Motor housing with silencer for a vacuum cleaning device

Abstract

A compact motor housing for housing a motor and a blower of a cleaning device and with integrated air outlet silencing. The motor housing encloses a flow passage between a flow inlet and outlet. The housing has a blower chamber fluidically connected to the flow inlet, and via first and second outlet openings also fluidically connected to at least two parallel, preferably similar, silencer ducts each being arranged in an area limited by an angle of less than 90, seen in a view parallel with the blower and motor axis. The silencer ducts each have at least one wall between the blower chamber and the external wall of the motor housing for causing at least one flow direction bend, so as to provide a noise attenuating effect. The areas occupied by the at least two silencer ducts are non-overlapping, seen in a view parallel with the blower and motor axis. With a circular blower chamber, a compact box shaped motor housing can be provided with corner volumes available for silencer ducts.

Claims

1. A motor housing for housing a motor and a blower of a cleaning device, the motor housing comprising an external wall for enclosing a blower arranged to rotate around an axis, a motor for driving the blower, and a flow passage between an externally accessible flow inlet and an externally accessible flow outlet, wherein the flow passage comprises, seen in a view parallel with said axis: a blower chamber for housing the blower, wherein the blower chamber has an opening fluidically connected to the externally accessible flow inlet, wherein the blower chamber further has separate first and second outlet openings, a first silencer duct fluidically connected to the first outlet opening of the blower chamber, wherein the first silencer duct is arranged in a first area limited by a first angle of less than 90 from the axis, wherein at least one wall between the blower chamber and the external wall of the motor housing serves to cause at least one flow direction bend, and wherein the first silencer duct has a first outlet opening, and a second silencer duct fluidically connected to the second outlet opening of the blower chamber, wherein the second silencer duct is arranged in a second area limited by a second angle of less than 90 from the axis, wherein at least one wall between the blower chamber and the external wall of the motor housing serves to cause at least one flow direction bend, and wherein the second silencer duct has a second outlet opening, wherein the first and second areas are non-overlapping.

2. The motor housing according to claim 1, comprising a third silencer duct fluidically connected to a third outlet opening of the blower chamber, wherein the third silencer duct is arranged in a third area limited by a third angle of less than 90 from the axis and non-overlapping with the first and second areas, wherein the third silencer duct has a third outlet opening.

3. The motor housing according to claim 2, comprising a fourth silencer duct fluidically connected to a fourth outlet opening of the blower chamber, wherein the fourth silencer duct is arranged in a fourth area limited by a fourth angle of less than 90 from the axis and non-overlapping with the first, second and third areas, wherein the fourth silencer duct has a fourth outlet opening.

4. The motor housing according to claim 1, having a general rectangular or substantially rectangular shape, seen in a view parallel with said axis.

5. The motor housing according to claim 1, wherein the blower chamber has a circular or substantially circular shaped outer wall, seen in a view parallel with said axis, in which the first and second openings are arranged.

6. The motor housing according to claim 1, wherein, seen in a view parallel with said axis, the blower chamber extends at least at one point to the external wall of the motor housing.

7. The motor housing according to claim 1, wherein the externally accessible flow inlet is arranged on a top surface part of the external wall of the motor housing.

8. The motor housing according to claim 1, wherein a first part of the external wall of the motor housing forms part of the first silencer duct, and wherein a second part of the external wall of the motor housing forms part of the second silencer duct.

9. The motor housing according to claim 1, wherein the motor housing is constituted by first and second separate polymeric elements arranged for being assembled, wherein the first separate polymeric element comprises a top surface part of the external wall of the motor housing and the at least one wall of both of the first and second silencer ducts.

10. The motor housing according to claim 1, wherein said at least one wall between the blower chamber and the external wall of the motor housing of both of the first and second silencer ducts serve to cause at least one flow direction bend of 90-180.

11. The motor housing according to claim 1, wherein both of the first and second silencer ducts comprise at least one wall element dimensioned to act as a quarter wavelength resonator to reduce tonal noise from the blower.

12. The motor housing according to claim 1, wherein both of the first and second silencer ducts extend, in a direction along said axis, from the bottom to the top of the motor housing.

13. A cleaning device for generating an air flow for vacuuming or high pressure cleaning dirt, comprising a motor housing according to claim 1.

