Electric shovel including a freely rotatable turret, suitable for autonomously installing / removing a set of batteries, methods for autonomously installing and removing a set of batteries of an electric shovel
The electric excavator with a rotating turret and articulated arm enables autonomous battery swap and continuous operation by using an auxiliary power circuit, addressing battery autonomy and management challenges in electric construction machinery.
Patent Information
- Application Number
- PCT/EP2024/088442
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2023-12-29
- Filing Date
- 2024-12-24
- Publication Date
- 2025-07-03
AI Technical Summary
Existing electric construction machinery faces limitations in battery autonomy due to insufficient battery pack size and the complexity of battery management, particularly when access to electricity networks is unavailable, complicating the use and management of a fleet of electric motor construction machinery.
An electric excavator with a freely rotating turret and an articulated arm allows for autonomous installation and removal of a main battery pack, using an auxiliary power circuit to maintain operation during the swap, enabling continuous use without needing external charging stations.
Facilitates the replacement of main battery packs without moving the excavator to a charging station, allowing continuous operation by switching between battery sets, thus overcoming autonomy constraints and simplifying battery management.
Smart Images

Figure EP2024088442_03072025_PF_FP_ABST
Abstract
Description
[0001] Description
[0002] Title: Electric excavator comprising a free-rotating turret and adapted for autonomously installing / removing a set of batteries, methods for autonomously installing and removing a set of batteries from an electric excavator
[0003] Technical field
[0004] The present invention relates to the field of construction machinery.
[0005] The invention relates more specifically to a hydraulic excavator or mechanical shovel comprising at least one electric motor which drives the hydraulic unit and / or the transmission of the excavator, the motor being electrically powered by a main battery pack.
[0006] The invention also relates to a method for autonomously removing a set of batteries from an electric excavator and a method for autonomously installing a set of batteries in an electric excavator.
[0007] In the context of the invention, the expression "construction machinery" is used to designate in particular machinery enabling public construction work, handling, railway work and / or river work to be carried out.
[0008] Prior art
[0009] Consideration is currently being given to using electric-powered construction machinery instead of combustion-powered machinery, primarily to meet greenhouse gas emission reduction targets.
[0010] However, to date, electric construction machinery using electrochemical batteries for their power supply is subject to specific usage constraints. Thus, the autonomy of an electric construction machine is limited by the volume available for the batteries and by their weight. The size of a battery pack is often insufficient to fully meet the needs of users, particularly for continuous use over a full working day. Furthermore, managing battery recharging can also be a significant constraint, especially when direct access to the electricity network is impossible, as is often the case on construction sites.In the absence of access to the electricity network, it becomes necessary either to move the construction equipment itself to an access point to the electricity network using suitable means of transport, or to set up a mobile charging solution such as a generator or power bank.
[0011] These constraints complicate the use and management of a fleet of electric motor construction machinery.
[0012] Among the known electric motor construction machines, some models have replaceable battery packs, in order to partially overcome the disadvantages mentioned above.
[0013] For example, Limach offers a model of electric motor construction machinery E88.1 with two sets of accumulators that can be mounted or removed independently of each other using mechanical arms. This allows at least one set of batteries to be kept installed on the construction machinery at all times and allows for the sets to be swapped. For example, it is possible to charge one set of batteries while two other sets are installed on the construction machinery and supply it with power for its operation.
[0014] Patent application EPI 770223 A1 relates to an electrically powered construction machine, in particular an excavator, powered by a replaceable battery. However, replacing the battery is impractical.
[0015] Mecalac sells electric construction machinery with mobile turrets that rotate relative to the chassis. However, the batteries in these construction machinery are fixed to the chassis and are not easily replaceable.
[0016] There is therefore a need to facilitate the operation of electrically powered construction machinery, and in particular to simplify the installation and removal of a set of batteries powering this construction machinery.
[0017] The aim of the invention is to meet at least part of this need.
