DESC:FORM 2

THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENT RULES, 2003

COMPLETE SPECIFICATION
(See Section 10 and Rule 13)

Title of invention:
PREVENTION OF TRAVEL DEVIATION OF A SIDE DISCHARGE LOADER VEHICLE AND METHOD OF WORKING THEREOF

Applicant:
BEML Limited
A company Incorporated in India under the Companies Act, 1956
Having address:
BEML Soudha, 23/1, 4th Main,
Sampangirama Nagar, Bengaluru - 560 027,
Karnataka, India

The following specification particularly describes the invention and the manner in which it is to be performed.
CROSS-REFERENCE TO RELATED APPLICATIONS AND PRIORITY

[001] The present invention claims priority from Indian patent Provisional Application 202041055061 filed on 17 December 2020.
TECHNICAL FIELD
[002] The present subject matter described herein, in general, relates to a prevention of travel deviation of a Side Discharge Loader and more specifically relates to optimized flow division in a hydraulic circuit of the Side Discharge Loader to prevent travel deviation.
BACKGROUND
[003] Generally, Side Discharge Loader (SDL) is used as loading machine in underground coal mines. SDLs are used in mines to scoop a blasted coal heap and load it to conveyor, tubs or chutes at extreme atmospheric conditions of 95% humidity & 45°C ambient temperature. SDL basically works on the principle of hydraulics. Hydraulics is used due to its advantages like greater safety, non-inflammability, and greater power transmission.
[004] The main parts of the Side Discharge Loader that runs on hydraulic power comprises a travel drive, bucket services including lift and tilt, Side Discharge door operation, cooling fan operation and cable reeling / unreeling operation.
[005] Conventionally, left and right travel drives are driven by independent pumps and the operator need to put effort in controlling the left and right travel drives independently. The existing Side Discharge Loader attempts to optimize a hydraulic power and to minimize travel deviation in an event of variation in volumetric efficiency of independent pumps driving left and right travel drives. Further, during variation in the volumetric efficiency of independent pumps, equal distribution of hydraulic flow to both the travel drives cannot be ensured resulting in travel deviation. To overcome the travel deviation, operator has to maneuver the equipment to travel in desired path resulting in increased operator fatigue. Also, if the independent pumps are used for left and right travel drives, the hydraulic power required for operation of work attachments is tapped from the hydraulic pump used for driving a cooling fan. Hence, constant speed of the cooling fan may not be ensured resulting in overheating of hydraulic oil. Further, to operate a cable reeler drum, an additional hydraulic pump needs to be dedicated resulting in added power consumption. So, overall, four pumps are required to meet an entire operational requirement of the existing SDL.
[006] Hence, an improvement in the hydraulic circuit is needed for optimizing the hydraulic power, to prevent the travel deviation, to avoid an overheating of the hydraulic oil, to reduce a number of pumpsand to enhance the operator comfort.
OBJECT OF THE INVENTION
[007] It is a main object of the present invention to provide effective flow division in a hydraulic circuit for optimized hydraulic power.
[008] It is an object of the present invention to eliminate travel deviation by providing a single dedicated pump for left and right travel drives.
[009] It is an object of the present invention to provide a flow divider in hydraulic line of travel drives for equal distribution of hydraulic oil flow to left and right travel drive.
[0010] It is another object of the present invention to deviate hydraulic flow of pump provided for work attachment and bucket operations to a flow divider when the attachment and bucket operations are not performed.
[0011] It is another object of the present invention to avoid an additional pump requirement by eliminating dedicated separate pump for travel operation, for bucket operations and for hydraulic oil cooling operation.
[0012] It is another object of the present invention to reduce an operator fatigue caused by manoeuvring a vehicle to travel, by separate pump provided for left and right travel drive.
[0013] It is another object of the present invention to provide dedicated pump for a cooling fan used to cool hydraulic oil and for cable reeling operation.
[0014] It is another object of the present invention to prevent an overheating of hydraulic oil of a hydraulic tank.by providing constant speed of a cooling fan used to cool hydraulic oil.
SUMMARY
[0015] Before the present system and method are described, it is to be understood that this application is not limited to the particular machine or an apparatus, and methodologies described, as there can be multiple possible embodiments that are not expressly illustrated in the present disclosures. It is also to be understood that the terminology used in the description is for the purpose of describing the particular versions or embodiments only, and is not intended to limit the scope of the present application. This summary is provided to introduce aspects related to flow division in a hydraulic circuit of a Side Discharge Loader. This summary is not intended to identify essential features of the proposed subject matter nor is it intended for use in determining or limiting the scope of the proposed subject matter.
