(19)
(11)EP 2 908 984 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
24.01.2018 Bulletin 2018/04

(21)Application number: 12886847.8

(22)Date of filing:  19.10.2012
(51)International Patent Classification (IPC): 
B25F 5/00(2006.01)
H02K 9/06(2006.01)
(86)International application number:
PCT/SE2012/051116
(87)International publication number:
WO 2014/062105 (24.04.2014 Gazette  2014/17)

(54)

OUTDOOR POWER DEVICE INTERNAL COOLING SYSTEM

INTERNES KÜHLSYSTEM FÜR ELEKTROWERKZEUG ZUR VERWENDUNG IM FREIEN

SYSTÈME DE REFROIDISSEMENT INTERNE DE DISPOSITIF ÉLECTRIQUE D'EXTÉRIEUR


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(43)Date of publication of application:
26.08.2015 Bulletin 2015/35

(73)Proprietor: Husqvarna AB
56182 Huskvarna (SE)

(72)Inventors:
  • BERGQUIST, Oskar
    S-561 82 Huskvarna (SE)
  • STEEN, Stefan
    S-561 91 Huskvarna (SE)


(56)References cited: : 
EP-A1- 1 715 565
WO-A1-2005/039823
DE-A1- 4 238 564
DE-A1-102010 030 376
GB-A- 2 423 420
US-A- 3 652 879
US-A- 6 043 575
US-A1- 2008 106 159
US-A1- 2009 245 958
US-B1- 6 543 549
WO-A1-03/051574
WO-A1-2005/039823
DE-A1-102010 030 376
DE-U1-202010 014 781
GB-A- 2 423 420
US-A- 3 652 879
US-A- 6 043 575
US-A1- 2009 245 958
US-A1- 2010 244 592
US-B1- 6 543 549
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description

    TECHNICAL FIELD



    [0001] Example embodiments generally relate to an outdoor power device that is electric powered and, more particularly, relate to an internal cooling system for such an outdoor power device.

    BACKGROUND



    [0002] 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. Although there are several options for powering such devices, including combustion engines, corded electric motors, or battery powered electric motors, each option may be viewed as having advantages in certain environments and for certain users.

    [0003] A common requirement for such devices, regardless of the power source, is that some components of the devices will need to be cooled. Electric powered devices typically employ electric components that heat up during powered operation and, for some such devices; air cooling may be employed internal to the device to manage internal temperatures. To employ the air cooling, it is often considered to be necessary to provide vents or louvers for the intake of air for internal circulation prior to exhausting heated air. However, the inclusion of vents for intake of air may be somewhat disadvantageous given that these devices operate in relatively harsh environments. In this regard, for example, the work these devices are employed to perform inherently generates and often stirs up debris. Moreover, the devices are often used in outdoor environments that may include moisture, dirt or other potential contaminants. Thus, large air vents or louvers may provide ample opportunity for unwanted contaminants to reach internal components of the devices.

    [0004] Accordingly, there is a need for an arrangement providing cooling of internal components of such devices with less risk of introducing unwanted contaminants. US2009/0245958 discloses an electric drill, where a cooling air current is directed through a plurality of holes in a battery enclosure and cooling the battery before getting to a motor. US 3,652,879 discloses a portable cord drill having intake air openings in the rear of a housing for cooling a commutator and a motor and outlet openings on the sides of the drill housing adjacent to a fan.
    DE 202010014781U1 discloses a manually operated mixer with an electric motor, where air intake openings are made in an outer shell and the air is directed through a gap into an inner motor shell of the motor for cooling.
    US 6,043,575 discloses an electric powered tool having an air deflector for facilitating venting out an exhaust cooling air and preventing it from entering inlet ports.
    US 2008/106159 discloses a portable brush cutter, where a cooling air is drawn into a motor housing from an inlet to an outlet, where the inlet and the outlet are positioned on a great distance form actuating part creating dust and provided at a distal end of an arm.
    EP1 715 565 discloses an impact driver having a cooling fan for cooling switch elements of an brushless motor.
    WO2005/039823 discloses a machine tool with a reduced nose due to making a cooling air passages openings in a hole patters in columns and rows.
    DE102010030376 discloses a jigsaw, where a cooling air is axially drawn into a motor housing and discharged via radial exit openings.

    BRIEF SUMMARY OF SOME EXAMPLES



    [0005] Some example embodiments may therefore provide a cooling system for internal components of outdoor power devices. In this regard, some embodiments may provide for cooling of such devices without a need for relatively large and accessible louvers or vents. Accordingly, some embodiments may provide for the provision of an internal cooling system arrangement that can be used in connection with relatively small or non-obvious air inlets. Some embodiments may therefore employ an air channel disposed within the device to facilitate internal cooling in an efficient manner.

    [0006] In one example embodiment, an electric power device is provided. The device may include a casing, a motor disposed within the casing, and an air channel. The motor may be configured to operate a working implement of the device and may include a motor housing having at least one outlet through which air cooling the motor exits the motor housing. The air channel may be configured to enclose the at least one outlet of the motor housing. The air channel may provide a passage for the air drawn from outside the casing and through the motor housing out of the casing via an exhaust outlet disposed in the casing at an end of the air channel.

    [0007] In another example embodiment, a method of cooling an electric power device is provided. The method may include drawing air from outside a casing of the device into the casing and drawing the air into a motor of the device and cooling the motor by passing the air through a motor housing containing the motor to generate motor exhaust air that is heated to a first temperature and exits the motor housing through at least one outlet formed in a body of the motor housing. The method may further include passing the motor exhaust air into an air channel that is disposed to enclose the at least one outlet. The air channel may provide a passage for the air drawn from outside the casing and through the motor housing out of the casing via an exhaust outlet disposed at an end of the air channel.

    BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)



    [0008] Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:

    FIG. 1 illustrates a perspective view of an electric powered hedge trimmer that may be configured in accordance with an example embodiment;

    FIG. 2 illustrates a rear perspective view of the hedge trimmer with part of a casing removed to reveal some of the internal components of the hedge trimmer according to an example embodiment;

    FIG. 3 illustrates a front perspective view having the same part of the casing removed as in FIG. 2 in order to provide a different perspective of the internals of the casing according to an example embodiment;

    FIG. 4 illustrates a cross-section view of the power device with the right half portion of the casing removed according to an example embodiment;

    FIG. 5 illustrates a perspective view of the air channel, in which the right half portion of the casing and thereby the right half portion of the air channel is removed, to show how the air channel is disposed to enclose a portion of the motor housing according to an example embodiment; and

    FIG. 6 illustrates a block diagram of a method of cooling an electric power device according to an example embodiment.


    DETAILED DESCRIPTION



    [0009] Some example embodiments now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all example embodiments are shown. Indeed, the examples described and pictured herein should not be construed as being limiting as to the scope, applicability or configuration of the present disclosure. Rather, these example embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like reference numerals refer to like elements throughout. Furthermore, as used herein, the term "or" is to be interpreted as a logical operator that results in true whenever one or more of its operands are true. As used herein, operable coupling should be understood to relate to direct or indirect connection that, in either case, enables functional interconnection of components that are operably coupled to each other.

    [0010] Some example embodiments described herein provide an internal cooling system for an electric powered device. The internal cooling system may include an air channel that is formed to enclose a portion of a motor housing of a motor of the device. In this regard, the air channel may enclose an air outlet of the motor housing at one end of the air channel so that air that passes through the motor housing to cool the motor can be drawn from outside a casing of the device and then passed through an inside of the casing. The air may cool other internal components of the device before entering the motor housing. Then after entering the motor housing, the air will be provided into the air channel, which may direct the air out of the casing via a casing outlet disposed at an opposite end of the air channel. The air channel may form an effective path for cooling of the motor, but may also ensure that the heated air may be channeled out of the device while avoiding any recirculation of the air within other portions of the device casing. Thus, for example, if any wear products from motor brushes are entrained into the heated air, those wear products will be removed from the device and not contaminate the internal surfaces of components of the device.

    [0011] Referring to the drawings, FIG. 1 shows an electric powered hedge trimmer 10 that may be configured in accordance with an example embodiment. However, it should be appreciated that the hedge trimmer 10 is merely one example of an electric 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 blowers, edgers, chainsaws, and/or the like. It should also be appreciated that the hedge trimmer 10 of FIG. 1 is a battery powered device. However, example embodiments could alternatively be employed in connection with corded versions of various electric powered, outdoor power devices. Thus, although an example embodiment will be described hereinafter with specific reference to the battery powered hedge trimmer 10 of FIG. 1, the applicability of alternative embodiments relative to other types of devices should be well understood.

    [0012] As shown in FIG. 1, the hedge trimmer 10 may include a working implement 20, which in this example is a series of fixed and movable cutters. A motor (not shown in FIG. 1) of the hedge trimmer 10 may be used to power movable cutters of the working implement 20 so that effective cutting may be employed relative to any vegetation that is between the fixed and movable cutters. In other embodiments, the working implement 20 could be any other working component of the outdoor power device employing an example embodiment. For example, if the outdoor power device is an electric chainsaw, the working implement may be the chainsaw bar and cutting chain disposed thereon.

    [0013] The motor of the hedge trimmer 10 may be powered, according to this example, by a battery pack 30. The battery pack 30 is received into a battery compartment of the hedge trimmer 10. The battery compartment is a recess or cavity formed in a casing 40 of the hedge trimmer 10. In some embodiments, the casing 40 may be formed from one or more plastic or other rigid components that may be molded to have a desired shape. The casing 40 may substantially enclose the motor, gear assemblies, control circuitry and other internal components of the hedge trimmer 10.

    [0014] In an example embodiment, the hedge trimmer 10 may include a rear handle 50 and a front handle 60. An operator of the hedge trimmer 10 may use one hand to hold the front handle 60 and the other hand to hold the rear handle 50 while operating the hedge trimmer 10. In some embodiments, the rear handle 50 may include a trigger 52 or other control mechanism for engaging operation of the motor to power the working implement 20. The rear handle 50 may be attached to a rear portion of the casing 40 and the front handle 60 may be attached to a front portion of the casing 40. In some embodiments, a hand guard 62 may be disposed between the working implement 20 and a portion of the casing 40 that is proximate to the front handle 60. The hand guard 62 may provide shielding for the operator's hand relative to any debris that may be projected back toward the casing 40 during operation of the working implement 20.

    [0015] As indicated above, some example embodiments may provide for cooling of internal components of the hedge trimmer 10. FIG. 2 illustrates a rear perspective view of the hedge trimmer 10 with part of the casing 40 that is closest to the viewer removed to reveal some of the internal components of the hedge trimmer 10. FIG. 3 illustrates a front perspective view having the same part of the casing 40 removed to provide a different perspective of the internals of the casing 40. In this regard, FIGS. 2 and 3 show a motor housing 100 that houses the motor of the hedge trimmer 10. In this example, the motor may be a DC motor or a brushless DC motor (BLDC) that is powered by the battery pack 30. The motor housing 100 may enclose the motor but allow cooling air to enter into the motor housing 100 via inlet ports 110 that may be disposed at top and bottom portions of the motor housing 100, respectively. The inlet ports 110 may enable air to be drawn into the motor housing 100 from void space 120 that exists between the internal sides of the casing 40 and any internal components disposed within the casing 40. The void space 120 may extend around the battery compartment that houses the battery pack 30, around the motor housing 100, and around a gear assembly 130 that may be operably coupled to the motor and the working implement to transfer power from the motor to the working implement 20. The void space 120 may also extend external to an air channel 140 and a control unit (e.g., PCB 150) that includes processing circuitry for controlling operation of the hedge trimmer 10.

    [0016] In an example embodiment, the casing 40 may be assembled by fitting molded parts together. For example, in some cases, the casing 40 may be composed of a right half portion and a left half portion that may form a majority of the casing. In such an example, a seam 160 may extend along a longitudinal centerline of the casing 40 to divide the casing 40 along the right half and left half portions. The seam 160 may include (either in discrete locations or along an entirety thereof) air gaps through which air may be drawn into internal portions of the casing 40 (i.e., into the void space 120). Additionally or alternatively, fittings with some components that have openings to the outside of the casing 40 or are otherwise coupled to the casing 40 in some manner (e.g., the battery compartment, the gear assembly 130 or other components) may provide air gaps through which air may be drawn internal to the casing 40. In the context of this discussion, air gaps should be understood to correlate to relatively loose fittings between parts that are not formed into air inlets, vents or louvers, which should be understood in the context of this description to correlate to air inlets specifically formed and designed to allow air to enter into the casing without having any other function. Thus, air gaps are gaps that exist by virtue of the natural tolerances or gaps that exist between components, but are not specifically formed holes that are provided to enable air entry into the casing 40. However, it should be appreciated that in some embodiments, one or more formed air inlets may be included in the casing 40. For example, in one embodiment, an air inlet 170 (see FIG. 4) may be formed at a rear portion of the casing 40, proximate to the rear handle 50.

    [0017] In embodiments that do not employ an air inlet, the air gaps between portions of the casing 40 may be sufficient to provide enough air to enter the casing 40 to permit cooling air to be drawn from outside of the casing 40 into the void space 120. The air drawn into the void space 120 may cool internal components of the hedge trimmer 10 (e.g., the motor, gear assembly 130, etc.) prior to being exhausted from the casing 40. In embodiments where the air inlet 170, or multiple such inlets are employed, the air inlets may be of a relatively small size (e.g., smaller than 4 mm2). However, in other embodiments, the air inlet 170, or multiple such inlets may have a combined size of smaller than about 15 cm2.

    [0018] FIG. 4 illustrates a cross-section view of the hedge trimmer 10 with the right half portion of the casing 40 removed. As shown in FIG. 4, air drawn into the inside of the casing 40 may be initially drawn into the void space 120. Arrows 180 illustrate some of the flow paths that the air within the void space 120 may take while being circulated inside the casing 40 and cooling various components therein. Thus, components such as the gear assembly 130, and the battery pack 30 may be cooled by movement of air within the casing 40. Movement of air within the casing 40 may be driven, at least in part, by the motor. In this regard, movement of the rotor of the motor (e.g., a DC motor in this example) may cause air to be drawn out of the void space 120 and into the inlet ports 110 of the motor housing 100 to cool the motor inside the motor housing 100. The rotor may include fins or a fan attached thereto to further facilitate initiation of air flow. However, inclusion of such fins or fan is not required.

    [0019] In an example embodiment, the air channel 140 may be formed to enclose the outlet ports 190 of the motor housing 100. Of note, the air channel 140 in FIGS. 2 and 3 is shown partially cutaway in order to expose the outlet ports 190. However, it should be appreciated that all air drawn through the motor housing 100 to be expelled from the inside of the casing 40 may be passed through the outlet ports 190 and into the air channel 140. The air channel 140 may then pass the air out of the casing (and out of the air channel 140) as exhaust air. The air channel 140 may extend from a first end (e.g., a proximal end) that encloses the outlet ports 190 forward within the casing 40 to an exhaust port 192 that may be disposed proximate to the hand guard 62 at a second end (e.g., a distal end) of the air channel 140. Accordingly, the air channel 140 may be configured to pass the air drawn from outside the casing 40 and through the motor housing 100 out of the casing 40 via a casing outlet (i.e., the exhaust port 192) disposed at a distal end of the air channel 140.

    [0020] The air that is drawn into the inside of the casing 40 may be at an ambient external temperature. However, as air is circulated within the casing 40 the air may be heated to an intermediate temperature by cooling various components inside the casing 40. As air is drawn from the void space 120 (at the intermediate temperature) and passed into the motor housing 100 via the inlet ports 110, the air may be heated again as the motor itself is cooled. Thus, air leaving the motor housing 100 through one or more outlet ports 190 of the motor housing 100 may be heated to a higher temperature. In some cases, the exhaust air that is ejected out of the air channel 140 through the exhaust port 192 may be at the higher temperature. However, in some embodiments, the PCB 150 may be disposed within or proximate to the air channel 140 so that air passing through the air channel 140 to be ejected therefrom (indicated by line 194 in FIG. 4) may be further heated to exhaust temperature by cooling the PCB 150 prior to leaving the air channel through the exhaust port 192. In some embodiments, the PCB 150 may form a portion of one of the walls of the air channel 140. However, in some alternative embodiments, the PCB 150 may be disposed outside of the air channel 140 and the air channel 140 may therefore be made completely by material or parts that do not form a part of another component.

