GB2628795A

GB2628795A - Electric work machine

Info

Publication number: GB2628795A
Application number: GB2305008.1A
Authority: GB
Inventors: Richard Cawdery Andrew; Lee Gorman Corey
Original assignee: Caterpillar Inc
Current assignee: Caterpillar Inc
Priority date: 2023-04-04
Filing date: 2023-04-04
Publication date: 2024-10-09
Also published as: WO2024211026A1; GB202305008D0

Abstract

An electric work machine 300 comprises a body 110 comprising a battery 302, an arm 105 connected to the body, and an actuation assembly 120 connected to the arm. The machine further comprises a DC power cable (dotted lines in Figure 3) extending between the battery and the actuation assembly. The actuation assembly comprises: an invertor 126 configured to receive DC power from the DC power cable and to output AC power; and an AC powered electromechanical actuator configured to receive AC power from the first invertor. The machine could comprise further actuation assembles 140,160 and associated invertors 146,166 to control the arm, boom, a telescopic element, or a tool 190. The invention allows for the invertor(s) to be situated outside the body of the machine, creating space therein. Furthermore, only a DC cable need be extended across the arm and boom instead of a heavier, less flexible AC cable (possibly 3-phase, dashed lines in Figure 2).

Description

Electric work machine

Field of the disclosure

The disclosure relates to the field of electric work machines. In particular, the disclosure relates to distributing electric power on electric work machines having electric work machine arms and tools.

Background

Work machines such as excavators, back-hoe loaders, wheel loaders and the like comprise arms for carrying out work operations, such as excavating or loading operations. Since work machine arms and tools may comprise moving parts, it is necessary to supply mechanical power to work machine arms and tools. Conventionally, the mechanical power of such work machine arms and tools is provided by hydraulic systems which may themselves be powered by an internal combustion engine.

In recent years, there is a trend towards providing the mechanical power on a work machine with electricity, for example by making use of electric motors and/or electromechanical actuators. The trend towards electrification means there is a need to distribute electricity efficiently on an electric work machine to power the various components.

Electric work machine arms and tools can place a high power demand on the electric energy source. Accordingly, electric work machines are conventionally provided with large batteries to fulfil the high power demand. Additionally, electric work machines often make use of inverters which invert a DC battery power supply into three phase AC power, since three phase AC power is capable of providing a more consistent power delivery and load capacity compared with single phase AC power.

The various embodiments disclosed in this document provide solutions and/or useful alternatives to one or more of the above noted issues.

Summary of the disclosure

Against this background, there is provided:

an electric work machine, comprising: a body comprising a battery; an arm comprising connected to the body; a first actuation assembly connected to the arm; and a DC power cable extending between the battery and the first actuation assembly; wherein the first actuation assembly comprises: a first invertor configured to receive DC power from the DC power cable and to output AC power; and a first AC powered electromechanical actuator configured to receive AC power from the first inverter.

In this way, by providing the first invertor on the actuation assembly which is connected between the body and the first element, it is not necessary to accommodate the first invertor on the machine body. This, in turn, vacates space on the machine body for other components, such as additional batteries. Furthermore, it reduces the amount of power cabling required.

Brief description of the drawings

A specific embodiment of the disclosure will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 shows a simplified view of a conventional electric work machine, showing the mechanical and electromechanical components.

Figure 2 shows an electric work machine useful for understanding the disclosure.

Figure 3 shows an electric work machine according to a first embodiment of this disclosure.

Figure 4 shows an electric work machine according to a second embodiment of this disclosure.

Figure 5 shows an electric work machine according to a third embodiment of this

disclosure.

Figure 6 shows an electric work machine according to a fourth embodiment of this disclosure.

Detailed description

According to one or more aspects of this disclosure, an electric work machine is provided. The electric work machine may be, for example, an excavator, a wheel loader, a telescopic arm work machine, a backhoe, and/or the like. The electric work machine comprises a body and an arm. The electric work machine further comprises one or more AC powered electromechanical actuators which receive AC power and output a mechanical force. The mechanical force from the one or more electromechanical actuators may be used to manipulate the arm.

The arm may extend from the body to a tool connector. Throughout this disclosure a proximal direction refers to a direction along the arm towards the body. A distal direction refers to a direction along the arm towards the tool connector. A proximal position refers to a position along the arm closer to the body. A distal position refers to a position along the arm closer to the tool connector.

