JPH05330358A - Main shift of transmission - Google Patents

Abstract

PURPOSE:To improve an operating feeling by providing so that a main shift lever is disposed near an operator's position without lowering the mechanical strength of a transmission case. CONSTITUTION:A window part 16 is installed in the side of a main shaft mechanism part 14 of a transmission case 12. Each one end 23a, 24a of two shifter arms 23 and 24 is projected to the outside from this window part 16, extending these parts 23a, 24a to the rearward, and a main shift lever 18 is attached to these ends 23a, 24a of these extended shifter arms. Then, a cover 17 is attached to the window part 16 for covering.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a main transmission of a transmission, and more particularly to a main transmission of a transmission of a power farm.

[0002]

2. Description of the Related Art Conventionally, many power agricultural machines such as tractors and transmissions for work vehicles are provided with a main transmission mechanism and an auxiliary transmission mechanism, and a window is opened in a transmission case formed by casting, One end of a shifter arm for main shift is projected from the window, and the main shift lever is attached to this projected portion.

[0003]

A conventional transmission of this type is as follows.
As described above, the window is opened in the transmission case, one end of the shifter arm is projected, and the main shift lever is attached to this, so the position of the main shift lever is restricted,
A curved long main transmission lever must be used to get close to the operator's hand. For this reason, the work posture is not good, and the operation feeling of the operator is not good.

Further, if the window of the mission case is enlarged in order to bring one end of the shifter arm closer to the operator, the mechanical strength of the mission case is reduced, and there is a risk of cracks or the like occurring in the window. Therefore, there is a technical problem to be solved in order to bring one end of the shifter arm close to the operator and to improve the operation feeling of the main transmission without lowering the mechanical strength of the mission case. The present invention aims to solve this problem.

[0005]

SUMMARY OF THE INVENTION The present invention has been proposed in order to achieve the above-mentioned object, and a window is opened at the side of the main transmission mechanism of the transmission case, and one end of the shifter arm is provided. Provided is a main transmission device for a transmission, which projects outward from the window portion and extends rearward, and a main transmission lever is attached to one end portion of the extended shifter arm, and the window portion is covered with a cover. It is a thing.

[0006]

The one end of the shifter arm projects outward from the window of the mission case and extends rearward.
The main shift lever is attached to one end of the shifter arm extending rearward, and thus can be brought close to the operator. Therefore, the operation feeling of the main transmission can be improved.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 shows a transmission of a power farm machine such as a tractor. The power of an engine (not shown) is transmitted from an input shaft 11 to a transmission in a mission case 12. 1
Reference numeral 3 denotes a PTO transmission mechanism section, and a main transmission mechanism section 14 and an auxiliary transmission mechanism section 15 are provided in the subsequent stage.

On the side of the main transmission mechanism portion 14, a window portion 16 is opened on the side surface of the mission case 12, and the window portion 1 is formed.
6 is covered with a cover 17. Then, the main transmission lever 18 is attached to the rear position of the window 16. Also, reference numeral 19
Is a sub-transmission lever, and 20 is a 4WD switching lever. FIG. 2 shows a main shift lever 18 and a sub shift lever 19
FIG. 3 is an enlarged view of a main part of the attachment part of FIG. 3, and FIG. First, the main transmission will be described. In the window portion 16 opened on the side surface of the mission case 12, the shifter support shafts 21 and 2 are vertically moved in the front-rear direction.
2 is bolted, and shifter arms 23 and 24 are loosely fitted to the shifter support shafts 21 and 22 so as to be slidable in the front-rear direction.

One end 23a of one shifter arm 23
Extends outward from the window 16 and extends rearward. A spherical actuating portion 25 connected to the lower end of an actuating piece 35 of the main speed change lever 18 described later has a spherical engaging portion 26 at the one end 23a.
Is engaged with. Then, the one shifter arm 2
The other end portion 23b of the third member 3 is extended inward from the window portion 16 to form an engagement portion 27 having a C shape in a front view described later, and the engagement portion 27 is provided to the first shifter 28 of the main transmission mechanism portion. It is fitted.

Further, one end 2 of the other shifter arm 24
4a also projects outward from the window portion 16 and extends rearward to form an engaging portion 29. When the main speed change lever 18 is pressed inward as will be described later, a spherical operation portion of the main speed change lever is provided. 25 is the engaging portion 2 of one shifter arm 23
6, the engaging portion 29 of the other shifter arm 24
Is formed so as to move into and engage with. The intermediate portion 24b of the other shifter arm 24 has a window portion 16b.
Extending inwardly from the inside to form an engaging portion 30 having a C-shape in a front view, which will be described later, and this engaging portion 30 is the second main transmission mechanism portion.
It is fitted to the shifter 31 of.

