JP5659278B2 - Transmission for motorcycle - Google Patents

Description

  The present invention relates to a motorcycle transmission, and more particularly to a gear-type transmission.

  FIG. 11 shows a conventional example of a gear-type transmission for a six-speed motorcycle. A transmission input shaft 201 and a transmission output shaft 202 are parallel to each other in a transmission case (not shown). I have. The input shaft 201 includes an input-side transmission gear train including input gears 211, 212, 213, 214, 215, and 216 for first to sixth speeds, and a crankshaft (not shown) via a clutch 219. )) So that power can be transmitted. The output shaft 202 includes an output side transmission gear train including output side gears 221, 222, 223, 224, 225, and 226 that always mesh with the input side gears 211, 212, 213, 214, 215, and 216.

  In the conventional example, the gear arrangement order of each of the transmission gear trains is, in order from the clutch 219 side, the first speed gears 211 and 221, the fourth speed gears 214 and 224, the third speed gears 213 and 223, and the fifth speed gear 215. , 225, sixth speed gears 216, 226 and second speed gears 212, 222.

  As the shift mechanism, on the input shaft 201, the input third speed gear 213 and the input fifth speed gear 215 arranged at the center in the axial direction are integrally formed and splined to the speed change input shaft 201 so as to be movable in the axial direction. The remaining input side first speed, fourth speed, sixth speed, and second speed gears 211, 214, 216, 212 are fixed to the transmission input shaft 201 so that they cannot move in the axial direction. A dog-tooth clutch mechanism 231 between the input side fourth speed gear 214 and the input side third speed gear 213 and between the input side fifth speed gear 215 and the input side sixth speed gear 216, respectively. 232 is provided.

  On the other hand, on the output shaft 202, the output-side fourth speed gear 224 and the output-side sixth speed gear 226 are spline-fitted to the transmission output shaft 202 so as to be independently movable in the axial direction, and the remaining output-side gears The 1st speed, 3rd speed, 5th speed and 2nd speed gears 221, 223, 215, 222 are fixed to the output shaft 202 so as not to move in the axial direction. Then, between the output side fourth speed gear 224 and the output side first speed gear 221, and between the output side sixth speed gear 226 and the output side second speed gear 222, the dog-tooth clutch mechanism 233, respectively. 234 is provided.

  Although not shown, an input side third speed gear 213 and a fifth speed gear 215, an output side fourth speed gear 224, and an output side sixth speed gear 226 are shifted by a shift operation mechanism including a shift cam drum and a shift fork. The gears are shifted to a desired gear position by moving in the axial direction and selectively meshing the dog-tooth clutch mechanisms 231, 232, 233, and 234. Such a structure is disclosed in Patent Document 1 and the like.

JP 2007-009737 A (FIG. 4)

  By the way, in a racing or sports type motorcycle, there may be a demand for the number of shift stages of 7 or 8 or more. However, in the structure in which dog clutch teeth are formed on the gear for shifting itself and moved in the axial direction as described above, the number of gears on the input shaft 201 and the output shaft 202 is increased in order to increase the number of gears. Is increased, the shaft length of both shafts 201 and 202 is increased, the axial width of the transmission case, that is, the width in the vehicle width direction is increased, and the foot space of the rider is limited. In addition, as the shaft length increases, shaft deflection increases, shift touch decreases, and power transmission efficiency between gears also decreases.

  Further, when the gear for shifting itself is moved, the gear itself may fall down, and the gear tooth tip may not hit well, which may cause pitching or the like.

  Also, in a motorcycle with a large reduction ratio compared to a four-wheel vehicle, the diameter of the output-side transmission gear becomes extremely larger than the diameter of the input-side transmission gear. There is a demand for a structure that is provided with an engagement hole that meshes with teeth, and that can withstand transmission torque and impact during shifting.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a motorcycle capable of solving the above-mentioned problems and effectively utilizing lubricating oil while maintaining compactness in the width and radial direction of a motorcycle transmission.

