WO2009144257A2

WO2009144257A2 - Leaf vacuum

Info

Publication number: WO2009144257A2
Application number: PCT/EP2009/056484
Authority: WO
Inventors: Ralph Diehl; Christian Stewen; Rolf Lindauer; Rainer Kurmann; Andreas MÜLLER; Eugen Schlötzer
Original assignee: Alfred Kärcher Gmbh & Co. Kg
Priority date: 2008-05-30
Filing date: 2009-05-27
Publication date: 2009-12-03
Also published as: DE112009000859A5; WO2009144257A3

Abstract

The invention relates to a leaf vacuum comprising a housing (12; 152) with an inlet (14) for sucking up items to be vacuumed, an outlet (16) for distributing the vacuumed items to a collection container (20) and comprising a fan (30) which has a fan impeller (62; 156) that can rotate about a rotational axis (64) and is coupled to a drive motor (38; 154) for generating a process air flow from the inlet to the outlet. To improve the handling of the leaf vacuum, according to the invention, the fan impeller is designed as an axial fan impeller (62; 156) and the drive motor (38; 154) is located in the housing (12; 152) in the flow path of the process air between the inlet (14) and the outlet (16). A flow channel (36; 170) for the process air delivered by the axial fan impeller (62; 156) runs between the drive motor (38; 154) and the housing wall.

Description

leaf Blower

The invention relates to a leaf vacuum with a housing having an inlet for sucking in suction material and an outlet for discharging suction material to a collecting container, and with a fan having a rotatable about a rotation axis impeller and is coupled to a drive motor for generating a Process air flow from the inlet to the outlet.

Leaf vacuum cleaners are used to remove leaves and other material such as paths, courtyards and squares. They have for this purpose a fan which is driven by a drive motor and within a housing generates a process air flow from the inlet to the outlet of the housing. At the outlet, a collecting container can be connected, for example a collecting bag, in which the sucked up suction material can be collected.

The fan often has a radial fan in known vacuum cleaners, so that it sucks in process air in the axial direction and discharges in the radial direction. By means of such radial fan wheels, a considerable pressure difference between the inlet and the outlet of the housing can be generated, but they require a not inconsiderable drive power of the drive motor and are in many cases associated with a significant noise. Another disadvantage is the considerable size of the known leaf vacuum cleaner in many cases, which impairs their handling.

Object of the present invention is to develop a leaf vacuum cleaner of the type mentioned in such a way that it has improved handling.

This object is achieved with a leaf blower of the generic type in that the fan is designed as Axiallüfterrad and the drive motor in the flow path of the process air between the inlet and the outlet is arranged in the housing, wherein between the drive motor and the housing wall, a flow channel runs for Process air delivered by the axial fan.

According to this solution, the fan is designed in the form of an axial fan and the drive motor is disposed within the housing of the leaf vacuum, wherein the process air, which is required by the Axiallüfterrad is passed over a flow channel on the drive motor. The size of the leaf vacuum can be kept relatively low, and this in turn increases the handling of the leaf vacuum.

The axial fan sucks the process air in the axial direction and also releases it in the axial direction. By means of Axiallüfterräder can be at the same

Drive power of the drive motor generate a larger volume flow of process air than a comparable radial fan. Since the volume flow of the process air is decisive for the achievable cleaning performance of the leaf vacuum, the use of an axial fan wheel is thus advantageous. To achieve a desired volumetric flow, the axial fan requires less drive power than a comparable radial fan. As a result, the energy consumption can be kept low and it can

Noise emission can be reduced. The leaf vacuum cleaner according to the invention is characterized by a relatively low noise.

By means of the fan wheel not only process air can be conveyed and thereby a suction flow can be generated, but the fan wheel can be used at the same time for shredding the sucked in suction material, that is to say the leaf extractor can also be used in the form of a shredder. This increases the absorption capacity of the connectable to the outlet of the housing collecting container.

It is advantageous if the drive motor is arranged in alignment with the axis of rotation of the axial fan. In particular, it can be provided that the drive motor is positioned in the flow direction of the process air behind the Axiallüfterrad, wherein the motor shaft is aligned in alignment with the axis of rotation of the Axiallüfter- rad.

