Device for driving a compressor, and method for manufacturing the device

A device and a method for manufacturing the device for driving a compressor, in particular an electric motor, with a rotor and a stator with a stator core, which are arranged along a longitudinal axis. The stator exhibits connecting cables produced as sections of conducting wires of coils, and connection lines, that are arranged on a first end face of the stator, one insulation element whose wall that is produced essentially with a hollow-cylinder shape projects beyond the stator core on the first end face of the stator in the axial direction, as well as one cover element with mounting elements with connection passages for mounting plug-in connectors, which each are fully enclosed by a wall. A volume enclosed by the stator core, the cover element and the wall of the insulation element which projects beyond the stator core is filled at least zonally with potting compound.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This patent application is a United States nation phase patent application based on PCT/KR2020/017225 filed on Nov. 30, 2020, which claims the benefit of German Patent Application No. 10 2019 133 998.7 filed on Dec. 11, 2019, the entire disclosures of which are hereby incorporated herein by reference.

TECHNICAL FIELD

The invention relates to a device for driving a compressor, in particular an electric motor, for compressing a vaporous fluid, specifically a refrigerant. The compressor can be used in a refrigerant circuit of a motor vehicle air-conditioning system. The device exhibits a rotor and a stator which extend along a common longitudinal axis. The stator exhibits connecting cables and connection lines that are produced as sections of conducting wires of coils.

BACKGROUND ART

Compressors for mobile applications known from prior art, in particular for motor vehicle air-conditioning systems, and used to convey refrigerant through a refrigerant circuit, which are also called refrigerant compressors, are often produced as piston compressors with variable displacement or as scroll compressors. The compressors are driven either via a pulley or electrically.

An electrically driven compressor exhibits, in addition to the electric motor for driving the appropriate compressing mechanism, an inverter for driving the electric motor. The inverter is used to convert the direct current from a motor vehicle battery into alternating current supplied to the electric motor via electrical connections.

Conventional electric motors of the electrically driven compressors are produced with a ring-shaped stator core with coils arranged thereon and a rotor, wherein the rotor is arranged inside the stator core. Rotor and stator are aligned on a common symmetry axis or rotational axis of the rotor and enclosed by a housing. To be able to reduce the mounting space inside the power vehicle, on the one hand and, on the other hand, to fix the stator in the housing, the clearances between the components of the electric motor, in particular between stator and housing, are very narrow.

The inverter exhibits plug connections for plug-in connectors for electrical connection to connections of the electric motor, which are produced as separate components and pins and electrically connected with connection lines of conducting wires of the coils of the stator. The connecting cables are routed along end faces of the stator core and in most cases not covered by a stator insulation against the housing of the motor. In addition, the clearance to components of the housing is often very narrow.

To be able to provide both an electrical connection and a high insulation resistance, e.g. between the connection lines of the conducting wires, the connection lines or conducting wires, also called phase conductors, are to be insulated electrically both from each other and from other electrically conductive components of the stator and of the motor housing. Areas of the connection lines of the individual phases of the electric motor as sections of the conducting wires of the coils, which are produced, in particular of enamelled copper wire, can be plastic-insulated.

Furthermore, depending on the voltage level, it can be required to provide sufficient insulation clearances between electrically conductive components, e.g. to avoid short-circuits arising from insufficient creepage distances and clearances. The insulation can also exhibit imperfections or porosities which arise during the manufacturing process and substantially reduce the insulation resistance, in particular pinholes, resulting in the risk of electrical flashover, in particular to components of the housing. If two of the copper wires each exhibiting an imperfection in the insulation are arranged side by side and the imperfections are positioned directly opposite one another or at least close to each other, the risk of an electrical flashover between the copper wires is very high.

In particular, the requirements in an electrically driven compressor are extremely high, in particular when operating it in the range of high voltage, e.g. up to 1,000 V. International standards, for example, require that the creepage distances and clearances between two conducting wires or to adjacent electrically conductive components are at least 10 mm to 14 mm for the specified voltage range. The insulation system for use at ultra-high voltages (abbreviated UHV) of at least 800 V for hermetically sealed electric motors for applications in air-conditioning systems installed inside a highly modern electric motor for extra-high voltages (abbreviated “EHV”) of approximately 400 V, in which the shortest air gap between two coils is typically approximately 4 mm and the shortest creepage distance typically approximately 5 mm, is the greatest challenge in automotive engineering.

To be able to reach the required insulation clearances or insulation distances, the electric motors of the electrically driven compressors from prior state of the art require either sufficiently large distances between the connection lines of the conducting wires and further electrically conductive components of the compressor, or the areas of the connection lines of the conducting wires with insufficient distance to other electrically conductive components are to be fully encapsulated. With encapsulation of the connection lines, narrower clearances are also possible between the connection lines of the conducting wires and further electrically conductive components of the compressor compared to unencapsulated connection lines, depending on the voltage level. When using a motor with unencapsulated connection lines, a large mounting space is required by the motor and hence also for the electrically driven compressor.

SUMMARY

The task of the invention is to provide and improve a device for driving an electrically driven compressor of a vaporous fluid, in particular an electric motor. The device is to be designed such that the relevant requirements with reference to insulation coordination are also met for voltage levels of at least 800 V to 1,000 V wherein, in particular, the conducting wires or the connecting cables or connection lines of the conducting wires must be electrically insulated to each other and to adjacent electrically conductive components. The device must be designed such that it can be assembled in an easy and thus time-saving manner and is to exhibit as few individual components as possible and is also be easy to construct to be able to minimize e.g. the weight and the required space, as well as the manufacturing costs.

The task of the invention is solved by way of the objects with the features as disclosed herein.

The task of the invention is solved by way of a device according to the invention, used to drive a compressor of a vaporous fluid, in particular an electric motor. The device exhibits a rotor and a fixed stator with a stator core, which extend along a common longitudinal axis between two end faces.

The stator exhibits connecting cables and connection lines produced as sections of conducting wires of coils, which are arranged on a first end face of the stator, and is positioned preferably in the radial direction on an outer surface of the rotor, enclosing the rotor.

The conducting wires are produced preferably from enamelled and wound copper wire in the area of the coils, wherein ends of the conducting wires which are not wound are brought out from the corresponding winding as connecting cables or connection lines and each as magnetically inactive sections of the conducting wires. The connecting cables, e.g. for connection and for connecting coils of the same phase, are produced preferably merely enamelled in the area of the coils, similarly to the conducting wires in the area of the coils, whereas the connection lines, e.g. for electrical connection with connections of the electric motor, are in addition insulated preferably with a plastic jacket.

The stator exhibits an insulation element whose essentially hollow-cylinder-shaped, in particular hollow-circular-cylinder-shaped wall projects beyond the stator core on the first end face of the stator in the axial direction, wherein the connecting cables or the connection lines are arranged in the circumferential direction on the wall of the insulation element.

The term ‘axial direction’ in this context is to be understood as the direction of the longitudinal axis of the stator, which also corresponds to the longitudinal axis and rotational axis of the rotor. An end face aligned in the axial direction is arranged on a plane that extends vertically relative to the longitudinal axis.

Furthermore, according to the invention, the stator exhibits a cover element with mounting elements with connection passages, each enclosed around the perimeter by a wall, which are intended for mounting plug-in connectors. The cover element is on the first end face of the stator, covering the wall of the insulation element with the connecting cables or connection lines, which projects beyond the stator core, arranged in such a way that it is in contact with the stator core and fully encloses it on its perimeter.

According to the concept of the invention, a volume enclosed by the stator core, the cover element and the wall of the insulation element, which projects beyond the stator core, is filled at least zonally with potting compound.

The insulation element is arranged preferably in a radial direction in such a way that it is in contact with the inside of an outer wall of the stator core. The insulation element can be firmly connected to the stator core.

According to a further embodiment of the invention, the reversing sections of the conducting wires wound to produce coils, which are aligned in the direction of the first end face of the stator, are hidden by the cover element at least zonally and encapsulated with potting compound.

According to an advantageous embodiment of the invention, the cover element exhibits the form of a hollow circular cylinder that is aligned in the axial direction and is produced as a ring, preferably with a full closed perimeter, and with two axially aligned ring surfaces and one radially aligned ring surface.

