Visible motor saw head layout

A housing assembly (26) for a working assembly (10) of an outdoor power device (20) may include a first, second, and third housing portion. The second and third housing portions may be operably coupled to the first housing portion to at least partially enclose a motor housing (60), which may comprise a body portion (62), a top endplate (64), and a bottom endplate (66) to house an electric motor for driving the working assembly (10). The first, second, and third housing portions may combine to define a first opening and a second opening (132, 134) such that two opposing sides of the body portion (62) are exposed in respective ones of the first and second openings (132, 134). In addition, or alternatively, a gap (130) may separate the housing assembly (26) from the entirety of the top endplate (64), the entirety of the body portion (62), and a substantial majority of the bottom endplate (66).

TECHNICAL FIELD

Example embodiments generally relate to an outdoor power device that is electrically powered and, more particularly, relate to a cutting device with a cutting head that has an open housing, such that the motor is exposed and visible.

BACKGROUND

Handheld outdoor power devices such as trimmers, blowers, chainsaws, and/or the like, are often used to perform tasks relating to yard/grounds maintenance or even commercial resource harvesting activities that require them to be mobile. Such devices often have a working implement adjacent to, or extending from, a battery powered electric motor. In designing these devices, it is important that the devices remain lightweight to ensure comfortable and ergonomic operation. In addition, it is important the motor be properly cooled, so that the motor does not overheat during operation, resulting in damage to itself, other device components, or the device housing.

In actively cooled devices, a fan or other means for forcing air is incorporated into the device on or near the motor head. In this manner, the fan forces ambient air past the motor to enhance cooling. However, while effective, active cooling results in additional weight due to the fan, its support structure, and its control electronics. In this regard, the additional size and weight may make the device too heavy.

Passive cooling eliminates the need for including a cooling fan in the cutting head and thus reduces the size and weight of the device significantly. However, to be effective, passive cooling systems must be carefully designed to ensure sufficient cooling air flow rate. In addition, it is desirable to design passive cooling systems in a manner that keeps the overall weight of the device as light as possible.

To improve upon this situation, it is desirable to design outdoor power devices in a manner that is small, lightweight, ergonomic, and provides sufficient cooling capacity for the motor.

BRIEF SUMMARY OF SOME EXAMPLES

Some example embodiments may therefore provide an outdoor power device with a working assembly that comprises a motor housing that is exposed and visible. In this regard, the housing of the working assembly may comprise a chassis base, an oil reservoir, and a housing arm which combine to partially enclose a motor housing, thereby defining two openings through which the motor housing is directly exposed to cooling air on two opposing sides. In addition, some embodiments provide a motor housing that only contacts the working assembly housing where it is attached by support towers. A gap may exist around substantially the entire motor housing, resulting in improved passive cooling and reduced need for active cooling systems. Accordingly, some embodiments may provide a low profile, lightweight, and passively cooled motor housing for an outdoor power device. An operator of the device may therefore experience less fatigue and improved visibility of the working implement, while the motor experiences improved cooling capacity without the need for an active cooling system.

In accordance with an example embodiment, a housing assembly for a working assembly of an outdoor power device is provided. The housing assembly may include a first, second, and third housing portion, wherein the second and third housing portions may be operably coupled to the first housing portion to at least partially enclose a motor housing. The motor housing may comprise a body portion, a top endplate, and a bottom endplate to house an electric motor for driving the working assembly. The first, second, and third housing portions may combine to define a first opening and a second opening such that two opposing sides of the body portion are exposed in respective ones of the first and second openings.

A working assembly of an outdoor power device may comprise an electric motor for driving the working assembly, the motor being housed in a motor housing comprising a body portion; a bottom endplate; and a top endplate. The working assembly may further comprise a housing assembly comprising a plurality of housing portions enclosing the motor housing in a space defined by said plurality of housing portions, wherein the plurality of housing portions combine to define a first opening and a second opening such that two opposing sides of the body portion of the motor housing are exposed in respective ones of said first and second openings. Said plurality of housing portions may comprise a first housing portion; a second housing portion operably coupled to the first housing portion; and a third housing portion operably coupled to the first housing portion to define said space, wherein said first, second, and third housing portions combine to define said first opening and said second opening.

A number of embodiments of the housing assembly and the working assembly hereinabove are conceived. By way of example, said exposed, opposing sides of the body portion may be unobscured by any gratings or louvers, so as to allow an unobstructed passive cooling flow of ambient air past said exposed, opposing sides of the body portion. A respective total area of each of said first and second openings may be more than 5%; preferably more than 10%; and even more preferred, more than 15% of a total outer surface area of the motor housing, to allow a substantial passive cooling. Said exposed, opposing sides of the body portion of the motor housing may protrude out of said space defined by said plurality of housing portions, to even further increase heat exchange with the ambient air. The motor housing may have a substantially cylindrical, and preferably, substantially circular-cylindrical shape, the mantle of the cylindrical shape defining said body portion.

The first housing portion may comprise a chassis base that is configured to receive the motor housing such that the bottom endplate is proximate to and covered by the chassis base, but such that a majority of the bottom endplate is not in contact with the chassis base. The bottom endplate of the motor housing may comprise a plurality of support towers for rigidly fixing the motor housing to the chassis base. An insulating gasket may be interposed between the one or more support towers and the chassis base.

The second housing portion may comprise an oil reservoir that covers a portion of the body portion without contacting the motor housing.

The third housing portion may comprise a housing arm that extends over the motor housing such that the housing arm covers at least a portion of both the top endplate and the body portion without contacting either the top endplate or the body portion. The housing arm may extend from the first housing portion to the second housing portion such that it defines the first opening and the second opening, and wherein a portion of the top endplate is exposed in each of the first and second openings. The housing arm may be configured to receive electrical wiring.

A gap may separate the housing assembly from the entirety of the top endplate, the entirety of the body portion, and a substantial majority of the bottom endplate. The gap between the motor housing and the first, second, and third housing portions may be approximately 1-3 mm.

The body portion may comprise a plurality of radially extending cooling fins. The first housing portion may be proximate to and cover the bottom endplate. The second housing portion may be proximate to and cover a portion of the body portion. The third housing portion may comprise a housing arm proximate to and covering a portion of the body portion and the top endplate. The two opposing sides of the body portion that are exposed in respective ones of the first and second openings may be formed on either side of the housing arm. An entire height of the body portion, and preferably a portion of the top endplate, may be exposed in respective ones of the first and second openings to allow for a substantial exposure of the motor housing to ambient air.

A working assembly of an outdoor power device may, according to an exemplary embodiment, comprise a motor housing comprising a cylindrical body portion, a top endplate, and a bottom endplate; and a housing assembly comprising a chassis base, an oil reservoir, and a chassis arm, wherein the bottom endplate of the motor housing is attached to the chassis base such that chassis base covers only the bottom endplate, wherein the oil reservoir is connected to the chassis base such that it covers only a first portion of the cylindrical body portion, wherein the chassis arm extends over the motor housing from the oil reservoir to the chassis base such that it only covers a portion of the top endplate and a second portion of the cylindrical body portion, and wherein the first portion and the second portion of the cylindrical body portion are on opposite sides of the motor housing.

The bottom endplate of the motor housing may comprise a plurality of support towers for rigidly fixing the motor housing to the chassis base, the support towers defining a contacting portion of the bottom endplate. A gap may separate the housing assembly from the entirety of the top endplate, the entirety of the body portion, and all but the contacting portion of the bottom endplate. The gap between the motor housing and the housing assembly may be approximately 1-3 mm. An insulating gasket may be interposed between the plurality of support towers and the chassis base. The chassis arm may extend from the chassis base to the oil reservoir such that it defines the first opening and the second opening, and wherein portions of the cylindrical body and the top endplate are exposed in each of the first and second openings. The chassis arm may be configured to receive electrical wiring.