In an advantageous embodiment, the drive motor is surrounded by an annular space which forms a flow channel for the process air conveyed by the axial fan and which is penetrated by at least one retaining web, wherein the retaining web connects the drive motor with the housing. The process air sucked in by the fan can be passed through the annular space which surrounds the drive motor. As a result, the process air also serve to dissipate heat from the drive motor, that is, it causes cooling of the drive motor. The drive motor is held on at least one holding web, which passes through the annular space and connects the drive motor to the housing.

It can be provided that the drive motor is rigidly connected to the housing via the at least one holding web.

In a preferred embodiment of the invention, the connection is made by the drive motor via the at least one holding web to the housing via a vibration-damping material. As a result, the noise emission of the leaf vacuum can be further reduced. For example, the at least one retaining web may be made of a vibration-damping material, in particular of an elastic plastic material. It may alternatively or additionally be provided that a vibration-damping material between the holding web and the housing and / or between the holding web and the drive motor is positioned.

In an advantageous embodiment of the drive motor is connected via a single holding web with the housing. The available for the process air flow cross-section of the surrounding the drive motor annular space can be kept particularly large. This reduces the risk that sucked suction material clogged the annulus. In addition, the flow resistance of the annular space is kept particularly low when using a single holding web.

Preferably, at least one retaining web is aligned radially to the axis of rotation of the Axiallüfterrades. However, it can also be provided that at least one retaining bar is skewed in the direction of the axis of rotation of the axial fan wheel. For example, at least one holding web can be inclined both in the radial direction and in the axial direction with respect to the axis of rotation of the axial fan wheel.

In order to avoid a deposition of suction material, at least one holding web in an advantageous embodiment of the invention in a plane perpendicular to the radial direction has a contour with a first contour section, which widens in the flow direction of the process air, and with a second contour section extending in the flow direction the process air is not extended. The process air can thereby be guided around the latter while forming a relatively small flow resistance of the at least one holding section. The risk of sucked suction material depositing on at least one retaining bar is thereby considerably reduced.

It is particularly advantageous if the second contour section tapers in the flow direction of the process air. This results in a further reduction of the flow resistance of the retaining web.

It can be provided that the contour of the holding web in a plane perpendicular to the radial direction in addition to the first and second contour portion has a further contour portion which is arranged between the first and the second contour portion. However, it has been found that the risk of deposits on the at least one retaining web can be kept particularly low if the second contour section adjoins the first contour section in the flow direction of the process air.

Surprisingly, the risk of deposits on the at least one retaining web can be kept particularly low if the first contour section and / or the second contour section are asymmetrical to a radial contour.

level is configured. In this case, a radial plane is understood as meaning a plane that runs in the radial direction relative to the axis of rotation of the axial fan wheel. The contour of the at least one retaining web is preferably asymmetrical to such a radial plane.

In an advantageous embodiment, the first contour section has an arcuate first side area. This can advantageously extend from a contour tip to the second contour section.

Conveniently, the first side region of the first contour section is convexly curved. The risk of deposits on the at least one retaining web can be kept particularly low in such a contour.

It is favorable if the first contour section has a rectilinear second side area.

It is particularly advantageous if the second side area is aligned parallel to a radial plane.

The second contour portion of the at least one retaining web is designed in a preferred embodiment of the invention U-shaped and has a first and a second side region, which are interconnected via an arcuate end region.

Conveniently, the first side region of the second contour section is aligned obliquely to the first side region of the second contour section.

The second side region of the second contour section is favorably aligned parallel to a radial plane.

As already explained, cooling of the drive motor can be achieved by the process air guided along the drive motor. An additional cooling effect is achieved in an advantageous embodiment of the invention in that at least one of the annular space surrounding the drive motor, cross-holding web is hollow and forms a supply channel for cooling air, which is fed to the drive motor, wherein the

Supply channel connects to a cooling air opening of the housing. Cooling air can thus be supplied to the drive motor via the cooling air opening and the supply channel, with the aid of which waste heat from the drive motor can be dissipated. The annular web by cross-holding web thus has not only the function to connect the drive motor with the housing of the leaf vacuum, but it also serves to supply cooling air to the drive motor.