The present invention relates to an input shaft, an output shaft arranged in parallel with the input shaft, a plurality of input-side transmission gears provided on the input shaft, and the input-side transmission gear, respectively, and provided on the output shaft. A plurality of output-side transmission gears, and selecting a power transmission path between the input-side transmission gear and the output-side transmission gear between the input shaft and the output shaft to automatically change the speed. In the two-wheeled vehicle transmission, the plurality of transmission gears provided on one of the input shaft and the output shaft are fixed in the axial direction and around the shaft, and on the other shaft, The plurality of transmission gears provided on the other shaft are fixed in the axial direction and are rotatably fitted around the shaft, and a plurality of dog coupling slider rings are arranged around the shaft on the other shaft. Fixed and slidable in the axial direction Provided, the transmission gear provided on the slider ring and the other axis is the axial movement of the slider ring engaging portion engageable disengagement are formed respectively, the slider ring The slider is connected to a shift cam drum via a shifter member that engages with an annular groove on the outer periphery of the slide ring so as to slide in the axial direction , and an inner peripheral surface and an outer peripheral surface in the radial direction of the slider, The shift cam drum is disposed below the other shaft so that the lubricating oil that lubricates the lubrication portion on the other shaft is supplied to the shift cam drum. Yes.

  In the present invention, preferably, the following configuration can be adopted.

(A) A sliding groove that is recessed outward in the radial direction is formed on the inner peripheral surface of the slider ring, and a radially inner end of the lubricating oil passage reaches the sliding groove. .

(B) It has the said structural requirement (a), and the groove bottom of the radial direction outer end of the said sliding groove is radial direction rather than the radial direction inner peripheral end of the said engaging part of the said slider ring. Located on the outside .

(C) The engagement portion of the slider ring is an engagement hole penetrating in the axial direction, and the engagement portion of the transmission gear is engaged with the engagement hole by the movement of the slider ring in the axial direction. It is an engaging protrusion that can be detached .

(D) It has the said structural requirement (c), and the said lubricating oil channel | path is formed between the circumferential directions of the said some engagement hole .

(E) The shifter member is disposed below the other shaft .

(F) The structural requirement (e) is provided, and the shifter member is supported by the shift shaft so as to be slidable in the axial direction, and the shift cam drum is disposed below the shift shaft.

  According to the present invention, (1) on the input shaft and the output shaft, only the slider ring for the shift mechanism is provided to be movable in the axial direction, and all the transmission gears on the input side and the output side are fixed in the axial direction. Therefore, even if the speed change operation is performed, the speed change gear itself does not fall down, the contact of the gear tooth tip is maintained well, and there is no fear of causing pitching or the like.

(2) Since all the transmission gears on the input side and the output side are fixed in the axial direction, the shaft length of the input shaft and the output shaft can be kept short, so that the shaft diameter can be made thin and light. At the same time, the shaft deflection due to the load during operation can be reduced, and the shift touch becomes smooth.

(3) As the engaging portion, for example, when an engaging hole is formed in the slider ring and an engaging protrusion that engages with the engaging hole is formed in the transmission gear, the slider ring has a shearing force when engaged. As well as being able to receive a driving load even with a circumferential compressive force, it becomes possible to reduce the thickness of the slider ring, and this also keeps the axial length of the input shaft and output shaft short. be able to.

(4) Since the slider ring for the shift mechanism is provided only on one of the input shaft and the output shaft, for example, when a shift cam drum and a shift fork are used as the shift mechanism, one shift shaft is used. The shift cam drum and the shift fork can be compactly collected in a space near the one shaft. Further, even when an electromagnetic or hydraulic mechanism is used as the shift mechanism, these mechanisms can be compactly assembled on one shaft and in the vicinity thereof.

(5) Since no gear teeth are formed on the outer peripheral surface of the slider ring that slides in the axial direction, dog teeth or the like are formed on the side end surface of the transmission gear as in the conventional example of FIG. The outer diameter of the slider ring can be made smaller and lighter than the structure in which the slider is slid in the axial direction.

(6) Since all the transmission gears are locked so as not to move in the axial direction, it is possible to employ a helical gear with a thrust force as the transmission gear, and noise is reduced compared to the case of using a spur gear. it can.

