JPS629782B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a cooling device for a belt-type power transmission mechanism, and particularly to a cooling device that performs cooling using outside air.

"Prior Art" Conventionally, for example, in a motorcycle, a belt-type transmission mechanism is sometimes employed to transmit the output of the engine to the rear wheel.

By the way, in the above-mentioned belt type transmission mechanism, heat is generated due to friction between the belt and the pair of pulleys around which the belt is wound, which may affect the power transmission efficiency of the transmission mechanism. There is. In particular, in belt-type transmission mechanisms used in motorcycles and the like, stepless speed change is achieved by changing the distance between the left and right parts of the pulley to change the effective diameter of the pulley, which reduces the heat generation described above. There is a great demand for countermeasures against this problem.

Therefore, in the past, fins were attached to the drive shaft, that is, the drive pulley provided on the output shaft of the engine, and the fins were used to agitate the air in the transmission case in which the belt and pulley were housed. Therefore, attempts are being made to remove heat from the pulleys and belts.

"Problems to be Solved by the Invention" The present invention aims to solve the above-mentioned problems such as the joints in the conventional technology.

That is, since auxiliary equipment such as a starter is generally housed in the transmission case of the aforementioned motorcycle, its internal space is larger than the space for housing the belt, and the belt housing space is larger than the belt housing space. As a result, the air stirred by the fins flows to areas other than the pulley and belt, and the flow velocity becomes low, which reduces the cooling effect of the pulley and belt. This is a problem that can result in a decrease in

"Means for Solving the Problems" The present invention aims to provide a cooling device for a belt type transmission mechanism that can effectively solve the problems in the conventional technology described above.
The case body and the cover form a transmission case, and the tips of the drive shaft and driven shaft pivotally supported by the case body, as well as the drive pulley and driven pulley attached to the tips of each, are connected to the cover side. A cooling device used in a belt-type power transmission mechanism arranged in a space, wherein a centrifugal fan is provided on one of the pulleys, and an air intake is provided at a position of the cover facing the axis of the centrifugal fan. An exhaust port is formed at a position facing the other pulley, and a partition plate is provided between the case body and the cover, so that between the partition plate and the cover, It is characterized in that a cooling air passage is formed that surrounds both the pulleys and connects the intake port and the exhaust port.

"Function" The cooling device for a belt-type transmission mechanism according to the present invention sucks outside air from the intake port using fins provided on one pulley, and distributes this sucked outside air between the cover and the partition plate. Through the formed cooling air passage, the air is moved along the pulley and belt, and during the movement, heat is exchanged with the pulley and belt, and then the air that has undergone heat exchange is transferred to the other pulley. By discharging to the outside from a nearby exhaust port, diffusion of the intake air is prevented and most of the air is used for heat exchange between the pulley and the belt.

“Embodiment” An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of a belt-type transmission mechanism of a motorcycle, and a crankshaft 2 of an engine 1 is used as a drive shaft of this belt-type transmission mechanism (hereinafter referred to as transmission mechanism) A.

The case body 3 of the transmission mechanism A is connected to the engine body, and the case body 3 opens to the side of the vehicle body.
A cover 4 is provided in the opening, and the case body 3 and the cover 4 form a transmission case 5.

A drive pulley 6 is attached to the tip of the crankshaft 2, and a driven pulley 9 is attached to the tip of the driven shaft 8 on the rear wheel 7 side, and a belt 10 is attached to the drive pulley 6 and the driven pulley 9. It's wrapped around. The crankshaft 2 and the driven shaft 8 are attached to the case body 3, and the pulleys 6, 9 and the belt 10 are located in a space on the side of the cover 4 inside the transmission case 5. .

Further, an intermediate shaft 12 is provided between the axle 11 of the rear wheel 7 and the driven shaft 8, and the rotation of the driven shaft 8 is controlled by the gear 13 of the driven shaft 8 and the gear 1 of the intermediate shaft 12.
4, gear 15 of intermediate shaft 12 and axle 1
The signal is transmitted to the axle 11 by meshing with the gear 16 of No. 1.