Many aspects of this disclosure relate to the provision of electrical power to the one or more AC powered electromechanical actuators. The electric work machine may comprise a battery. The battery may be used to store electrical energy, which may then be provided to the AC powered electromechanical actuators. A battery is typically a source of DC power.

Therefore, in order to power an AC powered electromechanical actuator from a battery, an inverter may be used to invert the DC power to AC power.

Figure 1 shows a simplified view of an electric work machine, showing the mechanical and electromechanical components. Because Figure 1 shows only the mechanical and electromechanical components, power cables and power sources are not shown in Figure 1. The electric work machine comprises a body 110 and an arm 105. The arm 105 comprises one or more elements. In some embodiments, the arm 105 may comprise a first element 130, a second element 150 and a third element 170. The first element 130 may be a boom, the second element 150 may be a stick, and the third element 170 may be a tool manipulator. The first element 130 may be pivotable with respect to the body 110. The first element 130 may be pivotably connected to the body 110 at a body-first element pivot 131. The second element 150 may be pivotable with respect to the first element 130. The second element 150 may be pivotably connected to the first element 130 at a first element-second element pivot 151. The third element may be pivotable with respect to the second element 150. The third element 170 may be pivotably connected to the second element 150 at a second element-third element pivot 171.

The electric work machine may further comprise a first actuation assembly 120 connected between the body 110 and the first element 130 and configured to move the first element with respect to the body 110. The first actuation assembly 120 may comprise a first AC powered electromechanical actuator, the first AC powered electromechanical actuator comprising a first actuator housing 122 and a first rod 124. A proximal end of the first actuator housing 122 may be pivotably connected to the body 110 at a body-first actuator pivot 121. A distal end of the first rod 124 may be pivotably connected to the first element at a first actuator-first element pivot 125. The first actuator housing 122 may comprise a first AC motor configured to receive AC power. The first AC motor may rotate when provided with AC power. The first AC motor may be configured to turn a screw which provides a linear force to the first rod 124, causing the first rod 124 to extend or retract from the first actuator housing 122. In this way, the first actuation assembly 120 may apply a force between the body 110 and the first element 130, causing the first element 130 to pivot about the body-first element pivot 151.

The electric work machine may further comprise a second actuation assembly 140 connected between the first element 130 and the second element 150 and configured to move the second element 150 with respect to the first element 130. The second actuation assembly 140 may comprise a second AC powered electromechanical actuator, the second AC powered electromechanical actuator comprising a second actuator housing 142 and a second rod 144. A proximal end of the second actuator housing 142 may be pivotably connected to the first element 130 at a first element-second actuator pivot 141. A distal end of the second rod 144 may be pivotably connected to the second element 150 at a second actuator-second element pivot 145. The second actuator housing 142 may comprise a second AC motor configured to receive AC power. The second AC motor may rotate when provided with AC power. The second AC motor may be configured to turn a screw which provides a linear force to the second rod 144, causing the second rod to extend or retract from the housing 142. In this way, the second actuation assembly 140 may apply a force between the first element 130 and the second element 150, causing the second element 150 to pivot about the first element-second element pivot 151.

The electric work machine may further comprise a third actuation assembly 140 connected between the second element 150 and the third element 170 and configured to move the third element 170 with respect to the second element 150. The third actuation assembly 160 may comprise a third AC powered electromechanical actuator, the third AC powered electromechanical actuator comprising a third actuator housing 162 and a third rod 164. A proximal end of the third actuator housing 162 may be pivotably connected to the second element 150 at a second element-third actuator pivot 161. A distal end of the third rod 164 may be pivotably connected to the third element 170 at a third actuator-third element pivot 165. The third actuator housing 162 may comprise a third AC motor configured to receive AC power. The third AC motor may rotate when provided with AC power. The third AC motor may be configured to turn a screw which provides a linear force to the third rod 164, causing the third rod to extend or retract from the housing 162. In this way, the third actuation assembly 160 may apply a force between the second element 150 and the third element 170, causing the third element 170 to pivot about the second element-third element pivot 171.

The third element 170 may be connected or connectable to a tool 190 such as a bucket 190, forks, a platform or any other tool configured for connection to the third element 170.

As has been explained previously, an electric work machine according to this disclosure may provide improvements in the provision of AC power to one or more electromechanical actuators. A number of arrangements for providing AC power to electromechanical actuators will now be described.

