DE102008014624A1 - electric motor - Google Patents

Abstract

The invention relates to an electric motor (1) having a rotor and a stator (5), an impeller (3) and a stator (4) radially assigned to the impeller (3), the impeller (3) being opposite to the running direction (r) of the impeller Fan blades (3) directed fan blades (6) which are arranged on an impeller disc (7) and covered by a cover plate (9), with an opening diameter (D1) and an overall diameter (D2). In order to develop an electric motor of the type in question with the smallest possible dimension both in the radial and in the axial direction in such an advantageous manner that cooling by means of the driven impeller is achieved, it is proposed that the ratio of opening diameter (D1) and overall diameter ( D2) is in the range of 0.5 to 0.65, preferably 0.55 to 0.6, wherein in the radially outer region (10) a parallel design of cover plate (9) and impeller disc (7) is formed, which radially outer region (10) 6 to 15%, preferably 8 to 12%, of the total diameter (D2) corresponds.

Description

The The invention relates to an electric motor with a rotor and a Stator, an impeller and an impeller radially associated with Leitstufe, the impeller counter has blower blades directed towards the running direction of the blower wheel, arranged on an impeller disc and covered by a cover plate are, with an opening diameter and a total diameter.

Electric motors of the type in question are known. For example, on the WO 98/38899 directed. Such electric motors are used, for example, as motor-blower units use. To increase the efficiency of the blower, it is known the blower wheel downstream of a master stage in the form of a diffuser, so in the manner of a radial feedback blading, which directs the air to the inside of the engine to cool it.

nozzles like spiral housings and unscrewed plate diffusers increase the radial space and guide the air away from the engine, making such facilities only useful for Applications are those that are sponsored by the blower Do not use air to cool the engine. In these cases will For engine cooling, an additional fan attached to the engine. Alternatively, this is powered by a separate motor Cooling fan supplied with air. Radial diffusers, which are arranged around the impeller, communicate with a subsequent radial feedback blading Although the cooling of the engine safe, but increase the radial space. Diaphragms with axially aligned blade beginning and then radial return blading Build in the radial direction as large as radial nozzles.

in the With regard to the above-described prior art, a technical Problems of the invention seen in an electric motor of in question ste existing type with the smallest possible dimensions both in the radial and in the axial direction so in an advantageous Way to develop that cooling by means of the driven Blower wheel is reached.

These The problem is first and foremost through the The subject matter of claim 1 is solved, with a focus on it is that the ratio of opening diameter and overall diameter in the range of 0.5 to 0.65, preferably 0.55 to 0.6, wherein in the radially outer region a parallel design of cover plate and impeller disc is formed is, which radially outer area 6 to 15%, preferably 8 to 12% of the total diameter corresponds. The impeller is particularly suitable for electric motors in speech standing type, which are fast-running, so in particular reluctance motors with a speed of more than 400 rpm, more than 1000 RPM up to 60000 rpm. The known solutions regarding of the impeller show directed in the opposite direction to the direction Fan blades, continue at reverse curved blades usually have a conical cover plate with a cone angle of 5 ° to 30 ° about the entire area or a hyperbolic design. such Impellers find especially with a downstream axial master stage use. The proposed parallel guidance from cover disk or radially outer region of the Cover disc and impeller disc proves to be a high-speed Electric motor both in terms of efficiency and in terms a stable behavior in many areas of advantage. About that In addition, this design also proves in terms of process reliability when balancing the impeller of advantage. This is how it works Balancing on an impeller according to the invention by means of an axially parallel nibbler tool, by means of which the processed radially outer region of the cover plate can be. This proves to be cheaper than editing with a tool positioned at the inclination angle of the cover disc.

width Features of the invention are below, also in the figure description, often in their preferred assignment to the subject of the claim 1 or explained features of further claims. But they can also be in an assignment to only individual Features of claim 1 or the respective further claim or each independently.

So is provided in a development of the subject invention, that in the inlet region of the opening diameter in the Parallel arrangement formed radius on the fan blades the 0.25 to 0.35 times, preferably 0.3 times the opening diameter equivalent. The proposed inlet radius is correspondingly much larger than that according to the solutions of the state of Technology. There radii factors of 0.14 to 0.2 are provided.

