Rotor Lamella Bundle Pretensioning for Deformation-Free Press Joining
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for producing rotors for electrically excited electrical machines face challenges with eddy current losses and deformation of sheet metal bundles due to stamping tensions, which require additional components for axial tension and increase production complexity and costs.
Innovation Solution
A method involving the arrangement of lamella elements to form a bundle with webs, axial support by end plates, pretensioning by winding conductor material around the webs or end plates, and press-joining or transverse-joining of a rotor shaft into the pretensioned lamella bundle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If sheet metal bundles are heated and rotor shaft is cooled for press-joining, then joining strength is improved, but lamella bundle deforms due to stamping tensions
Solution Approach 1:
The patent applies preliminary action by pre-tensioning the lamella bundle with a tensioning device before the press-joining process. This pre-tensioning counteracts the stamping tensions that would otherwise cause deformation during cooling, allowing the bundle to maintain its shape while still achieving strong joining through the subsequent thermal press-joining process.
2Manufacturing precision
If additional components are used to axially tension sheet metal bundles, then deformation is compensated, but device complexity and costs increase
Solution Approach 1:
The patent merges the tensioning function with the existing press-joining device by integrating a tensioning device into the press-joining apparatus. This combination allows the same equipment to perform both pre-tensioning and press-joining operations, eliminating the need for separate tensioning components and reducing overall device complexity while maintaining effective deformation compensation.
3Stability of the object's composition
If additional components are used for axial tension, then lamella bundle stability is improved, but production costs increase
Solution Approach 1:
The patent implements self-service by designing the press-joining device to automatically provide the necessary axial tension through its integrated tensioning mechanism. The system uses its own structural components to generate and apply the tensioning force, eliminating the need for external tensioning components and reducing production costs while maintaining lamella bundle stability throughout the joining process.
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 effectively prevents deformations of the lamella bundle during cooling, eliminates the need for additional axial tension components, and simplifies the production process while reducing costs and structural space requirements.
Implementation Method 1
the sheet metal bundle is heated and the rotor shaft is cooled
Implementation Method 2
the sheet metal bundle is heated and the rotor shaft is cooled
Implementation Method 3
axially fixing or pretensioning the lamella bundle by winding conductor material around the webs or the end plates
Data Source
AI summary
A method for producing a rotor includes providing lamella elements and arranging the lamella elements to form a lamella bundle where the lamella bundle has webs. End plates are arranged at respective end faces of the lamella bundle where the end plates axially support the lamella bundle. The lamella bundle is axially fixed or pretensioned by winding conductor material around the webs and a rotor shaft is arranged in the fixed or pretensioned lamella bundle.