DE102023203566A1 - Electric motor and refrigerant compressor with such an electric motor - Google Patents

Abstract

The invention relates to an electric motor (4). This comprises a stator (20), a connection unit (26) with a number of conductor tracks (28) for connecting coils (22) of the stator (20), wherein the connection unit (26) is arranged in the axial direction (A) above the stator (20), and electronics (34) for operating the stator (20), and a housing (11) with an electronics compartment (36) for the electronics (34) and with a motor compartment (12) for the stator (20) and for the connection unit (26), wherein the electronics compartment (36) and the motor compartment (12) have a common housing partition (38). Feedthrough conductors (40) protrude through the housing intermediate wall (38) for contacting the electronics (34), each with a phase connection of the interconnection unit (26) designed as a spring contact element (32), wherein each of the spring contact elements (32) is designed to form a plug contact with the feedthrough conductor (40), and wherein a tab (48) of the spring contact element (32) is held in a clamping slot (50) of one of the conductor tracks (28).

Description

The invention relates to an electric motor which has a stator and a connection unit for connecting coils of the stator to one another and/or to phase connections of the connection unit. Furthermore, the invention relates to a refrigerant compressor with such an electric motor.

Such a refrigerant compressor expediently comprises electronics with a bridge circuit for controlling and/or energizing the coils of the stator. The phase branches of the bridge circuit are each electrically contacted with a phase connection of the switching unit.

The refrigerant compressor also includes a compressor device, which is designed, for example, as a scroll pair, and by means of which a refrigerant is compressed. Depending on the design of the refrigerant compressor, the refrigerant flows around the switching unit and the stator when the refrigerant compressor is in operation. The refrigerant can be electrically conductive.

Consequently, the electronics are housed in an electronics compartment of a housing that is sealed fluid-tight against a motor compartment of the housing that accommodates the stator and the switching unit. Conductors are provided that extend from the electronics compartment into the motor compartment to connect the electronics to the phase connections.

Due to the space-saving design of the refrigerant compressor, and in particular its interconnection unit, a material connection of the phase connections with the respective conductor is difficult or not possible during assembly.

From the DE 10 2019 109 393 A1 A circuit board feedthrough for guiding an electrical conductor in an opening through a circuit board is known, wherein the circuit board feedthrough has a carrier made of a plastic material with a continuous, essentially hollow-cylindrical receptacle and an essentially annular spring element made of a metal material arranged in the receptacle.

The invention is based on the object of facilitating the assembly of the electric motor.

This object is achieved according to the invention by an electric motor with the features of claim 1 and by a refrigerant compressor with the features of claim 8. Advantageous further developments and embodiments are the subject of the subclaims. The statements in connection with the electric motor also apply mutatis mutandis to the refrigerant compressor and vice versa.

The electric motor is preferably designed as a brushless electric motor and/or intended and set up for a refrigerant compressor. The electric motor has a stator. This suitably comprises a stator laminated core, the stator teeth of which each carry a coil, each of the coils being suitably wound from insulating wire. The electric motor also comprises a (switching unit) interconnection unit with conductor tracks, for example designed as a stamped grid, which are electrically contacted with the coil ends (winding wire ends) of the coils and/or with phase connections of the interconnection unit in order to interconnect the coils in a predetermined manner. The conductor tracks are suitably held by means of a conductor track carrier and electrically insulated from one another. The conductor track carrier is formed, for example, by means of a plastic overmolding of the conductor tracks. The interconnection unit is therefore preferably designed as a plastic injection-molded part with an integrated, i.e. overmolded, stamped grid.

The term “axial direction” is understood here and in the following to mean in particular a direction that is parallel (coaxial) to the axis of rotation of the electric motor, in particular its rotor.

The interconnection unit is arranged in the axial direction above the stator, in other words on an axial front side of the stator and is preferably joined to it.

The electric motor also includes electronics that are designed to operate the stator, in particular to supply current to the coils of the stator. For this purpose, the electronics expediently include a bridge circuit with semiconductor switches that are actuated by means of a PWM control.