The axial fan wheel is expediently connected in a rotationally fixed manner to an auxiliary fan wheel for conveying the cooling air, which is supplied to the drive motor via the supply channel, through the drive motor to the process air conveyed by the axial fan. In such a configuration, cooling air is conveyed from an auxiliary fan wheel which is non-rotatably connected to the axial fan, which is passed through the supply channel and the drive motor. The cooling air is then fed to the process air conveyed by the axial fan. So first it flows through the supply channel, then the drive motor and finally the annular space surrounding the drive motor and a flow

is formed for the process air, which can be discharged via the outlet of the housing. By means of the auxiliary fan wheel, a particularly efficient cooling air flow can be generated, so that the waste heat of the engine can be reliably dissipated.

It can be provided that the cooling air guided through the drive motor can be supplied to the process air downstream of the axial fan wheel, relative to the flow direction of the process air. For example, the auxiliary ventilator wheel can be arranged downstream of the axial fan in the direction of flow of the process air, so that the cooling air delivered by the auxiliary fan can be fed to the process air downstream of the axial fan.

It is particularly advantageous, however, if the auxiliary fan wheel is arranged in the flow direction of the process air in front of the axial fan. In such a configuration, the cooling air delivered by the auxiliary fan is supplied to the process air upstream of the axial fan in the flow direction. This increases the pressure on the suction side of the axial fan. This increases the delivery rate of the axial fan.

The auxiliary fan is preferably designed in the form of a radial fan, with the aid of which the cooling air can be sucked in the axial direction and discharged in the radial direction.

However, it can also be provided that the auxiliary fan is designed as a further Axiallüfterrad, by means of which the cooling air can be sucked in the axial direction and discharged in the axial direction.

The axial fan wheel that promotes the process air and the auxiliary fan wheel that conveys the cooling air can be designed as a combination component. This simplifies the installation of the leaf vacuum. The combination component sucks the process air in the axial direction and gives it also in the axial direction, and in addition promotes the combination component, the cooling air, which can for example be sucked in the axial direction and delivered in both the axial and in the radial direction.

The at least one holding web, which connects the drive motor with the housing of the leaf vacuum, extends in an advantageous embodiment in the axial direction over at least 50% of the length of the drive motor. In particular, it may be provided that the at least one holding web extends in the axial direction over at least 80% of the length of the drive motor. This increases the mechanical stability of the holding web and thus the entire leaf vacuum.

In the circumferential direction - with respect to the axis of rotation of the axial fan - extends the at least one holding web in an advantageous embodiment, practically over the entire width of the drive motor, that is, the maximum diameter of the at least one holding web transverse to the axis of rotation of Axiallüfterrades corresponds substantially to the diameter of the drive motor.

The diameter of the housing is greater in a preferred embodiment of the invention in the amount of the drive motor than in the amount of Axiallüfterrades. As a result, the flow cross section of the annular space surrounding the drive motor can be selected to be relatively large. This reduces the danger

a blockage of the annular space and reduces its flow resistance.

It is favorable if the housing continuously widens in a transition region between the axial fan and the drive motor.

The Axiallüfterrad has a hub from which protrude a plurality of blades to the outside. It is advantageous if an annular gap is arranged between the blades and the housing of the leaf vacuum with a maximum width of 5 mm. The blades of the Axiallüfterrades thus extend in the radial direction to in the immediate vicinity of the housing. As a result, the delivery capacity of the Axiallüfterrades is increased, that is at a given drive power of the drive motor, a particularly high flow rate of the process air can be achieved.

It is particularly advantageous if the width of the annular gap between the blades of the Axiallüfterrades and the wall of the housing is not greater than 3 mm.

It is advantageous if the housing of the leaf vacuum forms an intake channel, which defines the inlet of the housing and tapers in the flow direction. The intake passage may be configured, for example, funnel-shaped.

The object underlying the invention to improve the handling of the above-mentioned leaf vacuum, is also achieved in that the fan has a plurality of projecting from a hub to the outside blades,

at the front edge in the direction of rotation of the fan each a reinforcing element is arranged. The reinforcing elements form the region of the blades of the fan wheel, which have first contact with the process air or with the suction material upon rotation of the fan wheel and therefore experience the greatest mechanical load through the suction material. It has been shown that the suction material can be reduced particularly effectively by the reinforcing elements, without affecting the life of the fan wheel. The leaf vacuum cleaner according to the invention can therefore also be used as a shredder, this improves the handling of the leaf vacuum.

The mechanical reinforcement of the front edges of the blades of the fan wheel is not only advantageous if the fan is designed as Axiallüfterrad, but also in cases where the fan is designed as a radial fan.