FIG. 4 is a vertical cross-sectional front view of the main transmission mechanism portion 14. The mounting shaft 33 is pivotally supported by the linear ball bearings 32, 32, and the bellows 34 is mounted on the mounting shaft 33 protruding to the outside of the mission case 12. In addition, the mounting shaft 3
The lower end portion of the main shift lever 18 is fixed to one end portion 33a of No. 3. A compression coil spring (not shown) is provided inside the bellows 34 to urge the mounting shaft 33 to slide outward of the transmission case 12. Further, the actuating piece 35 is fixed to the intermediate portion of the mounting shaft 33, the spherical actuating portion 25 is formed at the lower end thereof, and is engaged with the engaging portion 26 of one shifter arm 23. In the figure, reference numeral 36 is a drive pinion shaft, 37 is a sub change shaft, and 38 is a PT.
An O drive shaft, 39 is a PTO counter shaft, 40 is a four-wheel drive shaft, and 41 is a full turn counter shaft. As described above, the shifter arms 23 and 24 are provided with the engagement portions 27 and 30 having a C-shape when viewed from the front, and the first shifter 28 and the second shifter 3 of the main transmission mechanism portion are respectively formed.
It is fitted to 1.

When the main transmission lever 18 is operated back and forth in such a state, the spherical actuating portion 25 causes the shifter arm 2 on one side to move.
3, the one shifter arm 23 slides on the shifter support shaft 21 in FIG. 3, and the engaging portion 27 is the first shifter as shown by an arrow X in FIG. The gear shift operation of the main gear shift mechanism portion is performed by moving 28 back and forth.

Further, from the state shown in FIG.
8 is pushed inward, the mounting shaft 33 is slid inward, and the main transmission lever 18 is moved to the position shown by the chain double-dashed line 18a, the operating piece 35 is also moved to the position shown by the chain double-dashed line 35a. The spherical actuating portion 25 provided at the lower end separates from the engaging portion 26 of the one shifter arm 23 and moves to the engaging portion 29 of the other shifter arm 24 to be engaged. Therefore, in FIG. 3, the spherical actuating portion 25 is fitted to the other engaging portion 29 as shown by the chain double-dashed line, the other shifter arm 24 slides on the shifter support shaft 22, and the arrow Y
As shown in FIG. 5, the engaging portion 30 moves the second shifter 31 back and forth, so that the main transmission mechanism portion is operated at high speed. And
When the inward pressing of the main shift lever 18 is released, the main shift lever 18 returns to the position indicated by the solid line again by the bias of the compression coil spring interposed in the bellows 34 of FIG.

Next, the auxiliary transmission will be described with reference to FIGS. 3 and 5. The mounting shaft 42 of the auxiliary transmission lever 19 is attached to the mission case 12 by a linear ball bearing 43.
The bellows 44 is mounted on the mounting shaft 33 that is pivotally supported on the transmission shaft 12. The bellows 44 is mounted on the mounting shaft 33 that projects to the outside of the transmission case 12, and the lower end of the auxiliary transmission lever 19 is fixed to one end 42a of the mounting shaft 42. A compression coil spring 45 is provided inside the bellows 44 as shown in FIG. 6, and urges the mounting shaft 42 to slide outward of the transmission case 12.

As shown in FIGS. 2 and 5, the shifter support shaft 46 extends inside the mission case 12 in the front-rear direction.
The shifter arm 47 is slidably fitted in the front part of the shifter support shaft 46 so as to be slidable in the front-rear direction, and the shifter arm 48 is slidably fitted in the front part in the rear part of the shifter support shaft 46. One end portion 47a of one shifter arm 47 extends rearward to form an engaging portion 49, and the other shifter arm 48 forms an engaging portion 50 at the rear portion thereof. An operating piece 51 is fixed to the inner end 42b of the mounting shaft 42, and a spherical operating portion 5 is attached to the lower end of the operating piece 51.
2 to form the engaging portion 49 of one shifter arm 47.
Engage with. Both shifter arms 47 and 48 are provided with engaging portions 53 and 54 having a C-shape in a front view, and the first shifter 55 and the second shifter 56 of the auxiliary transmission mechanism portion are respectively formed.
Is fitted to.

