WO2016180560A1

WO2016180560A1 - Electric machine having advantageous cooling

Info

Publication number: WO2016180560A1
Application number: PCT/EP2016/055522
Authority: WO
Inventors: Martin Fickert; Matthias Steinle; Barlas Turgay
Original assignee: Robert Bosch Gmbh
Priority date: 2015-05-13
Filing date: 2016-03-15
Publication date: 2016-11-17
Also published as: EP3295541A1; CN107534356B; DE102015208884A1; CN107534356A

Abstract

Proposed is an electric machine (10) which has a stator (12), a rotor (16) mounted so as to be able to rotate relative to the stator, a housing (18) and a guide (22) for cooling fluid for cooling the electric machine, which guide at least partially encircles the housing (18) around an external periphery of the housing. The electric machine is characterized in particular in that the housing (18) has, on the external periphery, a depression (20) which at least partially encircles the housing (18), wherein the guide (22) for cooling fluid is at least partially arranged in the depression (20), and the depression (20) forms, together with the guide (22), at least one at least partially encircling cooling channel (30). Thus, heat generated by the electric machine (10) can efficiently be removed via the cooling channel (20).

Description

description

title

Electric machine with advantageous cooling area of the invention

The invention relates generally to electrical machines. In particular, the invention relates to electrical machines having a fluid cooled housing.

State of the art

Electrical machines are used in a variety of industrial applications and increasingly in the automotive industry as a driver for

Used motor vehicles. In particular with regard to increased efficiency and / or increased power, electrical machines are being developed further.

With increased power of the electrical machines may also be required a comprehensive cooling and / or a comprehensive dissipation of power loss of the electrical machine. For this purpose, electrical machines in motor vehicles can have, for example, in one stationary part of the electrical machine, which may comprise a stator and / or a housing of the electrical machine, one or more cooling channels, through which cooling fluid can flow, so that losses are generated by the electrical machines Heat can be dissipated efficiently and a failure of components of the electrical machine, eg a stator winding, can be avoided by increased temperature.

Frequently, cooling channels are formed by milling in the housing or the housings are wrapped with a prefabricated cooling device. Also, cooling channels can be formed in a casting process of the housing. US 6,617,716 B2 discloses an electric machine having a rotor, a stator, a housing and a cooling tube, which is arranged on an outer surface of a stator core. Disclosure of the invention

Advantages of the invention

Embodiments of the present invention may advantageously enable to provide a reliable, robust, high performance, low cost, and fully cooled electrical machine. The electric machine may be, for example, an asynchronous machine or a synchronous machine. According to one aspect of the invention, an electric machine, such as a motor or a generator, is proposed, which has a stator, a rotor rotatably mounted relative to the stator about a rotation axis and a housing, which at least partially surrounds the stator and the rotor. Furthermore, the electric machine has a guide for cooling fluid for cooling the electrical machine, which rotates the housing at least partially along an outer circumference of the housing. The electric machine according to the invention is characterized in particular by the fact that the housing has on the outer circumference a recess which at least partially surrounds the housing, wherein the guide for cooling fluid is at least partially disposed in the recess. The recess forms together with the guide at least one at least partially surrounding the housing cooling channel. For example, the guide may be at least partially open in the direction of an outer surface of the housing arranged within the recess of the housing, and the outer surface may form the cooling channel together with the guide.

In other words, a cooling channel closed radially in both directions can be formed by the guide and the outer surface. As a result, it can be ensured that cooling fluid arranged in or flowing into the cooling channel can be in direct contact with the housing and / or the outer surface of the housing along the outer circumference. Thus, thermal contact resistance at junctions between the housing , ,

and the cooling channel can be avoided, which can arise in conventional electric machines such as air-filled gaps between the housing and the cooling channel. Such gaps can act as a thermal resistance in conventional electric machines due to a low thermal conductivity of air and cause temperature increases.

Accordingly, according to the invention, an efficiently and comprehensively cooled as well as durable and robust electric machine can be provided. Also can be increased by the advantageous and improved removal of heat, a power of the electric machine and a failure of components of the electric machine can be avoided by increasing the temperature.