14. A method for manufacturing the motor housing according to claim 1, comprising manufacturing a first polymeric element comprising motor a top surface part of the external wall of the motor housing and said at least one wall between the blower chamber and the external wall of the motor housing of both of the first and second silencer ducts, and manufacturing a second polymeric element comprising a lower part of the external wall of the motor housing comprising the blower chamber.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) The invention will now be described in more detail with regard to the accompanying figures of which

(2) FIGS. 1-3 illustrate top view sketches of three different embodiments with different configurations of two silencer ducts around a circular motor and blower chamber,

(3) FIG. 4 shows a top view sketch of an embodiment with four silencer ducts around a circular motor and blower chamber,

(4) FIGS. 5-9 show different views of the embodiment with four silencer ducts around a circular motor and blower chamber,

(5) FIGS. 10-13 show different photos of a prototype similar to the embodiment shown in FIGS. 4-9, and

(6) FIG. 14 shows steps of a method of manufacturing embodiment.

(7) The figures illustrate specific ways of implementing the present invention and are not to be construed as being limiting to other possible embodiments falling within the scope of the attached claim set.

DETAILED DESCRIPTION OF EMBODIMENTS

(8) FIG. 1 shows a top view sketch of an embodiment of a motor housing iment arranged to house a motor and a blower for generating an air flow in a cleaning device, such as a vacuum cleaning device, a floor cleaning device or a high pressure cleaning device. The motor housing comprises an external wall XW for enclosing a blower and a motor for driving the blower. The blower is arranged to rotate around an axis, and in the view in FIG. 1, which is a view parallel with said axis, i.e. a cross section view perpendicular to the axis x, only the centre of the axis is seen and indicated by x. Thus, as seen the rotation axis x of the blower is arranged for being positioned in a central portion of the motor housing, referring to the view in FIG. 1.

(9) The motor housing further encloses a flow passage between an externally accessible flow inlet and an externally accessible flow outlet, none of the are visible in view of FIG. 1. Still referring to the view in FIG. 1, the flow passage comprises a blower chamber BC, and first and second silencer ducts SD1, SD2. The blower chamber BC is arranged for housing the blower, and the blower chamber BC has an opening fluidically connected to the externally accessible flow inlet, e.g. directly via an opening in the top surface part of the external wall XW of the motor housing. Further, the blower chamber BC further has separate first and second outlet openings O1, O2 through its generally circular shaped outer wall to the adjacently positioned respective silencer ducts SD1, SD2.

(10) The first silencer duct SD1 is arranged in a first area limited by a first angle A1 of less than 90 from the axis x, in the Fig. A1 is seen to be such as 80-85. A wall W1 between the blower chamber BC and the external wall XW of the motor housing serves to cause at least one flow direction bend of 180, or at least about 180, from the blower chamber output O1 to a first outlet opening S_O1 of the first silencer duct. This first outlet opening S_O1 is indicated by a dashed line, since it is located below the view shown in FIG. 1. In a preferred embodiment, the blower chamber BC and the first blower chamber output O1 is arranged in an upper part of the motor housing, while the first outlet opening S_O1 of the first silencer duct SD1 is arranged on a lower part, such as a bottom surface, of the exernal wall XW of the motor housing. Preferably, the first silencer duct SD1 occupies the entire extension of the motor housing from its bottom to its top, i.e. in a direction parallel with the axis x. Thus, a substantial volume is avaibale to generate a noise attenuating resonator chamber effect, together with the labyrinth bending effect provided by the wall W1, in this embodiment shown as a place shaped wall parallel with the axis x. Further, wall elements like wall W1 may be designed to provide quarter wavelength resonator effects to attenuate tonal noise from the blade frequency of the blower when operating at its normal rotation speed.

(11) A second silencer duct SD2 fluidically connected to the second outlet opening O2 of the blower chamber BC is arranged in a second area limited by a second angle A2. Preferably, the first and second silencers are identical, or very close to identical, seen from an acoustic point of view. I.e. the second silencer duct SD2 preferably has a configuration similar to the first silencer SD1, which is preferred to provide a high noise attenuation, since effectively the fluid flow from the blower chamber BC is split into two parallel flow paths. Thus, the explanation above for the first silencer duct SD1 applies with respect to the angle A1, the wall W2, and the outlet opening S_O2 of the second silencer duct SD2 as well. However being non-overlappint, i.e. being angularly distributed, seen from the axis x, the first and second silencer ducts SD1, SD2 provides a high efficiency with respect to utilizing space available for silencing due to their limited angular extension of less than 90, respectively.

(12) As seen, the outer dimensions are compact, since the external wall XW forms the wall of half of the circular shaped blower chamber BC, and also in a smaller part located between the first and second silencer ducts SD1, SD2. The silencer ducts SD1, SD2 occupy the space in the corners of the rectuangular shaped external wall portion XW of the motor housing. It is understood that the two silencer ducts SD1, SD2 may have been angularly distributed differently with respect to each other, thus resulting in a different outer shape of the external wall of the motor housing, but still within the scope of invention.

