Electric motor with stator housing, rotor shaft, fan cover, and fan wheel

Abstract

The invention relates to an electric motor with a stator housing, a rotor shaft, a fan cover, and a fan wheel. The fan wheel is rotationally fixed to the rotor shaft, and the rotor shaft is rotatably mounted relative to the stator housing. The fan cover is secured to a bearing shield which is connected to the stator housing, and the fan cover is at least partly radially surrounded by a cap which is arranged at a distance to the fan cover.

Description

[0001] Electric motor with stator housing, rotor shaft, fan cover and fan wheel

[0002] Description:

[0003] The invention relates to an electric motor with stator housing, rotor shaft, fan cover and fan wheel.

[0004] It is known that a driven fan impeller promotes an air flow which can be used for cooling.

[0005] An electric motor is known from DE 10 2008 028 622 A1.

[0006] An electric motor with a fan cover is known from DE 10 2022 001 258 A1.

[0007] An engine is known from DE 10 2015 121 698 A1.

[0008] A pump motor is known from JP 2009 - 278 810 A1.

[0009] An electric motor with a housing part and fan cover is known from DE 10 2009 024 690 A1.

[0010] An electric motor is known from De 10 2006 016 271 A1.

[0011] An electric motor with ventilation is known from JP S56 - 145 341 U.

[0012] The invention is therefore based on the object of developing an electric motor for outdoor use.

[0013] According to the invention, the object is achieved in the electric motor according to the features specified in claim 1.

[0014] Important features of the invention in the electric motor with stator housing, rotor shaft, fan cover and fan wheel are that the fan wheel is connected to the rotor shaft in a rotationally fixed manner, wherein the rotor shaft is arranged so as to be rotatable relative to the stator housing, wherein the fan cover is fastened to a bearing plate connected to the stator housing, in particular wherein a first bearing of the rotor shaft is received in the bearing plate and a second bearing of the rotor shaft is received in a bearing flange connected to the stator housing, wherein the fan cover is at least partially radially surrounded by a cap which is spaced from the fan cover.

[0015] The advantage here is that the fan shroud surrounds the fan impeller and thus protects it from mechanical influences from the outside and directs the air flow conveyed by the fan impeller. However, when used outdoors, rain can penetrate into the motor if there is no shroud. According to the invention, the shroud additionally protects against rain and mechanical influences without creating a high flow resistance for the air flow conveyed by the fan impeller. This is because the air flow sucked in by the fan impeller flows between the fan shroud and the shroud and then penetrates the grille openings in the fan shroud. When the electric motor is aligned vertically, the shroud is arranged above the fan shroud and thus acts as rain protection, particularly for the grille openings in the fan shroud. The shroud is therefore preferably designed to be wider.

[0016] In an advantageous embodiment, the area covered by the cap in the axial direction truly overlaps the area covered by the fan cover in the axial direction, with the cap being axially spaced from the stator housing and / or the bearing plate. Advantageously, the cap extends beyond the fan cover in all radial directions, thus extending further than the fan cover.

[0017] In an advantageous embodiment, the cap is designed to be watertight and airtight, particularly in the axial direction. In an advantageous embodiment, the radial clearance area covered by the cap encompasses the radial clearance area covered by the fan cover. This advantageously protects the grille openings of the fan cover from rain, since the cap is designed to be watertight across the entire radial clearance area covered by it.

[0018] In an advantageous embodiment, the fan cover has radially outward-facing elevations in a first axial region, which are spaced apart from one another in the circumferential direction. Between the elevations closest to one another in the circumferential direction, the fan cover has radially inward-facing depressions. This is advantageous in that swirling of the air flow is prevented or at least reduced. Thus, the air flow flows along the shortest path to the grille openings of the fan cover.

[0019] In an advantageous embodiment, the cap has a constant wall thickness. This is advantageous because it can be easily manufactured, particularly from sheet metal, particularly as a stamped and bent part.

[0020] In an advantageous embodiment, the fan cover has a constant wall thickness. This is advantageous because it is easy to manufacture, particularly from sheet metal, particularly as a stamped and bent part.

[0021] In an advantageous embodiment, the cap has, at least in a first axial region, elevations spaced apart from one another in the circumferential direction, directed radially outwards, in particular extending in the axial direction. In particular, the cap has a respective, radially inwardly directed depression in the circumferential direction between the respective nearest adjacent elevations, in particular so that the sucked-in air flow has no swirl, in particular, the elevations extend in the axial direction, in particular with a vanishing helix angle, in particular without a helix angle. The advantage here is that the air flow can be guided efficiently.

