JPH02256520A - Automatic transmission - Google Patents

Abstract

PURPOSE:To feed engine oil or the like to a centrifugal clutch for lubricating and cooling to improve durability by a method wherein a partition is placed between the centrifugal clutch and a V-belt automatic gear while these are placed in chambers partitioned from each other. CONSTITUTION:To a crank case 8 and a left side of a first gear ease 9 connected to it, a second gear case 20 is overlaid so that a clutch chamber 31 is formed between them. The left side of the second gear case 20 is covered with a case cover 23 to form a transmission chamber 24 between them. At this time the transmission chamber 24 is partitioned from the clutch chamber 21 by a side wall 20a of the second gear case 20. At the front part of the transmission chamber 24 a transmission shaft 25 is provided coaxially with a crank shaft 11 while at the rear part of the transmission chamber 24 a follower shaft 49 is provided parallel to the transmission shaft 25. Between the crank shaft 11 and a driving shaft 27 coaxial to this, a centrifugal clutch 30 is interposed. Further in the transmission chamber 24 a V-belt automatic gear 45 is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an automatic transmission equipped with an engine and a V-belt automatic transmission.

[Prior Art] For example, in scooter-type motorcycles, there is a so-called unit swing type automatic transmission in which an engine and a V-belt automatic transmission are integrated, and a rear wheel is provided at the rear end of the V-belt automatic transmission. It is used.

This automatic transmission device rotatably supports a transmission shaft coaxial with the crankshaft and a driven shaft parallel to the transmission shaft in a transmission case connected to the engine crankcase.
The power transmission shaft and the crankshaft are connected via a centrifugal clutch, and a V-belt is provided between the primary sheave on the driven shaft and the secondary sheave on the drive shaft.

Conventionally, the centrifugal clutch on the transmission shaft and the primary sheave forming the V-belt automatic transmission have been housed in the same chamber of the transmission case.

[Problems to be Solved by the Invention] However, when a centrifugal clutch and a V-belt automatic transmission are housed in the same room, taking into account slippage of the V-belt, the centrifugal clutch must be used in a dry state, a so-called dry type transmission. I have no choice but to do it.

For this reason, the centrifugal clutch relies on air cooling, which tends to be insufficiently cooled compared to when it is lubricated with oil. There are problems such as the temperature rising and ■ adversely affecting the life of the belt.

The present invention was made based on these circumstances, and
The centrifugal clutch can be efficiently cooled, and the effect of heat on the V-belt automatic transmission can be kept to a minimum.
The purpose of the present invention is to provide an automatic transmission device that improves the durability of the entire device.

[Means for Solving the Problems] Therefore, the present invention includes a transmission shaft connected to the crankshaft of an engine via a centrifugal clutch, and a driven shaft disposed parallel to the transmission shaft. In an automatic transmission device in which a shaft and a transmission shaft are interlocked via a V-belt automatic transmission, a partition wall is provided between the centrifugal clutch and the V-belt automatic transmission, and the centrifugal clutch and the V-belt automatic transmission are connected to each other. It is characterized by the fact that it is placed in a room separated from each other.

[Function] According to this configuration, the centrifugal clutch and the V-belt automatic transmission are housed in separate chambers, so oil such as engine oil is introduced into the centrifugal clutch, and the centrifugal clutch is forcibly lubricated and Can be cooled.

Furthermore, since the centrifugal clutch that generates heat is isolated from the V-belt automatic transmission, the centrifugal clutch is cooled with oil, and the heat of the centrifugal clutch is less likely to be transmitted to the V-belt automatic transmission.

Therefore, the durability of the V-belt automatic transmission including the centrifugal clutch can be improved.

[Embodiment] An embodiment of the present invention will be described below based on drawings in which the present invention is applied to a scooter type motorcycle.

Figure 3 shows a scooter-type motorcycle, in which reference numeral 1 is the vehicle body, 2 is the front fork, 3 is the front wheel, 4 is the handle,
5 indicates the respective sheets.

A swing type engine unit 6 is arranged below the seat 5. The front end of the engine unit 6 is swingably supported by the vehicle body 1. Details of the engine unit 6 will be described below with reference to FIGS. 1 and 2.

