DE102019215531A1 - Electric machine with a cooling function - Google Patents

Abstract

In the case of an electrical machine (100) with associated power electronics (150) and a motor housing (105) in which a motor unit (110) is arranged, a heat sink (130) is attached to one end face (107) of the motor housing (105), which has at least one cooling channel (140) open towards the end face (107) in order to enable the end face (107) to be cooled by a cooling liquid flowing along it, the cooling body (130) being liquid-tight from the at least one cooling channel (140) forms separate receptacle (135) which is at least partially surrounded by the at least one cooling channel (140), and wherein the receptacle (135) is designed to at least partially accommodate the associated power electronics (150).

Description

State of the art

The present invention relates to an electrical machine with associated power electronics and a motor housing in which a motor unit is arranged, a heat sink being attached to one end face of the motor housing. The present invention also relates to a corresponding heat sink.

Such an electrical machine with associated power electronics and a motor housing in which a motor unit is arranged is known from the prior art. In this electrical machine, the associated power electronics and the motor unit are cooled via a heat sink arranged on the motor housing, in particular a heat sink arranged on an end face of the motor housing. This has a liquid-tight cooling channel that is separate from the motor housing and through which a cooling liquid is passed through the heat sink.

Disclosure of the invention

The present invention relates to an electrical machine with associated power electronics and a motor housing in which a motor unit is arranged. A cooling body is attached to one end face of the motor housing, which has at least one cooling channel open towards the end face in order to enable the end face to be cooled by a cooling liquid flowing along it. The cooling body forms a receptacle which is separated from the at least one cooling channel in a liquid-tight manner and which is surrounded at least in sections by the at least one cooling channel. The receptacle is designed to at least partially accommodate the associated power electronics.

The cooling channel of the cooling body, which is open towards the end face, makes it possible to provide a compact electrical machine which advantageously requires little installation space. In this way, improved cooling of the motor housing can be achieved, since the cooling liquid flowing through the heat sink is in direct contact with the end face of the motor housing. By using the end face to close the cooling channel in a liquid-tight manner towards the motor housing, moreover, material for forming the cooling body can be saved.

According to one embodiment, the at least one cooling channel is provided with a multiplicity of cooling nipples.

A corresponding cooling function implemented by the heat sink can thus be further improved.

The at least one cooling channel preferably forms a plurality of cooling basins.

Thus, an area formed by the cooling channel for cooling the motor housing can be enlarged in a simple manner.

The plurality of cooling basins is preferably fluidically connected to one another via a plurality of connecting channels.

This enables the cooling liquid to be passed on between adjacent cooling basins in the cooling channel in a simple and uncomplicated manner.

The plurality of cooling nipples is preferably arranged in the plurality of cooling basins.

In this way, cooling that can be achieved via the cooling nipple can be further improved.

The plurality of connection channels preferably has a plurality of deflection elements in order to enable a cooling liquid flowing through the plurality of connection channels to be deflected from the plurality of connection channels into the plurality of cooling basins.

In this way, the cooling liquid flowing through the cooling basin, which flows into the cooling basin from the connecting channels, can be ensured in order to increase a corresponding cooling by the cooling liquid.

According to one embodiment, the cooling body has an inlet opening to allow cooling liquid to be introduced into the at least one cooling channel, and at least one outlet area to allow the cooling liquid to flow out of the at least one cooling channel. The at least one cooling channel spans an angular range of at least 180 ° between the inlet opening and the at least one outlet area.

A comparatively large angular range of the heat sink can thus be used in a simple manner to implement a suitable cooling function.

According to one embodiment, the heat sink is connected to the motor housing in a liquid-tight manner, in particular by welding.

This means that the use of additional components, such as seals and suitable fasteners, can advantageously be dispensed with, which would otherwise be required to seal the heat sink relative to the motor housing and to attach the heat sink to the motor housing. It should be noted, however, that the heat sink does not necessarily have to be molded onto the motor housing, for example by welding. Rather, in a simplified form of implementation, a suitable seal with appropriate fastening means can also be used.

