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Compression Moulded/Sintered Lamination Stack for Motors Or Generators

IP.com Disclosure Number: IPCOM000102369D
Original Publication Date: 1990-Nov-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 2 page(s) / 76K

Publishing Venue

IBM

Related People

Young, JT: AUTHOR

Abstract

A production method of high integrity, low acoustic noise lamination stacks suitable for electrical motors or generators is described. Injection moulding, or compression moulding techniques are used. A conventional lamination stack consists of the required number of soft iron or steel laminations piled up to give the required stack height and performance. Laminations are normally formed by sheet metal pressing which tends to render the lamination less than perfectly flat, with a pressing burr on one side. These imperfections detract from the magnetic and acoustic performance as they produce air gaps between each individual lamination, causing magnetic losses and lamination oscillations.

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Compression Moulded/Sintered Lamination Stack for Motors Or Generators

       A production method of high integrity, low acoustic noise
lamination stacks suitable for electrical motors or generators is
described.  Injection moulding, or compression moulding techniques
are used.  A conventional lamination stack consists of the required
number of soft iron or steel laminations piled up to give the
required stack height and performance.  Laminations are normally
formed by sheet metal pressing which tends to render the lamination
less than perfectly flat, with a pressing burr on one side.  These
imperfections detract from the magnetic and acoustic performance as
they produce air gaps between each individual lamination, causing
magnetic losses and lamination oscillations.

      Referring to the figure, a conventional lamination stack would
be replaced in the case of compression moulding by a lamination
mounting insert 1, e.g., stator shaft assembled on to the moulding
tool.  A metered amount of magnetically conductive plastic would be
put in the mould tool to allow winding radii and other features to be
moulded directly into the lamination stack.  A pressed soft iron
lamination 4 would be placed on the above material.  The stack would
then be constructed of layers of magnetically conductive plastic 3
and normal laminations 2 until the required lamination stack height
was achieved.  The final layer again is magnetically conductive
plastic to enable all special forms to be moulded in directly.  The
lamination stack would then go through a normal compresion moulding
cycle.

      The resulting assembly would be an integral l...