Figure 2 shows a first electrical arrangement for providing AC power to the electromechanical actuators of the electric work machine 100 shown in Figure 1, the first electrical arrangement being but useful for understanding this disclosure but falling outside the scope of the claims. The mechanical and electromechanical features of the electric work machine 200 are similar to those shown in the electric work machine 100 of Figure 1 and are indicated as such by like reference numerals.

Referring to Figure 2, the electric work machine 200 further comprises a battery 202, a first inverter 126 associated with the first actuation assembly 120, a second inverter 146 associated with the second actuation assembly 140, and a third inverter 166 associated with the third actuation assembly 160. Dotted lines extending from the top of the battery 202 may indicate a DC power cable to a positive terminal of the battery 202. Dotted lines extending from the bottom of the battery 202 may indicate a DC power cable to a negative terminal of the battery 202. In this way, each inverter 126, 146, and 166 is provided with DC power from the battery. Dashed lines extending from the top of each inverter 224, 244, and 266 to each actuation assembly 120, 140, and 160 indicate three phase AC power cables. Three power cables, one for each phase, may be provided.

In the electrical arrangement shown for the electric work machine 200, the three phase AC power cables are shown with a direct path to each actuation assembly 120, 140, and 160. While in general at least some effort may be made to bend the power cables over the arm 105, it will be appreciated by those skilled in the art that three phase AC power cables are bulky and have limited flexibility.

Figure 3 shows an electric work machine 300 according to a first embodiment of this disclosure. By comparison with the electric work machine 200 of Figure 2, the first actuation assembly may comprise a first inverter 126, the second actuation assembly may comprise a second inverter 146, and the third actuation assembly may comprise a third inverter 166. By providing the first inverter 126 as part of the first actuation assembly 120, the second inverter 146 as part of the second actuation assembly 140, and the third inverter 166 as part of the third actuation assembly 160, the first inverter 126, the second inverter 146, and the third inverter 166 do not occupy space in the body 110. Thus, the battery 302 of the work machine 300 may be larger than the battery 202 of the electric work machine 200. In this way, it may be possible for the battery 302 of the electric work machine 300 to store more energy than the battery 202 of the electric work machine 200.

The dotted lines extending from the top of battery 302 to the first inverter 126, the second inverter 146, and the third inverter 166 may indicate a DC power cable to a positive terminal of the battery 302. The dotted lines extending from the bottom of battery 302 to the first inverter 126, the second inverter 146, and the third inverter 166 may indicate a DC power cable to a negative terminal of the battery 302. The DC power cable shown by the dotted lines of the electric work machine 300 may be more flexible than the AC power cable shown by the dashed lines of the electric work machine 200. The improved flexibility may arise at least because fewer cables are required.

The first inverter 126 may be provided as part of the first actuation assembly 120. For example, the first inverter 126 may be rigidly coupled to the first actuator housing 122. The first inverter 126 may be provided within the first actuator housing 122. The second inverter 146 may be provided as part of the second actuation assembly 140. For example, the second inverter 146 may be rigidly coupled to the second actuator housing 142. The second inverter 146 may be provided within the second actuator housing 142. The third inverter 166 may be provided as part of the second actuation assembly 160. For example, the second inverter 166 may be rigidly coupled to the second actuator housing 162. The second inverter 166 may be provided within the second actuator housing 162.

As has been explained previously, the first actuation assembly 120 may cause the first element 130 to pivot with respect to the body 110, the second actuation assembly 140 may cause the second element 150 to pivot with respect to the first element, and the third actuation assembly 160 may cause the third element 170 to pivot with respect to the second element 150. The first actuation assembly may itself pivot about the body-first actuator pivot 121 and the first actuator-first element pivot 125. The second actuation assembly may itself pivot about the first element-second actuator pivot 141 and the second actuator-second element pivot 145. The third actuation assembly may itself pivot about the second element-third actuator pivot 161 and the third actuator-third element pivot 165.

Therefore, by providing the first inverter 126 as part of the first actuation assembly 120, the first inverter 126 may be configured to move with the first actuation assembly 120. By providing the second inverter 146 as part of the second actuation assembly 140, the second inverter 146 may be configured to move with the second actuation assembly 140. By providing the third inverter 166 as part of the third actuation assembly 160, the third inverter 166 may be configured to move with the first actuation assembly 160.