An outdoor power device may comprise a power assembly comprising an electric power source; a working assembly according to any of the embodiments described hereinabove; and a control assembly for selectively providing power from the power assembly to the electric motor of the working assembly.

According to an exemplary embodiment, an outdoor power device may comprise a working assembly comprising a housing assembly and an electric motor disposed in a motor housing, the motor housing comprising a body portion, a top endplate, and a bottom endplate; a power assembly comprising an electric power source; and a control assembly for selectively providing power from the power assembly to the working assembly via the electric motor; and wherein the housing assembly comprises a first housing portion that is operably coupled with a second housing portion and a third housing portion to at least partially enclose the motor housing such that two opposing sides of the motor housing are exposed, and wherein the first, second, and third housing portions combine to define a first opening and a second opening such that two opposing sides of the body portion are exposed in respective ones of the first and second openings.

The outdoor power device according to any of the embodiments described hereinabove may further comprise a front handle and a rear handle, wherein said front and rear handles are different from the housing assembly. Said housing portions and said front and rear handles may be separate components. Said power assembly and said working assembly may be attached to opposite ends of a pole. The outdoor power device may be an electrically powered gardening or forestry tool, such as a vegetation cutting tool. The first housing portion may comprise a chassis base that is configured to receive the motor housing such that the bottom endplate is proximate to and covered by the chassis base, but such that a majority of the bottom endplate is not in contact with the chassis base. The bottom endplate of the motor housing may comprise a plurality of support towers for rigidly fixing the motor housing to the chassis base. An insulating gasket may be interposed between the one or more support towers and the chassis base.

The second housing portion may comprise an oil reservoir that covers a portion of the body portion without contacting the motor housing. The third housing portion may comprise a housing arm that extends over the motor housing such that it covers at least a portion of both the top endplate and the body portion without contacting either the top endplate or body portion. The housing arm may extend from the first housing portion to the second housing portion such that it defines the first opening and the second opening, and wherein a portion of the top endplate is exposed in each of the first and second openings. The housing arm may be configured to receive electrical wiring. A gap may separate the housing assembly from the entirety of the top endplate, the entirety of the body portion, and a substantial majority of the bottom endplate. The gap between the motor housing and the first, second, and third housing portions may be approximately 1-3 mm.

DETAILED DESCRIPTION

Some example embodiments described herein provide an outdoor power device with a partially exposed and visible motor, thus providing a low profile, lightweight construction that provides improved cooling capacity. In this regard, some embodiments may employ a work assembly (e.g., a cutting head) that has a housing comprising a chassis base, an oil reservoir, and a housing arm which combine to partially enclose a motor housing. In this manner opposing sides of the motor housing are exposed to the ambient cooling air for improved cooling. In addition to improving the passive cooling of the motor, such a construction decreases the size of the working assembly, thus providing improved working visibility. The construction is also lightweight, such that operator comfort and device maneuverability is improved.

Referring to the drawings,FIG. 1shows a functional block diagram of a device configured in accordance with an example embodiment. The device may include a working implement or working assembly10that is operably coupled to a power assembly12. The power assembly12may have an elongated member, such as a pole14extending therefrom, which is operably connected to the working assembly10through an orientation adjustment assembly16. The power assembly12may further comprise an electric power source, such as a battery pack, for powering an electric motor, which may be a part of the working assembly10. The battery pack may be electrically connected to the electric motor by electrical wires which are passed from the power assembly12through the center of the hollow pole14to the working assembly10. A control assembly18controls the amount of electric power delivered from the power assembly12to the working assembly10. An orientation adjustment assembly16provides a means for connecting the pole14extending from the power assembly12with the working assembly10, such that the working assembly10may pivot relative to the pole14to provide multiple ergonomic modes of operation.