Furthermore, the electric machine can be produced inexpensively and easily by the inventive design of the cooling channel, since the cooling channel is not introduced as in conventional electric machines in complex and complicated milling processes in the housing.

The guide can be designed at least partially open, in particular over an entire length of the guide in the direction of the outer surface of the housing. The guide may, for example, designate a profile and / or insert partially configured in the transverse direction at least partially open, which may be inserted into the recess as a separate component of the electric machine. The outer surface arranged inside the depression can be directed toward an outside of the electric machine and / or in the direction of the guide.

According to one embodiment of the invention, the guide has at least one barrier rib which extends in the longitudinal direction of the guide, wherein the barrier rib at least partially surrounds the housing along the outer periphery and is arranged between an outer surface of the housing and an inner surface of the guide opposite this outer surface, and wherein a plurality of channels for cooling the electric machine is formed by the guide, the at least one separating rib of the guide and the outer surface of the housing. The channels may denote sub-channels and / or microchannels of the cooling channel. In other words, the cooling channel can be divided by the at least one barrier rib into at least two microchannels. In particular, the guide may include a plurality of

Have substantially parallel to each other separating ribs, so that - -

the cooling channel can be divided into a plurality of microchannels. By means of the at least one barrier rib, a cooling surface in contact with the cooling fluid can advantageously be increased, so that heat generated by losses can be efficiently dissipated. The barrier rib can extend over at least part of a length, preferably over the entire length, of the guide.

According to one embodiment of the invention, the guide has a plurality of mutually parallel groove-shaped channels, which are designed to be open towards one side, for example in the direction of the outer surface of the housing, and abut with this open side on an outer surface of the housing arranged in the recess. The outer surface of the housing may designate an outer surface of the recess. Due to the channel-shaped configuration of the channels, a cooling surface can advantageously be increased.

According to one embodiment of the invention, the barrier rib and the guide are made in one piece. On the one hand, this can increase the stability and robustness of the electrical machine and, on the other hand, simplify manufacture of the electrical machine.

According to one embodiment of the invention, the guide is made of metal and / or plastic. In particular, the guide can be made of steel or

Be made of aluminum. According to one embodiment of the invention, the guide is made of sheet metal with a wall thickness of 0.5 mm to 2.0 mm. In this way, the guide can be made stable and produced inexpensively.

According to one embodiment of the invention, the guide is welded to the housing and / or glued. For example, the guide can be welded and / or glued to a boundary or flank of the recess of the housing. In this way, the guide can be stably fixed in the recess of the housing and / or fixed. Also, the cooling channel can be advantageously and reliably sealed by welding and / or gluing the guide, without further sealing elements must be mandatory. According to one embodiment of the invention, the recess and the guide circulate the housing along the outer circumference annularly or spirally. The housing may also have a plurality of annularly circumferential guides and / or depressions.

According to one embodiment of the invention, the electrical further comprises a sealing housing for fixing the guide in the recess of the housing, wherein the sealing housing, the housing and the guide can rotate on the outside, and wherein the sealing housing closes the recess. The sealing housing may be made of metal and / or plastic, for example, and on the

Housing be pushed. An inner diameter of the sealing housing can be made smaller than an outer diameter of the guide, so that the guide can be pressed by the sealing housing in the direction of the outer surface of the housing. On the one hand, this can increase the stability of the electric machine and, on the other hand, the cooling channel can thus be further sealed.

According to one embodiment of the invention, the sealing housing is welded to the housing and / or the guide and / or glued. In this way, the sealing housing can be stably fixed to the housing and / or a sealing of the cooling channel can be provided by the welding or gluing.

According to one embodiment of the invention, at least one sealing element for sealing the cooling channel is arranged between the guide and the sealing housing, wherein the sealing element, the housing at least partially, preferably completely, rotates. The sealing element can be configured as an O-ring, for example, which can rest against a boundary or flank of the recess, the guide and / or the sealing housing, so that the cooling channel can be reliably sealed. The electric machine can also be a

Have a plurality of sealing element, which e.g. can be arranged on two opposing edges or walls or flanks of the recess, so that the cooling channel can be sealed on two opposite sides.

