DESC:FORM 2

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

COMPLETESPECIFICATION
(See Section 10 and Rule 13)

Title of invention:
AN ELECTRO-HYDRAULIC ACTUATION SYSTEM FOR A DUMP TRUCK

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] This patent application claims priority from Indian Provisional Application 202041003996 filed on January 29, 2020.
TECHNICAL FIELD
[002] The present subject matter described herein, in general, relates to an electro-hydraulic actuation system and more specifically to an electro-hydraulic actuation system for a dump truck.
BACKGROUND OF THE INVENTION
[003] A dump truck or vehicle is widely used as main transportation means in construction industries. The dump body is configured to be tilted to dump the cargo as and when required. The tilting of the dump body is achieved by hydraulic means by actuating switches. Further another hydraulic circuit is used for actuation of steering of the dump truck. There are two independent control valves used in hydraulic circuit to achieve steering & hoist functions in a dump truck. In the current system, in the event of steering pump failure the operator must choose emergency steering system to park the equipment from haul road to side. To reach the workshop, the equipment should be towed for replacing the pump. In the current hoist system there are three different stages of operation i.e. electrical to pneumatic, pneumatic to mechanical linkage and mechanical linkage to hydraulic spool which includes more number of parts and more time involved for identifying and troubleshooting and if one system fails it leads to malfunction of the entire hoist system.
[004] The present subject matter discloses a system to overcome the above mentioned shortcomings of the existing system.

OBJECTS OF THE INVENTION
[005] It is an object of the present invention to enhance steering and hoist system function with single manifold and with trouble free operation system.
[006] It is an object of the present invention to ensure oil flow to steering circuit in the event of steering pump failure.
[007] It is an object of the present invention to eliminate various leakage joints and complex routings.
[008] It is an object of the present invention to reduce number of actuation media for dump body actuation by introducing Electro hydraulic actuation.
[009] It is an object of the present invention to introduce an external actuation for dump body hoist and lowering in integral manifold design.

SUMMARY OF THE INVENTION
[0010] Before the present system is 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 an electro-hydraulic actuation system for a dump truck, and the aspects are further elaborated below in the detailed description. 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.
[0011] The present subject matter discloses an electro-hydraulic actuation system for a dump truck. The electro-hydraulic actuation system comprises a first hydraulic circuit, a second hydraulic circuit and a manifold block. The first hydraulic circuit comprises a first pump configured for actuation of a steering system. The second hydraulic circuit comprises a second pump configured for actuation of a hoist system of the dump truck. The first and second hydraulic circuits are configured to be connected to each other through the manifold block thereby enabling the hoist system and the steering system to receive hydraulic fluid through at least one of the first pump or the second pump.

BRIEF DESCRIPTION OF THE DRAWINGS
[0012] 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:
[0013] 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.
[0014] Figure 1 illustrates an electro-hydraulic actuation system for a dump truck, in accordance with an embodiment of the present subject matter.
[0015] Figure 2 illustrates a manifold block for the electro-hydraulic actuation system, in accordance with an embodiment of the present subject matter
[0016] 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 discussion that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION OF THE INVENTION
[0017] 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.
[0018] 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.
[0019] All the embodiments of the present subject matter are described by below list of reference numerals and part names.
Reference Numeral Part Name
100 Electro-hydraulic actuation system
105 Manifold block
110 First hydraulic circuit
112 First pump
114 First filter
116 Steering control unit
117 Crossover relief valve
118 Steering system
118L, 118R Steering cylinders
120 Second hydraulic circuit
122 Second pump
124 Second filter
128 hoist system
128L, 128R hoist cylinders

[0020] A dump truck is widely used for transportation of material at construction sites and mines. The dump truck is loaded with material at one place and for unloading the material a hoist system is used in the dump truck. The hoist system enables lifting or lowering of the dump body for unloading of material. The hoist system is actuated by a hydraulic system based on selective operation by an operator. Further the steering system of the dump truck is also actuated by the hydraulic system for maneuvering of the dump truck. Existing hydraulic system of the dump truck has separate hydraulic circuits and pumps for the steering system and the hoist system. In case of failure of any of the pump the respective system cannot be actuated. The hydraulic system of present subject matter enables actuation of both the systems even with working of any one of the both pumps.
[0021] Referring to figure 1, in one aspect of the present invention, a schematic of an electro-hydraulic actuation system 100 for a dump truck is disclosed. The electro-hydraulic actuation system 100 comprises a first hydraulic circuit 110, a second hydraulic circuit 120 and a manifold block 105.The first hydraulic circuit 110is configured for actuation of a steering system 118 of the dump truck. The second hydraulic circuit 120 is configured for actuation of a hoist system 128 of the dump truck. The first and second hydraulic circuits are configured to receive hydraulic fluid from a hydraulic fluid tank 102. Further the first and second hydraulic circuits (110, 120) are configured to be connected to each other through the manifold block 105.
[0022] The first hydraulic circuit 110 comprises a first pump 112, a first filter 114, the manifold block 105, and a steering control unit 116 and steering cylinders (118L, 118R). The first pump 112 transfers the hydraulic fluid from the hydraulic fluid tank 102 to the steering cylinders (118L, 118R) through the first filter 114 and the manifold block 105. The steering function on the dump truck is achieved based on the operator's action towards steering the wheel. Once steering wheel is rotated, the hydraulic fluid enters into the steering cylinders (118L, 118R) based on left or right rotation. During rotation of steering wheel, a dynamic signal or pilot signal or load sensing signal is created between the manifold block 105 and the steering control unit 116 which enables prioritizing of the hydraulic fluid towards the steering cylinders (118L, 118R). Further the first hydraulic circuit 110is configured with a Crossover relief valve 117 for relieving the pressure spikes between the steering cylinders (118L, 118R) due to ground reaction.
[0023] The second hydraulic circuit 120 comprises a second pump 122, a second filter 124, the manifold block 105 and hoist cylinders (128L, 128R). The second pump 122 transfers the hydraulic fluid from the hydraulic fluid tank 102 to the hoist cylinders (128L, 128R) through the second filter 114 and the manifold block 105. The hoist operation on the dump truck is achieved based on the operator's command through electrical switches inside operator's cabin (not shown) to enable raising, lowering, holding or floating the dump body. The hoist operation is achieved through an electro hydraulic valve (not shown) mounted on the manifold block 105 which enables flow of the hydraulic fluid in accordance with the operator’s command.
[0024] The first hydraulic circuit 110 and the second hydraulic circuit 120 are configured to be connected to each other by introducing logics such a way that any pump preference is given for steering system through the manifold block 105. The manifold block 105 is configured to prioritize flow of the hydraulic fluid to the steering system 118. As the manifold block 105 is configured to receive hydraulic fluid from both the pumps, in case of failure of the first pump 112, the manifold block 105 continues to receive the hydraulic fluid from the second pump 122. Therefore the steering system 118 continues to operate and thereby avoiding any downtime of the dump truck.
[0025] In another embodiment, in case of the second pump 122 failure the hoist system 128 also continues to receive the hydraulic fluid from the first pump 112. Therefore downtime of the hoist system 128 may be avoided because of the common manifold block 105 for the steering system 118 and the hoist system 128.
[0026] In another embodiment, the manifold block 105 is configured to selectively supply the hydraulic fluid to the steering system 118 in case of failure of either of the first pump 112 or the second pump 122 in dump truck running condition.
[0027] Further the manifold block 105 is configured to selectively supply the hydraulic fluid to the hoist system 128 in case of failure of either of the first pump 112 or the second pump 122 in dump truck standstill condition.
[0028] Referring to figure 2, the manifold block 105 for the electro-hydraulic actuation system 100 is illustrated. The manifold block 105 is configured with a plurality of openings for connection with the first and second hydraulic circuits (110. 120).
[0029] 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.
[0030] Some object of the present invention enables to enhance steering and hoist system function with single manifold block and with trouble free operation system.
[0031] Some object of the present invention enables to ensure oil flow to steering circuit even after failure of steering pump.
[0032] Some object of the present invention enables to eliminate various leakage joints and complex routings.
[0033] Some object of the present invention enables to reduce number of actuation media for dump body actuation by introducing Electro hydraulic actuation.
[0034] Some object of the present invention enables to introduce an external actuation for dump body hoist and lowering in integral manifold design.
[0035] Although implementations for the electro-hydraulic actuation system 100 for a dump truck have been described in language specific to structural features and/or methods, it is to be understood that the appended claims are not necessarily limited to the specific features described. Rather, the specific features are disclosed as examples of implementation for the electro-hydraulic actuation system 100.
,CLAIMS:
1. An electro-hydraulic actuation system (100) for a dump truck, wherein the electro-hydraulic actuation system (100) comprises:
a first hydraulic circuit (110) configured with a first pump (112) for actuation of a steering system (118) of the dump truck;
a second hydraulic circuit (120) configured with a second pump (122)for actuation of a hoist system (128) of the dump truck; and
a manifold block (105); wherein the first and second hydraulic circuits (110, 120) are configured to be connected to each other through the manifold block (105), thereby enabling the hoist system (128) and the steering system (118) to receive hydraulic fluid through at least one of the first pump (112) or the second pump (122).
2. The electro-hydraulic actuation system as claimed in claim 1, wherein the first hydraulic circuit (110) is configured with a first filter (114), a steering control unit (116), and steering cylinders (118L, 118R), wherein the first pump (112) is provided to transfer hydraulic fluid from the hydraulic fluid tank (102) to the steering cylinders (118L, 118R) through the first filter (114) and the manifold block (105).

3. The electro-hydraulic actuation system as claimed in claim 1, wherein the second hydraulic circuit (120) is configured with a second filter (124) and hoist cylinders (128L, 128R), wherein the second pump (122)is provided to transfer hydraulic fluid from the hydraulic fluid tank (102) to the hoist cylinders (128L, 128R) through the second filter (114) and the manifold block (105).

4. The electro-hydraulic actuation system as claimed in claim 1, wherein the hoist system (128) is configured to be actuated through an electro hydraulic valve mounted on the manifold block (105).

5. The electro-hydraulic actuation system as claimed in claim 1, wherein the manifold block (105) is configured to supply the hydraulic fluid to the steering system (118) from the second pump (122) on failure of the first pump (112).
6. The electro-hydraulic actuation system as claimed in claim 1, wherein the manifold block (105) is configured to supply the hydraulic fluid to the hoist system (128) from the first pump (112) on failure of the second pump (122).

7. The electro-hydraulic actuation system as claimed in claim 1, wherein the first hydraulic circuit (110) is configured with a crossover relief valve (117) for relieving the pressure spikes between the steering cylinders (118L, 118R) due to ground reactions.

8. The electro-hydraulic actuation system as claimed in claim 1, wherein the manifold block (105) is configured to selectively supply the hydraulic fluid to the steering system (118) in case of failure of either of the first pump (112) or the second pump (122) in dump truck running condition.

9. The electro-hydraulic actuation system as claimed in claim 1, wherein the manifold block (105) is configured to selectively supply the hydraulic fluid to the hoist system (128) in case of failure of either of the first pump (112) or the second pump (122) in dump truck standstill condition.