion and the engager come into contact with each other. The second feature is that the engaging element is positioned in the axial direction.

The present invention, in addition to the first or second feature, the inner peripheral surface of the outer race, the third feature that the engagement recess for engaging the said engager is provided in the power transmission And.

The present invention, in addition to the first to third any features, press fit coupling force of the boss portion with respect to the outer race, the fourth being larger than the maximum transmission torque of the friction clutch.

According to the first feature of the present invention, the clutch drum of the friction clutch has a cylindrical boss portion that concentrically surrounds the outer race of the one-way clutch, and the boss portion is press-fitted into the outer peripheral surface of the outer race. At least a part of the boss portion and at least a part of the engagement element of the one-way clutch are located in the same region in the axial direction of the driven shaft. As a result, the clutch drum can be coupled and fixed to the driven shaft by simply press-fitting the boss portion into the outer peripheral surface of the outer race, so that the number of parts can be reduced and the manufacturing process can be performed as compared with the case of fixing with rivets as in the conventional device. Simplification is achieved. In addition, the rigidity and strength of the outer race can be effectively increased by a simple reinforcing structure using the boss portion of the clutch drum. Moreover, unlike the conventional device, the outer race does not need to have a special flange for attaching the clutch drum, which is advantageous in terms of simplifying the structure and reducing the weight of the outer race itself. Further, the clutch drum has a boss portion and a drum portion extending radially outward from the boss portion and receiving power from a friction member, and the inner peripheral surface of the boss portion and the side surface of the drum portion form an inner circumference. Since it is continuous through a connecting surface that gradually expands in diameter from the surface to the side surface, the connecting surface can be used as a guide surface when the boss portion is press-fitted into the outer race, and the press-fitting work can be performed quickly and accurately. It can be carried out.

Further, according to the second feature, a flange portion capable of contacting the side surface of the engager is projected on the outer peripheral surface of the inner race, and the engagement element in the axial direction is formed by the contact between the flange portion and the engager. Since the positioning is performed, the engaging element can be positioned by the inner race, and a stopper such as a circlip for positioning becomes unnecessary. In addition, since the stopper is not required in this way, it is not necessary to process a locking groove for locking the stopper on the inner peripheral surface of the outer race, so that it is possible to avoid a decrease in the strength of the outer race, and the outer race can be changed accordingly. The press-fitting load of the boss portion can be increased, and the coupling force between the boss portion and the outer race can be increased. In addition, since it is not necessary to form the locking groove, the processing cost of the outer race can be reduced.

Further , according to the third feature, since the inner peripheral surface of the outer race is provided with an engaging recess for locking the engaging element during power transmission, the outer peripheral peripheral wall is partially thinned by the special provision of the engaging recess. Even if this happens, the boss portion can be press-fitted into the outer peripheral surface of the outer race to reinforce the outer race, so that the required rigidity and strength of the outer race can be easily secured.

Further , according to the fourth feature, since the press-fitting coupling force of the boss portion with respect to the outer race is larger than the maximum transmission torque of the friction clutch, the friction clutch is preferentially slid when an excessive driving force acts on the transmission device. By doing so, it is possible to prevent an excessive load from acting on the joint between the boss and the outer race, and therefore damage to the joint can be effectively prevented with a simple structure using a friction clutch. Become.

Cross-sectional view of a main part of a power unit for a motorcycle according to the first embodiment of the present invention. Enlarged cross-sectional view of the main part of the transmission device of the first embodiment (enlarged view of the 2 arrow-viewing portion in FIG. 1; cross-sectional view taken along line 2-2 in FIG. 3) Cross-sectional view of the one-way clutch of the first embodiment (cross-sectional view taken along line 3-3 in FIG. 2), a partially enlarged view, and a partial perspective view. It is a simplified cross-sectional view explaining the press-fitting process of the boss portion of the clutch drum into the outer race. (A) shows the state immediately before press-fitting, and (B) shows the state during press-fitting. Enlarged sectional view of a main part of the transmission device of the second embodiment (corresponding to FIG. 2) It is a simplified cross-sectional view (FIG. 4 correspondence figure) explaining the process of press-fitting the boss portion of the clutch drum of the second embodiment into the outer race, (A) is a state immediately before press-fitting, and (B) is a state during press-fitting. Show each

Embodiments of the present invention will be described below with reference to the accompanying drawings.

