GB2619089A

GB2619089A - Work machine system with machine power unit and interchangeable modular units

Info

Publication number: GB2619089A
Application number: GB2207871.1A
Authority: GB
Inventors: Massey Andrew
Original assignee: Caterpillar SARL
Current assignee: Caterpillar SARL
Priority date: 2022-05-27
Filing date: 2022-05-27
Publication date: 2023-11-29
Also published as: GB202207871D0; WO2023227244A1

Abstract

A machine power unit 11 for use with interchangeable working machine module units 12 comprising a machine drive system 18, a ground engager 21 such as a wheel, a power unit frame 22 to which the ground engager and machine drive system and an articulated joint 40 are mounted. A releasable power coupling 20 for coupling to the module units is mounted to the articulated joint such that it is pivotal relative to the power unit frame. A steering system 42 controls the pivoting of the articulated joint when the machine power unit is coupled to the module unit. There may be an oscillation hitch (fig.2, 45). A system comprising the machine power unit and a plurality of module units is provided. Module units can be interchangeably used with the machine power unit to perform multiple different work functions.

Description

WORK MACHINE SYSTEM WITH MACHINE POWER UNIT AND INTERCHANGEABLE MODULAR UNITS

TECHNICAL FIELD

This disclosure is directed towards a work machine system with a machine power unit and interchangeable modular units. The disclosure is further directed towards a machine power unit, a modular unit, a plurality of modular units and a method of operating a work machine system.

BACKGROUND

Machines, such as wheel loaders, commonly comprise a machine power unit connected to a modular unit. These machines commonly comprise one or more joints allowing for articulation between the power unit and modular units (e.g. for steering) and/or oscillation between the power unit and modular units (e.g. as the power unit and modular units independently roll at different angles as they move over a rough terrain).

The power unit and modular units are permanently coupled to each another about the joint and are fully integrated with one another so that the machine is purposively designed to perform a certain range of tasks. Worksites therefore often require a number of different work machines to suit different applications. Whilst such an approach ensures that an appropriate and efficient machine for a certain task is selected, it can mean that some types of machines remain idle on a worksite when they are not required, meaning they have a low rate of Furthermore, the power units with new power sources (electrical, hybrid and hydrogen for example) have a higher purchase cost than the traditional power units with internal combustion engines, meaning the low rate of utilisation makes the purchase of new machines harder to justify. Idle machines will also need to be maintained, the costs of which are increasing with decreasing availability of suitable technicians.

US9637190B2 discloses a modular industrial vehicle comprising a modular tractive complex comprising one or more cabin modules, at least one power unit module and at least one chassis module which comprises a frame module. Successive frame modules may be connected by a frame pivot module or the frame modules can be directly connected to one another at their ends. The cabin module(s) and the power unit module(s) are attached, wholly or partially, to one or more of the frame modules. The one or more modules communicate with a managing controller to provide an operating mode for the modular industrial vehicle based configuration and technical specifications of the one or more modules. However, such an arrangement does not enable, for example, significant flexibility in the different work functions performable.

SUMMARY

The present disclosure is directed towards a machine power unit, a plurality of modular units, a work machine system and a method of operating a work machine system in accordance with the claims.

The present disclosure is generally directed towards a work machine system with interchangeable modular units coupleable to a machine power unit via a releasable power unit-modular unit coupling.

The modular units and machine power unit comprise ground engagers such as wheels and at least the power unit ground engagers are driven by a machine drive system. The machine The machine power unit may comprise two ground engagers and in some aspects the two ground engagers may be coupled with a single axle. A steering system across an articulation joint is used to steer the work machine. The machine drive system may be operable to drive all of the ground engagers, such as in a four-wheel drive mode. Authentication of the modular unit may take place before it can be operated by the machine power unit. A power unit control system may enable dedicated control maps to be used for each type of modular unit.

The work machine system may result in a reduction in the number of power units in the industry and associated environmental impact (e.g. a reduction in emissions, hydrogen production and mining for battery materials), as well as on a worksite, bringing safety and increase space benefits. There may be a reduction in maintenance costs as only one machine power unit needs maintaining across a range of work functions. There is also a significant increase in rental flexibility and utilisation because the machine power unit may be operable for a more significant portion of time and through worksite job site evolution a machine power unit can remain on rent, with only the modular units needing to be swapped out based upon demand. This may reduce rental return costs, service overheads and customer rental costs. Furthermore, the selectable four-wheel drive system improves operational efficiency.

The present disclosure further provides a system comprising: a machine power unit comprising a power unit coupling and a machine drive system; a plurality of modular units each comprising a modular unit coupling for releasably coupling to the machine power unit and a modular drive system; wherein the power unit and modular units are only moveable about a terrain by the power unit and modular drive systems when the power unit and modular units are coupled together.

The present disclosure further provides a machine power unit for a work machine comprising: a main body comprising a power unit configured to drive at least one terrain engaging unit for conveying the machine power unit across a terrain; a power unit coupling for releasably coupling a modular unit to the machine power unit; and a joint mounted between the main body and power unit coupling and configured such that the power unit coupling can rotate relative to the main body.

The present disclosure further provides a work machine comprising: a machine power unit comprising a machine drive system for driving the work machine across a terrain and a machine power unit coupling; a modular unit comprising a work tool and a modular unit coupling, the power unit and modular unit couplings being releasably coupleable together; wherein the power unit and modular unit couplings comprise a pair of cantilevers for mounting in pockets for supporting the work unit against the machine power unit and at least one locking mechanism for selectively securing the pair of cantilevers in the pockets.

