WO2022096058A1

WO2022096058A1 - Stator

Info

Publication number: WO2022096058A1
Application number: PCT/DE2021/100841
Authority: WO
Inventors: Andreas Ruppert; Alexandre Fischer; Tim Schmid; Thomas Fritz
Original assignee: Schaeffler Technologies AG & Co. KG
Priority date: 2020-11-04
Filing date: 2021-10-20
Publication date: 2022-05-12
Also published as: DE102020129057A1

Abstract

The invention relates to a stator (1) for an electric machine (19), having a winding (2) comprising a plurality of conductors (3) which are allocated to one or more phases (3) and are interconnected, wherein ends of at least some of the conductors (3) project axially or radially beyond the winding (2), wherein an interconnection ring (28), which has at least one support ring (7) on which at least one busbar (29) is arranged, is placed axially onto the winding (2), on which the conductors (3) are connected, more particularly by means of welded or soldered connections, wherein the stator (1) has a stator support (20) in which the stator (1) is received at least in some sections and by means of which a torque of the stator (1) can be transferred to a machine housing (21) of the electricl machine (19), wherein the support ring (7) is arranged on the stator support (20) by means of a connection (22), and the connection (22) has resiliently articulated annular portions (23) which extend in the axial direction and in the radial direction and the free ends (25) of which have first friction-fit and/or interlocking-fit means (24) which form, with at least one second friction-fit and/or interlocking-fit means (26), an axially securing and/or radially securing connection (22) or a connection which secures in the circumferential direction.

Description

stator

The present invention relates to a stator for an electrical machine, with a winding comprising a plurality of conductors assigned to one or more phases, which are interconnected, with the ends of at least some of the conductors protruding axially or radially beyond the winding, with an interconnection ring having at least a carrier ring, on which at least one busbar is arranged, is placed axially on the winding, to which the conductors are connected, in particular by means of welded or soldered connections, the stator having a stator carrier in which the stator is accommodated at least in sections and by means of which Torque of the stator can be transmitted to a machine housing of the electric machine.

In many industrial applications - and increasingly also in the automotive industry - permanent magnet synchronous machines (PSM) are used. Such a PSM machine consists of a stator to be energized and a permanently excited rotor.

In such an electrical machine, the individual windings distributed around the circumference can be connected, for example, via a connection ring or a plurality of connection rings. In this case, busbars usually made of copper can be arranged on or in a common or separate carrier ring made of plastic. Occasionally, this type of interconnection rings were also referred to as switching rings or contact bridges. Such interconnection rings are generally placed axially onto the winding package.

DE102008007409A1, for example, describes a three-part switching ring for a stator, with three busbars and a star point ring being arranged in one plane, lying flat next to one another in a carrier ring made of a temperature-resistant plastic. The contact points of the busbars and the star point ring protrude from the carrier ring and are connected to the wire ends of the partial windings of the stator. This requires a high Positioning accuracy, accurate part tolerances, and multiple weld and joint locations.

The above construction of a connection ring is usually connected to the stator support with the stator teeth contained therein. According to the state of the art, this is placed axially on the stator carrier including the individual teeth. The fixation takes place by welding the individual phases and star points with the interconnection ring itself. These welds achieve an axial fixation, which, however, also has to compensate for the entire load caused by vibrations occurring in the vehicle, but also for tolerances. Therefore, permanent stress can lead to vibration-related material failure, particularly at the welds, so that the electrical machine can fail completely.

The object of the present invention is therefore to provide an electrical machine which is improved in terms of its service life in vibration-prone operation.

This object is achieved by a stator for an electrical machine, with a winding comprising a plurality of conductors assigned to one or more phases, which are interconnected, the ends of at least some of the conductors protruding axially or radially beyond the winding, with an interconnection ring having at least one carrier ring, on which at least one conductor rail is arranged, is placed axially on the winding, to which the conductors are connected, in particular by means of welded or soldered connections, the stator having a stator carrier in which the stator is accommodated at least in sections and by means of whose torque of the stator can be transmitted to a machine housing of the electrical machine, the carrier ring being arranged on the stator carrier by means of a connection, and the connection having ring sections running in the axial direction and resiliently articulated in the radial direction, the free ends of which have first R have friction and/or form-fitting means, which have at least one second friction and/or form-fitting means form an axially securing and/or radially securing and/or circumferentially securing connection.

This achieves the advantage that a form-fitting or friction-fitting connection is created between the stator carrier and the carrier ring, which connection can absorb loads from vibrations, oscillations and tolerances from the assembly and/or the manufacturing process. In particular, the busbars arranged on the carrier ring are thus at least partially decoupled from the loads from, for example, vibrations, oscillations and tolerances from the assembly and/or manufacturing process.

Furthermore, the design of the electric machine according to the invention provides strain relief for welding points of the busbar and conductor. Furthermore, the form-fitting means lead to simple assembly and centering of the support ring on the stator support.

First, the individual elements of the claimed subject matter of the invention are explained in the order in which they are mentioned in the set of claims, and particularly preferred configurations of the subject matter of the invention are described below.

Electrical machines are used to convert electrical energy into mechanical energy and/or vice versa, and generally include a stationary part referred to as a stator, stand or armature and a part referred to as a rotor or runner and arranged movably relative to the stationary part.

In the case of electrical machines designed as rotary machines, a distinction is made in particular between radial flux machines and axial flux machines. A radial flux machine is characterized in that the magnetic field lines extend in the radial direction in the air gap formed between rotor and stator, while in the case of an axial flux machine the magnetic field lines extend in the axial direction in the air gap formed between rotor and stator. In connection with the present invention, it is preferable to provide the stator for a radial flux machine. The electric machine is intended in particular for use within a drive train of a hybrid or all-electric motor vehicle. In particular, the electrical machine is dimensioned in such a way that vehicle speeds of more than 50 km/h, preferably more than 80 km/h and in particular more than 100 km/h can be achieved. The electric motor particularly preferably has an output of more than 30 kW, preferably more than 50 kW and in particular more than 70 kW. Furthermore, it is preferred that the electrical machine provides speeds greater than 5,000 rpm, particularly preferably greater than 10,000 rpm, very particularly preferably greater than 12,500 rpm.

The motor housing encloses the electrical machine at least in sections. A motor housing can also accommodate the control and power electronics. The motor housing can also be part of a cooling system for the electric machine and can be designed in such a way that cooling fluid can be supplied to the electric machine via the motor housing and/or the heat can be dissipated to the outside via the housing surfaces. In addition, the motor housing protects the electrical machine and any electronics that may be present from external influences.

A motor housing can be formed in particular from a metallic material. Advantageously, the motor housing can be formed from a cast metal material, such as gray cast iron or cast steel. In principle, it is also conceivable to form the motor housing entirely or partially from a plastic.

In connection with the present invention it is preferred that the stator is arranged inside the motor housing.

The stator of a radial flow machine can, in particular, be constructed cylindrically and consist of electrical laminations which are electrically insulated from one another and are constructed in layers and packaged to form laminated cores. through this structure the eddy currents in the stator caused by the stator field are kept low. Distributed over the circumference, grooves or circumferentially closed recesses can be let into the electrical lamination running parallel to the rotor shaft, which receive the stator winding or parts of the stator winding. Depending on the construction towards the surface, the slots can be closed with locking elements such as locking wedges or covers or the like in order to prevent the stator winding from being detached.

A carrier ring can accommodate one or more busbars and, in particular, can be arranged at a distance from one another and in an electrically insulating manner.

A carrier ring preferably has a circular ring-shaped basic shape with a plurality of circular ring-shaped and concentrically arranged receptacles, such as grooves, in which the corresponding busbars are arranged. In a likewise preferred embodiment variant of the invention, it can also be provided that the annular grooves have a contour that is U-shaped in cross section. A carrier ring is preferably made of a plastic material. In principle, it is conceivable for a support ring to be designed in one piece or in multiple pieces.

Furthermore, according to a likewise advantageous embodiment of the invention, it can be provided that the busbars are formed from copper and have a basic shape like a segment of a circular ring with a preferably rectangular cross section. According to a further particularly preferred embodiment of the invention, provision can be made for the conductors to be formed from copper.

