DE102020204357A1 - Drive device and housing for a drive device - Google Patents

Abstract

A drive device (1) is specified, comprising an electric motor (20) which has a motor shaft (21) aligned along a central axis (2), with a drive side (A) and an axially opposite non-drive side (B), - An electronics unit (30) - and a higher-level housing (10), the higher-level housing (10) having a first housing part (10a) in which the electric motor (20) is arranged, and a second housing part (10b), in which the electronics unit (30) is arranged, wherein the second housing part (10b) adjoins the non-drive side (B) of the first housing part (10a) in the axial direction and is connected to this by a connecting part (10i) located axially in between, and wherein the connecting part (10i) has one or more recesses in the area of its outer contour which form one or more radially outer separating gaps (15) with respect to the higher-level housing (10) n a housing (10) for such a drive device (1) is specified.

Description

The present invention relates to a drive device with an electric motor and an electronics unit and a superordinate housing for the electric motor and the electronics unit. The invention also relates to a housing for such a drive device.

Integrated electrical drives are known from the prior art, in which, for example, an electric motor and a converter are accommodated together in a superordinate housing as compactly as possible in order to form a compact functional unit. In the case of many such integrated drive devices, the components are cooled by self-cooling. In this context, self-cooling should generally be understood to mean passive cooling by free convection, in which no coolant (neither a cooling liquid nor air) has to be actively circulated. With such self-cooling, there is neither a coolant line nor a fan. By avoiding such components (in particular active forced air coolers), additional noise emissions can advantageously be avoided. In addition, without active cooling, a higher degree of protection can often be achieved more easily and / or wear can be reduced. For these reasons, self-cooled, integrated drive devices are often used, especially in servomotor drives (especially as industrial drives for conveyor belts or robots or the like).

A disadvantage of the common arrangement of the electric motor and the additional electronics unit in a common housing is that an additional heat source is introduced into the typically relatively compact motor housing by the additional electronics unit. This increases the amount of heat to be dissipated during cooling compared to a pure motor housing (without integrated electronics).

In particular in the case of a very compact design of the higher-level housing, it is therefore much more difficult to heat such an integrated drive unit solely through its own cooling.

From the prior art, designs are also known in which the electric motor and an associated electronics unit are each arranged in separate housings. In comparison to such a separate encapsulation, on the other hand, a combined, higher-level housing, in particular in the case of a compact design, typically has a smaller overall outer surface for dissipating heat to the environment. Another difficulty with the arrangement of the electric motor and electronics unit in a common housing and the associated common cooling is due to the fact that the individual components have different limit temperatures. In particular, the control electronics of a converter are comparatively temperature-sensitive and typically have an operating temperature below 100 ° C. The cooling in the corresponding area of the higher-level housing must therefore be particularly effective for such sensitive components.

A measure known from the prior art for improved cooling of an integrated drive unit is the arrangement of surface-enlarging structures in the outer area of a higher-level housing. For example, cooling fins or cooling spikes can be arranged on the outer housing wall. The disadvantage of this solution is that such complex geometric structures have to be avoided for reasons of hygiene, especially in many industrial applications such as, for example, in food processing or medical technology. In particular, cooling structures with high aspect ratios are difficult to keep clean when such a drive unit is in operation, since particles can easily get stuck between the cooling structures. Further disadvantages of this solution can be seen in the fact that the manufacturing expenditure is comparatively high and that the space requirement of the higher-level housing is increased by the cooling structures.

An alternative measure from the prior art is to introduce a thermal barrier within such a combined housing. For example, the higher-level housing for the electric motor and the electronics unit can be formed predominantly from a metallic material. However, between the area of the electric motor and the area of the electronics unit, this metallic shell can be interrupted and replaced in this transition area by a thermally poorly conductive material - for example by a plastic. Such a thermal barrier can possibly act at the same time as an electromagnetic barrier between the motor area and the electronics area. In this solution there are therefore two individual housing parts, seen from a thermal point of view, which are only weakly thermally coupled by the transition area, but are mechanically or geometrically connected to one another as a unit. Since only the material is changed in the transition area and not the shape, a uniform outer contour of the higher-level housing can be present, in particular despite the thermal decoupling. However, the disadvantage of this variant is the loss of the external surface available for self-cooling compared to two housings that are also geometrically separated. Such an integrated drive unit is therefore usually a smaller one Have power as a corresponding separate drive unit with a structurally identical motor.

