DE102015118623A1 - Electric motor and electric motor driven cleaning device - Google Patents

Abstract

The invention relates to an electric motor (2), in particular for a cleaning appliance (1), having a motor shaft (3), an impeller (6) connected in a rotationally fixed manner to the motor shaft (3) and a motor housing (7), wherein the electric motor (2) With reference to a geometrical motor shaft axis, an outer housing (9) arranged at a radial distance from the motor housing (7). In order to provide an electric motor (2) with an alternative embodiment of an outer housing (9), it is proposed that the outer housing (9) seen in a cross section in which the motor shaft axis is a line, two with respect to an axial direction offset housing parts ( 10, 11), of which a first housing part (10) facing the impeller (6) has a larger radial clearance (12) to the motor housing (7) than a second housing part (11) facing away from the impeller (6) and between the two Housing parts (10, 11) an air passage from within the outer housing (9) to outside of the outer housing (9) enabling the space (14) is formed.

Description

Field of engineering

The invention firstly relates to an electric motor, in particular for a cleaning device, with a motor shaft, a rotatably connected to the motor shaft impeller and a motor housing, wherein the electric motor relative to a geometric motor shaft axis arranged at a radial distance to the motor housing outer housing.

Moreover, the invention also relates to an electric motor driven cleaning device with such an electric motor.

State of the art

Electric motors of the aforementioned type are known in the art. These are designed, for example, as reluctance motors, wherein these have a rotor connected to the motor shaft and a stator. The rotor and the stator are housed inside the motor housing. Such high-speed electric motors are used, for example, in electrical cleaning devices such as vacuum cleaners, wherein a generated by the impeller of the electric motor air flow partially passes through the motor housing, namely is guided by the spaces between the rotor and stator, and partially out outside the motor housing, namely between the motor housing and outer housing along becomes. The outer housing is arranged for this purpose with a radial distance to the motor housing.

The publication DE 10200913 A1 discloses, for example, a high-speed electric motor, for example, for a vacuum cleaner, with a rotor having a motor shaft and a stator, wherein on the motor shaft, a fan is flanged, for cooling the motor and when using the electric motor in a vacuum cleaner for generating the suction, wherein the rotor and the stator are accommodated in a motor housing and wherein the motor housing has a fan pot and a motor outer housing extending at a radial distance from the motor housing. The blower pot surrounding the blower wheel is connected to the motor outer casing, thereby providing an engine encapsulation for forming an outer cooling air flow path.

Based on this prior art, it is an object of the invention to provide an electric motor with an alternative embodiment of an outer housing.

Summary of the invention

To solve the above object, the invention proposes an electric motor in which the outer housing seen in a cross section in which the motor shaft axis as a line, two relative to an axial direction staggered housing parts, of which a first blower housing facing the housing part greater radial clearance to the motor housing than a second fan housing facing away from the housing part and between the housing parts an air passage from within the outer housing to the outside of the outer housing enabling space is formed.

According to the invention, the outer housing now consists of two housing parts which have different sizes, in the sense that a first housing part has a greater radial distance from the motor housing than a second housing part of the outer housing. In this case, the first, larger housing part faces the impeller in the axial direction and the second, smaller housing part faces away from the impeller in the axial direction, so that viewed in the flow direction of the air conveyed by the impeller from the position of the impeller results in a tapered shape of the outer housing , As a result, the effect is achieved that initially the entire air flow conveyed by the fan wheel flows around the motor inside the first housing part of the outer housing, with subsequently only a smaller portion of the air flow flowing in the second housing part following thereon. The two housing parts are offset with respect to the axial direction of the electric motor, that is, starting from the impeller, the second housing part connects to the first housing part, but due to the differing radial clearances to the motor housing results in a step with a radial gap between the two housing parts, on which a part of the air flow can leave the outer housing to be discharged for example via a discharge grille of the cleaning device to the ambient air.

The outer housing serves not only to guide the air flow along the motor housing or the guide of the air flow to a discharge grille of the cleaning device, but also for the insulation of the sound generated by the electric motor. Due to the design of the outer housing with two housing parts, in particular two separate housing parts, the electric motor can be surrounded by the two corresponding housing parts, that except for the aforementioned radial gap substantially complete encapsulation of the electric motor by means of two Half shells results (regardless of the necessary air inlet and -austrittsöffnungen the outer housing). As a result, sound generated by the electric motor can be effectively damped. In addition, the use of two separate housing parts also manufacturing advantages, since the electric motor does not have to be pushed unilaterally into the outer housing, but rather the two housing parts can be arranged on opposite sides of the electric motor.

Furthermore, it is proposed that the housing parts are closed in the circumferential direction. In particular, the first housing part may have a curved cross-sectional shape and the second housing part may have a polygonal cross-sectional shape. By closed in the circumferential direction training of the housing parts results in except for the radial gap, which is formed by the different radial dimensions of the housing parts, a substantially closed enclosure, so that on the one hand optimal sound insulation is given and on the other a defined guidance of the air flow. Due to the preferably proposed deviation of the cross-sectional shapes of the first and the second housing part also a preferred direction for the air flow to escape from the outer housing can be created. For example, the larger first housing part may have a circular cross-sectional shape and the smaller second housing part has a substantially quadrangular cross-sectional shape, with their succession arrangement in the axial direction creates a gap between the housing parts, which widens and tapers along the circumference of the outer housing in the region of the two housing parts , Wherever the corners of the quadrangular second housing part point in the direction of the curvature of the first housing part, there is a smaller distance of the housing parts in the radial direction than on the sides of the quadrilateral shape. In the last-mentioned region of the sides, therefore, a larger part of the air flow can escape from the outer housing than in the region of the corners, so that it is advisable to make appropriate arrangements with respect to these radial directions for guiding the air flow within the cleaning device. The curved cross-sectional shape of the first housing part is in particular formed to enclose the circular in cross section impeller or a fan impeller receiving the fan. The polygonal cross-sectional shape of the second housing part results in particular by the design of the electric motor with a rotor and, for example, two stator coil pairs. Last but not least can be created by adapting the cross-sectional shapes of the housing parts to the cross-sectional shapes of the impeller or the electric motor, that is, in particular the stator, a smallest possible design of the outer housing and thus the entire electric motor, so that the electric motor optimally in the device housing of Insert cleaning device.

It is proposed that the first housing part surrounds the impeller and the second housing part is arranged with respect to the axial direction downstream of the impeller. According to this embodiment, the first housing part may surround the impeller and possibly also a partial region of the electric motor pointing beyond the impeller in the axial direction, while the second housing part is arranged completely next to the impeller with respect to the axial direction. As a result, the air conveyed by the impeller is first guided in the axial direction and can leave the outer housing only - based on the axial direction - behind the impeller. This ensures that initially the entire air conveyed by the impeller air flows along at least a portion of the motor housing and causes cooling there. Only in the area between the first housing part and the second housing part can at least part of the air flow leave the outer housing.

It is proposed that the second housing part in the axial direction has a distance of about 5 mm to 20 mm to the impeller. As a result of this configuration, the air conveyed by the blower wheel can flow both into the radial clearance between the motor housing and the second housing part, as well as into the radial clearance between the first and the second housing part. Only at a distance of 5 mm to 20 mm to the fan wheel, the air stream is divided at an end portion of the second housing part and either further contributes to the cooling of the electric motor or leaves the outer housing and flows, for example, to a discharge grille of the cleaning device. The greater the distance between the impeller and the second housing part, the larger the axial portion of the outer housing, in which the air flow as a whole, that is without a branch, sweeps along the motor housing and causes cooling of the electric motor.