First, the first embodiment of the present invention will be described with reference to FIGS. 1 to 4. In FIG. 1, a power unit P for driving a rear wheel is mounted on a body frame (not shown) of a motorcycle. The power unit P includes an engine E as a prime mover, a transmission T capable of shifting the rotation of the engine E and transmitting it to the rear wheels (only the input gear Ti which is an input unit of the transmission T is shown in FIG. 1), and an engine. It includes a transmission device I that interlocks and connects E and the transmission T. A transmission case 10 is detachably coupled to the crankcase Ec of the engine E, and the transmission case 10 accommodates the transmission T and the transmission device I.

As the transmission T, for example, a belt-type continuously variable transmission, a gear-type transmission using a combination of a plurality of gear trains, or the like can be used. Further, the output unit of the transmission T is interlocked with and connected to the rear wheels via an interlocking mechanism (not shown).

The transmission device I includes a drive shaft 11, a cylindrical driven shaft 12 that is rotatably fitted and supported on the outer periphery of the drive shaft 11 directly or via a bearing, and one end of the drive shaft 11 and the driven shaft 12. It is provided with a friction clutch C1 capable of connecting / disconnecting a transmission path between the two, and a one-way clutch C2 arranged in parallel with the friction clutch C1 and allowing power transmission from the driven shaft 12 to the drive shaft 11 in only one direction. ..

In the present embodiment, the drive shaft 11 is composed of a crankshaft extension shaft portion integrally extended to one end of the crankshaft Es of the engine E, and the outer end of the drive shaft 11 is rotatably supported by the transmission case 10. To. The drive shaft 11 may be configured separately from the crankshaft Es and may be interlocked and connected to the crankshaft Es via an interlocking mechanism.

An output gear 12g is formed on the outer periphery of the other end of the driven shaft 12. The output gear 12g meshes with the above-mentioned input gear Ti of the transmission T.

With reference to FIG. 2, the friction clutch C1 includes a clutch drum D that is concentrically arranged and fixed to one end of a driven shaft 12. The clutch drum D integrally includes a boss portion 15 and a bottomed cylindrical drum portion 16 extending radially outward from one end in the axial direction of the boss portion 15. The drum portion 16 is a circular ring plate-shaped drum end wall portion 16A connected to one end in the axial direction of the boss portion 15, and a cylinder extending from the outer peripheral end of the drum end wall portion 16A to one side in the axial direction (opposite side to the engine E). It has a drum peripheral wall portion 16B in the shape of a drum.

In the present embodiment, the clutch drum D is integrally formed by pressing a steel plate, and the inner peripheral surface 15i of the boss portion 15 and the side surface 16s (more specifically) of the drum portion 16 on the inner side in the axial direction. The inner side surface of the drum end wall portion 16A) is continuous with the connecting surface r whose diameter gradually increases from the inner peripheral surface 15i toward the side surface 16s. In particular, in the present embodiment, since the connecting surface r is formed in an arc shape in cross section by press working (drawing), the inner peripheral surface 15i and the side surface 16s are smoothly connected without a step. Further, the side surface 16s is a side surface facing forward in the press-fitting direction (white arrow direction in FIG. 4) when the boss portion 15 is press-fitted into the outer race 21, which will be described later.

Further, the friction clutch C1 is attached to the support plate 17 fixed to the drive shaft 11 and the support plate 17 at equal intervals in the circumferential direction with respect to the drum portion 16 (more specifically, the inner circumference of the drum peripheral wall portion 16B). A plurality of friction members 18 that can move between predetermined contact positions and non-contact positions, and a clutch spring interposed between the friction members 18 and the support plate 17 to urge each friction member 18 to the non-contact position side. 19 and.

