EPS Motor Stator Insulation Structure for Coil Separation
Solution Overview
Problem
The existing stator designs in electric power-assist steering systems are prone to short-circuits due to close contact between coils wound on adjacent split cores, which can lead to defects and operational failures during assembly.
Innovation Solution
The proposed stator design incorporates an insulation structure comprising insulators, insulation tubes, and insulation plates made of synthetic resin materials to prevent short-circuits by maintaining a gap between coils and ensuring proper spacing, thereby enhancing insulation and reducing assembly complexities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If coils are wound tightly on teeth of split cores to reduce size and increase density, then the motor can generate higher torque with smaller size, but the distance between adjacent coils becomes too close causing short-circuit risks and assembly defects
Solution Approach 1:
The patent introduces insulation tubes as intermediary components inserted into the coils, and insulation plates placed between adjacent coils. These intermediary insulation structures physically separate the coils, preventing direct contact and short-circuits while allowing the coils to maintain their tight winding configuration for high torque density.
2Reliability
If insulation structures are added between coils to prevent short-circuits, then insulation reliability is improved, but the device complexity and assembly process become more complicated
Solution Approach 1:
The patent merges the insulation function into integrated structures that combine multiple functions. The insulation plates are designed to simultaneously provide electrical insulation and structural support for coil positioning. The insulation tubes are integrated into the coil winding process itself, combining insulation and coil support functions in a single component rather than adding separate insulation elements.
3Reliability
If insulation structures are added between coils to prevent short-circuits, then insulation reliability is improved, but the manufacturing and assembly time increases
Solution Approach 1:
The patent implements preliminary action by pre-inserting insulation tubes into the coils before the winding process, and pre-positioning insulation plates in the stator core. This allows the insulation structures to be in place before coil installation, enabling parallel processing and reducing the overall assembly time. The insulation components are prepared in advance rather than being installed after coil winding, which would require disassembly and reassembly operations.
Data Source
AI summary
Disclosed is a stator of an EPS motor, the stator including a stator core including a plurality of teeth protrusively formed toward a center of an inner circumferential surface, a plurality of coils wound on the teeth at a predetermined counts, an insulator coupled to an upper surface and a bottom surface of the stator core to insulate the coil from the stator core, and an insulation tube situated nearest to a coil wound on an adjacent stator core and inserted into a coil wound on an outmost side of the teeth.