Storage system for gaseous fuel

Abstract

Disclosed herein is a work machine comprising: a ground engaging structure; a chassis mounted to the ground engaging structure; an operator cab mounted to the chassis; a gas engine for providing power to the ground engaging structure; and the at least one storage tank is used for storing gas fuel of the gas engine, and the at least one storage tank is arranged on a top cover of an operator cab.

Description

Technical Field

[0001] The present invention relates to a gas storage solution for a working machine, particularly but not exclusively a backhoe loader. Background Art

[0002] Off-highway vehicles / work machines generally refer to those used in the construction industry (e.g., backhoe loaders, swing excavators, telescopic handling machines, forklifts, skid steer loaders, dump trucks, bulldozers, motor graders), the agricultural industry (e.g., tractors, combines, wheel loader shovels, telescopic handling machines, self-propelled harvesters and sprayers), quarrying (e.g., excavators, wheel loader shovels, aggregate crushing equipment), and forestry (e.g., timber harvesters, feller bunchers). Many work machines have a primary function of moving material using a lift arm (e.g., a pivoting boom) or a work arm (e.g., an excavator arm) and may be referred to as material handling machines.

[0003] Traditionally, these types of work machines have been powered by diesel internal combustion engines. However, the general need to reduce vehicle emissions in the face of global warming has led work machine OEMs (original equipment manufacturers) to consider alternative prime movers. Proposed alternatives include batteries, hydrogen fuel cells, hydrogen internal combustion engines, and various hybrid options.

[0004] The present invention aims to provide a storage solution for gaseous fuel of a working machine comprising a gas engine. Summary of the Invention

[0005] The present invention provides a work machine according to the accompanying claims.

[0006] In a first aspect, the present invention provides a work machine comprising: a ground engaging structure; and an undercarriage mounted to the ground engaging structure. The work machine may include an operator cab mounted to the undercarriage.

[0007] The work machine may include a gas engine for powering the ground engaging structure and at least one tank for storing gas fuel for the gas engine, wherein the at least one tank is disposed on a roof of an operator's cab.

[0008] Locating the storage tanks on the operator's cab roof might seem counterintuitive in many ways, especially for a gas engine that relies solely on a single fuel type. Traditional work machines powered by diesel engines require diesel tanks. Therefore, replacing the diesel tanks with one or more gas tanks might be considered an obvious modification. This would make converting a conventional diesel engine to an equivalent hydrogen engine more straightforward and eliminate the need to redesign storage requirements. However, placing the tanks on the roof can be beneficial for a number of reasons.

[0009] For example, placing the tank on the roof helps protect the tank from damage in the event of an impact while driving on the road, particularly in the case of a backhoe loader with a higher cab. In addition, in the event of a leak, if the tank is located on the upper part of the machine, the discharge of escaping gases can be more direct, at least for gases that are lighter than air (such as hydrogen). Another advantage is that in the event of a vehicle fire, for example in one of the electrical systems in the engine compartment or chassis, locating the tank higher can provide more time to detect the fire before the tank is directly heated. In addition, locating the tank on the cab roof can help isolate the gas from the electrical system that could provide an ignition source. Locating the storage system above the operator's cab helps reduce potential operator exposure in the event of a leak, particularly for gas fuels that are lighter than air (such as hydrogen).

[0010] The at least one tank may comprise an elongated cylinder having a longitudinal axis.The at least one tank may comprise an elongated cylinder having rounded (eg hemispherical) end caps.

[0011] The longitudinal axis can be aligned with the main axis of the work machine. From a stress loading perspective, aligning the at least one storage tank with the longitudinal axis of the machine can be preferable. That is, it can more easily react to longitudinal loads during acceleration and deceleration (as opposed to a transverse orientation, which would result in potential rotational and shear or hoop stresses on the tank). This is particularly true for machines with a front shovel that are constantly maneuvered into the material being shoveled, etc. Furthermore, when longitudinally aligned, the tanks can be larger in size because they can more easily overhang the front or rear of the machine.

[0012] The roof may include a mounting frame to which the at least one tank may be mounted. The mounting frame may be attached to the tank and the structural frame of the cab to assist in transferring loads into the cab and chassis. Where the at least one tank comprises an elongated cylinder, a neck portion may be provided at either end of the tank. The at least one tank may be attached to the frame via the neck portion. Providing a neck mount allows the at least one tank to be positioned vertically within the mounting frame and closer to the roof of the operator's cab. In some embodiments of the present disclosure, the at least one tank may be belt mounted, wherein the tank is positioned in a saddle and held in place using a circumferential band, which will result in an increase in height.

[0013] The mounting frame may include a first neck attachment and a second neck attachment for attaching to respective neck portions at either end of the at least one storage tank. The neck attachments may be configured to allow axial and rotational movement of the at least one storage tank in an open configuration, while preventing axial and rotational movement in a closed configuration. This allows for temporary positioning of the tank and valve prior to closing the attachments so that they can be aligned with each other, which may be desirable for connecting gas lines, etc.

[0014] Either or both of the first neck attachment and the second neck attachment may comprise a clamp. The clamp may be tightened to provide a closed configuration. The first neck attachment and the second neck attachment may comprise an annular collar in which the respective neck portion may be received. The annular collar may be configured to tightly receive the neck portion in an open configuration to allow for closed control when manipulating the tank prior to clamping. The first neck attachment or the second neck attachment may comprise a support element to assist in positioning the tank within the attachment and / or to reduce the possibility of stress concentration on the neck.

[0015] The mounting frame may include a plurality of support legs. The support legs may be disposed within the interior of the neck attachment. The neck attachment may be supported on a cantilever arm that extends outwardly from the support legs.

[0016] The cantilever may be configured to deform under a falling object test in which 237 kg is dropped from a vertical height of 5 m.

[0017] The tank may include a cylindrical body extending between neck portions at opposite ends. The operator cab may include a structural member positioned below the cylindrical body. The structural member may be configured to provide an alternative load path for distributing the load of a falling object after the mounting frame collapses. The structural member may be a plate member extending across the width of the cab between the structural members.

[0018] When in the undeformed state, the cylindrical body of the tank may be located between 10 mm and 50 mm above the structural member.

[0019] The operator cab may include a front edge and a rear edge. The at least one storage tank overhangs the rear edge. The overhang at the rear edge of the cab may help accommodate larger tanks while not obstructing visibility at the front of the machine. This is generally applicable, but may be particularly advantageous for machines having a working arm (e.g., a lift or loading arm) that typically operates at a height relative to the operator cab.

[0020] The at least one storage tank may include a tank valve for controlling the flow of gaseous fuel. The tank valve may be located at the rear of the operator's cab. Locating the tank valve and associated gas lines at the rear of the cab may allow for improved access for maintenance purposes. Furthermore, this means that the front end of the housing in which the tank is located may be tapered at its front edge, thereby improving the efficiency and / or aesthetics of the machine.

[0021] The at least one storage tank may be enclosed in a housing. The housing may include an upper surface. The upper surface may include an elevated portion in which the at least one storage tank resides.

[0022] Further, the work machine may include at least two tanks, optionally three tanks, optionally four or more tanks.The tanks may be located in a side-by-side relationship in a common horizontal plane.

[0023] Each tank may be located in a respective elevated portion of the housing. The respective elevated portions may be separated by a channel having a base and sidewalls extending downwardly from the base. The upper surface of the housing may include an undulating profile.

[0024] The sidewall may include at least one vent. The vents may be distributed along the length of the channel / elevated portion. The sidewall may be inclined less than 60 degrees, optionally less than 50 degrees, optionally less than 40 degrees from the vertical.

[0025] The housing may comprise a multi-part shell comprising a lower portion and an upper portion. The lower portion and the upper portion are attached to enclose the at least one storage tank. The housing may be cantilevered from the rear of the operator cab and / or from the front of the operator cab.

[0026] The front of the housing may include front and rear tapered portions.The housing may include a peripheral channel for directing surface water to an outlet located at either or both of the front and rear of the operator cab.

[0027] The at least one storage tank may include a heat activated pressure relief device, which may be referred to as a temperature pressure relief device (TPRD), connected to a TPRD vent line.

[0028] The TPRD vent line may include a vent line outlet extending through the housing. The TPRD vent line outlet may be positioned above the operator cab. The TPRD vent line outlet may be positioned toward the rear of the operator cab or behind a rear wall of the operator cab. The TPRD vent line outlet may be positioned in an upper surface of the housing, optionally at the rear of the housing.