The object of the invention is therefore to provide a drive device which overcomes the disadvantages mentioned. In particular, an integrated drive device with a combined housing is to be made available, in which the cooling is particularly efficient and nevertheless a comparatively compact dimensioning can be achieved. Another object is to provide a combined housing for such a drive device.

These objects are achieved by the drive device described in claim 1 and the housing described in claim 15.

The drive device according to the invention comprises an electric motor, an electronics unit and a higher-level housing. The electric motor has a motor shaft aligned along a central axis, with a drive side (A-side) and an axially opposite non-drive side (B-side). The higher-level housing has a first housing part in which the electric motor is arranged. It also has a second housing part in which the electronics unit is arranged. The second housing part adjoins the non-drive side of the first housing part in the axial direction and is connected to it by a connecting part axially in between. In this case, the connecting part has one or more recesses in the area of its outer contour, which form one or more radially outer separating gaps with respect to the higher-level housing.

The A-side of the electric motor should be understood here to mean that axial end region of the electric motor in which the output motor shaft end is arranged. Accordingly, the B-side of the electric motor is the side facing away from the driven motor shaft end. The electronics unit is therefore arranged on this B-side of the electric motor. Correspondingly, the second housing part, which surrounds the electronics unit, adjoins the first housing part, which surrounds the electric motor, on the B-side. In this way, the A-side of the electric motor is sufficiently freely accessible to be able to derive or tap the torque generated here via the motor shaft.

A “higher-level housing” is to be understood here generally as a housing which encloses both the electric motor and the electronics unit. In particular, such a “superordinate housing” has a superordinate outer contour which extends over both housing parts in the manner of a common envelope. This has the effect that such a higher-level housing is perceived from the outside as a geometric unit and not as two separate components lying next to one another. In the case of such a “superordinate outer contour”, in particular the cross-sectional shape and the cross-sectional area are essentially aligned with one another across both housing parts. In this case, the cross-sectional shape and cross-sectional area can either be entirely uniform over both housing parts or they can vary essentially continuously over these two housing parts (for example by a bevel extending over both housing parts). It is essential that the higher-level housing is perceived as a unit across both housing parts. In the case of an "essentially aligned" design of the two housing parts, however, a smaller gradation in the transition area, in which, for example, the cross-sectional area changes by up to 10%, should not be explicitly excluded.

By means of the at least one recess in the connecting part between the two mentioned housing parts, at least one separating gap is formed in relation to this described superordinate outer contour. This separation gap is in particular generally filled with air. This at least one separating gap is characterized in that it does not extend into the center of the housing, in particular in the radial direction. In other words, it does not extend to the central axis. As a result, the two housing parts are not completely separated from one another, but rather remain connected to one another at least in the center of the drive device. As a result, a higher-level housing is formed that is encapsulated overall from the external environment. The number, size and shape of the separating gaps (or the separating gap) can be designed in various ways. However, it is essential for all design variants that the at least one separating gap in the connection area between the two housing parts increases the surface area available for self-cooling. In addition, the two housing parts are thermally separated by the at least one separating gap (compared to a housing wall that is continuous in the area of the enveloping outer contour). This can have the effect that the two housing parts have a different operating temperature when the drive device is in operation, which temperature is adapted to the respective thermal requirements of the electric motor or the electronic unit.

In comparison to the solution known from the prior art with a thermally poorly conductive material in the connection area Thus, in the solution according to the invention, an enlargement of the effective outer surface is achieved through the separating gap. In comparison to the alternative known solution with (large) cooling structures protruding outward from the housing wall, the solution according to the invention with the separating gap enables a less complex and / or easier to keep clean geometric shape to be realized. In contrast to the cooling structures protruding outward from the prior art, the at least one separating gap creates a shape that deviates locally from the superordinate outer contour towards the inside (that is to say towards the center). This increases the area effective for self-cooling, but without increasing the space required by the higher-level housing. The use of additional outwardly protruding cooling structures (in addition to the separating gap) should not be excluded in principle. Such optional cooling structures can, however, be designed significantly smaller and / or with a significantly lower aspect ratio compared to the prior art, so that they contribute significantly less to the space requirement of the housing and / or to potential contamination than those known from the prior art Solutions.