The electric motor also includes a housing. The electronics are housed in an electronics compartment of the housing to protect them from environmental influences (contamination, moisture) and/or, if the electric motor is intended for a refrigerant compressor, to protect them from refrigerant. The stator, the switching unit and the rotor of the electric motor are housed in a motor compartment of the housing, whereby the electronics compartment and the motor compartment have a common housing partition. In summary, the housing includes an electronics compartment for the electronics and a motor compartment for the stator and for the switching unit. The receiving area for the electronics enclosed by the electronics compartment is therefore separated from the area enclosed by the The motor compartment included a receiving area for the stator and for the interconnection unit, in particular in a fluid-tight manner and separated.

The electronics compartment is expediently arranged in the axial direction above the stator and/or above the switching unit. Consequently, the housing partition is arranged in the axial direction between the electronics and the stator or the switching unit.

The electric motor also comprises conductor elements, referred to below as feedthrough conductors or contact pins, which are passed through the housing partition wall, i.e. protrude through it. The feedthrough conductors are expediently electrically connected to the electronics, in particular to one phase (one phase branch) of the bridge circuit. For example, the feedthrough conductors are made of stainless steel.

The feedthrough conductors are suitably pin-shaped and/or extend in the axial direction through a common or preferably through a hole-like recess (feedthrough) in the housing partition wall. The feedthrough conductors are held in a fluid-tight manner in the respective recess by means of a seal, in particular a glass seal. The feedthrough conductors are electrically insulated from the housing partition wall by means of the seal.

Each of the phase connections is designed as a spring contact element, which is intended and set up to form a plug contact with the respective feedthrough conductor. Each of the spring contact elements also has a tab that is clamped in a clamping slot of one of the conductor tracks of the interconnection unit. Each of the spring contact elements is electrically conductive. In this way, the conductor track and the respective feedthrough conductor are electrically contacted using the spring contact element.

According to a suitable embodiment, the respective clamping slot is designed as a recess, in particular a groove-shaped recess, i.e. as a depression, in the conductor track. According to an alternative embodiment, the respective clamping slot is formed by two extensions of the conductor track, wherein the extensions are oriented parallel to one another and preferably extend in the axial direction.

During the assembly of the electric motor, the phase connections are connected to the respective feedthrough conductor by means of a plug-in process. This type of plug-in contact is advantageous, particularly when the installation space is relatively small, and is relatively easy to implement.

According to a suitable design of the electric motor, the respective clamping slot in the corresponding conductor track is continuous in a direction perpendicular to the axial direction, in particular continuous in a direction perpendicular to a central axis of the respective phase connection, in particular of the spring contact element, oriented parallel to the axial direction. In the assembled state, the tabs expediently protrude through the respective receptacle in this direction. This ensures particularly reliable clamping and electrical contact.

Each of the clamping slots is expediently open in the axial direction. In other words, the receptacle is not covered by a section of the conductor track in the axial direction. This makes it possible to insert the tab into the respective receptacle in a direction parallel to the axial direction, namely in a direction from the interconnection unit to the stator. Preferably, the tabs extend in a plane perpendicular to the axial direction when assembled. In this way, a space-saving design of the contact between the spring contact element and the respective conductor track is achieved.

In summary, to form the plug-in contact, the feedthrough conductors are inserted into the respective spring contact element. During assembly, the spring contact elements are first joined to the respective conductor element by inserting, in particular by clamping, its tabs in a direction parallel to the axial direction into the corresponding clamping slot. The feedthrough conductors are then inserted into the spring contacts, in particular in a direction parallel to the axial direction. In particular, the stator is adjusted in the axial direction together with the interconnection unit.

The tab preferably has a width that is slightly larger than the width of the receptacle. Consequently, the tab is at least slightly deformed when clamped in. This creates contact between the tab and the conductor track in the manner of an insulation displacement contact, although no insulation is severed here.

