Electric construction machine

Abstract

An electric construction machine is described with a working unit (7), with an undercarriage (2) having a running gear (3), and with an upper carriage (4) which can be pivoted relative to the undercarriage (2) via a slewing ring (8) and has a linkage (6) for the working unit (7), in which a drive unit (9) comprising an electric motor (10) and a pump (11) for driving the running gear (3) and / or the working unit (7), an electrical energy storage device (12) for supplying the electric motor (10) with electrical energy, and a tank (13) for supplying the pump (11) with a hydraulic working medium are arranged, wherein the tank (13) and the drive unit (9) are arranged on the same side with respect to a longitudinal axis (14) of the upper carriage running through the slewing ring (8).In order to provide the operator with a comprehensive field of vision (22) despite the compact design and to allow smooth control of the construction machine, it is proposed that an articulation-side end section (17) of the drive unit (9), viewed in the direction of the superstructure longitudinal axis (14), is located closer to the articulation (6) than an articulation-side end section (18) of the tank (13), and that a deck-side end section (19) of the drive unit (9) is arranged below a deck-side end section (20) of the tank (13).

Description

[0001] The invention relates to an electric construction machine with a working unit, with an undercarriage having a running gear and with an upper carriage which can be pivoted relative to the undercarriage via a slewing ring and has a linkage for the working unit, in which a drive unit comprising an electric motor and a pump for driving the undercarriage and / or the working unit, an electrical energy storage device for supplying the electric motor with electrical energy, and a tank for supplying the pump with a hydraulic working medium are arranged, wherein the tank and the drive unit are arranged on the same side with respect to a longitudinal axis of the upper carriage running through the slewing ring.

[0002] For applications in confined construction sites, efforts are being made to provide the most compact construction machines possible. Electric construction machines with zero tail overhang, such as zero-tail excavators, are known from the prior art (EP4306723A1). To ensure that the uppercarriage of the construction machine is sufficiently compact, the drive unit, comprising an electric motor and a hydraulic pump, is designed vertically, i.e., the rotational axis of the electric motor and the longitudinal axis of the hydraulic pump are aligned parallel to a vertical axis. In this way, the drive unit can be compactly arranged between a tank for a hydraulic working fluid and a cooling unit, so that these components can be arranged on the same side of the uppercarriage and in the direction of a longitudinal axis of the uppercarriage.The disadvantage, however, is that this results in restrictions regarding the free alignment of the electric motor and the hydraulic pump, which can lead to special designs of these components and complex contacting and routing of the hydraulic lines.

[0003] A further challenge with such compact construction machines, such as excavators, lies in providing a sufficient field of vision for the operator. To ensure an unobstructed field of vision in the direction of travel and toward the work area, the working unit is usually hinged off-center on the superstructure, particularly offset toward one edge of the front wall, and the driver's cab is offset toward the other edge of the front wall. However, this entails the problem of uneven weight distribution, which leads to disrupted construction machine control, and impaired visibility in the area close to the ground near the working unit, meaning the operator must accept blind spots in this area.

[0004] The invention is therefore based on the object of proposing an electric construction machine of the type mentioned at the outset which, despite its compact design, on the one hand offers a comprehensive field of vision for the operator and, on the other hand, allows smooth construction machine operation.

[0005] The invention achieves this objective by arranging a linkage-side end section of the drive unit, viewed in the direction of the superstructure's longitudinal axis, closer to the linkage than a linkage-side end section of the tank, and by arranging a deck-side end section of the drive unit below a deck-side end section of the tank. As a result of the measures according to the invention, a descending height profile of the components installed in the superstructure, in particular a cladding enclosing the tank and the drive unit, is obtained in the direction of the linkage, at which the working unit is arranged, along which the deck cladding of the superstructure can be adapted.The superstructure can thus be designed particularly low on the side of the tank and drive unit in the area of ​​the linkage, resulting in a clear field of vision for an operator located in a driver's cab adjacent to the tank and drive unit. This field of vision, in particular, allows a view of the edge areas of the construction machine near the ground. Even if the linkage is located off-center on the superstructure toward the side on which the tank and drive unit are located, the edge area near the ground on this side can be viewed, since the cover cladding of the superstructure, which is adapted to the envelope, can slope down significantly in front of the linkage in the longitudinal direction of the superstructure as a result of the arrangement according to the invention.The invention utilizes the advantage that, although the tank is the component that determines the height of the deck cladding, its shape can be easily influenced by selecting a suitable material, allowing it to be adapted to achieve an optimal deck cladding profile for the field of vision. According to the invention, the tank is sufficiently spaced from the linkage so that a user can see beyond the deck cladding defined by the tank into the areas near the ground. The drive unit, whose design is limited in its shape, can thus be arranged in an area closer to the linkage and, thanks to the adaptability of the tank, can be installed in the superstructure in various ways.A further advantage is that the tank and the drive unit can preferably be arranged in alignment on a common side of the superstructure, in particular in the region of a common side wall of the superstructure, more preferably adjacent to a common side wall, while the driver's cab is arranged on the side opposite the side wall closest to the drive unit and the tank.Although the arrangement according to the invention increases the distance between the electric motor and the electrical energy storage unit, so that longer cables must be provided, it has surprisingly been found that this arrangement results in particularly smooth construction machine guidance, particularly when the uppercarriage is pivoted relative to the undercarriage, so that the longer cables can be accepted, especially since the deformability of the tank in between allows for easy routing of the cables.

