TITLE OF THE INVENTION:

TRANSMISSION MECHANISM FOR CRAWLER TYPE AGRICULTURAL VEHICLES

FIELD OF THE INVENTION
The present invention relates generally to transmission mechanisms. Particularly, the present invention relates to a transmission mechanism, employable in crawler type agricultural vehicles which move on muddy terrain, such as agricultural vehicles which are employed during harvesting.

BACKGROUND OF THE INVENTION
Agricultural vehicles such as combined harvesters are employed during the agricultural season to accomplish harvesting operations such as reaping, threshing and so on. While the usage of combined harvesters expedites the harvesting process to a great extent., It is found that, due to the continual movement of the combined harvester on muddy terrain, mud or soil is deposited in the lower portion of the combine harvester. Persons skilled in the art know that, conventionally, the transmission mechanism of the crawler type combined harvester is associated with the drive sprocket within the track of the harvester. If mud is deposited in transmission mechanism, possibility of the combined harvester becoming dysfunctional due to Contamination is high. Such a dysfunctioning can be very detrimental to the harvesting process. Further, the motor used in the transmission mechanism conventionally is a gerotor motor, which is not efficient. Radial piston motors are far more efficient than Gerotor motors, however, they have the disadvantage of requiring heavy sealing in muddy operating conditions.
The gear box used conventionally, is a planetary gear box, which gets immersed in mud, occupies a large amount of space and therefore, necessitates the requirement for a larger diameter drive sprocket. There is a critical requirement for an efficient transmission mechanism, which does not get immersed in mud during harvesting.

There is therefore a need in the art, for an efficient transmission mechanism for crawler type agricultural vehicles that prevents immersion of the gearbox and the motor in mud.

OBJECTIVES OF THE INVENTION
The present invention as embodied by an efficient transmission mechanism for crawler type agricultural vehicles succinctly fulfils the abovementioned need(s) in the art. The objectives of the present invention are, as broadly enumerated in the present disclosure. However, it would be perfectly clear to a person skilled in the art that, inasmuch as the objectives have been enumerated, such objectives are only indicative of the scope and general coverage of the present invention.

This statement of enumerated objectives should be considered as merely indicative, and is no way restrictive of the scope and ambit of the present invention in its entirety. Not only the enumerated objectives should be considered as indicative of the scope and ambit of the present invention, in addition, any combination(s), variation(s), functional equivalent(s) and/or any structural alternative(s) should also be construed to be within the broad scope of the present invention, even though, such a scope of the present invention has not been explicitly stated herein and elsewhere in the present disclosure.

An objective of the present invention is to provide an efficient transmission mechanism for crawler type
agricultural vehicles that prevents immersion of the gearbox and the motor in mud.

Another objective of the present invention is to provide an efficient transmission mechanism for crawler type agricultural vehicles that reduces the sealing requirements (and associated reliability testing requirements) of the motor and the gear box to a minimum, which makes it economic.
Yet another objective of the present invention is to provide an efficient transmission mechanism for crawler type agricultural vehicles which is simple to install, maintain, and accommodate.

SUMMARY OF THE INVENTION

The present invention is embodied by an efficient transmission mechanism for crawler type agricultural vehicles, so as to fulfil the need(s) in the art, giving rise to the above-mentioned objectives sought to be fulfilled by the present invention. A person skilled in the art, is very well aware that, the objective(s) as enumerated and described in the present disclosure as embodied in the present invention, are merely illustrative of the scope and purview of the present invention, as described in the present disclosure. However, such an illustration may not be construed to restrict the present invention in any manner. It will be very clear to a person skilled in the art that, any additional variation(s), functional equivalent(s) and/or any structural altemative(s) to the 5 present invention, may also be understood to be within the scope and purview of the present invention, as described in the present disclosure. The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof.

The present disclosure discloses a transmission mechanism for crawler type agricultural vehicles.
.0 The transmission mechanism comprises a motor that has been configured to prevent it from getting immersed in mud which is associated with a top end of a gearbox , and a drive sprocket that is associated with a wheel of a crawler type agricultural vehicle. Unlike conventional gearboxes, the gearbox of the transmission mechanism in the present disclosure is not associated directly with the drive sprocket, and thus more space is available for the motor. The

.5 gearbox used is a spur gearbox and the motor used is a radial piston motor.