(7) The slider ring has a lubricating oil passage that connects the outer peripheral surface and the inner peripheral surface, and the lubricating oil that has lubricated the lubricating portion on the other shaft is supplied to the shift cam drum. Since the shift cam drum is disposed below the other shaft, the lubricating oil that lubricates the lubricated portion of the inner and outer peripheral surfaces of the slider ring of the other shaft using the lubricating oil passage is caused by the natural fall to cause the annular groove and It is efficiently supplied to the shift cam drum via the shifter member, and the lubricating effect on the lubrication portion of the shift cam drum can be enhanced.

1 is a simplified cross-sectional view of a neutral state in which a motorcycle transmission and an engine according to the present invention are cut along a plane passing through respective axes. FIG. 2 is an enlarged cross-sectional view of the motorcycle transmission of FIG. 1. It is the front enlarged view (seen in the axial direction) of the slider ring for high speed stages. FIG. 4 is an enlarged sectional view taken along the line IV-IV in FIG. 3. It is a front view of the output side 6th speed gear which is one of the output side transmission gears. It is an expanded sectional view of the engaging part of a slider ring and an output side transmission gear. It is a front view which shows the engagement state of the engagement hole of the slider ring for high speed stages, and the engagement protrusion of the output side 6th speed gear. It is a front view which shows the engagement state of the engagement hole of the low speed slider ring and the engagement protrusion of the output side first speed gear. It is an enlarged view fragmentary sectional view which shows the modification of a slider ring. It is an enlarged view fragmentary sectional view which shows another modification of a slider ring. FIG. 7 is a cross-sectional view showing a conventional motorcycle gear transmission.

[First Embodiment]
1 to 8 show a gear-type transmission for a motorcycle according to a first embodiment of the present invention, and the first embodiment will be described based on these drawings. In each figure, the vehicle width direction of the motorcycle is indicated by an arrow W, and the vehicle front (traveling direction) is indicated by an arrow F. In addition, the left-right direction viewed from the rider who rides is displayed as the left-right direction of the vehicle.

  In FIG. 1, an engine E is a four-cylinder engine, and a transmission case 2 is integrally provided on the rear side of the crankcase 1. A crankshaft 3 extending in the vehicle width direction W is disposed in the crankcase 1. In the transmission case 2, a transmission input shaft 5 and a transmission output shaft 6 are arranged in parallel with the crankshaft 3. The output shaft 6 is disposed behind the input shaft 5.

  The crankshaft 3 is rotatably supported by the crankcase 1 via left and right bearings 10 and 11 and a plurality of journal bearings 12 in the middle in the axial direction, and each crankpin in the crankcase 1 is connected via a connecting rod. Are connected to the piston 13 of the corresponding cylinder. A crank gear 21 is integrally formed on the outer peripheral surface of the second crank web 15 from the right side of the crankshaft 3.

  Both left and right end portions of the input shaft 5 are rotatably supported by the transmission case 2 by bearings 30 and 31, and the input side first speed gear 41 and the input side second gear are arranged on the input shaft 5 in order from the right side. The speed gear 42, the input side third speed gear 43, the input side fourth speed gear 44, the input side fifth speed gear 45, and the input side sixth speed gear 46 are fixed so as not to move in the axial direction.

  The right end portion of the input shaft 5 protrudes into the clutch chamber 20, and a multi-plate friction clutch 35 is provided at the protruding portion on the right side, and a clutch gear 28 is fitted in a freely rotating manner, and the clutch gear 28 is connected to the crank gear. 21 and is coupled to an input-side outer case (clutch housing) 36 of the clutch 35. The output-side inner hub 37 of the clutch 35 is fixed to the transmission input shaft 5. As is well known, the outer case 36 and the inner hub 37 are connected via a number of friction plates so as to be intermittently operated.

  In FIG. 2 showing the details of the transmission of FIG. 1, the output shaft 6 is rotatably supported on the transmission case 2 by bearings 55 and 57 at both left and right ends. 80 is fixed to the outer periphery of the intermediate cylinder shaft 80 in order from the right side, the output side first speed gear 61, the output side second speed gear 62, the output side third speed gear 63, and the output side fourth speed gear 64. The output-side fifth speed gear 65 and the output-side sixth speed gear 66 are fitted in a freely rotating manner, and the input-side first speed gear 41, the input-side second speed gear 42, and the input-side third speed, respectively. The gear 43, the input side fourth speed gear 44, the input side fifth speed gear 45, and the input side sixth speed gear 46 are always meshed.