[0018] Statement of the invention
[0019] To do this, the invention relates in one of its aspects to an electric excavator comprising: - a chassis comprising a housing configured to receive a main battery pack intended to electrically supply a main power circuit of the excavator;
[0020] - a turret mounted freely in rotation on the chassis and comprising an articulated arm configured to be able to be positioned above the main battery assembly when said assembly is arranged in the housing;
[0021] - an auxiliary battery pack configured to electrically power an auxiliary power circuit of the excavator which, when powered, allows at least the rotation of the turret and the use of the articulated arm so as to deposit the main battery pack from a position placed in the housing to a position placed outside the housing and vice versa by means of the articulated arm.
[0022] Thus, the invention relates to an electric excavator which comprises a turret which can freely rotate around a vertical axis. This allows the articulated arm to be oriented in any direction in a horizontal plane. In particular, this allows the articulated arm to be positioned above the housing which receives the main battery pack, the housing being typically arranged at the rear of the turret.
[0023] The auxiliary power circuit allows the turret and articulated arm to be operated at a minimum when the main battery pack is discharged or out of its housing. This allows the articulated arm to be used to remove the main battery pack from the excavator and / or to place it in the housing.
[0024] Typically, the main battery pack provides electrical power to all of the excavator's functions, while the auxiliary battery pack can only provide limited power to replace the main battery pack.
[0025] The excavator according to the invention therefore facilitates the replacement of the main battery pack. Indeed, since the main battery pack can be removed by the excavator autonomously with its own articulated arm, it is no longer necessary to move the excavator to an electric charging station or to implement another device to change the main battery pack. Advantageously, the main battery pack once removed from the housing can be transported to a charging station. This transport can be done with a standard trailer or a trailer specially designed to receive the pack, towed by means of a standard vehicle or directly by the excavator on a conventional road / motorway network to facilitate movement.
[0026] The invention also allows for functional switching between several sets of batteries. This solves the problem of autonomy of the construction machine: for example, switching between two main sets of batteries, each capable of powering the construction machine for four hours, makes it possible to use the construction machine continuously for eight hours, or even without a time limit if one of the sets, removed, is put into electrical charging while the other, installed in the housing, powers the excavator.
[0027] According to an advantageous characteristic, the articulated arm comprises at its free end a quick coupler and / or a bucket, the articulated arm and / or the quick coupler and / or the bucket comprising at least one lifting point, called a lifting hook, allowing the attachment of a connecting part intended to also be attached to the main battery assembly.
[0028] Any suitable means of attachment between the articulated arm and the main battery pack may, however, be used. For example, the main battery pack may have a gripping protrusion configured to receive the bucket or the quick coupler directly. Once the bucket or quick coupler is inserted into the gripping protrusion, the articulated arm can lift the main battery pack.
[0029] For the purposes of the invention, the term "quick coupler" means the usual meaning, namely a device allowing rapid attachment and detachment of buckets or other tools. A quick coupler may have a mechanical operation or a hydraulic operation.
[0030] Preferably, the housing includes guides for guiding the main battery pack as it is inserted into the housing.
[0031] More preferably, the capacity of the auxiliary battery pack is between 1 and 50 kWh. The main battery pack may advantageously comprise at least one battery, preferably a battery module, preferably forming a battery pack.
[0032] The main battery pack, being mobile, can be recharged outside the electric excavator with a stand-alone operating mode. It can also have an output electrical socket so that it can power other equipment as a generator.
[0033] According to another of its aspects, the invention relates to a method for removing a main battery pack from a position placed in a housing of an electric excavator to a position removed from the housing, the electric excavator comprising a turret mounted freely in rotation on a chassis and supporting an articulated arm, comprising the steps of: a) positioning the articulated arm above the main battery pack; b) attaching the main battery pack to the articulated arm and / or to a quick coupler and / or to a bucket of the articulated arm; c) removing the main battery pack to the ground or onto a receiving surface outside the excavator by means of the articulated arm.
[0034] Preferably, the electric excavator is electrically powered by an on-board auxiliary battery pack.
[0035] Alternatively, the electric excavator is powered by an external power source, such as an external battery pack or a power grid. In this case, the electric excavator does not necessarily have an additional battery pack.