According to one embodiment of the invention, the sealing housing has an inlet for introducing cooling fluid into the cooling channel and an outlet for - -

Discharging cooling fluid from the cooling channel. For example, a pump device may be suitably connected to the inlet and / or the outlet so that a flow of cooling fluid through the cooling channel can be ensured and heat can be dissipated efficiently.

It should be noted that some of the possible features and advantages of the electric machine herein with respect to different ones

Embodiments are described. A person skilled in the art recognizes that the

Characteristics can be suitably combined, adapted or replaced in order to arrive at further embodiments of the invention.

Brief description of the drawings

Embodiments of the invention will now be described with reference to the accompanying drawings, in which neither the drawings nor the description are to be construed as limiting the invention.

Fig. 1 shows a longitudinal section through an electrical machine according to an embodiment of the invention.

Fig. 2 shows a perspective view of a part of a housing for an electric machine according to an embodiment of the invention.

Fig. 3 shows a longitudinal section through a part of an electric machine according to an embodiment of the invention.

The figures are only schematic and not to scale. Like reference numerals in the figures designate the same or equivalent

Characteristics.

Embodiments of the invention

Fig. 1 shows a longitudinal section through an electrical machine 10 according to an embodiment of the invention.

The electric machine has a stator 12 and a rotor 16 rotatably mounted relative to the stator 12 about a rotation axis 14. The electric machine , ,

10 may be, for example, a permanent-magnet synchronous machine or an asynchronous machine excited via stator windings integrated in the stator 12. The rotor 16 may, for example, have a disk pack with a plurality of laminations stacked one above the other in the longitudinal direction of extension of the electric machine 10.

Furthermore, the electric machine 10 has a housing 18 which at least partially surrounds the stator 12 and the rotor 16. In particular, the housing 18 may surround the stator 12 and the rotor 16 in an annular manner. The housing 18 may be made of metal and / or plastic.

The housing 18 has on an outer circumference of the housing 18 and / or the electric machine 10 has a recess 20, which surrounds the housing 18 at least partially along the outer periphery. In particular, the recess 20, the housing 18 annular or spiral partially or completely rotate. The housing 20 may also include a plurality of in

Longitudinal extension direction spaced recesses 20 have. Furthermore, the electric machine 10 has a guide 22, which is designed to guide a cooling fluid for cooling the electric machine 10 in the housing 18. The guide 22 is at least partially, in particular completely, arranged and / or received in the recess 20 of the housing 18, the guide 22 partially or completely circumscribing the housing 18 on the outer circumference. The guide 22 may be designed as an insert, for example, which can be inserted or introduced into the recess 20. The guide 22 may be made of metal, such as aluminum and / or steel, and / or plastic. According to the configuration of the recess 20, the guide 22 can

Housing 18 thereby rotate annularly or spirally on the outer circumference. If the housing 18 has a plurality of recesses 20 spaced apart from one another in the longitudinal extension direction of the electric machine 10, such a guide 22 can be arranged in each or in a part of the recesses 20. , ,

The guide 22 can be glued to the housing 18 and / or welded, so that the guide 22 can be reliably fixed in the recess 20.

For example, at least one edge 24 of the guide 22, which may designate approximately one longitudinal side of the guide 22, be glued to a flank 26 or a boundary or a wall of the recess 20 and / or welded. In particular, two edges 24 of the guide 22 which lie opposite one another in the longitudinal direction of extension of the electric machine 10 can be adhesively bonded and / or welded to one flank 26 of the depression 20. The guide 22 may alternatively or additionally be glued and / or welded to other areas of the recess 20 and / or the housing 18.

The guide 22 is designed at least partially open in the direction of an outer surface 28 of the housing 18, which is directed radially outward with respect to the electric machine 10, and lies at least partially open on the outer surface 28. The outer surface 28 is arranged in the recess 20. The outer surface 28 of the housing 18 forms, together with the guide 22, a cooling channel 30, which is designed to be flowed through by cooling fluid. The guide 22 can thus be considered as a profile which is configured at least partially open on a longitudinal side 23 adjoining the outer surface 28 and / or on this at least partially adjacent part, and which at least partially, in particular, on a longitudinal side 25 opposite the longitudinal side 23 completely, closed designed. In this way it can be ensured that the cooling fluid is always in direct contact with the outer surface 28 of the housing 18 and thermal resistances, for example due to air inclusions or gaps, can be avoided.

