JPH05270288A - Front wheel drive device for tractor - Google Patents

Abstract

PURPOSE:To facilitate the assemblage and maintenance of a front wheel drive device by inserting attachably parts abutting directly against a king pin extending beneath a fixed case into a pivotable case to support thrust, radial load, etc., on the king pin through bearings provided above and below. CONSTITUTION:A king pin 3 is formed in the lower portion of a fixed case 6 in the outer end of a front axle case 2, upper and lower bearings 11, 12 are axially fixed to the king pin 3 by fixing fittings. While these are supported pivotably by a pivotable case 10 for supporting an axle 8, a bevel gear mechanism and others are received in the fixed case 6 and pivotable case 10 to drive the axle 8 through a front wheel drive shaft. The upper and lower bearings 11, 12 and oil seals 14 are externally fitted on the king pin 3 and inserted from an upper opening of the pivotable case 10 into a housing 15 so that the outer peripheral surfaces of the upper and lower bearings 11, 12 and oil seals 14 are located to abut against the inner surface of the pivotable case 10.

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 / steering section of a four-wheel drive tractor.

[0002]

2. Description of the Related Art The structure of a front wheel drive portion of a tractor has been conventionally known, and for example, it is disclosed in Japanese Utility Model Laid-Open No. 60-11572.
This is the technique disclosed in No. 2 and Japanese Utility Model Publication No. 3-34335. In such a front-wheel drive unit, the former assembly method is that the lower bearing is inserted into the rotating case, the axial direction is fixed with a stopper, the upper bearing and the oil seal are attached, and then the king pin is inserted before deceleration. The metal fitting was attached to the lower part of the king pin from the bevel gear meshing opening,
In the latter case, the king pin was equipped with the upper bearing and the oil seal, and was inserted into the fixed case for assembly.

[0003]

However, in the former case of the above-mentioned prior art, since the lower bearing must be mounted at the inner part of the rotating case and from the small opening, the workability is poor and the structure is low. Was also complicated, and it was difficult to perform maintenance at the time of disassembly at the same time as assembling. In the latter case, when there is no lower bearing and the bearings are rotatably supported by the cases, the durability is reduced and the turning resistance is increased. Since there is no bearing, the case has to be replaced and maintenance is poor. Furthermore, after inserting the king pin, the workability for attaching the stopper to the lower part of the king pin from the reduction bevel gear meshing opening or the lower opening is poor, and when the steering is turned, the stopper is slid on the king pin groove or the rotating case contact surface. Because of the movement, abrasion occurs, the amount of movement in the axial direction of the kingpin increases, and the sealing performance of the upper oil seal deteriorates.

[0004]

In order to solve such a problem, the present invention provides a king pin 3 having a substantially vertical axis at an outer end of a front axle case 2 having a front wheel drive shaft 1 incorporated therein. Extending downward, the kingpin 3
A vertical case 4 having a fixed case 6 provided on the upper side and a bevel gear mechanism 5 arranged on the upper side is internally provided, and an axle 8 is driven from the vertical axis 4 through a reduction bevel gear mechanism 9 to move around the kingpin 3 of the fixed case 6. In a structure in which the rotating case 10 is rotatably supported via an upper bearing 11 and a lower bearing 12, the lower bearing 12 is axially fixed to the king pin 3 by a fixing bracket 13, and an oil seal 14 is arranged on the upper portion. It is possible to insert at least a component between the king pin 3 and the rotating case 10 that directly abuts against the king pin 3 into the housing 15 of the rotating case 10 while being mounted on the king pin 3.

[0005]

The upper bearing 11, the lower bearing 12, and the oil seal 14, which are parts that directly contact the king pin 3 located below the fixed case 6, are fitted onto the lower bearing 12 to fix the lower bearing 12 to the fixing bracket 1.
3 is axially fixed to the king pin 3 and the vertical axis 4 is accommodated in the king pin 3, and is inserted into the housing 15 through the upper opening of the rotating case 10, the upper bearing 11 and the lower bearing 12 are formed. The outer peripheral surface of each of the oil seals 14 is positioned in contact with the inner surface of the rotating case 10, and the lower end of the vertical axis 4 is inserted into the bevel gear 9a for easy assembly. The rotating case 10 rotates about the kingpin 3. Since the steering wheel 23 can be freely turned and rotated by operating the handle 23, the power from the front wheel drive shaft 1 can drive the front wheels 7 through the bevel gear mechanism 5, the vertical axis 4, the reduction bevel gear mechanism 9, and the axle 8. is there.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The problems to be solved by the present invention and the means for solving the problems are as described above. Next, an embodiment shown in the accompanying drawings will be described. FIG. 1 is a front sectional view of a rotating portion of a front wheel drive device, 2 is a front sectional view of inserting the king pin into the rotating case, FIG. 3 is a front sectional view of inserting the vertical axis into the king pin and inserting into the rotating case, and FIG. 4 is a side view of the entire tractor.

[0007] Explaining from the overall configuration in FIG.
Is a front wheel, 20 is a rear wheel, 21 is a seat, and the hood 2
A battery 23, an engine E, and the like are housed in the inside 2, and a handle 24 is projected to the rear portion of the bonnet 22 so that the front wheel 7 can be steered and rotated by the rotation of the handle 5. A mission case 25 is disposed below the seat 21, and the power from the engine E is changed in speed by the mission case 25 and transmitted to a front wheel 7, a rear wheel 20, and a PTO shaft for driving a working machine. .. Then, the transmission of power to the front wheels 7 is transmitted to the front axle case 2 via the transmission shaft 26 to the front wheel drive output shaft protruding from the front portion of the transmission case 25, and the front wheel drive device of the present invention via the differential device. The front wheels 7 are driven by.

