FLUID-COOLED ACTIVE PART, ELECTRIC MACHINE, AND DRIVE SYSTEM

Abstract

The invention relates to a fluid-cooled active part (1) for an electric machine (38), wherein the active part (1) is substantially cylindrical or hollow cylindrical, having axially extending grooves (2), at least one electrical conductor (3), which is arranged in the associated groove (2) at least in some sections and which is composed of a plurality of partial conductors (4), one or more main insulators (5), each arranged between the associated conductor (3) and the associated groove (2), and partial-conductor insulators (6), each surrounding the associated partial conductor (4). The invention further relates to an electric machine (38), having such a fluid-cooled active part (1) designed as a stator (39) and/or such a fluid-cooled active part (1) designed as a rotatably mounted rotor (40), wherein the electric machine (38) can be operated with a voltage in the range of at least a few kilovolts, preferably a few tens of kilovolts. Finally, the invention relates to a drive System (41), having such an electric machine (38) and a fluid energy machine (42) for the fluid, wherein the fluid energy machine (42) is designed as a compressor, in particular for process gas, or as a pump, in particular for a process liquid. In order to provide, among other things, a high-performance fluid-cooled active part that is compact and, in particular, resistant in the environment of the fluid or of a process fluid, it is proposed, among other things, that the active part (1) has one or more cooling Channels (7) for conducting the fluid, in particular a process fluid, wherein each cooling Channel (7) is arranged between the associated main insulator (5) and the respective partial-conductor insulators (6).

Claims

1. A fluid-cooled active part (1) for an electric machine (38), wherein the active part (1) is essentially cylindrical or hollow cylindrical, having axially extending grooves (2), at least one electrical conductor (3), which in each case is arranged in the respective groove (2) at least in certain sections and which is composed of a plurality of sub-conductors (4), a respective main insulator (5) which is arranged between the respective conductor (3) and the respective groove (2), and a respective sub-conductor insulator (6) which surrounds the respective sub-conductor (4), characterized by a respective cooling channel (7) for guiding the fluid, in particular a process fluid, wherein the respective cooling channel (7) is arranged between the respective main insulator (5) and the respective sub-conductor insulator (6).

2. The fluid-cooled active part (1) as claimed in claim 1, wherein the respective cooling channel (7) has an inlet channel (8), an outlet channel (9) and a respective connecting channel (10) for fluidically connecting the inlet channel (8) to the outlet channel (9), wherein the respective groove (2) has a groove base (11) and two groove walls (12), wherein the respective inlet channel (8) or outlet channel (9) is arranged between the respective conductor (3) on the one hand and the groove base (11) or the groove opening (13) that opposes the groove base (11) in the radial direction (51) on the other hand, wherein the respective connecting channel (10) is arranged at least predominantly between the respective conductor (3) on the one hand and one of the two groove walls (12) on the other hand.

3. The fluid-cooled active part (1) as claimed in one of the preceding claims, wherein the respective main insulator (5) has two essentially C-shaped insulating half-shells (14) which together essentially surround the respective conductor (3) in a plane perpendicular to the axial direction (50), wherein the two respective insulating half-shells (14) are arranged essentially symmetrically to the center of the groove (15) in the circumferential direction (52) of the respective groove (2), wherein the two respective insulating half-shells (14) are sealed in the radial direction (51) by means of a respective sealing element (16), comprising in particular a fluororubber.

4. The fluid-cooled active part (1) as claimed in claim 1 or 2, wherein the respective main insulator (5) at least largely covers the groove base (11) and the two groove walls (12) of the respective groove (2), wherein a plurality of channel half-shells (17) is arranged one behind the other in the axial direction (50), wherein the respective channel half-shell (17) has an essentially U-shaped cross-section in a plane perpendicular to the axial direction (50) and largely surrounds the respective conductor (3) in this plane.

