Concentrated-Winding Stator Insulators to Suppress End Bulging
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Solution Overview
Problem
Existing stators in motors experience bulging of windings due to direct contact with the stator core, leading to increased size in the axial direction, which is undesirable for minimizing motor size.
Innovation Solution
The stator design incorporates insulators with specific geometric configurations, including tooth covering parts and curved corners, to prevent direct contact between windings and the stator core, ensuring the windings are bent around these corners during winding, with R/B between 1/4 and 3/4 and H/B between 1/8 and 1/2, where R is the radius of curvature and H is the curved height of the corners.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If insulators are added to prevent direct contact between windings and stator core, then reliability is improved, but device complexity increases
Solution Approach 1:
The patent introduces insulators as intermediary components positioned between the windings and the stator core teeth. These insulators prevent direct contact and potential short circuits while maintaining the functional relationship between the windings and the magnetic circuit. The insulators act as mediators that isolate electrically while allowing magnetic field penetration.
Solution Approach 2:
The insulators are designed with curved outer surfaces that have specific radius of curvature (R) and curved height (H). This curvature allows the windings to be smoothly bent around the insulator corners during the winding process, preventing sharp bends that could damage the windings. The curved geometry also helps distribute mechanical stresses uniformly.
2Productivity
If windings are wound tightly around teeth to improve space factor, then productivity is improved, but shape control deteriorates due to bulging
Solution Approach 1:
The insulators feature curved corners with specifically controlled radius of curvature (R) and curved height (H) that satisfy R/B ≥ 1/4 and H/B ≥ 1/8 (where B is tooth width). These curved geometries guide the windings to bend smoothly around the insulator corners, preventing the windings from bulging outward while maintaining tight winding around the teeth, thus improving both space factor and shape control.
3Volume of stationary object
If stator size is reduced in axial direction to minimize motor size, then volume is reduced, but manufacturing precision requirements increase to control winding protrusion
Solution Approach 1:
The curved corners of the insulators with controlled radius (R) and height (H) serve as precise geometric references that limit the axial protrusion of windings. By optimizing R and H relative to tooth width B, the design ensures that windings bent around these curved surfaces do not protrude excessively from the axial end faces, thereby reducing stator axial size while maintaining acceptable manufacturing precision.
Solution Approach 2:
The patent optimizes specific geometric parameters of the insulators, namely the radius of curvature (R) and curved height (H) of the corners, establishing minimum thresholds (R/B ≥ 1/4, H/B ≥ 1/8) that balance multiple requirements: sufficient curvature to guide windings smoothly, adequate height to provide insulation clearance, and controlled dimensions to limit winding protrusion and reduce axial stator size.
Data Source
AI summary
A stator includes a stator core, windings and insulators. The stator core has a plurality of teeth. The windings are wound respectively around the teeth in a concentrated winding manner. Each of the insulators is interposed between the stator core and a corresponding one of the windings. Moreover, each of the insulators has a tooth covering part that covers necessary portions of a corresponding one of the teeth. The tooth covering part has a tooth end face covering portion, a pair of side face covering portions, and curved corners. Each of the curved corners is configured to satisfy: B/4<R<B·3/4; and B/8<H<B/2, where B is a tooth width in a width direction of the corresponding tooth, R is a radius of curvature of an outer curved surface of the curved corner, and H is a curved height of the curved corner.