A high efficiency is achieved in that the 4 times the blade height in the inlet region in relation to the opening diameter of 1.6 to 2.3 times, preferably 1.8 to 2.1 times. According to these solutions, a small diameter impeller is achieved for high speeds, which despite the small size achieves sufficient negative pressure and high efficiency and in particular ensures an outflow from the impeller, which allows downstream nozzles, the Strö energy into pressure. A small radial dimension of the entire electric motor is further achieved in that the ratio of the total diameter to the stator diameter is 0.9 to 1.05, preferably 0.95 to 1, thus providing a compact motor-blower unit.

Of the the distributor downstream of the impeller has axially directed vanes. This master level leads the Air exiting from the impeller axially over the stator, so as to cool the engine. So is the next Leitstufe at least partially in radial overlap to Electric motor arranged. Contrary to the solutions from the known prior art in which an axially elongated Construction is chosen, which, however, to a strong Delay and flow separation and reducing the efficiency, is provided according to the invention, that the axial length of the master stage in proportion to the fan blade height at the outer diameter 2.3 to 2.9, preferably 2.45 to 2.75. The outer diameter the fan blades corresponds in a further embodiment of the 0.6 to 0.85 times the outside diameter of the master stage, preferably 0.68 to 0.72 times. Next corresponds to the inner diameter the Leitstufe the 0.52 to 0.82 times, preferably from 0.62 to 0.72 times the outside diameter of the master stage. Following this proposed Dimensions is the axial guide stage via the motor bridge the electric motor can be built so that only the impeller must be installed axially in front of the electric motor. Such is a motor-blower unit achieved low axial length.

Of the Blade radius of curvature of Leitstufenbeschaufelung is chosen small in a development of the subject invention and more preferably constant over the blade height. Thus, it is envisaged that the radius of the curved vanes the Leitstufe in relation to the outer diameter the conducting level is 0.18 to 0.34, preferably 0.22 to 0.30. The small Blade radius of curvature ensures that the Air after as short a distance as possible in the axial direction is deflected and largely free of spin over the lateral surface of the stator can flow. A swirling flow can cause additional flow losses produce. Next sets the constant radius of curvature a preferred embodiment of the Leitstufe as a plastic injection molded part the mold release in an injection mold safe. The axial Length of the master level is in relation to the Outer diameter of the same 0.18 to 0.33, preferably 0.25 to 0.26.

In further embodiment of the subject invention are the guide vanes, seen in the axial direction, against the direction of the fan blades tilted. Thus, taking into account a as low as possible an improved delay Engine cooling reached. Next is by the inclination ensures that the flowing air is a radial component is impressed in the direction of the motor axis and thus a possible large proportion of air close to the stator surface flows. This is especially in partial load ranges of Electric motor, especially in heavy throttling necessary. At the control stage exit the inclination of the vanes is 25 ° to 50 °, preferably 30 ° to 44 °.

to far improvement of the engine cooling points the Leitstufe radially inward one or more window-like openings on, for example, two to six, preferably four such openings. These are assigned to a window area of the stator, so that the off emerging from the window-like openings of the leading stage Air through corresponding openings in the engine bridges flows into the engine.

The close the given numerical bandwidths also - as far as such are not given by way of example are - all intermediate values in and in particular in 1/10 increments, further in 1/10 increments from the lower and / or upper Limiting the border to the other border, where "and" stands for both Push boundaries one or more tenths to the limit, that is to be limited.

below the invention with reference to the accompanying drawings, which merely illustrates two embodiments, closer explained. It shows:

1 the electric motor in side view with arranged impeller and a guide stage in a first embodiment;

2 the top view of this with a view of the impeller;

3 a perspective rear view of this;

4 the impeller in perspective detail view;

5 the side view to this;

6 the section according to the line VI-VI in 5 ;

7 the Leitstufe in perspective detail view overlooking a vane exit side;

8th a further perspective view of the master stage with a view of the vane inlet side;

9 the section according to the line IX-IX in 8th ;

10 the master level in side view;

11 the section according to the line XI-XI in 10 ;

12 in a perspective view of the master stage in a second embodiment, associated with the electric motor;

13 the section according to the line XIII-XIII in 12 , omitting the electric motor;

14 the section according to the line XIV-XIV in 12 but only concerning the master level;

15 a schematic representation of the arrangement of electric motor, impeller and master stage.