In the present embodiment, the support plate 17 is divided into a boss portion 17b for spline fitting SP1 on the outer periphery of the drive shaft 11 and a plate main body portion 17a extending radially outward from the boss portion 17b, both 17a and 17b. Are integrally joined by welding or other joining means. The entire support plate 17 may be formed as an integral body.

The friction member 18 includes, for example, a friction material 18a capable of frictionally contacting the inner peripheral surface of the drum peripheral wall portion 16B, and a movable support 18b that fixedly supports the back surface side of the friction material 18a. In the present embodiment, the movable support 18b is swingably supported by a support plate 17 (particularly, the plate body 17a) via a pivot 30 fixed to the support plate 17, and the swing causes the friction member 18 to be in contact position and non-contact position. It is possible to move between. The movable support 18b may be slidably supported by the support plate 17.

Further, a centrifugal weight 20 that applies a centrifugal force for urging the friction member 18 toward the contact position side to the friction member 18 is fixed to one side of the movable support 18b. The centrifugal weight 20 may be formed integrally with the movable support 18b. Further, in FIG. 2, reference numeral 31 is a disc spring for cushioning the friction member 18, and 32 and 33 are a pair of support plates supported by the pivot 30 and serving as a spring receiver for the disc spring 31.

Thus, the friction clutch C1 functions as a centrifugal start clutch in this embodiment. For example, in a low-speed rotation range (that is, an idling rotation range) in which the engine E is less than a predetermined rotation speed when the vehicle is stopped, the clutch spring 19 puts the friction member 18 in a non-contact position (that is, against the centrifugal force acting on the friction member 18). Therefore, the friction clutch C1 is elastically held (in the disconnected state). On the other hand, in the rotation range where the engine E has a predetermined rotation speed or more, the centrifugal force holds the friction member 18 at the contact position (thus, the friction clutch C1 is connected) against the urging force of the clutch spring 19. , Power can be transmitted from the friction member 18 to the clutch drum D, whereby the motorcycle can be started.

The friction clutch C1 of the present embodiment has basically the same structure as the centrifugal friction clutch conventionally known as a starting clutch for motorcycles, except for the structure of a part of the clutch drum D (that is, the boss portion 15). It is a function.

Next, an example of the one-way clutch C2 will be described with reference to FIG. The one-way clutch C2 has a bottomed cylindrical outer race 21 concentrically provided at one end of the driven shaft 12, and a cylindrical inner race fixed to the drive shaft 11 and concentrically surrounded by the outer race 21. A plurality of rollers 23, which are interposed between the outer race 21 and the inner race 22 and allow only power transmission from the outer race 21 to the inner race 22 side, are provided. The roller 23 is an example of an engager of the present invention.

In the present embodiment, the inner race 22 is spline-fitted SP2 on the outer periphery of the drive shaft 11 in a state of being adjacent to the boss portion 17b of the support plate 17 of the friction clutch C1. An intermediate step portion 22s that engages with the annular step portion 11s on the outer periphery of the drive shaft 11 is formed on the inner peripheral surface of the inner race 22. Then, the inner race 22 and the boss portion 17b are fastened together with the drive shaft 11 by the nut N screwed to the drive shaft 11. That is, the nut N clamps the inner race 22 and the boss portion 17b between the inner race 22 and the annular step portion 11s by pressing the nut N against the outer end surface of the boss portion 17b via a washer and tightening the nut N against the drive shaft 11. To conclude.

The outer race 21 extends from the outer peripheral end of the driven shaft 12 to the circular ring-shaped race end wall portion 21A rising outward in the axial direction and from the outer peripheral end of the race end wall portion 21A to one side in the axial direction (opposite side to the engine E). It has a cylindrical race peripheral wall portion 21B. A tapered surface t is formed on the outer surface of the race end wall portion 21A, that is, the side surface on the engine E side, at least on the outer peripheral portion, which is inclined toward the drum portion 16 of the friction clutch C1 in the radial direction.