The drive pulley 6 consists of a movable face 17 and a fixed face 18.
is fitted onto the outer periphery of a collar 19 fitted onto the crankshaft 2 so as to be slidable in the axial direction, and the fixed face 18 is fitted onto the shaft end of the crankshaft 2 and is screwed onto the shaft end. said collar 1 by the nut 20
It is press-fitted and fixed to the end of 9. A ramp plate 21 is fixed to the movable face 17, and a weight roller 22 is disposed between the ramp plate 21 and the back surface of the movable face 17.

The distance between the ramp plate 21 and the back surface of the movable face 17 is formed to become gradually narrower toward the outer circumference.
When the movable face 17 moves outward due to the centrifugal force, the movable face 17 is moved toward the fixed face 18 to a position balanced with the centrifugal force. This increases the effective radius around which the belt 10 is wound around the drive pulley 6.

On the side surface of the fixed face 18, that is, on the side facing the cover 4,
A plurality of fins 23 are arranged, and the fixed face 18
The fan itself functions as a centrifugal fan.

An annular guide plate 23a is provided at the end of the fin 23.
is provided.

The driven pulley 9 has a fixed face 27 welded to a boss 26 which is rotatably fitted onto the driven shaft 8 via bearings 24 and 25, and a fixed face 27 which is slidably fitted onto the boss 26. The movable face 28 has a cam groove 29 in its boss portion inclined at a predetermined angle (approximately 45 degrees) with respect to the axial direction.
A pin 30 implanted in the boss 26 is fitted into 9, so that when the movable face 28 moves in the axial direction, the movable face 28 itself rotates.

Further, a centrifugal clutch 31 is provided on the driven shaft 8 for connecting the driven pulley 9 and the driven shaft 8. The centrifugal clutch 31 includes a bowl-shaped clutch outer 33 with a substantially U-shaped cross section fixed to the end of the driven shaft 8 with a nut 32, and a clutch outer 33 fixed to the end of the boss 26 with a nut 34. The clutch plate 35 is connected to the inside of the cylindrical portion 33a of the clutch outer 33.
It consists of a clutch 36 which is pivotally connected to the clasp 36 and is expandable in the radial direction.

When the rotation speed of the boss 26 exceeds a preset value, the clutch 36 expands and joins the inner surface of the clutch outer 33 to transmit rotation to the driven shaft 8.

The movable face 28 also has a spring 37 disposed between the movable face 28 and the clutch plate 35.
is biased toward the fixed face 27 side by
The movable face 28 is positioned at a position where the tension of the belt 10 and the force of the spring 37 are balanced.

In the present invention, the space inside the transmission case 5 is divided into two parts: a chamber on the cover 4 side, that is, the belt chamber 38, and a chamber on the case body 3 side, that is, the auxiliary equipment chamber 39. A partition plate, in this embodiment a gasket 40, is provided to partition the chambers, and as a result, the drive pulley 6, driven pulley 9, and the belt 10 wound around them are positioned within the belt chamber 38. It is becoming more and more popular.

Further, on the drive pulley 6 side of the cover 4, an air suction passage is opened facing the rotation center of the fixed face 18 of the drive pulley 6, that is, the axis of the centrifugal fan formed on the side surface of the fixed face 18. 41 is formed, and an air exhaust passage 42 that communicates with the belt chamber 38 is formed on the driven pulley 9 side, and the outer end of the air exhaust passage 42 is opened downward to allow air exhaust. Exit 43 is provided.

Therefore, the belt chamber 38 surrounds both the pulleys 6, 9 and the belt 10, and
A cooling air passage connecting the air intake passage 41 and the air outlet 43 is formed.

In addition, the reference numeral 44 is a kick shaft of the starting device, and a gear 45 of the kick shaft 44 and a gear 47 of the intermediate shaft 46 are connected to each other.
Rotation is transmitted to the crankshaft 2 by the meshing with the gear 47b of the intermediate shaft 46 and the gear 48 of the crankshaft 2. Said Patsukin 4
0 is the movable face 17 portion of the drive pulley 6, the fixed face 27 portion of the driven pulley 9,
Regarding the hard shaft 44 part and the intermediate shaft 46 part,
Holes are made for these to be inserted, but there are minute gaps between each hole and each member inserted through these holes. Also, code 49
are meshing teeth from a starter motor (not shown).

Next, the effect will be explained.

