Patent ID: 12247371

DETAILED DESCRIPTION

The concepts disclosed in this discussion are described and illustrated with reference to exemplary implementations. These concepts, however, are not limited in their application to the details of construction and the arrangement of components in the illustrative examples and are capable of being practiced or being carried out in various other ways. The terminology in this document is used for the purpose of description and should not be regarded as limiting. Words such as “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.

As used herein in the context of a power machine, unless otherwise defined or limited, the term “lateral” refers to a direction that extends at least partly to a left or a right side of a front-to-back reference line defined by the power machine. Accordingly, for example, a lateral side wall of a cab of a power machine can be a left side wall or a right side wall of the cab, relative to a frame of reference of an operator who is within the cab or is otherwise oriented to operatively engage with controls of an operator station of the cab. Similarly, a “centerline” of a power machine refers to a reference line that extends in a front-to-back direction of a power machine, approximately halfway between opposing lateral sides of an outer spatial envelope of the power machine.

Also as used herein, unless otherwise defined or limited, the term “extends substantially along” (and the like) indicates that more than half of an elongate (or other maximum) length of the described component extends along a reference structure. In particular, a linear actuator that extends substantially along a particular structure can be viewed as extending along the structure in a direction of actuation of the actuator for more than half of an operationally fully retracted length of the linear actuator (e.g., 75% of the length, 95% of the length, etc.). Similarly, reference to “substantially all” of a length, width, or other dimension of a component indicates at least 90% of the dimension (e.g., 95%, 98%, 99%, 100%).

Also as used herein, unless otherwise defined or limited, two components or other elements that are described as “substantially aligned” overlap, relative to a particular reference direction (e.g., a front-to-back direction), across more than half of a dimension of at least one the components. Components that are described herein as “vertically aligned” are aligned at a common vertical distance from a common reference (e.g., two components, each having portions located at a particular height above a ground plane that is a defined by support surfaces of tractive elements of a power machine). Components that are described herein as “laterally aligned” are located at a common lateral distance from a common reference (e.g., a centerline of a power machine), on the same lateral side of a centerline of the power machine. Thus, for example, for an actuator that is substantially laterally aligned with a lift arm, at least half of a lateral width of the actuator is spaced from a centerline of the relevant power machine at a common lateral distance (or range of lateral distances) as a corresponding portion of the lift arm. Or, in other words, as viewed from a front-to-back elevation view or a top-to-bottom plan view, at least half of the lateral width of the actuator overlaps relative to a lateral direction with the relevant portion of the lift arm As another example, for an actuator that is vertically aligned with a reference line (or corresponding plane) at a particular front-to-back location, at least part of the actuator (e.g., a pivot connection point thereof) is located at a common vertical height with the reference line at the particular front-to-back location (e.g., a pivot connection point of an actuator is on a reference line).

While the power machines disclosed herein may be embodied in many different forms, several specific examples are discussed herein with the understanding that the examples described in the present invention are to be considered only exemplifications of the principles described herein, and the invention is not intended to be limited to the examples illustrated. Throughout the disclosure, the terms “about” and “approximately” mean plus or minus 5% of the number that each term precedes, unless otherwise specified.

Some discussion below describes improved components and configurations for power machines, including components and configurations that use electrical (e.g., as opposed to hydraulic) power to operate certain power machine components or otherwise implement certain power machine functionality. In some examples, electrically powered components can be mounted to a frame of a power machine to selectively move work elements of the power machine, including lift arms or implement carriers. In some examples, electrically powered components can provide motive power for a power machine, including for tracked power machines (e.g., compact tracked loaders).

Correspondingly, some examples can provide improvements over conventional power machines, including power machines that use hydraulic components for certain operations. For example, use of electrical components (e.g., motors and actuators) to execute particular functions, instead of conventional hydraulic components, can improve overall precision, control, and speed of certain power machine operations. Further, the use of electrical components can also reduce overall component size, potential for failure, and general maintenance requirements as compared to conventional hydraulic systems. However, some aspects of the technology disclosed below can be advantageously employed in power machines for which some (or all) of the relevant components are hydraulically operated.

Continuing, some examples can provide improved structural arrangements for power machine actuators, and electrical components (e.g., motors and other actuators) in particular. For example, some implementations can include lifts arms with tilt actuators (including any associated motors) that are in at least partial alignment, in a front-to-back direction, with a main portion of the lift arm, rather than being positioned entirely to a laterally interior side of the lift arm. In some examples, tilt actuators can be positioned to extend along laterally exterior portions of a lift arm. In some cases, these types of arrangement can allow the tilt actuators to be mounted so as to increase operator visibility and ease of access (e.g., providing additional space around a cab for operator egress and ingress).

Relatedly, some examples can provide structural advantages for supporting, maintaining, and operating actuators and other components. For example, some implementations can include lift arms with pockets (e.g., with metal panel housings) that can at least partly enclose associated actuators. For some such configurations, the tilt actuator pockets can additionally provide stable and robust support for pinned (or other) connections as can support particularly stable operation of tilt (or other) actuators. Further, in some cases, the tilt actuator pockets can at least partly shield the tilt actuators from debris or undesired contact, while also allowing for easy access to the tilt actuators for maintenance. Moreover, in some cases, the shape of lift arms (e.g., exterior profiles of tilt actuator pockets) can be configured to improve visibility of an attached implement for an operator. Thus, for example, exterior walls of tilt actuator pockets may be oriented so as to improve forward visibility while still providing appropriate support for a tilt actuator.

Additionally, some examples can include power assemblies that can provide improved accessibility, power routing, or weight distribution relative to conventional designs. For example, some implementations can include electrical systems with control or power wiring that is efficiently routed through structural features of a power machine, including side walls of a housing for an actuator and within lift arms or other structures. Further, electrical connectors (e.g., an electrical connector for a powered implement) can be provided on a top or an outboard side of a housing having a pocket for an actuator. In some cases, these and similar arrangements can provide for efficient installation and signal routing, and can also help to protect signal lines (e.g., lines for power or control) from pinch points or adverse contact.

Other benefits will also be apparent from the discussion below, including benefits relating to the orientation of traction motors, to control of actuators and attachment mechanisms (e.g., for implements), and to spatial considerations (e.g., relative to clearance for operator stations).

These concepts can be practiced on various power machines, as will be described below. A representative power machine on which the examples can be practiced is illustrated in diagram form inFIG.1and one example of such a power machine is illustrated inFIGS.2-3and described below before any embodiments are disclosed. For the sake of brevity, only one power machine is discussed. However, as mentioned above, the embodiments below can be practiced on any of a number of power machines, including power machines of different types from the representative power machine shown inFIGS.2-3. 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.

The embodiments of the disclosure are presented below in the context of compact tracked loaders, with electrical components and other relevant components arranged on and secured to a frame. In some embodiments, electrical components and related systems according to the disclosure can be used with other types of power machines, including with articulated power machines and with non-articulated power machines with tractive elements other than tracks (i.e., wheels). In addition, some embodiments of the disclosure are presented in the context of electrical sub-assemblies for controlling work functions, such as by controlling actuators to maneuver one or more implements. In some embodiments, electrical sub-assemblies according to the disclosure can also be configured for other uses, such as to control other features, actuations, or movements of power machines.

FIG.1illustrates a block diagram that illustrates the basic systems of a power machine100upon which the embodiments discussed below can be advantageously incorporated and can be any of a number of different types of power machines. The block diagram ofFIG.1identifies various systems on power machine100and the relationship between various components and systems. As mentioned above, at the most basic level, power machines for the purposes of this discussion include a frame, a power source, and a work element. The power machine100has a frame110, a power source120, and a work element130. Because the power machine100shown inFIG.1is a self-propelled work vehicle, it also has tractive elements140, which are themselves work elements provided to move the power machine over a support surface, and an operator station150that provides an operating position for controlling the work elements of the power machine. A control system160is 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.

