FORM 2
The Patent Act 1970
(39 OF 1970)
AND
THE PATENT RULES, 2005
COMPLETE SPECIFICATION (See Section 10; Rule 13)
TITLE OF THE INVENTION
A GEARBOX FOR CONTROLLING ROTATIONAL SPEED OF AN
ENGINE OF A PUMP
APPLICANT(S)
KIRLOSKAR OIL ENGINES LIMITED
an Indian Company
Laxmanrao Kirloskar Road,
Khadki, Pune – 411 003,
Maharashtra, India.
The following specification particularly describes and the invention and the manner in which it is to be performed:-

FIELD OF THE INVENTION
[0001] The present disclosure relates to water pumps, more particularly related to reducing a rotational speed of a diesel engine to match with a rotational speed of water pumps using a gearbox.
BACKGROUND OF THE INVENTION
[0002] Of all time ways are found to work on irrigation in better conditions with an increasingly usages of diesel engine pump sets and with maximum efficiency (where shortage of electricity and undeveloped irrigation region). Today's diesel engine pump sets are important in farming for irrigation where there is no electricity available or field conditions are challenging. With the pump sets, farmer can give water to their crop any time as per crop need. The continuous evolution of diesel engine pump sets was mainly aimed at the development of specific technological processes, constant increase of speed in operation mode and increase of engine power. Traditional agricultural engines are heavy and bulky in nature. It causes heavy efforts to handle and maintain at field. However now farmers are demanding light weight engines with standard water pumps. Currently there is no solution to couple high speed diesel engines with standard water pumps. Latest light weight diesel engines are available above 3000 RPM but traditional pumps are available in low rpm only. (i. e.,1500/1600/1800 RPM). In view of this, high speed lightweight aluminium engines cannot connect directly to standard water pumps. Hence there remains a need of light weight and efficient pump sets, which are more comfortable for irrigation purpose.
OBJECT OF THE INVENTION
[0003] The principal object of the embodiments herein is to provide a

[0004] gearbox for reducing a rotational speed of a diesel engine to match with a rotational speed of water pump. This will use to enhance the productivity and usage of small high speed diesel engine pump set in agricultural application with standard design –speed water pumps for crop irrigation application.
[0005] Another object of the embodiments herein is to provide light weight high speed diesel engines make compatible for all traditional water pumps without changing their design and basic mounting structure
SUMMARY OF THE INVENTION
[0006] In one aspect object is satisfied by providing a pump set for controlling rotational speed. The pump set comprising an engine mounted on a base frame, a pump, and a gearbox connected between the engine and the pump. The gearbox is mounted on a crank shaft of the engine and a pump shaft of the pump. The mechanical rotations of the crank shaft of the engine provides power to rotate the gearbox to match with a rotational speed of pump with a rotational speed of the engine by reducing the rotational speed of the engine.
[0007] In an embodiment, the gearbox comprises a first gear assembly mounted on the crank shaft of the engine, a second gear assembly connected to the pump shaft of the pump, an idler gear assembly meshing with the first gear assembly and the second gear assembly, a gasket for the gearbox case. The mechanical rotations of the crank shaft of the engine provides power to rotate the first gear assembly in an anti-clockwise direction which in turn rotates the idler gear assembly in a clockwise direction, and the rotation of the idler gear assembly in turn rotates the second gear assembly in an anti-clock wise direction to reduce the rotational speed of the engine to match the rotational speed of the engine with a rotational speed of pump.

