Electric Motor Rotor with Lamination Cavities for High Speed
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Solution Overview
Problem
Squirrel-cage motors face limitations in maximum speed due to mechanical constraints of short-circuit rings, and existing reinforcement methods are complex, costly, or reduce electromagnetic torque performance.
Innovation Solution
A rotor design with recesses in laminations forming a circumferential cavity to stabilize and house the short-circuit ring, using punched packaging technology for simplified manufacturing and integration of the short-circuit ring during die-casting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If support rings are added to increase mechanical resilience of short-circuit rings, then maximum speed is improved, but device complexity increases
Solution Approach 1:
The support function is merged with the rotor laminations themselves. The laminations are shaped to form a circumferential cavity that directly supports the short-circuit ring, eliminating the need for separate support rings. This integration maintains mechanical resilience while simplifying the overall device structure.
Solution Approach 2:
The support function is extracted from separate support rings and transferred to the rotor laminations. By shaping the laminations to include circumferential cavities, the structural support is built into the core component itself, reducing the number of additional parts needed.
2Stability of the object's composition
If cap rings are used to secure short-circuit rings, then mechanical stability is improved, but electromagnetic torque performance deteriorates
Solution Approach 1:
The stabilizing function is merged with the active laminations. The circumferential cavity is formed by shaping the laminations themselves, so the material that would be occupied by a separate cap ring is instead part of the active electromagnetic structure, maintaining torque performance while providing mechanical stability.
Solution Approach 2:
The laminations have different local functions: most of the lamination surface is active for electromagnetic torque generation, while specific regions are shaped to form circumferential cavities for mechanical support. This local differentiation allows both electromagnetic performance and mechanical stability without compromise.
3Strength
If reinforcement rings are cast directly, then mechanical strength is improved, but manufacturing complexity increases
Solution Approach 1:
The reinforcement structure is merged with the rotor laminations, which are already manufactured using established punching and stacking processes. The circumferential cavities are formed by punching recesses in the laminations, utilizing existing manufacturing capabilities rather than requiring complex die-casting molds.
Solution Approach 2:
The manufacturing process substitutes complex die-casting with simpler punching and stacking operations. The recesses are punched into the laminations using standard sheet metal forming techniques, and the short-circuit ring is then inserted into the pre-formed circumferential cavity, avoiding the need for complex mold introductions.
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 approach enhances the maximum speed of squirrel-cage motors while maintaining simplicity and reducing production costs, with improved mechanical resilience and electromagnetic performance.
Implementation Method 1
the short-circuit ring is surrounded and held by the rotor laminations themselves. The rotor laminations are supported on the shaft and can thus form a stable corset for the respective short-circuit ring
Implementation Method 2
In electric motors, the force exerted by a magnetic field on the current-carrying conductors of a coil is converted into movement
Data Source
AI summary
The invention relates to a rotor (1) for an electric motor, comprising a laminated core (2) arranged on a shaft (4), said core consisting of a number of laminations (10, 16) insulated from one another. The problem to be solved is that of allowing a particularly high maximum speed and output of the electric motor using a simplified production method. To solve this problem, cut-out sections (18) are introduced into a number of laminations (16) in an axial edge region of the laminated core (2), said cut-out sections being arranged such that they form a void (22) running around the shaft (4).