DE102019218654A1 - Electric machine and method of manufacturing the electric machine - Google Patents

Abstract

The invention relates to an electrical machine (10) having a stator (12) and a rotor (14), as well as having at least two housing parts designed as an outer housing (20) and an inner housing (18), the inner housing (18) being inside the outer housing (20) is arranged, the stator (12) is arranged within the inner housing (18), and between the inner housing (18) and the outer housing (20) an intermediate space (22) is formed, which allows a coolant to flow through it to cool the Stator (12) is provided, in the intermediate space (22) a plurality of webs (24) extending largely in an axial direction (23) parallel to the axis of rotation (16) for guiding coolant, each of the webs (24) extending along the Has two contact areas (26) which extend in the axial direction (23) and at which the web (24) contacts one of the housing parts (18, 20). It is proposed that at least one web (24) on a first contact area (26a) with one of the housing parts (18, 20), either the inner housing (18) or the outer housing (20), has a fixed connection, and the web (24 ) is in frictional contact with the other housing part (20, 18) at a second contact area (26b).

Description

The invention relates to an electrical machine according to the preamble of the independent claim. The invention also relates to a method for producing such an electrical machine.

State of the art

Electrical machines for traction drives, especially for motor vehicles, require liquid cooling for the power and size required today. Typically, a housing surrounding the stator is used for this purpose, which advantageously has a meandering cooling water flow around the stator.

Disclosure of the invention

advantages

The present invention describes an electrical machine having a stator and a rotor. The electrical machine has at least two housing parts, which are designed as an inner housing and an outer housing. The inner housing is arranged within the outer housing and the stator is arranged within the inner housing. An intermediate space is formed between the inner housing and the outer housing, which space is provided for a coolant to flow through for cooling the stator. A plurality of webs for guiding coolant, which extend largely in an axial direction parallel to the axis of rotation, are arranged in the intermediate space. Each of the webs has two contact areas which extend along the axial direction and at which the web makes contact with one of the housing parts. According to the invention, at least one web has a fixed connection at a first contact area with one of the housing parts, either the inner housing or the outer housing, and the web is in frictional contact with the respective other housing part at a second contact area. In this way, torsional vibrations can be reduced, in particular torsional vibrations between the two housing parts. In particular, the frictional contact between the web and one of the housing parts causes damping between the two housing parts. In this way, vibrations and noise emissions from the electrical machine can be reduced.

An electric machine is to be understood as meaning, in particular, an electric motor, preferably a rotary electric motor with a stator and a rotor. According to the invention, the stator has excitation coils. When the electrical machine is in operation, the excitation coils of the stator can generate a time-varying magnetic field, in particular a rotating field, which is provided to set the rotor in rotation. The rotor or the rotor of the electric motor can generally be equipped with permanent magnets, have current-commutated coils for the generation of magnetic fields, or be designed as a so-called squirrel-cage rotor of an asynchronous machine.

According to the present invention, the rotor is preferably designed as an internal rotor and the stator is accordingly designed as an external stator.

The rotor is preferably designed to be largely cylindrical. This is to be understood in particular to mean that the rotor is designed to be essentially cylinder-symmetrical, the cylinder axis largely corresponding to the axis of rotation about which the rotor of the electrical machine rotates during operation. For example, the spatial extent of the largely cylindrical rotor can be limited by a virtual, imaginary cylinder around the axis of rotation or cylinder axis; in particular, there can be an imaginary radius around the cylinder axis within which the rotor is arranged. For example, it is conceivable that the rotor has a cylindrical base element from which rotor teeth for receiving the bobbins extend.

The stator or stator base body is preferably embodied in the form of a hollow cylinder, at least in sections. This should in particular be understood to mean that the stator or stator base body is configured to be cylinder-symmetrical in sections, the cylinder axis largely corresponding to the axis of rotation about which the rotor of the electrical machine rotates during operation. The cylindrical cavity of the hollow cylinder is preferably provided for receiving a largely cylindrical rotor. For example, the spatial extent of the hollow cylindrical section of the stator can be limited by a virtual, imaginary hollow cylinder around the axis of rotation or cylinder axis, in particular an imaginary first radius and imaginary second radius can exist around the cylinder axis, the hollow cylindrical section of the stator between the first Radius and second radius is arranged. For example, it is conceivable that the stator or stator base body has a hollow cylindrical base element from which stator teeth extend, which are provided for receiving the excitation coils.

