JPH03231037A - Transmission for tractor - Google Patents

Abstract

PURPOSE:To reduce the height of the front portion of a transmission case by providing a main shaft connected to an engine in the longitudinal direction on the front portion of the interior of the transmission case, and disposing transmission shafts of a traveling system ad a PTO system in parallel on the right and left of the main shaft, which are associated with each other through the respective gear transmissions thereof. CONSTITUTION:A traveling system main gear transmission 10, a PTO system gear transmission 11 and a PTO system normal-reverse transmission 12 are disposed in the front portion in the interior of a transmission case M for transmitting the power of an engine to rear wheels and a PTO shaft. In this case, a PTO system transmission case 21 and a reverse shaft 22 are disposed on the right of a main shaft 20 to which the power of the engine is transmitted through a hydraulic main clutch C in a clutch case portion 19, and a traveling system transmission shaft 23 is disposed on the left thereof in parallel to each other. Further, A main gear transmission 10 is integrated extending over the main shaft 20 and the traveling system transmission shaft 23, and a gear transmission 11 is integrated extending over the main shaft 20 and the PTO system transmission shaft 21. By this arrangement, the height of the front portion of the transmission case can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a transmission device for a tractor in which a transmission case supporting a rear axle and an engine are directly connected.

[Conventional technology]

Conventionally, the transmission equipped with a drive system transmission mechanism and a PTO system gear transmission mechanism was
As shown in the publication, the transmission shafts constituting each of the two types of gear transmission mechanisms are arranged in parallel in the upper and lower positions,
The horizontal cross-sectional shape of the mission case was elongated.

[Problem to be solved by the invention]

When the transmission shafts constituting the gear transmission mechanism are arranged vertically in parallel as in the prior art, the cross-sectional shape of the transmission case becomes a vertically elongated shape with a large vertical dimension. Therefore, in tractors where the transmission case also serves as the vehicle body frame, the center area of the step board installed on the upper side of the transmission case bulges upwards, causing the step board to be completely separated to the left and right. The footwells are narrower, and the protruding parts can get in the way when getting on and off, making it easy for your feet to get caught, so there was room for improvement in comfort on the steps.

The present invention improves the above-mentioned disadvantages by configuring a transmission case with a low height in the vertical direction by rationally arranging a gear transmission mechanism of a traveling system gear transmission mechanism and an external power system gear transmission mechanism. With the goal.

[Means to solve the problem]

The characteristic configuration of the present invention for achieving the above object is that a main shaft receiving power from the engine is provided in the front part of the transmission case facing in the front-rear direction, and a transmission shaft for the traveling system and a PTO system are mounted on the left and right sides of the main shaft. Transmission shafts are distributed and arranged in parallel, and a gear type transmission mechanism for traveling is incorporated between the main shaft and the transmission shaft of the traveling system, and a gear type transmission mechanism for PTO is installed between the main shaft and the transmission shaft of the PTO system. There is a certain point that incorporates.

[Function] According to the above configuration, the running system and the PT are located in the front part of the mission case, on which the step board is arranged.
Since each O-system transmission mechanism can be arranged side by side in the horizontal direction, the cross-sectional shape of the front part of the transmission case can be made into a horizontally elongated and flattened shape compared to the conventional transmission case.

〔Effect of the invention〕

Therefore, we were able to reduce the height of the front part of the transmission case by arranging the drive system and PTO system transmission mechanisms and their transmission shafts, which made it possible to reduce the height at which the center of the step board rises upward. By making the step board as flat as possible, the area on which you can place your feet increases.
We were able to improve livability.

In addition, since the bulge near the center of the step board has been reduced, the possibility of the foot getting caught when getting on or off the step board has been reduced as much as possible.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

In FIG. 3, an agricultural tractor is shown. An engine (E) is arranged at the front of the tractor body, and a control section (1) is provided at the center, and the power of the engine (ε) is transmitted to the rear wheels (2) and the PTO shaft. The transmission case (1, 1) that transmits the power to (3) also serves as the fuselage frame, and is directly connected to the engine (E) and arranged facing forward and backward.

The control section (1) includes a handle (4) and a control section (5).
, and a step board (6) for boarding, and the mission case (J) is located below the left and right center portions of the step board (6).

As shown in FIG. 1, the mission case (+, D
The interior is roughly divided into three sections (7) in the front and rear directions.

(8), (9), and the front section (7)
The main gear transmission mechanism (10) of the driving system, the gear transmission mechanism (11) of the PTO system, and the forward/reverse transmission mechanism (11) of the PTO system are included.
12), and the intermediate section (8) is equipped with a hydraulic system for forward/reverse transmission of the traveling system (13), and a hydraulic system for shifting the transmission mechanism of the traveling system on the downstream side of the transmission from this forward/reverse transmission mechanism (13). A transmission clutch (14) and a hydraulic PTO clutch (15) are installed, and the rear compartment (9) is equipped with a drive system auxiliary gear transmission mechanism (16), a super reduction mechanism (7), and a drive system final shift power. a differential transmission mechanism (18) for driving the rear wheels (2), and a rear axle (3) that supports the rear wheels (2).
5) is in place.