  As shown in FIG. 1, the left end portion of the output shaft 6 protrudes outside the transmission case 2, and an output sprocket 67 is fixed to the left protruding end portion. The output sprocket 67 is connected to a rear wheel sprocket 69 via a drive chain 68.

  Between the axial direction of the output side first speed gear 61 and the output side second speed gear 62 on the output shaft 6, between the axial direction of the output side third speed gear 63 and the output side fourth speed gear 64, and the output side Between the axial directions of the fifth speed gear 65 and the output side sixth speed gear 66, the first slider ring 51, the second slider ring 52, and the third slider ring 53 for the shift mechanism are connected to the output shaft 6. The intermediate cylinder shaft 80 (FIG. 2) is spline-fitted so as to be movable in the axial direction, and has a plurality of engagement holes 54 spaced apart in the circumferential direction. The intermediate cylinder shaft 80 functions as a slider rail that supports the slider rings 51, 52, 53 slidably in the axial direction.

  On the other hand, on the end faces in the axial direction of the output side gears 61, 62, 63, 64, 65, 66, engagement protrusions that protrude toward the slider rings 51, 52, 53 and can be engaged with the engagement holes 54 are provided. 56 are formed.

  As an operation mechanism in the axial direction of each of the slider rings 51, 52, 53, a shift cam drum 75 having three cam grooves 71, 72, 73 and a drive pin engage with each cam groove 71, 72, 73. A first, second, and third shift forks 81, 82, and 83, and a shift shaft 85 that supports the shift forks 81, 82, and 83 so as to be axially movable are provided. The shift cam drum 75 and the shift shaft 85 are arranged in parallel to the output shaft 6 and the input shaft 5 and below the shafts 5 and 6, and the fork claws of the shift forks 81, 82, 83 The slider ring 51, 52, 53 is engaged with each annular groove 58 formed on the outer periphery. The three shift forks 81, 82, 83 are all of the same shape.

  In FIG. 2, a shift cam drum 75 is linked to a change pedal (not shown) via a swingable change arm mechanism 77 and a change shaft (not shown) in the same manner as a drum operation mechanism of a normal motorcycle. Has been. That is, the shift cam drum 75 is rotated by a predetermined amount of rotation through the change arm mechanism 77 by depressing or raising the change pedal, and the shift forks 81, 82, 83 is moved in the axial direction, and the slider rings 51, 52 and 53 are selectively moved in the axial direction.

FIG. 3 is a front view of the third slider ring 53 for the high speed stage. Four engagement holes 54 are formed at equal intervals in the circumferential direction, and the inner circumference of the third slider ring 53 is shown. Four sliding grooves (spline grooves) 78 are formed on the surface at equal intervals in the circumferential direction. Each sliding groove 78 is formed at a position shifted in the circumferential direction from the engagement hole 54, and is formed in a wall portion between the circumferential directions of adjacent engagement holes 54, and the groove of each sliding groove 78. The bottom (outer end in the radial direction) 78a is located more outward in the radial direction than the inner end 54a in the radial direction of each engagement hole 54. That is, each sliding groove 78 is formed to protrude outward in the radial direction from the inner end 54 a of the engagement hole 54 in the wall between the engagement holes 54. Further, a lubricating oil passage 79 extending outward in the radial direction and reaching the groove bottom of the annular groove 58 is formed in the groove bottom 78 a of each sliding groove 78.

  4 is an enlarged cross-sectional view taken along the line IV-IV of FIG. 3, and on both axial end faces of the third slider ring 3, a plane projecting outward in the axial direction from each end face by a predetermined overhang amount h1. An overhang surface 53a is formed. The radial formation range K of each projecting surface 53a is from the radially inner side of the engaging hole 54 to the radially outer side of the engaging hole 54 and radially outward from the outer end 54b of the engaging hole 54. It extends to the site and is formed over the entire circumference in the circumferential direction. The overhang h1 is set to about 0.5 to 1.0 mm, for example.