Certain work vehicles have work elements that are capable of performing a dedicated task. For example, some work vehicles have a lift arm to which an implement such as a bucket is attached such as by a pinning arrangement. The work element, i.e., the lift arm, can be manipulated to position the implement for the purpose of performing the task. The implement, in some instances, can be positioned relative to the work element, such as by rotating a bucket relative to a lift arm, 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 interface170shown inFIG.1. At its most basic, implement interface170is a connection mechanism between the frame110or a work element130and an implement, which can be as simple as a connection point for attaching an implement directly to the frame110or a work element130or more complex, as discussed below.

On some power machines, implement interface170can 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 a number of 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 as used herein 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 element130such as a lift arm or the frame110. Implement interface170can 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.

Frame110includes a physical structure that can support various other components that are attached thereto or positioned thereon. The frame110can 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 can have at least one portion that is capable of moving with respect to another portion of the frame. For example, excavators can have an upper frame portion that rotates with respect to a lower frame portion. Other work vehicles have articulated frames such that one portion of the frame pivots with respect to another portion for accomplishing steering functions.

Frame110supports the power source120, which is capable of providing power to one or more work elements130including the one or more tractive elements140, as well as, in some instances, providing power for use by an attached implement via implement interface170. Power from the power source120can be provided directly to any of the work elements130, tractive elements140, and implement interfaces170. Alternatively, power from the power source120can be provided to a control system160, which in turn selectively provides power to the elements that are capable of using it to perform a work function. Power sources for power machines typically include an engine such as an internal combustion engine and a power conversion system such as a mechanical transmission or a hydraulic system that is capable of converting the output from an engine into a form of power that is usable by a work element. Other types of power sources can be incorporated into power machines, including electrical sources or a combination of power sources, known generally as hybrid power sources.

FIG.1shows a single work element designated as work element130, 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 elements140are a special case of work element in that their work function is generally to move the power machine100over a support surface. Tractive elements140are shown separate from the work element130because 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 source120to propel the power machine100. Tractive elements can be, for example, wheels attached to an axle, track assemblies, and the like. Tractive elements can be mounted to the frame such that movement of the tractive element is limited to rotation about an axle (so that steering is accomplished by a skidding action) or, alternatively, pivotally mounted to the frame to accomplish steering by pivoting the tractive element with respect to the frame.

Power machine100includes an operator station150that includes an operating position from which an operator can control operation of the power machine. In some power machines, the operator station150is 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 machine100and others, whether or not 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. Alternatively, 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 is capable of controlling at least some of the operator controlled functions on the power machine.

FIGS.2-3illustrates a loader200, which is one particular example of a power machine of the type illustrated inFIG.1where the embodiments discussed below can be advantageously employed. Loader200is a track loader and more particularly, a compact tracked loader. A track loader is a loader that has endless tracks as tractive elements (as opposed to wheels). Track loader200is one particular example of the power machine100illustrated broadly inFIG.1and discussed above. To that end, features of loader200described below include reference numbers that are generally similar to those used inFIG.1. For example, loader200is described as having a frame210, just as power machine100has a frame110. Track loader200is described herein to provide a reference for understanding one environment on which the embodiments described below related to track assemblies and mounting elements for mounting the track assemblies to a power machine may be practiced. The loader200should not be considered limiting especially as to the description of features that loader200may have described herein that are not essential to the disclosed embodiments and thus may or may not be included in power machines other than loader200upon which the embodiments disclosed below may be advantageously practiced. Unless specifically noted otherwise, embodiments disclosed below can be practiced on a variety of power machines, with the track loader200being only one of those power machines. For example, some or all of the concepts discussed below can be practiced on many other types of work vehicles such as various other loaders, excavators, trenchers, and dozers, to name but a few examples.

Loader200includes frame210that supports a power system220, the power system being capable of generating or otherwise providing power for operating various functions on the power machine. Frame210also supports a work element in the form of a lift arm structure230that is powered by the power system220and can perform various work tasks. As loader200is a work vehicle, frame210also supports a traction system240, which is also powered by power system220and can propel the power machine over a support surface. The lift arm structure230in turn supports an implement carrier272, which can receive and secure various implements to the loader200for performing various work tasks. The loader200can be operated from an operator station255from which an operator can manipulate various control devices to cause the power machine to perform various functions. A control system260is provided for controlling the various functions of the loader200.

Various power machines that can include and/or interacting with the embodiments discussed below can have various different frame components that support various work elements. The elements of frame210discussed herein are provided for illustrative purposes and should not be considered to be the only type of frame that a power machine on which the embodiments can be practiced can employ. Frame210of loader200includes an undercarriage or lower portion211of the frame and a mainframe or upper portion212of the frame that is supported by the undercarriage. The mainframe212of loader200is attached to the undercarriage211such as with fasteners or by welding the undercarriage to the mainframe. Mainframe212includes a pair of upright portions214located on either side and toward the rear of the mainframe (only one is shown inFIG.2) that support a lift arm structure230and to which the lift arm structure230is pivotally attached. The lift arm structure230is illustratively pinned to each of the upright portions214. The combination of mounting features on the upright portions214and the lift arm structure230and mounting hardware (including pins used to pin the lift arm structure to the mainframe212) are collectively referred to as joints216(one is located on each of the upright portions214) for the purposes of this discussion. Joints216are aligned along an axis218so that the lift arm structure is capable of pivoting, as discussed below, with respect to the frame210about axis218. Other power machines may not include upright portions on either side of the frame or may not have a lift arm structure that is mountable to upright portions on either side and toward the rear of the frame. For example, some power machines may have a single arm, mounted to a single side of the power machine or to a front or rear end of the power machine. Other machines can have a plurality of work elements, including a plurality of lift arms, each of which is mounted to the machine in its own configuration. Frame210also supports a pair of tractive elements242on either side of the loader200(only one is shown inFIG.2), which on loader200are track assemblies.

The lift arm structure230shown inFIG.1is one example of many different types of lift arm structures that can be attached to a power machine such as loader200or other power machines on which embodiments of the present discussion can be practiced. The lift arm structure230has a pair of lift arms232that are disposed on opposing sides of the frame210. A first end232A of each of the lift arms232is pivotally coupled to the power machine at joints216and a second end232B of each of the lift arms is positioned forward of the frame210when in a lowered position as shown inFIG.2. The lift arm structure230is movable (i.e., the lift arm structure can be raised and lowered) under control of the loader200with respect to the frame210. That movement (i.e., the raising and lowering of the lift arm structure230) is described by a travel path, shown generally by arrow233. For the purposes of this discussion, the travel path233of the lift arm structure230is defined by the path of movement of the second end232B of the lift arm structure.