[0036] The invention also relates to a method for installing a main battery pack in a housing of an electric excavator from a position placed outside the housing, the electric excavator comprising a turret mounted freely in rotation on a chassis and supporting an articulated arm, comprising the steps of: a) positioning the articulated arm above the main battery pack; b) attaching the main battery pack to the articulated arm and / or to a quick coupler and / or to a bucket of the articulated arm; c) placing the main battery pack in the housing by means of the articulated arm.
[0037] Preferably, the electric excavator is electrically powered by an on-board auxiliary battery pack.
[0038] Alternatively, the electric excavator is powered by an external power source, such as an external battery pack or a power grid. In this case, the electric excavator does not necessarily have an additional battery pack.
[0039] Brief description of the drawings
[0040] [Fig 1] Figure 1 represents an excavator according to the invention.
[0041] [Fig 2] Figure 2 is a side view of an excavator according to the invention.
[0042] [Fig 3] Figure 3 is a side view of an excavator according to the invention equipped with a main battery pack with an opening cowling.
[0043] [Fig 4] Figure 4 schematically represents the main and auxiliary power supply circuits of an excavator according to the invention.
[0044] [Fig 5] Figure 5 is a side view of an excavator according to the invention placed in safety configuration and equipped with a main battery pack.
[0045] [Fig 6] Figure 6 is a side view of the excavator shown in Figure 5 with the articulated arm attached to the main battery pack.
[0046] [Fig 7] Figure 7 is a side view of the excavator shown in Figure 5 during removal of the main battery pack.
[0047] [Fig 8] Figure 8 is a top view of the excavator shown in Figure 5.
[0048] [Fig 9] Figure 9 is a side view of an excavator with a leveling blade having a fork supporting a battery pack.
[0049] [Fig 10] Figure 10 is a side view of an excavator having a trailer supporting a plurality of battery packs.
[0050] [Fig 11] Figure 11 is a top view of the excavator of Figure 1, with the articulated arm articulated laterally. [Fig 12] Figure 12 illustrates various embodiments of the sliding connection between the housing and the main battery assembly.
[0051] [Fig 13] Figure 13 illustrates an embodiment of a direct contact slide connection.
[0052] [Fig 14] Figure 14 illustrates an embodiment of a roller slide connection.
[0053] Detailed description
[0054] Throughout this application, the terms "vertical", "lower", "upper", "bottom", "top", "front", "rear", "below" and "above" are to be understood with reference to the orientation of a construction machine. For example, in the case of an excavator as illustrated in the figures, the turret is arranged at the front of the machine and the battery pack at the rear and the turret is free to rotate about a vertical axis.
[0055] Figure 1 illustrates an example of an excavator 1 according to the invention.
[0056] The excavator 1 comprises a chassis 2 which supports a turret 3. The turret 3 is rotatable about a vertical axis and can perform a complete rotation about this axis. Thus, the turret 3 can be oriented in any direction in a horizontal plane. As shown in Figure 1, it is oriented forward.
[0057] The turret 3 supports an articulated arm 4 which has at its free end a lifting hook 15 as well as a quick coupler 16. A bucket 5 is attached to the quick coupler 16. The articulated arm 4 has at least one articulation 14 called an offset. The movements of the arm can in particular be controlled by hydraulic cylinders powered by a hydraulic unit. The orientation of the articulated arm 4 is fixed relative to the turret 3. However, the articulation or offset 14 advantageously makes it possible to orient a distal part of the arm in two directions, in particular vertically and laterally. The bucket 5 can be removed.
[0058] The chassis 2 also includes a housing 7 which is configured to receive a main battery pack 6. The housing 7 is arranged at the rear of the turret 3.
[0059] Advantageously, the housing 7 is configured so that the main battery pack 6 can be inserted or extracted through an upper side of the housing. The excavator 1 may further comprise a leveling blade 8 mounted on the chassis 2 at the front of the excavator.
[0060] The main battery pack 6 may be protected by a cover 12 as illustrated in particular in FIG. 3 which may be part of the main battery pack or part of the chassis. The cover 12 may be fixed or opening, as illustrated in FIG. 3, in particular if it is part of the chassis.
