JPH11173413A - Gear type transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a size in the axial direction in a compact size while reducing the number of parts, and improve an operational property by shortening a stroke of a shift sleeve, in a gear type transmission provided with a dog clutch type switching mechanism. SOLUTION: A plurality of speed stage gears 90, 91 are arranged adjacent to each other on a speed change shaft, an engaging pawl 112 engaged with an engaging pawl of a shift sleeve 98 is arranged on the speed stage gear 91 arranged on the shift sleeve 98 side, an extending boss part 109 led to the sleeve side bypassing an inner circumferential side of the gear 91 interposed in the shift sleeve 98 is formed on the other speed stage gear 91, and an engaging pawl 115 is arranged on the extending boss part 109. The engaging pawl 123 is selectively engaged with the engaging pawls 115, 112 of the speed stage gears 90, 91 by moving one shift sleeve 98 in an axial direction. It is thus possible to form the size in the axial direction in a compact size, and it is also possible to improve an operational property by shortening a stroke.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gear transmission mainly suitable for mounting on a vehicle.

[0002]

2. Description of the Related Art In this type of gear type transmission, a shift sleeve is provided on a speed change shaft so as to be movable in an axial direction, and a shift sleeve is provided between the shift sleeve and a shift gear disposed axially laterally of the shift sleeve. Although a dog clutch mechanism is formed by the engagement of the engagement claws, only one speed change gear that meshes with the shift sleeve can be arranged on one side of the shift sleeve in the axial direction.

For example, in a gear transmission having two forward speeds and one reverse speed (or two forward speeds and two reverse speeds),
As shown in FIG. 19, a low-speed forward gear 201, a high-speed forward gear 202, and a reverse sprocket gear 203 are arranged on the input speed-change shaft 200 at a fixed interval from each other,
A shift sleeve 210 for switching forward is disposed between the forward gears 201 and 202, and another shift sleeve 211 for switching reverse is disposed beside the sprocket gear 203 for reverse. By shifting each of the sleeves 210 and 211 in the axial direction, the required gears 201 and
The engaging claws 225, 226 or 227 of the sleeve 210 or 211 are selectively and appropriately engaged with the engaging claws 220, 221 or 222 of 202 or 203, and power is transmitted at a desired gear.

[0004]

The configuration shown in FIG. 19 has the following problems. (1) To perform a three-stage shift of two forward steps and one reverse step,
Since the two shift sleeves 210 and 211 are required, the axial dimension of the transmission shaft 200 is increased, the transmission is increased in size, and the transmission shaft 200 becomes longer, so that the transmission shaft 200 is likely to bend. And the gears, especially the gears 202 and 230 at the center, decrease the meshing accuracy,
To prevent this, it is necessary to increase the diameter of the transmission shaft.

(2) Since the speed must be changed by operating the two sleeves 210 and 211,
When the operation of one of the shift levers engaging with the gears 10 and 211 becomes complicated, and when one of the sleeves 210 is shifted, the other sleeve 2 is moved in order to avoid double meshing.
11 must always be kept in the neutral position. Therefore, when shifting from a state in which it meshes with a certain gear to another gear, first, the meshing sleeve 211 is first returned to the neutral position, and thereafter, The shift operation of another sleeve 210 is performed. As described above, it is necessary to shift the two sleeves 210 and 211 in order when performing a shift change. Therefore, a shift operation mechanism such as an interlock mechanism (double meshing prevention mechanism) and a select mechanism is provided, and the number of parts is reduced. Are increasing, which is helping to increase the size.

(3) When shifting, one sleeve is returned to the neutral position, and the other sleeve is shifted from the neutral position. Therefore, when shifting, both sleeves must be in the neutral position at the same time. The shift stroke is lengthened, which also increases the size. The prior art documents include JP-A-63-38740.

[0007]

SUMMARY OF THE INVENTION The number of shift sleeves or the number of dog clutch engagement claws formed on the sleeve can be reduced, and the axial dimension of the speed change shaft can be reduced. It is to make the ring good.

[0008]

According to a first aspect of the present invention, there is provided a gear transmission according to the present invention, comprising:
A plurality of gears for gear positions are arranged close to each other in the axial direction, and a shift sleeve having a dog clutch engagement portion is arranged on one side of the gear group in the axial direction. The gear is provided with an engagement portion that faces the dog clutch engagement portion of the sleeve in the axial direction. An extension boss is formed to reach the space on the side of the side, and the extension boss is provided with an engagement portion that faces the dog clutch engagement portion of the sleeve in the axial direction. It is characterized in that the dog clutch engagement portion is selectively engaged with the engagement portion of each of the above-mentioned gears.

The gear type transmission according to the second aspect is the first aspect.
In the plurality of gear-type transmissions described above,
It is characterized in that it is arranged close to a bearing that supports the transmission shaft, and the shift sleeve is arranged on the opposite side of the bearing.

According to a third aspect of the present invention, there is provided a gear type transmission.
Alternatively, in the gear transmission according to the item 2, a low-diameter low gear and a large-diameter high gear are sequentially arranged from a position closest to the bearing.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a mechanism explanatory view showing a power transmission system of a motorcycle engine to which the present invention is applied in a skeleton style. The engine comprises a cylinder 1, a piston 2, a crankcase 3, and a crankshaft 4. A transmission case 6 is integrally formed at a rear portion of the crankcase 3, a bell-con case 5 and a bell-con cover 7 are sequentially attached to the right side, and the crankshaft 4 includes a bearing 13.
Are supported at both ends by the crankcase 3.

In the bell-con case 5 and the bell-con cover 7, a drive shaft 8, a driven shaft 9, a drive shed 10, a driven shed 11, a V-belt 12 wound around the two sheds 10, 11 and the like. A V-belt type automatic transmission T is arranged, and a transmission case 6 is provided with an input speed change shaft 20, an intermediate speed change shaft 21, an output shaft 22, and the like. Machine S is arranged.

Referring to FIG. 2, the structure of the V-belt type automatic transmission T will be described in detail. 2 shows a state in which the V-belt 12 is not clamped and the power is cut off, that is, an idling state, for the drive pulley 10, and the driven pulley 11 is located on the front side of the driven shaft O2 ( The state shown on the (drive shaft side) indicates a state in which the effective winding diameter is the maximum, that is, an idling state in which the reduction ratio is maintained at the maximum position, corresponding to the state of the drive shed 10, On the other hand, the state shown behind the driven shaft O2 indicates a state in which the effective winding diameter of the driven gear 11 is minimum, that is, a state in which the reduction ratio is minimum and the vehicle is traveling at high speed.

The drive shaft 8 is taperedly fitted to the right end of the crankshaft 4, is integrally connected by a fastening bolt 17, and is cantilevered by a bearing 18. The drive sheave 10 includes a left fixed sheave 14 and a right movable sheave 15 axially opposed to the fixed sheave 14. The fixed sheave 14 is fixed to the drive shaft 8 in the rotational direction and the axial direction. On the other hand, the movable sheave 15 is
, But is fitted so as to rotate integrally with the drive shaft 8. On the left end surface of the fixed sheave 14, a cooling fan 31 is formed.

On the back side (right side) of the movable sheave 15, a drive adjusting thrust generating mechanism 19 comprising a spider 23, a plurality of governor weights 24, a pressure adjusting spring 25 and the like is provided. The plurality of governor weights 24 are rotatably supported by a plurality of pins 27 provided on the back surface of the movable sheave 15, and expand to the right due to centrifugal force as the number of rotations of the drive shaft 8 increases. It is designed to open. A connecting arm 35 extending rightward through the spider 23 is formed on the rear surface of the movable sheave 15, and the right end of the connecting arm 35 is fitted to the drive shaft 8 movably in the axial direction. The cover 26 is integrally connected, so that the movable sheave 15 and the cover 26 rotate integrally with each other, and can move in the axial direction integrally with the drive shaft 8.

The spider 23 is disposed on the right side of the movable sheave 15 and is integrally fixed to the drive shaft 8 by screw-fitting to the drive shaft 8.
4 is provided with a pressure receiving roller 28 with which the roller 4 contacts. Pressure adjusting spring 2
5 is contracted between the spider 23 and the cover 26, and the cover 26 and the movable sheave 15 integrated with the cover 26 are urged rightward by the pressure adjusting spring 25 to stop the stopper portion 24 a of the governor weight 24. The movable sheave 15 is locked by being pressed against the stopper portion 15a.

That is, when the engine is stopped and idling, the movable sheave 15 is urged rightward integrally with the cover 26 by the pressure adjusting spring 25 as shown in FIG. When the engine rotates and the governor weight 24 starts expanding rightward, the cover 2 is pressed against the pressure adjusting spring 25.
6 and moves to the left integrally with the fixed sheave 14 to narrow the gap.

FIG. 3 is an enlarged sectional view of the driven gear 11 and the driven shaft 9 is also cantilevered by a bearing 77 at the left end. The driven gear 11 includes a fixed sheave 33 on the right side and a movable sheave 34 on the left side, and has a cylindrical cam shaft 38, a roller supporting sleeve 46, a roller 50, and a pressure adjusting spring 4.
9, the power of the belt 12 is transmitted to the driven shaft 9 via a torsion damper 42 disposed at the right end of the driven shaft 9. ing.

The torsion damper 42 is a well-known two-stage type disk type damper, and includes a flange 56 integrally having a hub 55 and a pair of side plates 60 disposed on both axial sides of the flange 56. , Flange 56
And a torsion spring 58 disposed in each of the window holes 62 and 63 of the side plate 60. Hub 55
Are spline-fitted to the driven shaft 9 and are fixed so as not to fall off by bolts 61 and washers. The formed boss portion 65 is connected by a bolt 66. The flange 56 and the side plate 60 are connected to the torsion spring 5.
It can be twisted around the driven shaft center O2 relatively against 8 etc.

FIG. 6 shows the torsion damper 42 of FIG.
FIG. 6 is a view taken in the direction of the arrow VI, and further includes a torsion spring 59 for a second-stage characteristic in addition to a torsion spring 58 for a first-stage characteristic;
The side plate 60 has a twist angle of 0 with respect to the flange 56.
At this time, both springs 58 and 59 are in contact with the circumferential edge of the window hole 63 of the side plate 60,
With respect to the circumferential edge of the window hole 62 of the flange 56, the first
The step characteristic torsion spring 58 abuts, while the second step characteristic torsion spring 59 has a certain play M.
Reference numeral 67 denotes an elongated hole formed in the flange 56 for regulating the maximum torsion range, and the side plate connecting bolt 66 is inserted therethrough.

That is, in the process of relative torsion between the flange 56 and the side plate 60, when the torsion starts from the torsion angle 0, only the torsion spring 58 for the first-stage characteristic is compressed, and the torsion spring 58 is twisted by a certain angle and the window of the flange 56 Hole 6
After the circumferential edge of the second torsion spring 59 abuts on the second-stage characteristic torsion spring 59, the second-stage characteristic torsion spring 59 is also compressed together with the first-stage characteristic torsion spring 58, thereby limiting the maximum torsional range. It is twisted until the long hole 67 for use and the bolt 66 engage in the circumferential direction.

FIG. 7 is a torsion characteristic diagram. In the section between the torsion angles 0 and θ1, only the torsion spring 58 for the first stage characteristic is compressed. This is a section where the springs 58 and 59 are compressed.

The pressure adjusting mechanism and the lubricating mechanism of the driven gear 11 will be described in detail with reference to FIGS. In FIG. 3, the cam shaft 38 is fitted to the outer periphery of the driven shaft 9 via a pair of left and right bearing metals 36 so as to be axially immovable and rotatable. An annular grease reservoir 37 sealed between the left and right oil seals 39 and 40 is formed between the inner peripheral surfaces. Fixed sheave 33
Is fixedly screwed (screw-fitted) to the outer periphery of the right end of the camshaft 38 and is coupled to the side plate 60 by bolts 66 so as to rotate integrally with the camshaft 38. The pressure adjusting mechanism is configured so that the movable sheave 34 can be spirally twisted with respect to 33.

FIG. 4 is an exploded perspective view of the cam shaft 38 and the sleeve 46.
The roller support holes 53 are formed at three locations at equal intervals in the circumferential direction, and a pair of O-ring fitting grooves 68 are formed on both axial sides of the roller support holes 53, and further, at the right end. Has an integral mounting flange 46b. Three rollers 50 are also provided, and each roller 50 is integrally formed with a small supporting diameter portion 52 via a step portion 50b, and is inserted into a roller supporting hole 53 from a radially inner side to support the roller. It is supported rotatably around the center of the hole. The camshaft 38 has a cylindrical cam groove 5 extending spirally in the axial direction.
Each roller 50 is slidably engaged with the cylindrical cam groove 51 in the axial direction.
The cam action causes the sleeve 46 to move spirally with respect to the camshaft 38.