Illustrated and described first with reference to the 1 to 3 an electric motor 1 with one on a rotor shaft 2 arranged impeller 3 and a master level 4 , The fan wheel 3 is non-rotatable on the rotor shaft 2 arranged and is rotated about this, wherein the rotor shaft 2 rotatably with a rotor, not shown, of the electric motor 1 connected is. The rotor interacts with a stator 5 of the electric motor 1 , The master level 4 is not rotatable on the stator 5 fastened, so in particular riveted with a bearing bridge, not shown, which is centrally penetrated by the rotor shaft 2 ,

The fan wheel 3 is described below on the basis of the individual presentation in the 4 to 6 explained in more detail.

The fan wheel 3 has in the illustrated embodiment seven counter to the direction of rotation r of the impeller 3 directed, curved fan blades 6 on. These are curved extending radially aligned and initially on a flat, annular impeller disc 7 arranged. The latter leaves a central opening 8th , Starting from the opening edge, the fan blades extend 6 radially outward to the peripheral edge of the impeller disc 7 ,

The on the impeller disc 7 standing fan blades 6 are covered by a cover disk 9 , This first has a radially outer region 10 on, which is aligned parallel to the impeller disc 7 , From the radially inner end of the outer, annular region 10 this goes over into a hyperbolic curved center section with increasing spacing to the impeller disc 7 , This rising region ends in a peripheral edge of a central opening of the cover disk 9 , which central opening 11 same diameter as the pulley side opening 8th dimensioned and coaxial with this is arranged.

wheel disc 7 , Cover disc 9 and the fan blades 6 are made of a metal material, alternatively of plastic, optionally with an upper cover made of aluminum, and interconnected, for example by riveting.

In the illustrated embodiment, an opening diameter D _{1 is} selected, which is 0.55 to 0.6 times the total diameter D _{2 of} the impeller 3 equivalent. This total diameter D ₂ further corresponds to about 0.84 to 0.99 times, preferably 0.89 to 0.94 times, for example, 0.91 times the stator diameter D ₃ .

The parallel design of the outer area 10 extends over a range of D ₄ / D ₂ = 0.88 to 0.92, making the radially outer region 10 about 8 to 12% of the total diameter D ₂ corresponds.

The inlet radius R _E corresponds to 0.3 times the opening diameter D ₁ in the illustrated embodiment. The 4 times the blade height h corresponds in the inlet region in relation to the opening diameter D ₁ 1.8 to 2.1 times, which in conjunction with the largely selected inlet radius R _{E is achieved} a high efficiency. The bucket angle of the fan blades 6 in the inlet (angle β ₁ ) is 29 ° and in the outlet (angle β ₂ ) 32.5 °, so both angles are about the same size.

The master level 4 The first embodiment is described below with reference to 7 to 11 explained in more detail.

This master level 4 is manufactured as a plastic injection molded part and is designed as an axial Leitstufe, has correspondingly substantially axially directed vanes 12 on. In the illustrated embodiment are about the circumference of the Leitstufe 4 evenly distributed twenty such vanes 12 intended.

The master level 4 has a small axial length compared to the axial guide stages known from the prior art solutions. Thus, a length l is provided which is 2.45 to 2.75 times, for example, 2.6 times the blade height h of the impeller 3 equivalent. The outer diameter D ₅ is in the range D ₂ / D ₅ = 0.68 to 0.72. The inner diameter D ₆ corresponds approximately to the impeller diameter D ₂ , wherein further the inner diameter D _{6 of} the master stage 4 about the 0.62- to 0.72 times, for example, equal to 0.665 times the outside diameter D _{5 of} the diffuser.

Due to the dimensions described above, the axial Leitstufe 4 Be installed over the already described motor bridges, so that only the impeller 3 axially in front of the electric motor 1 is installed. So a motor-blower unit is achieved with a small axial length.

