CN108292878B

CN108292878B - Cooling housing for an electric machine and method for producing the same

Info

Publication number: CN108292878B
Application number: CN201680069374.6A
Authority: CN
Inventors: M.迈耶; N.萨雷姆巴; G.克鲁斯; H.杰尔登
Original assignee: Volkswagen AG
Current assignee: Volkswagen AG
Priority date: 2015-10-28
Filing date: 2016-10-14
Publication date: 2020-09-08
Anticipated expiration: 2036-10-14
Also published as: KR20180073583A; DE102015221115A1; EP3369159A1; CN108292878A; WO2017071970A1

Abstract

The cooling housing for an electric machine according to the present invention comprises: a base body (2) for accommodating the electric machine (10), wherein the base body (2) has a groove (24) on its outer surface (21) extending in the circumferential direction of the base body (2); and a curved cover element (3), which cover element (3) is mechanically coupled to the base body (2), wherein the curved cover element (3) has a first end side (32), a second end side (33) spaced apart from the first end side (32) by a cover surface (31) of the cover element (3), and an interruption (34), which interruption (34) extends along a connecting line extending over the cover surface (31) between the first end side (32) and the second end side (33) of the cover element (3) and is defined by a first connecting edge (340) and a second connecting edge (341) opposite the first connecting edge (340). The first connecting edge (340) and the second connecting edge (341) of the cover element (3) are mechanically coupled to one another and/or to the base body (2) in a fluid-tight manner, while the cover element (3) covers the recess (24) in the base body (2) and rests against the base body (2).

Description

Cooling housing for an electric machine and method for producing the same

Technical Field

The present invention relates to a cooling housing for an electric machine, for example for an automotive electric machine, and to a method of manufacturing a cooling housing for an electric machine, for example for an automotive electric machine.

Background

Housings for electrical machines face a variety of functional and mechanical requirements that they must reliably meet over the entire life cycle of the electrical machine. To dissipate the power losses occurring in the stator and in the rotor, the Electric Machine (EM) is cooled by a surrounding cooling jacket, which is a component of the machine housing (EM housing). This cooling jacket is usually integrated into the cooling circuit on the vehicle side and is flowed through by a water-glycol mixture. It is therefore critical that the cooling jacket be sealed inwardly toward the machine and outwardly throughout the life of the machine. In addition to the tightness of the cooling jacket, cost, weight and installation space requirements are critical criteria in the design of the motor housing.

It is known that housings for electrical machines are composed of a plurality of parts, wherein the cooling jacket is produced by the connection of individual components ("build-up cooling jacket").

For example, the housing may have a two-part stator carrier with a cooling structure and a tube section which covers the cooling structure and is connected in a fluid-tight manner to the stator carrier. However, this housing has a plurality of sealing points, in particular depending on the design, which are located inward in the direction of the electric machine and which have to be sealed off in an expensive manner, for example by seals, adhesives or welding. Here, leaks often occur, in particular in the direction of the electric machine, which cannot be handled or can only be handled by hand, which means high production costs.

DE 102010042259 a1, DE 102010040399 a1 and DE 102006044785 a1 each propose a housing for an electric machine having a cylindrical stator carrier and tubes which are inserted onto the stator carrier and are connected thereto, such that the tubes cover the cooling structure in the stator carrier in a fluid-tight manner. The stator carrier must be manufactured with such great precision that the tubes can be inserted onto the stator carrier and can be connected to the latter in a fluid-tight manner.

Alternatively, one-piece cast housings ("cast cooling jackets") are known. This shell is created by a core, which is usually lost, which forms the structure of the cooling water jacket. But this manufacturing method is complicated and expensive.

Disclosure of Invention

The object of the present invention is therefore to provide a cooling housing for an electric machine and a method for producing a cooling housing for an electric machine, which at least partially overcome the above-mentioned disadvantages. In particular, an advantageous and simple housing design should be provided which does not require a lost core and avoids potential cooling water leakage, in particular in the direction of the electric machine.

This object is achieved by a cooling housing for an electric machine according to claim 1 and a method for producing a cooling housing for an electric machine according to claim 9.

According to a first aspect, the invention relates to a cooling housing for an electric machine, the cooling housing comprising:

a base body for accommodating the electric machine, wherein the base body has a groove on its outer surface extending in the circumferential direction of the base body; and a curved cover element which is mechanically coupled to the base body, wherein the curved cover element has a first end side, a second end side spaced apart from the first end side by a cover surface of the cover element, and an interruption which extends along a connecting line extending over the cover surface between the first end side and the second end side of the cover element and is defined by a first connecting edge and a second connecting edge opposite the first connecting edge, wherein the first connecting edge and the second connecting edge of the cover element are mechanically coupled to one another and/or to the base body in a fluid-tight manner, and the cover element covers a recess in the base body and rests on the base body.