[0006] The electric construction machine can be an excavator, in particular a zero-tail excavator. An excavator arm can thus be provided as the working unit. The working unit is connected to the superstructure via a linkage, which is preferably arranged on the front wall side of the superstructure. The tank and the drive unit are preferably aligned in the direction of the superstructure's longitudinal axis, and are thus arranged on a common alignment line that runs parallel to the superstructure's longitudinal axis. An end section of the drive unit on the linkage side, or in the case of an articulation arrangement in the region of the front wall of the superstructure, a front wall side, is located closer to the linkage or the front wall, viewed in the direction of the superstructure's longitudinal axis, than an end section of the tank on the linkage side or the front wall side.This allows the drive unit, comprising the electric motor and the hydraulic pump, to be arranged between the linkage and a slewing ring for pivoting the uppercarriage, as seen along the longitudinal axis of the superstructure, resulting in particularly advantageous pivoting conditions. This allows the drive unit to be positioned above the pivot cylinder for the working unit, resulting in particularly short hydraulic line paths.

[0007] For the purposes of the invention, the linkage-side end section is that section of the respective component which is closest to the linkage. In the case of the tank, this can be a side wall of the tank facing the linkage. In the case of the drive unit, this can be a housing section of the electric motor and / or the hydraulic pump facing the linkage. A deck-side end section of the drive unit is arranged below a deck-side end section of the tank. For the purposes of the invention, the deck-side end section is the highest section of the respective component. In the case of the tank, this can be a deck side of the tank. In the case of the drive unit, this can be a deck-side housing section of the electric motor and / or the hydraulic pump.In the sense of the invention, the feature of the linkage-side end section located closer to the linkage, as seen in the direction of the superstructure longitudinal axis, means that this linkage-side end section (of the drive unit) has a smaller minimum distance to a linkage transverse axis - horizontal normal to the superstructure longitudinal axis and running through the linkage - than the other linkage-side end section (of the tank).

[0008] The arrangement according to the invention provides various options for installing the drive unit in the superstructure, in particular flush with the tank, without restricting the field of vision. In one embodiment, the drive unit can be arranged between a front wall of the superstructure on the articulation side and the tank. In this way, the tank and drive unit can be arranged side by side. Alternatively, the tank can be arranged above the drive unit, with the projection surfaces of the tank and the drive unit projected in the direction of a vertical axis overlapping at least in sections. In such an embodiment, the tank can be lifted off the superstructure and supported against a side wall of the superstructure, creating a free space below the tank for the drive unit, in which space the drive unit can be arranged in sections and protrudes relative to the tank in the direction of the articulation.In a further embodiment, the tank can be arranged above the drive unit and in front of the drive unit, as seen in the direction of the linkage. This can be achieved by turning the tank into an upside-down L-shape.

[0009] Advantageous weight distribution and visibility conditions are further achieved when a cooling unit is arranged in the rear area of ​​the superstructure, so that the drive unit and the tank are arranged between a front wall on the articulation side and the cooling unit. The height of the cooling unit can exceed the height of the tank and the drive unit, so that the deck-side end section of the drive unit and the deck-side end section of the tank are arranged below a deck-side end section of the cooling unit. The definitions already introduced regarding the end section also apply to the cooling unit. The cooling unit, the tank, and the drive unit can be arranged laterally, preferably in alignment and adjacent to a driver's cab of the superstructure. A partition wall can be inserted between the driver's cab on the one hand and the cooling unit, the tank, and the drive unit on the other.In particular, the deck-side end sections of the cooling unit, the tank, and the drive unit can run below a window of the driver's cab facing them. The cooling unit can be used, in particular, to regulate the temperature of the electrical energy storage unit and the electric motor.