On the inner peripheral surface of the outer race 21 (more specifically, the race peripheral wall portion 21B), a plurality of engaging recesses 21c capable of engaging and disengaging a plurality of rollers 23 are recessed at equal intervals in the circumferential direction of the outer race 21. To. The bottom surface of each engaging recess 21c includes the first and second bottom surfaces 21c1, 21c2 that are adjacent to each other in the circumferential direction of the outer race 21. A roller 23 is rotatably inserted between the first bottom surface 21c1 of each engaging recess 21c and the outer peripheral surface of the inner race 22 so as to be rotatable, and the gap s between the opposite surfaces is the outer race. It is set so that it gradually narrows (that is, the gap s becomes a wedge-shaped gap) toward one side in the circumferential direction of 21 (the side away from the second bottom surface 21c2).

Further, on the inner peripheral surface of the outer race 21, a plurality of rollers 23 can be held at predetermined assembly positions (that is, engagement positions with the first bottom surface 21c1) even when the inner race 22 is not installed in the outer race 21. An annular retainer 25 is attached. The annular retainer 25 is, for example, erected on one side in the axial direction from the outer peripheral portion of the retainer main body 25 m and the circular ring plate-shaped retainer main body 25 m adjacent to the inner surface of the race end wall portion 21A of the outer race 21 and engaged with each other. It includes an outer claw portion 25s that engages with the second bottom surface 21c2 of the recess 21c, and an inner claw portion 25s' that is erected on one side in the axial direction from the inner peripheral portion of the retainer main body 25m and faces the outer claw portion 25s. The outer claw portion 25s has an L-shaped cross section and engages with the spring seat portion 25sb that engages with the second bottom surface 21c2, and is connected to the spring seat portion 25sb and bent inward in the radial direction to engage with the roller 23. It has a stopper portion 25sa to be obtained.

Each roller 23 comes into contact with a movable end of a roller spring 26 that repels the roller 23 toward the side where the first bottom surface 21c1 becomes shallower (that is, the locking direction) in the circumferential direction of the outer race 21. The fixed end of the roller spring 26 is engaged and supported by the inner surface of the spring seat portion 25sb, and the intermediate portion of the roller spring 26 is sandwiched between the outer claw portion 25s and the inner claw portion 25s'.

Therefore, for example, even if the inner race 22 is not installed in the outer race 21 during the assembly of the one-way clutch C2, the plurality of rollers 23 are held by the roller spring 26 while holding the roller spring 26 in the outer race 21. It is possible to elastically hold the stopper 25sa at the engagement position by the force. As a result, it is possible to effectively prevent the roller 23 from jumping out of the outer race 21 during the assembly process, and the assembly workability is improved. The annular retainer 25 is used for improving assembly workability and securing a spring seat, but can be omitted depending on the structure of the engaging recess 21c, the support mode of the roller spring 26, and the like.

Thus, as illustrated in FIG. 3, when the outer race 21 is stopped (that is, the vehicle is stopped) in a state where the inner race 22 is rotated in the direction a in the direction of the white arrow in conjunction with the drive shaft 11. Since the roller 23 follows the inner race 22 and tries to move in the same direction a (that is, the side where the wedge-shaped gap s between the first bottom surface 21c1 and the outer peripheral surface of the inner race 22 expands), the roller 23 moves into the gap s. The free state without biting, that is, the one-way clutch C2 is in the unlocked state. On the other hand, when the outer race 21 rotates in the same direction a at a speed faster than the inner race 22, the roller 23 bites into the wedge-shaped gap s, and the one-way clutch C2 is locked.

The situation in which the one-way clutch C2 is locked as in the latter case is, for example, the driven shaft 12 even though the friction clutch C1 is in the disconnected state because the drive shaft 11 (engine E) is stopped or rotates at a low speed. In this situation, the one-way clutch C2 is locked so that the drive shaft 11 and the driven shaft 12 are connected to each other. As a result, for example, the engine E can be pushed, and the engine brake can be applied even when the friction clutch C1 is disconnected.