  The third slider ring 53 is made of nitrided steel. An example of the manufacturing process will be described. First, shape processing is performed by machining or the like, polishing is performed, nitriding is performed, and surface compounds such as iron nitride generated by nitriding are polished and removed. The nitriding treatment reaches the inside from the surface to about 0.1 mm, but a surface compound layer (eg, iron nitride layer) of about 8 microns is scraped off by polishing after the nitriding treatment. The reason for scraping off the surface compound layer is that the compound on the surface is likely to become brittle by being integrated with the inside, and may be peeled off by collision during shifting. The polishing after the surface treatment includes shot peeling with a high-pressure gas or the like.

  FIG. 5 is a front view of the output-side sixth speed gear 66, and four engagement projections 56 are formed on the end face in the axial direction of the output-side sixth speed gear 66 at equal intervals in the circumferential direction. ing.

  Although the detailed structure of the output-side sixth speed gear 66 has been described with reference to FIG. 5, the outer diameters of the output-side first to fifth speed gears 61, 62, 63, 64, 65 are also based on the respective reduction ratios. Except being set, four engaging projections 56 are formed in the same arrangement as the output-side sixth speed gear 66.

  3 and 4, only the detailed structure of the third slider ring 53 has been described. However, the first and second slider rings 51 and 52 for the medium and low speed stages also have the same structure as the third slider ring 53. Similarly, as shown in FIG. 8, four engagement protrusions 54 are provided at equal intervals in the circumferential direction, and sliding grooves 78 are provided between the engagement holes 543 in the circumferential direction. Further, overhanging surfaces 51a and 52b (52b not shown) are formed on the end surface in the axial direction so as to protrude outward in the axial direction by a predetermined amount. Note that the circumferential length L1 of the first and second slider rings 51 and 52 is shorter than the circumferential length L3 of the third slider ring 53 shown in FIG.

  For example, in FIG. 7, the engagement protrusion 56 of the output-side sixth speed gear 66 in the engagement hole 54 of the third slider ring 53 is movable within a crank angle range of 41 ° at the maximum, In FIG. 8, the engagement protrusion 56 of the output first speed gear 61 in the engagement hole 54 of the first slider ring 54 is shorter than that for the sixth speed and moves within a crank angle range of about 31 ° at the maximum. Is possible.

  Further, similarly to the third slider ring 53, a nitriding layer is formed on the surfaces of the first and second slider rings 51 and 52.

  In the present embodiment, the second slider ring 52 has the same dimensions as the first slider ring 51.

(Operation of the embodiment)
1 and 2, the first to third slider rings 51, 52, 53 are all in the neutral position. When the clutch 35 is disengaged from this state and the change pedal is pushed down, the shift cam drum 75 is moved. The first shift fork 81 is moved rightward by the first cam groove 71, and the first slider ring 51 is engaged with the engagement protrusion 56 of the output first speed gear 61. The hole 54 is engaged, and the output first speed gear 61 and the output shaft 6 are coupled so that power can be transmitted.

  When the clutch 35 is connected in the first speed state, the power of the crankshaft 3 is transmitted to the input shaft 5 via the crank gear 21, the clutch gear 28, the outer case 36 of the clutch 35, the friction plate, and the inner hub 37, From the input shaft 5, the input side first speed gear 41, the output side first speed gear 61, the engagement protrusion 56 of the output side first speed gear 61, the engagement hole 54 of the first slider ring 51, the first It is transmitted to the output shaft 6 through the slider ring 51 and the intermediate cylinder shaft 80 (FIG. 2), and transmitted from the output shaft 6 to the rear wheel through the output sprocket 67, the drive chain 68, and the sprocket 69.

  When shifting from the first speed to the second speed, the shift cam drum 75 is further rotated by a predetermined amount by operating the change pedal, thereby moving the first slider ring 51 to the left and the first slider ring. The engagement hole 54 of 52 is engaged with the engagement protrusion 56 of the output second speed gear 62.

