Method for producing a squirrel-cage rotor

Abstract

A method for producing a squirrel-cage rotor of an asynchronous machine includes the following steps: providing a main body, which is magnetically conductive at least in parts and has substantially axially extending grooves; inserting electrical conductors into the grooves in such a way that the conductors protrude from the axial ends of the magnetically conductive main body; positioning electrically conductive end rings, which have a plurality of openings for receiving the respective conductors; and establishing electrical contact between the conductors and the end rings by way of one or more additive manufacturing processes.

Claims

1. A method of producing a squirrel-cage rotor of an asynchronous machine, the method comprising: providing a main body, which is magnetically conductive, at least in parts thereof, which has axial end faces, and which is formed with grooves that extend substantially in an axial direction; inserting electrical conductors into the grooves such that the conductors project from the axial end faces of the magnetically conductive main body; providing electrically conductive end rings, which are formed with a plurality of openings for receiving the respective conductors; each of the end rings being a ring being produced from of a plurality of ring disks or metal sheets arranged directly behind one another; positioning one or more of the end rings at each axial end face of the magnetically conductive main body; wherein a ring disk lying axially closest to the magnetic main body has a narrowest through-hole for the conductors, and a further ring disk adjoins the ring disk in the axial direction, said further ring disk having cutouts; and establishing electrical contact between the conductors and end rings by an additive manufacturing process, the additive manufacturing process being a cold spray process in which conductive material is introduced substantially axially into the cutout, as a result of which the conductors are contacted with the end rings.

2. The method for producing a squirrel-cage rotor according to claim 1, wherein the conductors protrude axially from the axial end faces of the magnetically conductive main body, and the end rings are positioned so that a squirrel-cage rotor is produced with end rings spaced away from the magnetically conductive main body.

3. The method for producing a squirrel-cage rotor according to claim 1, which comprises establishing electrical contact and also a balancing by accumulations of material at and/or on the end ring through the additive manufacturing process.

4. The method for producing a squirrel-cage rotor according to claim 1, wherein the openings in the end rings open out in the axial direction starting from the end faces of the magnetically conductive main body.

5. A squirrel-cage rotor produced by the method according to claim 1, the squirrel-cage rotor comprising: a main body, which is magnetically conductive, at least in parts thereof, which has axial end faces, and which is formed with grooves that extend substantially in an axial direction; electrical conductors inserted into said grooves and projecting from said axial end faces of said magnetically conductive main body; electrically conductive end rings formed with openings for receiving respective said conductors; each of said end rings being a ring consisting of a plurality of disks or metal sheets arranged directly behind one another; wherein one or more of said end rings are disposed at each end face of said magnetically conductive main body, and wherein the respective ring lying axially closest to said magnetic main body has a narrowest through-hole for said conductor; and said conductors and said end rings being electrically contacted by material deposited by at least one additive manufacturing process.

6. An asynchronous machine, comprising a squirrel-cage rotor according to claim 5.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

(1) FIG. 1 shows a longitudinal section of a rotor,

(2) FIG. 2 shows a side view of an end ring at the cross-section indicated by the line III-III of FIG. 2,

(3) FIG. 3 shows a detailed diagram of said end ring,

(4) FIG. 4 shows the principle of an AM method,

(5) FIG. 5 shows a detailed diagram of an end ring,

(6) FIG. 6 shows a ring disk of said end ring,

(7) FIG. 7 shows a further detailed diagram of the end ring,

(8) FIG. 8 shows a further disk,

(9) FIG. 9 shows a detailed diagram of a disk of the section indicated by the circle IX of FIG. 8,

(10) FIGS. 10 and 11 show further detailed diagrams of a disk.

DETAILED DESCRIPTION OF THE INVENTION

(11) FIG. 1 shows a rotor in a longitudinal section, especially a squirrel-cage rotor 3 of an asynchronous machine with its magnetically conductive main body, which is designed as a laminated core 4. Arranged in the laminated core in grooves running substantially axially are conductors 5, which protrude from the end faces 17 of the laminated core 4 and are connected electrically conductively there by end rings 6. The end rings 6 are at an axial distance 18 from the end face 17 of the laminated core 4, which improves the cooling of the squirrel-cage rotor 3, in particular in the area of the end rings 6. The laminated core 4 is connected in a torsion-proof manner to a shaft 7, which is supported rotatably about an axis 8.

(12) FIG. 2 shows an end ring 6, which is available cast or milled for subsequent manufacturing, and which has openings 9 arranged in it, viewed in the circumferential direction, which correspond to the number and the shape of the conductors 5. In the manufacturing method the end ring 6 is now placed on the conductors protruding axially from the laminated core 4 and contact is established by an AM method, preferably a cold-spray method. In this method the required material is inserted in powder form axially into the area between conductor bar 5 in a cutout 10 of the end ring 6. This establishes contact between the conductor bars 5 and the end ring 6.

(13) FIG. 3 shows a detailed diagram of an opening 9, wherein it is made possible for the cold-spray method to establish a contact through the opening 9 in the end ring, which opens out into a cutout 10.

(14) FIG. 4 shows a conductor bar 5 placed in this opening 9, wherein copper is being spayed axially into the cutout 10 by a cold-spray nozzle 11, so that electrical contact is established between the conductor bar 5 and the end ring 6 by the application of material 16.

(15) FIG. 5 shows a laminated core 4 with an end ring 6, which is constructed from two ring disks 12 and 13 arranged axially behind one another, in a detailed diagram.

(16) Ring disk 12, as shown in FIG. 6, again has openings 9 in this case, which are adapted in their shape and size to the cross section of the conductor bar 5. Ring disk 13, as in FIG. 8, has the cutouts 10 which are embodied in their size and shape in such a way that they guarantee a comparatively good establishment of contact between the conductor bar 5 and the end ring 6, i.e. the ring disks 12 and 13.

(17) FIG. 7 shows an option for how, by tangential shaping of a conductor bar, the surface between end ring 6 and conductor bar 5 can be increased. This leads to better contact being established.

(18) FIG. 9 shows bone-shaped, dumbbell-shaped or curved cutout 10 of the end ring 6, in particular of the ring disk 13, which fix a conductor bar 5 by means of how they are shaped by as few surface contacts as possible with the conductor bar in the end ring 6, in particular during the cold-spray method.

(19) FIG. 10 shows a basically tailored cutout 10 for fixing the conductor bar 5, wherein likewise by the way in which the cutout 10 is shaped, as few surface contacts as possible that fix the conductor bar in the end ring 6 are present.

(20) FIG. 11 shows further options for fixing the conductor bars 5 with as little contact surface as possible, in order to further improve the establishment of contact between the conductor bar 5 and the end ring 6, in particular the ring disk 13.

(21) The embodiments of the cutouts 10 in accordance with FIG. 9, FIG. 10 and FIG. 11 are suitable above all for the rings 13. Ring disk 12 primarily also serves to seal the gap between conductor 5 and the opening 9 in ring disk 12 to the end face 17 of the laminated core 4.