In FIG. 5, each roller 50 is prevented from coming out radially outward due to centrifugal force or the like due to the contact between the annular step portion 50b and the counterbore surface 53b of the roller support hole 53. Since the outer peripheral surface of the driven shaft 9 faces the inner edge of the roller 50 in the radial direction (the driven shaft core O2 side),
When the engine stops or the like, it is prevented from coming off inward in the radial direction.

In FIG. 3, the inner peripheral boss portion 34b of the movable sheave 34 is fitted to the outer peripheral surface of the sleeve 46 via an O-ring 69, and a bolt 4 is attached to the mounting flange portion 46b.
7 and the camshaft 38 integrally with the sleeve 46.
It makes a spiral motion with respect to. Sleeve 46
Are rotatably and axially movably fitted to the outer peripheral surface of the cam shaft 38 via a pair of left and right bearing metals 48, and annular seals 70 are fitted to the inner peripheral surfaces of the left and right ends of the sleeve 46. An annular grease reservoir 7 having a shallow bottom is provided on a portion of the inner peripheral surface of the sleeve corresponding to the roller support hole 53.
1 is formed. The annular grease reservoir 71 is sandwiched between the pair of O-rings 69. An appropriate amount of grease is applied to the annular grease reservoir 37 between the cam shaft 38 and the driven shaft 9, and grease is also applied to the roller support holes 53. A part of the grease pressed by the grease is held in the annular grease reservoir 71 through a fitting portion of the support hole 53, for example.

The pressure adjusting spring 49 is provided with a spring receiving ring 74 disposed on the left end surface of the inner peripheral boss portion 34b of the movable sheave 34.
And a spring receiving ring 73 locked to the left end of the camshaft 38 by a snap ring 75,
The movable sheave 34 is moved to the sleeve 46 by the pressure adjusting spring 49.
At the same time, it is urged to the right by a constant spring force. When the tension on the tension side of the V-belt 12 increases as the load increases and the movable sheave 34 is twisted in the rotational direction, the cam groove 51 and the roller 5
The movable sheave 34 generates a thrust in a direction to close rightward spirally by the cam action with 0, and in addition to this, a pressure adjusting spring 49
In addition to the spring load, a thrust according to the transmission power is applied.

The gear type transmission will be described in detail. In FIG. 9, the input speed change shaft 2 formed integrally with the driven shaft 9
0 and the intermediate transmission shaft 21 are arranged in parallel with each other, and each of the bearings 7 fitted to the left and right side walls of the transmission case 6.
6, 77 and bearings 78, 79, respectively, and the right end of the intermediate transmission shaft 21 is provided with another output gear chamber 8.
3 The output shaft 22 is connected to the transmission shaft 20,
21, a needle bearing 80 fitted to the right side wall of the transmission case 6, and an output gear chamber wall 84.
Are supported at both ends by a bearing 81 fitted to the bearing. The propeller shaft 16 is rotatably supported by a bearing 82 fitted to the rear wall of the transmission case 6, extends in the front-rear direction, and is always linked to the output shaft 22 via bevel gears 85 and 86. The rear end of the propeller shaft 16 is connected to the rear axle via a final deceleration mechanism (not shown), and the front end is connected to the front wheel propeller shaft via an appropriate universal joint or clutch.

On the input transmission shaft 20, a forward input low gear 90 is disposed at a position close to the right bearing 77, and a forward input high gear 91 is disposed adjacent to the low gear 90. A double reverse input sprocket gear 92 for reverse drive is disposed at a position close to the bearing 76, and one shift sleeve 98 is disposed at a central portion in the axial direction. That is, the reverse input sprocket gear 92 and the forward input gear groups 90 and 91 are separately arranged near the left and right bearings 76 and 77, and the shift sleeve 98 is arranged at the center.

