DESC:FIELD OF INVENTION

The present invention relates to front axle for tractors. In particular, the present invention relates to a tractor front axle having variable wheel base. More particularly, the present invention relates to an intelligent tractor front axle of variable wheel base.

BACKGROUND OF THE INVENTION

The safety of tractor operators highly depends on the tractor stability during operation thereof. One of the key parameter related to the tractor geometry is the wheel base ratio. Wheel base ratio is the ratio of the wheel base to the CG height. Any change in the wheel base ratio affects the locations of the CGs (centre of gravity) of tractor components and consequently this influences the tractor’s response to disturbances. The variations in the wheel base ratio result in more intense changes in tractor stability. Therefore, an increase in tractor speed or slope angle may immediately lead to a loss of contact and may even draw the tractor into a rollover.

PRIOR ART

Although, conventional tractor axles have means for wheelbase adjustment, using these means poses a risk of compromising with the tractor stability. This is due to the fact that by altering the wheelbase, the centre of gravity of different components, particularly heavy components are changed substantially, which in turn hampers tractor’s capability to resist the disturbances occurring during field operations. The poor stability also causes a loss of contact with field and so, there is imminent risk of tractor’s rollover.

DISADVANTAGES WITH THE PRIOR ART

The following are the disadvantages with the conventional tractors front wheel axles discussed above:

• Fixed wheel base ratio.

• Change in the wheel base ratio affects the locations of the CGs.

• Poor tractor’s response to disturbances.

• Poor tractor stability.

• Possibility of rollover or loss of contact, in case of an increased tractor speed or slope angle.

However, the tractor’s stability against rollover can be enhanced by increasing the wheel base ratio. Moreover, the chances of overturning can be nullified more rapidly after tractor has passed over a bump with this increased wheel base ratio. This also implies an improvement in the tractor’s capability of resist disturbances occurring due to external influences.

Accordingly, the tractor can be easily returned to a stable state and thus, sufficient stability can be regained to support operations at higher speeds or on steeper slopes.

OBJECTS OF THE INVENTION

Some of the objects of the present invention - satisfied by at least one embodiment of the present invention - are as follows:

An object of the present invention is to provide an tractor front axle with variable wheel base ratio.

Another object of the present invention is to provide a tractor front axle with improved tractor stability.

Still another object of the present invention is to provide an intelligent tractor front axle which improves the tractor’s response to disturbances.

Yet another object of the present invention is to provide a tractor front axle which reduces/eliminates rollover due to loss of contact.

A still further object of the present invention is to provide a tractor front axle which helps in high speed operation.

A yet further object of the present invention is to provide a tractor front axle which helps in operating in fields with higher slopes.

A yet further object of the present invention is to provide a tractor front axle which reduces the possibilities of overturning on crossing the bumps.

These and other objects and advantages of the present invention will become more apparent from the following description, when read with the accompanying figures of drawing, which are however not intended to limit the scope of the present invention in any way.

SUMMARY OF THE INVENTION

In accordance with the present invention, there is provided an intelligent front axle with variable wheelbase for farm tractors, wherein a reduced length pivot pin sleeve is configured flush with the outer surface of the front axle for adjusting the wheelbase ratio depending on the field operation requirements.

Typically, the wheelbase is adjusted by means of a plurality of split-type spacers swapped back and forth manually on said pivot pin to obtain the required wheelbase ratio.

Typically, the pivot pin sleeve is internally-threaded and a threaded pivot pin is inserted therein to obtain the required wheelbase ratio.

Typically, a screw joint is configured with a screw joint with a mechanical crank lever for quickly adjusting the wheel base ratio thereof by suitably rotating said threaded pivot pin.
Typically, the threaded pivot pin comprises ball screw for moving the axle to-and-fro by means of a recirculating ball-type nut integrated to the axle for obtaining the required wheelbase ratio.

Typically, the recirculating ball-type nut comprises a plurality of balls and ball return passages.