BRIEF DESCRIPTION OF THE DRAWINGS

By way of example only, embodiments of the present disclosure are now described with reference to, and as shown in, the accompanying drawings, in which: Figure 1 is a side elevation of a work machine in accordance with the present disclosure including a machine power unit and a modular unit; Figure 2 is a side elevation of a machine power unit for a work machine system in accordance with the present disclosure; Figure 3 is a side elevation of a further machine power unit for a work machine system in

accordance with the present disclosure;

Figure 4 is a side elevation of a modular unit for a work machine system in accordance with the present disclosure; 4 -Figures 5 is a power unit-modular unit coupling 25 for the work machine of the present disclosure; and Figure 6 is a schematic of a work machine control system for the work machine of the present disclosure.

DETAILED DESCRIPTION

Figure 1 schematically illustrates a work machine system 10 of the present disclosure comprising a machine power unit 11 and a modular unit 12 of a plurality of interchangeable modular units 12. The machine power unit 11 is coupleable to each of the modular units 12 and a work machine 13, in this case a compact wheel loader, is formed by the machine power unit 11 being coupled to one of the modular units 12.

In general, each of the power unit and modular units 11, 12 are not designed as standalone vehicles and may serve no practical purpose in isolation. However, once coupled together, the power unit and modular units 11, 12 together form a fully integrated work machine 13. In addition, the power unit 11 may be operable to provide hydraulic power or electrical power to consumer units when stationary and disconnected from a modular unit 12.

The work machine 13 formed from the machine power unit 11 and one of the modular units 12 may be configured predominantly for off-highway operation and/or the power unit and modular units 11, 12 comprise off-highway wheels or tracks mounted to an off-highway suspension system. The work machine 13 may be an earth moving machine. However, the work machine 13 may be approved for on highway use in certain configurations, such as when forming a telehandler or loader.

The modular units 12 may each be different and may be configured for performing different work functions. For example, each modular unit 12 may comprise at least one implement 14, which may be different in each modular unit 12 and may be for performing any suitable work function. As a result, when each modular unit 12 is coupled to the machine power unit 11 a different work machine 13 with different work functions or applications is formed. Thus, the same machine power unit 11 can be used to form different work machines 13 and/or perform different work functions by coupling different modular units 12 thereto.

By way of example, the work machine 13 and/or implement 14 may be or be for a wheel loader, fork truck mast, auger, vibrating pile rig, broom, excavator, backhoe, mulcher, planer, fixed teleboom, rotating loader, rotating teleboom, pipe handler, log handler, crane, snow pusher or plough, salt spreader, grader, shredder, feed mixer, water pump, generator,

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dumper, vacuum excavator, snow blower, tree trimmer, personal access platform, concrete mixer, roller, compactor, stacker, recovery, auto salvage cut out tool, auto salvage forks, military applications, water cannon, door knocker, fire and rescue applications, sweeper, concrete pump and/or concrete mixer. For example, Figure 1 illustrates a modular unit 12 comprises an excavator bucket such that the work machine 13 is a compact wheel loader.

In some configurations of the modular unit 12, such as comprising a dumper, bowser or skidder type implement 14, the work machine 13 may generally be configured to operate in a forward direction for a majority of its operation with the power unit 11 behind the modular unit 12. Therefore, the modular unit 12 may be configured to be pushed by the power unit 11 for a majority of its operating time. Whilst the work machine 13 in such configurations may be able to reverse, travelling with the power unit 11 in front of the modular unit 12, the components thereof are designed and configured to operate at a maximum forward speed in the forward direction with the power unit 11 pushing or behind the modular unit 12. In such configurations, the maximum rated forward speed, with the modular unit 12 in front of the power unit 11, may be greater than the maximum rated reversing speed, with the power unit 11 in front of the modular unit 12.

In alternative configurations of the modular unit 12, such as in a loader configuration, the work machine 13 may generally be configured to operate in a forward direction for a majority of its operation with the power unit 11 in front of the modular unit 12. Therefore, the modular unit 12 may be configured to be pulled by the power unit 11 for a majority of its operating time. Whilst the work machine 13 in such configurations may be able to reverse, travelling with the power unit 11 behind the modular unit 12, the components thereof are designed and configured to operate at a maximum forward speed in the forward direction with the power unit 11 pulling or in front of the modular unit 12. In such configurations, the maximum rated forward speed, with the modular unit 12 behind the power unit 11, may be greater than the maximum rated reversing speed, with the power unit 11 behind the modular unit 12.

Hence the different modular units 12 may be configured to be pulled or pushed by the power unit 11 for the majority of their operation, depending upon the application. The power unit 11 may be reversible in direction so as to pull or push the modular unit 12 for the majority of the operation of the configuration as applicable.

The machine power unit 11, embodiments of which are illustrated in Figures 1 to 3, comprises a power unit coupling 20 and at least one power unit ground engager 21 driven by a machine 6 -drive system 18. The machine power unit 11 may alternatively be referred to as a drive unit and generally refers to the unit that provides the main driving power to the work machine 13.

The at least one power unit ground engager 21 may be wheels as illustrated or may comprise tracks, a roller or the like. The at least one power unit ground engager 21 may rotate about a power unit rotational axis and in particular may comprise a pair of wheels driven about the power unit rotational axis.

The machine power unit 11 may comprise a pair of ground engagers 21. In such embodiments, the machine unit 11 is unstable unless coupled with the modular unit 12. In some embodiments, the machine power unit 11 may comprise a tractor of an articulated truck and the modular unit 12 may comprise a trailer for hauling material on a worksite.

The machine power unit 11 comprises a power unit frame 22 (which may be the chassis and/or main body of the machine power unit 11) and may comprise a cab 23 for an operator.