5. The fluid-cooled active part (1) as claimed in claims 2 and 4, wherein the respective channel half-shell (17), viewed in a plane perpendicular to the axial direction (50), has at least one radial web (18) extending in each case in the radial direction (51) along the respective conductor (3), as well as two pairs of circumferential webs (19) pointing in the circumferential direction (52), which are connected by means of the radial web (18), wherein the one pair of circumferential webs (19) is designed for forming the respective inlet channel (8) and the other pair of circumferential webs (19) for forming the respective outlet channel (9), wherein in at least a first channel half-shell (17A) in each case at least one of the two central circumferential webs (19) is designed for forming at least some of the respective connecting channel (10).

6. The fluid-cooled active part (1) as claimed in claim 5, wherein between at least one of the two central circumferential webs (19) of the respective first channel half-shell (17A) on the one hand and the respective main insulator (5) on the other hand, a respective through-opening (20) remains and/or at least one of the two central circumferential webs (19) of the respective first channel half-shell (17A) has a respective through-opening (20).

7. The fluid-cooled active part (1) as claimed in claim 5 or 6, wherein in at least one second channel half-shell (17B), in each case the circumferential webs (19) of at least one of the two pairs of circumferential webs (19) are connected in such a way by means of a respective end web (21) that the respective second channel half-shell (17B), viewed in a plane perpendicular (50) to the axial direction, has a rectangular cross-section for guiding the respective cooling channel (7).

8. The fluid-cooled active part (1) as claimed in one of claims 3 to 7, wherein at least two electrical conductors (3A, 3B) are arranged in the respective groove (2) one above the other in the radial direction (51), wherein a respective intermediate element (22) is provided for sealing and/or for tolerance compensation, and this is arranged in the radial direction (51) between one of the half-shells (14, 17) of the upper electrical conductor (3A) on the one hand and one of the half-shells (14, 17) of the lower electrical conductor (3b) on the other hand.

9. The fluid-cooled active part (1) as claimed in claim 1 or 2, wherein the respective main insulator (5) at least largely covers the groove base (11) and the two groove walls (12) of the respective groove (2), wherein at least two electrical conductors (3) are arranged in the respective groove (2) one above the other in the radial direction (51), wherein a respective conductor shell (23) is provided which surrounds the respective conductor (3) in a plane perpendicular to the axial direction (50), wherein both the respective groove (2), at least in the region of the lower electrical conductor (3B), as well as the respective conductor shell (23) of the lower electrical conductor (3B) taper in the direction of the groove base (11) in such a way that the respective conductor shell (23) of the lower conductor (3B) is positively fixed in the direction of the groove base (11), and a first, axially extending cavity (24), in particular for a first inlet channel (8A), remains between the groove base (11) and the respective conductor shell (23) of the lower electrical conductor (3B).

10. The fluid-cooled active part (1) as claimed in claim 9, wherein at least a first insert (25) is provided which in each case has an H-shaped cross-section in a plane perpendicular to the axial direction (50), wherein the respective first insert (25) is arranged between the respective conductor shell (23) of the lower conductor (3B) on the one hand, and the respective conductor shell (23) of the upper electrical conductor (3A) on the other hand, and is designed in such a way that a second or third, axially extending cavity (26 or 27), in particular for a first outlet channel (9A) and a second inlet channel (8B), remains between the respective conductor shell (23) of the lower conductor (3B) or the upper conductor (3A) on the one hand and the respective first insert (25) on the other hand.

11. The fluid-cooled active part (1) as claimed in claim 10, wherein the respective first insert (25), in a plane perpendicular to the axial direction (50), has two outer webs (29) which point in the direction of the groove opening (13) and are arranged at least in certain sections in the circumferential direction (52) between the respective conductor shell (23) of the upper conductor (3A) on the one hand and the respective groove wall (12) on the other hand, wherein the two outer webs (29) taper in the direction of the groove opening (13) and the respective conductor shell (23) of the upper conductor (3A) tapers in certain sections in the direction of the groove base (11) in such a way that the respective conductor shell (23) of the upper conductor (3A) is non-positively fixed in the radial direction (51).

