Power machine lectric excavator undercarriage

Abstract

A power machine or excavator (100, 200) includes an undercarriage or lower frame structure (212), a house or upper frame structure (211), and a swivel assembly (218) rotatably coupling the upper frame structure to the lower frame structure. An electric power source (220-1) is mounted on the lower frame structure. Tractive drive assemblies (240A, 240B) attached to the lower frame structure each include an electric drive motor (241A, 241B) configured to receive power from the electric power source.

Description

M297.2611WO1 / I2023-0041-PCT-1-ELECTRIC EXCAVATOR UNDERCARRIAGEBACKGROUND

[0001] This disclosure is directed toward power machines, such as excavators, which have an upper frame structure which rotates relative to a lower frame structure using a swivel assembly. More particularly, this disclosure is directed to a power machine having a fully electric undercarriage.

[0002] Power machines, for the purposes of this disclosure, include any type of machine that generates power to accomplish a particular task or a variety of tasks. One type of power machine is a work vehicle. Work vehicles are generally self-propelled vehicles that have a work device, such as a lift arm (although some work vehicles can have other work devices) that can be manipulated to perform a work function. Work vehicles include excavators, loaders, utility vehicles, tractors, and trenchers, to name a few examples.

[0003] Excavators are a known type of power machine that have an undercarriage or lower frame structure and an upper machine portion, commonly referred to as a house, which selectively rotates on the undercarriage about a swivel assembly. Frequently, power machines such as excavators include a power source such as a diesel engine positioned on the upper machine portion, with the power source driving a hydraulic pump also positioned on the upper machine portion. The hydraulic pump provides hydraulic fluid to power work group actuators. The hydraulic pump also provides hydraulic fluid through the swivel assembly to the undercarriage to power hydraulic drive motors.

[0004] Powering both the upper machine portion and the undercarriage with hydraulic fluid from a hydraulic system on the upper machine portion increases complexity of the swivel assembly by requiring hydraulic connections to pass through the assembly. It also requires a larger diesel engine to provide sufficient power for both the work group actuators and the drive motors, even though the drive motors are not typically heavily used when operating the work group. Further, a larger engine and higher flow hydraulic system would be necessary to increase speed capabilities using the drive motors. These and other factors limit functionality of the power machine for some tasks.

[0005] The discussion above is merely provided for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter.M297.2611WO1 / I2023-0041-PCT-2-SUMMARY

[0006] This Summary and the Abstract are provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter.

[0007] Disclosed are power machines, such as excavators which include an undercarriage or lower frame structure, a house or upper frame structure, and a swivel assembly rotatably coupling the upper frame structure to the lower frame structure. An electric power source is mounted on the lower frame structure. Tractive drive assemblies attached to the lower frame structure each include an electric drive motor configured to receive power from the electric power source.

[0008] The electric power source comprises at least one battery pack mounted on the lower frame structure. In some exemplary embodiments, the at least one battery pack is mounted at a front of the lower frame structure, though other mounting positions can also be utilized. The tractive drive assemblies are attached to the lower frame structure such that the electric drive motor of each tractive drive assembly is positioned proximate a rear of the lower frame structure. In some embodiments, the positioning of the at least one battery pack proximate the front of the lower frame structure allows the at least one battery pack to be mounted in a configuration which allows removal from the lower frame structure by lowering the at least one battery pack downward relative to the lower frame structure. Alternatively, the positioning of the at least one battery pack allows removal from the lower frame structure by moving the at least one battery pack in a direction forward of the front of the lower frame structure.

[0009] In some exemplary embodiments, the swivel assembly is configured to allow the transmission of high voltage electric power through the swivel assembly between the lower frame structure and the upper frame structure. In some such embodiments, the swivel assembly includes a high voltage slip ring.

[0010] The power machine can also include at least one hydraulic actuator mounted on the upper frame structure; an upper frame power source, such as a diesel engine, mounted on the upper frame structure; and a hydraulic system mounted on the upper frame structure and coupled to the upper frame structure power source to receive power from the upper frame structure power source.M297.2611WO1 / I2023-0041-PCT-3-The hydraulic system is configured to provide hydraulic fluid to the at least one hydraulic actuator mounted on the upper frame structure.

[0011] In some embodiments, the power machine further comprises an electric generator mounted on the upper frame structure and coupled to the upper frame structure power source. The electric generator is configured to generate electric power, and the swivel assembly is configured to transmit electric power from the generator to the electric power source on the lower frame structure to recharge the electric power source.

[0012] In some embodiments, the power machine further comprises an electric motor mounted on the upper frame structure and configured to receive electric power through the swivel assembly from the electric power source on the lower frame structure. The electric motor is coupled to the hydraulic system and is configured to assist the upper frame structure power source in providing power to the hydraulic system.

[0013] In some embodiments, the power machine further comprises at least one hydraulic actuator mounted on the lower frame structure. The swivel assembly is configured to allow the flow of hydraulic fluid from the hydraulic system mounted on the upper frame structure to the at least one actuator mounted on the lower frame structure.

[0014] This disclosure, in its various combinations, may also be characterized by the following listing of items:1. A power machine, comprising:a lower frame structure;an electric power source mounted on the lower frame structure;tractive drive assemblies attached to the lower frame structure, each tractive drive assembly including an electric drive motor configured to receive power from the electric power source;an upper frame structure; anda swivel assembly rotatably coupling the upper frame structure to the lower frame structure.2. The power machine of claim 1, wherein the electric power source comprises at least one battery pack mounted on the lower frame structure.M297.2611WO1 / I2023-0041-PCT-4-3. The power machine of claim 2, wherein the at least one battery pack is mounted at a front of the lower frame structure.4. The power machine of any one of claims 1 to 3, wherein the tractive drive assemblies are attached to the lower frame structure such that the electric drive motor of each tractive drive assembly is positioned proximate a rear of the lower frame structure.5. The power machine of any one of claims 2 to 4, wherein the at least one battery pack is removably mounted to the lower frame structure such that the at least one battery pack is configured to be removed from the lower frame structure by lowering the at least one battery pack downward relative to the lower frame structure.6. The power machine of any one of claims 2 to 5, wherein the at least one battery pack is removably mounted to the lower frame structure such that the at least one battery pack is configured to be removed from the lower frame structure by moving the at least one battery pack in a direction forward of the front of the lower frame structure.7. The power machine of any one of claims 2 to 6, and further comprising a remote charging unit and a DC-to-DC voltage converter mounted at a rear of the lower frame structure and configured to charge the at least one battery pack from an external power source.8. The power machine of claim 7. and further comprising a cooler and fan system mounted in close proximity to the remote charging unit and the DC-to-DC voltage converter at the rear of the lower frame structure.9. The power machine of any one of claims 1 to 8, wherein the swivel assembly is configured to allow the transmission of high voltage electric power through the swivel assembly between the lower frame structure and the upper frame structure.10. The power machine of any one of claims 1 to 9, wherein the swivel assembly includes a high voltage slip ring.11. The power machine of any one of claims 1 to 10, and further comprising:at least one hydraulic actuator mounted on the upper frame stracture;an upper frame power source mounted on the upper frame structure;a hydraulic system mounted on the upper frame structure and coupled to the upper frame structure power source to receive power from the upper frame stracture power source, theM297.2611WO1 / I2023-0041-PCT-5-hydraulic system configured to provide hydraulic fluid to the at least one hydraulic actuator mounted on the upper frame structure.12. The power machine of claim 11, and further comprising an electric generator mounted on the upper frame structure and coupled to the upper frame structure power source, the electric generator configured to generate electric power, wherein the swivel assembly is configured to transmit electric power from the generator to the electric power source on the lower frame structure to recharge the electric power source.13. The power machine of claim 11 or 12, and further comprising an electric motor mounted on the upper frame structure and configured to receive electric power through the swivel assembly from the electric power source on the lower frame structure, the electric motor further coupled to the hydraulic system and configured to assist the upper frame structure power source in providing power to the hydraulic system.14. The power machine of any one of claims 11 to 13, and further comprising at least one hydraulic actuator mounted on the lower frame structure, wherein the swivel assembly is configured to allow the flow of hydraulic fluid from the hydraulic system mounted on the upper frame structure to the at least one actuator mounted on the lower frame structure.15. An excavator undercarriage configured to be coupled to an excavator house by a swivel assembly such that the house is capable of rotation relative to the undercarriage, the excavator undercarriage comprising:an undercarriage frame;an electric power source mounted on the undercarriage frame; andtractive drive assemblies attached to the undercarriage frame, each tractive drive assembly including an electric drive motor configured to receive power from the electric power source.16. The excavator undercarriage of claim 15, wherein the electric power source comprises at least one battery pack mounted on the undercarriage frame.17. The excavator undercarriage of claim 16. wherein the at least one battery pack is mounted at a front of the undercarriage frame.M297.2611WO1 / I2023-0041-PCT-6-18. The excavator undercarriage of any one of claims 15 to 17, wherein the tractive drive assemblies are attached to the undercarriage frame such that the electric drive motor of each tractive drive assembly is positioned proximate a rear of the undercarriage frame.19. The excavator undercarriage of any one of claims 16 to 18, wherein the at least one battery pack is removably mounted to the undercarriage frame such that the at least one battery pack is configured to be removed from the undercarriage frame by lowering the at least one battery pack downward relative to the undercarriage frame.20. The excavator undercarriage of any one of claims 16 to 19, wherein the at least one battery pack is removably mounted to the undercarriage frame such that the at least one battery pack is configured to be removed from the undercarriage frame by moving the at least one battery pack in a direction forward of the front of the undercamage frame.BRIEF DESCRIPTION OF THE DRAWINGS

[0015] FIG. 1 is a block diagram illustrating functional systems of a representative power machine on which embodiments of the present disclosure can be practiced.

[0016] FIG. 2 is a front left perspective view of a representative power machine in the form of an excavator on which the disclosed embodiments can be practiced.

[0017] FIG. 3 is a rear right perspective view of the excavator of FIG. 2.

[0018] FIG. 4 is a top diagrammatic view of the excavator shown in FIGs. 2-3 and illustrating electric undercarriage features of an exemplary embodiment.

[0019] FIG. 5 is a front perspective view of portions of the excavator shown in FIGs. 1-4 illustrating battery pack placement on the undercarriage of the excavator.

[0020] FIG. 6 is a rear perspective view of portions of the undercarriage shown in FIG. 5 and illustrating arrangement of electric components in an exemplary embodiment.

[0021] FIG. 7 is a bottom perspective view of the undercarriage shown in FIGs. 5-6 and illustrating arrangement of electric components in accordance with an exemplary embodiment.

[0022] FIGs. 8-10 are block diagrams illustrating exemplary features of embodiments of the excavator shown in FIGs. 2-7.M297.2611WO1 / I2023-0041-PCT-7-

[0023] While the above-identified figures set forth one or more embodiments of the disclosed subject matter, other embodiments are also contemplated, as noted in the disclosure. In all cases, this disclosure presents the disclosed subject matter by way of representation and not limitation. It should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that fall within the scope of the principles of this disclosure.

[0024] The figures may not be drawn to scale. In particular, some features may be enlarged relative to other features for clarity. Moreover, where terms such as above, below, over, under, top, bottom, side, right, left, vertical, horizontal, etc., are used, it is to be understood that they are used only for ease of understanding the description. It is contemplated that structures may be oriented otherwise.

[0025] The terminology used herein is for the purpose of describing embodiments, and the terminology is not intended to be limiting. Unless indicated otherwise, ordinal numbers (e.g., first, second, third, etc.) are used to distinguish or identify different elements or steps in a group of elements or steps and do not supply a serial or numerical limitation on the elements or steps of the embodiments thereof. For example, "first," "second," and "third" elements or steps need not necessarily appear in that order, and the embodiments thereof need not necessarily be limited to three elements or steps. Unless indicated otherwise, any labels such as "left," "right." "front," "back," "top," "bottom," "forward," "reverse," "clockwise," "counterclockwise," "up," "down," or other similar terms such as "upper," "lower," "aft," "fore," "vertical," "horizontal," "proximal," "distal," "intermediate" and the like are used for convenience and are not intended to imply, for example, any particular fixed location, orientation, or direction. Instead, such labels are used to reflect, for example, relative location, orientation, or directions. The singular forms of "a," "an," and "the" include plural references unless the context clearly dictates otherwise.DETAILED DESCRIPTION

[0026] The concepts disclosed in this discussion are described and illustrated with reference to exemplary embodiments. These concepts, however, are not limited in their application to the details of construction and the arrangement of components in the illustrative embodiments and are capable of being practiced or being carried out in various other ways. The terminology in this document is used for description and should not be regarded as limiting. Words such asM297.2611WO1 / I2023-0041-PCT-8-“including,” “comprising,” and “having” and variations thereof as used herein are meant to encompass the items listed thereafter, equivalents thereof, as well as additional items.

[0027] Disclosed embodiments illustrate power machines, such as excavators, having a frame including a lower frame portion or undercarriage and an upper frame portion or house, with the house being mounted on the undercarriage by a swivel assembly such that it is capable of rotation relative to the undercarriage. The undercarriage, which has a tractive or other drive system, includes or supports one or more battery packs which provide electrical power to the drive system. Providing an electric undercarriage allows the power machine to utilize electric drive motors which provide higher speed and torque than provided by a conventional hydraulic drive system. This improved functionality can be utilized to allow an excavator type power machine to better perform functions more typical of loaders. The battery packs of the electric undercarriage can be rechargeable solely from an external power source, or in some hybrid power source embodiments, can be recharged using electric power generated from an engine supported on the house and passed through a high voltage slip ring component of the swivel assembly.

[0028] These concepts can be practiced on various power machines, as will be described below. A representative power machine on which the embodiments can be practiced is illustrated in diagram form in FIG. 1 and one example of such a power machine is illustrated in FIG. 2-3. For the sake of brevity, only one power machine is discussed. However, the disclosed teachings can be practiced on any of a number of power machines, including power machines of different types from the representative, illustrated power machine. Power machines, for the purposes of this discussion, include a frame, at least one work element, and a power source that can provide power to the work element to accomplish a work task. One type of power machine is a self-propelled work vehicle. Self-propelled work vehicles are a class of power machines that include a frame, work element, and a power source that can provide power to the work element. At least one of the work elements is a motive system for moving the power machine under power.

[0029] Referring now to FIG. 1, a block diagram illustrates the basic systems of a power machine 100 upon which the embodiments discussed below can be advantageously incorporated and can be any of several distinct types of power machines. The block diagram of FIG. 1 identifies various systems on power machine 100 and the relationship between various components and systems. As mentioned above, at the most basic level, power machines for the purposes of thisM297.2611WO1 / I2023-0041-PCT-9-discussion include a frame, a power source, and a work element. The power machine 100 has a frame 110, a power source 120, and a work element 130. Because power machine 100 shown in FIG. 1 is a self-propelled work vehicle, it also has tractive elements 140, which are themselves work elements provided to move the power machine over a support surface and an operator station 150 that provides an operating position for controlling the work elements of the power machine. A control system 160 is provided to interact with the other systems to perform various work tasks at least in part in response to control signals provided by an operator.

[0030] Certain work vehicles have work elements that can perform a dedicated task. For example, some work vehicles have a lift arm structure to which an implement 180 such as a bucket is attached such as by a pinning arrangement. The work element, i.e., the lift arm structure can be manipulated to position the implement 180 for performing the task. The implement 180, in some instances can be positioned relative to the work element, such as by rotating a bucket relative to a lift arm structure, to further position the implement. Under normal operation of such a work vehicle, the bucket is intended to be attached and under use. Such work vehicles may be able to accept other implements by disassembling the implement / work element combination and reassembling another implement in place of the original bucket. Other work vehicles, however, are intended to be used with a wide variety of implements and have an implement interface such as implement interface 170 shown in FIG. 1. At its most basic, implement interface 170 is a connection mechanism between the frame 110 or a work element 130 and an implement 180, which can be as simple as a connection point for attaching an implement directly to the frame 110 or a work element 130 or more complex, as discussed below.

[0031] On some power machines, implement interface 170 can include an implement carrier, which is a physical structure movably attached to a work element. The implement carrier has engagement features and locking features to accept and secure any of several implements to the work element. One characteristic of such an implement carrier is that once an implement is attached to it, it is fixed to the implement (i.e., not movable with respect to the implement) and when the implement carrier is moved with respect to the work element, the implement moves with the implement carrier. The term implement carrier is not merely a pivotal connection point, but rather a dedicated device specifically intended to accept and be secured to various different implements. The implement carrier itself is mountable to a work element 130 such as a lift armM297.2611WO1 / I2023-0041-PCT-10-structure or the frame 110. Implement interface 170 can also include one or more power sources for providing power to one or more work elements on an implement. Some power machines can have a plurality of work element with implement interfaces, each of which may. but need not, have an implement carrier for receiving implements. Some other power machines can have a work element with a plurality of implement interfaces so that a single work element can accept a plurality of implements simultaneously. Each of these implement interfaces can, but need not, have an implement carrier. Frame 110 includes a physical structure that can support various other components that are attached thereto or positioned thereon. The frame 110 can include any number of individual components. Some power machines have frames that are rigid. That is, no part of the frame is movable with respect to another part of the frame. Other power machines have at least one portion that can move with respect to another portion of the frame. For example, excavators can have an upper frame portion or house that rotates about a swivel with respect to a lower frame portion or undercarriage. Other work vehicles have articulated frames such that one portion of the frame pivots with respect to another portion for accomplishing steering functions.

[0032] In exemplary embodiments having a frame with an undercarriage and a house, at least a portion of the power source 120 is in the form of one or more electrical battery packs located in the undercarriage and configured to provide electrical power to electric drive motors. In some embodiments, another portion of the power source can be located in the upper frame portion or house. This second portion of the power source can be an engine, such as an internal combustion engine. The house mounted engine and the undercarriage mounted battery packs can form a hybrid power source in which the engine provides power through a high voltage slip ring to recharge the battery packs, or the engine and battery packs can be separate power systems which provide power, respectively, to the house actuators and the undercarriage actuators. Power source 120 can also include a power conversion system such as a mechanical transmission or a hydraulic system that can convert the output from an engine into a form of power that is usable by a work element.

[0033] Frame 110 supports the power source 120, which can provide power to one or more work elements 130 including the one or more tractive elements 140, as well as, in some instances, providing power for use by an attached implement via implement interface 170. Power from the undercarriage mounted battery packs portion of power source 120 can be provided directly to electric drive motors of the tractive elements 140. Power from the power source, including theM297.2611WO1 / I2023-0041-PCT-11-battery packs and / or a second portion of the power source, can be provided directly to any of the work elements 130 and implement interfaces 170. Alternatively, power from the power source 120 can be provided to a control system 160. which in turn selectively provides power to the elements that are capable of using it to perform a work function.

[0034] FIG. 1 shows a single work element designated as work element 130, but various power machines can have any number of work elements. Work elements are typically attached to the frame of the power machine and movable with respect to the frame when performing a work task. In addition, tractive elements 140 are a special case of work element in that their work function is generally to move the power machine 100 over a support surface. Tractive elements 140 are shown separate from the work element 130 because many power machines have additional work elements besides tractive elements, although that is not always the case. Power machines can have any number of tractive elements, some or all of which can receive power from the power source 120 to propel the power machine 100. Tractive elements can be, for example, wheels attached to an axle, track assemblies, and the like. Tractive elements can be rigidly mounted to the frame such that movement of the tractive element is limited to rotation about an axle or steerably mounted to the frame to accomplish steering by pivoting the tractive element with respect to the frame.

[0035] Power machine 100 includes an operator station 150, which provides a position from which an operator can control operation of the power machine. In some power machines, the operator station 150 is defined by an enclosed or partially enclosed cab. Some power machines on which the disclosed embodiments may be practiced may not have a cab or an operator compartment of the type described above. For example, a walk behind loader may not have a cab or an operator compartment, but rather an operating position that serves as an operator station from which the power machine is properly operated. More broadly, power machines other than work vehicles may have operator stations that are not necessarily similar to the operating positions and operator compartments referenced above. Further, some power machines such as power machine 100 and others, whether they have operator compartments or operator positions, may be capable of being operated remotely (i.e., from a remotely located operator station) instead of or in addition to an operator station adjacent or on the power machine. This can include applications where at least some of the operator-controlled functions of the power machine can be operated from an operating position associated with an implement that is coupled to the power machine.M297.2611WO1 / I2023-0041-PCT-12-Altematively, with some power machines, a remote-control device can be provided (i.e., remote from both of the power machine and any implement to which is it coupled) that can control at least some of the operator-controlled functions on the power machine.

[0036] FIGS. 2-3 are perspective views illustrating an excavator 200, which is one particular example of a power machine of the type illustrated in FIG. 1, on which the disclosed embodiments can be employed. FIG. 4 is a top diagrammatic view illustrating portions of excavator 200 including exemplary features of disclosed embodiments. Unless specifically noted otherwise, embodiments disclosed below can be practiced on a variety of power machines, with the excavator 200 being only one of those power machines.

[0037] Excavator 200 is described below for illustrative purposes. Not every excavator or power machine on which the illustrative embodiments can be practiced needs to have all of the features, or be limited to the features, described with reference to excavator 200. Excavator 200 has a frame 210 that supports a power system 220 which is represented in FIG. 3 as blocks, as the actual power system is enclosed within the frame 210. Power system 220 includes an undercarriage mounted power system 220-1, which in exemplary embodiments includes one or more battery packs 222 that provide power to the undercarriage mounted tractive system of the excavator. In some embodiments the power system 220 includes a house mounted power system 220-2 such as an engine that provides a power output to a hydraulic system, though power system 220-2 is not required in all embodiments. In such embodiments, the hydraulic system acts as a power conversion system that includes one or more hydraulic pumps for selectively providing pressurized hydraulic fluid to actuators that are operably coupled to work elements in response to signals provided by operator input devices. The hydraulic system also includes a control valve system that selectively provides pressurized hydraulic fluid to actuators in response to signals provided by operator input devices. In other embodiments, a hydraulic system may not be needed and actuators on the power machine can be electric actuators instead of hydraulic actuators. However, some embodiments which do not include an engine do include a hydraulic system driven by an electric motor. The excavator 200 includes a plurality of work elements in the form of a first lift arm structure 230 and a second lift arm structure 330 (not all excavators have a second lift arm structure). In addition, excavator 200, being a work vehicle, includes a pair of tractive elements inM297.2611WO1 / I2023-0041-PCT-13-the form of left and right track assemblies 240 A and 240B, which are disposed on opposing sides of the frame 210.

[0038] An operator compartment 250 is defined in part by a cab 252, which is mounted on the frame 210. The cab 252 shown on excavator 200 is an enclosed structure, but other operator compartments need not be enclosed. For example, some excavators have a canopy that provides a roof but is not enclosed A control system, shown as block 260, is provided for controlling the various work elements. Control system 260 includes operator input devices, which interact with the power system 220 to selectively provide power signals to actuators to control work functions on the excavator 200. In some embodiments, the operator input devices include at least two two-axis operator input devices to which operator functions can be mapped.

[0039] Frame 210 includes an upper frame portion or house 211 that is pivotally mounted on a lower frame portion or undercarriage 212 via a swivel joint 216 (shown in FIG. 4). The swivel joint includes a bearing or swivel assembly 218, a ring gear 217, and a slew motor 219 with a pinion gear (not pictured) that engages the ring gear to swivel the house 211. The slew motor 219, which can be an electric or hydraulic slew motor, receives a power signal from the control system 260 to rotate the house 211 with respect to the undercarriage 212. House 211 is capable of unlimited rotation about a swivel axis 214 under power with respect to the undercarriage 212 in response to manipulation of an input device by an operator. In exemplary embodiments in which power is provided from battery packs 222 mounted on the undercarriage 212, swivel assembly 218 can comprise or include a high voltage slip ring 221 configured to allow the transmission of electrical power through the slip ring to electric actuators mounted on the house 211, to provide electrical power to an electric motor assisting the engine in a hybrid power system, or again in the case of power machines having hybrid power systems to allow transmission of electrical power generated using the engine mounted on the house to (re-)charge the undercarriage mounted battery packs 222. However, if the power machine is configured to recharge the battery packs 222 only from external power sources and if the house mounted actuators receive power via pressurized hydraulic fluid or electricity generated by the engine, a high voltage slip ring 221 may not be required. Hydraulic conduits can, in some embodiments, be fed through the swivel assembly and high voltage slip ring to provide pressurized hydraulic fluid between the undercarriage and the house. For example, pressurized hydraulic fluid may be transmitted from a hydraulic pump drivenM297.2611WO1 / I2023-0041-PCT-14-by the engine in the house through the swivel assembly and to a lower lift aim actuator 332 to affect movement of the second lift arm structure 330.

[0040] The first lift aim structure 230 is mounted to the house 211 via a swing mount 215. (Some excavators do not have a swing mount of the type described here.) The first lift arm structure 230 is a boom-arm lift arm of the type that is generally employed on excavators although certain features of this lift arm structure may be unique to the lift arm illustrated in FIGs. 2-3. The swing mount 215 includes a frame portion 215 A and a lift arm portion 215B that is rotationally mounted to the frame portion 215A at a mounting frame pivot 231A. A swing actuator 233A is coupled to the house 211 and the lift aim portion 215B of the mount. Actuation of the swing actuator 233A causes the lift arm structure 230 to pivot or swing about an axis that extends longitudinally through the mounting frame pivot 231 A.

[0041] The first lift arm structure 230 includes a first portion 232, known generally as a boom, and a second portion 234, known as an arm or a dipper. The boom 232 is pivotally attached on a first end 232A to mount 215 at boom pivot mount 23 IB. A boom actuator 233B is attached to the mount 215 and the boom 232. Actuation of the boom actuator 233B causes the boom 232 to pivot about the boom pivot mount 231B, which effectively causes a second end 232B of the boom to be raised and lowered with respect to the house 211. A first end 234A of the arm 234 is pivotally attached to the second end 232B of the boom 232 at an arm mount pivot 231C. An arm actuator 233C is attached to the boom 232 and the arm 234. Actuation of the arm actuator 233C causes the arm to pivot about the arm mount pivot 231C. Each of the swing actuator 233A, the boom actuator 233B, and the arm actuator 233C can be independently controlled in response to control signals from operator input devices.

[0042] An exemplary implement interface 270 is provided at a second end 234B of the arm 234. The implement interface 270 includes an implement carrier 272 that can accept and securing a variety of different implements to the lift arm structure 230. Such implements have a machine interface that is configured to be engaged with the implement carrier 272. The implement carrier 272 is pivotally mounted to the second end 234B of the arm 234. An implement carrier actuator 233D is operably coupled to the arm 234 and a linkage assembly 276. The linkage assembly includes a first link 276A and a second link 276B. The first link 276A is pivotally mounted to the arm 234 and the implement carrier actuator 233D. The second link 276B is pivotally mounted toM297.2611WO1 / I2023-0041-PCT-15-the implement carrier 272 and the first link 276A. The linkage assembly 276 is provided to allow the implement carrier 272 to pivot about the arm 234 when the implement carrier actuator 233D is actuated.

[0043] The implement interface 270 also includes an implement power source (not shown) available for connection to an implement on the lift arm structure 230. In some embodiments, the implement power source includes pressurized hydraulic fluid port to which an implement can be coupled. The pressurized hydraulic fluid port selectively provides pressurized hydraulic fluid for powering one or more functions or actuators on an implement, hi addition, or in the alternative, the implement power source can include an electrical power source for powering electrical actuators and / or an electronic controller on an implement. The electrical power source can also include electrical conduits that are in communication with a data bus on the excavator 200 to allow communication between a controller on an implement and electronic devices on the excavator 200.

[0044] The lower frame portion or undercarriage 212 supports and has attached to it a pair of tractive elements, identified in FIG. 2-3 as left track drive assembly 240A and right track drive assembly 240B. Each of tractive drive assemblies 240A, 240B has a corresponding electric drive motor 241A, 241B (shown in FIGs. 6-7) configured to be powered by battery packs 222 mounted on the undercarriage 212. Use of electric drive motors 241A, 241B and undercarriage mounted battery packs 222 allows excavator 200 to take advantage of the benefits of an all-electric undercarriage, at least with respect to the drive functions of the machine. The electric drive motors 241A, 241B provide the opportunity for increased torque and an increased range of travel speeds, which in turn allow the excavator to perform functions typically reserved for loaders and other types of power machines. The ability to increase torque and speed rapidly using electric drive motors 241 A, 24 IB allows the excavator to be used to push material, move the machine and material longer distances and at higher speeds, and to perform other functions normally not practical or possible with a conventional excavator tractive drive design. Such rapid increases in torque and speed are difficult to achieve using hydraulically driven drive motors. Further, to provide increased speed with hydraulically driven drive motors, the excavator will typically need a larger diesel engine and increased hydraulic flow, and / or a multi-speed gearbox. This will correspondingly increase the cost, size, and weight of the excavator as well. Using the all-electric undercarriage drive system of the various disclosed embodiments allows the hydraulic system andM297.2611WO1 / I2023-0041-PCT-16-engine sizes to be designed based upon house work group requirements, and eliminates the need to have the hydraulic system and engine be oversized to accommodate the additional hydraulic flow and pressure requirements of the travel system.

[0045] In some embodiments, the use of an all-electric undercarriage also prevents the need for routing hydraulic power through the swivel joint, though that need not be the case in all embodiments. For example, while the drive functions of the undercarriage can be electric, a blade or other actuators mounted on the undercarriage can be hydraulically powered in some embodiments. Therefore, the disclosed embodiments include undercarriages with all-electric drive systems, regardless of whether the undercarriage includes some hydraulic actuators.

[0046] Each of tractive drive assemblies 240 A, 240B has a track frame 242 that is coupled to the lower frame portion or undercarriage 212. The track frame 242 supports and is surrounded by an endless track 244, which rotates under power to propel the excavator 200 over a support surface. Various elements are coupled to or otherwise supported by the track frame 242 for engaging and supporting the track 244 and cause it to rotate about the track frame. For example, a sprocket 246 is supported by the track frame 242 and engages the endless track 244 to cause the endless track to rotate about the track frame. An idler 245 is held against the track 244 by a tensioner (not shown) to maintain proper tension on the track. The track frame 242 also supports a plurality of rollers 248, which engage the track and, through the track, the support surface to support and distribute the weight of the excavator 200. An upper track guide 249 provides tension on track 244 and prevents the track from rubbing on track frame 242.

