Method of making electric machines
AssigneeCard-O-Matic Pty. Limited
InventorsLouis Stanley, Jacqualyne Stanley
Life of this patent
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Abstract
An electric machine, such as an induction motor, having a rotor and stator core formed of metal strip coiled about a centrally longitudinal axis extending generally normal to the plane of the strip, and wherein the strip is provided with depressions on longitudinally spaced locations along the length of the strip so as to enable coiling of the strip about the longitudinal axis.
Claims9
A method of forming a core for an electric machine, said method including the steps of:
- plastically deforming a metal strip by punching depressions therein at longitudinally spaced locations along the strip adjacent an edge thereof to cause the strip to coil about a longitudinal axis generally normal to the plane of the strip with said edge froming the radially inner edge of the strip;
- punching recesses in the strip at spaced locations along the strip so that the recesses align on the coiled core to form longitudinally extending slots on a peripheral surface of the core;
- stacking the coils of strip so that said slots are formed and the depressions are nested;
- and wherein said depressions are formed to have a width extending in the direction of the strip, which width decreases toward the radially outer edge of the strip.
A method of manufacturing an electric machine having a stator and a rotor, each comprising a core formed of a stack of coils of a respective metal strip and having a longitudinal axis generally normal to the plane of the strip, the stator being provided with field windings located in longitudinally extending slots on the radially inner peripheral surface of the stator core, said method including the steps of
- A. forming the stator core by
- a. punching apertures in a first said respective metal strip at spaced locations along the strip adjacent an edge thereof,
- b. plastically deforming said first strip by punching depressions in the strip at longitudinally spaced locations therealong correlated with the spaced locations of said apertures and adjacent said edge of the strip to cause the strip to coil about said longitudinal axis with said edge forming the radially inner edge of the strip, said depressions having a width extending in the direction of the strip and decreasing toward the radially outer edge of the strip, and
- c. stacking the coils of said first strip so that the depressions are nested, the correlation of the spaced locations of said depressions with those of the apertures being such that said apertures align on successive coils to form said longitudinally extending slots on the radially inner peripheral surface of the stack of coils;
- and
- B. forming the rotor core by
- a. plastically deforming a second said respective metal strip by punching depressions in the strip at longitudinally spaced locations therealong adjacent an edge of the strip to cause the strip to coil about said longitudinal axis with said edge forming the radially inner edge of the strip, said depressions having a width extending in the direction of the strip and decreasing toward the radially outer edge of the strip, and
- b. stacking the coils of said second strip so that the depressions are nested.
Dependencies are inferred from the claim text.