A stator base body is to be understood in particular as a base body for a stator, in particular formed by a plurality of axial layers of sheet metal lamellas or stator lamellas. In particular, a stator base body can be understood to mean a base body which has no excitation coils and is set up to accommodate excitation coils. For example, a stator can be produced from a stator base body if the stator base body is wound with excitation coils.

A housing part is to be understood in particular as a part of a stator housing which is provided to accommodate the stator largely completely and to provide cooling for the stator. The stator housing advantageously has at least one outer housing and one inner housing as housing parts. The stator housing particularly advantageously consists of an outer housing and an inner housing. In particular, the individual housing parts are designed as parts of the stator housing that are separate from one another, in particular are not materially connected to one another.

The stator housing and / or a housing part, in particular the inner housing and / or the outer housing, is advantageously designed to be rotationally symmetrical or largely rotationally symmetrical, the axis of symmetry being arranged largely parallel to the axis of rotation of the electrical machine. The axis of symmetry of the stator housing and / or of the housing part is particularly advantageously arranged largely on the axis of rotation of the electrical machine. This has the particular advantage that in this way the space between the inner housing and the outer housing is largely rotationally symmetrical. In this way, the coolant can flow evenly around the stator in the circumferential direction. This enables particularly uniform cooling of the stator.

A largely perpendicular or parallel arrangement is to be understood in particular as an arrangement which deviates from a perpendicular or parallel arrangement by no more than 8 °, advantageously no more than 5 °, particularly advantageously no more than 2 °.

The stator housing and / or a housing part is particularly advantageously designed largely as a hollow cylinder. The inner housing and / or the outer housing are particularly advantageously designed, at least in sections, largely in the shape of a hollow cylinder. In particularly advantageous variants, the inner housing and / or the outer housing is designed as a tube, at least in sections. The outer housing and the inner housing are advantageously arranged coaxially to the axis of rotation. This has the particular advantage that the space between the inner housing and the outer housing can be designed largely as a hollow cylinder. This enables uniform and efficient heat dissipation, especially in the case of a largely hollow-cylindrical stator.

It is conceivable, for example, that the stator or the stator base body is connected to the inner housing with a press connection. In this way, a particularly reliable and easy to manufacture fastening of the stator is guaranteed.

A press connection is to be understood in particular as a non-positive connection in which force is exerted by friction between the connected elements. Examples of press connections are cold stretching and shrinking or shrinking. Preferably, the connected elements are essentially only elastically deformed.

A web is provided in particular to enlarge a surface around which the coolant flows, so that heat can be better transferred to the coolant. A web is advantageously designed to be planar or essentially planar. A web can also be referred to as a fin or rib, in particular as a cooling fin or cooling fin. The web is advantageously arranged perpendicular or largely perpendicular to the circumferential direction. A flat web is particularly advantageously arranged parallel or largely parallel to the axial direction or axis of rotation and parallel or largely parallel to the radial direction.

A contact area is to be understood as meaning, in particular, a preferably linear area running parallel or largely parallel to the axial direction or in the direction of the axis of rotation, at which the web makes contact with one of the housing parts. The web preferably contacts the housing part in the contact area in a fluid-tight or largely fluid-tight manner for the coolant. At least one of the contact areas, preferably both contact areas of the web, particularly advantageously extends along the length of the web in the axial direction of extent or parallel to the axis of rotation. In other words, the web preferably contacts at least one housing part, particularly preferably the outer housing and the inner housing, along its length in the axial direction or radial direction.

The web particularly advantageously extends between the first contact area in the radial direction to the second contact area. The fact that a web extends in the radial direction is to be understood in particular as meaning that the web has a significantly larger extension in the radial direction than in the circumferential direction, for example at least 5 times the extension, preferably at least 10 times the extension, particularly preferably at least 15 -fold expansion.