Figure 4 shows an electric work machine 400 according to a second embodiment of this disclosure. The electric work machine 400 of the second embodiment is similar to the electric work machine 300 of the first embodiment, except for that in the second embodiment 300 at least one of the first actuation assembly, the second actuation assembly and the third actuation assembly does not comprise an inverter and, instead, the inverter is housed on the body 110. Thus, in the example of Figure 4, the first actuation assembly 120 does not comprise a first inverter 126 whereas the second actuation assembly 140 still comprises the second inventor and the third actuation assembly 160 still comprises the third inverter 166. In this way, additional space for a battery 402 on the body may be provided.

Due to differing loads on the first actuation assembly 120, the second actuation assembly and the third actuation assembly 160, any one of the first inverter 126, the second inverter 146, and the third inverter 166 may be larger than the other inverters. Additionally, the third actuation assembly 160 may be provided distally to the second actuation assembly 140 which is provided distally to the first actuation assembly 120. An inverter of an actuation assembly at a more distal position may require more AC power cables and more bending of the AC power cables. Thus, it is envisaged that one or more of the first inverter 126, the second inverter 146, and the third inverter 166 may be provided in the body 110, provided at least one of the first inverter 126, the second inverter 146, and the third inverter 166 is provided as part of its respective actuation assembly. In the embodiment shown in Figure 4, the first inverter 126 is provided in the body 110, however it will be understood that any of the first inverter 126, the second inverter 146, and the third inverter 166 may be provided in the body 110.

As has been explained previously, the electric work machine may be, for example, an excavator, a wheel loader, a telescopic arm work machine, a backhoe, and/or the like. One or more additional embodiments of the electric work machine will now be described. The principles of the following work machines are similar to those set out when describing the first and second embodiments.

Figure 5 shows an electric work machine 500 according to a third embodiment of this disclosure. The electric work machine 500 comprises a body 510 comprising a battery 502.

The electric work machine 500 further comprises an arm 505. The arm 505 may comprise a first element 550 and second element 570. The electric work machine 500 comprises a first actuation assembly 520 connected between a first element 550 and a body 510. The electric work machine 500 may further comprise a second actuation assembly 560 connected between the body 510 and a second element 570. The first element 550 may be a boom, and the second element 170 may be a rocker. Different to the first embodiment and the second embodiment, in the third embodiment both the first element 550 and the second element 570 may be connected to a tool 590. The first element 550 may be pivotably connected to the body 510 at a body-first element pivot 551. The second element 570 may be pivotably connected to the first element 550 at a first element-second element pivot 571.

The first actuation assembly 520 may comprise a first actuator housing 522 and a first actuator rod 524. A proximal end of the first actuator housing 522 may be pivotably connected to the body 510 at a body-first element pivot 521. A distal end of the first actuator rod 524 may be connected to the first element at a first actuator-first element pivot 525. As for the actuators described in the first and second embodiments, the first actuator housing 522 may comprise a first AC motor configured to receive AC power and provide a linear force to the first rod 524, causing the first rod 524 to extend or retract from the first actuator housing 522. In this way, the first actuation assembly 520 may be used to cause the first element 550 to pivot about the body-first element pivot 131.

The second actuation assembly 560 may comprise a second actuator housing 562 and a second actuator rod 564. A proximal end of the second actuator housing 562 may be pivotably connected to the body 510 at a body-second element pivot 561. A distal end of the second actuator rod 564 may be connected to the second element at a second actuator-second element pivot 565. As for the actuators described in the first and second embodiments, the first actuator housing 562 may comprise a second AC motor configured to receive AC power and provide a linear force to the second rod 524, causing the second rod 564 to extend or retract from the second actuator housing 562. In this way, the second actuation assembly 560 may be used to cause the second element 570 to pivot about the first element-second element pivot 571.

The provision of AC power to the first actuation assembly 520 and the second actuation assembly 560 of the third embodiment will now be described.