That is, the engine unit 6 includes a forced air-cooled engine 7 and a first transmission case 9 extending rearward from the left side of the crankcase 8 of the engine 7.
A crankshaft 11 is supported inside the crankcase 8 via a bearing 10.

Further, the crankcase 8 is provided with a cylinder 12, and a piston 13 within the cylinder 12 is connected to the crankshaft 11 via a connecting rod 14. A flywheel magneto 14 and a fan 15 are attached to one end of the crankshaft 11.

The fan 15 is for forced air cooling of the cylinder 12 of the engine 7, and the rotation of the fan 15 causes the outside air sucked in from the intake port 17 of the shroud 1B to cool the cylinder 12 of the engine 7.
After flowing between B and the cylinder 12, it is discharged to the outside through the exhaust port 18.

Crank case 8 and first transmission case 9 connected to it
A second transmission case 20 is superimposed on the left side of the transmission case 9 , and a clutch chamber 21 is formed between the first and second transmission cases 9 and 20 . The other end of the crankshaft 11 is introduced into the clutch chamber 21, and a one-way clutch 22 is provided on the outer periphery of the crankshaft 11 facing the clutch chamber 21, which allows only power transmission from a starter motor (not shown). It is being

Further, the left side surface of the second transmission case 20 is covered by a case cover 23, and a transmission chamber 24 is formed between the transmission case 20 and the case cover 23. The transmission chamber 24 is located on the side wall 2 of the first and second transmission case 20.
It is separated from the clutch chamber 21 by 0a, and in this embodiment, this side wall 20a constitutes a partition wall. A transmission shaft 25 is arranged at the front of the transmission chamber 24 so as to be coaxial with the crankshaft 11 . The transmission shaft 25 is supported between the side wall 20a of the transmission case 20 and the case cover 23 via a bearing 2B, and one end thereof is introduced into the clutch chamber 21. A drive shaft 27 is rotatably connected to one end of the transmission shaft 25. Drive shaft 27
is located in the clutch chamber 21 and is provided coaxially with the transmission shaft 25 and the crankshaft 11. A centrifugal clutch 30 is located between the drive shaft 27 and the crankshaft 11.
is mediated. The centrifugal clutch 30 is attached to the crankshaft 11
A centrifugal plate 31 that rotates integrally with the centrifugal plate 31, a centrifugal weight 32 supported by the centrifugal plate 31, and a clutch housing 33 with which the centrifugal weight 32 comes into contact with the centrifugal weight 32 so as to be removable.The clutch housing 33 is fixed to the drive shaft 27. has been done.

Therefore, when the rotational speed of the centrifugal plate 31 that rotates together with the crankshaft 11 reaches a predetermined value, the centrifugal weight 32 moves outward due to centrifugal force and contacts the clutch housing 33, thereby driving the rotation of the crankshaft 11. The signal is transmitted to the shaft 27.

Further, the transmission shaft 25 and the drive shaft 27 are interlocked via a planetary gear device 35. That is, a sun gear 3B is formed on the outer peripheral surface of the drive shaft 27, and this sun gear 3B
A plurality of planetary gears 37 are meshed with each other.

The planetary gears 37 are rotatably supported by a flange portion 39 at one end of the transmission wheel 27 via a support shaft 38, and these planetary gears 37 mesh with an internal gear 40.

The internal gear 40 includes a boss portion 41 that covers the outer periphery of the transmission shaft 25.
It is rotatably supported via 2.

Therefore, as shown in FIG. 2, when the drive shaft 27 is rotated in the direction of arrow A, the sun gear 3B is also rotated integrally in the same direction, so the planetary gears 37 are rotated in the direction of arrow B. .

Here, if the internal gear 40 is fixed,
The planetary gear 37 is caused to revolve in the direction of arrow C.

The revolution speed of the planet gear 37 is determined by the ratio of the number of teeth between the sun gear 3B and the planet gear 37, and the revolution speed of the planet gear 37 is smaller than the rotation speed of the sun gear 3B.

