CAGE ROTOR

Abstract

A cage rotor of an asynchronous machine includes radially closed or partially opened slot recesses. Arranged in the slot recesses are conductor bars which are fixed in the slot recesses by a metal foam. The slot recesses can be produced by punching individual sheet metals which are then stacked to form a laminated core. A short-circuit ring can be attached at one end face of the laminated core to contact the conductor bars.

Claims

What is claimed is:

1. A cage rotor of an asynchronous machine, comprising: radially closed or partially opened slot recesses; conductor bars arranged in the slot recesses; and a metal foam configured to fix the conductor bars in the slot recesses.

2. The cage rotor of claim 1, wherein the metal foam includes a metal selected from the group consisting of copper, zinc, steel, iron, and any combination thereof, in combination with a foaming agent.

3. A dynamo-electric machine, comprising at least one cage rotor which includes radially closed or partially opened slot recesses, conductor bars arranged in the slot recesses, and a metal foam configured to fixed the conductor bars in the slot recesses.

4. The dynamo-electric machine of claim 3, constructed in the form of a rotary asynchronous dynamo-electric machine or linear asynchronous dynamo-electric machine.

5. A machine tool, E-car or rail vehicle, comprising at least one dynamo-electric machine comprising at least one cage rotor which includes radially closed or partially opened slot recesses, conductor bars arranged in the slot recesses, and a metal foam configured to fixed the conductor bars in the slot recesses.

6. A method for producing a cage rotor, comprising: punching individual sheet metals with slot recesses; stacking the sheet metals to form a laminated core; inserting conductor bars into the slot recesses; and filling the slot recesses with metal foam;

7. The method of claim 6, wherein the conductor bars are received in the slot recesses by placing individual conductor bars into the slot recesses.

8. The method of claim 7, further comprising placing a short-circuit rings at each of both end faces of the laminated core to connect the conductor bars on both end faces to one another.

9. The method of claim 6, further comprising contacting a short-circuit ring at one of the end faces of the laminated core to the conductor bars, before the conductor bars are inserted into the slot recesses, to form a half-cage, and contacting the conductor bars at the other one of the end faces of the laminated core with one another, after the half-cage with the conductor bars have been inserted in the slot recesses.

10. The method of claim 6, further comprising rotating the laminated core in a predeterminable circumferential direction to produce a slot skewing to thereby form cavities between the conductor bars and the slot recesses; and filling the cavities with the metal foam.

11. The method of claim 6, wherein the slot recesses are produced by turning the cage rotor in a metal removing manner.

12. The method of claim 11, wherein the slot recesses produced by turning the cage rotor in a metal removing manner are partially open.

13. The method of claim 6, wherein the metal foam is made from a metal selected from the group consisting of copper, zinc, steel, iron, and any combination thereof, in combination with a foaming agent.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0035] Other features and advantages of the present invention will be more readily apparent upon reading the following description of currently preferred exemplified embodiments of the invention with reference to the accompanying drawing, in which:

[0036] FIG. 1 is a longitudinal section of an asynchronous machine according to the present invention;

[0037] FIG. 2 is a cross-section through a cage rotor according to the present invention;

[0038] FIG. 3 is a perspective illustration of a half cage; and

[0039] FIGS. 4 to 6 are cutaway views a rotor sheet with different shapes of a conductor bar in a slot recess of the cage rotor.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0040] Throughout all the figures, same or corresponding elements may generally be indicated by same reference numerals. These depicted embodiments are to be understood as illustrative of the invention and not as limiting in any way. It should also be understood that the figures are not necessarily to scale and that the embodiments are sometimes illustrated by graphic symbols, phantom lines, diagrammatic representations and fragmentary views. In certain instances, details which are not necessary for an understanding of the present invention or which render other details difficult to perceive may have been omitted.

[0041] Turning now to the drawing, and in particular to FIG. 1, there is shown a longitudinal section of an asynchronous machine, generally designated by reference numeral 1 and arranged in a housing 8. The asynchronous machine 1 has a stator 2, which is embodied bundled in laminations in an axial direction and which has a winding system 18, which is arranged in slots, which point to an air gap in the dynamo-electric machine 1. Substantially axially-running cooling ducts 14, through which a cooling air can pass, are arranged in the region of the rear of the laminated core of the stator 2.

[0042] A rotor 3, in this case, a short-circuit cage rotor, which is connected in a torque-proof manner with a shaft 5 which rotates about an axis 9, is arranged at a distance from the stator 2 through the air gap 4. The shaft 5 is supported by way of bearings 6 in the bearing shields 11 arranged in the housing 8. The bearing shields 7 have inlets 11 or outlets 12, in order to be able to operate the dynamo-electric machine 1 as an enclosed-ventilated machine.

[0043] FIG. 2 shows the rotor 3 with twelve slot recesses 15, in which, a conductor bar 16 is arranged in each case. The slot recess 15 is dimensioned significantly larger here than the conductor bar 16 itself, and thus represents, a universal lamination for other cage rotors of the same axle height. Conductor bars can thus now be used inserted into the slot recess 15, such as FIGS. 4 to 6 show, i.e. essentially double bars for double bar rotors with a different shape or also high bar cross-sections. Self-evidently also in the cross-section round bars or trapezoid bars can be inserted into the slot recesses 15.

[0044] Just one bar is normally provided per slot recess 15, however, slot recesses 15, in which, two or a number of bars are arranged are also conceivable. This reduces skin effects which can occur with bars with larger cross-sections. In accordance with the invention the remaining cavities are also provided here with metal foam.

[0045] In accordance with the invention the remaining space, in other words the cavity, between the conductor bars and the interior of the slot recess 15 is lined with a metal foam 17. The result is a fixing of the conductor bars 16 in the slot recess 15, and also a type of insulation of the conductor bar 16 relative to the laminated core of the rotor 3, similarly to an adequate magnetic conductivity in order to guarantee current displacement effects.

[0046] For graphical reasons the webs of the metal foam 17 or its pores in the slot recess 15 in FIGS. 2, 4, 5, and 6 are shown partially over dimensioned.

[0047] Either individual or a number of conductor bars 16 or a half cage according to FIG. 3 are inserted into the slot recesses 15. Here conductor bars 16 are already welded, cast or soldered on one side of a short-circuit ring 13, wherein the overall half cage is then inserted into a laminated core with slot recesses 15.

[0048] Advantageously a skewing of the slots can be created by twisting the laminated core about the axis 19, which is advantageous for reducing the torque ripple of the asynchronous machine.

[0049] In the method for producing a cage rotor of this type, the missing short circuit rings are now naturally to be contacted or welded or soldered to the conductor bars protruding axially out of the laminated core.

[0050] While the invention has been illustrated and described in connection with currently preferred embodiments shown and described in detail, it is not intended to be limited to the details shown since various modifications and structural changes may be made without departing in any way from the spirit and scope of the present invention. The embodiments were chosen and described in order to explain the principles of the invention and practical application to thereby enable a person skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated.