WO2018091722A1

WO2018091722A1 - Motor casing of an electric machine

Info

Publication number: WO2018091722A1
Application number: PCT/EP2017/079853
Authority: WO
Inventors: Patrick SANTHERR; Dietmar HANSER
Original assignee: Albert Handtmann Metallgusswerk Gmbh & Co. Kg
Priority date: 2016-11-21
Filing date: 2017-11-21
Publication date: 2018-05-24
Also published as: DE102017127374A1; WO2018091721A1; EP3542448A1

Abstract

Disclosed is a motor casing (2) of an electric machine (1), comprising an outer casing element (5), an inner casing element (6) inside the outer casing element (5), at least one cooling duct (9) through which a cooling medium can flow and which is located between the outer casing element (5) and the inner casing element (6), a first annular duct (12, 13) for distributing and/or collecting the cooling medium at a first end of the cooling duct (8), and a second annular duct (12, 13) for distributing and/or collecting the cooling medium at a second end of the cooling duct (9), said motor casing (2) improving the motor casing of the prior art. For this purpose, according to the invention, at least one of the two annular ducts (12, 13) is in the form of a recess (12, 13) in the inner housing element (6).

Description

"Motor housing of an electric machine"

The invention relates to a motor housing of an electrical machine according to the preamble of claim 1.

State of the art

An engine housing for an electric machine, in particular for a drive motor of a motor vehicle, is already known, for example, from DE 10 2015 202 918 A1 or DE 10 2011 080 199 A1. These motor housings each comprise an outer housing part and an inner housing part arranged in the outer housing part. In addition, this indicates

Motor housing arranged between the housing parts and limited by the housing parts cooling channel, i.

a cooling jacket through which a cooling medium for cooling at least the inner housing part flows.

In addition, these cooling systems have two ports through which the cooling medium, in particular the cooling water, flows in or out. For the inflow or the

Outflow are also each end of the cooling channel a collecting channel or a distribution channel provided so that can distribute the cooling medium over the entire circumferential surface or over the entire circumference and through the

hollow cylindrical cooling channel / cooling jacket can flow.

For the motor housings of the above two

Publications, the outer housing part respectively

Collection or distribution channels on. In contrast, the inner housing part is designed as a hollow cylindrical sleeve with a comparatively thin wall thickness.

A disadvantage of such motor housings, however, is that the outer housing part is comparatively thick form and thus is relatively heavy and bulky. At the same time, the comparatively thin-walled inner housing part is comparatively unstable under thermal loads, in particular a wide variety of thermal loads, so that in operation z.T. Impairs caused by thermally induced, different deformations of the two housing parts, resulting in adverse cooling or

Training the cooling channel can lead.

Purpose and advantages of the invention

Object of the invention is in contrast to propose a motor housing of the aforementioned type, which improves the previous engine housing. This object is achieved on the basis of a motor housing of the aforementioned type, by the features of claim 1. The measures mentioned in the dependent claims are advantageous embodiments and refinements of

Invention possible.

Accordingly, an inventive

Motor housing characterized in that at least one of the two annular channels as a recess of the inner housing element is trained.

With the help of such a trained inner housing element with a recess which is used as an annular channel for the distribution or for the collection of the cooling fluid, especially when using cast inner housing elements, this recess or the annular channel without much effort

be prepared by casting. Thus, a light metal can be advantageously used for the inner housing element of the motor housing according to the invention,

in particular aluminum, aluminum alloy or the like.

At the same time, the inner housing element is viewed in the radial direction in the region of the recess or of the annular channel

comparatively thick and thus stable formable, so that no adverse thermal deformations during operation

to be generated. This improves the operation or the life of the cooling system of the invention

Motor housing. This is also of particular advantage, since the annular channel or the collecting / distribution channel

Preferably, in the end region or in the vicinity of the front end portion of the inner housing member is located, so that just this end can be made very stable. Thus, if necessary, bearing forces of the stator unit and / or rotor unit can be advantageously achieved by

Motor housing according to the invention are received. In addition, this is e.g. also for a stable and permanent connection of the inner housing element with the

External housing element of particular advantage.

Advantageously, welding methods for connecting, in particular fluid-tight connection, the

Inner housing member provided with the outer housing member, preferably at the front end portion of / the

Housing elements. Not only very common

Faster method such as laser or electric welding methods can be used, but also newer or special welding methods such as the so-called. "LMD welding", ie a Powder coating laser cladding method, friction welding method, friction squeezing method or friction stir welding method or the like are used. Just here are comparatively thick walls in the welds or the end of the

Housing elements of particular advantage.

In addition, in such, newer or special

The advantage of the welding process is that not only the longevity but also the tightness during welding of die-cast components is guaranteed. For example, in the case of diecasting elements (trapped or not visible from the outside) imperfections such as pores, voids, etc. in

different size, distribution or frequency

present in some common welding methods too

Disadvantages, as might possibly lead to loss of tightness of the cooling system.

Advantageously, the first annular channel are the first

Recess of the inner housing member and the second annular channel formed as a second recess of the outer housing member. This ensures that the annular channels or recesses are advantageously distributed to the two housing parts, resulting in an advantageous or space-saving

Training the motor housing can be used.

Also, for example, the first recess of the

Inner housing element and the second recess of the

Outer housing element as thickening / widening of

Cooling channel can be formed. For example, in

radial direction considered the clear cross sections of the annular channels about twice as thick as the clear cross section of the cooling channel. For example, viewed in the radial direction, the clear cross sections of the annular channel are approximately 5 mm thick and the clear cross section of the cooling channel viewed in the radial direction is approximately 2 mm thick.

The advantage is a comparatively large Flow rate, in particular by the pressure with which the cooling liquid or the cooling medium

is applied, in an advantageous manner

changeable / adjustable.

In an advantageous variant of the invention, at least a first wall of the first annular channel or at least a second wall of the second annular channel is formed as an extension of a cooling channel wall of the cooling channel, in particular the first or the second wall is substantially rectilinear designed as an extension of one of the cooling channel walls, i. outside or inside. This means that the cooling channel or the cooling channel wall extends substantially rectilinearly into one of the annular channels, in particular once rectilinearly on the outside of the cooling channel or on the other hand on the inside of the cooling channel. Accordingly, the inner case member or the outer case member can be advantageously used

be produced by casting, since the respective element extends substantially straight across the cooling channel area out into the annular channel into and

if appropriate, also extends to the respective end region / end of the respective element.

Advantageously, the outer housing element comprises at least the first wall of the first annular channel and the

Inner housing member at least the second wall of the second annular channel.

In a particular embodiment of the invention, the first recess of the inner housing element and the second recess of the outer housing element has an offset to

Cooling channel and / or the cooling channel wall of the cooling channel.

Hereby, an advantageous widening of the cooling channel to an annular channel in the context of the invention can be realized in an advantageous manner. Thus, the cooling medium flows through the annular channel, ie in the distribution channel in the sense of the invention, continuously into the cooling channel and preferably in turn from this cooling channel out into the second / other annular channel, ie in the collecting channel in the sense of the invention.

In a preferred embodiment of the invention, at least one cooling channel wall of the inner housing element and / or the outer housing element is at least partially disposed at an acute angle with respect to a rotational axis of the electric machine and / or the inner housing element and the outer housing element. This means that this wall or at least one of the two cooling channel walls, i. of

Inner housing element and / or the outer housing element, not aligned parallel to the axis of rotation or not

cylindrically shaped but substantially

frustoconical or conical is realized. Such an oblique boundary or wall of the inner housing element and / or the outer housing element can be produced by casting in an advantageous manner. So can with one

corresponding acute angled orientation of the wall or

Surface / casing of the respective element, the mold advantageously in a solid state after solidification of the cast material, in particular aluminum or another light metal, are pulled out.