The mission case (M) is directly connected to a clutch case part (19) at the rear of the engine (E), and via a hydraulic main clutch (C) provided in the clutch case part (19), Main shaft (20) in said front compartment (7)
Power is transmitted to.

As shown in Figure 2, on the right side of the main shaft (20) is a PTO
The transmission shaft (21) of the system and the reversal shaft (22) of the PTO system,
On the left side, the driving system transmission shaft (23) is distributed and arranged in parallel, and the main shaft (20) and the driving system transmission shaft (23) are arranged in parallel.
The main gear transmission mechanism (10) is installed across the main shaft (20) and the PTO transmission shaft (21), and the gear transmission mechanism (11) is installed over the main shaft (20) and the PTO system transmission shaft (21).

In other words, the main shaft (20) is equipped with the gear (G4) in order from the front.
, intermediate gear (G5), third gear (G3), second gear (G
2) and 1st gear (G1), respectively, are installed in a state of integral rotation, and are mounted on the drive system transmission shaft (23) (from the front, 4th gear (G9), 3rd gear (G8), 2nd gear ( G7) and 1st gear (G6) are fitted on the transmission shaft (21) of the PTO system, and 3rd gear (G12),
The 4th speed gear (G13), the 2nd speed gear (Gll), and the 1st speed gear (GIO) are each fitted loosely,
The main gear transmission mechanism (10) includes two transmission members (24),
(24), the gear transmission mechanism (11) is equipped with a 4th gear (G13) and a 2nd gear.
A speed gear (Gll) is constructed as a mechanically operated constant mesh mechanism that also serves as a transmission member.

Then, the 1st, 2, and 3rd gear (G1) (G
2), (G3) is the 1st, 2nd, and 3rd gear (G3) of the driving system.
6) (G7), (G8) and the first PTO system.
2. 4th gear (GIO), (Gll), (G
13) in this order, and due to the speed ratio, the 4th gear (G9) of the traveling system and the PTO
The system's third gear (G12) has a separate main shaft (
20), the fourth gear (G4) and the intermediate gear (G5) mesh with each other. Further, a reversing gear (G14) that can engage with the second gear (G2) is slidably fitted onto the reversing shaft (22) to form a forward/reverse transmission mechanism (12), and the reversing gear (G14) to select the second
A reversal state can be obtained by engaging both the gear (G2) and the second speed gear (Gll).

The power that has passed through the PTO clutch (15) is transferred to the intermediate shaft (2
5) is transmitted to a working device (not shown) via the PTO shaft (3).

As shown in Fig. 4, the PTO clutch (15) has an inner body (2
6) and an outer body (27) externally fitted with a spline on an intermediate shaft (25).
) for press operation of the clutch body (28).
29) and an oil passage (30) for clutch lubrication are formed. Oil from the oil passage (30) enters the oil sump (S) between the transmission shaft (21) and the intermediate shaft (25), and enters the hair ring (
31) and is supplied to the clutch chamber (32) through the inner body (26) and transmission shaft (21).
In order to prevent oil leakage from the spline fitting part with the hair ring (31), a closed circular seal (33) is attached to the inner ring (31a) of the hair ring (31).

As shown in FIG. 1, the step board (6) is located approximately on the front section (7) of the mission case (M), which, as shown in FIG. The cross-sectional shape of the mission case (M) in this part is long horizontally.
Since it has a vertically low shape, the height of the bulge near the center of the step board (6) can be reduced.

In addition, (34) shown in the figure is a PTO-based gear transmission mechanism (
11) and a forward/reverse transmission mechanism (2).

Note that although reference numerals are written in the claims section for convenient comparison with the drawings, the present invention is not limited to the structure shown in the accompanying drawings.

[Brief explanation of drawings]

The drawings show an embodiment of the transmission device for a tractor according to the present invention, and FIG. 1 is a longitudinal sectional view showing the structure of the transmission device, and FIG. 2 is a cross sectional view of the transmission device as seen from the rear. FIG. 3 is a side view of the tractor, and FIG. 4 is a side view showing the structure of the PTO clutch. (10), (11)...Transmission mechanism, (20)
...Main axis, (21). (23)...Transmission shaft, (35)...Rear axle, 0.1)...Mission case.

Claims (1)

[Scope of Claims] A tractor transmission device in which a transmission case (M) supporting a rear axle (35) and an engine (E) are directly connected, comprising: A main shaft (20) which receives the power of
O-system transmission shafts (21) are distributed and arranged in parallel, and a gear type transmission mechanism (10) for traveling is incorporated between the main shaft (20) and the traveling system transmission shaft (23),
A tractor transmission device incorporating a gear type transmission mechanism (11) for PTO over the main shaft (20) and the transmission shaft (21) of the PTO system.