JPH0642612A - Air cooling device for vehicle with v-velt type transmission - Google Patents

Abstract

PURPOSE:To prevent choking of an air exhaust port and improve ventilation in a transmission case by forming an air exhaust port in the position, whose three sides are surrounded by a driving sheave, a driven sheave, and a V-velt wound around both of these sheaves in a horizontal view, situated below a transmission case on the external side of a V-velt. CONSTITUTION:Inside a transmission case 3 extended fore and aft on the outside of a rear wheel 6 in a motor cycle a driving shaft on an engine side and a rear shaft 5 for the rear wheel 6 are arranged longitudinally while a driven shaft 7 is arranged between the driving shaft and the rear shaft. A driving sheave and a driven sheave 13 are supported by the driving shaft and the driven shaft 7 respectively, the rear shaft 5 is connected to the driven sheave 13 via the driven shaft 7, and a V-velt 14 is wound around the driving sheave and the driven sheave 13. In this constitution, an air exhaust port 33 is formed at the lower part of the transmission case 3 on more external side than the V-velt 14 being surrounded from three sides by the driving sheave, the driven sheave 13, and the V-velt 14 in a horizontal view. The air exhaust port 33 is opened downward from the inside of the transmission case 3.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air cooling device for a vehicle with a V-belt type transmission such as a motorcycle. 2. Description of the Related Art Conventionally, there is a motorcycle constructed as follows. That is, an engine and a transmission case extending rearward from a crankcase of the engine are supported on the body frame of the motorcycle. A crankshaft end, which is a drive shaft on the engine side, is disposed in the front part of the transmission case, a rear axle for the rear wheels is supported at the rear part of the transmission case, and the transmission case is located outside the rear wheels. It is located towards A driven shaft is supported in the transmission case between the crankshaft end and the rear axle. The drive sheave is supported on the crankshaft end, while the driven sheave is supported on the driven shaft, and the rear axle is interlocked with the driven sheave via the driven shaft. A V-belt is wound around the drive sheave and the driven sheave. When the engine is driven, the power of the engine is automatically changed from the crankshaft end through the drive sheave, the V-belt, and the driven sheave and transmitted to the driven shaft, and further, from here, through the rear axle. It is transmitted to the rear wheels and the motorcycle can run. By the way, when power is transmitted as described above, the heat of the engine, the drive sheave, the driven sheave, and the V-belt are frictionally joined to each other at a high speed. The heat may raise the temperature of the air in the transmission case. Therefore, it is conceivable to form an air discharge port in any of the above-mentioned transmission cases and to ventilate the inside of the transmission case by discharging the air having a high temperature in the transmission case through the air discharge port. However, if the air outlet is simply formed, there are the following problems. That is, firstly, due to the arrangement of the above-mentioned components,
When the drive sheave, the driven sheave, or the V-belt greatly blocks the air outlet, the flow of air through the air outlet is blocked, ventilation in the transmission case is obstructed, and the inside of the transmission case is blocked. Air cooling may be insufficient. Secondly, when the air outlet is formed as described above, there is a risk that foreign matter such as mud splashed up by the rear wheel or rainwater at the time of rain will fly into the transmission case through the air outlet. . SUMMARY OF THE INVENTION The present invention has been made by paying attention to the above-mentioned circumstances, and can effectively ventilate the inside of the transmission case and sufficiently cool the drive sheave and the like inside the transmission case. Even if an air outlet is formed in the transmission case due to the above-mentioned air cooling, foreign matter such as mud splashed up by the rear wheel and rainwater during precipitation are transmitted through the air outlet. The purpose is to prevent it from easily jumping into the case. In order to achieve the above object, the present invention is characterized in that the drive shaft on the engine side is arranged in the front portion of the transmission case provided on the outer side of the rear wheel. Meanwhile, the rear axle for the rear wheels is supported by the rear portion of the transmission case, and the driven shaft is supported in the transmission case between the drive shaft and the rear axle, and the drive sheave is supported by the drive shaft. On the other hand, the driven sheave is supported by the driven sheave, and the rear axle is interlockingly connected to the driven sheave via the driven shaft,
When a V-belt is wound around the drive sheave and the driven sheave, in plan view, the drive sheave, the driven sheave,
And an air discharge port is formed in the lower portion of the transmission case at a position outside the V belt, which is surrounded by the V belt on three sides, and the air discharge port is opened downward from the inside of the transmission case. There is a point. [Operation] The operation of the above configuration is as follows. The terms in parentheses below correspond to the terms in the claims. The crankshaft (driving shaft) 4 on the engine 1 side is arranged in the front part of the transmission case 3 provided outside the rear wheel 6, while the rear part for the rear wheel 6 is provided in the rear part of the transmission case 3 as above. The axle 5 is supported, and the driven shaft 7 is supported between the crankshaft (drive shaft) 4 and the rear axle 5 in the transmission case 3 as above.