The axially aligned ring surfaces arranged preferably on an outer radius and on an inner radius of the cover element are aligned parallel to each other and connected to one another via the radial ring surface. A further advantage of the invention is that the radially aligned ring surface is arranged on a plane that is aligned vertically relative to the longitudinal axis of the stator, and the axially aligned ring surfaces are arranged with their end faces connected one to another in such a way the cover element exhibits a U shape in a cross-section through the ring contour.

An end face of at least one axially aligned ring surface, in particular the ring surface arranged on the inner radius of the cover element, which is distally aligned towards the radially aligned ring surface, is in contact with the stator core. The volume produced between the ring surfaces that are connected to one another can be used to accommodate the potting compound. The ring surfaces are produced preferably closed around the full perimeter, wherein merely the radial ring surface exhibits a pass-through opening in the area of a wall of a connection passage.

The cover element is made preferably of an electrically insulating material. Thus, the cover element arranged on the stator core, also in combination with the potting compound, is intended in particular to ensure the required insulation clearances.

A further advantage of the invention is that the mounting elements for the plug-in connectors are integral parts of the cover element so that the cover element and the mounting elements are produced as a unit, in particular as a single-piece injection mould element.

According to a preferred embodiment of the invention, the connecting cables or the connection lines of the conducting wires are arranged in such a way that they are in contact with an outer surface of the wall of the insulation element and aligned essentially along the circumferential direction of the wall, wherein the outer side of the wall of the insulation element exhibits preferably at least one collar that in the circumferential direction is produced as a recess, in particular as a groove, and intended for mounting of one connecting cable or one connection line. The connecting cable or connection line of a conducting wire can be fully integrated into a collar.

‘Full integration’ is to be understood as arrangement of the connecting cable or of the connection line of the conducting wire in the collar, wherein the conducting wire is embedded in the collar over its full diameter. The conducting wire does not project beyond the collar in any point. The maximum diameter of the conducting wire is less than the depth of the collar or corresponds to the depth of the collar.

The at least one collar inside the wall of the insulation element is arranged preferably on a plane aligned vertically relative to the longitudinal axis of the stator. In the case of arrangements with at least two collars inside the wall of the insulation element, the collars are arranged preferably on a plane that is vertically aligned relative to the longitudinal axis of the stator and arranged with an appropriate distance to each other.

According to a further embodiment of the invention, the plug-in connectors are produced of an electrically conductive material, with a cylinder shape, in particular with a circular cylinder shape or pin-like, and carried through a connection passage of a mounting element of the cover element, which is enclosed by the wall, whereby preferably a slot that is produced with the shape of a hollow circular cylinder and intended for mounting a contact element and for accommodation of the potting compound, is provided between the wall of the mounting element and the plug-in connector.

According to a further preferred embodiment of the invention, one contact element each is produced as a hollow-circular-cylinder-shaped sleeve for mounting the plug-in connector. The contact element is arranged in such a way that it encloses the plug-in connector preferably with an inner surface of a lateral surface and establishes electrical contact.

A further advantage of the invention is that an outer diameter of the contact element corresponds essentially to an internal diameter of the wall of the connection passage plus a slot that is produced over the full perimeter and is intended for accommodation of the potting compound so that potting compound can be arranged between the contact element and the wall of the mounting element so as to be able to connect the contact element with the mounting element and thus with the cover element.

According to a further advantageous embodiment of the invention, the connection lines of the conducting wires of the coils are in each case, by way of the contact element, in electrically conductive contact at one end with a plug-in connector arranged inside the contact element, wherein the end of the conducting wire is in electrically conductive contact with the contact element, preferably on an end face of the contact element, which is aligned towards the stator.

The task of the invention is also solved by way of a method according to the invention for manufacturing the device for driving a compressor of a vaporous fluid, in particular an electric motor. The method exhibits the following steps to be observed when assembling the stator:Arranging a stator core with an insulation element and conducting wires wound to produce coils and with connecting cables and connection lines, wherein the connecting cables and the connection lines are arranged on a wall of the insulation element, which projects beyond the stator core in an axial direction;Arranging a cover element with mounting elements, each produced with connection passages that are fully enclosed by a wall on an end face of the stator core aligned in the axial direction, wherein the connection passages are produced with one contact element each, which is each electrically connected to a connection line of a conducting wire, and one plug-connector each is inserted into each of the contact elements, as well asAt least zonally filling of a volume produced between the stator core, the cover element and the insulation element, as well as between the walls of the mounting elements and the contact elements, with potting compound, andArranging a rotor and a stator on a common longitudinal axis, wherein the stator encloses the rotor in the radial direction.