The cab 23 may be mounted to the power unit frame 22 and may comprise the operator controls 24 for controlling the work machine 13. The cab 23 may comprise dual controls with a rotatable seat for forward and rearward control.

The machine power unit 11 may comprise a power unit braking system 28 for braking the machine power unit 11, such as by applying a braking force to the at least one power unit ground engager 21.

The machine power unit 11 may comprise a power unit fluid system 60, which may hydraulic or pneumatic and may comprise at least one pump for pumping pressurised fluid around a circuit.

The machine power unit 11 may comprise an electrical machine power system 38, which may comprise at least one power unit battery and at least one auxiliary unit, such as lights or operator controls 24, powered by the at least one power unit battery.

The machine power unit 11 may comprise a power unit control system 80 for controlling the functions thereof. The power unit control system 80 may be connected to and control the machine drive system 18, power unit braking system 28, power unit fluid system 60 and/or electrical machine power system 38. 7 -

The machine power unit 11 may comprising a cooling system for cooling components of the machine power unit 11, such as the machine drive system 18 and/or electrical machine power system 38.

The at least one power unit ground engager 21 (for example via a power unit suspension system 44), cab 23, machine drive system 18, power unit braking system 28, electrical machine power system 38, power unit control system 80, power unit fluid system 60, and/or power unit coupling 20 may be mounted to the power unit frame 22.

The machine power unit 11 may not be independently moveable about the ground 15 by the machine drive system 18 when the machine power unit 11 is not coupled to a modular unit 12. The machine power unit 11 may comprise no further power unit ground engagers in contact with the ground 15 when the work machine 13 is driven across the ground 15, for example comprising only a pair of wheels rotatable around the power unit rotational axis. The centre of mass of the machine power unit 11 may also be offset from the at least one power unit ground engager 21 and/or power unit rotational axis such that the machine power unit 11 is unbalanced when not coupled to a modular unit 12. The coupling between the power unit and modular units 11, 12 may counterbalance rotation of the machine power unit 11 about the power unit rotational axis due to the offset centre of mass.

In some embodiments, the machine power unit 11 may be an autonomous unit that operates/controls the work machine without an operator. In such embodiments, the machine power unit 11 may not include a cab for an operator.

Embodiments of the modular unit 12 are illustrated in Figures 1 and 4. Each modular unit 12 comprises at least one modular unit ground engager 30 and a modular unit coupling 31, which may be mounted to a modular unit frame 32 (which may be the chassis and/or main body of the modular unit 12) of the modular unit 12. The power unit and modular unit couplings 20, 31 are couplable together and form a power unit-modular unit coupling 25.

The at least one modular unit ground engager 30 may comprise at least one pair of wheels as illustrated or may comprise tracks, a roller or the like depending upon the work function of the modular unit 12. The at least one modular unit ground engager 30 may be mounted to the modular unit frame 32 by a modular suspension system. 8 -

The modular unit 12 may comprise a modular unit braking system 29 for braking the modular unit 11, such as by applying a braking force to the at least one modular unit ground engager 30.

The modular unit 12 may comprise an electrical modular unit power system 19 for suppling power to the at least one modular unit ground engager 30 and/or auxiliary services, such as lights and/or the at least one implement 14.

The modular unit 12 may comprise a modular unit fluid system 61, which may hydraulic or pneumatic and may comprise at least one pump for pumping pressurised fluid around a circuit, for controlling the at least one implement 14.

The modular unit 12 may comprise a modular unit control system 90 for controlling the functions thereof. The modular unit control system 90 may be connected to and control the modular unit power system 19, at least one implement 14 and/or modular unit braking system 29.

The at least one modular unit ground engager 30 (for example via a modular unit suspension system), modular unit braking system 29, modular unit power system 19, modular unit fluid system 61 and/or modular unit control system 90 may be mounted to the modular unit frame 32.

The modular unit 12 may not be independently moveable about the ground 15, such as by the modular unit power system 19 when the modular unit 12 is not coupled to the machine power unit 11. The modular unit 12 may comprise no further power unit ground engagers in contact with the ground 15 when the work machine 13 is driven across the ground 15, for example comprising only a pair of wheels 30 rotatable around a modular unit rotational axis. The centre of mass of the modular unit 12 may also be offset from the at least one modular unit ground engager 30 and/or modular unit rotational axis such that the modular unit 12 is unbalanced when not coupled to the machine power unit 11. The power unit-modular unit coupling 25 between the power unit and modular units 11, 12 may counterbalance rotation of the modular unit 12 about the modular unit rotational axis due to the offset centre of mass.

The machine power unit 11 comprises an articulation joint 40, enabling pivoting about an articulation axis 41, mounted to the power unit frame 22 and to which the power unit coupling is mounted. The power unit coupling 20 is mounted on the opposing side of the articulation joint 40 to the power unit frame 22. The power unit coupling 20 is pivotable about the articulation joint 40 relative to the power unit frame 22. The pivoting may be in a horizontal plane substantially parallel to the ground 15. The articulation joint 40 may be of any suitable configuration, such as including a pin as illustrated.

The machine power unit 11 further comprises a steering system 42 for controlling the pivoting of the power unit coupling 20 relative to the power unit frame 22 for, when the machine power unit 11 is coupled to a modular unit 12, steering the work machine 13.

The steering system 42 may be of any suitable configuration. In particular, as illustrated the steering system 42 may comprise at least one actuator 43, for example at least one hydraulic cylinder, extending across the articulation joint 40 and for controlling the pivoting about the articulation joint 40. The steering system 42 may be mounted to the power unit frame 22 and/or power unit coupling 20.