According to a practical embodiment, the respective spring contact element has a flat, in particular circular, base section. In the assembled state, this base section is expediently oriented perpendicular to the axial direction. The tab is formed on this. The tab expediently extends in the base section. In addition, spring-elastic contact arms are formed on the base section, which form a socket-like plug-in receptacle for the respective feedthrough conductor. In particular, the contact arms extend in or essentially in the axial direction from the base section, wherein the contact arms enclose a receiving space for the feedthrough conductor in a cage-like manner, forming the plug-in receptacle. The plug-in receptacle is designed in particular such that the feedthrough conductor can be inserted into the plug-in receptacle in the axial direction.

The contact arms are expediently spring-elastically deformable in a direction perpendicular to the axial direction, in particular to or from a central axis of the plug-in receptacle, in other words perpendicular to the insertion direction. In the assembled state, the contact arms rest on the respective feedthrough conductor, with the contact arms being spring-elastically braced against it.

Due to the spring-elastic design of the contact arms, tolerance compensation for the position of the feed-through conductors relative to the phase connection is particularly advantageous.

In summary, a spring-loaded plug connection with tolerance compensation is formed using the spring contact elements. Such a plug connection can be removed without causing any damage and/or without using tools.

According to a suitable design of the electric motor, the section of the respective conductor track which has the clamping slot is designed like a sleeve and extends in the axial direction. This section of the conductor track therefore encloses a receiving area for the spring contact element, in particular for its base section. In other words, this section is essentially designed as a hollow cylinder, the hollow cylinder having a circle or a preferably regular polygon as its base, and its (cylinder) axis being parallel to the axial direction.

Alternatively, or preferably in addition to this, further clamping slots for further tabs of the spring contact element are arranged along the circumference of this section of the conductor track. These further tabs are clamped in the further clamping slots in an analogous manner. The spring contact element is therefore clamped to the conductor track at several points and is electrically contacted with it.

According to an advantageous embodiment, the spring contact element and/or the section of the conductor track having the clamping slot is enclosed by a sleeve-like extension, also referred to as a dome, which is formed onto the conductor track carrier of the interconnection unit and extends in the axial direction. The sleeve-like extension of the conductor track carrier therefore encompasses the spring contact element and/or the section of the conductor track having the clamping slot. In other words, the spring contact element and/or the section of the conductor track having the clamping slot are arranged completely within the sleeve-like extension in a plane perpendicular to the axial direction.

This extension serves to protect the plug connection between the spring contact element and the feedthrough conductor. A seal, in particular a lip seal, is expediently provided, which surrounds the respective feedthrough conductor and seals the dome in a fluid-tight manner.

A further aspect of the invention relates to a refrigerant compressor which has an electric motor in one of the variants mentioned above. The refrigerant compressor is also referred to as an electric or electromotive refrigerant compressor. The electric motor is used in particular to drive a compressor device, for example a scroll of a scroll pair. For example, the compressor device or a part thereof, in particular the fixed scroll of the scroll pair, is accommodated in the motor compartment.

• 1 schematisch in einer Schnittansicht einen Kältemittelverdichter, der einen Elektromotor mit einem Stator und mit einer Verschalteinheit aufweist,
• 2 ausschnittsweise in einer Schnittansicht den Kältemittelverdichter, wobei Durchführungsleiter mit jeweils einem Phasenanschluss der Verschalteinheit steckkontaktiert ist,
• 3a in perspektivischer Ansicht einen der als Federkontaktelement ausgebildeten Phasenanschluss, welches eine Lasche aufweist, die in einem Klemmschlitz einer zugeordneten Leiterbahn der Verschalteinheit aufgenommen ist,
• 3b in einer Seitenansicht eines der an der jeweiligen Leiterbahn gehaltene Federkontaktelement,
• 3c in einer Draufsicht das an der Leiterbahn gehaltene Federkontaktelement der 3b,
• 3d eine Schnittansicht durch die im Klemmschlitz klemmend gehaltenen Lasche gemäß der Schnittebene IIId der 3c,
• 4a eines der Federkontaktelemente in perspektivischer Ansicht mit Blick auf dessen Grundabschnitt, an welchen die Laschen angeformt sind,
• 4b eines der Federkontaktelemente in perspektivischer Ansicht mit Blick auf die anhand dessen federelastischen Kontaktarmen gebildete buchsenartige Steckaufnahme, und
• 5 in einer perspektivischen Ansicht eine alternative Ausgestaltung des Phasenanschlusses, wobei der Klemmschlitz der Leiterbahn als eine Aussparung der Leiterbahn ausgebildet sind.

