Molded Stator Motor With Non-Combustible Coil-End Shielding
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Solution Overview
Problem
Conventional motors with a stator covered in molding resin are prone to fires and smoke leakage due to excessive current causing layer shorts, as the insulating material can melt and lead to conductor short circuits, with existing safety protection circuits sometimes failing to prevent these incidents.
Innovation Solution
A non-combustible layer is provided to cover the coil ends and transition wires, extending in the shaft center and radial directions to block fires and smoke from escaping, which can be made of air or non-combustible materials like metal or ceramic, and further enhanced with metallic covers to ensure safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If molding resin is used to cover the stator, then the motor structure is simplified and manufacturing is easier, but fire and smoke can leak outside when a layer short occurs
Solution Approach 1:
The patent uses a composite structure combining molding resin with a non-combustible layer (metallic or ceramic) to create a fire-resistant coating on the stator. This composite approach maintains the manufacturing simplicity of molding resin while adding fire protection capability to prevent smoke and flame leakage during layer short incidents.
Solution Approach 2:
The non-combustible layer acts as an intermediary barrier between the coil ends (where layer shorts occur) and the external environment. This intermediate protective layer blocks the transmission of fire and smoke from the internal fault location to the outside, resolving the contradiction between easy manufacturing and fire safety.
2Reliability
If insulating material is used on winding wire, then electrical insulation is provided, but the insulating material can melt when excessive heat is generated
Solution Approach 1:
The patent combines traditional insulating material with a non-combustible coating layer to create a composite insulation system. The non-combustible material (metal or ceramic) provides superior heat resistance while the insulating material maintains electrical insulation properties, allowing the system to withstand excessive temperatures without melting.
Solution Approach 2:
The invention changes the thermal parameter of the insulation system by adding a non-combustible layer with high melting point and heat resistance. This parameter change allows the insulation system to maintain its structural integrity and protective function even when exposed to excessive heat from layer shorts.
3Ease of manufacture
If coil ends are exposed, then winding and connection is easier, but fire can be generated and spread to molding resin
Solution Approach 1:
The patent applies a non-combustible coating layer to the coil ends and transition wires before final assembly. This preliminary protective action ensures that even though the coil ends remain accessible for winding and connection operations, they are pre-protected against fire generation and spread to the molding resin.
Solution Approach 2:
The non-combustible layer serves as an intermediary protective barrier on the coil ends and transition wires. It allows easy access for winding and connection while preventing fire from being generated at these exposed locations and blocking any fire spread to the molding resin structure.
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
The non-combustible layer effectively prevents fires and smoke from leaking outside the motor even if the safety protection circuit fails, enhancing the motor's reliability and safety by blocking fires at various angles around the coil ends.
Implementation Method 1
a non-combustible layer provided to cover the coil end... effectively prevents fires and smoke from leaking outside the motor... by blocking fires at various angles around the coil ends
Data Source
AI summary
A motor according to the present invention includes: a stator having a stator core and a coil; a rotor having a rotary shaft and a rotation body; a shaft bearing rotatably supporting the rotor; and a molding resin covering the stator. The motor has a coil end that is the coil protruding from the stator core in a shaft center X direction, and has a non-combustible layer provided to cover the coil end. The non-combustible layer is a metallic cover made of, for example, metal. The metallic cover is disposed to cover a periphery of a coil assembly in which the coil is formed on the stator core through an insulator. The metallic cover is integrated with the coil assembly by a molding resin.