Stator Coil Oblique Angles for Pitch Deviation Correction
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Solution Overview
Problem
Conventional stators for rotating electric machines, such as automotive alternators, face issues with dimensional tolerances and manufacturing variations leading to undesirable loads on the stator coil, which can damage insulating coats and result in resonance due to improper mounting strength, making it difficult to achieve a smaller size and higher performance while maintaining reliability.
Innovation Solution
The stator coil is designed with obliquely extending coil end portions that can adjust their angles to correct deviations in circumferential pitch without altering the axial length or radial width, preventing interference and ensuring a suitable abutting load, thereby improving the stator's rigidity and space factor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the thickness of insulating coats is increased and gaps between coil end portions are widened to prevent interference, then reliability is improved, but space factor is lowered and axial length is increased
Solution Approach 1:
The patent changes the geometric parameters of the coil end portions by setting different oblique angles for different phases. This allows the coil end portions to fit more compactly in the axial direction while maintaining adequate spacing, thereby improving space factor without compromising insulating properties or increasing axial length
2Reliability
If the thickness of insulating coats is increased and gaps between coil end portions are widened to prevent interference, then reliability is improved, but axial length is increased
Solution Approach 1:
The patent modifies the axial projection lengths of coil end portions by assigning different oblique angles to different phases. This parameter change allows the coil end portions to be compacted in the axial direction while maintaining sufficient insulation spacing, thereby preventing increase in overall axial length of the stator
3Reliability
If different types of stator coils are employed according to need to control mounting strength, then reliability is improved, but manufacturing cost is increased
Solution Approach 1:
The patent applies different oblique angles to different phases of the same stator coil, creating local variations in mounting characteristics. This allows each phase to have optimized mounting strength suitable for its specific requirements while maintaining a single unified stator coil structure, thereby avoiding the need for multiple different coil types and reducing manufacturing cost
Data Source
AI summary
A stator includes a multi-phase stator coil comprised of phase windings. Each of the phase windings is formed of a continuous electric conductor and includes in-slot portions and coil end portions. Each of the in-slot portions is received in one of slots of a stator core. Each of the coil end portions is located outside the slots so as to connect one adjacent pair of the in-slot portions. Each of the coil end portions includes at least one oblique part that extends obliquely at an oblique angle with respect to either an axial direction or a circumferential direction of the stator core. The oblique angles of the oblique parts of the coil end portions in at least one of the phase windings of the stator coil are set to be different from the oblique angles of the oblique parts of the coil end portions in the other phase windings.