Each of the lift arms232of lift arm structure230as shown inFIG.2includes a first portion234A and a second portion234B that is pivotally coupled to the first portion234A. The first portion234A of each lift arm234is pivotally coupled to the frame210at one of the joints216and the second portion234B extends from its connection to the first portion234A to the second end232B of the lift arm structure230. The lift arms232are each coupled to a cross member236that is attached to the first portions234A. Cross member236provides increased structural stability to the lift arm structure230. A pair of actuators238(only one is shown inFIG.1), which on loader200are hydraulic cylinders configured to receive pressurized fluid from power system220, are pivotally coupled to both the frame210and the lift arms234at pivotable joints238A and238B, respectively, on either side of the loader200. The tilt actuators238are sometimes referred to individually and collectively as lift cylinders. Actuation (i.e., extension and retraction) of the tilt actuators238cause the lift arm structure230to pivot about joints216and thereby be raised and lowered along a fixed path illustrated by arrow233. Each of a pair of control links217(only one is shown) are pivotally mounted to the frame210and one of the lift arms232on either side of the frame210. The control links217help to define the fixed travel path of the lift arm structure230. The lift arm structure230shown inFIG.2is representative of one type of lift arm structure that may be coupled to the power machine100. Other lift arm structures, with different geometries, components, and arrangements can be pivotally coupled to the loader200or other power machines upon which the embodiments discussed herein can be practiced without departing from the scope of the present discussion. For example, other machines can have lift arm structures with lift arms that each has one portion (as opposed to the two portions234A and234B of lift arm234) that is pivotally coupled to a frame at one end with the other end being positioned in front of the frame. Other lift arm structures can have an extendable or telescoping lift arm. Still other lift arm structures can have several (i.e., more than two) portions segments or portions. Some lift arms, most notably lift arms on excavators but also possible on loaders, may have portions that are controllable to pivot with respect to another segment instead of moving in concert (i.e., along a pre-determined path) as is the case in the lift arm structure230shown inFIG.2. Some power machines have lift arm structures with a single lift arm, such as is known in excavators or even some loaders and other power machines. Other power machines can have a plurality of lift arm structures, each being independent of the other(s).

An exemplary implement interface270is provided at a second end234B of the lift arm234. The implement interface270includes an implement carrier272that is capable of accepting and securing a variety of different implements to the lift arm structure230. Such implements have a machine interface that is configured to be engaged with the implement carrier272. The implement carrier272is pivotally mounted to the second end234B of the lift arm234. Implement carrier actuators (e.g., tilt actuators) are operably coupled between second end232B of the lift arm structure230and the implement carrier272and are operable to rotate the implement carrier with respect to the lift arm structure230.

The implement interface270also includes an implement power source235available for connection to an implement on the lift arm structure230. The implement power source235includes 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. The implement power source can also include an electrical power source for powering electrical actuators and/or an electronic controller on an implement. The electrical power source235also exemplarily includes electrical conduits that are in communication with a data bus on the loader200to allow communication between a controller on an implement and electronic devices on the loader200. It should be noted that the specific implement power source on loader200does not include an electrical power source.

The lower frame211supports and has attached to it the pair of tractive elements242, identified inFIGS.2-3as left track assembly240A and right track assembly240B. Each of the tractive elements242has a track frame243that is coupled to the lower frame211. The track frame243supports and is surrounded by an endless track244, which rotates under power to propel the loader200over a support surface. Various elements are coupled to or otherwise supported by the track frame243for engaging and supporting the endless track244and cause it to rotate about the track frame. For example, a sprocket246is supported by the track frame243and engages the endless track244to cause the endless track to rotate about the track frame. An idler245is held against the track244by a tensioner (not shown) to maintain proper tension on the track. The track frame243also supports a plurality of rollers248, which engage the track and, through the track, the support surface to support and distribute the weight of the loader200.

Upper frame portion212supports cab250, which defines, at least in part, operator compartment or station255. A seat258is provided within the cab250in which an operator can be seated while operating the power machine. While sitting in the seat258, an operator will have access to a plurality of operator input devices of the control system260(e.g., joysticks) that the operator can manipulate to control various work functions, such as manipulating the lift arm structure230, the traction system240, and so forth.

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 be dedicated to providing 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. 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.

FIG.4illustrates power system220in more detail. Broadly speaking, power system220includes one or more power sources222that can generate and/or store power for operating various machine functions. On loader200, the power system220includes an internal combustion engine. Other power machines can include electric generators, rechargeable batteries, various other power sources or any combination of power sources that can provide power for given power machine components. The power system220also includes a power conversion system224, which is operably coupled to the power source222. Power conversion system224is, in turn, coupled to one or more actuators226, which can perform a function on the power machine. Power conversion systems in various power machines can include various components, including mechanical transmissions, hydraulic systems, and the like. In some cases, the power conversion system224of power machine200includes a hydrostatic drive pump224A, which provides a power signal to drive motors226A,226B,226C and226D. The four drive motors226A,226B,226C and226D, in turn, are each operably coupled to four axles,228A,228B,228C and228D, respectively. Although not shown, the four axles are coupled to the wheels242A,242B,244A, and244B, respectively. The hydrostatic drive pump224A can be mechanically, hydraulically, and/or electrically coupled to operator input devices to receive actuation signals for controlling the drive pump. The power conversion system also includes an implement pump224B, which is also driven by the power source222. The implement pump224B is configured to provide pressurized hydraulic fluid to a work actuator circuit237. Work actuator circuit237is in communication with work actuator239. Work actuator239is representative of a plurality of actuators, including the lift cylinder, tilt cylinder, telescoping cylinder, and the like. The work actuator circuit237can include valves and other devices to selectively provide pressurized hydraulic fluid to the various work actuators represented by block239inFIG.4. In addition, the work actuator circuit237can be configured to provide pressurized hydraulic fluid to work actuators on an attached implement.

The description of power machine100and loader200above 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 machine100shown in the block diagram ofFIG.1and more particularly on a loader such as track loader200, unless otherwise noted or recited, the concepts discussed below are not intended to be limited in their application to the environments specifically described above.

In conventional arrangements, the tilt actuators238may use hydraulic components (i.e., hydraulic actuators or motors), which can result in certain inefficiencies. For example, the use of hydraulic actuators may result in somewhat imprecise execution of certain operations, may require frequent maintenance and related activities (e.g., to address leakage of hydraulic fluid, wear of seals, etc.), may impose undesired size requirements, and may exhibit limited performance capabilities (e.g., relative to actuation speed, responsiveness to operator commands or external factors, etc.). Complex control of hydraulic actuators may also be difficult, including for synchronized operation of the tilt actuators and associated power machine work elements. Thus, although conventional power machines that use hydraulic actuators can provide substantial power and functionality, including for motive power and to operate lift arms and implements, optimal performance relative to multiple design constraints may be difficult to achieve.

Embodiments of the disclosure can address one or more of the issues noted above, or others. For example, some implementations can use electrical systems for motive power or for other operation of work elements, including lift arm structures and implements. In some embodiments, such electrical systems can be readily swapped for hydraulic systems on pre-existing power machine structures, such as by replacing hydraulic cylinders and motors with electrical actuators and motors, thereby potentially improving multiple aspects of machine performance with little or no required adaptation of existing power machine frames or other support structures.

As also noted above, the use of electrical components in some embodiments (e.g., instead of hydraulic components) can help to improve overall system functionality, including relative to precision and complexity of control for work elements. For example, electrical actuators can generally provide enhanced motion-control capabilities as compared to hydraulic actuators, including with regard to precise positioning of components (e.g., precise extension of lift or tilt actuators) and complex simultaneous control of multiple electrical components (e.g., simultaneous control of multiple drive motors or work actuators). Use of electrical components can also help to reduce maintenance frequency and diminish potential for component failures, including through the elimination of hydraulic leakage and of components that are prone to substantial wear (e.g., seals). As a result, using electrical systems as opposed to hydraulic systems can reduce the overall cost and time required to maintain power machines. Moreover, in some instances, hydraulic systems require more components and space than comparably capable electrical systems. As a result, using electrical systems as opposed to hydraulic systems can reduce the required spatial footprint on a power machine for these systems, with corresponding benefits for overall system design. For example, power machines that extensively use electrical systems rather than hydraulic systems can be more compact or more accessible for users, or can be more easily equipped with additional components for enhanced functionality.