12. The fluid-cooled active part (1) as claimed in claim 10 or 11, wherein at least a second insert (30) is provided, which in each case has a U-shaped cross-section in a plane perpendicular to the axial direction (50), wherein the respective second insert (30) is arranged and designed in such a way that a fourth, axially extending cavity (31), in particular for a second outlet channel (9B), remains between the respective conductor shell (23) of the upper conductor (3A) on the one hand and the respective second insert (30) on the other hand.

13. The fluid-cooled active part (1) as claimed in claim 12, wherein the respective second insert (30) in a plane perpendicular to the axial direction (50) has two inner webs (32) which point in the direction of the groove base (11) and are arranged at least in certain sections in the circumferential direction (52) between the respective conductor shell (23) of the upper conductor (3A) on the one hand and the respective groove wall (12) on the other hand, wherein the two inner webs (32) taper in the direction of the groove base (11) and the respective conductor shell (23) of the upper conductor (3A) tapers in certain sections in the direction of the groove opening (13) in such a way that the respective conductor shell (23) of the upper conductor (3A) and the respective second insert (30) are positively fixed in the radial direction (51).

14. The fluid-cooled active part (1) as claimed in claim 12 or 13, wherein two respective inserts (25, 30) are arranged one behind the other in the axial direction (50) and a respective axial gap (33) remains in the region of the axial center between the two respective inserts (25, 30), wherein the first cavity (24) and the third cavity (27) in the region of the axial center are closed by means of a respective cover (34), wherein the second cavity (26) and the fourth cavity (31) are closed at the respective axial end face by a respective cover (34).

15. The fluid-cooled active part (1) as claimed in one of claims 9 to 14, wherein the respective conductor shell (23) has recesses (35) extending in the radial direction (51) for forming the respective connecting channel (10).

16. The fluid-cooled active part (1) as claimed in one of the preceding claims, wherein the respective groove (2) is closed in the radial direction (51) in the region of the groove opening (13) by means of a groove closure element (36), wherein a tolerance compensating element is arranged between the respective groove closure element (36) and the at least one conductor (3).

17. The fluid-cooled active part (1) as claimed in one of the preceding claims, wherein the respective main insulator (5) and/or the respective sub-conductor insulator (6) comprises polytetrafluoroethylene (PTFE).

18. An electric machine (38) having a fluid-cooled active part (1) designed as a stator (39) as claimed in one of the preceding claims and/or a fluid-cooled active part (1) designed as a rotatably mounted rotor (40) as claimed in one of the preceding claims, wherein the electric machine (38) can be operated with an electrical voltage in the range of at least a few kilovolts, preferably a few tens of kilovolts.

19. A drive system (41) having an electric machine (38) as claimed in claim 18 and a fluid energy machine (42) for the fluid, wherein the fluid energy machine (42) is designed for example as a compressor, in particular for a process gas, or as a pump, in particular for a process liquid.

Description

[0082] The invention will be described and illustrated in more detail below with reference to the exemplary embodiments illustrated in the figures, in which:

[0083] FIG. 1-12 show first to fifth exemplary embodiments of the proposed fluid-cooled active part, and

[0084] FIG. 13 shows an exemplary embodiment of the proposed electric machine and the proposed drive system.

[0085] FIG. 1 shows a first exemplary embodiment of the proposed fluid cooled active part 1, with a perspective detail of a cross-section perpendicular to the axial direction 50 through the active part 1 being shown.

[0086] The active part 1 is essentially hollow cylindrical, so an axial direction 50, a radial direction 51 and a circumferential direction 52 are defined. The active part 1 has axially extending grooves 2 and 3 electrical conductors, which are each arranged at least in certain sections in the respective groove 2. For the sake of clarity, FIG. 1 only indicates one conductor 3.

