ELECTRIC MACHINE HAVING SEVERAL RIGID WINDING PIECES FORMED AS HOLLOW CONDUCTORS-HYDRAULIC CONNECTION CONCEPT II

Abstract

The invention relates to an electric machine (1) having a rotor (3), a stator (2) and several rigid winding pieces (5) formed as hollow conductors, which form various coils of a winding (4) of the electric machine (1) and are each part of a cooling circuit of the electric machine (1). According to the invention, the winding pieces (5) each have at least one lateral tap (34) in the region of their end sections (8), via which tap a coolant can be fed into the winding pieces (5) or removed from the winding pieces (5).

Claims

1. Electric machine (1) having a rotor (3), a stator (2) and several rigid winding pieces (5) formed as hollow conductors, which form various coils of a winding (4) of the electric machine (1) and are each part of a cooling circuit of the electric machine (1), wherein the winding pieces (5) each have at least one lateral tap (34) in the region of their end sections (8), via which tap a coolant can be fed into the winding pieces (5) or removed from the winding pieces (5); wherein a hydraulic connection part (15) is provided, to which several of the winding pieces (15) are connected, wherein the connection part (15) has at least one channel (31, 32) which is in fluidic connection with several of the winding pieces (5), such that the coolant can be fed into the individual winding pieces (5) via the lateral tap (34) of the winding pieces (5), or a coolant coming out of the lateral taps (34) of the winding pieces (5) can be collected in the at least one channel (31, 32).

2. Electric machine according to claim 1, wherein the winding pieces (5) have ends (33) which are closed.

3. Electric machine according to claim 1, wherein the at least one channel (31, 32) runs in the axial direction B of the electric machine (1) when seen at the height of the lateral taps (34).

4. Electric machine according to claim 1, wherein the connection part (15) has several openings (36) which are each formed for receiving an end section (1) of a winding piece (5).

5. Electric machine according to claim 4, wherein the openings (36) are provided on at least one side, pointing in the axial direction B of the electric machine (1), of the hydraulic connection part (15).

6. Electric machine according to claim 5, wherein the openings (36) for the end sections (8) of the winding pieces (5) run through the hydraulic connection part (15) in the axial direction B.

7. Electric machine according to claim 1, wherein the hydraulic connection part (15) is produced from an electrically insulating material.

8. Electric machine according to claim 4, wherein the hydraulic connection part (15) has sealant lines (37) on at least one face (40) pointing in the axial direction B, in which the openings (36) for the end sections (8) of the winding pieces (5) are provided, said sealant lines leading to the individual openings (36) and being designed in such a way that a sealant can be supplied via them in order to seal the openings (36).

9. Electric machine according to claim 1, wherein the hydraulic connection part (15) is formed in several parts and comprises at least two partial connection parts (15a, 15b), wherein the at least one internal channel (31, 32) is formed between the at least two partial connection parts (15a, 15b) adjacent to each other.

10. Electric machine according to claim 1, wherein the hydraulic connection part (15) comprises several sealant inputs (38) which lead to the openings (36) for the end sections (8) of the winding pieces (5) via sealant lines (37).

11. Electric machine according to claim 1, wherein the hydraulic connection part (15) has a central coolant input (34), which is fluidically connected to a first group of end sections (8) of the winding pieces (5), and a central coolant output (35) which is fluidically connected to a different second group of end sections (8) of the winding pieces (5).

12. Electric machine according to claim 11, wherein the coolant input (34) is in fluidic connection with at least one first channel (32), which is provided to feed coolant into the lateral taps (34) of several end sections (8) of winding pieces (5), and the coolant output (35) is in fluidic connection with at least one second channel (31), which is provided to collect the coolant emerging from the lateral taps (34) of the end sections (8) of several winding pieces (5).

