Stator Core Adhesive Segmentation for Vibration Control
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Solution Overview
Problem
The existing stator cores of rotary electric machines, either crimped or adhesive-fixed, suffer from conduction losses and excessive rigidity, leading to deteriorated noise and vibration (NV) characteristics due to vibratory forces transferred from the rotor to the machine casing.
Innovation Solution
A stator core configuration with an annular yoke portion, radially protruding tooth and fastening portions, and an adhesive layer that includes first and second adhering portions in specific regions, allowing reliable fixation and vibration absorption, thereby reducing the transfer of vibratory forces to the housing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If electromagnetic steel plates are fixed by crimping, then the holding force between plates is sufficient, but conduction loss occurs at the crimping portions
Solution Approach 1:
The yoke portion is divided into multiple independent pressing portions that can be pressed separately. This segmentation allows the adhesive layer to be applied in discrete locations, preventing continuous conduction paths while maintaining adequate holding force through distributed pressure points.
Solution Approach 2:
An adhesive layer is introduced as an intermediary substance between the electromagnetic steel plates. This adhesive layer replaces the direct metal-to-metal contact of crimping, eliminating conduction loss while providing the necessary bonding force to hold the plates together.
2Loss of energy
If electromagnetic steel plates are fixed by adhesive layer, then conduction loss is eliminated, but the rigidity of the stator core becomes too high causing NV characteristic deterioration
Solution Approach 1:
The adhesive layer is applied in segmented pressing portions rather than continuously across the entire yoke portion. This segmentation creates flexible zones between the pressed areas, allowing the stator core to absorb vibratory forces from the rotor while maintaining adequate structural integrity.
Solution Approach 2:
Different regions of the yoke portion have different adhesive application characteristics. The pressing portions have adhesive applied to provide strong bonding, while the non-pressing portions have no adhesive or reduced adhesive, creating local flexibility to reduce vibration transmission and improve NV characteristics.
3Strength
If the adhesive layer is applied continuously on the yoke portion, then the holding force is maximized, but vibratory forces are easily transferred to the casing deteriorating NV characteristics
Solution Approach 1:
The continuous adhesive layer is replaced with segmented adhesive applications at specific pressing portions. This segmentation interrupts the rigid connection between the stator core and the casing, preventing the direct transmission of vibratory forces from the rotor to the casing while maintaining sufficient holding force through the distributed pressing portions.
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 configuration effectively reduces noise and vibration characteristics by absorbing vibratory forces and stabilizing the axial force of fastening members, improving the NV characteristics of rotary electric machines while maintaining a balance between holding force and rigidity.
Implementation Method 1
a plurality of electromagnetic steel plates laminated via an adhesive layer
Data Source
AI summary
A stator core of a rotary electric machine includes a yoke portion which has an annular shape, plural tooth portions protruding radially from an inner peripheral edge of the yoke portion toward a center, and plural fastening portions protruding radially outward from an outer peripheral edge of the yoke portion and each formed with a fastening member insertion hole through which a fastening member is inserted. The stator core is configured by a plurality of electromagnetic steel plates laminated via an adhesive layer. The yoke portion includes plural fastening portion inner regions, and plural non-fastening portion inner regions. The adhesive layer is disposed on the yoke portion. The adhesive layer includes at least one first adhering portion provided in each of the fastening portion inner regions, and at least one second adhering portion provided in each of the non-fastening portion inner regions.