According to a second aspect, the present invention relates to a method for manufacturing a cooling housing for an electric machine, in particular according to the preceding requirements, comprising:

preparing a base body for receiving an electric machine, wherein the base body has, in an outer surface thereof, a groove extending in a circumferential direction of the base body;

preparing a curved cover element having a first end side, a second end side spaced apart from the first end side by a cover surface of the cover element, and an interruption extending along a connecting line extending over the cover surface between the first end side and the second end side of the cover element and being defined by a first connecting edge and a second connecting edge opposite the first connecting edge;

placing the cover element against the base body such that the cover element covers the recess; and

the first connecting edge and the second connecting edge of the cover element are mechanically coupled to one another and/or to the base body in a fluid-tight manner, while the cover element covers the recess in the base body and rests on the base body.

Further advantageous embodiments of the invention result from the dependent claims and the following description of preferred embodiments of the invention.

The cooling housing according to the invention for an electric machine comprises a base body for accommodating the electric machine, for example a stator carrier, and a curved, in particular elastic, cover element, for example a cover plate, which is mechanically coupled to the base body. The base body has in its outer surface a groove running in the circumferential direction of the base body, which groove is designed in particular such that it can be flowed through by a cooling liquid. The curved cover element, in particular after it has been placed around the base body and/or before and/or after it has been coupled to the base body, has a first end side, a second end side spaced apart from the first end side by a cover surface of the cover element, and an interruption. The interruption extends along a connecting line extending over the cover surface between a first end side and a second end side of the cover element and is defined by a first connecting edge and a second connecting edge opposite the first connecting edge. The first connecting edge and the second connecting edge of the cover element are mechanically coupled to one another and/or to the base body in a fluid-tight manner, wherein the mechanical coupling of the first connecting edge and the second connecting edge to one another and/or to the base body takes place, while the cover element is placed around the base body and rests on the base body in a manner covering the recess in the base body.

Since the connecting edge is first mechanically coupled, the cover element can be coupled in a fluid-tight manner to the base body in a simple manner, irrespective of the shape of the base body, as long as the cover element is placed on the outside around the base body. Thus, any one-piece substrate may also be used. Furthermore, the joining, in particular the welding connection, can be automated and produced in one process step with good accessibility from the outside. If a leak occurs in the case of a fluid-tight connection between the base body and the cover element or a fluid-tight connection between the connecting edges of the cover element, this leak can be detected, since it occurs to the outside and is therefore visible, so that a simple finishing can be achieved.

The electric machine may be an electric machine of a motor vehicle, such as a starter-generator, an electric supercharger and/or a drive electric motor. Alternatively, the electric machine may be an industrial electric motor or an industrial electric machine.

In some embodiments, the cover element may have a first end side edge on the first end side and a second end side edge on the second end side. Preferably, the first and second end side edges are mechanically coupled to the base in a fluid tight manner. If desired, the cover element can furthermore have a transition edge between the end-side edge and the connecting edge, which transition edge can also be coupled in a fluid-tight manner to the base body. Thus, the entire recess in the base body can be covered fluid-tightly along the outer edge of the cover element.

The base body can be designed as a hollow cylindrical element. The hollow cylindrical element can be open on both end sides or open on one end side and closed on the other end side, and is therefore designed in the shape of a basin. The hollow cylindrical element may have an inner side surface defining a particularly cylindrical hollow space for accommodating the electric machine. The hollow cylindrical element may have an outer side whose basic shape corresponds to the outer circumference of a geometric cylinder whose ground is, for example, circular, oblong, elliptical or polygonal with rounded edges and/or with rounded corners. A groove is provided in the outer side face.

The grooves may in particular have a uniform depth in the circumferential direction, in particular when the basic shape corresponds to the outer circumferential surface of a (cylindrical) geometric cylinder with a circular base surface. Alternatively, the depth of the groove in the circumferential direction may be variable, for example when the basic shape corresponds to a geometrically cylindrical outer circumferential surface with an oblong, elliptical bottom surface or a polygonal bottom surface with rounded edges and/or with rounded corners. In this case, the depth of the groove may be maximized in the region having the bottom surface with the smallest curvature.

On its outer side, the hollow cylindrical element has, in addition to a recess which is preferably positioned centrally in the longitudinal direction of the hollow cylindrical element, one or more connecting elements which project from the outside for fixing the electric machine in the housing and/or for integrating the cooling housing into the drive system. The connecting element is preferably arranged outside the recess, in particular adjacent to the longitudinal side end of the hollow cylindrical element. The connecting elements can be designed as bolt bosses, ribs and/or similar connecting structures. For example, the connecting element may be provided as a stationary bearing cap or another component for securing the electric machine to the housing and/or may be provided for coupling the electric machine with another drive component of the transmission or drive system. Since the cover element has an interruption and can thus be expanded in a particularly elastic manner when fitted to the base body, it can be guided past axially on the connecting element and similar interference contours.

The base body can be designed in one piece or in several pieces. Preferably, the base body is designed as a one-piece or core-free main part with a center, which has all recesses, so that no sealing points, in particular no welding seams, adhesives or seals, are present in the region facing the electric machine. In this way, positions that are not sealed in the direction of the electric machine are initially avoided and the electric machine is effectively protected from the cooling medium (coolant).