Since the transmission shaft 25 rotates together with the revolution of the planetary gear 37, the rotation of the crankshaft 11 is eventually decelerated and transmitted to the transmission shaft 25.

Further, if the internal gear 40 is rotated in the direction of the arrow at the same speed as the sun gear 3B, the sun gear 36 and the planetary gear 37
and the internal gear 40 are integrally moved at a constant speed by the arrow A (
Since the drive shaft 27 is rotated in directions C and D), the rotation of the drive shaft 27 is transmitted to the transmission shaft 25 without being decelerated.

Therefore, by controlling the rotational speed of the internal gear 40 in the direction of the arrow, the reduction ratio of the crankshaft 11 to the transmission shaft 25 can be changed.

On the other hand, a V-belt automatic transmission 45 is accommodated within the transmission chamber 24.

That is, on the transmission shaft 25 located in the transmission chamber 24,
Primary sheave 4B is attached.

In this primary sheave 46, when the rotational speed of the transmission shaft 25 increases, a flyweight 47 receives centrifugal force and moves radially outward, thereby reducing the groove width of the V-shaped groove 48.

Furthermore, a driven shaft 49 is arranged in parallel with the transmission shaft 25 at the rear of the transmission chamber 24 . The driven shaft 49 is supported between the second transmission case 20 and the case cover 23 via a bearing 50, and a secondary sheave 51 that pairs with the primary sheave 4B is provided on the driven shaft 49. ing. A V-belt 53 is provided between the V-shaped groove 52 of the secondary sheave 51 and the V-shaped groove 48 of the primary sheave 4B.
When the groove width of the V-shaped groove 48 of the primary sheave 4B is reduced as described above, the V-belt 53 is pulled radially inward on the secondary sheave 51 side, so that the secondary sheave 51 returns to its original position. coil spring 54
The width of the V-shaped groove 52 is expanded against the urging force of the V-shaped groove 52. As a result, V for each sheave 4L51
The diameter of the winding of the belt 53 changes automatically, and when the rotation speed of the transmission shaft 25 is low, the driven shaft 4 is rotated at a large reduction ratio.
9, as the rotational speed of the transmission shaft 25 increases,
The driven shaft 49 is rotated by gradually decreasing this reduction ratio.

Note that the driven shaft 49 is coaxially connected to a rear wheel shaft 55, and a rear wheel 56 is attached to this rear wheel shaft 55.

Further, the transmission chamber 24 accommodates another V-belt automatic transmission 60. This automatic transmission 60 includes a primary sheave 61 that rotates integrally with a driven shaft 49, and the internal gear 4.
Secondary sheave B attached to the outer periphery of the boss part 41 of 0
2, and the V-shaped grooves 83.8 of both these sheaves 61.82
4, a V-belt 85 is wound around it. When the rotation speed of the driven shaft 49 increases, the primary sheave 61
The flyweight 6B moves radially outward under centrifugal force and reduces the groove width of the V-shaped groove 63, so the V-belt 65 is pulled radially inward on the secondary sheave 62 side, and this secondary sheave The groove width of the V-shaped groove B4 of 51 is expanded against the return coil spring 67.

Therefore, the reduction ratio between the driven shaft 49 and the internal gear 40 becomes small, and the internal gear 40 is driven by the driven shaft 49.

An oil seal 70 is provided at a portion where the boss portion 41 of the internal gear 40 penetrates the side wall 20a to maintain fluid tightness between the clutch chamber 21 and the transmission chamber 24.

In such a configuration, when the rotational speed of the crankshaft 11 is low, the rotational speed of the internal gear 40 in the direction of the arrow is small, so a large reduction ratio can be obtained between the sun gear 36 and the planetary gears 37. The planetary gear 37 is rotated at the maximum reduction ratio with respect to the sun gear 3B.