The web advantageously creates an area in the space where the coolant cannot flow in the circumferential direction and in particular is guided in the axial direction or parallel to the axis of rotation. In this way, an advantageous coolant flow can be achieved, which guides the coolant largely through the entire gap. In this way it can be prevented that certain areas in the space are not flowed through by the coolant. This enables particularly uniform cooling of the stator.

A web particularly advantageously extends over a large part of the housing length of the stator housing or the inner housing or the outer housing, but is shorter than the housing length, for example 65% of the housing length, preferably 80% of the housing length, particularly preferably 90% of the housing length. In this way, the coolant is prevented from flowing in the circumferential direction of the web over a large part of the housing length through the web, only in the area in the axial direction in which the web no longer extends, the passage area, the coolant can flow in the circumferential direction. The web preferably extends from a first axial end face of the stator housing or the inner housing or the outer housing in the axial direction and on a second axial end face arranged opposite in the axial direction forms a passage area which is not blocked by the web and which can be flowed through in the circumferential direction.

The electrical machine preferably has a first group of webs which extend from the first axial end face and each form a passage area on the second axial end face, and a second group of webs which extend from the second axial end face and each form a passage area on the first axial end face. In particular, the webs of the first group each prevent a flow in the circumferential direction on the first end face. In particular, the webs of the second group each prevent a flow in the circumferential direction on the second end face. Preferably, the webs of the first group and the second group alternate in the circumferential direction. In this way, a cooling channel or a coolant duct is created, which can guide the coolant in a meandering shape around the stator.

For example, a coolant flowing around the stator in a first circumferential direction will flow in the circumferential direction in the first circumferential direction through a passage area formed by a web of the second group on the first axial end face. There it meets the adjacent web of the first group, which blocks the flow in the first circumferential direction. The coolant must therefore flow in the axial direction to the second axial end face, in both circumferential directions - the first circumferential direction and the opposite second circumferential direction - it is limited by the two adjacent webs. On the second axial end face, the web of the second group prevents it from flowing back in the second circumferential direction. On the second axial end face, the adjacent web of the first group forms a passage area so that the coolant can continue to flow in the first circumferential direction. There it meets another web of the second group, which prevents the flow in the first circumferential direction. The coolant therefore flows again parallel to the axial direction back to the first axial end face. There, the web of the second group forms a passage area which enables the coolant to flow further in the first circumferential direction. From here on, the flow path of the coolant is repeated on a further web of the first group in the axial direction to the second axial end face. In this way, the coolant can largely flow through the entire intermediate space.

The flow through the gap is particularly uniform if the majority of the webs are arranged uniformly in the circumferential direction. Advantageously, each web always has the same or largely the same predetermined spacing from its webs directly adjacent in the circumferential direction.

A fixed connection at the first contact area between the web and the housing part is to be understood in particular as a connection which does not allow any relative movement between the web and the housing part at the first contact area. In particular, the fixed connection can be an integral or non-positive connection. For example, the web can be designed in one piece with the housing part. It is also conceivable that the web is glued or welded to the housing part. It is possible for the web and the housing part to be formed at least in sections, preferably completely, from the same material, for example metal, in particular aluminum, or plastic. It is also conceivable that the web and the housing part are predominantly formed from different materials. For example, the housing part can be made predominantly or entirely of metal and the web can be made predominantly or entirely of plastic.

A frictional contact on the second contact area between the web and the housing part should in particular be a friction between a surface of the web and the surface of the web that touches one another on the second contact area Housing part. In this context, friction or frictional contact should not be understood to mean any internal or internal friction within the web and / or housing part.

The friction converts mechanical work or kinetic energy into thermal energy. In particular, oscillations and vibrations of the electrical machine can be damped in this way.

The frictional contact on the second contact area between the web and the housing part is advantageously fluid-tight or largely fluid-tight with respect to the coolant. Largely fluid-tight is to be understood as meaning that when the flow hits the second contact area, less than 10% flows through the second contact area between the web and the housing part, preferably less than 5%, particularly preferably less than 2%.