[0061] Figure 2 shows excavator 1 in side view, with turret 3 facing rearward.
[0062] Although not visible in figures 1 and 2, the excavator 1 still has an additional battery pack 13 mounted irremovably on the chassis 2.
[0063] Figure 4 schematically represents a main power circuit 20 and an auxiliary power circuit 30 of the excavator 1.
[0064] The main power circuit 20 is electrically powered by the main battery pack 6. When the latter is in the installed configuration on the excavator and when it is charged, it powers the electric motor 40 and various electrical components 41 of the excavator, which may include headlights, electronic components such as an on-board computer, a telematics device or other devices.
[0065] The electric motor 40 in particular powers the hydraulic unit 42 of the excavator which may in particular comprise a hydraulic pump, a distributor and a hydraulic reservoir and may power one or more hydraulic cylinders and / or motors.
[0066] In the example illustrated, the auxiliary power circuit 30 includes the auxiliary battery set 13. The auxiliary battery set 13 can be fixedly installed on the excavator, preferably in the chassis 2. It is not intended to be replaced regularly like the main battery set 6 because it provides a backup power supply allowing the main battery set 6 to be exchanged. It can be recharged by the latter.
[0067] When the main battery pack 6 is discharged or when it is not in the installed configuration on the support 7, the auxiliary battery pack 13 powers the electric motor 40 and the electrical components 41 of the excavator. Thus, the auxiliary power circuit 30 takes over from the main power circuit 20 when the main battery pack 6 is not providing power to the excavator. It therefore makes it possible to power the excavator during a phase of installation, removal or replacement of the main battery pack 6.
[0068] The auxiliary battery pack 13 is sized to provide at least a minimum power allowing the operations necessary for removing and installing a main battery pack 6 to be carried out. These operations include at least the rotation of the turret 3 and the use of the articulated arm 4 to move a battery pack 6. In certain embodiments, they may also include moving the excavator over short distances.
[0069] The sizing of the Annex 13 battery pack depends in particular on the characteristics of the excavator. For example, the Annex 13 battery pack may have a capacity greater than or equal to 1 kWh and / or less than or equal to 50 kWh depending on the system configuration and may deliver an electrical power of between at least 5 and 50 kW.
[0070] Figures 5 to 8 illustrate a method of removing the main battery pack 6 from the housing 7 of an electric excavator 1.
[0071] The main battery pack 6 is initially housed in the housing 7, as shown in Figure 5.
[0072] Preferably, the excavator 1 is placed on hard, stable, and level ground before commencing removal of the main battery pack 6. This facilitates the removal process.
[0073] The excavator 1 is then placed in a safety configuration in which the articulated arm 4 is folded, the parking brake is activated and the leveling blade 8 is placed on the ground.
[0074] Then, the turret 3 is oriented towards the main battery pack 6, so that the articulated arm 4 can be positioned above the latter.
[0075] Advantageously, a safety configuration of the excavator can then be activated by the operator. In this operating mode of the excavator, one or more functions of the excavator are locked. These may include the parking brake, the position of the leveling blade and / or the translation movement. Preferably, only the turret 3 and the articulated arm 4 can be controlled in the depositing mode, the other functions of the excavator being locked.
[0076] The power supply to the excavator is then switched to the auxiliary power circuit 30. This allows the excavator to continue to be used after the electrical disconnection of the main battery pack 6.
[0077] The auxiliary power circuit 30 may be powered by an auxiliary battery pack 13 on board the excavator but may also be powered by an external electricity source such as an external battery pack or an electrical network. The electric excavator 1 then does not necessarily have an auxiliary battery pack.
[0078] The operator then disconnects the electrical connection between the excavator 1 and the main battery pack 6. This can be done manually or automatically via a connection / disconnection device. The connection / disconnection device can be electrical, hydraulic or pneumatic, among other things.
[0079] The electrical connection between the main battery pack and the electric motor may be indirect and pass through an intermediate device such as a power controller.
[0080] If the main battery pack 6 is locked in the housing 7 by a locking device, the operator also unlocks the main battery pack.
