Rotating Electric Machine Compact Stator Cooling Passage
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Solution Overview
Problem
Conventional rotating electric machines face challenges in forming compact stator cooling passages, leading to increased size and weight, and require complex sealing mechanisms, which complicates layout and assembly.
Innovation Solution
A rotating electric machine design featuring a stator core with a straight inner diameter and a water jacket with a cylindrical portion that is press-fitted and welded to form a compact stator cooling passage, eliminating the need for axial direction sealing and reducing the outer diameter, thereby improving layout ease and reducing weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a stepped water jacket is retained by the outer circumference of a stepped stator frame, then a stator cooling passage can be formed, but the outer diameter size is increased
Solution Approach 1:
The water jacket is nested within the stator frame structure, with the water jacket fitting into the cylindrical portion of the stator frame. This nesting arrangement allows the cooling passage to be formed within the existing structural envelope, eliminating the need for additional stepped portions that would increase the outer diameter.
Solution Approach 2:
The invention transitions from using radial steps (changing outer diameter) to using axial positioning and interference fitting to create the cooling passage. The stator frame has a straight inner diameter without radial steps, and the cooling passage is formed by the axial arrangement and interference fit between the water jacket and stator frame, moving the solution from radial dimension to axial dimension.
2Volume of moving object
If a seal is provided on the end surface in the axial direction, then the stator cooling passage can be formed, but the size in the axial direction is increased
Solution Approach 1:
The invention extracts the sealing function from a separate seal component and integrates it into the interference fit mechanism between the water jacket and stator frame. The interference fit itself provides the sealing action, eliminating the need for additional seal elements that would increase the axial size.
Solution Approach 2:
The sealing function is merged with the mechanical fastening function. The interference fit between the water jacket and stator frame simultaneously provides both the mechanical retention and the sealing of the cooling passage, combining two functions into a single mechanism rather than requiring separate seal components.
3Ease of manufacture
If the stator frame and water jacket are retained by interference fit, then assembly is simplified, but sealing reliability may be compromised
Solution Approach 1:
The sealing function is merged with the mechanical fastening function. The interference fit between the water jacket and stator frame simultaneously provides both the mechanical retention and the sealing of the cooling passage, combining two functions into a single mechanism rather than requiring separate seal components.
Solution Approach 2:
The invention carefully controls the interference fit parameters (interference amount, fit length, material properties) to ensure that the contact pressure generated by the interference fit is sufficient to seal the cooling passage while maintaining assembly feasibility. By optimizing these parameters, the same interference fit mechanism achieves both easy assembly and reliable sealing.
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 design allows for a compact stator cooling passage in both radial and axial directions, enhancing layout flexibility, reducing motor weight, and improving sealing reliability and production efficiency.
Implementation Method 1
a stator frame (02) for retaining the stator core, the stator frame having a straight inner diameter
Implementation Method 2
The stator frame and the water jacket are sealed by press fitting and welding on the base side and the distal end side of the stator frame
Implementation Method 3
The stator frame and the water jacket are sealed by press fitting and welding on the base side and the distal end side of the stator frame
Implementation Method 4
A passage of a stator cooling refrigerant is formed by the stator frame and the water jacket
Data Source
AI summary
Provided is a rotating electric machine that allows a stator cooling passage to be formed compactly. A passage of a stator cooling refrigerant is formed by a water jacket fitted and fixed to both ends on a base side which is the flange side and a distal end side of a cylindrical portion of a stator frame on an outer circumference of the cylindrical portion, the stator frame has a difference between a diameter on the base side and a diameter on the distal end side, the diameter on the base side being formed to be larger, and the stator frame and the water jacket are sealed by press fitting and welding on the base side and the distal end side.