A limited contact pressure is advantageously applied to the web with the housing part at the second contact area. By choosing the contact pressure, it is possible to adjust the strength or level of friction and adapt it to the technical requirements. In particular, the damping of typical frequencies or frequency ranges of vibrations occurring during operation of the electrical machine can be optimized in this way.

It is conceivable that the majority of the webs, preferably all of the webs, have a first contact area with a fixed connection to one of the housing parts and a second contact area with frictional contact with the other housing part.

The electrical machine advantageously has connecting elements on the two axial end faces which connect the inner housing to the outer housing, in particular fix or fasten them to one another in the axial direction. It is conceivable that the connecting elements seal the intermediate space on the axial end faces in a fluid-tight manner with respect to the coolant. It is also conceivable that the connecting elements each have a coolant supply line, which is provided for the supply or introduction of the coolant into the space, and / or a coolant discharge line, which is provided for the removal or removal of the coolant from the space. It is conceivable that the connecting elements are formed in one piece or in several pieces. It is also conceivable that the electrical machine has end shields which have one or more connecting elements. It is particularly conceivable that a bearing plate is formed in one piece with at least one connecting element.

A bearing plate, sometimes also referred to as a flange, is to be understood as a component or an assembly of the electrical machine, which is provided in particular for mounting the rotor. In particular, a bearing plate has a bearing. A bearing plate is preferably designed in the form of a plate, in particular in the form of a disk. A bearing plate is advantageously arranged on one of the axial end faces of the electrical machine. A bearing plate can be designed to be cylindrically symmetrical or largely cylindrically symmetrical to the axis of rotation. It is conceivable that a bearing plate has the electronics of the electrical machine, in particular the power electronics. It is also conceivable that a bearing plate has coolant lines or channels, in particular for cooling the end of the stator. The end shield advantageously has a connection or connections for a supply line and / or discharge line for the coolant, so that the electrical machine can be connected to an external coolant circuit.

The features listed in the subclaims allow advantageous developments of the electrical machine.

A particularly effective damping of oscillations and vibrations is possible if the web on the second contact area is movable in the circumferential direction or along the contacted surface of the housing part relative to the housing part. In particular, it is advantageous if the web is designed to be elastically deformable at least in sections. It is also conceivable that the outer housing is arranged to be rotatable or at least partially rotatable relative to the inner housing in the circumferential direction and the rotational movement is damped by the frictional contact.

An advantageous form of a web is when the web has a connecting section extending between the inner housing and the outer housing, which extends essentially perpendicular to the contacted surface of the housing part on the first contact area and / or is essentially perpendicular to the contacted surface of the housing part extends the second contact area, preferably extends in the radial direction. The contacted surface of the housing part on the first contact area is advantageously arranged perpendicular or largely perpendicular to the radial direction. The contacted surface of the housing part on the second contact area is advantageously arranged perpendicular or largely perpendicular to the radial direction.

The geometry of the web is further improved if the web on the second contact area extends largely parallel to the contacted surface of the housing part Has contact portion, which preferably has largely the same radius of curvature as the contacted surface on the second contact area. The contact section is provided in particular to make full or largely complete contact with the surface of the housing part, in particular in order to establish frictional contact in this way. The contact area is advantageously designed flat, in particular extending in an area which is arranged parallel to the contacted surface and has a thickness or extent perpendicular to the contacted surface which is significantly smaller than the extent of the contact area along the contacted surface, for example at least five times smaller, preferably at least ten times smaller, particularly preferably at least fifteen times smaller. The contact area advantageously extends in the circumferential direction or largely in the circumferential direction.

It is possible to adjust the strength or level of friction by choosing the size of the contact area. It is conceivable that an extension of the contact area in the circumferential direction and / or along the contacted surface is between 50% and 150%, preferably 70% and 130%, particularly preferably 90% and 110%, advantageously 100% of an extension of the gap in the radial direction .

The contact area advantageously extends in the axial direction over the same length or largely the same length as the associated web or as the associated connecting section of the web.

It is conceivable that the contact area is formed in one piece with the connecting section.