The base or central body can be produced as a casting, for example as a die casting, die casting or other casting. The substrate may contain or be made of zinc, aluminum, copper, nickel, iron, titanium and/or other metals. The substrate may alternatively or additionally contain or be made of an aluminum alloy, a copper alloy such as brass or a copper-zinc-silicon alloy, or another alloy.

The cover element can be designed in one piece or in several pieces. Preferably, the cover element is designed in one piece, since automation can thus be improved and processing costs can be minimized.

In some embodiments, the interruption of the cover element may extend from a first end side of the cover element to a second end side thereof. The first end side can be open, partially open or closed, while the second end side is open. The cover element can have the shape of a hollow cylindrical arc segment, for example, or a hollow cylindrical arc segment with a rounded transition region or with a transition edge between the end-side edge and the connecting edge. Alternatively, the cover element can be a planar element, with a contour of a rectangular shape or of a rectangular shape with rounded corners, which deforms into a hollow cylindrical arc when resting on the base body and/or when the cover element is coupled to the base body, or a hollow cylindrical arc with a rounded transition region between the end-side edge and the connecting edge.

The cover element is preferably bendable and/or elastic. The cover element can thus simply be wound around the base body and not be inserted onto the base body in the form of a tube section.

The cover element may contain or be made of a metal, such as aluminium, and/or other metals, or an alloy, such as an aluminium alloy, a copper alloy, or other alloys. Alternatively, the cover element may contain or be made of a plastic, such as polyvinyl chloride (PVC) and/or other plastics.

The cover element can be a sheet made of metal, alloy or plastic, for example a flat rolled product, which is bent around the longitudinal axis into a hollow cylindrical arc or a hollow cylinder with rounded transition regions between the end edges and the connecting edges before and/or after the coupling of the cover element to the base body. For example, the plate may be a plate from a vehicle body structure or a tube section that is slit and bent in the longitudinal direction, which is available at low cost.

The cover element, in particular the plate, may have a thickness in the range of 1mm to 5mm, in particular in the range of 2mm to 3 mm.

The fluid-tight mechanical connection can be a material-fit connection, such as a soldered connection, an electric welded connection or an adhesive connection. Alternatively, the fluid-tight mechanical connection can also be realized by a separate seal, in particular by a rubber seal, for example an O-ring seal. It is also possible to make the fluid-tight mechanical coupling in many regions as a material-connected connection and in other regions by means of separate seals.

The electric welding connection may be a welding connection formed by a welding method additionally using a welding material, for example, by a MIG welding method (metal welding using an inert gas). The electrical welded connection may also be formed using another welding method, such as beam welding. The electrical welded connection can be further processed later, if desired.

In some embodiments, the base body can have a separation beam (Trennsteg) which interrupts a groove in the circumferential direction of the base body, wherein the first and second connection edges of the cover element are mechanically coupled in a fluid-tight manner with the separation beam. The connecting edge can be simply connected to the partition bar, in particular welded to the partition bar, for better accessibility. In particular, the length extension of the cover element in the circumferential direction, which is dependent on the welding process, can be compensated by a margin on the weld joint of the separation beam.

Preferably, the partition beam extends parallel to the longitudinal axis of the base body. Alternatively, the separating beam can also extend along a thread path with a large pitch in the longitudinal direction of the base body over the extent of the groove. The lead may be 1 or greater.

The separating beams can be designed in one piece with the base body. For example, the partition beam may be a cast partition beam. Alternatively, the partition beams can be designed as separate partition beams which are inserted into the recesses and are connected to the base body in the region of the recesses. Preferably, the partition beam is welded, soldered or glued flush with the base body in the region of the groove.

If the outer side of the base body has a different basic shape than the cylindrical outer circumference, the partition beams can be arranged in the region in which the base surface of the outer circumference of the cylindrical outer circumference forming the basic shape of the outer side of the base body has a minimum curvature.

The height of the separation beam may for example be equal to or less than the depth of the groove in the substrate, in particular the maximum depth of the groove. The connecting edges of the cover elements can be coupled with the partition beams in the area near the grooves, respectively, so that there are visible partition beams. Alternatively, the cover element may surround the base body along the entire circumference of the base body, so that the partition beam is located below the connection of the connection edge and is completely covered by the cover element.

In some embodiments, the separation beam may have a first through opening in its outer surface, said through opening into the recess of the base body. The first port may be a supply opening for supplying the cooling liquid into the recess or a discharge opening for discharging the cooling liquid from the recess. The first passage can have a circular diameter in the region of the outer surface and in the region of the recess changes into a wide gap leading into the recess.

In some embodiments, the separation beam may have a second through opening in its outer surface, said through opening into the groove, wherein the first through opening and the second through opening open into the groove on opposite sides of the separation beam. For example, the first port may be a supply opening for supplying the cooling liquid into the groove, and the second port may be a discharge opening for discharging the cooling liquid from the groove.

