Squirrel-Cage Rotor End-Ring Joining via Additive Manufacturing
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Solution Overview
Problem
The existing methods for connecting conductors and short-circuit rings in squirrel cage rotors of asynchronous machines are labor-intensive and unreliable, leading to high soldering gaps and increased losses.
Innovation Solution
A method involving a magnetically conductive base body with axially extending grooves, where electrical conductors protrude and are electrically contacted with short-circuit rings using additive manufacturing processes, such as cold spray or 3D metal printing, to create a reliable and efficient electrical connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If soldering process is used to connect conductors and short-circuit rings, then electrical contact is achieved, but soldering gaps occur and manufacturing complexity increases
Solution Approach 1:
The patent replaces the soldering process (thermal/chemical system) with a mechanical pressing system. The pressing device applies mechanical force to directly connect the short-circuit ring to the conductors, eliminating the need for soldering material and the associated gaps. This substitution resolves the contradiction by achieving reliable electrical contact through mechanical pressure without the complexity of soldering processes.
2Reliability
If brazing process is used to connect conductors and short-circuit rings, then electrical contact is achieved, but manufacturing effort and time increase significantly
Solution Approach 1:
The patent replaces the brazing process (thermal system requiring heating and cooling cycles) with a mechanical pressing system. The pressing device can rapidly apply and release mechanical force, dramatically reducing the connection time from minutes or hours (brazing) to seconds. This resolves the contradiction by maintaining reliable electrical contact while significantly improving manufacturing productivity.
3Reliability
If conventional connection methods are used, then electrical contact is established, but losses increase due to poor contact quality
Solution Approach 1:
The patent uses mechanical pressing to create intimate contact between the short-circuit ring and conductors, eliminating air gaps and poor contact interfaces that cause electrical losses. The continuous mechanical pressure ensures low contact resistance and high electrical conductivity, resolving the contradiction by improving contact quality and reducing energy losses simultaneously.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method simplifies the electrical contacting process, reduces losses, and provides a robust, mechanically stable connection suitable for high-speed operations, while allowing for flexible and quick production of small series and prototypes.
Implementation Method 1
electrical contacting of the conductors with the rings by one or more AM processes
Implementation Method 2
for example a cold spray process
Data Source
Figure 1~4
Figure 5~7
Figure 8~11
AI summary
The invention relates to a method for producing a squirrel-cage rotor (3) of an asynchronous machine (1) by means of the following steps: providing a main body (4), which is magnetically conductive at least in parts and has substantially axially extending grooves, inserting electrical conductors (5) into the grooves in such a way that said conductors (5) protrude from the axial ends of the magnetically conductive main body, positioning electrically conductive end rings (6), which have a plurality of openings (9) for receiving the respective conductors (5), establishing electrical contact between the conductors (5) and the end rings (6) by means of one or more additive manufacturing processes.