According to one embodiment, the motor housing is provided with a cover which closes the motor housing in a liquid-tight manner and forms the end face of the motor housing.

The motor housing can thus be closed in a simple manner in a liquid-tight manner.

In addition, the present invention relates to a heat sink for an electrical machine, to which power electronics are assigned and which has a motor housing with an end face in which a motor unit can be arranged. The heat sink has at least one cooling channel that is open along its longitudinal extension and can be attached to the end face of the motor housing in such a way that the end face closes the at least one open cooling channel along its longitudinal extension in order to allow a flow of cooling fluid to flow through the cooling channel. The cooling body forms a receptacle which is separated from the cooling channel in a liquid-tight manner and which is surrounded at least in sections by the at least one open cooling channel. The receptacle is designed to at least partially accommodate the associated power electronics.

Figure list

• 1 einen Schnitt durch eine beispielhafte elektrische Maschine mit einem Motorgehäuse, an dem ein Kühlkörper befestigt ist, gesehen entlang einer Schnittlinie I-I von 4,
• 2 einen Schnitt durch die beispielhafte elektrische Maschine von 1 mit dem Motorgehäuse, an dem der Kühlkörper befestigt ist, gesehen entlang einer Schnittlinie II-II von 4,
• 3 einen Schnitt durch die beispielhafte elektrische Maschine von 1 mit dem Motorgehäuse, an dem der Kühlkörper befestigt ist, gesehen entlang einer Schnittlinie III-III von 4,
• 4 eine perspektivische Ansicht der beispielhaften elektrischen Maschine von 1 bis 3, bei der der Kühlkörper geschnitten dargestellt ist,
• 5 eine perspektivische Ansicht des Kühlkörpers von 1 bis 4, gesehen in Richtung von seiner dem Motorgehäuse von 1 bis 4 zugewandten Unterseite, und
• 6 eine perspektivische Ansicht des Kühlkörpers von 1 bis 4, gesehen in Richtung von seiner vom Motorgehäuse von 1 bis 4 abgewandten Oberseite.

The invention is explained in more detail in the following description on the basis of exemplary embodiments shown in the drawings. Show it:

• 1 a section through an exemplary electrical machine with a motor housing to which a heat sink is attached, seen along section line II from FIG 4th ,
• 2 a section through the exemplary electrical machine from FIG 1 with the motor housing to which the heat sink is attached, viewed along a section line II-II from FIG 4th ,
• 3 a section through the exemplary electrical machine from FIG 1 with the motor housing to which the heat sink is attached, seen along a section line III-III from FIG 4th ,
• 4th FIG. 3 is a perspective view of the exemplary electric machine of FIG 1 to 3 , in which the heat sink is shown in section,
• 5 FIG. 3 is a perspective view of the heat sink of FIG 1 to 4th , viewed in the direction of its the motor housing from 1 to 4th facing bottom, and
• 6th FIG. 3 is a perspective view of the heat sink of FIG 1 to 4th , viewed in the direction of its from the engine housing from 1 to 4th facing away from the top.

Description of the exemplary embodiments

In the figures, elements with the same or comparable function are provided with identical reference symbols and are only described in more detail once.

1 shows an exemplary electrical machine 100 with a motor housing 105 . The motor housing 105 forms an interior 106 from where a motor unit 110 is arranged. The motor unit 110 includes, for example, a motor shaft 115 , which can be rotated via suitable bearing elements in the motor housing 105 is stored. The rotor shaft is an example 115 about rolling bearings 117 , 119 , in particular via ball bearings in the motor housing 105 stored and exemplarily with an assembly aid 167 provided, preferably after a corresponding assembly of the electrical machine 100 is removed from this.

It should be noted that there are no other elements of the motor unit 110 , such as a rotor and / or stator, are shown for the sake of simplicity and clarity of the drawing. Such components or components of the motor unit 110 are, however, sufficiently known to the person skilled in the art, so that it is also possible to dispense with their detailed representation.

