Electric motor having an electromagnetically actuatable brake

Abstract

An electric motor having an electromagnetically brake comprises a fan wheel and a cowl part radially surrounding the fan wheel, wherein: the cowl part radially surrounds the brake; and the flow of air conveyed by the fan wheel flows inside the space radially surrounded by the cowl part.

Description

[0001] Electric motor with electromagnetically operated brake

[0002] Description:

[0003] The invention relates to an electric motor with an electromagnetically actuated brake.

[0004] Fan covers for fans are well known.

[0005] From DE 10 2006 013 089 A1, the closest state of the art is an industrial truck with an electric drive unit and optimized cooling.

[0006] An electric motor is known from EP 2 633 603 B1.

[0007] The invention is therefore based on the object of designing an electric motor in a compact manner.

[0008] According to the invention, the object is achieved in the electric motor according to the features specified in claim 1.

[0009] Important features of the invention in the electric motor are that the electric motor is provided with an electromagnetically actuated brake, in particular for braking the rotor shaft of the electric motor and / or as a holding brake for the rotor shaft of the electric motor, wherein the electric motor has a fan wheel and a hood part radially surrounding the fan wheel, in particular forming a housing, wherein the hood part radially surrounds the brake, in particular forming a housing, wherein the air flow conveyed by the fan wheel is guided in a closed circuit, and / or wherein the air flow conveyed by the fan wheel flows within the spatial area radially surrounded by the hood part, in particular is separated from the ambient air by means of the hood part.

[0010] The advantage here is that the hood section is closed, preventing any airflow from passing through it. The airflow conveyed by the fan wheel remains within the hood section and thus flows in a closed circuit within the hood section.

[0011] Essential features of the invention are that the hood part is fastened to a bearing plate of the electric motor and recesses of the hood part passing through the hood part are covered by means of closure parts, in particular a cover, screw plug and / or cable gland, so that the air flow conveyed by the fan flows within the space area delimited and / or bordered by the hood part together with the closure parts and the bearing plate, in particular and is separated from the ambient air.

[0012] The advantage here is that the hood section is closed, preventing any airflow from passing through it. The airflow conveyed by the fan wheel remains within the hood section and therefore flows in a closed circuit within the hood section, particularly within the space enclosed by the hood section and the bearing plate.

[0013] In an advantageous embodiment, the brake has a magnetic body that is spaced axially from the fan impeller, in particular, the distance between the magnetic body and the fan impeller being greater than a quarter of the outer diameter of the fan impeller. This provides the advantage of providing sufficient space for swirling the air flow and also for replacing the brake with a double brake. In particular, the available free space can be utilized by replacing the brake with a double brake. Furthermore, sufficient installation space is available for swirling the air conveyed by the fan impeller.

[0014] In an advantageous embodiment, the area covered in the radial direction by the electrically energizable winding is encompassed by the area covered in the radial direction by the fan impeller blades. This has the advantage that direct cooling of the winding is achieved. In an advantageous embodiment, the magnet body is connected to the bearing shield in a rotationally fixed manner. It is advantageous that the electric motor has an integrated electromagnetically actuated brake, which is provided for braking or holding the rotor shaft of the electric motor. It is also advantageous that the brake can be fixed to the bearing shield. This means that the electric motor can be designed with a brake and the heat loss from the brake can be spread out using the air flow conveyed by the fan impeller. The heat-conducting design of the cover section enables efficient dissipation of the heat loss to the environment.

[0015] In an advantageous embodiment, an electrically energizable winding is accommodated in the magnetic body, in particular wherein the magnetic body has an annular recess in which the winding is accommodated, in particular wherein the annular axis of the annular recess is aligned coaxially with the axis of rotation of the shaft to be braked by the brake, in particular the rotor shaft. It is advantageous in this case that the heat loss from the brake can be dissipated via the air flow required by the fan impeller. It is further advantageous in this case that the annular axis of the annular recess and / or the winding axis of the winding are aligned coaxially with the axis of rotation of the rotor shaft.

[0016] In an advantageous embodiment, an annular driver is fitted onto the rotor shaft of the electric motor and is connected in a rotationally fixed manner to the rotor shaft, in particular by means of a key connection, wherein a disc-shaped brake pad carrier is fitted onto the driver and has an internal toothing which engages with an external toothing of the driver, in particular so that the brake pad carrier is connected in a rotationally fixed manner to the driver and is displaceable in the axial direction, wherein an armature disk made of ferromagnetic material is connected in a rotationally fixed manner to the magnetic body, in particular by means of bolts fastened to the magnetic body, which pass through recesses in the armature disk in the axial direction, wherein spring parts supported on the magnetic body press on the armature disk,In particular, when the winding is energized, the armature disk is pulled toward the magnetic body against the spring force generated by the spring parts, allowing the brake pad carrier to free itself from the braking surface, and / or when the winding is de-energized, the spring parts press the armature disk onto the brake pad carrier, which is thus pressed, on its side axially remote from the armature disk, onto the braking surface formed on the bearing plate or on a friction plate connected to the bearing plate. In particular, the armature disk is arranged axially between the brake pad carrier and the magnetic body, and / or the brake pad carrier is arranged axially between the armature disk and the braking surface, in particular, bolts attached to the magnetic body protrude through recesses in the armature disk. The advantage here is that the brake engages automatically, in particular automatically, in the event of a power failure. This increases safety.

[0017] In an advantageous embodiment, an air guide element is arranged radially within the hood part between the magnet body and the fan wheel, in particular with the air guide element being arranged axially between the fan wheel and the magnet body. This is advantageous because the air flow is used as efficiently as possible. In particular, the exhausted air is initially conveyed radially between the hood part and the air guide element axially toward the magnet body, and the air, which is then reheated around the magnet body, is sucked into the air guide element and transported to the fan wheel.

[0018] In an advantageous embodiment, the air guide element is attached to the magnet body. This is advantageous because the air guide element is securely attached, and a portion of the heat flow also flows from the magnet body into the air guide element, which is preferably made of stamped and bent sheet metal, and is transferred to the air flowing within the air guide element.

[0019] In an advantageous embodiment, lug areas projecting radially outward on the air guide part are integrally connected or formed as a single piece, which are pressed onto the magnet body by nuts screwed onto screw parts. The advantage here is that a simple, cost-effective and heat-conducting connection to the magnet body can be achieved. The fastening means, in particular on a

[0020] Threaded area of ​​a bolt

[0021] In an advantageous embodiment, the air guide part is essentially hollow-cylindrical, with the cylinder diameter and / or outer diameter of the hollow-cylindrical air guide part being smaller than the outer diameter of the fan wheel. This has the advantage that the air flow blown off by the fan wheel does not flow directly into the intake area of ​​the fan, and in particular, back turbulence is prevented.

[0022] In an advantageous embodiment, vanes that project radially outwards and are spaced apart from one another in the circumferential direction are arranged and / or formed on the air guiding part, which impose a swirl or angular momentum on the air flow conveyed by the fan wheel, in particular wherein a plurality of elevations, in particular cams, are formed on each vane, in particular on the respective vane surface of each vane. The advantage here is that the swirl or angular momentum can be used to swirl the air flow, thus improving heat dissipation. In particular, improved air guidance can be achieved, which causes greater swirl and thus more efficient heat dissipation. The elevations or cams cause even greater swirl in the air flow and thus contribute to a further improvement in heat dissipation.

[0023] In an advantageous embodiment, the rotor shaft of the electric motor extends axially through the air guide, and the fan impeller is non-rotatably connected to the rotor shaft. The advantage here is that the fan can be operated passively.

[0024] In an alternative advantageous embodiment, the fan wheel is driven by a fan motor. The advantage here is that the fan dissipates heat independently of the rotor shaft speed.

[0025] In an advantageous embodiment, the area covered by the cover part in the axial direction encompasses the area covered by the magnet body in the axial direction. It is advantageous that the magnet body is surrounded by the cover part to form a housing.