The intermediate transmission shaft 21 includes the input transmission shaft 2.
An intermediate forward low gear 101, an intermediate forward high gear 102, and an intermediate reverse sprocket gear 103 are arranged corresponding to the gears 90, 91, and 92 on the upper gear 0, respectively. Close to the right bearing 79,
The reverse sprocket gear 103 is distributed and arranged so as to approach the left bearing 78. Each gear 101,
The reference numerals 102 and 103 are configured to always rotate integrally with the intermediate transmission shaft 21 by being spline-fitted to the intermediate transmission shaft 21. The intermediate low gear 101 is always meshed with the input low gear 90, the intermediate high gear 102 is always meshed with the input high gear 91, and the reverse intermediate sprocket gear 103 rotates in the same direction as the reverse input sprocket gear 92 via the chain 104. It is linked and linked. An output-side first gear 106 located in the output gear chamber 83 is fixed to the right end of the intermediate transmission shaft 21.
2 is meshed with the second output side gear 107.

In FIG. 10 showing an enlarged view of the input shaft 20, the input-side low gear 90 is integrally formed with an extended boss 109 extending cylindrically to the left, and is rotatable by a pair of left and right needle bearings 94. On the left end side of the extension boss 109, an outward engaging claw 115 for a dog clutch and an inner peripheral notch 11 are provided.
7 is disposed, and the engagement body 11
6 is engaged with the engagement projection 118 formed on the left end surface of the extension boss 109, thereby forming the engagement body 116.
Is always rotated integrally with the extension boss 109. The engaging body 116 is axially locked by a retaining plate 120 and a locking ring 121.

The forward input high gear 91 is rotatably and axially immovably fitted and supported on the outer periphery of the extension boss 109 via a needle bearing 119, and has a left end substantially the same as the gear 91 at the left end. A cylindrical extension 110 extending leftward in diameter is integrally formed, and an inward engagement claw 112 for a dog clutch is integrally formed at the left end of the extension 110. The inner diameter of the inward engaging claw 112 is set slightly larger than the outer diameter of the engaging body 116,
The axial distance D1 between the inward engaging claw 112 and the engaging body 116 is set to be larger than the axial width D2 of the dog clutch engaging claw 123 of the shift sleeve 98. , 115 (D1), it is sufficient that there is a margin for the engagement claw 123 of the sleeve to be in a neutral state once. Specifically, the axial distance D1 is about 1.2 times the axial width D2.

The radial length (thickness) of the engaging claw 123 of the shift sleeve 98 is such that the outer half in the radial direction is substantially engaged with the inward engaging claw 112 for high, and The inner half is dimensioned so that it can engage with the row outward engaging claw 115. In addition, the axial width D2 of the dog clutch engagement claw 123 of the shift sleeve 98 is such that a slightly right portion protrudes beyond the inward engagement claw 112 at the high position as shown in FIG. The notches 136-1, 2, 3, and 4 of the positioning mechanism described later are set at substantially equal intervals, and the shift stroke is divided substantially equally.

FIG. 14 is a view of the forward gear group shown in FIG. 10 as seen from the direction of arrow XIV. For example, six engagement claws 112 and 115 for the dog clutch are formed at equal intervals in the circumferential direction. Is longer than the circumferential width W1 of the engaging claw 123 of the shift sleeve 98 shown in FIG. 15 by a certain distance, and as shown in FIGS. And engaging claw 11 of each gear
2, 115 are engaged with play N in the circumferential direction.

Returning to FIG. 10, the shift sleeve 98 integrally has the forward engaging claw 123 on the right end face as described above, and the reverse engaging claw 124 on the left end face. The reverse engagement claw 124 is freely meshable with an engagement claw 126 formed on the reverse input sprocket gear 92. An annular groove 125 is formed at an intermediate portion of the shift sleeve 98 in the axial direction, and a shift fork 127 is engaged.

The shift fork 127 is connected to the input transmission shaft 2.
The shift rod 128 is fixedly supported by support holes 130 and 131 formed in left and right side walls of the transmission case 6 so as to be slidable in the axial direction. .

Between the shift rod 128 and the transmission case 6, a steel ball 132, a spring 133, and notches 136-1,2,
A positioning and holding mechanism including 3, 4 and the like is provided. The notches 136-1, 2, 3, 4 are provided on the outer peripheral surface of the left end portion of the shift rod 128 in order from the right for reverse use, neutral, high, and low. , 3, and 4 are arranged at substantially equal intervals. A steel ball 132 and a spring 133 are disposed in a hole 137 formed in the transmission case 6, and the spring 133 urges the steel ball 132 toward the shift rod 128, and each notch 136-1, 2, 3, 4 To selectively engage
It locks in that position.