The second opening can also have a circular diameter in the region of the outer surface and change in the region of the recess into a wide gap opening into the recess.

Since the openings open into the recesses on opposite sides of the separating beam, the separating beam serves not only for the simple connection of the cover element to the main body, but also for separating hot and cold water.

In addition or alternatively, the base body can have one or more further openings which connect the outer side of the base body with the recess, in particular in the region of the longitudinal side end of the base body. The cap element may also have a through opening which opens from the outside of the cap element into the recess. The openings in the base body and/or the cover element can in turn be provided for supplying and/or discharging cooling fluid.

Each of the through openings may be provided with a connector. The connector may be screwed or inserted into the port, for example wedged into the port, and/or welded to the port.

The partition beam may also have one or more channels extending between the sides of the partition beam and allowing the coolant to flow through the partition beam in the circumferential direction of the base body.

In some embodiments, the base may have a resting rim defining a boundary of the recess for resting the cover element. The resting edge can be used for preparing the mechanical connection between the cover element and the base body. By resting against the rim, the coupling between the bell element and the base body is simplified and the quality of the fluid-tight coupling is improved.

The support edge can also extend along the separating webs, as long as the base body has the separating webs. The support edge can thus support the connecting edge of the cover element in the region of the partition bar, so that the connecting edge can be easily coupled to the partition bar. The cover element preferably has a shape which corresponds to the contour of the resting edge on the side of the resting edge facing away from the recess.

The resting edge can, for example, be introduced into the outer side of the base body. The depth of the resting edge may be equal to or less than the thickness of the cover element. Alternatively or additionally, the resting edge can be formed by projections on the outer side of the base body, which surround the recess at a predetermined distance. The height of the protrusion may be equal to or less than the thickness of the cover element. If the resting edge is formed by a combination of a depression and a projection on the outer side of the base body, the sum of the depth of the depression and the height of the projection is equal to or less than the thickness of the cover element.

In some embodiments, the grooves of the base may have a cooling structure. The cooling structure may for example have cooling ribs and/or cooling joints. The cooling ribs and/or cooling segments may be oriented or arranged in the circumferential direction or arranged serpentine within the groove. The height of the cooling ribs can be selected such that the cover element, when resting on the base body, rests at a distance from or on the cooling ribs and/or cooling ribs. The cooling ribs and/or cooling sections may also have different heights. For example, the height of the cooling ribs and/or cooling lands may be less than or equal to the depth of the grooves.

The cooling structure is used for improving the cooling rate and enhancing the rigidity of the substrate. The cooling structure increases the effective cooling surface in the direction of the cooling medium and contributes significantly to an improved stiffness against bending and tangential stresses. The cooling structure is also responsible for a suitable guidance of the cooling medium. By means of the rough casting surface, turbulent surface flows can additionally be promoted and the heat transfer between the internal cooling jacket and the cooling medium can be improved, while flow losses can be minimized by means of smooth jacket element surfaces.

If partition beams are provided, collecting areas can be provided in one or more regions on the side of the groove adjoining the partition beams, which collecting areas are free of cooling ribs and/or cooling nodes, so that a lateral flow can take place on the inflow side and/or the outflow side. The cooling liquid can thus be distributed over the entire extension of the groove in the longitudinal direction of the base body and flow through the groove in the circumferential direction. The cooling liquid can then be collected in a collecting area on the other side wall adjoining the partition beam and flow out of the groove through the through opening. The collecting area may preferably be arranged in the region of the groove where the depth of said area in the circumferential direction is greatest or at least greater than the smallest depth of the groove in the circumferential direction. Thereby, a large collecting area can be formed, which achieves an optimal distribution of the cooling medium parallel to the longitudinal axis of the basic body.

In some embodiments, the recess may have a support structure that serves as a rest for the cover element. The support structure can, for example, have support ribs and/or support sections, the height of which is selected such that the cover element rests on the support ribs and/or support sections when resting on the base body. The support ribs and/or support nodes are preferably oriented in the circumferential direction of the base body, but may also be arranged meanderingly within the groove.

The support structure serves to improve dimensional retention of the cover element after welding and to avoid acoustic abnormalities due to undefined or alternating contact between the cover element and the cooling structure. The cover element can be tensioned on the support structure before the welding process, so that a defined contact point is formed between the lateral weld seams in the region of the cooling cover. The tensioning can be further increased by expansion of the cover element during welding and then contraction during the cooling phase. The support structure can divide the cooling jacket into circumferential cooling channels with cooling structures in each case.

If desired, selected or all of the cooling ribs and/or cooling sections may also be used as support ribs and/or support sections, or the support ribs and/or support sections may also be used as cooling ribs and/or cooling sections.

The cooling housing can have a plurality of grooves which are interrupted by a corresponding number of partition beams. The recess can be covered fluid-tightly by a single cover element part. Alternatively, each groove or group of grooves may be covered fluid-tightly by a respective cover element component. The partition beams may be formed as described above. If the outer side of the base body has a different basic shape than the cylindrical outer circumference, the partition beams can be arranged in the region in which the base surface of the outer circumference of the cylindrical outer circumference forming the basic shape of the outer side of the base body has a minimum curvature.