While supporting the drive sheave 12 on the crankshaft (drive shaft) 4, the driven sheave 13 is supported on the driven shaft 7.
The driven sheave 13 is connected to the driven sheave 7 through the rear axle 5.
When the V belt 14 is wound around the drive sheave 12 and the driven sheave 13, the drive sheave 12, the driven sheave 13, and the V belt 14 are surrounded from three sides in a plan view, and An air outlet 33 is formed in the lower part of the transmission case 3 at a position outside the V-belt 14 on the vehicle side. Therefore, firstly, the air discharge port 33 is displaced from the drive sheave 12, the driven sheave 13, and the V-belt 14 in plan view.
3 is prevented from being blocked by the drive sheave 12 and the like. Therefore, the flow of air through the air outlet 33 becomes smooth. Secondly, the transmission case 3 has the rear wheel 6
Of the V-belt 14 in the transmission case 3 and the air outlet 33 is located outside the vehicle.
Moreover, the air exhaust port 33 is located further forward than the driven shaft 7 located in front of the rear axle 5 for the rear wheel 6. Therefore, the air exhaust port 33 has the rear wheel 6
It is farther outward and farther than the front. Moreover, the air outlet 33 is opened downward from inside the transmission case 3. Therefore, rainwater at the time of precipitation is prevented from passing through the air discharge port 33 and jumping into the transmission case 3. Embodiments of the present invention will be described below with reference to the drawings. The arrow Fr in FIGS. 1 and 2 indicates the front of the vehicle, and the left and right described below refer to the direction toward the front. A motorcycle, which is a vehicle, has an engine 1. The front portion of the transmission case 3 is fixed to the crankcase 2 of the engine 1, and the rear portion of the transmission case 3 extends rearward of the vehicle body. The crankcase 2 is pivotally supported on the vehicle body frame, and the rear portion of the transmission case 3 is vertically swingable. A rear axle 5 is supported on the rear portion of the transmission case 3, and a rear wheel 6, which is a traveling wheel, is supported on the rear axle 5. In the above case, the transmission case 3 is located on the left side of the rear wheel 6. In addition, a shock absorber (not shown) is installed on the body frame and the transmission case 3. The transmission case 3 has a two-part structure composed of a case body 3a integrally formed with the crankcase 2 and a cover portion 3b covering a left side opening of the case body 3a. Further, the middle part of the outer surface of the cover portion 3b in the up-down direction is a bulging portion 3c having a U-shaped cross-section to reinforce the transmission case 3 (see FIG. 5). A left end of a crank shaft 4 which is a drive shaft on the engine 1 side is arranged in the front portion of the transmission case 3. A driven shaft 7 is provided in the transmission case 3 between the left end of the crankshaft 4 and the rear axle 5, and the driven shaft 7 is provided with left and right side walls of the transmission case 3 by ball bearing type left and right bearings 11 ′ and 11. Barrel case 3a and cover 3
Both ends are supported across b. Incidentally, the case body 3a and the cover portion 3b.
And the bearings 11 ', 11 are molded together by die casting.
Position accuracy is difficult to obtain. Therefore, in this embodiment, the bearing 11 'is press-fitted on the cover portion 3b side, and the case body 3a is pressed.
