US-12627187-B2 - Rotor of an electric asynchronous machine and method for its production

US12627187B2US 12627187 B2US12627187 B2US 12627187B2US-12627187-B2

Abstract

A rotor of an electric asynchronous machine including a shaft, a rotor core and short-circuit rings attached to end faces of the rotor. The shaft has an outer lateral radial surface, a cavity extending axially, at least one passageway located on the lateral surface, and at least one channel connecting the cavity to the passageway. The rotor core has at least one channel extending therein. At least one of the short-circuit rings is composed of at least two ring-shaped disks interconnected to form a disk pack. At least one disk of at least one short-circuit ring has recesses arranged such that a channel structure is formed in the short-circuit ring and is in fluidic connection with at least one channel of the rotor laminated core and fluidically connects the at least one passageway on the shaft lateral surface to at least one channel of the rotor core.

Inventors

Gerhard Thumm
Volker Voggeser
Michael Wolf
Jochen Walliser

Assignees

WIELAND-WERKE AG

Dates

Publication Date: 20260512
Application Date: 20231002
Priority Date: 20221005

Claims (15)

1 . A rotor of an electric asynchronous machine comprising: a shaft defining an axial direction, a radial direction, and a circumferential direction, the shaft having an outer lateral surface in the radial direction, a cavity extending within the shaft in the axial direction, at least one passageway located on the lateral surface of the shaft, and at least one channel connecting the cavity to the at least one passageway; a rotor laminated core having a first end face and a second end face spaced from the first end face in the axial direction, the rotor laminated core having at least one channel extending within the rotor laminated core from the first end face to the second end face; short-circuit rings attached to the first and second end faces of the rotor laminated core, at least one of the short-circuit rings being composed of at least two disks disposed in side-by-side adjacent relation with one another and interconnected to form a disk pack, each disk having two circular ring-shaped surfaces, and surfaces of adjacent disks facing each other being in surface contact, wherein at least one disk of at least one short-circuit ring has recesses arranged such that a channel structure is formed inside the short-circuit ring between the at least two disks and is in fluidic connection with at least one channel of the rotor laminated core and fluidically connects the at least one passageway on the lateral surface of the shaft to at least one channel of the rotor laminated core.
2 . The rotor according to claim 1 , wherein each short-circuit ring is composed of at least two disks interconnected to form a disk pack, and at least one disk of each short-circuit ring has recesses arranged to form, inside each of the short-circuit rings between the at least two disks, a channel structure in fluidic connection with at least one channel of the rotor laminated core.
3 . The rotor according to claim 1 , wherein at least one disk of a short-circuit ring has, on one of its surfaces, at least one recess in the form of a groove- or notch-like depression, by which groove- or notch-like depression, in combination with another disk of the short-circuit ring, a channel is formed between two of the disks of the short-circuit ring which channel constitutes at least part of the channel structure.
4 . The rotor according to claim 3 , wherein groove- or notch-like depressions of adjacent disks of the short-circuit ring are disposed opposite each other in pairs and are formed such that the groove- or notch-like depressions supplement each other to together form a channel.
5 . The rotor according to claim 1 , wherein the channel structure of at least one short-circuit ring comprises at least one first recess extending in the radial direction and at least one second recess extending in the axial direction.
6 . The rotor according to claim 5 , wherein the second recess extending in the axial direction is formed by a hole in at least one disk of a short-circuit ring.
7 . The rotor according to claim 5 , wherein the channel structure of at least one short-circuit ring comprises at least one third recess extending in the circumferential direction.
8 . The rotor according to claim 3 , wherein first recesses of at least one short-circuit ring have flow cross-sections that are different within the short-circuit ring and/or second recesses of at least one short-circuit ring have flow cross-sections that are different within the short-circuit ring and/or third recesses of at least one short-circuit ring have flow cross-sections that are different within the short-circuit ring.
9 . The rotor according to claim 1 , wherein the channel structure of at least one short-circuit ring comprises at least one recess formed as a planar depression and extending both in the radial direction and in the circumferential direction, and at least second recesses extending in the axial direction.
10 . The rotor according to claim 1 , wherein the rotor laminated core has at least one first channel and at least one second channel, and the channel structure in one of the short-circuit rings is configured such that a fluid flowing from the first channel of the rotor laminated core into the channel structure of the short-circuit ring is deflected there, at least with respect to the axial direction, and is guided into the second channel of the rotor laminated core.
11 . A method for producing a rotor according to claim 1 , the method comprising the following steps: a) providing at least one disk having two circular ring-shaped surfaces; b) making recesses in at least one of the surfaces of the disk to form a channel structure; c) mounting the disk together with at least one further disk to form a disk pack, whereby the recesses form a channel structure between the disks; d) arranging the disk pack on the shaft of the rotor at one end face of the rotor laminated core; and e) producing a joint between adjacent disks of a disk pack to form a short-circuit ring.
12 . The method according to claim 11 , wherein the recesses are made in step b) by milling, stamping, punching and/or drilling.
13 . The rotor according to claim 1 , wherein: the short-circuit rings are made of copper, a copper alloy, aluminum or an aluminum alloy; the rotor comprises rotor bars extending substantially in the axial direction through the rotor laminated core, each rotor bar having an overhang beyond the rotor laminated core at both of the first and second end faces; and each disk having an outer edge and recesses adjacent the outer edge for receiving the overhangs of the rotor bars, and the rotor bars are mechanically and electrically conductively connected to the disks at the overhangs.
14 . The rotor according to claim 13 , wherein the rotor bars are disposed further away from the shaft in the radial direction than the at least one channel.
15 . A rotor of an electric asynchronous machine comprising: a shaft defining a central longitudinal axis and having an outer lateral surface radially spaced from the axis, a cavity extending axially within the shaft, at least one passageway opening on the lateral surface of the shaft, and at least one channel connecting the cavity to the at least one passageway; a rotor laminated core having a first end face and a second end face spaced therefrom in the axial direction, the rotor laminated core having at least one channel extending within the rotor laminated core from the first end face to the second end face; and first and second short-circuit rings respectively attached to the first and second end faces of the rotor laminated core, at least one of the first or second short-circuit rings comprising at least two disks interconnected to one another to form a disk pack, each of the at least two disks having circular and oppositely facing inner and outer ring-shaped surfaces, the at least two disks being disposed in side-by-side adjacent relation with one another such that the inner surfaces of the at least two disks face each other and are in surface contact, at least one disk of the at least one short-circuit ring having recesses arranged such that a channel structure is formed inside the at least one short-circuit ring between the at least two disks and is in fluidic connection with the at least one channel of the rotor laminated core and fluidly connects the at least one passageway on the lateral surface of the shaft to the at least one channel of the rotor laminated core.

Description

CROSS-REFERENCE TO RELATED APPLICATION This claims priority from German Application No. 10 2022 003 680.0, filed Oct. 5, 2022, the disclosure of which is hereby incorporated by reference in its entirety. TECHNICAL FIELD The invention relates to a rotor of an electric asynchronous machine and to a method for its production. BACKGROUND AND SUMMARY Such a rotor comprises a shaft, at least one rotor laminated core having a plurality of recesses, and at least one rotor cage. The rotor cage consists of electrically conductive rotor bars which are inserted into the recesses of the rotor laminated core in such a way that the rotor bars project beyond the rotor laminated core at their two end regions, and of short-circuit rings which are attached to the rotor laminated core at the end face and have a plurality of recesses which are arranged in the region of their outer circumference and into which the end regions of the rotor bars project. In electric asynchronous machines, high temperatures are generated by eddy current losses in the rotor laminated core of the rotor. This makes additional cooling by means of a cooling fluid, usually oil, necessary, in particular in high-power machines. The cooling fluid is supplied by the rotor shaft and then taken up by additional end plates, which are attached to the end face on the rotor laminated core. The cooling fluid is fed via holes, made in these end plates, into the rotor laminated core into channels or grooves provided there. The cooling fluid then flows through the rotor laminated core parallel to the rotor axis and is subsequently discharged from the rotor. The disadvantage here is that holes have to be made in the end plates. This requires additional effort and thus costs. One object of the invention is to provide a rotor of an electric asynchronous machine which eliminates these disadvantages, as well as a method for its production. The invention relates to a rotor of an electric asynchronous machine. The rotor comprises a shaft defining an axial direction, a radial direction, and a circumferential direction. The shaft has an outer lateral surface in the radial direction, a cavity extending within the shaft in the axial direction, at least one passageway located on the lateral surface of the shaft, and at least one channel connecting the cavity to the at least one passageway. In other words, the channel is arranged to allow a fluid to flow from the cavity through the channel to the at least one passageway. Further, the rotor comprises a rotor laminated core having a first end face and a second end face opposite in an axial direction thereto, the rotor laminated core having at least one channel extending within the rotor laminated core from the first end face to the second end face. Short-circuit rings are attached to the end faces of the rotor laminated core, at least one of the short-circuit rings being composed of at least two disks interconnected to form a disk pack. Each disk has two circular ring-shaped surfaces. Surfaces of adjacent disks facing each other are in surface contact. According to the invention, at least one disk of at least one short-circuit ring has recesses which are arranged in such a way that a channel structure is formed in the short-circuit ring and is in fluidic connection with at least one channel of the rotor laminated core and fluidically connects the at least one passageway on the lateral surface of the shaft to at least one channel of the rotor laminated core. The invention is based on the idea that short-circuit rings are provided on the end faces of the rotor laminated core in order to electrically connect the rotor bars inserted in the rotor laminated core to one another. At least one of the short-circuit rings is constructed here of at least two circular ring-shaped disks, and in that the disks are assembled and joined flat so that a disk pack is formed. Such short-circuit rings are known, for example, from DE 10 2017 010 685 A1. When the individual disks are produced, they can be provided with recesses without much additional effort. The recesses are made in at least one of the disks in such a way that, after the individual disks have been assembled and joined, a channel structure is formed by the recesses in the short-circuit ring and is designed in such a way that a fluid flowing in the cavity inside the rotor shaft can be supplied to the rotor laminated core through the channel structure. For this purpose, the channel structure is in fluidic connection with at least one channel of the rotor laminated core on the one hand, and, on the other hand, at the inner diameter of the short-circuit ring with the passageway on the lateral surface of the shaft. The channel structure, by means of which a fluid can be distributed from the rotor shaft to one or more channels in the rotor laminated core or can be taken up from one or more of these channels, is thus integrated in at least one of the short-circuit rings. The particular advantage