In the following, embodiments of the invention are explained in more detail with reference to a drawing. In the drawing:

• 1 schematically shows in a sectional view a refrigerant compressor having an electric motor with a stator and with a switching unit,
• 2 a partial sectional view of the refrigerant compressor, with the feedthrough conductor being plugged into a phase connection of the interconnection unit,
• 3a in perspective view one of the phase connections designed as a spring contact element, which has a tab that is received in a clamping slot of an associated conductor track of the interconnection unit,
• 3b in a side view of one of the spring contact elements held on the respective conductor track,
• 3c in a top view the spring contact element held on the conductor track of the 3b ,
• 3D a sectional view through the tab clamped in the clamping slot according to the section plane IIId of the 3c ,
• 4a one of the spring contact elements in perspective view with a view of its base section, to which the tabs are formed,
• 4b one of the spring contact elements in perspective view with a view of the socket-like plug receptacle formed by its spring-elastic contact arms, and
• 5 in a perspective view an alternative embodiment of the phase connection, wherein the clamping slot of the conductor track is designed as a recess in the conductor track.

Corresponding parts and sizes are always provided with the same reference symbols in all figures.

In the 1 an electromotive refrigerant compressor 2 is shown schematically in a longitudinal section. The refrigerant compressor 2 has an electric motor 4, which here is a brushless DC motor, and drives a compressor device 6, in particular one scroll of a scroll pair, in rotation. The compressor device 6 serves to compress refrigerant. The refrigerant compressed by the compressor device 6 is fed to an oil separator 8 and flows out via a refrigerant outlet 10.

A rotor 16 of the electric motor 4 comprises a number of permanent magnets (not further shown) and is rotatably mounted about a rotation axis R by means of a (rotor) shaft 18.

A stator 20 of the electric motor 4 comprises a laminated core which carries a number of coils 22, each of which is wound from a coil wire (winding wire, insulating wire) in a manner not shown in detail. The coil wire ends 24 of the coils 22 are connected to one another in a predetermined manner using a connection unit 26 of the electric motor 4, for example the coils 22 are connected in accordance with a star or delta connection. For this purpose, the connection unit 26 comprises conductor tracks 28, which are accommodated in a plastic overmolding referred to as a conductor track carrier 30.

The interconnection unit 26, also referred to as an interconnection ring or interconnection unit, is arranged in the axial direction A above the stator 20 and is joined to it in a manner not shown in detail. The axial direction A is understood here and below to mean a direction parallel (coaxial) to the rotation axis R of the electric motor 4 from the stator 20 to the interconnection unit 26.

The refrigerant compressor 2, in particular its electric motor 4, comprises a housing 11. The stator 20, the rotor 16 and the connection unit 26 of the electric motor 4 designed as an internal rotor are accommodated in a motor compartment 12 of the housing 11. The housing 11 also has a refrigerant inlet 14 for the refrigerant.

The oil separator 8 is arranged in a housing part referred to as compressor head housing, which is joined to the electronics compartment 12.

Electronics 34 for operating and/or controlling the electric motor 4, in particular for supplying current to the coils 22 of the stator, are accommodated in an electronics compartment 36 of the housing 11, wherein the electronics compartment 36 is arranged in the axial direction A above the stator 20 and above the interconnection unit 26. The interconnection unit 26 is therefore arranged in the axial direction A between the electronics 34 and the stator 20. The electronics compartment 36 and the motor compartment 12 are separated from one another in a fluid-tight manner (decoupled) by means of a common housing partition wall 38, wherein feedthrough conductors 40 protrude through the housing partition wall 38 to contact the electronics 34 with the phase connections 32 of the interconnection unit 26. For this purpose, the feedthrough conductors 40, made of stainless steel for example, are guided into a feedthrough of the housing partition wall 38, each formed by a hole-like recess 42, with a glass seal 44 holding the respective feedthrough conductor 40 in the recess 42 in a fluid-tight and electrically insulating manner with respect to the housing partition wall 38. The pin-shaped, i.e. cylindrical, feedthrough conductors 40 extend in the axial direction A, in other words, a central axis of the respective feedthrough conductor 34 is parallel to the axial direction A. The feedthrough conductors 40 are electrically connected to the electronics 34 in the electronics compartment 36 in a manner not shown in detail.