When the cover part 3b is assembled, the end of the driven shaft 7 is fitted by loose fitting in the inner hole of the bearing 11 '. In this case, the amount of eccentricity of the end of the driven shaft 7 with respect to the bearing 11 'is half the gap between the outer surface of the driven shaft 7 and the inner surface of the inner hole of the bearing 11'. The amount of eccentricity is set within a range that can be absorbed by the radial play of the bearing 11 'itself. Then, from this state, the washer 7a is fitted, and the end of the driven shaft 7 and the inner race of the bearing 11 'are fixed by the nut 7b, whereby the driven shaft 7 is supported at both ends. On the other hand, if the nut 7b is removed,
The case body 3a and the cover portion 3b can be disassembled, and the belt can be exchanged while the driven shaft 7 is cantilevered on the case body 3a side. A V-belt type transmission 8 for transmitting the power of the crankshaft 4 to the side of the driven shaft 7, a clutch 9 for connecting / disconnecting the transmission of power from the transmission 8 to the driven shaft 7, and from the driven shaft 7 Gear reduction device 10 for transmitting power to the rear wheels 6
And are provided. The speed change device 8 is an automatic speed change device in which the speed reduction ratio decreases with increasing speed, and includes a drive sheave 12 supported at the left end of the crankshaft 4, a driven sheave 13 supported by the driven shaft 7, It has a V-belt 14 wound around both of the sheaves 12 and 13. The drive sheave 12 has a drive-side fixed sheave 12a facing each other and forming a belt groove, and a drive-side movable sheave 12b. The drive sheave 12 is rotated by the centrifugal force of the weight 15 by the rotation of the drive sheave 12 more than a predetermined amount. The movable sheave 12b is configured to move in the axial direction to reduce the belt groove width. The driven sheave 13 has a driven side fixed sheave 13a and a driven side movable sheave 13b facing each other. The fixed sheave 13a is fixed to a support body 16 rotatably provided coaxially on the driven shaft 7, and the driven-side movable sheave 13b is provided on the support body 16 so as to be slidable in the axial direction. Is urged to reduce the belt groove width. Referring particularly to FIGS. 3 and 4, the clutch 9 is a dry friction clutch and a centrifugal automatic clutch, and is supported by the driven shaft 7 coaxially with the driven shaft 7. ing. The drive side 18 of the clutch 9 also uses the driven side fixed sheave 13a as the main body of the drive side 18, whereby the width dimensions of the driven sheave 13 and the clutch 9 are shortened. Further, the driven side fixed sheave 13
a to a plurality of engaging projections 19 in the circumferential direction in the axial direction of the clutch 9.
Is projected. The engagement hole 20 formed in the clutch plate 21 and the engagement projection 19 are fitted to each other, and the clutch plate 21 is axially movable along the engagement projection 19. On the other hand, the driven side 22 of the clutch 9 includes a rotating body 23 fixed to the driven shaft 7 and a friction plate 24 fitted to the rotating body 23 by a spline and inserted between the adjacent clutch plates 21. have. In addition, a weight 25 is provided on the driven-side fixed sheave 13a, and the weight 2 is generated when the driven sheave 13 rotates more than a predetermined amount.
The plates 21 and 24 are joined by the centrifugal force of 5 to transmit power. Reference numeral 26 is a disc spring, and 27 is a retaining ring, which is fitted on the outer peripheral surface of the free ends of the engaging projections 19 to prevent the free ends of the engaging projections 19 from being radially outwardly bent by centrifugal force. The outer edge of the clutch plate 21 projects radially outward from the engaging projection 19 to enhance the cooling effect. Further, a slit 28 is formed outward from the engagement hole 20 in the radial direction, so that stress due to thermal deformation of the clutch plate 21 is prevented. Further, the friction plate 24 is integrally formed of an asbestos-based non-metallic material having a low thermal conductivity, and its sound absorbing property prevents generation of contact noise with the rotating body 23. The gear reduction device 10 will be described. The gear reduction device 10 has a gear cover 34 attached to the case body 3a so as to cover the case body 3a, which is a side wall on the rear wheel 6 side of the transmission case 3, from the inside of the transmission case 3 as above. These case bodies 3
A space surrounded by a and the gear cover 34 is a gear chamber 35. Further, a space inside the transmission case 3 excluding the gear chamber 35 is a shift chamber 36. The left end of the rear axle 5 has a ball bearing type bearing 37 on the gear cover 34.
It is supported by. An intermediate shaft 29 is provided in the gear chamber 35 between the driven shaft 7 and the rear axle 5, and the intermediate shaft 29 is supported at both ends across the case body 3a and the gear cover 34. . In the gear chamber 35, the driven shaft 7 and the intermediate shaft 29 are interlockingly connected by the first gear set 30, and the intermediate shaft 29 and the rear axle 5 are interlockingly connected by the second gear set 38. . Then, the power of the driven shaft 7 is reduced in two stages by the gear reduction device 10 and transmitted to the rear axle 5. In the above case, the driven shaft 7 is the gear cover 3 described above.