The cooling housing may furthermore have a bearing cover system, which may comprise a bearing cover and a bearing cover. For example, the bearing cap system can be connected to the base body at the end face.

The invention further relates to a heat exchanger, in particular a multitubular heat exchanger or a tubular heat exchanger, which is designed as the above-described cooling housing for an electric machine.

The invention further relates to an electric machine having a stator, a rotor and a cooling housing according to the invention, wherein the cooling housing is shrink-fitted to the stator. The invention further relates to a drive system having such an electric machine coupled to a transmission, and to a motor vehicle having such an electric machine.

The invention further relates to a method for producing a cooling housing for an electric machine, in particular a method for producing a cooling housing as described above.

According to the method, a base body, for example a stator carrier, for accommodating an electric machine is first prepared, which base body has grooves on its outer surface running in the circumferential direction of the base body. The base body can be designed as described above with reference to the cooling housing. For the preparation of the base body, a casting method, for example a die casting method, a die casting method or another casting method, can be used. Alternatively, the base body can also be produced from a blank by machining. The preparation may also simply comprise providing a preformed stator carrier.

Furthermore, a curved cover element, for example a cover plate, is prepared, which is in particular elastic. The curved cover element has a first end face, a second end face spaced apart from the first end face by a cover surface of the cover element, and an interruption which extends along a connecting line running on the cover surface between the first end face and the second end face of the cover element and is defined by a first connecting edge and a second connecting edge opposite the first connecting edge. The cover element is designed as described above with reference to the cooling housing. To produce the cover element, a plate made of metal or plastic can be cut to shape, for example, and, if necessary, bent to resemble a hollow cylindrical cover element.

Then, the cover element is placed onto the base body such that the cover element covers the recess. For this purpose, the cut plate can be bent around the base body or a cover element similar to a hollow cylindrical arc segment can be unfolded and surround the base body. If the base body has a resting edge, the cover element can preferably be positioned such that the end-side edge and, if the base body also has separating webs, also the connecting edge and, if required, also the transition edge rest on the resting edge.

Furthermore, the first connecting edge and the second connecting edge of the cover element are mechanically coupled to each other and/or to the base body in a fluid-tight manner during the covering of the cover element over the recess in the base body and against the base body. Furthermore, the end-side edge and, if appropriate, the transition edge of the cover element can also be mechanically coupled in a fluid-tight manner to the base body.

In some embodiments, the cap element may be coupled fluid-tightly with the base by joining the cap element in material-bonding with the base, for example welding, brazing or gluing. Preferably, a welding method using additional welding material, for example a MIG welding method (metal welding with inert gas) can be used here. Welding methods using additional welding material achieve good gap closeability even with unfavorable tolerances by introducing welding material and thus also achieve an improved sealing effect compared to welding methods without additional welding material, such as beam welding methods. The welding process is preferably carried out on cast blanks, so that distortions occurring as a result of heat introduction can subsequently be compensated for by the final machining.

Alternatively, the cover element is also connected to the base body by a separate sealing means, for example a rubber seal, such as one or more O-rings.

If the base body has separate separation beams, the method may furthermore comprise the preparation of a separation sheet and the connection of the separation beams to the base body in the region of the grooves. The separate partition beams may be cast and/or manufactured by machining, for example. The separation beam may be welded, soldered or bonded to the substrate, for example.

According to the method, one or more openings for supplying and/or discharging cooling fluid, which openings are optionally provided with pipe connections, can additionally be formed in the base body, in particular in the partition bar and/or in the cover element.

Preferably, the tightness of the recess covered with the cover element is also tested after coupling of the cover element with the base body. If it is indicated that there is a non-seal along the sealed location, the sealed location is trimmed, for example by welding. By means of the weld seam located on the outside, the location of the fault can be detected and repaired simply, for example by locally liquefying the weld seam, in order to close the pores with the melt formed. For this purpose, any welding method may be used, preferably a WIG welding method (tungsten inert gas welding method).

According to the method, the cooling housing may preferably be shrink-fitted onto the stator of the electrical machine after the cover element is fluid-tightly coupled with the base body. Furthermore, a bearing cover system can be fastened to the base body to protect the rotor on the end side. The bearing cap system may be screwed onto the base body.

Drawings

Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 shows an exploded view of a drive with an electric motor having a cooling housing according to the present invention;

fig. 2 shows a schematic illustration of a first embodiment of a cooling housing according to the invention;

fig. 3 shows a schematic illustration of a base body of a cooling housing according to a first embodiment of the invention;

fig. 4 shows a schematic illustration of a cover plate of a cooling housing according to a first embodiment of the invention;

fig. 5 shows a schematic illustration of the basic body of the first embodiment, wherein the plates of the separation beam are shown as a top view;

fig. 6 shows a schematic illustration of the basic body of the first embodiment, wherein the plates of the separation beam are shown as side views;

fig. 7 shows a manufacturing method of a cooling housing according to a first embodiment of the invention;

FIG. 8 shows a cross-sectional illustration according to a second embodiment of the present invention; and

fig. 9 shows an enlarged portion of the cross-sectional illustration in fig. 8.

