Electric fan having an air-conducting housing

Abstract

The invention relates to an electric motor with an air battle and a fan, wherein the air baffle is designed to be hollow, and the fan has a fan motor which has a housing. The region covered by the fan in the axial direction is encompassed by the region covered by the air baffle in the axial direction, and the fan motor is secured to the air baffle by means of bolts. The bolts are connected to the housing of the fan motor at the radial inner end of the bolts and to the air baffle at the radial outer end of the bolts.

Description

[0001] Electric motor with air guide

[0002] Description:

[0003] The invention relates to an electric motor with an air guide.

[0004] It is well known that an electric motor generates waste heat, which is dissipated into the ambient air.

[0005] From DE 102022 001 426 A1, the closest prior art is an electric motor with a stator housing.

[0006] An electric motor with a fan is known from DE 10 2008 028 656 A1.

[0007] An engine is known from JP 2016 - 131 476 A.

[0008] The invention is therefore based on the object of developing an electric motor that is as robust and cost-effective as possible.

[0009] According to the invention, the object is achieved in the electric motor according to the features specified in claim 1.

[0010] Important features of the invention in the electric motor are that the electric motor is designed with an air guide part and a fan, wherein the air guide part is hollow, in particular wherein the area covered in the axial direction by the air guide part overlaps with the area covered in the axial direction by a stator housing and / or a bearing plate, wherein the fan has a fan motor which has a housing, wherein the area covered in the axial direction by the fan is encompassed by the area covered in the axial direction by the air guide part, in particular wherein the fan motor is arranged radially inside the air guide part, wherein the fan motor is fastened to the air guide part by means of bolts, wherein the bolts are connected at their radially inner end to the housing of the fan motor and at their radially outer end to the air guide part,in particular wherein the axial direction is aligned parallel to the direction of the rotational axis of the rotor shaft of the electric motor and / or the radial distances and the circumferential direction are related to the rotational axis of the rotor shaft of the electric motor.,

[0011] The advantage here is that the thin bolts essentially do not impair the air flow conveyed by the fan and yet the fan motor is suspended and held securely enough, especially within the air guide part.

[0012] It is important that the radial clearance area covered by the fan blades overlaps with the radial clearance area covered by the bolts, with the fan blades being axially spaced from the bolts. This ensures that the airflow conveyed by the fan flows past the bolts, which are preferably made of metal, so that they transfer the heat from the fan motor housing, which is preferably made of metal, to the airflow.

[0013] Bolt fastening is cost-effective. When mechanical stresses, such as vibrations, act on the air guide, the fan motor is decoupled or weakly coupled to the air guide. This allows the electric motor to operate reliably despite interference.

[0014] In particular, the air guide part is designed as a hollow cylindrical pipe section, wherein through holes or one or more half slots are introduced, in particular for fastening means, such as screws or the like.

[0015] In an advantageous embodiment, the bolts are radially aligned, in particular, the bolts are further extended in the radial direction than in the circumferential and axial directions, in particular, the bolts are all arranged at the same axial position and are all arranged at the same radial distance from the rotational axis of the fan driven by the fan motor. The advantage here is that the fan motor is suspended cost-effectively and robustly by means of the radially arranged bolts.

[0016] In an advantageous embodiment, the fan motor drives a fan wheel of the fan, which has fan blades, and / or sets it in rotation, in particular with the rotational axis of the fan wheel aligned coaxially with the rotational axis of the rotor shaft of the electric motor. It is advantageous that a fan motor is suspended from the bolts in the air guide part and can be operated robustly.

[0017] In an advantageous design, the bolts are wider in the radial direction than in the axial and circumferential directions. This allows for the use of thin bolts. The load-bearing capacity can be ensured cost-effectively by using metal bolts.