As another issue, including for power machines with electrical actuators, conventional lift arm designs may present obstructions to visibility for operators, may be subject to inefficient loading or stress distributions during use, and may be somewhat exposed to environmental objects and debris, in addition to presenting significant packaging challenges relative to other components of a power machine. Some embodiments presented herein can provide improved lift arm structures, including as may collectively address the issues noted above. In some cases, the improved lift arm structures may be particularly beneficial for use with electrical actuators (e.g., electrical tilt actuators) to provide improved loading, shielding, visibility, and overall packaging.

FIGS.5and6illustrate an example arrangement of components for an electrically powered power machine300, which is one particular example of the power machine100illustrated broadly inFIG.1and discussed above, and relative to which the embodiments discussed herein can be advantageously employed. The power machine300is similar in some ways to the loader200described above and like numbers represent similar parts unless otherwise indicated below. For example, like the loader200, the power machine300includes a frame310, a lift arm structure330, and a traction system340.

As shown inFIGS.5and6, the frame310is substantially similar to the frame210of the power machine200, although the specific elements of the frame310discussed herein are provided for illustrative purposes and are not intended to represent the only type of frame for a power machine on which the embodiments of this disclosure can be used. Generally, the frame310includes a rear frame end310A opposite a front frame end310B and is generally symmetrical about a longitudinal plane313(e.g., a central vertical plane of the power machine300). The frame310is configured to support a cab350that is similar to the cab250of power machine200and can correspondingly include an operator station355from which an operator can manipulate various control devices (i.e., an operator control system) to cause the power machine300to perform various work functions. Similar to the operator station255(seeFIG.2), the operator station355can include an operator seat and a plurality of operator input devices, for example, a joystick, although other operator input devices can include other control levers or other devices of known configurations that an operator can manipulate to control various machine functions.

The frame310is also configured to operatively support the lift structure330. In the illustrated embodiment, the lift arm structure330includes two lift arms332that are symmetrically configured on opposing lateral sides of the frame310(e.g., on opposing sides of the longitudinal plane313). Accordingly, discussion of one of the lift arms332herein generally applies to the other of the lift arms332. In some embodiments, a different number of lift arms (e.g., only one lift arm) may be provided, or lift arms may not be symmetrically configured.

As illustrated inFIG.5in particular, the lift arm332extends between a proximal end332A (e.g., a first end) located near the rear end310A of the frame310and a distal end310B (e.g., a second end) located near the front end310B of the frame310. Put another way, the first end332A of the lift arm332is disposed closer to the rear end310A of the frame310than to the front end310B of the frame310and the second end332B of the lift arm332is disposed closer to the front end310B of the frame310than to the rear end310A of the frame310. Additionally, the lift arm332generally includes a first portion334A that is pivotally coupled to the frame310at a joint316A and a second portion334B that extends from a pivotal connection to the first portion234A at joint316B toward the second end232B of the lift arm structure230. Thus, the lift structure330is generally configured to operate as a vertical path lift structure that can raise and lower an implement along a non-radial path. In other embodiments, other configurations (e.g., other linkage arrangements) can be used, or a lift structure may be configured to operate as a radial path lift structure.

A second (e.g., distal) portion of a lift arm can be configured as a generally elongate member that can made of one or more sections. For example, in the illustrated embodiment, the second portion334B of the lift arm332includes three sections that are fixedly coupled together to form a main beam of the lift arm332, namely, a first or rear beam portion339A, a second or middle beam portion339B, and a third or front beam portion339C. The first beam portion339A is disposed near the rear end310A of the frame310and includes the joint316B so that the first beam portion339A is coupled to the first portion334A of the lift arm332. The first beam portion339A is also fixedly coupled to (e.g., welded to or integrally formed with) the second beam portion339B opposite the joint316B. The second beam portion339B extends generally toward the front end310B of the frame310, from its connection with the first beam portion339A, to connect with the third beam portion339C proximate the front end310B of the frame310. As illustrated, the second beam portion339B is configured as a generally straight, generally hollow beam, but other embodiments may include various bends or other features and geometries. The third beam portion339C is fixedly coupled (e.g., welded) to the second beam portion339B near the front end310B of the frame310, and is configured to support a work element.

In general, a lift arm can define a lift arm axis that extends generally along a main beam or main section of the lift arm, from a rear end of the lift arm to a front end of the lift arm. For example, as illustrated inFIGS.5and8, the second beam portion339B defines a neutral (e.g., central or centroid) axis337of the second portion334B (and of the lift arm332, generally), which runs centrally along the length of the second portion334B (i.e., along a length taken between the first beam portion339A and the third beam portion339C). In other embodiments, where a main beam of a lift arm is curved, the neutral axis can be correspondingly curved to follow along a local center or centroid of the lift arm. In yet other embodiments, the lift arm axis can be defined in other ways. For example, a lift arm axis can be defined as a center line that follows local midpoints between upper and lower edges of a main beam of a lift arm for a length of the main beam.

With continued reference toFIGS.5and6, the frame310can also be configured to support a variety of other components. For example, similar to the frame210of power machine200, the frame310supports a power source335(seeFIG.6) that is configured to provide power for executing functions on the power machine300, including operations using the traction system340and the lift arm structure330. In the illustrated embodiment, the power source335is an electrical power source (e.g., a battery) that provides electrical power for operation of the traction system340, the lift arm structure330, and other subsystems of the power machine300. The power source335can include a control module (not shown) configured to control the distribution of electrical power to other electrical devices of the power machine300, including motors, linear actuators, and various work elements, as further discussed below. Further, in some embodiments, a control module can be configured to receive signals from other electrical devices, to allow feedback-based or other control of various devices or the power machine300in general.

As generally discussed above, electrical actuators can be usefully employed for non-tractive operations of a work machine. However, in some cases, size and other constraints that are inherent to certain electrical actuators may increase the difficulty of providing optimal physical reach, mechanical advantage, rear visibility, etc. for a lift arm assembly. For example, electrical actuators tend to be longer than hydraulic actuators with similar capacity or capabilities, with increased dead-band length (i.e., the part of overall actuator length that exceeds the length by which the actuator can be extended). Some embodiments of the disclosed technology can address this issue, including by improving the mounting locations and other aspects of mounting configuration for electrical lift actuators. For example, some implementations can use clevis-type connections alone or in combination with fold-back motor configurations or improved mounting locations on a main frame or a lift arm to generally improve packaging and performance for electrically actuated lift arms.

For example, with continued reference toFIGS.5and6, electrically powered lift actuators338and electrically powered tilt actuators373can be used to execute various functions with the lift arm structure330. In the illustrated embodiment, the lift actuators338and the tilt actuators373are supported on opposing lateral sides of the frame310so as to be substantially symmetrical about the longitudinal plane313of the power machine300. Accordingly, discussion of one of the lift actuators338or one of the tilt actuators373herein generally also applies to the other of the respective lift actuators338and tilt actuators373. In other embodiments, different numbers of lift actuators and/or tilt actuators may be provided, or they may not be symmetrically configured.

With additional reference toFIG.7, an example configuration of the lift actuator338is shown in greater detail. As illustrated, the lift actuator338is configured as an electrically powered ball screw actuator that can be controllably extended (e.g., by an operator via a control module) to raise and lower the lift arm332along a travel path (e.g., similar to the travel path233as shown inFIG.2). The lift actuator338includes an electrical motor341and an extendable portion configured as a ball screw342, which are operatively connected to one another via a gearbox343. More specifically, the lift actuator338is in a fold-back motor configuration wherein each respective motor341and ball screw342extend parallel to one another from the same side of the gearbox343. That is, the ball screw342extends away from the gearbox343to define an extension axis344of the lift actuator338, and the motor341extends parallel to and in the same direction as the extension axis344. The ball screw342is configured to linearly extend and retract along the extension axis344when powered by the motor341via the gearbox343.