The electronics 34 expediently comprise a bridge circuit for operating the electric motor 4 and a control device for this purpose. Furthermore, the electronics 34 is connected to a current or voltage source (not shown) external to the refrigerant compressor.

For cooling purposes, the electric motor 4 is flushed with coolant and/or a motor fluid (motor oil) during operation, for example. The fluid-tight separation of the electronics compartment 36 from the motor compartment 12 protects the electronics from damage.

The interconnection unit 26 further comprises in the 1 phase connections 32, which are only shown schematically and which are each plug-connected to one of the feedthrough conductors 40 and thus electrically connected. In particular, the phase connections 32 are plugged onto the feedthrough conductors 40 in the axial direction A.

As is particularly the case in the 2 to 5 As can be seen, each of the phase connections 32 is designed as a spring contact element (spring contact element 32). Each of the spring contact elements 32 comprises a flat, here for example circular, base section 46, on which tabs 48 are formed. The tabs 48 are arranged in the plane spanned by the base section 46, wherein they extend radially outwards with respect to a central axis M of the spring contact element, in particular the base section 46, i.e. perpendicular to the central axis M.

Each of the spring contact elements 32 is electrically and mechanically contacted with one of the conductor tracks 28 of the interconnection unit 36. For this purpose, these conductor tracks 28 comprise clamping slots 50 in which the tabs of the associated spring contact element 32 are received and held in a clamped manner. For this purpose, the tabs 48 are inserted, in particular pressed, into the respective clamping slot against the axial direction A. For this purpose, the clamping slots are open in the axial direction A.

According to a first embodiment of the refrigerant compressor 2 according to the 2 to 3d Each of the clamping slots 50 is formed by two extensions 52 of the respective conductor track 28. These extend from the conductor track 28 in the axial direction. They run parallel and spaced apart from one another, with a clamping receptacle for one of the tabs 48 being arranged between the clamping slots 50.

According to the alternative arrangement according to the 5 the clamping slots 50 are each formed as a recess in the respective conductor track 28.

In both variants, the respective clamping slot 50 is continuous in a direction perpendicular to the axial direction A, in particular in a direction perpendicular to the central axis M. In the assembled state, the tabs 48 protrude through the respective clamping slot 50.

As is particularly the case in the 3a , 3c and 5 As can be seen, the section of the conductor track 28 which has the clamping slots 50 is designed like a sleeve. This section extends in the axial direction and comprises a receiving space for the base section 46 of the respective spring contact element 32. This section expediently comprises several, according to the embodiments shown here three, clamping slots 50 with tabs 48 received therein.

Each of the spring contact elements 32 further comprises contact arms 54, which are formed on the base section 46. The contact arms 54 extend essentially in the axial direction A and, like a cage, enclose a receiving space for the respective feedthrough conductor 40, so that a socket-like plug-in receptacle 56 is formed for the feedthrough conductor. The receiving space enclosed by the contact arms 54 tapers starting from the base plane and widens at the free end, so that plugging in the respective feedthrough conductor 40 is made easier. The contact arms 54 are spring-elastically adjustable towards the central axis M or away from it. In the assembled state, the contact arms 54 rest against the outer surface of the feedthrough conductor 40 and are spring-elastically pre-tensioned.

In summary, the socket-like plug receptacle 56 is designed such that the feedthrough conductor 40 can be inserted into the plug receptacle 56 in the axial direction A.