[0018] In an advantageous embodiment, the bolts are spaced unevenly from one another in the circumferential direction, in particular, the distance in the circumferential direction between a first bolt and a second bolt closest to the first bolt in the circumferential direction is different from the distance between the first bolt and a bolt closest to the first bolt in the opposite circumferential direction. This advantageously allows for the suppression of resonance vibrations.

[0019] In an alternative embodiment, the bolts are evenly spaced from one another in the circumferential direction, in particular, the distance in the circumferential direction between a first bolt and a second bolt closest to the first bolt in the circumferential direction is equal to the distance between the first bolt and a bolt closest to the first bolt in the opposite circumferential direction. This is advantageous in that it enables simple manufacturing.

[0020] In an advantageous embodiment, each bolt has an external thread area on its radially inner end area, which is screwed into a respective radially directed threaded bore, which is each introduced into a respective radially directed elevation of the housing of the fan motor, in particular wherein the bolts are aligned radially starting from the fan motor, wherein the radially outer end of the bolts is fastened to the air guide part, in particular by means of respective screws which pass through the air guide part and are each screwed into a respective radially directed threaded bore of the respective bolt, in particular wherein the radially directed elevation is designed as a thickening of the wall thickness of the housing.The advantage here is that simple production is possible, since in a first production step the bolts are screwed into the threaded holes of the thickened portions of the housing of the fan motor and then in a second production step screws are screwed into the threaded holes of the bolts, whereby the screw heads of the screws press the air guide part onto the bolts.

[0021] In an advantageous embodiment, each bolt is cylindrical, with the cylinder diameter being at least five times smaller than the length of the respective cylindrical bolt measured in the radial direction relative to the axis of rotation of the fan wheel and / or the axis of rotation of the rotor shaft of the electric motor. The advantage here is that each bolt is thin, thus achieving a mechanically stable fastening with little material consumption. The cylindrical bolt has external teeth on its radially inner end region and a threaded hole on its radially outer end region. With the exception of the external teeth and the threaded hole, the respective bolt can be designed as a solid cylinder. The advantage here is that thin bolts can be used, thus ensuring that the air flow is not disrupted.In an advantageous embodiment, a cover part of the electric motor is connected to the air guide part by means of at least one holder, wherein the maximum outer diameter of the cover part is larger than the maximum outer diameter of the air guide part, in particular wherein the radial distance area covered by the cover part comprises and / or contains the radial distance area covered by the air guide part. It is advantageous in this case that a rain guard is implemented for the fan motor. Thus, operation that is robust even against rain can be carried out if the rotational axis of the fan, which is aligned coaxially to the rotational symmetry axis of the hollow cylindrical air guide part, is aligned parallel to the vertical direction and / or the direction of gravity.

[0022] In an advantageous embodiment, a hood part of the electric motor is connected to the air guide part by means of at least one bracket. Advantageously, a hood part that functions as a rain guard can also be attached to the air guide part.

[0023] In an advantageous embodiment, the maximum outer diameter of the hood section is larger than the maximum outer diameter of the air guide section. This advantageously allows the hood section to function as a rain shield.

[0024] In an advantageous embodiment, the radial distance area covered by the hood part encompasses and / or contains the radial distance area covered by the air guide part.

[0025] The axial direction is always aligned parallel to the direction of the rotational axis of the rotor shaft of the electric motor and / or the radial distances and the circumferential direction are related to the rotational axis of the rotor shaft of the electric motor.

[0026] The advantage here is that the cover section can be used as a rain cover. This is because, when the rotor shaft's axis of rotation is aligned vertically, the cover section keeps rain away from the fan. This makes the electric motor robust against environmental influences. In addition, the cover section increases the mass of the electric motor and thus dampens vibrations that occur during operation. For this purpose, it is important that the cover section is held by brackets on the air guide section, which in turn is directly or indirectly connected to the stator housing. The mass of the cover section is thus held by sheet metal parts, i.e. elastically attached. If vibrations occur during operation, a variety of vibration modes are available which have a damping effect. The mass of the cover section is considerable because the area covered by the cover section in the radial and circumferential directions is uninterrupted, in particular without recesses.