[0029] The vent line outlet may include a pressure responsive removable cap. The pressure responsive removable cap may be configured to be removed in the event of an evacuation event. The removable cap may be received within a hole in the housing or within a coupling attached to the TPRD vent line. The TPRD may be interference fit in the housing or may include a frangible portion configured to break during an evacuation event. The removable cap may be attached to the housing or the vent line.

[0030] The system may include a plurality of storage tanks, each of which may include a respective vent line outlet.

[0031] The TPRD vent line may include a u-shaped bend including a drain hole. The or each TPRD vent line may be coupled to a respective vent line outlet via a flexible collar. The flexible collar may include a concertinaed body.

[0032] The at least one storage tank may be in fluid communication with a fill nozzle inlet via an inlet line, the fill nozzle inlet being configured to receive a supply of gaseous fuel from the fill nozzle. The at least one storage tank may be in fluid communication with the gas engine via an outlet line. The inlet and outlet lines may be externally mounted to a column (e.g., a pillar) of the work machine. The column may be a front column supporting a cab roof.

[0033] The machine may further include an inlet fill nozzle. The inlet fill nozzle (which may be referred to as a fuel fill receptacle) may be configured to receive a fuel fill nozzle to allow refueling of the at least one storage tank. The inlet fill nozzle may be mounted adjacent to a purge valve.

[0034] The purge valve is operable to drain / empty the at least one storage tank of gaseous fuel.

[0035] The work machine may further include a shutoff valve configured to prevent gaseous fuel from flowing in either or both of the inlet line and the outlet line.

[0036] The purge valve and the shutoff valve may be disposed within a common valve block. The inlet line may include a check valve configured to prevent reverse flow along the inlet line. The check valve may be located adjacent to the at least one tank. The check valve may be located within the tank housing.

[0037] The fill nozzle inlet may be attached to the operator cab. The purge valve may be attached to the operator cab. During normal service, the engine may be movable relative to the operator cab. The outlet line may include at least one flexible portion configured to allow relative movement. The flexible portion may extend between the purge valve and the gas engine.

[0038] The operator cab may be movable relative to the chassis. The outlet line includes at least one flexible portion configured to allow relative movement between the cab and the chassis.

[0039] The fill nozzle inlet may be located near the operator cab door and / or access steps and / or the hydraulic oil tank.

[0040] The machine may also include a hydraulic oil tank located on a first side of the operator cab. The machine may also include a tool storage compartment located on an opposite side of the operator cab. The machine may also include a plurality of access steps (which may include step steps) for accessing the operator cab. The tool storage compartment is located between and / or behind the access steps.

[0041] The work machine may further include a compressible element positioned between the upper surface of the at least one storage tank and the housing. The compressible element may be configured to dampen vibratory movement between the housing and the at least one storage tank when in service.

[0042] The gas engine may be a hydrogen engine.The gas engine may be configured to run solely on hydrogen.

[0043] The work machine may include at least one work arm. The work arm may include an attachment for receiving a work tool (such as a shovel, bucket, carriage, tool carrier, or fork). The work arm may be a lift arm, a loading arm, or an excavating arm. The work machine may be a backhoe loader.

[0044] In a second aspect of the present disclosure, a work machine is provided that includes a ground engaging structure for providing propulsion on the ground and an undercarriage mounted to the ground engaging structure. The machine may have an operator cab mounted to the undercarriage.

[0045] The work machine may include a gas engine for providing propulsion power to the ground engaging structure and at least one tank for storing gas fuel for the gas engine.

[0046] The work machine may include a purge valve for removing gaseous fuel from the at least one storage tank.Providing a purge valve may facilitate emptying the at least one storage tank for, for example, storage or transport purposes.

[0047] The purge valve can be arranged on the local of the at least one storage tank. For example, the purge valve can be arranged in the tank valve or in the housing where the tank valve is located.

[0048] The purge valve may be positioned remotely from the at least one storage tank. The purge valve may be located externally to the storage tank housing. The purge valve may be located within the engine housing. Positioning the purge valve remotely from the tank and optionally externally to the storage tank housing may help prevent unnecessary disturbance of the gas lines and storage tanks prior to depressurizing the storage system and draining the fuel.

[0049] The purge valve may be located within 1.8 m, optionally within 1.5 m, optionally within 1.2 m from the ground. Placing the purge valve at a height that is easily accessible from ground level improves safety, particularly when the tank is located at a height (e.g., on an operator's cab).

[0050] The work machine may further comprise a shut-off valve for fluidly isolating the at least one storage tank from the gas engine. The shut-off valve may be solenoid operated. The purge valve and the shut-off valve may be provided in a common valve block.

[0051] The purge valve can be located near the entrance to the operator's cab. For example, the purge valve can be located near the cab entry and exit steps. The purge valve can be located at the height of the operator's cab floor.

[0052] The purge valve may be connected to the operator cab. The operator cab may include a plurality of vertically extending columns configured to support a roof of the operator cab. The purge valve may be attached to one of the columns.

[0053] The purge valve may be located adjacent to the engine housing where the gas engine is located.

[0054] The work machine may further include an outlet line connecting the purge valve to the outlet regulator and an engine line connecting the purge valve to the gas engine. The outlet line may include a rigid pipe, and the engine line may include a flexible pipe.

[0055] The work machine may further include a fill nozzle inlet for receiving a supply of gaseous fuel for the at least one storage tank.The fill nozzle inlet may be located adjacent the purge valve.

[0056] The filling nozzle inlet may be connected to the at least one tank via an inlet line, and the inlet line and the outlet line may extend parallel to each other along the vertically extending column.

[0057] The filling nozzle inlet may include a check valve. The filling nozzle inlet may include a filter for filtering the gaseous fuel received from the filling nozzle. The check valve is downstream of the filter. Providing a filter in the filling nozzle inlet facilitates filtering the gas as it enters the system. This is important for preventing contamination, to which gas injectors may be particularly sensitive. However, the presence of the filter may complicate emptying the at least one storage tank. Therefore, providing a separate purge valve may allow the filter to be more easily incorporated into the inlet valve.

[0058] When purging the system, it may be advantageous to include a purge valve adjacent to the fill nozzle inlet. Thus, a purging device may be connected to the purge valve to vent the system while a source of inert gas is connected to the fill nozzle inlet.

[0059] The inlet line may include a tank check valve local to the at least one tank.The tank check valve may be housed within the tank housing.

[0060] The work machine may further include an outlet regulator located between the at least one storage tank and the gas engine. The outlet regulator may be configured to reduce the pressure of the gas fuel stored in the storage tank. The purge valve may be located downstream of the outlet regulator.

[0061] It will be understood by those skilled in the art that, unless mutually exclusive, features described with respect to any one of the aspects, embodiments, or examples disclosed herein may be applied to any other aspect, embodiment, or example. Furthermore, unless mutually exclusive, any feature described herein may be applied to any aspect and / or combined with any other feature described herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Embodiments will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0063] Figures 1a to 1e The work machine is shown from left, right, front, top, and left front perspectives;

[0064] Figure 2a and Figure 2b shows rear and front perspective views of a gas storage system according to the present disclosure with an upper housing portion removed;

[0065] Figures 3a to 3c Shown Figure 2a and Figure 2b a side view, a rear perspective view, and a plan view of a gas storage tank mounting frame of a gas storage system;

[0066] Figures 4a to 4c Shown are the fill nozzle inlet, check valve, purge valve, and associated housing according to this embodiment;

[0067] Figure 5 Shows the settings Figures 1a to 1e The storage compartment in the embodiment of the work machine shown;

[0068] Figure 6a and Figure 6b shows alternative storage locations for a plurality of storage tanks according to the present disclosure;

[0069] Figure 7a and Figure 7b shows yet another alternative storage location for one or more storage tanks according to the present disclosure; and,

[0070] Figure 8 A schematic diagram of a gas storage system of the present disclosure is shown. DETAILED DESCRIPTION

[0071] In the following detailed description, numerous specific details are set forth to provide a thorough understanding of various embodiments and inventive concepts. However, those skilled in the art will appreciate that the present invention can be practiced without these specific details or with known equivalents thereof; that the present invention is not limited to the described embodiments; and that the present invention can be practiced in various alternative embodiments. It should also be appreciated that well-known methods, processes, components, and systems may not be described in detail.

