Rotary Electric Machine Cooling via Axial Coolant and Insulating Paper
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Solution Overview
Problem
Existing rotary electric machine cooling systems face challenges in effectively cooling armature windings without increasing axial dimensions, leading to uneven cooling and complexity in design.
Innovation Solution
The implementation of strip-shaped insulating paper between conductor portions of the armature winding coil ends, which directs liquid coolant to flow circumferentially and prevents radial outward flow, allowing for effective cooling with a simplified design and reduced axial dimensions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If coolant outlets are distributed circumferentially radially outside coil ends to cool the armature winding, then cooling effectiveness is improved, but device complexity increases
Solution Approach 1:
The patent extracts the cooling function from a complex distributed outlet system and concentrates it into a single axial coolant outlet. The coolant is supplied from above the armature winding along the rotation axis, eliminating the need for multiple circumferentially distributed outlets while maintaining effective cooling coverage.
Solution Approach 2:
The patent changes the cooling approach from radial cooling (outlets on the radial surface) to axial cooling (outlet on the axial surface). By supplying coolant from the axial direction along the rotation axis, the system achieves effective cooling with a simpler single-outlet configuration.
2Temperature
If electric power distributing portion is disposed above coil ends to support cooling, then cooling is achieved, but axial dimensions increase
Solution Approach 1:
The rotation axis serves multiple functions: it is both the mechanical rotation shaft and the coolant supply path. By integrating the coolant supply function into the existing rotation axis structure, the patent avoids adding separate cooling components that would increase axial dimensions.
Solution Approach 2:
The patent merges the coolant supply system with the rotation axis structure. The single coolant outlet is positioned on the housing along the rotation axis, combining the support structure and cooling delivery into a unified configuration that eliminates additional axial space requirements.
3Temperature
If coolant is sprayed radially onto coil ends, then cooling is provided, but coolant distribution becomes uneven
Solution Approach 1:
The patent transitions from radial coolant delivery to axial coolant delivery. By supplying coolant from above along the rotation axis, the system achieves more uniform coolant distribution across the coil ends, as the axial flow direction provides better coverage and reduces the uneven distribution issues associated with radial spraying.
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
This solution ensures even cooling of the armature winding, reduces the number of coolant outlets needed, and prevents axial dimension increases, enabling downsizing of the rotary electric machine while maintaining effective cooling performance.
Implementation Method 1
a liquid coolant being blown onto a coil end of the armature winding from a coolant suction aperture that is formed on the housing to cool the armature winding. The coolant suction aperture is formed at a position on the housing that is vertically above the coil end
Implementation Method 2
liquid coolant that is blown onto the coil end, contacts the insulating paper, is kept from flowing out to an radially inner side of the coil end, and flows through the coil end circumferentially. Thus, the liquid coolant spreads around evenly circumferentially inside the coil end, eliminating uneven cooling of the coil end, and enabling the armature winding to be cooled effectively.
Data Source
AI summary
A rotary electric machine is installed such that a central axis of a rotating shaft is horizontal, and coolant suction apertures are formed at positions on a cylindrical portion of a frame that are vertically above first and second coil ends, and strip-shaped insulating papers are inserted such that a thickness direction is in a radial direction between radially adjacent conductor portions of portions of the conductor wire that constitute the first and second coil ends, and are disposed so as to extend circumferentially across positions that are vertically below the coolant suction apertures inside the first and second coil ends.