WO2016119971A1

WO2016119971A1 - Stator for an electric machine having an encapsulated connecting apparatus

Info

Publication number: WO2016119971A1
Application number: PCT/EP2015/079703
Authority: WO
Inventors: Roland Lindwurm; Christoph Wieder; Alexander Schäflein; Jochen Wittmann
Original assignee: Zf Friedrichshafen Ag
Priority date: 2015-01-26
Filing date: 2015-12-15
Publication date: 2016-08-04
Also published as: DE102015201218A1

Abstract

The invention relates to a stator (16) for an electric machine (10) comprising a stator core (26), which has stator coils (36), and a connecting apparatus (38), which has a carrier element (56). Coil ends (36a, b) of the stator coils (36) are thereby inserted into an receiving space (55) of the carrier element, said receiving space being open from one side, and are connected to connecting conductors (52a-c) located there. According to the invention, in order to form a closure assembly of the connecting apparatus (38), by means of which the receiving space (55) of the carrier element (56) with the elements (36a, b; 52a-c) arranged therein can be closed against an outer environment, the carrier element (56) is to be formed with a cover (58).

Description

Stator for an electric machine with an encapsulated interconnection device

The present invention relates to a stator for an electric machine with a sealed interconnection device according to the preamble of claim 1.

A generic stator is for example already out of the

DE 10 2009 045 551 A1. The stator of the permanent magnet synchronous machine described therein comprises a laminated stator core with a plurality of stator coils whose coil ends are interconnected by means of an interconnection device with three connecting conductors to form a delta connection. For this purpose, the connecting conductors are arranged in a receiving space of a support element adjacent to the coils, wherein the coil ends are introduced into the receiving space by entry recesses provided on the support element and contacted with the connecting conductors within the receiving space. After the interconnection, a casting compound that is liquid at its processing temperature and solidifies on curing is introduced into the receiving space, which covers the elements arranged therein for protection against external influences, in particular the penetration of moisture and dirt particles. In this case, there is the problem that the potting compound during casting of the receiving space escape through the inlet recesses and can enter a winding region of the stator coils. As a result, on the one hand occurs a loss of potting compound, on the other hand, however, coil winding parts can be undesirable covered with the potting compound, damaged and the removal of a loss of operating heat are hindered, whereby the efficiency of the electric machine is lowered.

Based on this, the present invention has the object to represent a stator of the type mentioned, in which the receiving space of the interconnecting device can be safely encapsulated in a manner opposite to the aforementioned prior art alternative manner to external influences. This object is achieved by a stator for an electric machine having the features of patent claim 1. Advantageous embodiments and further developments of the invention will become apparent from the dependent claims.

It is therefore proposed in a generic stator to provide on the support member for forming the closure assembly a lid. With the lid, the open side of the receiving space can be closed so that at least from this side no moisture and foreign particles can penetrate and the Verschaltungsbereiche the coil ends are protected with the connecting conductors. In a further aspect, a stiffening of the connecting device is achieved by the cover. The introduction of a potting compound in the receiving space can thus be omitted, resulting in manufacturing and cost benefits. The cover can be designed in many ways, for example, such that it engages over the carrier element or that it engages in the carrier element. Preferably, the lid can be designed or shaped so that it covers the inside of the receiving space elements substantially, in particular form-fitting or that the lid substantially fills the receiving space and that an optionally remaining free space is minimized. Optionally, the cover may have a deformable and thus adaptable to the contour of the elements located in the receiving space area of a plastic or elastic material. This area can also be designed as a separate insert element assigned to the cover, as a result of which the cover is made in several parts. The advantage is that the remaining trapped gas volume or generally the free volume is minimized, so that a condensation of the residual moisture optionally contained therein in a temperature change is low. The carrier element can generally be arranged on the stator both radially and axially adjacent to the stator coils. In principle, the coil ends can also be brought out of the coils radially or axially aligned and enter the carrier element or the receiving space of the interconnection device.