13. Electric machine according to claim 1, wherein, when seen in the axial direction B of the electric machine (1), starting from the winding (4) of the electric machine (1), firstly a hydraulic connection part (15) is provided for hydraulically connecting end sections (8) of the winding pieces (5) and then an electrical contact arrangement follows for electrically connecting certain end sections (8) with the phase ports (L1, L2, L3).

14. Electric machine according to claim 13, wherein the electrical contact arrangement comprises several contact rings (18a-18d).

15. Electric machine according to claim 1, wherein a covering plate (42) is arranged on at least one face (40) of the hydraulic connection part (15) pointing in the axial direction B of the electric machine (1).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The invention is explained in more detail below by means of the attached drawing. Here are shown:

[0049] FIG. 1 a sectional view of an electric machine having a hydraulic connection part;

[0050] FIG. 2 a perspective view of a winding piece of an electric machine in the form of a hairpin;

[0051] FIG. 3a, 3b different views of an arrangement of several distributor elements for distributing the current fed in at the external phase ports;

[0052] FIGS. 4a to 4c contact rings of the individual phases of an electric machine according to the invention;

[0053] FIG. 5 an assembled contact ring arrangement of the contact rings of FIG. 4a-4c;

[0054] FIG. 6 an enlarged sectional view of a hydraulic connection part having winding pieces plugged through;

[0055] FIG. 7 a perspective view of the hydraulic connection part having two covering plates arranged thereon and a contact plate;

[0056] FIG. 8a, 8b different perspective views of the hydraulic connection part from FIG. 7;

[0057] FIG. 9a, 9b the two partial rings of the hydraulic connection part shown in FIG. 8a, 8b;

[0058] FIG. 10a, 10b perspective views of the hydraulic connection part depicted in FIG. 8a, 8b having covering plates arranged thereon; and

[0059] FIG. 11a, 11 b perspective views of the arrangement from FIG. 10a, 10b having an additional electrical contact plate.

[0060] FIG. 1 shows a sectional view of an electric machine 1 having a stator 2, a rotor 3 and a winding 4 formed from several rigid winding pieces 5. The rigid winding pieces 5 are here formed as hollow conductors and comprise a penetrating channel 9, through which a coolant is guided in order to cool the electric machine 1. The individual winding pieces 5 are here arranged hydraulically in parallel and are each part of a cooling circuit of the electric machine 1.

[0061] In the exemplary embodiment of FIG. 1, the winding pieces 5 are each arranged individually in grooves 24 of the stator 2 of the electric machine 1. The cross-section of the winding pieces 5 is here adjusted to the cross-section of the grooves 24, such that they are substantially received without clearance in the grooves 24. Yet alternatively, more than one winding piece 5 per groove 24 could be provided.

[0062] An oil, therminol, galden or carbon dioxide can be used as the coolant, for example.

[0063] The electric machine 1 further comprises a housing 13 having a housing cover 17 in which all components of the electrical and hydraulic connection arrangement are housed.

[0064] In the electric machine 1 depicted in FIG. 1, the winding pieces 5 are designed as so-called hairpins, as is depicted by way of example in FIG. 2. The winding piece 5 depicted in FIG. 2 comprises two substantially parallel running legs 6 and a curved transition region 10, which connects the two legs 6 to each other. The depicted hairpin is formed as a hollow conductor and comprises a penetrating channel 9, which passes through from one end section 8 to the other end section 8 and through which a coolant is guided, in order to cool the winding 4 of the electric machine 1 during operation. The hairpin is respectively open on its front-face ends 33. One of the front-face ends 33 can thus be used as a coolant inlet and the other front-face end 33 as a coolant outlet.

[0065] The winding piece 5 depicted in FIG. 2 can be produced, for example, from copper. On its outer face, it is preferably provided with an electrically insulating layer.

[0066] The winding piece 5 can, for example, have a round or angular profile. The winding piece 5 can also have a different profile on different sections. According to a preferred embodiment, the profile on the end sections is round.