[0087] The respective conductor 3 is composed of a plurality of sub-conductors 4. Arranged between the respective conductor 3 and the respective groove 2 is a respective main insulator 5, with the respective conductor 4 being surrounded by a sub-conductor insulator 6.

[0088] Furthermore, the active part has a respective cooling channel 7 for guiding the fluid, in particular a process fluid, with the respective cooling channel 7 being arranged between the respective main insulator 5 and the sub-conductor insulator 6.

[0089] As indicated in FIG. 1, the respective groove 2 has a groove base 11, two groove walls 12, and a groove opening 13, with the grooves 2 being open radially inwards in the framework of the exemplary embodiment. In principle, the grooves 2 can also be open radially outwards.

[0090] FIG. 2 shows a second exemplary embodiment of the proposed fluid-cooled active part 1. The same reference numerals as in FIG. 1 designate the same objects.

[0091] Since the second exemplary embodiment has some similarities with the first exemplary embodiment, some differences will be explained below. The active part 1 of the second exemplary embodiment is characterized inter alia by the fact that a defined flow direction 43 is specified for the fluid within the respective groove 2. The respective cooling channel 7 comprises an inlet channel 8, an outlet channel 9, and a respective connecting channel 10, which fluidically connects the inlet channel 8 to the outlet channel 9. The inlet channel 8 is arranged between the electrical conductor 3 and the groove base 11 and the outlet channel 9 is arranged between the respective conductor and the groove opening 13. The respective connecting channel 10 is primarily arranged between the conductor 3 and one of the two groove walls 12.

[0092] FIG. 3 shows a third exemplary embodiment of the proposed fluid-cooled active part 1, with a detail of a cross-section perpendicular to the axial direction 50 through the active part 1 being shown.

[0093] Within the framework of the exemplary embodiment, two electrical conductors 3a, 3b are provided in the respective groove 2, and these are arranged one above the other in the radial direction 51. The conductor 3A is the upper conductor facing the groove opening 13 and the conductor 3B is the lower conductor facing the groove base 11. However, it is also possible for just one of the two conductors 3A, 3B to be provided in a variation of the exemplary embodiment.

[0094] A respective main insulator 5 is associated with each of the two conductors 3A, 3B, and in each case comprises two essentially C-shaped insulating half-shells 14. The two respective insulating half-shells 14 together surround the respective conductor 3A, 3B in a plane perpendicular to the axial direction 50. The two insulating half-shells 14 are arranged essentially symmetrically to the groove center 15 in the circumferential direction 52 of the respective groove 2. In the radial direction 51, the two respective insulating half-shells 14 are sealed by a respective sealing element 16, with the respective sealing element 16 in particular comprising a fluororubber. Arranged within a pair of insulating half-shells 14 are an inlet channel 8 and an outlet 9.

[0095] To simplify the sealing of the two respective insulating half-shells 14 and make it more reliable, the respective insulating half-shell 14 can in each case have a sort of hook 44 in the region of the supporting or contact lines, and this points toward the respective conductor 3A, 3B in the radial direction 51. Said sealing element 16 is, as indicated in FIG. 3, arranged between two hooks 44 of two mating insulating half-shells 14. The hooks 44 should be regarded as optional. Similarly optional is a spacer 45 which is arranged between the plurality of sub-conductors 4 and the respective insulating half-shell 14, which, however, creates space for the respective connecting channel 10 in the framework of the exemplary embodiment.

[0096] An intermediate element (not shown) can be provided in the radial direction 51 between the insulating half-shells 14 of the upper conductor 3A and the lower conductor 3B a for sealing and for tolerance compensation.

[0097] FIGS. 4 to 8 show a fourth exemplary embodiment of the proposed fluid-cooled active part 1, with FIGS. 6 and 7 illustrating some details and otherwise a perspective detail of a cross-section perpendicular to the axial direction 50 through the active part 1 being shown.