According to a development of the invention, the coil ends can be formed by entry recesses formed in the support on the carrier element and / or on the cover. be introduced, wherein the coil ends are sealed in the region of these Eintrittsausnehmungen on the support member or the lid or on an at least indirectly cooperating with the support member or the lid member. The further element can, for example, as will be explained below, be an area of a coil winding body. In this way, the entry region of the coil ends is protected in the interconnection device against external influences.

In a further aspect, the interconnection device can have connecting conductors connected to the connecting conductors for supplying power to the stator, which likewise are sealed against the carrier element and / or the lid and inserted in the receiving space. By applying the aforementioned measures, the entire receiving space can be sealed tight.

According to one embodiment, a sealing means, for example in the form of a filler, can be introduced between a coil end and the carrier element, the cover or the element interacting therewith. In this case, the filler can surround the coil ends and fill a gap remaining in the region of the entrance recess to the carrier element, the cover or the element interacting therewith. For example, a lacquer or a resin to be applied in the region of the entrance recesses, which are customary for producing an insulation system on electric machines, can be used as the sealing means. Additionally or alternatively, the sealing means may also be designed as a separate sealing element, which is arranged in the region of the inlet recesses and is in abutting contact with the coil ends and the carrier element, the lid and / or a cooperating element. The sealing element can thus be arranged between the support element, the cover and a further element, for example, be inserted there. In particular, such a sealing element may be designed as a ring seal, which is pushed onto the coil ends.

According to an advantageous embodiment, the stator coils comprise a winding body with a base region and two legs projecting therefrom, which have a Limit winding area. At least one of the legs may have a guide structure for the coil ends, whereby they are aligned in the direction of the inlet recess and guided there. The cooperating with the support member element can thus be formed by a portion of a bobbin, in particular by the leg with the guide structure.

According to yet another advantageous embodiment of the invention, it is proposed to fix the sealing element on the guide structure of the winding body and bring the winding body in the region of the entrance recesses substantially gap-free on the support member or the cover in abutment. In this way, the entry recesses on the carrier element of the interconnecting device can be dimensioned relatively generously in order to achieve a light and tolerancesmoderaten installation. An entrance recess is at least partially covered by a winding body lying on the carrier element or its cover, in particular a limb. The sealing element, which is preferably already preassembled on the leg on the guide structure of the coil ends, seals the receiving space with respect to the surroundings, in particular with respect to the winding area of the stator coils.

Advantageously, a positional fixation of the connecting conductor located in the receiving space can be achieved by hold-downs arranged on the lid, for example in the form of projecting webs, wherein the hold-downs load the connecting conductors in the direction of a bottom or wall region of the carrier element or at least bear against the latter.

With further advantage, the carrier element and / or the lid can be made of a plastic material and preferably connected to one another in a material-locking manner. However, there are also alternatively positive or non-positive connections of support member and lid possible, such as a screw, latch or a bayonet connection.

The invention will be explained by way of example with reference to an embodiment shown in the figures. Show it:

Figure 1 is a schematic representation of an electric machine in Innenlauferbauart with an interconnecting device in an axial section.

Fig. 2 is an enlarged view of the interconnecting device of Fig. 1;

FIG. 3 is a schematic fragmentary front view of the interconnecting device of FIG. 2; FIG.

4a-d show an interconnecting device with a cover in several views, which has a plurality of radially protruding connecting conductors and axial entry recesses for coil ends;

Fig. 5 shows an interconnecting device with a lid in a perspective

View, which has a plurality of radially extending leads and radial entrance recesses for coil ends;

6 shows a representation of a cover which is intended for use in the interconnection devices according to FIGS. 4 a - d and 5,

Fig. 7 is an illustration of a lid, which is provided for use in a wiring device with frontally led out leads.