[0072] Throughout the drawings, the same reference numerals may be used for corresponding features. In such cases, the description of these features may not be repeated.

[0073] The present disclosure provides an advantageous storage system for a work machine. The primary storage location can include the roof of the operator's cab, providing sufficient floor space for multiple tanks. However, further embodiments illustrate additional or alternative locations along the side of the machine, between the front and rear wheels, or underneath the machine (optionally toward the rear). Providing multiple storage locations allows the amount of gaseous fuel to be adjusted based on the desired application.

[0074] The present disclosure provides a variety of solutions for storing gaseous fuel, each of which can be used in isolation or in combination with other features. To simplify the present disclosure, the various solutions are described with reference to a work machine in the form of a backhoe loader. However, it should be understood that similar storage solutions can be provided on other types of work machines, such as wheeled loader shovels, telehandlers, forklifts, tractors, excavators, or other machines disclosed in the background section. Therefore, while the storage solutions described herein are particularly advantageous for backhoe loaders due to existing machine layouts and architectures, references to backhoe loaders can be interchanged with other work machines where appropriate.

[0075] Like other work machines, conventional backhoe loaders typically include a prime mover in the form of a diesel engine. The present disclosure relates to work machines utilizing a gas engine that operates on a gaseous fuel. Of particular relevance to the present disclosure are gas engines in the form of hydrogen engines. Hydrogen engines are known in the art and, for the sake of brevity, are not described in detail in this disclosure. Suffice it to say that the gas engine of the work machine is configured to receive a flow of gaseous fuel from a gas storage system according to the present invention.

[0076] Gas engines can be configured to operate solely on gaseous fuel. Thus, gas engines can be considered single-fuel engines, rather than hybrid or dual-fuel engines that are configured to operate on, for example, compressed natural gas and hydrogen, or some other combination of gaseous or liquid fuels.

[0077] Figures 1a to 1e A work machine 10 in the form of a backhoe loader is shown having a chassis 12 supported by ground-engaging structures in the form of wheels 14. Mounted to the chassis is a lifting or loading arm 16, at the front of which is mounted an implement, in this example a loading shovel 18. The loading arm 16 and loading shovel 18 are mounted on the front of the machine 10. The machine 10 can be described with respect to a main axis 11 extending fore and aft along the centerline of the machine 10.

[0078] Mounted on the rear of the machine 10 is a working arm 20 (which may be referred to as a backhoe) having a boom 21, a dipper arm 22, and a bucket 23. The machine 10 includes a gas engine 25 that provides power to move the machine 10 over the ground. The gas engine 25 also provides power to operate a hydraulic pump (not shown) that can selectively provide pressurized hydraulic fluid to various rams 27 to operate the loading arm, loading shovel, boom, dipper, bucket, etc. to enable material to be processed. The gas engine 25 can be housed in a conventional engine housing that includes, for example, a forward-facing grille, side walls, a fire wall, and an engine hood (shown but not numbered).

[0079] Machine 10 includes an operator cab 30, which includes an operator seat and operator controls such as a steering wheel, foot brake, foot throttle, hand throttle, and backhoe control lever. The operator seat can face forward and can be rotated so that it faces rearward to facilitate operation of the working arm 20. As shown, operator cab 30 is accessible via a plurality of steps. These steps are conventional and will not be further explained. Depending on the layout of operator cab 30, steps may be provided on either or both sides of machine 10.

[0080] The working arm 20 is mounted to the chassis 12 via a vertical pivot mount (commonly referred to as a king post 24) that allows the arm to swing left and right relative to the chassis. The working arm 20 is shown in a pre-operating position, i.e., a longitudinally aligned position, such that the axes of extension of the dipper arm 22 and boom 21 are generally aligned with the longitudinal or main axis 11 of the machine 10. For transport, the working arm 20 is typically moved to a transverse position to be positioned alongside and parallel to the rear of the cab 30. Retractable telescopic stabilizer legs 15 may be provided to stabilize the machine 10 while the working arm 20 is in operation.

[0081] Additional references Figures 2a to 3c , work machine 10 includes a storage system 38 having a plurality of tanks 40a-c, along with associated valves 42 and gas lines 44, disposed within a housing 46 on operator cab 30. Storage system 38 is configured to receive, store, and deliver gaseous fuel to engine 25. In the illustrated embodiment, there are three elongated cylindrical tanks 40a-c having respective longitudinal axes arranged parallel in a fore-aft direction to align with main axis 11. It should be understood that in some embodiments, there may be more or fewer tanks 40a-c, and they may be oriented differently, for example, transverse to main axis 11.

[0082] The tanks 40a-c can be arranged in a common horizontal plane in a side-by-side axially aligned relationship. However, in some embodiments of the present disclosure, depending on the desired exterior shape or other packaging considerations, it may be preferred to vertically or axially offset the tanks 40a-c relative to each other.

[0083] The tanks 40a-c are enclosed in a housing 46 that is attached to the top of the operator cab 30. The housing 46 can be attached to or provide the operator cab roof 30-1. In embodiments, the housing 46 can be provided by a unitary structure that extends above the tanks 40a-c, etc., or, as shown, the housing 46 can comprise a multi-part structure assembled around the tanks 40a-c. Thus, it can be seen that the housing 46 can include a lower portion 46-1 that is positioned on the top of the operator cab 30 and an upper portion 46-2 that is received by the lower portion and attached to the lower portion via a plurality of suitable fasteners. The roof of the cab 30 can be understood as the upper member of the cab 30 that provides the roof under which the operator is positioned when operating the machine 10.

[0084] The cooperation of the upper portion 46-1 and the lower portion 46-2 can be provided by any suitable attachment means, such as a plurality of circumferentially distributed fixing members 46f, such as bolts. A compressible seal (not shown) can be additionally provided between the lower structure 46-1 and the upper structure 46-2 to prevent water from entering.

[0085] The lower portion 46-1 may include an annular member positioned around the plurality of tanks 40a-c and having a sidewall 46-4 that extends upwardly to partially surround the tanks 40a-c. The outer surface of the lower portion 46-1 may be angled relative to the horizontal plane for aesthetic purposes and to provide adequate runoff. The lower portion 46-1 may additionally provide support for one or more lights or other auxiliary components, such as Figure 1e Shown but not labeled.

[0086] The lower portion 46-1 can include a bottom wall (not shown) that extends below the storage tanks 40a-c and is attached to the operator cab 30. However, in some embodiments, the bottom wall can be omitted, with the side walls 46-4 attached to the roof of the operator cab 30 around the storage tanks 40a-c, or to the mounting frame 48 that carries the storage tanks 40a-c. Regardless of whether the lower portion 46-1 includes a bottom wall, the roof of the operator cab 30 can include an interior liner or structural panels to separate the interior of the operator cab 30 from the storage system 38. Typically, the operator cab 30 can be fluidly isolated from the storage system 38 such that the storage system prevents gaseous fuel from entering the cab 30.

[0087] The drainage passage 46-3 can be provided around the perimeter of the housing 46, such as around the base of the upper portion 46-2 where it mates with the lower portion 46-1. The drainage passage 46-3 can include one or more outlets 46-8 located at either or both the front and rear of the operator cab 30 so that water can drain at a desired location.

[0088] As shown, upper portion 46-2 may include a plurality of raised portions 46-5 extending longitudinally along housing 46, aligned with tanks 40a-c. Each raised portion 46-5 may correspond to a portion of a corresponding tank 40a-c and partially receive that portion of the corresponding tank. Thus, the number of raised portions 46-5 may correspond to the number of tanks 40a-c.

[0089] The raised portion 46-5 is partially defined by an elongated channel 46-6 that extends from front to back between adjacent cans 40a-c to provide a groove or channel. Each channel 46-6 can be formed by a bottom wall 46-6b and opposing side walls 46-6sw that extend between the bottom wall 46-6b and the upper surface of the raised portion 46-5. It should be understood that the side walls 46-6sw can also be considered part of the raised portion 46-5.

[0090] The side walls 46-6sw are angled relative to the vertical to be inclined approximately 40 degrees relative to the bottom wall 46-6b extending horizontally therebetween. It will be appreciated that the form of the raised portion 46-5 and the channel 46-6 may vary according to different embodiments and may also include rounded surfaces or replace the faceted surfaces shown in the drawings with rounded surfaces.