If the contact section is arranged largely centered on the connecting section, this has the advantage that the web is evenly loaded both when moving in a first circumferential direction and when moving in an opposite, second circumferential direction. This increases the durability and reliability of the electrical machine. A contact section arranged centrally on the connecting section is to be understood as meaning, in particular, a contact section which extends from the connecting section in a first circumferential direction just as far as in an opposite, second circumferential direction. Such a web is also referred to as a T-web; in particular, such a web has a T-shaped profile perpendicular to the axis of rotation.

The contact section is advantageously arranged perpendicularly or largely perpendicularly on the connecting section.

In advantageous variants, the web has a thickening in the first contact area, which is provided to stiffen the web. In this way, the stability of the web and the durability of the fixed connection can be increased. A thickening is to be understood in particular to mean that the web at the first contact area has a thickness or extent in the circumferential direction which is greater than a section following in the radial direction. In particular, it is conceivable that the web and / or connecting section has a largely constant first thickness in the circumferential direction, and has a greater second thickness in the circumferential direction at the first contact area and optionally has a further, different thickness or expansion at the second contact area. For example, the second thickness can be between 150% and 300%, preferably between 175 and 250%, particularly preferably between 200% and 225% of the first thickness. It is also conceivable that the thickness or extension of the web or connecting section decreases, for example linearly, at least in sections in the circumferential direction from the first contact area in the direction of the second contact area.

The electrical machine advantageously has a plurality of outer webs, each of which has the first contact area on the outer housing. All webs of the electrical machine are particularly advantageously designed as outer webs. This allows simple manufacture, because in particular the majority of the outer webs can be formed together with the outer housing in one manufacturing step or can be mounted or fastened to the outer housing.

In one variant, the electrical machine has a plurality of inner webs, each of which has the first contact area on the inner housing. All webs of the electrical machine are particularly advantageously designed as inner webs. This also allows simple manufacture, since the majority of the inner webs can easily be formed with the inner housing in one manufacturing step or can be mounted or fastened to the inner housing.

In a particularly advantageous variant, inner webs and outer webs alternate in each case along the circumferential direction. This enables a particularly simple and reliable production of an advantageous coolant guide. For example, it is conceivable that the inner webs form the first group of webs and the outer webs form the second group of webs. Conversely, the outer webs can also form the first group of webs and the inner webs can form the second group of webs. In addition, the variant has alternately arranged inner and outer Bars have the advantage that the frictional contacts of the bars are evenly distributed over the inner housing and outer housing, which enables a uniform distribution of the frictional heat.

A method for producing an electrical machine, in particular an electrical machine according to the present invention, having a stator and a rotor is also advantageous. The electrical machine has at least two housing parts designed as an outer housing and an inner housing, the inner housing being arranged within the outer housing and the stator being arranged within the inner housing. An intermediate space is formed between the inner housing and the outer housing, which space is provided for a coolant to flow through for cooling the stator. In the space there is a plurality of webs for coolant guidance that extend largely in an axial direction parallel to the axis of rotation, each of the webs having two contact areas extending along the axial direction at which the web makes contact with one of the housing parts. In the method, the inner housing is separate from the outer housing and at least one web has a fixed connection at a first contact area with one of the housing parts, either with the inner housing or the outer housing. The outer housing is then pushed onto the inner housing, so that the web is in frictional contact with the respective other housing part, with which the web has no fixed connection, at a second contact area.

The stator can be arranged and / or mounted in the inner housing before or after the outer housing is pushed onto the inner housing. After the outer housing has been pushed onto the inner housing, the connecting elements and / or end shields can advantageously be mounted on the axial end faces. Before the final assembly of the connecting elements and / or end shields on both axial end faces, the rotor should be arranged in the stator.

Figure list

• 1 eine schematische perspektivische Darstellung eines Außengehäuses und Innengehäuses mit einem Stator und Rotor der elektrischen Maschine wobei illustrativ das Innengehäuse aus dem Außengehäuse gezogen ist,
• 2 und 3 jeweils eine schematische Detailansicht eines Schnitts durch die elektrische Maschine senkrecht zur Rotationsachse zur Darstellung eines Stegs in verschiedenen Varianten und
• 4 bis 6 jeweils eine schematische Schnittdarstellung durch die elektrische Maschine senkrecht zur Rotationsachse in verschiedenen Ausfüh rungsbeispielen.