Illustratively, the motor housing 105 a housing wall 122 , 124 on that from an outside wall 122 and an inner wall 124 is formed. This case wall 122 , 124 is at her - in 1 - lower side with a lower housing flange 125 completed. At its axially the lower housing flange 125 opposite end face 107 is the motor housing 105 preferably with a lid 120 Mistake. This closes the motor housing 105 preferably liquid-tight and here forms the end face 107 of the motor housing 105 out.

According to one embodiment, it is on the end face 107 of the motor housing 105 a heat sink 130 arranged, the at least one to the end face 107 open cooling channel 140 has to a cooling of the end face 107 by a cooling liquid flowing along it. The heat sink 130 preferably forms a liquid-tight one of the at least one cooling channel 140 separate recording 135 from that at least in sections of the at least one cooling channel 140 is surrounded. The recording 135 is preferably for at least partially accommodating associated power electronics 150 educated.

The power electronics 150 is illustratively formed by a plurality of electrolytic capacitors ("electrolytic capacitors") and is referred to below as "the electrolytic capacitors 150" to simplify the description. From the electrolytic capacitors 150 is illustratively a single capacitor separately with the reference number 151 Mistake.

The electrolytic capacitors are preferred 150 on an assigned holder 152 attached to the in the recording 135 is arranged. The holder 152 is preferably designed in the manner of a stamped grid with which the electrolytic capacitors 150 are preferably welded. The holder 152 is illustrative in the recording 135 fixed, in each case in the area between the electrolytic capacitors 150 and the heat sink 130 a suitable thermal paste can be provided. The area between the electrolytic capacitor is illustrative 151 and the heat sink 130 in the recording 135 one with the reference number 154 marked thermal paste is provided.

The electrolytic capacitors 150 are part of an electronics unit according to one embodiment 160 of the electric machine 100 . A suitable electronics unit with which the electronics unit 160 can be realized and which are electrically conductive with the electrolytic capacitors 150 is sufficiently known to the person skilled in the art, so that a detailed illustration of the electronics unit is referred to here 160 for the sake of simplicity and clarity the drawing is omitted, in particular as the electronic unit 160 as such does not form part of the present invention.

The electronics unit is illustrative 160 in a housing cover 165 arranged of an interior 168 to accommodate the electronics unit 160 trains. The housing cover is preferred 165 with the motor housing 105 connected, for example via suitable fastening means, such as screws.

In the area between the housing cover 165 and the motor housing 105 is preferably the heat sink 130 arranged. Preferably the heat sink 130 , the housing cover 165 and the motor housing 105 Releasably connected to one another via suitable fastening means, such as screws, for example. Here the heat sink 130 , as in 1 shown using suitable sealing elements, in particular sealing rings 172 , 174 , liquid-tight with the motor housing 105 be connected.

However, it should be noted that a permanent connection of the heat sink 130 with the motor housing 105 , especially on the front 107 with the lid 120 , is possible. Such a permanent connection can be achieved, for example, by welding.

Illustratively, a sealing ring seals 172 the heat sink 130 liquid-tight to the outer wall 122 of the motor housing 105 off while a sealing ring 174 the heat sink 130 liquid-tight to the lid 120 seals out, illustratively in the area of the rotor shaft 115 , which is exemplified through an opening 139 in the heat sink 130 extends through this through. The rotor shaft engages here 115 preferably in its axial direction through the heat sink 130 by.

According to one embodiment, the heat sink 130 an inlet port 131 on to an introduction of cooling liquid into the heat sink 130 , or in the at least one cooling channel 140 of the heat sink 130 to enable. This is illustrated in the area of the inlet opening 131 an inlet port 132 arranged. In addition, the heat sink 130 at least one outlet area ( 136 in 3 ) to prevent the cooling liquid from flowing out of the at least one cooling channel 140 to enable. The at least one cooling channel preferably spans 140 between the inlet port 131 and the at least one outlet area ( 136 in 3 ) a specified angular range, as in 5 described.

It is preferred in the at least one cooling channel 140 a variety of cooling nipples 145 arranged. This multitude of cooling nipples 145 serves to improve the cooling function of the heat sink 130 .

The heat sink 130 is shown below, especially at 5 and 6th , described in detail. Here represents 5 a top view of a - in 1 - lower side of the heat sink 130 is seen in the direction of an arrow V, while 6th a top view of a - in 1 - upper side of the heat sink 130 viewed in the direction of an arrow VI.

As described above, the heat sink 130 at least one outlet area ( 136 in 3 ) to prevent the cooling liquid from flowing out of the at least one cooling channel 140 of the heat sink 130 to enable. The outlet area ( 136 in 3 ) immediately be provided with an outlet nozzle. Alternatively, the outlet area ( 136 in 3 ) with an optional cooling channel 180 be connected to the one in the housing wall 122 , 124 of the motor housing 105 is trained.

The optional cooling channel is illustrative 180 in the housing wall 122 , 124 between the Outer wall 122 and the inner wall 124 who have favourited the interior 106 limited, trained. Here, the inner wall 124 for example a radially outwardly extending rib 126 on, which is preferably spirally or helically around the inner wall 124 runs and thus the preferably spiral or helical optional cooling channel 180 trains. Alternatively, the rib 126 also on the outside wall 122 be formed and extend radially inward.

The spiral or helical optional cooling channel is preferred 180 in the area of the lower housing flange 125 with an outlet port 108 Mistake. In the area of the outlet opening 108 is an example of an outlet nozzle 109 arranged to allow the cooling liquid to flow out of the optional cooling channel 180 to enable. By providing the optional cooling duct 180 can provide efficient cooling of the motor housing 105 and thus the motor unit arranged therein 110 be made possible.

2 shows the electric machine 100 of 1 in a by approximately 90 ° with respect to 1 around the rotor shaft 115 rotated view. The electric machine 100 includes, as described above, the heat sink 130 that is between the housing cover 165 and the motor housing 105 is arranged.

In contrast to 1 shows 2 suitable fasteners 210 , which are illustratively designed in the manner of screws, as well as suitable fastening means 220 , which are also illustratively designed in the manner of screws. The screws 210 preferably attach the housing cover 165 detachable on the heat sink 130 and the screws 220 preferably attach the heat sink 130 detachable on the motor housing 105 .

It should be noted, however, that alternative fasteners, such as clips, may also be used. In addition, screws with nuts can also be used instead of just screws, etc.

3 shows the electric machine 100 of 1 in a by approximately 30 ° with respect to 1 around the rotor shaft 115 rotated view. The electric machine 100 includes, as described above, the heat sink 130 that is between the housing cover 165 and the motor housing 105 is arranged.

In contrast to 1 made clear 3 an outlet area 136 of the heat sink 130 , which serves to prevent cooling liquid from flowing out of the at least one cooling channel 140 of the heat sink 130 to enable. The outlet area forms this 136 an outlet port 137 . As above at 1 mentioned, the outlet opening 137 directly to a suitable outlet connection, e.g. the outlet connection 109 of 1 , be provided so that the cooling liquid can run off directly from the heat sink 130 to enable.

According to one embodiment, the outlet opening is 137 but via a transition channel 310 with the optional cooling duct 180 of 1 connected, the one in the housing wall 122 , 124 of the motor housing 105 is trained. The cooling liquid can thus be removed from the cooling channel 140 of the heat sink 130 via the transition channel 310 in the housing wall 122 , 124 and there through the optional cooling duct 180 to the outlet opening 108 of 1 flow as described above.

It also shows 3 for example a phase wire 320 from the motor unit 110 to the electronics unit 160 leads and connects them to one another in an electrically conductive manner. The phase wire 320 is exemplified by a wire guide element 330 from the interior 106 to the housing cover 165 guided. The wire guide element 330 is preferably liquid-tight with the end face 107 or the lid 120 of the motor housing 105 connected.

4th shows the electric machine 100 of 1 to 3 with the illustrative perpendicular to the axis of rotation of the rotor shaft 115 cut heat sink 130 . Clarified here 4th corresponding section lines II, II-II and III-III, along which the sectional views of FIG 1 to 3 are realized. In particular, clarifies 4th the one to the lid 120 of the motor housing 105 open design of the at least one cooling channel 140 of 1 to 3 .

The heat sink 130 has the at least one cooling channel 140 of 1 to 3 on, which preferably has a plurality of basin-like structures 510 has, for the sake of simplicity, hereinafter referred to as “the cooling basin 510 "Are designated. These cooling pools 510 are via an assigned plurality of connection channels 520 fluidically connected to each other. Illustratively include the cooling basins 510 six cooling basins, of which only a single cooling basin with the reference number is representative 510 is provided for the sake of simplicity and clarity of the drawing. These six cooling pools 510 are via five connection channels 520 connected, again only a single connection channel with the reference symbol 520 is provided for the sake of simplicity and clarity of the drawing. Here a connection channel connects 520 two each in the circumferential direction of the heat sink 130 adjacent cooling pools 510 .

A first cooling basin is illustrative 510 in the area of the inlet port 132 , or the inlet opening 131 of 1 , arranged. The cooling channel extends from this 140 in Circumferential direction of the heat sink 130 around the recording 135 of 1 to 3 around towards the outlet opening 137 in the outlet area 136 . The at least one cooling channel spans here 140 preferably an angular range of at least 180 °, and illustratively an angular range of approximately 270 °. This angular range can, however, be adapted to specific, by the motor unit 110 or the lid 120 of the motor housing 105 of 1 to 3 predefined geometries can be modified or designed for specific applications.

5 shows the heat sink 130 of 1 to 4th , or its underside, seen from the direction of the motor housing 105 of 1 to 4th . Clarified here 5 in particular an angular range 540 between the inlet port 131 and the outlet area 136 of 4th . The angular range 540 is, for example, about 270 °, as in 4th described.

In addition, also as with 4th described, the at least one cooling channel 140 of the heat sink 130 the multitude of cooling nipples 145 according to 1 to 3 on. In addition, the at least one cooling channel has 140 prefers the cooling basin 510 on that over the plurality of connection channels 520 is fluidically connected to each other. The plurality of cooling nipples is preferred 145 in the cooling basin 510 arranged.

A single cooling basin is an example of the cooling basin 510 with the reference number 512 marked, in which an exemplary one with the reference number 146 marked cooling nipple of the multitude of cooling nipples 145 is arranged. This cooling pool 512 is illustrative of a number designated 522 provided connection channel of the plurality of connection channels 520 connected to a further cooling basin, which is illustratively denoted by the reference number 514 is marked.

The plurality of connecting channels 520 has, according to one embodiment, a plurality of deflection elements 530 to divert one through the plurality of connecting channels 520 flowing cooling liquid from the plurality of connecting channels 520 in the cooling basin 510 to enable. It can thus be ensured that the cooling liquid is targeted in each case in the cooling basin 510 is introduced and there the majority of cooling nipples 145 flows around. An example is the connection channel 522 a with the reference number 532 characterized deflection element of the plurality of deflection elements 530 intended.

According to one embodiment, the heat sink 130 in addition, a plurality of access openings 550 on. This plurality of access openings 550 serves to hold an assigned plurality of wire guide elements ( 330 in 3 ), with each of which is assigned phase wires from the motor unit 110 of 1 to 3 to the electronics unit 160 of 1 to 3 can be guided. A single passage opening of the plurality of passage openings is illustrative 550 that are used to accommodate the wire guide element 330 of 3 serves, represented by the reference number 558 marked.

6th shows the heat sink 130 of 1 to 5 , or its top, viewed from the direction of the housing cover 165 of 1 to 3 . As described above, the heat sink includes 130 the recording 135 to accommodate the electrolytic capacitors 150 of 1 to 3 . In addition, the heat sink 130 preferably with a plurality of cooling surfaces on its upper side 610 provided, which are preferably used for cooling associated power semiconductors. The cooling surfaces are for this purpose 610 according to one embodiment provided with heat dissipation elements, of which a single heat dissipation element is represented by the reference number for the sake of simplicity and clarity of the drawing 612 is provided. These heat dissipation elements 612 serve to establish a close thermal connection between the assigned power semiconductors and the heat sink 130 to enable and thus to ensure a suitable heat dissipation. The heat dissipation elements are illustrative 612 provided with direct bonded copper substrates ("DBC substrates"), which preferably carry the assigned power semiconductors and are connected to the heat sink via a suitable heat-conducting medium, eg a heat-conducting paste, a heat-conducting adhesive and / or a heat-conducting film 130 are connected. As an alternative to this, a soldered connection between the DBC substrates and the heat sink can also be used instead of the suitable heat-conducting medium 130 be provided for heat transfer.