[0081] As illustrated in Figure 6, the operator then attaches the articulated arm 4 to the main battery pack 6 by means of a connecting piece 9. The connecting piece 9 may be flexible, for example a strap or a chain. Preferably, the connecting piece 9 is connected to the articulated arm 4 by a first lifting point 10 arranged on the outer surface of the quick coupler 16 and / or the bucket 5 and it is connected to the main battery pack 6 by a second lifting point 11 arranged on its upper surface. The main battery pack 6 may also be attached directly to the lifting hook 15 and / or to the structure of the articulated arm 4 without being attached to the quick coupler 16 or the bucket 5. Several connecting pieces 9 may be placed between several first and second lifting points 10, 11 to improve the stability of the battery pack 6 when it is lifted.
[0082] Any other suitable means of connection between the articulated arm 4 and the main battery assembly 6 may be implemented to attach the arm and the main battery assembly. For example, the main battery assembly 6 may have a gripping protrusion on its upper face shaped to be complementary to the bucket of the articulated arm so that insertion of the bucket or quick coupler into the gripping protrusion allows the main battery assembly to be lifted by the articulated arm. Once the main battery assembly 6 is connected to the articulated arm, it may be lifted out of the housing 7 by the action of the articulated arm 4 as illustrated in FIG. 7.
[0083] As illustrated in Figure 8, the main battery pack 6 can then be placed next to the excavator by rotating the turret 3 and by the action of the articulated arm 4. Preferably, the main battery pack 6 is placed on a suitable surface, which may in particular be a power bank allowing it to be recharged.
[0084] A second, pre-charged main battery pack 6' can then be placed in the empty housing 7. The installation process is as follows.
[0085] The excavator 1 is first preferably put into safety configuration. If necessary, the operator moves the articulated arm above the main battery pack 6'. The operator then attaches the main battery pack 6' to the articulated arm 4 by means of the connecting piece 9. The rotation of the turret 3 and the movement of the articulated arm 4, powered by the auxiliary power circuit 30, make it possible to lift and move the main battery pack 6' until it is deposited in the housing 7.
[0086] Preferably, the mechanical connection between the main battery assembly 6' and the housing 7 is a sliding connection. The main battery assembly 6' comprises sliders 19 arranged on at least two opposite faces, configured to slide inside the guides 18 arranged in the housing 7 in order to guide the main battery assembly 6' during its installation and to hold it in position during operation of the machine. Thus, the guides facilitate the insertion of the assembly 6 into the housing 7 and its good performance during operation. Figure 12 shows different possible embodiments of sliding connections between a guide 18 and a slider 19. Figures 13 and 14 respectively show an example of a direct contact sliding connection and a roller sliding connection that can be implemented within the scope of the invention.
[0087] Once the main battery pack 6' is placed in the housing 7, the operator can lock it if a locking device is present. The electrical connection between the main battery pack 6' and the excavator 1 can then be established manually by the operator or automatically and the main power circuit 20 takes over from the auxiliary power circuit 30 to electrically power the excavator.
[0088] The operator can then switch to normal operating mode to restore all the functions of the excavator, now powered by the main power circuit 20. Advantageously, the auxiliary battery pack 13 can be recharged by the main battery pack 6'.
[0089] The locking device may operate manually or automatically. In particular, it may comprise an axis or a lever which is manually placed by the operator between the chassis 2 and the main battery assembly 6 so as to lock the latter on the chassis. Alternatively or additionally, it may comprise one or more locking pins arranged on the housing 7 and / or on the chassis 2. These locking pins are movable between an unlocking position in which the pins are entirely arranged in receiving openings of the housing and / or the chassis and a locking position in which they protrude from said receiving openings so as to enter complementary openings of the assembly 6. The pins are moved for example by a hydraulic or pneumatic cylinder or by an electromagnet.
[0090] Advantageously, the main battery pack 6 is sized with standard dimensions and the housing 7 is sized to receive and support a standardized size battery pack. The use of standardized battery packs offers the possibility of swapping them across several construction machines, of different makes and models, in order to facilitate the management of a fleet of battery packs and to optimize their uses.