Both ends are supported by the left and right bearings 11 ', 11 through the case body 3a, which is the left and right side walls of the transmission case 3, and the cover portion 3b as described above. The first gear set 30 is located closer to the rear wheel 6 than the second gear set 38 in the vehicle width direction. A device for cooling the inside of the transmission case 3 is provided. That is, a plurality of blades 31 are provided on the driven movable sheave 13b so as to project therefrom. On the other hand, the bulging portion 3c of the transmission case 3 is provided with a rectangular tubular body 32, and an air outlet 33 is formed on the bottom surface of the bulging portion 3c at the base of the rectangular tubular body 32. In plan view (FIGS. 1 and 2), the air discharge port 33 is connected to the clutch 9, the drive sheave 12, and the driven sheave 1.
3, and is surrounded by the V belt 14 from three sides, and is located outside the V belt 14 with respect to the vehicle. Then, the blade 3 when the engine 1 is driven
With the rotation of 1, the outside air is sucked in through an intake hole (not shown), and the outside air flows in the transmission case 3 to cool the drive sheave 12, the driven sheave 13, the V-belt 14 and the like, and the air exhaust port 33. Is discharged. According to the present invention, the drive shaft on the engine side is arranged in the front portion of the transmission case provided on the outer side of the rear wheel, while the above-mentioned rear wheel for the rear wheel is arranged in the rear portion of the transmission case. The rear axle is supported, the driven shaft is supported between the drive shaft and the rear axle, and the driven shaft is supported in the transmission case.The drive shaft is supported by the driven sheave while the driven shaft is supported by the driven sheave. The rear axle is interlockingly connected to the sheave via the driven shaft,
When a V-belt is wound around the drive sheave and the driven sheave, in plan view, the drive sheave, the driven sheave,
Further, an air outlet is formed in the lower part of the transmission case at a position which is surrounded by the V-belt from three sides and is on the vehicle outer side than the V-belt. Therefore, firstly, since the air discharge port is displaced from the drive sheave, the driven sheave, and the V-belt in plan view, the air discharge port is blocked by the drive sheave or the like. Is prevented. Therefore, the flow of air through the air discharge port becomes smooth, and the ventilation in the transmission case is effectively performed correspondingly, so that the cooling of the transmission case is sufficiently performed. Secondly, the transmission case is located on the outer side of the rear wheel, and the air outlet is located on the vehicle exterior side of the V-belt in the transmission case. Moreover, the air outlet is located further forward than the driven shaft located in front of the rear axle for the rear wheels. Therefore, since the air outlet is largely separated from the rear wheel outward and forward, foreign matter such as mud splashed up by the rear wheel passes through the air outlet into the transmission case. Jumping in is prevented. Moreover, since the air discharge port is opened downward from the inside of the transmission case, rainwater at the time of precipitation can be prevented from passing through the air discharge port and jumping into the transmission case. Since foreign matter and rainwater are prevented from entering the air outlet as described above, there is no problem even if the opening area of the air outlet is increased to some extent. Therefore, since the opening area of the air discharge port can be enlarged to some extent, the ventilation in the transmission case is further effectively performed, and the air cooling in the transmission case becomes more sufficient.

[Brief description of drawings] FIG. 1 is a rear plan sectional view. FIG. 2 is a front plan sectional view. 3 is a partially enlarged view of FIG. FIG. 4 is a partial view taken along line 4-4 of FIG. 5 is a view taken along the line 5-5 of FIG. [Explanation of symbols] 1 engine 2 crankcase 3 transmission cases 4 Crankshaft (drive shaft) 5 rear axle 6 rear wheels 7 Driven shaft 8 gearbox 9 clutch 12 drive sheave 13 Driven sheave 14 V belt 33 Air outlet

Claims (1)

[Claims] 1. A transmission case extending forward and backward on the outer side of the rear wheel is provided, and a drive shaft on the engine side is arranged in the front portion of the transmission case, while the rear axle of the rear wheel is supported on the rear portion of the transmission case. Same as above, between the drive shaft and the rear axle, the driven shaft is supported in the transmission case, while the drive shaft supports the drive sheave, while the driven shaft supports the driven sheave, and the driven sheave passes through the driven shaft. Link the rear axles together,
V with a V-belt wrapped around the drive sheave and driven sheave
In a vehicle with a belt type transmission, in plan view, it is surrounded by the drive sheave, the driven sheave, and the V belt from three sides, and an air discharge port is provided below the transmission case at a position outside the V belt. Formed,
An air-cooling device for a vehicle with a V-belt type transmission in which this air outlet is opened downward from the inside of the transmission case.