BRIEF DESCRIPTION OF DRAWINGS
The present invention has been explained and can be understood and practiced by a person 0 skilled in the art in conjunction with disclosure and appended drawings. It will be succinctly clear to a person skilled in the art, that the drawings serve to elucidate the salient features of the present invention to a person skilled in the art, and do not restrict the scope and purview of the present invention in any manner.
5 Figure 1 (a) and 1 (b) illustrates the gearbox arrangement and its application in accordance with the conventional practice.
Figure 2(a) illustrates an transmission mechanism in a crawler type agricultural vehicle in accordance with the present invention. Figure 2(b) illustrates the magnified view of insert in o Figure 2(a).

Figure 3 illustrates the magnified view of the transmission mechanism shown as insert in Figure 2(b) in accordance with the present invention.
DETAILED DESCRIPTION OF DRAWINGS
To increase the productivity of harvesting, agricultural vehicles such as, combine harvester(s) are used. The fields in which harvesting is performed are generally muddy and it is very difficult to ply a combine harvester with tyres on such terrain, hence crawler type combine harvesters are used. In such crawler type combine harvesters, a motor (102) and a gear box (103) are associated with a drive sprocket (101) positioned at the lower portion, i.e. in the track, of the crawler type combine harvester. Typically, the motor used is gerotor motor and the gearbox used is a planetary gearbox; thus, there is a, space constraint in the drive sprocket (101). In addition, drive sprocket (101) tends to be immersed easily in the muddy terrain in which it generally operates. Such a conventional arrangement is shown in Figure 1(b).

Further the portion of the harvester where the conventional arrangement has been installed is shown in Figure 1(a).

Therefore, to solve the two-fold problem of efficiency and immersion of motor and gear box in muddy terrain, a transmission mechanism (201) is disclosed. Figures 2(a), 2(b) and 3 shows the transmission mechanism (201) in accordance with the present invention. The present invention comprises a motor (23) which delivers drive, wherein the motor (23) is configured so as to prevent it from getting immersed in mud during operation of said vehicle in an agricultural field (shown in Fig 2 (b)), said motor being associated with a top end of a gearbox, which comprises, a plurality of gear sets (3, 8, 24) enclosed within a gearbox housing (1), including a first gear set (8), a second gear set (3), and a third gear set ( 24). The gearbox receives the drive from the motor (23) and reduces it and a drive sprocket (15) which receives the reduced drive from the gearbox and drives the vehicle. Further, the gearbox comprises, a plurality of longitudinal shafts (2, 5,10), including a first shaft (2), a second shaft (5), and a third shaft (10) to drive the plurality of gear sets (3, 8, 24), a plurality of bearings (4, 6, 11, 12, 18) for enabling free rotation of the plurality of longitudinal shafts, wherein one or more of the plurality of bearings (4, 6,11,12,18) may be associated with one or more spacers (7,17) and/or bush(es) (13) for keeping the plurality of bearings intact in their respective positions, and a dummy (22) to close the first shaft (2). The
gearbox housing (1) further comprises a plurality of covers (19, 20, 21) for protection and for facilitating opening and closing of the gearbox housing (1) during maintenance and repair. The motor (23) is associated with both a top end of the gearbox housing (1), as well as with a first end of the second shaft (5). A second end of the second shaft (5) is connected to the first gear set (8) where first drive reduction happens. The second gear set (3) is connected to the first shaft (2) where the second drive reduction happens and finally the third gear set (24) is connected to the first end of the third shaft (10) where the final drive reduction happens and then transferred to the drive sprocket (15) which is connected with the second end of the third shaft (10). The third shaft (10) which extends towards the drive sprocket (15) is enclosed within a drive housing (9) and is closed by a endcap (14) at the drive sprocket (15) end. A cover (16) which is associated with the drive sprocket (15) is for protection and further to prevent it from getting immersed in mud during operation.

The gearbox employed in the present invention is preferably a spur gear box but can also be a helical gearbox or any other equivalent gearboxes. The motor used is preferably a radial piston motor. Preferably, the diameter of the drive sprocket (15) in the present invention is 235mm and number of teeth are 8. But not limited to this combination, the sprocket diameter and no of teeth are related to the pitch of the track selected and is guided by the following equation:

Sprocket Diameter (0) = Track Pitch (p) x No of Teeth (n) / n
It will be apparent to a person skilled in the art that the above description is for illustrative purposes only and should not be considered as limiting. Various modifications, additions, alterations, and improvements without deviating from the spirit and the scope of the invention may be made by a person skilled in the art. For example, although the present invention has been shown as being utilized for crawler type agricultural vehicles, it will be appreciated by persons skilled in the art that the same may be used in any crawler type vehicle apart from agricultural vehicle.

ADVANTAGES
The below-mentioned advantage(s) arising out of the application in conjunction with the enclosed drawing(s) are merely indicative and are not to be considered as exhaustive of the entire
5 advantage(s) arising by the deployment of the present invention. It will be amply clear to persons skilled in the art that, any primary advantage(s) arising out of the present invention as against the problem(s) in the conventional arrangements are to be construed to be well within the scope and purview of the present invention. Further, any secondary advantage(s) arising as a result of the primary advantage(s) are also to be construed to be well within the scope and purview of the present invention.

An advantage of the present invention is prevention of immersion of both the motor and the gear box in mud, as well as reduction in space of the transmission mechanism.

Since the motor employed is the radial piston motor, as against the conventional low-efficiency gerotor, the efficiency of the present invention is increased.

Since the gearbox used is the simple spur gearbox, instead of the planetary gearbox, said spur gearbox being positioned outside the drive sprocket, the space constraint problem in the 3 conventional gearbox is solved. Further, the diameter of the drive sprocket also significantly reduced as compared to the conventional drive sprocket.

We Claim:

1. A transmission mechanism (201) for crawler type agricultural vehicles, comprising;
a. a motor (23), which delivers drive, wherein the motor (23) is configured so as to prevent it from getting immersed in mud during operation of said vehicle in an agricultural field, said motor being associated with a top end of a gearbox;

b. the gearbox that is associated with the motor, said gearbox comprising a plurality of gear sets (3, 8, 24) enclosed within a gearbox housing (1), including a first gear set (8), a second gear set (3), and a third gear set (24) for reducing the drive received from the motor (23) and to transfer the drive to a drive sprocket (15);

c. a plurality of longitudinal shafts (2, 5, 10), wherein each shaft has a first end and a second end, including a first shaft (2), a second shaft (5), and a third shaft (10) to drive the plurality of gear sets (3, 8,24), wherein a first end of the second shaft (5) is associated with the motor (23), a second end of the second shaft (5) is connected to the first gear set (8), the first shaft (2) is connected to the second gear set (3), and a first end of the third shaft (10) is connected to the third gear set (24), and a second end of the third shaft (10) is connected to the drive sprocket (15);

d. a plurality of bearings (4, 6,11,12,18) for enabling free rotation of the plurality of longitudinal shafts;

e. a dummy to close the first shaft (2),,

f. the drive sprocket (15), that is associated with the wheel of said vehicle, which receives the reduced drive from the third gear set (24) and drives the vehicle;

g. the third shaft (10) which extends towards the drive sprocket (15) is enclosed within
a drive housing (9) and is closed by a endcap (14) at the drive sprocket end; and

h. a cover (16) which is associated with the drive sprocket (15) is for protection and further to prevent it from getting immersed in mud during operation.

2. A transmission mechanism (201) for crawler type agricultural vehicles as claimed in claim 1, wherein the motor used is a radial piston motor.

3. A transmission mechanism (201) for crawler type agricultural vehicles as claimed in claim 1, wherein the gearbox used is a spur gearbox or helical gearbox or any other equivalent gearboxes.

4. A transmission mechanism (201) for crawler type agricultural vehicles as claimed in claim 1, wherein the diameter of the drive sprocket is 235mm.

5. A transmission mechanism (201) for crawler type agricultural vehicles, wherein number of teeth in the drive sprocket is 8.

6. A transmission mechanism (201) for crawler type agricultural vehicles as claimed in claim 1, wherein one or more of the plurality of bearings (4, 6, 11, 12, 18) may be associated with one or more spacers (7, 17) and/or bush(es) (13) for keeping the plurality of bearings intact in their respective positions.

7. A transmission mechanism (201) for crawler type agricultural vehicles as claimed in claim 1, further comprising a plurality of covers (19, 20, 21) for protection and for facilitating opening and closing of the gearbox housing (1) during maintenance and repair.