[0091] Preferably, the main battery pack 6 has a capacity sufficient to power the operation of a construction machine for several hours. For example, the main battery pack 6 may have a length of between 1 m and 2.5 m and / or a width of between 0.8 m and 2 m and / or a height of between 1 m and 3 m. The capacity of the main battery pack 6 may be between 50 kWh and 400 kWh.
[0092] Advantageously, the main battery pack 6 can be configured to be used as an independent source of electricity whether it is installed in the housing 7 or not. The pack 6 can thus power equipment other than the excavator, in particular on a construction site.
[0093] Other variations and improvements may be provided without departing from the scope of the invention.
[0094] As illustrated in Figure 9, the leveling blade 8 may advantageously comprise a fork, in particular a pallet fork, extending towards the front of the excavator. This fork is configured to transport a set of batteries, directly or via a pallet.
[0095] Figure 10 shows an excavator 1 having a leveling blade 8 with fork. A trailer 17 supporting two sets of batteries 6 is mounted at the rear of the excavator. The excavator is thus capable of transporting a plurality of sets of batteries 6 allowing the excavator to be electrically powered for a long period without the need for recharging.
[0096] Figure 11 shows an advantageous configuration of excavator 1 in which the distal part of the arm 4 is oriented laterally thanks to the articulation 14 of the arm 4.
[0097] The illustrated examples of the excavator 1 show an arm 4 with an articulation 14 or offset which allows the arm to be oriented to the sides. It goes without saying that the invention can be implemented for all excavators, in particular excavators not equipped with an offset and which have single-piece arms.
Claims
Claims 1. Electric excavator (1) comprising: - a chassis (2) comprising a housing (7) configured to receive a main battery pack (6) intended to electrically supply a main power circuit (20) of the excavator; - a turret (3) mounted freely in rotation on the chassis and comprising an articulated arm (4) configured to be able to be positioned above the main battery assembly when said assembly is arranged in the housing; - an auxiliary battery pack (13) configured to electrically power an auxiliary power circuit (30) of the excavator which, when powered, allows at least the rotation of the turret and the use of the articulated arm so as to deposit the main battery pack from a position placed in the housing to a position placed outside the housing and vice versa by means of the articulated arm.
2. Electric excavator according to the preceding claim, the articulated arm comprising at its free end a quick coupler (16) and / or a bucket (5), the articulated arm and / or the quick coupler and / or the bucket comprising at least one lifting point (10) allowing the attachment of a connecting piece (9) intended to also be attached to the main battery assembly.
3. Electric excavator according to one of the preceding claims, the housing comprising guides for guiding the main battery pack when it is inserted into the housing.
4. Electric excavator according to one of the preceding claims, the capacity of the auxiliary battery pack being between 1 and 50 kWh.
5. A method of removing a main battery pack (6) from a position placed in a housing of an electric excavator to a position removed from the housing, the electric excavator comprising a turret mounted freely rotatably on a chassis and supporting an articulated arm, the method comprising the steps of: a) positioning the articulated arm above the main battery pack; (b) attaching the main battery pack to the articulated arm and / or to a quick coupler and / or to a bucket of the articulated arm; (c) depositing the main battery pack on a receiving surface outside the excavator by means of the articulated arm.
6. Removal method according to the preceding claim, the electric excavator being electrically powered by an on-board auxiliary battery pack.
7. Removal method according to claim 5, the electric excavator being electrically powered by an external electricity source, in particular an external battery pack or an electrical network.
8. A method of installing a main battery pack into a housing of an electric excavator from a position removed from the housing, the electric excavator comprising a turret mounted freely rotatably on a chassis and supporting an articulated arm, the method comprising the steps of: a) positioning the articulated arm above the main battery pack; b) attaching the main battery pack to the articulated arm and / or to a quick coupler and / or to a bucket of the articulated arm; c) depositing the main battery pack into the housing by means of the articulated arm.
9. Laying method according to the preceding claim, the electric excavator being electrically powered by an on-board auxiliary battery pack.
10. Laying method according to claim 8, the electric excavator being electrically powered by an external electricity source, in particular an external battery pack or an electrical network.
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