Segmented Rotor Lamination for Magnet Fixing and Strength
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Solution Overview
Problem
Existing rotors for permanently excited dynamo-electric machines face challenges in efficiently fixing permanent magnets, leading to inefficiencies and mechanical instability due to competing electromagnetic and mechanical properties, with current fixing methods being time-consuming and potentially demagnetizing the magnets.
Innovation Solution
A rotor design with axially running cut-outs and sectors having different configurations for adhesive/potting compound distribution and mechanical stabilization, using retaining elements and flux barriers to securely fix permanent magnets, allowing for efficient and simple production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If permanent magnets are fixed using reactive plastic adhesive or potting with reactive resin, then the permanent magnets are securely fixed in the pockets, but the process becomes time-consuming and costly, and high temperatures can result in partial demagnetization
Solution Approach 1:
The patent changes the temperature parameter from high-temperature curing (140°C for 2 hours) to room temperature or lower, enabling rapid setting of the potting compound without thermal demagnetization risks, thus reducing production time while maintaining fixing reliability
Solution Approach 2:
The patent uses a single-shot potting compound that sets rapidly at room temperature, replacing complex multi-step processes with a simple, inexpensive, and fast-curing material that eliminates the need for expensive furnace equipment and long curing cycles
2Loss of energy
If the rotor design is optimized for electromagnetic efficiency, then the machine efficiency increases, but the rotor strength decreases, reducing speed capability and production reliability
Solution Approach 1:
The patent applies different sector configurations to different regions of the rotor laminations, with some sectors optimized for electromagnetic efficiency (with elements for distribution of potting compound) and other sectors optimized for mechanical strength (with retaining elements), allowing both requirements to be satisfied simultaneously in different locations
Solution Approach 2:
The rotor laminations are divided into multiple sectors with different configurations, where first sectors have elements for potting compound distribution and second sectors have retaining elements for mechanical strength, segmenting the functional requirements across different spatial regions
3Ease of manufacture
If larger gaps are provided for joining and bonding the magnets, then production becomes easier, but the efficiency of the permanently excited dynamo-electric machine decreases
Solution Approach 1:
The patent introduces a potting compound as an intermediary material that fills the gaps between permanent magnets and the laminated core, providing both mechanical bonding (ease of manufacture) and maintaining tight magnetic coupling (efficiency), thus mediating between the conflicting requirements of large gaps for assembly and small gaps for electromagnetic performance
4Reliability
If paste-like adhesive is introduced into the pocket before magnet insertion, then the magnet is enrobed by the adhesive, but positional accuracy decreases and handling becomes difficult due to magnetic forces
Solution Approach 1:
The patent applies the potting compound to the laminated core surface before inserting the permanent magnets, allowing the adhesive to be in place and ready to bond, while the magnets can still be positioned accurately during insertion before the compound sets, thus achieving both reliable bonding and positioning accuracy
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
The design enhances the efficiency and mechanical stability of the dynamo-electric machine, ensuring secure magnet fixation and reduced production time, while maintaining high efficiency and mechanical strength.
Implementation Method 1
at least one circumferential annular duct (18), which is open toward the laminated core (30), is provided on the side facing the laminated core (30), with a feed opening (15) for introduction of a thixotropic potting compound (20) into the circumferential annular duct (18)
Implementation Method 2
the permanent magnets are usually glued into the pockets by means of a reactive plastic adhesive
Implementation Method 3
cut-outs (21) have regions of pockets (10) to accommodate the permanent magnets (9), and flux barriers (13) to guide a magnetic flux
Implementation Method 4
the poles of the rotor are formed in each case by one or more permanent magnets (9) and form sectors (29)
Data Source
AI summary
A rotor of a dynamo-electric permanently excited machine has a predefinable number of poles, with the laminated core having laminations, which each form sectors with at least two different configurations in a predefinable axial order and rotation or axial order and rotation and overlap. The laminations, independent of the configuration of the sectors, each have a shaft bore, an identical number of poles or sectors, axially aligned cut-outs and an identical outer diameter. Sectors of a first configuration have elements for distributing a potting compound or an adhesive within the laminated core, and sectors of a second configuration have retaining elements for mechanical strength of the laminated core. The flux barriers and gaps running substantially axially between the permanent magnets and the laminated core surrounding same, are filled with the adhesive and/or a potting compound.