The guide 22 has a plurality of in the longitudinal direction of the electric machine 10 and in the transverse direction of the guide 22 spaced-apart separating ribs 32, which between the outer surface 28 of

Housing 18 and one of the outer surface 28 opposite inner surface 34 of the guide 22 are arranged. By the separating ribs a plurality of parallel trough-shaped channels 38 are formed, which are open to one side and bear with this open side on an at least partially disposed in the recess 20 outer surface 28 of the housing 18. The channels, for example, each have a U-shaped or V-shaped

Cross-section. , ,

The separating ribs 32 extend substantially parallel to one another in the longitudinal direction of the guide 22 over at least part of a length of the guide 22. Preferably, the separating ribs 32 extend over an entire length of the guide 22 and rotate around the housing 10 at least partially annularly analogous to the guide 22 or spiral. The separating ribs 32 are preferably in each case with one end on the outer surface 28 and with a further end opposite the end of the inner surface 34 of the guide 22 at. The barrier ribs 32 may also be spaced from the

Outer surface 28 between the outer surface 28 and the inner surface 34th

be arranged. The separating ribs 32 are formed integrally with the guide 22. Alternatively, the separating ribs 32 can also be glued and / or welded as separate components to the guide 22 and / or the housing 18. As can be clearly seen in FIG. 1, the separating ribs 32 are formed by reshaping and / or bending the guide 22 so that the edges 24 of the guide 22 each have a separating rib 32 directly adjacent to the longitudinal direction of the electric machine 10 or two each in the longitudinal direction the electric machine 10 directly adjacent separating ribs 32 together with the inner surface 34 of the guide 22 each form a in the direction of the outer surface 28 open U-shaped profile 36. The U-shaped profiles 36 in turn in each case together with the outer surface 28 a channel 38 or

Microchannel, which is designed to be flowed through by cooling fluid. In other words, the separating ribs 32 divide the cooling channel 30 into a plurality of channels 38 arranged side by side in the longitudinal direction of the electric machine 10 and arranged in the recess 20. a cooling surface of the guide 22, which may be in contact with cooling fluid can be increased.

In accordance with the above, the guide 22 has a cross-section with several in the longitudinal extension of the electrical

Machine juxtaposed U-shaped areas, which are open in the direction of the outer surface 28 respectively. The guide 22 may also have a cross-section with opened in the direction of the outer surface 28 V-shaped, polygonal, angular, rounded or any differently designed areas. The guide 22 can be made in one piece or it can also such areas connected to each other, for example, glued and / or welded, to form the guide 22. - -

For sealing the cooling channel 30 and / or the channels 38 and for fixing the guide 22 in the recess 20, the electric machine 10 further comprises a sealing housing 37 which surrounds or encloses the housing 18 and / or the guide 22 on the outside. An outer diameter of the guide 22 may be configured smaller than an inner diameter of the sealing housing 37, so that the guide 22 can be pressed by the sealing housing 37 against the outer surface 28 of the housing 18. The sealing housing 37 can be pushed onto the housing 18, for example, and welded to the housing 18 at each end face 39 of the sealing housing 37 and / or adhesively bonded. Also, the sealing housing 37 may be glued to the guide 22 and / or welded.

FIG. 2 shows a perspective view of a housing 18 for an electric machine 10 according to an embodiment of the invention. Unless otherwise described, the housing 18 of FIG. 2 may have the same elements and features as the housing 18 of FIG. 1.

As clearly shown in Fig. 2, the recess 20 does not completely surround the housing 18, but the recess 20 is interrupted by a portion 40 of the housing 18 or two ends of the recess 20 are separated and / or spaced apart by the portion 40. Also, the guide 22 circumscribes the housing 18 only partially, with one end 42 and another end 43 of the guide 22 each spaced from the region 40, so that between the end 42 of the guide 22 and the region 40, an inlet 44 for introducing Cooling fluid is formed in the cooling passage 30. Between the further end 43 of the guide 22 and the region 40, an outlet 46 for discharging cooling fluid from the cooling channel 30 is further formed. The inlet 44 and / or the outlet 46 may, for example, to a cooling circuit with a

Pump device to be connected. For this purpose, for example, a suitable valve and / or a suitable connecting element can be provided at the inlet 44 and / or the outlet 46.