Detailed Description

Fig. 1 shows an exploded illustration of an electric drive 1 for a motor vehicle. The drive 1 has an electric motor 10, a cooling housing 11 with a cast bearing cap (not shown) and a screw-mounted bearing cap 12.

The motor 10 comprises a stator 100 and a rotor 13, the rotor 13 being supported in a cast bearing cap and a screw-mounted bearing cap 12. The cooling housing 11 has a cast stator carrier 2 and a cover plate 3. The stator 100 of the electric machine 10 is partially introduced into the cooling housing 11 in the illustration of fig. 1 and is completely accommodated by the cooling housing 11 in the assembled state. The bearing cap 12 on the spiral is designed as a baffle and, together with the cast bearing cap, serves to support the rotor 13 in the stator 100. When the rotor 13 is pushed into the stator 100 and the motor 10 is received in the cooling housing 11, the bearing cap 12 covers the first end side of the cooling housing 11 and is screw-coupled with the cooling housing 11 to fix the stator 100 and laterally protect the motor 10 from the environment.

A first embodiment of the cooling housing 11 and the rotor carrier 2 and the cover plate 3 will now be described in detail with reference to fig. 2 to 6.

The stator carrier 2 is a hollow cylindrical one-piece part with an inner surface 20, an outer jacket surface 21, an open first end side 22 and a partially closed second end side 23, wherein the second end side 23 is partially closed by a cast bearing cap. The inner surface 20 defines a cylindrical hollow space for receiving the motor 10, the dimensions of which match the extension of the stator 10 of the motor 10.

On the mantle surface 21, the stator carrier 2 has grooves 24 and partition beams 25. The grooves 24 are located at a spaced distance relative to the first end side 22 and the second end side 23 and extend in the direction of the longitudinal axis of the cooling housing 11 for about 3/4 of the length of the stator carrier 2. The grooves 24 furthermore extend in the circumferential direction U of the cooling housing 11 and are interrupted in the circumferential direction U by partition webs 25. The partition beam 25 extends parallel to the longitudinal axis L of the cooling housing 11 and has an outer surface 250 and a first side 251 and a second side 252 which delimit the groove 24 by areas. Furthermore, the cover surface 21 has, adjacent to the first end side 22 and the second end side 23, a plurality of bolt bosses 26 for fixing the bearing cap 12 or the transmission and other various projecting connecting elements which project from the cover surface 21.

The partition beam 25 has a first opening 253 and a second opening 254 in its outer surface 250, into which the pipe connection 4 is introduced. The first through opening 253 opens into the recess 24 on the first side 251 of the partition beam 25 and the second through opening 254 opens into the recess 24 on the second side 252 of the partition beam 25. The

openings

253, 254 have a circular diameter in the region of the outer surface 250 and widen in the region of the

respective side

251, 252 of the partition beam 25 into a wide gap 2530, as shown in fig. 6. The cooling water is supplied into the pocket 24 through the first port 253, and the cooling water is discharged from the pocket 24 through the second port 254. The supply of cooling water is marked by arrow Z in fig. 5 and 6, and the discharge of cooling water is marked by arrow a. The partition beams 25 thus take care of the spatial separation of the supply and discharge of the cooling water and the flow S of the cooling water through the grooves 24 oriented in the circumferential direction U.

The groove 24 has a cooling structure with a plurality of cooling ribs 240 extending through the groove 24 in the circumferential direction U of the cooling housing 2. Adjacent to the first side 251 of the partition beam 25, the groove 24 has a collecting region 241 for fresh cold water, so that the cold water can be distributed over the entire extension of the groove 24 in the longitudinal direction L. Adjoining the second side 252 of the partition beam 25, the groove 24 has a collecting area 242 for heated cooling water, so that cooling water flowing along the cooling ribs can be collected and drained. By distributing the supply and discharge of cooling water as symmetrically as possible over the length of the cooling housing 11, a uniform flow through the cooling housing 11 is achieved, since the pressure losses or lengths of the individual flows compensate one another.

The recess 24 is surrounded by a resting rim 27 introduced into the mantle surface 20. The resting rim 27 extends along a first side 251 of the partition beam 25, along a first boundary 243 of the groove 24 running in the circumferential direction U, along a second side 252 of the partition beam 25 and along a second boundary 244 of the groove 24 running in the circumferential direction U.

The cover plate 3 is a plate made of aluminum alloy bent into a hollow cylindrical arc section with rounded transition regions. The mantle element 3 has an inner surface 30, an outer surface 31, a first end side 32 and a second end side 33. The inner surface 30 and the outer surface 31 have an interruption 34, said interruption 34 being defined by a first connecting edge 340 and a second connecting edge 341. The region of the inner jacket element 3 on the first end side 32 has a first end-side edge 320, and the region of the inner jacket element 3 on the second end side 33 has a second end-side edge 330. The rounded transition region is defined by the transition edges between the end-

side edges

320, 330 and the connecting

edges

340, 341.