[0008] In an embodiment, the first gear assembly comprises a driving gear with spline meshing with the idler gear assembly, a support washer placed on the driving gear, a cap screw for fixing the support washer on the driving gear, a punched washer, and a socket head screw for fixing the punched washer and the driving gear on the crank shaft of the engine.
[0009] In an embodiment, the idler gear assembly comprises an idler gear shaft, an internal circlip placed on the idler gear shaft, a bearing idle shaft, an idler gear with spline meshing with the first gear assembly and the second gear assembly, an external circlip placed on the idler gear, and a set bolt with a coarse pitch for fixing the idler gear shaft on the gearbox.
[0010] In an embodiment, the second gear assembly comprises a first bearing in the gearbox, an output driven shaft, a driven gear with spline meshing the idler gear assembly, a spacer for the output driven shaft, a second bearing in the gearbox, an external circlip, at least one oil seal rubber with O-Ring, a punched washer, and a self-locking nut.
[0011] In an embodiment, the gearbox comprises a breather bolt, a dipstick, a flanged nut, a socket head screw, a copper washer, a drain plug, and a gasket for the gearbox.
[0012] In an embodiment, the gearbox comprises a breather bolt, a dipstick, a flanged nut, a socket head screw, a copper washer, a drain plug, a gasket for the gearbox, and a gearbox cover.
[0013] In an embodiment, a coupler and a U-shaped frame is assembled on the pump shaft.
[0014] In an embodiment, a cover plate is assembled on the gearbox.

[0015] Another aspect of the invention provides a gearbox for controlling rotational speed of an engine of a pump. The gearbox comprising a first gear assembly mounted on the crank shaft of the engine, a second gear assembly connected to the pump shaft of the pump, an idler gear assembly meshing with the first gear assembly and the second gear assembly, and a gasket for the gearbox case. The mechanical rotations of the crank shaft of the engine provides power to rotate the first gear assembly in an anti-clockwise direction which in turn rotates the idler gear assembly in a clockwise direction. Further, the rotation of the idler gear assembly in turn rotates the second gear assembly in an anti-clock wise direction to reduce the rotational speed of the engine to match the rotational speed of the engine with a rotational speed of pump.
[0016] The first gear assembly comprises a driving gear with spline meshing with the idler gear assembly, a support washer placed on the driving gear, a cap screw for fixing the support washer on the driving gear, a punched washer, and a socket head screw for fixing the punched washer and the driving gear on the crank shaft of the engine. The idler gear assembly comprises an idler gear shaft, an internal circlip placed on the idler gear shaft, a bearing idle shaft, an idler gear with spline meshing with the first gear assembly and the second gear assembly, an external circlip placed on the idler gear, and a set bolt with a coarse pitch for fixing the idler gear shaft on the gearbox. The second gear assembly comprises a first bearing in the gearbox, an output driven shaft, a driven gear with spline meshing the idler gear assembly, a spacer for the output driven shaft, a second bearing in the gearbox, an external circlip, at least one oil seal rubber with O-Ring, a punched washer, and a self-locking nut.
[0017] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiments and

numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.
BRIEF DESCRIPTION OF DRAWINGS
[0018] This connector is illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:
[0019] FIG. 1 illustrates an assembly of a mono pump set, according to embodiments as disclosed herein;
[0020] FIG. 2 illustrates an exploded view of the mono pump set as shown in the FIG. 1, according to embodiments as disclosed herein;
[0021] FIG. 3 illustrates a gearbox assembly mounted on the engine as shown in the FIG. 1, according to embodiments as disclosed herein;
[0022] FIG. 4 illustrates a power take off drive from engine crank shaft to the gearbox as shown in the FIG. 3, according to embodiments as disclosed herein;
[0023] FIG. 5 illustrates a gear train for speed reduction mounted on the engine crank shaft of the gearbox, according to embodiments as disclosed herein;
[0024] FIG. 6 illustrates a gear train for speed reduction, according to embodiments as disclosed herein;
[0025] FIG. 7 illustrates an exploded view of the gearbox as shown in the FIG. 6, according to embodiments as disclosed herein;
[0026] FIG. 8 illustrates an assembly of a coupled pump set, according to embodiments as disclosed herein;