The tip of a shift lever 140 is engaged with an engagement groove 138 formed in the shift fork 127 as shown in FIG. 8, and the shift lever 140 is provided on the upper wall of the transmission case 6. The shift arm 127 is fixed to a lever shaft 141 rotatably supported by a lever holder 142, and the shift arm 127 is moved in the axial direction by rotating the lever shaft 141 by an external shift operation mechanism. Has become.

Next, a lubrication system in the gear type speed reducer will be described. In FIG. 9, the input transmission shaft 20 has a lubricating oil hole 14 communicating from an oil chamber 144 to a lubricating oil passage in the transmission case 6.
3 is formed, and the lubricating oil hole 143 is formed in the low gear 9.
0 and the needle bearing 96 of the reverse sprocket gear 92. Oil is supplied to the oil chamber 144 from an oil passage (not shown).

[0040]

First, the operation of the entire power transmission path will be briefly described. In FIG. 1, the rotational force of the crankshaft 4 is controlled by a drive shaft 8, a drive gear 10,
The power is transmitted to the driven shaft 9 via the V-belt 12, the driven gear 11 and the torsional damper 42, and is automatically shifted in the V-belt type automatic transmission according to the rotation speed and the load from the wheel side. The torsional damper 42 eliminates the generation of impact noise during shifting of the gear type transmission or acceleration or deceleration.

The power transmitted from the driven shaft 9 to the input transmission shaft 20 of the gear transmission S is arbitrarily switched from a neutral state to a forward high state, a forward low state or a reverse state by operating the shift fork 127. And the intermediate transmission shaft 2
1 is transmitted to the propeller shaft 16 via the output shaft 22 and the bevel gears 85 and 86.

The gear shifting operation in the gear type transmission S will be described in detail. FIG. 9 shows a neutral state. The neutral position of the shift sleeve 98 is maintained by fitting the steel ball 132 into the neutral notch 136-2. The engagement claws 123, 124 of the shift sleeve 98
The power transmission is cut off by the input transmission shaft 20 because neither of the engagement claws 115, 112, 126 is engaged. By shifting the shift sleeve 98 to the right by a predetermined stroke from the neutral position, a forward high state is set.

FIG. 12 shows the forward high state, in which the forward engaging claw 123 of the shift sleeve 98 is connected to the high gear 91.
Of the high notch 136-3
The forward high state is maintained by the steel ball 132 being fitted into the arm. The rotational power of the input transmission shaft 20 is supplied by a sleeve 98, engagement claws (dog clutches) 123 and 112, a cylindrical extension 110, an input high gear 91, and an intermediate high gear 102.
, And transmitted to the output gear 106 via the intermediate transmission shaft 21.

In the operation of the vehicle, normal starting and running are performed in a forward high state. With the forward high state maintained, an appropriate wheel rotation speed is obtained by automatic shifting by the V-belt type automatic transmission T. The vehicle is switched to the low state on special road conditions such as steep slopes and uneven terrain. Therefore, normally, as described above, the state is first switched from the neutral position in FIG. 9 to the high state in FIG.

When the shift sleeve 98 is shifted from the neutral position to the forward high position, even if the circumferential phase between the engaging claw 123 of the sleeve 98 and the engaging claw 112 of the high gear 91 is shifted, FIG. As shown in FIG.
12 is configured to engage with a play N in the circumferential direction, so that the state in which the axial edges of the engaging claws 123 and 112 are in contact with each other is maintained for a while, and then the engaging claws 123 and 1 are engaged.
At the time when the phase shifts relatively slightly in the circumferential direction and the phases coincide, the two engaging claws 123 and 112 automatically mesh.

When shifting from the forward high state to the forward low state in FIG. 12, the shift sleeve 98 is further moved rightward from the state in FIG. Set to the low state.