Therefore, since the transmission shaft 25 rotates at a lower speed than the crankshaft 11, the centrifugal force applied to the flyweight 47 of the primary sheave 46 also becomes smaller, and the groove width of the V-shaped groove 48 of the primary sheave 46 becomes wider. , the diameter of the winding of the V-belt 53 becomes smaller. On the other hand, on the secondary sheave 51 side, the winding diameter of the V-belt 53 becomes larger, so the reduction ratio between the transmission shaft 25 and the driven shaft 49 becomes larger, and the driving torque of the rear wheel 5B increases.

On the other hand, during low speed rotation when the driven shaft 49 is driven at a large reduction ratio, the reduction ratio of the other V-belt automatic transmission 80 is also large, so the internal gear 40 integrated with the secondary sheave 62
It will rotate at a lower speed than the driven shaft 49. Therefore, the reduction ratio of the planetary gear device 35 and, by extension, the reduction ratio between the crankshaft 11 and the transmission shaft 25 becomes large.

When the rotational speed of the crankshaft 11 increases and the reduction ratio of the automatic transmission 45 approaches 1, the driven shaft 49 rotates at approximately the same speed as the transmission shaft 25. Then, the groove width of the V-shaped groove 63 of the primary sheave at on the driven shaft 49 is reduced, and the V-shaped groove 63 of the primary sheave at on the driven shaft 49 is reduced.
The diameter of the V-belt 65 becomes smaller on the secondary sheave B2 side. Therefore, since the reduction ratio of the automatic transmission 60 also approaches 1, the rotational speed of the internal gear 40 in the direction of the arrow increases.

If the rotational speed of the internal gear 40 is equal to the rotational speed of the sun gear 3B, the sun gear 38. Planetary gear 3
7 and the internal gear 40 rotate together at a constant speed, the rotation of the crankshaft 11 is transmitted to the transmission shaft 25 without being decelerated.

By the way, in the above configuration, the clutch chamber 21 that accommodates the centrifugal clutch 30 and the one-way clutch 22, and the transmission chamber 24 that accommodates the V-belt automatic transmission 45.60 are located on the side wall 20a of the second transmission case 20. Since the centrifugal clutch 30 and the one-way clutch 22 are separated by
The engine oil in the crankcase 8 can be guided to the crank case 8.

Therefore, both clutches 22.30 can be lubricated and cooled by engine oil, improving the durability of the clutches 22.30.

Moreover, since the centrifugal clutch 30 that generates heat due to friction is isolated from the transmission chamber 24, the centrifugal clutch 30
In addition to being cooled by engine oil, the heat of the centrifugal clutch 30 becomes difficult to be transmitted to the transmission chamber 24.

Therefore, the ambient temperature of the automatic transmission 45.60 can be kept low, thermal deterioration of the V-belt 53.85 is reduced, and the V-belt automatic transmission 45. The durability of H is improved.

[Effects of the Invention] According to the present invention described in detail above, engine oil and the like can be guided to the centrifugal clutch, and the centrifugal clutch can be lubricated and cooled by the oil.

Moreover, the centrifugal clutch, which generates heat due to friction, is isolated from the chamber housing the V-belt automatic transmission, making it difficult for the centrifugal clutch's heat to be transmitted to the V-belt automatic transmission.
The ambient temperature of this automatic transmission can be kept low.

Therefore, the durability of the centrifugal clutch and the V-belt automatic transmission can be improved.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, in which Fig. 1 is a sectional view of the entire engine unit, Fig. 2 is a sectional view taken along the line ■-■ in Fig. 1, and Fig. 3 is a side view of a scooter type motorcycle. It is. 6...Engine, 11...Crankshaft, 20a...
・Partition wall (side wall), 21...Clutch chamber, 24...
・Transmission chamber, 25... Transmission shaft, 30... Centrifugal clutch, 45... V-belt automatic transmission, 49... Driven shaft. Applicant's agent Patent attorney Takehiko Suzue Figure 12

Claims (1)

[Claims] The transmission shaft is connected to the crankshaft of the engine via a centrifugal clutch, and the driven shaft is arranged parallel to the transmission shaft. In an automatic transmission linked via a machine, a partition wall is provided between the centrifugal clutch and the V-belt automatic transmission, and the centrifugal clutch and the V-belt automatic transmission are arranged in a room separated from each other. An automatic transmission featuring: