STATOR, APPARATUS AND METHOD FOR PEPARING A PRE-SHAPED INSULATOR

Abstract

The invention relates to a stator (1) which may be used within an electric rotating machine, an apparatus for preparing pre-shaped insulators and a method for preparing a pre-shaped insulator. The stator (1) comprises a stator core (10) which has a plurality of axially extending slots (11) arranged in a circumferential direction (C) of the stator core (10) and at least two conductors (20, 21) arranged along a radial direction (R) of the same slot (11). Each conductor (20, 21) is peripherally wrapped by an individual insulator (30) which extends around the outer circumference (22) of the conductor (20, 21), such that in circumferential direction the insulator (30) comprises a one-layer-section (37) and an overlapping section (31) which extend along the complete axial length (29) of the insulator (30).

Claims

1-17. (canceled)

18. A stator for a rotating electric machine, the stator comprising: a stator core which has a plurality of axially extending slots arranged in a circumferential direction of the stator core; at least two conductors each arranged along a radial direction of at least one slot of the axially extending slots, wherein: each conductor of the at least two conductors is peripherally wrapped by an individual insulator which extends around an outer circumference of each conductor, such that in a circumferential direction the insulator comprises a one layer section and an overlapping section which extend along the complete axial length of the insulator.

19. The stator according to claim 18, wherein the insulators wrapped around each conductor overlap at a lateral side of the conductor.

20. The stator according to claim 19, wherein all insulators of conductors arranged in one slot overlap at a same lateral side.

21. The stator according to claim 18, wherein: each slot is open towards an axial center of the stator core; each slot comprises a narrowing at a radially inner end of each slot with a radially extending centerline; and a circumferential distance between a first lateral wall of each slot and a respective centerline is smaller than a circumferential distance between a second lateral wall of the slot and the respective centerline.

22. The stator according to claim 21, wherein the circumferential distance between a first lateral wall of the slot and the centerline is smaller than the circumferential distance between a second lateral wall of the slot and the centerline by the thickness of the insulator.

23. The stator according to claim 18, wherein the conductors are formed by a plurality of conductor elements.

24. An apparatus for preparing at least one pre-shaped insulator from an insulator sheet, the apparatus comprising: a bending station, the bending station comprising: a base station comprising a recess with a contact surface defining a first part of an outer circumference of the at least one pre-shaped insulator; a stamp member laterally moveable with respect to the recess from an open to a closed position, the stamp member comprising: an inner contact surface for pressing a middle part of the insulator sheet against the contact surface of the recess and defining a first part of the inner circumference of the pre-shaped insulator, and an outer contact surface defining a second part of the inner circumference of the pre-shaped insulator; a first bending operator moveable with respect to the base station from an open position to a closed position, comprising a first bending surface for bending a first tail of the insulator sheet against the outer contact surface of the stamp member; and a second bending operator moveable with respect to the base station from an open position to a closed position, comprising a second bending surface for bending a second tail of the insulator sheet against one or more of the first tail or the outer contact surface of the stamp member.

25. The apparatus according to claim 24, wherein the apparatus is an apparatus for preparing pre-shaped insulators for a stator, the stator comprising: a stator core which has a plurality of axially extending slots arranged in a circumferential direction of the stator core; at least two conductors each arranged along a radial direction of at least one slot of the axially extending slots, wherein: each conductor of the at least two conductors is peripherally wrapped by an individual insulator which extends around an outer circumference of each conductor, such that in a circumferential direction the insulator comprises a one layer section and an overlapping section which extend along the complete axial length of the insulator.

26. The apparatus according to claim 24, wherein at least one of the first bending operator or the second bending operator is rotatably mounted at the base station.

27. The apparatus according to claim 24, wherein the sum of the width of the first bending surface and the width the second bending surface corresponds to the width of the outer contact surface of the stamp member.

28. The apparatus according to claim 27, wherein the second bending surface has a larger width than the first bending surface.

29. The apparatus according to claim 24, wherein the outer contact surface of the stamp member comprises a depression for receiving the first tail of the insulator sheet.

30. The apparatus according to claim 24, wherein the stamp member comprises at least one groove running in a direction parallel to a bending line of the insulator and the base station comprises at least one groove running in a direction parallel to a bending line of the insulator, said grooves being open in a direction opposite to each other when the stamp member is in the closed position and which allow introducing a removing tool for removing the shaped insulator from the bending station of the apparatus.

31. The apparatus according to claim 24, wherein: the stamp member comprises at least one groove running in a direction parallel to a bending line of the insulator; and the second bending surface comprises at least one groove running in a direction parallel to a bending line of the insulator, said at least one groove being open in a direction opposite to each other when the second bending operator is in the closed position, wherein the at least one groove allows introducing a removing tool for removing the shaped insulator from the bending station of the apparatus.

32. The apparatus according to claim 24, wherein the apparatus further comprises a transfer station for inserting at least two pre-shaped insulators into a slot of a stator core.

33. The apparatus according to claim 24, wherein the apparatus further comprises a feed station, the feed station comprising one or more of: a cutter for cutting flat sheets of insulating material from a continuously supplied sheet of insulating material; an embossing unit for applying longitudinal embossings into the flat sheets or into the continuously supplied sheet of insulating material; or a supply unit for supplying the cut sheets to the bending station or for supplying the continuously supplied sheet of insulating material to the bending station prior to cutting.

34. A method for preparing pre-shaped insulators comprising: providing a cut insulator sheet of a flat insulating material in a bending station of an apparatus between a base station comprising a recess and a stamp member; pressing a part of the insulator sheet into the recess by moving the stamp member laterally into the recess and thereby forming a U-shaped insulator sheet with a first tail and a second tail; contacting the first tail with an outer contact surface of the stamp member by moving a first bending operator with respect to the base station; and contacting the second tail to one or more of the outer contact surface of the stamp member or to the first tail by moving a second bending operator with respect to the base station.

35. The method according to claim 34, wherein the apparatus is an apparatus comprising: a bending station, the bending station comprising: a base station comprising a recess with a contact surface defining a first part of an outer circumference of the at least one pre-shaped insulator; a stamp member laterally moveable with respect to the recess from an open to a closed position, the stamp member comprising: an inner contact surface for pressing a middle part of the insulator sheet against the contact surface of the recess and defining a first part of the inner circumference of the pre-shaped insulator, and an outer contact surface defining a second part of the inner circumference of the pre-shaped insulator; a first bending operator moveable with respect to the base station from an open position to a closed position, comprising a first bending surface for bending a first tail of the insulator sheet against the outer contact surface of the stamp member; and a second bending operator moveable with respect to the base station from an open position to a closed position, comprising a second bending surface for bending a second tail of the insulator sheet against one or more of the first tail or the outer contact surface of the stamp member.

36. The method according to claim 34, wherein the first bending operator and the second bending operator are rotated around a respective rotation axis.

37. The method according to claim 34, wherein the second tail is pressed against the first tail to form an overlapping section. wherein:

38. The method according to claim 34, a removing tool is introduced in opposing slots of the stamp member and of at least one of the base station and the second bending operator; the removing tool contacts the pre-shaped insulator; and the removing tool is moved within the apparatus and thereby removes the pre-shaped insulator from the bending station of the apparatus.

39. The method according to claim 34, wherein at least two pre-shaped insulators are arranged in a transfer station.

40. The method according to claim 39, wherein the at least two pre-shaped insulators are inserted into a slot of a stator core in one step.

Description

[0093] The invention will now be described with reference to a preferred embodiment and the drawings, which show:

[0094] FIG. 1 a stator core in a perspective view,

[0095] FIG. 2 a schematic view of a slot of stator core with insulating sheets in top view;

[0096] FIG. 3 a schematic view of a slot of stator core in top view;

[0097] FIG. 4a-e schematic views of a bending station in top view in different positions;

[0098] FIG. 5 a schematic presentation of an apparatus;

[0099] FIG. 6a a schematic cross section along the longitudinal axis of a receiving section;

[0100] FIG. 6b a front view of the exit opening of the receiving section according to FIG. 6a.

[0101] FIG. 1 shows a stator core 10 in a perspective view. The stator core 10 has a plurality of slots 11 extending in an axial direction A and arranged in a circumferential direction C of the stator core 10. Two conductors 20, 21 are arranged along a radial direction R of each slot 11. Each conductor 20, 21 is peripherally wrapped by an individual insulator 30.

[0102] FIG. 2 shows a schematic view of the slot 11 of the stator core 10 with insulating sheets 30 in top view.

