Rotor Baffle Tapered Shape for Cooling Gas Flow Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing rotor design for rotary electric machines has limited cooling gas intake efficiency due to small cross-sectional air passage areas and increased air flow resistance, leading to insufficient cooling performance, especially at higher output levels.
Innovation Solution
The rotor design incorporates a tubular retaining ring with alternately connected rotor and insulation baffles that partition the space into first and second radial areas, featuring a tapered shape to expand the second space radially, allowing efficient discharge of cooling gas and reducing air flow resistance by increasing the cross-sectional area of the air passage inlet.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the inlet for cooling gas is divided into four portions in the circumferential direction, then the cooling gas can be distributed to different coil end portions, but the cross-sectional area of the inlet becomes small and air flow resistance increases
Solution Approach 1:
The patent merges the four separate first spaces into one continuous first space that extends around the entire circumference of the rotor. This allows cooling gas to flow continuously through the air passage without being blocked by partition walls, significantly reducing air flow resistance while still enabling distribution to different coil end portions through the continuous space configuration.
2Productivity
If guide boards are disposed at the inlet to increase cooling gas intake efficiency, then the cooling gas flow into first spaces is improved, but the air flow resistance at the inlet of gas passage inside the rotor increases due to flow separation
Solution Approach 1:
The patent removes the guide boards from the inlet configuration and instead uses the continuous first space and air passage structure to guide cooling gas flow. This extraction of the guide board element eliminates the flow separation problem and associated air flow resistance while maintaining effective cooling gas distribution through the inherent flow paths created by the continuous space design.
3Power
If the output of the rotary electric machine is increased, then the power generation capability is improved, but the cooling performance becomes insufficient and coil temperature increases
Solution Approach 1:
The continuous first space configuration allows for increased cooling gas flow rate to match higher output levels. By eliminating the partition walls that divided the cooling gas intake into four separate portions, the system can accommodate higher volumes of cooling gas without proportionally increasing air flow resistance, enabling effective cooling even at increased output power levels.
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 design enhances cooling gas supply to coil end portions and inside the rotor, improving cooling efficiency and reducing coil temperature, even at increased output levels.
Implementation Method 1
the rotor baffle includes, at a part thereof on a radially outer side of which the jumper portion is present, a first tapered shape part tilted so as to be more apart from the jumper portion toward a center side in the axial direction of the rotor
Implementation Method 2
spaces on the outer side in the radial direction of the insulation baffles are in communication with each other in the circumferential direction and integrated with spaces (gathering parts) on the outer side in the radial direction of the rotor baffles. In this portion, jumper portions of the coil end portions are accommodated.
Implementation Method 3
the amount of cooling gas passing between conductors of the coil ends of the rotor and flowing from the first spaces to the gathering parts of the second spaces so as to cool the coil ends
Data Source
AI summary
A rotor includes: a tubular retaining ring opened on an outer side thereof in an axial direction and covering a coil end portion of each of coils; and rotor baffles and insulation baffles alternately connected in a circumferential direction and partitioning a space in the retaining ring into a first space and a second space, the first space is formed over an entire circumference around a shaft, each rotor baffle includes, at a part thereof on a radially outer side of which a jumper portion is present, a first tapered shape part tilted so as to be more apart from the jumper portion toward a center side in the axial direction of the rotor.