Rotary Electric Machine Frame Grooves for Stator Rigidity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing rotary electric machines face challenges in maintaining the circularity of the holding member while reducing its rigidity, which affects the inhibition of stator core deformation and the distribution of press-fitting loads.
Innovation Solution
The rotary electric machine incorporates a tubular drum portion with multiple grooves on its end portion, reducing the rigidity of the frame while maintaining circularity, allowing for effective press-fitting and holding of the stator core, and includes flange portions with fastening members to ensure stable assembly and reduce thermal deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If cut-out portions are formed in the flange portion to reduce press-fitting load, then the press-fitting load is reduced and stator core deformation is inhibited, but the rigidity of the holding member decreases and circularity deteriorates
Solution Approach 1:
The invention transitions from forming cut-out portions in the flange portion (2D surface modification) to forming grooves in the drum portion (3D volumetric modification). This dimensional change allows the grooves to reduce rigidity and press-fitting load while the cylindrical geometry of the drum portion maintains the overall circularity of the holding member, resolving the contradiction between load reduction and shape preservation
2Stress or pressure
If two cut-out portions are provided in the flange portion with 90-degree deviation to distribute stress, then stress distribution is improved, but it remains difficult to maintain the circularity of the holding member
Solution Approach 1:
The invention segments the drum portion by forming multiple grooves (typically three or more) that divide the cylindrical structure into segments. This segmentation distributes stress uniformly around the circumference while maintaining the overall circular shape, unlike the flange cut-out approach which creates localized stress concentration points that compromise circularity
3Ease of manufacture
If grooves are formed on the drum portion to reduce rigidity, then press-fitting is facilitated, but the structural strength may be compromised
Solution Approach 1:
The grooves are formed locally in the drum portion rather than throughout the entire holding member. This localized modification reduces rigidity only where needed for press-fitting while preserving the structural strength of the flange portions and the overall frame, resolving the contradiction between ease of assembly and structural integrity
Data Source
AI summary
Provided is a rotary electric machine that decreases the rigidity of a frame into which a stator core is press-fitted and is also able to maintain the circularity of the frame. The rotary electric machine includes a rotatably held rotor, a stator having a stator core on which a coil is wound and which is disposed so as to oppose the rotor, and an annular frame holding the stator core. The frame has a tubular drum portion holding the stator core and a plurality of flange portions, and a plurality of grooves are formed on an end portion of the drum portion in an axial direction of the drum portion by cutting the drum portion.