Although ball screws and fold-back motor configurations may be particularly beneficial relative to lift arm structures discussed herein, in other embodiments, other configurations are possible. For example, a lift actuator can be another type of electrical actuator, including a lead screw, belt driven, or other geared actuator, or can include with motors with in-line or perpendicular configurations.

As also discussed below, a lift actuator can further include one or more mounting features (i.e., connection structures) to pivotally secure and operatively couple the lift actuator between, for example, a frame and a lift arm of a power machine. Although a lift actuator can include various types of connection structures, some arrangements may provide particular stability and utility for electrical actuators, including when implemented in combination with other principles discussed herein. For example, as illustrated inFIG.7, the lift actuator338includes an upright flange345(e.g., similar to a pillow block structure) coupled with and extending from the gearbox343opposite the motor341and the screw342. The flange345is stationary relative to the gearbox343and is configured to receive a bushing or a bearing346that is configured to rotatably couple with, for example, the frame310.

In some cases, the flange345can be configured so that the bearing346is substantially aligned with the extension axis344. In some cases, the flange345may be removably coupled or integrally formed with the gearbox343. Further, in the illustrated embodiment, the bearing346is configured as a spherical bearing that can allow for more axial displacement (i.e., misalignment) than other conventional approaches, and can help to prevent induced side-loading on the body of an associated actuator. In some embodiments, other types of bearings and bushings may also be used.

The lift actuator338further includes an extendable end348that can be extended and retracted with the ball screw342to move linearly relative to the gearbox343. In the illustrated example, the extendable end348has a spherical bearing349that is configured to rotatably couple with, for example, the lift arm332, although other types of ends, bearings, and/or bushings may also be used. The bearing349is configured similarly to the bearing346in the illustrated embodiment, although other configurations are possible.

With additional reference toFIGS.8and9, the lift actuator338is secured to the frame310within a lift actuator pocket336that is disposed proximate the rear end310A of the frame310. The lift actuator338is positioned so that it is in lateral alignment with an associated lift arm332of the lift arm structure330(i.e., is disposed vertically above or below the lift arm332at a common lateral displacement from a centerline of the machine300). In the illustrated example in particular, as shown inFIG.9, the lift actuators338are positioned within the lift actuator pocket336in lateral alignment with the lift arm332, so that the extension axis344is coplanar with a neutral axis337of the lift arm332(or a center line of the lift arm332). Additionally, the lift actuator338is beneficially oriented within the lift actuator pocket336so that the motor341is positioned within the lift actuator pocket336and located rearward of the ball screw342(i.e., closer to the rear end310A of the frame310) at all operational positions of the lift arm332(e.g., throughout the entire travel path of the lift arm332).

For example, by mounting the lift actuator338in this manner, the frame310can be configured to include an angled lower-rear surface315so that a bottom side of the lift actuator pocket336angles upward proximate the rear end310A of the frame310. That is, the angled lower-rear surface315of the lift actuator pocket336angles upward, moving toward the rear end310A, relative to a horizontal plane defined by a bottom of the frame310or by level ground on which the power machine300rests. The inclusion of the angled surface315can increase a departure angle317(seeFIG.5) of the power machine300(i.e., an angle between the ground and a line drawn between the rear of the track and the bottom of the frame in the rear of the machine) as compared to conventional designs with otherwise similar configurations. Additionally, as also discussed below, such an arrangement can also allow for a relatively large actuator to be fitted to the power machine300, which can increase the overall range of motion of the lift arm structure330and provide improved load handling capabilities (e.g., increasing lift arm speed and acceleration, and increasing a maximum allowable load). Generally, an electrical lift actuator arranged as disclosed herein can allow for a departure angle of at least 25 degrees.

Relatedly, positioning a lift actuator within a lift actuator pocket can provide advantages over conventional mounting configurations. For example, by positioning the motor341within the lift actuator pocket336, sensitive motor components (e.g., electrical components) can be protected from damage, including from external impacts, with the lift actuator pocket336providing lateral and rear shielding for the motor341. Likewise, further protection of the motor341may be achieved when the motor341is disposed behind the ball screw342as a result of the fold-back configuration. Furthermore, positioning the motor341within the lift actuator pocket336can allow for particularly efficient routing of, for example, electrical power, control signal wire (e.g., control cables), and cooling lines (not shown). In this arrangement, the wires can also be protected from damage, as lengths of the wires can be run completely or substantially internal to the power machine300, and thus may not be exposed to the exterior of the power machine300. Moreover, pinch points that may catch and damage the wires can be reduced or eliminated. In particular, some examples can include high voltage wires (i.e., cables or other wires for signals of 40V or more), that can extend within a lift arm for substantially all of a length of the wires or of a portion of the lift arm. In some examples, high voltage or other wires can be entirely enclosed along all or substantially all of a length of a main beam or other portion of a lift arm, including within a fully enclosed volume defined by a body of the lift arm or by a partly enclosed volume defined by a body of the lift arm in combination with an attached cover. In other embodiments, other components, for example, hydraulic lines, of the power machine300can be run through a lift arm and into a pocket in a similar manner.

In other embodiments, a lift actuator can be mounted to a power machine differently. For example, a lift actuator may be connected to different parts of a frame or a lift arm and can be oriented differently (e.g., inverted from the orientation shown inFIG.8). Additionally, a lift actuator may sometimes not be secured within a lift actuator pocket, for example, in retrofit applications where an electric lift actuator is used to replace a conventional hydraulic lift actuator.

A lift actuator can be operatively coupled between a frame and a lift arm of a power machine so as to move (e.g., lift) the lift arm relative to the frame. For example, in the illustrated embodiment, the lift actuator338is pivotally coupled to the frame310within the lift actuator pocket336at a lower (e.g., first) pivot connection319and to the lift arm332at an upper (e.g., second) pivot connection321. The pivot connection319is configured as a pinned, clevis-joint connection, and the lift actuator338is positioned so that the bearing346can receive a pin319A supported by inboard and outboard sides of the lift actuator pocket336, to form the pivoting connection319and thereby allow the lift actuator338to pivot relative to the frame310. The pin319A can be secured on the exterior of the lift actuator pocket336by a plate or collar319B to prevent the pin319A from disengaging from the lift actuator338during operation or can be otherwise secured using various known arrangements.

With particular reference toFIG.9, the pivot connection321is also configured as a pinned, clevis-joint connection, with the extendable end348positioned so that the bearing349is in axial alignment with each of an outboard collar321A and an inboard collar321B on the lift arm332. Accordingly, a pin321C can then be inserted through each of the first collar321A, the second collar321B, and the bearing349to form the second pivot connection321, which allows the lift actuator338and the lift arm332to pivot relative to one another. In some embodiments, one or both of the first collar321A and the second collar321B can be configured as a locking collar to prevent a corresponding pin from disengaging from the lift actuator338during operation. For example, in the illustrated embodiment, only the first collar321A is configured as a locking collar.

In some embodiments, pinned clevis-joint connections, including those described above, can allow for an electrical lift actuator to be readily installed in place of a hydraulic lift actuator, including in operations to convert or repurpose a power machine or power machine frame for electrically powered operations. Further, particularly for pivotal connections between lift actuators and frames of power machines, clevis-joint connections can provide notable improvements in placement of a lift actuator of a given size, as can improve departure angle and available range of movement for a lift arm. In other embodiments, however, electrical lift actuators can be secured to a power machine frame in other ways (e.g., using different types of connections).

