JP2821311B2 - Tractor front wheel drive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a front wheel drive device for steering a tractor.

[0002]

2. Description of the Related Art Conventionally, the technology related to the structure of a front wheel drive device for steering a tractor has been known, for example, Japanese Utility Model Laid-Open No. 58-188225 and Japanese Utility Model Laid-Open No. 60-115722.
This is the technology of Japanese Patent Publication No. In the former technique, the power transmission shaft and the bevel gear are fixed in the axial movement so that the kingpin does not come off from the rotating case in such a front wheel drive unit, and the power transmission shaft and the bevel gear are extracted through the meshing tooth surfaces of each gear mechanism. In the latter technique, the lower portion of the kingpin bearing was fixed in the axial direction by a fastener.

[0003]

However, in the case of the former in the prior art, since it is impossible to extract through the meshing tooth surface of the gear mechanism, when a pulling force is applied, the mounting distance and the back are reduced when the gears mesh. Rush fluctuates, tooth contact worsens, there are problems such as reduced durability and tooth damage,
In the latter case, the structure is complicated because the lower bearing of the king pin is carried out by the fastener, and the fitting is installed at the back of the case, so that the assemblability is deteriorated, and the diameter for the fastener is further reduced. Direction, the axle support bearing cannot be brought close to the center of rotation of the kingpin, and as a result, the dimension from the kingpin to the axle increases, which increases the steering force during steering operation. There was a problem.

[0004]

SUMMARY OF THE INVENTION The present invention is configured as follows to solve such a problem. Contract
In claim 1, a kingpin 3 having a substantially vertical axis is formed downward at an outer end of a front axle case 2 in which a front wheel drive shaft 1 is provided, and a driving force is applied to a longitudinal axis 4 inside the kingpin. A fixed case 6 containing a bevel gear mechanism 5 for transmitting the driving force is provided. A rotating case 10 containing a reduction bevel gear mechanism 9 for transmitting a driving force from the longitudinal axis 4 is mounted on an axle 8 to which a front wheel 7 is mounted. In a structure in which the bearing 11 is rotatably supported via a bearing 11 and the movement of the bearing 11 in the axial direction downward with respect to the kingpin 3 is restricted by a restricting fitting 12 fitted on the lower surface, On the upper surface side, attach the balk fitting 13 from the rotating case 10
Insert the rotating case 10 into contact with the king pin 3
And the balk fitting 13 is not rotatable.
Fitting of bearing 14 for supporting axle 8 which is opened at 10
From the innermost part of the opening 10b for the bearing to the upper part of the bearing 11a
Thus, the insertion hole 10c is opened and inserted into the insertion hole 10c . According to claim 2, the bork fitting 1
Reference numeral 3 denotes a bearing 14 for supporting the axle 8
By being fitted into the opening 10b, it is possible to prevent it from coming off .

[0005]

With such a configuration, the upper side of the bearing 11 externally fitted to the kingpin 3 is fixed by the step formed in the kingpin 3 and the lower side is fixed by the regulating fitting 12, so that the axial movement is fixed. When the king pin 3 is inserted into the rotating case 10 in this state, the lower part of the outer peripheral surface of the bearing 11 is positioned in contact with the step of the rotating case 10, and the upper part is fixed by the balk fitting 13 of the present invention. The king pin 3 cannot be pulled out of the rotating case 10.
The outer surface of the balk fitting 13 is brought into contact with a bearing 14 interposed between the case of the reduction gear mechanism and the axle 8,
They are prevented from falling out and never fall off.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The problems to be solved and means to be solved by the present invention are as described above. Next, the embodiment shown in the attached drawings will be described. FIG. 2 is a front sectional view showing an embodiment in which a balk fitting is similarly arranged on a lower bearing side, FIG. 3 is a front sectional view of a boke fitting assembly, and FIG. 4 is a front view of a balk fitting assembly in FIG. FIG. 5 is a sectional view of FIG.
-A sectional view, FIG. 6 is a side view of the entire tractor.

[0007] Referring to FIG.
Is a front wheel, 20 is a rear wheel, 21 is a seat, and a bonnet 2
A battery 23, an engine E, and the like are housed in the handle 2. A handle 24 projects from the rear of the bonnet 22 so that the front wheel 7 can be steered and rotated by the rotation of the handle 24. The power from the engine E is shifted in the transmission case below the seat 21 and transmitted to the PTO shafts for driving the front wheels 7 and the rear wheels 20 and the work implement, and the transmission of the power to the front wheels 7 is performed in the transmission case 25. A front wheel drive output shaft protruding from the front portion is transmitted to a differential device in the front axle case 2 via a transmission shaft 26 and the front wheel drive shaft 1 is
, The front wheels 7 are driven via the front wheel drive device of the present invention.

As shown in FIG. 1, the front wheel drive device of the present invention has a fixed case 6 at both ends of the front axle case 2.
The upper cylindrical portion 6a is inserted and, as shown in FIG.
The lower part of the fixed case 6 forms a cylindrical kingpin 3 and extends downward. An end of the front wheel drive shaft 1 inserted into the fixed case 6 is fixed by being spline-fitted with a bevel gear 5a, and the bevel gear 5a is rotatably supported by the cylindrical portion 6a via a bearing 16, and the bevel gear 5a Is engaged with a bevel gear 5b which is spline-fitted and fixed to the upper end of the vertical axis 4.

The longitudinal axis 4 is formed with a pinion 4a at the lower portion thereof and meshes with a bevel gear 9a of a reduction bevel gear mechanism 9 to be described later. The upper end is spline-fitted to the bevel gear 5b, and is rotatably supported by the fixed case 6 via a bearing 17 which is externally fitted to the boss portion of the bevel gear 5b. The lower end protrudes from the king pin 3, It is rotatably supported at the lower part of the rotating case 10 via a bearing 18.