Each spring contact element 32 and the section of the conductor track 28 connected to this spring contact element 32 that has the clamping slot 50 is enclosed by a cuff-like, i.e. sleeve-like, extension 58. This is formed on the conductor track carrier 30 of the interconnection unit 26 and extends in the axial direction A.

According to the design of the refrigerant compressor according to the 2 to 3d the sleeve-like extension 58 is closed at its end facing the housing intermediate wall 38 by means of a cap 60 and the respective feedthrough conductor 40, in particular in a fluid-tight manner. According to an alternative not shown in more detail, the sleeve-like extension 58 is closed in a fluid-tight manner at its end facing the housing intermediate wall 38 by means of a seal enclosing the feedthrough conductor 40.

In the 5 is shown with a cutting plane through the cuff-like extension 58. For example, the extension 58 is joined to the cap 60 in a manner not shown in detail.

The invention is not limited to the embodiments described above. Rather, other variants of the invention can be derived from this within the scope of the claims by a person skilled in the art without departing from the subject matter of the invention. In particular, all details described in connection with the embodiments and/or in the claims are also features can also be combined in other ways without departing from the subject matter of the invention.

list of reference symbols

2

Electric refrigerant compressor

4

electric motor

6

compressor element

8

oil separator

10

refrigerant outlet

11

Housing

12

engine compartment

14

refrigerant inlet

16

rotor

18

rotor shaft

20

stator

22

Sink

24

coil wire ends

26

interconnection unit

28

conductor track

30

conductor carrier

32

phase connection/ spring contact element

34

electronics

36

electronics compartment

38

housing partition

40

implementation manager

42

recess

44

glass seal

46

basic section

48

tab

50

clamping slot

52

appendix

54

contact arm

56

socket-like receptacle for the leadthrough

58

appendix

60

cap

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions.

Cited patent literature

• DE 102019109393 A1 [0006]

Claims (8)

Electric motor (4), comprising - a stator (20), - a connection unit (26) with a number of conductor tracks (28) for connecting coils (22) of the stator (20), the connection unit (26) being arranged in the axial direction (A) above the stator (20), - electronics (34) for operating the stator (20), - a housing (11) with an electronics compartment (36) for the electronics (34) and with a motor compartment (12) for the stator (20) and for the connection unit (26), the electronics compartment (36) and the motor compartment (12) having a common housing partition wall (38), - feedthrough conductors (40) which protrude through the housing partition wall (38) for contacting the electronics (34) with a phase connection of the connection unit (26) designed as a spring contact element (32), - each of the spring contact elements (32) for forming a plug contact with the feedthrough conductor (40), and wherein a tab (48) of the spring contact element (32) is held in a clamping slot (50) of one of the conductor tracks (28). Electric motor (4) after claim 1 , characterized in that the respective clamping slot (50) is continuous in a direction perpendicular to the axial direction (A). Electric motor (4) after claim 1 or 2 , characterized in that - the respective spring contact element (32) has a flat base section (46) onto which the tab (48) is integrally formed, and - wherein spring-elastic contact arms (54) are integrally formed on the base section (46), which form a socket-like plug receptacle (56) for the feedthrough conductor (40). Electric motor (4) according to one of the claim 1 until 3 , characterized in that - the section of the respective conductor track (28) having the clamping slot (50) is designed like a sleeve and extends in the axial direction (A), and/or - wherein it has further clamping slots (50) for further tabs (48) of the spring contact element (32) along its circumference. Electric motor (4) according to one of the Claims 1 until 4 , characterized in that the respective clamping slot (50) is formed by means of two extensions (52) of the conductor track (28), which are oriented parallel to one another. Electric motor (4) according to one of the Claims 1 until 4 , characterized in that the respective clamping slot (50) is designed as a recess in the respective conductor track (28). Electric motor (4) according to one of the Claims 1 until 6 , characterized in that the spring contact element (32) and/or the section of the conductor track (28) having the clamping slot (50) is enclosed by a sleeve-like extension (58) which is formed on a conductor track carrier (30) of the interconnection unit (26) and extends in the axial direction (A). Refrigerant compressor (2) with an electric motor (4) according to one of the Claims 1 until 7 .

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