Inner-Rotor Motor Insulating Layer for Leakage Current Prevention
Solution Overview
Problem
Conventional inner-rotor motors suffer from operational instability and safety issues due to electromagnetic interference and leakage currents caused by the conductive nature of their components, leading to noise and vibration during rotation.
Innovation Solution
An insulating layer is introduced between the housing and the iron core of the inner-rotor motor, made of insulating material, to prevent the formation of electrical conducting paths and provide electrical isolation, thereby enhancing safety and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the iron core is made of conductive material (silicon steel plates) and the housing is made of metal for structural strength, then the mechanical strength and electromagnetic performance are improved, but electrical conducting paths are formed between the iron core and housing, causing leakage currents and safety issues
Solution Approach 1:
An insulating layer is introduced as an intermediary component between the metal housing and the iron core. This insulating layer acts as a mediator that prevents direct electrical contact while allowing the structural and electromagnetic functions to be maintained. The insulating layer blocks the formation of electrical conducting paths, thereby preventing leakage currents and improving electrical safety without compromising the mechanical strength provided by the metal housing.
2Volume of moving object
If the iron core is adjacent to the housing for compact structure, then the device size is reduced, but electromagnetic interference is generated when conducting wires are arranged outside the housing, causing noise and vibration
Solution Approach 1:
The insulating layer serves as a protective intermediary between the iron core and the external environment. When conducting wires are arranged outside the housing, the insulating layer on the iron core prevents electromagnetic interference from coupling to the iron core, thereby eliminating noise and vibration while maintaining the compact structure with the housing.
3Ease of manufacture
If the insulating coating of the coil is worn and conducting material is exposed to air, then the manufacturing simplicity is maintained, but electrical conducting paths are formed between the iron core and housing through the exposed conducting material, causing leakage currents
Solution Approach 1:
The insulating layer is pre-installed on the iron core before the coil is assembled. This beforehand protective measure ensures that even if the coil's insulating coating becomes worn or the conducting material is exposed during operation, the insulating layer already in place prevents the formation of electrical conducting paths between the iron core and housing, thereby preventing leakage currents and maintaining electrical safety throughout the product lifecycle.
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 insulating layer effectively prevents electromagnetic interference and leakage currents, improving the operational stability and safety of the inner-rotor motor by maintaining a non-conductive gap between the housing and the iron core, even when the coil's conducting material is exposed.
Implementation Method 1
an insulating layer (12) arranged between the housing (11) and the iron core (13)... prevents the electrical conducting path from forming between the housing (11) and the iron core (13)
Data Source
AI summary
An inner-rotor motor for preventing the formation of an electrical conducting path between an iron core and a housing of the motor includes a stator and a rotor. The stator includes the housing, an insulating layer and the iron core. The insulating layer is arranged between the housing and the iron core and prevents the electrical conducting path from forming between the housing and the iron core. The rotor includes a shaft rotatably coupled with the housing, and a permanent magnet unit is arranged around the shaft.