Identical objects, functional units or comparable components are denoted by the same reference numerals across the figures. Further, summary reference numbers are used for components and objects that occur multiple times in one embodiment or in one representation, but are described together in terms of one or more features. Components or objects which are described by the same or in a combination of reference numerals may be identical in terms of their characteristics, for example their dimensions, but may also be different if the description does not explicitly or implicitly make reference to the description.

1 schematically shows an electric machine 10, more particularly a permanent magnet synchronous machine of internal rotor type, with a rotor 14 which is rotatable about a rotor shaft 12 and with a stator surrounding it radially outwardly. The rotor 14 comprises a cup-shaped rotor carrier 18, on the cylindrical outer peripheral surface of a laminated rotor laminated core 20 is arranged, which carries a plurality of circumferentially spaced-apart permanent magnets 22.

The stator 16 comprises an annular stator carrier 24, in the central recess of which an annular stator lamination stack 26 likewise formed from laminations is arranged. The stator support 24 may, for example, constitute an outer or an intermediate housing of the electric machine 10. The laminated stator core 26 is segmented and assembled from a plurality of identical T-shaped stator segments that are received and held together by the stator support 24. Alternatively, the laminated stator core 26 may also consist of a stack of annular lamellae in a conventional manner.

Regardless of the specific structure, the laminated stator core 26 forms a voltage applied to the stator 24 annularly closed Statorjoch 30 with radially inwardly facing teeth 32, which are equipped to form the stator winding in a known manner with stator coils 36. The coil ends 36a, b of the stator coils 36 are connected by means of a switching device 38 shown only schematically in FIG. 1 and connected to power electronics, not shown in the drawing, which can act on the winding to drive the electrical machine 10 with a variable phase and amplitude current ,

The stator coils 36 are wound before the assembly of the stator 16 by means of two, consisting of a heat-resistant plastic insulating or bobbins 40, 42 of a copper wire around the teeth 32 and there are formed by a radially inwardly, in Fig. 1st invisible tooth head secured against slipping.

The bobbins 40, 42 each include a front side on the laminated core 26 adjacent base portion 40a; 42a and two of them approximately at right angles and on the stator 16 axially projecting leg 40b, c; 42b, c, which limit the winding area in the radial direction. At the radially inner leg 40b guide structures 41 are in shape provided by insertion grooves, in which the coil ends 36a, b inserted and aligned in the direction of the interconnection device 38. In the region of this guide structure or generally at the leg 40b adjacent to a carrier element 56 which will be explained in more detail below, sealing means in the form of sealing elements 43 are arranged, which seal the coil ends 36a, b with respect to the legs 40b. The legs 40b are also substantially gap-free and thus in the present sense sealingly on the support member 56 and support this so. To secure the circumferential position, the legs 40b have recesses 40d which are open towards the carrier element 56, into which projections 56d of the carrier element 56 pointing in this direction engage in a form-fitting manner.

The coils 36 are electrically associated with individual strands and are interconnected by means of the interconnection device 38 via common connection conductors 52a-c in a predetermined manner. For connection to the coil ends 36a, b, the connection conductors 52a-c have raised connection areas 53a-c opposite their base body. In this case, in each case two adjacent coil ends 36a, b of two circumferentially adjacent coils 36 are connected to a connection region 53a-c for realizing a delta connection. The contacting of the coil ends 36a, b with the connecting conductors 52a-c preferably takes place cohesively, for example by soldering or welding, wherein a coupled process heat in the direction of the winding region and the winding body can propagate. The sealing means or the sealing elements 43 are temperature-resistant to this process heat, so that thereby the winding body 40 are securely protected from an undesirably high heat input and associated deformation.

The connection conductors 52a-c are accommodated for their arrangement on the stator 16 within an open, trough-shaped receiving space 55 of an annular carrier element 56 formed of plastic. The open area points into the axial side facing away from the stator 16 and is thus freely accessible for the interconnection.

For interconnecting the coil ends 36a, b, the carrier element 56, optionally with the already inserted therein connecting conductors 52a-c, as shown schematically in FIG Fig. 1, arranged on the stator 16 and fixed there, for example by means of a snap-in connection not shown in the drawing.