Furthermore, a special advantage of the invention is that a volume produced as a coherent hollow space facilitates grouting with the potting compound as a single process step.

According to a further embodiment of the invention, a volume enclosed by the cover element and by the reversing sections of the conducting wires wound to produce the coils and aligned in the direction of the end face of the stator is at least zonally filled with potting compound during the process of filling, wherein the volumes produced between the stator core, the cover element and the insulation element, as well as between the wall of the mounting elements and the contact elements, and the volume enclosed by the cover element and the reversing sections of the conducting wires wound to produce the coils and aligned in the direction of the end face of the stator are produced as a coherent unit.

The advantageous embodiment of the invention allows the use of the device for driving a compressor, in particular of an electric motor, for compressing a vaporous fluid for a compressor of a refrigerant in a refrigerant circuit of a motor vehicle air-conditioning system.

The device according to the invention for driving a compressor of a vaporous fluid with a minimal number of required components and the method for manufacturing the device in summary exhibit various further advantages:Ease of assembly and ease of fixing of the cover element on the insulation element or stator core, with best possible electrical insulation of the connecting cables and connection lines of the conducting wires, in particular by encapsulating the cover element by way of filling the U section with potting compound, wherein the connecting cables, connection lines, in particular with the connections on the contact elements, and all further electrically conductive connections arranged inside the volume enclosed by the cover element and the stator core are insulated from each other and hermetically against the environment in one process step; furthermore, complete insulation of the current-carrying connections from the refrigerant, and thus minimal degree of contamination inside the encapsulated areas;Increasing the insulation resistances and reducing the footprint, depending on the voltage level, including also insulation of the electrical plug connections between plug-in connectors and contact elements;Avoiding the occurrence of short-circuit currents between the conducting wires and further electrically conductive, inactive components by providing the required insulation distances, depending on the voltage level;Reducing the scrap in manufacturing due to insufficient insulation resistance, resulting in minimal costs, as well asMaximizing the service life of the compressor.

With a single step of assembly for the cover element, in particular magnetically inactive connections between the coils or conducting wires, in particular connection lines of the conducting wires, specifically of the connecting cables, are fully covered to be able to enlarge the insulation clearance and thus to increase the insulation resistance. Furthermore, the end face of the stator which is aligned towards the housing of the motor is mechanically reinforced, which has a positive effect on the shrinking process of the stator in the housing.

DETAILED DESCRIPTION OF AN EMBODIMENT

FIG.1Ashows a stator1of an electric motor as a device for driving a compressor of a vaporous fluid, specifically for a motor vehicle air-conditioning system, for conveying refrigerant through a refrigerant circuit, in a perspective view. The stator1is shown with a stator core2and a cover element3that is arranged on a first end face of the stator1and fitted with mounting elements4for mounting plug-in connectors in a perspective representation.FIGS.1B and1Care each a detail view of the first end face of the stator1with the coils5arranged on the stator core2without cover element in a perspective representation, whereasFIG.1Dshows a detail view of the stator1fromFIG.1Awith the cover element3in a cross-sectional view.

The electric motor, e.g. an AC motor with three phases, exhibits a rotor that is not represented and the stator core2that is arranged in the radial direction on an outer surface of the rotor and thus around the rotor. The stator core2, that is produced preferably as a stack of sheets, and an insulation element6, that is produced of an electrically insulating material, extend along a longitudinal axis7that also corresponds to the longitudinal axis of the stator1and the rotational axis of the rotor, from the first end face to a second end face of the stator1. The insulation element6is produced preferably as an overmould of the stator core2and thus as a single-piece component.

The coils5consist of one wire each that is also called conducting wire8and produced as an electrical conductor and wound around an area of the stator core2, which extends inside in the radial direction, wherein the all conducting wires8are produced from enamelled copper wire. The ends of the conducting wires8which are not wound are brought out from the corresponding winding as connecting cables8aor connection lines8b, each being magnetically inactive sections.