According to one embodiment, there is also the top of the heat sink 130 optionally a plurality of axial protrusions 620 , 630 formed, which are hereinafter also referred to as "cooling domes". A first plurality of cooling domes 620 , of which, for the sake of simplicity and clarity of the drawing, only a single cooling dome is represented by the reference number 622 is marked, illustratively forms an outer, interrupted cooling dome ring on the top of the heat sink 130 . Analogously to this, a second plurality of cooling domes is formed 630 , of which, for the sake of simplicity and clarity of the drawing, only a single cooling dome with the reference number is representative 632 is marked, an inner cooling dome ring. The majority of cooling domes 620 , 630 are preferably used to store a corresponding printed circuit board of the electronics unit 160 of 1 to 3 . Thus, through the plurality of cooling domes 620 , 630 this circuit board and in particular special components that are arranged on the circuit board, such as driver modules and central processing units (“CPU”), are efficiently cooled.

Claims (10)

Electrical machine (100) with associated power electronics (150) and a motor housing (105) in which a motor unit (110) is arranged, with a heat sink (130) being attached to one end face (107) of the motor housing (105) has at least one cooling channel (140) open towards the end face (107) in order to enable the end face (107) to be cooled by a cooling liquid flowing along it, the cooling body (130) being separated from the at least one cooling channel (140) in a liquid-tight manner Forms receptacle (135) which is at least partially surrounded by the at least one cooling channel (140), and wherein the receptacle (135) is designed to at least partially accommodate the associated power electronics (150). Electric machine after Claim 1 , characterized in that the at least one cooling channel (140) is provided with a plurality of cooling nipples (145). Electric machine after Claim 1 or 2 , characterized in that the at least one cooling channel (140) forms a plurality of cooling basins (510). Electric machine after Claim 3 , characterized in that the plurality of cooling basins (510) are fluidically connected to one another via a plurality of connecting channels (520). Electric machine after Claim 2 and 4th , characterized in that the plurality of cooling nipples (145) are arranged in the plurality of cooling basins (510). Electric machine after Claim 4 , characterized in that the plurality of connection channels (520) has a plurality of deflection elements (530) in order to deflect a cooling liquid flowing through the plurality of connection channels (520) from the plurality of connection channels (520) into the plurality of cooling basins (510 ) to enable. Electrical machine according to one of the preceding claims, characterized in that the heat sink (130) has an inlet opening (131) to allow cooling liquid to be introduced into the at least one cooling channel (140), and at least one outlet area (136) to allow a To enable the cooling liquid to flow out of the at least one cooling channel (140), the at least one cooling channel (140) spanning an angular area (530) of at least 180 ° between the inlet opening (131) and the at least one outlet area (136). Electrical machine according to one of the preceding claims, characterized in that the cooling body (130) is connected to the motor housing (105) in a liquid-tight manner, in particular by welding. Electrical machine according to one of the preceding claims, characterized in that the motor housing (105) is provided with a cover (120) which closes the motor housing (105) in a liquid-tight manner and forms the end face (107) of the motor housing (105). Heat sink (130) for an electrical machine (100) to which power electronics (150) are assigned and which has a motor housing (105) with an end face (107) in which a motor unit (110) can be arranged, the heat sink (130 ) has at least one cooling channel (140) open along its longitudinal extent and can be fastened to the end face (107) of the motor housing (105) in such a way that the end face (107) closes the at least one open cooling duct (140) along its longitudinal extent in order to allow passage a flow of cooling liquid through the cooling channel (140), the cooling body (130) forming a receptacle (135) which is separated from the cooling channel (140) and which is at least partially surrounded by the at least one open cooling channel (140), and wherein the Recording (135) is designed to at least partially accommodate the associated power electronics (150).

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