[0047] As illustrated in FIGS. 2-3, in some embodiments, a second or lower, lift arm structure 330 is pivotally attached to the undercarriage 212. A lower lift arm actuator 332 is pivotally coupled to the undercarriage 212 at a first end 332A and to the lower lift arm structure 330 at a second end 332B. The lower lift arm structure 330 is configured to carry a lower implement 334, which in one embodiment is a blade as is shown in FIGS. 2-3. The lower implement 334 can be rigidly fixed to the lower lift arm structure 330 such that it is integral to the lift arm structure. Alternatively, the lower implement can be pivotally attached to the lower lift arm structure via an implement interface, which in some embodiments can include an implement carrier of the type described above. Lower lift arms with implement interfaces can accept and secure various different types of implements thereto. Actuation of the lower lift arm actuator 332, in response to operatorM297.2611WO1 / I2023-0041-PCT-17-input, causes the lower lift arm structure 330 to pivot with respect to the undercarriage or lower frame portion 212, thereby raising and lowering the lower implement 334.

[0048] Upper frame portion or house 211 supports cab 252, which defines, at least in part, operator compartment or station 250. A seat 254 is provided within cab 252 in which an operator can be seated while operating the excavator. While sitting in the seat 254, an operator will have access to a plurality of operator input devices 256 that the operator can manipulate to control various work functions, such as manipulating the lift arm structure 230, the lower lift arm structure 330, the traction system 240A, 240B, pivoting the house 211 and so forth.

[0049] Excavator 200 provides a variety of different operator input devices 256 to control various functions. For example, joysticks are provided to control the lift arm stnrcture 230 and swiveling of the house 211 of the excavator. Foot pedals with attached levers are provided for controlling travel and lift arm swing. Electrical switches are located on the joysticks for controlling the power provided to an implement attached to the implement carrier 272. Other types of operator inputs that can be used in excavator 200 and other excavators and power machines include, but are not limited to, switches, buttons, knobs, levers, variable sliders and the like. The specific control examples provided above are exemplary in nature and not intended to describe the input devices for all excavators and what they control. Also, in some embodiments, excavator 200 is configured to be operated remotely, instead of or in addition to from operator station 250. This can include applications where at least some of the operator-controlled functions of the power machine can be operated from an operating position associated with an implement that is coupled to the power machine. Alternatively, with some embodiments, a remote-control device can be provided (i.e., remote from both of the power machine and any implement to which is it coupled) that can control at least some of the operator-controlled functions on the power machine.

[0050] Display devices are provided in the cab to give indications of information relatable to the operation of the power machines in a form that can be sensed by an operator, such as, for example audible and / or visual indications. Audible indications can be made in the form of buzzers, bells, and the like or via verbal communication. Visual indications can be made in the form of graphs, lights, icons, gauges, alphanumeric characters, and the like. Displays can provide dedicated indications, such as warning lights or gauges, or dynamic to provide programmable information, including programmable display devices such as monitors of various sizes and capabilities.M297.2611WO1 / I2023-0041-PCT-18-Display devices can provide diagnostic information, troubleshooting information, instructional information, and various other types of information that assists an operator with operation of the power machine or an implement coupled to the power machine. Other information that may be useful for an operator can also be provided.

[0051] The description of power machine 100 and excavator 200 above is provided for illustrative purposes, to provide illustrative environments on which the embodiments discussed below can be practiced. While the embodiments discussed can be practiced on a power machine such as is generally described by the power machine 100 shown in the block diagram of FIG. 1 and more particularly on an excavator such as excavator 200. unless otherwise noted, the concepts discussed below are not intended to be limited in their application to the environments specifically described above.

[0052] Referring now to FIGs. 5-7, shown are portions of excavator 200 which illustrate positioning of battery packs 222 and other electric components on undercarriage 212. As shown in the front perspective view of FIG. 5, battery packs 222 are mounted to a front portion 302 of undercarriage 212. Positioning the battery packs 222 on the undercarriage 212 lowers the center of gravity of excavator 200 and provides increased stability to the excavator. Further, this position at the front 302 of the undercarriage allows for improved access to the battery packs 222 for charging, removal, and / or installation. In some exemplary embodiments, battery packs 222 are configured to be removable from the undercarriage by lowering the battery packs in the downward direction, toward the ground and perpendicular to the forward direction of travel of the excavator. This can be the case regardless of whether the battery packs are mounted at the front 302 of the undercarriage, at the rear 304 of the undercarriage, or at an intermediate position of the undercarriage. The downward removal direction 306 of battery packs 222 is represented in FIG.5. hi other exemplary embodiments, the battery packs 222 are configured to be removable from the undercarriage by moving the battery packs in the forward direction 308 from the front 302 as is also shown in FIG. 5. Either of these embodiments allow for easier access to the batteries for maintenance operators. In some alternative embodiments, the battery pack or packs 222 may be mounted to the rear 304 of the undercarriage 212. In such an embodiment, the weight of the battery packs may similarly provide increased stability to the excavator and in addition act as a counterweight during trenching operations. Moreover, access, service and removal of the batteryM297.2611WO1 / I2023-0041-PCT-19-pack(s) may be facilitated by the absence of the second lift arm structure 330 at the rear of the machine.

[0053] Along with FIG. 5, the rear perspective view of FIG. 6 and the bottom perspective view of FIG. 7 illustrate positioning of electric components of the undercarriage 212. As shown in FIG.5, a controller or hub-controller 280 is positioned near the front of the undercarriage to a side of the battery packs 222. Hub-controller 280 is in some exemplary embodiments configured to receive and execute commands on control signals received from house 211 to control operation of the undercarriage and its various systems and components. FIGs. 6 and 7 illustrate positioning of a remote charging unit 284 and a DC-to-DC converter 282 at the rear 304 of the undercarriage. The remote charging unit 284 allows the battery packs 222 to be charged using an external power source, with the DC-to-DC converter 282 increasing the DC charging voltage as required for the battery pack specifications. For example, converter 282 can be a 48V to 400V converter.