In the front wheel drive system of the present invention, as shown in FIG. 1, the power from the differential device is transmitted to the front wheel drive shaft 1 mounted on the front axle case 2 and fixed to both ends of the front axle case 2. A case 6 is fixedly provided, and a lower portion of the fixed case 6 forms a king pin 3 and extends downward. An end portion of the front wheel drive shaft 1 inserted into the fixed case 6 is rotatably supported at a joint portion between the front axle case 2 and the fixed case 6 via a bearing 16, and a bevel gear 5a is splined at the end of the front wheel drive shaft 1. The bevel gear 5a is fitted and fixed, and is meshed with the bevel gear 5b which is spline-fitted and fixed to the upper end of the vertical axis 4.

The vertical axis 4 extends from the fixed case 6 through the kingpin 3, the upper end is rotatably supported by the fixed case 6 via a bearing 17 fitted on the bevel gear 5b, and the lower end is held by the kingpin 3. Projecting and rotating case 1
0 is inserted into the shaft core of a bevel gear 9a that is rotatably supported at the bottom through a bearing 18, and spline-fitted,
It is configured to transmit power. The bevel gear 9a is meshed with the large-diameter bevel gear 9b,
Is a rotating case 10 and a support case 19 fixed to the side thereof.
Is fixedly mounted on an axle 8 which is rotatably supported by bearings 27 and 28, and a front wheel 7 is fixed by bolts to a flange portion 8a provided at the outer end of the axle 8. Axis 4
Power is transmitted to the axle 8 via the deceleration bevel gear mechanism 9 to drive the front wheels 7.

The rotating case 10 is configured to be rotatable via a knuckle arm or the like in conjunction with the rotation of the handle 24, and an upper bearing 11 and a lower bearing are provided between the king pin 3 and the rotating case 10. It is rotatably supported via 12 and has an oil seal 14 to prevent dust and the like from entering through a gap between the upper king pin 3 and the rotating case 10.
Is installed.

A method of assembling the kingpin 3 and the rotating case 10 in such a structure will be described.
As shown in FIG. 2 and FIG. 3, first, the bevel gear 5 is attached to the upper end of the fixed case 6 fixed to the front axle case 2.
The vertical axis 4 to which b is fixed is inserted via a bearing 17, and the bearing 17 is fixed in the axial direction by a fixing metal fitting 29 such as a C ring, and the opening 6a in the upper part of the fixed case 6 is attached to the lid 30. It can be closed. Then, the oil seal 14 and the upper bearing 1 are provided above the king pin 3 below the fixed case 6.
1 is externally fitted, the spacer 31 and the lower bearing 12 are externally fitted to the lower part of the king pin 3 and fixed by the fixing fitting 13, while the bearing 18 is fitted to the lower part in the housing 15 of the rotating case 10.
When the bevel gear 9a is supported via the king pin 3 and the king pin 3 is inserted into the rotating case, the tip of the vertical axis 4 is inserted into the bevel gear 9a, and the king pin 3 is rotated by the upper bearing 11 and the lower bearing 12 in the rotating case. It is rotatably supported by 10.

[0012]

Since the present invention is configured as described above, it has the following effects. That is, by mounting a component that directly abuts the king pin portion extending below the fixed case so that the component can be inserted into the rotating case, the workability of mounting each component can be significantly improved, and it is also possible to attach the component to the rotating case. Since there is no mounting of components through the narrow opening after insertion of the, the assembly is facilitated and the maintainability is improved. Further, since loads such as thrust and radial in the kingpin portion are supported through the bearings provided above and below, the steering force can be reduced and the durability can be improved.

[Brief description of drawings]

FIG. 1 is a front sectional view of a rotating portion of a front wheel drive device.

FIG. 2 is a front cross-sectional view of inserting a kingpin into a rotating case.

FIG. 3 is a front sectional view in which the vertical axis is inserted into a king pin and then inserted into a rotating case.

FIG. 4 is a side view of the entire tractor.

[Explanation 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 Upper Bearing 12 Lower Bearing 13 Fixing Bracket 14 Oil Seal 15 Housing

Claims (1)

[Claims] 1. A front axle case 2 in which a front wheel drive shaft 1 is housed has a king pin 3 extending downward at an outer end of the front axle case 2 and a fixed case 6 provided above the king pin 3. A vertical axis 4 having a bevel gear mechanism 5 arranged in the upper part is incorporated, and a reduction bevel gear mechanism 9 is provided from the vertical axis 4.
The axle 8 is driven through the rotary case 10, and the rotary case 10 is rotatably supported around the kingpin 3 of the fixed case 6 via the upper bearing 11 and the lower bearing 12, and the lower bearing 12 is fixed to the kingpin by the fixing bracket 13. In the structure in which the oil seal 14 is arranged on the upper part of the king pin
And between the rotating case 10 and at least the king pin 3
A front wheel drive device for a tractor, wherein a component that directly abuts against the king pin 3 can be inserted into the housing 15 of the rotating case 10 in a mounted state.