Overall, the solution according to the invention can therefore provide an integrated drive device which can be effectively cooled by its own cooling and which at the same time has a compact size and / or a relatively simple geometrically shaped enveloping outer contour, so that existing hygiene requirements can also be met comparatively easily . In this way, a particularly powerful and at the same time compact drive device can be implemented overall.

The housing according to the invention is designed as a housing for a drive device. This is, for example, an integrated drive device with an electric motor and an electronics unit, in particular a drive device according to the present invention. The housing has a first housing part which is provided for an electric motor of the drive device. In addition, the housing has a second housing part which is provided for an electronic unit of the drive device. The second housing part adjoins a non-drive side of the first housing part in the axial direction and is connected to this by a connecting part axially in between. In the area of its outer contour, the connecting part has one or more recesses which form one or more radially outer separating gaps with respect to the higher-level housing. The advantages of the housing according to the invention result analogously to the advantages of the drive device according to the invention described above.

Advantageous refinements and developments of the invention emerge from the claims dependent on claim 1 and the following description. The described configurations of the drive device and the housing can generally be advantageously combined with one another.

Thus, according to a generally advantageous embodiment, the electronics unit is designed for electronic control and / or supply of the electric motor. In particular, the motor control can therefore be integrated together with the electric motor in a higher-level drive device. The electronics unit can be designed to supply the electric motor with electrical energy. In this embodiment in particular, it is generally advantageous if the electronics unit has one or more power electronic components. In particular, the electronics unit can comprise at least one frequency converter. Such a converter is understood to mean a converter which converts the mains voltage with constant frequency and voltage into a three-phase voltage system with variable frequency and / or variable voltage. This three-phase voltage system is fed, for example, to a three-phase motor to be driven (for example an asynchronous machine or synchronous machine) in order to specify the speed of the electric motor by selecting the output frequency of the converter accordingly.

In general and regardless of the specific design of the power electronics, it is advantageous to integrate precisely such power electronic components together with the electric motor in a compact unit. On the one hand, the required space requirement can be significantly reduced and, moreover, the required electromagnetic compatibility of the overall system can be realized much more easily.

As an alternative or in addition to the electronic control and / or supply components described, the electronics unit can also have one or more sensors for monitoring a motor property. For example, this can be a sensor for measuring a temperature, a speed, a vibration and / or a noise of the electric motor. Furthermore, the electronics unit can also have additional optional components for regulation and / or communication.

According to a generally advantageous embodiment of the at least one separating gap, it can run perpendicular to the central axis. He can therefore in particular extend mainly in the radial and / or azimuthal direction.

Such an orientation of the separating gap enables the higher-level housing to be subdivided into axial subsections in a symmetrical manner.

Generally advantageously, the at least one separating gap can have an axial gap width which is in the range between 2% and 15%, particularly preferably between 5% and 10% of the axial length of the higher-level housing. Such an axial gap dimension is in particular large enough to divide the drive device into two separate partial areas in a thermally effective manner and to promote self-cooling of the two housing parts, in particular also by convection in the area of the gap. On the other hand, such an axial gap dimension is, in particular, also small enough that the higher-order housing nevertheless appears to the outside as a geometric unit. In particular in comparison to an even more axially separated configuration, there is a relatively small overall space requirement with such a limited axial gap width despite the thermal separation. This effectively combines the advantages of a certain thermal separation and close spatial integration.