In the drawings, exemplary embodiments of the electrical machine according to the present invention are shown and explained in more detail in the following description. Show it

• 1 a schematic perspective illustration of an outer housing and inner housing with a stator and rotor of the electrical machine, the inner housing being drawn out of the outer housing by way of illustration,
• 2 and 3rd in each case a schematic detailed view of a section through the electrical machine perpendicular to the axis of rotation to illustrate a web in different variants and
• 4th to 6th each a schematic sectional view through the electrical machine perpendicular to the axis of rotation in various Ausfüh insurance examples.

description

In the various design variants, the same parts are given the same reference numbers.

1 shows a schematic representation of an electrical machine 10 with a stator 12th and a rotor 14th , which, for example, are largely rotationally symmetrical to an axis of rotation 16 of the rotor 14th are trained. A stator housing has two housing parts, an inner housing 18th and an outer case 20th . The stator 12th In the exemplary embodiment, it has a disk pack which, for example, consists of a plurality of in an axial direction 23 stacked stator laminations is formed. The axial direction 23 is a direction which is parallel to the axis of rotation 16 is arranged.

The inner case 18th is designed largely as a hollow cylinder in the exemplary embodiment, the cylinder axis on the axis of rotation 16 is arranged. The inner housing is an example 18th designed as a tube or tubular. In the inner case 18th is an example of the stator 12th pressed in. The stator 12th is for example largely formed as a hollow cylinder.

The outer casing 20th is designed largely as a hollow cylinder in the exemplary embodiment, the cylinder axis on the axis of rotation 16 is arranged. The outer housing is an example 18th designed as a tube or tubular. For illustration is in 1 the inner case 18th outside the outer case 20th pictured. In the fully assembled electrical machine 10 is the inner case 18th inside the outer case 20th arranged. Between the inner case 18th and the outer case 20th is a space 22nd trained (see 2 to 6th ), which is provided for a coolant to flow through.

In 1 are bridges for the sake of clarity 24 (please refer 2 to 6th ) not illustrated. To illustrate the arrangement of the bars 24 and how the coolant guide is provided are contact areas 26th the footbridges 24 marked as solid lines. The contact areas are exemplary 26th on the inner case 18th marked, which in the in 1 embodiment shown all as first contact areas 26a are trained. At a first contact area 26a there is a fixed connection between the web 24 and housing part in front. The bridges 24 or contact areas 26th extend parallel to the axis of rotation 16 or in the axial direction 23 .

The webs are exemplary 24 or the contact areas 26th or first contact areas 26a a bridge length 28 in the axial direction 23 which, for example, 70% of an inner housing length 30th of the inner housing 18th in the axial direction 23 amounts to. The inner housing length is exemplary 30th 94% of an outer housing length 32 of the outer housing 20th in the axial direction 23 . In this way the outer casing 20th the inner case 18th fully absorb. The outer housing preferably has 20th in the assembled state opposite the inner housing 18th on both axial faces 34 an overhang in the axial direction 23 on. In this way, for example, the bearing shields and / or connecting elements (not shown) can be attached to the axial end faces 34 at least partially from the outer housing 20th be recorded or covered.

In the exemplary embodiment, the electrical machine 10 a first group 36a of jetties 24 as well as a second group 36b of jetties 24 on. The bridges 24 or contact areas 26th the first group 36a extend starting from a first axial end face 34a in the axial direction 23 . According to the bridge length 28 ends the footbridge 24 or contact area 26th and has a distance of, for example, 30% of the inner housing length 30th to a second axial end face 34b on, which has a passband 38 defines which one is in a circumferential direction 40 can be flowed through. The second axial face 34b lies the first axial face 34a in the axial direction 23 across from.

The bridges 24 or contact areas 26th the second group 36b extend starting from the second axial end face 34b against the axial direction 23 in the direction of the first axial end face 34a . According to the bridge length 28 ends the footbridge 24 or contact area 26th and has a distance of, for example, 30% of the inner housing length 30th to the first axial end faces 34a on, which has a passband 38 defines which one is in a circumferential direction 40 can be flowed through.

In the exemplary embodiment, they alternate in the circumferential direction 40 one bridge each 24 the first group 36a with a bridge 24 the second group 36b from. In this way, passage areas alternate in the circumferential direction 38 from which on the first axial face 34a or on the second axial end face 34b are arranged. In this way there is a meandering flow through the space 22nd possible because a coolant which passes through a passage area 38 in the circumferential direction 40 has flowed, has to go to the next passage area 38 to arrive, first in the axial direction 23 or against the axial direction 23 stream. In dashed lines is an exemplary flow path 42 shown in which a coolant in a first circumferential direction 40a flows and every bridge 24 in the axial direction 23 and against the axial direction 23 must flow around. It is also conceivable that the coolant against the flow path 42 flows and thus overall in a to the first circumferential direction 40a opposite second circumferential direction 40b flows.

2 shows a section perpendicular to the axis of rotation 16 through a footbridge 24 . In the exemplary embodiment, the web 24 is T-shaped. The bridge 24 has, for example, a connecting section 44 on, which is perpendicular to the one in the gap 22nd arranged surface of the inner housing 18th is arranged. The connecting section 44 extends advantageously in the radial direction 46 from the inner housing 18th to the outer housing 20th .

On the outer housing 20th arranged has the web 24 in the exemplary embodiment a contact section 48 on. The contact section 48 stands with a second contact area 26b on the outer housing 20th in frictional contact. The contact section 48 is essentially parallel to the one in the gap 22nd arranged surface of the outer housing 20th arranged. By way of example, the contact section 48 perpendicular to the axis of rotation 16 the shape of a segment of a circle, with largely the same radius as the outer housing 20th . In particular, the contact section 48 largely the same curvature as the outer housing 20th on the second contact area 26b .

For example is the contact section 48 perpendicular to the connecting section 44 arranged. The contact section is advantageous 48 in the plane perpendicular to the axis of rotation 16 centered on the connecting section 44 arranged. In the in 2 illustrated embodiment has the contact section 44 a contact expansion 50 in the circumferential direction 40 which is 125% of a gap width 52 of the space 22nd in radial direction 46 corresponds to. The gap width 52 is in particular the distance from the inner housing 18th to the outer housing 20th in radial direction 46 . In the exemplary embodiment, the gap width corresponds 52 the extension of the bridge 24 in radial direction 46 . In advantageous embodiments, the web 24 at least the extension of the gap width 52 .

3rd illustrates a variant of the in 2 embodiment shown, in which the web 24 at the first contact area 26a a thickening 54 having. Without the thickening 54 has the connecting portion 44 of the jetty 24 in the circumferential direction 40 a largely constant first thickness 56 on, see 2 . In the in 3rd the variant shown has the bridge 24 at the first contact area 26a a second thickness 58 in the circumferential direction 40 on which, for example, 300% of the first thickness 56 corresponds to. The thickness of the connecting portion 44 takes exemplary from the first contact area 26a starting with the distance in the radial direction 46 linearly until it reaches the value of the first thickness 56 reached. With a further distance in the radial direction, the thickness of the connecting section remains 44 constant at the value of the first thickness 56 until reaching the contact section 48 . In the example shown, the thickness advantageously increases on both circumferential areas of the web 24 same off, so the thickening 54 has a largely triangular shape. The triangular shape of the thickening is advantageous 54 largely symmetrical in the direction of the radial direction 46 aligned.

4th shows a section perpendicular to the axis of rotation 16 by an electric machine 10 according to the in 1 and 2 embodiment shown. The electric machine 10 has eight equidistant in the circumferential direction 40 distributed bars 24 on. In other embodiments, any other number of webs are also possible 24 conceivable, advantageously there should be at least three webs 24 , so that these enable a stable fit of the housing parts. In the exemplary embodiment, they are all webs 24 as inner bars 60 formed, in each of which the first contact area 26a on the inner housing 18th is arranged. In the exemplary embodiment, the webs are 24 or inner webs 60 integral with the inner housing 18th educated.

5 shows a variant in which all webs 24 as outer bars 62 educated. With outer bars 62 is always the first contact area 26a on the outer housing 20th arranged. In the in 5 The example shown are the bars 24 or outer webs 62 integral with the outer housing 20th educated.