Furthermore, it is proposed that the first housing part and the second housing part are arranged overlapping in the axial direction. In particular, it is proposed that the first housing part and the second housing part overlap each other by at least 5 mm and a maximum of 50 mm. This results in respect to the axial direction no flush sequential arrangement of the two housing parts. Rather, the housing parts overlap in such a way that the second housing part is arranged coaxially in the first housing part with an end region and projects out of the first housing part with the partial region facing away from the blower wheel. The Length of the overlap can be 5 mm to 50 mm. This overlap length has proven to be particularly advantageous with respect to electric motors for cleaning equipment, which usually have an axial length of about 10 cm to 15 cm (including impeller). The axial overlap of the housing parts causes a double-walledness of the outer housing in the overlapping region of the first and second housing part, so that on the one hand the outflow of a portion of the air flow is enabled, on the other hand, however, at the same time the best possible sound insulation is given. The larger the overlap area, the better the noise reduction.

It is proposed that an axial length of the first housing part and / or of the second housing part varies in the circumferential direction. The first housing part and the second housing part thus have transverse to the axial direction not only lying in a plane end face, but the housing part in question along the circumference times longer and sometimes shorter. As a result, areas are advantageously created in which a portion of the fan air leaving the air flow is passed over a greater axial length of the motor housing than another portion of the air flow relative to a different radial direction of the housing part in the region of a shorter axial length. Optionally, the varying axial length may also be used to better dampen certain angular ranges of the electric motor with respect to noise emission.

Furthermore, it is proposed that the first housing part has an axial length of at least 50 percent and not more than 95 percent of the total length of the outer housing. In this case, the axial length can either be constant in the circumferential direction or change in the circumferential direction, with a shortest area still having at least an axial length of 50 percent and a longest area having a maximum length of 95 percent of the overall length of the outer housing. With an overall length of the outer housing of, for example, 10 cm, the first housing part covers an axial length of at least 5 cm and a maximum of 9.5 cm. Thus, the first housing part can cover almost the entire length of the electric motor, but within this outer housing two parallel flow paths are created, namely on the one hand, a flow path between the motor housing and the second housing part and on the other hand, a flow path between the two surrounding the motor housing housing parts. The noise insulation is particularly effective.

It is further proposed that with respect to a cross section perpendicular to the motor shaft between the first housing part and the second housing part, a substantially annular space is formed. When looking at the electric motor in the axial direction of the impeller to the annular space between the two housing parts can be seen. Through this, a part of the air flow conveyed by the impeller leaves the outer casing. The annular gap is advantageously formed in the circumferential direction without interruption, wherein the shape of the annular gap may vary depending on the cross-sectional shape of the first housing part and the second housing part. As explained above, resulting in a circular cross-sectional shape of the first housing part and a quadrangular cross-sectional shape of the second housing part, for example, a gap which widens and tapers in the circumferential direction, so that different volume flows relative to different peripheral regions of the outer housing can escape.

Furthermore, it is proposed that the first housing part and the second housing part have corresponding latching elements. By means of the corresponding locking elements, the housing parts can be locked together, whereby during assembly of the outer housing of the optimum distance between the two housing parts - both in the axial and radial direction - and the desired orientation of the housing parts can be ensured each other. For example, a latching element of the second housing part snap into a latching element of the first housing part or the like.

Finally, with the invention, in addition to the electric motor described above, an electric motor operated cleaning device proposed, which has an electric motor of the aforementioned type. The electric motor operated cleaning device is preferably a vacuum cleaner or a suction and wiper device. The cleaning device can be designed as a hand-held cleaning device, for example as a vacuum cleaner or battery-operated hand vacuum cleaner, or as a self-cleaning robot cleaning.

Brief description of the drawings

In the following the invention will be explained in more detail by means of exemplary embodiments. Show it:

1 an inventive cleaning device;

2 the cleaning device in a broken view with an electric motor;

3 a portion of the cleaning device with a cross section through the electric motor;

4 a perspective cross-sectional view of the electric motor;

5 an external perspective view of the electric motor;

6 a cross section along a first plane of the electric motor;

7 a cross section along a second plane of the electric motor;

8th a side view of the electric motor;

9 a plan view of a first plane of the electric motor;

10 a plan view of a second plane of the electric motor;

11 an exploded view of the electric motor according to a first perspective and

12 an exploded view of the electric motor according to a second perspective.