The blade radius of curvature R _{L of} the vanes 12 is chosen very small with R _L / D ₅ = 0.22 to 0.30, for example 0.255 and constant over the blade height. This small blade radius of curvature ensures that the air is deflected in the axial direction after as short a distance as possible and as far as possible free of swirl over the lateral surface of the stator 5 can flow.

The axial length further corresponds to about 0.18 to 0.33 times, for example, 0.253 times the outer diameter D ₅ .

The vanes 12 are against the direction of rotation r of the impeller 3 tilted. So is at the Leitstufenaustritt each vane 12 inclined by approx. 35 ° (see angle β ₃ in 11 ). In an alternative embodiment, the angle β _{3 is} 31 ° or 43 °.

The blade entry angle β ₄ , that is to say the angle of attack to the entry surface of the guide stage, is preferably 1 ° to 5 °. At the outlet of the blade angle is 90 °, that is, the air flows axially parallel from the master stage 4 out.

The blade number ratio of impeller 3 to master level 4 is in the illustrated embodiment 7:20, so as to optimize the rotary sound.

To greatly improve the engine cooling, four are between the vanes 12 remaining vane channels 13 on the outlet side by a radially aligned barrier wall 14 locked. The through the blade channels 13 In this case, guided air becomes window-like openings 15 guided radially inward and through corresponding openings in the engine bridges in the engine.

The barrier walls 14 can in a training for attaching a blower wheel 3 Serving overlapping fan cover.

The axial distance a between Leitstufe 4 and blower wheel 3 corresponds in the illustrated embodiment about 0.1 to 0.4 times, for example, 0.13 times the height h _{1 of} the impeller 3 in the area of parallel sections of impeller disc 7 and cover disc 9 ,

The axial Leitstufe 4 is installed over the motor bridges, which proves to save space and can with regard to the structural rigidity, the outer me chanical loads that may be introduced via a blower cover, record. The fan cover may continue to be the inclined vanes 12 be absorbed with backlash radially backlash.

The 12 to 14 show the master level 4 in a second embodiment, essentially, in particular with regard to the arrangement, formation and orientation of the guide vanes 12 as well as the diameter and length dimensions of the master stage 4 the embodiment described above.

12 shows the assignment position to the electric motor 1 and to the motor housing comprising the electric motor 16 , The master level 4 is arranged in a cross-shaped, uniform material with the vanes 12 carrying pilot stage ring 17 shaped bridge sections 18 on the ceiling side with the motor housing 16 connected, in particular riveted (cf. 13 ). The bridge sections 18 leave centrally a passage opening 19 for the rotor shaft 2 ,

The pilot stage ring 17 includes the ceiling portion of the motor housing 16 with a radial distance of a few millimeters, such as 2 mm.

Adjacent to the guide stage fixing portions of the motor housing 16 is the ceiling section with openings 20 provided through which via the radial openings 15 in the control stage ring 17 inwardly flowing air into the engine housing interior for direct cooling of the electric motor 1 is directed.

According to the proposed solution, a small radial and axial dimension of the entire motor-blower unit is given, further achieving a high fan efficiency of about 60%. This is under one-piece ger embodiment of the control stage 4 Ensures sufficient cooling of the engine. Through the parallel to the impeller disc 7 extending outer edge region 10 the cover disk 9 can the fan wheel 3 be balanced in the simplest way by means of a nibbling tool.

All disclosed features are essential to the invention. The disclosure of the associated / attached priority documents (copy of the prior application) is hereby also incorporated in full in the disclosure of the application, also for the purpose of disclosing features of these documents in claims of the present application to take.

1

electric motor

2

rotor shaft

3

blower

4

vane

5

stator

6

fan blade

7

wheel disc

8th

opening

9

cover disc

10

outer Area

11

opening

12

vane

13

blade channel

14

barrier wall

15

opening

16

motor housing

17

Leitstufenring

18

bridge sections

19

Through opening

20

perforations

a

axial distance

H

blade height

l

length

r

direction of rotation

D ₁

Opening diameter

D ₂

Overall diameter

D ₃

Stator

D ₄

Inner diameter

D ₅

outer diameter

D ₆

Inner diameter

R _E

entry radius

R _L

Leitschaufelradius

β ₁

blade angle enema

β ₂

blade angle outlet

β ₃

blade angle exit

β ₄

blade angle entry

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• WO 98/38899 [0002]