The first actuation assembly 520 may comprise a first inverter 526, the second actuation assembly 560 may comprise a second inverter 566. The dotted lines extending from the top of battery 502 to the first inverter 526 and the second inverter 566 may indicate a DC power cable to a positive terminal of the battery 502. The dotted lines extending from the bottom of battery 502 to the first inverter 526 and the second inverter 546 may indicate a DC power cable to a negative terminal of the battery 502.The first inverter 526 may be provided as part of the first actuation assembly 520. For example, the first inverter 526 may be rigidly coupled to the first actuator housing 522. The first inverter 526 may be provided within the first actuator housing 522. The second inverter 566 may be provided as part of the second actuation assembly 560. For example, the second inverter 566 may be rigidly coupled to the second actuator housing 562. The second inverter 566 may be provided within the second actuator housing 562. As for the first embodiment and the second embodiment, by providing the first inverter 526 as part of the first actuation assembly 520, the first inverter 526 may be configured to move with the first actuation assembly 520. By providing the second inverter 566 as part of the second actuation assembly 560, the second inverter 566 may be configured to move with the second actuation assembly 560.

In this way, an electric work machine 500 according to the third embodiment may provide increased space for the battery 502 on the body 510.

Similar to the second embodiment, it is envisaged that one or more of the first inverter 526 and the second inverter 566 of the electric work machine 500 may be provided in the body 510, provided at least one of the first inverter 526 and the second inverter 566 is provided as part of its respective actuation assembly.

Because an electromechanical actuator outputs a mechanical force by rod extending or retracting from an actuator housing, it will be appreciated that such a mechanical force may be used to move a telescopic component of an arm. Figure 6 shows an electric work machine 600 according to a fourth embodiment of this disclosure. Compared with the first, second, and third embodiments, in the fourth embodiment an arm 605 comprises a telescopic component. It will be appreciated from the fourth embodiment that the disclosure is not limited an arm comprising pivotable connections between elements of the arm and to other parts of the work machine such as the body.

Referring to Figure 6, the electric work machine 600 comprises a body 610 comprising a battery 602. The electric work machine 600 may comprise an arm 605 comprising a telescopic element 6002. The electric work machine 600 may comprise a telescopic element actuation assembly 660 configured to actuate the telescopic component 6004. The telescopic component actuation assembly 660 may comprise a telescopic component actuator housing 662 and a telescopic component rod 664. A proximal end of the telescopic actuator housing 662 may be connected to the body 610 at a body-telescopic actuator joint 661. A distal end of the telescopic component rod 664 may be connected to the telescopic element 6004 at a rod-telescopic component joint 665. The telescopic actuator housing 662 may be configured to output a linear force to the telescopic actuator rod 664 as has been described in actuation assemblies of previous embodiments. As the linear force is provided the telescopic actuator rod 664, the telescopic actuator rod 664 may extend or retract causing the telescopic component 6004 to extend or retract. The electric work machine 600 may further comprise a tool 690 coupled to the telescopic element 6004.

The tool 690 may comprise a bucket, a fork, a platform or any other tool configured for connection to the telescopic element 6004.

The arm 605 of electric work machine 600 may comprise a first element 6002. The first element 6002 may be a telescopic guide from which the telescopic element 6004 may extend and/or retract. Similar to the first element of the first embodiment, the second embodiment and the third embodiment, the telescopic guide 6002 may caused to pivot about a body-telescopic guide pivot 6001 by providing an telescopic guide actuation assembly 620 connected between the telescopic guide 6002 and the body 610. The telescopic The telescopic guide actuation assembly 620 may comprise a telescopic guide actuator housing 622 and a telescopic guide actuator rod 624. A proximal end of the telescopic guide actuator housing 622 may be pivotably connected to the body 610 at a body-telescopic guide pivot 621. A distal end of the telescopic guide actuator rod 624 may be connected to the telescopic guide element at a telescopic guide actuator-telescopic guide pivot 625. As for the actuators described in the first and second embodiments, the telescopic guide actuator housing 622 may comprise a telescopic guide AC motor configured to receive AC power and provide a linear force to the telescopic guide rod 624, causing the telescopic guide rod 624 to extend or retract from the telescopic guide actuator housing 622. In this way, the first actuation assembly 620 may be used to cause the telescopic guide 6002 to pivot about the body-telescopic guide pivot 6001.

The provision of AC power to the telescopic guide actuation assembly 520 and the telescopic element actuation assembly 560 of the third embodiment will now be described.