6th shows an advantageous variant in which in the circumferential direction 40 each inner webs 60 and outer bars 62 alternate. By way of example, the electrical machine 10 four inner bars 60 and four outer bars 62 on. In the example shown, the inner bars correspond 60 the jetties 24 the second group 36b . The outer webs 62 correspond to the bars 24 the first group 36a . But it is also conceivable that the inner webs 60 the jetties 24 the first group 36a and the outer bars 62 the jetties 24 the second group 36b correspond.

Claims (10)

Electrical machine (10) having a stator (12) and a rotor (14), as well as having at least two housing parts designed as an inner housing (18) and an outer housing (20), the inner housing (18) being arranged within the outer housing (20) is, the stator (12) is arranged within the inner housing (18), and an intermediate space (22) is formed between the inner housing (18) and the outer housing (20) through which a coolant can flow to cool the stator (12) is provided, in the intermediate space (22) a plurality of webs (24) extending largely in an axial direction (23) parallel to the axis of rotation (16) for guiding the coolant, each of the webs (24) extending along the axial direction (23) having extending two contact areas (26), at which the web (24) contacts one of the housing parts (18, 20), characterized in that at least one web (24) at a first contact area (26a) with a de r housing parts (18, 20), either the inner housing (18) or the outer housing (20), has a fixed connection and the web (24) is in frictional contact with the other housing part (20, 18) at a second contact area (26b) stands. Electric machine (10) according to Claim 1 , characterized in that the web (24) on the second contact area (26b) is movable in the circumferential direction (40) or along the contacted surface of the housing part (18, 20) relative to the housing part (18, 20). Electrical machine (10) according to one of the preceding claims, characterized in that the web (24) has a connecting section (44) extending between the inner housing (18) and outer housing (20) which is essentially perpendicular to the contacted surface of the housing part (18, 20) extends on the first contact area (26a) and / or extends essentially perpendicular to the contacted surface of the housing part (20, 18) on the second contact area (26b), preferably extends in the radial direction (46). Electrical machine (10) according to one of the preceding claims, characterized in that the web (24) on the second contact area (26b) has a contact section (48) which extends largely parallel to the contacted surface of the housing part (20, 18), which preferably has largely the same radius of curvature as the contacted surface on the second contact area (26b). Electric machine (10) according to Claim 4 , characterized in that the contact section (48) is arranged largely centered on the connecting section (44). Electrical machine (10) according to one of the preceding claims, characterized in that the web (24) on the first contact area (26a) has a thickening (54) which is provided to stiffen the web (24). Electrical machine (10) according to one of the preceding claims, characterized in that a plurality of outer webs (62) each have the first contact area (26a) on the outer housing (20). Electrical machine (10) according to one of the preceding claims, characterized in that a plurality of inner webs (60) each have the first contact area (26a) on the inner housing (18). Electric machine (10) according to Claim 8 , characterized in that inner webs (60) and outer webs (62) alternate along the circumferential direction (40). Method for producing an electrical machine (10), in particular according to one of the preceding claims, having a stator (12) and a rotor (14), and having at least two housing parts designed as an outer housing (20) and an inner housing (18), wherein the inner housing (18) is arranged within the outer housing (20), the stator (12) is arranged within the inner housing (18), and a gap (22) is formed between the inner housing (18) and the outer housing (20), which for a coolant to flow through is provided for cooling the stator (12), a plurality of webs (24) extending largely in an axial direction (23) parallel to the axis of rotation (16) for guiding the coolant being arranged in the intermediate space (22), each the webs (24) has two contact areas (26) extending along the axial direction (23), at which the web (24) makes contact with one of the housing parts (18, 20) The housing (18) is separate from the outer housing (20) and at least one web (24) is fixed to a first contact area (26a) with one of the housing parts (18, 20), either the inner housing (18) or the outer housing (20) Has connection, and then the outer housing (20) is pushed onto the inner housing (18) so that the web (24) with the respective other housing part (20, 18), with which the web (24) has no fixed connection, on a second contact area (26b) is in frictional contact.

Images