The cover plate 3 is welded to the stator carrier 2 along the circumferential weld seam 28 shown in fig. 2. The cover plate 3 rests with its

edges

320, 330, 340, 341 on the resting edge 27 and completely covers the groove 24. The cover plate 3 is welded along all its edges in a fluid-tight manner to the stator carrier 2 and closes the cooling jacket outwards.

A manufacturing method 5 of the cooling housing 11 according to the first embodiment will be described below with reference to fig. 7.

In step 50, a stator carrier 2 as described above is prepared. For this purpose, a non-machined blank produced by a die casting method is prepared in the form of the stator carrier described above.

The mask sheet 3 as described above is prepared in step 51. For this purpose, the plate is cut into a rectangle with rounded corners, so that the length of the subsequent connecting

edges

340, 341 is longer than the

sides

250, 251 of the partition beam 25 by twice the width of the resting edge 27, and so that the length of the subsequent end-

side edges

320, 330 is longer than the

borders

243, 244 of the groove 24 by twice the width of the resting edge 27. The plate is then bent into a shroud similar to a hollow cylindrical arc segment.

The cover plate 3 is placed on the stator carrier 2 in 52 such that the cover plate 3 covers the groove 24. For this purpose, the cover plate 3 is elastically stretched open and thus placed around the stator carrier 2 such that the first end-side edge 320 rests on the resting edge 27 in the region of the first boundary 243 of the groove 24, the second end-side edge 330 rests on the resting edge 27 in the region of the second boundary 244 of the groove 24, the first connecting edge 340 rests on the resting edge 27 in the region of the first side 251 of the partition beam 25, and the second connecting edge 341 rests on the resting edge 27 in the region of the second side 252 of the partition beam 25.

The cover plate 3 is welded fluid-tightly 53 to the stator carrier 2 by means of MIG welding, while the cover plate 3 covers and rests on the groove 24 in the stator carrier 2. For this purpose, a circumferential weld seam 28 is produced in the region of the support rim 27, which weld seam connects each of the

edges

320, 330, 340, 341 of the cover plate 3 to the stator carrier 2 in a fluid-tight manner.

The weld 28 is tested for tightness at 54. For this purpose, for example, air is introduced into the recess 24 closed with the cover plate 3 through the first through-opening 253 and the second through-opening 254 is closed. It is detected whether the pressure can be maintained for a defined period of time.

If no pressure drop occurs, the cooling housing 11 may be further processed, such as by shrink-fitting, onto the stator 100. Otherwise, the location within the weld 28 that is not sealed is determined and the location is trimmed and sealed by the WIG welding method.

Fig. 8 and 9 show a second embodiment of the cooling housing 11'. The cooling housing 11 'has a stator carrier 2' and a cover plate 3.

The stator carrier 2' has, similarly to the stator carrier 2 of the first embodiment, a hollow cylindrical body piece with recesses 24 and separation beams (not shown in fig. 7 and 8) on its outer side 21. The recess 24 is surrounded by a rest edge 27.

In contrast to the stator carrier 2 of the first exemplary embodiment, the recesses 24 of the stator carrier 2 'of the second exemplary embodiment have a bearing structure in the form of two bearing ribs 244 which run in the circumferential direction U of the cooling housing 11'. The height of the supporting ribs 244 is approximately relative to the depth of the groove 24 and divides the groove 24 in the direction of the longitudinal axis L of the cooling housing into three symmetrically circumferential cooling channels each having six cooling ribs 240 extending in the circumferential direction U. The support ribs 244 form defined contact locations with the cover plate 3 and avoid contact between the cooling ribs 240 and thus undesired adverse effects of acoustic or flow techniques.

Furthermore, the stator carrier 2' has a projection 29 which surrounds the resting edge 27. The projections 29 are designed to form with the cover plate 3 wedge-shaped grooves between the cover plate 3 and the stator carrier 2', into which additional welding material can be placed during welding in order to improve the quality of the weld and to improve the tightness.

The cover plate 3 is designed as described with reference to the first embodiment. The cover plate 3 is in turn welded around the stator carrier 2' to cover the groove 24 in a fluid-tight manner.

To summarize, the cooling housing for an electric machine according to the invention can be produced simply and cost-effectively and is robust. The cooling housing may be manufactured as a lost-core-free casting, as is required for manufacturing a "cast cooling water jacket", and may be manufactured as a single casting. In contrast to the "built cooling water jacket", there is no sealing position in the direction of the electric machine. The stability is thus increased and the damaging consequences are reduced in the event of a possible failure of the sealing position. The mounting of the shroud plate can be automated and performed in batches with a MIG welding process.