Generally and independently of the axial gap width, the at least one separating gap can have a radial gap depth which is in a range between 5% and 90% of the axial height, particularly preferably between 10% and 80% of the axial height. The axial height of the drive device should generally be understood to mean the radial distance between the central axis and the outer wall of the housing, which is geodetically underneath (in the normal installation position of the drive device). If this dimension varies over the length of the housing, the axis height should be understood as the largest such dimension. Such a radial gap depth is particularly large enough to effectively subdivide the drive device into two thermally separated subregions. Generally advantageous, the radial gap depth is at least as great as the thickness of the housing wall in the remaining areas of the higher-level housing. In other words, the housing wall is indented so far inwardly in the region of the separating gap (and optionally at the same time thinned) that the thermal coupling of the housing parts by the housing wall is locally significantly impaired. However, the housing is not completely interrupted: At least one residual housing wall remains in the connecting part, which mechanically connects the two housing parts and contributes to an encapsulation of the entire higher-level housing. Because of the radial depth of the separating gap, this remaining housing wall is therefore located radially further inward than the remaining parts of the housing wall. It can optionally be made thinner than the other parts of the housing wall, but alternatively they can also be made essentially the same thickness. According to a first variant, the remaining housing wall is made from the same material as the remaining parts of the housing wall. This can be a metallic material, for example. Alternatively, however, a different material can in principle also be used in the area of the rest of the housing wall. The remaining housing wall can either be formed in one piece with the remaining areas of the housing wall or, alternatively, be attached to them as a separate element (in particular hermetically sealed).

The radial gap depth in the advantageous area mentioned is dimensioned so that a sufficiently large residual housing remains in the center of the drive device to connect the electric motor and the electronics unit to form a higher-level component that is encapsulated towards the outside. In particular, a cable duct for the electrical connection of the electric motor and the electronics unit can advantageously be guided in this remaining housing.

According to a generally advantageous embodiment, the size ratio between the radial gap depth and the axial gap width is at most 5 to 1. Such a moderate aspect ratio of the at least one separating gap ensures that this too does not contribute excessively to the drive device being susceptible to contamination. Due to the presence of a separating gap, there is in principle a susceptible point for the increased deposition of particles. By choosing a relatively moderate aspect ratio as described, however, the restrictions resulting therefrom with regard to the hygienic requirements can advantageously be mitigated.

According to a first advantageous embodiment variant for realizing the thermal separation, the housing can have exactly one separating gap running around the outer contour of the connecting part. In other words, the separating gap then extends annularly over the entire circumference of the housing. In this way, the higher-level housing can be divided particularly effectively into two thermally separated sub-areas. As an alternative to the one circumferential separating gap, there could in principle also be a plurality of axially spaced, annular circumferential separating gaps. Such an azimuthally circumferential separating gap can in principle also be designed in a stepped manner, so that it is subdivided, for example, into two (or more) axially adjacent subregions with different radial gap depths.

According to an alternative advantageous embodiment, the housing has a plurality of separating gaps arranged offset in the axial direction and / or in the circumferential direction. In the variant with several axially spaced separating gaps, a kind of rib structure can be formed by these separating gaps, which, similar to the outwardly protruding cooling fins of a heat sink, increases the surface effective for self-cooling even more than would be the case with a single separating gap. The variant with several separating gaps spaced apart in the circumferential direction is particularly advantageous when the outer contour is composed of individual partial areas and only these partial areas (but not the entire outer contour) are to be interrupted by the separating gaps. This is the case, for example, with an essentially rectangular cross-sectional geometry in which the corners are rounded and / or notched so that the corner regions are not covered by the separating gaps.

According to a further advantageous embodiment, the connecting part has one or more connecting rods which additionally connect the first housing part and the second housing part to one another across the separating gap. In addition to the rest of the housing located radially on the inside, a further connection is created which gives the higher-level housing greater mechanical stability. This embodiment is particularly advantageous when there is only a single, comparatively deeply cut separating gap, which mechanically separates the two housing parts strongly. In this case, a mechanically stable higher-level unit can nevertheless be implemented by means of the connecting rods.

In a generally advantageous embodiment, the first housing part and the second housing part can have an outer contour that is essentially aligned with one another. In other words, these two housing parts can merge into one another over the connecting part and thus also over the at least one separating gap in the sense of a substantially uniform outer contour. This ensures that the higher-level housing forms a coherent geometric unit towards the outside despite the separating gap.