[0016] The present subject matter discloses an improved hydraulic circuit for a Side Discharge Loadervehicle with prevention of travel deviation. The hydraulic circuit for low height Side Discharge Loadervehicle of the present subject matter may be pilot operated. The hydraulic circuit of the Side Discharge Loader comprises at least one electric motor may configured to drive at least one pump for supplying a hydraulic oil to a plurality of pressure lines, at least one flow divider may be configured to be inserted in one of the pressure lines for equally dividing an available flow of hydraulic oil to supply equal flow to left travel drive and right travel drive for obtaining straight travel of the Side Discharge Loader and a plurality of joysticks for performing a movement of the Side Discharge Loader vehicle and for an operation of various accessories of the Side Discharge Loader vehicle. The said flow divider may configured to be connected to one or more pumps to optimize a hydraulic power. The electric motor of the present invention may be configured to drive a tandem triple gear pump. A first pump of the said tandem triple gear pump may configured to supply flow for a plurality of bucket operations or a plurality of work attachment operations. The said bucket or work attachment operations may be configured to be bucket lifting, bucket tilting, operating Side Discharge Loader conveyor and bucket door opening. The bucket operations may be configured to perform even while performing travel operation. Also, the flow from the first pump is configured to be directed to the flow divider for travel operation when the bucket operations are inactive. Further, a second pump of the said tandem triple gear pump may be configured to supply flow for a travel operation comprising left travel drive and right travel drive. A third pump is configured to supply flow for a cooling fan wherein the cooling fan may be configured to cool the hydraulic oil leading to hydraulic tank. Further, a third pump of the said tandem triple gear pump ensures a constant speed of the cooling fan, performs a cable reeling / unreeling operation, and configured for pilot control of bucket & travel control operation. Furthermore, the first joystick of the Side Discharge Loader vehicle comprises two segments configured to perform LH & RH travel operation, a second joystick comprises three segments configured to perform bucket lifting, dumping and side discharge operation.
[0017] Further, a method of working of the hydraulic circuit for prevention of travel deviation of a low height Side Discharge Loader comprises the steps of: operating a first joystick of a travel drive for moving the Side Discharge Loader vehicle either in forward and reverse direction by providing hydraulic flow from a second pump or first & second pump to a flow divider through an in-line filter to supply equal flow to a left travel drive and a right travel drive and operating a second joystick to perform bucket lifting operation, dumping operation and side discharge operation respectively, by providing the hydraulic flow of a first pump to a control valve through in-line relief valve and pressure line filter. In the event of work attachment and bucket operations are not performed the flow from the first pump is led to flow divider to supply equal flow to left travel drive and right travel drive giving priority to travel operation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The foregoing summary, as well as the following detailed description of embodiments, is better understood when read in conjunction with the appended drawing. For the purpose of illustrating the disclosure, there is shown in the present document example constructions of the disclosure, however, the disclosure is not limited to the specific methods and apparatus disclosed in the document and the drawing.
[0019] The detailed description is described with reference to the accompanying figure. In the figure, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the drawing to refer like features and components.
[0020] Figure 1 illustrates a hydraulic circuit for low height Side Discharge Loader.
[0021] Figure 2 illustrates a hydraulic circuit for standard height Side Discharge Loader.
[0022] Figure 3 illustrates a low height Side Discharge Loader.
[0023] Figure 4 illustrates a standard height Side Discharge Loader.
[0024] Figure 5 illustrates a hydraulic tank.
[0025] Figure 6 illustrates an electric motor.
[0026] Figure 7 illustrates a tandem triple gear pump.
[0027] Figure 8 illustrates an in-line pressure relief valve.
[0028] Figure 9 illustrates a pressure line filter.
[0029] Figure 10 illustrates a joystick.
[0030] Figure 11 illustrates a control valve with attachments.
[0031] Figure 12 illustrates a travel drive.
[0032] Figure 13 illustrates a flow divider.
[0033] The figure depicts various embodiments of the present disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following discussionthat alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DETAILED DESCRIPTION
[0034] Some embodiments of this disclosure, illustrating all its features, will now be discussed in detail. The words "comprising", “having”, and "including," and other forms thereof, are intended to be equivalent in meaning and be open ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items, or meant to be limited to only the listed item or items. Although any systems and methods similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present disclosure, the exemplary, systems and methods are now described. The disclosed embodiments are merely exemplary of the disclosure, which may be embodied in various forms.
[0035] Various modifications to the embodiment will be readily apparent to those skilled in the art and the generic principles herein may be applied to other embodiments. However, one of ordinary skill in the art will readily recognize that the present disclosure is not intended to be limited to the embodiments illustrated, but is to be accorded the widest scope consistent with the principles and features described herein.
[0036] The present subject matter discloses a hydraulic circuit for prevention of travel deviation of a Side Discharge Loader vehicle. A flow divider is introduced in a hydraulic circuit of a Side Discharger Loader wherein the flow from one or morepumpsmay be equally divided and further supplied to left and right travel circuit, ensuring the Side Discharger Loader to travel without travel deviation and with minimum operator effort. A tandem triple gear pump may be used wherein each pump flow may be effectively utilized resulting inoptimization of a hydraulic power, avoids overheating of a hydraulic oil and reduces operator fatigue by eliminating travel deviation. However, in conventional Side Discharger Loader, the operator continuously puts effort to travel in both straight and curved paths of the gallery.
[0037] Referring to figure 1, a hydraulic circuit for low height Side Discharge Loader vehicle with a flow divider (14) is shown. The hydraulic circuit of figure 1 may be pilot operated. The hydraulic circuit comprises an electric motor (2) of predefined rating wherein the electric motor (2) may be used as prime mover todrive a tandem triple gear pump (Pump-1, 2 & 3). In an embodiment, a first pump (3) may be used for operations such as bucket lifting, bucket tilting / dumping, side discharge conveyor and side discharge bucket door operation. The flow of the first pump (3) may be diverted to the flow divider (14) if the aforesaid operations are not performed. Further, in an embodiment, a second pump (4) may be dedicatedly used for travel operation of the Side Discharger Loader. The travel operation circuit may comprise a left travel drive (10) and a right travel drive (11). Furthermore, in an embodiment, a third pump (5) maybe used for a cooling fan for hydraulic oil cooling operation through hydraulic fan motor, a cable reeling / unreeling operation, to provide pilot pressure for two speed travel drive (10 & 11) operation that may be used to meet varying load requirements and gradient conditions and for pilot operation of bucket & travel control operation. The dedicated pump (5) for the cooling fan operation ensures a constant speed of the cooling fan thereby overcoming the problem of overheating of the hydraulic oil. Further, a plurality of joysticks may be provided to control a movement of the Side Discharge Loader vehicle and to control accessories of the Side Discharge Loader vehicle wherein the first joystick (12) is configured for travel drive operation which comprises two segments (12A, 12B) for LH travel drive for RH travel drive respectively and may control a forward and reverse movement of the Side Discharge Loader vehicle. A second joystick (8) is configured with three segments, joystick (8A) to control the bucket lifting operation, joystick (8B) for dumping operation and joystick (8C) for side discharge operation.
[0038] The hydraulic circuit of the present invention may further comprises the flow divider (14) inserted in hydraulic line of the travel drive where in the flow divider (14) divides the available flow equally in 50:50 ratio.The equal distribution of the available flow through the flow divider (14) results in elimination of travel deviation of the Side Discharge Loader vehicle.In the present invention, the second pump (4) delivers the hydraulic oil from hydraulic tank (1) to the flow divider (14) through an inline relief valve (16) and a pressure line filter (15). The inline relief valve (16) may be used to maintain a set pressure in the hydraulic circuit and the pressure line filter (15) may be used to filter foreign particles from the hydraulic oil.Further, in the event bucket operations are not performed, the flow from the first pump (3) may be directed to the flow divider (14) wherein the combined flow from the second pump (4) and the first pump (3) may be divided equally by the flow divider (14). Further, the flow from the flow divider (14) may be directed to a travel control valve (13) wherein travel control valve (13) controls the left and right travel drives (9,10).
[0039] Further, a method of working of the said hydraulic circuit is described. For moving the Side Discharge Loader vehicle either in forward or reverse direction, a joystick of a pilot operated joystick control valve (12) may be operated. Upon operating the joystick, the hydraulic power of the pump-2 (4) may be transmitted to left travel drive (10) and right travel drive (11) through the flow divider (14) and travel control valve (13). In an embodiment, other operations like bucket tilting, bucket lifting, side discharge conveyor operation and work attachment operations may also be performed while performing the travel operation. To perform the aforesaid services, the corresponding joystick of the pilot operated work attachment control valve (9) may be operated. On operating the joystick, the hydraulic power of pump-1 (3) delivers the hydraulic oil from hydraulic tank (1) to work attachment control valve (9) through in-line relief valve (6) and pressure line filter (7). In an embodiment, when the bucket operations and work attachment operations are not performed, the hydraulic oil from hydraulic tank (1) passes through work attachment control valve (9) and reaches the flow divider (14), there by the adding the hydraulic power of pump-1 (3) to the existing hydraulic power of pump-2 (4).The combined hydraulic power of both the pumps may be equally divided by the flow divider (14) and may be further supplied to the travel drive circuit. Thus, the travel operation may be prioritized in the event when bucket operationsare not performed, thereby optimizes the usage of available hydraulic power to the maximum extent.