List of reference numerals

1 driver

10 electric machine

1111' Cooling casing

12 bearing cap

13 rotor

22' stator carrier

20 inner surface

21 outer side cover surface

22 first end side

23 second end side

24 groove

240 cooling rib

241 collecting area for fresh cooling water

242 collecting area for heated cooling water

243 first boundary

244 second boundary

245 support rib

25 partition beam

250 outer surface

251 first side portion

252 second side portion

253 first through opening

2530 Wide slit

254 second port

26 bolt boss

27 is close to putting the border

28 weld seam

29 of a circular projection

3 cover plate

30 inner surface

31 outer surface of the container

32 first end side

320 first end side edge

33 second end side

330 second end side edge

34 interruption part

340 first connecting edge

341 second connection edge

4 pipe joint

5 method of manufacture

50 preparation of stator Carrier

51 preparation of cover plate

52 placing the cover plate against the stator carrier

53 welding a cover plate to the stator carrier

54 testing the tightness

L longitudinal axis

U circumferential direction

Z Cooling Water supply

A discharge of cooling water

Flow of S Cooling Water

Claims

1. A cooling housing for an electric machine, the cooling housing comprising:

a base body (2) for accommodating the electric machine (10), wherein the base body (2) has a recess (24) on its outer surface (21) extending in the circumferential direction of the base body (2); and

a curved cover element (3), which cover element (3) is mechanically coupled to the base body (2), wherein the curved cover element (3) has a first end side (32), a second end side (33) spaced apart from the first end side (32) by a cover surface (31) of the cover element (3), and an interruption (34), which interruption (34) extends along a connecting line extending over the cover surface (31) between the first end side (32) and the second end side (33) of the cover element (3) and is defined by a first connecting edge (340) and a second connecting edge (341) opposite the first connecting edge (340),

wherein the first connecting edge (340) and the second connecting edge (341) of the cover element (3) are mechanically coupled to the base body (2) in a fluid-tight manner, and the cover element (3) covers the recess (24) in the base body (2) and rests against the base body (2).

2. The cooling housing according to claim 1, wherein the hood element (3) has a first end-side edge (320) on the first end side (32) and a second end-side edge (330) on the second end side (33), wherein the first end-side edge (320) and the second end-side edge (330) are mechanically coupled in a fluid-tight manner to the base body (2).

3. A cooling housing according to claim 1 or 2, wherein the interruption (34) of the mantle element (3) extends from a first end side (32) of the mantle element (3) to a second end side (33) of the mantle element (3).

4. The cooling housing according to claim 1 or 2, wherein the base body (2) has a partition beam (25), which partition beam (25) interrupts the groove (24) in the circumferential direction of the base body (2), wherein the first connecting edge (340) and the second connecting edge (341) are coupled fluid-tightly with the partition beam (25).

5. A cooling housing according to claim 4, wherein the partition beam (25) has a first through opening (253) in its outer face (250), said first through opening (253) opening into the recess (24) of the base body (2).

6. A cooling housing according to claim 5, wherein the partition beam (25) has a second through opening (254) in its outer face (250), said second through opening (254) opening into the recess (24), wherein the first through opening (253) and the second through opening (254) open into the recess (24) on opposite sides (251, 252) of the partition beam (25).

7. A cooling housing according to claim 1 or 2, wherein the base body (2) has a resting rim (27) for resting the cover element (3) delimiting the groove (24) for preparing the mechanical coupling between the cover element (3) and the base body (2).

8. Cooling housing according to claim 7, wherein the resting edge (27) is introduced into the outer side (21) of the base body (2); or by projections (29) on the outer side (21) of the base body (2), said projections (29) surrounding the recesses (24) at predetermined intervals.

9. A cooling housing according to claim 1 or 2, wherein the groove (24) of the base body (2) has:

a cooling structure; and/or

A support structure (244) serving as a resting portion for the cover element.

10. A cooling housing according to claim 9, wherein the cooling structure is a cooling rib (240).

11. A manufacturing method for a cooling housing (11) of an electric machine (10), the manufacturing method comprising:

preparing (50) a base body (2) for accommodating an electric machine (10), wherein the base body (2) has in its outer surface (21) a groove (24) running in the circumferential direction of the base body (2);

preparing (51) a curved cover element (3) having a first end side (32), a second end side (33) spaced apart from the first end side (32) by a cover surface (31) of the cover element (3), and an interruption (34), the interruption (34) extending along a connecting line extending over the cover surface (31) between the first end side (32) and the second end side (33) of the cover element and being defined by a first connecting edge (340) and a second connecting edge (341) opposite the first connecting edge (340);

placing (52) the cover element (3) against the base body (2) such that the cover element (3) covers the recess (24); and

the first connecting edge (340) and the second connecting edge (341) of the cover element (3) are mechanically coupled (53) to the base body (2) in a fluid-tight manner, while the cover element (3) covers the recess (24) in the base body (2) and rests on the base body (2).

12. Method according to claim 11, wherein the first connecting edge (340) and the second connecting edge (341) of the mantle element (3) are welded fluid-tight with the base body (2).

13. The method of claim 12, wherein the welding is performed using additional welding material.

14. Use of a method according to any of claims 11 to 13 for manufacturing a cooling housing (11) according to any of claims 1 to 10.