[0027] In an advantageous embodiment, the bracket is manufactured as a stamped and bent part made of sheet metal, with the bracket having a base region and a first tab region and a second tab region. This is advantageous because it enables cost-effective production.

[0028] In an advantageous embodiment, the first tab region adjoins the base region and the second tab region adjoins the base region, with the first tab region being spaced apart from the second tab region. It is advantageous that, after punching, the two tab regions are bent out of the plane of the base region, in particular by 90°.

[0029] In an advantageous embodiment, the first tab region is angled, in particular bent by forming, relative to the base region, in particular by 90°. It is advantageous that the first tab region rests against the hood part, in particular against an axially directed collar region of the hood part that is continuously circumferentially formed.

[0030] In an advantageous embodiment, the second tab region is angled, in particular bent by forming, relative to the base region, in particular by 90°, in particular with the base region being flat and both the first tab region and the second tab region also being flat. It is advantageous in this case that the second tab region rests flatly against the air guide part.In an advantageous embodiment, a reinforcing rib is formed on the holder in that a raised portion is formed into the holder, which extends continuously from the base region to the second tab region, in particular also through the kink, in particular angle, created by the angling of the second tab region, in particular wherein the raised portion is elongated and / or extends further along its extent or in its direction of extension than transversely, in particular perpendicular to the extent or to its direction of extension. The advantage here is that the holder is particularly load-bearing and dampens vibrations. This is achieved in particular by the raised portion extending beyond the kink.

[0031] In an advantageous embodiment, the elevation is surrounded, in particular completely, by a recess formed in the holder. The recess extends at least on both sides along the elevation, in particular the elongated elevation, and in particular also through the bend, in particular the angle, created by bending the second tab area. This is advantageous in that the holder is particularly load-bearing and dampens vibrations. This is because the recess, in conjunction with the elevation, dampens high-frequency vibrations more effectively than lower-frequency vibrations.

[0032] In an advantageous embodiment, at least one press-in nut is arranged in a recess, particularly a blind hole-like recess, of the first tab region, into which a screw is screwed, which projects through the hood part and through the first tab region of the bracket, in particular wherein the screw head of the screw presses the air guide part onto the bracket and / or the press-in nut presses the bracket onto the hood part. It is advantageous that the press-in nut is very rigidly integrated into the bracket and rests against the bottom of the blind hole, thus being limited.

[0033] In an advantageous embodiment, the press-in nut has external teeth cut into the holder, in particular into the first tab area, in particular such that the press-in nut is positively connected to the holder, in particular at least in its actuation direction and / or at least in the screwing direction of the internal thread of the press-in nut. This is advantageous in that a high tightening torque of the screw screwed into the press-in nut is possible.

[0034] In an advantageous embodiment, the brackets are arranged at the same axial position and at the same radial distance, in particular wherein the brackets are evenly spaced from one another in the circumferential direction, in particular regularly, in particular wherein the brackets are identical to one another. This is advantageous in that a cost-effective rain protection device can be realized. Uneven spacing in the circumferential direction suppresses the formation of resonant vibrations. Uniform spacing, on the other hand, enables an isotropic, robust fastening.

[0035] In an advantageous embodiment, the air guide part is hollow-cylindrical.

[0036] The advantage here is that the air guide part can be easily plugged onto the stator housing of the electric motor from the axial direction or onto a bearing plate connected to the stator housing of the electric motor.

[0037] In an advantageous embodiment, the axis of rotation of the rotor shaft is oriented vertically, in particular parallel to the direction of gravity, in particular with the cover part being arranged above the stator housing of the electric motor. Advantageously, the cover part functions as a rain shield, since the vertical projection of the cover part in a plane whose normal is parallel to the axis of rotation of the rotor shaft and / or to the vertical direction and / or the direction of gravity encompasses the vertical projection of the air guide part and / or the rest of the electric motor.

