JP3317005B2 - Transmission for two-stroke engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission for a two-stroke engine.

[0002]

2. Description of the Related Art Generally, in a two-cycle engine of a motorcycle, for example, lubricating oil is mixed into an air-fuel mixture and lubricating oil is fed into a crank chamber to lubricate the crank chamber. Oil of the same system is contained, and the transmission gear, primary driven gear, clutch housing, etc. are immersed in this oil to perform lubrication. And
In the transmission of a two-stroke engine having such a droplet lubrication system, as shown in FIGS. 5 and 6, the transmission communicates with an upper part of a partition wall d that partitions a transmission chamber side b and a clutch chamber side c of a crankcase a. A hole e is provided so that oil in the clutch chamber is splashed by a primary driven gear or the like after the engine is started, and the splashed oil is sent into the transmission chamber through the communication hole e. As shown in FIG. 5, a balance hole f is provided in the partition wall d of the crankcase a so that when the engine is stopped, the oil level at that time is stabilized at the position shown by the two-dot chain line in FIG. ing.

[0003]

However, in the transmission of the conventional two-stroke engine, as shown in FIG. 7, the rotation of the clutch housing h to which the primary driven gear g is fixed causes the oil in the transmission chamber j to rotate. To the clutch chamber i.
The oil in the transmission chamber j flows into the clutch chamber i from between the inner ring m1 and the outer ring m2 of the ball bearing m which rotatably supports the counter shaft k, and the oil is transmitted from the communication hole e to the transmission chamber j. Even if the oil is sent, the oil level in the transmission chamber j does not rise sufficiently, and there is a risk that the gears for shifting in the transmission chamber j will not be lubricated sufficiently.

Therefore, there is a method of isolating the clutch chamber i from the transmission chamber j by using a so-called seal bearing or a shield bearing n as shown in FIG. 8 for the ball bearing m. Some motorcycles use special bearings designed with a narrow width.
In this case, since the space of the bearing is too narrow, there arises a problem that the seal bearing or the shield bearing n cannot be assembled.

SUMMARY OF THE INVENTION The present invention has been made in view of the problems of the conventional transmission of a two-stroke engine, and has as its object to provide an inexpensive and compact structure for sufficiently increasing the oil level in the transmission chamber. It is another object of the present invention to provide a two-stroke engine transmission that improves the lubrication performance in the transmission chamber.

[0006]

To achieve the above object, the present invention has the following arrangement. That is, the present invention provides a shaft hole provided in a partition wall between the transmission chamber and the clutch chamber, a rolling bearing provided in the partition wall in accordance with the shaft hole, and supported by the rolling bearing,
A rotating shaft having a primary driven gear and a transmission gear in each of the clutch chamber and the transmission chamber. When the primary driven gear rotates, lubricating oil in the clutch chamber is sprayed, and the sprayed lubricating oil is sprayed on the partition wall. In the transmission of a two-stroke engine, which is sent into a transmission chamber through a communication hole provided in the rolling bearing, an annular ring abutting on an inner ring of the rolling bearing is provided between the rolling bearing and the primary driven gear. disc member is interposed, the circular plate member state, and are not the outer diameter is formed larger than the inner diameter of the outer ring of the rolling bearing, the outer edge
The annular relief of the outer ring of the rolling bearing
For the primary driven gear rolling bearing side
That is a transmission of an annular relief and two-cycle engine characterized that you have provided.

A substantially cylindrical spacer is interposed between the primary driven gear and the rotary shaft, and the disc member is integrally formed in a flange shape at the end of the spacer on the rolling bearing side. May be.

[0008]

According to the structure of the present invention, the disc member closes the side surface between the inner ring and the outer ring of the rolling bearing, so that the oil flows from the transmission chamber into the clutch chamber through the space between the inner ring and the outer ring. Is significantly reduced as compared to the prior art. Therefore, during operation of the engine, oil is sent from the clutch chamber into the transmission chamber through the communication hole, so that the oil level in the transmission chamber rises sufficiently without lowering.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a two-cycle engine transmission according to an embodiment of the present invention. FIG. 1 is a cross-sectional view of the overall configuration of the transmission of a two-cycle engine according to the present embodiment in a plan view. FIG. FIG. 3
(A) is a longitudinal sectional view of a spacer of the transmission of the two-stroke engine according to the present embodiment, and (b) is A of the same (a).
It is a part enlarged view. FIG. 4 is an exploded cross-sectional view illustrating a washer member and a spacer, showing a modification of the transmission of the two-cycle engine according to the present embodiment.

The transmission of a two-cycle engine according to this embodiment is applied to a transmission 2 of a motorcycle, and as shown in FIGS. 1 and 2, a transmission in which a transmission gear 4 is included. A shaft hole 14 provided in a partition wall 12 between the chamber 6 and a clutch chamber 10 in which the clutch 8 is included;
A ball bearing (an example of a rolling bearing) 16 fixed to the partition 12 in alignment with the shaft hole 14 from the mission chamber 6 side, and supported by the ball bearing 16;
The clutch chamber 10 and the transmission chamber 6
And a counter shaft (rotating shaft) 20 on which the primary driven gear 18 and the speed change gear 4 are pivotally supported. When the primary driven gear 18 rotates,
The lubricating oil in the clutch chamber 10 splashes, and the splashed lubricating oil is sent into the transmission chamber 6 through a communication hole provided in the partition wall 12.