The steering system 42 may be controlled by the power unit fluid system 60, for example by the pump thereof controlling the extension and retraction of the at least one actuator 43. The steering system 42 may be controlled by the power unit control system 80, such as by the power unit control system 80 controlling the power unit fluid system 60.

The machine power unit 11 may only allow movement of the power unit frame 22 relative to the power unit coupling and trailer unit 12 in a single horizontal plane via the articulation joint 40. Alternatively, rolling movement through the horizontal plane may be enabled by an oscillation hitch 45, which may be separate and/or integrated with the articulation joint 40.

The power unit and/or modular units 11, 12 may comprise an oscillation hitch 45 for enabling oscillation of the power unit and modular units 11, 12 relative to one another when the power unit and modular unit couplings 20, 31 are coupled. The oscillation hitch 45 may enable oscillation about an oscillation axis such that the power unit and modular units 11, 12 can roll relative to one another. The oscillation axis may be orthogonal to the articulation axis 41 and the articulation and oscillation axes 41, 46 may extend in the same plane, which may be orthogonal to a plane parallel to the ground 15.

As illustrated in Figure 2, the machine power unit 11 may comprise the oscillation hitch 45 and the oscillation hitch 45 may be mounted between the power unit coupling 20 and power unit frame 22 such that the power unit coupling 20 can oscillate relative to the power unit -10 -frame 22. As in Figure 2, the oscillation hitch 45 and articulation joint 40 may be substantially formed together, for example as an oscillating centre hitch. They may comprise lower and upper articulation bearings 140, 240 allowing pivoting about lower and upper articulation axes 141, 241 and an oscillation bearing 145. Each bearing 140, 240, 145 may enable oscillation and/or articulation.

Alternatively, the oscillation hitch 45 may be mounted between the articulation joint 40 and power unit coupling 20 such that the power unit coupling 20 can oscillate relative to the non-oscillating articulation joint 40 (and thus power unit frame 22).

Further alternatively, as illustrated in Figure 3, the work machine 13 may not comprise an oscillation hitch 45 and may only comprise the articulation joint 40 between the power unit frame 22 and power unit coupling 20. Oscillation may instead be achieved at the at least one power unit ground engager 21 through the power unit suspension system 44.

Figures 2 to 5 illustrate in more detail the power unit and modular unit couplings 20, 31 together forming the power unit-modular unit coupling 25 in accordance with the present disclosure. The power unit-modular unit coupling 25 may be the only part carrying the mechanical load between the power unit and modular units 11, 12. The power unit-modular unit coupling 25 may be a quick disconnect coupler and may have any suitable arrangement allowing for the quick changing of a modular unit 12. The power unit-modular unit coupling 25 may be configured to be coupled and uncoupled to change the modular unit 12 attached to the machine power unit 11 by an operator on a worksite without external assistance. The power unit-modular unit coupling 25 may not require any tools to couple and uncouple and is not permanent. Hence the machine power unit 11 and power unit coupling 20 are configured to be coupled and uncoupled from a plurality of modular units 12 throughout their rated lifetimes.

The power unit coupling 20 may comprise a power unit load bearer 50 for bearing the load of the modular unit 12 and a power unit lock 150 for fastening or locking the power unit coupling 20 to the modular unit coupling 31. The power unit coupling 20 may comprise a power unit coupling mount 51, such as in the form of a rectangular cuboidal body as illustrated, to which the power unit load bearer 50 and/or a power unit coupling lock 151 may be mounted. The articulation joint 40, oscillation hitch 45 and/or steering system 42 may be mounted to the power unit coupling mount 51 such that the power unit coupling mount 51 can be mounted to the power unit frame 22 via the articulation joint 40 and/or oscillation hitch 45.

The power unit load bearer 50 may be engageable with a modular unit load bearer 52. The power unit load bearer 50 may support the mechanical load of the modular unit 12 and the modular unit load bearer 52 may support the mechanical load of the machine power unit 11. As illustrated, the power unit load bearer 50 may comprise at least one cantilever 53, 54 for mounting the modular unit 12 thereon and/or therein. The modular unit load bearer 52 may comprise at least one modular unit recess 55, 56 in the modular unit 12 for receiving the at least one cantilever 53, 54. The at least one cantilever 53, 54 may comprise a fork with flat upper surfaces of each cantilever 53, 54 with sufficient surface area to spread the load of the modular unit 12.

The modular unit coupling 31 may comprise a modular unit coupling mount 57 and the modular unit coupling mount 57 may comprise the modular unit load bearer 52. The at least one modular unit recess 55, 56 may extend into the modular unit coupling mount 57. When coupled, the modular unit coupling mount 57 may face and/or contact the power unit coupling mount 51. The modular unit coupling mount 57 may be in the form of a rectangular cuboidal body as illustrated.

The power unit coupling lock 151 may be lockable with a modular unit coupling lock 152 of the modular unit 12. The power unit coupling lock 151 may comprise a hydraulic pin system comprising at least one pin 153, 154, 155 each engageable in at least one pin bore 156, 157 of the modular unit coupling lock 152. The at least one pin 153, 154, 155 may be extendable and retractable from the corresponding at least one pin bore 156, 157 and may be controlled by the electrical machine power system 38, power unit control system 80 and/or power unit fluid system 60.

As illustrated, an upper pin 153 may be mounted in an upper portion of the power unit coupling mount 51 for extension into an upper pin bore 156 in an upper portion of the modular unit coupling mount 57. At least one lower pin 154, 155, such as two lower pins 154, 155 as illustrated, may be mounted to the power unit load bearer 50, such as to the at least one cantilever 53, 54, for extension into at least one lower pin bore 157 in a lower portion of the modular unit coupling mount 57. The at least one lower pin bore 157 may be within the at least one modular unit recess 55, 56 such that when the at least one cantilever 53, 54 is -12 -mounted in the at least one modular unit recess 55, 56 the at least one lower pin 154, 155 is aligned with, for extension into, the at least one lower pin bore 157.

In an alternative embodiment in accordance with the present disclosure, the power unit coupling lock 151 may comprise the at least one pin bore 156, 157 and the modular unit coupling lock 152 may comprise the at least one pin 153, 154, 155. The at least one pin 153, 154, 155 may be controllable by the modular unit power system 19, modular unit fluid system 61 and/or modular unit control system 90.

In such a multi-point locking arrangement, the power unit coupling lock 151 and modular unit coupling lock 152 provide locking across the height of the power unit-modular unit coupling 25 and thus provide a secure lock between the power and modular units 11, 12.

The machine power unit 11 may comprise a power unit services connection 65 and each modular unit 12 may comprise a modular unit services connection 66 and the power unit services connection 65 may be releasably coupleable to each modular unit services connection 66 for the transfer of electrical power (e.g. high voltage power), fluid and/or control signals (e.g. low voltage control signals) between the power unit and modular units 11, 12.

The power unit and modular unit services connection 65, 66 may together form a power unit-modular unit services connection 67. The power unit-modular unit services connection 67 may enable the transfer of electrical power between the electrical machine and modular unit power systems 38, 19, the transfer of fluid (pneumatic and/or hydraulic) between the power unit and modular unit fluid systems 60, 61 and/or the transfer of control signals between the power unit and modular unit control systems 80, 90. Thus the machine power unit 11 may be able to control the modular unit 12 and vice-versa.

Thus, when the power unit-modular unit services connection 67 between the machine power unit 11 and one of the modular units 12 is coupled, machine and modular unit power system 38, 19 may form an integrated work machine electrical power system, the power unit and modular unit fluid systems 60, 61 may form an integrated work machine fluid system 63 and/or the power unit and modular unit control systems 80, 90 may form an integrated work machine control system 78.

In the work machine electrical power system, electrical power may be transferred between the machine and modular unit power system 38, 19 such that, for example, electrical power -13 -from batteries in the machine and modular unit power system 38, 19 may be shared with electrical consumers in the electrical machine and modular unit power systems 38, 19 respectively. In the work machine fluid system 63, pressurised fluid may be shared between the power unit and modular unit fluid systems 60, 61 such that fluid actuators in either of the power unit and modular units 11, 12 may be controlled by pumps in either of the power unit and modular units 11, 12. In particular, the work machine fluid system 63 may enable the control of fluid actuators in the modular unit 12 by at least one pump in the machine power unit 11.

The power unit services connection 65 may be mounted to or form part of the power unit coupling 20 and may be mounted to, such as on the top of, the power unit coupling mount 51. The modular unit services connection 66 may be mounted to or form part of the modular unit coupling 31 and may be mounted to, such as on the top of, the modular unit coupling mount 57.

The power and modular unit services connections 65, 66 may be fixed as illustrated and may be connected to one another when the power and modular unit couplings 20, 31 are coupled together. Alternatively, at least one of the power and modular unit services connections 65, 66 may be at least partly extendable and retractable by a connection actuator to form the connection after the power and modular unit couplings 20, 31 are coupled together. The connection actuator may be controlled by the electrical machine power system 38, power unit control system 80 and/or power unit fluid system 60 if on the machine power unit 11 or the modular unit power system 19, modular unit fluid system 61 and/or modular unit control system 90 if on the modular unit 12.

The machine drive system 18 may comprise a power source, for example an internal combustion engine, a turbine, a battery or a fuel cell, for providing power to drive the at least one power unit ground engager 21, for example via a mechanical or electrical power train and/or motor. If the machine drive system 18 is electrical, comprising at least one motor driven by power from a battery and/or fuel cell, then the electrical machine power system 38 may comprise and/or be the machine drive system 18. If the machine drive system 18 comprises an internal combustion engine, or turbine then it may comprise a generator for supplying electrical power to the electrical machine power system 38.

The modular unit power system 19 may be configured to drive the at least one modular unit ground engager 30. The modular unit power system 19 may comprise a power transfer -14 -system for transferring power electrically (via an electrical system and at least one motor) to the at least one modular unit ground engager 30. The modular unit 12 may comprise a modular unit electrical power source, such as a battery or power cell, and at least one auxiliary unit, such as lights, operator controls and the like. The modular unit battery or power cell may be mounted in the modular unit frame 32 and/or modular unit coupling mount 57.

The electrical machine power system 38 and modular unit power system 19 may be electrically connected to on another across the power unit-modular unit services connection 67. The machine drive system 18 may be connectable to the modular unit power system 19 through the electrical machine power system 38 and power unit-modular unit services connection 67 such that the machine drive system 18 can drive the at least one modular unit ground engager 30 via the modular unit power system 19. Either independently or by receiving power from the power unit electrical system, the modular unit power system 19 may be configured to drive the at least one modular unit ground engager 30 simultaneously to the machine drive system 18 driving the at least one power unit ground engager 21.

The power and modular unit fluid systems 60, 61 are in communication with each other via the power and modular unit services connections 65, 66 when the machine power unit 11 and modular unit 12 are coupled together. The power unit and/or modular unit fluid system 60, 61 may each comprise at least one pump for selectively directing fluid between a reservoir and at least one actuator 43, 62. The power unit and modular unit fluid system 60, 61 may be controlled by the power unit and modular unit control systems 80, 90 respectively. The power unit fluid system 60 may be configured to, when the power unit services connection 65 is connected to the modular unit services connection 66, operate the at least one implement 14 of the modular unit 12.

The work machine control system 78 is illustrated further in Figure 6. The power unit and/or modular unit control systems 80, 90 may each comprise a power unit and/or modular unit controller 81, 91, for controlling the various parts of the power unit and modular units 11, 12 respectively. The power unit and/or modular unit controller 81, 91 may be of any suitable known type and may comprise an engine control unit (ECU) or the like. The power unit and/or modular unit controller 81, 91 may comprise multiple control units, such as an ECU, auxiliary ECU(s) or control unit(s), artificial intelligence control unit(s) and the like. Generally, the power unit and/or modular unit controller 81, 91 may comprise a power unit and/or modular unit memory 82, 92 (e.g. multiple memories on different control units), which may store instructions or algorithms in the form of data, and a power unit and/or modular unit processing -15 -unit 83, 93 (e.g. multiple processing units on different control units), which may be configured to perform operations based upon the instructions. The power unit and/or modular unit memory 82, 92 may comprise one or more suitable computer-accessible or non-transitory storage mediums for storing computer program instructions, such as RAM, SDRAM, DDR SDRAM, RDRAM, SRAM, ROM, magnetic media, optical media and the like. The power unit and/or modular unit processing unit 83, 93 may comprise one or more suitable processors capable of executing memory-stored instructions, such as a microprocessor, uniprocessor, a multiprocessor and the like. The power unit and/or modular unit controller 81, 91 may further comprise one or more graphics processing units (e.g. multiple graphics processing units on different control units) for rendering objects for viewing on a power unit and/or modular unit display 84, 94, which may only be present on the machine power unit 11 such as in the cab 23, and any other computing system equipment required for performing the functions of the machine power unit 11 and modular unit 12.

The power unit controller 81 may be communicatively connected (via a wired or wireless connection), to receive inputs from and/or exchange data with operator controls 24, which may be in the cab 23. The modular unit controller 91 may be communicatively connected (via a wired or wireless connection), to receive inputs from and/or exchange data with, at least one modular unit operator input 95, which may be on a control panel of the modular unit 12.

The power unit and/or modular unit control systems 80, 90 may each comprise a power unit and/or modular unit external communication system 86, 96 for transferring data between the control system(s) 80, 90 and a remote computer system 79. The power unit and/or modular unit external communication system(s) 86, 96 may comprise any type of suitable apparatus for communication therebetween, particularly a wireless network. Exemplary wireless networks include a satellite communication network, broadband communication network, cellular, Bluetooth, microwave, point-to-point wireless, point-to-multipoint wireless, multipoint-to-multipoint wireless, Wireless Local Service (WiFi Dongle), Dedicated Short-Range Communications (DSRC) or any other wireless communication network.

The remote computer system 79 may be under the control of the owner or manufacturer of the work machine system 10. The remote computer system 79 may enable remote monitoring, grade control, remote diagnostics and remote flash of the work machine system 10 by communication with the power unit and/or modular unit control systems 80, 90.

-16 -The power unit and/or modular unit control systems 80, 90 may each comprise a power unit and/or modular unit control communication module 87, 97 for transferring control signals between the power unit and/or modular unit control system(s) 80, 90. The power unit and/or modular unit control unit communication modules 87, 97 may be the same as the power unit and/or modular unit external communication system 86, 96 and may be configured for wirelessly transferring control signals between the power unit and/or modular unit control unit systems 80, 90. Alternatively, the power unit and/or modular unit control communication modules 87, 97 may comprise connectable interfaces for a wired connection between the power unit and/or modular unit control systems 80, 90 and may be configured to be connected during the connection of the power unit-modular unit services connection 67.

The power unit control system 80 and/or power unit controller 81 may be connected to and operable to control (a) the machine drive system 18 and/or power unit braking system 28 to control the speed of the work machine 13, (b) the electrical machine power system 38 and/or power unit fluid system 60, (c) the steering system 42 to control the steering and direction of travel of the work machine 13, (d) the power unit-modular unit coupling 25, such as by actuation of the power unit coupling lock 151, to control coupling of the power unit and modular units 11, 12 and/or (e) power unit-modular unit services connection 67, such as by actuation of the connection actuator, to control the coupling of the power unit and modular unit power system 38, 19, power unit and modular unit control systems 80, 90 and/or power unit and modular unit fluid systems 60, 61.

The modular unit control system 90 and/or controller 91 may be connected to and operable to control (f) the modular unit braking system 29 and/or the modular unit power system 19 to control the speed of the work machine 13, (g) the modular unit fluid system 61, and/or (h) the implement 14 for performing work functions.

The power unit and/or modular unit control systems 80, 90 may be configured to control (a) to (h) based upon inputs from the operator to the power unit and/or modular unit operator input 24, 95 and/or via a control strategy, which may be implemented by the power unit and/or modular unit processing units 83, 93 implementing instructions stored on the power unit and/or modular unit memories 82, 92 and/or received from the remote computer system 79.

By virtue of the connection between the power unit and modular unit control systems 80, 90, such as via the power unit and/or modular unit control communication modules 87, 97, control signals may also be exchanged between the power unit and modular units 11, 12. Therefore, -17 -when the power unit and modular units 11, 12 are coupled together, the power unit control system 80 may be configured to control (f) to (h) and/or the modular unit control system 90 may be configured to control (a) to (c). Therefore, the machine power unit 11 may be operable to control (f) to (h) on a plurality of modular units 12 when the machine power unit 11 is coupled to each of the modular units 12.

The power unit control system 80 may control the power unit 11 based upon the type of modular unit 12 attached thereto. Thus the power unit control system 80 sense the type of modular unit 12 attached to the power unit 11 and may automatically change its control characteristics, such as by operating different control maps, to match those of the requirements of the modular unit 12 attached to the power unit 1 1.

For example, the power unit memory 82 may store engine maps thereon suitable for controlling the machine drive system 18 to meet the different requirements for the modular unit 12 attached to the power unit 11. If the machine drive system 18 comprises an internal combustion engine, the engine maps are within the relevant emissions certification and power rating of the engine but with differing torque characteristics.

The power unit memory 82 may also comprise fluid system maps for controlling the power unit fluid system 18 based upon the at least one implement of the attached modular unit 12.

The engine and/or fluid system maps may alternatively be stored upon the modular unit memory 83 and transferred to the power unit control system 80 when the power and modular units 1 1, 12 are connected together.

The power unit control system 80 may in particular be configured to control the machine drive system 18, power unit and modular unit power system 38, 19 and the power unit and modular unit braking systems 28, 29 (the latter optionally via the modular unit control system 90) simultaneously so as to control the drive, braking and/or traction across the work machine 13.

The power unit control system 80 may be configured to determine whether to drive the at least one modular unit ground engager 30 when the machine drive system 18 drives the at least one power unit ground engager 21. The power unit control system 80 may monitor the traction of the at least one power unit ground engager 21, such as by monitoring the wheel speed of the at least one power unit ground engager 21 compared to the speed of travel over -18 -the ground 15. If the traction is reduced, such as by the wheel speed being greater than the travel speed, the power unit control system 80 may drive the at least one modular unit ground engager 30 via the power unit power system 38 and modular unit power system 19.

As a result, in the case of the power unit and modular unit ground engagers 21,30 comprising pairs of wheels, the work machine 13 may operate in two-wheel drive for most of the time and only swap to four-wheel drive (i.e. including driving the wheels 30 of the modular unit 12) when it is needed for traction. For example, four wheel drive may only be needed for under 10% of the normal use of the work machine 13. This significantly reduces the power consumption of the work machine 13 in normal use, resulting in efficiency gains, reducing emissions and reducing the time needed between charges in the case of the machine drive system 18 comprising an electrical power source.

An operator control 24 may also be for instructing the power unit control system 80 to operate the work machine 13 to drive the power unit and modular ground engagers 21, 30 simultaneously (i.e. manually implementing a four-wheel drive mode). Therefore, an operator can engaged the full drive mode when they anticipate it will be needed.

The power unit and modular unit control systems 80, 90 may also be operable to perform an authentication operation to ensure that there is permission for the modular unit 12 to connect to and be operated by the power unit 11.

The authentication operation may be utilised as an anti-theft feature such that stolen modular units 12 can be identified in a database on the remote computer system 79 and modular units 12 connected to a machine power unit 11 can be checked against the database and, if found on the database, operation of the modular unit 12 may be prevented.

The modular unit control system 90 may store an authentication codes, such as on the modular unit memory 82, 92. Upon coupling of the power unit 11 to the modular unit 12 the power unit control system 80 may exchange authentication signals with the modular unit control system 90 to determine whether to authenticate the modular unit control system 90. In particular, the authentication code from the modular unit 12 may be verified by the power unit control system 80 and/or via the power unit control system 80 on the remote computer system 79 via the power unit external communication system 86. The power unit control system 80 is configured to, if the power unit control system 80 authenticates (such as via authentication of the remote computer system 79) the modular unit control system 90 and -19 -based upon input received from an operator and/or instructions from the power unit controller 81, send control signals to the modular unit control system 90 to control the modular unit control system 90.

The authentication code(s) on each modular unit control system 90 may be updatable remotely from the remote computer system. Therefore, an owner, such as the operator of a rental fleet, may be able to change the authentication code(s) so as to control authentication of each modular unit 12.

Industrial Applicability

The method of operating the work machine system 10 therefore comprises coupling and uncoupling different modular units 12 from the machine power unit 11 to form different types of work machines 13. In particular, a first work machine 13 comprising the machine power unit 11 coupled to a first modular unit 12 may be operated to perform a first work function.

The machine power unit 11 may be uncoupled from the first modular unit 12 by uncoupling the power unit coupling 20 from the modular unit coupling 31 of the first modular unit 12. The machine power unit 11 may be aligned with a second modular unit 12. The machine power unit 11 may be coupled to the second modular unit 12 by coupling the power unit coupling 20 with the modular unit coupling 31 of the second modular unit 12, thereby forming a second work machine 13. The second work machine 13 may then be operated to perform a second work function different to the first work function.

The machine power unit 11 may be coupled to further modular units 12 to form further, different work machines 13 with different work functions.

A method of coupling the coupling the machine power unit 11 to the second modular unit 12 comprises bringing the power unit and modular unit couplings 20, 31 together such that the power unit and modular unit bearers 50, 52 are mounted to one another. Subsequently the power unit and modular unit couplings 20, 31 may be locked together by locking the power unit coupling lock 151 with a modular unit coupling lock 152.During operation, the power unit and modular unit bearers 50, 52 may transfer the load between the power unit and modular units 11, 12 whilst the power unit coupling lock 151 locked with the modular unit coupling lock 152 may keep the power unit and modular unit couplings 20,31 coupled together.