[0040] Referring to figure 2, a hydraulic circuit for standard height Side Discharge Loader equipment with a flow divider (14) is shown. The hydraulic circuit for standard height Side Discharge Loader may be same except that the hydraulic circuit is not pilot operated.
[0041] Referring to figure 3, a low height Side Discharge Loader is shown. The low height Side Discharge Loader is pilot operated.
[0042] Referring to figure 4, a standard height Side Discharge Loader is shown. The standard height Side Discharge Loader is not pilot operated.
[0043] Referring to figure 5, a hydraulic tank is shown. The hydraulic tank may be configured to store hydraulic oil.
[0044] Referring to figure 6, an electric motor of the present invention is shown. The said electric motor (2) may be an induction motor and may be flameproof. The induction motor may configured to be as prime mover to drive a pump.
[0045] Referring to figure 7, a tandem triple gear pump is shown. The tandem triple gear pump (3, 4, 5) of the present invention may supply hydraulic oil from hydraulic tank (1) to various pressure lines.
[0046] Referring to figure 8, an in-line pressure relief valve is shown. The in-line pressure relief valves (6, 16) may be configured to maintain a set pressure in the hydraulic circuit.
[0047] Referring to figure 9, a pressure line filter is shown. The pressure line filters (7, 15) may be configured to filter foreign particles from hydraulic oil.
[0048] Referring to figure 10, a joystick is shown. The joysticks of the present invention may configured to be used as lever to initiate multiple operations. Upon operating the joystick of work attachments, a pilot pressure may be supplied to a work attachment control valve. Upon operating the joystick of travel drive, a pilot pressure may be supplied to a travel control valve.
[0049] Referring to figure 11, a control valve attachment is shown. The work attachment control valve (9) directs hydraulic oil to corresponding work attachments. And, the travel control valve (13) may receive equally divided oil flow from a flow divider (14) and directs the oil flow to a left travel drive (10) and right travel drive (11).
[0050] Referring to figure 12, a travel drive is shown. The travel drive comprises a left travel drive (10) and a right travel drive (11). The travel drive may converts the hydraulic power to torque required for travel operation.
[0051] Referring to figure 13, a flow divider is shown. The flow divider (14 or 12) of the present invention divides an available flow equally in 50:50 ratio and delivers the flow to a travel control valve (13).
[0052] Exemplary embodiments discussed above may provide certain advantages. Though not required to practice aspects of the disclosure, these advantages may include those provided by the following features.
[0053] Some object of the present invention provides effective flow division in a hydraulic circuit.
[0054] Some object of the present invention provides optimized hydraulic power in a hydraulic circuit.
[0055] Some object of the present invention provides elimination of travel deviation of a Side Discharge Loader.
[0056] Some object of the present invention prevents overheating of a hydraulic oil.
[0057] Some object of the present inventionreduce an operator fatigue.
[0058] Some object of the present invention is suitable to provide constant speed of a cooling fan.
[0059] Some object of the present invention is suitable to provide equal distribution of flow to a left and right travel drive.
,CLAIMS:
1. A system for prevention of travel deviation of a Side Discharge Loader vehicle comprising:
at least one electric motor (2) configured to drive at least one pump for supplying a hydraulic oil to a plurality of pressure lines;
at least one flow divider (14) configured to be inserted in one of the pressure lines of any one of pump delivery line of any one of pumps for providing equal flow to left travel drive (10) and right travel drive (11) to assist straight travel of the Side Discharge Loader vehicle; and
a plurality of joysticks for performing a movement of the Side Discharge Loader vehicle and for an operation of various accessories of the Side Discharge Loader vehicle.
2. The system for prevention of travel deviation of the Side Discharge Loader vehicle as claimed in claim 1, wherein the said electric motor (2) configured to drive a tandem triple gear pump (3,4,5) wherein the first pump (3) is configured to supply flow to operate a plurality of bucket operations or a plurality of work attachment operations, a second pump (4) is configured to supply flow to operate left travel drive (9) and right travel drive (10) and a third pump (5) is configured to supply flow to operate a cooling fan configured to cool the hydraulic oil of the hydraulic tank (1) and to perform a cable reeling / unreeling operation, to provide pilot pressure for varying speed of travel motor operation and for pilot control of bucket & travel control operation.