The receiving space 55 of the support member 56 is bounded by a bottom 56a and vertically projecting side walls 56b, c. With regard to the further structure and the arrangement of the elements in the receiving space 55, reference is made to the relevant content of DE 10 2009 045 551 A1.

For entry of the coil ends 36a, b into the carrier element 56, entrance recesses 56d are provided in the radial wall region 56b (FIGS. 2, 3). These are designed as trough-shaped or slot-like recesses and with respect to the stator starting from the free axial side of the side wall 56b and arranged such that the guided in the guide structure 41 coil ends 36a, b radially and on a comparatively short path through the radial wall portion 56b in the receiving space 55 of the interconnection arrangement 38 can be inserted. The entrance recesses 56d are made slightly larger in the circumferential direction than corresponds to the mutual distance of two each adjacent to the stator 16 coil ends of two immediately adjacent coils. As a result, in the position shown, the coil ends 36a, b can be securely inserted into the carrier element 56 even with a small positional deviation.

To protect the arranged within the receiving space 55 elements from external influences, especially from corrosion and also to increase the stability of the interconnecting device 38 of the receiving space 55 of the support member 56 is closed after the interconnection with an adapted to the geometry of the receiving space annular cover 58 as this in partially different versions in Figs. 4-7 is shown. In the present case, the lid 58 and the support member 56 are made of a plastic and materially connected by welding permanently connected to each other. The cover 58 has a main body 58a and a plurality of centering projections 58b arranged in the region of the inner and / or outer circumference, which come to rest against the corresponding wall regions 56b of the carrier element 56. Furthermore, on the cover 58 projecting from the main body 58a formed holder 58c, which can bear against the connecting conductors 52a-c and secure them in their position. In the case of the covers 58 shown in FIGS. 6, 7, the hold-downs 58c closest to the circumferential boundary of a cover 58 serve simultaneously as centering projections 58b. Furthermore, for the mutual electrical insulation of the connecting conductors 52a-c, separating webs 56e are provided which can be formed both on the carrier element 56 itself (see FIGS. 4b-d) and / or on the cover 58. In FIGS. 4-7, a plurality of radial extensions 58d are formed on the lid 58, which engage on the carrier element 56 in a form-fitting manner in correspondingly engaging and likewise radially projecting engagement formations, in particular protruding pockets 56, or alternatively embrace them in a form-fitting manner. In this way, at least during assembly of the cover 58, its circumferential position to the carrier element 56 is determined. In addition, connecting means for forming a latching connection, a bayonet closure or further may also be formed at these positions. Still further, according to a variant, which is not shown in the drawing, the cover 58 may be made in one piece as well as in several parts, in particular segmented in the circumferential direction. In the latter case, the individual segments can interlock positively, in particular with the formation of a labyrinth seal.

For connecting the stator 16 to an electric current source, the interconnecting device 38 further has connecting conductors 60a-c connected to the connecting conductors 52a-c, which are inserted sealed into the receiving space 55 relative to the carrier element 56 and / or the cover 58. For this purpose, the connecting conductors 60a-c are provided, at least in their entry region into the receiving space 55, in each case with a sealing element 62 in the form of an insulating plastic sheath, whereby the said inlet regions are protected against the entry of moisture and foreign particles. For this purpose, the connection conductors 60a-c can basically be inserted radially through one of the circumferential surfaces, that is to say the inner circumferential surface 56c or the outer circumferential surface 56b of the carrier element 56 or the cover 58. Alternatively, the connecting conductors 60a-c can also be introduced on the front side, for which purpose corresponding recesses 58e are provided in the cover 58 with a view to FIG. In detail, FIGS. 4a-d show an interconnection device 38 with a cover 58 in several views, which has a plurality of radially protruding connection conductors 60a-c and axial entry recesses 56d for coil ends 36a, b. FIG. 5 shows an interconnecting device 38 with a lid 58 in a perspective view, which likewise has a plurality of radially protruding connecting conductors 60a-c, but radial inlet recesses 56d for coil ends 36a, b. FIG. 6 is an illustration of a lid 58 provided for use in the interconnect devices 38 of FIGS. 4a-d and 5. A representation of a cover 58, which is provided for use in a wiring device 38 with frontally through connection openings 58 e led out leads 60 a-c, Fig. 7.

Instead of the radial staggering of the connecting conductors shown in the figures, these can also be arranged axially staggered to the stator, wherein the other elements, if they are required, are adapted accordingly. Likewise, instead of a radial positioning of the coils to the carrier element of the interconnection device, these also take place in the axial direction. Also, the special design of the electrical machine with respect to the basic design of the stator interconnection device is irrelevant; For example, it may also be an external-type electric machine.

Reference number electrical machine

rotor shaft

rotor

stator

rotorarm

Laminated core

permanent magnet

stator

stator lamination

stator yoke

tooth

stator

a, b coil end

Connecting device

, 42 winding body

a, 42a base area

b, c thighs

d recess

management structure

b, c thighs

sealing element

a-c connection conductor

a-c connection area

accommodation space

support element

a floor

b, c side wall

d projection

d entrance recess

e divider

f bag Deckela basic body centering projection down holder radial extensions recessa-c connecting conductor sealing element

Claims

claims

1 . Stator (16) for an electrical machine (10) comprising

a stator lamination stack (26) with stator coils (36) having coil ends (36a, b),

- An interconnection device (38) with a support member (56) which has an at least one side open receiving space (55) and arranged in the receiving space (55) connecting conductors (52a-c), wherein

- The coil ends (36 a, b) inserted into the receiving space (55) and are electrically connected within the receiving space (55) with the connecting conductors (52 a-c) and wherein

- the interconnection device (38) has a closure arrangement, by which the receiving space (55) of the carrier element (56) with the elements (36a, b; 52a-c) arranged therein is closed to an external environment,

characterized in that the carrier element (56) for forming the closure arrangement comprises a cover (58).

2. Stator according to claim 1, characterized in that the cover (58) is designed so that it substantially fills the receiving space (55), wherein in the receiving space (55) remaining free volume is minimized.

3. Stator according to claim 1 or 2, characterized in that the coil ends (36 a, b) by on the support element (56) and / or on the lid (58) formed entrance recesses (56 d) are inserted into the receiving space (55) and that the Coil ends (36a, b) in the region of the inlet recesses (56d) are sealed to the carrier element (56) or the cover (58) or to an element (40b) interacting at least indirectly with the carrier element (56) or the cover (58) ,

4. Stator according to one of claims 1 - 3, characterized in that the interconnection device (38) connected to the connecting conductors (52a-c) An End conductor (60a-c), which are sealed against the support member (56) and / or the lid (58) inserted into the receiving space (55).

5. Stator according to one of claims 1 - 4, characterized in that between a coil end (36 a, b) and the carrier element (56), the cover (58) or the cooperating with this element (40 b) introduced a sealing means (43) is.

6. Stator according to one of claims 3 - 5, characterized in that a stator coil (36) comprises a winding body (40), wherein the cooperating with the carrier element (56) or with the cover (58) element (40b) of a section the winding body (40) is formed.

7. Stator according to claim 6, characterized in that the sealing element (43) on a guide structure (41) of the winding body (40) for the coil ends (36a, b) is fixed and that the winding body (40) in the region of the Eintrittsausnehmun- gene (56d) rests substantially gap-free on the carrier element (56) or on the cover (58).

8. Stator according to one of claims 1-7, characterized in that the cover (58) with the connecting conductors (52a-c) cooperating down device (58c).

9. Stator according to one of claims 1-8, characterized in that the carrier element (56) and the cover (58) are made of plastic and materially connected to each other.