[0010] In order to ensure a short coolant route, particularly efficient cooling conditions are achieved when the electrical energy storage device is also located in the rear area of ​​the superstructure. This can be achieved by positioning an end section of the electrical energy storage device on the linkage side further away from the linkage than the end section of the drive unit and tank on the linkage side, as seen in the direction of the superstructure's longitudinal axis. Furthermore, this has the advantage that the battery arranged in this way acts as a counterweight to the working unit, further improving construction machine control. Furthermore, this creates a free space in the area between the front wall and the battery and next to the tank and drive unit, in which the driver's cab can be located. Regarding the different spacing of the respective end sections from the linkage, the above considerations regarding the transverse axis of the linkage can be applied analogously.

[0011] To further improve compactness, an energy storage fuse can be provided above the electrical energy storage device, wherein the projection surfaces of the electrical energy storage device and the energy storage fuse, projected in the direction of a vertical axis, overlap at least in sections. The energy storage fuse can comprise a drawer guide via which the energy storage fuse can be pulled out of the superstructure, preferably at least in sections, along the superstructure's longitudinal axis. The rear wall can comprise an access flap for easier access to the interior of the superstructure. The energy storage fuse can also comprise interfaces for charging the electrical energy storage device or charging devices. Several charging devices can also be provided, which can be stacked vertically one above the other for the purpose of a compact arrangement.

[0012] In principle, the inventive arrangement of the components in the superstructure allows for flexible alignment of the drive unit. However, the floor area of ​​the superstructure can be used particularly efficiently if the electric motor forms a rotation axis parallel to a normal axis perpendicular to the superstructure floor. The electric motor is thus aligned vertically. The hydraulic pump, which together with the electric motor forms the drive unit, can be arranged below the electric motor.

[0013] In order to provide a sufficiently stable superstructure despite a compact and lightweight design of the construction machine, it is proposed that two struts be arranged on the floor of the superstructure, the normal distance between which increases from the articulation point towards a rear wall of the superstructure. The struts can be formed by web plates. In plan view, the struts can form an A-shaped structure. Viewed in the direction of the articulation, the cooling unit, the tank and the drive unit can be located on the right side of this A-shaped structure. A control block can be arranged to the left of the A-shaped structure. The electrical energy storage device, for example a battery pack, can be arranged within the strut extensions.

[0014] To reduce power line lengths and thus further improve space availability, an inverter for the electric motor can be supported on a wall of the superstructure near the electric motor. This also improves the electromagnetic compatibility of the construction machine. Placing the inverter on the wall provides mechanical decoupling from the electric motor, preventing the transmission of vibrations from the electric motor to the inverter.

[0015] To facilitate maintenance work, the electric motor and the hydraulic pump can be arranged on a common support, which can be moved between a starting position and a maintenance position. In particular, the maintenance position is achieved by moving the support transversely to the longitudinal axis of the superstructure, so that the distance of the support from the longitudinal axis of the superstructure is greater in the maintenance position than in the starting position. Preferably, the support and / or the electric motor and / or the hydraulic pump can protrude beyond a contour of the superstructure in the maintenance position. An opening can be provided in the superstructure for this purpose. The support can be detachably connected to the superstructure and designed to be displaceable and / or pivotable relative to the superstructure.

[0016] The drawing shows an example of the subject matter of the invention. Fig. 1 a schematic side view of an electric construction machine according to the invention, Fig. 2 a sectional plan view of an electric construction machine according to the invention according to Fig. 1 and Fig. 3 a schematic side view of a second embodiment of an electric construction machine according to the invention.