The telescopic guide actuation assembly 520 may comprise a telescopic guide inverter 526, the telescopic element actuation assembly 560 may comprise a telescopic element inverter 566. The dotted lines extending from the top of battery 502 to the telescopic guide inverter 526 and the telescopic element inverter 566 may indicate a DC power cable to a positive terminal of the battery 502. The dotted lines extending from the bottom of battery 502 to the telescopic guide inverter 526 and the telescopic element inverter 546 may indicate a DC power cable to a negative terminal of the battery 502. The telescopic guide inverter 526 may be provided as part of the telescopic guide actuation assembly 520. For example, the telescopic guide inverter 526 may be rigidly coupled to the telescopic guide actuator housing 522. The telescopic guide inverter 526 may be provided within the telescopic guide actuator housing 522. The telescopic element inverter 566 may be provided as part of the telescopic element actuation assembly 560. For example, the telescopic element inverter 566 may be rigidly coupled to the telescopic element actuator housing 562. The telescopic element inverter 566 may be provided within the telescopic element actuator housing 562. As for the first embodiment and the second embodiment, by providing the telescopic guide inverter 526 as part of the telescopic guide actuation assembly 520, the telescopic guide inverter 526 may be configured to move with the telescopic guide actuation assembly 520. By providing the telescopic element inverter 566 as part of the telescopic element actuation assembly 560, the telescopic element inverter 566 may be configured to move with the telescopic element actuation assembly 560.

In this way, an electric work machine 500 according to the third embodiment may provide increased space for the battery 502 in the body 510.

Similar to the second embodiment, it is envisaged that one or more of the telescopic guide inverter 526 and the telescopic element inverter 566 of the electric work machine 500 may be provided in the body 510, provided at least one of the telescopic guide inverter 526 and the telescopic element inverter 566 is provided as part of its respective actuation assembly.

In any of the above embodiments, an inverter may be configured to receive DC power from a DC power cable and to output AC power. In any of the above embodiments an AC powered electromechanical actuator may be configured to receive AC power from an inverter. The AC power may be three phase AC power. The three phase AC power may be triple phase AC power, where three voltage or current signals are provided, each voltage or current signal with a sinusoidal waveform with equivalent magnitude and frequency but separated in phase by 120 degrees. As will be understood by those skilled in the art, triple phase AC power may be used to easily produce a rotating magnetic field at constant rotation speed and as such may allow for a simplified motor design compared with single phase AC power. Another advantage of triple phase AC power over single phase AC power is that triple phase AC power has a constant electrical power transfer.

In any of the above embodiments, an AC power cable or a DC power cable may comprise a conductor and a cable sheath for electrical isolation. In some embodiments, a coaxial arrangement of conductors and cable sheaths may be used.

For providing DC power, a first DC power cable may extend from a positive terminal of a battery and a second DC power cable may extend from a negative terminal of a battery.

For providing three phase AC power and/or triple phase AC power, a first AC power cable may extend from a first terminal of an inverter, a second AC power cable may extend from a second terminal of an inverter, and a third AC power cable may extend from a third terminal of an inverter.

In any of the above embodiments, a DC power cable may be shown by a dotted line. In the example shown in Figure 2, which is not according to the claims, AC power cables are shown by dashed lines. It will be understood by those skilled in the art that AC power cables may extend internally in an actuation assembly comprising an inverter from the inverter to an AC motor. As such, in the first to fourth embodiments as illustrated by Figures 3 to 6, AC power cables are not shown.

In any of the above embodiments, a controller configured to receive and/or store instructions for the actuation assemblies may be provided. In any of the above embodiments, a controller configured to send the instructions to the actuation assemblies may be provided. The electric work machine may comprise a communications pathway configured to send the instructions from the controller to one or more of the actuation assemblies. In any of the above embodiments, the electric work machine may comprise a cab. The cab may comprise a control panel for a user to provide instructions to the controller. In the first embodiment the electric work machine 300 may comprise a cab 104.

In the second embodiment the electric work machine 400 may comprise a cab 104. In the third embodiment the electric work machine 500 may comprise a cab 504. In the third embodiment the electric work machine 600 may comprise a cab 604.

In the first embodiment, the controller may be configured to send the instructions to the first actuation assembly 120 and, where present, any one or more of the second actuation 140 assembly, and the third actuation assembly 160. In the second embodiment, the controller may be configured to send the instructions to the first actuation assembly 120 and, where present, any one or more of the second actuation assembly 140, and the third actuation assembly 160. In the third embodiment, the controller may be configured to send the instructions to the first actuation assembly 520 and, where present, the second actuation assembly 560. In the fourth embodiment, the controller may be configured to send the instructions any one or more of the telescopic guide actuation assembly 620 and the telescopic element actuation assembly 660.