  When shifting to the third speed or the fourth speed, the shift cam drum 75 is further rotated by a predetermined amount to move the second slider ring 52 to the right (third speed) or to the left (first 4th)

  When shifting to the fifth speed and the sixth speed, the third slider ring 53 is moved rightward (fifth speed) or leftward (first speed) by further rotating the shift cam drum 75 by a predetermined amount. 6th)

(Effect of embodiment)
(1) FIG. 6 shows a state in which the third slider ring 53 has moved to the left and the engagement hole 54 has engaged with the engagement protrusion 56 of the output-side sixth speed gear 66. The left projecting surface 53 a of the third slider ring 53 is in contact with the right end surface of the sixth speed gear 66. Thereby, the over-operation of the third slider ring 53 is prevented, the right end surface of the output-side sixth speed gear 66 and the third slider ring 53 are prevented from coming into contact with each other (per part), and noise generation is prevented. it can.

  Of course, even when the speed is changed to the first to fifth speeds, the stopper action by the projecting surfaces 51a, 52a, 53a of the slider rings 51, 52, 53 prevents the same gear piece and prevents the generation of noise. Can do.

(2) As shown in FIG. 7, in order to shift to the sixth speed, the engagement hole 54 of the third slider ring 53 is engaged with the engagement protrusion 56 of the output-side sixth speed gear 66 (not shown). In this case, the circumferential length L3 of the engagement hole 54 is formed to be longer than the circumferential length L1 of the engagement hole 54 of the first slider ring 51 in FIG. Even in the output-side sixth speed gear 66, the engagement chance between the engagement protrusion 56 and the engagement hole 54 can be lengthened, whereby the engagement of the sixth speed gear 66 can be performed quickly even at high speed rotation. The mating protrusion 56 and the engagement hole 54 of the third slider ring 53 can be engaged with each other to shift to the sixth speed state.

  Further, when shifting to the fifth speed, since the third slider ring 53 is used as in the case of the sixth speed, the meshing chance can be lengthened, and the fifth speed gear 65 that rotates at high speed can be obtained. The engagement projection 56 and the engagement hole 54 of the third slider ring 53 can be quickly engaged to shift to the fifth speed state.

(3) As shown in FIG. 8, in order to shift to the first speed, the engagement hole 54 of the first slider ring 51 is engaged with the engagement protrusion 56 of the output first speed gear 61 (not shown). In this case, since the output first speed gear 61 rotates at the lowest speed, even if the circumferential length L1 of the engagement hole 54 of the first slider ring 51 is short, a sufficient meshing chance is ensured. can do. Further, since the amount of movement of the engagement protrusion 56 in the engagement hole 54 is short when meshing, the engagement protrusion 56 is formed at the end edge of the engagement hole 54 in the case of the output first speed gear 61 where a large torque is applied. The impact force at the time of a collision can be suppressed small, and an impact sound can also be suppressed.

  In the case of shifting to the second speed, as in the case of the first speed, even when the circumferential length L1 of the engagement hole 54 of the first slider ring 51 is short, a sufficient engagement chance can be ensured. . In addition, since the amount of movement of the engagement protrusion 56 in the engagement hole 54 during engagement is short, the engagement protrusion 56 collides with the edge of the engagement hole 54 in the case of the second speed gear 62 with a large torque. The impact force at the time of performing can be suppressed small, and the impact sound can also be suppressed.

(4) As shown in FIGS. 7 and 8, the sliding groove 78 on the inner periphery, the sliding protrusion (spline protrusion) 81, and the intermediate cylinder shaft 80 in a state where the engaging protrusion 56 and the engaging hole 54 are engaged. However, since the groove bottom 78a of the sliding groove 78 is positioned radially outward from the inner end 54a of the engagement hole 54, the engagement protrusion 56 is used. The load applied to the slider rings 51, 53, etc. can be received not only by the shearing force but also by a compressive load that compresses the wall between the engagement holes 54 in the circumferential direction. Therefore, even if the thickness of the slider ring 53 or the like is reduced, sufficient load bearing strength can be maintained. Moreover, the radial dimension of the slider rings 51, 52, 53 can be shortened, and the slider ring can be reduced in size and weight.