[0017] An electric construction machine according to the invention, for example a Fig. 1 The excavator 1 shown has an undercarriage 2 with a chassis 3 and a superstructure 4. The superstructure 4 comprises a driver's cab 5 and a linkage 6, to which a working unit 7, for example an excavator arm, is pivoted. The superstructure 4 can be pivoted about a pivot axis relative to the undercarriage 2 via a slewing ring 8. In the superstructure 4, namely in the interior of the superstructure 4, a drive unit 9 is arranged, which comprises an electric motor 10 and a hydraulic pump 11 for driving the chassis 3 and / or the working unit 7, an electrical energy storage unit 12 for supplying the electric motor 10 with electrical energy, and a tank 13 for supplying the hydraulic pump 11 with a hydraulic working fluid. As can be seen from the Fig. 2 As can be seen, the tank 13 and the drive unit 9 are arranged on the same side, in particular in the region of a side wall 15 of the superstructure 4, with respect to a longitudinal axis 14 of the superstructure running through the slewing ring 8. Preferably, the tank 13 and the drive unit 9 are arranged in alignment, i.e., on a common alignment line 16. In particular, from the Figs. 1 and 3It can be seen that a linkage-side end section 17 of the drive unit 9, viewed in the direction of the superstructure longitudinal axis 14, is located closer to the linkage 6 than a linkage-side end section 18 of the tank 13. In addition, a deck-side end section 19 of the drive unit 9 is arranged below a deck-side end section 20 of the tank 13. Due to the resulting sloping height profile of the components installed in the superstructure 4 in the direction of the linkage 6 and a corresponding adaptation of the deck cladding 21 of the superstructure 4, the superstructure 4 can be designed to be particularly low on the linkage side on the side of the tank 13 and the drive unit 9, thus creating a clear field of vision 22 for an operator located in a driver's cab 5, which in particular allows a view into the edge areas of the construction machine close to the ground. As shown in the Fig. 2 As disclosed, the linkage 6 can be arranged off-center with respect to the longitudinal axis 14 of the superstructure running through the slewing ring 8. This results in a clear field of vision 22 for the operator on the side opposite the linkage 6. Due to the possibility according to the invention of a steeply sloping cover cladding 21, preferably running continuously below the window 31 of the driver's cab 5, in the direction of the linkage 6 and on the side of the linkage 6, the operator can also be provided with a comprehensive field of vision 22 on the side of the linkage 6. Furthermore, the arrangement according to the invention results in advantageous construction machine guidance, in particular smooth rotation guidance by the slewing ring 8 due to the maintained weight distribution.

[0018] In a first in the Figs. 1 and 2In the embodiment shown, the drive unit 9 can be arranged between a linkage-side front wall 23 of the superstructure 4 and the tank 13. In an alternative, in the Fig. 3 In the embodiment shown, tank 13 can be arranged above drive unit 9, i.e., above electric motor 10 and pump 11. The projection surfaces of tank 13 and drive unit 9 projected in the direction of a vertical axis can overlap.

[0019] A cooling unit 24 for the electrical energy storage unit 12 can be arranged in the rear area of ​​the superstructure 4, so that the drive unit 9 and the tank 13 are arranged between a linkage-side front wall 23 and the cooling unit 24. The deck-side end section 25 of the cooling unit 24 can be arranged above the deck-side end section 19 of the drive unit 9 and the deck-side end section 20 of the tank 13. The cooling unit 24, the tank 13, and the drive unit 9 can be arranged adjacent to the driver's cab 5 of the superstructure 4, wherein, in particular, a partition wall 26 can be arranged therebetween. The cooling unit 24, the tank 13, and the drive unit 9 can preferably be arranged between the side wall 15 of the superstructure 4 and the driver's cab 5 of the superstructure 4, preferably aligned along a common alignment line 16.

[0020] An energy storage fuse 27 can be provided above the electrical energy storage unit 12. The energy storage unit 12 can be arranged in the rear area of ​​the superstructure 4, which allows for a variety of cooling unit types 24. For example, liquid cooling can be used for the energy storage unit 12, which can benefit from the short coolant lines. Alternatively, air cooling can also be used, which also offers favorable cooling conditions due to the juxtaposition of the energy storage unit 12 and the cooling unit 24.

[0021] Out of Fig. 1 It can be seen that the electric motor 9 can have a rotation axis 28 which can run parallel to a normal axis perpendicular to the upper carriage floor, whereby particularly compact spatial conditions can be created. Fig. 3 shows a horizontally aligned rotation axis 28 of the electric motor 9.

[0022] Fig. 2clarifies that two struts 29 can be arranged on the floor of the superstructure 4, the normal spacing of which, extending transversely to the superstructure longitudinal axis 14, increases from the articulation point 6 in the direction of a rear wall 32 of the superstructure 4 opposite the front wall 23. In the exemplary embodiment, the struts 29 form an A-shaped structure in plan view. The electrical energy storage device 12, for example, a battery pack, can be arranged within the strut extensions.