Claims

CLAIMS: 1. An electric work machine, comprising: a body comprising a battery; an arm comprising connected to the body; a first actuation assembly connected to the arm; and a DC power cable extending between the battery and the first actuation assembly; wherein the first actuation assembly comprises: a first invertor configured to receive DC power from the DC power cable and to output AC power; and a first AC powered electromechanical actuator configured to receive AC power from the first inverter.
2. The electric work machine of claim 1, wherein the arm comprises a first element; the first actuation assembly is connected between the first element and the body, and the first actuation assembly is configured to more the first element with respect to the body; and the arm further comprises a second element attached to the first element; and the electric work machine further comprises: a second actuation assembly connected between the second element and the first element, and configured to move the second element with respect to the first element, wherein the second actuation assembly comprises: a second invertor configured to receive DC power from the DC power cable and to output AC power; and a second AC powered electromechanical actuator configured to receive AC power from the second inverter.
3. The electric work machine of claim 2, wherein the arm further comprises a third element attached to the second element; and the electric work machine further comprises: a third actuation assembly connected between the third element and the second element, and configured to move the third element with respect to the second element, wherein the third actuation assembly comprises: a third invertor configured to receive DC power from the DC power cable and to output AC power; and a third AC powered electromechanical actuator configured to receive AC power from the third inverter.
4. The electric work machine of claim 3, wherein the first element comprises a boom, the second element comprises a stick, and the third element comprises a tool manipulator connectable to a tool, and the first element is pivotable with respect to the body, the second element is pivotable with respect to the first element, and the third element is pivotable with respect to the second element.
5. The electric work machine of claim 1, wherein the arm comprises a first element; the first actuation assembly is connected between the first element and the body, and the first actuation assembly is configured to more the first element with respect to the body; and the arm further comprises a second element attached to the body; and the electric work machine further comprises: a second actuation assembly connected between the second element and the body, and configured to move the second element with respect to the body, wherein the second actuation assembly comprises: a second invertor configured to receive DC power from the DC power cable and to output AC power; and a second AC powered electromechanical actuator configured to receive AC power from the second inverter.
6. The electric work machine of claim 5, wherein the first element and the second element are connectable to a tool, the first element comprises a boom configured to lift the tool when the first element is moved with respect to the body by the first actuation assembly, the second element comprises a rocker configured to tilt the tool when the second element is moved with respect to the body by the second actuation assembly.
7. The electric work machine of claim 1, wherein the arm comprises a first element and a second element; the first actuation assembly is connected between the first element and the second element; and the first actuation assembly is configured to move the second element with respect to the first element;
8. The electric work machine of claim 7, wherein the arm further comprises a third element attached to the second element; and the electric work machine further comprises: a second actuation assembly connected between the third element and the second element, and configured to move the third element with respect to the second element, wherein the second actuation assembly comprises: a second invertor configured to receive DC power from the DC power cable and to output AC power; and a second AC powered electromechanical actuator configured to receive AC power from the second inverter.
9. The electric work machine of any preceding claim, wherein the arm comprises a telescopic element. 20
10. The electric work machine of claim 9 wherein the arm further comprises a telescopic element actuation assembly connected between the telescopic element and one of the body and the first element configured to actuate the telescopic component, wherein the telescopic element actuation assembly comprises: a telescopic element invertor configured to receive DC power from the DC power cable and to output AC power; and a telescopic element AC powered electromechanical actuator configured to receive AC power from the telescopic element inverter.
11. The electric work machine of any preceding claim, wherein the AC power is three phase AC power provided by first, second and third conductors configured to carry three phase AC power from the first inverter to the first electromechanical actuator, and, where present, any one or more of: from the second inverter to the second electromechanical actuator, from the third inverter to the third electromechanical actuator, and the telescopic element inverter to the telescopic component electromechanical actuator.
12. The electric work machine of any preceding claim, wherein the DC power cable comprises a first conductor connected to a positive terminal of the battery and a second conductor connected to a negative terminal of the battery.
13. The electric work machine of claim 12, wherein the first conductor and the second conductor are housed together in a coaxial cable. 10
14. The electric work machine of any preceding claim, further comprising a communications pathway configured to send instructions from a controller to the first actuation assembly and, where present, any one or more of the second actuation assembly, the third actuation assembly, and the telescopic component actuation assembly.
15. The electric work machine of claim 14, wherein the communications pathway comprises any one or more of: an ethernet cable, a wireless connection.