Typically, the screw joint is coupled to an electric motor for adjusting the wheelbase to obtain the required wheelbase ratio.

Typically, the electric motor is a brushless DC motor connected to a reduction gear box for adjusting the wheelbase to obtain the required wheelbase ratio.

Typically, the electric motor is operated clockwise or anti-clockwise for respectively moving said axle forward or backward by actuating a switch on the tractor’s dashboard by supplying power by the tractor battery connected to the electric motor.

Typically, an electronic control unit (ECU) is integrated to said front axle for changing the wheelbase ratio depending on the field operation requirements.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The present invention will be briefly described with reference to the accompanying drawings, wherein:

Figure 1a shows a perspective view of the conventional tractor front axle assembly with a pivot pin sleeve welded at the central portion thereof.

Figure 1b shows a perspective enlarged central portion of the tractor front axle (boxed) in Figure 1a.

Figure 1c shows a perspective view of the pivot pin to be inserted into the pivot pin sleeve of Figure 1a.

Figure 2a shows a perspective view of the first embodiment of the improved tractor front axle configured in accordance with the present invention.

Figure 2b shows a perspective enlarged central portion of the tractor front axle (boxed) in Fig. 2a.

Figure 2c shows a perspective view of the improved pivot pin configured as a threaded shaft to be inserted into the improved pivot pin sleeve of Fig. 2a.

Figure 3 shows a side view of the conventional tractor front axle with its axle support, wherein spacers cannot be changed to adjust wheelbase ratio.

Figure 4a shows a side view of the first embodiment of the improved tractor front axle with its axle support, configured according to the present invention.

Figure 4b shows a perspective view of the split type spacer used in the improved axle of Figure 4a.

Figure 5 shows in perspective view, a pin sleeve assembly configured in accordance with the present invention and fitted on the front axle of Fig. 2a.

Figure 6a shows a second embodiment of the improved tractor front axle configured in accordance with the present invention.

Figure 6b shows a detailed sectional view of pin sleeve assembly of Fig.6a.

Figure 7a shows a third embodiment of the improved tractor front axle configured in accordance with the present invention.

Figure 7b shows a fourth embodiment of the improved tractor front axle configured in accordance with the present invention.

DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS

In the following, the intelligent tractor front axle with variable wheelbase configured in accordance with the present invention will be described in more details with reference to the accompanying drawings without limiting the scope and ambit of the present invention in any way.

Figure 1a shows a perspective view of the conventional tractor front axle assembly with a front axle 10 having a pivot pin sleeve 20 welded substantially at the central portion thereof.

Figure 1b shows a perspective view of the central (boxed) portion of the tractor front axle assembly 10 of Fig. 1a.

Figure 1c shows a perspective view of the pivot pin 22 to be inserted into the pivot pin sleeve 20 of Fig. 1a.

Figure 2a shows a perspective view of the first embodiment of the tractor front axle assembly equipped with a front axle 100 configured in accordance with the present invention. Here, the pivot pin sleeve 120 is flush with the outer surface of the front axle 100. The pivot pin sleeve 120 (boxed) is integrated with a bush/recirculating ball type nut (not shown here).

Figure 2b shows a perspective view of the central (boxed) portion of the tractor front axle 100 of Fig. 2a. Here, the length of the pivot pin sleeve 120 is substantially reduced to make is flush with the outer surface of the tractor front axle 100.

Figure 2c shows a perspective view of the improved pivot pin 122 configured as a threaded shaft to be inserted into the pivot pin sleeve 120 of Fig.2a.

Figure 3 shows a detailed view of the conventional tractor front axle assembly 10 with the axle support 50 thereof, which has wheel base 25 without any option for adjusting the wheelbase ratio thereof.