[0091] To provide proper ventilation for the housing 46 , some embodiments may include vent holes positioned to allow any gaseous fuel that has escaped from the tanks 40a - c , valve 42 , or gas line 44 disposed within the housing 46 to escape.

[0092] Ideally, for hydrogen and other gaseous fuels that are lighter than air, ventilation is preferably provided at the highest point in the housing 46, thereby eliminating the need for forced ventilation. In the embodiment shown, the sidewall 46-6sw includes a plurality of holes 46-7 suitable for venting any escaping gas from the tanks 40a-c. The vent holes 46-7 can be provided in any desired suitable location, but in the described embodiment are advantageously distributed along the length of the channel sidewalls to prevent any localized accumulation of escaping gas. Each sidewall 46-6sw includes three holes evenly distributed along the length of the housing 46, but more or fewer holes may be provided. The outermost raised portion 46-5 may include downwardly sloping wings located along its outer side edges, which may also include suitable vent holes 46-7, as described above.

[0093] Providing holes 46-7 on an elevated and inclined surface can help reduce the entry of water (e.g., rain) into the interior of the housing 46. Like this, the holes 46-7 can always be open and have a relatively small diameter to prevent water or other foreign matter from entering the housing 46 during normal use. However, in some embodiments, it may be preferred to provide a cover for the hole that overhangs the hole 46-7 to help deflect water away. In some embodiments, the present disclosure may include a housing 46 with forced ventilation, wherein a blower unit (e.g., a fan) is arranged to provide an air flow to exhaust any leaked gas. The diameter of the hole 46-7 can be between 3 mm and 15 mm, optionally between 5 mm and 10 mm.

[0094] The storage system 38 may include one or more compressible elements 41 between the upper surface of one or more tanks 40a-c and the underside of the upper portion 46-2 to provide some cushioning therebetween and, optionally, some force distribution from foreign object impacts.

[0095] The storage tanks 40a-c can be carried by a mounting frame 48. The mounting frame 48 can include one or more mounting members for receiving the tanks 40a-c and any suitable arrangement of structural members for distributing the weight of the tanks 40a-c across the structural frame of the operator cab 30. Thus, the mounting frame 48 can include a frame of cross members 48-1, 48-2 and a plurality of interconnected longitudinal members 48-4 extending transverse to the longitudinal axes of the tanks 40a-c to provide sufficient strength and rigidity. The mounting frame 38 can be mounted to the cab 30 via one or more attachment members that are attached to one or more structural members of the operator cab 30.

[0096] The mounting frame 48 and the tanks 40a-c and associated valves 42 and gas lines 44 may be provided as a subassembly for stowage as a single unit on the cab 30. In doing so, a convenient manner is provided for assembling and testing the gas storage system 38 for a work vehicle 10 prior to installation on the work machine 10.

[0097] In the illustrated embodiment, the mounting frame 38 includes front and rear cross-members 48-1, 48-2 extending transversely in front of and behind the tanks 40a-c. One or more longitudinal members 48-4 may span the cross-members 48-1, 48-2, providing rigidity and stability to the cross-members 48-1, 48-2 and helping to prevent stress in the tanks 40a-c spanning therebetween.

[0098] The cross beams 48-1, 48-2 and / or longitudinal members 48-4 can be attached to the operator cab 30 via a plurality of attachment members in the form of legs 48-3. The legs 48-3 can be attached via any suitable fasteners (e.g., bolts) or, for example, welding. In the embodiment shown, the legs 48-3 extend from the cross beams 48-1, 48-2 or longitudinal members 48-4 to a height slightly below the underside of the tank, where they terminate in rectangular pads that are bolted to the cab.

[0099] Mounting frames 48 can be attached to the structural frame of the operator cab 30 to provide adequate support. The structural frame of the operator cab 30 can vary between embodiments, but in the illustrated machine, includes a plurality of columns 30-2 with crossbeams 30-3 extending therebetween. More specifically, front, rear, and center cab pillars 30-2 are provided, extending upward from the operator cab floor, with crossbeams 30-3 connecting their ends to form a ring beam. Front and rear transverse crossbeams 30-3, extending between the front and rear cab pillars 30-2, respectively, are configured with mounting frames 48 mounted thereto so that the weight of the tanks 40a-c can be reacted to the chassis 12 via the crossbeams 30-3 and cab pillars 30-2. While the mounting frames 38 of the illustrated embodiment extend between the transverse crossbeams, additional or alternative attachments may be made to side crossbeams extending fore and aft between the front, center, and rear columns.

[0100] It should be appreciated that the lower portion 46 - 1 and / or the upper portion 46 - 2 of the housing 46 may be attached to the mounting frame 48 or directly to the structural frame of the cab 30 .

[0101] The tanks 40a-c can be mounted to the mounting frame 38 by any suitable means. In the illustrated embodiment, the tanks 40a-c are neck-mounted. Thus, each tank 40a-c includes a neck portion 41 at either end that is received by suitable mounting features provided on the mounting frame 48. The tank neck portion 41 may include a relatively short cylindrical boss that extends axially and concentrically with the longitudinal axis of the respective tank 40a-c. Thus, the mounting frame 48 may include first and second neck attachments 48-5 for receiving the respective neck portions 41 at either end of the tanks 40a-c.

[0102] The neck attachment 48-5 can include any suitable attachment mechanism. In the depicted embodiment, the neck attachments 48-4, 48-5 include an annular collar comprising a cubic block having a circular hole therethrough for snugly receiving the neck portion 41. The neck attachment 48-5 and the corresponding neck portion 41 can include a close tolerance fit that allows axial and rotational movement to allow for proper positioning after installation. Thus, the tank valve 42 provided on the end of each tank 40a-c can be axially and rotationally aligned for connection to the gas line 44.

[0103] Either or both of the collars 48-5 disposed at the opposing ends may comprise a clamp operable to fixedly attach the respective cartridge 40a-c to prevent axial or rotational movement in the correct position. Thus, either or both of the neck attachments 48-5 may comprise an open configuration in which the cartridge position is adjustable and a closed configuration in which the cartridge position is fixed relative to the mounting frame 48.

[0104] The clamp can be provided by closing the diameter of an annular collar around the neck portion 41. In the embodiment shown, the neck attachment 48-4 comprises a non-adjustable, closed, full annular collar, while the neck attachment 48-5 comprises a split ring with radially separated ends that are closed via tangential clamping bolts. Alternatively, the clamp can be provided by a two-part fixture comprising a semicircular saddle mounted to the mounting frame 48 and an opposing semicircular clasp located on the neck and bolted to the saddle.

[0105] As shown, the neck attachment 48-5 can be secured to the crossbeam via bolts, the heads of which can be Figure 2b The fixing bolt can also be used as a clamping bolt.

[0106] In some embodiments, either or both of the neck attachments 48 - 5 may include a lining that serves as a support element to assist in positioning and / or to help prevent localized stress concentrations on the corresponding neck portion 41 .

[0107] An alternative method of attaching the tanks 40a-c to the operator's cab 30 could be to use tank straps that extend circumferentially around the tanks. However, tank straps typically require a saddle onto which the tanks 40a-c can be mounted, thereby increasing the height of the overall structure. Providing neck attachments 48-4, 48-5 is advantageous because it allows the height of the tanks 40a-c to be lowered relative to the roof of the operator's cab 30. Thus, the underside of the tanks 40a-c can be positioned adjacent to the operator's cab roof lining that provides the interior of the cab 30.

[0108] As in Figure 3a As best seen in the side view of the backhoe loader, the tanks 40a-c can be configured to overhang the front and / or rear of the cab 30, effectively increasing the capacity of the tanks 40a-c or reducing the height of the tank storage system 38 and the height of the machine 10. In the illustrated embodiment, the front of the tanks 40a-c, as seen on the right-hand side of the drawing, is positioned generally in line with the front cross member of the operator cab, with an overhang provided at the rear. Providing no or limited overhang at the front of the operator cab 30 can be advantageous when using the loading arm 16, which is typically operated at height, for example, to improve visibility. However, visibility requirements are generally lower at the rear of a backhoe loader because it utilizes the working arm 20 for operation, and thus the overhang at the rear may be greater. In this embodiment, the overhang at the rear is limited to prevent any potential contact with the working arm during normal operating activities or when the arm 20 is in the lateral transport position. In machines without such working arms or with low visibility requirements, the tanks 40a-c may be configured to overhang further.