The connecting cables8athat serve for connecting coils5of the same phase with each other are produced as first sections of the conducting wires8exclusively as enamelled wires, whereas the connection lines8bconfigured for electrical connection to the connections of the electric motor as second sections of the conducting wires8are additionally insulated preferably with a plastic material.

The areas of the stator core2extending inwards in the radial direction exhibit the form of a web and are evenly distributed around the perimeter of an outer wall of the stator core2. The insulation element6, that insulates the stator core2and the conducting wires8of the coils5from each other electrically, is arranged between the conducting wires8of the coils5and the corresponding areas of the stator core2. The insulation element6is produced as an extended element in the axial direction on the ends of the webs aligned inwards and in the axial direction. The reversing sections20of the insulation element6which project in the way as described above serve for fixing the conducting wires8of the coils5, which are wound around the webs of the stator core2.

The stator core2, the coils5and the insulation element6form the stator unit of the electric motor.

The insulation element6, that is produced preferably as an overmould of the stator core2, is in the radial direction in contact with the inside of the outer wall of the stator core2with an outer lateral surface. The wall of the insulation element6projects beyond the stator core2on the end faces of the stator1in the axial direction, as shown, in particular inFIGS.1B and1C. The magnetically active sections of the conducting wires8, that are wound to produce coils, are arranged around the areas of the insulation element6, which extend inwards in the radial direction, wherein the insulation element6is arranged between the stator core2and the conducting wire8of the coils5.

The area of the insulation element6which projects beyond the stator core2exhibits a wall that extends in the radial direction, is produced essentially with a hollow-cylinder shape and is interrupted in the circumferential direction. The sections of the conducting wires8, which are magnetically inactive and not wound to produce coils and are routed as connecting cables8abetween the windings of the coils5, are arranged in such a way that they run around the whole perimeter in the area of the insulation element6, which projects beyond the stator core2, and are integrated into the collars produced in the form of a groove. In addition, the magnetically inactive sections of the conducting wires8, that are produced as connection lines8b, can also be arranged inside such collars, also called mounting areas. The area of the insulation element6with the magnetically inactive sections of the conducting wires8, which projects on the first end face of the stator1beyond the stator core2, is also called connection ring.

Depending on the voltage level of the motor, it is imperative to observe the relevant clearances, also called insulation distances, in accordance with the relevant standards between the conducting wires8and other electrically conductive, metal components of the motor, such as the housing, or components of the compressor, to be able e.g. to avoid short-circuits or flashovers between the conducting wires8and adjacent electrically conductive components. Thanks to installation of the cover element3, the insulation clearances are extended, compared to the insulation clearances without cover element, reducing the risk of short-circuits or flashovers.

The cover element3with the mounting elements4with connection passages40, that are fully enclosed by a wall4aand intended for mounting plug-in connectors, as shown inFIG.1D, is arranged on the first end face of the stator1, covering the wall of the insulation element6, which projects beyond the stator core2in the axial direction.

In a state when the stator1is fitted, the cover element3, that is produced in the form of a ring around the longitudinal axis7, is in the axial direction in full-area contact with the stator1, in particular with the stator core2, wherein the outer diameter of the cover element3is smaller than the outer diameter of the stator core2. The mounting elements4for the plug-in connectors9are integral parts of the cover element3so that the cover element3and the mounting elements4are produced as a unit, in particular as a single-piece injection mould element. The single-piece form is realized in a shaping process.

The cover element3produced as an axially aligned ring, that is closed around its full circumference and produced essentially with a cylinder shape, in particular with the shape of a hollow cylinder, specifically the shape of a hollow circular cylinder, exhibits two axially aligned ring surfaces3aand one radially aligned ring surface3b. The axial ring surfaces3a, that are produced on the outer radius and on the inner radius of the cover element3, are aligned parallel to each other and connected to one another via the radial ring surface3b. The radial ring surface3b, that is arranged on a plane aligned vertically relative to the longitudinal axis7, connects the axial ring surfaces3ato one another in such a way that the cover element3exhibits a U shape in a cross-section through the ring contour, preferably with like leg lengths. A first of the axial ring surfaces3ais produced as an outer wall, whereas a second of the axial ring surfaces3ais produced as an inner wall. The radial ring surface3bconnects the axial ring surfaces3aon their end faces to one another. The ring surfaces3a,3bare each produced as surfaces that are closed around the full circumference, wherein the radial ring surface3bis only interrupted in the area of the walls4aof the connection passages40to be able to mount the plug-in connectors9.