[0067] The electric machine 1 depicted in FIG. 1 is here designed with three phases and correspondingly has three external phase ports L1, L2 and L3, on which the electrical phases U, V and W abut. The winding 4 of the electric machine 1 is here designed in such a way that it respectively comprises several coils arranged in parallel for each electrical phase U, V and W. The individual winding pieces 5 are correspondingly 3 electrically interconnected in such a way that in each case several winding pieces are interconnected in series to a coil, and several such coils, which belong to the same electrical phase U, V, W, are arranged in parallel. According to a specific embodiment of the invention, each phase U, V, W can comprise, for example, eight parallel coils. The winding 4 of the electric machine can, of course, also have more or fewer coils arranged in parallel.

[0068] The end sections 8 of those winding pieces 5 that lie on the phase potential U, V, W are connected to the respectively corresponding external phase port L1, L2, L3 via an electrical contact arrangement, which will be elaborated on in more detail below.

[0069] In this embodiment, said electrical contact arrangement comprises a set of three distributor elements 11a, 11 b, 11c, as is depicted by way of example in FIGS. 3a, 3b. Each of the distributor elements 11a, 11b, 11c is electrically connected to one of the external phase ports L1, L2, L3. In the depicted exemplary embodiment, the distributor element 11a is electrically connected to the phase port L1, the distributor element 11b to the phase port L2 and the distributor element 11c to the phase port L3. The three distributor elements 11a to 11c are arranged one next to the other in the axial direction B of the electric machine 1 and are electrically insulated from one another.

[0070] Each distributor element 11a, 11 b, 11c further comprises several receivers 45 for electrical connection elements 12a-12d, which are arranged preferably distributed evenly across the periphery of the distributor element. The individual distributor elements 11a, 11b, 11c substantially serve to distribute the current supplied at the phase ports L1, L2, L3 across the periphery of the electric machine 1 and to lead them to the subsequent contact rings 18a-18d. Each of the distributor elements 11a-11d is electrically connected to one respective contact ring 18a-18d via several electrical connection elements 12a-12d.

[0071] FIGS. 4a-4c show different contact rings 18a-18c according to a specific embodiment of the invention. The contact ring 18a is here electrically connected to the corresponding distributor element 11a and the phase port L1, the contact ring 18b to the corresponding distributor element 11b and the phase port L2, and the contact ring 18c to the corresponding distributor ring 11c and the phase port L3.

[0072] As can be seen in FIGS. 4a-4c, the electrical connection elements 12a-12c are each fixed on the corresponding contact rings 18a-18c and distributed evenly across the periphery of the contact rings 18a-18c. In the mounted state, the contact rings 18a-18c lie substantially transversely to the axial direction B of the electric machine 1, and the electrical connection elements 12a-12c run substantially in the axial direction B.

[0073] Each of the contact rings 18a-18c comprises several arms 23 for electrically contacting end sections 8 of the unwinding pieces 5 that lie on a certain electrical phase U, V or W. In the present exemplary embodiment, each contact ring 18a-18c comprises eight arms 23, in order to thus contact in each case one of eight winding pieces 5 from eight coils arranged in parallel. The arms 23 have a different length in order to contact end sections 8 of the winding pieces 5 lying radially further inwards or further outwards. Each arm 23 comprises a contact opening 16, through which the end section 8 of one winding piece 5 is inserted and soldered tightly.

[0074] With an electric machine 1 according to the invention, the end sections 8 of the individual winding pieces 5 are preferably arranged in several, in particular circular, rows. The end sections 8 of the winding pieces 5 are preferably arranged in parallel one next to the other and preferably all point in the axial direction B. The end sections 8 preferably all end at the same axial height, i.e. roughly on the same plane. This facilitates the electrical contacting of the individual winding pieces 5 and their hydraulic connection to the cooling circuit.

[0075] FIG. 5 shows the contact rings 18a-18b of FIG. 4a-4c in an assembled state. As can be seen, the individual contact rings 18a-18c are arranged one next to the other in axial direction B of the electric machine 1 and are here electrically insulated from one another.