FIG. 2shows an electrically powered polesaw20that may be configured in accordance with an example embodiment. However, it should be appreciated that the polesaw20is merely one example of an electrically powered, outdoor power device that may be configured in accordance with an example embodiment. Thus, for example, some embodiments may be practiced in connection with other outdoor power devices such as edgers, brush cutters, and/or the like. It should also be appreciated that the polesaw20ofFIG. 2is a battery powered device. However, example embodiments could alternatively be employed in connection with corded versions of various electrically powered, outdoor power devices. Moreover, in some cases, example embodiments could also be practiced in connection with combustion engines that are configured to enable conversion of the direction that the output shaft turns. Thus, although an example embodiment will be described hereinafter with specific reference to the battery powered polesaw20ofFIG. 2, the applicability of alternative embodiments relative to other types of devices should be well understood.

As shown inFIG. 2, the polesaw20may include a working implement or working assembly10, which in this example includes a rotatable cutting blade assembly22. The working assembly10may further include a motor, such as electric motor disposed in a housing26of the working assembly10. The motor may be used to power a cutting chain (not shown) which is disposed on the guide bar28for the effective cutting of any branches or vegetation. In this regard, in the example embodiment ofFIG. 2, the motor turns a drive shaft and a sprocket drive wheel (not shown). The cutting chain is operably coupled to the sprocket drive wheel and is supported in a peripheral groove which extends around the guide bar28. The guide bar28is attached to the housing26by a tensioning and clamping assembly (not shown) provided at the proximal end of the guide bar28.

The motor of the polesaw20may be powered, according to this example, by a battery pack30. The battery pack30is received in a battery compartment of the polesaw20. In an example embodiment, the battery compartment may be a recess or cavity formed in a casing32of the power assembly12. The battery compartment can be located in the top, bottom, or sides of the casing32. The casing32may substantially enclose the battery compartment, control circuitry, and/or other components associated with powering and/or controlling the operation of the polesaw20. In some embodiments, the casing32may be formed from one or more plastic or other rigid components that may be molded to have a desired shape. For example, in some cases, the casing32may be composed of a right half portion and a left half portion that may form a majority of the casing32.

In an example embodiment, an elongated member, such as pole14operably couples the working assembly10to the power assembly12, which are disposed at opposite ends of the pole14. Although depicted as a pole14in the example embodiment, the elongated member may be a hollow tube, pipe, rod, or other such member that may be straight or curved in different embodiments. The elongated member may also provide operable communication between the working assembly10and the battery pack30such that the battery pack30can power the working assembly10. In this regard, wires (indicated by dotted line36inFIG. 2) extend from the battery pack30through the pole14to the working assembly10to provide power to the motor. However, it should be appreciated that alternative means for electrically connecting the motor and power source are also contemplated. It should also be appreciated that the battery pack of some alternative embodiments may be housed within a backpack that may be worn on the operator's back. In such an example, the battery pack may be connected to the polesaw20via a cord or other adaptor.

The polesaw20may include a rear handle40and a front handle42. The rear handle40may be disposed in-line with the pole14proximate to the casing32, while the front handle42may be disposed between the casing32and the working assembly10along the pole14. An operator of the polesaw20may use one hand to hold the front handle42and the other hand to hold the rear handle40while operating the polesaw20. In some embodiments, the rear handle42may include a trigger44or other control mechanism for engaging operation of the motor to power the working assembly10. AlthoughFIG. 2shows the front handle42being positioned forward of the rear handle40along the pole14, it should also be appreciated that other arrangements for holding and operating the polesaw20may be provided. For example, in some cases, a “handlebar” embodiment may be provided in which the front and rear handles42/40are replaced by a single handle assembly attached to the pole14, where both handles on the handle assembly are substantially equidistant from the working assembly10and disposed spaced apart from the pole14on opposites sides thereof on a handlebar assembly. In addition, the front handle42may be fully adjustable, and may be rotated about the pole14or moved axially with respect to the pole. After being adjusted to the desired position and orientation, the front handle42may be fixed by a screw clamp, set screw, or any other suitable securing means. Other arrangements are also possible.