[0022] In an advantageous embodiment, the fan cover in the first axial region has elevations spaced from one another in the circumferential direction, directed radially outward, in particular extending in the axial direction, in particular such that a respective, radially inward-directed depression is formed in the circumferential direction between the respectively nearest adjacent elevations, in particular such that the sucked-in air flow has no swirl, in particular wherein the elevations of the fan cover extend in the axial direction, in particular with a vanishing helix angle, in particular thus without a helix angle. The advantage here is that the air flow can be guided efficiently.

[0023] In an advantageous embodiment, particularly for each of the elevations of the fan cover, a respective elevation of the cap is arranged at the circumferential position of each elevation of the fan cover. Advantageously, the spatial area guiding the air flow has as constant an extension as possible perpendicular to the flow direction. This allows for uniform air flow guidance and low specific flow resistance or air resistance.

[0024] In an advantageous embodiment, in particular for each of the elevations of the fan shroud, a respective recess in the cap is arranged at the circumferential position of a respective recess in the fan shroud. It is advantageous in this case that the spatial area guiding the air flow has as constant an extension as possible perpendicular to the flow direction. This allows the air flow to be guided evenly and with low specific flow resistance or air resistance. In an advantageous embodiment, the cap is held by means of at least one holding part. It is advantageous in this case that the cap can be easily held at a distance from the fan shroud.

[0025] In an advantageous embodiment, the cap and / or fan shroud are manufactured as a stamped or bent part and / or from sheet metal. This allows for cost-effective production.

[0026] In an advantageous embodiment, a holding part designed as an angle plate rests with a first end region on the fan cover and with a second end region on the inside of the cap. It is advantageous in this case that the two end regions are preferably flat and each rest on flat regions of the fan cover. The two end regions are spaced apart from one another and therefore do not adjoin one another. Preferably, the first end region is enclosed by a first plane and the second end region is enclosed by a second plane, wherein the first plane is spaced apart from the second plane and is aligned parallel. The first end region is connected to the second end region via an intermediate region. The intermediate region is preferably aligned perpendicular to the first and second end regions.

[0027] In an advantageous embodiment, the fan cover is fastened to the bearing plate connected to the stator housing by means of a first screw, in particular wherein the first screw, which has a threaded region, projects through a recess in the fan cover and is screwed with its threaded region into a threaded hole, in particular one directed radially, in the bearing plate, in particular wherein the screw head of the first screw presses the first end region against the fan cover. The advantage here is that simple fastening of the fan cover to the bearing plate is possible, wherein the same screw which serves to fasten the fan cover also serves to fasten the cap. For this purpose, the holding part is fastened by pressing it together with the fan cover by the first screw. The cap is fastened to a region of the holding part which is spaced apart from the first screw.In an advantageous embodiment, a screw part, in particular a threaded bushing or nut, in particular an external hexagon nut, is integrally connected to the holding part on the side of the second end region of the holding part facing away from the cap, in particular welded or adhesively bonded. A second screw protrudes through a recess in the cap and a threaded portion of the second screw is screwed into an internal thread of the screw part, with a screw head of the second screw pressing against the outside of the cap. This allows for simple fastening.

[0028] The axial direction, the radial direction and the circumferential direction are always related to the axis of rotation of the rotor shaft.

[0029] In an advantageous embodiment, the air flow drawn in by the fan impeller flows radially inward between the cap and the stator housing, is deflected in the axial direction, flows between the cap and the fan cover, and after being deflected on the inside of the cap, flows through the grille openings in the fan cover in the opposite direction to the axial direction. And / or the air flow conveyed by the fan impeller exits between the fan cover and the bearing plate and flows along the cooling fins of the stator housing, which extend in the axial direction. The advantage here is that, with a vertical orientation, the penetration of large dirt particles is prevented, as these would first have to be drawn upwards and then pass through the grille openings in the fan cover.

[0030] 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. The invention will now be explained in more detail with reference to schematic illustrations:

[0031] Figure 1 shows a section of an electric motor according to the invention in a side view.

[0032] Figure 2 shows a holding part 5 in an oblique view.

[0033] As shown in the figures, the electric motor according to the invention has a stator housing 1, on which cooling fins protrude radially outwards, which are spaced from one another in the circumferential direction and extend in the axial direction.

[0034] The axial direction is parallel to the direction of the rotational axis of the electric motor's rotor shaft, which is mounted so it can rotate relative to the stator housing. The radial direction and the circumferential direction are also related to the rotational axis of the rotor shaft.

[0035] Connected to one axial end of the stator housing 1 is a bearing shield, which houses a bearing for rotatably supporting the rotor shaft. The rotor shaft protrudes through the bearing and the bearing shield on the side of the bearing shield facing away from the stator housing 1 and is connected at its end region there in a rotationally fixed manner to a fan impeller 3. When the rotor shaft rotates, this fan impeller 3 promotes an air flow that flows along the cooling fins of the stator housing 1, in particular, and thus cools the electric motor.

[0036] A fan cover 2 surrounding the fan wheel 3 radially, in particular completely and continuously, is fastened to the bearing plate of the electric motor by means of a first screw 6.

[0037] The fan cover 2 has grille openings on its end facing away from the stator housing, through which the drawn-in air flow enters. At the axially opposite end of the fan cover 2, the air flow exits through recesses arranged between the fan cover 2 and the bearing plate and then flows axially along the cooling fins of the stator housing 1. The cap 4 is secured by means of retaining parts 5 and the same screw 6 that secures the fan cover 2.

[0038] The respective holding part 5 is designed as an angled sheet and manufactured as a stamped and bent part.

[0039] A first end region of the respective retaining part 5 is fastened to the inside of the cap 4, in particular by means of a further screw 7, which extends through a recess in the cap 4 and through a recess in the retaining part 5 designed as an angled plate, and to whose threaded region a nut 20 is screwed. The nut presses against the inside of the retaining part 5, and the screw head of the screw 7 presses against the outside of the cap 4.

[0040] A second end portion of the respective retaining part 5 is attached to the outside of the fan cover 2, in particular by means of the first screw 6, which extends through a recess in the fan cover 2 and through another recess in the retaining part 5, which is designed as an angled plate, and onto whose threaded portion a further nut is screwed. The nut presses against the inside of the fan cover 2, and the screw head of the screw 6 presses against the retaining part 5.

[0041] The clear inner diameter of the cap 4 decreases monotonically with decreasing distance from the stator housing, particularly opposite to the axial direction

[0042] The area covered in the axial direction by the cap 4 overlaps with the area covered in the axial direction by the fan cover 2.

[0043] The cap 4 is spaced from the fan cover 2. Thus, the sucked air flow

[0044] In all radial directions, the cap 4 projects beyond the fan cover 2. Thus, the cap 4 acts as a rain cover when the rotational axis of the rotor shaft of the electric motor is aligned vertically.

[0045] For this purpose, the cap 4 is designed to be airtight and watertight, thus, in particular, without holes. A nut 20 is welded to the retaining part 5, so that the additional screw 7, which extends through the retaining part 5, can be screwed into the internal thread of the nut 20.

[0046] The nut 20 is round on its outer circumference. In further embodiments of the invention, the nut 20 is designed as an external hexagon on its outer circumference.

[0047] The cap 4 has a wall thickness that is as constant as possible and, at least in a first axial region, radially outward-directed elevations spaced from one another in the circumferential direction, in particular such that a respective recess is formed in the circumferential direction between the nearest adjacent elevations. This prevents any swirl of the intake air flow. This is because the elevations extend in the axial direction, in particular with a vanishing helix angle, i.e., in particular, without a helix angle.

[0048] The air flow sucked in by the fan flows radially inward into a spacing area between cap 4 and stator housing 1 and is then deflected in the axial direction, so that the air flow flows along the inside of the cap 4 and - guided by the above-mentioned elevations - is deflected on the inside of the cap 4 radially inward and in the direction opposite to the axial direction.

[0049] Thus, the air flow then penetrates the grille openings of the fan cover 2 and is then conveyed axially along the stator housing 1 by the fan, in particular the fan wheel 3.

[0050] Preferably, the fan cover 2 also has a wall thickness that is as constant as possible and, at least in the first axial region, elevations that are spaced apart from one another in the circumferential direction and directed radially outwards, in particular such that a respective depression is formed between the nearest adjacent elevations in the circumferential direction. These elevations are particularly preferably arranged at the same circumferential position as the elevations on the cap 4. The same applies to the depressions. In particular, the air duct carrying the air flow is uniformly delimited on the inside and outside. Thus, the speed of the air flow guided between the fan cover 2 and the cap 4 is as constant as possible in the circumferential direction. A swirl of the air flow is prevented as far as possible.

[0051] This prevents any swirl in the intake airflow. Because the raised portions extend axially, particularly with a vanishing helix angle, or rather, without any helix angle.

[0052] In particular, when the axis of rotation of the rotor shaft is aligned vertically, the penetration of foreign bodies is prevented, since a foreign body would first have to flow in horizontally and then flow vertically upwards in order to be stopped by the grid openings at the latest.

[0053] Since the fan is driven by the rotor shaft, i.e. the fan wheel 3 is firmly connected to the rotor shaft, fan power is only required when the electric motor is operating.

[0054] Preferably, the two end regions are flat and each abut flat regions of the fan cover. The two end regions are spaced apart from one another, i.e., they do not adjoin one another. Preferably, the first end region is encompassed by a first plane, and the second end region is encompassed by a second plane, wherein the first plane is spaced apart from the second plane and aligned parallel. The first end region is connected to the second end region via an intermediate region. The intermediate region is preferably aligned perpendicular to the first and second end regions.