[0103] The individual insulators 30 extend around the outer circumference 22 of the conductors 20, 21, such that the insulator 30 comprises a one-layer-section 37 and an overlapping section 31 which extends along the complete axial length 29 (see FIG. 4) of the insulator 30.

[0104] Both insulators 30 arranged in one slot 11 overlap at the same lateral side 23 of the conductors 20, 21.

[0105] FIG. 3 shows a schematic view of a slot 11 in a top view.

[0106] The slot 11 is open towards the axial centre 12 of the stator core 10 and comprises a narrowing 13 at the radially inner end 14 of the slot 11 with a radially extending centreline 15.

[0107] A circumferential distance 16 between a first lateral wall 17 of the slot 11 and the centreline 15 is larger than a circumferential distance 18 between a second lateral wall 19 of the slot 11 and the centreline 15. The difference corresponds to the thickness 32 of the insulator 30 (see FIG. 2).

[0108] FIGS. 4a-e show schematic views of a bending station 39 for forming a pre-shaped insulator from an insulator sheet 33 in a top view, that is in a plane perpendicular to the axial direction A (see FIG. 1), during different steps of a bending process.

[0109] The bending station 39 comprises a base station 40 with a recess 41.

[0110] The recess 41 comprises a contact surface 42 for forming a first part of an outer circumference of the pre-shaped insulator 30.

[0111] The contact surface 42 is made up of a central bottom part 47 and two opposing wall parts 46 of the base station 39.

[0112] The bending station 39 comprises a stamp member 50. The stamp member 50 and the base station 40 can be translated relatively to each other, such that the stamp member is laterally moveable with respect to the recess 41 from an open position as shown in FIG. 4a to a closed position as shown in FIGS. 4c to 4e.

[0113] An insulator sheet 33 may be inserted between the base station 40 and the stamp member 50 and may be held in position by a spring-loaded clamping element 56. The clamping element 56 can be pushed into a recess of the base station 40, for example when the base station 40 and the stamp member 50 approach each other so that the stamp member 50 gets into the closed position.

[0114] The stamp member 50 has an inner contact surface 51, which presses a middle part 34 of the insulator sheet 33 against the contact surface 42 of the recess 41 when moved into the closed position as shown in FIGS. 4b and 4c.

[0115] The inner contact surface is made up of a central inner bottom part 48 and two opposing inner side parts 49.

[0116] The contact surface 42 of the base member 40 and the inner contact surface 51 of the stamp member 50 form a first part of the pre-shaped insulator 30 to be formed from a middle part 34 of the insulator sheet 33.

[0117] The stamp member 50 further comprises an outer contact surface 52 which is opposite to the inner bottom part 48.

[0118] The bending station 39 comprises a first bending operator 60 moveable with respect to the base station 40 from an open position as shown in FIGS. 4a-4c, to a closed position as seen in FIGS. 4d and 4e.

[0119] The first bending operator 60 comprises a first bending surface 61 for bending a first tail 35 of the insulator sheet 33 against the outer contact surface 52 of the stamp member 50, as shown in FIG. 4d.

[0120] The bending station 39 comprises a second bending operator 70 moveable with respect to the base station 40 from an open position as shown in FIGS. 4a-4d, to a closed position, as shown in FIG. 4e, comprising a second bending surface 71. The second bending operator 70 presses a second tail 36 of the insulator sheet 33 against the first tail 35 and the outer contact surface 52 of the stamp member 50 as shown in FIG. 4e. Thereby an overlapping section 31 is formed.

[0121] The first bending operator 60 and the second bending operator 70 may be rotated around a respective rotation axis 63, 74.

[0122] The rotational movement may be driven by a lever system being connected to air cylinders (not shown in the figures).

[0123] The sum of the width 62 of the first bending surface 61 (see FIGS. 4c and 4e) and of the width 72 of the second bending surface 71 (see FIGS. 4c and 4e) corresponds to a width 44 of the stamp member 50, such that the first bending surface 61 and the second bending surface 71 together with the outer contact surface 52 of the stamp member 50 form the second part of the outer circumference of the pre-shaped insulator 30.

[0124] As shown in FIGS. 4d and 4e the stamp member 50 comprises two grooves 54 running in a direction parallel to a bending line of the insulator 33 and the base station 40 comprises two grooves 45 running in a direction parallel to a bending line of the insulator. Said grooves 45, 54 are open in a direction opposite to each other when the stamp member 50 is in the closed position (see FIG. 4d).