In an example embodiment, the motor may be a DC motor or a brushless DC motor (BLDC) that is powered by the battery pack30. The power assembly12and battery pack30may be controlled by the trigger44and/or the control panel46. In the example embodiments shown inFIG. 2, the trigger44and control panel46are positioned on the casing32of the power assembly12proximate to the rear handle40. However, the trigger44and control panel46could be positioned at any of a number of other locations on the polesaw20in alternative embodiments, such as on front handle42. The control panel46may be configured to control numerous aspects of the operation of the polesaw20. For example, the control panel46may monitor motor speed, set speed limits, apply cruise control, etc

FIGS. 3-5illustrate several close-up perspective views of a working assembly10of the polesaw20according to an example embodiment to more clearly illustrate some of the features of the working assembly10. As is illustrated in the figures, the working assembly10may comprise an electric motor in a self-contained motor housing60. The motor housing60comprises a cylindrical portion62capped on both ends by endplates (top endplate64is visible inFIG. 3and bottom endplate66is visible inFIG. 6). In addition, the cylindrical portion62of the motor housing60may include a plurality of radially extending cooling fins68around its periphery to improve cooling efficiency. In alternative embodiments, cooling fins may also be located on the endplates of the motor housing60. Each endplate may be screwed or otherwise fastened onto the cylindrical portion62to form a self-contained and sealed environment for the motor. In some embodiments, the bottom endplate66is not a separate part, but is instead integrally formed with the cylindrical portion62. While the illustrated motor housing60is cylindrical, one skilled in the art will appreciate that it is possible to use many other motor shapes and remain within the scope of the invention. For example, the motor housing may be square, non-symmetrical, or any other shape sufficient to house the electric motor. All such embodiments are contemplated as within the scope of the inventions.

Example embodiments are directed to a motor housing60that forms a part of the working assembly10and is exposed to the environment. Therefore, the motor housing60must be sufficiently rugged and durable to withstand potentially harsh environmental exposure or working conditions. For example, the motor housing60should be rust resistant and capable of withstanding direct impacts which may be more likely to occur because the motor is exposed. Therefore, the motor housing60is preferably constructed of aluminum, a light metal/alloy, or any other sufficiently rigid and durable material capable of housing the electric motor. In addition, the motor housing60may be treated with an anti-rust coating to inhibit the formation of rust and increase durability.

The working assembly10may further comprise a housing26that at least partially encloses motor housing60. In some embodiments, the housing26may comprise a first, second, and third housing portion. For example, in the illustrated embodiment, the first, second, and third housing portions are a chassis base70, an oil reservoir72, and a housing arm74, respectively. Although the remainder of this description refers to these three components as making up the housing26, one skilled in the art will appreciate that each portion may include a variety of additional functional components or parts, and that additional housing portions may also be used. In addition, in some cases the housing arm74may be removed.

The chassis base70may serve as a base of the working assembly10. In this regard, the pole14may be connected to the chassis base70through the orientation adjustment assembly16. The motor housing60may also be fixed to the chassis base70such that the motor shaft extends through an aperture76(seeFIG. 6) in the chassis base70and is operably coupled to the cutting chain through the rotatable cutting blade assembly22.

The oil reservoir72may be disposed at the distal end of the working assembly10proximate to the cutting blade28, and may be secured to the chassis base70by one or more fasteners (e.g., fastening screw78inFIG. 6). The oil reservoir cap80is provided for filling the oil reservoir72with lubricating oil for lubricating the cutting chain. As shown inFIG. 6, the oil reservoir72may be shaped with a curved surface82for conforming to the contour of the cylindrical portion62of the motor housing60.