[0054] Motor inverters 286A and 286B are shown positioned in close proximity to electric drive motors 241A and 241B at the rear 304 of the undercarriage 212. An auxiliary power unit (APU) 292 is also shown positioned on the undercarriage 212, with the APU generating electric power to power other onboard functions, for example those requiring lower voltages than the high voltage battery packs. A battery management system (BMS) 288 is positioned on the undercarriage, for example generally between battery packs 222 and the converter 282 and remote charging unit 284, with the BMS 288 configured to manage battery charging and discharging, providing data to machine controllers, etc. A cooler and fan system 290 is positioned on the undercarriage, for example toward the rear 304 and in close proximity to the DC-to-DC converter 282, battery packs 222, APU 292 and other electric components to maintain operating temperatures of the components below specified limits. While FIGs. 5-7 illustrate a number of electrical components of one example all-electric undercarriage embodiment consistent with the present disclosure, it is to be understood that not all of the components represented are required. For example, in various embodiments and applications of the present disclosure, a cooler and fan system 290 may not be required to achieve the desired power delivery from the battery to the electric drive motors. Similarly, a remote charging unit 284 and / or DC-to-DC converter 282 may be located off-board or remote from the undercarriage.M297.2611WO1 / I2023-0041-PCT-20-

[0055] While FIGs. 5-7 illustrate one example embodiment of an all-electric undercarriage and with specific placement for the various electronic components relative to a front 302 and rear 304 of the undercarriage 212, it is to be understood that various additional packaging solutions for these electronic components within the undercarriage 212 would be understood by a skilled artisan in view of the present disclosure.

[0056] In various embodiments of the present disclosure a structure of the undercarriage 212 between track frames 242 house various electronic components including, for example, one or more battery packs 222 and other power electronics (e.g., motor inverters 286A and 286B). In some specific embodiments, electric drive motors 241 may be packaged with a transmission (such as a planetary gearbox) and / or power electronics (e.g., motor inverters 286A and 286B). Accordingly, in some embodiments, the motor inverters 286A and 286B in addition to the electric drive motors may be positioned in or coupled to the track frames as opposed to within or on the undercarriage 212 structure between the track frames 242.

[0057] As noted above, slew motor 219 (as illustrated in FIG. 6, for example) can be an electric slew motor in some embodiments. While slew motors are conventionally mounted on the house or upper frame portion 211, in some embodiments slew motor 219 is mounted on undercarriage 212. This can prevent the need for high voltage transfer through the swivel assembly in some embodiments. Moreover, an electric slew motor may allow for re-generation of electricity and battery pack charging in response to deceleration / braking of a house / upper structure movement relative to the lower structure (at the end of a requested slew operation). However, disclosed embodiments are not limited to embodiments with an undercarriage mounted slew motor.

[0058] Disclosed embodiments include various configurations of a power machine such as an excavator having an electrically powered lower frame structure or undercarriage 212, with an upper frame structure or house 211 rotatably coupled to the undercarriage through a swivel assembly 218. As shown in the block diagram of FIG. 8, this includes having an electric power source 220-1 (i.e., with battery packs) positioned on the undercarriage 212 and configured to power at least electric drive motors 241 of track assemblies or tractive elements supported by the undercarriage. Such a configuration provides the improved excavator stability, increased drive motor torque, and higher drive motor speeds with improved responsiveness discussed above as compared to conventional excavators with hydraulic drive systems.M297.2611WO1 / I2023-0041-PCT-21-

[0059] In other embodiments, high pressure hydraulic fluid and / or high voltage electrical power are passed through the swivel assembly 218 between the undercarriage and house. FIG. 9 illustrates various examples of such other embodiments. In embodiments in which high voltage electrical power is provided through the swivel assembly 218, the swivel assembly can utilize a high voltage slip ring 221 as shown in FIG. 4. Dashed lines in FIG. 9 indicate various optional features which can be used separately or in combinations. Various disclosed embodiments do not require all of the features illustrated in dashed lines.

[0060] As one example, in some embodiments, the excavator 200 includes a house mounted power source 220-2 such as a diesel engine which powers a house mounted hydraulic system 320 to supply pressurized hydraulic fluid through conduits 322 to hydraulic actuators 333 on the house. Examples of hydraulic actuators 333 include swing actuator 233A, boom actuator 233B, and arm actuator 233C discussed above. In some embodiments, the hydraulic system 320 also provides pressurized hydraulic fluid through conduits 324 in the swivel assembly 218 to hydraulic actuators 335 positioned on the undercarriage. An example of a hydraulic actuator 335 mounted or positioned on the undercarriage is lower lift arm actuator 332 discussed above. In some corresponding embodiments, therefore, swivel assembly 218 is configured to allow the flow of pressurized hydraulic fluid between the undercarriage and house, but does not necessarily require the transfer of high voltage power between the undercarriage and house.

[0061] As another example, in some embodiments, the excavator represented in FIG. 9 utilizes a hybrid power source in which the power source 220-2 (e.g., a diesel engine) positioned on the house is used to charge the electric power source 220-1 positioned on the undercarriage. In one such optional example, an electric generator 340 positioned on the house is powered by the power source 220-2 and is used to generate electric power. The electric power from generator 340 is provided, through high voltage power transfer connections 326 in the swivel assembly 218, to the electric power source 220-1 for recharging the battery packs of the power source. Again, in some embodiments swivel assembly 218 is configured to provide such high voltage power transfer in combination with high pressure fluid transfer, but in other embodiments no high-pressure fluid transfer is provided through the conduit. Also, in yet other embodiments, the electric generator 340 can be a hydraulically powered electric generator positioned on undercarriage 212 andM297.2611WO1 / I2023-0041-PCT-22-powered with hydraulic fluid passing through conduits 324 in swivel assembly 218, potentially eliminating the need for the swivel assembly to be capable of high voltage energy transfer.

[0062] In yet other embodiments, with swivel assembly 218 configured to be capable of high voltage energy transfer, the undercarriage mounted electric power source 220-1 can provide power, through high voltage power transfer connections 328, to power an electric motor 350 located on the house 211. The electric motor 350 can assist the power source 220-2 in powering the hydraulic system 320. This allows increased hydraulic system flow rates or capacity, without requiring a larger diesel engine in power source 220-2 to facilitate peak-demand conditions. In yet some alternative embodiments the electric motor 350 mounted on upper frame 211 may be a slew motor 219 as shown in FIG. 6 or the upper frame 211 may include both a slew motor 219 and an electric motor 350 both powered by the electric power source 220-1 on the lower frame 212.