The stator has a stator carrier, in which the stator is accommodated at least in sections and by means of which the torque of the stator can be transmitted to a machine housing of the electrical machine. The basic functions of the stator carrier in an electrical machine are to support the stator itself and to transmit the torque of the electrical machine from the stator into the motor housing of the electrical machine. The torque can be transmitted from the stator carrier to the motor housing, for example by means of fastening lugs on the stator carrier, which can be drawn as drawn Sheet metal parts can be formed. Furthermore, it is conceivable that the stator carrier can be axially pretensioned by means of clamping claws, ie brackets. Furthermore, torque can also be transmitted, for example, by means of a tongue and groove system and additional axial prestressing via clamping claws.

According to an advantageous embodiment of the invention, it can be provided that the ring sections are formed on the carrier ring and the at least one second friction and/or form-fitting means are formed on the stator carrier. According to an alternative configuration, it can also be provided that the ring sections are formed on the stator carrier and the at least one second friction and/or form-fitting means are formed on the carrier ring.

Furthermore, according to a likewise advantageous embodiment of the invention, it can be provided that the first form-fitting means and the at least one second form-fitting means form a snap-lock connection, as a result of which simple assembly of the carrier ring is made possible.

According to a further particularly preferred embodiment of the invention, it can be provided that the ring sections on the carrier ring rest radially on the inside of the stator carrier, so that a particularly compact design of the electrical machine can be implemented.

Furthermore, the invention can also be further developed such that the stator carrier has a ramp via which the free ends of the ring sections are deflected radially inwards when the interconnection ring is pushed onto the stator carrier axially. As a result, the ease of assembly of the carrier ring can be further improved.

In a likewise preferred embodiment variant of the invention, it can also be provided that the ring sections are arranged equidistantly over the circumference of the interconnection ring and/or the stator carrier, as a result of which a particularly advantageous vibration decoupling between the stator carrier and the interconnection ring can be implemented. It can also be advantageous to further develop the invention in such a way that the carrier ring is formed from a plastic and the ring sections and/or the at least one second friction and/or form-fitting means are formed monolithically with the carrier ring, so that a particularly inexpensively manufactured carrier ring is provided can be.

According to a further preferred embodiment of the subject matter of the invention, it can be provided that the support ring has at least three concentric annular grooves, in each of which a busbar is arranged. As a result, the carrier ring is particularly suitable for a 3-phase control of the electrical machine.

The invention will be explained in more detail below with reference to figures without restricting the general inventive idea.

Show it:

FIG. 1 shows a perspective cross-sectional view of a section of an electrical machine,

FIG. 2 shows a detailed view of the carrier ring of the electrical machine in a cross-sectional view, and

FIG. 3 shows a perspective cross-sectional view of a detail of an electrical machine with a carrier ring to be mounted.

1 and FIG. 3 show a stator 1 for an electrical machine 19, with a winding 2 comprising a plurality of conductors 3 assigned to one or more phases, which are interconnected, the ends of at least some of the conductors 3 extending axially or radially the winding 2 protrude. In FIG. 1, the support ring 7 is shown in a construction situation fixed to the stator support 20. while FIG. 3 shows an assembly situation in which the support ring 7 is placed on the stator support 20 but not yet fixed.

The stator 1 has the stator carrier 20, in which the stator 1 is accommodated at least in sections and by means of which the torque of the stator 1 can be transmitted to a machine housing of the electrical machine.

It can also be seen that a conductor 3 leads to the phase or busbar 29 of the interconnection ring 28, where it is fixed to the busbar in a materially bonded manner by means of a welded or soldered connection. The connection ring 28 with the support ring 7 is placed axially onto the winding 2 . The carrier ring 7 is formed from a plastic and, in the embodiment shown, has four annular grooves which are concentrically and radially spaced apart and run in a radial plane, in each of which a busbar 29 is arranged.

The carrier ring 7 is placed axially onto the winding 2 and is arranged on the stator carrier 20 by means of a connection 22 . The connection 22 has ring sections 23 which run in the axial direction and are resiliently articulated in the radial direction, which can be seen particularly well from FIG. The free ends 25 first have friction and/or form-fitting means 24 which form an axially securing and/or radially securing and/or circumferentially securing connection 22 with at least one second friction and/or form-fitting means 26 . The ring sections 23 are formed on the carrier ring 7 and the at least one second friction and/or form-fitting means 26 is formed on the stator carrier 20 .