In the example embodiment ofFIGS. 3-5, the housing arm74may connect to the oil reservoir72and the chassis base70, such that the housing arm74extends over the top endplate64and the cylindrical portion62of the motor housing60such that the motor housing60is only partly covered. Housing arm mounting screws102and104can be received by the threaded bores106and108, respectively, to secure the housing arm74to the chassis base70and oil reservoir72. In the illustrated embodiment ofFIG. 6, the housing arm74may be a two-piece construction that may be, for example, snapped together or secured in place by mounting screws102and104. The housing arm74may be further configured to receive electrical wiring112and/or a motherboard for the electric motor. In an alternative embodiment, the housing arm74may be a single-piece construction. One skilled in the art will appreciate that the size, shape, and material of the housing arm74could be changed to meet the needs of a particular application. For example, the housing arm might be a thin bar intended to decrease weight a improve the profile of the working assembly. By contrast, the housing arm might be a bulky, wide piece of rigid plastic intended to provide more impact protection for the motor housing.

In the illustrated embodiment ofFIGS. 3-5, the housing26is constructed so that the chassis base70is proximate only to the bottom endplate66, and does not cover any part of the cylindrical portion62or the top endplate64. Similarly, the oil reservoir72is constructed such that it connects to the chassis base70, but only covers the cylindrical portion62of the motor housing60. The housing arm74extends from the oil reservoir72around the motor housing60to the chassis base70, thereby covering two sides of the motor housing60—i.e., the top endplate64and the cylindrical portion62.

FIG. 6illustrates an exploded view of work assembly10of the polesaw20according to an example embodiment. The chassis base70has a receiving neck16for receiving the pole14and is configured to receive the motor housing60. The motor housing60may comprise one or more structural supports that receive motor housing fasteners to secure the motor housing60to the chassis base70. For example, the motor housing60may have four support towers120that are cylindrical bosses with internal threaded bores that are configured to receive motor mounting screws122. In this manner, the motor mounting screws122may secure the motor housing60to the chassis base70while the support towers120provide clearance over substantially the entire portion of the bottom endplate66of the motor housing60.

In order to insulate the motor housing60from the chassis base70, a gasket126may be interposed between the support towers120of the motor housing60and the chassis base70. The gasket may be paper, rubber, or any other insulating material suitable for minimizing heat transfer between the motor housing60and the chassis base70. In an example embodiment, once the working assembly10has been assembled, the only portions of the motor housing60that are in contact with other components are the ends of the support towers120and the drive shaft128.

Once assembled, the motor housing60is disposed within the housing26. The chassis base70, oil reservoir72, and housing arm74may define two large openings in the housing26—one on either side of the housing arm74(e.g., first opening132and second opening134as shown inFIG. 3). In this manner, two large portions of the motor housing60are not covered by the housing26and are visible and exposed to the environment. For example, in the illustrated embodiment, the entire height of the cylindrical portion62of the motor housing60is exposed on opposing sides. In addition, a majority of the periphery of the cylindrical portion62is exposed.

In addition, the housing arm74may extend over the top endplate64in a manner that essentially splits its surface area in two, thus exposing at least a portion of the top endplate64on either side of the housing arm74. The top endplate64of the motor housing60may thereby be largely exposed, because the narrow housing arm74only covers a small portion of the surface area of the top endplate64. As a result, the motor housing60experiences enhanced cooling because it is exposed to the environment. In this manner, it may transfer heat away from the motor and to the environment without having to go through or around a portion of the housing or other obstructions, such as louvers, for example.

In addition to having exposed surfaces, the motor housing60may be disposed within the housing26such that there is a clearance gap130between nearly the entire outer surface of the motor housing60and the housing26. In this regard, as is shown in the example embodiment, air may circulate about the entire cylindrical periphery62, top endplate64, and bottom endplate66of the motor housing. This circulation is achieved by virtue of the fact that the only place that the motor housing60is in contact with the housing26is where it is attached to the chassis base70through the support towers120.