(5) The output side gears 61, 62, 63, 64, 65, 66 and the input side gears 41, 42, 43, 44, 45, 46 go from one end side in the axial direction to the other end side. Accordingly, the gears are arranged so that the gear position is gradually increased, that is, the diameter is sequentially increased or decreased, so that the assembly order of gears and the like is not mistaken at the time of assembly, and the efficiency of the assembly work is improved. Further, since the transmission gears having the same diameter are adjacent to each other and the slider rings 51, 52, 53 are disposed between the transmission gears having the same diameter, the engagement of the slider rings 51, 52, 53 is performed. The holes 54 and the engagement protrusions 56 of the transmission gears on both sides can be easily aligned in the radial direction, and manufacturing is easy.

(6) Since the gear teeth are not formed on the slider rings 51, 52, and 53 that move in the axial direction, dog teeth or the like are formed on the end face of the transmission gear as in the conventional example of FIG. Compared with the structure in which the slider itself is slid in the axial direction, the outer diameters of the slider rings 51, 52, and 53 can be made smaller and lighter.

(7) Since the three slider rings 51, 52, 53 for the shift mechanism are all provided on the output shaft 6, the arrangement of the shift forks 81, 82, 83 and the shift cam drum 75 can be made compact in one place. And the structure can be simplified.

(8) In motorcycles, the gear ratio between the input-side transmission gear and the output-side transmission gear is increased to reduce the speed of the engine that rotates at a higher speed than the four-wheeled vehicle. In such a transmission for a motorcycle, when all the slider rings 51, 52, 53 are arranged on the output shaft 6, the engaging holes 54 of the slider rings 51, 52, 53 are engaged. The formation process of the possible engagement protrusion 56 is more advantageous in terms of strength or processing than the case of forming the input side transmission gear having a small diameter.

(9) The gears 41, 42, 43, 44, 45, 46 and 61, 62, 63, 64, 65, 66 on the input side and the output side do not move in the axial direction. However, the gear for shifting itself does not fall down, the contact of the gear tooth tip is maintained well, and there is no fear of causing pitching or the like.

(10) Since all the shifting gears 41, 42, 43, 44, 45, 46, 61, 62, 63, 64, 65, 6641 on the input side and the output side are fixed in the axial direction, The shaft lengths of the input shaft 5 and the output shaft 6 can be kept short, the shaft diameter can be reduced and the weight can be reduced, the shaft deflection due to the load during operation can be reduced, and the shift touch can be smooth.

(11) Since the engagement holes 54 are formed in the slider rings 51, 52, 53, and the engagement protrusions 56 that engage with the engagement holes 54 are formed in the transmission gear, the slider rings 51, 52, 53 are formed. Since the driving load can be received not only by the shearing force but also by the compressive force in the circumferential direction at the time of engagement, it is possible to reduce the thickness of the slider rings 51, 52, 53. The axial lengths of the input shaft 5 and the output shaft 6 can be kept short.

(12) Since the shift cam drum 75 and the shift shaft 85 are disposed below the output shaft 6 and the input shaft 5, the lubricating oil that lubricates the gear fitting portions of the output shaft 5 and the input shaft 6 has a lower shift fork. 81, 82, 83 and the shift cam drum 75 are dropped and automatically used for lubricating the shift forks 81, 82, 83 and the shift cam drum 75.

(13) Since the nitriding layer is formed on the surfaces of the slider rings 51, 52 and 53, the durability against impact is improved as compared with the process of increasing the internal hardness like the charcoal process.

(14) Since the three shift forks 81, 82, 83 having the same shape are used, the productivity of the shift forks 81, 82, 83 is improved, and the parts management is simplified.

[Other embodiments]
(1) FIG. 9 is a modified example of the slider ring 51 (and 52, 53), and the position of the radially outer end of the protruding surface 51a formed on the axial end surface is the radial direction of the engagement hole 54. It is set to the middle position of the width.

(2) FIG. 10 shows another modification of the slider ring 51 (and 52, 53). The sliding groove 78 formed on the radially inner peripheral surface has a groove bottom 78a within the engagement hole 54. It is formed so as to be positioned inward in the radial direction from the side edge 54a, and is formed with about 10 to 12 at intervals in the circumferential direction.