(13) FIG. 2 shows a variant of the embodiment of FIG. 1, still with the corner position of the two similarly configured silencer ducts SD1, SD2, but in FIG. 2 with a smaller angular extension A1, A2 of such as 50-60. Thus with smaller volumes for silencing effect, the outer shape can be even more compact, since here the external wall XW of the motor housing forms more than half of the circular shaped blower chamber BC. A further difference from FIG. 1 is the location of blower chamber openings O1, O2, the location of the outlets S_O1, S_O2, and the configurations of the plane walls W1, W2 which are positioned differently compared to FIG. 1 the angular, and thus result in other flow direction paths than in FIG. 1.

(14) FIG. 3 is yet another variant of the embodiments of FIGS. 1 and 2. The outer shape is similar to FIG. 1, but the location of the outlets S_O1, S_O2 is different. Further, in this embodiment, a plurality of separate plane walls W1, W2, specifically four wall elements, are arranged to provide a labyrinth effect with several flow direction bends between blower chamber outlets O1, O2 and outlets of the silencer ducts SD1, SD2.

(15) FIGS. 1-3 only serve to illustrate a few variants of the concept of non-overlapping angularly limited, preferably similarly configured, parallel silencer ducts.

(16) In the following, referreing to skethes in FIGS. 4-9, and photos in FIGS. 10-13, a specific square box shaped motor housing embodiment suited for a floor cleaning device with a vacuum suction system will be described.

(17) FIG. 4 shows a top view sketch of this specific embodiment, having with four identical or at least practically identical silencer ducts SD1, SD2, SD3, SD4 distributed angularly around a circular blower chamber B. At least the silencer ducts SD1, SD2, SD3, SD4 have similar or substantially similar configurations with respect to silencing. Only angular extensions A1, A2 of the first and second silencer ducts are show for clarity reasons, however all of the silencer ducts occupy angles of such as 75-85.

(18) The general shape of the external wall XW of the motor housing is square, seen in a view parallel with the axis x, but with the corners cut off. This provides a high utilization of space available in combination with the fact that, as seen, the circular blower chamber BC extends at four points or positions to the external wall XW of the motor housing, located between the silencer ducts SD1, SD2, SD3, SD4. The blower chamber outlet openings O1, O2, O3, O4 are located in the blower chamber wall BCW adjacent to these points or positions, wherein the blower chamber wall BCW and the external wall XW of the motor housing meet.

(19) The silencer duct outlet openings S_O1, S_O2, S_O3, S_O4 are located near the corner positions of the motor housing, and in a bottom part of the motor housing, as also explained in connection with FIG. 1, and curved walls W1, W2, W3, W4 parallel with the circular shaped outer wall BCW of the blower chamber BC serves to provide flow direction bends to generate noise attenuation effects.

(20) FIG. 5 shows a 3D view of the embodiment of FIG. 4, where it is seen that the motor housing is constituted by first and second separate monolithic polymeric elements P1, P2 arranged for being assembled. The first separate polymeric element P1 comprises a top surface part TP of the motor housing external wall, a flat top or lid serving as upper wall of the blower chamber BC, and structurally connected to the full extension parallel with axis x of the walls W1, W2, W3, W4 of the respective four silencer ducts. The externally accessible flow inlet E_I of the motor housing is seen as a circular opening in the centre of the top surface part TP.

(21) The second separate polymeric element P2 comprises a bottom part BP of the motor housing which forms the raiming part of the motor housing, i.e. including a bottom surface and side walls extending parallel or substantially parallel with the axis x. Further, in the corner positions of the bottom part BP, channels CHB are positioned for receiveing bolts of the like for fastening the motor housing to parts of a device, e.g. cleaning device. The externally accessible flow outlet of the motor housing is not visible in FIG. 5, i.e. the four outlets of the respective silencer ducts, as these are positioned on the flat lower surface part of the bottom part BP of the motor housing.

(22) By splitting all elements into two polymeric elements P1, P2, it is possible to manufacture the entire motor housing using only two element, and by placing the walls W1, W2, W3, W4 on the first polymeric element P1, the inner parts of the motor housing has dimensions large enough to allow injection moulding of both elements P1, P2 even in the rather compact embodiment shown which has a square top view with side lengths of 15.5 cm and a height of 14.5 cm.