Therefore, the motor housing60is supported in the housing26such that there is a small gap130around substantially the entire motor housing60and all sides are open to circulating cooling air. For example, the radial edge at the bottom of the motor housing has a gap130between the motor housing60and the chassis base70to permit air to flow underneath the motor housing60(seeFIG. 3). Similarly, a gap130is present between the motor housing60and the oil reservoir72(seeFIG. 3) and the housing arm74(seeFIG. 4). In an example embodiment, the gap130is approximately 1-3 mm wide and extends around the entire motor housing60, except where the support towers120secure the motor housing60to the chassis base70. However, the gap size may vary depending on the needs of a specific application. In addition, the gap size may be constant or vary depending on which portions of the surface area of the motor housing60need more cooling capacity. By having a working assembly housing26that is partially open, the motor housing60that is disposed therein may experience enhanced cooling.

The first, second, and third housing portions of the housing26may be constructed with any material or materials sufficient to support the motor housing60while achieving their respective functions. For example, in order to maintain a lightweight frame, rigid plastic may be used to construct each portion. Alternatively, a light metal or light alloy, such as aluminum may also be used in some embodiments. In addition, one skilled in the art will appreciate that the size and shape of the first, second, and third housing portions can be changed as needed to meet the needs of a particular application.

In accordance with an example embodiment, a housing assembly for a working assembly of an outdoor power device is provided. The housing assembly may include a first, second, and third housing portion, wherein the second and third housing portions may be operably coupled to the first housing portion to at least partially enclose a motor housing. The motor housing may comprise a body portion, a top endplate, and a bottom endplate to house an electric motor for driving the working assembly. The first, second, and third housing portions may combine to define a first opening and a second opening such that two opposing sides of the body portion are exposed in respective ones of the first and second openings.

The device of some embodiments may include additional features that may be optionally added. For example, in an example embodiment, the first housing portion may comprise a chassis base that is configured to receive the motor housing such that the bottom endplate is proximate to and covered by the chassis base, but such that a majority of the bottom endplate is not in contact with the chassis base. In some embodiments, the bottom endplate of the motor housing comprises a plurality of support towers for rigidly fixing the motor housing to the chassis base. In some cases, an insulating gasket is interposed between the one or more support towers and the chassis base. However, the gasket is not required.

According to some example embodiments, the second housing portion may comprise an oil reservoir that covers a portion of the body portion without contacting the motor housing. In some embodiments, the third housing portion may comprise a housing arm that extends over the motor housing such that it covers at least a portion of both the top endplate and the body portion without contacting either the top endplate or body portion. In a still further embodiment, the housing arm may extend from the first housing portion to the third housing portion such that it defines the first opening and the second opening, and wherein a portion of the top endplate is exposed in each of the first and second openings. Additionally or alternatively, a gap may separate the housing assembly from the entirety of the top endplate, the entirety of the body portion, and a substantial majority of the bottom endplate. The gap between the motor housing and the first, second, and third housing portions may be, for example, approximately 1 mm.

In yet another example embodiment, a working assembly of an outdoor power device may be provided. The working assembly may comprise a motor housing which may comprise a cylindrical body portion, a top endplate, and a bottom endplate; and a housing assembly may comprise a chassis base, an oil reservoir, and a chassis arm. The bottom endplate of the motor housing may be attached to the chassis base such that chassis base covers only the bottom endplate. Additionally or alternatively, the oil reservoir may be connected to the chassis base such that it covers only a first portion of the cylindrical body portion. In some embodiments, the chassis arm may extend over the motor housing from the oil reservoir to the chassis base such that it only covers a portion of the top endplate and a second portion of the cylindrical body portion. The first portion of the cylindrical body portion may be on the opposite side of the motor housing from the second portion of the cylindrical body portion.