[0027] FIG. 9 illustrates an exploded view of the coupled pump set as shown in the FIG. 8, according to embodiments as disclosed herein;
[0028] FIG. 10 illustrates the gearbox assembly mounted on the engine of FIG. 8, according to embodiments as disclosed herein;
[0029] FIG. 11 illustrates a power take off drive from engine crank shaft to the gearbox of the FIG. 10, according to embodiments as disclosed herein;
[0030] FIG. 12 illustrates a gear train for speed reduction mounted on the engine crank shaft of the gearbox as shown in the FIG. 8, according to embodiments as disclosed herein;
[0031] FIG. 13 illustrates a gear train for speed reduction as shown in the FIG. 8, according to embodiments as disclosed herein; and
[0032] FIG. 14 illustrates an exploded view of the gearbox as shown in the FIG. 13, according to embodiments as disclosed herein.
DETAILED DESCRIPTION OF THE INVENTION
[0033] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. Also, the various embodiments described herein are not necessarily mutually exclusive, as some embodiments can be combined with one or more other embodiments to form new embodiments. The term “or” as used herein, refers to a non-exclusive or, unless otherwise indicated. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein can be practiced and to further enable those skilled in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.

[0034] The accompanying drawings are used to help easily understand various technical features and it should be understood that the embodiments presented herein are not limited by the accompanying drawings. As such, the present disclosure should be construed to extend to any alterations, equivalents and substitutes in addition to those which are particularly set out in the accompanying drawings. Although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are generally only used to distinguish one element from another.
[0035] Referring now to the drawings, and more particularly to FIGS. 1 through 14, there are shown preferred embodiments.
[0036] FIG. 1 illustrates an assembly of a mono pump (100), according to embodiments as disclosed herein. The pump set (100) comprising an engine (1) mounted on a base frame (2), a pump (3), and a gearbox (4) connected between the engine (1) and the pump (3). The gearbox (4) is mounted on a crank shaft (5) of the engine (1) and a pump shaft of the pump (3). The mechanical rotations of the crank shaft (5) of the engine (1) provides power to rotate the gearbox to match with a rotational speed of pump (3) with a rotational speed of the engine (1) by reducing the rotational speed of the engine (1).
[0037] FIG. 2 illustrates an exploded view of the mono pump set (100) as shown in the FIG. 1, according to embodiments as disclosed herein. The exploited view indicates the connection between various components. The diesel engine (1) is mounted on base frame (2). The diesel engine (1) described herein is a high speed diesel engine. The gearbox (4) for speed reduction is mounted on the crank shaft (5) of the engine (1) and drive gear of compact innovative gearbox mounted on engine output shaft. Then a cover plate (6) assembled on the gearbox (4). Finally, the water pump (3) is connected on the

cover plate (6). This makes ready to use the entire pump set (100) for any crop irrigation applications such as River, Canal, Ponds, Open wells, lakes and poly-ponds, dewatering, etc.
[0038] FIG. 3 illustrates the gearbox (4) assembly mounted on the engine (1) and FIG. 4 illustrates a power take off drive from engine crank shaft to the gearbox, according to embodiments as disclosed herein. FIG. 3 shows the gearbox (4) mounted directly on the engine crank case. Gears used mainly driver, driven and idler for achieve required speed reduction. The input to the gearbox (4) comes from the crank shaft (5) of the engine (1). The mechanical rotation of the crank shaft (5) of the engine (1) delivers power to the pump shaft of the pump (3).
[0039] FIG. 5 illustrates a gear train for speed reduction mounted on the engine crank shaft of the gearbox (4), according to embodiments as disclosed herein. The gearbox (4) comprises a first gear assembly (7) mounted on the crank shaft (5) of the engine (1), a second gear assembly (8) connected to the pump shaft of the pump (3), an idler gear assembly (9) meshing with the first gear assembly (7) and the second gear assembly (8), and a gasket for the gearbox (4) case. The mechanical rotations of the crank shaft (5) of the engine (1) provides power to rotate the first gear assembly (7) in an anti-clockwise direction which in turn rotates the idler gear assembly (9) in a clockwise direction, and the rotation of the idler gear assembly (9) in turn rotates the second gear assembly (8) in an anti-clock wise direction to reduce the rotational speed of the engine (1) to match the rotational speed of the engine (1) with a rotational speed of pump (3).
[0040] For example, the three gears which form gear train are used for reducing speed of 3000 RPM to match with speed of the water pump as shown in the FIG. 6. The first gear assembly (7) mounted on engine crank shaft (5)