In a preferred variant, wherein both the

Inner housing member and the outer housing member have an acute-angled outer surface / lateral surface, i.

are formed according to a frusto-conical shape, a cooling channel is generated, the corresponding as

Truncated cone sleeve or truncated cone ring is realized. This comprises substantially uniform over its entire length in the direction of rotation considered

Wall thickness or clear cross section. Accordingly, both elements can have a frusto-conical wall / surface

have and are produced by casting technology in an advantageous manner, in particular of light metal, steel or the like.

Preferably, one or both of them

Housing elements, ie, the inner housing member and / or the outer housing member, advantageously one of arranged at an acute angle aligned lateral surface opposite the second lateral surface, which is formed substantially cylindrical.

Thus, especially the inner surface of the inner housing element as exactly as cylindrical form, since this in

advantageous manner for receiving the electrical

Drive system, in particular of the stator with the electric coil system or the like, is formed. Usually, commercially available stator systems are externally / circumferentially cylindrical.

Advantageously, an outer housing element advantageous cooling elements / ribs or the like and connecting pieces, etc., which can be produced in an advantageous manner by casting, in particular with a die-casting process, in particular light metal alloys can for this purpose

be used advantageously.

For example, the inner housing member may also be made of a light metal alloy, although it is quite possible also to use shaped aluminum or even shaped steel, e.g. Extruded or extruded components.

Especially with a material combination of the two

Housing elements of aluminum or light metal with steel welding methods such as the friction stir welding or the friction-crushing welding method are preferable.

In the present invention is of particular advantage that the motor housing with the inner housing member and the outer housing member is particularly inexpensive to produce and the cooling system with the channels is reliably sealed, especially when using two frontally or end-mounted annular shitty joints or shitty seams. embodiment

An embodiment of the invention is illustrated in the drawing and will be explained in more detail with reference to FIGS.

1 shows a schematic cross section through an electrical machine with a motor housing according to the invention,

Figure 2 shows a first, schematic, enlarged

Section of FIG. 1,

3 shows a second, schematic, enlarged

Section of Figure 1 and

FIG. 4 shows a schematic perspective view in a partially sectioned view of the electrical machine according to FIG. 1.

In Figure 1, an electric machine 1 with a

Motor housing 2 according to the invention schematically in

Cross section shown cut. It becomes clear that a rotor unit 3 is arranged centrally within a stator unit 4. This electromagnetic drive system of the electric machine 1 or of the electric motor 1 furthermore comprises, on the circumference, a motor housing 2 according to the invention.

The motor housing 2 in this case has an outer housing element 5 and an inner housing element 6 in the sense of the invention.

In addition, the rotor unit 3 by means of a

schematically illustrated bearing point 7 mounted frontally. Merely for reasons of clarity, the second bearing on the opposite side is not shown in detail. For stable mounting of the bearing 7, the outer motor housing element 5 has a flange 8 arranged on the front side. Thus, the outer housing element 5 is designed as a "cup element", ie a cylinder jacket with a "bottom", which in terms of casting, in particular by means of

Die casting process or the like can be produced in an advantageous manner and at the same time enables a stable and exact storage of the rotor unit 3 by means of the bearing 7.

Especially in the enlarged sections A and B according to Figures 2 and 3 it is clear that between the two housing parts 5, 6 is a cooling channel 9, wherein in each case two terminals 10 and 11 for supply and discharge of the not closer illustrated cooling fluids, in particular cooling water are provided. In the region of the terminals 10, 11, the motor housing 2 also has a collecting strip or in each case an annular channel 12, 13 in the sense of the invention, on the one hand for distributing the cooling medium or the cooling fluid and

on the other hand are provided for collecting the cooling medium or the cooling fluid.

As is clear in Figures 2 and 3, has an annular channel

12 and 13 about a twice as large clear cross-sectional thickness viewed in the radial direction, as the clear

Cross-section of the cooling channel 9 is formed. The cooling medium or the cooling liquid thus flows from a port 10, 11 in one of the two annular channels 12, 13 and in the axial direction along the cooling channel 9 to each

opposite annular channel 12, 13 and through this in the radial direction through the corresponding terminal 10 and 11. For this purpose, a wall 17, 18 of the / of the ring channels 12,

13 as a substantially straight-line extension of a

Cooling channel wall 16 formed, i. especially in longitudinal or cross-section, e.g. cut along the

Rotation axis D. On the opposite side of this rectilinear wall extension, the respective annular channel 12, 13 an offset 19 and paragraph 19 in order to realize the recess 12, 13 in the sense of the invention.

