JPS6321449Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a front wheel drive tractor in which the front wheels are used as steering wheels and are further driven.

Front-wheel drive tractors have become popular in recent years, but
After many years of use, problems have arisen regarding its durability. Particularly, rattling and cracking of the joint between the front gear case and the front gear box and the joint between the front axle case and the front axle case due to long-term use has become a problem.

The present invention particularly strengthens the joint between the front axle case and the front gear case.

The load applied to the front wheel is transmitted to the front gear case via the front gear box, and from the front gear case to the front axle case, but the load between the front gear box and the front gear case is transmitted via bearings. The thrust load is transmitted from the front gear case to the front axle case, but the transmission from the front gear case to the front axle case was supported by the shearing force of the fixing bolt between the two members. When this part became loose after years of use, the bolts would shear, resulting in many accidents resulting in vehicles being unable to run.

The present invention aims to provide a coupling device for a front axle case and a gear case that can withstand shocks caused by running on rough roads.

The purpose of the present invention is as described above, and the structure of the present invention will be explained based on the structure of the embodiment shown in the attached drawings.

FIG. 1 is an overall side view of a front wheel drive tractor.

It is configured to be able to drive the front wheels 5 at the same time as driving the rear wheels 24. An engine 19 is disposed within the hood 16, and a front wheel drive device is installed below the engine 19. The rotational driving force of the engine 19 is transmitted through a clutch housing 2 fixedly installed at the rear of the engine.
0 to the transmission case 21 and the rear axle case 22 at the rear thereof. A front wheel drive gearbox 23 is suspended from the lower surface of the transmission case 21 for extracting rotational force in synchronization with the rotation of the rear wheels 24, and a front wheel drive shaft 18 projects forward from the front wheel drive gearbox 23. The front wheel drive shaft 18 fits into the center box 17 and drives the front differential device 12.

FIG. 2 is a sectional view showing a conventional front wheel drive device. FIG. 3 is a sectional view showing a front wheel drive device of the present invention.

A front axle case 1 protrudes from both sides of a center box 17, and a differential shaft 11 passes through the inside thereof.

The differential shaft 11 has a bevel gear 14 fixed at its tip,
The bevel gear 14 rotates the bevel gear 9. The bevel gear 9 is fixed to the king pin 10,
Rotate bevel gear 8. The bevel gear 8 drives a large-diameter bevel gear 7, which in turn drives the front axle 6. The front wheel 5 is attached to the flange of the front axle 6.
to be fixed.

The load applied to the front wheel 5 is transmitted from the front axle 6 to the front gear box 3, and from the front gear box to the front gear case 2 via the king pin 10. Conventionally, transmission from the front gear case to the front axle case was carried out using bolts 1 on the flange that fastened both parts, as shown in Figure 2.
It was reported by 5.

The present invention aims to increase the strength by fitting the front axle case and the front gear case together as shown in FIG. 3, instead of connecting by tightening the flange.

In the conventional device, as shown in Fig. 2, the bearing 1
3 was fixed to the front gear case 3 side,
In this proposal, it is fixed to the front axle case side and inserted into the structure as is. However, a structure that fits into the front gear case may also be used.

However, just by fitting, if the wall of the fitting part is thin, it cannot withstand the shearing force, as is the case with bolts, so the weaker part of the casting is made thicker and uneven in thickness. In FIG. 3, the front axle case 1 has a fitting structure in which the tip of the front axle case 1 is fitted into the inner diameter of the front gear case 2 at the joint between the front axle case 1 and the front gear case 2.
The lower side 1a of the fitting part is made thicker than the upper side 1b, and conversely, the upper side 2b of the fitting part of the outer front gear case 2 is made thicker than the lower side 2a. The front wheel load is applied to the lower side 1a of the insertion part of the inner front axle case and the lower side 2a of the insertion part of the front gear case 2, so it is necessary to make both of these parts thick.

In addition, a sliding hole 2c for rotation of the king pin support 4 is provided in the thick part of the upper side 2b of the front gear case 2.
is opened, and the rotation center shaft of the king pin support is inserted into this opening, making it possible to rotate for steering. Since the upper side 2b of the front gear case 2 is thick, the fitting sliding hole 2c for rotation can be opened directly in this part, and sufficient strength for supporting rotation can be obtained. There would be no problem if the thickness of the casting was made thicker for both the upper and lower parts, but the outer diameter was limited due to the position of the king pin support 4, so a method was devised to thicken only the necessary parts. The reason why the front axle case on the inner diameter is made thicker is because the diameter is smaller and the cross-sectional area of the supporting material is narrower.The front gear case on the outer diameter has a wider cross-sectional area of the material, so even if it is a little thinner, the inner diameter member is thicker. This is because the strength is equivalent to that of .

FIG. 4 is a sectional view taken along the line A-A' in FIG. 3.

Insert the front axle case 1 into the inner diameter,
The insertion portion 1a is configured to have a thick wall.

As described above, the present invention has a fitting structure in which the tip of the front axle case 1 is fitted into the inner diameter of the front gear case 2 at the joint part between the front axle case and the front gear case, and the fitting part of the fitted front axle case 1 is provided. Among them, the lower side 1a is made thicker than the upper side 1b, and conversely, the upper side 2b of the fitting part of the outer front gear case 2 is made thicker than the upper side 1b.
is made thicker than the lower side 2a, and a sliding hole 2c for rotation of the king pin support 4 is provided in the thicker part of the upper side 2b.
Since it is opened, the following effects can be achieved.

First, because of the positional relationship with the rotating front gear box 3 etc., the outer diameter of the mating portion between the front gear case and the front axle case cannot be increased any further. By keeping the mating portion between the two cases as it was before and making it into a cylindrical body with an uneven thickness, it is possible to obtain maximum strength for the same diameter.

Second, even if the front wheels receive repeated shocks from driving on rough roads, the joints will not shear.

Thirdly, it is possible to obtain a front wheel drive device that is approximately the same size as the conventional joint.

Fourthly, since the upper side 2b of the front gear case 2 is thick, it is possible to directly open the rotation fitting sliding hole 2c in this part and to support the rotation of the king pin support. be. With this configuration, it is no longer necessary to provide a lid body on the front gear case 2 and provide therewith a rotation center axis of the king pin support 4, etc., as in the conventional case.

[Brief explanation of the drawing]

Fig. 1 is an overall side view of a front wheel drive tractor, Fig. 2 is a sectional view of a conventional front wheel drive device, Fig. 3 is a sectional view of the front wheel drive device of the present invention, and Fig. 4 is an A-A in Fig. 3. It is a sectional view of the arrow part. 1...Front axle case, 2...Front gear case, 3...Front gear box, 4
...Kingpin support, 5...Front wheel, 6...Front axle.

Claims (1)

[Scope of utility model registration request] At the joint between the front axle case and the front gear case, the front axle case 1
has a fitting structure in which the tip of the front gear case 2 is fitted into the inner diameter of the front gear case 2, and of the fitting part of the fitted front axle case 1, the lower side 1a is connected to the upper side 1b.
The front gear case 2 is made thicker and on the outside.
The upper side 2b of the insertion part is made thicker than the lower side 2a, and a king pin support 4 is attached to the thicker part of the upper side 2b.
A front wheel drive device for an agricultural tractor, characterized in that a fitting sliding hole 2c for rotation is opened.