In FIG. 11 showing the forward low state, after the forward engaging claw 123 of the shift sleeve 98 once passes through the intermediate neutral position as described above, the low gear engaging claw 11
5 and the steel ball 132 is fitted into the row notch 136-4, whereby the row position is maintained. Input speed change shaft 2
0 rotation power is sleeve 98, engagement claw (dog clutch)
123, 115, extension boss 109, input low gear 9
0, and transmitted to the output side gear 106 via the intermediate low gear 101 and the intermediate transmission shaft 21.

FIG. 13 shows a reverse state, in which the shift sleeve 98 is moved to the left from the neutral position in FIG. 9 to engage the engaging claw 126 of the reverse sprocket gear 92 with the reverse engaging claw 124 of the shift sleeve 98. Are engaged. The rotational power of the input transmission shaft 20 is supplied by the sleeve 98, the engagement claws 124 and 12.
6, reverse input sprocket gear 92, chain 10
4, transmitted to the output side gear 106 via the reverse intermediate sprocket gear 103 and the intermediate transmission shaft 21.

As described above, one shift fork 12
By operating only one shift sleeve 98 by the operation of 7, it is possible to switch between forward high, forward low, neutral and reverse.

The operation is also performed by the positioning notch 136.
By arranging -1, 2, 3, and 4 at substantially equal intervals, good operability can be maintained.

[0051]

[Other Embodiments] (1) FIG. 18 shows an example in which the first aspect of the present invention is applied to a transmission having three forward speeds. 151, a second gear 152 and a high gear 153 are disposed adjacent to each other in this order from the right side, and the low gear 151 integrally includes an extension boss 161 that passes through the inner circumference of the second gear 152 and the high gear 153 to the left and reaches the shift sleeve 98 side. The second gear 152 is rotatably supported on the outer periphery of the extension boss 161 of the low gear 151, and integrally extends with the extension boss 162 that passes through the inner periphery of the high gear 153 to the left and reaches the shift sleeve side. Have, high gear 15
3 is rotatably supported on the outer periphery of the extension boss 162 of the second gear 152.

The extension boss 16 of the low gear 151
1 is formed with a dog clutch engaging claw 181 at the left end,
At the left end of the extension boss 162 of the second gear 152, a cylindrical extension 172 extending leftward is formed.
3 is formed at the left end with a cylindrical extension 173 extending further to the left outside the cylindrical extension 172.
Inward engaging claws 182, 183 for dog clutches are formed at the left ends of the 72, 173, respectively.

[0053] Thus, only one shift sleeve 98 and one side (right side) of the engagement claw 123 can be used to perform forward three-speed shifting. In addition, the three gears 151, 152, and 153 for the speed change step are arranged close to the bearing 77 and adjacent to each other, so that it is possible to prevent a reduction in gear engagement accuracy due to the bending of the speed change shaft 20.

(2) In FIG. 1, the shift sleeve 98 is applied to the gear type transmission in which the shift sleeve 98 is disposed on the input side transmission shaft 20. The present invention can also be applied.

[0055]

As described above, (1) According to the first aspect of the present invention, a plurality of gears for gears are arranged adjacent to each other on the speed change shaft 20 so that the gear 91 closest to the shift sleeve and the sleeve 98 are connected to each other. Since the dog clutch engagement claws 112 and 115 of the gears 90 and 91 extend between the gear groups 90 and 91, at least two-stage switching is performed only by moving one shift sleeve 98 disposed on one side of these gear groups. The size of the transmission shaft 20 in the axial direction can be reduced, and the transmission shaft 20 is less likely to bend.
A reduction in the meshing accuracy of the gears can be prevented, and the diameter of the transmission shaft 20 does not need to be increased.

(2) As shown in FIG. 9, it is possible to operate two forward steps and one reverse step (or two forward steps and two reverse steps) simply by moving one shift sleeve 98, as shown in FIG. As in the case where two shift sleeves are used, the state where both sleeves are once set to the neutral position at the same time is not transferred to the next switching operation. Therefore,
The shift stroke can be shortened, the operation feeling is improved, and a shift operation mechanism such as an interlock mechanism (double meshing prevention mechanism) and a select mechanism is not required, so that downsizing can be achieved.

(3) A plurality of gears 90 and 91 for the gears arranged adjacent to each other are connected to the transmission shaft 20 as in the second aspect of the present invention.
Can be arranged close to the bearing 77 that supports
As described above, in addition to shortening the shaft dimension of the transmission shaft 20,
Since the gears are concentrated at a position near the bearing where the deflection is small, the accuracy of meshing between the gears can be maintained even higher.