A bevel gear 9a meshing with a pinion 4a formed below the longitudinal axis 4 is spline-fitted to the axle 8, and bearings 14 and 27 are externally fitted on both sides of the bevel gear 9a.
0 and the support case 19 rotatably support the axle 8 on the
A front wheel 7 is fixed to a flange portion 8 a provided at an outer end portion of the axle 8 by bolts, and power is transmitted from the longitudinal axis 4 to the axle 8 via a reduction bevel gear mechanism 9 to drive the front wheel 7. It is.

The turning case 10 is configured so as to be able to be steered and turned through a knuckle arm or the like in conjunction with the turning of the handle 24. The lower part is rotatably supported with bearings 11a and 11b interposed therebetween, as shown in FIG.
When the upper bearing 11a is inserted into the kingpin 3 from below, it hits the step 3a and can be fixed by externally fitting the restricting fitting 12 to the kingpin 3. The lower bearing 11b is inserted into the kingpin 3 from below to insert the step 3b. When the rotating case 10 is inserted from below in this state, the step portion 10a of the rotating case 10 abuts and can be positioned, and the axle 8 is attached to the rotating case 10 as shown in FIG. By inserting the balk fitting 13 from the supporting opening 10b into the upper part of the bearing 11a through the insertion hole 10c opened at the bottom of the opening 10b and making contact therewith, the turning case 10 is prevented from coming off in the axial direction. is there. The balk fitting 13 does not fall out by fitting the bearing 14 into the opening 10 b of the rotating case 10. 29 is an oil seal.

In FIGS. 2 and 4, another rotating case 1 is shown.
A zero-retaining configuration is disclosed. In FIGS. 2 and 4, the upper part of the upper bearing 11a contacts the step 3a of the kingpin 3, and the upper part of the lower bearing 11b contacts the step 3b of the kingpin 3, and the lower bearing 11b Of the upper bearing 11a is abutted against the step 10d of the rotating case 10 and is positioned by contacting the lower portion of the upper bearing 11a with the stepped portion 10d of the rotating case 10.
Is screwed from the screw hole 10e and inserted into the upper part of the lower bearing 11b to make contact with the lower bearing 11b, thereby preventing the rotating case 10 from coming off.

[0013]

As described above, the present invention has the following advantages. As described in claim 1, the rotating case cannot be pulled out by the balk fitting mounted on the rotating case on the bearing in which the axial movement of the kingpin is restricted, and the balk fitting 13 is opened when the rotating case 10 is opened.
Opening 10 b for fitting bearing 14 for supporting shaft 8
Insertion hole 10c from the innermost part toward the upper part of bearing 11a.
Is opened and inserted into the insertion hole 10c,
The bearing 14 of the rotating case 10 is supported regardless of the force transmission system.
To the balk fitting 13 inserted into the opening 10b
It can prevent pulling out of the rotating case more
As in the past, it was impossible to pull out the bevel gear part
Improved bevel gear durability compared to conventional technology, and
The bevel gear can be prevented from being damaged.
Also, a portion of the opening 10b which is a support bearing portion of the axle 8.
Can be brought closer to the center of the kingpin 3 and the front wheel
The size from 7 to kingpin 3 can be reduced
This reduces the steering force during steering operation.
You can do it. As described in claim 2, the balk metal fitting is rotated.
Attached to the moving case from the axle side and removed with the axle support
By stopping inside the case,
There is no danger of falling off, and the structure is simple,
The maintenance can be improved.

[Brief description of the drawings]

FIG. 1 is a front cross-sectional view of a turning case turning portion in which a balk fitting is arranged on an upper bearing side.

FIG. 2 is a front sectional view showing an embodiment in which a balk fitting is similarly arranged on a lower bearing side.

FIG. 3 is a front sectional view of a balk fitting assembly.

FIG. 4 is a front sectional view of a balk fitting assembly in FIG. 2;

FIG. 5 is a sectional view taken along line AA in FIG. 1;

FIG. 6 is an overall side view of the tractor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Front wheel drive shaft 2 Front axle case 3 King pin 4 Vertical axis 5 Bevel gear mechanism 6 Fixed case 7 Front wheel 8 Axle 9 Reduction bevel gear mechanism 10 Rotating case 11 Bearing 12 Restriction fitting 13 Boke fitting

Claims (2)

(57) [Claims] At the outer end of a front axle case (2) containing a front wheel drive shaft (1), a kingpin (3) having a substantially vertical axis is formed downward, and a driving force is applied to a vertical axis (4) inside the kingpin (3). the stationary case 6 was furnished a bevel gear mechanism 5 to convey provided, the axle 8 of front wheel 7 is mounted, the rotary case 10 that furnished the reduction bevel gear mechanism 9 for transmitting the driving force from the longitudinal axis 4, bearing 11 to the kingpin 3 The bearing 11 is further rotatably supported via a pin, and the bearing 11 is axially moved with respect to the kingpin 3 by a restricting fitting 12 fitted on the lower surface .
In a structure in which downward movement is restricted, the bearing 11
The balk fitting 13 is inserted from the rotating case 10 into the upper surface of the
And bring the rotating case 10 out of the kingpin 3.
And the balk fitting 13 is not rotatable.
For fitting a bearing 14 for supporting the axle 8
From the innermost part of the opening 10b toward the upper part of the bearing 11a
A front wheel drive device for a tractor , wherein an insertion hole 10c is opened and inserted into the insertion hole 10c . 2. The balk fitting 13 supports an axle 8.
The bearing 14 is fitted into the opening 10 b of the rotating case 10.
The front wheel drive device for a tractor according to claim 1, wherein the tractor is prevented from falling off .