(23) It is understood that in motor housing embodiments with larger dimensions, it may be possible to injection moulded with the walls W1, W2, W3, W4 integrated in the bottom part P2, but still the splitting at least a part of the walls of the silencer ducts into a separate element may allow injection moulding of rather complicated labyrinth silencer designs with narrow flow paths. E.g. this may also facilitate

(24) FIG. 6 shows the same two elements P1, P2 as in FIG. 5, but in a different view. Here, a part of the blower chamber BC is visible with two of its outlets O1, O2 as seen in the form of slids extending in the direction parallel with the axis x. Below the blower chamber BC, the motor chamber MC is located. These chambers BC, MC are sealed by a water-tight sealing to avoid liquid or moist penetrating from the blower chamber BC into the motor chamber MC. The motor chamber MC has a separate cooling air inlet and outlet on the bottom surface of the bottom part, thus not visible in FIG. 6, but the inlet opening MCL_I from an annular passage for cooling air into the motor chamber MC is visible.

(25) FIG. 7 shows the two elements P1, P2 in an assembled state.

(26) FIGS. 8 and 9 show different exploded views of the motor housing with the motor M and blower BL visible. The motor M and blower BL are arranged to rotate around one common axis, namely axis x. The plane bottom part of the external wall of the motor housing is at least partly visible in FIG. 9. The end of the motor M opposite the blower BL comprises a cooling fan for cooling the motor M.

(27) FIGS. 10-13 show different photos of a prototype similar to the embodiment shown in FIGS. 4-9. FIG. 10 shows a top view similar to the view in FIG. 4. FIG. 11 shows a bottom view of the upper part of the motor housing including the walls.

(28) FIG. 12 shows a bottom view of the motor housing, i.e. the bottom surface part of the external wall of the motor housing. Here, four outlet openings S_O1, S_O2, S_O3, S_O4 from the respective silencer ducts are seen and located at respective separate positions on the bottom surface part of the motor housing, so as to constitute the externally accessible flow outlet. It is to be understood that other locations on the external wall of the motor housing may be preferred for being applied in a differently configured cleaning device. Further, the bottom surface part of the motor housing comprises a motor cooling inlet MC_I shaped as an annular opening and connected to the motor chamber via an annular channel, see FIG. 6 for cooling air connection to the motor chamber driven by a fan on the motor. Further, the bottom surface part of the motor housing comprises a motor cooling air outlet MC_O which is seen to be shaped as a slid located in an area within the annular inlet opening MC_I.

(29) FIG. 13 shows a photo with another view of the bottom part of the motor housing.

(30) FIG. 14 shows steps of a method of manufacturing a motor housing embodiment, such as motor housing embodiment described in the foregoing. In one step IM_1 the method comprises manufacturing a first polymeric element in an injection moulding process, wherein the first polymeric element comprises a motor a top surface part of the external wall of the motor housing, and at least one wall between the blower chamber and the external wall of the motor housing of both of the first and second silencer ducts. In a second step IM_2, the method comprises manufacturing a second polymeric element comprising a lower part of the external wall of the motor housing comprising one or more walls defining the blower chamber. Finally, the first and second polymeric elements are assembled ASM_1_2.

(31) To sum up: the invention provides a compact motor housing for housing a motor and a blower of a cleaning device and with integrated air outlet silencing. The motor housing encloses a flow passage between a flow inlet and outlet. The housing has a blower chamber fluidically connected to the flow inlet, and via first and second outlet openings also fluidically connected to at least two parallel, preferably similar, silencer ducts each being arranged in an area limited by an angle of less than 90, seen in a view parallel with the blower and motor axis. The silencer ducts each have at least one wall between the blower chamber and the external wall of the motor housing for causing at least one flow direction bend, so as to provide a noise attenuating effect. The areas occupied by the at least two silencer ducts are non-overlapping, seen in a view parallel with the blower and motor axis. With a circular blower chamber, a compact box shaped motor housing can be provided with corner volumes available for silencer ducts.

(32) Although the present invention has been described in connection with the specified embodiments, it should not be construed as being in any way limited to the presented examples. The scope of the present invention is to be interpreted in the light of the accompanying claim set. In the context of the claims, the terms including or includes do not exclude other possible elements or steps. Also, the mentioning of references such as a or an etc. should not be construed as excluding a plurality. The use of reference signs in the claims with respect to elements indicated in the figures shall also not be construed as limiting the scope of the invention. Furthermore, individual features mentioned in different claims, may possibly be advantageously combined, and the mentioning of these features in different claims does not exclude that a combination of features is not possible and advantageous.