In some cases, the position of a connection between a lift arm and a lift arm actuator can provide benefits for electrical lift actuators (and other types of actuators, in some cases). In that regard, in some embodiments, the position of a connection between a lift arm and a lift arm actuator can be beneficially located along a height of a power machine. For example, with continued reference toFIGS.8and9, the upper pivot connection321is disposed within the lift arm332, thereby increasing a minimum straight-line distance (e.g., a distance taken with the lift arm332in a fully lowered position) between a rotational axis319C of the pivot connection319(e.g., an axis of the pin319A) and a rotational axis321D of the pivot connection321(e.g., an axis of the pin321C), as compared with conventional mounting configurations (e.g., wherein a lift actuator is mounted below a lift arm).

In some embodiments, as shown inFIG.8in particular, the second pivot connection321can be provided so that the corresponding rotational axis321D is at or above the neutral axis337of the lift arm332or another relevant reference axis (e.g., center line of the lift arm332). Put another way, the rotational axis321D can be disposed so that the neutral axis337intersects the rotational axis321D or so that the neutral axis337passes between the rotational axes319C,321D (i.e., so that the rotational axis319C of the first pivot connection319and the rotational axis321D of the second pivot connection321are on opposite sides of the neutral axis337when viewed from a lateral side of the power machine300). Relatedly, the rotational axis321D of the second pivot connection321can be beneficially disposed at a midpoint between a local top side of the lift arm332and a local lower side of the lift arm332, as measured along the extension direction of the lift actuator338, or closer to the local top side of the lift arm332than to the local lower side.

Furthermore, the position of a connection between a lift arm and a lift arm actuator can be beneficially located along a length of a power machine or a lift arm. For example, as illustrated inFIGS.5and8, the upper rotational axis321D can be disposed so that it is rearward of a rotational axis of a rearmost idler347of a tractive element of the traction system340(seeFIG.5). In other embodiments, for example, on a wheeled power machine, the rotational axis321D of the second pivot connection321can be disposed rearward of an axle of a rear wheel of the power machine300(or, similarly, rearward of a rear axle of a quad-track or other power machine).

In some embodiments, it may provide favorable kinematics and otherwise improve performance, while also improving the protective value of pockets for lift arm actuators, to locate a pivotal connection between a lift actuator and a lift arm toward a rear portion of the lift arm. For example in some embodiments, the rotational axis321D of the second pivot connection321can be disposed along a rear half, a rear third, or a rear quarter of the lift arm332or of a portion thereof (e.g., the second portion334B or main beam of the lift arm332). In some embodiments, it may be similarly useful to dispose the rotational axis321D to remain rearward of the operator station350or an axis of a drive shaft (e.g., a drive shaft351of a tractive element of the traction system340, as shown inFIG.5) of a power machine for all orientations of the lift arm332.

As a result of the different configurations discussed above, alone and in various combinations, a power machine can generally be fitted with larger lift actuators than may be possible with conventional designs, which may, for example, provide increased power and allow for an increased range of motion of a lift arm. Additionally, the improved lift actuator configurations discussed herein can also provide a power machine with an increased mechanical advantage as compared to some conventional designs, as may also improve overall power machine utility.

In some cases, with a lift actuator in lateral alignment with an associated lift arm (e.g., disposed vertically below, as shown), the lift arm can be configured to receive at least a portion of the lift actuator, as can improve protection of certain components and range of motion of a lift arm in general. For example, with continued reference toFIGS.8and9, the lift arm332includes a pocket323that is configured to receive a distal end of the ball screw342and the extendable end348within the lift arm332to form the second pivot connection321. More specifically, in the illustrated embodiment, the first beam portion339A includes opposing flared lateral side portions325that extend as sidewalls below the main body of the main portion334B of the lift arm, on inboard and outboard sides of the pocket323, to define the lower opening331that opens into the pocket323and allow the ball screw342to pivot freely within the lift arm332. In that regard, the flared portions325and the pocket323are sized and shaped to ensure that the ball screw342does not contact the lift arm332throughout an entire range of travel of the lift arm332(i.e., along an entire travel path). Additionally, the second beam portion339B includes a recessed profile327at a proximal end thereof (seeFIG.8) to ensure that the extendable end348also does not contact the lift arm332throughout an entire range of travel of the lift arm332.

As also similarly discussed relative to the lift arm332generally, it may be beneficial in some cases to locate a lift actuator to extend through a particular part of a pocket in a lift arm at a particular orientation of the lift arm. For example, as shown inFIG.8in particular, the ball screw342of the lift actuator338extends through a forward half of the pocket323when the lift arm332is in the fully lowered configuration.

Providing an opening within a lift arm to receive a lift actuator can also provide benefits in some configurations. For example, by including flared portions around an opening, larger lift actuators can be fitted to a power machine. Additionally, the lift arm can thereby provide protective shielding for any components disposed within the lift arm, including, for example, a bearing of an extendable portion of the lift arm that forms part of the pivot connection with the lift arm.

Continuing, with reference toFIG.10, the tilt actuator373is secured to the lift arm332near the front332B of the second portion334B of the lift arm332and proximate the front frame end310B. More specifically, the tilt actuator373is secured and extends within a tilt actuator pocket380formed in the third beam portion339C of the lift arm332, so that it is in lateral alignment with the second beam portion339B (e.g., a main beam) of the lift arm332. In some cases, a tilt actuator can be substantially laterally aligned with a main beam of a lift arm. That is, at least half of a width (e.g., a dimension taken perpendicular to the longitudinal plane313, as shown inFIG.6) of the tilt actuator may be in lateral alignment with a main portion of a lift arm.

A tilt actuator can be configured to operatively connect between a lift arm of a lift arm structure and an implement carrier or implement. In particular, and as will be discussed in greater detail below, the tilt actuator373is rotatably coupled between the lift arm332and an implement carrier372(seeFIG.6), which is generally similar to the implement carrier272(seeFIG.2). In this regard, the tilt actuator373is configured to controllably rotate the implement carrier372and any attached implement relative to the lift arm structure330. Thus, for example, a control module can electronically control operation of the tilt actuators373, as powered by the power source335, in order to selectively change an attitude of an implement secured to the implement carrier372with respect to the lift arm332. In some embodiments, an implement may be directly attached to a lift arm structure, rather than being attached to a lift arm structure via an implement carrier. In such cases, the tilt actuator373can be used in a similar manner to adjust the attitude of an implement directly, rather than by adjusting an attitude of an implement carrier.

Referring now toFIGS.10-15, in the illustrated embodiment, the tilt actuator373is configured as an electrically powered ball screw actuator, which is similar to the lift actuator338described above (seeFIG.7). In particular, each tilt actuator373includes a motor374(i.e., an electrical motor) and an extendable portion configured as a ball screw375, which are operatively connected to one another via a gearbox376. More specifically, the tilt actuators373are in a fold-back motor configuration wherein each respective motor374and screw375extend parallel to one another from the same side of the gearbox376(seeFIG.13), with the motors374beneficially located rearward of the screws375. That is, the screw375defines and extends away from the gearbox376along an extension axis377(seeFIG.12) and the motor374extends parallel to and in the same direction as the screw375. The screw375is configured to linearly extend and retract along the extension axis377when powered by the motor374via the gearbox376. More specifically, the motor374can be controlled by commands from a control module (i.e., in response to operator input), thereby controlling the extension and retraction of the screw375.

Although ball screws and fold-back motor configurations may be particularly beneficial relative to lift arm structures discussed herein, in other embodiments, other configurations are possible. For example, a tilt actuator can be another type of electrical actuator, including a lead screw, belt driven, or other geared actuator, or can include with motors with in-line or perpendicular configurations. Moreover, a tilt actuator may be otherwise arranged differently than illustrated, including with in-line motor configurations.