[0023] In the area of ​​the electric motor 9, an inverter 30 can be supported on a wall of the superstructure 4.

[0024] In order to create sufficient space for the driver's cab 5, there can be a greater distance in the direction of the superstructure longitudinal axis 14 between a linkage-side end section 33 of the electrical energy storage device 12 and the linkage 6 than between the linkage-side end section 18 of the tank 13 and the linkage 6.

[0025] The electric motor 10 and the hydraulic pump 11 can be arranged together on a support (not shown for reasons of clarity), which is preferably detachably connected to the superstructure 4. The support can be moved into a maintenance position together with the electric motor 10 and the hydraulic pump 11, for which purpose the attachment of the support to the superstructure 4 is detachable and the support is displaceable and / or pivotable relative to the superstructure. In particular, the maintenance position is obtained by displacing the support transversely to the superstructure longitudinal axis 14. Preferably, the support and / or the electric motor 10 and / or the hydraulic pump 11 can protrude beyond a contour of the superstructure 4 in the maintenance position. The distance of the hydraulic pump 11 from the superstructure longitudinal axis 14 is greater in the maintenance position than in the starting position.

Claims

1. An electric construction machine with a working unit (7), with an undercarriage (2) having a running gear (3), and with an uppercarriage (4) which can be pivoted relative to the undercarriage (2) via a slewing ring (8) and has a linkage (6) for the working unit (7), in which a drive unit (9) comprising an electric motor (10) and a pump (11) for driving the undercarriage (3) and / or the working unit (7), an electrical energy storage device (12) for supplying the electric motor (10) with electrical energy, and a tank (13) for supplying the pump (11) with a hydraulic working medium are arranged, wherein the tank (13) and the drive unit (9) are arranged on the same side with respect to a longitudinal axis (14) of the uppercarriage running through the slewing ring (8), characterized in thata linkage-side end section (17) of the drive unit (9), viewed in the direction of the superstructure longitudinal axis (14), is located closer to the linkage (6) than a linkage-side end section (18) of the tank (13), and that a deck-side end section (19) of the drive unit (9) is arranged below a deck-side end section (20) of the tank (13).

2. Electric construction machine according to claim 1, characterized in that the drive unit (9) is arranged between a linkage-side front wall (23) of the superstructure (4) and the tank (13).

3. Electric construction machine according to claim 1, characterized in that the tank (13) is arranged above the drive unit (9), wherein the projection surfaces of the tank (13) and the drive unit (9) projected in the direction of a vertical axis overlap at least in sections.

4. Electric construction machine according to one of claims 1 to 3, characterized in thatthe drive unit (9) and the tank (13) are arranged between a linkage-side front wall (23) and a cooling unit (24).

5. Electric construction machine according to claim 4, characterized in that the deck-side end section (19) of the drive unit (9) and the deck-side end section (20) of the tank (13) are arranged below a deck-side end section (25) of the cooling unit (24).

6. Electric construction machine according to claim 4 or 5, characterized in that the cooling unit (24), the tank (13) and the drive unit (9) are arranged laterally adjacent to a driver's cab (5) of the superstructure (4).

7. Electric construction machine according to one of claims 1 to 6, characterized in that , viewed in the direction of the superstructure longitudinal axis (14), a linkage-side end section (32) of the electrical energy storage device (12) is located further away from the linkage (6) than the linkage-side end section (17, 18) of the drive unit (9) and the tank (13).

8. Electric construction machine according to one of claims 1 to 7, characterized in that an energy storage fuse (27) is provided above the electrical energy store (12), wherein the projection surfaces of the electrical energy store (12) and the energy storage fuse (27) projected in the direction of a vertical axis overlap at least in sections.

9. Electric construction machine according to one of claims 1 to 8, characterized in that the electric motor (9) forms a rotation axis (28) running parallel to a normal axis perpendicular to the upper carriage floor.

10. Electric construction machine according to one of claims 1 to 9, characterized in that two struts (29) are arranged on the floor of the superstructure (4), the normal distance between which increases from the articulation (6) in the direction of a rear wall (32) of the superstructure (4).

11. Electric construction machine according to one of claims 1 to 10, characterized in thatan inverter (30) for the electric motor (9) is supported on a wall of the superstructure (4) in the area of ​​the electric motor (9).

Images