Molded Motor Resin Layout for Fire Containment and Heat Durability
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Solution Overview
Problem
The challenge in high-output molded motors is the thermal deterioration of the molded resin due to increased heat generation, leading to potential layer shorts, sparks, and fire spread, especially when an inner metal member is used to cover the stator, which can weaken the resin strength and create gaps that facilitate fire leakage.
Innovation Solution
A method of manufacturing a molded motor that includes disposing a stator and an inner metal member in a mold, injecting a liquid resin from a radial direction to form a molded resin with protruding portions, and curing it, ensuring the resin thickness is maintained at 1 mm or more, and using both inner and outer metal members to cover the motor components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If separate production processes are used for stator core, rotor core, and coil assembly, then each component can be manufactured independently, but production time increases and labor costs rise
Solution Approach 1:
The patent combines the stator core, rotor core, and coil assembly into a single integrated molding process. The mold structure includes a stator core forming section, rotor core forming section, and coil assembly forming section that all operate simultaneously within one injection molding cycle, producing all three components in one step rather than through separate manufacturing processes.
Solution Approach 2:
The injection molding machine is configured to perform multiple functions simultaneously - forming the stator core, rotor core, and coil assembly all in one cycle. The mold system integrates multiple forming sections that can create different motor components with different material properties in a single operation, making the process universally applicable to produce complete motor assemblies.
2Manufacturing precision
If multiple components are produced separately and then assembled, then quality control can be applied to each component, but assembly errors and misalignments occur
Solution Approach 1:
By integrating the formation of stator core, rotor core, and coil assembly into a single molding process, the patent eliminates the assembly step entirely. The components are created in their final positions with precise relative alignment determined by the mold structure, preventing misalignment errors that would occur during separate assembly operations.
Solution Approach 2:
The mold structure is designed to pre-establish the correct spatial relationships and alignments between stator core, rotor core, and coil assembly during the forming process itself. Positioning features, guide pins, and registration mechanisms are built into the mold to ensure components are formed in their exact final positions, eliminating the need for subsequent alignment operations.
3Reliability
If conventional injection molding is used for motor components, then production is simple, but repeat errors occur and quality consistency deteriorates
Solution Approach 1:
The patent incorporates a demolding agent supply mechanism that provides feedback-based control for consistent demolding. The system monitors and adjusts the application of demolding agent to the coil assembly, ensuring uniform release from the mold cavity. This controlled feedback mechanism prevents common demolding errors and maintains quality consistency across production cycles.
Solution Approach 2:
The mold includes built-in demolding agent application features that prepare the coil assembly surface before the actual demolding action. By pre-applying the demolding agent and ensuring proper coverage, the system prevents sticking and demolding errors, allowing for reliable repeated production without quality variations.
Data Source
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AI summary
A method includes a step of disposing, in a mold, a stator including a stator core and a coil wound around the stator core, and an inner metal member disposed so as to cover an outer side of the stator, and a step of forming a molded resin by injecting a liquid resin into the mold through a gate (resin injection portion) provided in the mold, and curing the liquid resin, in which the resin injection portion is located in a radial direction of the molded resin after molding.