Insulating Bobbin Corner Section Curvature Design
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Solution Overview
Problem
The existing insulating bobbin designs for rotary machines suffer from insulation failures and heat retention issues due to the formation of spaces between the bobbin and stator winding, caused by 'wound expansion', which reduces heat conductivity and output torque performance.
Innovation Solution
The insulating bobbin features a corner section with varying radii of curvature, where the second radius at the slot side section is larger than the first radius at the coil end section, reducing the reaction force and space formation during winding, and incorporating thickened wall sections to minimize thermal resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the corner section is rounded with a single circular arc radius, then the insulation layer protection is improved, but a space is formed between the insulating bobbin and stator winding due to wound expansion
Solution Approach 1:
The corner section is divided into two regions with different radii of curvature: a first radius at the coil end section and a second radius at the slot side section. This local differentiation allows the coil end section to have sufficient rounding for insulation protection while the slot side section has a larger radius to reduce wound expansion and minimize spacing, thereby resolving the contradiction between insulation protection and space reduction.
Solution Approach 2:
The radius of curvature parameter is changed along the corner section rather than maintaining a uniform value. By transitioning from a smaller first radius at the coil end to a larger second radius at the slot side, the design optimizes both the protective rounding needed for insulation and the space minimization needed to reduce thermal resistance, eliminating the harmful space formation.
2Reliability
If the corner section is rounded to protect insulation, then insulation failure is prevented, but thermal conductivity decreases due to space formation
Solution Approach 1:
Different radii of curvature are applied to different locations of the corner section: the coil end section uses a smaller first radius to provide sufficient rounding for insulation protection, while the slot side section uses a larger second radius to minimize wound expansion and reduce spacing. This local differentiation ensures insulation failure prevention while minimizing heat retention by reducing the thermal resistance-causing space.
3Reliability
If the corner section thickness is increased to prevent breakage, then reliability is improved, but the slot side section thickness increases reducing manufacturing efficiency
Solution Approach 1:
The corner section is designed with non-uniform thickness distribution through varying radii of curvature. The coil end section has sufficient thickness for breakage prevention, while the slot side section uses a larger radius to maintain appropriate thickness without excessive material. This local differentiation prevents corner section breakage while avoiding unnecessary material increase that would reduce manufacturing efficiency.
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 design reduces the space due to 'wound expansion', decreases thermal resistance by up to 49%, and enhances the output torque characteristics of the rotary machine by improving heat dissipation and maintaining a sufficient thickness for the corner section.
Implementation Method 1
the corner section has a curved surface shape obtained by varying radii of a plurality of circular arcs
Data Source
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AI summary
An insulating bobbin (10; 10A; 10B; 10C. 20, 30) for disposition between a stator core and a stator winding (50) of a stator of a rotating machine, the stator winding (50) being wound around the stator core by way of the insulating bobbin (10; 10A; 10B; 10C, 20, 30), the insulating bobbin (10; 10A; 10B; 10C, 20, 30) comprising a coil end section (11) at which an end portion of the stator winding (50) is disposed, a slot side section (12) forming a slot for winding thereon the stator winding (50), and a corner section (13; 13A; 13C) having a curved surface and connecting between the coil end section (11; 11C) and the slot side section (12; 12C), the corner section (13; 13A; 13C) having a first radius (r1) of curvature at a side closer to the coil end section (11; 11C) and a second radius (r2) of curvature at a side closer to the slot side section (12; 12C), the second radius (r2) of curvature being larger than the first radius (r1) of curvature.