rotates (in anti-clockwise direction) with 3000 RPM and mesh with the idler gear assembly (9) to change direction of rotation (in clockwise direction) then pump shaft assembled with the second gear assembly (8) rotates (in anti¬clockwise) same as per engine direction of rotation and reduce speed of 1500 rpm engine to match water pump speed.
[0041] FIG. 7 illustrates an exploded view of the gearbox (4), according to embodiments as disclosed herein. The first gear assembly (7) comprises a driving gear (10) with spline meshing with the idler gear assembly (9), a support washer (11) placed on the driving gear (10), a cap screw (12) for fixing the support washer (11) on the driving gear (10), a punched washer (13), and a socket head screw (14) for fixing the punched washer (13) and the driving gear (10) on the crank shaft (5) of the engine (1). The idler gear assembly (9) comprises an idler gear shaft (15), an internal circlip (16) placed on the idler gear shaft (15), a bearing idle shaft (17), an idler gear (18) with spline meshing with the first gear assembly (7) and the second gear assembly (8), an external circlip (19) placed on the idler gear (18), and a set bolt with a coarse pitch (20) for fixing the idler gear shaft (15) on the gearbox (4).
[0042] The second gear assembly (8) comprises a first bearing (21) in the gearbox (4), keys (22 and 24), an output driven shaft (23), a driven gear (25) with spline meshing the idler gear assembly (9), a spacer (26) for the output driven shaft (23), a second bearing (27) in the gearbox (4), an external circlip (28), at least one oil seal rubber (29) with O-Ring, a punched washer (30), and a self-locking nut (31).
[0043] Further, the gearbox (4) comprises a breather bolt (33), a dipstick (34), a flanged nut (35), a socket head screw (37), a copper washer (36), a drain plug (38), and a gasket (32) for the gearbox (4).

[0044] Unlike the conventions system, the mechanical rotations of the crank shaft (5) of the engine (1) provides power to rotate the first gear assembly (7) in an anti-clockwise direction which in turn rotates the idler gear assembly (9) in a clockwise direction, and the rotation of the idler gear assembly (9) in turn rotates the second gear assembly (8) in an anti-clock wise direction to reduce the rotational speed of the engine (1) to match the rotational speed of the engine (1) with a rotational speed of pump (3). The proposed gearbox imparts capacity to the farmers to carry out irrigation with ease and freedom from traditional heavy engines. It helps the farmers to achieve irrigation inexpensive, light weight, compact with better efficiency, specifically for the high speed diesel engines with standard water pumps. Using the proposed invention, the high speed lightweight aluminum engines (above 3000RPM) can be connected directly to standard water pumps using the proposed speed reduction gear box serve. Hence, the there is no need to change the design of the existing water pump. This gives advantages for usages of high speed diesel engines with any standard speed water pump. Also it makes compact, lightweight, and mobile during handling at field.
[0045] FIGS. 8-14 illustrates the proposed invention in a coupled pump set for reducing a rotational speed of a diesel engine.
[0046] FIG. 8 illustrates an assembly of a coupled pump (100), according to embodiments as disclosed herein. The coupled pump set (100) comprising an engine (1) mounted on a base frame (2), a pump (3), and a gearbox (4) connected between the engine (1) and the pump (3). The gearbox (4) is mounted on a crank shaft (5) of the engine (1) and a pump shaft of the pump (3). Then a coupling (39) and a U-shaped frame (40) assembled on pump shaft. The mechanical rotations of the crank shaft (5) of the engine (1) provides power to rotate the gearbox to match with a rotational speed of pump (3) with a