[0038] In an advantageous embodiment, a grille is attached to the air guide element, in particular with a fan attached to the grille. The advantage here is that the air flow drawn in by the fan flows through the grille, thus keeping dirt particles away from the fan.

[0039] In an advantageous embodiment, the air guide element is attached to the stator housing of the electric motor or to a bearing plate of the electric motor connected to the stator housing. The air flow conveyed by the fan exits between the stator housing and the air guide element or between the bearing plate and the air guide element and flows along cooling fins formed on the stator housing. Advantageously, the air guide element radially surrounds the bearing plate, thus extending the radial envelope of the cover element. The air flow conveyed by the fan exits between the air guide element and the stator housing or bearing plate.

[0040] In an advantageous embodiment, a terminal box for the fan is arranged on the air guide element, in particular, the fan's electrical connection cables are routed into the terminal box and connected there to connection elements, which are connected to electrical supply lines. This is advantageous because the fan motor can be electrically supplied independently of the electric motor. Furthermore, the terminal box increases the mass of the air guide element and thus dampens vibrations.

[0041] In an advantageous embodiment, the fan has a fan motor, wherein the radially inner end, in particular the radially inner end region, of radially directed bolts, which are spaced apart from one another in the circumferential direction, is each fastened to the housing of the fan motor, in particular in that each bolt has an external thread region at its radially inner end region, which is screwed into a respective radially directed threaded bore, which is each introduced into a respective radially directed elevation of the housing of the fan motor, in particular wherein the bolts are aligned radially starting from the fan motor, wherein the radially outer end of the bolts is fastened to the air guide part, in particular by means of respective screws passing through the air guide part and each screwed into a respective radially directed threaded bore of the respective bolt,The fan motor drives a fan wheel of the fan, which has fan blades, and / or sets it in rotation, in particular, the bolts being more radially extended than axially and circumferentially. Advantageously, the fan motor is designed to be low-vibration. The bolts are preferably identical to each other. The fan motor is thus arranged centrally between the bolts, which are arranged radially radiating from the fan motor.

[0042] Further advantages emerge from the dependent claims. The invention is not limited to the combination of features in the claims. Further possible combinations of claims and / or individual claim features and / or features of the description and / or the figures will become apparent to those skilled in the art, particularly from the problem and / or the problem posed by comparison with the prior art.

[0043] The invention will now be explained in more detail using schematic illustrations:

[0044] Figure 1 shows a side view of an area of ​​an electric motor according to the invention, wherein a hood part 2 is fastened to an air guide part 1 by means of holders 4.

[0045] Figure 2 shows an enlarged section of Figure 1.

[0046] Figure 3 shows an oblique view of the area.

[0047] In Figure 4, the hood part 2 is shown in an oblique view.

[0048] In Figure 5, one of the brackets 4 is shown in an oblique view.

[0049] Figure 6 shows the fan including air guide part 1 exploded

[0050] As shown in the figures, the electric motor has the hood part 2 which is attached to the air guide part 1 via the brackets 4.

[0051] The air guide part 1 is connected to a bearing plate of the electric motor, which accommodates a bearing for the rotatable mounting of the rotor shaft of the electric motor.

[0052] Another bearing of the rotor shaft is housed in a bearing flange that is connected to the stator housing of the electric motor. The bearing shield is also connected to the stator housing on the side of the stator housing axially facing away from the bearing flange.

[0053] The axial direction is parallel to the direction of the rotor shaft's rotational axis. The circumferential direction and the radial direction are related to the rotor shaft's rotational axis.

[0054] The air guide part 1 is shaped as a hollow cylinder and has a grille 5 at its axial end region facing away from the stator housing. A fan 30 is arranged within the air guide part 1. The fan 30 is preferably arranged and / or attached to the side of the grille 5 facing the stator housing.

[0055] The brackets 4 are preferably evenly spaced from each other in the circumferential direction. The number of brackets 4 is three or more.

[0056] The brackets 4 are identical to each other.

[0057] The respective holder 4 is designed as a stamped and bent part and has a base region on which a first tab region 51 and a second tab region 52 are arranged at an angle.

[0058] A raised portion extending from the second tab region 52 into the base region acts as a reinforcing rib 50. Thus, this reinforcing rib 50 extends not only in the preferably otherwise flat base region, but also in the preferably otherwise flat second tab region 52. It also extends over the angled region.

[0059] A first screw projects through a recess of the second tab area 52 and through a recess of the air guide part 1 and is screwed into a threaded bore of a bolt 22, so that the screw head of the first screw 20 presses the bracket against the air guide part 1.

[0060] Further second screws 21 each protrude through a respective recess of the first tab area 51 and each through a respective recess of the hood part 2. A respective nut is screwed onto the respective threaded area of ​​the respective second screw 21, so that the screw head of the respective second screw 21 presses the hood part 2 onto the respective holder 4.

[0061] A terminal box 3 is attached to the air guide part 1, into which supply lines from the environment are routed and connected to connection elements, to which the electrical connection lines of the fan motor of the fan 30 are also connected. When the electric motor is oriented vertically, i.e., with the rotational axis of the rotor shaft parallel to the direction of gravity, the air flow from the fan 30 is directed downwards, regardless of the speed of the rotor shaft.

[0062] In the radial direction, the hood part 2 extends beyond the air guide part 4 at all circumferential angles. This provides rain protection, i.e., protection against liquid falling from above.

[0063] The air flow sucked in by the fan 30 flows in counter to the direction of gravity, in particular upwards, between the air guide part 2 and the hood part 2 and is then deflected by the air guide part 1 so that the air flow flows downwards through the grille 5, in particular in the direction of gravity, to the fan 30, which then conveys the air flow further downwards so that the air flow exits between the air guide part 1 and the bearing plate and flows along cooling fins of the stator housing which are formed on the stator housing and point radially outwards.

[0064] Preferably, the bearing flange has a circular outer circumference whose maximum outer diameter is smaller than the maximum outer diameter of the hood part 2.

[0065] Preferably, the stator housing also has a circular outer circumference whose maximum outer diameter is smaller than the maximum outer diameter of the hood part 2.

[0066] The curved reinforcement rib of the respective bracket 4 increases the rigidity of the bracket 4 and thus also allows the hood part 2 to be made of metal. This protects the electric motor not only from rain but, thanks to its robust design, also from the impact of massive objects.

[0067] Preferably, the fan 30 is fastened to the bolt 22. For this purpose, the housing of the fan motor is held by the bolt 22 and further bolts 22, which are fastened to the air guide part 1 by means of fastening screws. The bolts 22 are arranged radially on the housing of the fan motor. The second screws 21 are each screwed with their threaded area into the internal thread of a respective press-in nut 60, which is each pressed into a respective recess in the holder 4. The press-in nuts 60 each have an external thread, which is cut into the holder 4, in particular in the second tab area 52, during pressing in. A step is formed on the respective press-in nut 60, with which the press-in nut 60 rests against the holder 4.By pressing in the external thread, the respective press-in nut 60 is connected to the holder 4 in a form-fitting manner, in particular at least in a form-fitting manner in the circumferential direction with respect to the screw axis of the screw.

[0068] The bolts 22 have an external thread at their radially inner end region, which is screwed into a respective threaded bore, which is each introduced into a radially directed elevation, which is created by a respective thickening of the housing part.

[0069] Resonance vibrations can be suppressed by an uneven circumferential arrangement of the thickenings on the outer circumference of the fan motor housing.