[0026] In an advantageous embodiment, thickened portions spaced apart from one another in the circumferential direction are formed on the hood part, with at least one of the thickened portions having a threaded bore extending radially through the hood part, into which a screw plug is screwed. The advantage here is that the thickened portions provide a wall thickness sufficient for a threaded bore.

[0027] In an advantageous embodiment, the fan wheel is a radial fan wheel. This has the advantage that the intake air flows radially outward in all radial directions.

[0028] In an advantageous design, all recesses in the hood section are covered. This has the advantage that the air flow conveyed by the fan impeller flows within the hood section.

[0029] In an advantageous embodiment, the hood section has a monotonically decreasing maximum outer diameter with increasing axial distance from the bearing plate. This advantageously allows the air flow to be curved accordingly within the hood section.

[0030] In an advantageous embodiment, the hood part has a distance from the magnetic body in the circumferential direction between each two tab regions that are closest to one another in the circumferential direction such that an air flow flows axially between the hood part and the magnetic body radially inwards, in particular into the spatial region arranged radially inside the hood part and radially outside the rotor shaft.

[0031] The advantage here is that the air flows radially inwards between the hood part and the magnet body and is then deflected in the axial direction, so that the air flow then flows along the rotor shaft in the axial direction towards the fan wheel, from which the air flow is sucked in.

[0032] 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:

[0033] Figure 1 shows a first electric motor according to the invention in an oblique view, wherein a hood part 1 covers a fan of the electric motor.

[0034] Figure 2 shows a corresponding sectional view through the area of ​​the electric motor comprising the hood part 1.

[0035] Figure 3 shows an oblique view of the area with the hood part 1 removed.

[0036] Figure 4 shows a sectional view through the area of ​​a second electric motor according to the invention comprising the hood part 1, wherein, in contrast to the first electric motor, an air guide part 40 is provided.

[0037] Figure 5 shows an oblique view of the area of ​​Figure 4 with the hood part 1 removed.

[0038] Figure 6 shows an oblique view of the area of ​​a third electric motor, the air guiding part of which, in contrast to the air guiding part 40 of the second electric motor, additionally has vanes 60.

[0039] As shown in Figures 1 to 3, the electric motor comprises a stator housing 2 which is connected at its first axial end to a bearing shield 25 and at its other axial end to a bearing flange, wherein for the rotatable mounting of the rotor shaft 4, the bearing shield 25 accommodates a first bearing and the bearing flange a second bearing.

[0040] The rotor shaft projects, in particular on the B-side, through a magnetic body 22 of an electromagnetically actuated brake and is connected in a rotationally fixed manner to a fan wheel 21 at its end region.

[0041] The brake has a disc-shaped brake pad carrier with internal teeth. The brake pad carrier is mounted on an annular carrier with external teeth and is connected to the rotor shaft 4 in a rotationally fixed manner by means of a keyway. The internal teeth mesh with the external teeth. Thus, the brake pad carrier is rotationally fixed to the carrier and arranged for axial displacement.

[0042] The magnet body 22 is made of ferromagnetic material, in particular of a GGG cast.

[0043] An annular recess is formed in the magnet body 22, in which an electrically energizable winding 23 is accommodated.

[0044] The ring axis of the annular recess and / or the winding axis of the winding 23 is aligned coaxially with the axis of rotation of the rotor shaft 4.

[0045] Spring parts 24 supported on the magnet body 22 press on an armature disk which is arranged in the axial direction between the brake pad carrier and the magnet body 22.

[0046] The armature disk is made of ferromagnetic material and is connected to the magnet body 22 in a rotationally fixed manner and arranged to be displaceable in the axial direction. In particular, bolts supported on the magnet body 22 protrude through recesses in the armature disk.

[0047] The brake pad carrier is arranged in the axial direction between the armature disc and a braking surface which is formed either on a friction plate connected to the bearing plate 25 in a rotationally fixed manner or directly on the bearing plate.

[0048] When the winding 23 is energized, the armature disk is attracted to the magnetic body 22 against the spring force generated by the spring parts 24, so that the brake pad carrier can run free from the braking surface.

[0049] When de-energized, the spring parts 24 press the armature disk onto the brake pad carrier, forcing it onto the braking surface and thus creating a frictional connection on both sides. The cover part 1 surrounds the brake and the fan wheel 21 radially and / or by forming a housing.

[0050] The hood part 1 is fastened to the bearing plate 25, in particular by means of screws.

[0051] The hood part 1 has a centrally arranged recess which is closed by a cover 20 which is pressed onto the hood part by means of screws.

[0052] The hood part 1 with the cover 20 is designed as a closed housing such that the air flow conveyed by the fan wheel 21 remains within the interior area delimited by the cover 20, hood part 1 and bearing plate 25.

[0053] In this way, the airflow conveyed by the fan impeller 21 transports heat from hotter areas to cooler areas. This improves heat dissipation to the environment.

[0054] The air flow flows past the magnet body 22 and is preferably drawn in axially, particularly along the rotor shaft 4. The air blown off by the fan wheel 21 flows essentially radially away from the fan wheel 21 and then along the inside of the hood part 1.

[0055] The hood part 1 has thickened portions 6 spaced apart from one another in the circumferential direction on its circumference, in particular wherein the wall thickness of the hood part 1 is smaller in the areas directly adjacent to the thickened portions 6 than in the areas of the thickened portions 6.

[0056] In one of the thickened portions 6, a threaded hole is provided through the hood part 1, into which a screw plug 5 is screwed. Thus, the threaded hole functions as an inspection opening for checking or monitoring the brake, in particular an air gap of the brake, which varies due to wear of the brake pads over the course of operation, in particular, and in the de-energized operating case of the brake, is arranged between the armature disk and the magnet body 22.

[0057] The electrical connection cables of the winding 23 are routed through holes in the bearing plate 25 or through a cable gland 7 extending through the cover part 1. A terminal box 3 is mounted on the stator housing 2, in which the stator winding cables of the electric motor can be connected to electrical supply cables.

[0058] As can be seen in Figure 2 and Figure 3, the distance between the magnet body 22 and the fan wheel 21 is greater than a quarter of the outer diameter of the fan wheel 21. Thus, there is sufficient space to replace the brake with a double brake.

[0059] As shown in Figures 4 and 5, in contrast to the electric motor according to Figures 1 to 3, a substantially hollow-cylindrical air guide part 40 can be arranged axially between the magnet body 22 and the fan wheel 21, in particular with the cylinder axis of the hollow-cylindrical air guide part 40 aligned coaxially with the axis of rotation of the rotor shaft. The figures only show a schematic representation of the air guide part 40. The cylinder diameter or outer diameter of the air guide part 40 is preferably smaller than the outer diameter of the fan wheel 21, in particular to achieve more efficient intake of air from the tubular air guide part 40 and to reliably distance the air stream blown off by the fan wheel from the intake area, thus in particular to avoid back-turbulence.

[0060] On the air guide part 40, lug areas 41 projecting radially outward are materially bonded or formed integrally. These lug areas are pressed against the magnet body 22 by nuts 42, which are screwed onto screw parts. In particular, the screw parts are designed as threaded bolts that protrude through the magnet body 22 and the armature disk and are screwed into threaded holes in the bearing plate 25.

[0061] The air guide part 40 is preferably designed as a stamped and bent part made of sheet metal.

[0062] By means of the air guide 40, the air flowing back along the inside of the hood part 1 is separated from the air flowing along the rotor shaft 4 toward the fan wheel 21. The improved air flow reduces eddy losses.

[0063] As shown in Figure 6, however, in contrast to the electric motor according to Figures 4 and 5, the essentially hollow-cylindrical air guide part 40 can also be formed with radially outwardly projecting vanes 60, wherein the vanes 60 are shaped such that the air flowing between the hood part 1 and the air guide part 40 not only flows in the axial direction but also acquires a swirl, in particular angular momentum, in particular a circumferential velocity component in addition to the axial velocity component. In this way, turbulence and eddies can be created, which improve heat transfer.