[0076] Along with the electrical connection of individual winding pieces 5 to the respectively corresponding external phase connection L1, L2, L3, it is also necessary to interconnect certain winding pieces 5 in series with one another, in order to form the coils of the winding 4 of the electric machine 1. For the purposes of the serial interconnection, simple electrical conductors can be used, for example, which are soldered between the desired winding pieces.

[0077] However, according to a preferred embodiment of the invention, an electrical contact plate 39 is provided with electrical connectors 40, as is depicted in FIG. 7. Before reference is made to this contact plate 39, firstly the hydraulic connection of the individual winding pieces 5 is elaborated on below:

[0078] As is shown in FIG. 6, the end sections 8 of the individual winding pieces 5 each have a lateral pin 34 which goes through the periphery and can be fed into the winding pieces via the coolant or from which the coolant can emerge. This has the advantage that the individual end sections 8 of the winding pieces 5 can be electrically contacted by laser welding. Laser welding is a particularly simple, quick and cost-effective method, yet has the disadvantage that the winding pieces 5 can be damaged during welding, such that the channel 9 running in the winding pieces 5 is closed and thus a line of coolant is no longer possible. If the lateral pins 34 are located sufficiently far away from the respective welding point, the winding pieces 5 can be fixed by laser welding without problem. The distance between the welding points and the lateral taps 34 can be, for example, one or more centimetres.

[0079] The lateral taps 34 can be produced e.g. by boring or grinding.

[0080] The individual end sections 8 are arranged in parallel and respectively run through a hydraulic connection part 15, which comprises several internally lying channels 31, 32, by means of which the coolant can be fed into the individual winding pieces 5 via the lateral pins 34 or coolant emerging from the winding pieces 5 is collected. The individual end sections 8 are here arranged in such a way that the lateral pins 34 substantially lie on the same plane in the region of a channel 31, 32 and communicate with this.

[0081] As can be seen in FIG. 6, the front-face ends 33 of the individual winding pieces 5 are closed. In order to achieve this, the front-face ends 33 of the winding pieces 35 are simply squashed, for example.

[0082] In each case, a covering plate 42 is arranged on the two outer faces, pointing in the axial direction B, of the hydraulic connection part 15, said covering plat being elaborated on in more detail below. Furthermore, a contact plate 39 is arranged on the side, depicted on the right in FIG. 6, of the hydraulic connection part 15, said contact plate serving to contact certain end sections 8 of the winding pieces 5 and to allow series connection corresponding to the electrical interconnection of the winding 4.

[0083] FIG. 7 shows a perspective view of the hydraulic connection part 15 having covering plates 42 arranged on both sides and the contact plate 39 described above. The hydraulic connection part 15, the two covering plates 42 and the contact plate 39 each have a plurality of passage openings 36, through which the end sections 8 of the individual winding pieces 5 run. As can be seen, the end sections 8 of the winding pieces 5 project through the entire arrangement and protrude outwardly beyond the contact plate 39. A plurality of electrical connectors 40 is provided on the outer surface of the contact plate 39 pointing in the axial direction B, via which certain winding pieces 5 are arranged in series. The end sections 8 of the winding pieces 5 are preferably electrically welded there. Such a contact plate 39 can also be provided with every other embodiment of the electric machine 1.

[0084] FIGS. 8a and 8b show different perspective views of the hydraulic connection part 15 from FIG. 7. The hydraulic connection part 15 comprises a plurality of passage openings 36, through which in each case one end section 8 of a winding piece 5 runs in the assembled state. The passage openings 36 run substantially in the axial direction B of the electric machine 1, whereby the end sections 8 of the winding pieces 6 are arranged substantially in parallel.

[0085] Furthermore, a central coolant input 46 and a central coolant output 35 are provided on the outer periphery of the hydraulic connection part 15, via which the coolant is supplied or removed.