In a particularly advantageous manner, the first housing part and the second housing part even have an outer contour that essentially matches in terms of shape and size. However, smaller deviations in the shape and / or size of the cross-sectional area in the area of the transition between the housing parts should not be excluded. In particular, there can be a change in the cross-sectional area of up to 10% in the transition area, for example. Alternatively or additionally, with an essentially identical basic shape (for example a rectangular shape), there may be minor deviations in the type of rounding of the corners or in the form of additional or modified recesses and / or projections, in particular in the area of the corners.

Generally preferred, both the electric motor and the electronics unit can be designed to be self-cooled. In such a completely self-cooled embodiment, the advantages of the invention as described above are particularly effective. Alternatively, however, in principle, in spite of the embodiment according to the invention, which is particularly favorable for self-cooling, active cooling could also be provided at least in a partial area. For example, the second housing part with the thermally particularly sensitive electronics unit could be cooled by additional active cooling. This can be, for example, an additional active fan or an active circulation of a liquid coolant such as water or oil.

Optionally, the first housing part and / or the second housing part can have one or more additional cooling structures in a partial area of the respective outer contour. These cooling structures can in particular be surface-enlarging cooling structures which protrude outward from the general envelope of the outer contour. For example, outwardly protruding cooling ribs, spines, fins, waves, knobs or other types of surface-enlarging projections can be provided. It is particularly preferred here if these cooling structures have a radial depth of at most 10% and in particular only at most 5% of the axial height. Such a small dimensioning of these optional additional cooling structures has the advantage that the associated restrictions with regard to the hygienic requirements are effectively mitigated in comparison to larger structures. To achieve this goal, the aspect ratio between the radial depth of such a cooling structure and the axial and / or azimuthal distance to a corresponding adjacent cooling structure can be at most 3 to 1 and in particular at at most 2 to 1.

In particular, this optional additional cooling structure can be arranged in the area of the B-side of the first housing part. This is the area of the housing part assigned to the motor which, due to its integration into the higher-level housing, can be particularly poorly cooled. In order to compensate for this effect, in this locally limited area of the housing, the described, advantageously comparatively small dimensioned cooling structures can be used particularly effectively.

The drive device can generally be a servo drive device, for example. With such a drive device, the advantages of the invention in relation to a very compact implementation of a powerful integrated drive come into play particularly effectively.

In general, the drive device can be a drive device for an industrial installation (a so-called industrial drive), for example a drive device for a conveyor belt or a robot.

• 1 einen schematischen Längsschnitt einer Antriebseinrichtung nach einem ersten Beispiel der Erfindung zeigt,
• 2 eine schematische perspektivische Darstellung einer Antriebseinrichtung nach einem zweiten Beispiel der Erfindung zeigt,
• 3 eine schematische Seitenansicht einer Antriebseinrichtung nach einem dritten Beispiel zeigt und
• 4 eine schematische perspektivische Darstellung der Antriebseinrichtung der 3 zeigt.

The invention is described below on the basis of a few preferred exemplary embodiments with reference to the attached drawings, in which:

• 1 shows a schematic longitudinal section of a drive device according to a first example of the invention,
• 2 shows a schematic perspective illustration of a drive device according to a second example of the invention,
• 3 shows a schematic side view of a drive device according to a third example and
• 4th a schematic perspective illustration of the drive device of 3 shows.

Identical or functionally identical elements are provided with the same reference symbols in the figures.

In 1 is a drive device 1 shown according to a first embodiment of the invention, in a schematic longitudinal section along the central axis 2 the drive device. The drive device 1 has a higher-level housing 10 on, in which both an electric motor 20th as well as an electronics unit 30th are arranged. For this purpose, the housing 10 a first housing part 10a on, in which the electric motor is arranged, and a second housing part 10b in which the electronics unit 30th is arranged. These two housing parts 10a and 10b are arranged axially adjacent to each other and are connected to each other by a connecting part 10i tied together. The housing is in the radial direction 10 to the outside through a higher-level housing wall 11 limited which between the two housing parts 10a and 10b in this example a uniform wall thickness d having. In the axial direction, the housing is on the side of the first housing part 10a through a first housing cover 12a limited and on the side of the second housing part 10b through a second housing cover 12b .

The electric motor 20th includes a motor shaft 21 which is in the area of the central axis 2 and is aligned along this. On the side of the drive device shown on the left 1 protrudes this motor shaft 21 out of the case 10 out, so that the generated torque can be diverted here. This side of the engine is therefore also called the drive side A. designated. The opposite side of the motor is the non-drive side B. . The second part of the housing 10b closes in the area of the non-drive side B. in the axial direction on the first housing part 10a at.

The electric motor 20th has in this example an external and fixed to the first housing part 10a connected stator 23 on. The stator includes a laminated stator core 24 embedded stator winding 25th . Inside the stator 23 is a rotatably mounted rotor 22nd arranged, which transmits torque to the motor shaft 21 connected is. The other elements of the rotor 22nd (in particular a rotor winding or permanent magnets) are not shown here for the sake of clarity. The motor shaft 21 is about appropriate stock 14th on the first housing cover 12a and an axially opposite, inner bearing shield 13th rotatably supported.

The electric motor 20th is via one or more connecting lines, shown here only extremely schematically 31 with the electronics unit 30th tied together. This is used to control and / or supply the electric motor with electricity 20th . Some possible electrical and electronic components are shown here by way of example, which can be present either individually or in combination with one another within the electronic unit. For example, 32 denotes a component of the power electronics, which can in particular be designed as a frequency converter or can include such a frequency converter. With 33 is a control electronics for the electric motor. With 34 is communication electronics for communication in particular with components located outside the drive device. With 35 Here, several elements of the sensor electronics are referred to, with which, for example, a temperature, a speed, a vibration and / or a noise of the electric motor can be measured and / or processed.

In the axially between the two housing parts 10a and 10b lying connection area 10i lie in the area of the outer contour of the higher-level housing 10 one or more recesses in front, through which corresponding separating gaps 15th are trained. For further details This separating gap or these separating gaps are shown in the upper area and in the lower area of the cross-sectional representation, different realizations: Thus, in the upper part of the drawing, there is only a single separating gap 15th shown, which has a comparatively large axial gap width b and a medium-sized radial gap depth t having. In the lower part of the drawing, in contrast, there is an axially adjacent arrangement of three adjacent separating gaps 15th shown. Compared to the separating gap shown above, these are due to a smaller axial gap width b and a smaller radial gap depth t marked. These two different shapes are only to be understood as examples and are intended to show the possible variations. In a real embodiment of the drive unit, however, a uniform shape will typically be selected which extends symmetrically over the circumference of the housing.

The essential function of the at least one separating gap 15th is, the higher-level housing in two thermally separated individual parts 10a and 10b to subdivide and at the same time to enlarge the effective external area for self-cooling. The enlargement of the surface can be clearly seen in the cross-sectional view. The thermal separation is also partly due to an extension of the thermal path length in the area of the outer wall and partly in this example also to a lower remaining wall thickness in the area of the separation gap. The remainder of the housing, which is shown in the upper area of the figure and is located radially further inward, thus has 19th a reduced wall thickness compared to the other housing parts. However, this is not absolutely necessary. In any case, however, it is essential that the thermal coupling of the two housing parts 10a and 10b is deteriorated in some form by the separation gap. This is advantageously achieved in that the radial depth t the recess at least in the range of the typical wall thickness d lies. The ones in the other areas 10a and 10b present case wall 11 should therefore be broken in the area of the separating gap. The radial depth t can generally be advantageous in a range between 10% and 80% of the shaft height H the drive device lie. In any case, a residual housing located radially on the inside remains 19th . The axial length (= gap width b ) the recess can advantageously be in a range between 2% and 15% of the total axial length 1 of the housing 10 lie.

The rest of the case wall 19th can be in one piece or in several pieces with the remaining parts of the housing wall 11 be trained. In 1 a multi-part design is indicated by the hatching only by way of example. The rest of the housing wall 19th hermetically sealed to be attached to the remaining housing wall (perforated in the area of the separating gap).