    [0021] In an example embodiment, the inlet ports 110 of the motor housing 100 may be disposed at the top and/or bottom of the motor housing 100. Thus, air moving through the motor housing 100 may be drawn into the motor housing 100 from two opposite directions (e.g., oriented vertically) and the one or more outlet ports 190 of the motor housing 100 may be disposed to direct air into the air channel 140 in a direction substantially perpendicular to the two opposite directions (e.g., oriented horizontally) as shown in FIG. 4. The air may thereafter move forward in the air channel 140 from the proximal end to the distal end thereof to exit the air channel 140 (and the casing 40) via the exhaust port 192. The air may be drawn from all portions of the void space 120 and consolidated in the motor housing 100 prior to being combined for exhaust through the air channel 140. This arrangement may help to ensure that all air that is preheated prior to entering the motor housing 100 and is heated in the motor housing 100 is thereafter provided directly out of the casing 40 via the air channel 140. Thus, the heated air is not allowed to recirculate inside the casing 40. This arrangement provides an efficient removal of the heated air via a duct that is dedicated to removal of the heated air. It should be noted that although the pictured example embodiment includes a single exhaust port 192 disposed proximate to the hand guard 62, multiple exhaust ports may be employed in alternative embodiments. Furthermore, although the air channel 140 extends forward along the casing 40 to terminate at a forward most end of the casing at the exhaust port 192, it should be appreciated that the air channel 140 could be arranged to extend in any desirable direction and the exhaust port 192 (or ports) would then be oriented to exhaust air from wherever the air channel 140 ends (e.g., at a side, bottom, or back of the casing 40).

    [0022] In an example embodiment, an upper boundary of the air channel 140 may be formed by a portion of the casing 40 that extends from a point proximate to the motor housing 100 to the hand guard 62. Alternatively, the air channel 140 may be a separate duct provided inside the casing 40 with all of the sidewalls of the duct being formed from a single unitary piece of material (e.g., plastic, metal or composite material). However, in some cases, the air channel 140 may be formed as a duct having multiple assembled parts that have relatively air tight connections therebetween. Accordingly, in some cases, the only openings in the air channel 140 may be the outlet ports 190, which allow air to enter the air channel 140, and the exhaust port 192, which allows air to exit the air channel 140

    [0023] By providing separation between air in the void space 120 that is drawn into the motor housing 100 and air in the air channel 140 that is being moved out of the exhaust port 192, example embodiments may provide for efficient heat removal while also effectively removing any contaminants that may be entrained into the air currents. For example, in embodiments in which the motor is a DC motor, the brushes may wear over time and wear products may be entrained into air streams that pass through and cool the motor. If the cooling air passed through the motor housing were allowed to reenter the void space 120 prior to exiting the casing 40, such wear products may coat, foul, or otherwise adhere to internal components (e.g., the gear assembly 130 and battery pack 30) of the hedge trimmer 10. Any dust, moisture or debris that found its way into the void space 120 may also have the opportunity to pass through the motor housing and adhere to internal components. However, by making air that is to be exhausted pass through a dedicated channel that leads to the exhaust port 192, air currents within the void space 120 may consistently tend toward the motor housing 100 and ultimately out of the casing 40 via the air channel 140. Accordingly, any dust, debris, moisture, wear products and/or the like that are entrained into the air currents that pass through the motor housing 100 can be consolidated for direct removal via the air channel 140.

    [0024] FIG. 5 illustrates a perspective view of a left half portion of the air channel 140, in which the right half portion of the casing 40 and the right half portion of the channel 140 have been removed, to show how the air channel 140 is disposed to enclose a portion the motor housing 100 that is proximate to the one or more outlet ports 190. In this regard, the motor housing 100 of one example may be arranged such that at least a portion of the longitudinal length of the motor housing 100 that includes the one or more outlet ports 190 is surrounded by the air channel 140. Thus, all the air exiting the one or more outlet ports 190 enters into the air channel 140 to be moved forward and out of the casing 40 as described above. It should be appreciated that a portion of the air channel 140 that is closest to the viewer has been cut away in FIG. 5 to expose the outlet ports 190. However, these outlet ports 190 are enclosed by the air channel 140 as it wraps around the motor housing 100. As shown in FIGS. 3-5, the air channel 140 may be formed to have a width dimension that is larger than its height dimension. The length dimension of the air channel 140 (i.e., extending from the proximal end to the distal end) may be longer than both the width and height dimensions of the air channel 140. In the context used herein, the length dimension of the air channel 140 should be understood to extend along a direction of the longitudinal centerline of the casing 40. Meanwhile, the width dimension of the air channel 140 may be in the same direction as the width of the hedge trimmer (e.g., extending in a direction from one half portion of the casing 40 to the other half portion) and the height dimension of the air channel 140 may extend from a top portion of the casing 40 toward a bottom portion of the casing 40. Accordingly, as shown in FIG. 5, the longitudinal length of the motor housing 100 may be substantially perpendicular to the length dimension of the air channel 140.

    [0025] Having the entire periphery of the motor housing 100 surrounded by the air channel 140 at the point along the longitudinal length of the motor housing 100 at which the one or more outlet ports 190 are located may provide a relatively simple way to ensure that the air that exits the motor housing 100 is directed into the air channel 140. However, it is not necessary that the air channel 140 surround the periphery of the motor housing 100. Instead, in some alternative embodiments, the air channel 140 may simply be formed proximate to the one or more outlet ports 190 and may not extend all the way around the periphery of the motor housing 100.

    [0026] An electric power device of an example embodiment may therefore include a casing, a motor disposed within the casing, and an air channel. The motor may be configured to operate a working implement of the device and may include a motor housing having at least one outlet through which air cooling the motor exits the motor housing. The air channel may be configured to enclose the at least one outlet of the motor housing. The air channel may provide a passage for the air drawn from outside the casing and through the motor housing out of the casing via an exhaust outlet disposed in the casing at an end of the air channel.