Although a tilt actuator can include various connection structures to pivotally secure the tilt actuator to a lift arm, some arrangements may provide particular stability and utility for electrical actuators, including when implemented in combination with other principles discussed herein (e.g., the disclosed lateral alignments, pocket-mounted configurations, etc.) For example, as also shown for the illustrated embodiment inFIGS.13and14, each tilt actuator373includes an upright flange378(e.g., similar to a pillow block structure) coupled with and extending from the gearbox376opposite the motor374and the screw375. The flange378is stationary relative to the gearbox376and is configured to receive a bushing or bearing379that is configured to rotatably couple with a portion of the respective lift arm232. Here, the bearing379is configured as a spherical bearing that can allow for some axial displacement (i.e., misalignment) or can help to prevent induced side-loading on the body of an associated actuator, although other types of bearings and bushings may also be used. The flange378may be removably coupled or integrally formed with the gearbox376.

Additionally, each of the tilt actuators373further includes an extendable end381disposed at a distal end of the screw375(i.e., an end of the screw375disposed furthest away from the gearbox376). Here the extendable end381includes a similar spherical bearing382that is configured to rotatably couple with the implement carrier372, although other types of ends, bearings, and/or bushings may also be used. The extendable end381can be extended and retracted with the screw375to move linearly relative to the gearbox376and thereby, via the spherical bearing382, adjust the attitude of the implement carrier372.

With continued reference toFIGS.10-14, the third beam portion339C (i.e., the second end332B of the lift arm332) includes a leg334C (e.g., an inner leg) of the lift arm332and an inward jog383that extends between the second beam portion339B of the lift arm332and the leg334C (e.g., an inner leg) of the lift arm332. As shown in the illustrated embodiment, the inward jog383and the leg334C can be integrally formed with one another. Further, the inward jog383is configured so that the leg334C of the lift arm332is generally positioned closer to the longitudinal plane313ofFIG.6(i.e., more laterally inward) than the second beam portion339B (e.g., a main beam) of the lift arm332. In other words, the leg334C is generally offset laterally inward from the second beam portion339B. In particular, in the illustrated example, the inward jog383angles downward and laterally inward from the second beam portion339B to connect with the leg334C. The leg334C is shown as being generally parallel to the second beam portion339B, as viewed from the front, but it may also be laterally angled (i.e., not parallel) relative to the second beam portion339B.

As shown in the illustrated embodiment, the inward jogs383and the legs334C can be integrally formed with one another. Taken together, the inward jogs383and the legs334C form a lower beam as a front portion of the lift arm332, which is coupled with the main beam or second portion334B of the lift arm332at a bent knee of the lift arm332. Here, the front portion of the lift arm332is welded to the second portion334B but other configurations are possible. For example, a front portion of a lift arm may be fastened to a second portion of the lift arm to allow the front portion to be replaced with a different front portion or other structure.

As mentioned above, the third beam portion339C of the lift arm332is generally configured to couple with and support the tilt actuator373in the desired orientation for rotating the implement carrier372(seeFIG.6) to adjust the attitude of the implement carrier372relative to the lift arm332. Correspondingly, the third beam portion339C of the lift arm332is coupled with and extends downwardly from the front-most part of the second beam portion339B of the lift arm332(i.e., an end of the second beam portion339B that is nearest the second end332B of the lift arm332). In this way, the third beam portion339C of the lift arm332is the lowest portion of the lift arm332when the lift arm332is in its lowest configuration (see.FIG.5) so that the implement carrier and implement can be positioned near or in contact with a support surface (e.g., the ground).

The inward jogs383of the third beam portion339C of the lift arm332can provide beneficial lift arm geometries in some cases. For example, the inward jog383can allow the tilt actuator373to extend along a laterally exterior side of the leg334C of the lift arm332, without excessively extending the lateral footprint of the lift arm structure330. Because the tilt actuator373can be mounted to extend laterally outward of the leg334C, the available lateral space near the implement carrier372and a front frame end310B can be increased, as compared to conventional arrangements. This increased lateral space can provide operators with more room to enter and exit the power machine300. Additionally, as will be discussed below, operator visibility can be improved. Further, the tilt actuator373can be positioned below and in substantial lateral alignment with the second beam portion339B of the lift arm332, which can reduce moments and other stresses on the lift arm332due to loading, thereby providing for a more efficient operation of the lift arm structure330and the power machine300generally. Relatedly, the tilt actuator373can also be coupled higher and further rearward towards the second beam portion339B of the lift arm332, allowing for improved mechanical advantage and increased actuator stroke length.

In some cases, a tilt actuator pocket can be formed at an inward jog. A tilt actuator pocket can provide a variety of benefits for mounting tilt actuators, including by improving structural strength as well as shielding actuators, including any associated connectors and/or cables, from debris or damage from certain impacts. With continued reference toFIGS.10-14, in the illustrated embodiment, the tilt actuator pocket380is disposed generally in front of and below the second beam portion339B of the lift arm332and laterally exterior to the leg334C of the respective lift arm332.

The tilt actuator pocket380is configured to form a protective housing that at least partially surrounds (i.e., encloses) the tilt actuator373. More specifically, the tilt actuator pocket380is formed as downward opening recess that receives at least a portion of the tilt actuator373. Accordingly, the tilt actuator pocket380is configured to receive at least part of the corresponding tilt actuator373therein, with a width and a length of the tilt actuator pocket380being correspondingly sized. In particular, in the illustrated embodiment, an interior of the tilt actuator pocket380has a first width (i.e., a dimension perpendicular to the longitudinal plane313) that is larger than a corresponding first width of the motor374of the tilt actuator373, and a second width (i.e., a dimension that is parallel to the longitudinal plane313) that is larger than a corresponding second width of the tilt actuator373. Thus, as further discussed below, at least a portion of the tilt actuator373can be received within the tilt actuator pocket380to be shielded on front, rear, lateral, and top sides thereof during operation, thereby helping to reduce or prevent impacts on the tilt actuator373and also provide improved debris or water shielding.

In some embodiments, the tilt actuator pocket380may include an interior opening384(seeFIG.13) that receives and opens into the second beam portion339B of the lift arm332. Because the second beam portion339B of the lift arm332is hollow, power and/or signal cables (not shown) for the tilt actuator373can thus be run through the second beam portion339B of the lift arm332and into the tilt actuator pocket380. In this arrangement, the cables can be protected from damage, as they can be run completely or substantially internal to the power machine300, and thus may not be exposed to the exterior of the power machine300. Relatedly, pinch points that may catch and damage the cables can be reduced or eliminated. In other embodiments, other components, for example, hydraulic lines, of the power machine300can be run through a lift arm and into a pocket in a similar manner.

A tilt actuator pocket can have a variety of shapes and is configured to generally shield the front, back, and both lateral sides of the respective tilt actuator, particularly along an upper portion of the tilt actuator. In the illustrated embodiment, the tilt actuator pocket380includes a first, laterally outward wall385generally opposite a second, laterally inward wall386, and a third, front wall387generally opposite a fourth, back wall388, all of which are coupled with and extend generally downward from a fifth or top wall389to provide an inward taper toward the top wall389. The laterally outward wall385is coupled with and extends between each of the second portion334B of the lift arm332, the top wall389, and the front wall387and thus provides a structural connection between the second and third beam portions339B,339C (i.e., between the second beam portion339B and the leg334C). The laterally inward wall386is coupled with and extends between each of the front wall387, the back wall388, and the top wall389and thus also provides a structural connection between the second and third beam portions339B,339C. The front wall387is coupled with and extends between each of the laterally outward wall385, the laterally inward wall386, and the top wall389. The back wall388is coupled with and extends between each of the second portion334B of the lift arm332, the laterally inward wall386, and the top wall389. In other embodiments, the tilt actuator pocket380can be formed from more or less panels and/or other portions of the lift arm332. In that regard, the various panels that define the tilt actuator pocket380may also be arranged and connected differently.