[0125] A further groove 73 is arranged in the second bending surface 71 running in a direction parallel to a bending line of the insulator. Also the stamp member 50 comprises a further groove 55 on the side facing away from the base station 40 running in a direction parallel to a bending line of the insulator 30. Said grooves 55, 73 are open in a direction opposite to each other when the second bending operator 70 is in the closed position (see FIG. 4e).

[0126] The pairs of grooves 55, 74 and 45, 54 facing each other when the bending station 39 is in the closed position allow introducing a removing tool 91 (see FIG. 5) for pushing the shaped insulator 30 out of the bending station 39. The removing tool comprises a blade (not explicitly shown in the figures) for each of the pairs of grooves 55 and 74, 55 and 74 and 45 and 54.

[0127] The axial lengths of the bending station 39 may correspond to the axial lengths of the pre-shaped insulator 30 to be formed.

[0128] Alternatively, a plurality of bending stations 39 may be arranged along the axial length for forming one pre-shaped insulator 30.

[0129] The axial length of the stamp member 50, the first bending operator 60 and the second bending operator 70 may correspond to the axial length of the base station 40. Alternatively, a plurality of stamp members 50, first bending operators 60 and/or second bending operators 70 may be arranged along the axial length of the base station 40.

[0130] FIG. 5 shows a schematic presentation of an apparatus 100. The apparatus 100 comprises a bending station 39 as described in FIGS. 4a-4e.

[0131] The apparatus 100 further comprises a feed station 80.

[0132] The feed station 80 comprises an embossing unit 81 for applying longitudinal embossings into a continuously supplied sheet of insulating material 38.

[0133] The feed station 80 comprises a supply unit 82 for supplying the embossed insulating material 38 to the bending station 39.

[0134] The feed station 80 comprises a cutter 83 for cutting flat sheets 33 (see FIG. 4a) of insulating material from the continuously supplied sheet of insulating material 38.

[0135] The feed station 80 comprises a supply unit 83 for supplying the cut sheets 33 to the bending station 39.

[0136] The apparatus 100 comprises a removing tool 91 for pushing pre-shaped insulators 30 out of the bending station 39 into a transfer station 90.

[0137] The transfer station 90 collects at least two pre-shaped insulators 30 which are introduced into one slot 11 (see FIG. 6a) of a stator core 10.

[0138] FIG. 6a shows a schematic cross-section of a bending station 39, a transfer station 90 and part of a stator 10. The transfer station 90 has three channels 98a, 98b, 98c having respective receiving openings 99a, 99b, 99c. The transfer station 90 is laterally displaceable (see arrow in FIGS. 5 and 6a) with respect to bending station 39. Therewith, the receiving openings 99a, 99b, 99c can be aligned with a pre-shaped insulator 30 (see FIG. 4e) arranged around the stamp member 50 of the bending station 39.

[0139] FIG. 6b shows a side view of the transfer station 90 with the receiving openings 99a, 99b, 99c. When a pre-shaped insulator is translated along the bending station 39 by a removing tool 91 (see FIG. 5) it will exit the bending station 39 and will be transferred into the aligned receiving opening 99c. Once a pre-shaped insulator has been transferred into the receiving opening 99c and into channel 98c, the transfer station 90 will be laterally translated such as to have another receiving opening (e.g. receiving opening 99b) aligned with the bending station 39 so that another pre-shaped insulator can be received by the transfer station 90.

[0140] The receiving channels 98a, 98b, 98c are separated from each other by walls 101. The walls 101 are only present in about ⅔ of the length of the transfer station 90 such that the channels 98a, 98b, 98c merge together to form one joint channel 102 in the transfer station 90 (shown on the right hand side in FIG. 6a). The walls 101 slightly taper such as to slightly converge in the axial direction in FIG. 6a (from left to right). By pushing three pre-shaped insulators axially through the channels 98a, 98b, 98c, the pre-shaped insulators will be pushed towards each other in the joint channel 102. The three pre-shaped insulators can then be jointly transferred from an exit opening 97 of the transfer station 90 to one slot 11 of a stator 10. Of course, less than three or more than three channels can be used in case less or more pre-shaped insulators should be inserted into one slot.