Due to the rotation of the crankshaft 2, the drive pulley 6
The fins 23 provided on the fixed face 18 function as a centrifugal fan and suck in cold air from the outside from the air intake passage 41. In this case, the gap between the fin end face in the axial direction and the fin portion 4a of the cover 4 is narrow, and the guide plate 23a is provided on the fin end face, so that the fin 23 allows fast air to move toward its outer peripheral end. Cause a flow.

The cold air sucked by the fin 23 is first
It is brought into contact with the drive pulley 6 to perform heat exchange with the drive pulley 6, and then the belt chamber 38
While moving toward the driven pulley 9 inside, it is brought into contact with the belt 10 and exchanges heat with the belt 10, and is brought into contact with the driven pulley 9 and exchanges heat with the driven pulley 9. Then, the air is discharged to the outside through the air discharge passage 42 and the air discharge port 43.

During such cooling, the air intake passage 41 and the air outlet 43 are connected almost linearly by a cooling air passage formed by the belt chamber 38, and the cooling air passage is connected to both pulleys 6. , 9 and the belt 10, the cold air sucked in from the air intake passage 41 flows without stagnation within the belt chamber 38 and is discharged to the outside, and also flows within the restricted space. This speeds up the flow.

Therefore, the cold air is vigorously applied to the pulleys 6 and 9, which generate a particularly large amount of heat, and the above-mentioned cooling can be carried out efficiently.

In the embodiment described above, the gasket 40 was used as a partition plate between the belt chamber 38 and the auxiliary equipment chamber 39, but the gasket does not necessarily have to be a gasket, and a plate made of metal or synthetic resin may be used.

Further, in the embodiment described above, the fins 23 are formed on the side surface of the fixed face 18 of the drive pulley 6 to form a centrifugal fan, but the invention is not limited to this, and the fins 23 may be attached to the driven shaft 8 side if the mounting space is available. .

"Effects of the Invention" As explained above, the cooling device for a belt type power transmission mechanism according to the present invention includes a case body and a cover that form a transmission case, and a drive shaft and a driven shaft that are pivotally supported by the case body. A cooling device used in a belt-type power transmission mechanism in which a tip of a shaft and a drive pulley and a driven pulley attached to each tip are arranged in a space on the cover side, A centrifugal fan is provided on the pulley, an intake port is formed in the cover at a position facing the axis of the centrifugal fan, and an exhaust port is formed in a position facing the other pulley, and By providing a partition plate between the case body and the cover, a cooling air passage is formed between the partition plate and the cover, surrounding both the pulleys and communicating the intake port and the exhaust port. The air inlet and the exhaust port are connected almost linearly through a cooling air passage formed by the cover and the partition plate, and the cooling air passage is a restricted space. , the cold air sucked into the cover flows through the cooling air passage without stagnation and at a high flow rate, and then is quickly discharged, whereby the cold air is forcefully applied to both pulleys that generate a particularly large amount of heat. This provides excellent effects such as efficient cooling and improved durability of the belt-type power transmission mechanism.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; FIG. 1 is a sectional view of a belt-type power transmission mechanism in a motorcycle, FIG. 2 is a partially cutaway schematic side view,
FIG. 3 is a side view with only the cover removed. 2... Crankshaft (drive shaft), 3... Case body, 4... Cover, 5... Transmission case, 6... Drive pulley, 8... Driven shaft, 9... Driven pulley, 10... Belt , 17...Movable face, 18...Fixed face, 23...Fin (centrifugal fan), 27...Fixed face, 28...Movable face, 31...Centrifugal clutch, 38...Belt chamber, 39...Supplementary Aircraft compartment, 40...Packing (partition plate), 41...Air intake passage (intake port), 42
...Air discharge passage, 43...Air discharge port (exhaust port).

Claims (1)

[Claims] 1 The case body and the cover form a transmission case, and the tips of the drive shaft and driven shaft pivotally supported by the case body, and the drive pulley and driven pulley attached to the tips of each, are attached to the cover side. A cooling device for use in a belt-type power transmission mechanism arranged in a space, wherein a centrifugal fan is provided on one of the pulleys, and a centrifugal fan is provided on the cover at a position opposite to the axis of the centrifugal fan. By forming an intake port, forming an exhaust port at a position facing the other pulley, and providing a partition plate between the case body and the cover, there is a gap between the partition plate and the cover. A cooling device for a belt-type power transmission mechanism, characterized in that a cooling air passage is formed that surrounds both the pulleys and connects the intake port and the exhaust port.