The volume produced between the ring surfaces3a,3bserves for accommodation of the area of the insulation element6, which projects beyond the stator core2, with the connecting cables8aand connection lines8bof the conducting wires8, which are arranged thereon, and thus for accommodation of the connection ring and as mould for accommodation of the potting compound, wherein the cover element3, produced with an essentially hollow cylinder shape, is arranged with an inner surface of the first axial ring surface3aproduced as an outer wall, and an outer surface of the second axial ring surface3a, produced as an inner wall each in the direction of a lateral surface of the wall of the area of the insulation element6, which projects beyond the stator core2.

The cover element3covers, in particular, the sections of the enamelled connecting cables8a, that are not wound to produce coils and are brought out from the corresponding windings or brought in into the corresponding windings, and the connection lines8bof the conducting wires8, as well as the reversing sections20of the conducting wires8, that are wound to produce the coils5and aligned towards the first end face of the stator1, towards the environment of the stator1. In particular, the connecting cables8aand the connection lines8bof the conducting wires8are arranged in the radial direction in such a way that they are protected between the insulation element6and the cover element3. Since the cover element3and also the insulation element6are electrically insulating components, the conducting wires8, produced in the insulation element6and covered by the cover element3, are fully enclosed by an electrical insulation.

The cover element3is intended to provide the insulation clearances to other electrically conductive components, such as the housing of the motor, or the required insulation resistances, in particular by way of an enlarged creepage distance, depending on the voltage level, against the housing of the motor, for example.

The volume produced as a hollow space and enclosed by the ring surfaces3a,3bof the cover element3and the connection ring, as well as the reversing sections20of the conducting wires8that are wound to produce the coils5and aligned in the direction of the first end face of the stator1is at least zonally filled or grouted with potting compound so that the insulation element6and the cover element3are firmly and inseparably connected with the conducting wires8arranged between them.

With grouting of the volume or hollow space with potting compound as an additional adhesive, so-called cemented connections are produced to be able to close any gaps for current flow and thus possible flow paths for leakage current or creeping current, wherein the cover element3, the insulation element6and the connecting cables8aand connection lines8barranged thereon are connected to one another, in particular cemented, to avoid creepage distances between adjacent components and, in particular to extend the creepage distances between electrically conductive elements to the minimum required.

A cemented connection is hence to be understood as connecting two materials by way of an appropriate adhesive, such as a glue, resin, epoxy or other grouting material that prevents current flow between two electrically conductive components.

The cover element3consequently serves, in addition to the protection of the connection ring, also as a mould for the potting compound that separates the conducting wires8of different phases from each other. Due to the fact that the conducting wires8are arranged with very narrow clearances to each other, the required creepage distances and clearances are ensured by grouting the entire hollow space produced between the wall of the insulation element6, which projects beyond the stator core2, and the cover element3, by way of the potting compound, with the conducting wires8embedded therein. Thus, for example, an insulation system is provided which meets the requirements placed on applications with ultra-high voltages of at least 800 V.

With covering of the insulation element6, that projects on the end face of the stator1beyond the stator core2, by way of the cover element3and the potting compound, in addition, complete hermetical sealing of the conducting wires8, that are arranged on the connection ring, is provided against the refrigerant as a fluid flowing inside the housing of the electric motor and between the conducting wires8.

After installation of the electric motor or of the compressor, especially during operation, self-detaching of the connection of cover element3and insulation element6is excluded. The cover element3is connected with the insulation element6as firmly as in particular during operation the components cannot be separated without force, e.g. detached due to vibrations.

FIGS.2A and2Bshow the cover element3with the plug-in connectors9inserted into the mounting elements4in a detail representation, as well as the connection lines8beach in a top view, whereasFIG.2Cshows the cover element3in a cross-sectional view through a mounting element4for inserting the plug-in connector9. The conducting wires8of each of the phases are connected to the inverter separately by way of the plug-in connectors9as electrical connection elements between stator1and the inverter.