The mechanical stability of the fan wheel can be additionally increased by the reinforcing elements of all blades are held on a reinforcing ring which is fixed to the hub of the fan wheel.

The reinforcing elements and the reinforcing ring favorably form a one-piece reinforcing part. They may preferably be permanently connected to the hub and the blades of the fan wheel. For example, the hub and vanes of the fan may form a one-piece plastic injection molded part, and the reinforcing elements and the reinforcing ring may form an insert which is inserted in the mold of the fan during the injection process.

The reinforcing elements and preferably also the reinforcing ring are conveniently made of metal. In particular, it can be provided that the reinforcing elements are made of steel. Here, a hardened or even an uncured steel can be used. An unhardened steel gives the user the opportunity to subsequently sharpen the reinforcing elements.

It is favorable if the reinforcing elements have a cutting edge. As a result, the chaff effect of the leaf vacuum can be improved.

In order to reduce the risk of clogging, in an advantageous embodiment the fan impeller has a plurality of blades projecting outwardly from a hub, which blades are connected to one another only via the hub. The fan wheel is thus configured as a star-shaped overall, the show fine from the hub projecting outward, but otherwise freestanding are formed without additional connecting elements between adjacent blades. Outside the hub, the blades therefore have no connection to one another. The risk of clogging by suctioned suction material is thereby further reduced.

It is advantageous if by means of the leaf vacuum also a blast flow can be generated. The leaf vacuum can then also be used as a so-called leaf blower, with the aid of suction material can be brought together on a surface. For this purpose, a considerable blow flow is provided by the leaf vacuum. This can be achieved by connecting the outlet of the housing to a blowpipe extending to the level of the inlet of the housing, the diameter of the end portion of the blowpipe

smaller than the diameter of the inlet of the housing. The process air sucked in via the inlet can thus be discharged via the blower tube, whereby a strong blow flow is generated due to the relatively small diameter of the blower tube. After the suction material has been brought together on one surface, the blowing flow can be interrupted. Subsequently, by means of the suction flow prevailing at the inlet of the housing, the merged foliage can be sucked up and delivered to a collecting container connected to the outlet of the housing.

The following description of preferred embodiments of the invention is used in conjunction with the drawings for further explanation. Show it :

Figure 1 is a perspective view of a deciduous teat according to the invention according to a first embodiment with an inlet to which a suction tube is connected, and with an outlet to which a collecting bag is connected;

Figure 2 is a perspective, partially separated view of the leaf sucker of Figure 1;

Figure 3 is a sectional view of a housing and a fan and a drive motor of the leaf vacuum from Figure 1;

Figure 4 is a perspective, partially separated view of the housing with the drive motor and the fan of Figure 3;

FIG. 5 shows a partially cutaway plan view of the drive motor and the fan from FIG. 3;

FIG. 6 is a perspective view of the fan and the drive motor, which is surrounded by a housing part;

Figure 7 is a front view of the housing of the leaf vacuum from Figure 1;

FIG. 8 shows a perspective, partially cutaway view of a second embodiment of a leaf extractor according to the invention and FIG

9 shows a perspective view of a third embodiment of a leaf vacuum according to the invention.

In the figures 1 to 7, a first embodiment of a leaf extractor according to the invention is shown schematically, which is generally occupied by the reference numeral 10. It comprises a housing 12 with an inlet 14 and an outlet 16. Connected to the inlet 14 is an approximately triangular suction tube 18 in cross section, and a collecting container in the form of an air-permeable collecting bag 20 is connected to the outlet 16. The housing 12 is circumferentially surrounded by a aligned with the suction pipe 18 and a triangular shape as the suction tube 18 having holding tube 22. About not shown in the drawing holding ribs, the housing 12 is held on the holding tube 22. On the outside can protrude from the holding tube 22 in the drawing, not shown handles, with which the user can take the leaf vacuum 10.

As becomes clear in particular from FIG. 2, the housing 12 is formed in three parts. It comprises a first housing part, which forms an intake passage 26. This defines the inlet 14 and tapers in the direction away from the suction pipe. To the intake passage 26, a second housing part connects, which forms a fan housing 28 and surrounds a fan 30. By means of the fan 30, process air can be conveyed, which can be sucked into the housing 12 via the inlet 14 and the suction pipe 18 situated upstream therefrom and can be discharged via the outlet 16 to the catch bag 20. The flow direction of the process air conveyed by the fan 30 is illustrated in FIG. 2 by the arrow 32.