[0064] Preferably, the fan wheel 21 is designed such that the flow direction of the air flow conveyed by the fan wheel 21 is independent of the direction of rotation of the rotor shaft 4.

[0065] An air gap is present between the hood part and the magnet body, in particular between two adjacent tab areas 41 in the circumferential direction, so that the sucked-in air flow flows radially inwards through this air gap and then radially inside the hood part

[0066] In particular, the area radially covered by the electrically energizable winding is encompassed by the area radially covered by the fan blades 60 of the fan wheel 21. Thus, the air flow conveyed by the fan wheel 21 impinges on the magnet body with such a radial width that the entire radial area on the magnet body covered by the winding is exposed to a cooled air flow, so that the heat from the winding can be dissipated as directly as possible through the magnet body to the air flow.

[0067] In further embodiments according to the invention, the fan wheel 21 is not connected in a rotationally fixed manner to the rotor shaft 4, but a fan motor is additionally arranged within the hood part 1, which drives the fan wheel 21.

[0068] In further embodiments according to the invention, a fan wheel 21 can be used which reverses the conveying direction of the fan wheel depending on the direction of rotation of the fan wheel 21.

[0069] In further embodiments according to the invention, the air guide part 40 is not shaped like a hollow cylinder, but rather as a nozzle, thus narrowing in the flow direction, with the flow direction in the intake area being selected away from the magnet body 22. The outer diameter of the air guide part 40 thus decreases with increasing distance from the magnet body 22. This allows for an optimized flow velocity. Alternatively, the air guide part 40 is designed as a diffuser, so that the outer diameter of the air guide part 40 increases with increasing distance from the magnet body 22. This allows for greater turbulence.

[0070] List of reference symbols

[0071] 1 hood part

[0072] 2 stator housings

[0073] 3 junction box

[0074] 4 Rotor shaft

[0075] 5 locking screw

[0076] 6 Thickening for locking screw

[0077] 7 Cable gland

[0078] 20 lids

[0079] 21 Fan wheel

[0080] 22 magnetic bodies

[0081] 23 winding

[0082] 24 spring part

[0083] 25 Bearing shield

[0084] 40 Air guide part

[0085] 41 Tab area of ​​the air guide element

[0086] 42 mother

[0087] 60 wings

Claims

Patent claims:

1. An electric motor with an electromagnetically actuated brake, in particular for braking the rotor shaft of the electric motor and / or as a holding brake for the rotor shaft of the electric motor, comprising a fan wheel and a cover part radially surrounding the fan wheel, in particular forming a housing, wherein the cover part radially surrounds the brake, in particular forming a housing, characterized in that the air flow conveyed by the fan wheel is guided in a closed circuit, and / or that the air flow conveyed by the fan wheel flows within the space radially surrounded by the cover part, in particular and by means of the cover part is separated from the ambient air, and / or that the cover part is attached to a bearing plate of the electric motor and recesses of the cover part passing through the cover part are covered by means of closure parts, in particular a cover, screw plug and / or cable gland,so that the air flow conveyed by the fan flows within the space delimited and / or bordered by the hood part together with the closure parts and the bearing plate, in particular and is separated from the ambient air surrounding the hood part and / or the electric motor.

2. Electric motor according to claim 1, characterized in that the brake has a magnetic body which is spaced apart from the fan wheel in the axial direction, in particular wherein the distance between the magnetic body and the fan wheel is greater than a quarter of the outer diameter of the fan wheel.

3. Electric motor according to one of the preceding claims, characterized in that the magnetic body is connected to the bearing plate in a rotationally fixed manner and is heat-conducting.

4. Electric motor according to one of the preceding claims, characterized in that an electrically energizable winding is accommodated in the magnetic body, in particular wherein the area covered in the radial direction by the electrically energizable winding is encompassed by the area covered in the radial direction by the fan wheel blades of the fan wheel, in particular wherein the magnetic body has an annular recess in which the winding is accommodated, in particular wherein the annular axis of the annular recess is aligned coaxially to the axis of rotation of the shaft to be braked by the brake, in particular the rotor shaft.

5. Electric motor according to one of the preceding claims, characterized in that an annular driver is fitted onto the rotor shaft of the electric motor and is connected in a rotationally fixed manner to the rotor shaft, in particular by means of a key connection, wherein a disc-shaped brake pad carrier is fitted onto the driver and has an internal toothing which engages with an external toothing of the driver, in particular so that the brake pad carrier is connected in a rotationally fixed manner to the driver and is displaceable in the axial direction, wherein an armature disk made of ferromagnetic material is connected in a rotationally fixed manner to the magnetic body, in particular by means of bolts fastened to the magnetic body, which pass through recesses in the armature disk in the axial direction, wherein spring parts supported on the magnetic body press on the armature disk,in particular so that when the winding is energized, the armature disk is pulled towards the magnetic body against the spring force generated by the spring parts and thus the brake pad carrier can run free from the braking surface and / or so that when the winding is not energized, the spring parts press the armature disk onto the brake pad carrier, which is thus pressed on its side axially facing away from the armature disk onto the braking surface formed on the bearing plate or on a friction plate connected to the bearing plate, in particular wherein the armature disk is arranged axially between the brake pad carrier and the magnetic body and / or wherein the brake pad carrier is arranged axially between the armature disk and the braking surface, in particular wherein bolts attached to the magnetic body protrude through recesses in the armature disk.

6. Electric motor according to one of the preceding claims, characterized in that an air guide part is arranged radially inside the hood part between the magnetic body and the fan wheel, in particular wherein the air guide part is arranged axially between the fan wheel and the magnetic body.

7. Electric motor according to one of the preceding claims, characterized in that the air guide part is attached to the magnet body.

8. Electric motor according to one of the preceding claims, characterized in that on the air guide part, tab regions projecting radially outwards are materially connected or are formed in one piece, which are pressed onto the magnet body by nuts screwed onto screw parts.

9. Electric motor according to one of the preceding claims, characterized in that the air guiding part is substantially hollow-cylindrical, wherein the cylinder diameter and / or outer diameter of the hollow-cylindrical air guiding part is smaller than the outer diameter of the fan wheel.

10. Electric motor according to one of the preceding claims, characterized in that radially outwardly projecting vanes are arranged and / or formed on the air guiding part, which vanes are spaced apart from one another in the circumferential direction and impose a swirl or angular momentum on the air flow conveyed by the fan wheel, in particular wherein a plurality of elevations, in particular cams, are formed on each vane, in particular on the respective vane surface of each vane.

11. Electric motor according to one of the preceding claims, characterized in that the rotor shaft of the electric motor extends axially through the air guide member, and the fan wheel is connected to the rotor shaft in a rotationally fixed manner. Advantageously, the fan can be operated passively and is thus cost-effective, or the fan wheel is driven by a fan motor.

12. Electric motor according to one of the preceding claims, characterized in that the area covered by the hood part in the axial direction comprises the area covered by the magnet body in the axial direction.

13. Electric motor according to one of the preceding claims, characterized in that thickened portions spaced apart from one another in the circumferential direction are formed on the hood part, wherein at least in one of the thickened portions a threaded bore extending radially through the hood part is introduced, into which a screw plug is screwed.

14. Electric motor according to one of the preceding claims, characterized in that the fan wheel is a radial fan wheel, and / or that all recesses of the cover part are covered, and / or that the cover part has a monotonically decreasing maximum outer diameter with increasing axial distance from the bearing plate.

15. Electric motor according to one of the preceding claims, characterized in that in the circumferential direction between each two tab regions which are closest to one another in the circumferential direction, the hood part has such a distance from the magnetic body that an air flow flows axially between the hood part and the magnetic body radially inwards, in particular into the spatial region arranged radially inside the hood part and radially outside the rotor shaft.

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