Especially in Figures 2 and 3, these "extensions" of the cooling channel 9 in the context of the invention in the respective

Ring channels 12,13 or recesses 12, 13 clearly. Thus, in the variant according to FIG. 2 in the sense of the invention, the inner wall 18 or annular channel inner wall 18 is designed as a substantially rectilinear extension of the inner cooling channel wall 16 or cooling channel inner wall 16, wherein both "inner walls" 16, 18 form the wall of the Inner housing element 6. That is, here a portion of an annular upper / outer surface of the inner housing member 6, the inner walls

form on the one hand of the annular channel 12 and the other part of the cooling channel 9.

In contrast, in the variant according to FIG. 3 in the sense of FIG

Invention the outer wall 17 or annular channel outer wall 17 as a substantially rectilinear extension of the outer

Cooling channel wall 16 and cooling channel outer wall 16 is formed, wherein both "outer walls" 16, 17, the wall of the

Outer housing member 5 are. That means that here is one

Section of an annular upper / inner surface of the

Outer housing element 5, the outer walls on the one hand of the

Ring channel 13 and on the other hand of the cooling channel 9 form.

According to the invention, the inner housing member 6 to

Forming one of the two ring channels 13 a recess 13, as illustrated especially in Figure 3. Here in the embodiment, the wall thickness of

Inner housing element 6 conical or wedge-shaped and preferably in the region of the annular channel 13 thicker than in the region of the cooling channel 9. In the region of the front end portions of the

Inner housing member 6 is advantageously in each case a weld not shown 14, 15 for

Connection of the inner housing member 6 with the Outer housing member 5 is provided. Here is in the end region or for the connection / weld 14.15 each one

Advantageous chamfering of the inner housing member 6 and / or the outer housing member 5 is advantageous, i. In particular, a (cutting) milling or turning operation for forming a surface as exactly as possible round or fit of the two housing elements 5, 6. This is especially of great advantage to a concentric storage of

To realize rotor unit 3.

In contrast, no exciting post-processing of the respective surfaces is necessary according to the invention in the region of the annular channels 12, 13 and the cooling channel 9, so that at a

The casting skin of the respective material, in particular of the light metal such as an aluminum alloy or the like, is not impaired and thus also the tightness of the respective element 5, 6 is not impaired casting technology production of the inner housing member 6 and Außengehäuseelementes 5. Otherwise, a casting error such as a Pores or voids etc. are exposed or the like, so that quite leaks could arise.

For the advantageous production of a complete seal between the two housing elements 5, 6, in addition to the end-side weld seam 14 or to the end region 14 on the side opposite the end face, there is likewise one

Weld 15 or provide a welding area 15. This means that also on the second front end of the

Inner housing element 6 a weld, fully, i. is made annular over 360 degrees, so that between the two welds 14, 15, the cooling fluid can flow completely sealed. In addition, it is clear above all in FIG. 1 that the cooling channel 9 is not parallel to the central axis of rotation D of the

Electric motor 1 is aligned, but acute-angled

is aligned. Accordingly, the outer surface of the inner housing element 6 at an acute angle to the central

Rotary axis D arranged, as well as the inner surface of the outer housing element 5. Since the two surfaces

are aligned with the same acute angle with respect to the axis of rotation D, the cooling channel 9 is uniformly formed over the entire length in the direction of the axis of rotation D, so that an advantageous

Flow is feasible.

The acute-angled or frustoconical design of the annular cooling channel 9 allows an advantageous

casting-technical production of the two elements 5, 6 of

2. Thus, a casting mold can be designed in a correspondingly conical or frusto-conical shape, so that after solidification of the elements 5 or 6, this can be advantageously removed from the respective casting mold.