Figure 4a shows a detailed view of the improved tractor front axle 100 with the axle support 150 thereof, in which the split-type spacers 130 can be placed on the pivot pin 122 made in accordance with the present invention, to be swapped back and forth thereon for adjusting the wheel base ratio based on the field operation requirements.

Figure 4b shows a perspective view of the split-type spacer 130 to be placed on the axle 100 for adjusting a desired wheel base ratio.

Figure 5 shows in perspective view a pin sleeve 120 inserted with a pivot pin 122 and fitted with a plurality of split-type spacers 130 on the front axle 100 of Figure 2a.

Figure 6a shows a second embodiment of the tractor front axle 100 configured in accordance with the present invention, in which a screw joint with mechanical crank lever 132 is provided for quick adjustment of the wheel base ratio thereof. The shaft or screw threaded pivot pin 120 contains ball screw on which the axle moves to-and-fro with the help of a recirculating ball type nut integrated to the axle (Fig.6b). The shaft rotation causes a linear motion of the axle. The shaft is coupled to the crank lever 132 to be rotated for moving the axle 100 to a defined wheel base.

Figure 6b shows a detailed sectional view of the pin sleeve assembly of Fig.6a. It includes a screw threaded pivot pin 122 integrated with a recirculating ball type nut 124 containing balls 126 and ball return passages 128.

Figure 7a shows a third embodiment of the tractor front axle 100 configured in accordance with the present invention, in which a screw joint is coupled to an electric motor 240 with or without a reduction gear box provided for adjusting the wheel base ratio thereof. Here, the shaft or screw threaded pivot pin 122 is coupled to the electric motor 240 which replaces the crank lever 132 of the second embodiment in Fig. 6a. A 2-way switch 250 is also provided on the tractor dash board, by which motor 240 is operated clockwise or anticlockwise for moving the axle 100 forward or backward respectively by supplying power through the tractor battery 260 connected thereto.

Figure 7b shows a fourth embodiment of the tractor front axle 100 configured in accordance with the present invention, in which an ECU 370 is integrated to the front axle 100of Figure 7a for changing the wheel base ratio when and wherever required.

DESCRIPTION OF THE INVENTION

In accordance with the present invention, a provision is made for altering the wheelbase for utilizing the advantages of both long and short wheelbase in a tractor front axle.

For this purpose, several optional configurations of the tractor’s front axle have been developed in accordance with the present invention, which are described below:

Option I

• Spacers are swapped manually.

• Spacers are swapped back and forth for adjusting the wheelbase.

Option II:

• The shaft contains ball screw on which the axle moves to-and-fro with the help of a recirculating ball type nut integrated with the tractor front axle.

• Rotation of the shaft leads to linear motion of the axle.

• The shaft is coupled to a hand lever.

• This lever is rotated in order to move the front axle to a defined wheelbase.

Option III:

• The shaft is coupled to a BLDC motor.

• The motor replaces the hand lever seen in Option II.

• A 2-way switch is provided on the tractor dash board for operating the motor clockwise or anti-clockwise for moving the front axle forward or backward.

• The motor is connected to the tractor battery.

Option IV:

• Setup is similar to option III.

• An ECU is integrated for altering the wheelbase as and when/where required.

• Done automatically without human intervention.

• ECU takes inputs like wheelbase ratio, steering angle, tire rotation, velocity, etc. and in turn gives input to the motor correspondingly.

• Roll over and front-end lift is reduced.

• Most dragging issues occurred while turning in fields are avoided by correcting the wheelbase.

• Front tire wear is substantially minimized.

Therefore, the aforementioned options for increasing the wheelbase ratio substantially enhance the tractor ability for resisting the loss of contact between the front wheel tire and ground, while the decrease in this wheel base ratio would have a reversed effect.

The higher values of the wheelbase ratio help in stabilizing the tractor more quickly.

This also improves the tractor stability by restraining the sensitive tire from lifting up and shortening the recovery time after experiencing a disturbance in the field.