The pin-like plug-connectors9that are produced of an electrically conductive material are inserted through the connection passages40of the mounting elements4of the cover element3, which are enclosed by the walls4aand each serve as components of an electrical connection between the coils5of the electric motor and the inverter. One ring-shaped or hollow-circular-cylinder-shaped slot10is produced between the wall4aof the mounting element4and the plug-in connector9, which is shown, in particular inFIG.2A. The slot10serves for mounting of a contact element11, produced in the form of a sleeve, and for accommodation of potting compound12.

The connection lines8bof the conducting wires8of the coils5are on their ends8cand via the contact element11electrically connected to a plug-in connector9arranged inside a mounting element4or the contact element11, wherein the end8cof the conducting wire8is in both mechanical and electrically conductive contact with the contact element11on a first end face of the contact element11, which is aligned towards the stator1. The second end face of the contact element11is aligned in a direction pointing away from the stator1and pointing towards the inverter that is not represented here.

The contact element11, that is also produced in the shape of a hollow circular cylinder, is arranged in such a way that it encloses the plug-in connector9with one inner surface of a lateral surface in full-area electrical contact, wherein the internal diameter of the inner surface of the contact element11corresponds essentially to the outer diameter of the hollow-cylinder-shaped plug-in connector9or is a little smaller to be able to facilitate press fitting between the plug-in connector9and the contact element11.

The contact element11is arranged inside a connection passage of a mounting element4, wherein the outer diameter of the contact element11corresponds essentially to the internal diameter of the wall4aof the connection passage plus the slot10for accommodation of the potting compound12. Consequently, the potting compound12is arranged between the contact element11and the wall4aof the mounting element4so as to be able to connect the contact element11with the mounting element4and thus with the cover element3.

When fitting the stator1and after arranging the individual components, such as the stator core2with the insulation element6and the conducting wires8, each with connecting cable8aand connection line8b, the cover element3, as well as the contact element11and the plug-in connector9, the hollow spaces produced between the cover element3and the insulation element6, as well as the walls4aand the contact elements11, are filled or grouted with potting compound12. Since the hollow spaces produce a coherent volume, grouting with the potting compound12can be performed as a single process step, wherein the volume30enclosed by the ring surfaces3a,3bof the cover element3and the connection ring, as well as by the reversing sections of the conducting wires8wound to produce the coils5and the walls4aof the mounting elements4and the contact elements11is filled or grouted with potting compound12in such a way that the cover element3is firmly and inseparably connected both with the insulation element6and the conducting wires8that are arranged between the cover element3and the insulation element6, as well as with the contact elements11or the plug-in connectors9.

The connecting cables8aand the connection lines8bof the conducting wires8, as well as the plug-in connectors9with the contact elements11are fully enclosed or covered by potting compound12and thus electrically insulated from each other and from adjacent electrically conductive components.

The grouting with the potting compound can alternatively also be performed in separate process steps, wherein the hollow spaces, produced between the contact elements11and the walls4aof the mounting elements4, are grouted after assembly of the plug-in connectors9in the mounting elements4, in particular the contact elements11arranged in the mounting elements4, inside the already grouted cover element3, thus insulating the plug-in connectors9from each other.

The volume is to be filled with the potting compound12up to a certain level which is indicated inFIG.2Cby way of the dotted line so that all areas that are critical for creeping currents are grouted. With grouting of the volume, adjacent, in particular electrically conductive components are insulated from each other in such a way that the formation of creepage distances, also called potential paths, that allow the formation of creeping current or short-circuit currents, is avoided, wherein flow paths or paths for potential creeping currents are interrupted and the extension of the stator1with stator core2, insulation element6and conducting wires8is minimized, in particular in the direction of longitudinal axis7. With separation of the current-carrying components from each other and from other electrically conductive components, the requirements with reference to the insulation in the specified voltage range are fully met.

The invention relates to a device for driving a compressor, in particular an electric motor, for compressing a vaporous fluid, specifically a refrigerant. The compressor can be used in a refrigerant circuit of a motor vehicle air-conditioning system. The device exhibits a rotor and a stator which extend along a common longitudinal axis. The stator exhibits connecting cables and connection lines that are produced as sections of conducting wires of coils.