3. The system for prevention of travel deviation of the Side Discharge Loader vehicle as claimed in claim 1, wherein the said flow divider (14) is configured to receive hydraulic flow from one or more pumps of the tandem triple gear pump (3, 4) to optimize a hydraulic power.

4. The system for prevention of travel deviation of the Side Discharge Loader vehicle as claimed in claim 1, wherein the first pump (3) is configured to provide flow to the flow divider (14) in the absence of the bucket operations and the work attachments operations.

5. The system for prevention of travel deviation of the Side Discharge Loader vehicle as claimed in claim 1, wherein the third pump (5) is configured to provide a constant speed of a cooling fan to cool the hydraulic oil.

6. The system for prevention of travel deviation of the Side Discharge Loader vehicle as claimed in claim 1, wherein the hydraulic circuit of a low height Side Discharge Loader is pilot operated.

7. The system for prevention of travel deviation of the Side Discharge Loader vehicle as claimed in claim 1, wherein the first joystick (12) configured with two segments (12A, 12B) for LH travel drive and RH travel drive respectively to perform travel operation and a second joystick (8) is configured with three segments (8A, 8B, 8C) for bucket lifting operation, for dumping operation and forperforming side discharge operation byopening the doors of the bucket.

8. A method of working of the said hydraulic circuit for prevention of travel deviation of aSide Discharge Loadervehicle comprises the steps of:
operating a first joystick (12) for moving the Side Discharge Loader vehicle either in forward and reverse directionby providing equalhydraulic flow from a second pump to a flow divider (14) through an in-line filter (15) to supply equal flow to a left travel drive (10) and a right travel drive (11)
operating a second joystick (8) to perform bucket lifting operation, dumping operation, to perform the side discharge operation byopening the doors of the bucket respectively, to supply the hydraulic flow of a first pump to a control valve (9) through in-line relief valve (6) and pressure line filter (7).