[0086] As mentioned, various channels 31, 32 are arranged in the inner chamber of the hydraulic connection part 15 which fluidically communicate with the lateral taps 34 of the winding pieces 5 and via which the coolant is fed into the winding pieces 5 or the coolant emerging from the winding pieces 5 is collected. Said channels 31, 32 are depicted in more detail in FIGS. 9a and 9b.

[0087] According to an alternative embodiment of the invention, openings 36 for the end sections 8 of the winding pieces 5 could also be provided on only one side of the hydraulic connection part 15. In this case, the end sections 8 of the winding pieces 5 would end in the inner chamber of the hydraulic connection part 5. The hydraulic connection of the winding pieces 5 could nevertheless be implemented as described above.

[0088] On both faces, pointing in the axial direction B, of the hydraulic connection part 15, sealant lines 37 or channels are further provided, via which a sealant can be led to the individual passage openings 36. In this case, the sealant serves to seal the hydraulic connection part 15 from the outside.

[0089] Several sealant inputs 38 are located on the lateral peripheral face of the hydraulic connection part 15, via which sealant inputs the sealant can be injected into the sealant lines 37 or channels. The sealant inputs 36 communicate with the sealant lines 37 mentioned above, such that, when it is injected into the hydraulic connection part 15 via the sealant inputs 36, the sealant flows via the sealant lines 37 to the individual passage openings 36 for the winding pieces 5.

[0090] In this embodiment, the sealant lines 37 are formed as channels or grooves provided in the surface of the hydraulic connection part 15. So that the sealant does not leak out of the sealant lines 37, in each case one covering plate 42 is provided on both sides of the hydraulic attachment part 15. One or both of the covering plates 42 can here optionally also function as a contact plate 39, in order to arrange individual winding pieces 5 electrically in series.

[0091] As can be seen in FIG. 9a, 9b, in this exemplary embodiment, the hydraulic connection part 15 is designed as a multi-part element that comprises two partial rings 15a, 15b, on the opposite sides of which in each case fluid channels 31, 32 are provided, via which the coolant is supplied or removed. The central channel 32 is here formed more widely than the channels lying radially outwards or radially inwards and correspondingly straddles two rows lying one next to the other of end sections 8 of the electrical winding pieces 5. The two other channels 31, in contrast, communicate only with one row of end sections 8 in each case. In this exemplary embodiment, the coolant is preferably supplied via the central channel 32 and removed via the two other channels 31. Yet the flow direction can also be changed at any time.

[0092] FIGS. 10a and 10b each show the assembled hydraulic connection part 15 with covering plates 42 arranged on both sides. The central coolant input 46 and output 35 can also be recognised.

[0093] FIGS. 11a and 11b schematically show the whole arrangement of FIGS. 10a and 10b with an additionally placed contact plate 39 and a plurality of end sections 8 of the winding pieces 5.

[0094] In the exemplary embodiment depicted in FIG. 1 of the electric machine 1, the coolant flows into the electric machine 1 via a coolant input 19 provided on the housing 13 of the electric machine 1 and is supplied from there to the hydraulic connection part 15 via one or more channels. The coolant enters there from outside into the central coolant channel 32 via the coolant input 46 and is then fed into the end sections 8 of the winding pieces 5 fluidically connected to it via the lateral taps 34, runs through the individual winding pieces 5 and re-emerges at the two channels 31. From there, the coolant is led into a chamber 21, in which the distributor elements 11a-11c are located. The coolant finally re-emerges from the electric machine 1 at the coolant output 20.

[0095] Furthermore, a power electronic system of the electric machine 1 (not shown) can be integrated into the cooling circuit and cooled using the coolant. As a result of the corresponding design of the coolant path through the electric machine 1, in principle any components can be cooled, if desired. The person skilled in the art will correspondingly adjust the coolant path according to the requirements within the scope of their specialist knowledge.