    [0027] The electric power device of some embodiments may include additional features that may be optionally added. For example, in some embodiments, (1) the casing may include a plurality of body portions, and the air may be drawn in from outside the casing exclusively through gaps between the body portions or otherwise formed in the casing. As an alternative to (1), (2) the casing may include a plurality of body portions, and the air may be drawn in from outside the casing through gaps between the body portions and through at least one air inlet provided specially for drawing in sufficient air. However, it should be appreciated that some alternative embodiments may employ one or more air inlets without relying on gaps between body portions. In some cases, (3) the at least one inlet (if used) is disposed proximate to a rear handle of the device. In some embodiments, (4) the device further includes a battery compartment configured to house a battery for powering the device and the battery compartment is disposed within the casing of the device. If the at least one inlet is provided, the at least one inlet may have a size of less than about 15 cm2.

    [0028] In some embodiments, any or all of (1) to (4) may be employed in addition to the optional modifications or augmentations described below. For example, in some embodiments, air passing through the motor housing and the air channel may transport motor wear products out of the casing to inhibit entry of the wear products inside the casing. Additionally or alternatively, the air channel may be disposed proximate to the control unit to enable air passed through the air channel to cool the control unit prior to exiting the air channel. In some embodiments, the casing outlet may be located proximate to a hand guard disposed between a front handle and the working implement (which may include at least one cutting blade). In an example embodiment, the motor is a DC or a brushless DC motor having a fan to facilitate movement of air into the cooling channel. In an example embodiment, air being drawn into the motor housing is preheated by other device components within the casing of the device prior to entering into the motor housing. For example, air drawn into the motor housing may be preheated by cooling a battery or gear assembly of the device. In some embodiments, air is drawn into the motor housing from two opposite directions and the at least one outlet of the motor housing is disposed to direct air into the air channel in a direction substantially perpendicular to the two opposite directions.

    [0029] In an example embodiment, a method of cooling an electric power device is provided as shown in the block diagram of FIG. 6. The method may include drawing air from outside a casing of the device into the casing at operation 200 and drawing the air into a motor of the device and cooling the motor by passing the air through a motor housing containing the motor to generate motor exhaust air that is heated to a first temperature (e.g., the higher temperature mentioned above) and exits the motor housing through at least one outlet formed in a body of the motor housing at operation 210. The method may further include passing the motor exhaust air into an air channel that is disposed to enclose the at least one outlet at operation 220. The air channel may provide a passage for the air drawn from outside the casing and through the motor housing out of the casing via an exhaust outlet disposed at an end of the air channel.

    [0030] In some cases, the method described above may be augmented or modified according to any or all of the options described below in any combination. For example, in some embodiments, the method may further include passing the air drawn into the casing proximate to components inside the casing to generate air preheated to a second temperature (e.g., the intermediate temperature mentioned above) that is lower than the first temperature at operation 230. In an example embodiment, passing the motor exhaust air into the air channel may further include passing the motor exhaust air proximate to the control unit to generate air heated to a third temperature (e.g., the exhaust temperature mentioned above) that is higher than the first temperature. In some example embodiments, drawing air from outside the casing of the device comprises drawing the air into the casing through an inlet disposed proximate to a rear handle of the device. Alternatively, drawing air from outside the casing of the device may include drawing the air exclusively through gaps between body portions of the casing or otherwise formed in the casing. In some cases, drawing the air into the motor may include drawing the air into the motor housing from two opposite directions, and the at least one outlet of the motor housing may be disposed to direct air into the air channel in a direction substantially perpendicular to the two opposite directions.

    [0031] Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Moreover, although the foregoing descriptions and the associated drawings describe exemplary embodiments in the context of certain exemplary combinations of elements and/or functions, it should be appreciated that different combinations of elements and/or functions may be provided by alternative embodiments without departing from the scope of the appended claims. In this regard, for example, different combinations of elements and/or functions than those explicitly described above are also contemplated as may be set forth in some of the appended claims. In cases where advantages, benefits or solutions to problems are described herein, it should be appreciated that such advantages, benefits and/or solutions may be applicable to some example embodiments, but not necessarily all example embodiments. Thus, any advantages, benefits or solutions described herein should not be thought of as being critical, required or essential to all embodiments or to that which is claimed herein. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.


    Claims

    1. An electric outdoor power device comprising:

    a casing (40) comprising a plurality of body portions;

    a motor disposed within the casing (40), the motor being configured to operate a working implement (20) of the device and including a motor housing (100) having at least one outlet (190) through which air cooling the motor exits the motor housing (100);

    characterized in that

    an air channel (140) configured to enclose the at least one outlet (190) of the motor housing (100), the air channel (140) providing a passage for the air drawn from outside the casing (40) exclusively through gaps between the body portions, and through the motor housing (100) out of the casing (40) via an exhaust outlet (192) disposed in the casing (40) at an end of the air channel (140), said air channel (140) being arranged to ensure that the heated air may be channeled out of the electric power device while avoiding any recirculation of the air within other portions of the device casing (40).


     
    2. The device of claim 1, further comprising a battery compartment configured to house a battery (30) for powering the device, the battery compartment being disposed within the casing (40) of the device.
     
    3. The device of any of claims 1 to 2, wherein air passing through the motor housing (100) and the air channel transports motor wear products out of the casing (40) to inhibit entry of the wear products inside the casing (40).
     
    4. The device of any of claims 1 to 2, further comprising a control unit (150) providing control over operation of the device, wherein the air channel (140) is disposed proximate to the control unit (150) to enable air passed through the air channel (140) to cool the control unit (150) prior to exiting the air channel (140).
     
    5. The device of any of claims 1 to 2, wherein the air channel (140) is arranged to extend in a direction and the exhaust port (192) is oriented to exhaust air in the direction of the air channel (140) ends, wherein said air channel (140) ends at t a side, bottom, or back of the casing (40).
     
    6. The device of any of claims 1 to 2, wherein the working implement includes at least one cutting blade.
     
    7. The device of any of claims 1 to 2, wherein the device is an electric chainsaw and the working implement is a chainsaw bar.
     
    8. The device of any of claims 1 to 2, wherein the device is a hedge trimmer (10).
     
    9. The device of any of claims 1 to 2, wherein the device is a handheld device.
     
    10. The device of any of claims 1 to 2, wherein the motor is a DC or a brushless DC motor having a fan to facilitate movement of air into the cooling channel.
     
    11. The device of any of claims 1 to 2, wherein the air drawn into the motor housing (100) is preheated by cooling one of the battery (30) and a gear assembly (130) of the device.
     
    12. The device of claim 11, wherein the gear assembly (130) is operably coupled to the motor and the working implement (20) to transfer power from the motor to the working implement (20).
     
    13. The device of any of claims 1 to 2, wherein the air is drawn into the motor housing (100) from two opposite directions and wherein the at least one outlet (190) of the motor housing (100) is disposed to direct air into the air channel (140) in a direction substantially perpendicular to the two opposite directions.
     
    14. The device of any of claims 1 to 2, wherein air being drawn into the motor housing (100) is preheated by other device components within the casing (40) of the device prior to entering into the motor housing (100).
     
    15. A method of cooling an electric outdoor power device comprising:

    providing a casing (40) comprising a plurality of body portions,

    drawing air from outside a casing (40) of the device into the casing (40);

    drawing the air into a motor of the device and cooling the motor by passing the air through a motor housing containing the motor to generate motor exhaust air that is heated to a first temperature and exits the motor housing (100) through at least one outlet (190) formed in a body of the motor housing (100); characterized by passing the motor exhaust air into an air channel (140) that is disposed to enclose the at least one outlet, the air channel (140) passing the air drawn from outside the casing (40) exclusively through gaps between the body portions, and through the motor housing (100) out of the casing via an exhaust outlet (192) disposed at an end of the air channel (140), said air channel (140) being arranged to ensure that the heated air may be channeled out of the electric power device while avoiding any recirculation of the air within other portions of the device casing (40).
     
    16. The method of claim 15, further comprising passing the air drawn into the casing (40) proximate to components inside the casing to generate air preheated to a second temperature that is lower than the first temperature before the air enters the motor.
     
    17. The method of claim 16, wherein the air channel passing the air out of the casing comprises passing the motor exhaust air proximate to a control unit (150) of the device to generate air heated to a third temperature that is higher than the first temperature.
     
    18. The method of any of claims 15 to 17, wherein drawing the air into the motor comprises drawing the air into the motor housing (100) from two opposite directions, wherein the at least one outlet (190) of the motor housing (100) is disposed to direct air into the air channel (140) in a direction substantially perpendicular to the two opposite directions.
     


    Ansprüche

    1. Elektrisches Werkzeug für den Außenbereich, umfassend:

    ein Gehäuse (40) mit einer Vielzahl von Körperabschnitten;

    einen Motor, der in dem Gehäuse (40) angeordnet ist, wobei der Motor dazu ausgestaltet ist, einen Arbeitsaufsatz (20) des Werkzeugs zu betreiben, und ein Motorgehäuse (100) mit zumindest einem Auslass (190) aufweist, durch welchen Luft, die den Motor kühlt, aus dem Motorgehäuse (100) austritt;

    gekennzeichnet durch

    einen Luftkanal (140), der dazu ausgestaltet ist, den zumindest einen Auslass (190) des Motorgehäuses (100) einzuschließen, wobei der Luftkanal (140) einen Durchgang für Luft bereitstellt, die von außerhalb des Gehäuses (40) ausschließlich durch Spalte zwischen den Körperabschnitten eingezogen wird,

    und durch das Motorgehäuse (100) aus dem Gehäuse (40) heraus über einen Abluftauslass (192), der in dem Gehäuse (40) an einem Ende des Luftkanals (140) angeordnet ist, wobei der Luftkanal (140) angeordnet ist, um sicherzustellen, dass die erwärmte Luft aus dem elektrischen Handwerkzeug ausgeleitet werden kann, während eine Rückführung der Luft in andere Abschnitte des Werkzeuggehäuses (40) verhindert wird.


     
    2. Werkzeug nach Anspruch 1, ferner umfassend ein Batteriefach mit einer Batterie (30) zur Versorgung des Werkzeugs, wobei das Batteriefach innerhalb des Gehäuses (40) des Werkzeugs angeordnet ist.
     
    3. Werkzeug nach einem der Ansprüche 1 bis 2, wobei Luft, die durch das Motorgehäuse (100) und den Luftkanal strömt, Motorverschleißprodukte aus dem Gehäuse (40) heraus transportiert, um das Eindringen von Verschleißprodukten in das Gehäuse (40) zu verhindern.
     
    4. Werkzeug nach einem der Ansprüche 1 bis 2, ferner umfassend eine Steuereinheit (150), die eine Steuerung über den Betrieb des Werkzeugs bereitstellt, wobei der Luftkanal (140) in der Nähe der Steuereinheit (150) angeordnet ist, um Luft, die durch den Luftkanal (140) strömen kann, zu ermöglichen, die Steuereinheit (150) zu kühlen, bevor sie aus dem Luftkanal (140) austritt.
     
    5. Werkzeug nach einem der Ansprüche 1 bis 2, wobei der Luftkanal (140) angeordnet ist, um sich in eine Richtung zu erstrecken, und der Abluftanschluss (192) orientiert ist, um Luft in jene Richtung auszustoßen, in der der Luftkanal (140) endet, wobei der Luftkanal (140) an einer Seite, einem Boden oder einer Rückseite des Gehäuses (40) endet.
     
    6. Werkzeug nach einem der Ansprüche 1 bis 2, wobei der Arbeitsaufsatz zumindest eine Schneidklinge umfasst.
     
    7. Werkzeug nach einem der Ansprüche 1 bis 2, wobei das Werkzeug eine elektrische Kettensäge ist und der Arbeitsaufsatz eine Kettensägenschiene ist.
     
    8. Werkzeug nach einem der Ansprüche 1 bis 2, wobei das Werkzeug ein Heckentrimmer (10) ist.
     
    9. Werkzeug nach einem der Ansprüche 1 bis 2, wobei das Werkzeug ein Handwerkzeug ist.
     
    10. Werkzeug nach einem der Ansprüche 1 bis 2, wobei der Motor ein Gleichstrommotor oder ein bürstenloser Gleichstrommotor mit einem Gebläse ist, um die Bewegung von Luft in den Kühlkanal zu erleichtern.
     
    11. Werkzeug nach einem der Ansprüche 1 bis 2, wobei die Luft, die in das Motorgehäuse (100) eingezogen wird, vorgewärmt wird, indem sie entweder die Batterie (30) oder eine Getriebeanordnung (130) des Werkzeugs kühlt.
     
    12. Werkzeug nach einem der Ansprüche 1 bis 11, wobei die Getriebeanordnung (130) wirkmäßig mit dem Motor und dem Arbeitsaufsatz (20) gekoppelt ist, um Leistung von dem Motor auf den Arbeitsaufsatz (20) zu übertragen.
     
    13. Werkzeug nach einem der Ansprüche 1 bis 2, wobei die Luft in das Motorgehäuse (100) von zwei entgegengesetzten Richtungen eingezogen wird, und wobei der zumindest eine Auslass (190) des Motorgehäuses (100) angeordnet ist, um Luft in einer Richtung im Wesentlichen senkrecht auf die beiden entgegengesetzten Richtungen in den Luftkanal (140) zu leiten.
     
    14. Werkzeug nach einem der Ansprüche 1 bis 2, wobei Luft, die in das Motorgehäuse (100) eingezogen wird, durch andere Werkzeugkomponenten innerhalb des Gehäuses (40) des Werkzeugs vorgewärmt wird, bevor sie in das Motorgehäuse (100) eintritt.
     
    15. Verfahren zur Kühlung eines elektrischen Werkzeugs für den Außenbereich, umfassend:

    Bereitstellen eines Gehäuses (40) mit einer Vielzahl von Körperabschnitten,

    Einziehen von Luft von außerhalb eines Gehäuses (40) des Werkzeugs in das Gehäuse (40);

    Einziehen von Luft in einen Motor des Werkzeugs und Kühlen des Motors durch Durchleiten der Luft durch ein Motorgehäuse, das den Motor enthält, um Motorabluft zu erzeugen, die auf eine erste Temperatur erwärmt wird, und aus dem Motorgehäuse (100) durch zumindest einen Auslass (190) austritt, der in einem Körper des Motorgehäuses (100) ausgebildet ist; gekennzeichnet durch Leiten der Motorabluft in einen Luftkanal (140), der angeordnet ist, um den zumindest einen Auslass einzuschließen, wobei der Luftkanal (140) die Luft, die von außerhalb des Gehäuses (40) eingezogen wird, ausschließlich durch Spalte zwischen den Körperabschnitten leitet, und durch das Motorgehäuse (100) aus dem Gehäuse (40) heraus über einen Abluftauslass (192), der an einem Ende des Luftkanals (140) angeordnet ist, wobei der Luftkanal (140) angeordnet ist, um sicherzustellen, dass die erwärmte Luft aus dem elektrischen Werkzeug ausgeleitet werden kann, während jegliche Rückführung der Luft in andere Abschnitte des Werkzeuggehäuses (40) verhindert wird.


     
    16. Verfahren nach Anspruch 15, ferner umfassend das Leiten der Luft, die in das Gehäuse (40) eingezogen wird, in der Nähe von Komponenten innerhalb des Gehäuses, um Luft zu erzeugen, die auf eine zweite Temperatur vorgewärmt wird, die niedriger ist als die erste Temperatur, bevor die Luft in den Motor eintritt.
     
    17. Verfahren nach Anspruch 16, wobei der Luftkanal, der die Luft aus dem Gehäuse leitet, umfasst, dass die Motorabluft in der Nähe einer Steuereinheit (150) des Werkzeugs geleitet wird, um Luft zu erzeugen, die auf eine dritte Temperatur erwärmt ist, die höher als die erste Temperatur ist.
     
    18. Verfahren nach einem der Ansprüche 15 bis 17, wobei das Einziehen der Luft in den Motor das Einziehen von Luft in das Motorgehäuse (100) von zwei entgegengesetzten Richtungen umfasst, wobei der zumindest eine Auslass (190) des Motorgehäuses (100) angeordnet ist, um Luft in einer Richtung im Wesentlichen senkrecht auf die beiden entgegengesetzten Richtungen in den Luftkanal (140) zu leiten.
     


    Revendications

    1. Dispositif extérieur d'alimentation électrique comprenant :

    un carter (40) comprenant une pluralité de parties de corps ;

    un moteur disposé à l'intérieur du carter (40), le moteur étant configuré pour faire fonctionner un instrument de travail (20) du dispositif et comportant un boîtier de moteur (100) ayant au moins une sortie (190) à travers laquelle l'air refroidissant le moteur sort du boîtier de moteur (100) ;

    caractérisé en ce qu'un canal d'air (140) configuré pour enfermer l'au moins une sortie (190) du boîtier de moteur (100), le canal d'air (140) fournissant un passage pour l'air aspiré depuis l'extérieur du carter (40) exclusivement à travers des espaces entre les parties de corps, et à travers le boîtier de moteur (100) hors du carter (40) par l'intermédiaire d'une sortie d'échappement (192) disposée dans le carter (40) à une extrémité du canal d'air (140), ledit canal d'air (140) étant agencé pour s'assurer que l'air chauffé puisse être acheminé hors du dispositif d'alimentation électrique tout en évitant toute recirculation de l'air à l'intérieur d'autres parties du carter (40) de dispositif.