Further, an annular flange portion 22f projecting outward in the radial direction of the inner race 22 is integrally projected on the outer peripheral surface of the inner race 22. The flange portion 22f can come into contact with the side surface 23s of the roller 23 on the side not covered by the annular retainer 25, and this contact allows the roller 23 to be positioned in the axial direction of the clutch drum D. Therefore, there is no possibility that the roller 23 will inadvertently separate from the outer race 21.

Further, a clutch drum D of the friction clutch C1, particularly a boss portion 15 concentrically surrounding the outer race 21 is press-fitted onto the outer peripheral surface of the outer race 21 (more specifically, the race peripheral wall portion 21B). , The outer race 21 and the boss portion 15 are integrally connected to each other.

Therefore, the press-fitting coupling force of the boss portion 15 with respect to the outer race 21 is made larger than the maximum transmission torque of the friction clutch C1 (that is, the transmission torque capacity corresponding to the maximum value of the transmission torque that the friction clutch C1 can transmit). A tightening allowance between the outer race 21 and the boss portion 15 is set.

At least a part of the boss portion 15 (in the present embodiment, a region of half or more in the axial direction) and at least a part of the roller 23 (in the present embodiment, all) are located in the same region in the axial direction of the driven shaft 12. (That is, they are arranged so as to overlap each other in a layered manner in the radial direction).

Next, the operation of the embodiment will be described with reference to FIG.

The driven shaft 12 of the transmission device I is formed as an integral body by forging and machining as a whole shaft including the outer race 21 of the one-way clutch C2 and the output gear 12g. On the other hand, the entire clutch drum D of the friction clutch C1 is integrally formed by press working, and then the boss portion 15 of the clutch drum D is press-fitted and fixed to the outer peripheral surface of the outer race 21.

At the time of the above press-fitting, for example, as shown in FIG. 4, a driven shaft 12 in an upright posture with the outer race 21 facing downward is placed on the support base 100 and fixed with a jig (not shown), and from above, the driven shaft 12 is fixed. The boss portion 15 of the clutch drum D is press-fitted into the outer peripheral surface of the race peripheral wall portion 21B of the outer race 21 by a pressing device (not shown).

In this case, the inner peripheral surface 15i of the boss portion 15 and the side surface 16s of the drum portion 16 on the inner side in the axial direction (that is, the side surface facing the front side in the press-fitting direction of the boss portion 15 with respect to the outer race 21) are the inner circumferences. Since the connecting surface r is smoothly continuous through the connecting surface r that gradually increases in diameter from the surface 15i toward the side surface 16s, the connecting surface r serves as a guide surface when the boss portion 15 is press-fitted into the outer race 21, and the press-fitting work is performed. Can be performed quickly and accurately. Moreover, since the outer peripheral portion of the outer peripheral surface of the race end wall portion 21A of the outer race 21 is formed on the tapered surface t whose diameter gradually increases as the distance from the engine E increases, this tapered surface t also functions as a guide surface for press fitting. Workability is further improved.

After the boss portion 15 of the clutch drum D is integrally coupled to the outer periphery of the outer race 21 by the above press fitting, the annular retainer 25 is attached to the inner peripheral surface of the outer race 21 (more specifically, the race peripheral wall portion 21B). In this case, by engaging the outer claw portion 25s of the annular retainer 25 with the engaging recess 21c (particularly the second bottom surface 21c2) on the inner peripheral surface of the race peripheral wall portion 21B of the outer race 21, the annular retainer 25 is engaged with the inner circumference of the outer race 21. Can be fixed to.

Then, one end of the roller spring 26 is engaged and supported by the spring seat portion 25sb of the annular retainer 25, and the roller 23 is sandwiched between the other end of the roller spring 26 and the stopper portion 25sa. As a result, a plurality of rollers 23 can be temporarily fixed in the outer race 21 at a predetermined assembly position (that is, an engagement position with the first bottom surface 21c1) even when the inner race 22 is not installed. ..

Most of the components of the friction clutch C1 except the clutch drum D (for example, the friction member 18, the pivot 30, the clutch spring 19, the disc spring 31, and the support plates 32, 33) are supported in advance by another assembly line. It is assembled together on the plate 17, and the whole can be handled as one sub-assembly.