The material of the housing wall can be in the area of the at least one separating gap 15th in principle be chosen to be the same as the material in the other housing parts 10a and 10b . A one-piece, axially continuous housing wall can then be particularly advantageous 11 Act. In principle, however, could be in the area 10i a different material can also be used. The housing wall is typically and generally advantageous at least in the area of the housing parts 10a and 10b formed from a metallic material. This can be, for example, aluminum, an aluminum alloy or also a steel. Die-cast aluminum housings are particularly preferred. However, milled metallic housing walls can also be used, for example.

In the example of the 1 show the two housing parts 10a and 10b an identical cross-sectional geometry and cross-sectional area, as can be seen from the uniform outer contour in the sectional view. It is advantageous in any case in connection with the present invention if the two housing parts 10a and 10b are designed essentially in alignment with one another.

In the lower part of the 1 it is shown that the first housing part 10a in a sub-area 16 its outer contour a plurality of optional cooling structures 17th may have. These cooling structures 17th are here, for example, formed as cooling fins and can (if they are present) in particular over the entire circumference of the corresponding housing section 16 extend. But they can also be omitted completely, as shown here as an example in the upper part of the drawing. If they are present, however, it is particularly advantageous if such cooling structures have a limited radial depth t17 have, so that a contamination in the area of these cooling structures 17th can be kept low. It is also advantageous if the aspect ratio between the radial depth t17 and the axial distance s17 of such neighboring cooling structures is also relatively small.

In 2 is a schematic perspective illustration of a drive device 1 shown according to a second example of the invention. The arrangement of the electric motor 20th and the electronics unit 30th inside the two housing parts 10a and 10b is essentially analogous to the example 1 even if the components 20th and 30th are not recognizable in this external view. In the example shown, the connection area 10i of the housing 10 a series of four axially adjacent separating gaps 15th on. These Separating gaps do not extend over the entire circumference of the housing: As can be clearly seen in the perspective view, the outer contour of the housing has an approximately rectangular cross-sectional shape, but the corner areas are turned inwards and each rounded. This results in a total of four flat outer surfaces 40 , which by the more complex shaped corner areas 41 are connected to each other. In the example shown, the separating gaps extend 15th in each case not over the entire circumference, but only in the area of the respective flat outer surface 40 . In this way, there is therefore both an axial sequence of four separating gaps and an azimuthally adjacent arrangement of four separating gap segments in each case at a given axial position. The (again optional) cooling fins are also in a corresponding manner 17th each divided into four azimuthal subsegments, namely one for each of the flat outer surfaces 40 .

Also with the example of 2 are the cross-sectional shapes and cross-sectional areas between the two housing parts 10a and 10b essentially uniform. However, it lies between the connecting part here 10i and the second housing part 10b a small gradation, through which the cross-sectional area in the area of the second housing part 10b is reduced in size. However, this insignificant reduction in the cross section reduces the effect of the higher-level housing 10 as a geometric and mechanical unit is not affected.

In 3 is a schematic side view of a drive device 1 shown according to a third example of the invention. Here, too, the arrangement of the electric motor and the electronics unit is in the two housing parts 10a and 10b analogous to the two previous examples. In contrast to the previous examples, lies in the connection area 10i here only a single separating gap 15th before, which extends over the entire circumference of the higher-level housing. This is also in 4th easy to see, which shows a schematic perspective illustration of the same embodiment. The ring-shaped separating gap 15th is here in two axially adjacent sub-areas 15a and 15b divided. The radial gap depth falls in the process t different in these two sub-areas: In the sub-area 15a is the separation gap 15th significantly less deep than in the sub-area (which is comparatively narrower in the axial direction) 15b . But also in part 15b What remains is a residual housing located radially on the inside 19th , in which, in particular, the connecting lines between the electric motor and the electronics unit are routed. To with this comparatively narrow remaining housing 19th Nevertheless, the two housing parts are to ensure sufficient mechanical stability 10a and 10b here additionally through a number of connecting rods distributed over the circumference 19th tied together. Due to the relatively high gap depth t especially in the sub-area 15b In this example, there is a comparatively strong thermal separation of the two housing parts 10a and 10b and also causes a comparatively strong increase in the thermally effective housing surface.

List of reference symbols

1

Drive device

2

central axis

10

higher-level housing

10a

first housing part

10b

second housing part

10i

Connecting part

11

Housing wall

12a

first housing cover

12b

second housing cover

12c

third housing cover

13th

internal bearing shield

14th

camp

15th

Separation gap

15a

first separating gap section

15b

second separation gap section

16

Sub-area

17th

Cooling structure

18th

Connecting rod

19th

Remaining housing wall

20th

Electric motor

21

Motor shaft

22nd

rotor

23

stator

24

Stator laminated core

25th

Stator winding

30th

Electronics unit

31

Connecting line

32

Power electronics (frequency converter)

33

Control electronics

34

Communication electronics

35

Sensor electronics

40

Exterior surface

41

Corner area

A.

Drive side

B.

Non-drive side

b

axial gap width

d

Wall thickness

H

Axle height

1

axial length of the housing

s17

axial spacing of the cooling structures

t

radial gap depth

t17

radial depth of the cooling structures

Claims (15)

Drive device (1) with - An electric motor (20), which has a motor shaft (21) aligned along a central axis (2), with a drive side (A) and an axially opposite non-drive side (B), - an electronic unit (30) - and a superordinate housing (10), the superordinate housing (10) having a first housing part (10a) in which the electric motor (20) is arranged, and a second housing part (10b) in which the electronics unit (30) is arranged wherein the second housing part (10b) adjoins the non-drive side (B) of the first housing part (10a) in the axial direction and is connected to this by a connecting part (10i) located axially in between, and wherein the connecting part (10i) has one or more recesses in the area of its outer contour which form one or more radially outer separating gaps (15) with respect to the superordinate housing (10). Drive device (1) according to Claim 1 , in which the electronics unit (30) is designed for the electrical control and / or supply of the electric motor. Drive device (1) according to one of the Claims 1 or 2 in which the electronics unit (30) has one or more power electronic components (32), in particular at least one frequency converter. Drive device (1) according to one of the preceding claims, in which the at least one separating gap (15) runs perpendicular to the central axis (2). Drive device (1) according to one of the preceding claims, in which the at least one separating gap (15) has an axial gap width (b) which is in the range between 2% and 15% of the axial length (1) of the superordinate housing (10). Drive device (1) according to one of the preceding claims, in which the at least one separating gap (15) has a radial gap depth (t) which is in a range between 10% and 80% of the axis height (h). Drive device (1) according to one of the preceding claims, the housing (10) of which has exactly one separating gap (15) running around the outer contour of the connecting part (10i). Drive device (1) according to one of the Claims 1 until 6th , the housing (10) of which has a plurality of separating gaps (15) arranged offset in the axial direction and / or in the circumferential direction. Drive device (1) according to one of the preceding claims, in which the connecting part (10i) has one or more connecting rods (18) which additionally connect the first housing part (10a) and the second housing part (10b) to one another across the separating gap (15) . Drive device (1) according to one of the preceding claims, in which the first housing part (10a) and the second housing part (10b) have an outer contour that is aligned with one another. Drive device (1) according to Claim 10 , in which the first housing part (10a) and the second housing part (10b) have an outer contour that is essentially identical in shape and size. Drive device (1) according to one of the preceding claims, in which both the electric motor (20) and the electronics unit (30) are designed to be self-cooled. Drive device (1) according to one of the Claims 1 until 11 , in which the electric motor (20) and / or the electronics unit (30) is cooled by an additional active cooling device. Drive device (1) according to one of the preceding claims, in which the first housing part (10a) and / or the second housing part (10b) has one or more cooling structures (17) which have a radial depth (t17 ) have a maximum of 10% of the axle height. Housing (10) for a drive device (1), - which has a first housing part (10a) which is provided for an electric motor (20) of the drive device (1), and which has a second housing part (10b) which for a Electronic unit (30) of the drive device (1) is provided, - the second housing part (10b) adjoining a non-drive side (B) of the first housing part (10a) in the axial direction and connected to it by a connecting part (10i) located axially in between - and wherein the connecting part (10i) has one or more recesses in the area of its outer contour which form one or more radially outer separating gaps (15) with respect to the higher-level housing (10).

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