The primary driven gear 18
A spacer 22 having a substantially cylindrical shape and a needle bearing 26 for rotating the primary driven gear 18 with respect to the counter shaft 20 are interposed between the shaft 22 and the counter shaft 20.

The ball bearing 16 is a radial ball bearing, and is fitted into a fitting portion of the partition wall 12 having an outer diameter slightly larger than the diameter of the shaft hole 14, and is provided with an inner race 16a.
And an outer ring 16b and a plurality of balls 16c.

The primary driven gear 18 is connected to a clutch housing 8a constituting the clutch 8 by a connecting member 28.
Are integrally connected with each other. A kick starter driven gear 18a is formed integrally with the primary driven gear 18 on the ball bearing 16 side.

The counter shaft 20 has an integrally formed counter shaft low gear 20a, and the side surface of the counter shaft low gear 20a on the clutch chamber 10 side is in contact with the side surface of the inner ring 16a of the ball bearing 16.

The spacer 22 is a flange (an example of a disc member) integrally formed at an end of the spacer 22 on the ball bearing 16 side.
24. The flange 24 is provided with the ball bearing 16.
And is in contact with the inner ring 16 a of the ball bearing 16. Also, as shown in FIGS. 3A and 3B,
The outer diameter D1 of the flange portion 24 is equal to the outer ring 1 of the ball bearing 16.
6b is formed larger than the inner diameter d1. further,
The outer ring 1 of the ball bearing 16 is provided on the outer edge of the flange 24.
An annular relief 24a for the kick starter driven gear 18a and an annular relief 24b for the kick starter driven gear 18a are provided.

According to the transmission 2 of the two-stroke engine of the present embodiment having the above-described configuration, the side face between the inner ring 16a and the outer ring 16b of the ball bearing 16 is closed by the flange 24 of the spacer 22. Inner ring 16a and outer ring 16
b between the transmission chamber 6 and the clutch chamber 10
The amount of oil flowing into the inside is greatly reduced as compared with the conventional case. Therefore, during operation of the engine, oil is sent from the clutch chamber 10 into the transmission chamber 6 through the communication hole provided in the partition wall 12, so that the oil level in the transmission chamber 6 rises sufficiently without lowering. Therefore, according to the transmission 2 of the two-cycle engine of the present embodiment, the transmission chamber 6 is inexpensive and compact with little change in the configuration other than the spacer 22.
The oil level in the transmission chamber 6 can be increased, and the lubrication performance in the transmission chamber 6 can be improved.

The transmission 2 of the two-stroke engine of the present embodiment is a preferred embodiment of the present invention, and the technical scope of the present invention is not limited to this embodiment. For example,
The flange portion 24 as an example of the disk member is not integrally formed with the spacer 22, but may be a washer member 24A separate from the cylindrical spacer 22A without a flange as shown in FIG. You can also.

[0018]

As described above, according to the present invention, it is possible to sufficiently raise the oil level in the transmission chamber and improve the lubrication performance in the transmission chamber with an inexpensive and compact configuration.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of the entire configuration of a transmission of a two-cycle engine according to an embodiment, as viewed in a plane.

FIG. 2 is a cross-sectional view of a main part of the transmission of the two-stroke engine according to the embodiment, as viewed in plan.

3A is a longitudinal sectional view of a spacer of the transmission of the two-stroke engine according to the embodiment, and FIG. 3B is a sectional view of FIG.
FIG.

FIG. 4 is an exploded sectional view showing a washer member and a spacer, showing a modification of the transmission of the two-cycle engine according to the embodiment.

FIG. 5 is a side view of the crankcase.

FIG. 6 is a sectional view taken along line BB of FIG. 5;

FIG. 7 is a cross-sectional view of a main part of a transmission of a conventional two-stroke engine as viewed in plan.

FIG. 8 is a cross-sectional view of a main part of another conventional two-stroke engine transmission as viewed in plan.

[Explanation of symbols]

 2 Transmission device for two-cycle engine 4 Transmission gear 6 Clutch room 10 Transmission room 12 Partition wall 14 Shaft hole 16 Ball bearing (an example of a rolling bearing) 16a Inner ring 16b Outer ring 18 Primary driven gear 20 Counter shaft (rotating shaft) 22 Spacer 22A Spacer 24 Flange (an example of a disk member) 24A Washer member (an example of a disk member) D1 Outer diameter of flange d1 Inner diameter of outer ring

Claims (2)

(57) [Claims] A shaft hole provided in a partition wall between a transmission chamber and a clutch chamber; a rolling bearing provided in the partition wall in accordance with the shaft hole; A rotating shaft having a primary driven gear and a transmission gear in each of the chamber and the transmission chamber, and when the primary driven gear rotates, lubricating oil in the clutch chamber is sprayed,
In the transmission apparatus for a two-cycle engine, in which the splashed lubricating oil is sent into a transmission chamber through a communication hole provided in the partition wall, the transmission between the rolling bearing and the primary driven gear may include: disc member abutting against an annular inner ring of the rolling bearing is interposed circular plate member state, and are not the outer diameter is formed larger than the inner diameter of the outer ring of the rolling bearing, on its outer edge
An annular relief for the outer race of the rolling bearing,
Ring for rolling bearing side of Lima lead driven gear
Jo of the transmission clearance and two-cycle engine characterized that you have provided. 2. A substantially cylindrical spacer is interposed between the primary driven gear and the rotating shaft, and the disc member is integrally formed in a flange shape at an end of the spacer on a rolling bearing side. The transmission of a two-stroke engine according to claim 1, wherein the transmission is formed.