rotational speed of the engine (1) by reducing the rotational speed of the engine (1).
[0047] FIG. 9 illustrates an exploded view of the coupled pump set (100) as shown in the FIG. 8, according to embodiments as disclosed herein. The exploited view indicates the connection between various components. The diesel engine (1) is mounted on base frame (2). The diesel engine (1) described herein is a high speed diesel engine. The gearbox (4) for speed reduction is mounted on the crank shaft (5) of the engine (1) and drive gear of compact innovative gearbox mounted on engine output shaft. Then a cover plate (6) assembled on the gearbox (4). Finally, the water pump (3) is connected on the cover plate (6). This makes ready to use the entire pump set (100) for any crop irrigation applications such as River, Canal, Ponds, Open wells, lakes and poly-ponds, dewatering, etc.
[0048] FIG. 10 illustrates the gearbox (4) assembly mounted on the engine (1) and FIG. 11 illustrates a power take off drive from engine crank shaft to the gearbox (4), according to embodiments as disclosed herein. FIG. 10 shows the gearbox (4) mounted directly on the engine crank case. Gears used mainly driver, driven and idler for achieve required speed reduction. The input to the gearbox (4) comes from the crank shaft (5) of the engine (1). The mechanical rotation of the crank shaft (5) of the engine (1) delivers power to the pump shaft of the pump (3).
[0049] FIG. 12 illustrates a gear train for speed reduction mounted on the engine crank shaft of the gearbox (4), according to embodiments as disclosed herein. The gearbox (4) comprises a first gear assembly (7) mounted on the crank shaft (5) of the engine (1), a second gear assembly (8) connected to the pump shaft of the pump (3), an idler gear assembly (9) meshing with the first gear assembly (7) and the second gear assembly (8), and a gasket for the gearbox (4) case. The mechanical rotations of the crank shaft (5) of the engine

(1) provides power to rotate the first gear assembly (7) in an anti-clockwise direction which in turn rotates the idler gear assembly (9) in a clockwise direction, and the rotation of the idler gear assembly (9) in turn rotates the second gear assembly (8) in an anti-clock wise direction to reduce the rotational speed of the engine (1) to match the rotational speed of the engine (1) with a rotational speed of pump (3).
[0050] For example, the three gears which form gear train are used for reducing speed of 3000 RPM to match with speed of the water pump as shown in the FIG. 13. The first gear assembly (7) mounted on engine crank shaft (5) rotates (in anti-clockwise direction) with 3000 RPM and mesh with the idler gear assembly (9) to change direction of rotation (in clockwise direction) then pump shaft assembled with the second gear assembly (8) rotates (in anti¬clockwise) same as per engine direction of rotation and reduce speed of 1500 rpm engine to match water pump speed.
[0051] FIG. 14 illustrates an exploded view of the gearbox (4), according to embodiments as disclosed herein. The first gear assembly (7) comprises a driving gear (10) with spline meshing with the idler gear assembly (9), a support washer (11) placed on the driving gear (10), a cap screw (12) for fixing the support washer (11) on the driving gear (10), a punched washer (13), and a socket head screw (14) for fixing the punched washer (13) and the driving gear (10) on the crank shaft (5) of the engine (1). The idler gear assembly (9) comprises an idler gear shaft (15), an internal circlip (16) placed on the idler gear shaft (15), a bearing idle shaft (17), an idler gear (18) with spline meshing with the first gear assembly (7) and the second gear assembly (8), an external circlip (19) placed on the idler gear (18), and a set bolt with a coarse pitch (20) for fixing the idler gear shaft (15) on the gearbox (4).