Description of the embodiments

1 shows a cleaning device 1 , which is designed here as a hand-held vacuum cleaner. The cleaning device 1 has a base unit 16 and a header 17 on. On the base unit 16 is a telescopic handle 18 arranged, by means of which a user the cleaning device 1 during a cleaning activity. The stem 18 has a handle 19 on, on which here, for example, a switch 20 for switching the cleaning device on and off 1 is arranged. On the base unit 16 are exhaust grille 21 arranged by which means of an electric motor 2 of the cleaning device 1 through the attachment 17 and the base unit 16 conveyed air from the cleaning device 1 can escape to the environment.

2 shows a longitudinal section through the cleaning device 1 , wherein the plane of the longitudinal section outside the electric motor 2 runs. The electric motor 2 is here exemplified as a reluctance motor, this being described in detail with reference to 3 is described. The electric motor 2 has an outer casing 9 on, which consists of a first housing part 10 and a second housing part 11 consists. The two housing parts 10 . 11 are arranged coaxially with each other, wherein the second housing part 11 with an end area 15 in the first housing part 10 protrudes and with a second the end area 15 remote area from the first housing part 10 protrudes. Between the first housing part 10 and the second housing part 11 is a radial gap 14 formed by which of an impeller 6 of the electric motor 2 conveyed air from the outer housing 9 of the electric motor 2 escape and to the outlet grilles 21 of the cleaning device 1 can flow.

3 shows a cross section through the electric motor 2 , where the section through a motor shaft 3 of the electric motor 2 is guided. The electric motor 2 is a reluctance motor with a rotor 4 and a stator 5 formed with two stator coil pairs. The rotor 4 is non-rotatable with the motor shaft 3 connected to the impeller 6 wearing. The electric motor 2 further includes a motor housing 7 on which the stator 5 and the rotor 4 surrounds, as well as a blower pot 8th for the fan wheel 6 , The blower pot 8th has a central intake opening 25 through which air can flow.

The electric motor 2 also has an outer casing 9 on which a first housing part 10 and a second housing part 11 having. The outer housing 9 serves to guide one of the impeller 6 promoted air flow. The two housing parts 10 . 11 surround the electric motor 2 capsule-shaped. The first housing part 10 is the fan wheel 6 facing, while the second housing part 11 the blower wheel 6 turned away. Both the first housing part 10 as well as the second housing part 11 have a radial clearance 12 to the motor housing 7 on, wherein the first housing part 10 a larger radial clearance 12 to the motor housing 7 has as the second housing part 11 , The outer housing 9 surrounds the electric motor 2 completely in the circumferential direction. In the axial direction, the first housing part 10 also an air inlet opening 23 on while the second housing part 11 on his the first housing part 10 facing away from an air outlet opening 24 having. Due to the differing radial clearances 12 of the first housing part 10 and the second housing part 11 to the motor housing 7 results in a radial gap 14 through which of the impeller 6 conveyed air from the outer housing 9 can escape. The housing parts 10 . 11 are staggered relative to each other with respect to the axial direction, wherein an axial overlap 13 the housing parts 10 . 11 consists. The second housing part 11 does not close in the axial direction directly to the impeller 6 but is at a defined distance to the impeller 6 arranged.

4 shows the electric motor 2 in a perspective view, in which the electric motor 2 across from 3 is cut in a plane perpendicular thereto.