To the fan housing 28 connects in the flow direction 32, a third housing part. It forms a cylindrical channel wall 34, which surrounds a drive motor 38 in the circumferential direction while forming an annular space 36. The drive motor 38 forms the rotary drive for the fan 30. It comprises a two-part motor housing 40 with a motor sleeve 42 which adjoins a motor flange 44, via which the drive motor 38 is connected to the fan 30, and with a motor pot 46 adjoining the motor sleeve 42 in the flow direction 32, which has a jacket 48 and a floor 50.

The motor housing 40 is held on the retaining wall 52 on the channel wall 34. The holding web 52 passes through the annular space 36 in the radial direction and is hollow. It forms a cooling air channel 54, which adjoins a cooling air opening 56 of the channel wall 34. In the region of the jacket 48, the engine pot 46 has a cooling air inlet 58 via which the cooling air flowing through the cooling air duct 54 is supplied to the drive motor 38

can. The cooling air can then flow against the flow direction 32 of the process air, the drive motor 38 and the fan 30, then to be discharged by means of an auxiliary fan 60 radially outward to the process air, which is supported by an axial fan 62 of the fan 30 from the inlet 14 to the outlet 16 becomes. The auxiliary fan 60 is rotatably with the

Axial fan 62 connected, which is rotated by the drive motor 38 about a rotation axis 64 in rotation.

The holding web 52, which passes through the annular space 36, is formed in two parts. It comprises a first web portion 66, which forms a one-piece plastic molded part in combination with the motor sleeve 42 and the channel wall 34, and a second web portion 68, which forms in combination with the motor pot 46 another one-piece plastic molded part and in a rear receptacle 70 of the first web portion 66 is used. This becomes clear in particular from FIG.

The contour of the holding web 52 in a plane perpendicular to the radial direction with respect to the axis of rotation 34 of the axial fan 62 is particularly clear from Figure 5. The holding web 52 has a first contour section 72 and a second contour section 74 adjoining it directly in the flow direction 32. The first contour section 72 comprises an arc-shaped first side region 76, which is convexly curved, and a rectilinear second side region 78, which is aligned parallel to a radial plane and thus runs parallel to the axis of rotation 64. The first side area 76 and the second side area 78 define a web tip 80 facing the fan 30, from which they extend in the flow direction 32 as far as the second contour section 74. The second contour portion 74 is

designed essentially U-shaped. It has a first side region 82 and a second side region 84, which are connected to one another on the side facing away from the web tip 80 via an arcuate end region 86. The second side region 84 of the second contour section 74 is aligned in alignment with the second side region 78 of the first contour section 72 and likewise extends parallel to a radial plane. The first side region 82 of the second contour section 74 is aligned obliquely to the second side region 84. Starting from the web tip 80 thus widens the contour of the holding web 52 in the flow direction 32 within the first contour portion 72, and in the second contour portion 74 tapers the contour of the holding web 52 in the flow direction 32. Overall, the contour of the holding web 52 is configured asymmetrically to a radial plane , It has been shown that the contour of the holding web 52 keeps the risk of deposits particularly low. Thus, the risk is low that the annular space 36 is blocked by adhering to the retaining web 52 suction material.

As already mentioned, the process air is conveyed by the axial fan 62. This has a hub 88, which widens continuously in the flow direction 32 and projecting from the outside a plurality of blades 90. By means of the blades 90, which are rotated by the drive motor 38 about the rotation axis 64, process air can be sucked in from the inlet 14 in the axial direction and discharged in the axial direction via the outlet 16. In this case, the process air flows through the annular space 36 defined by the channel wall 34 and the motor housing 40, and cooling air is supplied to the process air via the auxiliary fan wheel 60 in the flow direction immediately before the show fin 90, as has already been explained above.

The blades 90 extend in the radial direction to a small distance from the wall 92 of the fan housing 28. Relative to the flow direction 32 of the process air, the fan housing 28 at the level of the blades 90 defines a first cylindrical housing portion 94 which via an extension portion 96 in a second cylindrical housing portion 98 passes. At the second cylindrical housing portion 98 of the fan housing 28, the channel wall 34 connects.

Between the blades 90 and the wall 92 of the first cylindrical housing portion 94 extends an annular gap 100 whose width is a maximum of 5 mm. This becomes clear in particular from FIG. Preferably, the width of the annular gap 100 is not greater than about 3 mm.