Fig. 3 shows a longitudinal section through a part of an electric machine 10 according to an embodiment of the invention. Unless otherwise described, the electric machine 10 of FIG. 3 may have the same elements and features - -

as the housing 18 of FIG. 2 and / or the electric machine 10 of FIG. 1.

For sealing the cooling channel 30, the electric machine 10 of FIG. 3 has two sealing elements 48, which between the guide 22 and the

Seal housing 37 are arranged. The sealing element 48 may be received in each case between one of the edges 24 and one of the flanks 26 of the recess 20. The sealing elements 48 can thereby at least partially circulate the housing 18 along the outer circumference analogously to the guide 22. The sealing elements 48 may be as an O-ring made of an elastomer, e.g. Silicone, plastic and / or rubber, be made.

Finally, it should be noted that terms such as "comprising," "comprising," etc., do not exclude other elements or steps, and terms such as "a" or "an" do not exclude a multitude. Reference signs in the claims are not to be considered as limiting.

Claims

claims

An electric machine (10), comprising:

a stator (12);

a rotor (16) rotatably mounted relative to the stator about an axis of rotation (14); a housing (18) which at least partially surrounds the stator (12) and the rotor (16); and

a cooling fluid guide (22) for cooling the electric machine (10) which rotates the housing (18) at least partially along an outer circumference of the housing (18);

characterized in that

the housing (18) has on the outer circumference a depression (20) which at least partially surrounds the housing (18),

wherein the guide (22) for cooling fluid is at least partially disposed in the recess (20), and

wherein the depression (20) together with the guide (22) forms at least one at least partially circumferential cooling channel (30).

2. Electric (10) machine according to claim 1,

wherein the guide (22) has at least one separating rib (32) which extends in the longitudinal direction of extension of the guide (22),

said barrier rib (32) at least partially circumscribing said housing (18) along said outer circumference and disposed between an outer surface (28) of said housing (18) and an inner surface (34) of said guide (22) opposite said outer surface (28); and

wherein a plurality of channels (38) for cooling the electric machine (10) is formed by the guide (22), the at least one barrier rib (32) of the guide (22) and the outer surface (28) of the housing (18).

3. Electrical machine (10) according to any one of the preceding claims, wherein the guide (22) has a plurality of parallel trough-shaped channels (38) which are formed open to one side and with this open side at an at least partially in the recess (20) arranged

Outer surface (28) of the housing (18) abut.

4. Electric (10) machine according to claim 2,

wherein the barrier rib (32) and the guide (22) are made in one piece.

5. Electrical machine (10) according to one of the preceding claims, wherein the guide (22) made of metal, in particular aluminum, and / or from

Plastic is made.

6. Electrical machine (10) according to any one of the preceding claims, wherein the guide (22) is made of sheet metal with a wall thickness of 0.5 mm to 2 mm.

7. Electrical machine (10) according to one of the preceding claims, wherein the guide (22) welded to the housing (18) and / or glued.

8. Electrical machine (10) according to any one of the preceding claims, wherein the recess (20) and the guide (22) rotate around the housing (18) along the outer circumference annular or spiral.

9. Electrical machine (10) according to one of the preceding claims, further comprising:

a sealing housing (37) for fixing the guide (22) in the recess (20) of the housing, wherein the sealing housing (37) closes the recess (20).

10. Electrical machine (10) according to claim 9,

wherein the sealing housing (37) with the housing (18) and / or the guide (22) is welded and / or glued.

11. Electrical machine (10) according to claims 9 and 10,

wherein between the guide (22) and the sealing housing (37) at least one sealing element (48) for sealing the cooling channel (30) is arranged, wherein the sealing element (48) at least partially surrounds the housing (18).

12. Electrical machine (10) according to one of claims 9 to 11,

wherein the sealing housing (37) has an inlet (44) for introducing cooling fluid into the cooling passage (30) and an outlet (46) for discharging cooling fluid from the cooling passage (30).