Rotating Electrical Machine

Abstract

A rotating electrical machine, especially a turbogenerator, includes a rotor and a stator, which concentrically surrounds the rotor and is terminated at each of the two axial ends by a laminated press plate (14), which is constructed from a stack of individual press plate laminates (30). The electrical properties are improved by providing the press plate laminates (30) at least partially with slits (26) for reducing the eddy current losses.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be explained in more detail below with reference to exemplary embodiments in connection with the drawing, in which:

FIG. 1 shows a sectional illustration of the arrangement of a laminated press plate in a turbogenerator in accordance with the prior art;

FIG. 2 shows a photographic illustration of damage in a stator end part of the conventional type;

FIG. 3 shows, in two subfigures, a conventional press plate laminate in the form of a ring segment in accordance with the prior art (FIG. 3a) and the press plate laminates being stepped back in layers;

FIG. 4 shows, in an illustration comparable to that in FIG. 3, the press plate laminate (FIG. 4a) and the longitudinal section through the press plate (FIG. 4b) constructed therefrom, the press plate laminates being stepped back in blocks (block step 24);

FIG. 5 shows, in two subfigures, a press plate laminate with slits in accordance with a first exemplary embodiment of the invention (FIG. 5a) and the longitudinal section through the press plate (FIG. 5b) constructed therefrom, the press plate laminates being stepped back in layers, and the slits emerging from each slot;

FIG. 6 shows, in an illustration comparable to that in FIG. 5b, the longitudinal section through a press plate in accordance with a second exemplary embodiment of the invention, the press plate laminates being stepped back in layers, and the lengths of the slits changing with the laminate layer;

FIG. 7 shows, in an illustration comparable to that in FIG. 5a, a press plate laminate in accordance with a third exemplary embodiment of the invention, the slits only emerging from every second slot;

FIG. 8 shows, in an illustration comparable to that in FIG. 5a, a press plate laminate in accordance with a fourth exemplary embodiment of the invention, the slits running in the teeth and ending centrally in the press plate laminate;

FIG. 9 shows, in an illustration comparable to that in FIG. 5a, two press plate laminates in accordance with a fifth exemplary embodiment of the invention, the slits, starting from the slot base, being arranged such that they are laterally offset with respect to the center of the slot base, and press plate laminates of successive layers being installed such that they are turned in relation to one another, with the result that the slits of the press plate laminates are not aligned;

FIG. 10 shows exemplary eddy current paths in a press plate laminate with slits according to the invention;

FIG. 11 shows comparable eddy current paths in a press plate laminate without slits according to the prior art; and

FIG. 12 shows a press plate laminate having a slit, which extends, starting from the slot base, into the interior of the press plate laminate in a direction which deviates from the radial direction.

Claims

1. A rotating electrical machine comprising: a rotor;a stator which concentrically surrounds the rotor and has a laminated press plate and a laminated stator core terminated at each of two axial ends by the laminated press plate, the laminated press plate comprising a stack of individual press plate laminates;wherein the press plate laminates at least partially comprise slits configured and arranged to reduce eddy current losses.

2. The machine as claimed in claim 1, wherein the press plate laminates comprise ring segments, and wherein the slits run in the radial direction.

3. The machine as claimed in claim 1, wherein the press plate laminates comprise ring segments, and wherein the slits run in a direction which deviates from the radial direction.

4. The machine as claimed in claim 2, wherein the press plate laminates include an inner edge, and wherein the slits, starting from the inner edge of the press plate laminates, extend into the interior of the press plate laminates and end therein.

5. The machine as claimed in claim 4, wherein all of the slits end at the same radius.

6. The machine as claimed in claim 5, further comprising: holes configured and arranged for passing through clamping bolts in the press plate laminates on a predetermined radius, and wherein the slits end at the predetermined radius.

7. The machine as claimed in claim 6, wherein at least some of the slits end in the holes for the clamping bolts.

8. The machine as claimed in claim 4, further comprising: slots which reach radially into the laminate up to a predetermined depth, configured and arranged to accommodate a stator winding, positioned in some of the press plate laminates, each slot having a slot base, the slots distributed over the press plate laminate inner circumference, and wherein the slits each extend, starting from a slot base, into the interior of the press plate laminates.

9. The machine as claimed in claim 8, wherein the slits start from the center of the slot base.

10. The machine as claimed in claim 8, wherein the slits start from a point on the slot base which is laterally offset with respect to the center of the slot base.

11. The machine as claimed in claim 8, wherein a slit extends from each slot into the interior of the press plate laminate.

12. The machine as claimed in claim 8, wherein a slit extends only from some of the slots into the interior of the press plate laminate.

13. The machine as claimed in claim 4, further comprising: slots which reach radially into the laminate up to a predetermined depth, configured and arranged to accommodate a stator winding, positioned at least in some of the press plate laminates, the slots distributed over the press plate laminates inner circumference, the slots configured and arranged such that teeth remain between the slots, each tooth having an inner edge, and wherein the slits each extend from said inner edges of the teeth through the teeth into the interior of the press plate laminates.

14. The machine as claimed in claim 13, wherein the slits run precisely in the center of the teeth.

15. The machine as claimed in claim 13, wherein the slits run, from the center of the teeth, such that they are circumferentially offset.

16. The machine as claimed in claim 1, wherein the press plate laminates are stepped back in layers or blocks so that the press plates extend conically outwards at their inner circumference.

17. The machine as claimed in claim 1, wherein the slits of press plate laminates which lie one above the other are aligned and form slits which pass into the press plate in the axial direction.

18. The machine as claimed in claim 1, wherein the slits of press plate laminates which lie one above the other are offset with respect to one another in the circumferential direction of the press plate.

19. The machine as claimed in claim 18, wherein the offset of the slits of press plate laminates which lie one above the other is formed by changing the position of the press plate laminates in layers, by turning in layers press plate laminates with eccentric slits, or by both.

20. The machine as claimed in claim 1, wherein the slits end centrally in the press plate laminate, and further comprising: holes arranged at the ends of the slits.

21. The machine as claimed in claim 20, wherein the holes form axial cooling channels in the press plate.

22. The machine as claimed in claim 1, wherein the slits have a width in the range of between 0.3 and 1.0 mm.

23. The machine as claimed in claim 1, wherein the slits are produced by a laser cutting process.

24. The machine as claimed in claim 1, comprising a turbogenerator.

25. The machine as claimed in claim 3, wherein the press plate laminates include an inner edge, and wherein the slits, starting from the inner edge of the press plate laminates, extend into the interior of the press plate laminates and end therein.

26. The machine as claimed in claim 8, wherein a slit extends only from every second slot into the interior of the press plate laminate.

27. The machine as claimed in claim 6, further comprising: clamping bolts passing through said holes in the press plate laminates, the clamping bolts axially pressing the press plates against the laminated stator core.