With the help of the blades 90 not only process air and entrained by this suction material can be promoted, but by means of the blades 90, the suction material can also be chopped, that is, the suction material is reduced. As a result, the absorption capacity of the catch bag 20 can be increased.

In order to avoid damaging the blades 90 during the reduction of suction material, a radially aligned reinforcing element 106 is arranged on the front edge 104 of the axial fan 62 in the direction of rotation 102 of the axial fan 62, the reinforcing ring 108 fixed to the hub 88 of the axial fan wheel 62 is held. The reinforcing elements 106 of the blades 90, in combination with the reinforcing ring 108, form a one-piece reinforcing member 110 made of metal, preferably a hardened or uncured steel. The vanes 90 may be injection molded in combination with the hub 88,

wherein the reinforcing member 110 can be inserted into the injection mold. The reinforcing member 110 can thereby be inseparably connected to the hub 88 and the blades 90. If it is made of unhardened steel, the reinforcing elements 106 can be subsequently sharpened by the user of the vacuum cleaner 10.

The reinforcing elements 106 each form a cutting edge 112, with the aid of which suction material can be chopped particularly effectively, without thereby affecting the blades 90.

The blades 90 are not connected to each other outside the hub 88, but rather are freestanding. This reduces the risk of clogging of the Axiallüfterrades 62 during operation of the leaf vacuum 10th

By providing the Axiallüfterrades 62, a considerable volume flow of the process air can be achieved at relatively low drive power of the drive motor 38, so that by means of the leaf vacuum 10, a high cleaning performance can be achieved, the noise emission can be kept low. From the user, the leaf vacuum 10 can be guided along a surface to be sucked. The leaf vacuum 10 is made portable and is characterized by a particularly good handling and a long life.

FIG. 8 shows a second embodiment of a deciduous aspirator according to the invention and is designated overall by the reference numeral 150. It is largely identical in design to the vacuum cleaner 10 explained above with reference to FIGS. 1 to 7, in contrast to the leaf vacuum

However, in the case of the vacuum cleaner 150, a housing 152 is used whose diameter in the region of the drive motor 154 is the same as in the region of an axial fan 156. The axial fan 156 is surrounded by a cylindrical fan housing 158, to which a two-part flow in the direction of flow 32 of the process air cylindrical duct wall 160 with the same

Diameter as the fan housing 158 connects. The channel wall 160 comprises a first cylindrical wall section 162, which adjoins the fan housing 158 in the flow direction 32 of the process air, and a second cylindrical wall section 164, which adjoins the first cylindrical wall section 162 in the flow direction 32 of the process air.

According to the drive motor 38 of the leaf vacuum 10, the drive motor 154 of the leaf vacuum 150 is surrounded by an annular space 170, which forms a flow channel for the process air conveyed by the axial fan 156. However, the annular space 170 is penetrated not only by a single retaining web in the radial direction but by a plurality of retaining webs. In fact, the drive motor 154 is supported at the level of the first wall section 162 of the channel wall 160 by way of four first retaining webs 172 which are arranged at equal distances from one another in the circumferential direction of the drive motor 154. In addition, the drive motor 154 is supported at the level of the second wall section 164 of the channel wall 160 via four holding webs 174 which are arranged at the same distance from one another in the circumferential direction. In the flow direction 32 of the process air, in each case a second holding web 174 is arranged in alignment with a first holding web 172. The second holding webs 174 are formed in a similar manner as the holding web 52 of the leaf vacuum 10 hollow. They each define a cooling air channel 176, via the

the drive motor 154 cooling air can be supplied. To promote the cooling air, the axial fan 156 is non-rotatably connected to an auxiliary fan 178 arranged in the flow direction 32 of the process air upstream of the axial fan 156.

In a manner corresponding to the axial fan 62 of the leaf vacuum cleaner 10, it is also possible for the axial fan 156 of the leaf vacuum cleaner 150 to chop up suction material carried by the process air. For this purpose, a metal-made reinforcing element 186 is held on each of the front edges 182 of the blades 184 of the axial fan wheel 156 in the direction of rotation 180 of the axial fan wheel 156. The reinforcing elements 186 of all blades 184 are held on a front side of the hub 188 of the Axiallüfterrades 156 fixed reinforcing ring 190. In addition, the reinforcing elements 186 are fixed to a radially outer, concentric with the reinforcing ring 190 aligned outer ring 192. By means of the outer ring 192, the reinforcing elements 186 receive a very high mechanical stability. The outer ring 192 in combination with the reinforcing members 186 and the reinforcing ring 190 forms a one-piece reinforcing member 194 made of metal, preferably a hardened or uncured steel.

