Drive comprising an electric motor having a connection box

Abstract

The invention relates to a drive comprising an electric motor having a connection box, wherein: the electric motor comprises a motor housing which comprises a stator housing, an end shield and a bearing flange; the connection box comprises a lower part arranged on the stator housing and comprises an upper part mounted on the lower part; a power module of a set of power electronics is accommodated in the lower part; and a fan impeller which is surrounded at least by a fan cowl conveys air, which has been drawn in axially through grille openings in the fan cowl, in a radial direction into an annular space region from which air emerges both through a gap formed between the fan cowl and the stator housing along cooling fins of the stator housing and also through ventilation slots in the fan cowl.

Description

[0001] drive comprising an electric motor with a junction box

[0002] Description:

[0003] The invention relates to a drive comprising an electric motor with a terminal box.

[0004] It is generally known that an electric motor has a terminal box in which a supply cable and the stator winding connection lines are routed.

[0005] From DE 102005 032 968 A1, a converter motor is known as the closest prior art.

[0006] An engine is known from the JP H11 - 234 954 A.

[0007] The invention is therefore based on the objective of further developing a drive system that is as compact and powerful as possible.

[0008] According to the invention, the problem is solved in the drive according to the features specified in claim 1.

[0009] Important features of the invention for the drive are that the drive comprises an electric motor with a terminal box, wherein the electric motor has a motor housing which includes a stator housing, a bearing shield and a bearing flange, wherein the terminal box has a lower part which is arranged, in particular laterally, on the stator housing, and an upper part mounted on the lower part, wherein a power module of power electronics is accommodated in the lower part, wherein a fan wheel, at least surrounded by a fan cover, conveys air drawn in axially through grille openings of the fan cover in a radial direction into an annular space area, from which air exits on the one hand through a gap formed between the fan cover and the stator housing along cooling fins of the stator housing and on the other hand, in particular in the opposite direction or in a transverse direction to the airflow exiting through the gap along the cooling fins,through ventilation slots in the fan housing, in particular those formed between the fan housing and the lower part, in particular wherein the annular space area is radially surrounded by the fan housing and the lower part and / or wherein the annular space area radially surrounds the fan wheel, in particular wherein the fan wheel is rotationally fixed to a rotor shaft of the electric motor, in particular which is rotatably mounted via a first bearing received in a bearing shield and via a second bearing received in a bearing flange, in particular wherein the stator housing is connected to the bearing shield and to the bearing flange and wherein the bearing flange and the bearing shield are spaced apart from each other.

[0010] An advantage of this design is that the air flowing out of the annular space does not flow in a single direction, but in different directions, thus achieving a more uniform airflow through the annular space, particularly in the area where the lower section, acting as a heat sink, dissipates heat. This enables efficient removal of the waste heat from the power module, allowing the drive to be designed to be compact and efficient or high-performance.

[0011] In an advantageous embodiment, the power module rests against a region of the lower part, particularly the trough-shaped lower part, wherein this region has a thicker wall than the rest of the lower part, especially outside of this region. It is advantageous that the heat loss from the power module can be dissipated directly to the airflow in the annular space via the lower part and its area acting as a heat sink, wherein the area acting as a heat sink has cooling fingers formed on the lower part.

[0012] In an advantageous embodiment, cooling fins and / or, in particular, dome-shaped cooling fingers are formed on the lower part, projecting into the annular space. This is advantageous because it enables efficient dissipation of the waste heat from the power module. In particular, a low thermal resistance can be achieved because the cooling fingers have a high surface area to volume ratio.

[0013] In an advantageous embodiment, the air exiting through a first of the fan slots moves away from the stator housing, particularly in the opposite direction to the axial direction, or flows away. This is advantageous because it allows for a more uniform airflow around the cooling fingers, thus reducing hotspots and temperature gradients in the area of ​​the lower part that acts as a heat sink.

[0014] In an advantageous embodiment, a first of the ventilation slots is arranged and oriented such that the air exiting through the first of the ventilation slots flows away from the stator housing and / or flows in the opposite direction to the axial direction, in particular wherein the air exiting along the cooling fins of the stator housing flows parallel to the axial direction away from the fan wheel or moves away from the fan wheel. It is advantageous that the air flows out in different, in particular opposite, directions. Thus, the overpressure built up in the annular space by the fan wheel dissipates in different directions, resulting in a more uniform flow in the area of ​​the cooling fins.

[0015] In an advantageous embodiment, air exiting through a second of the fan slots flows transversely and / or perpendicularly to the axial direction between the lower part and the fan housing, particularly towards the surrounding environment, out of the annular space. The advantage here is that the overpressure built up by the fan wheel in the annular space is dissipated in different directions, thereby homogenizing the airflow around the cooling fingers of the lower part's heat sink area. This prevents the formation of excessively large temperature gradients in this area.

[0016] In an advantageous embodiment, the power module is mounted on a printed circuit board of the power electronics. This enables cost-effective mass production and allows for efficient heat dissipation from the power module via the base. In another advantageous embodiment, the power module comprises power semiconductor switches arranged in parallel half-bridges, particularly for forming an inverter arrangement. The advantage here is that a plurality of power semiconductors are integrated into the power module, thus enabling cost-effective manufacturing and efficient heat dissipation. Preferably, the power module has a ceramic plate on one of its outer surfaces, which is pressed against the inner surface of the metallic base, thereby transferring the heat loss to the base with a low thermal resistance.

[0017] In an advantageous embodiment, the cooling fins of the stator housing project into and / or through the gap, particularly in the axial direction. An advantage of this is that the exiting airflow absorbs heat loss from the stator and dissipates it to the surroundings.

[0018] In an advantageous embodiment, cooling fingers, particularly dome-shaped ones, project into the annular space area from the lower part, particularly in the area of ​​the fan wheel. This design is advantageous because it allows for efficient dissipation of heat loss from the power electronics into the annular space.

[0019] In an advantageous embodiment, signal electronics are arranged in the upper part and are plugged into a mating connector of the power electronics via an electrical connector, particularly wherein the mating connector is mounted on the circuit board of the power electronics. An advantage of this is that the signal electronics can be easily and quickly replaced. Signal electronics with one functionality can be exchanged for signal electronics with a second functionality.

[0020] In an advantageous embodiment, the grille openings of the fan housing have a smaller radial distance to the axis of rotation of the rotor shaft than the ventilation slots, particularly where the maximum radial distance of the fan wheel to the axis of rotation of the rotor shaft is smaller than the radial distance of the ventilation slots and larger than the minimum radial distance of the ventilation slots. It is advantageous that the air is drawn in radially further inward than the ventilation slots through which the air flows out. This enables efficient airflow.

[0021] In an advantageous embodiment, the stator housing radially surrounds a stator winding supplied by the power electronics including the power module, in particular wherein the signal electronics generate pulse-width modulated control signals for the power semiconductor switches, in particular wherein the current supplied to the stator winding by the power module is detected and the control signals for the power semiconductor switches are generated such that the detected current, in particular the actual current value, is regulated by the signal electronics to a setpoint current value. It is advantageous that the stator winding is protected in this arrangement.

[0022] In an advantageous embodiment, the fan cover rests against the lower part, with the ventilation slots being designed as recesses in the fan cover located between the lower part and the fan cover. An advantage of this design is that the ventilation slots can be produced simply and without additional effort by shaping the edge of the fan cover, specifically by creating recesses along its edge.

[0023] In a preferred design, the fan housing is manufactured as a plastic injection-molded part. The advantage here is that it allows for simple and cost-effective production.

[0024] In a preferred embodiment, the lower part is made of metal, in particular aluminum. The advantage here is that high thermal conductivity is achieved, thus enabling efficient heat dissipation from the power module.

[0025] Further advantages arise from the dependent claims. The invention is not limited to the combination of features in the claims. For those skilled in the art, further meaningful combinations of claims and / or individual claim features and / or features of the description and / or the figures will become apparent, particularly from the problem statement and / or the problem arising from a comparison with the prior art. The invention will now be explained in more detail with reference to schematic illustrations.

[0026] Figure 1 shows a longitudinal section through a drive according to the invention, in particular an inverter motor, which has a terminal box.

[0027] Figure 2 shows an oblique view of the drive from a first viewing direction.

[0028] Figure 3 shows an oblique view of the drive from a second viewing direction.

[0029] Figure 4 shows an exploded view of the drive.

[0030] Figure 5 shows a lower part 9 of the terminal box in oblique view.

[0031] As shown in the figures, the drive has an electric motor, in whose connection box an inverter or converter is integrated, which supplies the electric motor.

[0032] A fan wheel 11 is connected in a rotationally fixed manner to a rotatably mounted rotor shaft 4 of the electric motor and drives an airflow which flows past cooling fingers of a lower part of the connection box which also functions as a heat sink.

[0033] The fan wheel 11 draws in the airflow from an axial direction and conveys the airflow in a radial direction, in particular into an annular space area radially surrounding the fan wheel 11. The drawn-in airflow passes through grille openings of a fan hood 12, in particular wherein the grille openings are arranged on the end face, in particular on the B-side, of the fan hood 12.

[0034] The airflow conveyed by the fan wheel 11 causes an increased air pressure at the radial outer circumference of the fan wheel 11, particularly in the annular space. Thus, the air flows out of the annular space through ventilation slots 19 of the fan housing 12 into the surrounding environment and also along cooling fins of the stator housing 2 of the electric motor, the fan housing 12 at least partially surrounding the stator housing 2. The stator housing 2 surrounds a stator winding 3, within which the active part 5, located on the rotor shaft 4, is arranged and rotatably connected to the rotor shaft 4.

[0035] The rotor shaft 4 is rotatably mounted via a first bearing 7, which is received in a bearing flange 6, and via a second bearing 8, which is received in a bearing shield.

[0036] The stator housing 2 is arranged between the bearing flange 6 and the bearing shield 1. The bearing shield 1 and the bearing flange 6 are both connected to the stator housing 2, in particular the bearing flange 6 being spaced apart from the bearing shield 1.

[0037] A lower part 9 of the terminal box is arranged on the stator housing 2, in which power electronics including a power module 16 are accommodated.

[0038] A top part 10 is placed on the bottom part 9, and together with the bottom part 9, it forms the terminal box. A supply line is led from the surroundings, in particular through a cable gland, into the terminal box to a connection area 14, which is also located in the bottom part 9 and includes connection elements that electrically connect contact elements of the power electronics 15 to the stator winding wires of the stator winding.

[0039] The power electronics 15 including power module 16 are designed as inverters, with the inverter feeding the stator winding.

[0040] For this purpose, the power module 16 has three half-bridges connected in parallel to each other and supplied from an intermediate circuit voltage, in particular DC voltage.

[0041] Each of the half-bridges has a series connection of semiconductor switches that are controlled by pulse-width modulated control signals generated by a signal electronics unit 17, which is housed in the upper part 10 of the terminal box. The signal electronics unit 17 is connected to the power electronics unit via a connector 18.

[0042] The power electronics preferably also include at least one capacitor for

[0043] Smoothing of the intermediate circuit voltage supplying the power module 16, which is provided by a rectifier of the power electronics, in particular of the power module 16.

[0044] Preferably, the power electronics 15 comprises a printed circuit board on which the power module 16 is mounted, wherein the side of the power module 16 facing away from the printed circuit board rests against the inside of the base 9. Thus, the heat generated by the power module 16 is dissipated to the base 9.

[0045] The wall thickness of the preferably trough-shaped lower part 9 is reinforced and / or thickened in the area of ​​contact with the power module 16.

[0046] The thickened area also serves as the base plate of a heat sink 13, whose cooling fingers or fins project towards the fan wheel 11 and thus into the airflow conveyed by the fan wheel 11. In this way, the heat from the lower part 9 can be dissipated to the environment via the airflow conveyed by the fan wheel 11.

[0047] The signal electronics 17 are cooled to the environment via the upper part 10.

[0048] The rotor shaft 4 protrudes on the side of the bearing 8, which is housed in the bearing shield 1, facing away from the active part 5 and the stator winding 3 in the axial direction, so that the fan wheel 11 is mounted on this protruding area of ​​the rotor shaft.

[0049] The area covered by the heat sink in the axial direction overlaps with the area covered by the fan wheel 11 in the axial direction.

[0050] The area covered in the axial direction by the thickened wall area of ​​the lower part 9 also overlaps with the area covered in the axial direction by the fan wheel 11.

[0051] The area covered by the power module 16 in the axial direction overlaps with the area covered by the fan wheel 11 in the axial direction.

[0052] The trough-shaped lower part 9 has a recess in its base through which the connection area projects. The lower part 9 projects beyond the fan housing 12. In particular, the area covered by the lower part 9 in the axial direction overlaps with the area covered by the fan housing 12 in the axial direction and with the area covered by the stator housing in the axial direction.

[0053] Cooling fins protrude radially outwards from the stator housing 2 and extend in an axial direction.

[0054] Between the lower part 9 and the cooling fins of the stator housing 2, channels extending in the axial direction are formed through which the airflow conveyed by the fan wheel 11 flows. Additionally, an airflow flows into the surroundings through the ventilation slots 19, ensuring that the cooling fingers projecting radially into the space surrounding the fan wheel 11 are exposed to the airflow as evenly as possible.

[0055] One of the ventilation slots 19 is open on the B-side. Thus, air flows out through this first ventilation slot 19 in the opposite direction to the air drawn in through the grille openings, and in particular also in the opposite direction to the airflow flowing out along the cooling fins of the stator housing.

[0056] A second of the ventilation slots 19 is open laterally, thus allowing air to flow out in a direction perpendicular to the axial direction.

[0057] The fan cover 12 adjoins the lower part 9 and rests against it with an edge area. The ventilation slots 19 are preferably created by recesses in this edge area of ​​the fan cover 12.

[0058] The fan hood 12 is preferably manufactured as a plastic injection molded part.

[0059] The fan wheel 11 is thus surrounded by the fan cover 12, the motor housing, and the lower part 9. The motor housing is formed from the position plate 1, the stator housing 2, and the bearing flange 6.

[0060] The lower part 9 is connected to the stator housing 2 and is in contact with it. The fan shroud 11 adjoins the lower part 9 and is separated from the stator housing 2 by a gap into which cooling fins of the stator housing project. The air conveyed by the fan wheel 11 then exits through this gap along the cooling fins of the stator housing and thus flows towards the axial front face, i.e., in the direction of the bearing flange 6. A portion of the conveyed air also exits through the ventilation slots 19, i.e., through the first ventilation slot 19 in the opposite direction to the air flowing towards the axial front face, and through the other ventilation slots 19 laterally, i.e., perpendicular to the air flowing towards the axial front face.

[0061] The ventilation slots 19 are each limited by the fan hood 12 and the lower part 9.

[0062] The area of ​​thickened wall thickness of the lower part 9 has a large heat capacity, so that peaks in heat loss can be dampened.

[0063] The ventilation slots 19 are radially outside the grille openings of the fan hood 12, in particular they have a larger radial distance to the axis of rotation of the rotor shaft 4.

[0064] In further embodiments of the invention, the fan hood has continuous recesses which also allow the conveyed air to escape. These continuous recesses are either present in addition to the ventilation slots 19 or as an alternative to them. In the latter case, the fan hood 12 then connects directly to the lower part, in particular without ventilation slots 19.

[0065] Reference symbol list

[0066] 1 Storage sign

[0067] 2 Stator housings

[0068] 3 Stator winding

[0069] 4 Rotor shaft

[0070] 5 Active part

[0071] 6 bearing flange

[0072] 7 first camp

[0073] 8 second camp

[0074] 9 Lower part of the junction box

[0075] 10. Top part of the junction box

[0076] 11 Fan wheel

[0077] 12 Fan hood

[0078] 13 heat sinks

[0079] 14 Connection area

[0080] 15 Power Electronics

[0081] 16 Power module

[0082] 17 Signal electronics

[0083] 18 connectors

[0084] 19 ventilation slots

Claims

Patent claims:

1. Drive comprising an electric motor with a terminal box, wherein the electric motor has a motor housing comprising a stator housing, a bearing shield and a bearing flange, wherein the terminal box has a lower part which is arranged, in particular laterally, on the stator housing, and an upper part mounted on the lower part, characterized in that a power module of power electronics is accommodated in the lower part, wherein a fan wheel surrounded at least by a fan cover conveys air drawn in axially through grille openings of the fan cover in a radial direction into an annular space area, from which air exits on the one hand through a gap formed between the fan cover and the stator housing along cooling fins of the stator housing and on the other hand, in particular in the opposite direction or in a transverse direction to the airflow exiting through the gap along the cooling fins, through ventilation slots of the fan cover.in particular which are formed between the fan housing and the lower part, in particular wherein the annular space area is radially surrounded by the fan housing and the lower part and / or wherein the annular space area radially surrounds the fan wheel, in particular wherein the fan wheel is rotationally fixed to a rotor shaft of the electric motor, in particular which is rotatably mounted via a first bearing received in a bearing shield and via a second bearing received in a bearing flange, in particular wherein the stator housing is connected to the bearing shield and to the bearing flange and wherein the bearing flange and the bearing shield are spaced apart from each other.

2. Drive according to claim 1, characterized in that the power module rests against a region of the lower part, in particular the trough-shaped lower part, wherein the region has a thicker wall thickness than the rest of the lower part, in particular outside the region, and / or that cooling fins and / or in particular dome-shaped cooling fingers are formed on the lower part, which project into the annular space region.

3. Drive according to one of the preceding claims, characterized in that the air exiting through a first of the fan slots flows away from or away from the stator housing, in particular in the opposite direction to the axial direction.

4. Drive according to one of the preceding claims, characterized in that a first of the ventilation slots is arranged and aligned such that the air exiting through the first of the fan slots flows away from the stator housing and / or flows against the axial direction, in particular wherein the air exiting along the cooling fins of the stator housing flows away from the fan wheel or moves away from the fan wheel parallel to the axial direction.

5. Drive according to one of the preceding claims, characterized in that air exiting through a second of the fan slots exits transversely and / or perpendicularly to the axial direction between the lower part and the fan hood, in particular towards the environment, from the annular space area.

6. Drive according to one of the preceding claims, characterized in that the power module is mounted on a printed circuit board of the power electronics.

7. Drive according to one of the preceding claims, characterized in that the power module has power semiconductor switches arranged in parallel half-bridges, in particular for forming an inverter arrangement.

8. Drive according to one of the preceding claims, characterized in that the cooling fins of the stator housing project into the gap and / or project through the gap, in particular in the axial direction.

9. Drive according to one of the preceding claims, characterized in that cooling fingers formed on the lower part, in particular on the area, projecting towards the fan wheel, in particular dome-shaped, into the annular space area.

10. Drive according to one of the preceding claims, characterized in that a signal electronics is arranged in the upper part, which is plugged into a mating connector part of the power electronics by means of an electrical connector part, in particular wherein the mating connector part is mounted on the circuit board of the power electronics.

11. Drive according to one of the preceding claims, characterized in that the grid openings of the fan hood have a smaller radial distance to the axis of rotation of the rotor shaft than the ventilation slots, in particular wherein the maximum radial distance of the fan wheel to the axis of rotation of the rotor shaft is smaller than the radial distance of the ventilation slots and is larger than the minimum radial distance of the ventilation slots.

12. Drive according to one of the preceding claims, characterized in that the stator housing radially surrounds a stator winding supplied by the power electronics including the power module, in particular wherein the signal electronics generate pulse-width modulated control signals for the power semiconductor switches, in particular wherein the current supplied to the stator winding by the power module is detected and the control signals for the power semiconductor switches are generated in such a way that the detected current, in particular the actual current value, is regulated by the signal electronics to a setpoint current value.

13. Drive according to one of the preceding claims, characterized in that the fan hood rests against the lower part, wherein the ventilation slots are designed as recesses of the fan hood arranged between the lower part and the fan hood.

14. Drive according to one of the preceding claims, characterized in that the fan hood is designed as a plastic injection molded part.

15. Drive according to one of the preceding claims, characterized in that the lower part is made of metal, in particular of aluminum.

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