[0052] The second gear assembly (8) comprises a first bearing (21) in the gearbox (4), keys (22 and 24), an output driven shaft (23), a driven gear (25) with spline meshing the idler gear assembly (9), a spacer (26) for the output driven shaft (23), a second bearing (27) in the gearbox (4), an external circlip (28), at least one oil seal rubber (29) with O-Ring, a punched washer (30), and a self-locking nut (31).
[0053] Further, the gearbox (4) comprises a breather bolt (33), a dipstick (34), a flanged nut (35), a socket head screw (37), a copper washer (36), a drain plug (38), a gasket (32) for the gearbox (4), and a gearbox cover (41).
[0054] Unlike the conventions system, the mechanical rotations of the crank shaft (5) of the engine (1) provides power to rotate the first gear assembly (7) in an anti-clockwise direction which in turn rotates the idler gear assembly (9) in a clockwise direction, and the rotation of the idler gear assembly (9) in turn rotates the second gear assembly (8) in an anti-clock wise direction to reduce the rotational speed of the engine (1) to match the rotational speed of the engine (1) with a rotational speed of pump (3). The proposed gearbox imparts capacity to the farmers to carry out irrigation with ease and freedom from traditional heavy engines. It helps the farmers to achieve irrigation inexpensive, light weight, compact with better efficiency, specifically for the high speed diesel engines with standard water pumps. Using the proposed invention, the high speed lightweight aluminum engines (above 3000RPM) can be connected directly to standard water pumps using the proposed speed reduction gear box serve. Hence, the there is no need to change the design of the existing water pump. This gives advantages for usages of high speed diesel engines with any standard speed water pump. Also it makes compact, lightweight, and mobile during handling at field.

[0055] 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. 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, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

We Claim:
1. A pump set (100) for controlling rotational speed, comprising:
an engine (1) mounted on a base frame (2);
a pump (3); and
a gearbox (4) connected between the engine (1) and the pump (3), wherein the gearbox (4) is mounted on a crank shaft (5) of the engine (1) and a pump shaft of the pump (3), wherein mechanical rotations of the crank shaft (5) of the engine (1) provides power to rotate the gearbox to match with a rotational speed of pump (3) with a rotational speed of the engine (1) by reducing the rotational speed of the engine (1).
2. The pump set (100) as claimed in claim 1, wherein the gearbox (4)
comprises:
a first gear assembly (7) mounted on the crank shaft (5) of the engine (1);
a second gear assembly (8) connected to the pump shaft of the pump (3);
an idler gear assembly (9) meshing with the first gear assembly (7) and the second gear assembly (8); and
a gasket for the gearbox (4) case,
wherein mechanical rotations of the crank shaft (5) of the engine (1) provides power to rotate the first gear assembly (7) in an anti¬clockwise direction which in turn rotates the idler gear assembly (9) in a clockwise direction, and wherein the rotation of the idler gear assembly (9) in turn rotates the second gear assembly (8) in an anti-clock wise direction to reduce the rotational speed of the engine (1) to match the rotational speed of the engine (1) with a rotational speed of pump (3).

3. The pump set (100) as claimed in claim 1, wherein the first gear
assembly (7) comprises:
a driving gear (10) with spline meshing with the idler gear assembly (9);
a support washer (11) placed on the driving gear (10);
a cap screw (12) for fixing the support washer (11) on the driving gear (10);
a punched washer (13); and
a socket head screw (14) for fixing the punched washer (13) and the driving gear (10) on the crank shaft (5) of the engine (1).
4. The pump set (100) as claimed in claim 1, wherein the idler gear
assembly (9) comprises:
an idler gear shaft (15);
an internal circlip (16) placed on the idler gear shaft (15);
a bearing idle shaft (17);
an idler gear (18) with spline meshing with the first gear assembly (7) and the second gear assembly (8);
an external circlip (19) placed on the idler gear (18); and
a set bolt with a coarse pitch (20) for fixing the idler gear shaft (15) on the gearbox (4).
5. The pump set (100) as claimed in claim 1, wherein the second gear
assembly (8) comprises:
a first bearing (21) in the gearbox (4);
an output driven shaft (23);
a driven gear (25) with spline meshing the idler gear assembly (9);
a spacer (26) for the output driven shaft (23);
a second bearing (27) in the gearbox (4);