The leaf vacuum 150 is characterized by a particularly high mechanical stability of the Axiallüfterrades 156 and by a particularly effective cooling of the drive motor 154.

In Figure 9, a third embodiment of a leaf extractor according to the invention is shown schematically, which is generally designated by the reference numeral 200. He is largely identical to that of the above

With reference to Figures 1 to 7 illustrated leaf vacuum 10. For identical components, therefore, the same reference numerals are used in Figure 9 as in Figures 1 to 7. To avoid repetition, reference is made in this regard to the above explanations.

In contrast to the vacuum cleaner 10 can be generated by means of the leaf vacuum cleaner 200 not only a suction flow but if necessary, a blast flow. Instead of the suction tube 18, which is used in the leaf vacuum cleaner 10, the leaf vacuum cleaner 200 has a suction blower tube 202 with a suction channel 204 and a parallel to the suction channel 204 extending blower channel

206. Between the outlet 16 of the leaf vacuum cleaner 200 and the collecting bag 20, a deflection device 210 is arranged, by means of which the process air fed by the axial fan 62 can optionally be supplied to the collecting bag 20 or the blast channel 206. For this purpose, the deflection device 210 has an actuator in the form of a rotary knob 212, which can be actuated by the user. If the user desires only a suction flow, the rotary knob 212 can be transferred to a position in which the deflection device 210 releases the flow connection between the outlet 16 and the catch bag 20, so that suction material are sucked into the suction channel 204 and transferred into the catch bag 20 can. However, if the user desires a blast flow with which he wishes to combine suction material, for example leaves, on a surface, he can rotate the rotary knob 212 in such a way that the deflector 210 connects the outlet 16 to the blast channel 206, so that the axial fan impeller 62 suctioned suction air can be discharged through the blow port 206 again. The blow channel 206 has a significantly smaller flow cross-section than the suction channel 202, so that a strong blow flow can be generated by means of the sucked process air.

Claims

A vacuum cleaner having a housing (12, 152) having an inlet (14) for sucking in suction material and an outlet (16) for discharging suction material to a collecting container (20), and having a fan (30), which a fan (62; 156) rotatable about an axis of rotation (64) and coupled to a drive motor (38; 154) for generating process air flow from the inlet to the outlet, characterized in that the fan is configured as axial fan (62; 156) and the fan

The drive motor (38; 154) is arranged in the flow path of the process air between the inlet (14) and the outlet (16) in the housing (12; 152), wherein between the drive motor (38; 154) and the housing wall a flow channel (36; ) runs for the process air conveyed by the axial fan (62, 156).

2. Leaf vacuum cleaner according to claim 1, characterized in that the drive motor (38; 154) is arranged in alignment with the axis of rotation (64) of the axial fan wheel (62; 156).

3. Leaf vacuum according to claim 1 or 2, characterized in that the drive motor (38; 154) in the flow direction (32) of the process air behind the Axiallüfterrad (62; 156) is arranged.

4. Leaf blower according to one of the preceding claims, characterized in that the drive motor (38; 154) by an annular space (36; 170) is surrounded, which forms the flow channel for the Axiallüfterrad (62; 156) funded process air and of at least a retaining web (52; 172, 174) is penetrated, wherein the retaining web (52; 172, 174) connects the drive motor (38; 154) with the housing (12; 152).

5. Leaf vacuum according to claim 4, characterized in that the drive motor (38) via a single holding web (52) with the housing (12) is connected.

6. Leaf blower according to claim 4 or 5, characterized in that at least one holding web (52; 172, 174) is aligned radially to the axis of rotation (64) of the axial fan wheel (62; 156).

7. Leaf vacuum according to claim 4, 5 or 6, characterized in that at least one holding web (52) in a plane perpendicular to the radial direction has a contour with a first contour portion (72) which widens in the flow direction (32) of the process air, and a second contour section (74) which does not expand in the flow direction (32) of the process air.