After that, the inner race 22 and the sub-assembly (more specifically, the boss portion 17a of the support plate 17) are sequentially spline-fitted SP2 and SP1 on the outer periphery of the drive shaft 11, and both 22 and 17a are combined with the nut N. Tighten. Thus, the assembly of the transmission device I is completed.

In the transmission device I of the present embodiment described above, the clutch drum D of the friction clutch C1 has a cylindrical boss portion 15 that concentrically surrounds the outer race 21 of the one-way clutch C2, and the boss portion 15 is the outer race. It is press-fitted onto the outer peripheral surface of 21 (more specifically, the race peripheral wall portion 21B). As a result, the clutch drum D can be coupled and fixed to the driven shaft 12 by simply press-fitting the boss portion 15 onto the outer periphery of the outer race 21 without using special fastening parts such as rivets. Therefore, as compared with the case where the clutch drum D is fixed to the outer race 21 with rivets as in the conventional apparatus (Patent Document 1), the number of parts can be reduced and the manufacturing process can be simplified, and the rivets are stretched inside the clutch drum D. Since there is no need to worry about the clutch drum D being released, it is possible to effectively utilize the internal space of the clutch drum D and, by extension, to reduce the size of the clutch drum D.

Further, since it is not necessary to specially provide the clutch drum mounting flange portion on the outer race D as in the conventional device, it is advantageous in terms of simplifying the structure and reducing the weight of the outer race 21 itself. Further, since the clutch drum D of the friction clutch C1 is also used as a reinforcing means for the outer race 21, the structure of the transmission device I can be simplified accordingly.

Moreover, at least a part of the boss portion 15 (more than half of the area in the axial direction in this embodiment) and at least a part of the roller 23 (all in the present embodiment) are the same area in the axial direction of the driven shaft 12. (That is, they are arranged so as to overlap each other in layers in the radial direction). As a result, the area corresponding to the roller 23, which has a particularly large power transmission load, of the race peripheral wall portion 21B of the outer race 21 can be effectively reinforced by the boss portion 15 of the clutch drum D. Therefore, it is possible to secure the required rigidity and strength of the outer race 21 without forming the outer race 21 itself to be particularly sturdy and thick, which contributes to the reduction in size and weight of the outer race 21 (and thus the one-way clutch C2). Can be done.

Further, in the assembled state of the transmission device I of the present embodiment, the flange portion 22f on the outer circumference of the inner race 22 is close to the outer surface of the roller 23 of the one-way clutch C2 (that is, the side surface 23s on the side not covered by the annular retainer 25). It is possible to face each other. Then, by this contact, the roller 23 is positioned in the axial direction of the clutch drum D (in other words, it is prevented from coming off from the outer race 21). As a result, the roller 23 can be positioned by the inner race 22, and a stopper such as a circlip for positioning becomes unnecessary. Further, since the stopper is not required in this way, it is not necessary to process a locking groove for locking the stopper such as a circlip on the inner peripheral surface of the race peripheral wall portion 21B of the outer race 21. It is possible to avoid a decrease in the strength of the outer race 21 due to the formation of the stop groove, and the press-fitting load of the boss portion 15 to the outer race 21 can be increased accordingly, and the coupling force between the boss portion 15 and the outer race 21 can be increased. Moreover, since it is not necessary to form the locking groove, the processing cost of the outer race 21 can be reduced.

Further, in the present embodiment, an engaging recess 21c for locking the roller 23 at the time of power transmission is recessed on the inner peripheral surface of the race peripheral wall portion 21B of the outer race 21, and in the corresponding region of the engaging recess 21c. The race peripheral wall portion 21B is partially thin. However, in the present embodiment, the boss portion 15 of the clutch drum D can be press-fitted into the outer peripheral surface of the race peripheral wall portion 21B to reinforce the outer race 21 (that is, the boss portion 15 substantially thickens the race peripheral wall portion 21B). The required rigidity and strength of the outer race 21 can be easily secured by using the clutch drum D.