(4) According to the third aspect of the present invention, the low gear 90 to which the largest rotational torque is applied is disposed at a position close to the bearing 77 having the smallest deflection, so that the accuracy of gear engagement between the gears is reduced due to the deflection. Can be more effectively prevented.

[Brief description of the drawings]

FIG. 1 is a mechanism explanatory view showing a power transmission system of a motorcycle engine to which the present invention is applied in a skeleton style.

FIG. 2 is a cross-sectional view of the V-belt type automatic transmission shown in FIG. 1 cut along a cut surface passing through each shaft.

FIG. 3 is an enlarged view of a driven gear change portion of the V-belt type automatic transmission shown in FIG. 2;

4 is an exploded perspective view of a pressure adjusting mechanism of the driven vehicle shown in FIG. 2;

FIG. 5 is a sectional view taken along line VV of FIG. 3;

FIG. 6 is a right side view of the torsional damper of FIG. 2;

FIG. 7 is a torsional characteristic diagram of the torsional damper of FIG. 6;

FIG. 8 is a partial vertical sectional view of the gear transmission shown in FIG. 1;

FIG. 9 is a sectional view taken along line IX-IX of FIG.

FIG. 10 is an enlarged view of an input-side transmission shaft portion of FIG. 9;

FIG. 11 is a cross-sectional view of an input-side transmission shaft showing a forward low state.

FIG. 12 is a cross-sectional view of an input-side transmission shaft showing a forward high state.

FIG. 13 is a cross-sectional view of the input-side transmission shaft showing a reverse state.

14 is a side view of the forward gear group of FIG. 10 as viewed in the direction of arrow XIV.

15 is a side view of the shift sleeve of FIG. 10 as viewed in the direction of arrow XV.

FIG. 16 is an enlarged cross-sectional view taken along the line XVI-XVI of FIG. 12, showing a state in which the engagement claws are engaged with each other at the time of forward high.

17 is an enlarged cross-sectional view taken along the line XVII-XVII in FIG. 11, illustrating a state in which the engagement claws are engaged with each other at the time of forward low.

FIG. 18 is an explanatory view of a mechanism showing another embodiment in a skeleton style.

FIG. 19 is a mechanism explanatory view showing a conventional example in a skeleton style.

[Explanation of symbols]

 Reference Signs List 8 drive shaft 9 driven shaft 10 drive shed 11 driven shed 12 V-belt 14 fixed sheave (drive shed side) 15 movable sheave (drive shed side) 19 drive shed thrust generating mechanism 20 input shifting shaft 21 intermediate Transmission shaft 22 Output shaft 76, 77 Bearing 90 Forward input low gear 91 Forward input high gear 92 Reverse input sprocket gear 98 Shift sleeve 101 Forward intermediate low gear 102 Forward intermediate high gear 103 Reverse intermediate sprocket gear 109 Extended boss Part 110 Cylindrical extension part 112, 115, 126 Engagement claw of shift gear 123, 124 Engagement claw of shift sleeve

Claims (3)

[Claims] 1. A plurality of gears for a plurality of gears are arranged on a speed change shaft so as to approach each other in the axial direction, and a shift sleeve having a dog clutch engaging portion is arranged on one axial side of the gear group. The shift gear closest to the shift sleeve is provided with an engaging portion axially opposed to the dog clutch engaging portion of the sleeve, and the remaining shift gear is interposed between the shift gear and the shift sleeve. Forming an extension boss portion passing through the inner peripheral side of the gear and reaching the space on the sleeve side, and providing the engagement portion for the dog clutch engagement portion of the sleeve in the axial direction with the extension boss portion; The gear type transmission is characterized in that the dog clutch engagement portion of the shift sleeve is selectively engaged with the engagement portion of each of the above-mentioned gears by the axial movement of the shift sleeve. 2. The gear according to claim 1, wherein a plurality of gears for a plurality of gears are arranged close to a bearing supporting the transmission shaft, and a shift sleeve is arranged on a side opposite to the bearing. Gear type transmission. 3. The gear transmission according to claim 1, wherein a low-diameter low gear and a large-diameter high gear are arranged in order from a position closest to the bearing.