Rotor Oil Runner Layout for Even Motor Cooling
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Solution Overview
Problem
Existing electric vehicle motors face issues with uneven oil flow distribution in the oil cooling structure, leading to local hot spots and performance limitations due to differences in oil throwing at the ends of the rotating shaft, which affects heat dissipation of the rotor and stator windings.
Innovation Solution
The rotor design incorporates first and second runners on the end plates that are spaced along the circumferential and radial directions, allowing cooling oil to enter and spread uniformly through oil passages, ensuring consistent oil film thickness and preventing interference between oil inlets and outlets, thereby promoting even oil throwing and reducing local hot spots.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If cooling oil is used in the oil cooling structure, then better cooling effect is achieved compared to water cooling, but uneven flow distribution occurs leading to local hot spots
Solution Approach 1:
The end plate is segmented into multiple independent runners (first runners and second runners) that are spatially separated and not directly connected. Each runner independently receives cooling oil through oil passages, dividing the cooling flow into multiple controlled paths to ensure uniform distribution and prevent local hot spots.
Solution Approach 2:
Different regions of the end plate are assigned different functions through localized runner placement. First runners are positioned to receive cooling oil from specific oil passages while second runners are positioned to discharge oil, creating functionally distinct zones that optimize both cooling effectiveness and flow uniformity.
2Device complexity
If first runner and second runner are directly connected on the end plate, then structural simplicity is achieved, but oil inlet and outlet interfere with each other causing uneven oil throwing
Solution Approach 1:
The runner system is segmented into first runners for oil inlet and second runners for oil outlet, with spatial separation in the circumferential and radial directions. This segmentation prevents interference between oil inlet and outlet flows while maintaining functional efficiency.
Solution Approach 2:
The runners are arranged in multiple spatial dimensions (circumferential direction and radial direction) rather than being directly connected in a single plane. This dimensional separation allows independent oil flow paths while maintaining structural compactness.
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 ensures even oil distribution, improving motor performance by reducing temperature by 15°C while maintaining cost-effectiveness and compatibility with both positive and reverse motor rotations.
Implementation Method 1
cooling oil in an oil cooling structure can directly enter a stator and a rotor of the motor, and is closer to a heat source, thereby achieving better cooling effect
Implementation Method 2
when the motor rotates, the oil cooling structure has a problem of uneven flow distribution, that is, there is a difference in flow of oil throwing holes at two ends of a rotating shaft
Data Source
Figure 1
Figure 2
Figure 3A
AI summary
Embodiments of this application provide a rotor, a motor, and an electric vehicle. The rotor includes: a rotating shaft, having a hollow channel, where a plurality of oil holes connected to the hollow channel are disposed; and a rotor iron core assembly, sleeved on the rotating shaft, and including a first end plate, a second end plate, and an iron core body located between the first end plate and the second end plate. A plurality of first runners connected to the plurality of oil holes and a plurality of second runners connected to the outside are disposed on inner sides of the end plate, and the first runner and the second runner are spaced along a circumferential direction and a radial direction and are not connected. A plurality of oil passages that run through the iron core body along an axial direction are spaced on the iron core body around the rotating shaft; if either the plurality of first runners or the plurality of second runners are respectively connected to outer portions of ports of the plurality of oil passages away from the rotating shaft, the plurality of second runners or the plurality of first runners are respectively connected to inner portions of the ports of the plurality of oil passages close to the rotating shaft; and the first runner and the second runner each are connected to at least one oil passage. According to the solutions in embodiments of this application, oil of the rotor can be evenly thrown, a local hot spot can be avoided, and costs are low.