Rotor Cooling Holes Absorb Shaft Tightening Loads
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Solution Overview
Problem
Existing electric rotary machine rotors face performance degradation due to heat generation, with insufficient cooling of magnets, and refrigerant flow passage holes are prone to deformation under tightening loads, affecting cooling efficiency.
Innovation Solution
A rotor design with refrigerant flow passage holes arranged radially inward of magnetic pole portions, featuring inner radial side apex portions protruding inward and outer radial side apex portions protruding outward, which absorb tightening loads and maintain cooling performance by positioning the flow passages further outward, thereby reducing deformation and enhancing cooling efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If refrigerant supply holes are arranged in the vicinity of the magnetic pole portion to cool the magnet, then cooling performance is improved, but the refrigerant supply holes may be deformed by the tightening load of the rotor shaft to the rotor shaft hole
Solution Approach 1:
The refrigerant flow passage hole is divided into multiple functional regions: a first hole portion group radially inward of the magnetic pole portion and a second hole portion group radially outward. This segmentation allows the inward portion to absorb tightening loads while the outward portion maintains cooling functionality near the magnet, resolving the contradiction between cooling performance and deformation resistance.
Solution Approach 2:
Different portions of the refrigerant flow passage hole are given different structural characteristics. The first hole portion group (inward) is positioned to absorb tightening loads, while the second hole portion group (outward) is positioned to provide cooling. This local differentiation allows each region to fulfill its specific function without compromising the other.
2Strength
If the rotor shaft is tightened to the rotor shaft hole to secure rotational stability, then mechanical strength is improved, but the outer peripheral portion of the rotor core may be deformed
Solution Approach 1:
The refrigerant flow passage hole structure is segmented into inward and outward portions, where the inward portion specifically absorbs tightening loads from the rotor shaft, preventing these loads from being transmitted to the outer peripheral portion of the rotor core, thus maintaining both connection strength and shape stability.
Solution Approach 2:
The first hole portion group of the refrigerant flow passage hole acts as an intermediary structure between the rotor shaft and the outer peripheral portion. It absorbs and dissipates the tightening loads, serving as a buffer that prevents direct transmission of deformation forces to the rotor core's outer perimeter.
3Temperature
If the refrigerant flow passage hole is positioned further outward to improve cooling performance, then heat dissipation is improved, but the hole becomes more susceptible to deformation from tightening loads
Solution Approach 1:
The refrigerant flow passage hole is segmented into two functional groups: the first group positioned radially inward to provide structural stability and absorb loads, and the second group positioned radially outward to maximize cooling efficiency. This segmentation allows the system to simultaneously achieve both reliability and high cooling performance.
Solution Approach 2:
The patent merges the refrigerant flow passage hole with the magnetic pole portion structure, integrating cooling functionality into the rotor's structural framework. This integration allows the hole to serve dual purposes: maintaining structural integrity through the inward portion while providing efficient cooling through the outward portion.
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 effectively absorbs tightening loads, suppresses deformation of the rotor core's outer peripheral portion, and improves cooling performance by forming a more extensive refrigerant flow path on the outer periphery, effectively addressing heat management issues in electric rotary machines.
Implementation Method 1
a refrigerant flowing through the refrigerant flow passage hole provided in the rotor core is supplied to a coil end using a centrifugal force generated by rotation of the rotor
Data Source
AI summary
A rotor includes: a rotor core having a rotor shaft hole into which a rotor shaft is tightened and a plurality of magnet insertion holes provided along a circumferential direction; and a plurality of magnetic pole portions constituted by magnets inserted into the magnet insertion holes. The rotor core includes a cooling portion having a plurality of refrigerant flow passage holes provided radially inward of the plurality of magnetic pole portions and arranged along a circumferential direction, the plurality of refrigerant flow passage holes are arranged on both circumferential end portion sides of each magnetic pole portion, the refrigerant flow passage hole includes an inner radial side apex portion protruding radially inward, and an outer peripheral wall of the refrigerant flow passage hole includes an outer radial side apex portion protruding radially outward.