5 shows the electric motor 2 with the outer housing 9 in a perspective exterior view. The housing parts 10 . 11 are arranged coaxially with each other, wherein the second housing part 11 partly in the first housing part 10 is in and with the blower wheel 6 facing away from the first housing part 10 protrudes. Both housing parts 10 . 11 are closed in the circumferential direction, wherein the first housing part 10 essentially a circular cross-sectional shape in a plane perpendicular to the motor shaft 3 and the second housing part 11 a quadrangular cross-sectional shape in a plane perpendicular to the motor shaft 3 having. The second housing part 11 has relative to adjacent peripheral sections on an equal axial length, that is, the frontal edges of the second housing part 11 lie on a single common plane, which is perpendicular to the motor shaft 3 is arranged. In contrast, the first housing part 10 along the circumference peripheral portions on which have different lengths in the axial direction, so that the axial overlap 13 with the second housing part 11 along the circumference of the outer housing 9 sometimes bigger and smaller.

6 shows a cross section of in 5 illustrated electric motor 2 in a direction perpendicular to the motor shaft 3 standing plane, which the second housing part 11 cuts, but not the shorter in the axial direction first housing part 10 ,

7 shows a further cross section of the electric motor 2 , which is perpendicular to the motor shaft 3 stands and only the first housing part 10 cuts, but not the second housing part 11 , The outer housing 9 is in an axial portion of the blower pot 8th cut, leaving the impeller 6 is recognizable.

The 8th shows a side view of the electric motor 2 with the outer housing 9 , Visible here is in particular the different axial length of the first housing part 10 based on different peripheral portions of the housing part 10 ,

The 9 and 10 show the electric motor 2 each perpendicular to the motor shaft 3 cut from above, the section according to 9 only the second housing part 11 cuts and the cut according to 10 only the first housing part 10 cuts. The cutting planes of the 9 and 10 correspond to the cutting planes according to the 6 and 7 ,

9 shows in detail the cross-sectional shapes of the housing parts 10 . 11 , wherein the first housing part 10 has a circular cross-sectional shape and the second housing part 11 a substantially quadrangular basic shape. The cross-sectional shapes arise here on the one hand from the circular cross section of the impeller 6 and from the substantially quadrangular shape of the stator 5 , Due to the different shape of the housing parts 10 . 11 points that between the housing parts 10 . 11 trained annular space 14 no constant radial thickness, but widens in the circumferential direction of the outer housing 9 on or rejuvenates again. As well as the second housing part 11 a radial clearance 12 to the motor housing 7 may be that of the impeller 6 conveyed air both between the second housing part 11 and the motor housing 7 as well as between the first housing part 10 and the second housing part 11 to flow along. The proportion of air flow coming from the impeller 6 between the second housing part 11 and the motor housing 7 flows, strokes directly on the motor housing 7 along this until the outer casing 9 through the air outlet 24 of the second housing part 11 leaves. A second air flow component, which starting from the impeller 6 in the radial gap 14 between the first housing part 10 and the second housing part 11 flows, leaves the outer casing 9 in the area of the axial overlap 13 the housing parts 10 . 11 , In the axial direction of the electric motor 2 is the second housing part 11 from the impeller 6 spaced so that from the impeller 6 conveyed air both on the motor housing 7 can flow along as well as in the interspace 14 between the housing parts 10 . 11 , An air flow component thus does not carry over the entire axial length of the outer housing 9 for cooling the electric motor 2 at, but leaves the outer casing 9 according to an axial length, which is the length of the first housing part 10 equivalent. This air flow component then flows within the base unit 16 to the exhaust grilles 21 and leaves the cleaning device 1 , As is the outer case 9 in the axial direction, starting from the impeller 6 to the the air outlet opening 24 having end face of the second housing part 11 rejuvenated, the electric motor can 2 overall space-saving in the base unit 16 of the cleaning device 1 are introduced, wherein at the same time by the axial overlap 13 the housing parts 10 . 11 optimum noise insulation is created and the electric motor 2 continues to be effectively cooled.