an external circlip (28);
at least one oil seal rubber (29) with O-Ring;
a punched washer (30); and
a self-locking nut (31).
6. The pump set (100) as claimed in claim 1, wherein the gearbox (4) comprises a breather bolt (33), a dipstick (34), a flanged nut (35), a socket head screw (37), a copper washer (36), a drain plug (38), and a gasket (32) for the gearbox (4).
7. The pump set (100) as claimed in claim 1, wherein the gearbox (4) comprises a breather bolt (33), a dipstick (34), a flanged nut (35), a socket head screw (37), a copper washer (36), a drain plug (38), a gasket (32) for the gearbox (4), and a gearbox (4) cover (20).
8. The pump set (100) as claimed in claim 7, wherein a coupler (39) and a U-shaped frame (40) is assembled on the pump shaft.
9. The pump set (100) as claimed in claim 1, wherein a cover plate (6) is assembled on the gearbox (4).
10. A gearbox (4) for controlling rotational speed of an engine (1) of a pump (3), comprising:
a first gear assembly (7) mounted on the crank shaft (5) of the engine (1);
a second gear assembly (8)connected to the pump shaft of the pump (3);
an idler gear assembly (9) meshing with the first gear assembly (7) and the second gear assembly (8); and
a gasket for the gearbox (4) case,

wherein mechanical rotations of the crank shaft (5) of the engine (1) provides power to rotate the first gear assembly (7) in an anti¬clockwise direction which in turn rotates the idler gear assembly (9) in a clockwise direction, and wherein the rotation of the idler gear assembly (9) in turn rotates the second gear assembly (8)in an anti-clock wise direction to reduce the rotational speed of the engine (1) to match the rotational speed of the engine (1) with a rotational speed of pump (3).
11. The gearbox (4) as claimed in claim 10, wherein the first gear
assembly (7) comprises:
a driving gear (10) with spline meshing with the idler gear assembly (9);
a support washer (11) placed on the driving gear (10);
a cap screw (12) for fixing the support washer (11) on the driving gear (10);
a punched washer (13); and
a socket head screw (14) for fixing the punched washer (13) and the driving gear (10) on the crank shaft (5) of the engine (1).
12. The gearbox (4) as claimed in claim 10, wherein the idler gear
assembly (9) comprises:
an idler gear shaft (15);
an internal circlip (16) placed on the idler gear shaft (15); a bearing idle shaft (17);
an idler gear (18) with spline meshing with the first gear assembly (7) and the second gear assembly (8);
an external circlip (19) placed on the idler gear (18); and a set bolt with a coarse pitch (20) for fixing the idler gear shaft (15) on the gearbox (4).

13. The gearbox (4) as claimed in claim 10, wherein the second gear
assembly (8) comprises:
a first bearing (21) in the gearbox (4);
an output driven shaft (23);
a driven gear (25) with spline meshing the idler gear assembly (9);
a spacer (26) for the output driven shaft (23);
a second bearing (27) in the gearbox (4);
an external circlip (28);
at least one oil seal rubber (29) with O-Ring;
a punched washer (30); and
a self-locking nut (31).
14. The gearbox (4) as claimed in claim 10, wherein the gearbox (4) comprises a breather bolt (33), a dipstick (34), a flanged nut (35), a socket head screw (37), a copper washer (36), a drain plug (38), and a gasket (32) for the gearbox (4).
15. The gearbox (4) as claimed in claim 10, wherein the gearbox (4) comprises a breather bolt (33), a dipstick (34), a flanged nut (35), a socket head screw (37), a copper washer (36), a drain plug (38), a gasket (32) for the gearbox (4), and a gearbox cover (41).