[0070] Since the wall thickness of the air guide part 1 is equal to the sheet thickness of the sheet metal used to manufacture the air guide part 1, and preferably a sheet with a thin sheet thickness is used for this purpose, mechanical vibrations of the fan motor are transmitted via the bolts 22 to the air guide part 1 and from there via the brackets 4 to the hood part 2. Since damping of the waves occurs at each transition from one part to the next, vibration energy of the vibrations can be absorbed and thus the vibrations are dampened. Preferably, one of the screws protruding through one of the press-in nuts 60 is screwed into the threaded hole of the respective bolt 22. This results in a particularly rigid mechanical coupling of the bolts 22 to the brackets 4. The clamped air guide part 1 then suppresses vibrations that do not have a node in the area of ​​the air guide part 1.

[0071] In further embodiments according to the invention, the bolt 22 is designed as a single piece, particularly in one piece, with the air guide part 1 and / or with the grille 5, particularly as an edge region. In further embodiments according to the invention, the reinforcing rib 50 is surrounded by a recess in the holder 4. Thus, improved rigidity and simultaneously improved vibration damping are achieved, particularly in the angled region, i.e., in the transition region between the base region and the second tab region 52.

[0072] List of reference symbols

[0073] 1 Air guide part 2 Hood part

[0074] 3 junction box

[0075] 4 Bracket

[0076] 5 grids

[0077] 20 first screw 21 second screw

[0078] 22 bolts

[0079] 30 fans

[0080] 50 reinforcing rib

[0081] 51 first tab area 52 second tab area

[0082] 60 press-in nut

Claims

Patent claims:

1. An electric motor with an air guide and a fan, wherein the air guide is hollow, in particular wherein the air guide is designed as a hollow cylindrical tube section, in particular wherein the area covered in the axial direction by the air guide overlaps the area covered in the axial direction by a stator housing and / or a bearing plate, wherein the fan comprises a fan motor having a housing, wherein the area covered in the axial direction by the fan is encompassed by the area covered in the axial direction by the air guide, in particular wherein the fan motor is arranged radially inside the air guide, characterized in that the fan motor is fastened to the air guide by means of bolts, wherein the bolts are connected at their radially inner end to the housing of the fan motor and at their radially outer end to the air guide,in particular wherein the axial direction is aligned parallel to the direction of the rotational axis of the rotor shaft of the electric motor and / or the radial distances and the circumferential direction are related to the rotational axis of the rotor shaft of the electric motor., 2. Electric motor according to claim 1, characterized in that the bolts are radially aligned, in particular wherein the bolts are further extended in the radial direction than in the circumferential direction and than in the axial direction, in particular wherein the bolts are all arranged at the same axial position and are all arranged at the same radial distance from the axis of rotation of the fan driven by the fan motor.

3. Electric motor according to one of the preceding claims, characterized in that the fan motor drives a fan wheel of the fan having fan blades and / or sets it in rotation, in particular wherein the axis of rotation of the fan wheel is aligned coaxially with the axis of rotation of the rotor shaft of the electric motor, and / or that the bolts are further extended in the radial direction than in the axial direction and than in the circumferential direction.

4. Electric motor according to one of the preceding claims, characterized in that the bolts are spaced unevenly from one another in the circumferential direction, in particular wherein the distance in the circumferential direction between a first bolt and a second bolt which is closest to the first bolt in the circumferential direction is different from the distance between the first bolt and a bolt which is closest to the first bolt opposite the circumferential direction.

5. Electric motor according to one of claims 1 to 3, characterized in that the bolts are evenly spaced from one another in the circumferential direction, in particular wherein the distance in the circumferential direction between a first bolt and a second bolt which is closest to the first bolt in the circumferential direction is equal to the distance between the first bolt and a bolt which is closest to the first bolt opposite the circumferential direction.

6. Electric motor according to one of the preceding claims, characterized in that each bolt has an external thread area on its radially inner end area, which is screwed into a respective radially directed threaded bore, which is each introduced into a respective radially directed elevation of the housing of the fan motor, in particular wherein the bolts are aligned radially starting from the fan motor, wherein the radially outer end of the bolts is fastened to the air guide part, in particular by means of respective screws which pass through the air guide part and are each screwed into a respective radially directed threaded bore of the respective bolt, in particular wherein the radially directed elevation is designed as a thickening of the wall thickness of the housing.

7. Electric motor according to one of the preceding claims, characterized in that each bolt is cylindrically shaped, wherein the cylinder diameter is at least five times smaller than the length of the respective cylindrically shaped bolt measured in the radial direction relative to the axis of rotation of the fan wheel and / or the axis of rotation of the rotor shaft of the electric motor.

8. Electric motor according to one of the preceding claims, characterized in that a hood part of the electric motor is connected to the air guiding part by means of at least one holder, wherein the maximum outer diameter of the hood part is greater than the maximum outer diameter of the air guiding part, in particular wherein the radial distance region covered by the hood part comprises and / or contains the radial distance region covered by the air guiding part.

9. Electric motor according to one of the preceding claims, characterized in that the holder is manufactured as a stamped and bent part from sheet metal, wherein the holder has a base region and a first tab region and a second tab region, and / or that the first tab region adjoins the base region and the second tab region adjoins the base region, wherein the first tab region is spaced from the second tab region.

10. Electric motor according to one of the preceding claims, characterized in that the first tab region is angled, in particular bent by forming, to the base region, in particular by 90°, and / or that the second tab region is angled, in particular bent by forming, to the base region, in particular by 90°, in particular wherein the base region is flat and both the first tab region and the second tab region are flat, and / or that a reinforcing rib is formed on the holder by a raised portion being formed into the holder, which extends continuously from the base region to the second tab region, in particular also by the bend, in particular angle, created by the bending of the second tab region,in particular wherein the elevation is elongated and / or is further extended along its extension or in its direction of extension than transversely, in particular perpendicular to the extension or to its direction of extension.

11. Electric motor according to one of the preceding claims, characterized in that the elevation is surrounded, in particular completely, by a depression introduced into the holder, in particular wherein the depression extends at least on both sides along the elevation, in particular the elongated elevation, in particular also through the kink, in particular angle, created by the angling of the second tab region.

12. Electric motor according to one of the preceding claims, characterized in that in a recess, in particular a blind hole-like recess, of the first tab region (51) at least one press-in nut is arranged, into which a screw is screwed, which projects through the hood part and through the first tab region of the holder, in particular wherein the screw head of the screw presses the air guide part onto the holder and / or the press-in nut presses the holder onto the hood part, and / or that the press-in nut has an external toothing which is cut into the holder, in particular into the first tab region, in particular such that the press-in nut is positively connected to the holder, in particular at least in its actuating direction and / or at least in the screwing direction of the internal thread of the press-in nut.

13. Electric motor according to one of the preceding claims, characterized in that the holders are arranged at the same axial position and at the same radial distance, in particular wherein the holders are spaced apart from one another uniformly, in particular regularly, in the circumferential direction, in particular wherein the holders are designed identically to one another.

14. Electric motor according to one of the preceding claims, characterized in that the air guide part is hollow-cylindrical, and / or that the axis of rotation of the rotor shaft is aligned vertically, in particular parallel to is aligned in the direction of gravity, in particular wherein the hood part is arranged above the stator housing of the electric motor.

15. Electric motor according to one of the preceding claims, characterized in that a grille is fastened to the air guide part, in particular wherein a fan is fastened to the grille, and / or that the air guide part is fastened to the stator housing of the electric motor or to a bearing plate of the electric motor connected to the stator housing, wherein the air flow conveyed by the fan exits between the stator housing and the air guide part or between the bearing plate and the air guide part and flows along cooling fins formed on the stator housing, and / or that a connection box for the fan is arranged on the air guide part, in particular wherein the electrical connection lines of the fan are led into the connection box and are connected there to connection elements which are connected to electrical supply lines.

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