The 11 and 12 finally show an exploded view of the electric motor 2 with the rotor 4 , the stator 5 , the blower wheel 6 and the first housing part 10 and the second housing part 11 , The two housing parts 10 . 11 are shown on opposite sides of the rotor as shown 4 , the stator 5 and the blower pot 8th surrounding motor housing 7 arranged and with the help of corresponding locking elements 22 latched together in the desired position and orientation. In the composite form of the outer casing 9 is the motor housing 7 in the circumferential direction of the first housing part 10 and / or the second housing part 11 surround. To enter or exit from the fan wheel 6 conveyed air have the housing parts 10 . 11 the air intake or -austrittsöffnungen 23 . 24 on. In addition, an air flow component of the outer housing 9 over the gap 14 between the housing parts 10 . 11 leave.

LIST OF REFERENCE NUMBERS

1

cleaner

2

electric motor

3

motor shaft

4

rotor

5

stator

6

blower

7

motor housing

8th

fan pot

9

outer casing

10

First housing part

11

Second housing part

12

Radial clearance

13

Axial overlap

14

gap

15

end

16

basic unit

17

header

18

stalk

19

handle

20

switch

21

exhaust grille

22

locking element

23

Air inlet opening

24

Air outlet opening

25

suction

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 10200913 A1 [0004]

Claims (10)

Electric motor ( 2 ), in particular for a cleaning device ( 1 ), with a motor shaft ( 3 ), a non-rotatable with the motor shaft ( 3 ) associated impeller ( 6 ) and a motor housing ( 7 ), wherein the electric motor ( 2 ) relative to a geometric motor shaft axis with a radial distance to the motor housing ( 7 ) arranged outer housing ( 9 ), characterized in that the outer housing ( 9 ) seen in a cross section in which the motor shaft axis as a line, two relative to an axial direction offset housing parts ( 10 . 11 ), of which a first the impeller ( 6 ) facing housing part ( 10 ) a larger radial clearance ( 12 ) to the motor housing ( 7 ) has as a second the impeller ( 6 ) facing away from the housing part ( 11 ) and between the housing parts ( 10 . 11 ) is formed an air passage from within the outer housing to the outside of the outer housing enabling space. Electric motor ( 2 ) according to claim 1, characterized in that the housing parts ( 10 . 11 ) are closed in the circumferential direction, wherein the first housing part ( 10 ) in particular has a curved cross-sectional shape and wherein the second housing part ( 11 ) in particular has a polygonal cross-sectional shape. Electric motor ( 2 ) according to claim 1 or 2, characterized in that the first housing part ( 10 ) the impeller ( 6 ) surrounds and the second housing part ( 11 ) relative to the axial direction of the impeller ( 6 ) is arranged. Electric motor ( 2 ) according to one of the preceding claims, characterized in that the second housing part ( 11 ) in the axial direction a distance of about 5 mm to 20 mm to the impeller ( 6 ) having. Electric motor ( 2 ) according to one of the preceding claims, characterized in that the first housing part ( 10 ) and the second housing part ( 11 ) are overlapping in the axial direction, in particular by at least 5 mm and a maximum of 50 mm overlapping, are arranged. Electric motor ( 2 ) according to one of the preceding claims, characterized in that an axial length of the first housing part ( 10 ) and / or the second housing part ( 11 ) varies in the circumferential direction. Electric motor ( 2 ) according to one of the preceding claims, characterized in that the first housing part ( 10 ) an axial length of at least 50 percent and a maximum of 95 percent of the total length of the outer housing ( 9 ) having. Electric motor ( 2 ) according to one of the preceding claims, characterized in that, relative to a cross-section perpendicular to the motor shaft ( 3 ) between the first housing part ( 10 ) and the second housing part ( 11 ) a substantially annular space ( 14 ) is trained. Electric motor ( 2 ) according to one of the preceding claims, characterized in that the first housing part ( 10 ) and the second housing part ( 11 ) corresponding locking elements ( 22 ) exhibit. Electromotive operated cleaning device ( 1 ), in particular a vacuum cleaner, characterized by an electric motor ( 2 ) according to any one of the preceding claims.

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