[0109] The extent of overhang in the illustrated embodiment is less than 10% of the length of the tanks 40a-c from the end of the tank valve 42 to the tank cap at the opposite end inserted into the neck portion 41. However, in some embodiments, the overlap may be greater.

[0110] To provide the necessary support for the tanks 40a-c when cantilevered, rear support legs 48-3 may be provided on the longitudinal members 48-4 inboard of the cross members 48-1, 48-2.

[0111] It is well known that work machines need to withstand fall loads and rollover loads that may occur during use. Therefore, work machines include so-called ROPS (Rollover Protective Structure) and FOPS (Falling Object Protective Structure) and are tested for compliance against well-known standards. See, for example, ISO 3449:2005 Earth-moving machinery — Falling object protective structures or ISO 3471:2008 Earth-moving machinery — Rollover protective structures.

[0112] Such a standard might specify, for example, that a weight (e.g., 237 kg) be dropped from a predetermined height (e.g., 5 m) onto the operator cab roof at various locations to determine whether the structure deforms into the space occupied by the operator. A corresponding ROPS test might involve applying a load equivalent to approximately twice the weight of the machine via a spreader plate across the roof. For a backhoe loader, the ROPS load might be approximately 18 tonnes (for a machine weight of approximately 9 tonnes).

[0113] Typically, when performing ROPS and FOPS testing, OEMs typically remove auxiliary equipment (e.g., air conditioning units, GNSS antennas, etc.) mounted to the roof of the work machine because they do not provide meaningful structural resistance. Therefore, one method of obtaining ROPS and FOPS compliance for a machine with a canister mounted on the roof may be to remove the canister for testing.

[0114] In the present disclosure, the tank 30 can be designed to form part of a ROPS and / or FOPS structure due to its inherent structural rigidity and robustness. However, due to the inherent weakness of the neck mount against vertical loads, the ability to rely on the tank for ROPS and FOPS protection may be limited when using a neck mount. That is, the load imposed on the neck mount by a falling object may overload the tank at the neck mount, resulting in shear failure and sudden escape of gas. Therefore, the use of a tank mount that engages the main cylindrical body of the tank may be preferred.

[0115] In embodiments where the neck attachment 48-5 is preferred, for example so that the overall height of the structure can be reduced, some additional protection of the tank may be required to prevent catastrophic shear loads during a falling object or rollover incident. This may be provided in the form of a protective housing or cage, for example.

[0116] However, adding a substantial enclosure or protective structure may add undesirable weight, cost, maintenance, and assembly difficulties. In the present disclosure, for example, the enclosure may be made of a lightweight non-structural shell, which has benefits with respect to installation, maintenance, machine weight, and size of the canopy structure, but provides little benefit as a ROPS or FOPS.

[0117] In some embodiments, the mounting frame 48 to which the tanks 40a-c are mounted can be configured to mechanically collapse in a controlled manner during an extreme load event, thereby absorbing some of the impact energy and preventing excessive loading at the neck portion 41 of the tanks 40a-c. In some embodiments, the mounting frame 48 can collapse to redefine the load path from the impact location on the upper surface of the tanks 40a-c, and the falling object can be redistributed through the tanks and into the load-bearing structure of the cab 30.

[0118] To provide for collapse within the mounting frame 48, the neck attachment 48-5 can be cantilevered from a support member attached to the cab 30. Thus, in the illustrated embodiment, the neck attachment 48-5 is disposed on crossbeams 48-1, 48-2 that cantilever relative to support legs 48-3 at one or both ends of the tanks 40a-c. That is, the crossbeams 48-1, 48-2 can be connected to the support legs 48-3 via one or more longitudinal cantilever members 48-4, thereby allowing the longitudinal members to deform under typical falling object or rollover loads. Upon flexing, the neck mount and the tank body can move downwardly toward the roof of the operator cab 30 until they contact the cab structure and the load can be distributed through the cab structure.

[0119] It will be appreciated that the force required to deflect the cantilever support and redistribute the load path through the tank body will be less than the shear load that would cause the neck mount to fail. It will also be appreciated that the cab roof may be provided with one or more structural members or panels positioned to contact the tank body when the mounting structure collapses.

[0120] In the illustrated embodiment, the overhang of the tank can provide a means to provide sufficient deformability in the longitudinal member so that the tank can be lowered to contact the roof 30-1 of the operator's cab, as described. However, it should be understood that the size and material type of the various portions of the mounting frame 48 can be adjusted to control deformation based on the predicted shear limits of the neck portion.

[0121] The amount of force required to deform the mounting frame 48 and redistribute the load path through the tank will be application specific and depend on the location where the load is applied, the configuration of the tank, etc. In one embodiment, deformation of the mounting frame and redistribution of the load path can be achieved when a 237 kg weight is dropped onto the top of the tank from a height of 5 m near the end of the tank (e.g., where the cylindrical body begins to taper to the hemispherical end caps).

[0122] The separation between the underside of the cylindrical tank and the structural members of the top cover is sufficient to allow deformation of the support frame and redistribution of the load path, which provides suitable clearance for assembly and any operational movements. In some embodiments, the separation can be between greater than 10 mm, or 15 mm, or 20 mm and less than 30 mm, 40 mm, or 50 mm, or any combination of these upper and lower values.

[0123] The width of the mounting frame 48 and the combined width of the tanks 40a - c may be constrained to fit within the width of the operator cab 30 to help prevent impacts from foreign objects that do not contact the cab sidewalls.

[0124] The height of storage system 38, including tanks 40a-c and housing 46, can be any desired height. In embodiments where work machine 10 is a backhoe loader, the height of housing 46 can advantageously be lower than the upper extent of work arm 20 when in the transport position, thereby helping to reduce the likelihood of accidental collisions with overhead obstacles while maneuvering machine 10.

[0125] Each storage tank 40a-c may be provided with a tank valve 42 mounted to the corresponding neck portion 41. Each tank valve 42 may include one or more of the following: a shutoff valve, a pressure transducer, a temperature sensor and a thermally activated pressure relief device (TPRD), an inlet port, and an outlet port. The tank valve may be communicatively connected to a controller 64 configured to control the valve 42 in use and receive operational data therefrom.

[0126] like Figure 3b As best shown in FIG. 1 , the tank valve 42 can be connected in flow communication via a single gas line 44-1 that connects multiple tanks 40a-c together. Thus, there is a connecting gas line 44-1 extending between the first tank 40a and the second tank 40b, and between the second tank 40b and the third tank 40c. An inlet line 44-2 is connected to the gas line 44-1 between the first tank 40a and the second tank 40b via a T-piece, and an outlet line 44-3 is connected to the connecting line between the second tank 40b and the third tank 40c via a second T-piece.

[0127] A regulator 45 may be provided locally on the tank valve 42 to reduce the pressure in the storage tanks 40a-c and the outlet line 44-3 to a usable pressure. Placing the regulator 45 locally on the tank valve 42, i.e., within the housing 46, allows the pressure to be reduced before being delivered to the engine 25, thereby reducing the length of the high-pressure line. Furthermore, providing the regulator 45 as part of the storage system 38 subassembly allows it to be tested before being installed in the machine 10.

[0128] Inlet line 44-2 may include a check valve 44-4 that prevents backflow of gas from tanks 40a-c back to the filling nozzle inlet 50 (described below). Check valve 44-4 may be located anywhere along inlet line 44-2, however, it is advantageous to locate it locally on tanks 40a-c and within housing 46 because it prevents reverse flow of high-pressure gas from tanks 40a-c even if high-pressure inlet line 44-1 becomes damaged between filling nozzle inlets 50. In an alternative embodiment, check valve 44-4 may be located in first tank valve 42. In such an embodiment, high-pressure inlet line 44-1 would need to be connected to a separate port of valve 42, rather than being connected to connecting line 44-1 via a T-piece.

[0129] Depending on the application, the storage tanks 40a-c can be configured to have a rated operating pressure of up to 35 MPa (350 bar / 5076 psi), 50 MPa (500 bar / 7251 psi), or 70 MPa (700 bar / 10 kpsi). In some embodiments, higher or lower pressures are possible. It should be understood that the inlet line 44-1 will be configured to carry a pressure at least as high as the pressure rating of the tanks 40a-c.

[0130] The operating pressure of the gas delivered to the engine 25 may be between 5 and 15 bar (0.5 MPa and 1.5 MPa / 72 psi and 218 psi).

[0131] Storage tanks 40a-c may be configured to hold up to 20 kg, optionally 15 kg, optionally 9 kg of hydrogen when full.

[0132] Each storage tank 42 can include a thermally activated pressure relief device (TPRD) connected to a TPRD vent line 52. The TPRD can be configured to function as a temperature-responsive valve that fully opens to allow the contents of the tank to vent (vent) via the TPRD vent line 52 when the ambient temperature exceeds a predetermined threshold. TPRDs are well known and are often required to ensure hydrogen venting in the event of a fire. In other words, the TPRD provides a thermal cutoff that blows when a fire is present to prevent pressure buildup in the tanks 40a-c.

[0133] In the embodiment shown in the figures, the TPRD is disposed within the tank valve 42 and is therefore not separately shown. The TPRD vent line 52 includes an open passage extending from the TPRD port on the tank valve 42 to the TPRD vent line outlet in the housing 46.

[0134] The TPRD vent line outlet can be provided on the housing in any suitable form and location. In the embodiment shown, the TPRD vent line outlet 54 is provided by a covered hole in the upper portion 46-2 of the tank housing 46. More specifically, it is located in the upper surface of the raised portion 46-5, as shown in FIG. Figure 1d and Figure 2b Best shown.

[0135] Each vent line outlet 54 includes a pressure-responsive, removable vent cap 56 that is retained within a hole in the housing 46 by a suitable interference fit. The fit between the cap 56 and the hole is such that, in the event of a sudden venting event, the fit will be overcome by the venting gases. As can be seen, the removable cap 56 can include a tether 56-1 that is attached to the housing 46 or elsewhere so that if the cap 56 is removed during a venting event, the cap 56 remains. This not only prevents the cap 56 from being lost or causing possible injury or damage near the machine 10, but also provides a clear indication that venting has occurred through a quick visual inspection by the operator.

[0136] It can be seen that the vent line outlet 54 is provided at the rear of the canister housing 46 so that the exhausted gases can be further exhausted from the engine compartment and any potential ignition source. The uppermost position of the vent line outlet 54 also helps to safely exhaust the escaping gases.

[0137] In the embodiment shown, there are four vent line outlets 54, one for each of the tanks 40a-c within the corresponding raised portion 46-5, and another vent line outlet 54 for the regulator 45. The distal ends of the vent lines 52 may be supported by an elongated crossbeam extending between each vent line 52.

[0138] To reduce the weight of housing 46, the structure may comprise relatively thin sheets. Consequently, in use, there may be some movement between housing 46 and tanks 40a-c or TPRD vent line 52. To allow for some relative movement and a lighter weight housing, a flexible connector 58 may be provided between vent line 52 and the aperture in housing 46.

[0139] The flexible connector 58 may comprise a flexible portion of the vent line 52, or may comprise a flexible collar configured to flex axially during use to accommodate misalignment between the housing 46 and the vent line 52. The flexible collar may engage with the aperture and receive the vent line 52 within the central aperture. In the illustrated embodiment, the flexible connector 58 has a form similar to a gearstick or CV joint boot as known in the art. Thus, there is a base that attaches to the aperture in the housing 46 and engages with the cap 56, and a corrugated, tapered body that can be axially flexed in any direction and includes a central aperture that sealably receives the vent line 52.

[0140] As will be appreciated, a removable vent cap 56 may be sealably received within the housing aperture or flexible connector 58 to help prevent water from entering the vent line 52. To help further reduce water ingress, the vent outlets 54 may be disposed on elevated portions of the housing 46, as previously described, where they are exposed to less surface water than the passages.

[0141] In the event that water enters the vent line 52, it is important to allow the water to drain to prevent potential blockage of water, especially in the event that freezing may occur. Therefore, the vent line 52 may include a u-shaped bend portion located below the tank valve 42 and / or TPRD, the u-shaped bend portion including a small drain hole 52-1 ( Figure 3b ) to allow any water to drain. The drain hole 52-1 can be located in the lowermost portion of the vent line 52.

[0142] Inlet line 44-1 provides fluid communication between the filling nozzle inlet 50 and the tanks 40a-c. The filling inlet nozzle 50 can be positioned at any convenient location that is easily accessible to an operator for connecting a refueling filling nozzle. In the present disclosure, the filling nozzle can be positioned in a fixed relationship with the tanks 40a-c so that there is minimal relative movement between the filling nozzle inlet 50 and the tanks 40a-c. In doing so, the high-pressure inlet line 44-1 can be provided with rigid piping because it is not necessary to allow for differential movement. An alternative solution could be to use a flexible connection in the high-pressure line, however, this is generally more cumbersome and prone to failure.

[0143] In the present disclosure, work machine 10 may include an operator cab 30 that is configured to move relative to chassis 12 to increase operator comfort. The relative movement may be provided using antivibration mounts as known in the art.

[0144] In such an arrangement, the fill nozzle inlet 50 can be attached to the structural frame of the operator cab 30, such as the column 30-2. In the illustrated embodiment, the fill nozzle inlet 50 is located on the front column 30-2, adjacent to the cab entry step, at a conveniently accessible height. Thus, this location is between and inboard of the front and rear wheels to help prevent accidental damage to the inlet 50 due to impact with foreign objects while the machine 10 is in use. This height can be determined by the top of the cab entry step 68 and / or located near or below the cab door handle.

[0145] It is advantageous to locate the fill nozzle inlet 50 in this location on a backhoe loader because this height is generally convenient for most users, and the front cab pillar provides suitable support for the gas inlet line 44-2 extending upward to the tank. For example, in some embodiments, the fill nozzle inlet 50 can be located adjacent to one or more other regularly accessible service points, such as the hydraulic oil tank 66 or the screen wash bottle. This provides convenience for the operator.

[0146] The inlet line 44-2 can be surface extended on the front pillar 30-2 by appropriately spaced fixings. The surface extension of the inlet line 44-2 ensures that any escaping gas is exhausted. However, one or more inflatable housing elements (not shown) can be set around the inlet line 44-2 to provide mechanical shielding. The housing element can include a cage or perforated plate positioned around the inlet line 44-2, or simply include an open channel or sidewall that extends beside the pillar 30-2 and protrudes outward from the pillar 30-2 further than the inlet line 44-2. In some embodiments of the present disclosure, the inlet line 44-2 can be internal to the cab pillar 30-2, so long as suitable ventilation is provided.

[0147] The filling nozzle inlet 50 can be located within a housing 50-1 having a hinged door 50-2 to provide access. The door 50-2 can be hinged horizontally along a lower edge so that once unlocked, the door easily remains in an open position under gravity and, once attached, can provide a rest for the filling nozzle.

[0148] A low-pressure outlet line 44-3 extending between the outlet regulator 45 and the engine 25 may be surface-extended on the same front post 30-2 as the high-pressure inlet line 44-2. The outlet line 44-3 may pass through a shutoff valve 60 operable to prevent flow from the outlet regulator 45 to the gas engine 25 when the engine is not in use. The valve 60 may be an electrically operated solenoid valve operably connected to a controller 64. The controller 64 may be or form part of a conventional engine control unit (ECU) of the engine 100, or may be a separate controller.

[0149] Controller 64 may include any suitable circuitry to implement control of valve 60 as required by the operation of engine 25. Thus, for example, valve 60 may be opened and closed as part of startup and shutdown procedures.

[0150] The controller 64 may include: control circuitry; and / or processor circuitry; and / or at least one application-specific integrated circuit (ASIC); and / or at least one field-programmable gate array (FPGA); and / or a single-processor or multi-processor architecture; and / or a sequential / parallel architecture; and / or at least one programmable logic controller (PLC); and / or at least one microprocessor; and / or at least one microcontroller; and / or a central processing unit (CPU) to perform the described methods. The controller 150 may include associated memory, or the memory may be located locally or remotely from the controller. The memory may be non-volatile memory, such as read-only memory, erasable programmable read-only memory, flash memory, a solid-state drive, or magnetic storage.

[0151] It should be understood that the gas storage system 38 may need to be emptied for maintenance or shipping purposes, etc. Therefore, the gas storage system 38 may include one or more purge points that are operable to remove gas from the storage system 38. The one or more purge points may be located anywhere in the storage system 38. In the present disclosure, the purge point may include a purge valve 62 located in the outlet line 44-3 that connects the outlet regulator 45 and the engine 25. The purge valve 62 is operable to remove the contents of the tanks 40a-c and the gas line. Placing the purge valve 62 in the low-pressure outlet line 44-3 allows for simpler valves and minimizes the risk of high-pressure leaks.

[0152] exist Figure 4c In the example shown, purge valve 62 is juxtaposed with fill nozzle inlet 50 and, optionally for convenience, is included in the same valve stack as shutoff valve 60. Purge valve 62 can be fluidly located upstream of shutoff valve 60 so that the system can be purged if power to the system is lost or valve 62 is inoperable.

[0153] The purge valve 62 may include a manually removable plug to which a ventilation tool (not shown) may be attached to capture the purged gas. Once the ventilation tool is connected, the purge valve 62 may be opened and the gas removed. The purge valve 62 may be a service valve that may be operated under the control of the ventilation tool so that it can only be operated by trained and authorized personnel. In some embodiments, the ventilation tool may capture the exhausted gas in a suitable container. This not only saves fuel for use elsewhere, but also prevents it from escaping into the atmosphere and potentially being harmful to the environment.

[0154] As described above, during normal use, the operator cab 30 and the storage system 38 can move relative to the chassis 12. To provide a connection between the storage system 38 and the engine 25, the outlet line 44-3 can include a flexible portion 44-5, which can be referred to as an engine line. Providing the flexible portion 44-5 in the outlet line 44-3 is preferred due to the lower pressure compared to the inlet line 44-2.

[0155] The flexible portion 44-5 of the outlet line 44-3 may comprise one or more flexible hoses known in the art. The flexible hose may comprise a laminate of one or more suitable materials to provide a mechanically suitable hose that is sufficiently resilient to hydrogen embrittlement. The flexible and rigid portions of either or both of the inlet and outlet lines 44-2 and 44-3 may be made of one or more of the following: stainless steel (e.g., 316L), nylon, PTFE (polytetrafluoroethylene), polyamide, steel braid, and the like. In some embodiments, the flexible portion may comprise a laminated polymer hose comprising one or more braids.

[0156] The work machine may include one or more hydraulic actuators for operating various hydraulic services, such as the rams 27 on the work arms and lift arms. Thus, the work machine may include a hydraulic oil tank 66 located on a first side of the operator cab 30, in which hydraulic oil may be stored. In the present disclosure, the hydraulic tank 66 is located near the fill nozzle inlet 50 to provide a convenient maintenance location for the operator.

[0157] The storage system 38 previously described herein includes a plurality of tanks 40a-c located on the roof of the operator cab 30. The location of the tanks 40a-c provides the potential for substantial storage, thereby extending the duration of use between refuelings. In some embodiments of the present disclosure, the tanks 40a-c can be distributed in alternative locations around the work machine. For example, one or more tanks 40' can be located away from the operator cab 30, such as on the side of the chassis 12 or on the underside of the chassis 12.

[0158] Figure 6a and Figure 6b An example is provided of a plurality of storage tanks 40' positioned longitudinally on the sides of the work machine 10 between the front and rear wheels 14 and below the operator cab 30. The storage tanks 40' are disposed within a housing 46' and supported by a structural mounting frame 48' attached to the chassis 12. In the illustrated embodiment, four cylindrical tanks are provided, however, there may be more or fewer tanks in alternative embodiments.

[0159] In conventional machines including diesel engines, the fuel tank may be located in the same location as the storage tank 40' located on one side of the machine 10. Thus, the presence of the storage tank 40' in this location may represent an exchange of one storage system for another. However, the placement of the tank 40' in this location may obstruct the cab access step 68 ( Figure 5 Thus, in some embodiments, the tank 40' may supplement the primary storage system 38 (as described herein) provided on the roof of the cab 30, rather than being the sole storage location.

[0160] Although shown on the right hand side of the machine 10, the present disclosure contemplates providing the tank 40' on either side of the machine centerline. Thus, a tank is provided on either or both the left and right hand sides of the machine 10.

[0161] The side tanks 40' may each comprise a smaller volume than the header tanks and have similar normal operating pressures as the tanks 40a-c disclosed above. When fully loaded, the weight of hydrogen stored in the side tanks 40' may be between 2 kg and 7 kg.

[0162] In embodiments where side tanks 40' are not implemented, this space may usefully be replaced with one or more tool storage compartments 70. Thus, as Figure 5 As shown, an upper tool storage compartment 70a and a lower tool storage compartment 70b are provided, each having a hinged access door 70a-1, 70b-1. The tool storage compartment 70 can be provided behind the cab access steps 68, wherein the doors 70a-1, 70b-1 are provided in a suitable position between or above the steps 68.

[0163] The tool storage compartment 70 may include an outer shell defining an enclosed space in which one or more items may be stored. The shell may include at least one lateral wall facing outward, in which a hinged entry door 70b-1 (or other form of removable panel) may be provided. The shell 70 may also include at least one upward-facing wall. The upward-facing wall may include a hinged entry door 70a-1 (or other removable panel) to provide access from above. The tool storage compartment 70 may be a single compartment with a side entrance and a top entrance, or the compartments 70a, 70b may be isolated with separate entry doors, as shown.

[0164] When viewed from the side, the upper access door 70a-1 is generally L-shaped and hinged on the outer side wall. However, in some embodiments, the door 70a-1 can be hinged to the rear of the opening and / or hinged on the upper surface.

[0165] Figure 7a and Figure 7bYet another alternative storage system is shown having a tank 40" located beneath the chassis 12. The tank 40" is positioned toward the rear of the machine between the rear wheels 14. The tank 40" may include a laterally oriented elongated cylindrical body. The tank 40" may be positioned to the rear of the rear axle 14-1, behind the rear differential 14-2, and in front of the working arms 20 and / or rear stabilizer legs 15. The tank 40" may include mechanical protection in the form of a shell 46" which surrounds at least the underside of the tank to prevent foreign objects from being struck from below. The shell 46" may include one or more drain holes 46" and may typically be perforated.

[0166] Figure 8 A schematic diagram of a gas storage system 80 of the present disclosure is shown. The gas storage system 80 can be implemented in any work machine having a gas engine, but may be particularly suitable for use with the backhoe loader 10 disclosed herein. Corresponding features may use the same reference numerals as previously used. In such cases, the description of these features may not be repeated.

[0167] The gas storage system 80 includes a plurality of storage tanks 40a-c, each having a tank valve 42. The tank valves 42 include ports to which gas lines 44 are connected to provide serial flow communication between the valves 42. Thus, a connecting line 44-1 can be seen extending between the first tank 40a and the second tank 40b, and between the second tank 40b and the third tank 40c. An inlet line 44-2 is connected to the connecting line 44-1 extending between the first tank 40a and the second tank 40b via a T-piece. An outlet line 44-3 extends between the final tank 40c and an outlet regulator 45. The tanks 40a-c, the tank valves 42, and the outlet regulator 45 are disposed within a housing 46 disposed on the operator cab 30 or elsewhere on the machine.

[0168] As mentioned above, in some embodiments of the present disclosure, there may be more or fewer tanks 40a - c , for example, where the tanks 40a - c are positioned on the sides or below the machine 10 .

[0169] Upstream of the storage tanks 40a-c and housing 46, a filling nozzle inlet 50 connected to the inlet line 44-2 is provided. The filling nozzle inlet 50 includes a filter 50-3 to help remove particulate matter from the gaseous fuel flow as it enters. The inlet 50 may also include a check valve 50-4 that prevents gas from flowing back from the tanks 40a-c when the filling nozzle (not shown) is removed. In some embodiments, the check valve may be selectively openable to allow gas to be purged from the system 80 and to capture gas during reverse fueling. Removal of fuel may be performed for transport or storage purposes, with the tanks 40a-c purged of gaseous fuel and optionally filled with an inert gas, such as nitrogen.