Further, in the present embodiment, the press-fitting coupling force of the boss portion 15 with respect to the outer race 21 is set to be larger than the maximum transmission torque of the friction clutch C1. As a result, when an excessive driving force (particularly reverse load) acts on the transmission device I, the friction clutch C1 is preferentially slid, so that an excessive load is applied to the press-fitting coupling portion between the boss portion 15 and the outer race 21. Since it can be prevented from acting, damage to the joint portion can be effectively prevented with a simple structure using the friction clutch C1.

Next, a second embodiment of the present invention will be described with reference to FIGS. 5 and 6. In the second embodiment, the clutch drum structure of the friction clutch C1 and the mounting structures of the support plate 17 and the inner race 22 on the drive shaft 11 are different from those in the first embodiment. Next, only the different structures will be specifically described.

That is, in the drum portion 16'of the clutch drum D', one end of the drum peripheral wall portion 16B' on the engine E side has a tapered shape that is inclined so as to bulge toward the engine E side (that is, the diameter is gradually reduced as it approaches the engine E). The drum end wall portion 16A'is continuously provided, and the boss portion 15'is inverted from the inner peripheral end portion of the drum end wall portion 16A'to the side opposite to the engine E and is continuously provided so as to extend in the axial direction. To. Then, between the side surface 16s'(more specifically, the outer surface of the drum end wall portion 16A') on the outer side in the axial direction of the drum portion 16'and the inner peripheral surface 15i of the boss portion 15', It is smoothly connected by a connecting surface r'consisting of a curved surface having an arcuate cross section.

Further, in the second embodiment, the boss portion 17b'of the support plate 17'is formed long in the axial direction and is fitted in the inner race 22'of the one-way clutch C2, and the fitting surface, that is, the boss portion 17b The outer peripheral surface of ′ and the inner peripheral surface of the inner race 22 ′ are spline-fitted SP2 ′ with each other. Then, the drive shaft 11 boss 17b 'only spline SP1' is, the inner end of the boss portion 17b 'engages the drive shaft 11 outside circumference of the annular step 11s. Therefore, the nut N screwed into the drive shaft 11 is engaged with the outer end of the boss portion 17b'via a washer and tightened, so that the boss portion 17b'is fastened on the drive shaft 11.

Since the other structures of the second embodiment are basically the same as those of the first embodiment, only the reference codes of the corresponding components of the first embodiment are added to each component, and the structure is more than that. The description is omitted.

Also in the second embodiment, basically the same action and effect as in the first embodiment can be achieved. Further, in the clutch drum D'of the second embodiment, the drum end wall portion 16A' bulges toward the engine E side and the boss portion 15' reverses to the side opposite to the engine E, so that the friction clutch C1 can be miniaturized in the axial direction. The internal space of the clutch drum D'can be expanded while trying to increase the degree of freedom in arranging the friction member 18 and the support plate 17'in the clutch drum D'.

Further, when the boss portion 15'of the clutch drum D'is press-fitted into the outer peripheral surface of the race peripheral wall portion 21B of the outer race 21, for example, as shown in FIG. It is placed on the support base 100'and fixed with a jig (not shown), and the boss portion 15'of the clutch drum D'is pressed into the outer peripheral surface of the outer race 21 from above by a pushing device (not shown). Fit.

In this case, the inner peripheral surface 15i of the boss portion 15'and the side surface 16s' of the drum portion 16'on the outer side in the axial direction (that is, the side surface of the boss portion 15' facing the front side in the press-fitting direction with respect to the outer race 21). Is smoothly continuous through the connecting surface r', which gradually expands in diameter from the inner peripheral surface 15i toward the side surface 16s', so that the connecting surface r'is a press-fitting guide surface, and the press-fitting work can be performed quickly and accurately. Can be done.

Although the embodiments of the present invention have been described above, the present invention is not limited to the embodiments, and various design changes can be made without departing from the gist thereof.