Each of the respective walls of the tilt actuator pocket380can be comprised of one or more panels (i.e., portions) that are coupled with one another. For example, the top wall389includes a first, rear top panel389A, and a second, front top panel389B that is angled downward and forward from the rear top panel389A, the laterally inward wall386includes a first, lower laterally inward panel386A and a second, upper laterally inward panel386B extending upward and laterally outward from the laterally inward panel386A, and the front wall387includes a first, lower front panel387A and a second, upper front panel387B.

Additionally, the walls that make up a tilt actuator pocket can be sized to provide varying amounts of protection for the tilt actuator. That is, a tilt actuator pocket may fully enclose a tilt actuator for at least a portion of a length of the tilt actuator (i.e., a length taken along an axis of extension of the tilt actuator). For example, in the illustrated embodiment, the flange378, gearbox376, and a portion of each of the motor374and the screw375are enclosed by the tilt actuator pocket380. As a result, comparatively sensitive electric connections and related components can be particularly well protected by the tilt actuator pocket380from possible damage, including due to contact or water ingress. Further, the particular configuration illustrated can also help to reduce overall lift arm weight and improve access for maintenance. Similarly, substantially all of the laterally interior side of the tilt actuator373is protected from contact by the laterally inward wall386of the tilt actuator pocket380and the extension of the leg334C beyond the tilt actuator pocket380. In other embodiments, the various walls of the tilt actuator pocket380may enclose more or less of the tilt actuator373.

In some cases, tilt actuator pockets or similar other mounting configurations for a tilt actuator can help to reduce or eliminate interference with a line of sight of an operator relative to an implement or other reference frame. For example, with reference toFIG.12in particular, the upper front panel387B is obliquely angled between the lower front panel387A, the front top panel389B, and the upper laterally inward panel386B. More specifically, the upper front panel387B is angled downward from a perspective moving from back to front of the power machine300, and laterally outward relative to the longitudinal plane313. Thus, the lift arm332, and more specifically the inward jog383, may not substantially protrude (e.g., may not protrude at all) into a field of view of the operator (i.e., as partially represented by line of sight390) that may be defined by a reference operator height (e.g., 5.0 ft. to 6.5 ft., inclusive) and a reference implement width (seeFIGS.6,11, and13). With the upper front panel387B oriented as shown, an operator may be able to see all or substantially all of the (e.g., an entire) width of a cutting edge of a bucket attached to the lift arm structure330(seeFIG.6), which may not be possible with electrical actuators attached to conventional lift arm designs. In other embodiments, lift arms and the various panels that comprise the tilt actuator pockets may be configured differently to achieve similar results. For example, tilt actuator pockets can alternatively or additionally include cut-outs or recesses.

In addition to other benefits described above and below, tilt actuator pockets may be beneficial for reducing weight of a lift arm structure while maintaining appropriate structural integrity of the lift arm structures. In this regard, for example, some tilt actuator pockets in lift arms can be formed to partly include walls (e.g., for shielding rather than structural support between lift arm portions) that are made of separate, lighter material than the material of other parts of the lift arms.

As well as providing an otherwise beneficial lift arm geometry and protection for a tilt actuator, an inward jog and an associated tilt actuator pocket can also provide useful mounting features and configurations for tilt actuators. Specifically, with reference toFIGS.13and14, the tilt actuator373is rotatably coupled (e.g., by a pinned connection) to the lift arm332within and at a proximal end of each of the tilt actuator pocket380, thereby placing the tilt actuator373in a relatively protected position. In the illustrated embodiment, a first attachment structure392is provided in the tilt actuator pocket380, near the inward jog383, to rotatably couple to the motor and gearbox end of the tilt actuator373at the flange378.

In some embodiments, particular configurations of attachment structures for tilt actuators may be particularly beneficial, and in some cases, particularly for use with electrical tilt actuators. In this regard, in the illustrated example, the first attachment structure392is configured as a double-sided pinned connection, with a clevis joint formed for the tilt actuator373by a pair of bosses393extending laterally inward into the tilt actuator pocket380from each of the laterally outward wall385and the laterally inward wall386. The bosses393are aligned with one another to define a pivot axis396of the first attachment structure392. Additionally, the bosses393are spaced from one another within the tilt actuator pocket380to allow the flange378and the corresponding bearing379to be disposed between the bosses393. Thus, the pin394can be inserted through the bosses393and the bearing379of the tilt actuator373to secure the tilt actuator373in the tilt actuator pocket380. When the pin394is received by the bearing379, the bearing379is aligned with the pivot axis396. In that regard, the pin394can be fixed relative to the bosses393so that the relative rotation of the tilt actuator373about the pivot axis396is provided solely by the bearing379. This arrangement, as facilitated by the location and geometry of the corresponding pocket(s), can help to reduce adverse moments or torsional stresses on relevant components, although other configurations, including methods for securing a tilt actuator in a pocket are also possible.

In some embodiments, a clevis-joint arrangement to secure an electrical actuator can provide additional benefits. For example, referring toFIG.13, the clevis-joint connection between the tilt actuator373and the third beam portion339C (e.g., at the bearing379and the flange378, in particular) can be laterally aligned with a lateral side wall of the second beam portion339B (e.g., the laterally interior side wall of the second beam portion339B, as shown). This arrangement can help to provide improved stability and loading of electrical (or other) tilt actuators, while also allowing for improvements in shielding, as generally discussed above. Further, in some cases, the structural supports for a clevis-joint connection can also help to provide improved visibility. For example, with the illustrated arrangement, a support wall for the boss393can stand proud of the wall386(and the panel386B in particular) with a relatively small profile, thereby ensuring appropriate structural support for the tilt actuator373while also facilitating a relatively substantial outward angling of the wall386and a corresponding increase in visibility. Similarly, a clevis-joint arrangement can help to facilitate improved packaging by allowing a tilt actuator to extend only laterally to the inside of a laterally exterior boundary of a lift arm structure as a whole (e.g., as shown for the tilt actuator373and the lift arm structure330inFIG.13) so that the tilt actuator does not increase the overall lateral footprint of the lift arm structure.

Turning now toFIGS.15and16, tilt actuator pockets can also provide beneficial arrangements of auxiliary connectors to supply power to powered implements. In the illustrated embodiment, the top wall389of the tilt actuator pocket380includes an electrical connector398. Due to the tilt actuator pocket380being internally connected with the second beam portion339B of the lift arm332, power cables (not shown) for the electrical connector398can be run internally (e.g., within the second beam portion339B of the lift arm332) to protect them from damage, pinch points, etc. Furthermore, by placing the electrical connector398on the top wall389, it may be easier for an operator to use the electrical connector398, as compared to conventional designs in which the connector may be in more confined space. In some embodiments, a guard399may be provided to protect the electrical connector398from damage. In other embodiments, an electrical connector can be provided on other portions of a pocket or lift arm generally, for example a front wall, a laterally exterior wall, a back wall, or a laterally interior wall of a tilt actuator pocket. Furthermore, other types of connectors may be provided in a similar manner, including, for example, a hydraulic connector.

Thus, embodiments of the disclosed power machine and components thereof can provide improvements over conventional designs. For example, the quick response and precise control provided by electrical actuators can allow work elements, including traction elements, lift arms, and implement carriers, to be adjusted quickly and accurately, including with complex and adaptable control strategies as implemented by electronic control modules. Further, electrical actuation and control can, in some instances, simplify automated implementation of repetitive or iterative movements of work elements, while also reducing the need for maintenance and eliminating problems associated with leakage of hydraulic fluid and other related issues.

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 to the disclosed embodiments without departing from the spirit and scope of the concepts discussed herein.