8. Leaf vacuum according to claim 7, characterized in that the second contour portion (74) tapers in the flow direction (32) of the process air.

9. Leaf vacuum according to claim 7 or 8, characterized in that the second contour section (74) in the flow direction (32) of the process air directly adjoins the first contour section (72).

10. Leaf blower according to claim 7, 8 or 9, characterized in that the first contour portion (72) and / or the second contour portion (74) is designed asymmetrically to a radial plane.

11. Leaf blower according to one of claims 7 to 10, characterized in that the first contour section (72) has an arcuate first side region (76).

12. Leaf blower according to claim 11, characterized in that the first side region (76) is convexly curved.

13. Leaf Vacuum according to one of claims 7 to 12, characterized in that the first contour section (72) has a rectilinear second side region (78).

14. Leaf blower according to claim 13, characterized in that the second side region (78) is aligned parallel to a radial plane.

15. Leaf vacuum according to one of claims 7 to 14, characterized in that the second contour portion (74) is U-shaped with a first and a second side region (82, 84) which are interconnected via an arcuate end portion (86) ,

16. Leaf blower according to claim 15, characterized in that the first side region (82) is aligned obliquely to the second side region (84).

17. Leaf blower according to claim 15 or 16, characterized in that the second side region (84) is aligned parallel to a radial plane.

18. Leaf blower according to one of claims 4 to 17, characterized in that at least one retaining web (52; 174) is hollow and forms a cooling air channel (54; 176) for cooling air, which is the drive motor (38; 154) can be fed, wherein the cooling air duct (54; 176) adjoins a cooling air opening (56) of the housing (12; 152).

19. Leaf blower according to claim 18, characterized in that the Axiallüfterrad (62; 156) rotatably connected to an auxiliary fan (60; 178) for conveying via the cooling air passage (54; 176) to the drive motor (38; 154) supplied cooling air through through the drive motor (38, 154) to the process air conveyed by the axial fan (62, 156).

20. Leaf blower according to claim 19, characterized in that the auxiliary fan wheel (60; 178) in the flow direction (32) of the process air in front of the axial fan (62; 156) is arranged.

21. Leaf vacuum according to claim 19 or 20, characterized in that the auxiliary fan (60; 178) is designed as a radial fan.

22. Leaf blower according to one of the preceding claims, characterized in that the diameter of the housing (12) in height of the drive motor (38) is greater than in the amount of Axiallüfterrades (62).

23. Leaf vacuum according to claim 22, characterized in that the housing (12) in a transition region (96) between the Axiallüfterrad (62) and the drive motor (38) extends continuously.

24. Leaf blower according to one of the preceding claims, characterized in that the Axiallüfterrad (62; 156) has a hub (88; 188) from which a plurality of blades (90; 184) protrude outwards, wherein between the blades (90; 184 ) and the housing (12; 152) an annular gap (100) is arranged with a maximum width of 5 mm.

25. Leaf vacuum according to one of the preceding claims, characterized in that the housing (12; 152) forms an intake channel (26) which defines the inlet (14) and tapers in the flow direction (32) of the process air.

26. Leaf vacuum cleaner with the features of the preamble of claim 1, in particular according to one of the preceding claims, characterized in that the fan wheel (62; 156) has a plurality of blades (90; 184) projecting outwardly from a hub (88; 188), A reinforcing element (106, 186) is arranged on each of the front edges (104, 182) in the direction of rotation (102, 180) of the fan wheel (62, 156).

A leaf extractor as claimed in claim 26, characterized in that the reinforcing elements (106; 186) of all the blades (90; 184) are retained on a reinforcing ring (108; 190) fixed to the hub (88; 188).

A leaf vacuum according to claim 27, characterized in that the reinforcing elements (106; 186) and the reinforcing ring (108; 190) form a one-piece reinforcing part (110; 194).

29. Leaf vacuum according to claim 26, 27 or 28, characterized in that the reinforcing elements (106; 186) are made of metal.

30. Leaf blower according to one of claims 26 to 29, characterized in that the reinforcing elements (106; 186) have a cutting edge (112).

31. Leaf Blower according to one of the preceding claims, characterized in that the fan wheel (62) comprises a plurality of a hub (88) outwardly projecting blades (90), which are interconnected only via the hub (88).

32. Leaf vacuum according to one of the preceding claims, characterized in that by means of the leaf vacuum (200), a blast flow can be generated.