TECHNICAL ADVANTAGES AND ECONOMIC SIGNIFICANCE

Accordingly, the intelligent tractor front axle with variable wheelbase configured in accordance with the present invention has the following technical and economic advantages:

1. Roll over reduction.

2. Front end lift.

3. Improved stability on road.
4. Reduced Turning circle radius on field.

5. Improve steering dynamics

6. Pioneering technology introduced for the first time in the market.

7. Improves market share.

8. Improves customer-satisfaction.

The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments.

The description provided herein is purely by way of example and illustration. The various features and advantageous details are explained with reference to this non-limiting embodiment in the above description in accordance with the present invention.

The descriptions of well-known components and manufacturing and processing techniques are consciously omitted in this specification, so as not to unnecessarily obscure the specification.

It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, the skilled person will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments described herein and can easily make innumerable changes, variations, modifications, alterations and/or integrations in terms of materials and method used to configure, manufacture and assemble various constituents, components, subassemblies, assemblies and in terms of the size, shapes, orientations and interrelationships without departing from the scope and spirit of the present invention.

It is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.

The numerical values given of various physical parameters, dimensions and quantities are only approximate values and it is envisaged that the values higher or lower than the numerical value assigned to the physical parameters, dimensions and quantities fall within the scope of the disclosure unless there is a statement in the specification to the contrary.

Throughout this specification, the word “comprise”, or variations such as “comprises” or “comprising”, shall be understood to implies including a described element, integer or method step, or group of elements, integers or method steps, however, does not imply excluding any other element, integer or step, or group of elements, integers or method steps.

The use of the expression “a”, “at least” or “at least one” shall imply using one or more elements or ingredients or quantities, as used in the embodiment of the disclosure in order to achieve one or more of the intended objects or results of the present invention. ,CLAIMS:We claim:

1. An intelligent front axle with variable wheelbase for farm tractors, wherein a reduced length pivot pin sleeve is configured flush with the outer surface of the front axle for adjusting the wheelbase ratio depending on the field operation requirements.

2. Front axle with variable wheelbase as claimed in claim 1, wherein the wheelbase is adjusted by means of a plurality of split-type spacers swapped back and forth manually on said pivot pin to obtain the required wheelbase ratio.

3. Front axle with variable wheelbase as claimed in claim 1, wherein said pivot pin sleeve is internally threaded and a threaded pivot pin is inserted therein to obtain the required wheelbase ratio.

4. Front axle with variable wheelbase as claimed in claim 1, wherein a screw joint is configured with a screw joint with a mechanical crank lever for quickly adjusting the wheel base ratio thereof by suitably rotating said threaded pivot pin.

5. Front axle with variable wheelbase as claimed in claim 4, wherein said threaded pivot pin comprises ball screw for moving the axle to-and-fro by means of a recirculating ball-type nut integrated to the axle for obtaining the required wheelbase ratio.

6. Front axle with variable wheelbase as claimed in claim 5, wherein said recirculating ball-type nut comprises a plurality of balls and ball return passages.

7. Front axle with variable wheelbase as claimed in claim 4, wherein said screw joint is coupled to an electric motor for adjusting the wheelbase to obtain the required wheelbase ratio.

8. Front axle with variable wheelbase as claimed in claim 7, wherein said electric motor is a brushless DC motor connected to a reduction gear box for adjusting the wheelbase to obtain the required wheelbase ratio.

9. Front axle with variable wheelbase as claimed in claim 8, wherein said electric motor is operated clockwise or anti-clockwise for respectively moving said axle forward or backward by actuating a switch on the tractor’s dashboard by supplying power by the tractor battery connected to the electric motor.

10. Front axle with variable wheelbase as claimed in claim 9, wherein an electronic control unit (ECU) is integrated to said front axle for changing the wheelbase ratio depending on the field operation requirements.

Dated: this 30th day of May 2017. SANJAY KESHARWANI
APPLICANT’S PATENT AGENT