When the auxiliary transmission lever 19 is operated back and forth in such a state, the spherical operating portion 52 causes the shifter arm 4 on one side to move.
7, the one shifter arm 47 slides on the shifter support shaft 46 in FIG. 2, and the engaging portion 53 moves the first shifter 55 back and forth to move the auxiliary shift mechanism portion. Gear shifting operation is performed. If the auxiliary shift lever 19 is pushed inward from the state shown in FIG. 5 and the mounting shaft 42 is slid inward to move the auxiliary shift lever 19 to the position shown by the chain double-dashed line 19a, the operating piece 51 will also be moved. Moved to the position indicated by the chain double-dashed line 51a, and provided a spherical operating portion 5 provided at the lower end thereof.
2 moves away from the engaging portion 49 of the one shifter arm 47, moves to the engaging portion 50 of the other shifter arm 48, and engages. Therefore, in FIG. 2, the other shifter arm 48 slides on the shifter support shaft 46, and the engaging portion 5
4 moves the second shifter 56 back and forth, and the shift operation of the auxiliary transmission mechanism portion is performed.

The mounting shaft 42 of the auxiliary transmission lever 19 is pivotally supported on the mission case 12 by the linear ball bearing 43 as described above, but as shown in FIG.
The bearing metal 57 may be retrofitted to the inner end 42b of the mounting shaft 42. The bearing metal 57 is the mission case 12
Can be mounted from the inside of the wall 58 of the linear ball bearing 43, the stepped portion 57a of the bearing metal 57 is fitted into the hole 59 provided in the end face of the linear ball bearing 43, and the bolt 61 is inserted into the mounting hole 60 of the bearing metal 57. And is screwed onto the wall portion 58.
In that case, the stepped portion 57a is fitted into the hole 59, and the bearing metal 57 and the linear ball bearing 43 are integrally supported by only one bolt tightening to support the mounting shaft 42,
The supporting force of the mounting shaft 42 can be improved with a simple structure.

Here, in FIG. 1, a rear PTO shaft 62 is projectingly provided at the rear of the mission case 12, and a pivot 63 of the rear PTO shaft 62 has a bearing 63 as shown in FIG. An oil seal 64 is fitted on the outside of the rear part. The oil seal 64 is a combination of a cylindrical oil seal 65 having a generally Z-shaped cross section and a hollow oil seal 66 having a generally T-shaped cross section in a locking groove 66a. A soft scraper-shaped lip 67 is fixed to the inside of the cylindrical oil seal 65, and the lip 67 is in contact with the outer peripheral surface of the sleeve 68 fitted to the rear PTO shaft 62. Hard hollow dust seals 66b and 66c are provided on the hollow oil seal 66, and an oil lip 66d is formed on the bearing 63 side of the hollow oil seal 66. Is in contact with.

As described above, the oil seal 64 is more flexible than the conventional one and has a cylindrical oil seal 65 having a scraper-like lip 67 and a hard dust lip 66.
Since it is combined with the hollow oil seal 66 having b and 66c, intrusion of muddy water and dust becomes extremely small.
The present invention can be variously modified without departing from the spirit of the present invention, and it goes without saying that the present invention extends to the modified one.

[0020]

As described in detail in the above-mentioned embodiment, the present invention does not increase the size of the window by enlarging one end of the shifter arm from the window of the mission case and extending it rearward. The main shift lever can be brought close to the operator. Therefore, the operation feeling of the main transmission is remarkably improved without impairing the mechanical strength of the mission case, the workability is improved, and an optimal driving posture can be taken, which contributes to the improvement of safety. It is an invention that exhibits various kinds of effects.

[Brief description of drawings]

FIG. 1 is a side view of a transmission of a power farm machine such as a tractor.

FIG. 2 is an enlarged view of a main part of a mounting portion of a main shift lever and a sub shift lever.

3 is a cross-sectional view taken along the line AA of FIG. 2 showing a shifter arm protruding outward from the window of the mission case.

FIG. 4 is a cross-sectional view taken along the line BB of FIG. 2, showing a main transmission mechanism section.

5 is a cross-sectional view taken along the line CC of FIG. 2 showing an auxiliary transmission mechanism section.

FIG. 6 is an enlarged vertical sectional front view of a main part of a mounting shaft of an auxiliary transmission lever.

FIG. 7 is an enlarged longitudinal sectional end view of a main portion showing a pivotal support portion of a rear PTO shaft.

[Explanation of symbols]

 12 mission case 14 main transmission mechanism 16 window 17 cover 18 main transmission lever 23, 24 shifter arm 23a, 24a one end 25 (spherical) operating part 26, 29 engagement part

Claims (1)

[Claims] 1. A window portion is opened at a side portion of a main transmission mechanism portion of a transmission case, one end portion of a shifter arm is extended outward from the window portion and extends rearward, and the extended shifter arm is provided. A main transmission device for a transmission, characterized in that a main transmission lever is attached to one end of the vehicle, and the window is covered with a cover.