Claims (15)

Electric motor ( 1 ) with a rotor and a stator ( 5 ), an impeller ( 3 ) and an impeller ( 3 ) radially assigned master stage ( 4 ), the impeller ( 3 ) counter to the running direction (r) of the impeller ( 3 ) directed fan blades ( 6 ), which on an impeller disc ( 7 ) and from a cover plate ( 9 ) are covered with an opening diameter (D ₁ ) and an overall diameter (D ₂ ), characterized in that the ratio of opening diameter (D ₁ ) and total diameter (D ₂ ) in the range of 0.5 to 0.65, preferably 0 , 55 to 0.6, wherein in the radially outer region ( 10 ) a parallel design of cover plate ( 9 ) and impeller disc ( 7 ), which radially outer region ( 10 ) Corresponds to 6 to 15%, preferably 8 to 12% of the total diameter (D ₂ ). Electric motor according to Claim 1 or in particular according thereto, characterized in that the radius (R _E ) formed in the inlet arrangement of opening diameter (D ₁ ) on the fan blades ( 6 ) corresponds to 0.25 to 0.35 times, preferably 0.3 times the opening diameter (D ₁ ). Electric motor according to one or more of the preceding claims or in particular according thereto, characterized in that four times the blade height (h) in the inlet region in relation to the opening diameter (D ₁ ) 1.6 to 2.3 times, preferably the 1 , 8- to 2.1-fold corresponds. Electric motor according to one or more of the preceding claims or in particular according thereto, characterized in that the ratio of the total diameter (D ₂ ) to the stator diameter (D ₃ ) is 0.9 to 1.05, preferably 0.95 to 1. Electric motor according to one or more of the preceding claims or in particular according thereto, characterized in that the associated master stage ( 4 ) axially directed vanes ( 12 ) exhibit, Electric motor according to one or more of the preceding claims or in particular according thereto, characterized in that the master stage ( 4 ) at least partially in radial overlap to the electric motor ( 1 ) is arranged. Electric motor according to one or more of the preceding claims or in particular according thereto, characterized in that the axial length (l) of the master stage ( 4 ) in relation to the fan blade height (h) at the outer diameter of 2.3 to 2.9, preferably 2.45 to 2.75. Electric motor according to one or more of the preceding claims or in particular according thereto, characterized in that the outer diameter (D ₂ ) of the fan blades ( 6 ) from 0.6 to 0.85 times the outer diameter (D ₅ ) of the master stage ( 4 ), preferably 0.68 to 0.72 times. Electric motor according to one or more of the preceding claims or in particular according thereto, characterized in that the inner diameter (D ₆ ) of the master stage ( 4 ) from 0.52 to 0.82 times, preferably from 0.62 to 0.72 times, the outer diameter (D ₅ ) of the master stage ( 4 ) corresponds. Electric motor according to one or more of the preceding claims or in particular according thereto, characterized in that the radius (R _L ) of the curved guide vanes ( 12 ) of the master level ( 4 ) in relation to the outside diameter (D ₅ ) of the master stage ( 4 ) Is 0.18 to 0.34, preferably 0.22 to 0.30. Electric motor according to one or more of the preceding claims or in particular according thereto, characterized in that the axial length (l) of the master stage ( 4 ) with respect to the outer diameter (D ₅ ) is 0.18 to 0.33, preferably 0.25 to 0.26. Electric motor according to one or more of the preceding claims or in particular according thereto, characterized in that the guide vanes ( 12 ), seen in the axial direction, against the running direction (r) of the fan blades ( 6 ) are inclined. Electric motor according to one or more of the preceding Claims or in particular according thereto, characterized that the inclination 25 ° to 50 °, Favor 30 ° to 44 ° corresponds. Electric motor according to one or more of the preceding claims or in particular according thereto, characterized in that the master stage ( 4 ) radially inward one of the plurality of window-like openings ( 15 ) having. Electric motor according to one or more of the preceding claims or in particular according thereto, characterized in that the opening ( 15 ) a window region of the electric motor ( 1 ) assigned.