For example, in the above embodiment, the transmission device I is implemented in the rear wheel drive system of the motorcycle, but in the present invention, the transmission device I may be implemented in the wheel drive system of a vehicle other than the motorcycle. Alternatively, it may be applied to a transmission device of various mechanical devices other than the vehicle.

Further, in the above embodiment, the friction clutch C1 is composed of a centrifugal friction clutch that engages and disengages according to a change in the rotational speed of the drive shaft 11, but the friction clutch of the present invention is a centrifugal friction clutch. It is not limited, and can be applied to, for example, a friction clutch that is engaged and disconnected at any time according to a manual operation or a mechanical operation.

Further, in the above-described embodiment, the roller 23 is exemplified as the engager of the one-way clutch C2, but the engager of the present invention is not limited to the embodiment, and for example, a ball, a sprag, or the like may be used.

Further, in the above embodiment, an engaging recess 21c for engaging the engaging element (roller 23) so as to be able to transmit power is provided on the inner peripheral surface of the outer race 21 of the one-way clutch C2. In the third feature, an engaging recess that exhibits the same function may be provided on the outer peripheral surface side of the inner race 22.

C1 ... Friction clutch C2 ... One-way clutch D, D'... Clutch drum E ... Engine (motor)
I ... Transmission device r, r'... Connection surface 11 ... Drive shaft 12 ... Drive shaft 15, 15'... Boss portion 15i ... Inner peripheral surface 16, 16'.・ Drum part 16s, 16s ′ ・ ・ Side surface 18 of the drum part ・ ・ ・ ・ Friction member 21 ・ ・ ・ ・ Outer race 21c ・ ・ ・ Engagement recesses 22, 22 ′ ・ ・ Inner race 22f ・ ・ ・ Flange part 23 ・ ・・ ・ Roller (engager)
23s ... Side surface of roller (engager)

Claims (4)

A drive shaft (11) connected to the prime mover (E), a hollow driven shaft (12) that is rotatably fitted to the outer periphery of the drive shaft (11), the drive shaft (11), and the driven shaft (12). A friction clutch (C1) capable of connecting and disconnecting between the two) and a one-way clutch (C2) that allows power transmission in only one direction from the driven shaft (12) to the drive shaft (11). The clutch (C1) has a clutch drum (D, D') capable of transmitting power from the drive shaft (11) via a friction member (18), and the one-way clutch (C2) has the driven shaft (12). ) Concentrically provided with a cylindrical outer race (21) and an inner race (22, 22) fixed to the drive shaft (11) and transmitted from the outer race (21) via an engager (23). In the transmission device having ′) and
The clutch drum (D, D') has a cylindrical boss portion (15, 15') that concentrically surrounds the outer race (21) and a radial outer side of the boss portion (15, 15'). 'together and a, the boss portion (15, 15 extends and the drum unit which receives power from the friction member (18) (16, 16)' in) is press-fitted to the outer peripheral surface of the outer race (21),
At least a part of the boss portion (15, 15') and at least a part of the engager (23) are located in the same region in the axial direction of the driven shaft (12) .
The drum portion (16, 16') facing forward in the press-fitting direction of the inner peripheral surface (15i) of the boss portion (15, 15') and the outer race (21) of the boss portion (15, 15'). ) Is continuous via a connecting surface (r, r') whose diameter gradually increases from the inner peripheral surface (15i) toward the side surface (16s, 16s'). A transmission device characterized by the fact that. On the outer peripheral surface of the inner race (22, 22'), a flange portion (22f) capable of contacting the side surface (23s) of the engaging element (23) is projected, and the flange portion (22f) and the engagement are provided. The transmission device according to claim 1, wherein the engaging element (23) is positioned in the axial direction by abutting with the flange (23). The first or second aspect of the outer race (21), wherein an engaging recess (21c) for locking the engaging element (23) is provided on the inner peripheral surface of the outer race (21). Transmission device. Any one of claims 1 to 3 , wherein the press-fitting coupling force of the boss portion (15, 15') with respect to the outer race (21) is larger than the maximum transmission torque of the friction clutch (C1). The transmission device described in.

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