Claims

-20 -CLAIMS: 1. A machine power unit for attachment to interchangeable modular units for forming a work machine, the machine power unit comprising: a machine drive system; at least one power unit ground engager operable to be driven by the machine drive system for driving the work machine across the ground; a power unit coupling for releasably coupling to a modular unit coupling of each modular unit; a power unit frame to which the power unit coupling, at least one power unit ground engager and machine drive system are mounted; an articulation joint mounted to the power unit frame, to which the power unit coupling is mounted and about which the power unit coupling is configured to pivot relative to the power unit frame; and a steering system for controlling the pivoting of the power unit coupling relative to the power unit frame for, when the machine power unit is coupled to a modular unit, steering the work machine.
2. A machine power unit as claimed in claim 1 further comprising an oscillation hitch for enabling oscillation between the power unit frame and power unit coupling such that, when the machine power unit is coupled to a modular unit, the power unit frame can oscillate relative to the modular unit about the oscillation hitch.
3. A machine power unit as claimed in claim 1 or claim 2 further comprising: a power unit fluid system and/or power unit control system; and a power unit services connection for connection to a modular unit services connection for transferring fluid from the power unit fluid system and/or control signals from the power unit control system to the modular unit coupled to the machine power unit.
4. A machine power unit as claimed in claim 3 wherein the power unit fluid system is configured to, when the power unit services connection is connected to the modular unit services connection, operate at least one implement of the modular unit.
5. A machine power unit as claimed in any one of the preceding claims wherein the power unit coupling comprises a power unit load bearer for bearing the load of the modular unit and a power unit lock for locking the power unit coupling to the modular unit coupling.
-21 - 6. A machine power unit as claimed in claim 5 wherein the power unit load bearer comprises at least one cantilever for mounting the modular unit thereon and/or therein.
7. A machine power unit as claimed in any one of the preceding claims wherein the machine power unit comprises two power unit ground engagers.
8. A plurality of modular units, each modular unit being for mounting to the machine power unit of any one of the preceding claims and comprising: at least one modular unit ground engager for supporting the modular unit on the ground; a modular unit coupling for releasably coupling to the power unit coupling; at least one implement; and a modular unit frame to which the at least one modular unit ground engager, modular unit coupling and at least one implement are mounted.
9. A plurality of modular units as claimed in claim 8 wherein each modular unit comprises two ground engagers.
10. A plurality of modular units as claimed in claims 8 or 9 wherein each modular unit further comprises a modular unit power system for driving the at least one modular unit ground engager and being connectable to the machine drive system such that the at least one modular unit ground engager is drivable by the machine drive system.
11. A work machine system comprising: a plurality of modular units, each modular unit comprising at least one modular unit ground engager and a modular unit coupling; and a machine power unit comprising: a power unit coupling for releasably coupling to a modular unit coupling of each modular unit to form a work machine from the coupled power unit and modular units; at least one power unit ground engager operable to be driven by a machine drive system for driving the work machine across the ground; an articulation joint to which the power unit coupling is mounted; and a steering system for controlling pivoting of the power unit coupling about the articulation joint for, when the machine power unit is coupled to a modular -22 -unit, steering the machine power unit relative to the modular unit about the articulation joint.
12. A work machine system as claimed in claim 11 wherein each modular unit further comprises a modular unit power system for driving the at least one modular unit ground engager simultaneously to the machine power unit driving at least one power unit ground engager, optionally wherein the modular unit power system receives power from the machine drive system to drive the at least one modular unit ground engager.
13. A work machine system as claimed in claim 11 or claim 12 wherein the power unit comprises a power unit services connection for releasable connection to a modular unit services connection of each modular unit, the power and modular unit services connections being configured for transferring fluid and/or control signals between the modular unit and the machine power unit.
14. A work machine system as claimed in any one of claims 11 to 13 wherein the machine power unit comprises a power unit control system and the modular unit comprises a modular unit control system, wherein: the power and modular unit control systems are in communication with each other via the power and modular unit services connections when the machine power unit and modular unit are coupled together; the power unit control system is configured to exchange authentication signals with the modular unit control system to determine whether to authenticate the modular unit control system; and the power unit control system is configured to, if the power unit control system authenticates the modular unit control system and based upon input received from an operator and/or instructions from a controller, send control signals to the modular unit control system to control the modular unit control system.
15. A work machine system as claimed in any one of claims 11 to 14 wherein the machine power unit further comprises a power unit fluid system and the modular unit comprises a modular unit fluid system for controlling at least one implement, wherein the power and modular unit fluid systems are in communication with each other via the power and modular unit services connections when the machine power unit and modular unit are coupled together and the power unit fluid system is configured to control the at least one implement via the modular unit fluid system.
-23 - 16. A method of operating a work machine system, the work machine system comprising: a machine power unit releasably coupleable to a modular unit of a plurality of interchangeable modular units to form a work machine and comprising a steering system for steering the work machine by pivoting the work machine about an articulation joint, wherein the method comprises: operating a first work machine comprising the machine power unit coupled to a first modular unit to perform a first work function, the machine power unit comprising at least one power unit ground engager driven by a machine drive system; uncoupling the machine power unit from the first modular unit by uncoupling a power unit coupling of the machine power unit from a modular unit coupling of the first modular unit; aligning the machine power unit with a second modular unit; coupling the machine power unit to the second modular unit by coupling the power unit coupling with a modular unit coupling of the second modular unit, thereby forming a second work machine; and operating the second work machine to perform a second work function different to the first work function.
17. A method as claimed in claim 16 wherein coupling the machine power unit to the second modular unit comprises bringing the power unit and modular unit couplings together such that power unit and modular unit bearers thereof are mounted to one another and subsequently locking the power unit and modular unit couplings together by locking a power unit coupling lock with a modular unit coupling lock.
18. A method as claimed in claim 16 or claim 17 further comprising: uncoupling a power unit services connection from a modular unit services connection of the first modular unit; and coupling the power unit services connection with the modular unit services connection of the second modular unit such that electrical power, fluid and/or control signals can be exchanged between the power unit and second modular units.