(3) In the embodiment shown in FIGS. 1 and 2, all the slider rings 51, 52, 53 are provided on the output shaft 6, but all the slider rings 51, 52, 53 are provided on the input shaft 5. It is also possible to provide it.

(4) The present invention can also be applied to a transmission in which the gear position is 4th speed, 5th speed, 7th speed or more.

(5) The output-side transmission gear and slider rings 51, 52, and 53 shown in FIG. 2 are provided on the intermediate cylindrical shaft 80 fixed to the output shaft 6, but can also be provided directly on the output shaft 6. is there.

(6) The present invention can be variously modified and changed without departing from the spirit and scope of the present invention described in the claims.

3 Crankshaft 5 Input shaft 6 Output shaft 21 Crank gear 28 Clutch gear 35 Multi-plate friction clutch 41, 42, 43, 44, 45, 46 Input side first speed to sixth speed gear (transmission gear)
51, 52, 53 First, second and third slider rings 51a, 52a, 53a Overhang surface 54 Engagement hole (engagement portion)
54a Inner end 54b Outer end 56 Engagement protrusion (engagement part)
61, 62, 63, 64, 65, 66 Output side first speed to sixth speed gear (transmission gear)
71, 72, 73 Cam groove 75 Shift cam drum 78 Sliding groove 78a Groove bottom (outward end)
81, 82, 83 Shift fork

Claims (7)

An input shaft, an output shaft arranged in parallel with the input shaft, a plurality of input side transmission gears provided on the input shaft, and a plurality of outputs provided on the output shaft, respectively meshing with the input side transmission gears A transmission for a motorcycle that changes speed by selecting a power transmission path through the input transmission gear and the output transmission gear between the input shaft and the output shaft. In
Among the input shaft and the output shaft, one of the plurality of transmission gears provided on the one shaft is fixed in the axial direction and around the shaft, and the other shaft is provided on the other shaft. The plurality of transmission gears fixed in the axial direction and fitted so as to be rotatable about the axis;
The other shaft is provided with a plurality of dog coupling slider rings fixed around the shaft and slidable in the axial direction.
The transmission gears provided on the slider ring and the other shaft are respectively formed with engaging portions that can be disengaged by the movement of the slider ring in the axial direction.
The slider ring is connected to a shift cam drum via a shifter member that engages with an annular groove on the outer periphery of the slide ring so as to be slid in the axial direction , and the radial inner peripheral surface of the slider And a lubricating oil passage communicating with the outer peripheral surface ,
The transmission for a motorcycle , wherein the shift cam drum is disposed below the other shaft so that lubricating oil that has lubricated a lubricating portion on the other shaft is supplied to the shift cam drum. . The transmission for a motorcycle according to claim 1,
A sliding groove that is recessed outward in the radial direction is formed on the inner peripheral surface of the slider ring,
A transmission for a motorcycle , wherein a radially inner end of the lubricating oil passage reaches the sliding groove . The motorcycle transmission according to claim 2, wherein
The transmission for a motorcycle , wherein a groove bottom at a radially outer end of the sliding groove is located on a radially outer side than a radially inner peripheral end of the engagement portion of the slider ring . The transmission for a motorcycle according to any one of claims 1 to 3,
The engaging portion of the slider ring is an engaging hole penetrating in the axial direction, and the engaging portion of the transmission gear can be disengaged from the engaging hole by movement of the slider ring in the axial direction. A transmission for a motorcycle, which is a simple engaging projection . The transmission for a motorcycle according to claim 4,
The transmission for a motorcycle, wherein the lubricating oil passage is formed between circumferential directions of the plurality of engagement holes . The transmission for a motorcycle according to any one of claims 1 to 5,
The transmission for a motorcycle , wherein the shifter member is disposed below the other shaft . The transmission for a motorcycle according to claim 6,
The shifter member is supported on the shift shaft so as to be slidable in the axial direction,
A transmission for a motorcycle, wherein a fork claw portion of a shifter member is engaged with the annular groove, and a drive pin is engaged with a cam groove of the shift cam drum .

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