     
    2. Dispositif de la revendication 1, comprenant en outre un compartiment de batterie configuré pour recevoir une batterie (30) pour alimenter le dispositif, le compartiment de batterie étant disposé à l'intérieur du carter (40) du dispositif.
     
    3. Dispositif de l'une des revendications 1 et 2, dans lequel l'air traversant le boîtier de moteur (100) et le canal d'air transporte des produits d'usure de moteur hors du carter (40) pour empêcher l'entrée des produits d'usure à l'intérieur du carter (40).
     
    4. Dispositif de l'une des revendications 1 et 2, comprenant en outre une unité de commande (150) assurant la commande du fonctionnement du dispositif, dans lequel le canal d'air (140) est disposé à proximité de l'unité de commande (150) pour permettre à l'air traversant le canal d'air (140) de refroidir l'unité de commande (150) avant de sortir du canal d'air (140).
     
    5. Dispositif de l'une des revendications 1 et 2, dans lequel le canal d'air (140) est agencé pour s'étendre dans une direction et l'orifice d'échappement (192) est orienté pour évacuer l'air dans la direction des extrémités du canal d'air (140), dans lequel ledit canal d'air (140) se termine sur le côté, au fond ou à l'arrière du carter (40).
     
    6. Dispositif de l'une des revendications 1 et 2, dans lequel l'instrument de travail comporte au moins une lame de coupe.
     
    7. Dispositif de l'une des revendications 1 et 2, dans lequel le dispositif est une scie à chaîne électrique et l'instrument de travail est une barre de scie à chaîne.
     
    8. Dispositif de l'une des revendications 1 et 2, dans lequel le dispositif est un taille-haie (10).
     
    9. Dispositif de l'une des revendications 1 et 2, dans lequel le dispositif est un dispositif portable.
     
    10. Dispositif de l'une des revendications 1 et 2, dans lequel le moteur est un moteur à courant continu ou un moteur à courant continu sans balais ayant un ventilateur pour faciliter le déplacement d'air dans le canal de refroidissement.
     
    11. Dispositif de l'une des revendications 1 et 2, dans lequel l'air aspiré dans le boîtier de moteur (100) est préchauffé en refroidissant l'un(e) parmi la batterie (30) et un ensemble d'engrenages (130) du dispositif.
     
    12. Dispositif de la revendication 11, dans lequel l'ensemble d'engrenages (130) est couplé de manière fonctionnelle au moteur et à l'instrument de travail (20) pour transférer l'énergie du moteur à l'instrument de travail (20).
     
    13. Dispositif de l'une des revendications 1 et 2, dans lequel l'air est aspiré dans le boîtier de moteur (100) à partir de deux directions opposées et dans lequel l'au moins une sortie (190) du boîtier de moteur (100) est disposée pour diriger l'air dans le canal d'air (140) dans une direction essentiellement perpendiculaire aux deux directions opposées.
     
    14. Dispositif de l'une des revendications 1 et 2, dans lequel l'air aspiré dans le boîtier de moteur (100) est préchauffé par d'autres composants de dispositif à l'intérieur du carter (40) du dispositif avant d'entrer dans le boîtier de moteur (100).
     
    15. Procédé de refroidissement d'un dispositif extérieur d'alimentation électrique comprenant le fait :

    de fournir un carter (40) comprenant une pluralité de parties de corps ;

    d'aspirer de l'air depuis l'extérieur d'un carter (40) du dispositif dans le carter (40) ;

    d'aspirer l'air dans un moteur du dispositif et de refroidir le moteur en faisant passer l'air à travers un boîtier de moteur contenant le moteur pour générer de l'air d'échappement de moteur qui est chauffé à une première température et sort du boîtier de moteur (100) à travers au moins une sortie (190) formée dans un corps du boîtier de moteur (100) ;

    caractérisé par le fait de faire passer l'air d'échappement du moteur dans un canal d'air (140) qui est disposé pour enfermer l'au moins une sortie, le canal d'air (140) faisant passer l'air aspiré depuis l'extérieur du carter (40) exclusivement à travers des espaces entre les parties de corps, et à travers le boîtier de moteur (100) hors du carter par l'intermédiaire d'une sortie d'évacuation (192) disposée à une extrémité du canal d'air (140), ledit canal d'air (140) étant agencé pour s'assurer que l'air chauffé puisse être acheminé hors du dispositif d'alimentation électrique tout en évitant toute recirculation de l'air à l'intérieur d'autres parties du carter (40) de dispositif.


     
    16. Procédé de la revendication 15, comprenant en outre le fait de faire passer l'air aspiré dans le carter (40) à proximité de composants à l'intérieur du carter pour générer de l'air préchauffé à une deuxième température qui est inférieure à la première température avant que l'air n'entre dans le moteur.
     
    17. Procédé de la revendication 16, dans lequel le canal d'air faisant sortir l'air hors du carter comprend le fait de faire passer l'air d'échappement du moteur à proximité d'une unité de commande (150) du dispositif pour générer de l'air chauffé à une troisième température qui est supérieure à la première température.
     
    18. Procédé de l'une des revendications 15 à 17, dans lequel l'aspiration de l'air dans le moteur comprend l'aspiration de l'air dans le boîtier de moteur (100) à partir de deux directions opposées, dans lequel l'au moins une sortie (190) du boîtier de moteur (100) est disposée pour diriger l'air dans le canal d'air (140) dans une direction essentiellement perpendiculaire aux deux directions opposées.
     




    Drawing























    Cited references

    REFERENCES CITED IN THE DESCRIPTION



    This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

    Patent documents cited in the description