The first form-fitting means 24 and the at least one second form-fitting means 26 form a snap-lock connection, with the ring sections 23 on the carrier ring 7 resting radially on the inside of the stator carrier 20 . The stator carrier 20 has a ramp 27 via which the free ends 25 of the ring sections 23 are deflected radially inwards when the interconnection ring 28 is pushed axially onto the stator carrier 20, which is also clearly evident from the synopsis of FIGS. 1-3. In the embodiment shown in FIG. 1, the ring sections 23 are arranged equidistantly over the circumference of the interconnection ring 7 . means With the snap-lock connection shown in FIG. 1, the support ring 7 can be fixed on the stator support 20 in an easy-to-install and secure manner.

Vibrations and/or manufacturing tolerances between the stator carrier 20 and the carrier ring 7 can be compensated for or absorbed by the ring sections 23 that are resiliently pivotable in the radial direction. There is thus a certain decoupling between the stator carrier 20 and the carrier ring 7.

As can also be seen in particular from FIG. 2, the first form-fitting means 24 in the embodiment shown are designed as radially outward-pointing lugs on the free end 25 of the ring section 23, which engage in the second form-fitting means 26 designed as a corresponding groove. The groove is formed circumferentially in the stator support 20 . The lugs are monolithic with the ring portions 23 .

The invention is not limited to the embodiments shown in the figures. The foregoing description is therefore not to be considered as limiting but as illustrative. The following patent claims are to be understood in such a way that a mentioned feature is present in at least one embodiment of the invention. This does not exclude the presence of other features. If the patent claims and the above description define 'first' and 'second' feature, this designation serves to distinguish between two features of the same type, without establishing a ranking.

Reference List

1 stator

2 winding

3 conductors

7 carrier ring

19 electric machine

20 stator carrier

21 machine housing

22 connection

23 ring sections

24 form-fitting means

25 ends

26 form-fitting means

27 ramp

28 interconnection ring

29 power rail

Claims

Expectations

1 . Stator (1) for an electrical machine (19), with a winding (2) comprising a plurality of conductors (3) assigned to one or more phases, which are interconnected, the ends of at least some of the conductors (3) being axial or radial protrude beyond the winding (2), a connection ring (28) with at least one carrier ring (7) on which at least one busbar (29) is arranged being placed axially on the winding (2) on which the conductors (3) , in particular by means of welded or soldered connections, the stator (1) having a stator support (20) in which the stator (1) is accommodated at least in sections and by means of which the torque of the stator (1) is applied to a machine housing (21) of the electrical machine (19) is transferrable, characterized in that the support ring (7) by means of a connection (22) on the stator support (20) is arranged, and the connection (22) extending in the axial direction and in the radial direction ng has spring-elastically articulated ring sections (23), the free ends (25) of which have first friction and/or form-fitting means (24), which, together with at least one second friction and/or form-fitting means (26), have an axially securing and/or radially securing and /or form a connection (22) that secures in the circumferential direction.

2. Stator (1) according to claim 1, characterized in that the ring sections (23) on the support ring (7) and the at least one second friction and / or form-fitting means (26) are formed on the stator support (20). Stator (1) according to claim 1, characterized in that the ring sections (23) on the stator support (20) and the at least one second friction and / or form-fitting means (26) are formed on the support ring (7). Stator (1) according to one of the preceding claims, characterized in that the first form-fitting means (24) and the at least one second form-fitting means (26) form a snap-lock connection. Stator (1) according to any one of the preceding claims, characterized in that the ring sections (23) on the support ring (7) rest radially on the inside of the stator support (20). Stator (1) according to one of the preceding claims, characterized in that the stator support (20) has a ramp (27) via which the free ends (25) of the ring sections (23) when the interconnection ring (7) is axially plugged onto the Stator carrier (20) are deflected radially inwards. Stator (1) according to one of the preceding claims, characterized in that the ring sections (23) are arranged equidistantly over the circumference of the interconnection ring (7) and / or the stator support (20). Stator (1) according to one of the preceding claims, characterized in that the carrier ring (7) is formed from a plastic and the ring sections (23) and / or the at least one second friction and / or form-fitting means (26) monolithically with the Carrier ring (7) are formed. Stator (1) according to one of the preceding claims, characterized in that the carrier ring (7) has three concentric annular grooves, in each of which a busbar (29) is arranged.