[0055] List of reference symbols

[0056] 1 Stator housing with cooling fins 2 Fan cover

[0057] 3 Fan wheel

[0058] 4 cap

[0059] 5 Holding part

[0060] 6 Screw 7 Screw

[0061] 20 Nut, welded

Claims

Patent claims:

1. Electric motor with stator housing, rotor shaft, fan cover and fan wheel, wherein the fan wheel is connected to the rotor shaft in a rotationally fixed manner, wherein the rotor shaft is arranged so as to be rotatable relative to the stator housing, wherein the fan cover is fastened to a bearing shield connected to the stator housing, in particular wherein a first bearing of the rotor shaft is received in the bearing shield and a second bearing of the rotor shaft is received in a bearing flange connected to the stator housing, characterized in that the fan cover is at least partially radially surrounded by a cap which is spaced from the fan cover.

2. Electric motor according to claim 1, characterized in that the area covered by the cap in the axial direction overlaps with the area covered by the fan cover in the axial direction, wherein the cap is axially spaced from the stator housing and / or the bearing plate.

3. Electric motor according to one of the preceding claims, characterized in that the cap is designed to be water-impermeable and air-impermeable, in particular in the axial direction, and / or that the radial distance area covered by the cap comprises the radial distance area covered by the fan cover.

4. Electric motor according to one of the preceding claims, characterized in that the fan cover has, in a first axial region, radially outwardly directed elevations which are spaced apart from one another in the circumferential direction, wherein the fan cover has, in the circumferential direction, radially inwardly directed depressions between the elevations which are closest to one another in the circumferential direction.

5. Electric motor according to one of the preceding claims, characterized in that the cap has a constant wall thickness and / or that the fan cover has a constant wall thickness.

6. Electric motor according to one of the preceding claims, characterized in that the cap has, at least in a first axial region, elevations which are spaced apart from one another in the circumferential direction and directed radially outwards, in particular extending in the axial direction, in particular so that in the circumferential direction between the respective nearest adjacent elevations a respective depression directed radially inwards is formed, in particular so that the sucked-in air flow has no swirl, in particular wherein the elevations extend in the axial direction, in particular with a vanishing helix angle, in particular therefore without a helix angle.

7. Electric motor according to one of the preceding claims, characterized in that the fan shroud in the first axial region has elevations which are spaced apart from one another in the circumferential direction and directed radially outwards, in particular extending in the axial direction, in particular so that in the circumferential direction between the respectively nearest adjacent elevations a respective depression directed radially inwards is formed, in particular so that the sucked-in air flow has no swirl, in particular wherein the elevations of the fan shroud extend in the axial direction, in particular with a vanishing helix angle, in particular therefore without a helix angle.

8. Electric motor according to one of the preceding claims, characterized in that in particular for each of the elevations of the fan cover, a respective elevation of the cap is arranged at the circumferential position of a respective elevation of the fan cover.

9. Electric motor according to one of the preceding claims, characterized in that in particular for each of the elevations of the fan cover, a respective recess of the cap is arranged at the circumferential position of a respective recess of the fan cover.

10. Electric motor according to one of the preceding claims, characterized in that the cap is held by means of at least one holding part, and / or that the cap and / or the fan cover are made as a stamped and bent part and / or from sheet metal.

11. Electric motor according to one of the preceding claims, characterized in that a holding part designed as an angle plate rests with a first end region on the fan cover and with a second end region on the inside of the cap.

12. Electric motor according to one of the preceding claims, characterized in that the fan cover is fastened to the bearing plate connected to the stator housing by means of a first screw, in particular wherein the first screw, which has a threaded region, projects through a recess of the fan cover and is screwed with its threaded region into a threaded bore, in particular directed radially, of the bearing plate, in particular wherein the screw head of the first screw presses the first end region against the fan cover.

13. Electric motor according to one of the preceding claims, characterized in that on the side of the second end region of the holding part facing away from the cap, a screw part, in particular a threaded bushing or nut, in particular an external hexagon nut, is integrally connected to the holding part, in particular welded or adhesively bonded, wherein a second screw projects through a recess in the cap and a threaded region of the second screw is screwed into an internal thread of the screw part, wherein a screw head of the second screw presses against the outside of the cap.

14. Electric motor according to one of the preceding claims, characterized in that the axial direction, the radial direction and the circumferential direction are each related to the axis of rotation of the rotor shaft.

15. Electric motor according to one of the preceding claims, characterized in that the air flow sucked in by the fan wheel flows radially inwards between the cap and the stator housing and is deflected in the axial direction between the cap and the fan cover and, after being deflected on the inside of the cap, flows through grille openings in the fan cover in the opposite direction to the axial direction, and / or that the air flow conveyed by the fan wheel exits between the fan cover and the bearing plate and flows along the cooling fins of the stator housing extending in the axial direction.

Images