As is also clear in FIG. 1, the inside or the inner surface of the inner housing element 6 is the sixth

cylindrical or non-conical, so that a cylindrical stator or a cylindrical

Stator unit 4 can be inserted in an advantageous manner in the motor housing 2 and in the inner housing member 6.

Due to the conical orientation / design of the cooling channel 9 shows that the motor housing 2, which is preferably also formed on the outer surface is substantially cylindrical and optionally without further illustration also cooling elements or cooling fins or the like, a change in the wall thickness of the outer Housing element 5 and a change in the wall thickness of the inner

Housing element 6. Thus, the recess 13 of the

Inner housing element 6 in an advantageous manner on the

The front side of the housing member 6 to be arranged with the thick wall thickness, so that the recess 13 and the groove 13 is space-saving feasible. The same applies to the recess or groove 12 of the outer housing element 5 on the opposite side, in which the wall thickness accordingly is thicker. Again, the recess 12 and groove 12 of the outer housing element can be realized to save space and also be provided with a connection 10. So can just when using casting technology

produced elements of the motor housing 2 by the inventive arrangement or design of the annular channels 12, 13 on the one hand on the inner housing member 6 and on the other hand on the outer housing member 5, a space-saving and lightweight design and also stable design for mounting the stator 4 and the rotor unit 3 can be realized.

Reference sign list

1 electric motor

2 motor housing

3 rotor unit

4 stator unit

5 housing element

6 housing element

7 bearing point

8 front side

9 cooling channel

10 connection

11 connection

12 ring channel

13 ring channel

14 weld

15 weld

16 cooling channel wall

17 wall

18 wall

Claims

claims

1. Motor housing (2) of an electrical machine (1) with an outer housing element (5) and one in the

Outside housing member (5) arranged inner housing element (6), wherein between the outer housing element (5) and the

Inner housing element (6) at least one of a cooling medium can be flowed through cooling channel (9) is arranged, wherein the

Distributing and / or collecting the cooling medium at a first end of the cooling channel (8), a first annular channel (12, 13) and at a second end of the cooling channel (9), a second annular channel (12, 13) is arranged, characterized in that

at least one of the two annular channels (12, 13) as a recess (12, 13) of the inner housing element (6) is formed.

2. Motor housing according to claim 1, characterized in that the first annular channel (13) as a first recess (13) of the inner housing element (6) and that the second annular channel (12) as a second recess (12) of the outer housing element (5) are formed.

3. Motor housing according to one of the preceding claims, characterized in that at least a first wall (17) of the first annular channel (13) or at least a second wall (18) of the second annular channel (12) as an extension of a

Cooling channel wall (16) of the cooling channel (9) is formed.

4. Motor housing according to one of the preceding claims, characterized in that at least one cooling channel wall (16) of the cooling channel (9) and a first wall (17) of the first annular channel (13) or at least a second wall (18) of the second annular channel (12 ) in the direction of an axis of rotation (D) of the inner housing element (6) are formed as a substantially straight wall / line.

5. Motor housing according to one of the preceding claims, characterized in that the outer housing element (5) at least the first wall (17) of the first annular channel (13) and that the inner housing element (6) at least the second wall (18) of the second annular channel ( 12).

6. Motor housing according to one of the preceding claims, characterized in that the first recess (13) of the inner housing element (6) and the second recess (12) of the outer housing element (5) has an offset (19) to the cooling channel (9) and / or Cooling channel wall (16) of the cooling channel (9).

7. Motor housing according to one of the preceding claims, characterized in that at least one cooling channel wall

(16) of the inner housing element (6) and / or the

Outer housing member (5) with respect to a rotation axis (D) of the electric machine (1) and / or the inner housing member

(6) and the outer housing member (5) is at least partially disposed at an acute angle.

8. Motor (1) with a motor housing (2) according to one of the preceding claims.

9. Electric motor (1) with an electromagnetic

Drive system (3, 4) and a motor housing (2) according to one of the preceding claims.

10. vehicle with an electric motor (1) and a

Motor housing (2) according to one of the preceding claims.