[0170] In addition to the check valve 50-3 provided in the inlet 50, another check valve 44-4 may be provided locally in the tank 40a-c, i.e., in the housing 46, upstream of the first tank valve 42. The check valve 44-4 may be provided as part of a T-piece connecting the connecting line 44-1 and the inlet line 44-2, or at the location where the inlet line 44-2 enters the tank valve 42, which may be a preferred connection in some embodiments. Figure 8 , check valve 44-4 is shown separate from the T-piece, tank valve 42 and connecting line 44-1, but located within housing 46. The purpose of check valve 44-4 is to prevent a large discharge of gas if the exposed portion of inlet line 44-2 is severed or otherwise damaged during use.

[0171] Each tank valve 42 may include one or more of the following: a shutoff valve 81, a pressure transducer 82, a filter 83, a temperature sensor 84, a thermally activated pressure relief device TPRD 85; a first port 86; a second port 87; an excess flow valve 88; and one or more tank valves 89, 91 for allowing flow into and out of the tank. As can be seen, the ports may be interconnected by flow channels.

[0172] Tank valve 42 connects to the interior volume of storage tanks 40a-c via two paths. The first path includes a manually operated normally open valve 89, a solenoid-operated check valve 90, a relief valve 88, and a filter 83. The solenoid-operated check valve is configured to allow gaseous fuel to flow into the corresponding tank 40a-c when gaseous fuel is provided from fill nozzle inlet 50 via inlet line 44-2, while preventing reverse flow. The solenoid valve can be activated by a controller, removing the check valve from the flow path to allow reverse flow for draining tanks 40a-c.

[0173] The second path comprises a normally closed manually operated valve 91. If the machine loses power or the solenoid valve becomes inoperable, this valve 91 can be manually operated to manually empty the tank.

[0174] The TPRD connects the interior volume of the respective tank 40a - c to the atmosphere via a vent line 52 via a suitable vent line outlet 54 .

[0175] A temperature sensor 84 may be provided as part of the tank valve 42 to monitor the gas temperature of the gaseous fuel within the tank 42. A pressure transducer 82 is provided to monitor the pressure within the tanks 40a-c and is also provided on either side of the outlet regulator 45.

[0176] The outlet regulator 45 may be a two-stage regulator that reduces the pressure from the high pressure reservoir to the pressure required by the engine. The purge valve 62 and the shutoff valve 60 may be those described above.

[0177] One or more embodiments have been described above by way of example only, and it will be appreciated that modifications to the embodiments described above are possible without departing from the scope of protection provided by the appended claims.

Claims

1. A working machine comprising: ground engaging structures; a chassis mounted to the ground engaging structure; an operator cab mounted to the chassis; a gas engine for providing power to the ground engaging structure; as well as, at least one storage tank for storing gas fuel for said gas engine, Wherein, the at least one storage tank is disposed on top of the operator cab.

2. The working machine according to claim 1, wherein: The at least one tank comprises an elongated cylinder having a longitudinal axis, wherein, optionally, the longitudinal axis is aligned with a main axis of the work machine.

3. The working machine according to claim 1 or 2, wherein: The top cover includes a mounting frame to which the at least one tank is mounted, wherein the at least one tank includes an elongated cylinder having a neck portion at either end thereof, and wherein the at least one tank is attached to the frame via the neck portion.

4. The working machine according to claim 3, wherein: The frame comprises a first neck attachment and a second neck attachment for attaching to a corresponding neck portion at either end of the at least one tank, wherein the neck attachments are configured to allow axial and rotational movement of the at least one tank in an open configuration and to prevent axial and rotational movement in a closed configuration, and optionally, either or both of the first neck attachment and the second neck attachment comprise a clamp, wherein the clamp is tightened to provide the closed configuration.

5. A work machine according to any one of the preceding claims, wherein: The operator cab includes a front edge and a rear edge, wherein the at least one tank overhangs the rear edge.

6. A work machine according to any one of the preceding claims, wherein: The at least one storage tank includes a tank valve for controlling the flow of gaseous fuel, wherein, optionally, the tank valve is provided at the rear of the operator cab.

7. A work machine according to any one of the preceding claims, wherein: The at least one tank is enclosed in a housing, wherein the housing includes an upper surface including a raised portion, wherein the at least one tank resides in the raised portion.

8. The work machine according to claim 7, comprising at least two storage tanks, wherein: Each of the tanks is located in a respective elevated portion of the housing, wherein the respective elevated portions are separated by a channel having a base and a sidewall extending between the base and the elevated portion, the sidewall including at least one vent.

9. The working machine according to claim 8, wherein: The ventilation holes are distributed along the length of the channel.

10. The working machine according to claim 9, wherein: The side wall is inclined less than 60 degrees away from the vertical direction.

11. The working machine according to any one of claims 7 to 10, wherein: The housing comprises a multi-part shell including a lower portion and an upper portion attached to enclose the at least one tank.

12. The working machine according to any one of claims 7 to 11, wherein: The housing is cantilevered to the rear of the operator cab.

13. The working machine according to any one of claims 7 to 12, wherein: The front portion of the housing includes front and rear tapered portions.

14. A work machine according to any one of the preceding claims, wherein: The housing includes a peripheral channel for directing surface water to an outlet located at either or both of the front or rear of the operator cab.

15. The working machine according to any one of claims 7 to 14, wherein: The at least one storage tank comprises a thermal pressure relief device TPRD connected to a TPRD vent line, wherein the TPRD vent line comprises a vent line outlet extending through the housing, optionally through an upper surface of the housing, optionally at a rear portion of the housing.

16. The work machine according to claim 15, wherein: The vent line outlet includes a pressure-responsive removable cover, wherein the removable cover is optionally fastened to the housing.

17. The work machine according to any one of claims 15 to 16, further comprising a plurality of storage tanks, wherein Each storage tank includes a corresponding TPRD vent line outlet.

18. The working machine according to any one of claims 15 to 17, wherein: The TPRD vent line includes a U-shaped bend portion, and the U-shaped bend portion includes a drainage hole.

19. The work machine according to any one of claims 15 to 18, wherein: The or each TPRD vent line is coupled to a respective vent line outlet via a flexible collar.

20. A work machine according to any one of the preceding claims, wherein The at least one storage tank is in fluid communication with a fill nozzle inlet via an inlet line and with the gas engine via an outlet line, the fill nozzle inlet being configured to receive a supply of gaseous fuel from a fill nozzle.

21. The work machine according to claim 20, wherein: The inlet line and the outlet line are externally mounted on a column of the work machine.

22. The work machine according to claim 21, wherein The pillar is a front pillar that supports the cab roof.

23. The work machine according to any one of claims 20 to 22, wherein: The inlet line includes a check valve configured to prevent reverse flow along the inlet line.

24. The work machine according to any one of claims 20 to 23, wherein: The fill nozzle inlet is attached to the operator cab.

25. The work machine according to any one of claims 20 to 24, wherein: The engine is movable relative to the operator cab, and the outlet line includes at least one flexible portion configured to allow the relative movement.

26. The work machine according to any one of claims 20 to 25, wherein: The operator cab is movable relative to the chassis, and the outlet line includes at least one flexible portion configured to allow relative movement.

27. The work machine of claim 26, further comprising a plurality of access steps for entering and exiting the operator cab, and a tool storage compartment located behind the access steps.

28. The work machine of any one of claims 7 to 27, further comprising a compressible element located between an upper surface of the at least one tank and the housing.

29. A work machine according to any one of the preceding claims, wherein: The gas engine is a hydrogen engine, optionally based solely on hydrogen.

30. A work machine according to any one of the preceding claims, wherein The work machine comprises at least one work arm, optionally wherein the work machine is a backhoe loader.

31. The work machine according to any one of claims 3 to 30, wherein: The mounting frame includes a plurality of support legs, wherein the support legs are disposed inside the neck attachment that engages the neck portion such that the neck attachment is supported on cantilevered arms that extend outwardly from the support legs.

32. The work machine according to claim 31, wherein The cantilever is configured to deform under a falling object test in which 237 kg is dropped from a vertical height of 5 m.

33. The work machine according to any one of claims 3 to 32, wherein: The tank includes a cylindrical body extending between opposing end neck portions, and the operator cab includes a structural member below the cylindrical body configured to provide an alternate load path for distributing a falling object load after the mounting frame is collapsed.

34. The work machine according to claim 33, wherein: The cylindrical body of the tank is located between 10 mm and 50 mm above the structural member.

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