[0063] FIG. 10 illustrates yet another embodiment of excavator 200, with features similar to those illustrated in FIG. 9. The embodiment shown in FIG. 10 utilizes an electric generator 360, which is also configured to act as an electric motor, instead of the electric generator 350 shown in FIG. 9. The generator 360 is coupled between the engine or power source 220-2 and a hydraulic pump of the hydraulic system such that the generator 360 can be decoupled from the diesel engine, for example using a clutch or clutch assembly 370, and used as an electric motor. This allows the electric motor function of generator 360 to independently drive the hydraulic pump and pressurize the hydraulic system. This embodiment enables electric-only functionality of the machine, for relatively short periods of time depending upon battery pack capacity, with the generator 360 using power from electric power source 220-1 (or a secondary electric power source positioned on the house) to pressurize the hydraulic system. This electric-only functionality is beneficial where there is a desire to reduce or eliminate diesel exhaust emissions, for example when moving into and out of livestock barns, warehouses, or other buildings. In some embodiments, the user can set areas where emissions are prohibited, either via geofencing or with sensors such as electric light-sensing diodes to detect such environments, to automatically switch between diesel hybrid and electric only modes of operation. Control system 260 is configured to provide such control functionality in these exemplary embodiments.M297.2611WO1 / I2023-0041-PCT-23-

[0064] Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the scope of the discussion.

Claims

M297.2611WO1 / I2023-0041-PCT-24-WHAT IS CLAIMED IS:

1. A power machine, comprising:a lower frame structure;an electric power source mounted on the lower frame structure;tractive drive assemblies attached to the lower frame structure, each tractive drive assembly including an electric drive motor configured to receive power from the electric power source;an upper frame structure; anda swivel assembly rotatably coupling the upper frame structure to the lower frame structure.

2. The power machine of claim 1, wherein the electric power source comprises at least one battery pack mounted on the lower frame structure.

3. The power machine of claim 2, wherein the at least one battery pack is mounted at a front of the lower frame structure.

4. The power machine of any one of claims 1 to 3, wherein the tractive drive assemblies are attached to the lower frame structure such that the electric drive motor of each tractive drive assembly is positioned proximate a rear of the lower frame structure.

5. The power machine of any one of claims 2 to 4, wherein the at least one battery pack is removably mounted to the lower frame structure such that the at least one battery pack is configured to be removed from the lower frame structure by lowering the at least one battery pack downward relative to the lower frame structure.

6. The power machine of any one of claims 2 to 5, wherein the at least one battery pack is removably mounted to the lower frame structure such that the at least one battery pack is configured to be removed from the lower frame structure by moving the at least one battery pack in a direction forward of the front of the lower frame structure.M297.2611WO1 / I2023-0041-PCT-25-7. The power machine of any one of claims 2 to 6, and further comprising a remote charging unit and a DC-to-DC voltage converter mounted at a rear of the lower frame structure and configured to charge the at least one battery pack from an external power source.

8. The power machine of claim 7. and further comprising a cooler and fan system mounted in close proximity to the remote charging unit and the DC-to-DC voltage converter at the rear of the lower frame structure.

9. The power machine of any one of claims 1 to 8, wherein the swivel assembly is configured to allow the transmission of high voltage electric power through the swivel assembly between the lower frame structure and the upper frame structure.

10. The power machine of any one of claims 1 to 9, wherein the swivel assembly includes a high voltage slip ring.

11. The power machine of any one of claims 1 to 10, and further comprising:at least one hydraulic actuator mounted on the upper frame structure;an upper frame power source mounted on the upper frame structure;a hydraulic system mounted on the upper frame structure and coupled to the upper frame structure power source to receive power from the upper frame stracture power source, the hydraulic system configured to provide hydraulic fluid to the at least one hydraulic actuator mounted on the upper frame structure.

12. The power machine of claim 11, and further comprising an electric generator mounted on the upper frame stracture and coupled to the upper frame structure power source, the electric generator configured to generate electric power, wherein the swivel assembly is configured to transmit electric power from the generator to the electric power source on the lower frame structure to recharge the electric power source.M297.2611WO1 / I2023-0041-PCT-26-13. The power machine of claim 11 or 12, and further comprising an electric motor mounted on the upper frame structure and configured to receive electric power through the swivel assembly from the electric power source on the lower frame structure, the electric motor further coupled to the hydraulic system and configured to assist the upper frame structure power source in providing power to the hydraulic system.

14. The power machine of any one of claims 11 to 13, and further comprising at least one hydraulic actuator mounted on the lower frame structure, wherein the swivel assembly is configured to allow the flow of hydraulic fluid from the hydraulic system mounted on the upper frame structure to the at least one actuator mounted on the lower frame structure.

15. An excavator undercarriage configured to be coupled to an excavator house by a swivel assembly such that the house is capable of rotation relative to the undercarriage, the excavator undercarriage comprising:an undercarriage frame;an electric power source mounted on the undercarriage frame; andtractive drive assemblies attached to the undercarriage frame, each tractive drive assembly including an electric drive motor configured to receive power from the electric power source.

16. The excavator undercarriage of claim 15, wherein the electric power source comprises at least one battery pack mounted on the undercarriage frame.

17. The excavator undercarriage of claim 16, wherein the at least one battery pack is mounted at a front of the undercarriage frame.

18. The excavator undercarriage of any one of claims 15 to 17, wherein the tractive drive assemblies are attached to the undercarriage frame such that the electric drive motor of each tractive drive assembly is positioned proximate a rear of the undercarriage frame.M297.2611WO1 / I2023-0041-PCT-27-19. The excavator undercarriage of any one of claims 16 to 18, wherein the at least one battery pack is removably mounted to the undercarriage frame such that the at least one battery pack is configured to be removed from the undercarriage frame by lowering the at least one battery pack downward relative to the undercarriage frame.

20. The excavator undercarriage of any one of claims 16 to 19. wherein the at least one battery pack is removably mounted to the undercarriage frame such that the at least one battery pack is configured to be removed from the undercarriage frame by moving the at least one battery pack in a direction forward of the front of the undercarriage frame.

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