[0098] Within the framework of the exemplary embodiment, two electrical conductors 3a, 3b are provided in the respective groove 2, and these are arranged one above the other in the radial direction 51. The conductor 3A is the upper conductor facing the groove opening 13 and the conductor 3B is the lower conductor facing the groove base 11. However, it is also possible for just one of the two conductors 3A, 3B to be provided in a variation of the exemplary embodiment.

[0099] The respective main insulator 5 is designed in such a way that it largely covers the groove base 11 and the two groove walls 12 of the respective groove 2.

[0100] As is clear in particular from FIGS. 5 and 8, a plurality of channel half-shells 17 is arranged one behind the other in the axial direction 50, with some of the channel half-shells being arranged mirror-inverted to other channel half-shells 17 with respect to the groove center 15 in the circumferential direction 52 of the respective groove 2. In a plane perpendicular to the axial direction 50, the respective channel half-shell 17 has an essentially U-shaped cross-section and largely surrounds the respective conductor 3A, 3B.

[0101] Viewed in a plane perpendicular to the axial direction 50, the respective channel half-shell 17 has a radial web 18 as well as two pairs of circumferential webs 19. The respective radial web 18 extends in the radial direction along the respective conductor 3 and the respective circumferential web 19 points in the circumferential direction 52, with the circumferential webs 19 being connected by means of the radial web 18.

[0102] The respective inlet channel 8 and the respective outlet channel 9 are designed as follows by means of circumferential webs 19. The inlet channel 8 is arranged in the region of that pair of circumferential webs 19 which is closer to the groove base 11, (in other words, at the bottom in FIGS. 4 to 8), and the outlet channel 9 is arranged in the region of that pair of circumferential webs 19 which is closer to the groove opening 13 (in other words, at the top in FIGS. 4 to 8).

[0103] The active part 1 has first channel half-shells 17A, which, as shown in FIG. 7, have middle circumferential webs 19 which have a respective through-opening 20 (upper one of the middle circumferential webs 19 in FIG. 7) or form a respective through-opening 20 which remains between the respective middle circumferential ridge 19 and the respective main insulator 5 (lower one of the central circumferential webs 19 in FIG. 7). The last-mentioned embodiment is achieved in that the corresponding circumferential web is designed somewhat shorter in the circumferential direction 19 than the remaining circumferential webs 19 and therefore the through-opening 20 is formed. By way of such an embodiment of the respective first channel half-shell 17A, at least some of the respective connecting channel 10 is formed by means of at least one of the two central circumferential webs 19. In a variation of the exemplary embodiment, the respective first channel half-shell 17A can have just one through-opening 20 or two identical ones of the above through-openings 20.

[0104] Furthermore, the active part 1 has second channel half-shells 17B in which in each case the circumferential webs 19 of a pair or both pairs of circumferential webs 19 are connected by means of a respective end web 21, as shown in FIG. 6. The second channel half-shells 17B are designed in such a way that, viewed in a plane perpendicular to the axial direction 50, they each have a rectangular cross-section for guiding the respective cooling channel 7. In the present exemplary embodiment, two such rectangular cross-sections are formed, one for the inlet channel 8 and one for the outlet channel 9.

[0105] Provided in the radial direction 51 between the channel half-shells 17 of the upper conductor 3A and the lower conductor 3B is an intermediate element 22 for sealing and for tolerance compensation.

[0106] As indicated in FIG. 8 by the arrows 43 for the flow direction of the fluid, the fluid is introduced into the respective inlet channel 8 and it is guided firstly in the axial direction 50 by means of the second channel half-shells 17B. Subsequently, the fluid is guided by means of the first channel half-shells 17A through corresponding through-openings 20 in the radial direction 51 into the respective connecting channel 10, to be then led into the respective outlet channel 9 and finally to be led out in the axial direction 15 from the arrangement of the channel half-shells 17.

[0107] FIGS. 9 to 12 show a fifth exemplary embodiment of the proposed fluid-cooled active part 1, with a detail or a perspective detail of a cross-section perpendicular to the axial direction 50 through the active part 1 being shown and FIG. 10 showing details of a conductor shell 23 for an upper electrical conductor 3A.

[0108] Within the framework of the exemplary embodiment, two electrical conductors 3A, 3B are provided in the respective groove 2, and these are arranged one above the other in the radial direction 51. The conductor 3A is the upper conductor facing the groove opening 13 and the conductor 3B is the lower conductor facing the groove base 11. However, it is also possible for just one of the two conductors 3A, 3B to be provided in a variation of the exemplary embodiment.

[0109] The respective main insulator 5 is designed in such a way that it largely covers the groove base 11 and the two groove walls 12 of the respective groove 2.

[0110] In the present exemplary embodiment, a respective conductor shell 23 is provided which surrounds the respective conductor 3A, 3B in a plane perpendicular to the axial direction 50. The respective groove 2 has a groove region 47 along which the groove width 28 decreases in the radial direction 51 toward the groove base 11 so the respective groove 2 tapers there in the direction of the groove base 11. The respective conductor shell 23 of the lower conductor 3B likewise tapers in the corresponding region in the direction of the groove base 11, with the respective tapered portions being designed in such a way that the respective conductor shell 23 of the lower conductor 3B is positively fixed in the direction of the groove base 11, and a first, axially extending cavity 24 remains for the first inlet channel 8A between the groove base 11 and the respective conductor shell 23 of the lower conductor 3B. In particular, the groove width 28 can remain constant in the region of the first cavity 24.

[0111] Furthermore, a respective first insert 25 is provided which has an H-shaped cross-section in a plane perpendicular to the axial direction 50. The respective first insert 25 is arranged between the respective conductor shell 23 of the lower conductor 3B and the respective conductor shell 23 of the upper electrical conductor 3A. The respective first insert 25 is designed in such a way that a second axially extending cavity 26 for a first outlet 9A remains between the respective conductor shell 23 of the lower conductor 3B on the one hand and the respective first insert 25 on the other hand. Furthermore, a third, axially extending cavity 27 for a second inlet channel 8B remains between the respective conductor shell 23 of the upper conductor 3A on the one hand and the respective first insert 25 on the other hand.

[0112] In a plane perpendicular to the axial direction 50, the respective first insert 25 has two outer webs 29, which point in the direction of the groove opening 13 and are arranged in certain sections in the circumferential direction 52 between the respective conductor shell 23 of the upper conductor 3A on one hand and the respective groove wall 12 on the other hand. The two outer webs 29 of the respective first insert 25 taper in the direction of the groove opening 13 and the respective conductor shell 23 of the upper conductor 3A tapers in certain sections in the direction of the groove base 11, with the tapered sections being designed in such a way that the respective conductor shell 23 of the upper conductor 3A is non-positively fixed in the radial direction 51.

[0113] Furthermore, a respective second insert 30 is provided which has a U-shaped cross-section in a plane perpendicular to the axial direction 50. The respective second insert 30 is arranged and designed in such a way that a fourth axially extending cavity 31 for a second outlet channel 9B remains between the respective conductor shell 23 of the upper conductor 3A on the one hand and the respective second insert 30 on the other hand.

[0114] In a plane perpendicular to the axial direction 50, the respective second insert 30 has two inner webs 32 which point in the direction of the groove base 11 and in certain sections in the circumferential direction are arranged between the respective conductor shell 23 of the upper conductor 3A on the one hand and the respective groove wall 12 on the other hand. The two inner webs 32 of the respective second insert 30 taper in the direction of the groove base 11, with the respective conductor shell 23 of the upper conductor 3A tapering in certain sections in the direction of the groove opening 13. The tapered sections are designed in such a way that the respective conductor shell 23 of the upper conductor 3A and the respective second insert are non-positively fixed in the radial direction 51 30.

[0115] Within the framework of the exemplary embodiment, the respective conductor shell 23 is designed in two parts by comprising a first conductor shell part 23A, having an essentially U-shaped cross-section in a plane perpendicular to the axial direction 50, and a second conductor shell part 23B, as shown in FIGS. 9 and 10. The second conductor shell part 23B is in this case designed as a kind of cover for the first conductor shell part 23A. In order to surround the respective conductor 3A, 3B, particularly well, the second conductor shell part 23B has two grooves and the first conductor shell part 23A two corresponding tongues for a respective tongue and groove joint. For sealing and therefore protection of the respective conductor 3A, 3B from the fluid flowing into the respective cavity, in particular, owing to its advantageous properties described above, a fluororubber can be used in the region of the tongue and groove joint.

[0116] As is clear in particular from FIGS. 11 and 12, within the framework of the exemplary embodiment, two respective inserts 15, 30 are arranged one behind the other in the axial direction 50, with a respective axial gap 33 remaining in the region of the axial center between the two respective inserts 25, 30. The first cavity 24 and the third cavity 27 are closed in the region of the axial center by means of a respective cover 34. Further covers 34 are provided for closing the second cavity 26 and the fourth cavity 31 at the respective axial end face.

[0117] As illustrated in FIG. 10, the respective conductor shell 23 has recesses 35, which run in the radial direction 51 and form the respective connecting channel 10.

[0118] In order to minimize the risk of potential electrical breakdowns in the region of the winding heads at the respective axial end face of the active part 1, no such recesses 35 are provided in the respective conductor shell 23 in the immediate vicinity of the respective axial end. Analogously, no such recesses 35 are provided in the respective conductor shell 23 in the immediate vicinity of the illustrated gap 33 either.

[0119] FIG. 13 shows an exemplary embodiment of the proposed electric machine 38 and the proposed drive system 41, with a cross-section along the axial direction 50 being shown.

[0120] The electric machine 38 has a stator 39 and a rotatably mounted rotor 40, with the stator 39 and/or the rotor 40 being designed as the proposed, fluid-cooled active part. The electric machine 38 can be operated with an electrical voltage in the range of a few kilovolts, in particular a few tens of kilovolts.

[0121] The electric machine 38 is part of the drive system 41, further comprising a fluid energy machine 42 for the fluid, with the fluid energy machine 42 being designed as a compressor, in particular for a process gas, or as a pump, in particular for a process fluid. The arrows 43 indicate the flows of the fluid in the electric machine 38 and in the fluid energy machine 42.

[0122] To summarize, the invention relates to a fluid cooled active part for an electric machine, wherein the active part is essentially cylindrical or hollow-cylindrical, having axially extending grooves, at least one electrical conductor, which in each case is arranged at least in certain sections in the respective groove and which is composed of a plurality of sub-conductors, a respective main insulator, which is arranged between the respective conductor and the respective groove, and a respective sub-conductor insulator which surrounds the respective sub-conductor. Furthermore, the invention relates to an electric machine having a fluid-cooled active part of this kind designed as a stator, and/or a fluid-cooled active part of this kind designed as a rotatably mounted rotor, wherein the electric machine can be operated with an electrical voltage in the range of at least a few kilovolts, preferably a few tens of kilovolts. Finally, the invention relates to a drive system having an electric machine of this kind, and a fluid energy machine for the fluid, wherein the fluid energy engine is designed, for example, as a compressor or, in particular for a process gas, or as a pump, in particular for a process fluid.

[0123] In order to overcome drawbacks from the prior art and to provide a fluid-cooled active part which is powerful, compact and in particular resistant in the environment of the fluid and a process fluid, it is proposed that the active part has a respective cooling channel for guiding the fluid, in particular a process fluid, wherein the respective cooling channel is arranged between the respective main insulator and the respective sub-conductor insulator. Furthermore, a corresponding electric machine and a corresponding drive system are proposed.